Science.gov

Sample records for mitomycin c-induced apoptosis

  1. Involvement of apoptosis in mediating mitomycin C-induced teratogenesis in vitro.

    PubMed

    Singh, Gyanendra; Sinha, Neeraj

    2010-05-01

    Mitomycin C (MMC) is among the most commonly used drugs worldwide and is known to cause congenital malformations and fetal death in animals. In this study, the effect of MMC on major organogenesis period and the role of apoptosis in mediating congenital malformations have been carried out. In the present study, post-implantation rat embryos of day 11 were cultured for 24 h with various concentrations of MMC, i.e. 1, 10, and 100 microg/ml cultures. The growth and developmental of each embryo was evaluated and compared with control ones for the presence of any malformations. The MMC decreased all growth and developmental parameters in a concentration-dependent manner, when compared with control. However, exposure to MMC at 1 microg/ml culture did not show any significant effect on embryonic growth and development. Parallel to this, flow cytometric analysis (cell cycle and annexin V binding) and DNA fragmentation assay were carried out followed by quantitation by 3'-OH labeling of cultured rat embryos to evaluate the role of apoptosis in bringing about MMC-induced teratogenesis. All results were found to be dose-dependent and an increase in apoptosis in embryonic tissues may be related to the increased risk of congenital malformations. The data suggested that apoptosis might be involved in mediating teratogenesis of MMC in vitro.

  2. Mitomycin C induces fibroblasts apoptosis and reduces epidural fibrosis by regulating miR-200b and its targeting of RhoE.

    PubMed

    Sun, Yu; Ge, Yingbin; Fu, Yuxuan; Yan, Lianqi; Cai, Jun; Shi, Kun; Cao, Xiaojian; Lu, Chun

    2015-10-15

    Mitomycin C (MMC) is known to reduce epidural fibrosis, but the underlying mechanisms have not yet been elucidated. Aberrant miR-200b expressions have been reported in multiple types of fibrotic tissues from many diseases. The aim of this study was to clarify the mechanism by which MMC induces fibroblasts apoptosis and reduces epidural fibrosis. The expression of miR-200b in human fibroblasts was determined after MMC treatment, and the targeted association between miR-200b and RhoE was determined using the luciferase activity assay. The effects of MMC and miR-200b on human fibroblasts apoptosis were evaluated using flow cytometry and western blot analysis. The effects of MMC and miR-200b on epidural fibrosis were evaluated using the Rydell classification, hydroxyproline content, apoptotic cell count and histological analysis. The study revealed that MMC could significantly downregulate miR-200b expression and induce human fibroblasts apoptosis. The direct downregulation of miR-200b could induce human fibroblasts apoptosis. Furthermore, we identified the binding sequence for miR-200b within the 3' untranslated region of RhoE. RhoE was confirmed to be a direct target of miR-200b, and RhoE itself acted as a promoter of fibroblasts apoptosis. The inhibition of miR-200b increased fibroblasts apoptosis and reduced epidural fibrosis in rats, which was in accordance with the effect of MMC. This study suggests that MMC induces fibroblasts apoptosis and reduces epidural fibrosis by regulating miR-200b expression and its targeting of RhoE.

  3. Mitomycin C-induced synthesis of cloacin DF13 and lethality in cloacinogenic Escherichia coli cells.

    PubMed Central

    van Tiel-Menkveld, G J; Veltkamp, E; De Graaf, F K

    1981-01-01

    Treatment of cloacinogenic cultures with increasing concentrations of mitomycin C induced an increasing synthesis of cloacin DF13 accompanied by a decreasing number of colony-forming cells. Cells grown in the presence of glucose required a 10-fold-higher concentration of mitomycin C for optimal induction of cloacin production than did cells grown with lactate. Release of the cloacin was hampered in glucose-grown cells. Experiments with various CloDF13 insertion and deletion mutants revealed that the transcription of CloDF13 deoxyribonucleic acid sequences adjacent to the cloacin structural gene was essential for mitomycin C-induced lethality. PMID:7012123

  4. Modification of mitomycin C-induced clastogenicity by Terminalia catappa L. in vitro and in vivo.

    PubMed

    Liu, T Y; Ho, L K; Tsai, Y C; Chiang, S H; Chao, T W; Li, J H; Chi, C W

    1996-07-19

    The water extract of the leaves of Terminalia catappa L. was tested for inhibition of mitomycin C-induced micronuclei in CHO-K1 cells. The simultaneous and pre-treatment of CHO-K1 cells with T. catappa extract (75 and 150 micrograms/ml) significantly (P < 0.05) suppressed mitomycin C-induced micronuclei. Furthermore, gastric intubation of T. catappa extract (4.8 and 24 mg/animal per day) to male ICR mice for 8 days significantly (P < 0.01) reduced mitomycin C-induced micronuclei in peripheral blood. In addition, T. catappa dose dependently inhibited lipid peroxidation in vitro and TPA-induced hydrogen peroxide formation in human mononuclear leukocytes. The anticlastogenic effects of T. catappa in vitro and in vivo may be attributed to its antioxidative potential.

  5. Mitomycin C and decarbamoyl mitomycin C induce p53-independent p21WAF1/CIP1 activation

    PubMed Central

    Cheng, Shu-Yuan; Seo, Jiwon; Huang, Bik Tzu; Napolitano, Tanya; Champeil, Elise

    2016-01-01

    Mitomycin C (MC), a commonly used anticancer drug, induces DNA damage via DNA alkylation. Decarbamoyl mitomycin C (DMC), another mitomycin lacking the carbamate at C10, generates similar lesions as MC. Interstrand cross-links (ICLs) are believed to be the lesions primarily responsible for the cytotoxicity of MC and DMC. The major ICL generated by MC (α-ICL) has a trans stereochemistry at the guanine-drug linkage whereas the major ICL from DMC (β-ICL) has the opposite, cis, stereochemistry. In addition, DMC can provoke strong p53-independent cell death. Our hypothesis is that the stereochemistry of the major unique β-ICL generated by DMC is responsible for this p53-independent cell death signaling. p53 gene is inactively mutated in more than half of human cancers. p21WAF1/CIP1 known as a major effector of p53 is involved in p53-dependent and -independent control of cell proliferation and death. This study revealed the role of p21WAF1/CIP1 on MC and DMC triggered cell damage. MCF-7 (p53-proficient) and K562 (p53-deficient) cells were used. Cell cycle distributions were shifted to the G1/S phase in MCF-7 treated with MC and DMC, but were shifted to the S phase in K562. p21WAF1/CIP1 activation was observed in both cells treated with MC and DMC, and DMC triggered more significant activation. Knocking down p53 in MCF-7 did not attenuate MC and DMC induced p21WAF1/CIP1 activation. The α-ICL itself was enough to cause p21WAF1/CIP1 activation. PMID:27666201

  6. Mitomycin C-induced cell death in mouse lens epithelial cells.

    PubMed

    Park, Hyun-Kyung; Lee, Kwang-Won; Choi, Jun-Sub; Joo, Choun-Ki

    2002-01-01

    The mode of action of mitomycin C (MMC)-induced cell death in lens epithelia was investigated using cell culture system. The cytotoxicity of MMC on alpha-TN4 mouse lens epithelial cells (LECs) was measured by using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT)-based assay. To determine the type of cell death induced by MMC, we stained LECs with acridine orange and ethidium bromide, and performed TUNEL assay and electron microscopic examination. The activation of MMC was also investigated with N-acetly-L-cystein (NAC), a free radical scavenger, and dicumarol, an inhibitor of DT-diaphorase, to analyze one- and two-electron reduction pathways involved in the activation of MMC. MTT assay showed that 400 microg/ml of MMC decreased the cell viability of the control cells to 45%, and the cytotoxicity of MMC on alpha-TN4 cells was increased in a dose-dependent manner. Based on the results obtained from acridine orange and ethidium bromide staining, the TUNEL assay, and transmission electron microscopic examination, we confirmed that MMC-induced cell death, at 400 microg/ml of MMC, occurs with necrosis as well as apoptotis. The treatment of cells with 2 mM NAC for 1 h or 20 microM dicumarol for 30 min, prior to 5 min of MMC (400 microg/ml) treatment, restored the growth suppression to 76 and 80% of the control level, respectively. In addition, the cotreatment of cells with NAC and dicumarol restored cell viability to 90% of the control level. The cellular death in MMC-treated LECs showed the involvement of oxidative stress in this apoptosis accounting for 22% of the observed cell death at 400 microg/ml of MMC.

  7. Anticlastogenic effects of galangin against mitomycin C-induced micronuclei in reticulocytes of mice.

    PubMed

    Heo, M Y; Jae, L H; Jung, S S; Au, W W

    1996-05-17

    We investigated the suppressive effect of galangin on the induction of micronucleated reticulocytes (MNRETs) by mitomycin C (MMC) in mouse peripheral blood. When galangin was given to mice 24 h before the intraperitoneal injection of MMC (1 mg/kg), a more marked decrease in the frequency of MNRETs was observed than in mice with simultaneous and post-treatment of galangin. On the other hand, when galangin was given to mice for 7 consecutive days before MMC injection, galangin showed potent anticlastogenic effects, even at the lowest dose level of 0.1 mg/kg. Results from our in vivo studies indicate that galangin is capable of suppressing the clastogenic activity of the direct acting MMC. Together with our earlier observations, it appears that galangin is capable of protecting cells from the toxic effects of a variety of hazardous chemicals. Therefore, galangin may be an useful chemopreventive compound.

  8. Mitomycin C induces bystander killing in homogeneous and heterogeneous hepatoma cellular models

    PubMed Central

    Kumari, Ratna; Sharma, Aanchal; Ajay, Amrendra Kumar; Bhat, Manoj Kumar

    2009-01-01

    Background Hepatocellular carcinoma (HCC) is one of the most common cancers worldwide that is particularly refractory to chemotherapy. Several studies have proposed combination chemotherapy regimen for HCC treatment. However, these therapies are not effective in regressing tumor and prolonging survival of patient's suffering from HCC. Therefore, the development of more effective therapeutic tools and new strategies for the treatment of HCC are urgently needed. Over the last decade much attention has been focused on "bystander effect" as a possible therapeutic strategy for the treatment of certain human tumors. Interest in this therapeutic approach originated from numerous reports describing the radiation induced bystander effect. However, the knowledge about chemotherapy induced bystander effect is still limited. Hence, chemotherapy induced bystander phenomenon in hepatoma cells was explored by utilizing Mitomycin C (MMC). Results MMC induced bystander killing was observed only in hepatoma cells and it did not occur in cervical cancer cells. MMC induced bystander killing was transferable via medium. It occurred in co-cultured cells indicating the involvement of secreted as well as membrane bound factors. FasL and TRAIL were detected in the conditioned medium from treated cells. In medium transfer experiment, pre-treatment with EDTA (a broad range protease inhibitor) diminished MMC induced bystander killing. Following drug exposure, expression of Fas and TRAIL receptors increased and treatment with neutralizing antibodies against FasL and TRAIL inhibited bystander killing. Conclusion Our results highlight the therapeutic importance of MMC in the treatment of HCC and implicate role of membrane bound and secreted forms of FasL and TRAIL in MMC induced bystander killing. PMID:19845939

  9. Genotoxic and anti-genotoxic effects of esculin and its oligomer fractions against mitomycin C-induced DNA damages in mice.

    PubMed

    Mokdad Bzeouich, Imen; Mustapha, Nadia; Maatouk, Mouna; Ghedira, Kamel; Ghoul, Mohamed; Chekir-Ghedira, Leila

    2016-12-01

    Mitomycin C is one of the most effective chemotherapeutic drugs against various solid tumors. However, despite its wide spectrum of clinical benefits, this agent is capable of inducing various types of genotoxicity. In this study, we investigated the effect of esculin and its oligomer fractions (E1, E2 and E3) against mitomycin C induced genotoxicity in liver and kidney cells isolated from Balb/C mice using the comet assay. Esculin and its oligomer fractions were not genotoxic at the tested doses (20 mg/kg and 40 mg/kg b.w). A significant decrease in DNA damages was observed, suggesting a protective role of esculin and its oligomer fractions against the genotoxicity induced by mitomycin C on liver and kidney cells. Moreover, esculin and its oligomer fractions did not induce an increase of malondialdehyde levels.

  10. Proteasomal inhibition sensitizes cervical cancer cells to mitomycin C-induced bystander effect: the role of tumor microenvironment.

    PubMed

    Singh, S V; Ajay, A K; Mohammad, N; Malvi, P; Chaube, B; Meena, A S; Bhat, M K

    2015-10-22

    Inaccessibility of drugs to poorly vascularized strata of tumor is one of the limiting factors in cancer therapy. With the advent of bystander effect (BE), it is possible to perpetuate the cellular damage from drug-exposed cells to the unexposed ones. However, the role of infiltrating tumor-associated macrophages (TAMs), an integral part of the tumor microenvironment, in further intensifying BE remains obscure. In the present study, we evaluated the effect of mitomycin C (MMC), a chemotherapeutic drug, to induce BE in cervical carcinoma. By using cervical cancer cells and differentiated macrophages, we demonstrate that MMC induces the expression of FasL via upregulation of PPARγ in both cell types (effector cells) in vitro, but it failed to induce bystander killing in cervical cancer cells. This effect was primarily owing to the proteasomal degradation of death receptors in the cervical cancer cells. Pre-treatment of cervical cancer cells with MG132, a proteasomal inhibitor, facilitates MMC-mediated bystander killing in co-culture and condition medium transfer experiments. In NOD/SCID mice bearing xenografted HeLa tumors administered with the combination of MMC and MG132, tumor progression was significantly reduced in comparison with those treated with either agent alone. FasL expression was increased in TAMs, and the enhanced level of Fas was observed in these tumor sections, thereby causing increased apoptosis. These findings suggest that restoration of death receptor-mediated apoptotic pathway in tumor cells with concomitant activation of TAMs could effectively restrict tumor growth.

  11. Rapamycin-enhanced mitomycin C-induced apoptotic death is mediated through the S6K1–Bad–Bak pathway in peritoneal carcinomatosis

    PubMed Central

    Song, X; Dilly, A-K; Kim, S-Y; Choudry, H A; Lee, Y J

    2014-01-01

    Peritoneal carcinomatosis (PC) is the most common secondary cancerous disease, and more effective novel regimens are needed. In this study, we identified a novel combination treatment for PC, chemotherapeutic agent mitomycin C in combination with mTOR (mammalian target of rapamycin) inhibitor rapamycin. We observed that the combination of mitomycin C and rapamycin induced synergistic cytotoxicity and apoptosis, which was mediated through an increase in caspase activation. The combination of mitomycin C and rapamycin inactivated p70 S6 ribosomal kinase (S6K1) and dephosphorylated Bad, leading to dissociation of Bcl-xL from Bak, which resulted in Bak oligomerization, mitochondria dysfunction and cytochrome c release. PF-4708671, a S6K1-specific inhibitor, enhanced the combination treatment-induced apoptosis, whereas S6K1 E389 DeltaCT-HA (S6K1 active form) dramatically decreased the induction of apoptosis. In addition, the combination treatment significantly inhibited LS174T intraperitoneal tumor growth in vivo. This study provides a preclinical rationale for apoptosis induction linked with the mTOR pathway through a combination of chemotherapeutic agents and mTOR inhibitor, and will support this combinatorial strategy to PC patients. PMID:24901052

  12. Rapamycin-enhanced mitomycin C-induced apoptotic death is mediated through the S6K1-Bad-Bak pathway in peritoneal carcinomatosis.

    PubMed

    Song, X; Dilly, A-K; Kim, S-Y; Choudry, H A; Lee, Y J

    2014-06-05

    Peritoneal carcinomatosis (PC) is the most common secondary cancerous disease, and more effective novel regimens are needed. In this study, we identified a novel combination treatment for PC, chemotherapeutic agent mitomycin C in combination with mTOR (mammalian target of rapamycin) inhibitor rapamycin. We observed that the combination of mitomycin C and rapamycin induced synergistic cytotoxicity and apoptosis, which was mediated through an increase in caspase activation. The combination of mitomycin C and rapamycin inactivated p70 S6 ribosomal kinase (S6K1) and dephosphorylated Bad, leading to dissociation of Bcl-xL from Bak, which resulted in Bak oligomerization, mitochondria dysfunction and cytochrome c release. PF-4708671, a S6K1-specific inhibitor, enhanced the combination treatment-induced apoptosis, whereas S6K1 E389 DeltaCT-HA (S6K1 active form) dramatically decreased the induction of apoptosis. In addition, the combination treatment significantly inhibited LS174T intraperitoneal tumor growth in vivo. This study provides a preclinical rationale for apoptosis induction linked with the mTOR pathway through a combination of chemotherapeutic agents and mTOR inhibitor, and will support this combinatorial strategy to PC patients.

  13. Spontaneous and mitomycin-C-induced micronuclei in human lymphocytes exposed to extremely low frequency pulsed magnetic fields

    SciTech Connect

    Scarfi, M.R.; Bersani, F.; Cossarizza, A.; Monti, D.; Castellani, G.; Cadossi, R.; Franceschetti, G.; Franceschi, C. )

    1991-04-15

    The cytokinesis block micronucleus method, a very sensitive cytogenetic assay, was used to ascertain the possible genotoxic effects of extremely low frequency pulsed magnetic fields in phytohemagglutinin-stimulated human lymphocytes cultures from 16 healthy donors. Four conditions were studied: lymphocytes not exposed to the field (control cultures); lymphocytes exposed to the field; lymphocytes treated with mitomycin-C and not exposed to the field; and lymphocytes treated with mitomycin-C and exposed to the field. Mitomycin-C-treated cultures were used as control for the micronucleus method, because it is known that mitomycin-C is a potent genotoxic agent, capable of inducing micronuclei. The frequency of micronuclei in field-exposed cultures was similar to the spontaneous frequency observed in control unexposed-cultures. Moreover, the exposure to pulsed magnetic fields did not affect the frequency of micronuclei induced by mitomycin-C, suggesting that, in the experimental conditions used, this kind of field neither affected the integrity of chromosomes nor interfered with the genotoxic activity of mitomycin-C.

  14. Mitomycin-C-Induced TTP/HUS Treated Successfully with Rituximab: Case Report and Review of the Literature

    PubMed Central

    Yamin, Hanah; Smith, Hedy

    2013-01-01

    Microangiopathic hemolytic anemia (MAHA), thrombocytopenia, fever, renal failure, and neurologic symptoms comprise the cardinal features of thrombotic thrombocytopenic purpura and hemolytic uremic syndrome. Etiologies can include medications, infections, cancers, or transplantation. We present a patient with a history of rectal cancer treated with mitomycin-C who developed MAHA, acute kidney injury, and thrombocytopenia 6 months after completing therapy and to did not respond the plasmapheresis or steroids. She was treated with four weekly doses of rituximab with full recovery. PMID:23762670

  15. Genotoxicity and cytotoxicity evaluation of oenothein B and its protective effect against mitomycin C-induced mutagenic action.

    PubMed

    Silva, Cinthia Aparecida; Silva, Carolina Ribeiro; Véras, Jefferson Hollanda; Chen-Chen, Lee; Ferri, Pedro Henrique; Santos, Suzana da Costa

    2014-06-01

    The natural product oenothein B (OeB), a dimeric macrocyclic ellagitannin, has a wide range of biological activities, such as antioxidant, anti-inflammatory, anti-viral, antifungal, and antitumor. However, investigations concerning its genotoxicity have not been carried out. This study assessed the cytotoxicity, genotoxicity, and protective effects of oenothein B using in vitro SOS-Inductest and in vivo mouse bone marrow micronucleus (MN) assay through oral and intraperitonial routes. In both assays oenothein B did not produce genotoxic effects in any of doses tested; in contrast, cytotoxic effect in cells was detected only in mice groups treated by both routes and exposed for 24 and 48h. Antigenotoxic and anticytotoxic activities of oenothein B were evaluated using both assays in combination with mitomycin C (MMC), a bioreductive alkylating agent. In the MN assay, a significant reduction was observed in MN frequency in all groups co-treated with MMC and OeB compared to those which received only MMC. Anticytotoxicity was observed in mice groups exposed to OeB and MMC for 24 and 48h. In the SOS-Inductest, oenothein B failed to show antigenotoxic and anticytotoxic effects; thus, it undoubtedly showed an in vivo protective activity against primary DNA damage induced by mitomycin C.

  16. p53 modulates the AMPK inhibitor compound C induced apoptosis in human skin cancer cells

    SciTech Connect

    Huang, Shi-Wei; Wu, Chun-Ying; Wang, Yen-Ting; Kao, Jun-Kai; Lin, Chi-Chen; Chang, Chia-Che; Mu, Szu-Wei; Chen, Yu-Yu; Chiu, Husan-Wen; Chang, Chuan-Hsun; Liang, Shu-Mei; Chen, Yi-Ju; Huang, Jau-Ling; Shieh, Jeng-Jer

    2013-02-15

    Compound C, a well-known inhibitor of the intracellular energy sensor AMP-activated protein kinase (AMPK), has been reported to cause apoptotic cell death in myeloma, breast cancer cells and glioma cells. In this study, we have demonstrated that compound C not only induced autophagy in all tested skin cancer cell lines but also caused more apoptosis in p53 wildtype skin cancer cells than in p53-mutant skin cancer cells. Compound C can induce upregulation, phosphorylation and nuclear translocalization of the p53 protein and upregulate expression of p53 target genes in wildtype p53-expressing skin basal cell carcinoma (BCC) cells. The changes of p53 status were dependent on DNA damage which was caused by compound C induced reactive oxygen species (ROS) generation and associated with activated ataxia-telangiectasia mutated (ATM) protein. Using the wildtype p53-expressing BCC cells versus stable p53-knockdown BCC sublines, we present evidence that p53-knockdown cancer cells were much less sensitive to compound C treatment with significant G2/M cell cycle arrest and attenuated the compound C-induced apoptosis but not autophagy. The compound C induced G2/M arrest in p53-knockdown BCC cells was associated with the sustained inactive Tyr15 phosphor-Cdc2 expression. Overall, our results established that compound C-induced apoptosis in skin cancer cells was dependent on the cell's p53 status. - Highlights: ► Compound C caused more apoptosis in p53 wildtype than p53-mutant skin cancer cells. ► Compound C can upregulate p53 expression and induce p53 activation. ► Compound C induced p53 effects were dependent on ROS induced DNA damage pathway. ► p53-knockdown attenuated compound C-induced apoptosis but not autophagy. ► Compound C-induced apoptosis in skin cancer cells was dependent on p53 status.

  17. Effect of recombinant human erythropoietin on mitomycin C-induced oxidative stress and genotoxicity in rat kidney and heart tissues.

    PubMed

    Rjiba-Touati, K; Ayed-Boussema, I; Guedri, Y; Achour, A; Bacha, H; Abid-Essefi, S

    2016-01-01

    Mitomycin C (MMC) is an antineoplastic agent used for the treatment of several human malignancies. Nevertheless, the prolonged use of the drug may result in a serious heart and kidney injuries. Recombinant human erythropoietin (rhEPO) has recently been shown to exert an important cytoprotective effect in experimental brain injury and ischemic acute renal failure. The aim of the present work is to investigate the cardioprotective and renoprotective effects of rhEPO against MMC-induced oxidative damage and genotoxicity. Our results showed that MMC induced oxidative stress and DNA damage. rhEPO administration in any treatment conditions decreased oxidative damage induced by MMC. It reduced malondialdehyde and protein carbonyl levels. rhEPO ameliorated reduced glutathione plus oxidized glutathione modulation and the increased catalase activity after MMC treatment. Furthermore, rhEPO restored DNA damage caused by MMC. We concluded that rhEPO administration especially in pretreatment condition protected rats against MMC-induced heart and renal oxidative stress and genotoxicity.

  18. Inhibition of mitomycin C-induced chromosomal aberrations by micrometer powder of selenium-enriched green tea in mice spermatocytes.

    PubMed

    Li, Feng; Xu, Juan; Zhou, Jing; Zhao, Liyan; Sheng, Jianchun; Sun, Guiju; Hu, Qiuhui

    2009-04-30

    The anticlastogenic effect of micrometer powder of selenium-enriched green tea (MSTP) was evaluated by using a chromosomal aberration assay in mouse testicular cells. Animals fed with a Se-deficient diet were treated with MSTP, micrometer powder of regular green tea (MRTP), selenite, and MRTP + selenite for 30 days by an intragastric route, followed by treatment of mitomycin C (MMC) on day 19 through intraperitoneal injection (ip). Selenium status and antioxidant enzymes were measured. Results indicated that MSTP showed a significant capability to reduce the incidence of MMC-induced chromosomal aberrations in spermatocytes from 22.7% to 6.7%. This inhibitory was highest, for MSTP, at 73.1%, while it was only 38.4% for MRTP. After 30 days of a Se-deficient diet, mice, either with or without the MMC treatment, showed a lower selenium concentration in blood and liver as well as lower enzyme activity of the antioxidants, GPx and SOD. Supplementation with MSTP, selenite, or selenite + MRTP enhanced the activities of these antioxidant enzymes. This enhancement was accompanied with a concomitant elevation of selenium levels, which favored the synthesis of the seleno-enzyme GPx and protected the cells from the MMC-induced oxidative stress. Our results indicate that MSTP is both able to prevent the chromosomal aberrations induced by MMC in mouse spermatocytes and to enhance GPx and SOD activity in blood serum and liver.

  19. Ultraviolet-C-induced apoptosis protected by 635-nm laser irradiation in human gingival fibroblasts.

    PubMed

    Lim, Wonbong; Ko, Mikyung; Lee, Sungga; Kim, Inae; Jung, Mina; Kim, Okjoon; Cho, Seonghoun; Yang, Kyuho; Choi, Namki; Kim, Sunmi; Choi, Hongran

    2008-06-01

    The purpose of this study was to examine the protection afforded by 635-nm irradiation against ultraviolet (UV)-C-induced apoptosis in primary human gingival fibroblasts (hGFs). UV irradiation is known to cause photoaging and cellular apoptosis of skin cells and is considered to be one of the leading causes of skin carcinogenesis. To induce apoptosis, UV-C (100 mJ/cm2) was used to irradiate hGFs. To protect them from apoptosis, pretreatment with 635-nm irradiation was performed for 1 h immediately after cell plating 36 or 48 h before UV-C irradiation. The light source used for irradiation was a continuous-wave 635-nm LED laser emitting at 1 mW/cm2. Experimental samples were selected 24 h after UV-C irradiation. To measure the numbers of apoptotic cells, MTT assay and flow cytometric analyses were performed. For histomorphologic findings, Diff-Quick staining was carried out. Also, the activities and mRNA expression of caspase-3, caspase-8, and caspase-9 were measured. In the present study, the number of apoptotic cells declined in the cells that were pretreated with 635-nm light irradiation in a time-dependent manner. In addition, the activities and mRNA expression of caspase-3, caspase-8, and caspase-9 were significantly recovered by pretreatment with 635-nm irradiation. These results suggest that 635-nm visible light irradiation may be used as a protective tool to prevent UV-C-induced apoptosis.

  20. Neurotrophin-3 production promotes human neuroblastoma cell survival by inhibiting TrkC-induced apoptosis

    PubMed Central

    Bouzas-Rodriguez, Jimena; Cabrera, Jorge Ruben; Delloye-Bourgeois, Céline; Ichim, Gabriel; Delcros, Jean-Guy; Raquin, Marie-Anne; Rousseau, Raphaël; Combaret, Valérie; Bénard, Jean; Tauszig-Delamasure, Servane; Mehlen, Patrick

    2010-01-01

    Tropomyosin-related kinase receptor C (TrkC) is a neurotrophin receptor with tyrosine kinase activity that was expected to be oncogenic. However, it has several characteristics of a tumor suppressor: its expression in tumors has often been associated with good prognosis; and it was recently demonstrated to be a dependence receptor, transducing different positive signals in the presence of ligand but inducing apoptosis in the absence of ligand. Here we show that the TrkC ligand neurotrophin-3 (NT-3) is upregulated in a large fraction of aggressive human neuroblastomas (NBs) and that it blocks TrkC-induced apoptosis of human NB cell lines, consistent with the idea that TrkC is a dependence receptor. Functionally, both siRNA knockdown of NT-3 expression and incubation with a TrkC-specific blocking antibody triggered apoptosis in human NB cell lines. Importantly, disruption of the NT-3 autocrine loop in malignant human neuroblasts triggered in vitro NB cell death and inhibited tumor growth and metastasis in both a chick and a mouse xenograft model. Thus, we believe that our data suggest that NT-3/TrkC disruption is a putative alternative targeted therapeutic strategy for the treatment of NB. PMID:20160348

  1. Curcumin enhances the mitomycin C-induced cytotoxicity via downregulation of MKK1/2-ERK1/2-mediated Rad51 expression in non-small cell lung cancer cells

    SciTech Connect

    Ko, Jen-Chung; Tsai, Min-Shao; Weng, Shao-Hsing; Kuo, Ya-Hsun; Chiu, Yu-Fan; Lin, Yun-Wei

    2011-09-15

    Curcumin (diferuloylmethane), a major active component of turmeric (Curcuma longa), has been reported to suppress the proliferation of a wide variety of tumor cells. Rad51 is a key protein in the homologous recombination (HR) pathway of DNA double-strand break repair, and HR represents a novel target for cancer therapy. A high expression of Rad51 has been reported in chemo- or radio-resistant carcinomas. Therefore, in the current study, we will examine whether curcumin could enhance the effects of mitomycin C (MMC), a DNA interstrand cross-linking agent, to induce cytotoxicity by decreasing Rad51 expression. Exposure of two human non-small lung cancer (NSCLC) cell lines (A549 and H1975) to curcumin could suppress MMC-induced MKK1/2-ERK1/2 signal activation and Rad51 protein expression. Enhancement of ERK1/2 activation by constitutively active MKK1/2 (MKK1/2-CA) increased Rad51 protein levels in curcumin and MMC co-treated human lung cells. Moreover, the synergistic cytotoxic effect induced by curcumin combined with MMC was decreased by MKK1-CA-mediated enhancement of ERK1/2 activation by a significant degree. In contrast, MKK1/2 inhibitor, U0126 was shown to augment the cytotoxicity of curcumin and MMC through downregulation of ERK1/2 activation and Rad51 expression. Depletion of endogenous Rad51 expression by siRad51 RNA transfection significantly enhanced MMC and/or curcumin induced cell death and cell growth inhibition. In contrast, an overexpression of Rad51 protected lung cancer cells from synergistic cytotoxic effects induced by curcumin and MMC. We concluded that Rad51 inhibition may be an additional action mechanism for enhancing the chemosensitization of MMC by curcumin in NSCLC. - Highlights: > Curcumin downregulates MKK-ERK-mediated Rad51 expression. > Curcumin enhances mitomycin C-induced cytotoxicity. > Rad51 protects cells from cytotoxic effects induced by curcumin and mitomycin C. > Rad51 inhibition enhances the chemosensitization of mitomycin C by

  2. Cytogenetic effects of grape extracts (Vitis vinifera) and polyphenols on mitomycin C-induced sister chromatid exchanges (SCEs) in human blood lymphocytes.

    PubMed

    Stagos, Dimitrios; Spanou, Chrysa; Margariti, Maria; Stathopoulos, Constantinos; Mamuris, Zissis; Kazantzoglou, Georgios; Magiatis, Prokopios; Kouretas, Demetrios

    2007-06-27

    In the present study, the effects of extracts and polyphenol-rich fractions as well as monomer polyphenols identified in them, from both red and white grapes, on mitomycin C (MMC) induced sister chromatid exchanges (SCEs) in human peripheral blood lymphocytes were investigated. The grape extracts and two of the three polyphenol-rich fractions promoted MMC-induced SCEs at concentrations from 75 to 300 microg/mL. However, none of the extracts or fractions alone induced SCEs. Thus, these results suggest caution especially with regard to the use of grape extracts as dietary supplements. On the other hand, the fact that these extracts were not genotoxic alone may indicate a selective activity against genetically damaged cells. This is the first study regarding the clastogenic effects of grape extracts in human cells. Moreover, from the tested polyphenols, caffeic acid, gallic acid, and rutin hydrate enhanced MMC-induced clastogenicity, whereas ferulic acid, protocatechuic acid, (+)-catechin, (-)-epicatechin, and trans-resveratrol had no effect at concentrations between 5 and 100 microM. The differences in the chemical structures of the tested polyphenols may account for their differential effects on MMC clastogenicity.

  3. Role of caffeic acid phenethyl ester on mitomycin C induced clastogenesis: analysis of chromosome aberrations, micronucleus, mitotic index and adenosine deaminase activity in vivo.

    PubMed

    Sulaiman, Ghassan Mohammad

    2012-05-01

    The aim of the present investigation is to determine whether the caffeic acid phenethyl ester (CAPE) in combination with mitomycine-C (MMC) can ameliorate MMC-induced clastogenesis in the bone marrow cells of mice. The scoring of chromosomal aberrations, mitotic activity and micronuclei were undertaken in the current study as markers of clastogenicity. The action of CAPE in adenosine deaminase enzyme (ADA) activities of serum, thymus and spleen were also investigated. The animals were orally administered CAPE alone at the doses 5 or 10 mg kg b.wt.(-1) for 5 days then sacrificed 24 hours after the CAPE administration. MMC was administered to mice either alone at a single dose (2 mg kg b.wt.(-1)) by intraperitoneal injection, before or after CAPE treatment. Pre or post - treatment with two doses of CAPE significantly decreased the number of chromosomal aberrations, micronuclei and adapted the mitotic activity reduction in the bone marrow cells of mice induced by MMC when compared with only MMC given group. In addition, combination treatment with MMC caused a significant decrease in the activities of ADA in serum, thymus and spleen. The results of this study showed that ADA activity probably related to high levels of reactive oxygen species. This study concluded that the protective effect of CAPE against MMC clastogenesis resides at least in part, in its antioxidant effects.

  4. NER and HR pathways act sequentially to promote UV-C-induced germ cell apoptosis in Caenorhabditis elegans

    PubMed Central

    Stergiou, L; Eberhard, R; Doukoumetzidis, K; Hengartner, M O

    2011-01-01

    Ultraviolet (UV) radiation-induced DNA damage evokes a complex network of molecular responses, which culminate in DNA repair, cell cycle arrest and apoptosis. Here, we provide an in-depth characterization of the molecular pathway that mediates UV-C-induced apoptosis of meiotic germ cells in the nematode Caenorhabditis elegans. We show that UV-C-induced DNA lesions are not directly pro-apoptotic. Rather, they must first be recognized and processed by the nucleotide excision repair (NER) pathway. Our data suggest that NER pathway activity transforms some of these lesions into other types of DNA damage, which in turn are recognized and acted upon by the homologous recombination (HR) pathway. HR pathway activity is in turn required for the recruitment of the C. elegans homolog of the yeast Rad9-Hus1-Rad1 (9-1-1) complex and activation of downstream checkpoint kinases. Blocking either the NER or HR pathway abrogates checkpoint pathway activation and UV-C-induced apoptosis. Our results show that, following UV-C, multiple DNA repair pathways can cooperate to signal to the apoptotic machinery to eliminate potentially hazardous cells. PMID:21151025

  5. Astaxanthin down-regulates Rad51 expression via inactivation of AKT kinase to enhance mitomycin C-induced cytotoxicity in human non-small cell lung cancer cells.

    PubMed

    Ko, Jen-Chung; Chen, Jyh-Cheng; Wang, Tai-Jing; Zheng, Hao-Yu; Chen, Wen-Ching; Chang, Po-Yuan; Lin, Yun-Wei

    2016-04-01

    Astaxanthin has been demonstrated to exhibit a wide range of beneficial effects, including anti-inflammatory and anti-cancer properties. However, the molecular mechanism of astaxanthin-induced cytotoxicity in non-small cell lung cancer (NSCLC) cells has not been identified. Rad51 plays a central role in homologous recombination, and studies show that chemo-resistant carcinomas exhibit high levels of Rad51 expression. In this study, astaxanthin treatment inhibited cell viability and proliferation of two NSCLC cells, A549 and H1703. Astaxanthin treatment (2.5-20 μM) decreased Rad51 expression and phospho-AKT(Ser473) protein level in a time and dose-dependent manner. Furthermore, expression of constitutively active AKT (AKT-CA) vector rescued the decreased Rad51 mRNA and protein levels in astaxanthin-treated NSCLC cells. Combined treatment with phosphatidylinositol 3-kinase (PI3K) inhibitors (LY294002 or wortmannin) further decreased the Rad51 expression in astaxanthin-exposed A549 and H1703 cells. Knockdown of Rad51 expression by transfection with si-Rad51 RNA or cotreatment with LY294002 further enhanced the cytotoxicity and cell growth inhibition of astaxanthin. Additionally, mitomycin C (MMC) as an anti-tumor antibiotic is widely used in clinical NSCLC chemotherapy. Combination of MMC and astaxanthin synergistically resulted in cytotoxicity and cell growth inhibition in NSCLC cells, accompanied with reduced phospho-AKT(Ser473) level and Rad51 expression. Overexpression of AKT-CA or Flag-tagged Rad51 reversed the astaxanthin and MMC-induced synergistic cytotoxicity. In contrast, pretreatment with LY294002 further decreased the cell viability in astaxanthin and MMC co-treated cells. In conclusion, astaxanthin enhances MMC-induced cytotoxicity by decreasing Rad51 expression and AKT activation. These findings may provide rationale to combine astaxanthin with MMC for the treatment of NSCLC. Copyright © 2016 Elsevier Inc. All rights reserved.

  6. Minocycline enhances mitomycin C-induced cytotoxicity through down-regulating ERK1/2-mediated Rad51 expression in human non-small cell lung cancer cells.

    PubMed

    Ko, Jen-Chung; Wang, Tai-Jing; Chang, Po-Yuan; Syu, Jhan-Jhang; Chen, Jyh-Cheng; Chen, Chien-Yu; Jian, Yun-Ting; Jian, Yi-Jun; Zheng, Hao-Yu; Chen, Wen-Ching; Lin, Yun-Wei

    2015-10-01

    Minocycline is a semisynthetic tetracycline derivative; it has anti-inflammatory and anti-cancer effects distinct from its antimicrobial function. However, the molecular mechanism of minocycline-induced cytotoxicity in non-small cell lung cancer (NSCLC) cells has not been identified. Rad51 plays a central role in homologous recombination and high levels of Rad51 expression are observed in chemo- or radioresistant carcinomas. Our previous studies have shown that the MKK1/2-ERK1/2 signal pathway maintains the expression of Rad51 in NSCLC cells. In this study, minocycline treatment inhibited cell viability and proliferation of two NSCLC cells, A549 and H1975. Treatment with minocycline decreased Rad51 mRNA and protein levels through MKK1/2-ERK1/2 inactivation. Furthermore, expression of constitutively active MKK1 (MKK1-CA) vectors significantly rescued the decreased Rad51 protein and mRNA levels in minocycline-treated NSCLC cells. However, combined treatment with MKK1/2 inhibitor U0126 and minocycline further decreased the Rad51 expression and cell viability of NSCLC cells. Knocking down Rad51 expression by transfection with small interfering RNA of Rad51 enhanced the cytotoxicity and cell growth inhibition of minocycline. Mitomycin C (MMC) is typically used as a first or second line regimen to treat NSCLC. Compared to a single agent alone, MMC combined with minocycline resulted in cytotoxicity and cell growth inhibition synergistically in NSCLC cells, accompanied with reduced activation of phospho-ERK1/2, and reduced Rad51 protein levels. Overexpression of MKK1-CA or Flag-tagged Rad51 could reverse the minocycline and MMC-induced synergistic cytotoxicity. These findings may have implications for the rational design of future drug regimens incorporating minocycline and MMC for the treatment of NSCLC.

  7. FHL1C induces apoptosis in Notch1-dependent T-ALL cells through an interaction with RBP-J.

    PubMed

    Fu, Wei; Wang, Kai; Zhao, Jun-Long; Yu, Heng-Chao; Li, San-Zhong; Lin, Yan; Liang, Liang; Huang, Si-Yong; Liang, Ying-Min; Han, Hua; Qin, Hong-Yan

    2014-06-22

    Aberrantly activated Notch signaling has been found in more than 50% of patients with T-cell acute lymphoblastic leukemia (T-ALL). Current strategies that employ γ-secretase inhibitors (GSIs) to target Notch activation have not been successful. Many limitations, such as non-Notch specificity, dose-limiting gastrointestinal toxicity and GSI resistance, have prompted an urgent need for more effective Notch signaling inhibitors for T-ALL treatment. Human four-and-a-half LIM domain protein 1C (FHL1C) (KyoT2 in mice) has been demonstrated to suppress Notch activation in vitro, suggesting that FHL1C may be new candidate target in T-ALL therapy. However, the role of FHL1C in T-ALL cells remained unclear. Using RT-PCR, we amplified full-length human FHL1C, and constructed full-length and various truncated forms of FHL1C. Using cell transfection, flow cytometry, transmission electron microscope, real-time RT-PCR, and Western blotting, we found that overexpression of FHL1C induced apoptosis of Jurkat cells. By using a reporter assay and Annexin-V staining, the minimal functional sequence of FHL1C inhibiting RBP-J-mediated Notch transactivation and inducing cell apoptosis was identified. Using real-time PCR and Western blotting, we explored the possible molecular mechanism of FHL1C-induced apoptosis. All data were statistically analyzed with the SPSS version 12.0 software. In Jurkat cells derived from a Notch1-associated T-ALL cell line insensitive to GSI treatment, we observed that overexpression of FHL1C, which is down-regulated in T-ALL patients, strongly induced apoptosis. Furthermore, we verified that FHL1C-induced apoptosis depended on the RBP-J-binding motif at the C-terminus of FHL1C. Using various truncated forms of FHL1C, we found that the RBP-J-binding motif of FHL1C had almost the same effect as full-length FHL1C on the induction of apoptosis, suggesting that the minimal functional sequence in the RBP-J-binding motif of FHL1C might be a new drug candidate for T

  8. The inhibitor of histone deacetylases sodium butyrate enhances the cytotoxicity of mitomycin C.

    PubMed

    Gospodinov, Anastas; Popova, Stanislava; Vassileva, Ivelina; Anachkova, Boyka

    2012-10-01

    The use of histone deacetylase inhibitors has been proposed as a promising approach to increase the cell killing effect of DNA damage-inducing drugs in chemotherapy. However, the molecular mechanism of their action remains understudied. In the present article, we have assessed the effect of the histone deacetylase inhibitor sodium butyrate on the DNA damage response induced by the crosslinking agent mitomycin C. Sodium butyrate increased mitomycin C cytotoxicity, but did not impair the repair pathways required to remove mitomycin C-induced lesions as neither the rate of nucleotide excision repair nor the homologous recombination repair rate were diminished. Sodium butyrate treatment abrogated the S-phase cell-cycle checkpoint in mitomycin C-treated cells and induced the G(2)-M checkpoint. However, sodium butyrate treatment alone resulted in accumulation of reactive oxygen species, double-strand breaks in DNA, and apoptosis. These results imply that the accumulation of reactive oxygen species-mediated increase in DNA lesion burden may be the major mechanism by which sodium butyrate enhances the cytotoxicity of mitomycin C.

  9. Mitomycin C potentiates TRAIL-induced apoptosis through p53-independent upregulation of death receptors: evidence for the role of c-Jun N-terminal kinase activation.

    PubMed

    Cheng, Hairong; Hong, Bo; Zhou, Lanlan; Allen, Joshua E; Tai, Guihua; Humphreys, Robin; Dicker, David T; Liu, Yingqiu Y; El-Deiry, Wafik S

    2012-09-01

    The discovery of the molecular targets of chemotherapeutic medicines and their chemical footprints can validate and improve the use of such medicines. In the present report, we investigated the effect of mitomycin C (MMC), a classical chemotherapeutic agent on cancer cell apoptosis induced by TRAIL. We found that MMC not only potentiated TRAIL-induced apoptosis in HCT116 (p53-/-) colon cancer cells but also sensitized TRAIL-resistant colon cancer cells HT-29 to the cytokine both in vitro and in vivo. MMC also augmented the pro-apoptotic effects of two TRAIL receptor agonist antibodies, mapatumumab and lexatumumab. At a mechanistic level, MMC downregulated cell survival proteins, including Bcl2, Mcl-1 and Bcl-XL, and upregulated pro-apoptotic proteins including Bax, Bim and the cell surface expression of TRAIL death receptors DR4 and DR5. Gene silencing of DR5 by short hairpin RNA reduced the apoptosis induced by combination treatment of MMC and TRAIL. Induction of DR4 and DR5 was independent of p53, Bax and Bim but was dependent on c-Jun N terminal kinase (JNK) as JNK pharmacological inhibition and siRNA abolished the induction of the TRAIL receptors by MMC.

  10. A novel LMP1 antibody synergizes with mitomycin C to inhibit nasopharyngeal carcinoma growth in vivo through inducing apoptosis and downregulating vascular endothelial growth factor.

    PubMed

    Mao, Yuan; Zhang, Da-Wei; Wen, Juan; Cao, Qing; Chen, Ren-Jie; Zhu, Jin; Feng, Zhen-Qing

    2012-01-01

    Combined therapy emerges as an attractive strategy for cancer treatment. The aim of this study was to investigate the inhibitory effects of mitomycin C (MMC) combined with a novel antibody fragment (Fab) targeting latent membrane protein 1 (LMP1) on nasopharyngeal carcinoma (NPC) xenograft nude mice. The inhibitory rates of MMC (2 mg/kg), Fab (4 mg/kg), MMC (2 mg/kg) + Fab (4 mg/kg), and MMC (1 mg/kg) + Fab (4 mg/kg) were 20.1%, 7.3%, 42.5% and 40.5%, respectively. Flow cytometry analysis showed that the apoptotic rate of xenograft tumor cells in the MMC and Fab combination group was 28 ± 4.12%, significantly higher than the MMC (2 mg/kg) group (P < 0.01). Immunohistochemical staining showed that VEGF expression in NPC xenografts was significantly inhibited in the combination group compared to the Fab (4 mg/kg) group (P < 0.05). In conclusion, both MMC and Fab could inhibit NPC xenograft tumor growth in vivo and combination therapy showed apparent synergistic anti-tumor effects, which may be due to the induction of tumor cell apoptosis and the downregulation of VEGF expression. These results suggest that the novel combined therapy utilizing traditional chemotherapeutics and antibody-targeted therapy could be a promising strategy for the treatment of NPC.

  11. p53 mutant human glioma cells are sensitive to UV-C-induced apoptosis due to impaired cyclobutane pyrimidine dimer removal.

    PubMed

    Batista, Luis F Z; Roos, Wynand P; Kaina, Bernd; Menck, Carlos F M

    2009-02-01

    The p53 protein is a key regulator of cell responses to DNA damage, and it has been shown that it sensitizes glioma cells to the alkylating agent temozolomide by up-regulating the extrinsic apoptotic pathway, whereas it increases the resistance to chloroethylating agents, such as ACNU and BCNU, probably by enhancing the efficiency of DNA repair. However, because these agents induce a wide variety of distinct DNA lesions, the direct importance of DNA repair is hard to access. Here, it is shown that the induction of photoproducts by UV light (UV-C) significantly induces apoptosis in a p53-mutated glioma background. This is caused by a reduced level of photoproduct repair, resulting in the persistence of DNA lesions in p53-mutated glioma cells. UV-C-induced apoptosis in p53 mutant glioma cells is preceded by strong transcription and replication inhibition due to blockage by unrepaired photolesions. Moreover, the results indicate that UV-C-induced apoptosis of p53 mutant glioma cells is executed through the intrinsic apoptotic pathway, with Bcl-2 degradation and sustained Bax and Bak up-regulation. Collectively, the data indicate that unrepaired DNA lesions induce apoptosis in p53 mutant gliomas despite the resistance of these gliomas to temozolomide, suggesting that efficiency of treatment of p53 mutant gliomas might be higher with agents that induce the formation of DNA lesions whose global genomic repair is dependent on p53.

  12. Juglanthraquinone C Induces Intracellular ROS Increase and Apoptosis by Activating the Akt/Foxo Signal Pathway in HCC Cells

    PubMed Central

    2016-01-01

    Juglanthraquinone C (JC), a naturally occurring anthraquinone extracted from Juglans mandshurica, could induce apoptosis of cancer cells. This study aims to investigate the detailed cytotoxicity mechanism of JC in HepG2 and BEL-7402 cells. The Affymetrix HG-U133 Plus 2.0 arrays were first used to analyze the mRNA expression exposed to JC or DMSO in HepG2 cells. Consistent with the previous results, the data indicated that JC could induce apoptosis and hyperactivated Akt. The Western blot analysis further revealed that Akt, a well-known survival protein, was strongly activated in HepG2 and BEL-7402 cells. Furthermore, an obvious inhibitory effect on JC-induced apoptosis was observed when the Akt levels were decreased, while the overexpression of constitutively active mutant Akt greatly accelerated JC-induced apoptosis. The subsequent results suggested that JC treatment suppressed nuclear localization and increased phosphorylated levels of Foxo3a, and the overexpression of Foxo3a abrogated JC-induced apoptosis. Most importantly, the inactivation of Foxo3a induced by JC further led to an increase of intracellular ROS levels by suppressing ROS scavenging enzymes, and the antioxidant N-acetyl-L-cysteine and catalase successfully decreased JC-induced apoptosis. Collectively, this study demonstrated that JC induced the apoptosis of hepatocellular carcinoma (HCC) cells by activating Akt/Foxo signaling pathway and increasing intracellular ROS levels. PMID:26682007

  13. Juglanthraquinone C Induces Intracellular ROS Increase and Apoptosis by Activating the Akt/Foxo Signal Pathway in HCC Cells.

    PubMed

    Hou, Ya-Qin; Yao, Yao; Bao, Yong-Li; Song, Zhen-Bo; Yang, Cheng; Gao, Xiu-Li; Zhang, Wen-Jing; Sun, Lu-Guo; Yu, Chun-Lei; Huang, Yan-Xin; Wang, Guan-Nan; Li, Yu-Xin

    2016-01-01

    Juglanthraquinone C (JC), a naturally occurring anthraquinone extracted from Juglans mandshurica, could induce apoptosis of cancer cells. This study aims to investigate the detailed cytotoxicity mechanism of JC in HepG2 and BEL-7402 cells. The Affymetrix HG-U133 Plus 2.0 arrays were first used to analyze the mRNA expression exposed to JC or DMSO in HepG2 cells. Consistent with the previous results, the data indicated that JC could induce apoptosis and hyperactivated Akt. The Western blot analysis further revealed that Akt, a well-known survival protein, was strongly activated in HepG2 and BEL-7402 cells. Furthermore, an obvious inhibitory effect on JC-induced apoptosis was observed when the Akt levels were decreased, while the overexpression of constitutively active mutant Akt greatly accelerated JC-induced apoptosis. The subsequent results suggested that JC treatment suppressed nuclear localization and increased phosphorylated levels of Foxo3a, and the overexpression of Foxo3a abrogated JC-induced apoptosis. Most importantly, the inactivation of Foxo3a induced by JC further led to an increase of intracellular ROS levels by suppressing ROS scavenging enzymes, and the antioxidant N-acetyl-L-cysteine and catalase successfully decreased JC-induced apoptosis. Collectively, this study demonstrated that JC induced the apoptosis of hepatocellular carcinoma (HCC) cells by activating Akt/Foxo signaling pathway and increasing intracellular ROS levels.

  14. The Marine Metabolite SZ-685C Induces Apoptosis in Primary Human Nonfunctioning Pituitary Adenoma Cells by Inhibition of the Akt Pathway in Vitro

    PubMed Central

    Wang, Xin; Tan, Ting; Mao, Zhi-Gang; Lei, Ni; Wang, Zong-Ming; Hu, Bin; Chen, Zhi-Yong; She, Zhi-Gang; Zhu, Yong-Hong; Wang, Hai-Jun

    2015-01-01

    Nonfunctioning pituitary adenoma (NFPA) is one of the most common types of pituitary adenoma. The marine anthraquinone derivative SZ-685C has been isolated from the secondary metabolites of the mangrove endophytic fungus Halorosellinia sp. (No. 1403) which is found in the South China Sea. Recent research has shown that SZ-685C possesses anticancer and tumor suppressive effects. The tetrazolium-based colorimetric assay (MTT assay) to investigate the different effect of the marine compound SZ-685C on the proliferation of primary human NFPA cells, rat normal pituitary cells (RPCs) and rat prolactinoma MMQ cell lines. Hoechst 33342 dye/propidium iodide (PI) double staining and fluorescein isothiocyanate-conjugated Annexin V/PI (Annexin V-FITC/PI) apoptosis assays detected an enhanced rate of apoptosis in cells treated with SZ-685C. Enhanced expression levels of caspase 3 and phosphate and tensin homolog (PTEN) were determined by Western blotting. Notably, the protein expression levels of Akt were decreased when the primary human NFPA cells were treated with SZ-685C. Here, we show that SZ-685C induces apoptosis of human NFPA cells through inhibition of the Akt pathway in vitro. The understanding of apoptosis has provided the basis for novel targeted therapies that can induce death in cancer cells or sensitize them to established cytotoxic agents and radiation therapy. PMID:25806467

  15. Tenascin-C induces resistance to apoptosis in pancreatic cancer cell through activation of ERK/NF-κB pathway.

    PubMed

    Shi, Meiyan; He, Xiaodan; Wei, Wei; Wang, Juan; Zhang, Ti; Shen, Xiaohong

    2015-06-01

    As a glycol-protein located in extracellular matrix (ECM), tenascin-C (TNC) is absent in most normal adult tissues but is highly expressed in the majority of malignant solid tumors. Pancreatic cancer is characterized by an abundant fibrous tissue rich in TNC. Although it was reported that TNC's expression increased in the progression from low-grade precursor lesions to invasive cancer and was associated with tumor differentiation in human pancreatic cancer, studies on the relations between TNC and tumor progression in pancreatic cancer were rare. In this study, we performed an analysis to determine the effects of TNC on modulating cell apoptosis and chemo-resistance and explored its mechanisms involving activation in pancreatic cancer cell. The expressions of TNC, ERK1/2/p-ERK1/2, Bcl-xL and Bcl-2 were detected by immunohistochemistry and western blotting. Then the effects of exogenous and endogenous TNC on the regulation of tumor proliferation, apoptosis and gemcitabine cytotoxicity were investigated. The associations among the TNC knockdown, TNC stimulation and expressions of ERK1/2/NF-κB/p65 and apoptotic regulatory proteins were also analyzed in cell lines. The mechanism of TNC on modulating cancer cell apoptosis and drug resistant through activation of ERK1/2/NF-κB/p65 signals was evaluated. The effect of TNC on regulating cell cycle distribution was also tested. TNC, ERK1/2/p-ERK1/2, and apoptotic regulatory proteins Bcl-xL and Bcl-2 were highly expressed in human pancreatic cancer tissues. In vitro, exogenous TNC promoted pancreatic cancer cell growth also mediates basal as well as starved and drug-induced apoptosis in pancreatic cancer cells. The effects of TNC on anti-apoptosis were induced by the activation state of ERK1/2/NF-κB/p65 signals in pancreatic cell. TNC phosphorylate ERK1/2 to induce NF-κB/p65 nucleus translocation. The latter contributes to promote Bcl-xL, Bcl-2 protein expressions and reduce caspase activity, which inhibit cell apoptotic

  16. Intracellular delivery of poly(I:C) induces apoptosis of fibroblast-like synoviocytes via an unknown dsRNA sensor

    SciTech Connect

    Karpus, Olga N.; Hsiao, Cheng-Chih; Kort, Hanneke de; Tak, Paul P.; Hamann, Jörg

    2016-08-26

    Fibroblast-like synoviocytes (FLS) express functional membranous and cytoplasmic sensors for double-stranded (ds)RNA. Notably, FLS undergo apoptosis upon transfection with the synthetic dsRNA analog poly(I:C). We here studied the mechanism of intracellular poly(I:C) recognition and subsequent cell death in FLS. FLS responded similarly to poly(I:C) or 3pRNA transfection; however, only intracellular delivery of poly(I:C) induced significant cell death, accompanied by upregulation of pro-apoptotic proteins Puma and Noxa, caspase 3 cleavage, and nuclear segregation. Knockdown of the DExD/H-box helicase MDA5 did not affect the response to intracellular poly(I:C); in contrast, knockdown of RIG-I abrogated the response to 3pRNA. Knockdown of the downstream adaptor proteins IPS, STING, and TRIF or inhibition of TBK1 did not affect the response to intracellular poly(I:C), while knockdown of IFNAR blocked intracellular poly(I:C)-mediated signaling and cell death. We conclude that a so far unknown intracellular sensor recognizes linear dsRNA and induces apoptosis in FLS. - Highlights: • Intracellular poly(I:C) and 3pRNA evoke immune responses in FLS. • Only intracellular delivery of poly(I:C) induces FLS apoptosis. • FLS do not require MDA5 for their response to intracellular poly(I:C). • FLS respond to intracellular poly(I:C) independent of IPS and STING. • An unknown intracellular sensor recognizes linear dsRNA in FLS.

  17. Cudraflavone C Induces Tumor-Specific Apoptosis in Colorectal Cancer Cells through Inhibition of the Phosphoinositide 3-Kinase (PI3K)-AKT Pathway

    PubMed Central

    Soo, Hsien-Chuen; Chung, Felicia Fei-Lei; Lim, Kuan-Hon; Yap, Veronica Alicia; Bradshaw, Tracey D.; Hii, Ling-Wei; Tan, Si-Hoey; See, Sze-Jia; Tan, Yuen-Fen; Leong, Chee-Onn

    2017-01-01

    Cudraflavone C (Cud C) is a naturally-occurring flavonol with reported anti-proliferative activities. However, the mechanisms by which Cud C induced cytotoxicity have yet to be fully elucidated. Here, we investigated the effects of Cud C on cell proliferation, caspase activation andapoptosis induction in colorectal cancer cells (CRC). We show that Cud C inhibits cell proliferation in KM12, Caco-2, HT29, HCC2998, HCT116 and SW48 CRC but not in the non-transformed colorectal epithelial cells, CCD CoN 841. Cud C induces tumor-selective apoptosis via mitochondrial depolarization and activation of the intrinsic caspase pathway. Gene expression profiling by microarray analyses revealed that tumor suppressor genes EGR1, HUWE1 and SMG1 were significantly up-regulated while oncogenes such as MYB1, CCNB1 and GPX2 were down-regulated following treatment with Cud C. Further analyses using Connectivity Map revealed that Cud C induced a gene signature highly similar to that of protein synthesis inhibitors and phosphoinositide 3-kinase (PI3K)-AKT inhibitors, suggesting that Cud C might inhibit PI3K-AKT signaling. A luminescent cell free PI3K lipid kinase assay revealed that Cud C significantly inhibited p110β/p85α PI3K activity, followed by p120γ, p110δ/p85α, and p110α/p85α PI3K activities. The inhibition by Cud C on p110β/p85α PI3K activity was comparable to LY-294002, a known PI3K inhibitor. Cud C also inhibited phosphorylation of AKT independent of NFκB activity in CRC cells, while ectopic expression of myristoylated AKT completely abrogated the anti-proliferative effects, and apoptosis induced by Cud C in CRC. These findings demonstrate that Cud C induces tumor-selective cytotoxicity by targeting the PI3K-AKT pathway. These findings provide novel insights into the mechanism of action of Cud C, and indicate that Cud C further development of Cud C derivatives as potential therapeutic agents is warranted. PMID:28107519

  18. Photoprotective effect of flax seed oil (Linum usitatissimum L.) against ultraviolet C-induced apoptosis and oxidative stress in rats.

    PubMed

    Tülüce, Yasin; Ozkol, Halil; Koyuncu, Ismail

    2012-03-01

    The aim of this study is to determine antioxidant and antiapoptotic effects of flax seed oil (FSO) on rats exposed to ultraviolet C (UVC). Malondialdehyde (MDA), protein carbonyl (PC) and reduced glutathione (GSH) levels as well as glutathione peroxidase (GPx) and superoxide dismutase (SOD) activities were measured in lens, skin and serum. In addition, β-carotene, vitamin A, C and E contents were measured in serum, while apoptosis was determined in retina. Rats were divided into three groups as control, UVC and UVC + FSO. UVC and UVC + FSO groups were exposed to UVC light for 1 h twice a day for 4 weeks. FSO (4 ml/kg bw) was given by gavage before each irradiation period to the UV + FSO group. While MDA and PC levels of the UVC group increased compared to the control group, their levels decreased in the UVC + FSO group compared with the UVC group in skin, lens and serum. Skin GSH level decreased significantly in the UVC and UVC + FSO groups. As GPx and SOD activities of the UVC group were lower, their activities were higher in the UVC + FSO group in skin, lens and serum. There was only marked elevation of vitamin A level in the UVC group compared to the control group. Apoptosis increased in the UVC group and the UVC + FSO groups in retina. However, retinal apoptosis were lower in the UVC + FSO group compared with the UVC group. This investigation demonstrated that UVC exposure led to oxidative stress and apoptosis in rats as reflected by increased MDA, PC contents and decreased enzymatic and nonenzymatic antioxidant levels, FSO may be useful for preventing photoreactive damage.

  19. Effects of plant phenolics and grape extracts from Greek varieties of Vitis vinifera on Mitomycin C and topoisomerase I-induced nicking of DNA.

    PubMed

    Stagos, Demetrios; Kazantzoglou, Georgios; Magiatis, Prokopios; Mitaku, Sofia; Anagnostopoulos, Konstantinos; Kouretas, Demetrios

    2005-06-01

    In recent years, a number of reports have shown the anticancer activity of grape extracts and wine against various types of cancer such as breast, lung and gastric cancer. This property is mainly attributed to the plant polyphenols identified in grapes. The aim of the present study was to investigate the mechanisms by which grape extracts and plant polyphenols found in them exert their chemopreventive and antitumour activities. Thus, aqueous and methanolic extracts from two Greek varieties of Vitis vinifera, fractions enriched in polyphenols of these extracts and polyphenolics (caffeic acid, ferulic acid, gallic acid, protocatechuic acid and rutin) found in grapes were screened using two in vitro assays: i) the topoisomerase I relaxation assay and ii) the mitomycin C-induced DNA strand breakage. The grape extracts, the polyphenol-rich fractions and some of the polyphenolics (caffeic acid and protocatechuic acid) were potent inhibitors of topoisomerase I, indicating that the inhibition of this enzyme may be one of the mechanisms accounting for the anticancer activity of these compounds. Moreover, the grape extracts inhibited the mitomycin C-induced DNA strand breakage suggesting that they could prevent ROS-mediated DNA damage. On the other hand, the polyphenol-rich fractions and the plant polyphenols enhanced the mitomycin C-induced DNA strand breakage indicating prooxidant activity. Thus, it is of interest that whole grape extracts act as chemopreventive agents by inhibiting topo I and mitomycin C-induced DNA damage, while polyphenol enriched fractions and plant polyphenolics exert prooxidant activity leading to enhancement of DNA damage which may account for the cytotoxic and apoptosis-inducing properties of plant polyphenols against cancer cells.

  20. Isoindolone derivative QSN-10c induces leukemic cell apoptosis and suppresses angiogenesis via PI3K/AKT signaling pathway inhibition

    PubMed Central

    Lv, Wen-wen; Qin, Si-ning; Chen, Cong-qin; Zhang, Jin-jie; Ren, Tian-shu; Xu, Yong-nan; Zhao, Qing-chun

    2014-01-01

    Aim: 2-(4,6-Dimethoxy-1,3-dioxoisoindolin-2-yl) ethyl 2-chloroacetate (QSN-10c) is one of isoindolone derivatives with antiproliferative activity against human umbilical vein endothelial cells (HUVECs). The aim of this study was to investigate its antitumor activity in vitro and anti-angiogenic effects in vitro and in vivo. Methods: K562 leukemic cells and HUVECs were used for in vitro studies. Cell viability was examined using MTT assay. Cell apoptosis and mitochondrial transmembrane potential (Δψm) were detected with flow cytometry. Tube formation and migration of HUVECs were studied using two-dimensional Matrigel assay and wound-healing migration assay, respectively. VEGF levels were analyzed with RT-PCR and Western blotting. A zebrafish embryo model was used for in vivo anti-angiogenic studies. The molecular mechanisms for apoptosis in K562 cells and antiangiogenesis were measured with Western blotting. Results: In antitumor activity studies, QSN-10c suppressed the viability of K562 cells and induced apoptosis in dose- and time-dependent manners. Furthermore, QSN-10c dose-dependently decreased the Δψm in K562 cells, increased the release of cytochrome c and the level of Bax, and decreased the level of Bcl-2, suggesting that QSN-10c-induced apoptosis of K562 cells was mediated via the mitochondrial apoptotic pathway. In anti-angiogenic activity studies, QSN-10c suppressed the viability of HUVECs and induced apoptosis in dose dependent manners. QSN-10c treatment did not alter the Δψm in HUVECs, but dose-dependently inhibited the expression of VEGF, inhibited the tube formation and cell migration in vitro, and significantly suppressed the number of ISVs in zebrafish embryos in vivo. Furthermore, QSN-10c dose-dependently suppressed the phosphorylation of AKT and GSK3β in both HUVECs and K562 cells. Conclusion: QSN-10c is a novel antitumor compound that exerts both antitumor and anti-angiogenic effects via inhibiting the PI3K/AKT/GSK3β signaling pathway

  1. A Management Algorithm for Mitomycin C Induced Cystitis.

    PubMed

    Luckenbaugh, Amy N; Marks, Rory M; Miller, David C; Weizer, Alon Z; Stoffel, John T; Montgomery, Jeffrey S

    2017-04-27

    Background/Objective: A post-bladder tumor resection dose of MMC can reduce non-invasive papillary (pTa) bladder cancer recurrences by up to 40%; this treatment is recommended in both the AUA and EUA non-muscle-invasive bladder cancer guidelines. A common complication of this treatment is eosinophilic cystitis. Symptoms range from mild urinary frequency and urgency to debilitating pain and dysuria. Currently, there is no established treatment algorithm for MMC-induced cystitis. Methods: Members of the Urologic Surgery Quality Collaborative (USQC), a group composed of over 160 private and academic urologists, met to discuss the management of patients with cystitis following MMC therapy. They devised a treatment algorithm based on experiences of urologic oncologists and neurourologists to aid in the diagnosis and management of MMC-induced cystitis. Results: The assessment begins with urinalysis and culture, followed by cystoscopy. For mild symptoms, behavioral therapy, including timed voids, fluid restriction and Kegel exercises are trialed. If symptoms have not resolved, treatment with an antihistamine, followed by a combination of anticholinergic and alpha-blocker medications. For persistent symptoms or severe symptoms at presentation, a course of prednisone plus antihistamine is prescribed. If symptoms are improving but have not resolved, this treatment is extended for a full 4 weeks prior to steroid taper. If symptoms do not improve, any visible bladder ulcerations are resected intraoperatively followed by an additional course of prednisone and antihistamine. Intravesical DMSO instillations and intra-ulcer steroid injection can be used as a final effort to treat this condition. Conclusion: We present the first formal management algorithm with escalating treatment intensity tailored to patient symptoms.

  2. Recombinant activated protein C induces dose-dependent changes in inflammatory mediators, tissue damage, and apoptosis in in vivo rat model of sepsis.

    PubMed

    Shires, G Tom; Fisher, Orna; Murphy, Patrick; Williams, Shelley; Barber, Annabel; Johnson, Gayle; Davis, Brett; Pahulu, Stacey

    2007-06-01

    Sepsis is the tenth leading cause of death in the U.S. and creates a $16.7 billion burden on the healthcare system every year. Sepsis is characterized by a severe uncontrolled inflammatory response to the infection. Various cells and mediators are activated, and the result is a complex interaction between the inflammation and coagulation cascades leading to capillary leakage and end-organ ischemia. Current therapeutic strategies, such as recombinant human activated protein C, focus on this interplay. However, this drug's precise mechanism of action is not well understood. The aim of this study was to assess cytokine production, tissue damage, and apoptosis in a rat model of sepsis in response to various doses of this drug. Sprague-Dawley rats were divided into eight groups, including negative control, sham, sepsis only, and five treatment groups. The sepsis and treatment groups were given Escherichia coli. Each of the treatment groups received a different dose of recombinant activated protein C to complete 30-min or 270-min infusion times from the onset of sepsis. Serum and tissue samples were collected. Interleukin (IL)-6 concentrations were measured, and serum malondialdehyde (MDA) concentrations were determined to assess generalized tissue damage. Apoptosis in the lung was evaluated using a semi-quantitative ligation-mediated polymerase chain reaction assay. The physiologic effects of recombinant activated protein C are dose dependent and determined by the duration of infusion. Higher doses of the drug were associated with less inflammation, apoptosis, and generalized tissue damage. Sepsis increased the mean concentration of MDA (2.1 vs. 10.9 pmol/mg of protein) and IL-6 (0 vs. 10,763 pg/mL) compared with sham-treated animals, as well as the magnitude of apoptosis in lung (2,037 vs. 8,709 pixels) (all p < 0.05). Infusion of recombinant activated protein C attenuated these responses in a dose-response manner. Interleukin-6 and MDA concentrations were increased by

  3. 40 CFR 721.5175 - Mitomycin C.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Mitomycin C. 721.5175 Section 721.5175... Mitomycin C. (a) Chemical substance and significant new use subject to reporting. (1) The chemical substance mitomycin C (CAS No. 5007-7) is subject to reporting under this section for the significant new...

  4. 40 CFR 721.5175 - Mitomycin C.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 32 2013-07-01 2013-07-01 false Mitomycin C. 721.5175 Section 721.5175... Mitomycin C. (a) Chemical substance and significant new use subject to reporting. (1) The chemical substance mitomycin C (CAS No. 5007-7) is subject to reporting under this section for the significant new...

  5. 40 CFR 721.5175 - Mitomycin C.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 31 2011-07-01 2011-07-01 false Mitomycin C. 721.5175 Section 721.5175... Mitomycin C. (a) Chemical substance and significant new use subject to reporting. (1) The chemical substance mitomycin C (CAS No. 5007-7) is subject to reporting under this section for the significant new...

  6. 40 CFR 721.5175 - Mitomycin C.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 31 2014-07-01 2014-07-01 false Mitomycin C. 721.5175 Section 721.5175... Mitomycin C. (a) Chemical substance and significant new use subject to reporting. (1) The chemical substance mitomycin C (CAS No. 5007-7) is subject to reporting under this section for the significant new...

  7. 40 CFR 721.5175 - Mitomycin C.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 32 2012-07-01 2012-07-01 false Mitomycin C. 721.5175 Section 721.5175... Mitomycin C. (a) Chemical substance and significant new use subject to reporting. (1) The chemical substance mitomycin C (CAS No. 5007-7) is subject to reporting under this section for the significant new...

  8. Effect of mitomycin on normal dermal fibroblast and HaCat cell: an in vitro study

    PubMed Central

    Wang, Yao-wen; Ren, Ji-hao; Xia, Kun; Wang, Shu-hui; Yin, Tuan-fang; Xie, Ding-hua; Li, Li-hua

    2012-01-01

    Objective: To evaluate the effects of mitomycin on the growth of human dermal fibroblast and immortalized human keratinocyte line (HaCat cell), particularly the effect of mitomycin on intracellular messenger RNA (mRNA) synthesis of collagen and growth factors of fibroblast. Methods: The normal dermal fibroblast and HaCat cell were cultured in vitro. Cell cultures were exposed to 0.4 and 0.04 mg/ml of mitomycin solution, and serum-free culture medium was used as control. The cellular morphology change, growth characteristics, cell proliferation, and apoptosis were observed at different intervals. For the fibroblasts, the mRNA expression changes of transforming growth factor (TGF)-β1, basic fibroblast growth factor (bFGF), procollagen I, and III were detected by reverse transcription polymerase chain reaction (RT-PCR). Results: The cultured normal human skin fibroblast and HaCat cell grew exponentially. A 5-min exposure to mitomycin at either 0.4 or 0.04 mg/ml caused marked dose-dependent cell proliferation inhibition on both fibroblasts and HaCat cells. Cell morphology changed, cell density decreased, and the growth curves were without an exponential phase. The fibroblast proliferated on the 5th day after the 5-min exposure of mitomycin at 0.04 mg/ml. Meanwhile, 5-min application of mitomycin at either 0.04 or 0.4 mg/ml induced fibroblast apoptosis but not necrosis. The apoptosis rate of the fibroblast increased with a higher concentration of mytomycin (p<0.05). A 5-min exposure to mitomycin at 0.4 mg/ml resulted in a marked decrease in the mRNA production of TGF-β1, procollagen I and III, and a marked increase in the mRNA production of bFGF. Conclusions: Mitomycin can inhibit fibroblast proliferation, induce fibroblast apoptosis, and regulate intracellular protein expression on mRNA levels. In additon, mitomycin can inhibit HaCat cell proliferation, so epithelial cell needs more protecting to avoid mitomycin’s side effect when it is applied clinically. PMID

  9. Evolving role of mitomycin-C laryngology

    NASA Astrophysics Data System (ADS)

    Richards, Steven V.; Garrett, C. Gaelyn

    2001-05-01

    Topical mitomycin-C, a chemotherapeutic agent and a fibroblast inhibitor, has been successfully used in larynx, primarily to treat stenosis. Subglottic, tracheal, and anterior glottic stenosis have all shown promising results in a canine model. Less favorable results have been obtained when topical mitomycin-C is used on the vocal folds following surgical excision of mucosa. In the vocal fold studies, laryngeal videostroboscopy revealed diminished mucosal wave vibration in the vocal folds treated with mitomycin-C as well as a more atrophic appearance to the vibratory surface. The tissue treated with mitomycin-C showed fewer fibroblasts and less collagen. However, inflammatory infiltrate was not significantly different between the treated and untreated tissue. These results are consistent with the known suppression of fibroblast proliferation by mitomycin-C. In contrast to the positive effects of mitomycin-C on stenosis, the observed decrease in the healing response in the vocal fold had negative consequences on vocal fold vibratory pattern.

  10. Mitomycins syntheses: a recent update

    PubMed Central

    2009-01-01

    Summary Mitomycins are a class of very potent antibacterial and anti-cancer compounds having a broad activity against a range of tumours. They have been used in clinics since the 1960’s, and the challenges represented by their total synthesis have challenged generations of chemists. Despite these chemical and medicinal features, these compounds, in racemic form, have succumbed to total synthesis only four times over the last 30 years. PMID:19777135

  11. Mitomycin

    MedlinePlus

    ... used in combination with other medications to treat cancer of the stomach or pancreas that has spread to other parts of the body and has not improved or worsened after treatment with other ... that is only used in cancer chemotherapy. It slows or stops the growth of ...

  12. Dorzolamide synergizes the antitumor activity of mitomycin C against Ehrlich's carcinoma grown in mice: role of thioredoxin-interacting protein.

    PubMed

    Ali, Belal M; Zaitone, Sawsan A; Shouman, Samia A; Moustafa, Yasser M

    2015-12-01

    The antitumor activity of carbonic anhydrase (CA) inhibitors is attributed to their ability to induce a state of intracellular acidification. In fact, acidic intracellular pH was demonstrated to upregulate several tumor suppressor proteins and increase the activity of many chemotherapies. The present study aimed to investigate the antitumor activity of the CA inhibitor, dorzolamide, in combination with mitomycin C and to study the effect of these drugs on tumoral thioredoxin-interacting protein (TXNIP) as well as tumor cell proliferation and apoptosis. Solid tumors were induced by subcutaneous inoculation of Ehrlich's ascites carcinoma (EAC) cells in female mice. Mice were treated with dorzolamide (3, 10, or 30 mg/kg/day, i.p.) and/or mitomycin C (1 mg/kg, i.p.) weekly for 3 weeks. Treatment with mitomycin C increased TXNIP level in EAC solid tumors in mice. Likewise, treatment with dorzolamide upregulated TXNIP and p53 while downregulated bcl-2. Both drug therapies increased tumoral caspase 9, caspase 3, and PARP-1 cleavage in addition to decreasing the proliferative Ki-67-stained nuclear fraction. Indeed, a synergistic effect was detected between mitomycin C and dorzolamide. The current data demonstrated that the antitumor activity of mitomycin C and dorzolamide was, at least in part, mediated through stimulating tumoral expression of TXNIP and enhancing tumor apoptosis.

  13. Mitomycin C in pterygium treatment

    PubMed Central

    Martins, Thiago Gonçalves dos Santos; Costa, Ana Luiza Fontes de Azevedo; Alves, Milton Ruiz; Chammas, Roger; Schor, Paulo

    2016-01-01

    Pterygium is a benign lesion usually growing from the nasal side of the conjunctiva onto the cornea. Most cases of pterygium does not cause problem or requires specific treatment. The exact cause of pterygium is not clear yet, but some factors are pointed as causes, being the most important the long-term ultraviolet ray exposure. Pterygium surgery is usually considered when there are symptoms that do not respond to conservative treatment. Recurrence is the main complication of the surgery, and much has been done to avoid it. Mitomycin C (MMC) has been used as a fibroblast proliferation inhibitor during the surgery to reduce the chance of recurrence of the pterygium. This review describes the use of MMC as an adjunctive, the optimal dosage, the duration of administration of MMC and possible complications, when used during, after and before the surgery. Most studies suggest that increased exposure (dose or duration) of MMC is associated with a lower recurrence, but with higher risks of complications. PMID:27158622

  14. Pharmacokinetics of mitomycin C in rabbit and human.

    PubMed

    van Hazel, G A; Kovach, J S

    1982-01-01

    A sensitive and specific high-pressure liquid chromatographic assay was developed to characterize the plasma elimination and urinary excretion of mitomycin C in humans. Extraction of mitomycin C and an internal standard, porfiromycin, from plasma by chromatography over a non-ionic resin, Porapak Q, yields high recovery of both compounds and facilitates measurement of as little as 5 ng mitomycin C by reversed-phase high-pressure liquid chromatography. The assay was used to characterize the plasma elimination of mitomycin C in rabbits and was shown to be applicable to the characterization of the pharmacokinetics of mitomycin C in humans receiving as little as 8 mg/m2.

  15. Tetrathiomolybdate sensitizes ovarian cancer cells to anticancer drugs doxorubicin, fenretinide, 5-fluorouracil and mitomycin C.

    PubMed

    Kim, Kyu Kwang; Lange, Thilo S; Singh, Rakesh K; Brard, Laurent; Moore, Richard G

    2012-04-13

    Our recent study showed that tetrathiomolybdate (TM), a drug to treat copper overload disorders, can sensitize drug-resistant endometrial cancer cells to reactive oxygen species (ROS)-generating anticancer drug doxorubicin. To expand these findings in the present study we explore TM efficacy in combination with a spectrum of ROS-generating anticancer drugs including mitomycin C, fenretinide, 5-fluorouracil and doxorubicin in ovarian cancer cells as a model system. The effects of TM alone or in combination with doxorubicin, mitomycin C, fenretinide, or 5-fluorouracil were evaluated using a sulforhodamine B assay. Flow cytometry was used to detect the induction of apoptosis and ROS generation. Immunoblot analysis was carried out to investigate changes in signaling pathways. TM potentiated doxorubicin-induced cytotoxicity and modulated key regulators of apoptosis (PARP, caspases, JNK and p38 MAPK) in SKOV-3 and A2780 ovarian cancer cell lines. These effects were linked to the increased production of ROS, as shown in SKOV-3 cells. ROS scavenging by ascorbic acid blocked the sensitization of cells by TM. TM also sensitized SKOV-3 to mitomycin C, fenretinide, and 5-fluorouracil. The increased cytotoxicity of these drugs in combination with TM was correlated with the activity of ROS, loss of a pro-survival factor (e.g. XIAP) and the appearance of a pro-apoptotic marker (e.g. PARP cleavage). Our data show that TM increases the efficacy of various anticancer drugs in ovarian cancer cells in a ROS-dependent manner.

  16. Inhibition of DNA cross-linking by mitomycin C by peroxidase-mediated oxidation of mitomycin C hydroquinone.

    PubMed

    Penketh, P G; Hodnick, W F; Belcourt, M F; Shyam, K; Sherman, D H; Sartorelli, A C

    2001-09-14

    Mitomycin C requires reductive activation to cross-link DNA and express anticancer activity. Reduction of mitomycin C (40 microm) by sodium borohydride (200 microm) in 20 mm Tris-HCl, 1 mm EDTA at 37 degrees C, pH 7.4, gives a 50-60% yield of the reactive intermediate mitomycin C hydroquinone. The hydroquinone decays with first order kinetics or pseudo first order kinetics with a t(12) of approximately 15 s under these conditions. The cross-linking of T7 DNA in this system followed matching kinetics, with the conversion of mitomycin C hydroquinone to leuco-aziridinomitosene appearing to be the rate-determining step. Several peroxidases were found to oxidize mitomycin C hydroquinone to mitomycin C and to block DNA cross-linking to various degrees. Concentrations of the various peroxidases that largely blocked DNA cross-linking, regenerated 10-70% mitomycin C from the reduced material. Thus, significant quantities of products other than mitomycin C were produced by the peroxidase-mediated oxidation of mitomycin C hydroquinone or products derived therefrom. Variations in the sensitivity of cells to mitomycin C have been attributed to differing levels of activating enzymes, export pumps, and DNA repair. Mitomycin C hydroquinone-oxidizing enzymes give rise to a new mechanism by which oxic/hypoxic toxicity differentials and resistance can occur.

  17. Expression of the dnaN and dnaQ genes of Escherichia coli is inducible by mitomycin C.

    PubMed

    Kaasch, M; Kaasch, J; Quiñones, A

    1989-10-01

    The dnaN and dnaQ genes encode the beta subunit and the epsilon subunit of the DNA polymerase III holoenzyme. Using translational fusions to lacZ we found that DNA damage caused by mitomycin C induces expression of the dnaA and dnaQ genes. This induction was not observed in lexA and recA mutants which block the induction of the SOS response, suggesting a relationship between the mechanism(s) of genetic control of DNA polymerase III holoenzyme and the SOS regulatory network. Nevertheless, there is evidence that the mitomycin C induction of dnaN and dnaQ is not a simple lexA-regulated process, because nalidixic acid (an excellent SOS inducer) does not increase dnaN and dnaQ gene expression, and the time course of induction is abnormally slow.

  18. Reductive activation of mitomycins A and C by vitamin C.

    PubMed

    Paz, Manuel M

    2013-06-01

    The anticancer drug mitomycin C produces cytotoxic effects after being converted to a highly reactive bis-electrophile by a reductive activation, a reaction that a number of 1-electron or 2-electron oxidoreductase enzymes can perform in cells. Several reports in the literature indicate that ascorbic acid can modulate the cytotoxic effects of mitomycin C, either potentiating or inhibiting its effects. As ascorbic acid is a reducing agent that is known to be able to reduce quinones, it could be possible that the observed modulatory effects are a consequence of a direct redox reduction between mitomycin C and ascorbate. To determine if this is the case, the reaction between mitomycin C and ascorbate was studied using UV/Vis spectroscopy and LC/MS. We also studied the reaction of ascorbate with mitomycin A, a highly toxic member of the mitomycin family with a higher redox potential than mitomycin C. We found that ascorbate is capable to reduce mitomycin A efficiently, but it reduces mitomycin C rather inefficiently. The mechanisms of activation have been elucidated based on the kinetics of the reduction and on the analysis of the mitosene derivatives formed after the reaction. We found that the activation occurs by the interplay of three different mechanisms that contribute differently, depending on the pH of the reaction. As the reduction of mitomycin C by ascorbate is rather inefficiently at physiologically relevant pH values we conclude that the modulatory effect of ascorbate on the cytotoxicity of mitomycin C is not the result of a direct redox reaction and therefore this modulation must be the consequence of other biochemical mechanisms.

  19. Electrochemical and quantum chemical studies on mitomycin and adriamycin

    NASA Astrophysics Data System (ADS)

    Özalp-Yaman, Şeniz; Önal, Ahmet M.; Türker, Lemi

    2003-06-01

    In-situ spectroelectrochemical redox behaviour of two prominent chemotherapeutic agents, mitomycin and adriamycin were studied at constant potential. AM1 (UHF) type quantum chemical calculations on the neutral as well as radical anion and cation forms of mitomycin and adriamycin were performed.

  20. Molecular imprinted magnetic nanoparticles for controlled delivery of mitomycin C.

    PubMed

    Türkmen, Deniz; Bereli, Nilay; Çorman, M Emin; Shaikh, Huma; Akgöl, Sinan; Denizli, Adil

    2014-10-01

    Controlled drug delivery system is a technique which has considerable recent potential in the fields of pharmacy and medicine. Mitomycin C is commonly used drug in the treatment of superficial bladder and breast cancers. In the present study, mitomycin C-imprinted magnetic poly(hydroxyethyl methacrylate)-based nanoparticles (MIMNs) were prepared using surfactant free emulsion polymerization for controlled delivery of mitomycin C. The MIMNs were characterized by fourier transform infrared spectroscopy, scanning electron microscopy, atomic force microscopy, electron spin resonance, and elemental analysis. The average particle diameter of MIMNs was about 200 nm.

  1. Hypoxia Promotes Synergy between Mitomycin C and Bortezomib through a Coordinated Process of Bcl-xL Phosphorylation and Mitochondrial Translocation of p53

    PubMed Central

    Song, Xinxin; Dilly, Ashok-Kumar; Choudry, Haroon Asif; Bartlett, David L.; Kwon, Yong Tae; Lee, Yong J.

    2015-01-01

    Colorectal peritoneal carcinomatosis (CPC) exhibits severe tumor hypoxia, leading to drug resistance and disease aggressiveness. This study demonstrates that the combination of the chemotherapeutic agent mitomycin C with the proteasome inhibitor bortezomib induced synergistic cytotoxicity and apoptosis, which was even more effective under hypoxia in colorectal cancer cells. The combination of mitomycin C and bortezomib at sub-lethal doses induced activation of c-Jun NH2-terminal kinase and p38 mitogen-activated protein kinase and resulted in Bcl-xL phosphorylation at Serine 62, leading to dissociation of Bcl-xL from pro-apoptotic Bak. Interestingly, the intracellular level of p53 became elevated and p53 translocated to the mitochondria during the combinatorial treatment, in particular under hypoxia. The coordinated action of Bcl-xL phosphorylation and p53 translocation to the mitochondria resulted in conformational activation of Bak oligomerization, facilitating cytochrome c release and apoptosis induction. In addition, the combinatorial treatment with mitomycin C and bortezomib significantly inhibited intraperitoneal tumor growth in LS174T cells and increased apoptosis, especially under hypoxic conditions in vivo. This study provides a preclinical rationale for the use of combination therapies for CPC patients. Implications The combination of a chemotherapy agent and proteasome inhibitor at sub-lethal doses induced synergistic apoptosis, in particular under hypoxia, in vitro and in vivo through coordinated action of Bcl-xL and p53 on Bak activation. PMID:26354682

  2. Variability of mitomycin C adsorption by activated charcoal.

    PubMed

    Shah, I A; Lindup, W E; McCulloch, P G

    1998-03-01

    A saline suspension of mitomycin C adsorbed on activated charcoal and administered intraperitoneally has been reported to be safe and effective in the treatment of gastric carcinoma. Activated charcoal specifically targets tumour and lymph-node tissues and the sustained higher local drug concentration is thought to be beneficial. The charcoal particles used in these suspensions have varied in size from > 147 microm to < 20 nm in diameter, but no data have been published to show how this might affect drug adsorption and delivery. Any variability in drug adsorption could pose a serious clinical risk for drugs with a narrow therapeutic index. We have, therefore, investigated the adsorption of mitomycin C on activated charcoal in-vitro. Activated charcoal was ground and sieved to yield four size-fractions between 180 and 53 microm. Adsorption isotherms (n > or = 3) were constructed and applied to the Freundlich model with 0-l00 microg mL(-1) mitomycin C measured by HPLC with detection at 365 nm. Adsorption of mitomycin C by activated charcoal varied by a factor of three under identical conditions at room temperature (21 degrees C) and at 37 degrees C. The specific adsorption (microg mitomycin C (mg activated charcoal)(-1)) was generally higher at 37 degrees C than at room temperature. The variability of mitomycin C adsorption was greatly reduced by addition of the surface-active agent polyvinylpyrollidone, used to determine that adsorption of mitomycin C was independent of activated charcoal particle size. The characteristics of adsorption of mitomycin C by activated charcoal are complex and should be thoroughly investigated to discover the critical controlling factors before submitting the suspensions for further clinical evaluation.

  3. Cross-linking of dithiols by mitomycin C.

    PubMed

    Paz, Manuel M

    2010-08-16

    Upon reduction, the antitumor drug mitomycin C undergoes a cascade of reactions to give a bis-electrophile that alkylates cellular nucleophiles. We recently reported that dithiols activate mitomycin C by reduction, and we report here that dithiols, after executing the reductive activation of mitomycin C, are bis-alkylated by the activated drug to form S,S'-cross-links as the predominant end products. The diastereomeric pair of adducts formed by 1,3-propanedithiol has been fully characterized by UV, HRMS, CD, and NMR experiments. Racemic dithiol (+/-)-dithiothreitol gave four diastereomeric cross-links, and (+/-)-dihydrolipoic acid gave eight cross-links (two regioisomers with four diastereomers each) that were partially characterized by UV and MS. The observed dependence of cross-link formation on dithiol concentration indicated the requirement of a second reduction step by dithiol, prior to the alkylation of the second arm of the dithiol. The existence of unidentified reaction pathways was manifested by the formation of unexpected intermediates during the course of the reaction of mitomycin C with dithiols and by the formation of unsoluble mitosene derivatives in the reaction between equimolar amounts of dithiol and mitomycin C. Mechanistic details of the reaction are addressed in light of these results. Finally, we discuss the potential relevance of our findings for the interaction of mitomycin C with dithiol-containing proteins.

  4. Structural characterization of the mitomycin 7-O-methyltransferase

    SciTech Connect

    Singh, Shanteri; Chang, Aram; Goff, Randal D.; Bingman, Craig A.; Grüschow, Sabine; Sherman, David H.; Phillips, Jr., George N.; Thorson, Jon S.

    2014-10-02

    Mitomycins are quinone-containing antibiotics, widely used as antitumor drugs in chemotherapy. Mitomycin-7-O-methyltransferase (MmcR), a key tailoring enzyme involved in the biosynthesis of mitomycin in Streptomyces lavendulae, catalyzes the 7-O-methylation of both C9{beta}- and C9{alpha}-configured 7-hydroxymitomycins. We have determined the crystal structures of the MmcR-S-adenosylhomocysteine (SAH) binary complex and MmcR-SAH-mitomycin A (MMA) ternary complex at resolutions of 1.9 and 2.3 {angstrom}, respectively. The study revealed MmcR to adopt a common S-adenosyl-L-methionine-dependent O-methyltransferase fold and the presence of a structurally conserved active site general acid-base pair is consistent with a proton-assisted methyltransfer common to most methyltransferases. Given the importance of C7 alkylation to modulate mitomycin redox potential, this study may also present a template toward the future engineering of catalysts to generate uniquely bioactive mitomycins.

  5. LACE1 interacts with p53 and mediates its mitochondrial translocation and apoptosis

    PubMed Central

    Cesnekova, Jana; Spacilova, Jana; Hansikova, Hana; Houstek, Josef; Zeman, Jiri; Stiburek, Lukas

    2016-01-01

    p53 is a major cellular tumor suppressor that in addition to its nuclear, transcription-dependent activity is also known to function extranuclearly. Cellular stressors such as reactive oxygen species can promote translocation of p53 into mitochondria where it acts to protect mitochondrial genome or trigger cell death via transcription-independent manner. Here we report that the mammalian homologue of yeast mitochondrial Afg1 ATPase (LACE1) promotes translocation of p53 into mitochondria. We further show that LACE1 exhibits significant pro-apoptotic activity, which is dependent on p53, and that the protein is required for normal mitochondrial respiratory function. LACE1 physically interacts with p53 and is necessary for mitomycin c-induced translocation of p53 into mitochondria. Conversely, increased expression of LACE1 partitions p53 to mitochondria, causes reduction in nuclear p53 content and induces apoptosis. Thus, LACE1 mediates mitochondrial translocation of p53 and its transcription-independent apoptosis. PMID:27323408

  6. Topical Mitomycin C in functional endoscopic sinus surgery.

    PubMed

    Venkatraman, Vaidyanathan; Balasubramanian, Deepak; Gopalakrishnan, Suria; Saxena, Sunil Kumar; Shanmugasundaram, Nirmal

    2012-07-01

    In recent literature, there has been an interest in the use of Mitomycin C to reduce post-operative complications following endoscopic sinus surgery. We report our results on a prospective, randomized controlled trial involving 50 patients with chronic bilateral rhino sinusitis. We eliminated various confounding factors by studying a single group of patients, with symmetrical disease, without pre-existing gross anatomical abnormalities. Patients requiring revision sinus surgery were excluded. On completion of the surgery, a cotton pledget soaked in Mitomycin C was placed in one nostril (test) and saline-soaked pledget (control) was placed in the other side of the nose, both in the middle meatus. The side of the nasal cavity receiving the topical Mitomycin C was randomized. The patients were assessed periodically (first week, first month, third month and sixth month) for synechiae formation and presence or absence of their symptoms. At the first week follow up, there was a statistically significant difference in the incidence of synechiae between the saline and Mitomycin C side. Furthermore, there was a statistically significant improvement with regards to patient symptoms (nasal block and discharge) in the Mitomycin C side when compared to the saline side. At the third and sixth month, there was no difference between the two groups. The incidence of adverse tissue reaction (granulation, discharge, polypoidal mucosa and crusting) was less in the Mitomycin C side when compared to the saline side at the first month follow up. Topically applied Mitomycin C reduces the incidence of synechiae in the immediate post-operative period in patients undergoing endoscopic sinus surgery. There is also an improvement in nasal obstruction and discharge with a reduction in the incidence of adverse tissue reaction in the early post-operative period.

  7. Enhanced healing of mitomycin C-treated healing-impaired wounds in rats with PRP-containing fragmin/protamine microparticles (PRP&F/P MPs).

    PubMed

    Takikawa, Megumi; Ishihara, Masayuki; Takabayashi, Yuki; Sumi, Yuki; Takikawa, Makoto; Yoshida, Ryuichi; Nakamura, Shingo; Hattori, Hidemi; Yanagibayashi, Satoshi; Yamamoto, Naoto; Kiyosawa, Tomoharu

    2015-04-13

    The purpose of this study was to evaluate the accelerating effects of platelet-rich plasma-containing (PRP&) fragmin/protamine microparticles (F/P MPs) for repairing mitomycin C-treated healing-impaired wounds. Staining with terminal deoxynucleotidyl transferase-mediated dUTP nick-end labelling (TUNEL-staining) showed that apoptosis of dermal fibroblast cells (DFCs) and epidermal keratinocyte cells (EKCs) were significantly induced in the skin of the mitomycin C-treated rats. Full-thickness skin defects were made on the back of rats and mitomycin C was applied on the wounds to prepare a healing-impaired wound. After washing out the mitomycin C, saline (control), F/P MPs alone, PRP alone, and PRP&F/P MPs were injected around the wounds. The rats were later euthanised and histological sections of the wounds were then prepared at indicated time periods after the treatment. These results indicated the numbers of large, medium, and small capillary lumens 7 days after injection of PRP&F/P MPs were significantly higher than those after injection of PRP or F/P MPs alone. Furthermore, epithelium and granulation tissue formations were significantly stimulated in the healing-impaired wounds treated with PRP&F/P MPs 3, 7 and 14 days after injection of PRP&F/P MPs.

  8. Enhancement of Agrobacterium tumefaciens infectivity by mitomycin C.

    PubMed

    Heberlein, G T; Lippincott, J A

    1967-11-01

    The ability of Agrobacterium tumefaciens to induce pinto leaf tumors may be enhanced two- to threefold after treatment with mitomycin C. The enhancement may be obtained with either lethal or nonlethal concentrations. With 10-min treatments, an optimal response was obtained with 0.005 mug of mitomycin C per ml in the absence of any change in the number of viable cells. Both the tumor induction process and the tumors induced by treated cultures appear qualitatively the same as controls. To account for these results, the antibiotic must increase the proportion of viable cells that will subsequently initiate tumors. One, or at most a few, random lesions in the bacterial chromosome seem to be the necessary requirement for this promotion. At mitomycin concentrations of 1 and 5 mug/ml, the ability of A. tumefaciens to initiate tumors is rapidly lost, indicating that a fairly intact bacterial chromosome is one of the essentials for the tumor induction process.

  9. Mitomycin C from birth to adulthood.

    PubMed

    Serretta, Vincenzo; Scalici Gesolfo, Cristina; Alonge, Vincenza; Di Maida, Fabrizio; Caruana, Giovanni

    2016-10-04

    Mitomycin C (MMC) intravesical therapy for "superficial" papillary bladder tumors was firstly introduced in the early seventies with promising results. In the following years, several pharmacokinetic studies investigated its mechanism of action to optimize the intravesical administration. Numerous studies confirmed thereafter both the ablative and the prophylactic efficacy and the low toxicity of MMC when intravesically given. In 1984, a complete response rate of 42% in 60 patients not responsive to thiotepa was reported with intravesical MMC at the dose of 40 mg diluted in 40 ml for 8 weeks. In the following decades, many large randomized studies showed the benefit of intravesical prophylaxis with MMC versus transurethral resection (TUR) alone. Since 2002, the role of adjuvant intravesical chemotherapy and of an early MMC instillation in preventing recurrence compared with TUR alone has been confirmed by large meta-analyses and stated by the European Association of Urology (EAU) guidelines. The need for further intravesical chemotherapy after the early instillation in patients at intermediate-high risk of recurrence has been proved by several trials. Although intravesical Bacillus Calmette-Guerìn (BCG) is considered the best choice for high-risk patients and MMC for the low-risk group, both MMC and BCG can be given to prevent recurrence in intermediate-risk patients. However, the higher efficacy of BCG over MMC is evident only if maintenance regimen is administered. Despite its proven efficacy, immediate intravesical MMC is not yet fully entered in common clinical practice and efforts should be made by the urologists to optimize its adoption.

  10. Effects of Chinese herbal medicine in combination with mitomycin C on gastric cancer cells.

    PubMed

    Kuo, Che-Chang; Chen, Jian-Jung; Tsai, James Y; Hsueh, Chung-Tsen

    2014-01-01

    Chinese herbal medicine (CHM) is frequently used by cancer patients in Chinese community. It remains largely unknown about the interaction between CHM and chemotherapeutic agents. Herein, we evaluated 3 commonly used CHM formulas for cancer patients: Bu-Zhong-Yi-Qi-Tang (BZYQT), Bao-Yuan-Tang (BYT), and Ju-Yuan-Jian (JYJ). We examined the effects of these 3 formulas in human gastric cancer cells MKN-74, in terms of cytotoxicity and apoptosis induction when used alone or in combination with mitomycin C (MMC). Cytotoxicity was determined by tetrazolium dye colorimetric assay. The 10% inhibitory concentration of CHM was used in this study. Cells were first exposed to CHM or phosphate buffered saline (as control) for 48 h. Then MMC at final concentration of 0.25 μg/ml was added to media for another 24-h. Among these 3 CHM formulas, BZYQT showed the most pronounced effect in augmenting MMC-induced cytotoxicity. The viability of MKN-74 cells was decreased to 43.1% when treated with BZYQT and MMC, compared to 94.9% with MMC alone. We subsequently examined apoptosis induction by quantitative florescent microscopy and single-strand DNA enzyme-linked immunosorbent assay, and found BZYQT did not enhance MMC-induced apoptosis. Our findings indicate BZYQT in combination with MMC induces cell death in gastric cancer cells via non-apoptotic mechanism. Our results provide a rationale for further investigation in the interaction of CHM and anti-cancer treatment.

  11. Impact of Mitomycin-C application time on the scleral Mitomycin-C concentration.

    PubMed

    Vass, C; Georgopoulos, M; El Menyawi, I; Radda, S; Nimmerrichter, P

    2001-04-01

    The aim of this study was to determine the effect of varying the application time of Mitomycin-C (MMC) on the scleral concentration of MMC. The sclerae of 14 human donor eyes were used for this study. The episcleral sides of the 4 scleral quadrants of each donor eye were exposed for 0.5, 1, 3 and 5 min to round, 8 mm-diameter sponges soaked with 50 microl of 0.2 mg/ml MMC. After 40-ml irrigation with saline, a central 8-mm diameter scleral disk was punched out, homogenized and analyzed with high performance liquid chromatography (HPLC). The scleral MMC concentrations (microg/g) after 0.5, 1, 3 and 5 min application times were 6.40 (+/-3.38), 9.02 (+/-2.40), 12.31 (+/-3.37), and 13.97 (+/-3.83). The differences of scleral MMC concentration in paired t-tests were statistically significant comparing 0.5 with 1 and 1 with 5 min application. However the effect was relatively small within the range of usual application times (1 to 5 min), and 64% of the MMC was delivered to the sclera within the first min.

  12. Synthesis of a major mitomycin C DNA adduct via a triaminomitosene.

    PubMed

    Champeil, Elise; Paz, Manuel M; Lukasiewicz, Elaan; Kong, Wan S; Watson, Stephanie; Sapse, Anne-Marie

    2012-12-01

    We report here the synthesis of two amino precursors for the production of mitomycin C and 10-decarbamoylmitomycin C DNA adducts with opposite stereochemistry at C-1. The triamino mitosene precursors were synthesized in 5 steps from mitomycin C. In addition synthesis of the major mitomycin C-DNA adduct has been accomplished via coupling of a triaminomitosene with 2-fluoro-O(6)-(2-p-nitrophenylethyl)deoxyinosine followed by deprotection at the N(2) and O(6) positions.

  13. Mitomycin C as an adjuvant in resected gastric cancer.

    PubMed Central

    Alcobendas, F; Milla, A; Estape, J; Curto, J; Pera, C

    1983-01-01

    As a result of their previous experience with mitomycin C at high discontinuous doses in advanced gastric cancer, the authors studied its role as an adjuvant for locally advanced cases after surgical complete resection. Results from 70 evaluable patients are presented. Patients were allocated randomly to receive mitomycin C, 20 mg/m2 I.V. direct once every 6 weeks, four courses, or a placebo. After a follow-up period of 250 weeks, seven patients of treatment arm and 23 controls have already relapsed (p less than 0.001). Toxicity was moderate and controllable by symptomatic measures. The authors consider this investigation a positive contribution in the field of adjuvant therapy of gastric cancer. PMID:6407408

  14. Utilizing topical therapies and mitomycin to reduce scars.

    PubMed

    Cupp, Craig; Gaball, Curtis Wesley

    2012-10-01

    Minimizing scar size, width, and contour of elevation is a common goal for the facial plastic surgeon. Various standard techniques are employed to reduce tension and enhance the rapid and uneventful healing of incisions. In some cases, these routine measures are not judged to be adequate, and additional intraoperative and postsurgical measures are employed to control the body's innate healing processes. Mitomycin C and self-drying silicone gel have been particularity useful in our practice.

  15. Design, synthesis, and evaluation of mitomycin-tethered phosphorothioate oligodeoxynucleotides.

    PubMed

    Huh, N; Rege, A A; Yoo, B; Kogan, T P; Kohn, H

    1996-01-01

    Mitomycin C (1) is the prototypical bioreductive alkylating agent. Studies have shown that mitomycin C and its derivatives selectively alkylate guanine residues within di- and trinucleotide DNA sequences. This investigation sought to improve the selective DNA bonding properties of the mitomycins by coupling them with antisense oligodeoxynucleotides. Two procedures were developed that allowed the attachment of a phosphorothioate oligodeoxynucleotide containing a hexylamino spacer at the 5' terminus with a C(10)-activated mitomycin. In the first procedure, decarbamoylation of 1 (NaOCH3/ benzene) afforded 10-decarbamoylmitomycin C (10), which was treated with either dimethyl sulfate or methylthiochloroformate and base to yield 10-decarbamoylporfiromycin (11) and N(1a)-[(methylthio)-carbonyl]-10-decarbamoylmitomycin C (12), respectively. Activation of the C(10) site in 11 and 12 with 1,1'-carbonyldiimidazole or with 1,1'-thiocarbonyldiimidazole provided the N(1a)-substituted mitomycin 10-decarbamoyl-10-O-carbonylimidazoles (5, 7) and 10-decarbamoyl-10-O-thiocarbonylimidazoles (6, 8), respectively. Compounds 5-8 were reacted with glycine methyl ester hydrochloride (17) and base in both methylene chloride and aqueous buffered solutions to determine the ease and efficiency in which these C(10)-activated mitomycin derivatives coupled to amines. It was found that 5-8 all reacted with 17 in methylene chloride to give the coupled products 18-21 but that improved amine coupling yields in water were observed for the 10-decarbamoyl-10-O-thiocarbonylimidazoles 6 and 8 as compared with the 10-decarbamoyl-10-O-carbonylimidazoles 5 and 7. This finding led to the coupling of the phosphorothioate oligodeoxynucleotide, H2N(CH2)6-P(S)(OH)-GGCCCCGTG-GTGGCTCCAT (22) to 8. Compound 22 complemented a 19-base sequence in the translation initiation region of the human A-raf-1 gene. Use of excess 8 (28 equiv) with 22 gave only a 36% yield of the coupled product 23, which proved difficult to

  16. Effect of beta-adrenergic stimulants on cytotoxicity of mitomycin C in HeLa cells.

    PubMed

    Miyamoto, K; Sanae, F; Iwasaki, M; Koshiura, R

    1982-12-01

    Effects of several autonomic agents on the cytotoxicity of mitomycin C in HeLa cells were studied. When beta-adrenergic stimulants such as isoproterenol, epinephrine, terbutaline and turobuterol were added at concentrations over 10(-14) M 15 to 60 min before mitomycin C, the colony-forming ability of HeLa cells was significantly inhibited more than by mitomycin C alone. The action of isoproterenol and epinephrine on the colony-forming ability of the cells was abolished by propranolol. The intracellular cyclic AMP level of HeLa cells reached the peak of about two-fold the basal level at 30 min after the addition of 10(-8) M isoproterenol. In combination with mitomycin C, the high level of intracellular cyclic AMP induced by isoproterenol was maintained for a significantly longer period in comparison with that by isoproterenol alone, while mitomycin C alone caused essentially no change in the cyclic AMP level. The pretreatment with dibutyryl cyclic AMP also enhanced the effect of mitomycin C. From these findings, it is strongly suggested that the synergistic effect of beta-adrenergic stimulants on the cytotoxicity of mitomycin C is mediated via stimulation of the beta-adrenoceptors of HeLa cells which elevates the intracellular cyclic AMP for a long time in combination with mitomycin C.

  17. Potential risk of mitomycin C at high concentrations on peripheral nerve structure

    PubMed Central

    Sui, Tao; Zhang, Jinhong; Du, Shihao; Su, Changhui; Que, Jun; Cao, Xiaojian

    2014-01-01

    Although the local application of mitomycin C may prevent epidural adhesion after laminectomy, mitomycin C can induce neurotoxicity in optic and acoustic nerves at high concentrations. To determine the safe concentration range for mitomycin C, cotton pads soaked with mitomycin C at different concentrations (0.1, 0.3, 0.5, and 0.7 mg/mL) were immediately applied for 5 minutes to the operation area of rats that had undergone laminectomy at L1. Rat sciatic nerves, instead of dorsal nerves, were used in this study. The results showed that mitomycin C at 0.1-0.5 mg/mL did not damage the structure and function of the sciatic nerve, while at 0.7 mg/mL, mitomycin C significantly reduced the thickness of the sciatic nerve myelin sheath compared with lower concentrations, though no functional change was found. These experimental findings indicate that the local application of mitomycin C at low concentrations is safe to prevent scar adhesion following laminectomy, but that mitomycin C at high concentrations (> 0.7 mg/mL) has potential safety risks to peripheral nerve structures. PMID:25206895

  18. Stability after freezing and thawing of solutions of mitomycin C in plastic minibags for intravesical use.

    PubMed

    Stolk, L M; Fruijtier, A; Umans, R

    1986-12-12

    Solutions of 0.6 mg/ml mitomycin C (Mutamycin) in NaCl solution 0.9% in plastic minibags for intravesical use were stored at -20 degrees C and -30 degrees C and thawed by microwave radiation. Both unbuffered solutions and solutions buffered to approximately pH 7.5 were investigated. Concentrations were measured with HPLC. During freezing and storage at -20 degrees C sometimes crystallization of mitomycin C occurred. However, both buffered and unbuffered solutions could be frozen at -30 degrees C during at least four weeks and subsequently thawed without loss of content. Unbuffered mitomycin C solutions could be refrozen at -30 degrees C for another four weeks. Also buffered and unbuffered solutions of another brand of mitomycin C (Mitomycin-C Kyowa) could be frozen at -30 degrees C during four weeks without significant deterioration.

  19. pH-dependent inactivation of DT-diaphorase by mitomycin C and porfiromycin.

    PubMed

    Siegel, D; Beall, H; Kasai, M; Arai, H; Gibson, N W; Ross, D

    1993-12-01

    Mitomycin C and porfiromycin were found to inactivate rat hepatic DT-diaphorase. Inactivation was pH dependent; little inactivation was detected at pH 5.8, but inactivation increased as the pH was raised to 7.8. Inactivation was concentration and time dependent and displayed pseudo-first-order kinetics. Inactivation was NADH dependent, indicating that reductive metabolism was necessary for inhibition. [3H]Mitomycin C was covalently bound to DT-diaphorase during inhibition, and the stoichiometry for inactivation of DT-diaphorase by mitomycin C was approximately 0.8 nmol of mitomycin C bound/nmol of enzyme. A higher molecular mass product (60 kDa) was detected by sodium dodecyl sulfate-polyacrylamide gel electrophoresis and Western blot analysis of DT-diaphorase preincubated with NADH and mitomycin C at pH 7.8, suggesting that mitomycin C is capable of cross-linking DT-diaphorase. The kinetics of inhibition, requirement for NADH for inhibition, covalent binding of [3H] mitomycin C to DT-diaphorase, and approximate 1:1 stoichiometry suggest that this inactivation process may be mechanism based. Inhibition of DT-diaphorase by mitomycin C and porfiromycin is not limited to a cell-free system and could also be observed in HT-29 cells in culture at pH 7.2. Bioactivation of mitomycin C or porfiromycin by DT-diaphorase is favored at lower pH, whereas at higher pH values enzyme alkylation and inactivation of DT-diaphorase occur. These data suggest that the success of attempts to exploit the elevated DT-diaphorase content of certain human tumors for improved chemotherapeutic response using mitomycin C or porfiromycin will depend on intracellular pH.

  20. Mutagenic chemistry of heteroaromatic amines and mitomycin C

    SciTech Connect

    Hashimoto, Y.; Shudo, K.; Okamoto, T.

    1984-11-01

    From the viewpoint of organic chemistry, the metabolic activity of mitomycin (MMC) and heteroaromatic amines and the modification of DNA by these compounds are reviewed. Four different methods were used for the study: (1) reaction of the mutagens with DNA in vitro with purification of the modified nucleic acid components by high-performance liquid chromatography, (2) synthesis of modified nucleic acid bases and active metabolites for identification purposes, (3) reaction of synthetic active metabolites with DNA, and (4) reaction of mutagens in vivo. 54 references.

  1. Enhancement of lutetium texaphyrin phototherapy with Mitomycin C

    NASA Astrophysics Data System (ADS)

    Thiemann, Patricia A.; Woodburn, Kathryn W.

    1998-05-01

    Lutetium texaphyrin (Lu-Tex) photodynamic therapy (PDT) relies on the presence of the water-soluble Lu-Tex, oxygen, and light (activation around 730 nm). Cytotoxic oxygen species are produced that cause irreversible damage to biological substrates. Damage may be inflicted via direct cell kill mechanisms or through vasculature effects that cause hypoxia. The addition of hypoxia enhanced drugs, such as Mitomycin C (MMC), can potentially increase the anti-tumor response. RIF-1 bearing C3H mice received 10 micrometers ol Lu-Tex/kg and were illuminated with 100 J/cm2 3 hours postinjection. Mice received MMC (2.5 or 5 mg/kg, before and after light) in conjunction with PDT and were compared to subsets of drug alone controls. A significant improvement in PDT response was observed when MMC was added to the dosing regimen; the effect was more pronounced at the highest MMC dose of 5 mg/kg: MMC prior to PDT gave a median tumor regrowth time (10X original volume) of 28 days compared to MMC and PDT alone, 16.3 and 14.9 days, respectively. The anti-tumor activity of lutetium texaphyrin induced PDT was improved by the addition of the bioreductive alkylating agent mitomycin C.

  2. Reductive activation of mitomycin C by thiols: kinetics, mechanism, and biological implications.

    PubMed

    Paz, Manuel M

    2009-10-01

    The clinically used antitumor antibiotic mitomycin C requires a reductive activation to be converted to a bis-electrophile that forms several covalent adducts with DNA, including an interstrand cross-link which is considered to be the lesion responsible for the cytotoxic effects of the drug. Enzymes such as cytochrome P450 reductase and DT-diaphorase have traditionally been implicated in the bioreduction of mitomycin C, but recent reports indicate that enzymes containing a dithiol active site are also involved in the metabolism of mitomycin C. The reductive activation can also be effected in vitro with chemical reductants, but until now, mitomycin C was considered to be inert to thiols. We report here that mitomycin C can, in fact, be reductively activated by thiols. We show that the reaction is autocatalytic and that the end product is a relatively stable aziridinomitosene that can be trapped by adding several nucleophiles after the activation reaction. Kinetic studies show that the reaction is highly sensitive to pH and does not proceed or proceeds very slowly at neutral pH, an observation that explains the unsuccessful results on previous attempts to activate mitomycin C with thiols. The optimum pH for the reactions is around the pK(a) values of the thiols used in the activation. A mechanism for the reaction is hypothesized, involving the initial formation of a thiolate-mitomycin adduct, that then evolves to give the hydroquinone of mitomycin C and disulfide. The results presented here provide a chemical mechanism to explain how some biological dithiols containing an unusually acidic thiol group (deprotonated at physiological pH) participate in the modulation of mitomycin C cytotoxicity.

  3. 7-N-(mercaptoalkyl)mitomycins: implications of cyclization for drug function.

    PubMed

    Na, Younghwa; Wang, Shuang; Kohn, Harold

    2002-05-01

    The Kyowa Hakko Kogyo and Bristol-Myers Squibb companies reported that select mitomycin C(7) aminoethylene disulfides displayed improved pharmacological profiles compared with mitomycin C (1). Mechanisms have been advanced for these mitomycins that differ from 1. Central to many of these hypotheses is the intermediate generation of 7-N-(2-mercaptoethyl)mitomycin C (5). Thiol 5 has been neither isolated nor characterized. Two efficient methods were developed for mitomycin (porfiromycin) C(7)-substituted thiols. In the first method, the thiol was produced by a thiol-mediated disulfide exchange process using an activated mixed mitomycin disulfide. In the second route, the thiol was generated by base-mediated cleavage of a porfiromycin C(7)-substituted thiol ester. We selected four thiols, 7-N-(2-mercaptoethyl)mitomycin C (5), 7-N-(2-mercaptoethyl)porfiromycin (12), 7-N-(2-mercapto-2-methylpropyl)mitomycin C (13), and 7-N-(3-mercaptopropyl)porfiromycin (14), for study. Thiols 5 and 12-14 differed in the composition of the alkyl linker that bridged the thiol with the mitomycin (porfiromycin) C(7) amino substituent. Thiol generation was documented by HPLC and spectroscopic studies and by thiol-trapping experiments. The linker affected the structure of the thiol species and the stability of the thiol. We observed that thiols 5 and 12 existed largely as their cyclic isomers. Evidence is presented that cyclization predominantly occurred at the mitomycin C(7) position. Correspondingly, alkyl linker substitution (13) or extension of the linker to three carbons (14) led to enhanced thiol stability and the predominant formation of the free thiol species. The dominant reaction of thiols 5 and 12-14 or their isomers was dimerization, and we found no evidence that thiol formation led to mitosene production and aziridine ring-opening. These findings indicated that thiol generation was not sufficient for mitomycin ring activation. The potential pharmacological advantages of

  4. Ocular concentrations of mitomycin C using different delivery devices.

    PubMed

    Mietz, H; Diestelhorst, M; Rump, A F; Theisohn, M; Klaus, W; Krieglstein, G K

    1998-01-01

    Hypotony and its sequelae are a frequent complication of trabeculectomies performed with mitomycin C (MMC), possibly related to intraocular toxicity of the substance. In an animal model with rabbits, we used different devices for the application of MMC and measured extra- and intraocular concentrations by HPLC. In addition, the concentrations of MMC remaining in the devices were determined. The devices were (1) a regular surgical sponge, (2) a scleral shield, (3) a presoaked soft contact lens, (4) a soft contact lens with MMC application, and (5) subconjunctival injection. Ocular concentrations of MMC were similar within the first 4 groups and were highest in the last. The measurements suggest that MMC penetrates intraocularly regardless of the device used. The variability of remaining MMC concentrations in the devices was lowest in the soft contact lenses suggesting an improved delivery system compared to the usually used surgical sponges.

  5. Sensitivity of mitomycin C and nitrogen mustard crosslinks to extreme alkaline conditions

    SciTech Connect

    Gruenert, D.C.; Cleaver, J.E.

    1984-09-17

    DNA-DNA crosslinks in cells treated with mitomycin C, nitrogen mustard, or decarbamoyl mitomycin C were measured in alkaline isopycnic gradients as a function of pH. Crosslinks from cells treated with mitomycin C and nitrogen mustard, which react with DNA purines, could be detected at pH 12.5 but not at pH 14. No crosslinks from cells treated with decarbamoyl mitomycin C were detected at either pH. Previous studies with cells exposed to psoralen derivatives plus 360 nm light, which produce DNA-DNA crosslinks with pyrimidines, demonstrated stable crosslinks at pH 14. These studies indicate that DNA-DNA crosslinks involving DNA purines are much less stable at high pH than those involving pyrimidines, and that methods involving exposure to extreme alkaline conditions may give inaccurate information for some agents. 25 references, 1 figure.

  6. Mitomycin-C: 'a ray of hope' in refractory corrosive esophageal strictures.

    PubMed

    Nagaich, N; Nijhawan, S; Katiyar, P; Sharma, R; Rathore, M

    2014-04-01

    Increasingly frequent dilation may become a self-defeating cycle in refractory stricture as recurrent trauma enhance, scar formation, and ultimately recurrence and potential worsening of the stricture. In 12 patients of caustic induced esophageal stricture, who failed to respond despite rigorous dilatation regimen for more than one year, a trial of topical mitomycin-C application to improve dilatation results was undertaken, considering the recently reported efficacy and safety of this agent. Mitomycin-C was applied for 2-3 minutes at the strictured esophageal segment after dilation with wire-guided Savary-Gilliard dilator. Patient was kept nil by mouth for 2-3 hours. After 4-6 sessions of mitomycin-C treatment, resolution of symptoms and significant improvement in dysphagia score and periodic dilatation index was seen in all 12 patients. Mitomycin-C topical application may be a useful strategy in refractory corrosive esophageal strictures and salvage patients from surgery.

  7. Relative toxicities of DNA cross-links and monoadducts: new insights from studies of decarbamoyl mitomycin C and mitomycin C.

    PubMed

    Palom, Yolanda; Suresh Kumar, Gopinatha; Tang, Li-Qian; Paz, Manuel M; Musser, Steven M; Rockwell, Sara; Tomasz, Maria

    2002-11-01

    Mitomycin C (MC), a cytotoxic anticancer drug and bifunctional DNA DNA alkylating agent, induces cross-linking of the complementary strands of DNA. The DNA interstrand cross-links (ICLs) are thought to be the critical cytotoxic lesions produced by MC. Decarbamoyl mitomycin C (DMC) has been regarded as a monofunctional mitomycin, incapable of causing ICLs. Paradoxically, DMC is slightly more toxic than MC to hypoxic EMT6 mouse mammary tumor cells as well as to CHO cells. To resolve this paradox, EMT6 cells were treated with MC or DMC under hypoxia at equimolar concentrations and the resulting DNA adducts were analyzed using HPLC and UV detection. MC treatment generated both intrastrand and interstrand cross-link adducts and four monoadducts, as shown previously. DMC generated two stereoisomeric monoadducts and two stereoisomeric ICL adducts, all of which were structurally characterized; one was identical with that formed with MC, the other was new and unique to DMC. Overall, adduct frequencies were strikingly higher (20-30-fold) with DMC than with MC. Although DMC monoadducts greatly exceeded DMC cross-link adducts ( approximately 10:1 ratio), the latter were equal or higher in number than the cross-link adducts from MC. DMC displayed a much higher monoadduct:cross-link ratio than MC. The similar cytotoxicities of the two drug show a correlation with their similar DNA cross-link adduct frequencies, but not with their total adduct or monoadduct frequencies. This provides specific experimental evidence that the ICLs rather than the monoadducts are critical factors in the cell death induced by MC. In vitro, overall alkylation of calf thymus DNA by DMC was much less efficient than by MC. Nevertheless, ICLs formed with DMC were clearly detectable. The chemical pathway of the cross-linking was shown to be analogous to that occurring with MC. These results also suggest that the differential sensitivity of Fanconi's Anemia cells to MC and DMC is related to factors other

  8. Analysis of caspase-3 in ASTC-a-1 cells treated with mitomycin C using acceptor photobleaching techniques

    NASA Astrophysics Data System (ADS)

    Wang, Huiying; Chen, Tongsheng; Sun, Lei

    2008-02-01

    Caspase-3 is a key activated death protease, which catalyzes the specific cleavage of many cellular proteins and induces DNA cleavage eventually. In this report, cells were treated with mitomycin C (MMC) at different concentration and its activity was detected by cell counting kit (CCK-8). Based on results of CCK-8, cells were treated with 10μg/mL MMC and Hoechst 33258 has been used to observe cell apoptosis. Fluorescence resonance energy transfer (FRET) and confocal microscopy have been used to the effect of MMC on the caspase3 activation in living cells. Human lung adenocarcinoma cells (ASTC-a-1) was transfected with plasmid SCAT3 (pSCAT3)/CKAR FRET receptor. Acceptor photobleaching techniques of FRET plasmid has been used to destruct fluorophore of cells stably expressing SCAT3 reporter on a fluorescence confocal microscope. The activity of caspase3 can be analyzed by FRET dynamics of SCAT3 in living cells. Our results show that MM C can induce ASTC-a-1 cell apoptosis through activation of caspase3.

  9. Prevention of Intraabdominal Adhesions: An Experimental Study Using Mitomycin-C and 4% Icodextrin

    PubMed Central

    Urkan, Murat; Özerhan, İsmail Hakkı; Ünlü, Aytekin; Can, Mehmet Fatih; Öztürk, Erkan; Günal, Armağan; Yağcı, Gökhan

    2017-01-01

    Background: Intraabdominal adhesions remain a significant cause of morbidity and mortality. Moreover, intraabdominal adhesions can develop in more than 50% of abdominal operations. Aims: We compared the anti-adhesive effects of two different agents on postoperative adhesion formation in a cecal abrasion model. Study Design: Experimental animal study. Methods: Forty Wistar albino type female rats were anesthetized and underwent laparotomy. Study groups comprised Sham, Control, Mitomycin-C, 4% Icodextrin, and Mitomycin-C +4% Icodextrin groups. Macroscopic and histopathological evaluations of adhesions were performed. Results: The frequencies of moderate and severe adhesions were significantly higher in the control group than the other groups. The mitomycin-C and Mitomycin-C +4% Icodextrin groups were associated with significantly lower adhesion scores compared to the control group and 4% Icodextrin group scores (p=0.002 and p=0.008, respectively). The adhesion scores of the Mitomycin-C group were also significantly lower than those of the 4% Icodextrin group (p=0.008). Conclusion: Despite its potential for bone marrow toxicity, Mitomycin-C seems to effectively prevent adhesions. Further studies that prove an acceptable safety profile relating to this promising anti-adhesive agent are required before moving into clinical trials. PMID:28251021

  10. Type III and type IV hypersensitivity reactions due to mitomycin C.

    PubMed

    Kunkeler, L; Nieboer, C; Bruynzeel, D P

    2000-02-01

    A 71-year-old man developed an exfoliative dermatitis of the palms of the hands and soles of the feet, and a generalized itch, during treatment with intravesical instillations of mitomycin C for an undifferentiated carcinoma of the bladder. Patch tests with mitomycin C 0.03%, 0.1% and 0.3% aq. were positive. Because of the serious consequences of this finding, the patient was retested with mitomycin C in pet. (same concentrations), a more stable preparation. This showed clear positive reactions. During this last series of patch tests, he developed palpable purpura on the legs. We postulated that this reaction was an immune-complex-mediated reaction, caused by the 2nd series of patch tests with mitomycin C. To prove this, we performed histopathological and immunofluorescence investigations, and these showed the reaction to be consistent with Henoch-Schonlein-type purpura. We therefore conclude that this patient developed systemic reactions to mitomycin C, characterized by an eczematous dermatitis as well as purpuric reactions. The intravesical installations with mitomycin C have been stopped. The patient's skin problems (the purpura as well as the eczema) have completely resolved and have not recurred.

  11. Prevention of Intraabdominal Adhesions: An Experimental Study Using Mitomycin-C and 4% Icodextrin.

    PubMed

    Urkan, Murat; Özerhan, İsmail Hakkı; Ünlü, Aytekin; Can, Mehmet Fatih; Öztürk, Erkan; Günal, Armağan; Yağcı, Gökhan

    2017-01-01

    Intraabdominal adhesions remain a significant cause of morbidity and mortality. Moreover, intraabdominal adhesions can develop in more than 50% of abdominal operations. We compared the anti-adhesive effects of two different agents on postoperative adhesion formation in a cecal abrasion model. Experimental animal study. Forty Wistar albino type female rats were anesthetized and underwent laparotomy. Study groups comprised Sham, Control, Mitomycin-C, 4% Icodextrin, and Mitomycin-C +4% Icodextrin groups. Macroscopic and histopathological evaluations of adhesions were performed. The frequencies of moderate and severe adhesions were significantly higher in the control group than the other groups. The mitomycin-C and Mitomycin-C +4% Icodextrin groups were associated with significantly lower adhesion scores compared to the control group and 4% Icodextrin group scores (p=0.002 and p=0.008, respectively). The adhesion scores of the Mitomycin-C group were also significantly lower than those of the 4% Icodextrin group (p=0.008). Despite its potential for bone marrow toxicity, Mitomycin-C seems to effectively prevent adhesions. Further studies that prove an acceptable safety profile relating to this promising anti-adhesive agent are required before moving into clinical trials.

  12. P-glycoprotein Blockers Augment the Effect of Mitomycin C on Human Tenon's Fibroblasts

    PubMed Central

    White, Andrew J. R.; Kelly, Elizabeth; Healey, Paul R.; Crowston, Jonathan G.; Mitchell, Paul; Zoellner, Hans

    2013-01-01

    Purpose: Mitomycin C (MMC), which induces apoptosis in human Tenon's fibroblasts (HTF), is frequently used to retard wound healing after glaucoma surgery. The aim of this in vitro study was to examine whether adjunctive Verapamil and Cyclosporine could augment the cytotoxic effect of MMC on HTF. Methods: Fibroblast cell lines were established by explant culture from human tissue biopsy samples obtained during trabeculectomy procedures. Cells were exposed to MMC at varying concentrations (0.01–0.4 mg/ml) for 3 minutes, prior to washing in the presence or absence of the following drugs: Staurosporine (0.003mg/ml), Verapamil (2.5–0.25 mg/ml), or Cyclosporine (50–0.5 mg/ml). Following exposure, cells were cultured for 6 hours and surviving cells quantitated by haemocytometer counts. Results: Both Verapamil and Staurosporine exhibited mild toxic effects on their own, but greatly enhanced the apoptotic effect of MMC. Staurosporine is too toxic to be considered clinically, so its augmentive effect on the activity of MMC was not studied further here. Doses as low as 0.25 mg/ml of Verapamil continued to show significant augmentation of the apoptotic effect of MMC Cyclosporine at a clinically used concentration (5 mg/ml) exhibited modest augmentation of the effect of MMC. Conclusions: Verapamil and Cyclosporine in clinically acceptable concentrations potentiate the effect of MMC and may obviate the need for high dose antimetabolites in trabeculectomy; however, further preclinical study is required. Translational Relevance: Adjunctive Verapamil or Cyclosporine may allow lower dose MMC to be used in glaucoma filtration surgery while maintaining the same antifibrotic effects. PMID:24049721

  13. Preclinical rationale for combination of crizotinib with mitomycin C for the treatment of advanced colorectal cancer.

    PubMed

    Lev, Avital; Deihimi, Safoora; Shagisultanova, Elena; Xiu, Joanne; Lulla, Amriti R; Dicker, David T; El-Deiry, Wafik S

    2017-09-08

    Colorectal cancer (CRC) is a leading cause of cancer-related deaths in the United States. We analyzed 26 MSI-High and 558 non-MSI-High CRC tumors. BRCA2 mutations were highly enriched (50%) in MSI-High CRC. Immunohistochemistry showed that BRCA2-mutated MSI-High CRC had high c-MET (64%) expression compared with BRCA-WT (17%). We hypothesized a mechanistic link between BRCA2-deficiency and c-MET overexpression and synergistic interaction between drugs that treat BRCA-deficient tumors (mitomycin C (MMC) or PARP inhibitors) and c-MET inhibitors (crizotinib). We tested CRC cell lines for sensitivity to MMC plus crizotinib or other drug combinations including PARP-inhibitors. Combined treatment of tumor cells with crizotinib and MMC led to increased apoptosis as compared with each drug alone. Additionally, combination treatment with increasing concentrations of both drugs demonstrated a synergistic anti-cancer effect (CI = 0.006-0.74). However, we found no evidence for c-MET upregulation upon effective BRCA2 knockdown in tumor cells -/+DNA damage. Although we found no mechanistic link between BRCA2 deficiency and c-MET overexpression, c-MET is frequently overexpressed in CRC and BRCA2 is mutated especially in MSI-H CRC. The combination of crizotinib with MMC appeared synergistic regardless of MSI or BRCA2 status. Using an in-vivo CRC xenograft model we found reduced tumor growth with combined crizotinib and MMC therapy (p = 0.0088). Our preclinical results support clinical testing of the combination of MMC and crizotinib in advanced CRC. Targeting cell survival mediated by c-MET in combination with targeting DNA repair may be a reasonable strategy for therapy development in CRC or other cancers.

  14. Pegylated liposomal mitomycin C prodrug enhances tolerance of mitomycin C: a phase 1 study in advanced solid tumor patients.

    PubMed

    Golan, Talia; Grenader, Tal; Ohana, Patricia; Amitay, Yasmine; Shmeeda, Hilary; La-Beck, Ninh M; Tahover, Esther; Berger, Raanan; Gabizon, Alberto A

    2015-10-01

    Mitomycin C (MMC) has potent cytotoxicity but cumulative toxicity limits widespread use. In animals, pegylated liposomal mitomycin C lipid-based prodrug (PL-MLP) was well tolerated and more effective than free MMC. We evaluated PL-MLP in patients with advanced cancer. Twenty-seven patients were treated in escalating dose cohorts of 0.5-3.5 mg/kg (equivalent to 0.15-1.03 mg/kg MMC) every 4 weeks for up to 12 cycles, unless disease progression or unacceptable toxicity occurred. Pharmacokinetics were assessed during cycles 1 and 3. Per protocol maximum tolerated dose was not reached at 3.5 mg/kg. However, prolonged thrombocytopenia developed after repeated doses of 3 mg/kg or cumulative doses of 10-12 mg/kg. Dose-related grade 3 or higher adverse events included fatigue, anemia, and decreased platelets. Cmax and AUC0-∞ increased linearly over the dose range 0.5-2.0 mg/kg, and greater than linearly from 2.5 to 3.5 mg/kg; there were no significant differences in clearance of MLP between cycles 1 and 3. Median t1/2 was 23 h among dose cohorts, with no trend by dose or cycle. One patient had a partial response. Stable disease was observed in 10 patients across all dose levels. PL-MLP has a long circulation time, was well tolerated, and can be administered to heavily pretreated patients at a single dose of 3.0 mg/kg and cumulative dose of 10-12 mg/kg before development of prolonged thrombocytopenia; this is nearly threefold the equivalent dose of MMC tolerated historically. This formulation may be active in a variety of tumor types and is better tolerated than free MMC.

  15. Mapping DNA adducts of mitomycin C and decarbamoyl mitomycin C in cell lines using liquid chromatography/ electrospray tandem mass spectrometry.

    PubMed

    Paz, Manuel M; Ladwa, Sweta; Champeil, Elise; Liu, Yanfeng; Rockwell, Sara; Boamah, Ernest K; Bargonetti, Jill; Callahan, John; Roach, John; Tomasz, Maria

    2008-12-01

    The antitumor antibiotic and cancer chemotherapeutic agent mitomycin C (MC) alkylates and crosslinks DNA, forming six major MC-deoxyguanosine adducts of known structures in vitro and in vivo. Two of these adducts are derived from 2,7-diaminomitosene (2,7-DAM), a nontoxic reductive metabolite of MC formed in cells in situ. Several methods have been used for the analysis of MC-DNA adducts in the past; however, a need exists for a safer, more comprehensive and direct assay of the six-adduct complex. Development of an assay, based on mass spectrometry, is described. DNA from EMT6 mouse mammary tumor cells, Fanconi Anemia-A fibroblasts, normal human fibroblasts, and MCF-7 human breast cancer cells was isolated after MC or 10-decarbamoyl mitomycin C (DMC) treatment of the cells, digested to nucleosides, and submitted to liquid chromatography electrospray-tandem mass spectrometry. Two fragments of each parent ion were monitored ("multiple reaction monitoring"). Identification and quantitative analysis were based on a standard mixture of six adducts, the preparation of which is described here in detail. The lower limit of detection of adducts is estimated as 0.25 pmol. Three initial applications of this method are reported as follows: (i) differential kinetics of adduct repair in EMT6 cells, (ii) analysis of adducts in MC- or DMC-treated Fanconi Anemia cells, and (iii) comparison of the adducts generated by treatment of MCF-7 breast cancer cells with MC and DMC. Notable results are the following: Repair removal of the DNA interstrand cross-link and of the two adducts of 2,7-DAM is relatively slow; both MC and DMC generate DNA interstrand cross-links in human fibroblasts, Fanconi Anemia-A fibroblasts, and MCF-7 cells as well as EMT6 cells; and DMC shows a stereochemical preference of linkage to the guanine-2-amino group opposite from that of MC.

  16. Effects of mitomycin C alone and in combination with X-rays on EMT6 mouse mammary tumors in vivo

    SciTech Connect

    Rockwell, S.

    1983-10-01

    The effects of mitomycin C alone and in combination with radiation on the cells of EMT6 mouse mammary tumors in BALB/cKaRw mice were examined. At doses near the toxic level, approximately 98% of the tumor cells were killed by a single injection of mitomycin C. Both proliferating and quiescent cells and both hypoxic and aerobic cells were killed by the drug. Cytotoxicity with mitomycin C occurred rapidly and was apparently complete within 30 minutes after injection of the drug. No evidence was found for repair of potentially lethal mitomycin C damage or sublethal mitomycin C damage by the tumor cells. Mitomycin C and radiation in combination produced an additive cytotoxicity; neither agent was found to alter significantly the shape of the dose-response curve for the other agent. The cytotoxicity of mitomycin C and radiation in combination depended on the sequence and timing of the treatments; additive toxicities were obtained when mitomycin C was given just after, just before, or up to 24 hours before irradiation, but the combination was less effective when mitomycin C was given 2-12 hours after irradiation.

  17. Evaluation for safety of cultured corneal fibroblasts with cotreatment of alcohol and mitomycin C.

    PubMed

    Kim, Tae-im; Tchah, Hungwon; Cho, Eun Hee; Kook, Michael S

    2004-01-01

    To investigate the effects of alcohol and mitomycin C (MMC) on cultured corneal fibroblast of the rabbit to determine the safety of this compound for clinical use. Corneal fibroblasts of New Zealand rabbits were cultured. Various concentrations (0%, 10%, 20%, 30%, 40%, and 60%) of ethanol were applied for 10, 20, 30, and 40 seconds to estimate dose- and time-dependent responses of cultured corneal fibroblasts. Cell viability was assessed using the MTT assay. Treated cells were additionally stained with Hoechst and annexin V for the identification of apoptosis. To investigate the coeffects of ethanol and MMC, dose and time dependency were evaluated after treatment with various concentrations of ethanol and MMC at different exposure times, and cell viability was established. To determine the latent effects of ethanol and MMC, cultured corneal fibroblasts were cotreated with various concentrations of ethanol and 0.02% MMC for various periods and washed out, and then one group was incubated for 24 hours and another group was not incubated. Cell viability was estimated, and Hoechst and annexin V staining were performed before and after incubation. To establish the pathway of cell death, caspase-3 activities were measured in cultured corneal fibroblasts treated with ethanol or MMC. Cell viability after ethanol treatment was dose and time dependent. After application of ethanol for 10 seconds, cell viability was significantly reduced with 20% ethanol (P = 0.001). At 20, 30, and 40 seconds of treatment with 10% ethanol, cell viability was significantly reduced (P < 0.01). Hoechst and annexin V staining revealed typical characteristics of apoptosis, such as bright fluorescent chromatin condensation, low fluorescence of nuclear fragmentation, and cell membrane shrinkage. Cell viability was more significantly reduced after cotreatment with alcohol and MMC, compared with treatment with alcohol alone. Moreover, cell viability was considerably decreased in the incubated group

  18. Pharmacokinetics of mitomycin C in dogs: application of a high-performance liquid chromatographic assay.

    PubMed

    Barbhaiya, R H; Papp, E A; Van Harken, D R; Smyth, R D

    1984-09-01

    A normal-phase high-performance liquid chromatographic (HPLC) assay was developed for the determination of mitomycin C in plasma and urine. The method involves extraction of mitomycin C from plasma or urine into ethyl acetate-2-propanol-chloroform (70:15:15) with UV detection at 365 nm. Quantitation was performed with an internal standard (porfiromycin) by the peak height ratio method. Excellent correlation was obtained between the HPLC assay and the established microbiological cup-plate bioassay. The pharmacokinetics of mitomycin C were investigated in beagle dogs following a 1-mg/kg iv (22-mg/m2) bolus dose. The plasma mitomycin C concentration versus time data were analyzed by using an open three-compartment model. The average volume of distribution was 1.90 L or 17% of body weight for the central compartment and 7.7 L or 68% of body weight for the terminal elimination phase. The volumes of distribution at steady state, calculated by model-dependent and -independent methods, compared very well with each other and were 6.5 L or 58% of body weight. Total body clearance averaged 112 mL/min, and the mean terminal plasma half-life was 53 min. The 0-24-h urinary excretion of intact mitomycin C accounted for 19% of the dose. The terminal half-life and percent urinary recovery of mitomycin C in dogs is similar to that in humans. Based on these observations, the dog appears to be a good model for studying the disposition of mitomycin C.

  19. Pharmacokinetic characteristics of 5-fluorouracil and mitomycin C in intraperitoneal chemotherapy.

    PubMed

    Kuzuya, T; Yamauchi, M; Ito, A; Hasegawa, M; Hasegawa, T; Nabeshima, T

    1994-08-01

    Eight patients with malignancies confined to the peritoneal space participated in this study. Five hundred milligrams 5-fluorouracil or 10 mg mitomycin C was diluted in 1 L saline. The mixed solution was injected intraperitoneally through the semi-permanent peritoneal catheter. Blood and peritoneal fluid were collected after injection. 5-Fluorouracil concentrations in the peritoneal fluid were 1000 times those in serum, while mitomycin C concentrations were 100 times those in serum. Areas under the concentration vs time curve (AUC) were calculated by the trapezoidal method with extrapolation to infinity. The ratio of peritoneal fluid AUC to serum AUC was about 1400 for 5-fluorouracil and 80 for mitomycin C. Patterns for the absorption and elimination from systemic circulation were similar for both compounds. Drug concentrations in the peritoneal fluid and serum were analysed according to the compartment model. The half-life in the peritoneal fluid (t1/2p) and the rate constant from the peritoneal fluid to the systemic circulation (ka) were nearly equal for both 5-fluorouracil and mitomycin C (t1/2p, 1.0 h for 5-fluorouracil and 1.3 h for mitomycin C; ka 0.71 h-1 for 5-fluorouracil and 0.68 h-1 for mitomycin C), although the apparent volume of distribution (Vds/F) and clearance in the peritoneal cavity (CLp) for mitomycin C (78 L m-2 and 1.8 L h-1 m-2) were about twice the values for 5-fluorouracil (149 L m-2 and 0.8 L h-1 m-2).

  20. A bioassay to measure cytotoxicity of plasma from patients treated with mitomycin C.

    PubMed

    Marshall, R S; Erlichman, C; Rauth, A M

    1985-11-01

    The unpredictable clinical toxicity observed in patients treated with mitomycin C and the observation that this agent must be reduced to an active form before alkylating target molecules have led to the development of a bioassay which is capable of detecting biologically active forms of mitomycin C in the plasma of drug-treated patients. The bioassay makes use of a repair-deficient mutant of Chinese hamster ovary cells, UV-20, which is 40 to 60 times more sensitive to mitomycin C than its wild-type parent. A standard curve relating in vitro cell colony-forming ability of UV-20 versus drug concentration in the plating medium has been determined. Mitomycin C levels in patient plasma as low as 1 ng/ml can be detected, compared to the 5-ng/ml limit of detection obtained with a high-pressure liquid chromatography assay for the parent compound. This assay has been utilized to detect active drug in plasma obtained from patients with colorectal cancer treated with mitomycin C as a single agent. At the completion of drug injection, serial blood samples were collected in heparinized tubes, and aliquots of plasma were extracted and assayed for mitomycin C levels by high-pressure liquid chromatography, diluted and assayed directly for their toxicity for UV-20 cells, or frozen at -20 degrees C to be assayed at a later time. The activity detected by immediate bioassay was stable up to 2 mo in frozen samples. Plasma pharmacokinetics determined by the bioassay in seven patients were no different than those determined by high-pressure liquid chromatography. No stable, cytotoxic species other than the parent compound were detected by the bioassay in the plasma of patients treated with mitomycin C.

  1. Intravesical electro-osmotic administration of mitomycin C.

    PubMed

    Di Stasi, Savino M; Verri, Cristian; Celestino, Francesco; De Carlo, Francesco; Pagliarulo, Vincenzo

    2016-10-04

    Bladder cancer is very common and most cases are diagnosed as nonmuscle invasive disease, which is characterized by its propensity to recur and progress. Intravesical therapy is used to delay recurrence and progression, while cystectomy is reserved for patients who are refractory to transurethral resection and intravesical therapy. There is an increasing interest in methods to enhance the delivery of intravesical chemotherapeutic agents to improve efficacy. In vitro and in vivo studies demonstrated that electro-osmosis of mitomycin C (MMC) is more effective in delivering this drug into the urothelium, lamina propria, and superficial muscle layers of the bladder wall than is passive transport. Higher MMC tissue concentrations might have a clinical impact in the treatment of nonmuscle invasive bladder cancer (NMIBC). In randomized trials, intravesical electro-osmotic MMC was associated with superior response rate in high-risk NMIBC cancer, compared with passive diffusion MMC transport. New strategies such as intravesical Bacillus Calmette-Guerin (BCG) combined with electro-osmotic MMC as well as intravesical pre-operative electro-osmotic MMC provided promising results in terms of higher remission rates and longer remission times.Device-assisted intravesical chemotherapy may be a useful ancillary procedure in the treatment of NMIBC. Its evaluation must be planned with respect to the technical functioning of equipment and their use for a clear purpose to avoid the financial and human costs associated with incorrect therapies.

  2. Efficacy of adjunctive mitomycin C in transcanalicular diode laser dacryocystorhinostomy.

    PubMed

    Ozsutcu, Mustafa; Balci, Ozlem; Tanriverdi, Cafer; Demirci, Goktug

    2017-02-01

    The objective of the study was to compare the success rate of transcanalicular laser dacryocystorhinostomy (TCL-DCR) with or without the use of adjunctive mitomycin C (MMC) in cases with primary nasolacrimal duct obstruction (NLDO). This retrospective study was comprised of 68 patients with uncomplicated primary NLDO. There were two groups in the study: the Group 1 (n = 35) patients underwent TCL-DCR surgery with MMC and the Group 2 (n = 33) patients underwent TCL-DCR surgery without MMC. All patients had bicanalicular silicone tube intubation. The main outcome measures were patent osteotomy as visualized endoscopically and patent nasolacrimal irrigation. The follow-up period was 12 months. All patients had unilateral TCL-DCR with silicone tube intubation. Six months following surgery, the silicone tubes were removed. At the final evaluation, success rates were 80 % in Group 1 and 78.8 % in Group 2. There was no statistically significant difference between the two groups (p = 0.52). No complications related to MMC usage were recorded during the study period. Intraoperative use of MMC has no beneficial effect on the success rate in TCL-DCR.

  3. Ocular concentrations of mitomycin C after extraocular application in rabbits.

    PubMed

    Mietz, H; Rump, A F; Theisohn, M; Klaus, W; Diestelhorst, M; Krieglstein, G K

    1995-01-01

    To determine the intraocular concentrations of Mitomycin C (MMC) after extraocular application, we used pigmented rabbits and placed sponges soaked with MMC under the conjunctiva on top of the intact episclera. First, we soaked the sponges with volumes ranging from 0.025 ml to 0.3 ml of the solution containing MMC and sampled aqueous humour after 30 minutes. The concentrations, as determined by high performance liquid chromatography, did not correlate to the amount of MMC given. Then, we soaked the sponges with different concentrations of MMC with a volume of 0.1 ml and sampled aqueous humour, vitreous humour and sclera after 60 minutes. The concentrations of MMC were higher in the vitreous than in the aqueous, and, relative to these values, very high in the sclera. These results indicate that the amount of MMC reaching the interior of the eye after standard extraocular application may be highly variable, and that the concentrations of MMC in the sclera and formed vitreous can be considerably higher than in the aqueous humour.

  4. Electromotive delivery of mitomycin C into human bladder wall.

    PubMed

    Di Stasi, S M; Vespasiani, G; Giannantoni, A; Massoud, R; Dolci, S; Micali, F

    1997-03-01

    The aim of this investigation was to establish an appropriate tissue pharmacokinetic model to compare concentrations of mitomycin C (MMC) in the human bladder wall after either passive delivery or electromotive administration (EMDA) and to evaluate the effects of EMDA on tissue morphology and MMC structure. Tissue sections of human bladder were inserted into two chamber cells with urothelium exposed to donor compartments containing MMC (10 mg in 100 ml of 0.24% NaCl solution) and an anode and with serosa exposed to receptor compartments containing 100 ml of 0.9% NaCl solution and a cathode. Fourteen paired experiments ("current 5 mA/no current") were conducted over 15 min; MMC tissue content was assessed by high-pressure liquid chromatography. Tissue viability and morphology and MMC stability were assessed by trypan blue exclusion test, tissue pH, histological analysis, and mass spectrometry analysis. MMC concentrations were increased, and variability in drug delivery rate was reduced in all tissue in samples exposed to electric current. Tissues were viable and undamaged histologically, and no MMC structural modification was observed. In conclusion, EMDA enhances administration of MMC into viable bladder wall tissue and reduces the variability in drug delivery rates.

  5. Phase I study of the mitomycin C analogue BMS-181174.

    PubMed Central

    Macaulay, V. M.; O'Byrne, K. J.; Green, J. A.; Philip, P. A.; McKinley, L.; LaCreta, F. P.; Winograd, B.; Ganesan, T. S.; Harris, A. L.; Talbot, D. C.

    1998-01-01

    BMS-181174 is an aminodisulphide derivative of Mitomycin C (MMC) with activity against a range of tumour cell lines and xenografts, including MMC-resistant tumours. In a phase I study of 82 patients with confirmed malignancy, we administered BMS-181174 at doses of 0.8-75 mg m(-2) by intravenous injection every 28 days. At least three patients were evaluated at each dose level, and 174 courses were administered. The pharmacokinetics were dose linear at BMS-181174 doses of 11.5-75 mg m(-2) and the drug appeared to undergo wide distribution. The maximum-tolerated dose was 65 mg m(-2) in previously treated patients and 75 mg m(-2) in chemotherapy-naive cases. The dose-limiting toxicity was myelosuppression, particularly thrombocytopenia, which was prolonged and cumulative. Three patients treated at 65-75 mg m(-2) died suddenly with evidence of pneumonia/pneumonitis, thought to be drug-related. Other toxicities included thrombophlebitis, possible cardiotoxicity (asymptomatic, reversible decline in left ventricular function) and renal impairment. The partial response rate was 5% (4 out of 82) overall, and 9% (3 out of 32) in patients treated at 65-75 mg m(-2). Responses occurred in treated and previously-untreated patients, including cases of colorectal cancer, non-small-cell lung cancer, ovarian cancer and adenocarcinoma of unknown primary site. BMS-181174 has anti-cancer activity but, because of its toxicity, particularly pneumonitis and thrombophlebitis, no phase II studies are planned. PMID:9667686

  6. [Intravesical therapy with mitomycin through electromotive drug administration].

    PubMed

    Verri, Cristian; Liberati, Emanuele; Celestino, Francesco; De Carlo, Francesco; Torelli, Fiammetta; Di Stasi, Savino M

    2013-01-01

    In the management of non-muscle invasive bladder cancer (NMIBC), high-level evidence supports the widespread practice of intravesical therapy with mitomycin-C (MMC). Randomized trials showed a significant reduction in short-term recurrence compared with transurethral resection of bladder tumor (TURBT) alone, but little effect on long-term and no impact at all in preventing progression. Electromotive drug administration (EMDA®) offers a means of controlling and enhancing the tissue transport of certain drugs, in order to increase their efficacy. In both laboratory and clinical studies, intravesical electromotive drug administration (EMDA) increases MMC bladder uptake, resulting in an improved clinical efficacy in NMIBC without systemic side effects. New frameworks for treatment of NMIBC - e.g., sequential intravesical BCG and EMDA/MMC, as well as intravesical EMDA/MMC immediately before TURBT - have provided promising preliminary results with higher remission rates and longer remission times, and they are a priority to minimise the costs of disease management. These findings suggest EMDA-enhanced MMC efficacy against urothelial cancer could be a major therapeutic breakthrough in the treatment of NMIBC.

  7. A comparison between 5-fluorouracil/mitomycin and capecitabine/mitomycin in combination with radiation for anal cancer

    PubMed Central

    Wan, Dante D.; Schellenberg, Devin; Lim, Howard J.

    2016-01-01

    Background There are no randomized phase III trials comparing 5-fluorouracil/mitomycin (FM) versus capecitabine/mitomycin (CM) in combination with radiotherapy (RT) for locally advanced anal cancer. We aim to evaluate the outcomes of patients treated with FM and CM at our institution. Methods Patients with stage I–III anal cancer who initiated curative-intent RT (50–54 Gy) with either CM or FM between 1998 and 2013 at the BC Cancer Agency were reviewed. Cox proportional models were used to analyze the impact of regimen on disease-free survival (DFS) and anal cancer-specific survival (ACSS). Results A total of 300 patients were included. Baseline characteristics were well-distributed between the groups. A total of 194 patients (64.6%) received FM and 106 (35.3%) CM. The 2-year DFS was 79.7% for CM [95% confidence intervals (95% CI), 71.1–88.3%] and 78.8% for FM (95% CI, 73–84.6%); 2-year ACSS was 88.7% for CM (95% CI, 81.8–95.5%) and 87.5% for FM (95% CI, 82.8–92.2%). On multivariate analysis, only HIV status, clinical T size (≤5 vs. >5 cm), and N status (negative vs. positive) remained as significant prognostic factors for both DFS and ACSS. Chemotherapy regimen (CM vs. FM) had no impact on either DFS [P=0.995; hazard ratios (HR) =0.99; 95% CI, 0.57–1.74] or ACSS (P=0.847; HR =0.93; 95% CI, 0.46–1.86). Conclusions In our population-based study, CM and FM concomitant with RT achieved similar DFS and ACSS. Substitution of capecitabine for infusional 5-FU may therefore be a reasonable option for patients and physicians who prefer to avoid the inconvenience and potential complications of a central infusional device. PMID:27563458

  8. Decrease of intraocular pressure after subconjunctival injection of mitomycin in human glaucoma.

    PubMed

    Gandolfi, S A; Vecchi, M; Braccio, L

    1995-05-01

    To investigate the effects of a subconjunctival injection of mitomycin on the intraocular pressure in human eyes affected by glaucoma. Consecutive case series, prospective study, intraocular pairwise comparison (paired samples Student's t test adopted). Hospital-based glaucoma clinic. Twelve consecutive patients with bilateral glaucoma and monolateral blindness, intraocular pressure greater than 30 mm Hg in the blind eye (mean of the two highest values of the diurnal curve, confirmed at 96-hour interval), and no previous bulbar surgery. Subconjunctival injection of 0.5 mL of 0.2% mitomycin in the upper temporal quadrant, preceded and followed by treatment with topical indomethacin. Analysis of the variance of the mean intraocular pressure before and after the injection of mitomycin in each eligible eye. An intraocular pressure decrease was observed in each eligible eye the day after the treatment (mean [+/- SD] decrease, 7.15 +/- 1.46 mm Hg). The effect was still detectable at the end of the 60 days of follow-up (mean [+/- SD] decrease, 5.67 +/- 1.61 mm Hg). No change of intraocular pressure, in the meantime, was observed in the fellow eye. Topically applied mitomycin induces a decrease of intraocular pressure in human glaucomatous eyes. Our data confirm previous results obtained in albino rabbits and support the hypothesis that mitomycin exerts a still unknown direct effect on aqueous humor dynamics in the eye.

  9. Amniotic membrane graft for primary pterygium: comparison with conjunctival autograft and topical mitomycin C treatment

    PubMed Central

    Ma, D. H.; See, L.; Liau, S.; Tsai, R. J.

    2000-01-01

    AIM—To study the efficacy and safety of amniotic membrane graft as an adjunctive therapy after removal of primary pterygium, and to compare the clinical outcome with conjunctival autograft and topical mitomycin C.
METHODS—80 eyes of 71 patients with primary pterygia were treated with excision followed by amniotic membrane graft. The result was compared retrospectively with 56 eyes of 50 patients receiving conjunctival autograft, and 54 eyes of 46 patients receiving topical mitomycin C. Patients were followed for at least 6 months, and the averaged follow up periods for the three groups were 13.8, 22.8, and 18.4 months, respectively.
RESULTS—There were three recurrences (3.8%) in the amniotic membrane graft group, three recurrences (5.4%) in the conjunctival autograft group, and two recurrences (3.7%) in the topical mitomycin C group. There was no significant difference in recurrence rate among the three groups (p = 0.879). No major complications occurred in the amniotic membrane graft group or the conjunctival autograft group. One case of infectious scleritis due to scleral ischaemia occurred in the topical mitomycin C group.
CONCLUSION—This study showed that amniotic membrane graft was as effective as conjunctival autograft and mitomycin C in preventing pterygium recurrence, and can be considered as a preferred grafting procedure for primary pterygium.

 PMID:10966947

  10. Topical application of mitomycin C prevents epineural scar formation in rats.

    PubMed

    Ilbay, Konuralp; Etus, Volkan; Yildiz, Kursat; Ilbay, Gul; Ceylan, Savas

    2005-04-01

    The role of topically applied mitomycin C in preventing postoperative perineural fibrosis was examined by gross anatomical dissection and histological analysis in rats. The sciatic nerve was exposed bilaterally in 24 Wistar adult male rats, and an abrasion injury was produced on the exposed surface of the biceps femoris muscle in all animals. In the experimental group, cotton pads soaked with mitomycin C (0.5 mg/ml) were placed around the nerves for 5 min, whereas cotton pads soaked with saline were applied to the control group. Four weeks after surgery, the neurolysis sites were evaluated by blinded surgical dissection. Perineural adhesions were graded using a numerical grading scheme. The scar tissue formation index was also calculated, and a grading was made according to the number of fibroblasts/fibrocytes counted around the epineurium in histological evaluation. Mitomycin C-treated nerves showed significantly less perineural adhesions than controls. Quantification of the dense connective tissue surrounding the nerves revealed a statistically significant reduction around nerves treated with mitomycin C, and the number of fibroblast/fibrocytes was also significantly reduced. Application of topical mitomycin C might be effective in preventing epineural scar formation after neurolysis of peripheral nerves.

  11. [Variability of beta-1,3/1,4-glucanglucanohydrolase-forming Streptomyces narbonensis induced by UV rays and mitomycin C].

    PubMed

    Elinov, N P; Pronina, M I; Zaikina, N A; Azizov, R G

    1982-01-01

    The effect of mitomycin C and UV on spores before germination and two hours after it was investigated with Streptomyces narbonensis 2a producing beta-1,3/1,4-glucanglucan hydrolase (beta-glucanase). The lethal effect of mitomycin C on the germinating spores was considerably greater than that on the spores. The mutagenic activity of mitomycin C was closely related to the process of spore germination. The frequency of mutations was higher when mitomycin C acted on germinated spores. UV caused a lesser frequency of morphological mutations than mitomycin C did. The action of UV produced mutants which synthesized beta-glucanase of the exotype in the course of fermentation in a medium without an inductor.

  12. Mitomycin C binding to poly[d(G-m5C)].

    PubMed Central

    Portugal, J; Sánchez-Baeza, F J

    1995-01-01

    Poly[d(G-m5C)] was modified by reductively activated mitomycin C, an anti-tumour drug, under buffer conditions which are known to favour either the B or the Z conformations of DNA. C.d. and 31P-n.m.r. were used to characterize the poly[d(G-m5C)]-mitomycin cross-linked complexes, as well as the effects on the equilibrium between the B and Z forms of the polynucleotide. Mitomycin C appears to inhibit the B-->Z transition, even in the presence of 3 mM MgCl2, while the Z-form of poly[d(G-m5C)] does not interact significantly with the drug under bifunctionally activating conditions; thus no reversion from the Z-form to the B-form of the polynucleotide can be observed under the salt conditions which are required for the Z-form to exist. PMID:7864808

  13. [Response of HeLa cells to mitomycine C. I. Cell division].

    PubMed

    Petrov, Iu P

    2013-01-01

    Using light microscopy, time-lapse imaging, and digital image analysis, the effect of mitomycine C (10 μg/ml) on HeLa-M cells has been studied. It has been shown that, after a 2 h contact with mitomycine, the cells could be separated into 2 groups: M-1--the functional cells surviving after division but non-entering mitosis any more; M-II--the cells entering mitosis but incapable to finish it; they are lost. Mitomycine C is known to specifically block DNA replication being located in the DNA minor groove. It should inhibit PHK synthesis if one follows the standard hypothesis of a transcription bubble formation. However, increasing the cell and nucleolus area during the M-I cell growth suggests that RNA and protein synthesis is not blocked. The author concludes that the presented data confirm his hypothesis about RNA synthesis in the major DNA groove (Petrov, 2006).

  14. Response of a human colon adenocarcinoma (DLD-1) to x irradiation and mitomycin C in vivo

    SciTech Connect

    Spremulli, E.N.; Leith, J.T.; Bliven, S.F.; Campbell, D.E.; Dexter, D.L.; Glicksman, A.S.; Calabresi, P.

    1983-08-01

    Mice hosting a heterogeneous human colon xenograft tumor produced by subcutaneous injection of the DLD-1 tumor cell line were treated either with x irradiation alone, with mitomycin C alone (4 mg/kg), or with x irradiation given two hours after intraperitoneal injection of mitomycin C (4 mg/kg). Radiation alone produced a dose dependent delay in the time needed for tumors to regrow to twice their size at the time of irradiation, and in the mice receiving mitomycin C plus x irradiation, an additional growth delay equivalent to that produced by 3 to 3.5 Gy of x rays was seen at all x ray dose levels. As the DLD-1 tumor xenografts do not appear to possess a significant hypoxic fraction, we conclude that the two agents are acting in a simple additive cytotoxic manner by the killing of oxic tumor cells.

  15. Modulation of corneal wound healing after excimer laser keratomileusis using topical mitomycin C and steroids

    SciTech Connect

    Talamo, J.H.; Gollamudi, S.; Green, W.R.; De La Cruz, Z.; Filatov, V.; Stark, W.J. )

    1991-08-01

    A 193-nm excimer laser system was used to create deep stromal ablations in seven New Zealand white rabbits and shallow ablations in three. Eyes were randomized for treatment with topical mitomycin C, steroids, and erythromycin; topical steroids and erythromycin; or topical erythromycin only. All treatment regimens were instituted twice daily for 14 days. All eyes reepithelialized normally within 3 to 5 days. During 10 weeks of follow-up, all eyes developed moderate reticular subepithelial haze without significant differences among treatment groups. Results of light, fluorescence, and electron microscopic examination showed anterior stromal scarring and markedly reduced new subepithelial collagen formation in the group treated with mitomycin C, corticosteroids, and erythromycin. Focal abnormalities of Descemet's membrane and endothelial abnormalities were present in all treatment groups. Combination therapy with topical steroids, mitomycin C, and erythromycin to control the corneal wound healing response after refractive laser surgery appears promising and warrants further study.

  16. Corneal Melting Two Weeks after Pterygium Excision with Topical Mitomycin C: Successfully Treated with Lamellar Keratoplasty and Amnion Membrane Transplantation

    PubMed Central

    Menghini, Moreno; Watson, Stephanie L.; Bosch, Martina M.

    2012-01-01

    Purpose To report the management of a case of corneal melting two weeks after pterygium excision with intraoperative topical mitomycin C (MMC). Methods Case report. Results A 57-year-old male was referred to our Department for therapy of rapidly progressive corneal melting two weeks after primary pterygium surgery with MMC (0.2 mg/ml) in September 2009. Initial treatment consisted of topical and systemic immunosuppression along with topical antibiotics. Eight days after presentation, the patient underwent successful lamellar keratoplasty and amnion membrane transplantation. Subconjunctival injection of triamcinolone (40 mg/ml) and topical bevacizumab were used to manage the increased fibrovascular activity around the site of the former pterygium. Conclusion Topical use of MMC during pterygium surgery may be related to serious postoperative complications such as progressive inflammatory corneal melting. The etiology may be multifactorial, which is related to MMC-induced inflammation and/or induced apoptosis. A therapeutic option is the described combination of systemic and local anti-inflammatory treatment along with lamellar keratoplasty and amniotic membrane transplantation. Adjunctive therapy may be needed if recurrence occurs. PMID:22615697

  17. Orthogonally functionalized nanoscale micelles for active targeted codelivery of methotrexate and mitomycin C with synergistic anticancer effect.

    PubMed

    Li, Yang; Lin, Jinyan; Wu, Hongjie; Chang, Ying; Yuan, Conghui; Liu, Cheng; Wang, Shuang; Hou, Zhenqing; Dai, Lizong

    2015-03-02

    The design of nanoscale drug delivery systems for the targeted codelivery of multiple therapeutic drugs still remains a formidable challenge (ACS Nano, 2013, 7, 9558-9570; ACS Nano, 2013, 7, 9518-9525). In this article, both mitomycin C (MMC) and methotrexate (MTX) loaded DSPE-PEG micelles (MTX-M-MMC) were prepared by self-assembly using the dialysis technique, in which MMC-soybean phosphatidylcholine complex (drug-phospholipid complex) was encapsulated within MTX-functionalized DSPE-PEG micelles. MTX-M-MMC could coordinate an early phase active targeting effect with a late-phase synergistic anticancer effect and enable a multiple-responsive controlled release of both drugs (MMC was released in a pH-dependent pattern, while MTX was released in a protease-dependent pattern). Furthermore, MTX-M-MMC could codeliver both drugs to significantly enhance the cellular uptake, intracellular delivery, cytotoxicity, and apoptosis in vitro and improve the tumor accumulation and penetration and anticancer effect in vivo compared with either both free drugs treatment or individual free drug treatment. To our knowledge, this work provided the first example of the systemically administrated, orthogonally functionalized, and self-assisted nanoscale micelles for targeted combination cancer chemotherapy. The highly convergent therapeutic strategy opened the door to more simplified, efficient, and flexible nanoscale drug delivery systems.

  18. Mitomycin C pharmacokinetics in patients with recurrent or metastatic colorectal carcinoma.

    PubMed

    Erlichman, C; Rauth, A M; Battistella, R; Fine, S

    1987-03-01

    The pharmacokinetics of mitomycin C as a single agent have been determined in 25 treatment courses given to 18 patients with recurrent or metastatic colorectal carcinoma using a high performance liquid chromatography (HPLC) assay to analyze plasma and urine samples. The plasma pharmacokinetics conformed to a two-compartment linear model in 21 of 25 courses monitored with a mean t1/2 lambda 1 of 9.8 +/- 1.2 (SEM) min and mean t1/2 lambda z of 64.1 +/- 8.9 (SEM) min. The large variation observed in t1/2 lambda z was not related to dose or treatment, but an interaction of these two factors approached significance (p = 0.057). Renal excretion in the 12 courses in which it was determined averaged only 2.3% of the total administered dose during the first 4 h monitored and no mitomycin C metabolites were detected in plasma or urine by the HPLC technique used. The most common toxicity, thrombocytopenia, did not correlate with t1/2 lambda z or the area under the curve. This may be due to a failure to monitor active metabolites of mitomycin C; other factors besides plasma drug concentrations that mediate toxicity towards marrow elements; or the small number of courses associated with thrombocytopenia (less than 100,000/mm3). Our study indicates that an interaction of drug dose and treatment course may be associated with increasing t1/2 lambda z; the renal clearance contributes a small component of mitomycin C elimination; metabolites of mitomycin C cannot be detected by the present HPLC technique; and routine monitoring of mitomycin C using present methods cannot be recommended for clinical use to predict toxicity.

  19. Low-dose mitomycin C trabeculectomy in patients with advanced glaucoma.

    PubMed

    Costa, V P; Comegno, P E; Vasconcelos, J P; Malta, R F; José, N K

    1996-06-01

    The purpose of this study was to analyze the efficacy and safety of low-dose (0.2 mg/ml) intraoperative mitomycin C in primary trabeculectomy. Twenty-eight eyes of 28 patients with advanced primary open-angle glaucoma undergoing primary trabeculectomy were randomized to either mitomycin C (0.2 mg/ml) or saline solution intraoperatively for 3 min. Intraocular pressure was measured at 1 day; 1 week; 1, 3, and 6 months postoperatively; and at the final visit. Mean follow-up was 17.0 +/- 5.6 months for the mitomycin C group and 15.7 +/- 5.1 months for the control group. Mean intraocular pressures were significantly lower in the treated group on the first postoperative day (p = 0.021), at the 6-month interval (p = 0.001), and at the final visit (p = 0.001). At the last follow-up examination, intraocular pressure was < or = 15 mm Hg in 12 (85.7%) of the mitomycin C-treated eyes and in four (28.6%) of the control eyes (p = 0.002). Life table analysis showed a significantly higher probability of intraocular pressure control in the mitomycin C group than in the control group (p = 0.0065). Choroidal effusion was observed in five (35.7%) treated eyes and two (14.3%) control eyes, whereas shallow anterior chamber were present in five (35.7%) treated eyes and one control eye (7.1%). Despite inducing a higher short-term complication rate, low-dose mitomycin C may be an alternative in the treatment of eyes with advanced glaucomatous damage requiring low final intraocular pressures.

  20. Studies on synthesis and activation mechanism of mitomycin dimers connected by 1,2-dithiolane and diol linkers.

    PubMed

    Kim, Hyoung Rae; Kim, Jae Jin; Park, Jung Jae; Lee, Sang Hyup

    2012-10-01

    We report the synthetic and mechanistic studies on a new cyclic disulfide mitomycin dimer, 7-N,7'-N'-(1″,2″-dithiolanyl-3″,5″-dimethylenyl)bismitomycin C (8), and a diol mitomycin dimer, 7-N,7'-N'-(2″,4″-dihydroxy-1″,5″-pentanediyl)bismitomycin C (9). Mitomycin 8 is a dimer connected by a 1,2-dithiolane (a five-membered cyclic disulfide) linker, and was specifically designed to undergo nucleophilic activation and double DNA alkylations leading to efficient production of DNA interstrand cross-link (DNA ISC) adducts. Disulfide cleavage in 8 would generate two thiol groups that could serve as probes to activate two mitomycin rings. At first, the target mitomycin 8 was synthesized using mitomycin A (1) and the key intermediate, cyclic disulfide (10), which was prepared through a seven-step synthetic sequence. Diol mitomycin 9 was also synthesized from 1 and diamine salt 13. Next, kinetic studies using solvolysis reaction revealed that the activation rates of 8 were much higher than those of 9 and mitomycin C (2) under nucleophilic conditions provided by Et(3)P presumably due to the presence of a cyclic disulfide unit in 8. These findings led us to propose a nucleophilic activation pathway for 8. Then, DNA ISC experiments further revealed that the levels of DNA ISC caused by 8 in the presence of Et(3)P were much higher (97%) than those by 9 (5%) and 2 (4%). More importantly, mitomycin 8 underwent much faster activation and produced slightly higher levels of DNA ISC than the previously reported mitomycins 5-7. Overall, we concluded that 8 was highly efficient for both nucleophilic activation and corresponding DNA ISC formation, and that this differentiation came from the crucial function of the cyclic disulfide unit in 8.

  1. Bioreduction of RSU 1069 and mitomycin C after dearterialization.

    PubMed

    Wang, L Q; Persson, B G; Bengmark, S

    1993-10-01

    RSU 1069 (1-(2-nitro-1-imidazolyl)-3-(1-aziridinyl)-2-propanol) and Mitomycin C (MMC) have both been shown to be directly cytotoxic to hypoxic cells. Repeat and transient dearterializations of a liver tumour would cause its cells to become intermittently hypoxic. In this experiment the therapeutic gain of RSU 1069 and MMC was evaluated when combined with either a single or repeat dearterializations of a transplanted liver tumour. The tumour growth during the first 6 days was significantly delayed when the administration of RSU 1069 (40 mg kg-1, i.p.) was followed 15 minutes later by a single dearterialization for 2 hours compared with sham operation (P = 0.0369) or either treatment alone (P = 0.0142 vs RSU 1069 alone and P = 0.0031 vs a single dearterialization for 2 hours alone). Furthermore, RSU 169 administered 15 min prior to a single dearterialization for 2 hours is more effective to retard tumour growth than MMC either alone (P = 0.0198) or with the same period of dearterialization (P = 0.0326). Repeat dearterializations (2 hours/day) during 5 days effectively retarded the growth of the tumour by itself (P = 0.015 vs sham operation). A larger growth delay was obtained when RSU 1069 was administered 15 min before the first dearterialization (P = 0.009 vs sham operation), though the growth delay between those two groups was not significant (P = 0.07). Survival time was significantly prolonged when repeat dearterializations were combined with RSU 1069 (P = 0.007 vs sham operation; P = 0.0009 vs RSU 1069 and P = 0.003 vs repeat dearterialization alone).(ABSTRACT TRUNCATED AT 250 WORDS)

  2. Effect of Mitomycin C on Myopic versus Astigmatic Photorefractive Keratectomy

    PubMed Central

    Fawzy, Samah M.

    2017-01-01

    Purpose. Long-term mitomycin C (MMC) effects on photorefractive keratectomy (PRK) were compared in simple myopic and astigmatic patients. Methods. In this observational cohort study, subjects were selected based on preoperative and postoperative data collected from medical records; they were divided into simple myopia with/without MMC and myopic astigmatism with/without MMC groups. Haze, uncorrected visual acuity (UCVA), best-corrected visual acuity (BCVA), subjective refraction, and K-reading were evaluated at 1-, 3-, 6-, and 12-month follow-ups. Results. One hundred fifty-nine eyes of 80 subjects (34 women and 46 men; mean age, 26.81 ± 7.74 years; range, 18–53 years; spherical powers, −0.50 to −8.00 DS; and cylindrical powers, −0.25 to −5.00 DC) were enrolled. One year postoperatively, the simple myopia with/without MMC groups showed no difference in UCVA (P = 0.187), BCVA (P = 0.163), or spherical equivalent (P = 0.163) and a significant difference (P = 0.0495) in K-reading; the haze formation difference was nonsignificant (P = 0.056). Astigmatic groups with/without MMC showed a significant difference in K-reading (P < 0.0001). MMC groups had less haze formation (P < 0.0001). Conclusion. PRK with intraoperative MMC application showed excellent visual outcomes. MMC's effect on astigmatic patients was significantly better with acceptable safety and minimal side effects. PMID:28392938

  3. Epiconjunctival mitomycin-C application for early failing filtering blebs.

    PubMed

    Rao, Aparna; Chatterjee, Sushanta

    2014-01-01

    To evaluate the effectiveness of epiconjunctival Mitomycin-C (MMC) application in early failing filtering blebs. Interventional case series. Patients with failing blebs and raised intraocular pressure (IOP) in the early (two weeks to one month) postoperative period following glaucoma filtering surgery. A retrospective analysis of records of failed blebs was done for the period of April 2011-March 2012. Patients who were subjected to three applications of MMC (0.04%) applied over the conjunctiva directly over the bleb at baseline (visit1), one week (visit 2) and at one month (visit 3) were included. Bleb characteristics were graded in a blinded fashion by one independent ophthalmologist, while IOP during follow-up visits were analyzed. Intraocular pressure, need for additional measure, or medications and bleb characteristics as graded by Indiana classification. Ten eyes of nine patients with failing blebs received topical MMC, including included eight males and one female with a mean age of 52 ± 18 years (trabeculectomy:combined surgery = 5:5). Complete success was seen in eight of 10 eyes with a final mean IOP of 14 ± 2.9 mm Hg at three months. Excluding the two eyes that required medications, IOP reduction of 9%-42% was seen at visit 2, 16-57% IOP reduction at visit 3, and 16-56% at three months' follow-up. Of eight eyes, all eyes showed decrease in vascularity of the blebs, p < 0.001. While the height of the blebs did not show significant increase, all had increase in the avascular area of the bleb. One eye developed spontaneously resolving adenoviral conjunctivitis without any sequelae. Three applications of epiconjunctival MMC may be a safe alternative for salvaging failing blebs in the early postoperative period. This may help maximize anti-fibrotic effect of MMC while minimizing complications by limiting the area of contact.

  4. Treatment of ocular surface squamous neoplasia with Mitomycin C.

    PubMed

    Gupta, A; Muecke, J

    2010-05-01

    AIM To report the outcome of treatment of non-invasive ocular surface squamous neoplasia (or conjunctival-corneal intra-epithelial neoplasia (CCIN)) where topical mitomycin C (MMC) has been used in the treatment regimen. DESIGN Prospective, non-comparative interventional case series. PARTICIPANTS 91 primary or recurrent CCIN lesions from 90 patients treated in a single ocular oncology centre over a 10.5-year period. INTERVENTION 73 cases of localised, non-invasive CCIN and eight cases of recurrent CCIN received a treatment regimen of surgical excision+/-cryotherapy, followed by two to three 1-week cycles of adjuvant topical MMC (0.04% four times a day). 10 cases of diffuse CCIN received two to three 1-week cycles of topical MMC (0.04% four times a day) as sole primary treatment. Main outcome measure Successful treatment was defined as no clinical recurrence of CCIN. RESULTS Mean follow-up of 56.8 months (range 5.8 to 119.8) and median 57.3 months, revealed no recurrences (0%) in the localised primary group, and one persistent case and two recurrences (30%) in the diffuse primary group. There was one recurrence (12.5%) in the recurrent group, but this was in the only eye with a diffuse type of recurrence. CONCLUSIONS MMC treatment following surgical excision appears to decrease the recurrence rate of localised CCIN and should be considered as adjuvant therapy in primary treatment. MMC should also be considered as adjuvant therapy in the treatment of localised recurrent disease. MMC may be used as sole therapy in more diffuse disease, but close ongoing follow-up is recommended in view of the significant risk of persistent or recurrent disease.

  5. [Metabolism of mitomycin C by human liver microsomes in vitro].

    PubMed

    Hao, Fu-rong; Yan, Min-fen; Hu, Zhuo-han; Jin, Yi-zun

    2007-02-01

    To provide the profiles of metabolism of mitomycin C (MMC) by human liver microsomes in vitro, MMC was incubated with human liver microsomes, then the supernatant component was isolated and detected by HPLC. Types of metabolic enzymes were estimated by the effect of NADPH or dicumarol (DIC) on metabolism of MMC. Standard, reaction, background control (microsomes was inactivated), negative control (no NADPH), and inhibitor group (adding DIC) were assigned, the results were analyzed by Graphpad Prism 4. 0 software. Reaction group compared with background control and negative control groups, 3 NADPH-dependent absorption peaks were additionally isolated by HPLC after MMC were incubated with human liver microsomes. Their retention times were 10. 0, 14. 0, 14. 8 min ( named as Ml, M2, M3) , respectively. Their formation was kept as Sigmoidal dose-response and their Km were 0. 52 (95% CI, 0. 40 - 0.67) mmol x L(-1), 0. 81 (95% CI, 0. 59 - 1. 10) mmol x L(-1), 0. 54 (95% CI, 0. 41 -0. 71) mmol x L(-1) , respectively. The data indicated that the three absorption peaks isolated by HPLC were metabolites of MMC. DIC can inhibit formation of M2, it' s dose-effect fitted to Sigmoidal curve and it' s IC50 was 59. 68 (95% CI, 40. 66 - 87. 61) micromol x L(-1) , which indicated DT-diaphorase could take part in the formation of M2. MMC can be metabolized by human liver microsomes in vitro, and at least three metabolites of MMC could be isolated by HPLC in the experiment, further study showed DT-diaphorase participated in the formation of M2.

  6. [Bladder necrosis after an immediate post-operative mitomycin C instillation].

    PubMed

    Branchereau, J; Luyckx, F; Hitier, M; Karam, G; Bouchot, O; Rigaud, J

    2011-02-01

    Administration of intravesical chemotherapy by mitomycin C decreases the risk of recurrence in non-muscle-invasive bladder tumours. We report the case of a man, who presented a full bladder necrosis after an immediate adjuvant mitomycin C instillation. The failure of resection of the necrotic area led us to perform a total cystectomy with an intestinal reconstruction. A review of the literature showed four other cases of necrosis of the bladder or of lower urinary tract. In all cases the rules of early instillation were observed. Copyright © 2010 Elsevier Masson SAS. All rights reserved.

  7. Treatment of Adenocarcinoma of the Liver with Mitomycin, Hyaluronidase, and Ethanol: An Experimental Study in the Rat

    SciTech Connect

    Harnek, Jan; Cwikiel, Wojciech; Zoucas, Evita; Seiving, Birgitta; Stenram, Unne

    1998-01-15

    Purpose: To evaluate the effect of intratumorally injected ethanol, mitomycin, mitomycin with hyaluronidase, and hyaluronidase on tumor growth in an experimental model. Methods: A suspension of 1 x 10{sup 6} cells of chemically induced adenocarcinoma was implanted into the liver of 52 rats. Seven days later the rats were divided into groups according to treatment and injected via a midline laparotomy with ethanol, mitomycin, mitomycin with hyaluronidase, or hyaluronidase. A control group was treated with saline. The rats were killed 7 days after treatment. The tumor growth ratio was calculated, and the results compared for the different groups. Wilcoxon's rank sum test was used for statistical evaluation. Results: The tumor growth ratio was significantly reduced after injection of mitomycin (p < 0.01) but not after ethanol. Hyaluronidase alone did not reduce the tumor growth ratio and had no synergetic effect with mitomycin. Conclusion: In an animal model intratumoral treatment of adenocarcinoma of the liver with mitomycin was significantly more efficient than similar treatment with saline or ethanol.

  8. A mitomycin-N6-deoxyadenosine adduct isolated from DNA.

    PubMed

    Palom, Y; Lipman, R; Musser, S M; Tomasz, M

    1998-03-01

    A minor N6-deoxyadenosine adduct of mitomycin C (MC) was isolated from synthetic oligonucleotides and calf thymus DNA, representing the first adduct of MC and a DNA base other than guanine. The structure of the adduct (8) was elucidated using submilligram quantities of total available material. UV difference spectroscopy, circular dichroism, and electrospray mass spectroscopy as well as chemical transformations were utilized in deriving the structure of 8. A series of synthetic oligonucleotides was designed to probe the specificities of the alkylation of adenine by MC. The nature and frequency of the oligonucleotide-MC adducts formed under conditions of reductive activation of MC were determined by their enzymatic digestion to the nucleoside level followed by quantitative analysis of the products by HPLC. The analyses indicated the following: (i) (A)n sequence is favored over (AT)n for adduct formation; (ii) the alkylation favors the duplex structure; (iii) at adenine sites only monofunctional alkylation occurs; (iv) the adenine-to-alkylation frequency in the model oligonucleotides was 0.3-0.6 relative to guanine alkylation at the 5'-ApG sequence but only 0.02-0.1 relative to guanine alkylation at 5'-CpG. The 5'-phosphodiester linkage of the MC-adenine adduct is resistant to snake venom diesterase. The overall ratio of adenine to guanine alkylation in calf thymus DNA was 0.03, indicating that 8 is a minor MC-DNA adduct relative to MC-DNA adducts at guanine residues in the present experimental residues in the present experimental system. However, the HPLC elution time of 8 coincides with that of a major, unknown MC adduct detected previously in mouse mammary tumor cells treated with radiolabeled MC [Bizanek, R., Chowdary, D., Arai, H., Kasai, M., Hughes, C. S., Sartorelli, A. C., Rockwell, S., and Tomasz, M. (1993) Cancer Res. 53, 5127-5134]. Thus, 8 may be identical or closely related to this major adduct formed in vivo. This possibility can now be tested by

  9. Multiphoton Imaging of Rabbit Cornea Treated with Mitomycin C after Photorefractive Keratectomy

    NASA Astrophysics Data System (ADS)

    Hsueh, Chiu-Mei; Lo, Wen; Wang, Tsung-Jen; Hu, Fung-Rong; Dong, Chen-Yuan

    2007-07-01

    In this work we use multiphoton microscopy to observe the post surgery structure variation of rabbit cornea after photorefractive keratectomy (PRK). In addition, we added mitomycin C (MMC) to the post surgery rabbit cornea in order to investigate the effect of MMC treatment on the postoperative regeneration.

  10. Effects of Mitomycin C and Thymidine Deprivation on Lysogenic and Sensitive Strains of Bacillus megaterium1

    PubMed Central

    Maisch, W. F.; Wachsman, J. T.

    1967-01-01

    A triple auxotroph of Bacillus megaterium strain KM was lysogenized with a phage suspension from B. megaterium 899a. The lysogenic and phage-sensitive derivatives of KM were found to die at the same exponential rate during thymineless incubation, despite the fact that the lysogenic strain became induced. The lysogenic strain was also induced by mitomycin C, and died at an exponential rate which was approximately twice that of the sensitive strain. With both strains, the lethality of mitomycin C was the same in the presence and absence of thymidine; thymidine was required for maximal phage production. Mitomycin C preferentially inhibited deoxyribonucleic acid (DNA) synthesis of both strains for the first 60 min. The (DNA) synthetic ability of the lysogenic strain was subsequently restored, due to phage production. Since there was no evidence that sensitive strains of KM contained other inducible elements (prophage or probacteriocins), it is concluded that both thymineless death and mitomycin C death can occur via mechanisms not involving induction. PMID:4963773

  11. Mitomycin C and Vinorelbine for second-line chemotherapy in NSCLC – a phase II trial

    PubMed Central

    Babiak, A; Hetzel, J; Godde, F; König, H-H; Pietsch, M; Hetzel, M

    2007-01-01

    Single-agent therapy with Docetaxel or Pemetrexed is the current therapy of choice for second-line treatment in advanced non-small-cell lung cancer (NSCLC). The role of older agents was underattended over the last years. This study presents the combination of Mitomycin C and Vinorelbine in pretreated patients. Forty-two patients (stage IIIB and IV, pretreated with platinum-based chemotherapy) received 8 mg m−2 Mitomycin C on day 1 and 25 mg m−2 Vinorelbine on days 1 and 8 of a 28-day cycle. End points were objective tumour response, survival, and toxicity. Additionally, quality of life (QoL) was assessed. Five patients (11.9 %) achieved partial responses and 13 patients (31.9%) stable disease. Progression-free survival was 16 weeks. The median overall survival was 8.5 month. Eleven patients (26.2 %) suffered from grade 3 or 4 neutropenia and four patients (9.52%) from grade 3 or 4 anaemia. Evaluation of QoL showed that some items ameliorated during therapy. The therapeutic concept including Mitomycin C and Vinorelbine offers an efficacious and well-tolerated regimen, with relatively low toxicity. Objective response and survival data correlate with other second-line studies using different medication. As costs of Mitomycin C and Vinorelbine are lower compared with current drugs of choice, this regimen is likely to be cost-saving. PMID:17353918

  12. DNA cross-linking by intermediates in the mitomycin activation cascade

    SciTech Connect

    Cera, C.; Egbertson, M.; Teng, S.P.; Crothers, D.M.; Danishefsky, S.J. )

    1989-06-27

    The authors have assayed the cross-linking of oligonucleotides containing repeated mitomycin-reactive CpG sites in order to assess the factors that enhance activation of the carbamoyl function at C{sub 10}, yielding efficient mitomycin cross-linking. Drugs studied include mitomycin C (MC), N-methylmitomycin A (NMA), and the aziridinomitosene of NMA (MS). Drugs were reduced both by catalytic hydrogenation and by dithionite. They find that cross-linking by fully reduced NMA can be increased severalfold by addition of either excess dithionite reductant or the oxidant FeCl{sub 3}. Enhancement by FeCl{sub 3} is not seen with MC or MS, but excess dithionite increases cross-linking by all three compounds. They explain the action of Fe{sup 3+} by postulating production of the semiquinone of the monoadduct of mitomycin reacted at the C{sub 1}-position; according to this mechanism, departure of the carbamate from C{sub 10} is more efficient for the semiquinone than for the hydroquinone. However, the results imply that the hydroquinone can also function as a cross-linking agent. Excess dithionite beyond that required for stoichiometric reduction, activates the carbamate 2-3-fold for cross-linking. They find that the fully reduced leucoaziridinomitosene is highly unstable in solution, yet it produces efficient cross-linking. Hence, this compound is highly reactive in DNA alkylation and a good candidate for the role of primary alkylating agent.

  13. Surgical management of corneal limbal dermoids: retrospective study of different techniques and use of Mitomycin C

    PubMed Central

    Lang, S J; Böhringer, D; Reinhard, T

    2014-01-01

    Purpose We retrospectively studied the efficacy and safety of different surgical approaches to treating pediatric limbal dermoids with regard to intra and postoperative complications. Methods The data of 12 consecutive patients (14 eyes), who underwent monocentric surgery of a limbal demoid in the past 9 years, were retrospectively analyzed for intra and postoperative complications. Group one consists of eleven eyes: seven eyes with a bare-sclera deep lamellar excision of the dermoid and four eyes with an additional amniotic membrane transplantation subsequent to excision. Group two consists of three eyes: two eyes treated with Mitomycin C 0.02% over 2 min following the excision, and one eye treated with Mitomycin C and amniotic membrane transplantation after removal of the dermoid. Follow-up ranged from 2 to 53 months (median 17 months). Results Intraoperative complications did not occur in any of the patients. Postoperatively, all patients showed corneal reepithelialization within a week. Limbal stem cell deficiency with a pseudopterygium developed in four eyes, one treated with bare-sclera excision and the others with amniotic membrane transplantation. One pseudopterygium had to be removed surgically because of visual acuity deterioration. Not a single eye treated with Mitomycin C developed a pseudopterygium. Conclusions The transplantation of amniotic membrane following removal of a limbal dermoid cannot prevent the occurrence of a pseudopterygium. However, the use of Mitomycin C seems to have a protective effect. PMID:24858530

  14. Amorfrutin C Induces Apoptosis and Inhibits Proliferation in Colon Cancer Cells through Targeting Mitochondria.

    PubMed

    Weidner, Christopher; Rousseau, Morten; Micikas, Robert J; Fischer, Cornelius; Plauth, Annabell; Wowro, Sylvia J; Siems, Karsten; Hetterling, Gregor; Kliem, Magdalena; Schroeder, Frank C; Sauer, Sascha

    2016-01-22

    A known (1) and a structurally related new natural product (2), both belonging to the amorfrutin benzoic acid class, were isolated from the roots of Glycyrrhiza foetida. Compound 1 (amorfrutin B) is an efficient agonist of the nuclear peroxisome proliferator activated receptor (PPAR) gamma and of other PPAR subtypes. Compound 2 (amorfrutin C) showed comparably lower PPAR activation potential. Amorfrutin C exhibited striking antiproliferative effects for human colorectal cancer cells (HT-29 and T84), prostate cancer (PC-3), and breast cancer (MCF7) cells (IC50 values ranging from 8 to 16 μM in these cancer cell lines). Notably, amorfrutin C (2) showed less potent antiproliferative effects in primary colon cells. For HT-29 cells, compound 2 induced G0/G1 cell cycle arrest and modulated protein expression of key cell cycle modulators. Amorfrutin C further induced apoptotic events in HT-29 cells, including caspase activation, DNA fragmentation, PARP cleavage, phosphatidylserine externalization, and formation of reactive oxygen species. Mechanistic studies revealed that 2 disrupts the mitochondrial integrity by depolarization of the mitochondrial membrane (IC50 0.6 μM) and permanent opening of the mitochondrial permeability transition pore, leading to increased mitochondrial oxygen consumption and extracellular acidification. Structure-activity-relationship experiments revealed the carboxylic acid and the hydroxy group residues of 2 as fundamental structural requirements for inducing these apoptotic effects. Synergy analyses demonstrated stimulation of the death receptor signaling pathway. Taken together, amorfrutin C (2) represents a promising lead for the development of anticancer drugs.

  15. Mitomycin C-DNA adducts generated by DT-diaphorase. Revised mechanism of the enzymatic reductive activation of mitomycin C.

    PubMed

    Suresh Kumar, G; Lipman, R; Cummings, J; Tomasz, M

    1997-11-18

    Mitomycin C (MC) was reductively activated by DT-diaphorase [DTD; NAD(P)H:quinone oxidoreductase] from rat liver carcinoma cells in the presence of Micrococcus lysodeicticus DNA at pH 5.8 and 7.4. The resulting alkylated MC-DNA complexes were digested to the nucleoside level and the covalent MC-nucleoside adducts were separated, identified, and quantitatively analyzed by HPLC. In analogous experiments, two other flavoreductases, NADH-cytochrome c reductase and NADPH-cytochrome c reductase, as well as two chemical reductive activating agents Na2S2O4 and H2/PtO2 were employed as activators for the alkylation of DNA by MC. DTD as well as all the other activators generated the four known major guanine-N2-MC adducts at both pHs. In addition, at the lower pH, the guanine-N7-linked adducts of 2,7-diaminomitosene were detectable in the adduct patterns. At a given pH all the enzymatic and chemical reducing agents generated very similar adduct patterns which, however, differed dramatically at the acidic as compared to the neutral pH. Overall yield of MC adducts was 3-4-fold greater at pH 7.4 than at 5. 8 except in the case of DTD when it was 4-fold lower. Without exception, however, cross-link adduct yields were greater at the acidic pH (2-10-fold within the series). The ratio of adducts of bifunctional activation to those of monofunctional activation was 6-20-fold higher at the acidic as compared to the neutral pH. A comprehensive mechanism of the alkylation of DNA by activated MC was derived from the DNA adduct analysis which complements earlier model studies of the activation of MC. The mechanism consists of three competing activation pathways yielding three different DNA-reactive electrophiles 11, 12, and 17 which generate three unique sets of DNA adducts as endproducts. The relative amounts of these adducts are diagnostic of the relative rates of the competing pathways in vitro, and most likely, in vivo. Factors that influence the relative rates of individual pathways

  16. Exploration of two methods for quantitative Mitomycin C measurement in tumor tissue in vitro and in vivo

    PubMed Central

    2013-01-01

    Two methods of quantifying Mitomycin C in tumor tissue are explored. A method of ultraviolet-visible absorption microscopy is developed and applied to measure the concentration of Mitomycin C in preserved mouse tumor tissue, as well as in gelatin samples. Concentrations as low as 60 μM can be resolved using this technique in samples that do not strongly scatter light. A novel method for monitoring the Mitomycin C concentrations inside a tumor is developed, based on microdialysis and ultraviolet-visible spectroscopy. A pump is used to perfuse a microdialysis probe with Ringer’s solution, which is fed to a flow cell to determine intratumor concentrations in real time to within a few μM. The success and limitations of these techniques are identified, and suggestions are made as to further development. To the authors’ knowledge these are the first attempts made to quantify Mitomycin C concentrations in tumor tissue. PMID:24206643

  17. Mitomycin C in combination with radiotherapy as a potent inhibitor of tumour cell repopulation in a human squamous cell carcinoma

    PubMed Central

    Budach, W; Paulsen, F; Welz, S; Classen, J; Scheithauer, H; Marini, P; Belka, C; Bamberg, M

    2002-01-01

    The potential of Mitomycin C in combination with fractionated irradiation to inhibit tumour cell repopulation of a fast growing squamous cell carcinoma after fractionated radiotherapy was investigated in vivo. A rapidly growing human squamous cell carcinoma (FaDudd) was used for the study. For experiments, NMRI (nu/nu) mice with subcutaneously growing tumours were randomly allocated to no treatment, Mitomycin C, fractionated irradiation (ambient: 11x4.5 Gy in 15 days), or fractionated irradiation combined with Mitomycin C. Graded top up doses (clamped blood flow: 0–57 Gy) were given at day 16, 23, 30 or 37. End point of the study was the time to local tumour progression. Data were examined by multiple regression analysis (Cox). Mitomycin C alone resulted in a median time to local tumour progression of 23 (95% confidence limits: 17–43) days, fractionated irradiation in 31 (25–35) days and combined Mitomycin C plus fractionated irradiation in 65 (58–73) days (P=0.02). Mitomycin C decreased the relative risk of local recurrence by 94% (P<<0.001) equivalent to 31.7 Gy top up dose. Repopulation accounted for 1.33 (0.95–1.72) Gy per day top up dose after fractionated irradiation alone and for 0.68 (0.13–1.22) Gy per day after fractionated irradiation+Mitomycin C (P=0.018). Mitomycin C significantly reduces the risk of local recurrence and inhibits tumour cell repopulation in combination with fractionated irradiation in vivo in the tested tumour model. British Journal of Cancer (2002) 86, 470–476. DOI: 10.1038/sj/bjc/6600081 www.bjcancer.com © 2002 The Cancer Research Campaign PMID:11875717

  18. Intralesional Injection of Mitomycin C at Transurethral Incision of Bladder Neck Contracture May Offer Limited Benefit: TURNS Study Group

    PubMed Central

    Redshaw, Jeffrey D.; Broghammer, Joshua A.; Smith, Thomas G.; Voelzke, Bryan B.; Erickson, Bradley A.; McClung, Christopher D.; Elliott, Sean P.; Alsikafi, Nejd F.; Presson, Angela P.; Aberger, Michael E.; Craig, James R.; Brant, William O.; Myers, Jeremy B.

    2015-01-01

    Purpose Injection of mitomycin C may increase the success of transurethral incision of the bladder neck for the treatment of bladder neck contracture. We evaluated the efficacy of mitomycin C injection across multiple institutions. Materials and Methods Data on all patients who underwent transurethral incision of the bladder neck with mitomycin C from 2009 to 2014 were retrospectively reviewed from 6 centers in the TURNS. Patients with at least 3 months of cystoscopic followup were included in the analysis. Results A total of 66 patients underwent transurethral incision of the bladder neck with mitomycin C and 55 meeting the study inclusion criteria were analyzed. Mean ± SD patient age was 64 ± 7.6 years. Dilation or prior transurethral incision of the bladder neck failed in 80% (44 of 55) of patients. Overall 58% (32 of 55) of patients achieved resolution of bladder neck contracture after 1 transurethral incision of the bladder neck with mitomycin C at a median followup of 9.2 months (IQR 11.7). There were 23 patients who had recurrence at a median of 3.7 months (IQR 4.2), 15 who underwent repeat transurethral incision of the bladder neck with mitomycin C and 9 of 15 (60%) who were free of another recurrence at a median of 8.6 months (IQR 8.8), for an overall success rate of 75% (41 of 55). Incision with electrocautery (Collins knife) was predictive of success compared with cold knife incision (63% vs 50%, p=0.03). Four patients experienced serious adverse events related to mitomycin C and 3 needed or are planning cystectomy. Conclusions The efficacy of intralesional injection of mitomycin C at transurethral incision of the bladder neck was lower than previously reported and was associated with a 7% rate of serious adverse events. PMID:25200807

  19. Combination therapy with misonidazole and mitomycin C: lack of chemosensitization of EMT6 tumor cells in vivo or in vitro

    SciTech Connect

    Rockwell, S.

    1984-09-01

    The effect of the nitroimidazole misonidazole on the cytotoxicity of mitomycin C was examined using EMT6 Rw tumors in mice and EMT6 cells in culture. In contrast to reports by others using a different tumor system, the authors were unable to detect any significant increase of mitomycin cytotoxicity by misonidazole in vivo using tumor cell survival or host toxicity endpoints. Studies with cells in vitro provided no evidence for marked chemosensitization of either hypoxic or aerobic cells.

  20. Comparison of cytoreductive surgery and hyperthermic intraperitoneal chemotherapy with mitomycin or carboplatin for diffuse malignant peritoneal mesothelioma.

    PubMed

    Shetty, Shreya J; Bathla, Lokesh; Govindarajan, Venkatesh; Thomas, Peter; Loggie, Brian W

    2014-04-01

    Diffuse malignant peritoneal mesothelioma is a rare, aggressive disease. Cytoreductive surgery (CRS) and hyperthermic intraperitoneal chemotherapy (HIPEC) have improved outcomes where systemic chemotherapy has not succeeded. In this study, we compare outcomes of patients treated with mitomycin or carboplatin as perfusate. In this retrospective study, 47 procedures (CRS + HIPEC) were conducted on 44 patients between March 2003 and August 2010 with either mitomycin or carboplatin. χ(2) and Student's t test were used for comparison of clinicopathological variables and Kaplan-Meier curves and log rank test were used to compare overall survival. Median survival of the mitomycin group was 18 months with 1- and 5-year survivals of 72.3 and 27.3 per cent, respectively. Median survival of the carboplatin group was not reached and 1- and 5-year survivals were 89.7 and 62.5 per cent, respectively (P = 0.014). Mean hospital and intensive care unit length of stay was 18.9 and 8.7 days in the mitomycin group and 12.5 and 2.3 days in the carboplatin group (P = 0.0069). Mean number of packed red blood cell units transfused was higher in the mitomycin group compared with the carboplatin group (3.54 vs 0.83, P < 0.05). There was no postoperative mortality. HIPEC with carboplatin in diffuse malignant peritoneal mesothelioma is associated with improved overall survival and shorter hospital stay compared with HIPEC with mitomycin.

  1. Transcription abnormalities potentiate apoptosis of normal human fibroblasts.

    PubMed Central

    Andera, L.; Wasylyk, B.

    1997-01-01

    BACKGROUND: Apoptosis is a natural process by which damaged and potentially tumorigenic cells are removed. Induction of apoptosis is important in chemotherapy aimed at eliminating cancer cells. We address the mechanisms by which this process can be triggered in cells that are recalcitrant to cell death induced by DNA-damaging agents. MATERIALS AND METHODS: Normal human fibroblasts and lymphoblasts, and fibroblasts with defined genetic changes, were treated with DNA-damaging agents and inhibitors of transcription. Western blotting was used to study the expression of some of the key factors involved in the response to DNA damage and the induction of apoptosis, namely, p53, p21WAFI,Cip1, Mdm2, Bax, and CD95 (Fas/APO1). Apoptosis was followed by various criteria, including DNA fragmentation, specific proteolysis, cell morphology, viability, and FACS scan for sub-G1 cells. RESULTS: Normal human fibroblasts were more resistant than lymphoblasts to DNA damage-induced apoptosis. The DNA-damaging agents mitomycin C and cisplatin induced rapid apoptosis of fibroblasts with defects in the repair of transcribed DNA, compared with wild-type cells or those with defects in overall genome repair. Short-term treatment with inhibitors of RNA polymerase II transcription, actinomycin D, and alpha-amanitin induced rapid cell death of normal fibroblasts. These results show that there is a link between defective transcription and apoptosis. Treatments and genetic backgrounds that favored apoptosis were associated with efficient and prolonged induction of p53 and often altered or imbalanced expression of its downstream effectors p21WAFI,Cip1 and Mdm2, whereas there were no changes in Bax or CD95 (Fas/APO1). CONCLUSION: Transcription inhibitors increase p53 levels and are better inducers of apoptosis than DNA-damaging agents in some cell types. Apoptosis might be triggered by blocked polymerases and/or faulty expression of downstream effectors. Images FIG. 1 FIG. 2 FIG. 3 FIG. 4 PMID

  2. Liquid chromatography-thermospray mass spectrometry of DNA adducts formed with mitomycin C, porfiromycin and thiotepa.

    PubMed

    Musser, S M; Pan, S S; Callery, P S

    1989-07-14

    High-performance liquid chromatography (HPLC) and thermospray mass spectrometry were combined for the analysis of DNA adducts formed from the interaction of the anticancer drugs mitomycin C, porfiromycin and thiotepa with calf thymus DNA. The adducts formed from reaction of mitomycin C and porfiromycin with DNA were separated from unmodified nucleosides by HPLC on a C18 column and identified by thermospray mass spectrometry. Thiotepa DNA adducts readily depurinated from DNA and were chromatographed and identified by thermospray liquid chromatography-mass spectrometry as the modified bases without the ribose moiety attached. The utility of thermospray mass spectrometry for the identification of microgram quantities of nucleoside adducts and depurinated base adducts of these anticancer drugs was demonstrated.

  3. A Comparative Study of Topical Mitomycin C, Cyclosporine, and Bevacizumab after Primary Pterygium Surgery

    PubMed Central

    Hwang, Shinyoung

    2015-01-01

    Purpose To compare the recurrence rates and complications associated with instillation of topical mitomycin C, cyclosporine, and bevacizumab after primary pterygium surgery. Methods Between July 2013 and June 2014, we performed surgery using the bare sclera method on 132 eyes (132 patients) with primary pterygium. We randomly selected 33 eyes (33 patients) and treated them with artificial tears four times a day for three months, 29 eyes (29 patients) were treated with topical 0.02% mitomycin C four times a day for five days, 34 eyes (34 patients) were treated with topical 0.05% cyclosporine four times a day for three months, and 36 eyes (36 patients) were treated with topical 2.5% bevacizumab four times a day for three months after surgery. We prospectively determined the recurrence rates of pterygium and complications at the six-month follow-up examination. Results At six months after surgery, the recurrence rates in each group were as follows: 45.5% (15 eyes) in the control group, 10.3% (three eyes) in the mitomycin C group, 20.6% (seven eyes) in the cyclosporine group, and 41.7% (15 eyes) in the bevacizumab group (p = 0.004). No serious complications, except subconjunctival hemorrhages, were observed in any group. Conclusions Groups receiving topical 0.02% mitomycin C and 0.05% cyclosporine after surgery showed lower recurrence rates than the control group; however, no difference in recurrence rate was observed between the control group and the group receiving topical 2.5% bevacizumab after surgery. PMID:26635453

  4. A comparison of irradiation and mitomycin as blocking agents in the mixed lymphocyte reaction

    SciTech Connect

    Anderson, R.E.; Pogue, L.; Troup, G.M.; Standefer, J.C.

    1984-05-01

    In comparison with administration of mitomycin, lethal irradiation (2,000 rad) of the stimulator cells in a one-way mixed leukocyte culture results in a reduced response due at least in part to the release of inhibitory materials by the irradiated cells. These inhibitory molecules may be partially removed by washing and possess differential reactivity with respect to phytohemagglutinin, concanavalin A, lipopolysaccharide, and pokeweed mitogen.

  5. Bronchial artery infusion of mitomycin C in carcinoma of the lung

    SciTech Connect

    Ekholm, S.; Albrechtsson, U.; Tylen, U.

    1983-06-01

    Fifteen patients with bronchial carcinoma were treated with infusions of 10 mg Mitomycin C (MMC) in the bronchial artery feeding the tumor. The treatment was repeated three times with 2-3 weeks interval between treatments. Half of the patients then received radiation to the tumor area and mediastinum. All tumors decreased in size, complete remission occurred in two and partial remission in five patients. Survival time, however, was not prolonged and esophageal complications occurred in several patients.

  6. Effect of mitomycin C on the neural tube defects of the curly-tail mouse.

    PubMed

    Seller, M J; Perkins, K J

    1986-06-01

    Around 60% of the mouse mutants called curly-tail, have tail aberrations in the form of a coil or a kink, with or without lumbosacral spina bifida, and rarely, exencephaly. These neural tube defects (NTD) are the result of an incompletely penetrant recessive gene. A single injection of various doses (1-6 mg/kg) of the DNA inhibitor mitomycin C was given to pregnant curly-tail mice on day 7, 8, or 9 of gestation, and its effect on the NTD of the embryos was noted. No dose used was lethal to the embryo. When given on day 7 or day 8, mitomycin C markedly increased the number of exencephalics, and additionally, on day 8, it reduced the number of posterior abnormalities. However, on day 9, no exencephaly was produced, and there was a drastic reduction in the number of tail and spinal defects, the overall incidence of NTD being as low as 15% with 2 mg/kg. A twofold effect of mitomycin C on the curly-tail embryos was thus observed--according to the time in development it was administered, firstly, a teratogenic effect, and later, a "remedial" or preventive effect.

  7. Development of a flexible strategy towards FR900482 and the mitomycins.

    PubMed

    Trost, Barry M; O'Boyle, Brendan M; Torres, Wildeliz; Ameriks, Michael K

    2011-07-04

    FR900482 and the mitomycins are two intriguing classes of alkaloid natural products that have analogous biological mechanisms and obvious structural similarity. Both classes possess potent anticancer activity, a feature that has led to their investigation and implementation for the clinical treatment of human cancer. Given the structural similarity between these natural products, we envisioned a common synthetic strategy by which both classes could be targeted through assembling the mitomycin skeleton prior to further oxidative functionalization. Realization of this strategy with respect to FR900482 was accomplished through the synthesis of 7-epi-FR900482, which displayed equal potency relative to the natural product against two human cancer cell lines. With the challenging goal of a synthesis of either mitomycin or FR900482 in mind, several methodologies were explored. While not all of these methods ultimately proved useful for our synthetic goal, a number of them led to intriguing findings that provide a more complete understanding of several methodologies. In particular, amination via π-allyl palladium complexes for the synthesis of tetrahydroquinolines, eight-membered heterocycle formation via carbonylative lactamization, and amination through late-stage C-H insertion via rhodium catalysis all featured prominently in our synthetic studies.

  8. Validation of an HPLC-MS/MS and Wipe Procedure for Mitomycin C Contamination

    PubMed Central

    B’Hymer, C.; Connor, T.H.; Stinson, D.; Pretty, J.R.

    2015-01-01

    A high-performance liquid chromatography-tandem mass spectrometric (HPLC-MS/MS) method was developed for the determination of mitomycin C, an anticancer drug, from contamination on various surfaces. Mitomycin C is often used in various forms of intraperitoneal chemotherapy, and operating room healthcare worker exposure to this drug is possible. The surface testing method consisted of a wiping procedure utilizing a solution of 20/45/35 (v/v/v) of acetonitrile-isopropanol-water made 0.01 M in ammonium citrate (apparent pH 7.0). The wipe solutions were analyzed by means of HPLC-MS/MS using a reversed-phase gradient system and electrospray ionization in positive ion-mode with a triple-quadrupole mass spectrometric detector. Accuracy and precision of this method were demonstrated by a series of recovery studies of both spiked solutions and extracted wipes from various surfaces (stainless steel, vinyl and Formica®) spiked with known levels of mitomycin C. Recoveries of spiked solutions containing the analyte demonstrate mean recoveries (accuracy) ranged from 93 to 105%. Precision as measured by the relative standard deviation (%RSD) of multiple samples (n=10) at each concentration level demonstrated values of 7.5% or less. The recoveries from spiked surfaces varied from 30 to 99%. The limit of detection (LOD) for this methodology is approximately 2 ng/100 cm2 equivalent surface area, and the limit of quantitation (LOQ) is approximately 6 ng/100 cm2. PMID:25129062

  9. Development of a Flexible Strategy Toward FR900482 and the Mitomycins

    PubMed Central

    O’Boyle, Brendan M.; Torres, Wildeliz; Ameriks, Michael K.

    2013-01-01

    FR900482 and the mitomycins are two intriguing classes of alkaloid natural products that have analogous biological mechanisms and obvious structural similarity. Both classes possess potent anti-cancer activity, a feature that has led to their investigation and implementation for the clinical treatment of human cancer. Given the structural similarity between these natural products, we envisioned a common synthetic strategy by which both classes could be targeted through assembling the mitomycin skeleton prior to further oxidative functionalization. Realization of this strategy with respect to FR900482 was accomplished through the synthesis of 7-epi-FR900482, which displayed equal potency relative to the natural product against two human cancer cell lines. With the challenging goal of a synthesis of either mitomycin or FR900482 in mind, several methodologies where explored. While not all of these methods ultimately proved useful for our synthetic goal, a number of them led to intriguing findings that provide a more complete understanding of several methodologies. In particular, amination via π-allyl palladium complexes for the synthesis of tetrahydroquinolines, 8-membered heterocycle formation via carbonylative lactamization, and amination through late-stage C-H insertion via rhodium catalysis all featured prominently in our synthetic studies. PMID:21618622

  10. Validation of an HPLC-MS/MS and wipe procedure for mitomycin C contamination.

    PubMed

    B'Hymer, Clayton; Connor, Thomas; Stinson, Derek; Pretty, Jack

    2015-04-01

    A high-performance liquid chromatography-tandem mass spectrometric (HPLC-MS/MS) method was developed for the determination of mitomycin C, an anticancer drug, from contamination on various surfaces. Mitomycin C is often used in various forms of intraperitoneal chemotherapy, and operating room healthcare worker exposure to this drug is possible. The surface testing method consisted of a wiping procedure utilizing a solution of 20/45/35 (v/v/v) of acetonitrile-isopropanol-water made 0.01 M in ammonium citrate (apparent pH 7.0). The wipe solutions were analyzed by means of HPLC-MS/MS using a reversed-phase gradient system and electrospray ionization in positive ion mode with a triple-quadrupole MS detector. Accuracy and precision of this method were demonstrated by a series of recovery studies of both spiked solutions and extracted wipes from various surfaces (stainless steel, vinyl and Formica(®)) spiked with known levels of mitomycin C. Recoveries of spiked solutions containing the analyte demonstrate mean recoveries (accuracy) ranged from 93 to 105%. Precision as measured by the relative standard deviation (% RSD) of multiple samples (n= 10) at each concentration level demonstrated values of 7.5% or less. The recoveries from spiked surfaces varied from 30 to 99%. The limit of detection for this methodology is ∼2 ng/100 cm(2) equivalent surface area, and the limit of quantitation is ∼6 ng/100 cm(2).

  11. Reversed-phase high-performance liquid chromatographic determination of mitomycin C in human serum.

    PubMed

    Buice, R G; Sidhu, P; Gurley, B J; Niell, H B

    1984-01-01

    A reversed-phase high-performance liquid chromatographic method is presented by which the cancer chemotherapeutic agent, mitomycin C, may be measured in human serum. A mobile phase of methanol:water (35:65) passed through a mu-Bondapak C-18 column at a rate of 1.0 ml/min produced a sharp, symmetrical band for mitomycin C. An improved serum extraction procedure, using a reversed-phase sample preparation cartridge, proved to be efficient and reproducible. Recovery over a concentration range of 10-100 ng/ml was 81.6% with a between-day coefficient of variation of 4.6% (n = 5). The within-day coefficient of variation at 50 ng/ml was 5.6% (n = 10). Ultraviolet detection at a wavelength of 365 nm was sensitive to serum concentrations of 10 ng/ml. Serum concentration-time course data from lung cancer patients receiving mitomycin C by rapid intravenous injection are presented.

  12. Sensitivity of pathogenic and free-living Leptospira spp. to UV radiation and mitomycin C

    SciTech Connect

    Stamm, L.V.; Charon, N.W.

    1988-03-01

    The habitats for the two major Leptospira spp. differ. The main habitat of L. biflexa is soil and water, whereas L. interrogans primarily resides in the renal tubules of animals. We investigated whether these two species, along with L. illini (species incertae sedis), differ with respect to their sensitivity to UV radiation. The doses of UV resulting in 37, 10 and 1% survival were determined for representive serovars from each species. L. interrogans serovar pomona was 3.0 to 4.8 times more sensitive to UV than the other Leptospira species under the 37, 10, and 1% survival parameters. In comparison to other bacteria, L. interrogans serovar pomona is among the most sensitive to UV. In a qualitative UV sensitivity assay., L. interrogans serovars were found to be in general more sensitive than L. biflexa serovars. All three species were found to have a photoreactivation DNA repair mechanism. Since organisms that are resistant to UV are often resistant to the DNA cross-linking agent mitomycin C, we tested the relative sensitivity of several Leptospira serovars to this compound. With few exceptions, L. biflexa and L. illini serovars were considerably more resistant to mitomycin C than the L. interrogans serovars. The mitomycin C sensitivity assay could be a useful addition to current characterization tests used to differentiate the Leptospira species.

  13. Comparison of incidence of ptosis after combined phacotrabeculectomy with mitomycin C and phacoemulsification.

    PubMed

    Koh, Victor; Tatsios, Janina; Chew, Paul T K; Amrith, Shantha

    2015-12-01

    To compare the incidence of upper eyelid blepharoptosis after combined phacotrabeculectomy with mitomycin C and phacoemulsification surgeries and the relationship of bleb morphology to the incidence of ptosis. Retrospective observation study. We included 46 patients after combined phacotrabeculectomy and 44 patients with phacoemulsification in the former group, and all eyes underwent a standardized two-site surgery with intra-operative mitomycin C. Postoperative ptosis was defined as a reduction of upper marginal reflex distance 2 mm in the operated eye compared to the fellow eye. Trabeculectomy bleb measurements were carried out using anterior segment optical coherence tomography (Visante™, Carl Zeiss Meditec, Dublin, CA, USA) which included bleb height and total area of the bleb. There were 8 eyes (17.4%) and 5 eyes (11.4%) with postoperative ptosis in the phacotrabeculectomy and phacoemulsification groups, respectively (P = 0.342). In multivariate regression analysis, reduced total bleb area was significantly associated with upper eyelid ptosis after adjusting for age, gender, and type of anesthesia. The trend seemed to show that increased bleb height was also associated with ptosis, but this did not reach statistical significance. Incidence of persistent ptosis after phacoemulsification combined with trabeculectomy and mitomycin C is similar compared to stand alone phacoemulsification surgery in a multiethnic Asian population. Bleb morphology may play an important role in postoperative ptosis development and should be considered in the evaluation of upper eyelid blepharoptosis.

  14. Comparison of incidence of ptosis after combined phacotrabeculectomy with mitomycin C and phacoemulsification

    PubMed Central

    Koh, Victor; Tatsios, Janina; Chew, Paul T K; Amrith, Shantha

    2015-01-01

    Objective: To compare the incidence of upper eyelid blepharoptosis after combined phacotrabeculectomy with mitomycin C and phacoemulsification surgeries and the relationship of bleb morphology to the incidence of ptosis. Design: Retrospective observation study. Participants: We included 46 patients after combined phacotrabeculectomy and 44 patients with phacoemulsification in the former group, and all eyes underwent a standardized two-site surgery with intra-operative mitomycin C. Materials and Methods: Postoperative ptosis was defined as a reduction of upper marginal reflex distance 2 mm in the operated eye compared to the fellow eye. Trabeculectomy bleb measurements were carried out using anterior segment optical coherence tomography (VisanteTM, Carl Zeiss Meditec, Dublin, CA, USA) which included bleb height and total area of the bleb. Results: There were 8 eyes (17.4%) and 5 eyes (11.4%) with postoperative ptosis in the phacotrabeculectomy and phacoemulsification groups, respectively (P = 0.342). In multivariate regression analysis, reduced total bleb area was significantly associated with upper eyelid ptosis after adjusting for age, gender, and type of anesthesia. The trend seemed to show that increased bleb height was also associated with ptosis, but this did not reach statistical significance. Conclusions: Incidence of persistent ptosis after phacoemulsification combined with trabeculectomy and mitomycin C is similar compared to stand alone phacoemulsification surgery in a multiethnic Asian population. Bleb morphology may play an important role in postoperative ptosis development and should be considered in the evaluation of upper eyelid blepharoptosis. PMID:26862093

  15. Sensitivity of pathogenic and free-living Leptospira spp. to UV radiation and mitomycin C.

    PubMed Central

    Stamm, L V; Charon, N W

    1988-01-01

    The habitats for the two major Leptospira spp. differ. The main habitat of L. biflexa is soil and water, whereas L. interrogans primarily resides in the renal tubules of animals. We investigated whether these two species, along with L. illini (species incertae sedis), differ with respect to their sensitivity to UV radiation. The doses of UV resulting in 37, 10, and 1% survival were determined for representative serovars from each species. L. interrogans serovar pomona was 3.0 to 4.8 times more sensitive to UV than the other Leptospira species under the 37, 10, and 1% survival parameters. In comparison to other bacteria, L. interrogans serovar pomona is among the most sensitive to UV. In a qualitative UV sensitivity assay, L. interrogans serovars were found to be in general more sensitive than L. biflexa serovars. All three species were found to have a photoreactivation DNA repair mechanism. Since organisms that are resistant to UV are often resistant to the DNA cross-linking agent mitomycin C, we tested the relative sensitivity of several Leptospira serovars to this compound. With few exceptions, L. biflexa and L. illini serovars were considerably more resistant to mitomycin C than the L. interrogans serovars. The mitomycin C sensitivity assay could be a useful addition to current characterization tests used to differentiate the Leptospira species. PMID:3132098

  16. OSTEOCYTE APOPTOSIS

    PubMed Central

    Jilka, Robert L.; Noble, Brendon; Weinstein, Robert S.

    2012-01-01

    Apoptotic death of osteocytes was recognized over 15 years ago, but its significance for bone homeostasis has remained elusive. A new paradigm has emerged that invokes osteocyte apoptosis as a critical event in the recruitment of osteoclasts to a specific site in response to skeletal unloading, fatigue damage, estrogen deficiency and perhaps in other states where bone must be removed. This is accomplished by yet to be defined signals emanating from dying osteocytes, which stimulate neighboring viable osteocytes to produce osteoclastogenic cytokines. The osteocyte apoptosis caused by chronic glucocorticoid administration does not increase osteoclasts; however, it does negatively impact maintenance of bone hydration, vascularity, and strength. PMID:23238124

  17. Calphostin-C induction of vascular smooth muscle cell apoptosis proceeds through phospholipase D and microtubule inhibition.

    PubMed

    Zheng, Xi-Long; Gui, Yu; Du, Guangwei; Frohman, Michael A; Peng, Dao-Quan

    2004-02-20

    Calphostin-C, a protein kinase C inhibitor, induces apoptosis of cultured vascular smooth muscle cells. However, the mechanisms are not completely defined. Because apoptosis of vascular smooth muscle cells is critical in several proliferating vascular diseases such as atherosclerosis and restenosis after angioplasty, we decided to investigate the mechanisms underlying the calphostin-C-induced apoptotic pathway. We show here that apoptosis is inhibited by the addition of exogenous phosphatidic acid, a metabolite of phospholipase D (PLD), and that calphostin-C inhibits completely the activities of both isoforms of PLD, PLD1 and PLD2. Overexpression of either PLD1 or PLD2 prevented the vascular smooth muscle cell apoptosis induced by serum withdrawal but not the calphostin-C-elicited apoptosis. These data suggest that PLDs have anti-apoptotic effects and that complete inhibition of PLD activity by calphostin-C induces smooth muscle cell apoptosis. We also report that calphostin-C induced microtubule disruption and that the addition of exogenous phosphatidic acid inhibits calphostin-C effects on microtubules, suggesting a role for PLD in stabilizing the microtubule network. Overexpressing PLD2 in Chinese hamster ovary cells phenocopies this result, providing strong support for the hypothesis. Finally, taxol, a microtubule stabilizer, not only inhibited the calphostin-C-induced microtubule disruption but also inhibited apoptosis. We therefore conclude that calphostin-C induces apoptosis of cultured vascular smooth muscle cells through inhibiting PLD activity and subsequent microtubule polymerization.

  18. Inactivation of bacteriophage phi X174 by mitomycin C in the presence of sodium hydrosulfite and cupric ions.

    PubMed

    Ueda, K; Morita, J; Yamashita, K; Komano, T

    1980-02-01

    Bacteriophage phi X174 was inactivated by mitomycin C reduced with sodium hydrosulfite in the presence of cupric ions (Cu2+). 99% of the phage particles lost their plaque-forming abilities when incubated with 1.5 . 10(-4) M mitomycin C, 5.7 . 10(-4) M sodium hydrosulfite and 1.0 . 10(-4) M CuCl2 for 120 min at 37 degrees C in 0.05 M Tris--HCl buffer (pH 8.1). Sodium borohydride and thiol-reducing agents such as L-cysteine, 2-mercaptoethanol or dithiothreitol could not serve as a substitute for sodium hydrosulfite and other transition metal ions such as Fe2+, Fe3+, Mn2+, Co2+ and Zn2+ were of no effect. Inactivated phage sedimented at 114S just as intact phage, but phage DNA was degraded. Strand-scission was observed when phi X174 single-stranded DNA was directly reacted with mitomycin C reduced with sodium hydrosulfite in the presence of CuCl2. Phage inactivation was inhibited bycatalase, EDTA and several scavengers such as cysteamine, 2-aminoethylisothiuronium bromide HBr (AET), 4,5-dihydroxy-1,3-benzene-disulfonic acid (Tiron), or 1,4-diazabicyclo[2,2,2]octane (DABCO). These results suggest that free oxygen radicals and mitomycin C semiquinone radical generated during autoxidation of reduced mitomycin C in the presence of cupric ions cause the degradation of phy X174 DNA.

  19. Electroporation enhances mitomycin C cytotoxicity on T24 bladder cancer cell line: a potential improvement of intravesical chemotherapy in bladder cancer.

    PubMed

    Vásquez, Juan L; Gehl, Julie; Hermann, Gregers G

    2012-12-01

    Intravesical mitomycin instillation combined with electric pulses is being used experimentally for the treatment of T1 bladder tumors, in patients unfit for surgery. Electroporation may enhance the uptake of chemotherapeutics by permeabilization of cell membranes. We investigated if electroporation improves the cytotoxicity of mitomycin. In two cell lines, T24 (bladder cancer cell line) and DC3F (Chinese hamster fibroblast), exposure to different concentrations of mitomycin (0.01-2000μM) was tested with and without electroporation (6 pulses of 1kV/cm, duration: 99μs, frequency: 1Hz). Cell viability was assessed by colorimetric assay (MTT). For both cell lines, mitomycin's IC_50 was approximately 1000μM in both pulsed and unpulsed cells. On T24 cells, electroporation and mitomycin caused (relative reduction) RR of survival of: 25%, 31% and 29%, by concentrations 0μM, 500μM and 1000μM respectively. For DC3F cells, the RRs of survival were: 28%, 29%, and 33%, by concentrations 0μM, 500μM and 1000μM respectively. In conclusion, electroporation and mitomycin together are about 30% more effective than mitomycin alone. The results help to elucidate the additive effect of mitomycin and electric pulses and support the use of this combination in the treatment of bladder cancer.

  20. The effects of three bioreductive drugs (mitomycin C, RSU-1069 and SR4233) on cell lines selected for their sensitivity to mitomycin C or ionising radiation.

    PubMed

    Keohane, A; Godden, J; Stratford, I J; Adams, G E

    1990-05-01

    We have investigated the cross-sensitivity of a number of cell lines to three different classes of bioreductive drugs under both aerobic and hypoxic conditions. The cell lines used were selected for their sensitivity to DNA-damaging agents and fall into two groups. One group, MMC cells derived from CHO-K1 cells (Robson et al., 1985), show a range of sensitivities to mitomycin C in air. The second group, irs cells were cloned from V79 Chinese hamster fibroblasts (Jones et al., 1987) and exhibit sensitivity to ionising radiation. The sensitivity of both groups of cells to mitomycin C (MMC), RSU-1069 and SR4233 was assessed under aerobic and hypoxic conditions. No difference in aerobic or hypoxic toxicity of MMC was observed for CHO-K1 or MMC sensitive cell lines (MMC-2 and MMC-3). However, the MMC-resistant cell line (MMCr) was 10 times more sensitive under hypoxic than aerobic conditions. This suggests that MMCr cells lack or are deficient in the enzymes responsible for activating MMC under aerobic conditions compared to other MMC cells. In contrast, differential toxicities of between 3 and 30 have been observed for all CHO cells treated with RSU-1069 and SR4233. Treatment of V79 and irs cells with RSU-1069 and SR4233 also resulted in selective toxicity towards hypoxic cells. Differential toxicities between 50 and 100 were observed for V79 cells. For both RSU-1069 and SR4233, the hypoxic toxicities were similar in V79 and irs cells but in air, the radiation sensitive cells were up to 10 times more sensitive than wild type cells.

  1. The effects of three bioreductive drugs (mitomycin C, RSU-1069 and SR4233) on cell lines selected for their sensitivity to mitomycin C or ionising radiation.

    PubMed Central

    Keohane, A.; Godden, J.; Stratford, I. J.; Adams, G. E.

    1990-01-01

    We have investigated the cross-sensitivity of a number of cell lines to three different classes of bioreductive drugs under both aerobic and hypoxic conditions. The cell lines used were selected for their sensitivity to DNA-damaging agents and fall into two groups. One group, MMC cells derived from CHO-K1 cells (Robson et al., 1985), show a range of sensitivities to mitomycin C in air. The second group, irs cells were cloned from V79 Chinese hamster fibroblasts (Jones et al., 1987) and exhibit sensitivity to ionising radiation. The sensitivity of both groups of cells to mitomycin C (MMC), RSU-1069 and SR4233 was assessed under aerobic and hypoxic conditions. No difference in aerobic or hypoxic toxicity of MMC was observed for CHO-K1 or MMC sensitive cell lines (MMC-2 and MMC-3). However, the MMC-resistant cell line (MMCr) was 10 times more sensitive under hypoxic than aerobic conditions. This suggests that MMCr cells lack or are deficient in the enzymes responsible for activating MMC under aerobic conditions compared to other MMC cells. In contrast, differential toxicities of between 3 and 30 have been observed for all CHO cells treated with RSU-1069 and SR4233. Treatment of V79 and irs cells with RSU-1069 and SR4233 also resulted in selective toxicity towards hypoxic cells. Differential toxicities between 50 and 100 were observed for V79 cells. For both RSU-1069 and SR4233, the hypoxic toxicities were similar in V79 and irs cells but in air, the radiation sensitive cells were up to 10 times more sensitive than wild type cells. PMID:2110815

  2. Selective activation of mitomycin A by thiols to form DNA cross-links and monoadducts: biochemical basis for the modulation of mitomycin cytotoxicity by the quinone redox potential.

    PubMed

    Paz, M M; Das, A; Palom, Y; He, Q Y; Tomasz, M

    2001-08-16

    Mitomycin A (MA) but not mitomycin C (MC) cross-linked linearized (32)P-pBR322 DNA in the presence of dithiothreitol (DTT) or glutathione (GSH), as shown by a sensitive DNA cross-link assay. Incubation of calf-thymus DNA with MA and DTT or mercaptoethanol (MER) resulted in the formation of MA-DNA adducts, which were isolated from nuclease digests of the drug-DNA complexes by HPLC. The adducts were characterized by their UV absorption spectra, electrospray ionization mass spectrometry (ESIMS), and facile conversion from 7-methoxy- to 7-amino-substituted mitosene type adducts upon 10% NH(4)OH treatment, which were identical with known adducts of MC. Both DNA interstrand and intrastrand cross-link adducts, linking two deoxyguanosine residues at N(2), as well as several deoxyguanosine-N(2) monoadducts of MA, were identified. No DNA adducts were formed with MC under the same conditions. A specificity of DNA cross-link formation for the CpG sequence was observed using 12-mer synthetic oligodeoxyribonucleotides as substrates and as DNA sequence models, in analogy to the known CpG sequence specificity of MC-induced DNA cross-links. MA is known to be more cytotoxic by 2-3 orders of magnitude than MC, and this property correlates with redox potentials of MA (-0.19 V) and MA analogues that are higher than those of MC (-0.40 V) and its analogues. It is suggested that the biochemical basis for the higher cytotoxic potency of MA is MA's propensity to be reductively activated by cellular thiols while MC is resistant to thiol activation. This distinction is probably derived from the large difference between the quinone redox potentials of the two drugs.

  3. Induction of single strand scission in bacteriophage phi X174 replicative form I DNA by mitomycin C.

    PubMed

    Ueda, K; Morita, J; Komano, T

    1981-03-01

    The action of mitomycin C on double-stranded replicative form I DNA (RF I DNA; supercoiled, covalently closed, circular duplex DNA) of bacteriophage phi X174 was investigated using the technique of agarose gel electrophoresis. Mitomycin C reduced with sodium hydrosulfite (sodium dithionite, Na2S2O4) caused single strand scission in phi X174 RF I DNA in the presence of Cu2+. Cu2+ was essential for this DNA cleave action, and other transition metal ions such as Fe2+, Fe3+, Mn2+, Co2+ and Zn2+ were of no effect. This DNA strand scission was inhibited by catalase (EC 1.11.1.6) and various radical scavengers. This DNA strand scission was caused by free oxygen radicals generated during autoxidation of reduced mitomycin C in the presence of Cu2+.

  4. VEGF111b, a new member of VEGFxxxb isoforms and induced by mitomycin C, inhibits angiogenesis

    SciTech Connect

    Gu, Fang; Li, Xiuli; Kong, Jian; Pan, Bing; Sun, Min; Zheng, Lemin; Yao, Yuanqing

    2013-11-08

    Highlights: •We discovered a new member of VEGFxxxb family-VEGF111b. •We found VEGF111b mRNA and protein can be induced by mitomycin C. •We confirmed VEGF111b over-expression inhibits angiogenesis. •VEGF111b inhibits angiogenesis through inhibiting VEGF-R2/PI3K/Akt and VEGF-R2/ERK1/2 phosphorylation. -- Abstract: Vascular endothelial growth factor (VEGF-A) stimulating angiogenesis is required for tumor growth and progression. The conventional VEGF-A isoforms have been considered as pro-angiogenic factors. Another family of VEGF-A isoforms generated by alternative splicing, termed VEGFxxxb isoforms, has anti-angiogenic property, exemplified by VEGF165b. Here, we identify a new number of VEGFxxx family-VEGF111b induced by mitomycin C, although not detected in mitomycin C-unexposed ovarian cancer cells. SKOV3 cells were transfected with pcDNA{sub 3.1} empty vector, pcDNA{sub 3.1}-VEGF111b or pcDNA{sub 3.1}-VEGF165b to collect conditioned mediums respectively. VEGF111b overexpression inhibits proliferation, migration and tube formation of endothelial cell by inhibiting VEGF-R2 phosphorylation and its downstream signaling, similar to VEGF165b but slightly lower than VEGF165b. The anti-angiogenic property depends on the six amino acids of exon 8b of the VEGFxxxb isoforms. Our results show that VEGF111b is a novel potent anti-angiogenic agent that can target the VEGF-R2 and its signaling pathway to inhibit ovarian tumor growth.

  5. Adjustable release of mitomycin C for inhibition of scar tissue formation after filtration surgery.

    PubMed

    Merritt, Sonia R; Velasquez, Gia; von Recum, Horst A

    2013-11-01

    The aim of this study is to demonstrate a drug delivery system with the capacity to adjust the release of mitomycin C (MMC), based on polymer composition, and inhibit fibroblast proliferation to a better effect than is currently used in glaucoma filtration surgery. The polymer used in this work is made from the oligosaccharide cyclodextrin, from which others and we have demonstrated adjustable release of small molecule drugs due to specific molecular interactions or "affinity" between drug and the cyclodextrin polymer. To adjust release rate, cyclodextrin polymers were synthesized in either dimethylformamide (DMF) or dimethyl sulfoxide, (DMSO) at a crosslinking ratio of 1:0.16 or 1:0:32 (molecule of glucose: molecule of crosslinker). The polymers were then loaded with mitomycin C, dried, and release evaluated in a physiological environment. Drug release was determined by visible spectroscopy. Released aliquots of mitomycin C were incubated with 3T3 fibroblast cells to determine cytotoxic or inhibitory effect through a cell proliferation assay. We show that by using affinity between drug and polymer, we can adjust MMC release rates to be slower and more sustained than from conventional, diffusion-only polymers, for both the DMF polymers (p = 0.00526) and the DMSO polymers (p = 0.0113). The incorporated and released MMC maintains inhibition of fibroblast proliferation much longer than is possible with a one-time application. Affinity polymers with 1:0.16 and 1:0.32 crosslink ratio showed significant inhibition of proliferation for up to 100 h (p = 0.018 and p = 0.014 respectively). The use of our controlled drug delivery technology applied after surgery could have a greater therapeutic impact than the current one-time applications of MMC.

  6. Trabeculectomy with mitomycin C in the treatment of post-traumatic angle recession glaucoma

    PubMed Central

    Manners, T; Salmon, J; Barron, A; Willies, C; Murray, A

    2001-01-01

    AIM—The presence of traumatic angle recession is a risk factor for failure of glaucoma filtration surgery and a previous study has suggested that antimetabolite treatment should be used in these patients. This study was undertaken to determine for the first time the mid term results of trabeculectomy with intraoperative application of mitomycin C in patients with post-traumatic angle recession glaucoma.
METHODS—A retrospective analysis was made of 43 consecutive trabeculectomy procedures in 41 young black/mixed race patients followed for a mean period of 25 months (range 2-66 months). Mitomycin C 0.02% was applied between the sclera and conjunctiva for 1-5 minutes at the time of surgery. The intraocular pressure and visual acuity were measured postoperatively. The success of this technique was analysed by using a Kaplan-Meier cumulative survival curve.
RESULTS—The intraocular pressure was successfully controlled at last follow up without topical treatment in 77% (33/43 eyes) and the visual acuity was the same or better in 81% (35/43 eyes). Cumulative probability of success was 85% at 1 year follow up, 81% at 2 years, and 66% at 3 years and thereafter. Hypotonous maculopathy occurred in one patient and no cases of late bleb infection were found.
CONCLUSIONS—In medically uncontrolled post-traumatic angle recession glaucoma trabeculectomy with mitomycin C is an effective surgical procedure with an acceptable complication rate. Good intraocular pressure control and preservation of vision can be expected in most patients.

 PMID:11159478

  7. Exploiting poly(I:C) to induce cancer cell apoptosis.

    PubMed

    Bianchi, Francesca; Pretto, Samantha; Tagliabue, Elda; Balsari, Andrea; Sfondrini, Lucia

    2017-09-07

    TLR3 belong to the Toll-like receptors family, it is mainly expressed on immune cells where it senses pathogen-associated molecular patterns and initiates innate immune response. TLR3 agonist poly(I:C) was developed to mimic pathogens infection and boost immune system activation to promote anti-cancer therapy. Accordingly, TLR agonists were included in the National Cancer Institute list of immunotherapeutic agents with the highest potential to cure cancer. Besides well known effects on immune cells, poly(I:C) was also shown, in experimental models, to directly induce apoptosis in cancer cells expressing TLR3. This review presents the current knowledge on the mechanism of poly(I:C)-induced apoptosis in cancer cells. Experimental evidences on positive or negative regulators of TLR3-mediated apoptosis induced by poly(I:C) are reported and strategies are proposed to successfully promote this event in cancer cells. Cancer cells apoptosis is an additional arm offered by poly(I:C), besides activation of immune system, for the treatment of various type of cancer. A further dissection of TLR3 signaling would contribute to greater resolution of the critical steps that impede full exploitation of the poly(I:C)-induced apoptosis. Experimental evidences about negative regulator of poly(I:C)-induced apoptotic program should be considered in combinations with TLR3 agonists in clinical trials.

  8. Evaluation of the structural modifications induced by mitomycin C on nucleic acids.

    PubMed

    Jolles, B; Laigle, A; Liquier, J; Chinsky, L

    1993-04-01

    The interaction of poly(dG-dC).poly(dG-dC) with mitomycin C, an antitumor antibiotic, has been studied by various spectroscopic methods: circular dichroism, Fourier transform infrared resonance Raman scattering and using fluorescence emission of terbium bound to unpaired guanines as local conformation probe. The results allowed us to confirm the lack of long range modification of the DNA secondary structure upon binding. They also brought first information concerning the modification of the local structure of the nucleic acid at the level of mono- or bifunctional adducts.

  9. Mitomycin C as an adjunct in the treatment of localised ocular surface squamous neoplasia

    PubMed Central

    Chen, C; Louis, D; Dodd, T; Muecke, J

    2004-01-01

    Aim: To report the outcome of topical mitomycin C (MMC) used as adjunctive treatment following primary excision of ocular surface squamous neoplasia (OSSN). Method: Prospective, non-comparative interventional case series of 27 primary OSSN lesions from 26 patients treated in a single ocular oncology centre over a 4 year period. Result: 27 cases of OSSN received a treatment regimen of surgical excision, followed by topical MMC. Mean follow up of 27 (SD 12) months (range 12–50, median 25 months) revealed zero recurrences. Conclusion: MMC treatment following surgical excision decreases the recurrence rate of primary ocular surface neoplasia and should be considered as adjunctive therapy in primary treatment. PMID:14693762

  10. Cyctotoxicities of mitomycin C and x rays to aerobic and hypoxic cells in vitro

    SciTech Connect

    Rockwell, S.

    1982-01-01

    Aerobic and hypoxic EMT6 mouse mammary tumor cells in exponential growth in vitro were used to study cell survival after treatment with radiation (250k V X rays) and mitomycin C in various combinations. The cytotoxicities of the two agents were found to be additive as judged by comparing dose-response curves for each agent alone with survival curves after combination therapy and by isobologram analysis. The cytotoxicities resulting from combination treatments were found to be independent of the sequence of the treatments or the interval between treatments.

  11. The efficacy of 5-fluorouracil, mitomycin C, and methyl CCNU in advanced colorectal cancer.

    PubMed

    Vaughn, C B; Chapman, J; Garland, M; Pederson, B; Demitrish, M M; Chinn, B; Ward, D; Enochs, K; Groshko, G; Rocchio, R

    1986-06-01

    Sixty-six patients with advanced colorectal cancer were treated with 5-fluorouracil, Mitomycin C, and 1-(2-chloroethyl)-3-(4-methylcyclohexyl)-1-nitrosourea. Fifty-seven patients were evaluable by completing 2 months of therapy. Nine patients (16.0%) achieved a complete remission (CR) with the above combination. A partial remission (PR) was seen in 9 patients. The response rate (CR + PR) was 32%. The average duration of response was 8.5 months. Mucositis, leukopenia, and thrombocytopenia were the significant toxicities experienced in this study.

  12. Use of a simian virus 40-based shuttle vector to analyze enhanced mutagenesis in mitomycin C-treated monkey cells.

    PubMed Central

    Roilides, E; Munson, P J; Levine, A S; Dixon, K

    1988-01-01

    When monkey cells were treated with mitomycin C 24 h before transfection with UV-irradiated pZ189 (a simian virus 40-based shuttle vector), there was a twofold increase in the frequency of mutations in the supF gene of the vector. These results suggest the existence of an enhancible mutagenesis pathway in mammalian cells. However, DNA sequence analysis of the SupF- mutants suggested no dramatic changes in the mechanisms of mutagenesis due to mitomycin C treatment of the cells. PMID:2851732

  13. Topical application of mitomycin C in the treatment of esophageal and tracheobronchial stricture: a report of 2 cases.

    PubMed

    Daher, Paul; Riachy, Edward; Georges, Beyrouthy; Georges, Dabar; Adib, Moukarzel

    2007-09-01

    We present 2 cases of successful treatment of recurrent anastomotic strictures using a topical application of mitomycin C. In the first case, a 4-year-old boy had a cervical cyst excised, which appeared to be an ectopic gastric mucosa. He consequently presented severe stenosis at the origin of the cervical esophagus that needed repeated balloon dilatations. The second case is about a 12-year-old girl who presented a traumatic complete rupture of the right mainstem bronchus managed by primary repair, with subsequent anastomotic stricture. Both patients were successfully managed with topical application of mitomycin C (1 mg/mL), and needed no more dilatations.

  14. Use of a simian virus 40-based shuttle vector to analyze enhanced mutagenesis in mitomycin C-treated monkey cells

    SciTech Connect

    Roilides, E.; Munson, P.J.; Levine, A.S.; Dixon, K.

    1988-09-01

    When monkey cells were treated with mitomycin C 24 h before transfection with UV-irradiated pZ189 (a simian virus 40-based shuttle vector), there was a twofold increase in the frequency of mutations in the supF gene of the vector. These results suggest the existence of an enhancible mutagenesis pathway in mammalian cells. However, DNA sequence analysis of the SupF- mutants suggested no dramatic changes in the mechanisms of mutagenesis due to mitomycin C treatment of the cells.

  15. Aberrant wound-healing response in mitomycin C-treated leaking blebs: a histopathologic study.

    PubMed

    Elner, Victor M; Newman-Casey, Paula Anne; Patil, A Jayaprakash; Flint, Andrew; Biswas, Jyotirmay; Moroi, Sayoko E; Pushparaj, Vaijayanthi; Edward, Deepak P

    2009-08-01

    To characterize histopathologic features of leaking mitomycin C-treated blebs and aberrant wound healing that may lead to persistent conjunctival thinning and leakage. Forty mitomycin C-treated filtering blebs excised for persistent leaks from 40 patients were examined histopathologically using hematoxylin-eosin, periodic acid-Schiff, Masson trichrome, and Alcian blue histochemical stains. Ninety percent of the leaking blebs contained epithelial-stromal domes with areas of acellular stroma covered by attenuated epithelium. Seventy-five percent of the blebs demonstrated varying degrees of fibrovascular repair growing from the bleb margin, either beneath or interdigitating with the acellular zone. A novel observation in 65% of specimens was Alcian blue-positive myxoid stroma at the interface between the fibrovascular proliferation and the epithelial-stromal dome. The association between the presence of fibrovascular proliferation and Alcian blue-staining myxoid stroma was significant by Fisher exact test (P = .002). A desirable filtration bleb requires a sufficient reparative fibrovascular response to maintain an epithelial-stromal barrier to prevent leakage. Fibroblasts must lay down a continuous collagen-rich fibrous layer, rather than merely myxoid stroma, beneath the conjunctival epithelium to promote bleb stability. Surgical techniques and postsurgical care should aim to attain this desired outcome.

  16. Aberrant Wound-Healing Response in Mitomycin C-Treated Leaking Blebs: A Histopathologic Study

    PubMed Central

    Elner, Victor M.; Newman-Casey, Paula Anne; Patil, A. Jayaprakash; Flint, Andrew; Biswas, Jyotirmay; Moroi, Sayoko E.; Pushparaj, Vaijayanthi; Edward, Deepak P.

    2014-01-01

    Objective To characterize histopathologic features of leaking mitomycin-C-treated blebs and aberrant wound healing that may lead to persistent conjunctival thinning and leakage. Methods Forty mitomycin C-treated filtering blebs excised for persistent leaks from 40 patients were examined histopathologically using hematoxylin-eosin, periodic acid-Schiff, Masson trichrome, and Alcian blue histochemical stains. Results Ninety percent of the leaking blebs contained epithelial-stromal domes with areas of acellular stroma covered by attenuated epithelium. Seventy-five percent of the blebs demonstrated varying degrees of fibrovascular repair growing from the bleb margin, either beneath or interdigitating with the acellular zone. A novel observation in 65% of specimens was Alcian blue-positive myxoid stroma at the interface between the fibrovascular proliferation and the epithelial-stromal dome. The association between the presence of fibrovascular proliferation and Alcian-blue staining myxoid stroma was significant by Fisher exact test (P=0.002). Conclusions A desirable filtration bleb requires a sufficient reparative fibrovascular response to maintain an epithelial-stromal barrier in order to prevent leakage. Fibroblasts must lay down a continuous collagen-rich fibrous layer, rather than merely myxoid stroma, beneath the conjunctival epithelium to promote bleb stability. Surgical techniques and postsurgical care should aim to attain this desired outcome. PMID:19667341

  17. Antisense sequence-directed cross-linking of DNA oligonucleotides by mitomycin C.

    PubMed

    Maruenda, H; Tomasz, M

    1996-01-01

    Oligodeoxyribonucleotides (ODNs) conjugated with mitomycin C (MC) via (-CH2-)n tethers of different lengths (n = 6, 12) to their terminal 5'-phosphate were synthesized, and their interaction with target complementary single-stranded DNA oligonucleotides was investigated. MC, a clinically used natural anticancer drug, is known to act as a bioreductive alkylating agent of duplex DNA with a remarkable preference for 5'-d(CG) sequences. The usual enzymatic bioreductive techniques known to trigger MC to alkylate DNA were employed in the reaction between the MC-oligonucleotide conjugates and their targets radiolabeled by 32P at their 5'-phosphate. A slow-moving radiolabeled product, detected by polyacrylamide gel electrophoresis using phosphorimaging techniques, was obtained in 15-25% yield with complementary DNA as target. Formation of these products was dependent upon complementary duplex formation. Evidence is presented that the DNA target is alkylated by the mitomycin C moiety of the ODN conjugate at the 2-amino group of a guanine base. These findings suggest that the MC-ODN conjugates may be useful specific inhibitors of cellular or viral gene expression. To our knowledge this is the first report on ODN conjugates of a reductively activated drug of known therapeutic value.

  18. Single-step assembly of polymer-lipid hybrid nanoparticles for mitomycin C delivery

    PubMed Central

    2014-01-01

    Mitomycin C is one of the most effective chemotherapeutic agents for a wide spectrum of cancers, but its clinical use is still hindered by the mitomycin C (MMC) delivery systems. In this study, the MMC-loaded polymer-lipid hybrid nanoparticles (NPs) were prepared by a single-step assembly (ACS Nano 2012, 6:4955 to 4965) of MMC-soybean phosphatidyhlcholine (SPC) complex (Mol. Pharmaceutics 2013, 10:90 to 101) and biodegradable polylactic acid (PLA) polymers for intravenous MMC delivery. The advantage of the MMC-SPC complex on the polymer-lipid hybrid NPs was that MMC-SPC was used as a structural element to offer the integrity of the hybrid NPs, served as a drug preparation to increase the effectiveness and safety and control the release of MMC, and acted as an emulsifier to facilitate and stabilize the formation. Compared to the PLA NPs/MMC, the PLA NPs/MMC-SPC showed a significant accumulation of MMC in the nuclei as the action site of MMC. The PLA NPs/MMC-SPC also exhibited a significantly higher anticancer effect compared to the PLA NPs/MMC or free MMC injection in vitro and in vivo. These results suggested that the MMC-loaded polymer-lipid hybrid NPs might be useful and efficient drug delivery systems for widening the therapeutic window of MMC and bringing the clinical use of MMC one step closer to reality. PMID:25324707

  19. Treatment of multiple-level tracheobronchial stenosis secondary to endobronchial tuberculosis using bronchoscopic balloon dilatation with topical mitomycin-C.

    PubMed

    Faisal, Mohamed; Harun, Hafaruzi; Hassan, Tidi M; Ban, Andrea Y L; Chotirmall, Sanjay H; Abdul Rahaman, Jamalul Azizi

    2016-04-14

    Tracheobronchial stenosis is a known complication of endobronchial tuberculosis. Despite antituberculous and steroid therapy, the development of bronchial stenosis is usually irreversible and requires airway patency to be restored by either bronchoscopic or surgical interventions. We report the use of balloon dilatation and topical mitomycin-C to successful restore airway patency. We present a 24-year old lady with previous pulmonary tuberculosis and laryngeal tuberculosis in 2007 and 2013 respectively who presented with worsening dyspnoea and stridor. She had total left lung collapse with stenosis of both the upper trachea and left main bronchus. She underwent successful bronchoscopic balloon and manual rigid tube dilatation with topical mitomycin-C application over the stenotic tracheal segment. A second bronchoscopic intervention was performed after 20 weeks for the left main bronchus stenosis with serial balloon dilatation and topical mitomycin-C application. These interventions led to significant clinical and radiographic improvements. This case highlights that balloon dilatation and topical mitomycin-C application should be considered in selected patients with tracheobronchial stenosis following endobronchial tuberculosis, avoiding airway stenting and invasive surgical intervention.

  20. The Effect of 0.02% Mitomycin C Injection into the Hair Follicle with Radiofrequency Ablation in Trichiasis Patients

    PubMed Central

    Kim, Gyu-Nam; Yoo, Woong-Sun; Kim, Seong-Jae; Han, Yong-Seop; Chung, In-Young; Park, Jong-Moon; Yoo, Ji-Myong

    2014-01-01

    Purpose To investigate the inhibitory effect of 0.02% mitomycin C on eyelash regrowth when injected to the eyelash hair follicle immediately after radiofrequency ablation. Methods We prospectively included 21 trichiasis patients from June 2011 to October 2012. Twenty eyes of 14 patients were treated with 0.02% mitomycin C to the hair follicle immediately after radiofrequency ablation in group 1, while radiofrequency ablation only was conducted in ten eyes of seven patients in group 2. Recurrences and complications were evaluated until six months after treatment. Results One hundred sixteen eyelashes of 20 eyes in group 1 underwent treatment, and 19 (16.4%) eyelashes recurred. Eighty-four eyelashes of ten eyes in group 2 underwent treatment, and 51 (60.7%) eyelashes recurred. No patients developed any complications related to mitomycin C. Conclusions Application of 0.02% mitomycin C in conjunction with radiofrequency ablation may help to improve the success rate of radiofrequency ablation treatment in trichiasis patients. PMID:24505196

  1. Abate Cytochrome C induced apoptosome to protect donor liver against ischemia reperfusion injury on rat liver transplantation model

    PubMed Central

    Zhuang, Zhuonan; Lian, Peilong; Wu, Xiaojuan; Shi, Baoxu; Zhuang, Maoyou; Zhou, Ruiling; Zhao, Rui; Zhao, Zhen; Guo, Sen; Ji, Zhipeng; Xu, Kesen

    2016-01-01

    Objective: Aim of this study is to protect donor liver against ischemia-reperfusion injury by abating Cytochrome C induced apoptosome on rat model. Methods: A total of 25 clean SD inbred male rats were used in this research. The rats in ischemia-reperfusion injury group (I/R group, n=5) were under liver transplantation operation; rats in dichloroacetate diisopropylamine group (DADA group, n=5) were treated DADA before liver transplantation; control group (Ctrl group, n=5); other 10 rats were used to offer donor livers. Results: In DADA therapy group, Cytochrome C expression in donor hepatocellular cytoplasm was detected lower than that in I/R group. And the Cytochrome C induced apoptosome was also decreased in according to the lower expressions of Apaf-1 and Caspase3. Low level of cleaved PARP expression revealed less apoptosis in liver tissue. The morphology of donor liver mitochondria in DADA group was observed to be slightly edema but less than I/R group after operation 12 h. The liver function indexes of ALT and AST in serum were tested, and the results in DADA group showed it is significantly lower than I/R group after operation 12 h. The inflammation indexes of IL-6 and TNF-α expressions in DADA group were significantly lower than that in I/R group after operation 24 h. Conclusion: The dichloroacetate diisopropylamine treatment could protect the hepatocellular mitochondria in case of the spillage of Cytochrome C induced apoptosome, and protect the liver against ischemia-reperfusion injury. Thus, it may be a method to promote the recovery of donor liver function after transplantation. PMID:27186297

  2. Transcriptomic landscape for lymphocyte count variation in poly I:C-induced porcine peripheral blood.

    PubMed

    Wang, H; Hou, Y; Guo, J; Chen, H; Liu, X; Wu, Z; Zhao, S; Zhu, M

    2016-02-01

    Lymphocyte count is an important phenotypic metric that has been reported to be related to the individual antiviral capacity of pigs and other mammals. To date, aside from information regarding several genes and pathways, little is known about the mechanism by which gene expression affects variation in lymphocyte count. In this work, we investigated the lymphocyte count variation after poly I:C stimulation and compared the transcriptomes of pigs with large and small differences of lymphocyte counts before and after poly I:C stimulation. Pigs with large and small differences of lymphocyte counts were designated as extreme response (ER) and moderate response (MR) pigs respectively. Lymphocyte counts in all animals were observed to decline after poly I:C stimulation. Transcriptomic analysis identified 1121 transcripts (981 differentially expressed genes) in MR pigs and 1045 transcripts (904 differentially expressed genes) in ER pigs. We found that the majority of the differentially expressed genes were involved in both innate and adaptive immune responses. However, the innate immune response of ER pigs was more rapid than that of MR pigs. Results indicated that the activation of signaling pathways associated with cell death, cytotoxicity and apoptosis may contribute to the poly I:C-induced decrease of lymphocyte counts in the periphery. Moreover, the differential expression patterns of chemokines and FAS either totally or partially provided an interpretation for the different degrees of decrease in the lymphocyte counts between MR and ER pigs. Overall, our study will provide further understanding of the molecular basis for the antiviral capacity of pigs and other mammals.

  3. Methods for direct determination of mitomycin C in aqueous solutions and in urine

    PubMed Central

    Pérez, Pedro; Teijeiro, Carmen; Palecek, Emil

    1998-01-01

    Stripping voltammetry (SV) is used to quantitatively determine concentrations of the anti-neoplastic drug mitomycin C (MMC) alone and in mixtures with 5-fluorouracil and cisplatin, both of which are used in combined chemotherapy with MMC. If the accumulation is performed at the potentials of MMC reduction (-0.35 V vs. SCE), reduced MMC is strongly adsorbed at the electrode. It is possible to prepare a MMC-modified electrode, which, after a washing step, is transferred to the background electrolyte to determine MMC by voltammetry. This procedure, which is termed transfer stripping voltammetry (TSV), helps to eliminate interferences and can be applied for a direct determination of MMC alone or in mixtures with other drugs in urine. PMID:12734598

  4. Electrochemical investigation of interaction between mitomycin C and DNA in a novel drug-delivery system.

    PubMed

    Karadeniz, Hakan; Alparslan, Levent; Erdem, Arzum; Karasulu, Ercument

    2007-10-18

    A novel drug-delivery system was developed by loading the anticancer drug, mitomycin C (MC) into an oil/water system with the aim of investigation by electrochemical sensing the interaction between the drug and DNA in microemulsion phase. The physical and physicochemical properties (droplet size, pH, viscosity, conductivity and refractive index) of this microemulsion were examined. The electrochemical detection of the interaction between MC and double-stranded DNA (dsDNA) in microemulsion phase was performed by using differential pulse voltammetry (DPV) in combination with a disposable sensor, pencil graphite electrode (PGE). The magnitude of guanine oxidation signal was monitored before and after interaction between MC and dsDNA. The effect of different experimental parameters, such as MC concentration, MC interaction time with dsDNA, and dsDNA concentration were also studied to find the optimum analytical performance based on electrochemical detection of this interaction in microemulsion phase.

  5. Severe vernal keratoconjunctivitis requiring trabeculectomy with mitomycin C for corticosteroid-induced glaucoma.

    PubMed

    Ang, Marcus; Ho, Ching-Lin; Tan, Donald; Chan, Cordelia

    2012-01-01

    To describe clinical features of severe vernal keratoconjunctivitis with steroid response in Asian children and risk factors for glaucoma filtration surgery. Retrospective non-controlled, comparative case series. Patients with severe vernal keratoconjunctivitis seen at a single centre over 6 years. Clinical features, symptoms and treatment modalities were recorded for patients (i) diagnosed with severe VKC (clinical grade ≥ 3); (ii) had >2 recordings of increased intraocular pressures of >21 mmHg; (iii) and a minimum follow-up period of 1 year post-presentation. Corticosteroid-induced glaucoma requiring trabeculectomy with mitomycin-C. Six patients (eight eyes) of 36 patients required trabeculectomy/mitomycin-C. All were male. Mean age of disease onset was 9.3 ± 4.5 years for a mean duration of 6.08 ± 3.5 years. Mean intraocular pressures increase from baseline was 29.0 ± 8.2 mmHg and all required >2 anti-glaucoma medications. The main risk factor for trabeculectomy was a greater increase in intraocular pressures from baseline (odds ratio 1.3; 95% confidence interval, 1.0-1.5; P = 0.011), which was independent of potential confounders such as type and duration of corticosteroid use. Comparing eyes pre- and post-trabeculectomy, all improved in clinical severity of vernal keratoconjunctivitis (mean clinical grade improvement 2.1; 95% confidence interval, 1.3-3.0; P < 0.001) and reduced dependence on topical corticosteroids for mean duration of 22.5 ± 15.3 months. In our study, patients with a 'greater steroid response', that is, higher increase in intraocular pressures from baseline are associated with a 30% higher risk toftrabeculectomy. © 2011 The Authors. Clinical and Experimental Ophthalmology © 2011 Royal Australian and New Zealand College of Ophthalmologists.

  6. Olaparib in combination with irinotecan, cisplatin, and mitomycin C in patients with advanced pancreatic cancer.

    PubMed

    Yarchoan, Mark; Myzak, Melinda C; Johnson, Burles A; De Jesus-Acosta, Ana; Le, Dung T; Jaffee, Elizabeth M; Azad, Nilofer S; Donehower, Ross C; Zheng, Lei; Oberstein, Paul E; Fine, Robert L; Laheru, Daniel A; Goggins, Michael

    2017-07-04

    Olaparib is an oral inhibitor of polyadenosine 5'-diphosphoribose polymerization (PARP) that has previously shown signs of activity in patients with BRCA mutations and pancreatic ductal adenocarcinoma (PDAC). In this phase 1 dose-escalation trial in patients with unresectable PDAC, we determined the maximum tolerated dose (MTD) of olaparib (tablet formulation) in combination with irinotecan 70 mg/m2 on days 1 and 8 and cisplatin 25 mg/m2 on days 1 and 8 of a 28-day cycle (olaparib plus IC). We then studied the safety and tolerability of adding mitomycin C 5 mg/m2 on day 1 to this regimen (olaparib plus ICM). 18 patients with unresectable PDAC were enrolled. The MTD of olaparib plus IC was olaparib 100 mg twice-daily on days 1 and 8. The addition of mitomycin C to this dose level was not tolerated. Grade ≥3 drug-related adverse events (AEs) were encountered in 16 patients (89%). The most common grade ≥3 drug-related toxicities included neutropenia (89%), lymphopenia (72%), and anemia (22%). Two patients (11%), both of whom had remained on study for more than 12 cycles, developed drug-related myelodysplastic syndrome (MDS). The objective response rate (ORR) for all evaluable patients was 23%. One patient who carried a deleterious germline BRCA2 mutation had a durable clinical response lasting more than four years, but died from complications of treatment-related MDS. Olaparib had substantial toxicity when combined with IC or ICM in patients with PDAC, and this treatment combination did not have an acceptable risk/benefit profile for further study. However, durable clinical responses were observed in a subset of patients and further clinical investigation of PARP inhibitors in PDAC is warranted. This clinical trial was registered on ClinicalTrials.gov as NCT01296763.

  7. Topical mitomycin C can effectively alleviate dysphagia in children with long-segment caustic esophageal strictures.

    PubMed

    El-Asmar, K M; Hassan, M A; Abdelkader, H M; Hamza, A F

    2015-07-01

    Caustic ingestion in children and the resulting long esophageal strictures are usually difficult to be managed, and eventually, esophageal replacement was required for cases refractory to frequent dilatation sessions. Topical mitomycin C (MMC) application has been used recently to improve the results of endoscopic dilatation for short esophageal strictures. The study aims to assess the role of MMC application in management of long-segment caustic esophageal strictures. From January 2009 to June December 2013, patients presented with long caustic esophageal stricture (>3 cm in length) were included in this study and subjected to topical MMC application after endoscopic esophageal dilatation on multiple sessions. Regular follow-up and re-evaluation were done. A dysphagia score was used for close follow-up clinically; verification was done radiologically and endoscopically. During the specified follow-up period, 21 patients with long caustic esophageal stricture were subjected to topical MMC application sessions. Clinical, radiological, and endoscopic resolution of strictures occurred in 18 patients (85.7% cure rate). Number of dilatation sessions to achieve resolution of dysphagia was (n = 14.3 ± 5.7) with application of mitomycin two to six times. There was no recurrence in short- and mid-term follow-up. No complications were encountered related to topical MMC application. MMC is a promising agent in management of long-segment caustic esophageal strictures. Long-term follow-up is needed to prove its efficacy and to evaluate potential long-term side-effects of MMC application.

  8. Ocular tissue concentrations of mitomycin C with variable dose and duration of application time in rabbits.

    PubMed

    Hara, T; Shirato, S; Suzuki, Y

    1998-01-01

    We measured mitomycin C (MMC) concentrations in ocular tissues in rabbits with variable dose (0.1, 0.2, or 0.4 mg) and duration of application time (1, 3, or 5 minutes) of MMC using high-performance liquid chromatography. Mitomycin C concentrations at the administered site after single subconjunctival application of MMC and after irrigation showed significant correlation with dose and duration of time of application. By multiple regression analysis, MMC concentrations (microg/g) at the conjunctiva were described as -6.73 + 67.4 x Dose (mg) + 1.66 x Time (minutes) (R2 0.65); at the sclera, -1.85 + 38.2 x Dose + 0.927 x Time (R2 0.63); at the cornea, -0.727 + 8.44 x Dose (R2 0.46). With a 0.2-mg MMC dose, in all three application times (1, 3, or 5 minutes), MMC concentrations in the conjunctiva at the administered quadrant were three times higher than in the neighboring quadrants and 6 to 7 times higher than in the opposite quadrant. In the sclera, MMC concentrations were 3.5 times higher than in the neighboring sites and over 8 to 9 times higher than in the opposite site. In the cornea, MMC concentrations were 2 to 3 times higher than in the neighboring sites and opposite site. In the iris-ciliary body, MMC concentrations were 0.61 microg/g at the administered site with 0.2 mg for 3-minute application, 2 times higher than in neighboring sites, and 2 times higher than in opposite sites.

  9. [Determination of mitomycin C in rabbit plasma by ultra-high performance liquid chromatography-tandem mass spectrometry].

    PubMed

    Tang, Yao; Zhang, Shuangqing; Li, Xiang; Sun, Xu; Wen, Nie; Yu, Min; Peng, Lili; Li, Jinrang; Li, Zuogang; Li, Bo

    2012-02-01

    An ultra-high performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS) method for the determination of mitomycin C (MMC) in rabbit plasma was established. The blank rabbit plasma sample solutions added with mitomycin C and triamcinolone acetonide (internal standard, IS) were prepared. The solutions containing MMC and IS were extracted from the plasma with ethyl acetate using liquid-liquid extraction method. A Hypersil Gold C18 column (50 mm x 2.1 mm, 1.9 microm) was employed and the column temperature was set at 35 degrees C. The isocratic elution of methanol and 0.1% (v/v) formic acid aqueous solution as mobile phase was performed at a flow rate of 0.2 mL/min, and a rapid separation was completed within 3 min. The electrospray was operated in the positive ionization mode and the MMC and IS were identified in selected reaction monitoring (SRM) mode. The monitoring ions of MMC and IS were m/z 335. 2 --> 242.2 and m/z 435.2 --> 397. 3/415.2, respectively, which were used to qualify and quantify the targets by the method of matrix-matched standard solution. The calibration curve showed good linearity within the mass concentrations of 1 to 1 000 microg/L (r = 0.997 8, weighting: 1/x2). The limit of detection (S/N = 3) was 0.2 microg/L. The recoveries were from 85% to 115% at the spiked levels of 1, 5, 100 and 800 microg/L, and the relative standard deviations (RSDs) of intra- and inter-day were both less than 15%. The method can meet the determination requirements of biological samples, and can be used for the determination of mitomycin C in rabbit plasma after the administration of mitomycin C. The method is selective, sensitive, convenient, rapid and reproducible in the determination of mitomycin C, and also can be used for the pharmacokinetics research of mitomycin C in plasma.

  10. Intrascleral concentration vs depth profile of mitomycin-C after episcleral application: impact of applied concentration and volume of mitomycin-C solution.

    PubMed

    Vass, C; Georgopoulos, M; el Menyawi, I; Radda, S; Nimmerrichter, P

    2000-05-01

    The purpose of this study was to investigate the impact of different concentrations and volumes of Mitomycin-C (MMC) on the intrascleral concentration vs depth profile of MMC in an experimental model. The episcleral sides of scleral quadrants of human donor eyes were exposed for 1 min to sponges (corneal light shield, Merocel Corp.) soaked with MMC. After irrigation with 40 ml saline a central 8 mm diameter scleral disk was horizontally dissected with a cryotome. MMC concentrations of six layers of 140 microns thickness were analysed by means of high-performance liquid chromatography. In Experiment 1 (11 eyes) the sponges were soaked with 50 microliters of 10, 100 and 200 micrograms ml-1 MMC solutions. In Experiment 2 (12 eyes) the sponges were soaked with 10, 30, 50 and 80 microliters of a 200 micrograms ml-1 isotonic MMC solution. In Experiment 1 the MMC concentrations (microgram g-1) of layer 1 were 0.35 (+/- 0.20; 10 micrograms ml-1 group) and 9.22 (+/- 2.92; 200 micrograms ml-1 group). In Experiment 2 the MMC concentrations were 2.57 (+/- 1.17; 10 microliters group), 7.35 (+/- 2.49; 30 microliters group) and 11.67 (+/- 3.25; 80 microliters group). The scleral MMC concentrations were significantly influenced by the applied concentrations (layers 1-5) and by the applied volumes (all layers) of MMC solution. The intrascleral MMC concentration increased linearly with increasing concentration and not linearly with increasing volume of the applied MMC solution. To achieve more predictable scleral concentrations of MMC after trabeculectomy with MMC it seems advisable to control both the concentration and the volume of the MMC solution used to soak the sponge.

  11. Optimization of intrinsic and extrinsic tendon healing through controllable water-soluble mitomycin-C release from electrospun fibers by mediating adhesion-related gene expression.

    PubMed

    Zhao, Xin; Jiang, Shichao; Liu, Shen; Chen, Shuai; Lin, Zhi Yuan William; Pan, Guoqing; He, Fan; Li, Fengfeng; Fan, Cunyi; Cui, Wenguo

    2015-08-01

    To balance intrinsic and extrinsic healing during tendon repair is challenging in tendon surgery. We hypothesized that by mediating apoptotic gene and collagen synthesis of exogenous fibroblasts, the adhesion formation induced by extrinsic healing could be inhibited. With the maintenance of intrinsic healing, the tendon could be healed with proper function with no adhesion. In this study, we loaded hydrophilic mitomycin-C (MMC) into hyaluronan (HA) hydrosols, which were then encapsulated in poly(L-lactic acid) (PLLA) fibers by micro-sol electrospinning. This strategy successfully provided a controlled release of MMC to inhibit adhesion formations with no detrimental effect on intrinsic healing. We found that micro-sol electrospinning was an effective and facile approach to incorporate and control hydrophilic drug release from hydrophobic polyester fibers. MMC exhibited an initially rapid, and gradually steadier release during 40 days, and the release rates could be tuned by its concentration. In vitro studies revealed that low concentrations of MMC could inhibit fibroblast adhesion and proliferation. When lacerate tendons were healed using the MMC-HA loaded PLLA fibers in vivo, they exhibited comparable mechanical strength to the naturally healed tendons but with no significant presence of adhesion formation. We further identified the up-regulation of apoptotic protein Bax expression and down-regulation of proteins Bcl2, collage I, collagen III and α-SMA during the healing process associated with minimum adhesion formations. This approach presented here leverages new advances in drug delivery and nanotechnology and offers a promising strategy to balance intrinsic and extrinsic tendon healing through modulating genes associated with fibroblast apoptosis and collagen synthesis.

  12. Superficial keratectomy and topical mitomycin C as therapy for a corneal squamous cell carcinoma in a dog.

    PubMed

    Karasawa, K; Matsuda, H; Tanaka, A

    2008-04-01

    A 10-year-old female West Highland white terrier was presented with refractory hyperplastic keratitis of the left cornea of one month's duration. At this time, a vascularised and rough lesion 5 mm in diameter was observed on the left cornea. No other abnormality was recognised on the affected eye. The corneal neoplasm was surgically removed and histologically diagnosed as a squamous cell carcinoma. For two months after the surgery, 0.04 percent mitomycin C (MMC) eye drops were applied as adjuvant chemotherapy. Primary corneal squamous cell carcinoma with no history of keratoconjunctivitis sicca is rare in dogs. In the present report, surgical removal of the neoplasm was combined with the topical administration of the anticancer drug mitomycin C and a good prognosis was obtained. The result indicates that the combination treatment used in this case may be an appropriate therapeutic choice for corneal squamous cell carcinoma in dogs.

  13. [Response of HeLa cells to mitomycine C. III. The analysis of nucleoli of mother and daughter cells].

    PubMed

    Petrov, Iu P; Neguliaev, Iu A; Tsupkina, N V

    2014-01-01

    The comparative analysis of the number of nucleoli in cells of the established HeLa-M line was carried out before and after exposure to mitomycin C in a concentration of 10 μg/ml for 2 h. Using time-lapse microscopy, nucleoli in mother and their respective daughter cells were computed. It has been shown that the average number of nucleoli per cell is generally higher in daughter cells than in mother cells, and a standard deviation, on the contrary, decreases. An average number of nucleoli in daughter cells, whose mother cells had been treated with mitomycin C, was higher than in corresponding cells of control group. The separate analysis has been performed for the cells having from 1 to 4 nucleoli. Nonrandom complete coincidence of the number of nucleoli in mather and daughter cells has been typicaly shown for about 1/7 of the total cell population. Mitomycin C reduces this value of about 1.5 times.

  14. Evidence for clinical efficacy of mitomycin C in heavily pretreated ovarian cancer patients carrying germ-line BRCA1 mutation.

    PubMed

    Moiseyenko, Vladimir M; Chubenko, Vyacheslav A; Moiseyenko, Fedor V; Zhabina, Albina S; Gorodnova, Tatiana V; Komarov, Yuri I; Bogdanov, Alexey A; Sokolenko, Anna P; Imyanitov, Evgeny N

    2014-10-01

    Ovarian carcinomas (OC) arising in BRCA1 and BRCA2 mutation carriers demonstrate pronounced sensitivity to platinum-based therapy due to deficiency of double-strand break DNA repair. However, the choice of subsequent treatment lines for this category of women remains complicated. We considered mitomycin C for heavily pretreated hereditary OC patients, based on multiple evidence for BRCA-specific activity of this drug. Twelve patients carrying BRCA1 germ-line mutation were included in the study. All women had a history of surgical intervention followed by adjuvant platinum-based therapy; three patients also received platinating agents prior the operation. The number of preceding treatment lines for metastatic disease was one for three patients, two for four patients, three for two patients, four for two patients and six for one woman. Administration of mitomycin C (10 mg/m2, every 4 weeks) resulted in one complete response (duration 36 weeks), two partial responses (duration 36 and 48 weeks) and six instances of disease stabilization (duration 12, 16, 20, 24, 24 and 24 weeks). In addition, three patients with the stable disease showed a decline of CA-125 level. We conclude that mitomycin C may deserve further evaluation in clinical trials involving BRCA1/2-related cancers.

  15. Sensitive and convenient high-performance liquid chromatographic method for the determination of mitomycin C in human plasma.

    PubMed

    Joseph, G; Biederbick, W; Woschée, U; Theisohn, M; Klaus, W

    1997-09-26

    An improved high-performance liquid chromatographic assay for the cytostatic drug mitomycin C in plasma is presented. The principal steps are precipitation of plasma proteins with acetonitrile, lyophilization of the supernatant and reversed-phase chromatography on a Hypersil ODS 5 microm column with 0.01 M NaH2PO4 buffer (pH 6.5)-methanol (70:30, v/v) in isocratic mode. At a flow-rate of 1.3 ml/min a column pressure of 180-220 bar resulted. Porfiromycin served as internal standard. UV detection was performed at 365 nm. Quantitation limit based on a coefficient of variation <10% in intra- and inter-day assay was 5 microg/l mitomycin C, detection limit based on a signal-to-noise ratio of 3 was 1 microg/l. Recovery was 100% and linearity was shown for the whole range of concentration (1-500 microg/l). None of the five drugs used during chemoembolisation interfered with the assay in vitro. The assay meets the requirements for pharmacokinetic studies of mitomycin C in patients as regards sensitivity and ease of use.

  16. In vitro mitomycin C absorption and delivery with different sponge materials used in filtering surgery

    PubMed Central

    Urbaneja, Diana; Morilla-Grasa, Antonio; Jimenez, Elisa; Montemayor, Judith; Marcobal, Nuria; Aragay, Carme; Gurdiel, Celia; Armillas, Marta; Ortiz, Pere; Antón, Alfonso

    2016-01-01

    Purpose The purpose of this study is to evaluate and compare mitomycin C (MMC) absorption and delivery in different materials used in filtering surgery. Methods This is an in vitro study comparing polyvinyl alcohol triangular sponges (TS6, TS8), polyvinyl alcohol fluid wicks (EFW), and absorbable gelatin sponges (AGS3, AGS5), from which five different types of transport units were obtained. Seven pieces of sponge of each transport unit type were obtained as follows: two transverse strips were obtained at 6 and 8 mm from the apex of TS and divided into three equal pieces; 4×4 mm pieces of EFW; 3×3 and 5×5 mm pieces of absorbable gelatin sponges were cut. Filter paper was placed on a precision scale (0.01 mg). The seven sponge pieces of each type were weighed three times consecutively in dry and wet states, the latter after immersion for 15 seconds in 0.2 mg/mL MMC. The difference between the weights of the dry and wet filter paper at the end of each measurement sequence was also calculated and considered as an estimate of the amount of mitomycin delivered. Results The amounts of MMC absorbed by each transport unit were as follows: (mean ± standard deviation) 27.43±5.13 for TS6, 31.91±6.63 for TS8, 15.96±2.23 for EFW, 17.96±2.05 for AGS3, and 33.81±2.05 for AGS5. The amounts of MMC delivered to the filter paper were as follows: 21.70±2.84 for TS6, 23.83±4.03 for TS8, 12.93±1.75 for EFW, 14.69±1.79 for AGS3, and 27.30±1.58 for AGS5. Conclusion Percentage MMC delivered was similar for all materials, but there was a tendency for greater delivery using larger sponges and greater homogeneity in delivery with AGS5. No statistical differences were found in percentage delivered by the different transport materials. PMID:27143843

  17. An optimization protocol for Swiss 3T3 feeder cell growth-arrest by Mitomycin C dose-to-volume derivation strategy.

    PubMed

    Chugh, Rishi Man; Chaturvedi, Madhusudan; Yerneni, Lakshmana Kumar

    2017-04-01

    Feeder cell functionality following growth-arrest with the cost-effective Mitomycin C vis-à-vis irradiation is controversial due to several methodological variables reported. Earlier, we demonstrated variability in growth arrested Swiss 3T3 feeder cell life-span following titration of feeder cell densities with Mitomycin C concentrations which led to the derivation of doses per cell. Alternatively, to counter the unexpected feeder regrowth at high exposure cell density, we proposed titration of a fixed density with arithmetically derived volumes of Mitomycin C solution that corresponded to permutations of specific concentrations and doses per cell. We now describe an experimental procedure of inducing differential feeder cell growth-arrest by titrating with such volumes and validating the best feeder batch through target cell growth assessment. A safe cell density of Swiss 3T3 tested for the exclusion of Mitomycin C resistant variants was titrated with a range of volumes of a Mitomycin C solution. The differentially growth-arrested feeder batches generated were tested for short-term and long-term viability and human epidermal keratinocyte growth supporting ability. The feeder cell extinction rate was directly proportional to the volume of Mitomycin C solution within a given concentration per se. The keratinocyte colony forming efficiency and the overall growth in mass cultures were maximal with a median extinction rate produced by an intermediate volume, while the faster and slower extinction rates by high and low volumes, respectively, were suboptimal. The described method could counter the inadequacies of growth-arrest with Mitomycin C.

  18. Formation of a major DNA adduct of the mitomycin metabolite 2,7-diaminomitosene in EMT6 mouse mammary tumor cells treated with mitomycin C.

    PubMed

    Palom, Y; Belcourt, M F; Kumar, G S; Arai, H; Kasai, M; Sartorelli, A C; Rockwell, S; Tomasz, M

    1998-01-01

    Treatment of EMT6 mouse mammary tumor cells with [3H]mitomycin C (MC) results in the formation of six major DNA adducts, as described earlier using an HPLC assay of 3H-labeled products of enzymatic hydrolysis of DNA isolated from MC-treated cells. Four of these adducts were identified as monofunctional and bifunctional guanine-N2 adducts in the minor groove of DNA. In order to establish relationships between individual types of MC-DNA adducts and biological responses it is necessary to identify all of the adducts formed in cells. To this end we have now identified a predominant, previously unknown adduct formed in MC-treated EMT6 cells as a derivative not of MC, but of 2,7-diaminomitosene (2,7-DAM), the major bioreductive metabolite of MC. Rigorous proof demonstrates that it is a DNA major groove, guanine-N7 adduct of 2,7-DAM, linked at C-10 to DNA. The adduct is relatively stable at ambient temperature, but is readily depurinated upon heating. Its isolation from MC-treated cells indicates that MC is reductively metabolized to 2,7-DAM, which then undergoes further reductive activation to alkylate DNA, along with the parent MC. Low MC:DNA ratios were identified as a critical factor promoting 2,7-DAM adduct formation in an in vitro model calf thymus DNA/ MC/reductase model system, as well as in MC-treated EMT6 cells. The 2,7-DAM-guanine-N7 DNA adduct appears to be relatively noncytotoxic, as indicated by the dramatically lower cytotoxicity of 2,7-DAM in comparison with MC in EMT6 cells. Like MC, 2,7-DAM exhibited slightly greater cytotoxicity to cells treated under hypoxic as compared to aerobic conditions. However, 2,7-DAM was markedly less cytotoxic than MC under both aerobic and hypoxic conditions. Thus, metabolic reduction of MC to 2,7-DAM represents a detoxification process. The differential effects of MC-DNA and 2,7-DAM-DNA adducts support the concept that specific structural features of the DNA damage may play a critical role in the cytotoxic response to a DNA

  19. Mitomycin-C suppresses mucus secretion in an ileal neobladder rat model.

    PubMed

    Fan, Weiwei; Yu, Yang; Shu, Junjie; Ming, Hao; Li, Weiping; Fan, Zhilu

    2015-08-01

    The aim of the present study was to investigate the mucus secretion status of mature goblet cells following the application of mitomycin-C (MMC) in ileal neobladder rat models. Bladder substitution models were established in Sprague Dawley rats, which had been divided into five groups, namely the control (sham), normal saline (NS), high-dose MMC (HMMC), low-dose MMC (LMMC) and dehydrated alcohol (DA) groups. To evaluate the total protein concentration and level of sialic acid following the therapy, urine from the rats in each group was collected on days 8, 11 and 14. In addition, to observe the variances between mucus secretion and the ileum goblet cells, immunohistochemistry and hematoxylin and eosin staining were conducted in the different groups on day 17. The results indicated that the ileal neobladder mucosas in the MMC groups were clearly undamaged, as compared with the DA group. Furthermore, the MMC and DA groups were shown to inhibit the proliferation of goblet cells. The concentration of protein and sialic acid in the LMMC group was found to be lower compared with the NS group, while the concentration in the HMMC group was considerably lower. In conclusion, HMMC was demonstrated to evidently reduce the mucin and sialic acid concentration in the urine, without visible damage to the ileal neobladder mucus membrane. Therefore, MMC may provide a novel therapeutic approach for the treatment of certain bladder conditions.

  20. Mitomycin-C suppresses mucus secretion in an ileal neobladder rat model

    PubMed Central

    FAN, WEIWEI; YU, YANG; SHU, JUNJIE; MING, HAO; LI, WEIPING; FAN, ZHILU

    2015-01-01

    The aim of the present study was to investigate the mucus secretion status of mature goblet cells following the application of mitomycin-C (MMC) in ileal neobladder rat models. Bladder substitution models were established in Sprague Dawley rats, which had been divided into five groups, namely the control (sham), normal saline (NS), high-dose MMC (HMMC), low-dose MMC (LMMC) and dehydrated alcohol (DA) groups. To evaluate the total protein concentration and level of sialic acid following the therapy, urine from the rats in each group was collected on days 8, 11 and 14. In addition, to observe the variances between mucus secretion and the ileum goblet cells, immunohistochemistry and hematoxylin and eosin staining were conducted in the different groups on day 17. The results indicated that the ileal neobladder mucosas in the MMC groups were clearly undamaged, as compared with the DA group. Furthermore, the MMC and DA groups were shown to inhibit the proliferation of goblet cells. The concentration of protein and sialic acid in the LMMC group was found to be lower compared with the NS group, while the concentration in the HMMC group was considerably lower. In conclusion, HMMC was demonstrated to evidently reduce the mucin and sialic acid concentration in the urine, without visible damage to the ileal neobladder mucus membrane. Therefore, MMC may provide a novel therapeutic approach for the treatment of certain bladder conditions. PMID:26622360

  1. Sensitivity of Roberts Syndrome Cells to gamma radiation, mitomycin C, and protein synthesis inhibitors

    SciTech Connect

    Van Den Berg, D.J.; Francke, U. )

    1993-07-01

    Roberts syndrome (RS) is a rare autosomal recessive disorder characterized by pre- and postnatal growth retardation, limb reduction abnormalities, and craniofacial anomalies. Mitotic chromosomes from RS individuals display repulsion of heterochromatin regions or centromere splitting, leading to a railroad-track appearance of mitotic chromosomes. Abnormalities in metaphase duration, anaphase progression, nuclear morphology, and increased frequency of micronucleation have been reported in RS cells. Cells from RS heterozygotes are normal in these respects, and in vitro complementation of the defects in somatic cell hybrids has been reported. Therefore, in preparation for the isolation of cDNAs that complement the RS defect, the authors investigated various drug treatments to identify an agent that specifically involves the growth of RS cells. Based on the cytogenetic and cell biologic findings, they chose agents that increase micronucleation or inhibit protein synthesis. They found that RS cells are hypersensitive to gamma radiation, mitomycin C, G418 and hygromycin B, but not to colcemid or streptonigrin when compared to normal cells. DNA content and cell viability analysis confirmed that the sensitivity to gamma irradiation was primarily due to increased cell death.

  2. Effectiveness of scraping and mitomycin C to treat haze after myopic photorefractive keratectomy.

    PubMed

    Spadea, Leopoldo; Verrecchia, Valerio

    2011-01-01

    To report the possibility of post myopic photorefractive keratectomy (PRK) haze treatment in a patient with expressed reluctance for any additional laser therapy. Seven months after bilateral PRK with subsequent development of corneal haze and refractive regression in both eyes, a 37-old-year male patient presented a best-spectacle corrected visual acuity (BSCVA) of 20/30 in the right eye and of 20/22 in the left eye. Both eyes were sequentially treated by scraping the stromal surface and application of mitomycin C (MMC) for 2 minutes. Both eyes had significant improvement in corneal transparency. Eighteen months after this treatment BSCVA had improved to 20/20 in each eye. No toxic effects were observed during either re-epithelialization or follow-up periods. In conclusion scraping and application of MMC could be considered a good tool in the treatment of selected cases of haze after myopic PRK, especially with patients that are reluctant to undergo a secondary laser procedure.

  3. Mechanisms for optimising photodynamic therapy: second-generation photosensitisers in combination with mitomycin C.

    PubMed Central

    van Geel, I. P.; Oppelaar, H.; Oussoren, Y. G.; Schuitmaker, J. J.; Stewart, F. A.

    1995-01-01

    Mechanisms for improving photodynamic therapy (PDT) were investigated in the murine RIF1 tumour using meso-tetrahydroxyphenylchlorin (m-THPC) or bacteriochlorin a (BCA) as photosensitisers and comparing these results with Photofrin-mediated PDT. The 86Rb extraction technique was used to measure changes in perfusion at various times after interstitial PDT. Non-curative combinations of light doses with m-THPC and BCA PDT markedly decreased vascular perfusion. This decrease was more pronounced for both new photosensitisers than for Photofrin. Comparison of tumour perfusion after PDT with tumour response revealed an inverse correlation for all three photosensitisers, but the relationship was less clear for m-THPC and BCA. In vivo/in vitro experiments were performed after Photofrin or m-THPC PDT in order to assess direct tumour kill (immediate plating) vs indirect vascular effects (delayed plating). For both photosensitisers, there was little direct cell killing but clonogenic survival decreased as the interval between treatment and excision increased. When m-THPC PDT was combined with mitomycin C (MMC), light doses could be decreased by a factor of 2 for equal tumour effects. Lower light and m-THPC doses could be used compared with Photofrin PDT in combination with MMC. BCA PDT with MMC did not result in a greater tumour response compared with BCA PDT alone. Reduction in both light and photosensitiser does for effective PDT regimes in combination with MMC offers substantial clinical advantages, since both treatment time and skin photosensitisation will be reduced. PMID:7640216

  4. Role of xanthine oxidase in the potentiation of doxorubicin-induced cardiotoxicity by mitomycin C.

    PubMed

    Gustafson, D L; Swanson, J D; Pritsos, C A

    1991-09-01

    Clinical evidence has suggested that mitomycin C (MMC) potentiates doxorubicin (DOX) induced cardiotoxicity. In this study a mouse model was used to examine the effect of DOX on the ability of cardiac tissue to bioactivate MMC to generate oxygen radicals. Cardiac damage was assessed by measuring serum CPK-MB isoenzyme levels and thiobarbituric acid reactive substances (TBARS) in the cardiac tissue. The exposure of animals to DOX or DOX and MMC over a three week period led to an increase in serum CPK-MB isoenzyme levels as well as TBARS. Treatment with DOX led to an increase in MMC-dependent, NADH-dependent, cyanide insensitive oxygen consumption, compared to control animals, thereby suggesting increased MMC-dependent oxygen radical generation. Levels of xanthine oxidase (XO; EC 1.1.3.22) and NADPH:cytochrome C reductase, two enzymes known to bioactivate MMC with subsequent oxygen radical generation, were measured in cardiac tissue with a 4.5 x increase in XO activity seen in DOX treated animals vs controls and no change in NADPH:cytochrome C reductase activity. Cardiac levels of xanthine dehydrogenase (XDH; EC 1.1.1.204) activity in DOX treated animals decreased while the XO/XDH ratio increased, suggesting a conversion of XDH to XO following DOX treatment.

  5. Trabeculectomy with mitomycin C in secondary glaucoma associated with Behçet disease.

    PubMed

    Elgin, Ufuk; Berker, Nilufer; Batman, Aygen; Soykan, Emel

    2007-01-01

    To determine the outcome of initial trabeculectomy with mitomycin C (MMC) in the management of secondary glaucoma associated with Behçet disease (BD) in a 1-year follow-up period. Twenty-three eyes of 13 cases with secondary glaucoma associated with BD, were evaluated prospectively. They underwent primary trabeculectomy with MMC. The operative success was defined as an intraocular pressure (IOP) < or =20 mm Hg (+/- medical therapy) in the absence of phthisis and without the necessity of further surgery for glaucoma and success rates at the postoperative first day, first month, sixth month, and first year were determined. Success was achieved in all of the eyes (100%) at the postoperative first day and month, in 21 eyes (91.3%) at the postoperative sixth month and in 19 eyes (82.6%) at the postoperative first year. The mean preoperative IOP was 30.9+/-5.3 mm Hg under the mean 3.3+/-0.7 antiglaucoma medications but it reduced to 16.8+/-3.1 mm Hg under the mean 1.7+/-0.8 medications at the postoperative sixth month and 18.5+/-3.2 mm Hg under the mean 2.6+/-1.1 medications at the postoperative first year. Trabeculectomy with MMC provides reduction of IOP and the number of antiglaucoma medications in cases with secondary glaucoma associated with BD in a 1-year follow-up period.

  6. Digoxin reduces the mutagenic effects of Mitomycin C in human and rodent cell lines.

    PubMed

    de Oliveira, Júlia Teixeira; Barbosa, Maria C da Silva; de Camargos, Luiz F; da Silva, Isabella Viana Gomes; Varotti, Fernando de Pilla; da Silva, Luciana M; Moreira, Leonardo Marmo; Lyon, Juliana Pereira; Dos Santos, Vanessa J da Silva Vieira; Dos Santos, Fabio Vieira

    2017-03-20

    Digoxin is a drug widely used to treat heart failure and studies have demonstrated its potential as anticancer agent. In addition, digoxin presents the potential to interact with a series of other compounds used in medicine. The aim of the present study was to evaluate in vitro the cytotoxicity, genotoxicity and mutagenicity of digoxin and its potential to interact with the mutagen Mitomycin C (MMC). The cytotoxicity of digoxin was assessed by employing the MTT method and the comet assay was performed to assess the genotoxicity of this medicine in CHO-K1 and HeLa cell lines. Besides, the cytokinesis-block micronucleus assay was performed to assess the mutagenicity and the antimutagenicity of this drug. The Ames assay was also performed with TA98 and TA100 strains of S. typhimurium. Results showed that digoxin was cytotoxic, genotoxic and mutagenic for HeLa and CHO-K1 cell lines at concentrations many times higher than those observed in human therapeutic conditions. Nevertheless, an antimutagenic effect against the mutagen MMC was observed on both cell lines in concentrations near those used therapeutically in humans. This chemoprotective effect observed is an interesting finding that should be better explored regarding its impact in anticancer chemotherapy.

  7. Mitomycin C treatment induces resistance and enhanced migration via phosphorylated Akt in aggressive lung cancer cells

    PubMed Central

    Lai, Liang-Chuan; Chuang, Eric Y.; Tsai, Mong-Hsun

    2016-01-01

    Since 1984, mitomycin C (MMC) has been applied in the treatment of non-small-cell lung cancer (NSCLC). MMC-based chemotherapeutic regimens are still under consideration owing to the efficacy and low cost as compared with other second-line regimens in patients with advanced NSCLC. Hence, it is important to investigate whether MMC induces potential negative effects in NSCLC. Here, we found that the malignant lung cancer cells, CL1-2 and CL1-5, were more resistant to MMC than were the parental CL1-0 cells and pre-malignant CL1-1 cells. CL1-2 and CL1-5 cells consistently showed lower sub-G1 fractions post MMC treatment. DNA repair-related proteins were not induced more in CL1-5 than in CL1-0 cells, but the levels of endogenous and MMC-induced phosphorylated Akt (p-Akt) were higher in CL1-5 cells. Administering a p-Akt inhibitor reduced the MMC resistance, demonstrating that p-Akt is important in the MMC resistance of CL1-5 cells. Furthermore, we revealed that cell migration was enhanced by MMC but lowered by a p-Akt inhibitor in CL1-5 cells. This study suggests that in CL1-5 cells, the activity of p-Akt, rather than DNA repair mechanisms, may underlie the resistance to MMC and enhance the cells' migration abilities after MMC treatment. PMID:27833080

  8. Complications of mitomycin C therapy in 100 eyes with ocular surface neoplasia

    PubMed Central

    Khong, J J; Muecke, J

    2006-01-01

    Aim To determine the complications associated with mitomycin C (MMC) in the treatment of ocular surface neoplasia. Methods A retrospective and consecutive study of 100 eyes in 91 patients with ocular surface neoplasia treated with MMC in a single centre between November 1998 and January 2005. Outcome measures included complications of MMC and the treatment required for these complications. Results One to three 7 day cycles of topical MMC 0.04% four times a day were given to 59 eyes with localised corneal‐conjunctival intraepithelial neoplasia (CIN), 19 eyes with diffuse CIN, six eyes with recurrent CIN, one eye with ocular surface squamous cell carcinoma, three eyes with primary acquired melanosis (PAM) with atypia, nine eyes with conjunctival malignant melanoma (MM), two eyes with sebaceous carcinoma with pagetoid spread, and one eye with recurrent atypical fibroxanthoma. Nine patients had bilateral CIN. 31 (34%) cases developed an allergic reaction to MMC and 14 (14%) eyes had epiphora secondary to punctal stenosis at a mean follow up period of 26.5 months. Conclusion In the largest study looking at complications of topical MMC in the treatment of ocular surface neoplasia, allergic reaction and punctal stenosis are relatively common. Serious complications were not observed suggesting the safe use of MMC in mid‐term follow up. PMID:16672325

  9. Excimer laser phototherapeutic keratectomy in conjunction with mitomycin C in corneal macular and granular dystrophies.

    PubMed

    Yuksel, Erdem; Cubuk, Mehmet Ozgur; Eroglu, Hulya Yazıcı; Bilgihan, Kamil

    2016-04-01

    To evaluate the visual outcomes, recurrence patterns, safety, and efficacy of excimer laser phototherapeutic keratectomy (PTK) in conjunction with mitomycin C (MMC) for corneal macular and granular diystrophies. The patients were divided into two groups. Group 1 included patients with macular corneal dystrophy (MCD) that caused superficial corneal plaque opacities, and Group 2 included patients with granular corneal dystrophy (GCD). Patients in both groups were pre-, peri-, and postoperatively evaluated. The groups were compared in terms of uncorrected visual acuity (VA), best spectacle-corrected VA, presence of mild or significant recurrence, and time of recurrence. Eighteen eyes (nine with MCD and nine with GCD) of 18 patients (10 men and eight women) were included. PTK was performed for each eye that was included in this study. The mean ablation amount was 117.8 ± 24.4 µm and 83.5 ± 45.7 µm in MCD and GCD, respectively, (p=0.18). The postoperative improvement of the mean VA was similar between the two groups before recurrences (p>0.43) and after recurrences (p>0.71). There were no statistically significant differences in the recurrence rate and the recurrence-free period for any recurrence type. PTK was an effective, safe, and minimally invasive procedure for patients with MCD and GCD. PTK in conjunction with MMC was similarly effective for both groups in terms of recurrence and visual outcomes.

  10. Deoxycholic acid-grafted PEGylated chitosan micelles for the delivery of mitomycin C.

    PubMed

    Zhang, Xiu-Rong; Shi, Nian-Qiu; Zhao, Yang; Zhu, He-Yun; Guan, Jiao; Jin, Ying

    2015-06-01

    Mitomycin C (MTC) was incorporated to a micelle system preparing from a polymer named deoxycholic acid chitosan-grafted poly(ethylene glycol) methyl ether (mPEG-CS-DA). mPEG-CS-DA was synthesized and characterized by (1)H nuclear magnetic resonance ((1)H-NMR) and Fourier transform infrared spectroscopy. mPEG-CS-DA formed a core-shell micellar structure with a critical micelle concentration of 6.57 µg/mL. The mPEG-CS-DA micelles were spherical with a hydrodynamic diameter of about 231 nm. After poly(ethylene glycol)ylation of deoxycholic acid chitosan (CS-DA), the encapsulation efficiency and drug loading efficiency increased from 50.62% to 56.42% and from 20.51% to 24.13%, respectively. The mPEG-CS-DA micelles possessed a higher drug release rate than the CS-DA micelles. For pharmacokinetics, the area under the curve (AUC) of the mPEG-CS-DA micelles was 1.5 times higher than that of MTC injection, and these micelles can enhance the bioavailability of MTC. mPEG-CS-DA micelles reduced the distribution of MTC in almost all normal tissues and had the potential to improve the kidney toxicity caused by MTC injection.

  11. Binding of mitomycin C to blood proteins: A spectroscopic analysis and molecular docking

    NASA Astrophysics Data System (ADS)

    Jang, Jongchol; Liu, Hui; Chen, Wei; Zou, Guolin

    2009-06-01

    Mitomycin C (MMC) was the first recognized bioreductive alkylating agent, and has been widely used clinically for antitumor therapy. The binding of MMC to two human blood proteins, human serum albumin (HSA) and human hemoglobin (HHb), have been investigated by fluorescence quenching, synchronous fluorescence, circular dichroism (CD) spectroscopy and molecular docking methods. The fluorescence data showed that binding of MMC to proteins caused strong fluorescence quenching of proteins through a static quenching way, and each protein had only one binding site for the drug. The binding constants of MMC to HSA and HHb at 298 K were 2.71 × 10 4 and 2.56 × 10 4 L mol -1, respectively. Thermodynamic analysis suggested that both hydrophobic interaction and hydrogen bonding played major roles in the binding of MMC to HSA or HHb. The CD spectroscopy indicated that the secondary structures of the two proteins were not changed in the presence of MMC. The study of molecular docking showed that MMC was located in the entrance of site I of HSA, and in the central cavity of HHb.

  12. Safety and efficacy of adjunctive intranasal mitomycin C and triamcinolone in endonasal endoscopic dacryocystorhinostomy.

    PubMed

    Li, Emmy Y; Cheng, Andy C; Wong, Alex C; Sze, Amy M; Yuen, Hunter K

    2016-02-01

    One of the common causes of failure in dacryocystorhinostomy for nasolacrimal duct obstruction (NLDO) is mucosal scarring and fibrosis around the ostium. Steroid and mitomycin C (MMC) can potentially reduce scarring by their action on the inflammatory and proliferative phase of wound healing, respectively. The purpose of this study is to evaluate the safety and efficacy of combined usage of adjunctive MMC and intranasal triamcinolone (TA) in endonasal endoscopic dacryocystorhinostomy (EE-DCR). This is a retrospective interventional case series. All patients underwent mechanical EE-DCR in two regional hospitals in Hong Kong from January 2005 to December 2006 were included. All received intraoperative MMC application for 5 min and gelfoam soaked with TA onto the ostium. Main outcome measures include the anatomical and functional success rate at follow-up at least 6 months after operation. Other outcomes include complications occurred during and after operation. A total of 73 EE-DCR were performed in 69 patients. Three patients had simultaneous bilateral DCR; one had sequential DCRs for both sides. At the last follow-up, anatomical success was achieved in 68 cases (93 %) and both anatomical with functional success in 67 cases (92 %). No major complication was observed. Minor complications included asymptomatic mucosal adhesion between the nasal septum and lateral nasal wall in one patient and moderate secondary hemorrhage in another. EE-DCR with adjunctive MMC and TA is a safe and successful procedure for the treatment of NLDO.

  13. Genome-Wide Mutational Signature of the Chemotherapeutic Agent Mitomycin C in Caenorhabditis elegans.

    PubMed

    Tam, Annie S; Chu, Jeffrey S C; Rose, Ann M

    2015-11-12

    Cancer therapy largely depends on chemotherapeutic agents that generate DNA lesions. However, our understanding of the nature of the resulting lesions as well as the mutational profiles of these chemotherapeutic agents is limited. Among these lesions, DNA interstrand crosslinks are among the more toxic types of DNA damage. Here, we have characterized the mutational spectrum of the commonly used DNA interstrand crosslinking agent mitomycin C (MMC). Using a combination of genetic mapping, whole genome sequencing, and genomic analysis, we have identified and confirmed several genomic lesions linked to MMC-induced DNA damage in Caenorhabditis elegans. Our data indicate that MMC predominantly causes deletions, with a 5'-CpG-3' sequence context prevalent in the deleted regions of DNA. Furthermore, we identified microhomology flanking the deletion junctions, indicative of DNA repair via nonhomologous end joining. Based on these results, we propose a general repair mechanism that is likely to be involved in the biological response to this highly toxic agent. In conclusion, the systematic study we have described provides insight into potential sequence specificity of MMC with DNA.

  14. Functional characterization of two SOS-regulated genes involved in mitomycin C resistance in Caulobacter crescentus.

    PubMed

    Lopes-Kulishev, Carina O; Alves, Ingrid R; Valencia, Estela Y; Pidhirnyj, María I; Fernández-Silva, Frank S; Rodrigues, Ticiane R; Guzzo, Cristiane R; Galhardo, Rodrigo S

    2015-09-01

    The SOS response is a universal bacterial regulon involved in the cellular response to DNA damage and other forms of stress. In Caulobacter crescentus, previous work has identified a plethora of genes that are part of the SOS regulon, but the biological roles of several of them remain to be determined. In this study, we report that two genes, hereafter named mmcA and mmcB, are involved in the defense against DNA damage caused by mitomycin C (MMC), but not against lesions induced by other common DNA damaging agents, such as UVC light, methyl methanesulfonate (MMS) and hydrogen peroxide. mmcA is a conserved gene that encodes a member of the glyoxalases/dioxygenases protein family, and acts independently of known DNA repair pathways. On the other hand, epistasis analysis showed that mmcB acts in the same pathway as imuC (dnaE2), and is required specifically for MMC-induced mutagenesis, but not for that induced by UV light, suggesting a role for MmcB in translesion synthesis-dependent repair of MMC damage. We show that the lack of MMC-induced mutability in the mmcB strain is not caused by lack of proper SOS induction of the imuABC operon, involved in translesion synthesis (TLS) in C. crescentus. Based on this data and on structural analysis of a close homolog, we propose that MmcB is an endonuclease which creates substrates for ImuABC-mediated TLS patches.

  15. Determination of mitomycin C in human aqueous humor and serum by high-performance liquid chromatography.

    PubMed

    Li, W Y; Seah, S K; Koda, R T

    1993-09-08

    Mitomycin C (MMC) is used in the treatment of disseminated adenocarcinoma of the stomach and pancreas and is used in ophthalmology as adjunctive therapy in trabeculectomy. Since only small volumes of aqueous humor are available for analysis, a sensitive method requiring limited sample preparation was developed. An internal standard, 4-aminoacetophenone, was added to aqueous humor specimens, and the solution was directly injected into the high-performance liquid chromatographic (HPLC) column. The use of a short 50-mm C18 reversed-phase column gave adequate resolution of peaks with improved sensitivity. The method was applicable for determination of MMC in serum, although solid-phase extraction for sample clean-up was required prior to injection into the HPLC column, and analytical columns of 150-250 mm were necessary for adequate resolution of peaks. The method has been validated and is linear from 6.25 to 50 ng/ml in aqueous humor and from 10 to 500 ng/ml in serum.

  16. Plasma mitomycin C concentrations determined by HPLC coupled to solid-phase extraction.

    PubMed

    Paroni, R; Arcelloni, C; De Vecchi, E; Fermo, I; Mauri, D; Colombo, R

    1997-04-01

    The aim of this study was to set up a method for quantification of plasma mitomycin C (MMC) concentrations during intravesical chemotherapy delivered in the presence of local bladder hyperthermia (HT). In comparison with existing methods, this assay, characterized by relative simplicity and efficiency, resulted in the facilitation of performance with nondedicated instrumentation or nonspecialized staff. Purification from plasma matrix was carried out by solid-phase extraction under vaccuum. The purified drug was then collected directly into the vials of the HPLC autosampler. Chromatographic analysis was performed on a reversed-phase C18 column with water:acetonitrile (85:15 by vol) as the mobile phase and the UV detector set at 365 nm. The use of porfiromycin as internal standard provided a method with good within-day precision (CV 6.0% at 5 micrograms/L, n = 6), linearity (0.5-50 micrograms/L), and specificity. The lower limit of detection (< or = 0.5 microgram/L) proved to be suitable for plasma pharmacokinetics monitoring in two tested patients treated with MMC + HT for superficial bladder cancer.

  17. Evaluation of the stability of extemporaneously prepared ophthalmic formulation of mitomycin C.

    PubMed

    Velpandian, Thirumurthy; Saluja, Vinay; Ravi, Alok Kumar; Kumari, Srinivasan Senthil; Mathur, Rajani; Ranjan, Nihar; Ghose, Supriyo

    2005-06-01

    Mitomycin C (MMC) is a cytostatic agent topically used in conjunctival neoplasms, secondary to glaucoma filtering, pterygium, and strabismus surgery to increase the success rate. The topical formulation of MMC for ocular use is always extemporaneously prepared. Our study evaluated the stability of extemporaneously prepared formulations of MMC at different concentrations (150, 300, & 600 microg/mL) kept at different temperatures (25 degrees , 4 degrees , and -70 degrees C) and at different pH range (6, 7, and 8). Aliquots from the above formulations were subjected for quantification of MMC on days 0, 7, 14, 21, and 28 using high-performance liquid chromatography. MMC stored at 25 degrees C for 6 months was also subjected to flow cytometry and compared to freshly prepared MMC. The results indicated that the degradation of MMC is very high in acidic pH at room temperature. Increasing the pH to 7 or 8 and keeping MMC at low temperatures significantly decreased the degradation of MMC. Interestingly, the flow cytometry data revealed that the 6-month-old MMC showed an antiproliferative effect compared to that of freshly prepared MMC. To conclude, the extemporaneously prepared MMC at pH between 7 and 8 and stored in the refrigerator can increase the duration of its stability. However, the antiproliferative study using flow cytometry revealed that degraded MMC retained its activity even after degradation.

  18. Cell growth inhibition and DNA incorporation of mitomycin C in cell culture.

    PubMed

    Takahashi, N; Murayama, T; Oda, M; Miyakoshi, M

    1998-01-01

    The present study was performed to clarify the effects of a 4-min exposure of mitomycin C (MMC) on cell growth, the cell cycle and MMC dose incorporated into DNA, using Chang's cultured human conjunctival cells. A low dose of MMC ranging from 0.00025 to 0.004% showed dose-dependent cytotoxicity when cell growth was active. Fifty percent cell viability was found when cells were treated with 0.001% MMC. A flow cytometer showed that 0.001% MMC inhibited the DNA synthetic phase. After 0.04% MMC was exposed to 3 x 10(6) cells and immediately rinsed, DNA was isolated to measure the dose of MMC detected from DNA. The total amount of DNA was 7 micrograms from which 3 micrograms of MMC was detected by high performance liquid chromatography. The above results revealed that the lowest concentration of MMC which caused 50% cell viability and cell cycle inhibition was 0.001% and that MMC was rapidly incorporated into DNA.

  19. Evaluation of antitumor and toxic side effects of mitomycin C-estradiol conjugates.

    PubMed

    Ishiki, Nobuyuki; Onishi, Hiraku; Machida, Yoshiharu

    2004-07-26

    The antitumor and toxic side effects of mitomycin C-estradiol conjugates (EB-glu-MMC and E-glu-MMC) were evaluated in detail for solutions in propylene glycol and suspensions in 10% (v/v) propylene glycol. Tumor growth, body weight and number of leukocytes were examined after i.p. administration to sarcoma 180 solid tumor-bearing mice. Body weight and number of leukocytes were also examined in normal mice after i.p. administration of the solution. In solution dosage forms, the two conjugates had almost the same suppressive effect on tumor growth at 30 mg MMC eq./kg as MMC at 5 mg/kg, did not lower body weight significantly, but reduced the number of leukocytes at 30 mg MMC eq./kg. MMC, lethally toxic at 10 mg, significantly lowered the body weight and leukocyte number. In the suspension dosage forms, these conjugates had a greater suppressive effect on tumor growth at 50 mg MMC eq./kg than MMC at 5 mg/kg, and reduced the body weight and leukocyte number, with E-glu-MMC more toxic than EB-glu-MMC. The presence of the tumor itself influenced the body weight and leukocyte number. However, toxic side effects could be evaluated from the body weight and leukocyte number to almost the same extent between tumor-bearing and normal mice.

  20. Mitomycin-C in dacryocystorhinostomy: From experimentation to implementation and the road ahead: A review.

    PubMed

    Nair, Akshay Gopinathan; Ali, Mohammad Javed

    2015-04-01

    Dacryocystorhinostomy (DCR) is the procedure of choice in patients with epiphora due to primary acquired nasolacrimal duct obstruction. The evolution of surgical tools, fiber-optic endoscopes, effective anesthesia techniques, and the adjunct use of antimetabolites intraoperatively; namely mitomycin-C (MMC) have significantly contributed to the advancement of DCR surgery. MMC is a systemic chemotherapeutic agent derived from Streptomyces caespitosus that inhibits the synthesis of DNA, cellular RNA, and protein by inhibiting the synthesis of collagen by fibroblasts. Even the cellular changes in the human nasal mucosal fibroblasts induced by MMC at an ultrastructural level have been documented. There, however, seems to be a lack of consensus regarding MMC: The dosage, the route of delivery/application, the time of exposure and subsequently what role each of these variables plays in the final outcome of the surgery. In this review, an attempt is made to objectively examine all the evidence regarding the role of MMC in DCR. MMC appears to improve the success rate of DCR.

  1. Outcomes of Trabeculectomy With Transconjunctival Application Versus Subconjunctival Application of Mitomycin C.

    PubMed

    Kwong, Tsong Qiang; Mahroo, Omar; Scoppettuolo, Elisabetta; Ansari, Ejaz

    2016-06-01

    To compare outcomes and complication rates of trabeculectomy with either transconjunctival mitomycin C (MMC) or subconjunctival MMC application. Retrospective cohort study-35 eyes in subconjunctival group and 29 eyes in transconjunctival group. All surgeries were performed by 1 surgeon (E.A.) at 1 center with an average follow-up duration of 40 to 51 months. The mean percentage intraocular pressure reduction at final follow-up was with 44.4±25.3% reduction in the subconjunctival group compared with 48.0±24.6% reduction in the transconjunctival group, with no statistical significant difference between the 2 groups (P=0.57). Both groups also showed a >40% reduction in intraocular pressure in approximately 67% of eyes. There were no cases of endophthalmitis. There was 1 reported case of choroidal hemorrhage following subconjunctival application of MMC. There were similar low rates of postoperative bleb leakage and requirement for postoperative application of 5-fluorouracil. There was a greater incidence of hyphema in the subconjunctival group (5 vs. 1) as well as choroidal effusions (8 vs. 4). One patient underwent revision of trabeculectomy and this was in the subconjunctival group. Transconjunctival application of MMC offers a safe and effective method of performing trabeculectomy with adjunctive MMC with lower rates of complication than subconjunctival application.

  2. Absence of mutagenic interaction between microwaves and mitomycin C in mammalian cells

    SciTech Connect

    Meltz, M.L.; Eagan, P. ); Erwin, D.N. )

    1989-01-01

    Evidence in the literature from in vitro and in vivo studies as to whether or not radiofrequency radiation (RFR) in the microwave range is mutagenic is predominantly negative, with some positive reports. No evidence is available as to whether FRF will alter the mutagenic activity of genotoxic chemicals during a simultaneous exposure, a likely real-life situation. Two hypotheses have been proposed: (a) that RFR by itself can cause mutations in a mammalian cell in vitro assay system; and (b) that a simultaneous exposure to RFR during a chemical treatment of the cells with a known genotoxic agent, mitomycin C (MMC), will alter the extent of mutagenesis induced by the treatment of the cells by the chemical alone. These studies were preformed using the forward mutation assay at the thymidine kinase locus in L518Y mouse leukemic cells. The pulsed wave RFR was broadcast from an antenna horn at a frequency of 2.45 GHz. The conclusions from five different experiments, employing three different concentrations of MMC, were that (a) RFR exposure alone, at moderate power levels which resulted in a temperature increase in the cell culture medium of less than 3{degree}C, is not mutagenic; and (b) when cells are simultaneously treated with MMC and RFR at these same moderate power levels, the RFR does not affect either the inhibition of cell growth or the extent of mutagenesis resulting from the treatment with the chemical MMC alone.

  3. Isolation and characterization of Chinese hamster ovary cell lines sensitive to mitomycin C and bleomycin

    SciTech Connect

    Robson, C.N.; Harris, A.L.; Hickson, I.D.

    1985-11-01

    Seven Chinese hamster ovary K1 cell lines exhibiting sensitivity to anticancer drugs have been isolated by a replica-plating technique. Five of the mutants are hypersensitive to the DNA cross-linking agent mitomycin C. Of these, one is also appreciably sensitive to UV light. Significant variations in their cross-sensitivity to cis-platinum(II) diammine dichloride, chlorambucil, and Adriamycin have also been observed. Two additional mutants have been isolated on the basis of sensitivity to the radiomimetic agent bleomycin. One of these shows greater than 6-fold sensitivity to bleomycin, while the other is approximately 14 times more sensitive than the parental strain to bleomycin and is also hypersensitive to a number of other DNA-damaging agents, including cis-platinum(II) diammine dichloride, chlorambucil, X-rays, and UV light. Both bleomycin-sensitive mutants also exhibit some degree of sensitivity to Adriamycin. In all cases, the cell lines have been grown in continuous culture for 3 months without evidence of reversion and should act as suitable recipients in DNA transfection experiments aimed at identifying human DNA repair genes.

  4. Graphene oxide integrated sensor for electrochemical monitoring of mitomycin C-DNA interaction.

    PubMed

    Erdem, Arzum; Muti, Mihrican; Papakonstantinou, Pagona; Canavar, Ece; Karadeniz, Hakan; Congur, Gulsah; Sharma, Surbhi

    2012-05-07

    We present a graphene oxide (GO) integrated disposable electrochemical sensor for the enhanced detection of nucleic acids and the sensitive monitoring of the surface-confined interactions between the anticancer drug mitomycin C (MC) and DNA. Interfacial interactions between immobilized calf thymus double-stranded (dsDNA) and anticancer drug MC were investigated using differential pulse voltammetry (DPV) and electrochemical impedance spectroscopy (EIS) techniques. Based on three repetitive voltammetric measurements of 120 μg mL(-1) DNA immobilized on GO-modified electrodes, the RSD % (n = 3) was calculated as 10.47% and the detection limit (DL) for dsDNA was found to be 9.06 μg mL(-1). EIS studies revealed that the binding of the drug MC to dsDNA leads to a gradual decrease of its negative charge. As a consequence of this interaction, the negative redox species were allowed to approach the electrode, and thus increase the charge transfer kinetics. On the other hand, DPV studies exploited the decrease of the guanine signal due to drug binding as the basis for specifically probing the biointeraction process between MC and dsDNA.

  5. Characterization of a mitomycin-binding drug resistance mechanism from the producing organism, Streptomyces lavendulae.

    PubMed Central

    Sheldon, P J; Johnson, D A; August, P R; Liu, H W; Sherman, D H

    1997-01-01

    In an effort to characterize the diversity of mechanisms involved in cellular self-protection against the antitumor antibiotic mitomycin C (MC), DNA fragments from the producing organism (Streptomyces lavendulae) were introduced into Streptomyces lividans and transformants were selected for resistance to the drug. Subcloning of a 4.0-kb BclI fragment revealed the presence of an MC resistance determinant, mrd. Nucleotide sequence analysis identified an open reading frame consisting of 130 amino acids with a predicted molecular weight of 14,364. Transcriptional analysis revealed that mrd is expressed constitutively, with increased transcription in the presence of MC. Expression of mrd in Escherichia coli resulted in the synthesis of a soluble protein with an Mr of 14,400 that conferred high-level cellular resistance to MC and a series of structurally related natural products. Purified MRD was shown to function as a drug-binding protein that provides protection against cross-linking of DNA by preventing reductive activation of MC. PMID:9045843

  6. Chromosome instability induced in vitro with mitomycin C in five Seckel syndrome patients.

    PubMed

    Bobabilla-Morales, Lucina; Corona-Rivera, Alfredo; Corona-Rivera, J Román; Buenrostro, C; García-Cobián, Teresa A; Corona-Rivera, Enrique; Cantú-Garza, José María; García-Cruz, Diana

    2003-12-01

    Seckel syndrome (SS) is an autosomal recessive entity characterized by proportionate pre- and post-natal growth retardation, microcephaly, typical facial appearance with beak-like protrusion, and severe mental retardation. A heterogeneous basis for SS was proposed since around 25% of SS patients have hematological anomalies, suggesting a subgroup of SS with chromosome instability and hematological disorders. Chromosome instability induced by mitomycin C (MMC) has been observed in previous reports. The purpose of this study is to report cytogenetic features in five patients with SS. The patients had low birth weight (mean 1,870 g), short stature (SD = 6.36), microcephaly (OFC, SD = 8.1), typical facial appearance, and multiple articular dislocations. None of them had anemia at the time of examination. In all cases their parents were healthy and non-consanguineous. Lymphocytes of SS patients and a control group (n = 9) matched by age and sex were cultured with and without MMC, and harvested at 72 and 96 hr. Chromosomal aberrations (chromatid and chromosomal gaps and breaks, deletions, fragments, and exchanges) were scored in 100 metaphases per culture. A statistical increase of chromosomal aberrations was observed in 96 hr MMC cultures in all patients (40.2% vs. 2.8%). Sister chromatid exchanges were also performed with no differences between groups. Clinical and cytogenetic findings support the idea that SS may correspond to a chromosome instability syndrome.

  7. Nedd8-activating enzyme inhibitor MLN4924 provides synergy with mitomycin C through interactions with ATR, BRCA1/BRCA2, and chromatin dynamics pathways.

    PubMed

    Garcia, Khristofer; Blank, Jonathan L; Bouck, David C; Liu, Xiaozhen J; Sappal, Darshan S; Hather, Greg; Cosmopoulos, Katherine; Thomas, Michael P; Kuranda, Mike; Pickard, Michael D; Liu, Ray; Bandi, Syamala; Smith, Peter G; Lightcap, Eric S

    2014-06-01

    MLN4924 is an investigational small-molecule inhibitor of the Nedd8-activating enzyme currently in phase I clinical trials. MLN4924 induces DNA damage via rereplication in most cell lines. This distinct mechanism of DNA damage may affect its ability to combine with standard-of-care agents and may affect the clinical development of MLN4924. As such, we studied its interaction with other DNA-damaging agents. Mitomycin C, cisplatin, cytarabine, UV radiation, SN-38, and gemcitabine demonstrated synergy in combination with MLN4924 in vitro. The combination of mitomycin C and MLN4924 was shown to be synergistic in a mouse xenograft model. Importantly, depletion of genes within the ataxia telangiectasia and Rad3 related (ATR) and BRCA1/BRCA2 pathways, chromatin modification, and transcription-coupled repair reduced the synergy between mitomycin C and MLN4924. In addition, comet assay demonstrated increased DNA strand breaks with the combination of MLN4924 and mitomycin C. Our data suggest that mitomycin C causes stalled replication forks, which when combined with rereplication induced by MLN4924 results in frequent replication fork collisions, leading to cell death. This study provides a straightforward approach to understand the mechanism of synergy, which may provide useful information for the clinical development of these combinations.

  8. Mechanism of Hepatocyte Apoptosis

    PubMed Central

    Cao, Lei; Quan, Xi-Bing; Zeng, Wen-Jiao; Yang, Xiao-Ou; Wang, Ming-Jie

    2016-01-01

    Hepatocyte apoptosis plays important roles in both the removal of external microorganisms and the occurrence and development of liver diseases. Different conditions, such as virus infection, fatty liver disease, hepatic ischemia reperfusion, and drug-induced liver injury, are accompanied by hepatocyte apoptosis. This review summarizes recent research on the mechanism of hepatocyte apoptosis involving the classical extrinsic and intrinsic apoptotic pathways, endoplasmic reticulum stress, and oxidative stress-induced apoptosis. We emphasized the major causes of apoptosis according to the characteristics of different liver diseases. Several concerns regarding future research and clinical application are also raised. PMID:28058033

  9. Corneal melanosis successfully treated using topical mitomycin-C and alcohol corneal epitheliectomy: a 3-year follow-up case report.

    PubMed

    Balcı, Mehmet; Yağcı, Ramazan; Güler, Emre; Haltaş, Hacer; Duman, Rahmi; Hepşen, İbrahim F

    2015-01-01

    We report a case of primary acquired corneal melanosis without atypia associated with corneal haze in a patient with a history of limbal malignant melanoma and the effect of mitomycin-C. A 75-year-old woman with a history of limbal malignant melanoma presented with loss of vision in right eye. Corneal examination showed a patchy melanotic pigmentation with a central haze. Topical mitomycin-C improved visual acuity and corneal haze. However, the pigmented lesions persisted, and they were removed with alcohol corneal epitheliectomy. Histopathological examination demonstrated primary acquired melanosis without atypia. The lesions were successfully removed, and there were no recurrences during the follow-up period of 36 months. The association of conjunctival and corneal melanosis without atypia is a rare condition. In addition, co-existence of central corneal haze and melanosis may decrease visual acuity. Topical mitomycin-C and alcohol corneal epitheliectomy can be useful treatments in this condition.

  10. Current treatment of nasal vestibular stenosis with CO2-laser surgery: prolonged vestibular stenting versus intraoperative mitomycin application. A case series of 3 patients.

    PubMed

    van Schijndel, Olaf; van Heerbeek, Niels; Ingels, Koen J A O

    2014-12-01

    These case studies describe three cases of unilateral nasal vestibular stenoses caused by chemical cauterization. Each case was treated with CO2-laser surgery together with intraoperative topic application of mitomycin or prolonged vestibular stenting for prevention of restenosis. Two patients received intraoperative mitomycin application and one patient received prolonged vestibular stenting. Results were documented using high-resolution photographs. The follow up period ranged from 1 year and 3 months to 4 years and 9 months. All patients improved after CO2-laser surgery. No complications were reported. We consider CO2-laser surgery for relief of nasal vestibular stenosis as a feasible surgical technique for relieve of nasal vestibular stenosis. Prolonged vestibular stenting seems to be an important factor for the prevention of restenosis in which the value of intraoperative mitomycin application without prolonged vestibular stenting remains uncertain.

  11. Pharmacokinetics of mitomycin C in pelvic stopflow infusion and hypoxic pelvic perfusion with and without hemofiltration: a pilot study of patients with recurrent unresectable rectal cancer.

    PubMed

    Guadagni, S; Aigner, K R; Palumbo, G; Cantore, M; Fiorentini, G; Pozone, T; Deraco, M; Clerico, M; Chaudhuri, P K

    1998-10-01

    This pilot study was conducted to evaluate the advantage in drug delivery for regional chemotherapy in patients with unresectable recurrent rectal carcinoma by different methods. For this research, the pharmacokinetic advantages of mitomycin C delivery by four different methods were compared: intraaortic infusion with aortic stopflow; intraaortic infusion with inferior vena cava stopflow; intraaortic infusion with aortic and inferior caval vein stopflow (hypoxic pelvic perfusion); and hypoxic pelvic perfusion with hemofiltration. The results of this study indicate that pelvic stopflow infusion followed by hypoxic pelvic perfusion significantly increases mitomycin C concentrations in the blood coming from the tumor site. Also, use of hemofiltration reduces mitomycin C levels in peripheral blood after high-dose regional chemotherapy. Further investigations involving more patients should be carried out in the future to validate these results.

  12. Effect of mitomycin c and 5-flurouracil adjuvant therapy on the outcomes of Ahmed glaucoma valve implantation.

    PubMed

    Cui, Qi N; Hsia, Yen C; Lin, Shan C; Stamper, Robert L; Rose-Nussbaumer, Jennifer; Mehta, Nitisha; Porco, Travis C; Naseri, Ayman; Han, Ying

    2017-03-01

    To examine the effect of mitomycin c and 5-flurouracil on treatment outcomes following Ahmed glaucoma valve implantation. Retrospective consecutive case series. Fifty patients who received Ahmed glaucoma valve implantation from 1999 to 2013 in the San Francisco Veterans Administration Hospital. The +INJECTION group received intraoperative mitomycin c followed by postoperative mitomycin c and/or 5-flurouracil, whereas the -INJECTION group did not. Primary outcome was treatment success at 1 year post-implantation. Intraocular pressure, hypertensive phase, and the number of glaucoma medications were also examined. Twenty-six patients/eyes in the +INJECTION group and 24 patients/eyes in the -INJECTION group were included. Treatment success was higher in the +INJECTION compared with the -INJECTION group (86 vs. 58%; P = 0.04). Intraocular pressure was lower in the +INJECTION compared with the -INJECTION group at 1, 3, 6 and 12 months (P ≪ 0.00001, P = 0.00003, 0.0008 and 0.024). Hypertensive phase occurred less often in the +INJECTION compared with the -INJECTION group (3.8 vs. 54%; P = 0.021). The +INJECTION group required fewer medications compared with the -INJECTION group (P = 0.02, 0.002, 0.003 and 0.008 at 1, 3, 6 and 12 months). Complication rates were comparable between groups (46.2 and 54.2%; P = 0.63). Adjuvant treatment with antifibrotics following Ahmed glaucoma valve implantation decreased the hypertensive phase and improved surgical outcomes without impacting complication rates at 1 year. This study postulates a role for antifibrotics in the postoperative management of Ahmed glaucoma valves. © 2016 Royal Australian and New Zealand College of Ophthalmologists.

  13. Mitomycin C: new strategies to improve efficacy of a well-known therapy.

    PubMed

    Ragonese, Mauro; Racioppi, Marco; Bassi, Pier Francesco; Di Gianfrancesco, Luca; Lenci, Niccolò; Filianoti, Alessio; Recupero, Salvatore M

    2016-10-04

    Mitomycin C (MMC) as an intravesical chemotherapeutic agent is a well-known option for treatment of nonmuscle invasive bladder cancer (NMIBC) recurrence; it is probably the most commonly used agent given its low rate of side effects and its efficacy.Both the American Urologic Association (AUA) and European Association of Urology (EAU) consider MMC as a standard treatment for immediate single-dose postoperative treatment and for adjuvant therapy in low and intermediate-risk NMIBC.Despite the popularity of this agent in the treatment of NMIBCs, many questions regarding the optimal approach to MMC therapy remain unanswered and the schedule widely used is empirical.Nevertheless, even when the current optimal approaches to MMC administration are used, a large proportion of NMIBCs recur.This apparent treatment resistance might be overcome by an optimization of standard MMC therapy or with a combination of MMC with other agents that have different mechanisms of action.Strategies to enhance passive delivery of MMC have been well studied and multiple measures are recommended for implementation of use in routine clinical practice.A modified scheme of instillation seems to be an easy and inexpensive alternative to increase efficacy of intravesical MMC and to also use this agent with an ablative intent.Enhancing tumor response with a sequential therapy is another option that has been investigated, mostly for chemo-immunotherapy wherein the different mechanisms of action of Bacillus of Calmette and Guerìn (BCG) and MMC are combined to achieve a higher response.

  14. Synthesis of Mitomycin C and Decarbamoylmitomycin C N(2) deoxyguanosine-adducts.

    PubMed

    Champeil, Elise; Cheng, Shu-Yuan; Huang, Bik Tzu; Conchero-Guisan, Marta; Martinez, Thibaut; Paz, Manuel M; Sapse, Anne-Marie

    2016-04-01

    Mitomycin C (MC) and Decarbamoylmitomycin C (DMC) - a derivative of MC lacking the carbamate on C10 - are DNA alkylating agents. Their cytotoxicity is attributed to their ability to generate DNA monoadducts as well as intrastrand and interstrand cross-links (ICLs). The major monoadducts generated by MC and DMC in tumor cells have opposite stereochemistry at carbon one of the guanine-mitosene bond: trans (or alpha) for MC and cis (or beta) for DMC. We hypothesize that local disruptions of DNA structure from trans or cis adducts are responsible for the different biochemical responses produced by MC and DMC. Access to DNA substrates bearing cis and trans MC/DMC lesions is essential to verify this hypothesis. Synthetic oligonucleotides bearing trans lesions can be obtained by bio-mimetic methods. However, this approach does not yield cis adducts. This report presents the first chemical synthesis of a cis mitosene DNA adduct. We also examined the stereopreference exhibited by the two drugs at the mononucleotide level by analyzing the formation of cis and trans adducts in the reaction of deoxyguanosine with MC or DMC using a variety of activation conditions. In addition, we performed Density Functional Theory calculations to evaluate the energies of these reactions. Direct alkylation under autocatalytic or bifunctional conditions yielded preferentially alpha adducts with both MC and DMC. DFT calculations showed that under bifunctional activation, the thermodynamically favored adducts are alpha, trans, for MC and beta, cis, for DMC. This suggests that the duplex DNA structure may stabilize/oriente the activated pro-drugs so that, with DMC, formation of the thermodynamically favored beta products are possible in a cellular environment.

  15. Combined ab externo and ab interno revision of failed filtering blebs with adjunctive mitomycin C.

    PubMed

    Magacho, Leopoldo; Shetty, Rajesh K

    2014-01-01

    To report the results of combined ab externo and ab interno revision with mitomycin C (MMC) of failed filtering blebs in glaucoma patients. Glaucoma patients with a failed trabeculectomy who had undergone internal and external revision with MMC in the last 6 years with at least 12 months of follow-up were considered. All study patients followed the same protocol in the operating room: injection of 0.2 mL of MMC (0.4 mg/mL) 2 cm lateral from the bleb followed by internal revision with an iris spatula and external revision with a 26-G × ½" needle. Success was defined as an intraocular pressure (IOP) ≥6 mm Hg and ≤18 mm Hg with (qualified) or without (absolute) any ocular hypotensive drugs. The study included 25 eyes of 22 glaucoma patients. Mean age was 65.2 ± 10.5 years. Mean follow-up was 26.9 ± 10.3 months. The IOP was reduced from 24.5 ± 6.0 mm Hg preoperatively to 10.0 ± 3.3 mm Hg at the last visit (p<0.001). The number of ocular hypotensive medications was reduced from 1.8 ± 1.0 to 0.2 ± 0.6 (p<0.001). There was no change in visual acuity (0.83 ± 0.75 vs 0.83 ± 0.74, p = 0.7). Three patients developed choroidal detachment, another eye had a transient hypotony with maculopathy, and 2 patients developed cataract. Absolute success was achieved in 80% of eyes, and qualified success in 16% of eyes. Combined ab externo and ab interno revision with MMC can be an effective technique to revitalize failed filtering blebs in glaucoma patients with minimal complications.

  16. Revision of trabeculectomy filtering blebs with mitomycin C: Long term results

    PubMed Central

    Tulidowicz-Bielak, Maria; Kosior-Jarecka, Ewa; Żarnowski, Tomasz

    2016-01-01

    Aim: The aim of the study is to assess the outcomes of transconjunctival mitomycin C (MMC)-augmented revision in eyes with failed trabeculectomy. Materials and Methods: This is a retrospective, noncomparative case series. One hundred and twenty-one eyes of 113 consecutive glaucoma patients with previously failed trabeculectomy who underwent transconjunctival revision with at least 12 months of follow-up were initially included in the study. The success was determined on the basis of intraocular pressure (IOP) alone. The main outcome measures were IOP, best-corrected distance visual acuity, complications, bleb appearance, lens status, visual field progression, and time between primary trabeculectomy and MMC revision. The main purpose of the study was to determine the efficacy of a single MMC-augmented needle revision. Results: Mean follow-up was 2.3 years. Twelve months after revision, IOP had declined from 26.1 ± 8.4 mmHg to 14.1 ± 4.8 mmHg (P < 0.05) and remained 16.0 ± 5.6 mmHg at 24 months, 15.7 ± 5.8 mmHg at 48 months, and 15.2 ± 4.0 mmHg at 60 months. Complete success was achieved in 53% of cases, 84% achieved qualified success, and 16% were classified as failures 12 months after revision. Early complications developed in 45 of the initial 121 eyes (37.2%). Conclusions: Transconjunctival MMC-augmented revision appears to be a safe and useful tool in reducing IOP and re-establishing filtration after trabeculectomy failure. This simple procedure has a high rate of success and helps avoid other surgical interventions which are more destructive for the conjunctiva. PMID:27958205

  17. New Method to Prepare Mitomycin C Loaded PLA-Nanoparticles with High Drug Entrapment Efficiency

    NASA Astrophysics Data System (ADS)

    Hou, Zhenqing; Wei, Heng; Wang, Qian; Sun, Qian; Zhou, Chunxiao; Zhan, Chuanming; Tang, Xiaolong; Zhang, Qiqing

    2009-07-01

    The classical utilized double emulsion solvent diffusion technique for encapsulating water soluble Mitomycin C (MMC) in PLA nanoparticles suffers from low encapsulation efficiency because of the drug rapid partitioning to the external aqueous phase. In this paper, MMC loaded PLA nanoparticles were prepared by a new single emulsion solvent evaporation method, in which soybean phosphatidylcholine (SPC) was employed to improve the liposolubility of MMC by formation of MMC-SPC complex. Four main influential factors based on the results of a single-factor test, namely, PLA molecular weight, ratio of PLA to SPC (wt/wt) and MMC to SPC (wt/wt), volume ratio of oil phase to water phase, were evaluated using an orthogonal design with respect to drug entrapment efficiency. The drug release study was performed in pH 7.2 PBS at 37 °C with drug analysis using UV/vis spectrometer at 365 nm. MMC-PLA particles prepared by classical method were used as comparison. The formulated MMC-SPC-PLA nanoparticles under optimized condition are found to be relatively uniform in size (594 nm) with up to 94.8% of drug entrapment efficiency compared to 6.44 μm of PLA-MMC microparticles with 34.5% of drug entrapment efficiency. The release of MMC shows biphasic with an initial burst effect, followed by a cumulated drug release over 30 days is 50.17% for PLA-MMC-SPC nanoparticles, and 74.1% for PLA-MMC particles. The IR analysis of MMC-SPC complex shows that their high liposolubility may be attributed to some weak physical interaction between MMC and SPC during the formation of the complex. It is concluded that the new method is advantageous in terms of smaller size, lower size distribution, higher encapsulation yield, and longer sustained drug release in comparison to classical method.

  18. Direct injection isocratic high-performance liquid chromatographic analysis of mitomycin C in plasma.

    PubMed

    Song, D; Au, J L

    1996-02-09

    A direct injection high-performance liquid chromatography method is described for the determination of mitomycin C (MMC) in human plasma. The stationary phase consisted of hydrophilic and hydrophobic functional groups covalently bound to silicone-coated silica beads (CAPCELL PAK MF Ph-1, 150x4.6 mm I.D., 5 microns). A mobile phase using 100% water gave a better separation of MMC from endogenous interferences as compared to a mobile phase with 12.5% acetonitrile and 2.5 mM phosphate buffer (pH 6.9). Using water as the eluent (1 ml/min) and UV detection at 365 nm, MMC was found to elute at 5.0 min with a peak width of 0.3 min, whereas endogenous interferences eluted before 3 min. Total assay time per sample was 6 min. Internal standard was not required because the recovery of MMC was nearly complete, about 90% from 20 to 5000 ng/ml. The standard curve was linear from 20 to 5000 ng/ml in plasma, and the intra-and inter-day variation was between 3 to 6%. The lower detection limit was 5 ng/ml with a 25 microliters sample, which represents a two- to four-fold improvement over the 10 ng/ml detection limit by previous methods using liquid-liquid extraction and comparable sample size. The simplicity of this method, i.e., no sample extraction, no internal standard, 100% aqueous mobile phase, isocratic elution and short analysis time (6 min/sample), makes it suitable for large scale routine sample analysis, whereas its small sample volume requirement and high sensitivity are useful for pharmacokinetic studies in small animals where limited sample is available.

  19. [Ocular tissue concentrations and results of filtration surgery after topical use of mitomycin C in rabbits].

    PubMed

    Hara, T; Shirato, S; Suzuki, Y

    1998-07-01

    We measured mitomycin C (MMC) concentrations in rabbit ocular tissues, using high-performance liquid chromatography, after the subconjunctival application of surgical sponges which had absorbed various doses (0.1, 0.2 or 0.4 mg) of MMC and with varying duration of application (1, 3, or 5 minutes). MMC concentrations at the administered site showed a significant correlation with the dose and duration of application. In multiple regression analysis the MMC concentration (microgram/g) in the conjunctiva was -6.73 + 67.4 x dose (mg) + 1.66 x time (minutes) (R-square 0.65); in the sclera, -1.85 + 38.2 x dose + 0.927 x time (R-square 0.63); and in the corena, -0.727 + 8.44 x dose (R-square 0.46). We also compared the results of filtering surgery on rabbits using 0.2 mg MMC intraoperative exposure of 1, 3, 5 minutes or 5-minute application of distilled water (control). The duration of maintained intraocular pressure reduction and filtering bleb was significantly longer in MMC-treated group (1 minute; 15 +/- 7.1, 3 minutes; 27 +/- 14.3, 5 minutes; 29 +/- 18.6 days, mean +/- standard deviation) than in the control group (7 +/- 3.7 days). Among the MMC-treated groups, good results were maintained significantly longer in the 3- or 5-minute application groups than in the 1-minute group. There was no difference between the 3-minute group and the 5-minute group.

  20. Pharmacokinetics of mitomycin C after resection of peritoneal carcinomatosis and intraperitoneal chemohyperthermic perfusion.

    PubMed

    Cerretani, D; Nencini, C; Urso, R; Giorgi, G; Marrelli, D; De Stefano, A; Pinto, E; Cioppa, T; Nastri, G; Roviello, F

    2005-12-01

    Over the last few years surgery on patients with abdominal malignancies has become more aggressive but the majority of patients present locoregional recurrence as peritoneal dissemination. Cytoreductive surgery followed by intraperitoneal chemohyperthermic perfusion (ICHP) has been described for treatment and prevention of locoregional cancer spread from various origins. This paper reports our study of the pharmacokinetics of mitomycin C (MMC) administered by intraperitoneal chemohyperthermic perfusion (ICHP) in patients with peritoneal carcinomatosis. 28 patients received MMC 20 mg/m2 intraperitoneally as a perfusion over 60 min. MMC was determined in perfusate, plasma and urine samples with a UV-HPLC method. A compartmental model was used to fit the drug concentrations in plasma and perfusate. Our results showed a mean maximum plasma concentration (Cmax) of 0.14 +/- 0.086 microg/ml with a peak time (Tmax) of 48..7 +/- 5.61 min. The mean area under the curve (AUC) and terminal half-life (t1/2) were 15.8 +/- 9.8 mg x min/L and 83.7 +/- 31.74 min respectively. Clearance (CL) was estimated by fitting the data by a compartmental model and the mean value was 72 +/- 66 L/h. The percent of the dose absorbed was very variable and ranged between 14 and 57% (mean 37 +/- 14%). The mean percentage of dose recovered unchanged in the urine during 24 hours was 7.21 +/- 3.73%. We conclude that ICHP in patients with peritoneal surface malignancies seems to have clinical value since it gives high peritoneal and tumor MMC concentrations with limited systemic exposure and toxicity.

  1. Synthesis of an oligodeoxyribonucleotide adduct of mitomycin C by the postoligomerization method via a triamino mitosene.

    PubMed

    Champeil, Elise; Paz, Manuel M; Ladwa, Sweta; Clement, Cristina C; Zatorski, Andrzej; Tomasz, Maria

    2008-07-23

    The cancer chemotherapeutic agent mitomycin C (MC) alkylates and cross-links DNA monofunctionally and bifunctionally in vivo and in vitro, forming six major MC-deoxyguanosine adducts of known structures. The synthesis of one of the monoadducts (8) by the postoligomerization method was accomplished both on the nucleoside and oligonucleotide levels, the latter resulting in the site-specific placement of 8 in a 12-mer oligodeoxyribonucleotide 26. This is the first application of this method to the synthesis of a DNA adduct of a complex natural product. Preparation of the requisite selectively protected triaminomitosenes 14 and 24 commenced with removal of the 10-carbamoyl group from MC, followed by reductive conversion to 10-decarbamoyl-2,7-diaminomitosene 10. This substance was transformed to 14 or 24 in several steps. Both were successfully coupled to the 2-fluoro-O(6)-(2-trimethylsilylethyl)deoxyinosine residue of the 12-mer oligonucleotide. The N(2)-phenylacetyl protecting group of 14 after its coupling to the 12-mer oligonucleotide could not be removed by penicillinamidase as expected. Nevertheless, the Teoc protecting group of 24 after coupling to the 12-mer oligonucleotide was removed by treatment with ZnBr2 to give the adducted oligonucleotide 26. However, phenylacetyl group removal was successful on the nucleoside-level synthesis of adduct 8. Proof of the structure of the synthetic nucleoside adduct included HPLC coelution and identical spectral properties with a natural sample, and (1)H NMR. Structure proof of the adducted oligonucleotide 26 was provided by enzymatic digestion to nucleosides and authentic adduct 8, as well as MS and MS/MS analysis.

  2. Repurposing the anticancer drug mitomycin C for the treatment of persistent Acinetobacter baumannii infections.

    PubMed

    Cruz-Muñiz, Martha Yumiko; López-Jacome, Luis Esau; Hernández-Durán, Melissa; Franco-Cendejas, Rafael; Licona-Limón, Paula; Ramos-Balderas, Jose Luis; Martinéz-Vázquez, Mariano; Belmont-Díaz, Javier A; Wood, Thomas K; García-Contreras, Rodolfo

    2017-01-01

    Acinetobacter baumannii is an emergent opportunistic bacterial pathogen responsible for recalcitrant infections owing to its high intrinsic tolerance to most antibiotics; therefore, suitable strategies to treat these infections are needed. One plausible approach is the repurposing of drugs that are already in use. Among them, anticancer drugs may be especially useful due their cytotoxic activities and ample similarities between bacterial infections and growing tumours. In this work, the effectiveness of four anticancer drugs on the growth of A. baumannii ATTC BAA-747 was evaluated, including the antimetabolite 5-fluorouracil and three DNA crosslinkers, namely cisplatin, mitomycin C (MMC) and merphalan. MMC was the most effective drug, having a minimum inhibitory concentration for 50% of growth in Luria-Bertani medium at ca. 7 µg/mL and completely inhibiting growth at 25 µg/mL. Hence, MMC was tested against a panel of 21 clinical isolates, including 18 multidrug-resistant (MDR) isolates, 3 of which were sensitive only to colistin. The minimum inhibitory concentrations and minimum bactericidal concentrations of MMC in all tested strains were found to be similar to those of A. baumannii ATCC BAA-747, and MMC also effectively killed stationary-phase, persister and biofilm cells. Moreover, MMC was able to increase survival of the insect larvae Galleria mellonella against an otherwise lethal A. baumannii infection from 0% to ≥53% for the antibiotic-sensitive A. baumannii ATCC BAA-747 strain and the MDR strains A560 and A578. Therefore, MMC is highly effective at killing the emergent opportunistic pathogen A. baumannii.

  3. XEN Glaucoma Implant with Mitomycin C 1-Year Follow-Up: Result and Complications

    PubMed Central

    Bilgic, Alper; Eltanamly, Rasha

    2017-01-01

    Purpose. To evaluate gel microstent (XEN, Aquesys, Inc) for treatment of primary open angle glaucoma (POAG). Methods. In this prospective interventional study, 13 eyes with POAG underwent XEN implantation with subconjunctival mitomycin-C. Of those eyes, 3 were pseudophakic and 10 underwent simultaneous phacoemulsification and XEN. Patients had uncontrolled IOP, had intolerance to therapy, or had maximal therapy but undergoing cataract extraction. Follow-up visits included IOP, number of medications, vision, and complications and lasted for 1 year. Complete success was defined as IOP reduction ≥20% from preoperative baseline at 1 year without any glaucoma medications while partial success as IOP reduction of ≥20% at 1 year with medications. Results. IOP dropped from 16 ± 4 mmHg pre-op to 9 ± 5, 11 ± 6, 12 ± 5, 12 ± 4, and 12 ± 3 mmHg at 1 week, 1, 3, 6, and 12 months (p = 0.004, 0.026, 0.034, 0.01, and 0.01, Wilcoxon Signed Ranks) consecutively. BCVA (LogMAR) was 0.33 ± 0.34 and improved to 0.13 ± 0.11 at 1 year. Mean number of medications dropped from 1.9 ± 1 preoperatively to 0.3 ± 0.49 (p = 0.003) at 1 year. 42% of eyes achieved complete success and 66% qualified success. Complications included choroidal detachment in 2 eyes, and implant extrusion in 1 eye, and 2 eyes underwent trabeculectomy. Conclusion. XEN implant is an effective surgical treatment for POAG, with significant reduction in IOP and glaucoma medications at 1 year follow-up. PMID:28348884

  4. Mitomycin C-augmented trabeculectomy: subtenon injection versus soaked sponges: a randomised clinical trial.

    PubMed

    Pakravan, Mohammad; Esfandiari, Hamed; Yazdani, Shahin; Douzandeh, Azadeh; Amouhashemi, Nassim; Yaseri, Mehdi; Pakravan, Parto

    2017-09-01

    To compare the efficacy and safety of subtenon injection of mitomycin C (MMC) with that of conventional application of MMC-soaked sponges in trabeculectomy. In this multicentre randomised clinical trial, 80 consecutive open-angle glaucoma cases were randomised into two groups; group 1 received a subtenon injection of 0.1 mL of 0.01% MMC, while group 2 received 0.02% MMC-soaked sponges. Primary outcome measure was intraocular pressure (IOP), and secondary outcome measures were endothelial cell count (ECC) changes and bleb morphology according to the Indiana Bleb Appearance Grading Scale. Outcome measures were compared at 1, 3 and 6 months postoperatively. Complete and qualified success was defined as IOP within 6-15 mm Hg without and with medications at month 6, respectively. Mean preoperative IOP was 21.8±5.1 in group 1, which reduced to 10.3±3.7 mm Hg at final visit (p<0.001). Corresponding values for group 2 were 21.8±5 and 10.8±3.5 mm Hg respectively (p<0.001). Complete success was 82.5% in both groups, and qualified success was 0 and 2.5% in groups 1 and 2, respectively. (p=0.316) The blebs tended to be more diffuse, less vascularised and shallower in group 1, at month 6 (p=0.45,<0.001 and <0.007 respectively). ECCs did not change significantly at final visit (p=0.813). Subtenon injection of MMC is a safe and effective alternative to the conventional soaked sponge method. This method produces more favourable bleb morphology after trabeculectomy. NCT02385370, Post-results. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/.

  5. Mitomycin C Pharmacokinetics as Predictor of Severe Neutropenia in Hyperthermic Intraperitoneal Therapy.

    PubMed

    Kemmel, Véronique; Mercoli, Henri-Alexis; Meyer, Nicolas; Brumaru, Daniel; Romain, Benoit; Lessinger, Jean-Marc; Brigand, Cécile

    2015-12-01

    Cytoreductive surgery (CRS) combined with hyperthermic intraperitoneal chemotherapy (HIPEC) is an approach to overcome peritoneal carcinomatosis from colorectal adenocarcinoma. Mitomycin C (MMC) is frequently used but not devoid of toxicity, of which the most common and feared is neutropenia. Our study explores the clinical and surgical risk factors of neutropenia and a possible link between MMC pharmacokinetics and neutropenia as HIPEC's supervention. A total of 45 patients undergoing CRS-HIPEC for peritoneal carcinomatosis of colorectal origin between 2004 and 2010 were followed. For each patient, MMC was measured in plasma at different times during HIPEC and the area under the MMC concentration-time curve (MMC-AUC) was calculated. The incidence of neutropenia was 40 %. No demographic, clinical, or surgical factors increased the risk of neutropenia. However, we found that the occurrence of neutropenia and its gravity increased in direct correlation with an increase in MMC plasma concentration 30 min (T30) and 45 min (T45) after the start of HIPEC. The same correlation was observed between the MMC-AUC and the risk of neutropenia. Neutropenia is a frequent complication associated with MMC-HIPEC. The results of our study indicate the feasibility and the potential benefit of a protocol including the MMC dosage at T30 after the start of HIPEC. A threshold of 572 µg/L gives a predictive sensitivity of 86 % and a specificity of 80 %. These results must be considered in the management of patients undergoing MMC-HIPEC in order to place high-risk patients under neutropenic monitoring while the other patients can undergo simple hematological monitoring.

  6. New drug delivery system for corneal administration of mitomycin-C.

    PubMed

    Pinheiro, Francisco Irochima; Araújo-Filho, Irami; Meneses do Rego, Amalia Cinthia; Pereira de Azevedo, Eduardo; Tabosa do Egito, Eryvaldo Socrates; Oréfice, Fernando; Alves de Souza Lima Filho, Acácio

    2016-08-01

    To develop a new corneal release system to deliver optimum amounts of mitomycin-C (MMC) during the perioperative period of photorefractive keratectomy (PRK). Ophthalmos S/A, São Paulo, Brazil. Experimental study. An in vitro experimental design was developed for studying a new MMC delivery system at a drug concentration of 0.02%. Whatman sterile filter paper disks with a diameter of 8.0 mm were impregnated with MMC solution. After drying, the disks were placed on agar plates seeded with Staphylococcus epidermidis; this was followed by instillation of a drop of sterile water. After 1 minute, the disks were removed and the plates were incubated for 48 hours at 35°C. The mean volume of the drops delivered from regular eyedrop bottles was determined, and the inhibition zone (in millimeters) was correlated with the amount of MMC loaded onto the disks. Analysis of the inhibition zones produced by MMC indicated that 16 μg was the optimum dose to be incorporated in the disks. The mean volume of a drop delivered from eyedrop bottles was 37.7 μL. One minute after the application of a single drop of a balanced salt solution, the system released an adequate concentration of MMC for PRK. A new delivery system for MMC was successfully developed for application during photorefractive keratectomy. Dr. de Souza Lima Filho is the managing director of Ophtalmos S/A. Drs. de Souza Lima Filho, Irochima Pinheiro, and Oréfice have exclusive rights to intellectual property of this invention secured by a patent application filed with the Instituto Nacional da Propriedade Industrial. Copyright © 2016 ASCRS and ESCRS. Published by Elsevier Inc. All rights reserved.

  7. Two-step versus Single Application of Mitomycin-C in Photorefractive Keratectomy for High Myopia.

    PubMed

    Fazel, Farhad; Roshani, Leila; Rezaei, Leila

    2012-01-01

    To evaluate the long-term outcomes of two-step versus single application of mitomycin-C (MMC) during photorefractive keratectomy (PRK) for high myopia. This randomized clinical trial included consecutive patients with high myopia (exceeding 7 D). Patients underwent PRK and were randomized to two methods of MMC 0.02% application as follows: in the single application group, MMC was applied for 45 seconds followed by irrigation; in the two-step group MMC was used identically followed by repeat application for another 15 seconds and corneal surface irrigation. Visual acuity, refractive error, pachymetry, topography, corneal haze and complications were compared between the two groups 18 months after surgery. One hundred and forty patients (70 subjects in either study arm) underwent PRK according to the study protocol. Mean spherical equivalent refractive error was significantly reduced from baseline to -1.16±0.39 D in the single application group and to -1.07±0.39 D in the two-step group. Sixteen (11.5%) versus 8 (5.7%) eyes lost one or more line(s) of best corrected visual acuity in the single application group as compared to the two-step group (P=0.05). Corneal haze was observed in 18 (12.9%) and 8 (5.7%) eyes in the single application versus two-step group, respectively (P=0.04). Grade 3 corneal haze was not observed in the two-step group but occurred in five eyes (3.6%) in the single application group (P=0.03). No eyes developed corneal ectasia during the follow-up period. Two-step intraoperative application of MMC 0.02% in highly myopic eyes undergoing PRK can reduce the frequency and severity of haze formation.

  8. Mitomycin-C- or Cisplatin-Based Chemoradiotherapy for Anal Canal Carcinoma: Long-Term Results

    SciTech Connect

    Olivatto, Luis O.; Cabral, Vania; Rosa, Arthur; Bezerra, Marcos; Santarem, Erick; Fassizoli, Ana; Castro, Leonaldson; Simoes, Jose Humberto; Small, Isabele A.; Ferreira, Carlos Gil

    2011-02-01

    Purpose: To evaluate the long-term efficacy of concurrent radiotherapy with mitomycin-C (MMC)-based or cisplatin (CP)-based combinations in a cohort of patients with locally advanced anal canal carcinoma. Methods and Materials: Between 1988 and 2000, 179 patients with locally advanced anal canal carcinoma were treated at the Instituto Nacional de Cancer with two cycles of chemotherapy during Weeks 1 and 5 of radiotherapy. 5-Fluorouracil (750 mg/m{sup 2} 120-hour infusion or 1,000 mg/m{sup 2} 96-hour infusion) plus CP (100 mg/m{sup 2}) on the first day of each cycle or MMC (10-15 mg/m{sup 2}) on the first day of Cycle 1 was administered concurrent with radiotherapy (total dose, 55-59.4 Gy). Of the 179 patients, 60% were included from a randomized trial initiated at the Instituto Nacional de Cancer in 1991 that compared concurrent chemoradiotherapy with MMC vs. CP. Results: The median follow-up for the whole chemoradiotherapy group was 83 months. The median patient age was 58 years, 57% had Stage T3-T4 tumors, and 35% had N-positive disease. The 5-year cumulative colostomy rate was not significantly different between the CP group (22%) and MMC group (29%; p = .28). The actuarial 10-year overall survival and disease-free survival rate for the CP group was 54% and 49% and for the MMC group was 52% and 53%, respectively (p = .32 and p = .92, respectively). On multivariate analysis, male gender (p = .042) and advanced Stage T3-T4 disease (p <.0001) were statistically significant for worse disease-free survival. Stage T3-T4 (p = .039) and N+ (p = .039) disease remained independently significant for overall survival. Conclusion: Long-term follow-up has confirmed the good results of chemoradiotherapy with CP plus 5-fluorouracil, which seem to provide results equivalent to those with MMC plus 5-fluorouracil.

  9. The exposure of cancer cells to hyperthermia, iron oxide nanoparticles, and mitomycin C influences membrane multidrug resistance protein expression levels

    PubMed Central

    Franke, Karolin; Kettering, Melanie; Lange, Kathleen; Kaiser, Werner A; Hilger, Ingrid

    2013-01-01

    Purpose The presence of multidrug resistance-associated protein (MRP) in cancer cells is known to be responsible for many therapeutic failures in current oncological treatments. Here, we show that the combination of different effectors like hyperthermia, iron oxide nanoparticles, and chemotherapeutics influences expression of MRP 1 and 3 in an adenocarcinoma cell line. Methods BT-474 cells were treated with magnetic nanoparticles (MNP; 1.5 to 150 μg Fe/cm2) or mitomycin C (up to 1.5 μg/cm2, 24 hours) in the presence or absence of hyperthermia (43°C, 15 to 120 minutes). Moreover, cells were also sequentially exposed to these effectors (MNP, hyperthermia, and mitomycin C). After cell harvesting, mRNA was extracted and analyzed via reverse transcription polymerase chain reaction. Additionally, membrane protein was isolated and analyzed via sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) and immunoblotting. Results When cells were exposed to the effectors alone or to combinations thereof, no effects on MRP 1 and 3 mRNA expression were observed. In contrast, membrane protein expression was influenced in a selective manner. The effects on MRP 3 expression were less pronounced compared with MRP 1. Treatment with mitomycin C decreased MRP expression at high concentrations and hyperthermia intensified these effects. In contrast, the presence of MNP only increased MRP 1 and 3 expression, and hyperthermia reversed these effects. When combining hyperthermia, magnetic nanoparticles, and mitomycin C, no further suppression of MRP expression was observed in comparison with the respective dual treatment modalities. Discussion The different MRP 1 and 3 expression levels are not associated with de novo mRNA expression, but rather with an altered translocation of MRP 1 and 3 to the cell membrane as a result of reactive oxygen species production, and with shifting of intracellular MRP storage pools, changes in membrane fluidity, etc, at the protein level. Our

  10. Recurrent verrucous carcinoma of the urinary bladder after transurethral resection followed by intravesical mitomycin, and a review of the literature.

    PubMed

    Hassan, Masroor; Qureshi, Asim; Nasir, Humaira

    2016-06-15

    Verrucous carcinoma (VC) is a locally invasive, non-metastasising well differentiated variant of squamous cell carcinoma. It is very rare in the urinary bladder and mostly associated with schistosomiasis. It has a characteristic multilobular appearance with small surface projections on contrast cystogram. Owing to its bland cytology, it is a challenging diagnosis. We report a case of VC of the bladder-unrelated to schistosomiasis and involving the prostate-that recurred after transurethral resection of the tumour and prostate followed by six doses of intravesical mitomycin. To the best of our knowledge, no such case has been reported from Pakistan. 2016 BMJ Publishing Group Ltd.

  11. Sister chromatid exchange induced by short-lived monoadducts produced by the bifunctional agents mitomycin C and 8-methoxypsoralen. [CHO cells

    SciTech Connect

    Linnainmaa, K.; Wolff, S.

    1982-01-01

    To see if DNA crosslinks are involved in the induction of sister chromated exchange (SCE), Chinese hamster ovary cells were exposed to two bifunctional alkylating agents,mitomycin C and 8-methoxypsoralen, and their monofunctional derivatives, decarbamoyl mitomycin C and angelicin. The data indicates that monoadducts, rather than crosslinks, are responsible for SCE formation. Furthermore, all agents but angelicin produced short-lived lesions that led to SCEs in the first period of DNA replication after treatment (twin SCEs). In contrast, angelicin, like methyl methanesulfonate and N-acetoxyacetylaminofluorene, produced lesions that lasted more than one cycle, indicating that several different types of DNA lesions are capable of SCE induction.

  12. [Apoptosis in allergic disease].

    PubMed

    Rojas Ramos, E; Martínez Jiménez, N E; Martínez Aguilar, N E; Garfias Becerra, J

    2000-01-01

    Apoptosis (cell programmed death) it is a mechanism that implicate a physiological suicide, to keep the cellular homeostasis in big amount of tissues. Fas (APO-1; CD95) system is one of the most important cellular responsible via to induce apoptosis on different tissues. Eosinophillia on peripheral blood and tissues are the main characteristics on allergic like asthma. Eosinophil apoptosis is upper regulated in those diseases by IL-5 y GM-CSF. Corticoids, teophyllin and some macrolids have been used like apoptosis inductors on eosinophills, these could be a novel mechanism to promote a better solution on inflammatory allergic diseases.

  13. Effect of mitomycin C on the tensile properties of the upper lacrimal canaliculi in a rabbit model.

    PubMed

    Lee, Jeong Kyu; Lee, Moo Yeol; Kim, Mi Kyung; Moon, Nam Ju

    2012-09-01

    The upper lacrimal canaliculus consists of a tubular structure, and the tensile properties which in lacrimal tissues might contribute to structural integrity and tear drainage. We evaluated the characteristics of the tensile properties of the upper lacrimal canaliculi and the clinical implications of using a mitomycin C (MMC)-treated rabbit model. Mitomycin C (0.04%) was applied to the punctum of rabbits for 5 min, and the upper lacrimal tissues including the punctum were excised and attached to a forced transducer to record the tensile properties in a resting state 1 month later. The recording showed continuing decrement of basal tension with time in the lacrimal tissues treated with MMC in contrast with normal controls which maintained initial tension throughout the experiment. The rabbits were then randomly divided into the following 3 groups: vertical punctal incision with the MMC application group; vertical punctal incision with a balanced salt solution application group; and a balanced salt solution application only group. Four weeks after surgery, the puncta of rabbits treated with an incision and MMC application were more dilated clinically and showed less elasticity as compared with the other groups. Histological staining revealed that MMC treatment combined with incision decreased the amount of collagen and elastin fibers in the canaliculi. These results suggest that lacrimal canaliculi of rabbits have rheological basal tension and elasticity, which can be decreased by the use of MMC treatment.

  14. Palliative hepatic intraarterial chemotherapy (HIC) using a novel combination of gemcitabine and mitomycin C: results in hepatic metastases.

    PubMed

    Vogl, Thomas J; Zangos, Stephan; Eichler, Katrin; Selby, J Bayne; Bauer, Ralf W

    2008-03-01

    To evaluate repeated hepatic intraarterial chemotherapy (HIC) as a palliative treatment option for unresectable cholangiocarcinoma and liver metastases of various origins that were progressive under systemic chemotherapy. Between 2002 and 2006, 55 patients were treated in 4-week intervals (mean five sessions). Combined gemcitabine/mitomycin was administered intraarterially within 1 h. Tumor response was evaluated after the third session according to RECIST. Treated tumor entities were colorectal carcinoma (CRC) (n = 12), breast cancer (BC) (n = 12), cholangiocarcinoma (CCC) (n = 10), pancreatic (n = 4), ovarian (n = 3), gastric, cervical, papillary (each n = 2), prostate, esophageal carcinoma, leiomyosarcoma (each n = 1), cancer of unknown primacy (CUP) (n = 5). All patients tolerated the treatment well without any major side effects or complications. In total, there were 1 complete response (CR), 19 partial responses (PR), 19 stable (SD) and 16 progressive diseases (PD). We observed 5 PR, 3 SD and 4 PD in CRC; 1 CR, 4 PR, 6 SD in BC; and 2 PR, 2 SD and 6 PD in CCC. Median survival after first HIC was 9.7 months for CRC, 11.4 months for BC and 6.0 months for CCC. HIC with gemcitabine/mitomycin is a safe, minimally invasive, palliative treatment for hepatic metastases that are progressive under systemic chemotherapy. The treatment yields respectable tumor control rates in CRC and BC patients.

  15. An Alzheimer Disease-linked Rare Mutation Potentiates Netrin Receptor Uncoordinated-5C-induced Signaling That Merges with Amyloid β Precursor Protein Signaling.

    PubMed

    Hashimoto, Yuichi; Toyama, Yuka; Kusakari, Shinya; Nawa, Mikiro; Matsuoka, Masaaki

    2016-06-03

    A missense mutation (T835M) in the uncoordinated-5C (UNC5C) netrin receptor gene increases the risk of late-onset Alzheimer disease (AD) and also the vulnerability of neurons harboring the mutation to various insults. The molecular mechanisms underlying T835M-UNC5C-induced death remain to be elucidated. In this study, we show that overexpression of wild-type UNC5C causes low-grade death, which is intensified by an AD-linked mutation T835M. An AD-linked survival factor, calmodulin-like skin protein (CLSP), and a natural ligand of UNC5C, netrin1, inhibit this death. T835M-UNC5C-induced neuronal cell death is mediated by an intracellular death-signaling cascade, consisting of death-associated protein kinase 1/protein kinase D/apoptosis signal-regulating kinase 1 (ASK1)/JNK/NADPH oxidase/caspases, which merges at ASK1 with a death-signaling cascade, mediated by amyloid β precursor protein (APP). Notably, netrin1 also binds to APP and partially inhibits the death-signaling cascade, induced by APP. These results may provide new insight into the amyloid β-independent pathomechanism of AD. © 2016 by The American Society for Biochemistry and Molecular Biology, Inc.

  16. Topical Mitomycin-C versus Subconjunctival 5-Fluorouracil for Management of Bleb Failure

    PubMed Central

    Pakravan, Mohammad; Miraftabi, Arezoo; yazdani, Shahin; Koohestani, Nasim; yaseri, Mehdi

    2011-01-01

    Purpose To compare the efficacy and safety of topical mitomycin-C (MMC) drops with that of subconjunctival 5-fluorouracil (5-FU) injections for management of early bleb failure after trabeculectomy or combined phacoemulsification and trabeculectomy with posterior chamber intraocular lens implantation (PT+PCIOL). Methods In a randomized comparative study, 37 eyes of 37 patients with impending early bleb failure received MMC 0.02% eye drops for 2 or 4 weeks (19 eyes) or subconjunctival 5-FU injections, 5 mg per dose (18 eyes). Complete success was defined as 5 < IOP ≤ 18 mmHg without medications. Results Baseline characteristics were comparable between the study groups. However, there were more cases of combined PT+PCIOL in the MMC group [11 (57.9%) eyes versus 3 (16.7%) eyes, P = 0.017]. Mean preoperative IOP was 20.5±8.85 mmHg in the MMC group and 25.82±11.35 mmHg in the 5-FU group (P = 0.129), which was decreased to 13.2±6.1 and 10.6±4.8 mmHg respectively after 12 months (P = 0.159). There was no significant difference between the study groups in terms of bleb extent (P = 0.170), height (P = 0.178) or vascularity (P = 0.366). At the end of the study, complete success was achieved in 13 eyes (68.4%) in the MMC group and 14 eyes (77.8%) in the 5-FU group (P = 0.714). The survival of success at 8 months (median follow-up) was 89.5% and 86.5% in the MMC and 5-FU groups respectively; the number of glaucoma medications (P = 0.707) and best-corrected visual acuity (P = 0.550) were also comparable. Complication rates were similar in the study groups (P = 0.140). Conclusion Topical MMC 0.02% has comparable safety and efficacy to subconjunctival 5-FU injections for management of early bleb failure. Topical MMC 0.02% drops are more convenient and can be initiated first, while 5-FU injections may be reserved for eyes with an insufficient response to topical MMC. PMID:22454715

  17. Effect of pH on DNA alkylation by enzyme-activated mitomycin C and porfiromycin.

    PubMed

    Yu, F; Pan, S S

    1993-06-01

    DNA adduct formation by enzyme-activated antibiotics, mitomycin C (MMC) or porfiromycin (PFM), at pH 7.6 or pH 6.0 under anaerobic conditions was analyzed by a 32P-postlabeling method. Antibiotic activation by rat liver NADPH-cytochrome P-450 reductase (EC 1.6.2.4) and bovine milk xanthine oxidase (EC 1.2.3.2) produced similar results. Five 32P-labeled MMC adducts were separated by thin layer chromatography and high performance liquid chromatography from DNA alkylated at either pH. Four of the radioactive spots separated by thin layer chromatography were identified as two monofunctional monoadducts [1" alpha and 1" beta forms of N2-(2" beta,7"-diaminomitosen-1"-yl)-2'-deoxyguanylic acid], one bifunctional monoadduct [N2-(10"-decarbamoyl-2",7"-diaminomitosen-1" alpha-yl)-2'-deoxyguanylic acid], and one cross-linked adduct [N2-(2" beta,7"-diamino-10"-deoxyguanyl-N2-yl-mitosen- 1" alpha-yl)-2'-deoxyguanylic acid]. One minor radioactive spot was not identified. By comparing DNA alkylated at the two pH values, based on equal amounts of 32P radioactivity, similar amounts of cross-links were detected. However, the DNA showed different ratios of the alpha and beta isomers of the monofunctional monoadduct. Furthermore, the DNA alkylated at pH 6.0 showed more bifunctional monoadducts than did the DNA alkylated at pH 7.6. Analysis of alkylated DNA by enzyme-activated PFM showed a similar spectrum of DNA adduct formation. The effect of pH on the distribution of the five PFM-DNA adducts was similar to that observed for the five MMC-DNA adducts. The distribution of adducts in DNA alkylated at the same pH was similar irrespective of which enzyme activated MMC or PFM. The pH of the reaction during DNA and MMC interaction was the determining factor for the quantitative distribution of the adducts. This pH effect may be important for the cytotoxicity of MMC and PFM in tumor cells that have high levels of reductive enzymes with low optimal pH values.

  18. The Effect of Adjuvant Intracameral Triamcinolone Acetonide on the Surgical Results of Trabeculectomy with Mitomycin C

    PubMed Central

    Alagöz, Neşe; Alagöz, Cengiz; Yıldırım, Yusuf; Yeşilkaya, Ceren; Altan, Çiğdem; Bozkurt, Ercüment; Şatana, Banu; Başarır, Berna; Taşkapılı, Muhittin

    2016-01-01

    Objectives: To evaluate the effect of adjuvant intracameral triamcinolone acetonide (TA) on the surgical results of trabeculectomy with mitomycin C. Materials and Methods: All consecutive trabeculectomy cases performed in the glaucoma clinic between July 2012 and December 2013 were retrospectively reviewed from the patient charts. Only those with follow-up of 12 months or longer were included. Patients with intraoperative intracameral TA (study group, n=19) were compared to those without TA (control group, n=21) in terms of surgical success, intraocular pressure (IOP) change, medication use and complications. Results: Forty eyes of 31 patients (21 male/10 female, mean age 64.2±13.8 years) were included in the study. The mean follow-up period was 20.9±5.1 months and 20.7±6.7 months in the study and control groups, respectively (p=0.830). Baseline IOP was 26.4±9.9 and 25.2±7.6 mmHg (p=0.979), and final IOP was 12.7±2.6 and 13.6±3 mmHg in both groups respectively (p=0.226). At the final follow-up, complete success was observed in 68.4% and 52.4% of the study and control groups (p=0.349) and anti-glaucoma medication was used by 31.6% (mean number of medications: 0.79±1.2) and 47.6% (mean number of medications: 1.33±1.7), respectively (p>0.05). Bleb encapsulation, leakage, suture-lysis and hypotony rates were similar in both groups (for all, p>0.05). Cataract progression was noted in six (35.3%) and in five (26.3%) of the phakic eyes in the study and control groups, respectively (p=0.720). Conclusion: When used intracamerally, TA did not increase the complication rate in trabeculectomy surgery. Although the group that received TA showed lower IOP levels, use of fewer medications and fewer eyes requiring medication, the differences did not reach significance. PMID:28058152

  19. Effect of hyperthermia on the apoptosis and proliferation of CaSki cells.

    PubMed

    Zhou, Jumei; Wang, Xiaowen; Du, Lehui; Zhao, Linyun; Lei, Fenglin; Ouyang, Weiwei; Zhang, Yingying; Liao, Yuping; Tang, Jintian

    2011-01-01

    Hyperthermia is a promising treatment for human cervical cancer. However, little is known about whether and under what conditions heat treatment exerts tumor inhibition effects on cervical cancer, and the molecular mechanisms behind these cellular responses have yet to be elucidated. We employed the human cervical cancer cell line CaSki as a cellular model and examined the effect of cell apoptosis and proliferation under gradient thermal conditions (43, 45 and 47˚C for 40 min). Heat treatment was found to induce CaSki cell apoptosis and necrosis. Cell cycle analysis showed that cells were arrested in S phase upon the application of hyperthermia, and MTT analysis revealed that cell viability was also reduced. Of the thermal conditions, 45˚C exhibited the best induction of apoptosis, while 47˚C induced direct fierce necrosis. This was further demonstrated by examining the expression level of several key apoptosis-related genes: caspase-3, Smac and Survivin. During apoptosis, caspase-3 and Smac levels were up-regulated, whereas anti-apoptotic Survivin was down-regulated, enhancing programmed cell death. Our results reveal that heating at ≥45˚C induced cell apoptosis and necrosis, and inhibited cell proliferation at both the cellular and molecular levels. These findings support the use of hyperthermia in a clinical setting for the treatment of human cervical cancer.

  20. Reaction of reductively activated mitomycin C with aqueous bicarbonate: Isolation and characterization of an oxazolidinone derivative of cis-1-hydroxy-2,7-diaminomitosene.

    PubMed

    Paz, Manuel M

    2010-01-01

    The reductive activation of mitomycin C in aqueous bicarbonate buffer resulted in the formation of a previously unknown compound, characterized as an oxazolidinone derivative of cis-1-hydroxy-2,7-diaminomitosene. This compound is the result of a cyclization reaction of bicarbonate with the aziridine ring of aziridinomitosene, and was observed at bicarbonate concentrations close to those present in physiological plasma.

  1. Enhanced healing of mitomycin C-treated healing-impaired wounds in rats with hydrosheets composed of chitin/chitosan, fucoidan, and alginate as wound dressings.

    PubMed

    Murakami, Kaoru; Ishihara, Masayuki; Aoki, Hiroshi; Nakamura, Shingo; Nakamura, Shin-Ichiro; Yanagibayashi, Satoshi; Takikawa, Megumi; Kishimoto, Satoko; Yokoe, Hidetaka; Kiyosawa, Tomoharu; Sato, Yasunori

    2010-01-01

    To create a moist environment for rapid wound healing, a hydrosheet composed of alginate, chitin/chitosan, and fucoidan (ACF-HS) has been developed as a functional wound dressing. The aim of this study was to evaluate the accelerating effect of ACF-HS on wound healing for rat mitomycin C-treated healing-impaired wounds. Full-thickness skin defects were made on the back of rats and mitomycin C was applied onto the wound for 10 minutes to prepare a healing-impaired wound. After thoroughly washing out the mitomycin C, ACF-HS was applied to the healing-impaired wounds. The rats were later euthanized and histological sections of the wounds were prepared. The histological examinations showed significantly advanced granulation tissue and capillary formations in the healing-impaired wounds treated with ACF-HS on days 7 and 14, in comparison with that in alginate fiber (Kaltostat), hydrogel wound dressing (DuoACTIVE), and nontreatment (negative control). Furthermore, in cell culture studies, ACF-HS-absorbed serum and fibroblast growth factor-2 was found to be proliferative for fibroblasts and endothelial cells, respectively, and ACF-HS-absorbed serum was found to be chemoattractive for fibroblasts. However, our results may not be strictly comparable with general healing-impaired wound models in humans because of the cell damage by mitomycin C. In addition, more biocompatibility studies of fucoidan are essential due to the possibility of renal toxicity.

  2. Evaluation of bioreductive activation of anticancer drugs idarubicin and mitomycin C by NADH-cytochrome b5 reductase and cytochrome P450 2B4.

    PubMed

    Celik, Haydar; Arinç, Emel

    2013-03-01

    This study attempted to investigate the ability of microsomal NADH-cytochrome b5 reductase and cytochrome P450 2B4 to reductively activate idarubicin and mitomycin C. In vitro plasmid DNA damage experiments and assays using purified hepatic enzymes were employed to examine their respective roles in the metabolic activation of anticancer drugs. Mitomycin C was found to be not a good substrate for microsomal b5 reductase unlike P450 reductase. It produced low amounts of strand breaks in DNA when incubated with b5 reductase and its one-electron reduction by purified enzyme was found as negligible. Our findings revealed that P450 reductase-mediated metabolism of idarubicin resulted in a large increase in single-strand DNA breaks, whereas, b5 reductase neither catalyzed the reduction of idarubicin nor mediated the formation of DNA damage in the presence of idarubicin. The reconstitution studies, on the other hand, have identified rabbit liver CYP2B4 isozyme as being a potential candidate enzyme for reductive bioactivation of idarubicin and mitomycin C. Thus, the present novel findings strongly suggest that while b5 reductase could not play a key role in the cytotoxic and/or antitumor effects of idarubicin and mitomycin C, CYP2B4 could potentiate their activity in combination with P450 reductase.

  3. Apoptosis and cancer mechanisms.

    PubMed

    Pan, H; Yin, C; Van Dyke, T

    1997-01-01

    For nearly two decades, studies in the cancer research field focussed on identifying genes that act as positive and negative regulators of cell growth. Only relatively recently was it recognized that the regulation of cell death (apoptosis) is also an important modulator of tumorigenesis. At least two genes linked to human cancers, BCL2 and TP53, have been shown to regulate apoptosis. The correlation between apoptosis modulating genes and human tumours raises an important question as to how dysregulation of apoptosis contributes to neoplastic transformation and malignant cell growth. Cell culture studies have clearly demonstrated that TP53 can induce and BCL2 can suppress apoptosis in response to various stimuli. Studies of mammalian viruses, which possess mechanisms for both inducing and evading apoptosis, have also extended our understanding of this process. On the basis of such findings, several animal models have been developed which begin to address the role of apoptosis regulation in tumorigenesis. This chapter discusses those animal models, focussing on bcl-2 (and its relatives) and p53.

  4. Lysosomes in apoptosis.

    PubMed

    Ivanova, Saska; Repnik, Urska; Bojic, Lea; Petelin, Ana; Turk, Vito; Turk, Boris

    2008-01-01

    Lysosomes are specialized organelles for protein recycling and as such are involved in the terminal steps of autophagy. However, it has become evident that lysosomes also play an important role in the progression of apoptosis. This latter function seems to be dependent on lysosomal proteases, which need to be released into the cytosol for apoptosis to be efficient. Among the lysosomal proteases, the most abundant are the cysteine cathepsins and the aspartic protease cathepsin D, which seem to be the major apoptosis mediators. This chapter reviews the methods used to study lysosomes and lysosomal proteases.

  5. Platelet-derived growth factor-C (PDGF-C) induces anti-apoptotic effects on macrophages through Akt and Bad phosphorylation.

    PubMed

    Son, Dain; Na, Yi Rang; Hwang, Eung-Soo; Seok, Seung Hyeok

    2014-02-28

    PDGF-C, which is abundant in the malignant breast tumor microenvironment, plays an important role in cell growth and survival. Because tumor-associated macrophages (TAMs) contribute to cancer malignancy, macrophage survival mechanisms are an attractive area of research into controlling tumor progression. In this study, we investigated PDGF-C-mediated signaling pathways involved in anti-apoptotic effects in macrophages. We found that the human malignant breast cancer cell line MDA-MB-231 produced high quantities of PDGF-C, whereas benign MCF-7 cells did not. Recombinant PDGF-C induced PDGF receptor α chain phosphorylation, followed by Akt and Bad phosphorylation in THP-1-derived macrophages. MDA-MB-231 culture supernatants also activated macrophage PDGF-Rα. PDGF-C prevented staurosporine-induced macrophage apoptosis by inhibiting the activation of caspase-3, -7, -8, and -9 and cleavage of poly(ADP-ribose) polymerase. Finally, TAMs isolated from the PDGF-C knockdown murine breast cancer cell line 4T1 and PDGF-C knockdown MDA-MB-231-derived tumor mass showed higher rates of apoptosis than the respective WT controls. Collectively, our results suggest that tumor cell-derived PDGF-C enhances TAM survival, promoting tumor malignancy.

  6. Cytostatic action of aspirin and its effect on mitomycin C activity. A study in vitro under irradiation

    NASA Astrophysics Data System (ADS)

    Kammerer, Cornelia; Getoff, Nikola

    2001-04-01

    Experiments in vitro using E. coli bacteria (AB 1157) proved that aspirin possesses a cytostatic ability under various experimental condition (pH=7.4) in airfree, aerated as well as in media containing N 2O (converting e aq- into OH- radicals). In the last case the highest effect of aspirin was observed. The combination of aspirin with the well-known cytostaticum, mitomycin C (MMC) leads in airfree as well as in aerated media to a significant decrease of the MMC activity. However, the mixture of aspirin and MMC in the presence of N 2O causes a synergistic effect, resulting in an enhancement of the MMC activity by a factor of 1.5. Probable reaction steps are presented and discussed. Using the pulse radiolysis method the rate constants for the reactions of e aq-, H and OH- species with aspirin were also determined.

  7. LC-ESI-MSD fast determination of residual mitomycin C in hen aqueous humour after corneal refractive surgery.

    PubMed

    Nozal, M J; Bernal, J L; Martín, M T; Bernal, J; Torres, R M; Merayo, J

    2006-01-23

    A simple, fast and reliable method has been developed for the assay of traces of mitomycin C (MMC) in hen aqueous humour samples. The determination was carried out by high-performance liquid chromatography with electrospray ionization mass spectrometric detection. In isocratic elution analysis, the mobile phase was a mixture of water-acetonitrile (78:22, v/v) and the chromatographic column was C(18) at 35 degrees C. The method has been validated over a range from 0.1 to 250 microg L(-1) in hen aqueous humour with correlation coefficients higher than 0.999. Limit of detection and limit of quantification for MMC based in signal to noise ratio of 3 and 10, respectively, were 20 and 71 ng L(-1). The developed method allows the analysis of MMC in hen aqueous humour samples obtained at different times and conditions in order to evaluate and compare the efficacy of the drug administration.

  8. Apoptosis in pneumovirus infection.

    PubMed

    van den Berg, Elske; van Woensel, Job B M; Bem, Reinout A

    2013-01-23

    Pneumovirus infections cause a wide spectrum of respiratory disease in humans and animals. The airway epithelium is the major site of pneumovirus replication. Apoptosis or regulated cell death, may contribute to the host anti-viral response by limiting viral replication. However, apoptosis of lung epithelial cells may also exacerbate lung injury, depending on the extent, the timing and specific location in the lungs. Differential apoptotic responses of epithelial cells versus innate immune cells (e.g., neutrophils, macrophages) during pneumovirus infection can further contribute to the complex and delicate balance between host defense and disease pathogenesis. The purpose of this manuscript is to give an overview of the role of apoptosis in pneumovirus infection. We will examine clinical and experimental data concerning the various pro-apoptotic stimuli and the roles of apoptotic epithelial and innate immune cells during pneumovirus disease. Finally, we will discuss potential therapeutic interventions targeting apoptosis in the lungs.

  9. Apoptosis in Pneumovirus Infection

    PubMed Central

    van den Berg, Elske; van Woensel, Job B.M.; Bem, Reinout A.

    2013-01-01

    Pneumovirus infections cause a wide spectrum of respiratory disease in humans and animals. The airway epithelium is the major site of pneumovirus replication. Apoptosis or regulated cell death, may contribute to the host anti-viral response by limiting viral replication. However, apoptosis of lung epithelial cells may also exacerbate lung injury, depending on the extent, the timing and specific location in the lungs. Differential apoptotic responses of epithelial cells versus innate immune cells (e.g., neutrophils, macrophages) during pneumovirus infection can further contribute to the complex and delicate balance between host defense and disease pathogenesis. The purpose of this manuscript is to give an overview of the role of apoptosis in pneumovirus infection. We will examine clinical and experimental data concerning the various pro-apoptotic stimuli and the roles of apoptotic epithelial and innate immune cells during pneumovirus disease. Finally, we will discuss potential therapeutic interventions targeting apoptosis in the lungs. PMID:23344499

  10. Neurofibromin and Neuronal Apoptosis

    DTIC Science & Technology

    2006-07-01

    role of familial pheochromocytoma genes, including succinate dehydrogenase (SDH) and Nf1, in modulating neuronal apoptosis following neurotrophin...gene products, in Nf1-/- sensory and sympathetic neurons; this work will also have relevance to the biology of familial pheochromocytoma . "So what...Schlisio, S. (2005). Neuronal apoptosis linked to EglN3 prolyl hydroxylase and familial pheochromocytoma genes: Developmental culling and cancer. Cancer

  11. Randomized dose-response analysis of mitomycin-C to prevent haze after photorefractive keratectomy for high myopia.

    PubMed

    Hofmeister, Elizabeth M; Bishop, Frank M; Kaupp, Sandor E; Schallhorn, Steven C

    2013-09-01

    To evaluate the safety and efficacy of mitomycin-C (MMC) 0.01% (0.1 mg/mL) in preventing haze formation after wavefront-guided photorefractive keratectomy (PRK) for higher myopia at 3 exposures. United States Navy Refractive Surgery Center, San Diego, California, USA. Double-masked randomized prospective trial. Sixty-, 30-, and 15-second exposures of MMC 0.01% were compared in wavefront-guided PRK for higher myopia. One eye received MMC (surgical sponge) and the other a placebo. All eyes received a 4-month tapering postoperative topical steroid regimen. Endothelial cell densities, haze scores, high- and low-contrast acuities, and manifest refraction were measured preoperatively and 1, 3, 6, and 12 months postoperatively. Outcomes were analyzed as repeated measures over time. The mean preoperative manifest refraction spherical equivalent was -5.98 diopters (D) (range -4.4 to -8.0 D). No eye developed more than trace haze. There was a significant difference in haze scores between MMC-treated eyes and untreated eyes at 1 and 3 months (P=.034) but no difference at 6 and 12 months. Endothelial cell densities decreased in the treated eyes and untreated eyes at all 3 exposures at 1 month but returned to baseline by 6 months. There was no difference in acuities or refractions with or without MMC. Mitomycin-C may not be needed to prevent haze after modern PRK with a 4-month steroid taper. There was no clinically significant difference in haze formation between MMC eyes and control eyes at the concentration and exposures used. Copyright © 2013 ASCRS and ESCRS. Published by Elsevier Inc. All rights reserved.

  12. Outcomes of Chemoradiotherapy With 5-Fluorouracil and Mitomycin C for Anal Cancer in Immunocompetent Versus Immunodeficient Patients

    SciTech Connect

    Seo, Yuji; Kinsella, Michael T.; Reynolds, Harry L.; Chipman, Gregory; Remick, Scot C.; Kinsella, Timothy J.

    2009-09-01

    Purpose: Information is limited as to how we should treat invasive anal squamous cell carcinoma (SCC) in patients with chronic immunosuppression, since the majority of clinical studies to date have excluded such patients. The objective of this study is to compare treatment outcomes in immunocompetent (IC) versus immunodeficient (ID) patients with invasive anal SCC treated similarly with combined modality therapy. Methods and Materials: Between January 1999 and March 2007, a total of 36 consecutive IC and ID patients received concurrent chemoradiotherapy using three-dimensional conformal radiotherapy with infusional 5-fluorouracil and mitomycin C. The IC and ID groups consisted of 19 and 17 patients, respectively, with 14 human immunodeficiency virus-positive (HIV+) and 3 post-solid organ transplant ID patients. There were no significant differences in tumor size, T stage, N stage, chemotherapy doses, or radiation doses between the two groups. Results: With a median follow-up of 3.1 years, no differences were found in overall survival, disease-specific survival, and colostomy-free survival. Three-year overall survival was 83.6% (95% CI = 68.2-100) and 91.7% (95% CI = 77.3-100) in the IC and ID groups, respectively. In addition, there were no differences in acute and late toxicity profiles between the two groups. In the human immunodeficiency virus-positive patients, Cox modeling showed no difference in overall survival by pretreatment CD4 counts (hazard ratio = 0.994, 95% CI = 0.98-1.01). No correlation was found between CD4 counts and the degree of acute toxicities. Conclusion: Our data suggest that standard combined modality therapy with three-dimensional conformal radiotherapy and 5-fluorouracil plus mitomycin C is as safe and effective for ID patients as for IC patients.

  13. Incorporation and release of chemically intact mitomycin C from albumin microspheres: a high performance liquid chromatography evaluation.

    PubMed

    Allan, L; Cummings, J; Willmott, N; Whateley, T L; Smyth, J F

    1993-01-01

    Preparation of mitomycin C-loaded human serum albumin (HSA) microspheres using a new technique that avoids the use of heat denaturation, which is known chemically to degrade incorporated drug, is described. This method is based on cross-linking of protein by glutaraldehyde (2.2%) during emulsification (W/O) at room temperature. The resultant particles have a mean (s.d.) diameter of 16.9 (0.34) microns (50% weight average), contain mean (s.d.) 1.15 (0.05%) mitomycin C (MMC) (w/w, n = 17) and maintain sustained release of drug over 20 h. High performance liquid chromatography (HPLC) with diode array detection was used to study the chemical integrity of the drug. Two classes of decomposition products were evaluated: chemical degradation products and drug/nucleophile covalent adducts. The HPLC separation was validated by a number of standards of proposed degradation products. To examine incorporated drug, a complete microsphere system was solubilized with 0.4% trypsin for 24 h, while to examine released drug, microspheres were immobilized on a flow-through glass wool column and fractions were collected. No evidence of significant chemical degradation or covalent coupling to protein was detected in microsphere digests. Two candidate decomposition products, representing approximately 10% of drug released from microspheres (assuming similar molar extinction coefficients to MMC), were identified in column fractions. One of these products appeared to be a covalent adduct, the other possibly an isomeric form of intact MMC. Thus, MMC is predominantly incorporated into and released (90%) chemically intact from HSA microspheres prepared by the technique described.

  14. Isolation and identification of the adducts of mitomycin C and porfiromycin with DNA formed in vitro and in vivo

    SciTech Connect

    Chowdary, D.R.

    1989-01-01

    The antitumor antibiotics, mitomycin C (MC) and porfiromycin (PM), are shown to form covalent complexes with DNA in vitro, under reductive activation conditions (both chemical and enzymatic). Three major covalent adducts have been isolated and identified as (1) N{sup 2}-guanine adduct with MC (structure 4a), (2) N{sup 2}-guanine adduct with 10-decarbamoyl mitomycin ((10-DMC); structure 16a), and a bisadduct of MC linked to two Gs at their N{sup 2}-positions (structure 6). The adducts of PM with DNA formed in vitro are analogous (structures 19, 20, and 21). Formation of adducts 6 and 16a in CHO mammalian cells has been shown after exposing them to MC or 10-DMC, whereas formation of crosslink 6 in vivo has been demonstrated after injecting rats with MC. The experiments done in tissue cultures with (1a-{sup 3}H)-polyfiromycin show ({sup 3}H)-label in the unmodified A, G, and T thus suggesting the demethylation of PM to MC in cells. The methyl group containing ({sup 3}H) label was incorporated into nucleosides via de novo purine and thymidylate biosynthesis. A consolidated enzymatic scheme for the hydrolysis of MC-modified DNA has been established and the resistance of such DNA to cleavage by several nucleases has been shown. Thus, only DNase I/SVD/alkaline phosphatase or nuclease P{sub 1}/SVD/alkaline phosphatase combinations can degrade MC-modified DNA into nucleosides. A modified version of {sup 32}P-postlabeling has been developed with in vitro authentic standards and this can be conveniently used in the future to detect MC-modified lesions obtained in vivo. By utilizing the alkaline ethidium bromide fluorescence assay, the crosslinking effect of MC, PM, and 10-DMC has been shown to occur in cells.

  15. A novel sphingosine kinase 1 inhibitor (SKI-5C) induces cell death of Wilms’ tumor cells in vitro and in vivo

    PubMed Central

    Li, Zhi-Heng; Tao, Yan-Fang; Xu, Li-Xiao; Zhao, He; Li, Xiao-Lu; Fang, Fang; Wu, Yi; Lu, Jun; Li, Yan-Hong; Du, Wei-Wei; Ren, Jun-Li; Li, Yi-Ping; Xu, Yun-Yun; Feng, Xing; Wang, Jian; He, Wei-Qi; Pan, Jian

    2016-01-01

    Sphingosine kinase 1 (SphK1) is over-expressed in many cancers and therefore serves as a biomarker for cancer prognosis. SKI-5C is a new SphK1 inhibitor, and until now its molecular function in Wilms’ tumor cells remained unknown. Here, using CCK-8 and nude mice experiments we assessed cell growth in Wilms’ tumor cell lines (SK-NEP-1 and G401) in vitro and in vivo. We demonstrated that SphK1 is highly expressed in SK-NEP-1 and G401 cells, and through annexin V/propidium iodide staining and flow cytometry analysis, we detected cell apoptosis. Treatment with SKI-5C inhibited proliferation and induced apoptosis of SK-NEP-1 and G401 cells in a dose-dependent manner. Moreover, SKI-5C treatment inhibited the growth of SK-NEP-1 xenograft tumors in nude mice, with few side effects. Our microarray analysis revealed that SKI-5C-treated SK-NEP-1 cells mostly downregulated PRKACA and significantly inhibited phosphorylation of ERK1/2 and NF-κB p65. These results imply that SKI-5C induces apoptosis of SK-NEP-1 cells through the PRKACA/MAPK/NF-κB pathway. While, further research is required to determine the underlying details, these results provide new clues for the molecular mechanism of cell death induced by SKI-5C and suggest that SKI-5C may act as new candidate drug for Wilms’ tumor. PMID:27904661

  16. A novel sphingosine kinase 1 inhibitor (SKI-5C) induces cell death of Wilms' tumor cells in vitro and in vivo.

    PubMed

    Li, Zhi-Heng; Tao, Yan-Fang; Xu, Li-Xiao; Zhao, He; Li, Xiao-Lu; Fang, Fang; Wu, Yi; Lu, Jun; Li, Yan-Hong; Du, Wei-Wei; Ren, Jun-Li; Li, Yi-Ping; Xu, Yun-Yun; Feng, Xing; Wang, Jian; He, Wei-Qi; Pan, Jian

    2016-01-01

    Sphingosine kinase 1 (SphK1) is over-expressed in many cancers and therefore serves as a biomarker for cancer prognosis. SKI-5C is a new SphK1 inhibitor, and until now its molecular function in Wilms' tumor cells remained unknown. Here, using CCK-8 and nude mice experiments we assessed cell growth in Wilms' tumor cell lines (SK-NEP-1 and G401) in vitro and in vivo. We demonstrated that SphK1 is highly expressed in SK-NEP-1 and G401 cells, and through annexin V/propidium iodide staining and flow cytometry analysis, we detected cell apoptosis. Treatment with SKI-5C inhibited proliferation and induced apoptosis of SK-NEP-1 and G401 cells in a dose-dependent manner. Moreover, SKI-5C treatment inhibited the growth of SK-NEP-1 xenograft tumors in nude mice, with few side effects. Our microarray analysis revealed that SKI-5C-treated SK-NEP-1 cells mostly downregulated PRKACA and significantly inhibited phosphorylation of ERK1/2 and NF-κB p65. These results imply that SKI-5C induces apoptosis of SK-NEP-1 cells through the PRKACA/MAPK/NF-κB pathway. While, further research is required to determine the underlying details, these results provide new clues for the molecular mechanism of cell death induced by SKI-5C and suggest that SKI-5C may act as new candidate drug for Wilms' tumor.

  17. Avian metapneumovirus subgroup C induces autophagy through the ATF6 UPR pathway.

    PubMed

    Hou, Lei; Wei, Li; Zhu, Shanshan; Wang, Jing; Quan, Rong; Li, Zixuan; Liu, Jue

    2017-09-26

    An increasing number of studies have demonstrated that macroautophagy/autophagy plays an important role in the infectious processes of diverse pathogens. However, it remains unknown whether autophagy is induced in avian metapneumovirus (aMPV)-infected host cells, and, if so, how this occurs. Here, we report that aMPV subgroup C (aMPV/C) induces autophagy in cultured cells. We demonstrated this relationship by detecting classical autophagic features, including the formation of autophagsomes, the presence of GFP-LC3 puncta and the conversation of LC3-I into LC3-II. Also, we used pharmacological regulators and siRNAs targeting ATG7 or LC3 to examine the role of autophagy in aMPV/C replication. The results showed that autophagy is required for efficient replication of aMPV/C. Moreover, infection with aMPV/C promotes autophagosome maturation and induces a complete autophagic process. Finally, the ATF6 pathway, of which one component is the unfolded protein response (UPR), becomes activated in aMPV/C-infected cells. Knockdown of ATF6 inhibited aMPV/C-induced autophagy and viral replication. Collectively, these results not only show that autophagy promotes aMPV/C replication in the cultured cells, but also reveal that the molecular mechanisms underlying aMPV/C-induced autophagy depends on regulation of the ER stress-related UPR pathway.

  18. Morphine enhances macrophage apoptosis.

    PubMed

    Singhal, P C; Sharma, P; Kapasi, A A; Reddy, K; Franki, N; Gibbons, N

    1998-02-15

    Laboratory data indicate that morphine decreases the numbier of peritoneal and alveolar macrophages (Mphi) and compromises their phagocytic capability for immune complexes and bacteria. We hypothesize that morphine decreases the number of, as well as compromises the phagocytic capability of, Mphi by programming their death. We studied the effect of morphine on Mphi apoptosis in vivo as well as in vitro. Peritoneal Mphi harvested from morphine-treated rats showed DNA fragmentation. Morphine enhanced murine Mphi (J 774.16) apoptosis in a dose-dependent manner. Human monocytes treated with morphine showed a classic ladder pattern in gel electrophoretic and end-labeling studies. Morphine promoted nitric oxide (NO) production both under basal and LPS-activated states. N(G)-nitro-L-arginine methyl ester (L-NAME) and N(G)-monomethyl-L-arginine monoacetate (L-NMMA), inhibitors of NO synthase, attenuated the morphine-induced generation of NO by Mphi. Morphine also enhanced Mphi mRNA expression of inducible NO synthase (iNOS). Since morphine-induced Mphi apoptosis was inhibited by L-NAME and L-NMMA, it appears that morphine-induced Mphi apoptosis may be mediated through the generation of NO. Morphine promoted the synthesis of Bax and p53 proteins by Mphi. Moreover, IL-converting enzyme (ICE)-1 inhibitor attenuated morphine-induced Mphi apoptosis. These studies suggest that morphine activates the induction phase of the apoptotic pathway through accumulation of p53. The effector phase of morphine-induced apoptosis appears to proceed through the accumulation of Bax and activation of ICE-1. The present study provides a basis for a hypothesis that morphine may be directly compromising immune function by promoting Mphi apoptosis in patients with opiate addiction.

  19. Apoptosis in metanephric development

    PubMed Central

    1992-01-01

    During metanephric development, non-polarized mesenchymal cells are induced to form the epithelial structures of the nephron following interaction with extracellular matrix proteins and factors produced by the inducing tissue, ureteric bud. This induction can occur in a transfilter organ culture system where it can also be produced by heterologous cells such as the embryonic spinal cord. We found that when embryonic mesenchyme was induced in vitro and in vivo, many of the cells surrounding the new epithelium showed morphological evidence of programmed cell death (apoptosis) such as condensed nuclei, fragmented cytoplasm, and cell shrinking. A biochemical correlate of apoptosis is the transcriptional activation of a calcium-sensitive endonuclease. Indeed, DNA isolated from uninduced mesenchyme showed progressive degradation, a process that was prevented by treatment with actinomycin- D or cycloheximide and by buffering intracellular calcium. These results demonstrate that the metanephric mesenchyme is programmed for apoptosis. Incubation of mesenchyme with a heterologous inducer, embryonic spinal cord prevented this DNA degradation. To investigate the mechanism by which inducers prevented apoptosis we tested the effects of protein kinase C modulators on this process. Phorbol esters mimicked the effects of the inducer and staurosporine, an inhibitor of this protein kinase, prevented the effect of the inducer. EGF also prevented DNA degradation but did not lead to differentiation. These results demonstrate that conversion of mesenchyme to epithelial requires at least two steps, rescue of the mesenchyme from apoptosis and induction of differentiation. PMID:1447305

  20. [The effect of combination chemotherapy to adapted to chronotherapy with 5-fluorouracil, leucovorin, mitomycin C and cisplatin in patients with gastric or colorectal cancer].

    PubMed

    Kamoshita, N; Yokomori, T; Iesato, H; Ohya, T; Nagaoka, H; Okabe, T; Kato, Y; Takeyoshi, I; Ohwada, S; Morishita, Y

    2000-05-01

    We performed combination chemotherapy adapted to chronotherapy with 5-fluorouracil, leucovorin, mitomycin C and cisplatin in 11 patients with gastric cancer and 7 with colorectal cancer. Treatment consisted of a 5-day course of continuous arterial or intravenous infusion of 5-FU (500 mg/body/day), arterial or intravenous infusion of leucovorin (20 mg/body/day) at 6:00 p.m. on days 1-5, arterial or intravenous infusion of mitomycin C (2 mg/body) at 9:00 a. m. on day 5, and arterial or intravenous infusion of cisplatin (20-80 mg/body) at 6:00 p.m. on day 5. The effective rate against gastric cancer was 73%; however, the effective rate against colorectal cancer was 29%. During and after this therapy, there was only a little appetite loss, nausea and stomatitis.

  1. Structural determination of the conjugate of human serum albumin with a mitomycin C derivative, KW-2149, by matrix-assisted laser desorption/ionization mass spectrometry.

    PubMed

    Yasuzawa, T; Tomer, K B

    1997-01-01

    A new mitomycin C derivative, KW-2149, is known to form a covalent conjugate with human serum albumin (HSA). This conjugate exhibits 1/20 of the anticellular activity of unconjugated KW-2149. Structural studies of this conjugate were carried out using a combination of enzymatic digestion, high-performance liquid chromatography (HPLC), and matrix-assisted laser desorption/ionization (MALDI) mass spectrometry. The tryptic peptide T5 (residues 21-41) was the only peptide found to be modified by KW-2149 moieties, the [(gamma-L-glutamylamino)ethyl]thio group or the (2-aminoethyl)thio group, through a disulfide bond. Although the latter peptide lost its mitomycin C moiety in the course of tryptic digestion, these data strongly suggest that KW-2149 was bound to Cys-34, the only free cysteine on HSA.

  2. Automated analysis of mitomycin C in body fluids by high-performance liquid chromatography with on-line sample pre-treatment.

    PubMed

    Tjaden, U R; de Bruijn, E A; van der Hoeven, R A; Jol, C; van der Greef, J; Lingeman, H

    1987-09-04

    A fully automated liquid chromatographic system for the bioanalysis of mitomycin C has been described. The isolation of the analyte from the biological matrix (plasma, ascites and urine) is performed using a continuous-flow system equipped with a dialysis membrane in order to remove proteins. The samples are concentrated on a reversed-phase pre-column and subsequently introduced on to a reversed-phase analytical column by applying column-switching techniques. The drug is detected by absorbance measurements at 360 nm. Using the described system up to 100 samples a day can be analysed with determination limits of the order of 1 ng/ml, with a linear dynamic range of at least three decades for plasma and urine samples. The procedure was applied to pharmacokinetic studies of ovarian cancer patients treated intraperitoneally with mitomycin C.

  3. First synthesis of mitomycins completely labeled at the C-6-methyl by [sup 13]CH[sub 3] and CD[sub 3

    SciTech Connect

    Arai, Hitoshi; Kasai, Masaji ); Kanda, Yutaka )

    1993-02-12

    The C-6-methyl group of mitomycins was completely labeled with carbon-13 or deuterium for the first time. The synthesis was accomplished by the C-6-methylation of 6-demethyl-7,7-(ethylenedioxy)-6-(phenylseleno)mitosane 8 that was formed by a novel replacement of the methylene moiety of 6-demethyl-7,7-(ethylenedioxy)-6-methylenemitosane 10 by a phenylseleno group, and followed by conversion to the mitomycins. For the synthesis of 8, the authors found that selenamide 11 is an excellent reagent for the replacement. They have also determined that the replacement proceeded via the addition of 11 to the methylene of 10 with a subsequent retro-Mannich reaction. 15 refs.

  4. Mitomycin C versus 5-Fluorouracil for wound healing in glaucoma surgery.

    PubMed

    Cabourne, Emily; Clarke, Jonathan C K; Schlottmann, Patricio G; Evans, Jennifer R

    2015-11-06

    Raised intraocular pressure is a risk factor for glaucoma. One treatment option is glaucoma drainage surgery (trabeculectomy). Antimetabolites are used during surgery to reduce postoperative scarring during wound healing. Two agents in common use are mitomycin C (MMC) and 5-Fluorouracil (5-FU). To assess the effects of MMC compared to 5-FU as an antimetabolite adjunct in trabeculectomy surgery. We searched CENTRAL (which contains the Cochrane Eyes and Vision Group Trials Register) (2015 Issue 9), Ovid MEDLINE, Ovid MEDLINE In-Process and Other Non-Indexed Citations, Ovid MEDLINE Daily, Ovid OLDMEDLINE (January 1946 to October 2015), EMBASE (January 1980 to October 2015), Latin American and Caribbean Health Sciences Literature Database (LILACS) (January 1982 to October 2015), the ISRCTN registry (www.isrctn.com/editAdvancedSearch), ClinicalTrials.gov (www.clinicaltrials.gov) and the World Health Organization (WHO) International Clinical Trials Registry Platform (ICTRP) (www.who.int/ictrp/search/en). We did not use any date or language restrictions in the electronic searches for trials. We last searched the electronic databases on 2 October 2015. We included randomised controlled trials where wound healing had been modified with MMC compared to 5-FU. Two review authors independently selected trials and collected data. The primary outcome was failure of a functioning trabeculectomy one year after surgery. Secondary outcomes included mean intraocular pressure at one year. We considered three subgroups: high risk of trabeculectomy failure (people with previous glaucoma surgery, extracapsular cataract surgery, African origin and people with secondary glaucoma or congenital glaucoma); medium risk of trabeculectomy failure (people undergoing trabeculectomy with extracapsular cataract surgery) and low risk of trabeculectomy failure (people who have received no previous surgical eye intervention). We identified 11 trials that enrolled 687 eyes of 679 participants. The

  5. Evaluation of the prophylactic use of mitomycin-C to inhibit haze formation after photorefractive keratectomy in high myopia: a prospective clinical study

    PubMed Central

    Hashemi, Hassan; Taheri, Seied Mohammad Reza; Fotouhi, Akbar; Kheiltash, Azita

    2004-01-01

    Background To study the effect of prophylactic application of mitomycin-C on haze formation in photorefractive keratectomy (PRK) for high myopia. Methods Fifty-four eyes of 28 myopic patients were enrolled in this prospective study. All eyes were operated by PRK followed by 0.02% mitomycin-C application for two minutes and washed with 20 ml normal saline afterwards. All eyes were examined thoroughly on the first 7 days and one month after surgery; 48 eyes (88.9%) at 3 and 6 months postoperatively. Hanna grading (in the scale of 0 to 4+) was used for assessment of corneal haze. Results The mean spherical equivalent refraction (SE) was -7.08 diopters (D) ± 1.11 (SD) preoperatively. Six months after surgery, 37 eyes (77.1%) achieved an uncorrected visual acuity (UCVA) of 20/20 or better, all eyes had a UCVA of 20/40 or better and 45 (93.7%) eyes had an SE within ± 1.00D. One month postoperatively, 2 eyes (3.7%) had grade 0.5+ of haze, while at 3 and 6 months after surgery no visited eye had haze at all. All eyes had a best corrected visual acuity (BCVA) of 20/40 or better and there were no lost lines in BCVA by 6 months after surgery. In spatial frequencies of 6 and 12 cycles per degree contrast sensitivity had decreased immediately after PRK and it had increased 1.5 lines by the 6th postoperative month compared to the preoperative data. Conclusions The results show the efficacy of mitomycin-C in preventing corneal haze after treatment of high myopia with PRK. This method- PRK + mitomycin-C – can be considered an alternative treatment for myopic patients whose corneal thicknesses are inadequate for laser in situ keratomileusis (LASIK). However, the results should be confirmed in longer follow-ups. PMID:15363107

  6. [Guidelines for good practice of intravesical instillations of BCG and mitomycin C from the French national cancer committee (CC-AFU) for non-muscle invasive bladder cancer].

    PubMed

    Rouprêt, M; Neuzillet, Y; Larré, S; Pignot, G; Coloby, P; Rébillard, X; Mongiat-Artus, P; Chartier-Kastler, E; Soulié, M; Pfister, C

    2012-11-01

    Intravesical BCG immunotherapy and mitomycin C are considered as the standard treatment for non-muscle invasive bladder cancer. These guidelines aim to describe the optimal condition to perform intravesical instillation of BCG or mitomycin C in order to increase its oncologic efficiency and to decrease its morbidity. Online systematic literature search was performed on PubMed(®) until April 2010. Regulation texts, published guidelines and results of recent urologists practice study were taken into consideration. Level of evidence was assigned to each recommendation. A bibliographic research in French and English using Medline(®) and Embase(®) with the keywords "BCG", "mitomycin C", "bladder", "complication", "toxicity", "adverse reaction", "prevention" and "treatment" was performed. Patient information must be prior to the first intravesical instillation and should be given through a medical exam by the physician performing the procedure. The check for formal contra-indication to BCG is systematically mandatory by the physician during the medical exam. Intravesical instillation must be realized in a health center where urologic endoscopic procedures are made frequently. A recent urine culture has to be checked systematically before any instillation done either by the urologist or a specialized nurse. Contingent upon a bladder catheter has been inserted in the bladder without any injury of the lower urinary tract, the instillation can be done. The pharmaceutical agent needs to be kept two hours in the bladder. After instillation, the patient must be seated to void and also has to keep in mind that he needs to drink at least 2 liters of water per day for 2 days. To improve the oncologic performance and to reduce the risk of complication and adverse event, achievement of intravesical instillations of BCG and/or mitomycin C should follow a standardized procedure. Copyright © 2012 Elsevier Masson SAS. All rights reserved.

  7. Characterization of pegylated liposomal mitomycin C lipid-based prodrug (Promitil®) by high sensitivity differential scanning calorimetry and cryogenic transmission electron microscopy.

    PubMed

    Wei, Xiaohui; Patil, Yogita; Ohana, Patricia; Amitay, Yasmine; Shmeeda, Hilary; Gabizon, Alberto; Barenholz, Yechezkel

    2017-01-03

    The effect of a lipidated prodrug of mitomycin C (MLP) on the membrane of a pegylated liposome formulation (PL-MLP), also known as Promitil®, was characterized through high-sensitivity differential scanning calorimetry (DSC), and cryo-TEM. The thermodynamic analysis demonstrated that MLP led to the formation of heterogeneous domains in the membrane plane of PL-MLP. MLP concentrated in prodrug-rich domains, arranged in high-ordered crystal-like structures, as suggested by the sharp and high enthalpy endotherm in the 1st heating scanning. After thiolytic cleavage of mitomycin C from MLP by dithiotreitol (DTT) treatment, the crystal-like prodrug domain disappears and a homogeneous membrane with stronger lipid interactions and higher phase transition temperature compared with the blank (MLP-free) liposomes is observed by DSC. In parallel, the rod-like discoid liposomes and the "kissing liposomes" seen by cryo-TEM in the PL-MLP formulation disappear, and liposome mean size and polydispersity increase after DTT treatment. Both MLP and the residual post-cleavage lipophilic moiety of the prodrug increased rigidity of the liposome membrane as indicated by DSC. These results confirm that MLP is inserted in the PL-MLP liposome membrane via its lipophilic anchor, and its mitomycin C moiety located mainly at the region of the phospholipid glycerol backbone and polar head-group. We hypothesize that Π-Π stacking between the planar aromatic rings of the mitomycin C moieties leads to the formation of prodrug-rich domains with highly ordered structure on the PL-MLP liposome membrane. This thermodynamically stable conformation may explain the high stability of the PL-MLP formulation. These results also provide us with an interesting example of the application of high sensitivity DSC in understanding the composition-structure-behavior dynamics of liposomal nanocarriers having a lipid-based drug as pharmaceutical ingredient.

  8. Spaceflight Associated Apoptosis

    NASA Technical Reports Server (NTRS)

    Ichiki, Albert T.; Gibson, Linda A.; Allebban, Zuhair

    1996-01-01

    Lymphoid tissues have been shown to atrophy in rats flown on Russian spaceflights. Histological examination indicated evidence for cell degradation. Lymphoid tissues from rats flown on Spacelab Life Sciences-2 mission were analyzed for apoptosis by evidence of fragmented lymphocytes, which could be engulfed by macrophages, or DNA strand breaks using the terminal deoxynucleotidyl transferase-mediated dUTP nick end-labeling (TUNEL) assay. Apoptosis was not detected in the thymus and spleen collected inflight or from the synchronous ground rats but was detected in the thymus, spleen and inguinal lymph node of the flight animals on recovery. These results indicate that the apoptosis observed in the lymphatic tissues of the rats on recovery could have been induced by the gravitational stress of reentry, corroborating the findings from the early space-flight observations.

  9. Glutathione and apoptosis

    PubMed Central

    Circu, Magdalena L.; Yee Aw, Tak

    2011-01-01

    Apoptosis or programmed cell death represents a physiologically conserved mechanism of cell death that is pivotal in normal development and tissue homeostasis in all organisms. As a key modulator of cell functions, the most abundant non-protein thiol, glutathione (GSH), has important roles in cellular defense against oxidant aggression, redox regulation of proteins thiols and maintaining redox homeostasis that is critical for proper function of cellular processes, including apoptosis. Thus, a shift in the cellular GSH-to-GSSG redox balance in favour of the oxidized species, GSSG, constitutes an important signal that could decide the fate of a cell. The current review will focus on three main areas: (1) general description of cellular apoptotic pathways, (2) cellular compartmentation of GSH and the contribution of mitochondrial GSH and redox proteins to apoptotic signalling and (3) role of redox mechanisms in the initiation and execution phases of apoptosis. PMID:18671159

  10. In vitro and in vivo antimutagenic effects of DIG, a herbal preparation of Berberis vulgaris, Taraxacum officinale and Arctium lappa, against mitomycin C.

    PubMed

    Di Giorgio, C; Boyer, L; De Meo, M; Laurant, C; Elias, R; Ollivier, E

    2015-07-01

    DIG, a liquid herbal preparation made from a mixture of diluted mother tinctures of Berberis vulgaris, Taraxacum officinale and Arctium lappa, was assessed for its antimutagenic properties against mitomycin C. The micronucleus assay on Chinese hamster ovary (CHO)-K1 cells was used to evaluate the in vitro anticlastogenic activity of DIG compared to those of separately diluted mother tinctures. The micronucleus assay was performed on mouse erythrocytes and the comet assay was performed on mouse liver, kidney, lung, brain and testicles to assess the protective effects of DIG (0.2 and 2 % at libitum) against an intraperitoneal injection of mitomycin C (1 mg Kg(-1)) in mice. DIG exerted a powerful anticlastogenic activity, under both pretreatment and simultaneous treatment conditions as assessed by the micronucleus assay in CHO-K1 cells. Its protective activity was greater than that observed for each mother tincture. DIG reduced micronuclei levels in mouse erythrocytes and suppressed >80 % of DNA strand breaks in the liver, kidney, lung, brain and testicles of mice exposed to mitomycin C.

  11. The biochemistry of apoptosis.

    PubMed

    Hengartner, M O

    2000-10-12

    Apoptosis--the regulated destruction of a cell--is a complicated process. The decision to die cannot be taken lightly, and the activity of many genes influence a cell's likelihood of activating its self-destruction programme. Once the decision is taken, proper execution of the apoptotic programme requires the coordinated activation and execution of multiple subprogrammes. Here I review the basic components of the death machinery, describe how they interact to regulate apoptosis in a coordinated manner, and discuss the main pathways that are used to activate cell death.

  12. Stable transfection of extrinsic Smac gene enhances apoptosis-inducing effects of chemotherapeutic drugs on gastric cancer cells

    PubMed Central

    Zheng, Li-Duan; Tong, Qiang-Song; Wang, Liang; Liu, Jun; Qian, Wei

    2005-01-01

    AIM: To explore the feasibility of enhancing apoptosis-inducing effects of chemotherapeutic drugs on human gastric cancer cells by stable transfection of extrinsic Smac gene. METHODS: After Smac gene was transferred into gastric cancer cell line MKN-45, subclone cells were obtained by persistent G418 selection. Cellular Smac gene expression was determined by RT-PCR and Western blotting. After treatment with mitomycin (MMC) as an apoptotic inducer, in vitro cell growth activities were investigated by trypan blue-staining method and MTT colorimetry. Cell apoptosis and its rates were determined by electronic microscopy, annexin V-FITC and propidium iodide staining flow cytometry. Cellular caspase-3 protein expression and its activities were assayed by Western blotting and colorimetry. RESULTS: When compared with MKN-45 cells, the selected subclone cell line MKN-45/Smac had significantly higher Smac mRNA (3.12±0.21 vs 0.82±0.14, t = 7.52, P<0.01) and protein levels (4.02±0.24 vs 0.98±0.11, t = 8.32, P<0.01). After treatment with 10 μg/mL MMC for 6-24 h, growth inhibition rate of MKN-45/Smac (15.8±1.2-54.8±2.9%) was significantly higher than that of MKN-45 (5.8±0.4- 24.0±1.5%, t = 6.42, P<0.01). Partial MKN-45/Smac cancer cells presented characteristic morphological changes of apoptosis under the electronic microscope with an apoptosis rate of 36.4±2.1%, which was significantly higher than that of MKN-45 (15.2±0.8%, t = 9.25, P<0.01). Compared with MKN-45, caspase-3 expression levels in MKN-45/Smac were improved significantly (3.39±0.42 vs 0.96±0.14, t = 8.63, P<0.01), while its activities were 3.25 times as many as those of MKN-45 (0.364±0.010 vs 0.112±0.007, t = 6.34, P<0.01). CONCLUSION: Stable transfection of extrinsic Smac gene and its over-expression in gastric cancer cell line can significantly enhance cellular caspase-3 expression and activities, ameliorate apoptosis-inducing effects of mitomycin C on cancer cells, which is a novel strategy to

  13. A Novel Herbal Medicine, KIOM-C, Induces Autophagic and Apoptotic Cell Death Mediated by Activation of JNK and Reactive Oxygen Species in HT1080 Human Fibrosarcoma Cells

    PubMed Central

    Kim, Aeyung; Im, Minju; Yim, Nam-Hui; Kim, Taesoo; Ma, Jin Yeul

    2014-01-01

    KIOM-C was recently demonstrated to have anti-metastatic activity in highly malignant cancer cells via suppression of NF-κB-mediated MMP-9 activity. In addition, it was reported to be effective for clearance of the influenza virus by increasing production of anti-viral cytokines, such as TNF-α and IFN-γ, and efficacious in the treatment of pigs suffering from porcine circovirus-associated disease (PCVAD). In this study, we investigated whether KIOM-C induces cancer cell death and elucidated the underlying anti-cancer mechanisms. In addition, we examined whether KIOM-C oral administration suppresses in vivo tumor growth of HT1080 cells in athymic nude mice. We initially found that KIOM-C at concentrations of 500 and 1000 µg/ml caused dose- and time-dependent cell death in cancer cells, but not normal hepatocytes, to approximately 50% of control levels. At the early stage of KIOM-C treatment (12 h), cells were arrested in G1 phase, which was accompanied by up-regulation of p21 and p27, down-regulation of cyclin D1, and subsequent increases in apoptotic and autophagic cells. Following KIOM-C treatment, the extent of caspase-3 activation, PARP cleavage, Beclin-1 expression, and LC3-II conversion was remarkably up-regulated, but p62 expression was down-regulated. Phosphorylation of AMPK, ULK, JNK, c-jun, and p53 was increased significantly in response to KIOM-C treatment. The levels of intracellular ROS and CHOP expression were also increased. In particular, the JNK-specific inhibitor SP600125 blocked KIOM-C-induced ROS generation and CHOP expression almost completely, which consequently almost completely rescued cell death, indicating that JNK activation plays a critical role in KIOM-C-induced cell death. Furthermore, daily oral administration of 85 and 170 mg/kg KIOM-C efficiently suppressed the tumorigenic growth of HT1080 cells, without systemic toxicity. These results collectively suggest that KIOM-C efficiently induces cancer cell death by both autophagy and

  14. A novel herbal medicine, KIOM-C, induces autophagic and apoptotic cell death mediated by activation of JNK and reactive oxygen species in HT1080 human fibrosarcoma cells.

    PubMed

    Kim, Aeyung; Im, Minju; Yim, Nam-Hui; Kim, Taesoo; Ma, Jin Yeul

    2014-01-01

    KIOM-C was recently demonstrated to have anti-metastatic activity in highly malignant cancer cells via suppression of NF-κB-mediated MMP-9 activity. In addition, it was reported to be effective for clearance of the influenza virus by increasing production of anti-viral cytokines, such as TNF-α and IFN-γ, and efficacious in the treatment of pigs suffering from porcine circovirus-associated disease (PCVAD). In this study, we investigated whether KIOM-C induces cancer cell death and elucidated the underlying anti-cancer mechanisms. In addition, we examined whether KIOM-C oral administration suppresses in vivo tumor growth of HT1080 cells in athymic nude mice. We initially found that KIOM-C at concentrations of 500 and 1000 µg/ml caused dose- and time-dependent cell death in cancer cells, but not normal hepatocytes, to approximately 50% of control levels. At the early stage of KIOM-C treatment (12 h), cells were arrested in G1 phase, which was accompanied by up-regulation of p21 and p27, down-regulation of cyclin D1, and subsequent increases in apoptotic and autophagic cells. Following KIOM-C treatment, the extent of caspase-3 activation, PARP cleavage, Beclin-1 expression, and LC3-II conversion was remarkably up-regulated, but p62 expression was down-regulated. Phosphorylation of AMPK, ULK, JNK, c-jun, and p53 was increased significantly in response to KIOM-C treatment. The levels of intracellular ROS and CHOP expression were also increased. In particular, the JNK-specific inhibitor SP600125 blocked KIOM-C-induced ROS generation and CHOP expression almost completely, which consequently almost completely rescued cell death, indicating that JNK activation plays a critical role in KIOM-C-induced cell death. Furthermore, daily oral administration of 85 and 170 mg/kg KIOM-C efficiently suppressed the tumorigenic growth of HT1080 cells, without systemic toxicity. These results collectively suggest that KIOM-C efficiently induces cancer cell death by both autophagy and

  15. [ESR spectra of paramagnetic centers of ferricytochrome c, induced by UV-radiation at 77 K].

    PubMed

    Artiukhov, V G

    1987-01-01

    Paramagnetic properties of ferricytochrome c aqueous glyceric solutions exposed to UV-light of various wave lengths at 77K have been investigated. Absorption of longwave UV- and visible light by hemin (5-240 min) does not induce the formation of paramagnetic centres in hemoprotein. However absorption of UV-light by chromophorms of a protein component of ferricytochrome c induces the formation of free radicals with a quantum yield of 0.07. During long-term (40 to 200 min) UV-irradiation (260-380 nm) of protein solutions several types of paramagnetic centres including HCO radicals are formed.

  16. Phacoemulsification combined with deep sclerectomy augmented with mitomycin and amniotic membrane implantation in chronic primary open angle glaucoma with cataract

    PubMed Central

    Helmy, Hazem

    2016-01-01

    Objective The aim of this study was to determine the safety and efficacy of combined phacoemulsification plus Intraocular lens (IOL) implantation with deep sclerectomy augmented with mitomycin C (MMC) and sub-flap implantation of amniotic membrane for the management of uncontrolled, chronic, primary open-angle glaucoma patients. Methods This prospective study included 41 patients with chronic, primary, open-angle glaucoma and cataract uncontrolled with medical treatment who underwent combined phacoemulsification augmented with mitomycin C (MMC) application and amniotic membrane implantation under the scleral flap. Intraocular pressure (IOP), visual acuity, glaucoma medications, stabilization of visual field, complications, and viability of the success rate were assessed a 36-month follow-up period. Results The mean age of cases was 54.8 ± 5.3 years. Sixty-one percent of cases were males, and 39% were females. The mean IOP decreased from 23.8 ± 1.8 mmHg preoperatively to 16.8 ± 2.3 mmHg postoperatively. The overall success rate was 97.5, 95, and 92.7% in the first, second, and third year, respectively. The overall success rate was 90% in the first year, but that decreased to 85.3 and 78% in the second and third year, respectively. Qualified success was 7.5, 10, and 14.7% in the first, second, and third year, respectively. Failure was recorded as 2.5, 5, and 7.3% in the first, second, and third year, respectively. IOP reduction was sustained through the follow-up period. Visual acuity improved from 0.13 ± 0.06 to 0.9 ± 0.07 (p < 0.001). The visual field improved significantly in the first assessment, from 14.0 ± 2.7 preoperatively to 12.6 ± 2.6 at three months postoperatively (p < 0.001), after which it became stable for the remainder of the follow-up period. One hundred percent of cases were on three anti-glaucoma drugs preoperatively, while postoperatively, 12.2% were on three drugs, 4.2% were on two drugs, and 82.9% were controlled without anti

  17. Ab-interno goniotrabeculotomy versus mitomycin C trabeculectomy for adult open-angle glaucoma: a 2-year randomized clinical trial.

    PubMed

    Quaranta, L; Hitchings, R A; Quaranta, C A

    1999-07-01

    To evaluate the effect of ab-interno goniotrabeculotomy (AIGT) on the intraocular pressure (IOP) in adult patients with primary open-angle glaucoma (POAG), compared with the effects of mitomycin C trabeculectomy (MT). Prospective, randomized, clinical trial. Thirty-two eyes of 32 patients with medically uncontrolled POAG. Standard limbus-based trabeculectomy with adjunct mitomycin C (0.3 mg/mL for 3 minutes) in 16 eyes of 16 patients; AIGT was performed in 16 eyes of 16 patients. The groups were matched for age, preoperative IOP, duration of preoperative antiglaucoma treatment, use of preoperative beta-blockers and parasympathomimetics, and use of beta-blockers in the fellow eye. The IOP (average of the two highest values measured in the diurnal curve, from 8 AM to 6 PM, every 2 hours) and complications were recorded 1, 3, 6, 12, 18, and 24 months after surgery. Identification of complications and IOP. All patients were followed up for 24 months. More postoperative complications occurred in the MT group during the 2-year follow-up. One month after surgery, IOP was 10 +/- 1.46 mmHg (range, 8-13) in the MT group and 12.12 +/- 1.63 mmHg (range, 8-14) in the AIGT group (Student's t test, P = 0.001). Three months after surgery, IOP was 11.5 +/- 1.59 mmHg (range, 8-14) and 12.75 +/- 1.57 mmHg (range, 10-16) in the MT and AIGT groups, respectively (Student's t test, P = 0.033). From the 6th to the 24th postoperative month, no statistically significant difference in IOP was found between the two groups. At the end of follow-up, 14 of 16 eyes (87.5%) of the AIGT group and 13 of the 16 eyes (81.25%) of the MT group showed an IOP < or = 14 mmHg. Ab-interno goniotrabeculotomy appears to be a viable and safe surgical treatment for adult POAG. More extended follow-up, however, and a larger series of patients are needed to ascertain the actual effectiveness of this procedure in adult POAG.

  18. The Safety and Efficacy of Two-site Phacotrabeculectomy with Mitomycin C under Retrobulbar and Topical Anesthesia

    PubMed Central

    Rodriguez, Raquel; Alburquerque, Rachel; Sauer, Tripper

    2016-01-01

    ABSTRACT Purpose: To evaluate and compare the safety and efficacy of combined two-site phacoemulsification and trabeculectomy surgery with mitomycin C (MMC) in glaucoma-cataract patients with retrobulbar or topical anesthesia. Patients and methods: A retrospective, nonrandomized review of consecutive phacotrabeculectomy patients with a minimum follow-up time of 6 months, no previous glaucoma surgeries, and a preoperative visual acuity (VA) greater than light perception. The main outcome measures were preoperative and postoperative VA, intraocular pressure (IOP), use of glaucoma medications, and complications. A complete surgical success required an IOP from 6 to 18 mm Hg, no visually devastating complications, no return to surgery, and no use of glaucoma medications. Qualified success allowed the use of up to two glaucoma medications. Anesthesia groups were compared by student t-tests and log rank comparison of Kaplan-Meier survival rates. Results: Eighty-seven eyes (83 patients) met inclusion criteria, with a mean follow-up of 19 ± 12 months (6-57 months). The average eye gained 3.1 ± 4.9 lines of VA, lost 4.0 ± 7.1 mm Hg of IOP, and decreased 1.0 ± 1.3 glaucoma medications. Retrobulbar and topical anesthesia groups had statistically equivalent mean changes in VA (p = 0.910), IOP (p = 0.268), and use of glaucoma medications (p = 0.964). Postoperative complication rates were also statistically similar (p = 0.580). Complete success was greater in the retrobulbar group (p = 0.006), however, qualified success was equivalent in both groups (p = 0.769). Conclusion: Two-site phacotrabeculectomy with MMC in West Indian patients is as safe and effective for glaucoma-cataract patients with topical anesthesia as it is under retrobulbar anesthesia, and without short-term losses in VA and the chance of serious complications from injection. How to cite this article: Rodriguez R, Alburquerque R, Sauer T, Batlle JF. The Safety and Efficacy of Two-site Phacotrabeculectomy with

  19. Role of Daxx in Apoptosis

    DTIC Science & Technology

    2002-07-01

    protection against cancer . We previously identified a pro-apoptotic protein Daxx (1). Daxx can be found in large amount in the promyelocytic leukemia protein...Words) Control of the activation of apoptosis is important in protection against cancer . PML oncogenic domains (PODs) are subnuclear macromolecular...apoptosis, and may help identify new approaches to modulate apoptosis for cancer therapy. 14. SUBJECT TERMS 15. NUMBER OF PAGES apoptosis, cancer , PML

  20. Morphological and cytogenetic studies of dominant lethality induced by mitomycin C and cyclophosphamide in female germ cells. The use of Robertsonian translocations as a 'marker system' to identify the zygote pronuclei.

    PubMed

    Jacquet, P; Pire, P

    1984-09-01

    Dominant lethal tests were performed on female mice injected intraperitoneally with cyclophosphamide (200 mg/kg) or with mitomycin C (0.2 or 5 mg/kg) at the preovulatory stage of oogenesis. Complementary experiments were undertaken to clarify the results obtained. Embryo culture showed that sterility found after treatment with cyclophosphamide or with the high dose of mitomycin C was the reflection of true dominant lethal effects. Mortality after cyclophosphamide treatment occurred predominantly at the 2- and 3-cell stages, while it was reported in all preimplantation stages after treatment with the high dose of mitomycin C. Embryos treated with the low dose of mitomycin C developed normally to the blastocyst stage, confirming the absence of preimplantation effects found with this dose in the dominant lethal test. Cytogenetic analysis of female pronuclei at the first cleavage division were performed after mating treated females with males homozygous for one Robertsonian translocation. This method allowed one to distinguish easily the female pronuclei from the male ones, which exhibited one translocated 'marker' chromosome. After treatment with cyclophosphamide, most female pronuclei showed multiple chromatid exchanges or shattering of the entire genome. After treatment with the high dose of mitomycin C, various types of premature chromosome condensation were found, and they were often accompanied by important interchromosome associations. After treatment with the low dose of mitomycin C, no structural chromosome aberrations were found, and the number of numerical anomalies was not significantly different from that found in control embryos. These last results suggest that the increase in rate of postimplantation loss obtained in the dominant lethal test with the low dose of mitomycin C was not due to clastogenic effects of this compound in the female germ cells, but rather to indirect effects on the maternal organism.

  1. The large conductance calcium-activated potassium channel affects extrinsic and intrinsic mechanisms of apoptosis.

    PubMed

    Sakai, Yoshihisa; Sokolowski, Bernd

    2015-05-01

    The large-conductance calcium-activated K(+) or BK channel underlies electrical signals in a number of different cell types. Studies show that BK activity can also serve to regulate cellular homeostasis by protecting cells from apoptosis resulting from events such as ischemia. Recent coimmunoprecipitation studies, combined with mass spectrometry, suggest putative protein partners that interact with BK to regulate intrinsic and extrinsic apoptotic pathways. This study tests two of those partners to determine the effects on these two signaling pathways. Through reciprocal coimmunoprecipitation (coIP) experiments, we show that BK interacts with p53 and fas-associated protein with death domain (FADD) in mouse brain and when overexpressed in a heterologous expression system, such as HEK293 cells. Moreover, coIP experiments with N- and C-terminal fragments reveal that FADD interacts with the C-terminus of BK, whereas p53 interacts with either the N- or the C-terminus. Immunolocalization studies show that BK colocalizes with p53 and FADD in the mitochondrion and plasmalemma, respectively. HEK cells that stably express BK are more resistant to apoptosis when p53 or FADD is overexpressed or when their intrinsic and extrinsic pathways are stimulated via mitomycin C or tumor necrosis factor-related apoptosis-inducing ligand (TRAIL), respectively. Moreover, when stimulating with TRAIL, caspase-8 activation decreases in BK-expressing cells. These data suggest that BK is part of a larger complex of proteins that protects against apoptosis by interacting with proapoptotic proteins, such as p53 and FADD. © 2015 Wiley Periodicals, Inc.

  2. Necrosis and Apoptosis in Hepatocellular Carcinoma Following Low-Dose Versus High-Dose Preoperative Chemoembolization

    SciTech Connect

    Lu Wei Li Yanhao He Xiaofeng; Zhao Jianbo; Chen Yong; Mei Quelin

    2008-11-15

    Our purpose was to study necrosis and apoptosis of hepatocellular carcinoma (HCC) cells after preoperative transcatheter arterial chemoembolization (TACE) with use of low-dose and high-dose anticancer drugs in HCCs. Fifty-four patients with advanced but surgically resectable HCC were studied. Thirty-four patients who elected to undergo preoperative superselective TACE were randomized to low- and high-dose TACE. Patients in group A (n = 16) received low-dose anticancer drugs: 2 mg mitomycin C (MMC), 10 mg epirubicin (EPI), and 100 mg carboplatin (CBP). Patients in group B (n = 18) were given high doses of anticancer drugs (10 mg MMC, 40 mg EPI, and 300 mg CBP). Hepatic resection was subsequently performed. Group C comprised 20 patients who underwent resection without TACE. In all patients the necrosis rates and apoptosis index of tumor cells were evaluated by pathologic examinations and terminal deoxynucleotidyl transferase-mediated nick-end labeling assay. There was no significant difference between group A and group B in tumor response (p > 0.05) after TACE. Necrosis rates in groups A, B, and C were 88.4 {+-} 11.1%, 87.1 {+-} 12.5%, and 7.3 {+-} 3.5%, respectively. There was no significant difference between group A and group B (p > 0.05), while statistical difference was found between group A and group C (p < 0.001) and between group B and group C (p < 0.001). Apoptosis indexes in the three groups were 11.0 {+-} 4.0%, 10.7 {+-} 3.9%, and 5.6 {+-} 2.6%, respectively. Statistical difference exhibited between group A and group C (p < 0.001) and group B versus group C (p < 0.001). No significant difference was observed between group A and group B (p > 0.05). In conclusion, superselective TACE with low- and high-dose chemotherapeutic agents induced similar degrees of cellular apoptosis and necrosis.

  3. Differential Behaviour of Selenium Analogs against Anticancer Drug Induced Apoptosis of Lymphocytes in Human Peripheral Blood.

    PubMed

    Elango, Sonaa; Subbiah, Usha; Jain, Jeong

    2016-01-01

    Sensitising cancer cells and at the same time desensitizing normal cells is a double task in cancer management. Agents which can combat the debilitating side effects of cancer therapeutics and simultaneously synergize with anticancer agents in specifically targeting cancer cells are needed. Selenium, a proven anticarcinogen, gains due importance in terms of its efficacy to combat the side effects of cancer therapy. This study is a comparative analysis of the chemoprotective effects of selenium compounds, methyl selenol (generated from organic selenomethionine (5mmol/L ; METase 40U/L)) and sodium selenite (inorganic form)(30μM) in peripheral blood human lymphocytes exposed to cisplatin and mitomycin. Biochemical alterations occurring in many cells during apoptosis include loss of plasma membrane phospholipid asymmetry, DNA fragmentation, and activation of caspase-3. The present study demonstrated that the selenium metabolite and selenite are efficient in protecting lymphocytes undergoing DNA damage and exerted their activity by reducing caspase 3 expression. Interestingly organic methylselenol (MeSe) was found to offer more protective effects compared to inorganic selenite (SeL), by reducing the induction of apoptosis by the cytotoxic agents. This suggests that MeSe and to a lesser extent selenite might have potential for assessment in clinical trials and could be considered as strong candidates in pharmacogenomics or in the nutriprotective arena.

  4. Protective effect of vitamin A on ARA-C induced intestinal damage in mice.

    PubMed

    Elli, Murat; Aydin, Oguz; Bilge, Sirri; Bozkurt, Ayhan; Dagdemir, Ayhan; Pinarli, Faruk Guclu; Acar, Sabri

    2009-01-01

    Cytarabine (ARA-C) has been used for many years in the treatment of patients with leukemia and lymphoma. Gastrointestinal ulceration and mucositis are two of the well-known side effects of ARA-C. We set out to investigate whether vitamin A (VA) can help prevent ARA-C-induced mucosal lesions in mice. Mice were divided into 5 groups. Group I (control group) received only saline; group II received ARA-C plus saline; group III received ARA-C plus VA; group IV received ARA-C plus a lipid solution, and group V received VA alone. VA (5000 IU/kg) was administered orally to the mice once daily for 7 days. ARA-C (3.6 mg) was administered intraperitoneally for 5 days to groups II, III and IV, starting on the third day of VA treatment. Intestinal segments from the proximal end of the jejunum of treated mice were isolated. There was improved mucosal integrity, less necrosis and increased villus length with advanced mucosal proliferation in crypts in the VA plus ARA-C group when compared to the ARA-C groups without VA. We conclude that VA has a protective effect against ARA-C-induced mucosal damage in mice.

  5. 68 and FX2149 Attenuate Mutant LRRK2-R1441C-Induced Neural Transport Impairment

    PubMed Central

    Thomas, Joseph M.; Li, Tianxia; Yang, Wei; Xue, Fengtian; Fishman, Paul S.; Smith, Wanli W.

    2017-01-01

    Leucine-rich repeat kinase 2 is a large protein with implications in genetic and sporadic causes of Parkinson's disease. The physiological functions of LRRK2 are largely unknown. In this report, we investigated whether LRRK2 alters neural transport using live-cell imaging techniques and human neuroblastoma SH-SY5Y cells. Our results demonstrated that expression of the PD-linked mutant, LRRK2-R1441C, induced mitochondrial, and lysosomal transport defects in neurites of SH-SY5Y cells. Most importantly, recently identified GTP-binding inhibitors, 68 and FX2149, can reduce LRRK2 GTP-binding activity and attenuates R1441C-induced mitochondrial and lysosomal transport impairments. These results provide direct evidence and an early mechanism for neurite injury underlying LRRK2-induced neurodegeneration. This is the first report to show that LRRK2 GTP-binding activity plays a critical role during neurite transport, suggesting inhibition of LRRK2 GTP-binding could be a potential novel strategy for PD intervention. PMID:28119604

  6. Anti-tumour activity of photodynamic therapy in combination with mitomycin C in nude mice with human colon adenocarcinoma.

    PubMed Central

    Ma, L. W.; Moan, J.; Steen, H. B.; Iani, V.

    1995-01-01

    The interaction of photodynamic therapy (PDT) and a chemotherapeutic drug, mitomycin C (MMC), was investigated using WiDr human colon adenocarcinoma tumours implanted on Balb/c athymic nude mice. The WiDr tumours were treated with PDT alone, MMC alone or with both. It was found that the combined treatment produced a greater retardation in the growth of the WiDr tumour than monotherapy with MMC or PDT. The synergistic effect was especially prominent when PDT was used in combination with a low dose of MMC (1 mg kg-1), since treatment of 1 mg kg-1 MMC alone had no effect on the tumour. The anti-tumour activity of PDT was found to be increased with MMC of 5 mg kg-1. The response of normal skin on mice feet to PDT slightly greater when PDT was combined with 5 mg kg-1 MMC than when PDT was applied alone, while no detectable additional effect on skin photosensitivity was observed when PDT was combined with 1 mg kg-1 MMC. An enhanced uptake of Photofrin in tumours was found 12 h and 24 h after administration of MMC. The effect of MMC on the cell cycle distribution of cell dissociated directly from the tumours was studied. The results suggest that the increased susceptibility to photoinactivation of Photofrin-sensitised tumours may be due to MMC-induced accumulation of the tumour cells in S-phase. PMID:7734319

  7. Effect of mitomycin C on the activation of adenylate cyclase in rat ascites hepatoma AH130 cells.

    PubMed

    Miyamoto, K; Matsunaga, T; Sanae, F; Koshiura, R

    1986-09-01

    Isoproterenol (IPN)-stimulated activity of adenylate cyclase was enhanced in a dose-dependent manner by exposure of AH130 cells to mitomycin C (MMC). The enhancement was also observed in prostaglandin E1-, guanine nucleotide analog-, NaF-, cholera toxin- and forskolin-stimulated activities of the enzyme but not in manganese-stimulated activity. In addition, even when the cells pretreated with islet-activating protein were exposed to MMC, IPN-stimulated activity of adenylate cyclase was enhanced. Anaerobic exposure of AH130 cells to MMC somewhat inhibited IPN-stimulated activity of adenylate cyclase in contrast with aerobic exposure. Exposure of cells to adriamycin also caused enhancement of IPN-stimulated activity of adenylate cyclase but exposure to nitrogen mustard inhibited the enzyme stimulation by IPN. The enhancing effect of MMC was lost by the combined treatment with alpha-tocopherol. From these results, it was shown that MMC modulated the activity of adenylate cyclase, probably through alterations in membrane structure.

  8. Mitomycin C modulates the circadian oscillation of clock gene period 2 expression through attenuating the glucocorticoid signaling in mouse fibroblasts.

    PubMed

    Kusunose, Naoki; Matsunaga, Naoya; Kimoto, Kenichi; Akamine, Takahiro; Hamamura, Kengo; Koyanagi, Satoru; Ohdo, Shigehiro; Kubota, Toshiaki

    2015-11-06

    Clock gene regulates the circadian rhythm of various physiological functions. The expression of clock gene has been shown to be attenuated by certain drugs, resulting in a rhythm disorder. Mitomycin C (MMC) is often used in combination with ophthalmic surgery, especially in trabeculectomy, a glaucoma surgical procedure. The purpose of this study was to investigate the influence of MMC on clock gene expression in fibroblasts, the target cells of MMC. Following MMC treatment, Bmal1 mRNA levels was significantly decreased, whereas Dbp, Per1, and Rev-erbα mRNA levels were significantly increased in the mouse fibroblast cell line NIH3T3 cells. Microarray analysis was performed to explore of the gene(s) responsible for MMC-induced alteration of clock gene expression, and identified Nr3c1 gene encoding glucocorticoid receptor (GR) as a candidate. MMC suppressed the induction of Per1 mRNA by dexamethasone (DEX), ligand of GR, in NIH3T3 cells. MMC also modulated the DEX-driven circadian oscillations of Per2::Luciferase bioluminescence in mouse-derived ocular fibroblasts. Our results demonstrate a previously unknown effect of MMC in GR signaling and the circadian clock system. The present findings suggest that MMC combined with trabeculectomy could increase the risk for a local circadian rhythm-disorder at the ocular surface.

  9. Simultaneous determination of the peptide-mitomycin KW-2149 and its metabolites in plasma by high-performance liquid chromatography.

    PubMed

    Zhang, Z D; Guetens, G; De Boeck, G; Van Cauwenberghe, K; Maes, R A; Ardiet, C; van Oosterom, A T; Highley, M; de Bruijn, E A; Tjaden, U R

    2000-03-10

    A gradient high-performance liquid chromatographic (HPLC) method is described for the quantification of KW-2149 and its two major metabolites in plasma. The method involves a sample clean-up by solid-phase extraction on C18 columns, separation of the respective compounds by HPLC on a YMC ODS-AQ column (5-microm particle size, 150x6 mm I.D.), using a methanol-water gradient system as an eluent, and measurement by UV absorbance detection at 375 nm. The limits of quantitation were 10 ng/ml for KW-2149 and M-16, and 15 ng/ml for M-18. Recoveries from plasma were higher than 92% on C18 extraction columns. Intra-day precision, expressed as %C.V., was between 1.4 and 6.5%. Intra-day accuracy ranged from 94 to 107%. Precision and accuracy of variability of inter-assays increased somewhat; however, were still within acceptable ranges. The ability of the method to quantify KW-2149 and two major metabolites simultaneously, with precision, accuracy and sensitivity, make it useful in monitoring the fate of this new mitomycin in cancer patients.

  10. Pharmacokinetics of intraarterial mitomycin C in hypoxic hepatic infusion with embolization in the treatment of liver metastases.

    PubMed

    Cerretani, Daniela; Roviello, Franco; Pieraccini, Massimo; Civeli, Letizia; Correale, Pierpaolo; Francini, Guido; Marrelli, Daniele; De Manzoni, Giovanni; Pinto, Enrico; Giorgi, Giorgio

    2002-07-01

    1. The pharmacokinetics of mitomycin C (MMC) was evaluated during hypoxic hepatic infusion (HHMI) with arterial embolization for the treatment of unresectable liver metastases. 2. Ten patients with hepatic metastases from colorectal cancer were considered. Antiblastic infusion with MMC (20 mg/m2 at 30 ml/min) was initiated after 10 min of hepatic arterial occlusion. Peripheral venous blood samples were collected at different time intervals. MMC was assayed by high-pressure liquid chromatography (HPLC), and pharmacokinetic parameters were determined using an open, two-compartment model and linear kinetics. 3. Cmax of MMC during HHMI was 708 +/- 336.6 ng/ml, and tmax was 9.3 +/- 1.1 min. The plasma concentration-time curve showed a t1/2 alpha ranging from 1.5 to 9 min, followed by a t1/2 beta ranging from 31 to 93 min. The Cltot was 35.5 l/h/m2 with an area under the plasma concentration-time curve (AUC) ranging from 251 to 850 micrograms h/l. The same AUC parameter standardized for the amount of MMC was 15.5 mg-1. The HHMI model that we used revealed a significant increase in Cltot and a reduction in AUC when compared to the locoregional intraarterial and peripheral intravenous models (p < .001). 4. The reduction in AUC following HHMI explains the limited systemic toxicity in treated patients, with a greater total tumor exposure to the drug and improved drug activation.

  11. Preparation and in vitro properties of N-succinylchitosan- or carboxymethylchitin-mitomycin C conjugate microparticles with specified size.

    PubMed

    Onishi, H; Takahashi, H; Yoshiyasu, M; Machida, Y

    2001-08-01

    The preparation of cross-linked conjugate microparticles of N-succinyl-chitosan (Suc) or 6-O-carboxymethylchitin (CM) with mitomycin C (MMC), which showed an adequate si-e for liver targeting (0.2-3 microm), was attempted by a combination of water-soluble carbodiimide (EDC) coupling and emulsification technique. As for Suc, microparticles with a diameter less than a few micrometers could be obtained easily, while the preparation of CM microparticles (CM-MPs) of the same diameter was not necessarily easy. First, preparation conditions were compared for CM-MPs, and some conditions gave CM-MPs with a diameter less than a few micrometers. As to CM-MMC conjugate microparticles, the method by addition of EDC after emulsification using CM with low molecular weight (CML) gave more appropriate microparticles with a mean diameter of 0.97microm (CM1-MP-MMC). Suc-MMC conjugate microparticles adequate for liver targeting could be produced by the addition of EDC both before and after emulsification, especially, the conjugate microparticles with a mean diameter of 0.45 microm (Suc-MP-MMC) were derived by the addition of EDC before emulsification. Suc-MP-MMC exhibited a higher drug content than CML-MP-MMC. CML-MP-MMC and Suc-MP-MMC exhibited 50% drug release times of 2.87h and 42.1 h, respectively.

  12. Use of high-performance liquid chromatography to detect hydroxyl and superoxide radicals generated from mitomycin C.

    PubMed

    Pritsos, C A; Constantinides, P P; Tritton, T R; Heimbrook, D C; Sartorelli, A C

    1985-11-01

    Distinguishing between short-lived reactive oxygen species like hydroxyl and superoxide radicals is difficult; the most successful approaches employ electron spin resonance (ESR) spin-trapping techniques. Using the spin trap 5,5-dimethyl-l-pyrroline N-oxide (DMPO) to selectively trap various radicals in the presence and absence of ethanol, an HPLC system which is capable of separating the hydroxyl- and superoxide-generated DMPO adduct species has been developed. The radical-generated DMPO adducts were measured with an electrochemical detector attached to the HPLC system and confirmed by spin-trapping techniques. The HPLC separation was carried out on an ODS reverse-phase column with a pH 5.1 buffered 8.5% acetonitrile mobile phase. The advantage of the HPLC system described is that it permits the separation and detection of hydroxyl and superoxide radicals without requiring ESR instrumentation. The antineoplastic bioreductive alkylating agent mitomycin C, when activated by NADPH-cytochrome c reductase, was shown to generate both hydroxyl and superoxide radicals.

  13. The use of mitomycin C with autologous limbal-conjunctival autograft transplantation for management of recurrent pterygium

    PubMed Central

    Fakhry, Mohamed A

    2011-01-01

    Purpose The purpose of this study is to evaluate and compare recurrence rates upon using mitomycin C (MMC) with limbal-conjunctival autograft for treating recurrent pterygia. Methodology An interventional, prospective, comparative clinical study was performed in 30 eyes (26 patients) with recurrent pterygia, allocated into two groups: Group A (19 eyes) operated by pterygium excision and limbal-conjunctival autograft transplantation (L-CAT) without MMC and Group B (20 eyes) operated with injection of 0.1 mL of MMC 0.15 mg/mL 1 month before L-CAT surgery. Exclusion criteria included patients with symblepharon, cicatricial conjunctival diseases, limbal stem cell deficiency, and other intraocular diseases. Results A total of four cases of recurrences for Group A (P = 0.012) and one case of recurrence for Group B (P < 0.001) were recorded. Conclusions Preoperative injection of MMC in low dose and concentration improves the results of L-CAT in recurrent pterygium. PMID:21339805

  14. Topical Mitomycin-C enhances subbasal nerve regeneration and reduces erosion frequency in the debridement wounded mouse cornea.

    PubMed

    Pal-Ghosh, Sonali; Pajoohesh-Ganji, Ahdeah; Tadvalkar, Gauri; Kyne, Briana M; Guo, Xiaoqing; Zieske, James D; Stepp, Mary Ann

    2016-05-01

    Corneal epithelial basement membrane dystrophies and superficial injuries caused by scratches can lead to recurrent corneal erosion syndrome (RCES). Patients and animals with reduced corneal sensory nerve innervation can also develop recurrent erosions. Multiple wild-type mouse strains will spontaneously develop recurrent corneal erosions after single 1.5 mm debridement wounds. Here we show that this wound is accompanied by an increase in corneal epithelial cell proliferation after wound closure but without a commensurate increase in corneal epithelial thickness. We investigated whether excess corneal epithelial cell proliferation contributes to erosion formation. We found that topical application of Mitomycin C (MMC), a drug used clinically to improve healing after glaucoma and refractive surgery, reduces erosion frequency, enhances subbasal axon density to levels seen in unwounded corneas, and prevents excess epithelial cell proliferation after debridement wounding. These results suggest that topically applied MMC, which successfully reduces corneal haze and scarring after PRK, may also function to enhance subbasal nerve regeneration and epithelial adhesion when used to treat RCES. Copyright © 2015 Elsevier Ltd. All rights reserved.

  15. Topical Mitomycin-C enhances subbasal nerve regeneration and reduces erosion frequency in the debridement wounded mouse cornea

    PubMed Central

    Pal-Ghosh, Sonali; Pajoohesh-Ganji, Ahdeah; Tadvalkar, Gauri; Kyne, Briana M.; Guo, Xiaoqing; Zieske, James D.; Stepp, Mary Ann

    2015-01-01

    Corneal epithelial basement membrane dystrophies and superficial injuries caused by scratches can lead to recurrent corneal erosion syndrome (RCES). Patients and animals with reduced corneal sensory nerve innervation can also develop recurrent erosions. Multiple wild-type mouse strains will spontaneously develop recurrent corneal erosions after single 1.5 mm debridement wounds. Here we show that this wound is accompanied by an increase in corneal epithelial cell proliferation after wound closure but without a commensurate increase in corneal epithelial thickness. We investigated whether excess corneal epithelial cell proliferation contributes to erosion formation. We found that topical application of Mitomycin C (MMC), a drug used clinically to improve healing after glaucoma and refractive surgery, reduces erosion frequency, enhances subbasal axon density to levels seen in unwounded corneas, and prevents excess epithelial cell proliferation after debridement wounding. These results suggest that topically applied MMC, which successfully reduces corneal haze and scarring after PRK, may also function to enhance subbasal nerve regeneration and epithelial adhesion when used to treat RCES. PMID:26332224

  16. Preoperative subconjunctival combined injection of bevacizumab and mitomycin C before the surgical excision of primary pterygium: clinical and histological results.

    PubMed

    Alsmman, Alahmady Hamad; Radwan, Gamal; Abozaid, Mortada Ahmed; Mohammed, Usama Ali; Abd Elhaleim, Nesreen Gamal

    2017-01-01

    The aim of this study was to detect the clinical and histological effects of preoperative subconjunctival injection of both bevacizumab and mitomycin C (MMC) 1 month before the surgical excision of primary pterygium using a bare sclera technique. A total of 20 patients with primary pterygium underwent subconjunctival combined injection of 0.1 mL of MMC (0.1 mg/mL) and 0.1 mL of bevacizumab (1.25 mg/0.1 mL) 1 month before bare sclera excision of the pterygium. The excised pterygium tissues were examined histologically and immunohistologically by CD31 staining, and the patients were followed up clinically for at least 2 years. The excised pterygia of two patients without preoperative injection were used for histological comparison. Clinically, there were no intraoperative or postoperative complications. No recurrence was noted during the follow-up period. Histologically, the previously injected pterygia showed a decreased number of epithelial cells and stromal fibroblasts. The latter were rounded or oval and swollen rather than spindle shaped, and some were degenerating or apoptotic. Collagen and elastic fibers were degenerated, distorted, and decreased in density, while blood capillaries were obliterated. There was a significant decrease in CD31-positive cells in previously injected pterygia. Preoperative subpterygium combined injection of bevacizumab and MMC is safe and effective in reducing the postoperative recurrence of primary pterygium. Histological and immunohistological changes in the form of decreased fibrovascular activity and degeneration of the extracellular matrix and nerve axons were noted.

  17. A tubular gelatin scaffold capable of the time-dependent controlled release of epidermal growth factor and mitomycin C.

    PubMed

    Zhu, Jixiang; Yang, Fanwen; He, Fupo; Tian, Xiumei; Tang, Shuo; Chen, Xiaoming

    2015-11-01

    A tubular gelatin scaffold for the time-dependent controlled release of epidermal growth factor (EGF) and mitomycin C (MMC) was fabricated. EGF was incorporated using silk fibroin carriers, and MMC was planted using polylactide (PLA) microspheres. The relationship between scaffold properties and crosslinking degrees was evaluated. As the crosslinking degree was increased from 23.7% to 65.3%, the mechanical properties of the scaffold obviously improved, and the compressive modulus increased to approximately 65kPa. The mass degradation of the scaffold was also controlled from 9 days to approximately 1 month. In vitro release tests indicated that the scaffold mainly released EGF in the early period and MMC in the later period. Urethral epithelial cells (UECs) and urethral scar derived fibroblast cells (UFCs) were coseeded in the scaffold at a ratio of 1:1. After 9 days of coculture, immunostaining results displayed that the proportion of UECs continuously increased to approximately 71%. These changes in cell proportion were confirmed by the results of Western blot analysis. Therefore, the scaffold promoted the growth but inhibited the regeneration of UFCs. This scaffold for time-dependent controlled release of multiple biofactors may be potentially useful in urethral reconstruction and other tissue engineering studies.

  18. Gadolinium induces macrophage apoptosis.

    PubMed

    Mizgerd, J P; Molina, R M; Stearns, R C; Brain, J D; Warner, A E

    1996-02-01

    Gadolinium (Gd) suppresses reticuloendothelial functions in vivo by unknown mechanisms. In vitro exposure of rat alveolar macrophages to GdCl3.6H20 caused cell death, as measured by trypan blue permeability, in both dose- and time-dependent fashions. Even a 10-min exposure to Gd caused significant cell death by 24 h. The morphology of Gd-treated cells, pyknosis and karyorrhexis prior to loss of membrane integrity, suggested apoptosis. Upon flow cytometric examination, Gd-treated propidium iodide-excluding cells demonstrated light scatter changes characteristic of apoptotic cells (decreased forward and increased right angle scatter). Gel electrophoresis of DNA from Gd-treated macrophages clearly showed the ladder pattern unique to apoptotic cells. Electron-dense structures containing Gd were observed via electron spectroscopic imaging within phagosomes and also within nuclei (associated with condensed chromatin). Gadolinium, endocytosed by macrophages and distributed to nuclei, causes apoptosis of macrophages in vitro.

  19. Genetic conflict and apoptosis.

    PubMed

    LeGrand, E K

    2001-01-01

    The benefits of apoptosis in the removal of unnecessary, damaged, or dangerous cells are dependent on the altruism resulting from the absence of genetic conflict between genes in cells. However, this altruism can be exploited by self-promoting or ultra-selfish genes. These self-promoting genes can be endogenous, as with neoplasia or germ cell mutations, or exogenous, as with cellular pathogens. The fundamental flaw of apoptosis is that its development and maintenance as a system is constantly opposed by the emergence of self-promoting genes. Since apoptotically impaired cells cannot be relied on to kill themselves, apoptotic input from other cells is required for controlling self-promoting genes. Certain unique features of germ cell development, such as linkage by cytoplasmic bridges and the requirement for granulosa or Sertoli cells, appear to serve this requirement for control of self-promoting genes.

  20. Mortalin, Apoptosis, and Neurodegeneration

    PubMed Central

    Londono, Carolina; Osorio, Cristina; Gama, Vivian; Alzate, Oscar

    2012-01-01

    Mortalin is a highly conserved heat-shock chaperone usually found in multiple subcellular locations. It has several binding partners and has been implicated in various functions ranging from stress response, control of cell proliferation, and inhibition/prevention of apoptosis. The activity of this protein involves different structural and functional mechanisms, and minor alterations in its expression level may lead to serious biological consequences, including neurodegeneration. In this article we review the most current data associated with mortalin’s binding partners and how these protein-protein interactions may be implicated in apoptosis and neurodegeneration. A complete understanding of the molecular pathways in which mortalin is involved is important for the development of therapeutic strategies for cancer and neurodegenerative diseases. PMID:24970131

  1. Evading apoptosis in cancer.

    PubMed

    Fernald, Kaleigh; Kurokawa, Manabu

    2013-12-01

    Carcinogenesis is a mechanistically complex and variable process with a plethora of underlying genetic causes. Cancer development comprises a multitude of steps that occur progressively starting with initial driver mutations leading to tumorigenesis and, ultimately, metastasis. During these transitions, cancer cells accumulate a series of genetic alterations that confer on the cells an unwarranted survival and proliferative advantage. During the course of development, however, cancer cells also encounter a physiologically ubiquitous cellular program that aims to eliminate damaged or abnormal cells: apoptosis. Thus, it is essential that cancer cells acquire instruments to circumvent programmed cell death. Here we discuss emerging evidence indicating how cancer cells adopt various strategies to override apoptosis, including amplifying the antiapoptotic machinery, downregulating the proapoptotic program, or both. Copyright © 2013 Elsevier Ltd. All rights reserved.

  2. Evading apoptosis in cancer

    PubMed Central

    Fernald, Kaleigh

    2013-01-01

    Carcinogenesis is a mechanistically complex and variable process with a plethora of underlying genetic causes. Cancer development consists of a multitude of steps that occur progressively starting with initial driver mutation(s), to tumorigenesis, and ultimately metastasis. During these transitions, cancer cells accumulate a series of genetic alterations that confer upon the cells an unwarranted survival and proliferative advantage. During the course of development, however, cancer cells also encounter a physiologically ubiquitous cellular program that aims to eliminate damaged or abnormal cells: Apoptosis. Thus, it is essential that cancer cells acquire instruments to circumvent programmed cell death. Here we discuss emerging evidence indicating how cancer cells adopt various strategies to override apoptosis including amplifying the anti-apoptotic machinery, downregulating the pro-apoptotic program, or both. PMID:23958396

  3. Apoptosis in canine distemper.

    PubMed

    Moro, L; de Sousa Martins, A; de Moraes Alves, C; de Araújo Santos, F G; dos Santos Nunes, J E; Carneiro, R A; Carvalho, R; Vasconcelos, A C

    2003-01-01

    Canine distemper is a systemic viral disease characterized by immunosuppression followed by secondary infections. Apoptosis is observed in several immunosuppressive diseases and its occurrence on canine distemper in vivo has not been published. In this study, the occurrence of apoptosis was determined in lymphoid tissues of thirteen naturally infected dogs and nine experimentally inoculated puppies. Healthy dogs were used as negative controls. Samples of lymph nodes, thymus, spleen and brain were collected for histopathological purposes. Sections, 5 microm thick, of retropharingeal lymph nodes were stained by HE, Shorr, Methyl Green-Pyronin and TUNEL reaction. Shorr stained sections were further evaluated by morphometry. Canine distemper virus nucleoprotein was detected by immunohistochemistry. Retropharingeal lymph nodes of naturally and experimentally infected dogs had more apoptotic cells per field than controls. In addition, DNA from thymus of infected dogs were more fragmented than controls. Therefore, apoptosis is increased in lymphoid depletion induced by canine distemper virus and consequently play a role in the immunosuppression seen in this disease.

  4. Apoptosis, fibrosis and senescence.

    PubMed

    Portilla, Didier

    2014-01-01

    Fibrosis is a major hallmark of progressive kidney disease. The cellular mechanisms that lead to kidney tissue fibrosis are complex and include, for example, increased inflammation, increased oxidative stress, and proximal tubule cell death in the form of apoptosis or senescence. Recent studies have identified TWEAK, a tumor necrosis factor-like weak inducer of apoptosis, as a novel cytokine that mediates kidney inflammation in models of renal fibrosis. Inhibition of apoptosis via TWEAK inhibition has been shown to reduce kidney fibrosis. Recent studies using lineage tracing suggest that interstitial pericytes/perivascular fibroblasts differentiate into myofibroblasts and undergo proliferative expansion during fibrosis. Furthermore, increased expression of nuclear peroxisome proliferator-activated receptor-α in proximal tubules can directly reduce increased expression of transforming growth factor-β1 and interstitial inflammation in models of renal fibrosis, which suggests preservation of proximal tubule cell metabolism and integrity represents an important new therapeutic target. In this review, the current evidence and potential molecular mechanisms involved in the development of kidney fibrosis are discussed. 2014 S. Karger AG, Basel.

  5. UV-C induces K sup + efflux from bean but not from oat leaves

    SciTech Connect

    Huerta, A.J.; Gueltig, B.G. )

    1990-05-01

    Previous reports have shown that ultraviolet radiation (UV) induces a specific leakage of K{sup +} from cells in culture as well as from guard cells of bean leaves resulting in stomatal closure. In an effort to determine how general this response may be in photosynthetic leaf cells, we measured the UV-C-induced K{sup +} efflux from irradiated 10-14 day-old bean and oat leaf sections. Our results show that oat leaves do not respond to UV-C irradiation with K{sup +} efflux. However UV-C irradiated bean leaves leaked K{sup +} at a rate of approximately 47 nmoles cm{sup {minus}2} h{sup {minus}1} and the leakage was linear for at least 3.5 hours. The source cells for K{sup +} efflux and the possible mechanisms responsible for this difference in UV-sensitivity will be discussed.

  6. Iron prevents ascorbic acid (vitamin C) induced hydrogen peroxide accumulation in copper contaminated drinking water.

    PubMed

    Jansson, Patric J; Lindqvist, Christer; Nordström, Tommy

    2005-11-01

    Ascorbic acid (vitamin C) induced hydrogen peroxide (H(2)O(2)) formation was measured in household drinking water and metal supplemented Milli-Q water by using the FOX assay. Here we show that ascorbic acid readily induces H(2)O(2) formation in Cu(II) supplemented Milli-Q water and poorly buffered household drinking water. In contrast to Cu(II), iron was not capable to support ascorbic acid induced H(2)O(2) formation during acidic conditions (pH: 3.5-5). In 12 out of the 48 drinking water samples incubated with 2 mM ascorbic acid, the H(2)O(2) concentration exceeded 400 microM. However, when trace amounts of Fe(III) (0.2 mg/l) was present during incubation, the ascorbic acid/Cu(II)-induced H(2)O(2) accumulation was totally blocked. Of the other common divalent or trivalent metal ions tested, that are normally present in drinking water (calcium, magnesium, zinc, cobalt, manganese or aluminum), only calcium and magnesium displayed a modest inhibitory activity on the ascorbic acid/Cu(II)-induced H(2)O(2) formation. Oxalic acid, one of the degradation products from ascorbic acid, was confirmed to actively participate in the iron induced degradation of H(2)O(2). Ascorbic acid/Cu(II)-induced H(2)O(2) formation during acidic conditions, as demonstrated here in poorly buffered drinking water, could be of importance in host defense against bacterial infections. In addition, our findings might explain the mechanism for the protective effect of iron against vitamin C induced cell toxicity.

  7. Increased superoxide levels in ganglia and sympathoexcitation are involved in sarafotoxin 6c-induced hypertension.

    PubMed

    Li, Melissa; Dai, Xiaoling; Watts, Stephanie; Kreulen, David; Fink, Gregory

    2008-11-01

    Endothelin (ET) type B receptors (ET(B)R) are expressed in multiple tissues and perform different functions depending on their location. ET(B)R mediate endothelium-dependent vasodilation, clearance of circulating ET, and diuretic effects; all of these should produce a fall in arterial blood pressure. However, we recently showed that chronic activation of ET(B)R in rats with the selective agonist sarafotoxin 6c (S6c) causes sustained hypertension. We have proposed that one mechanism of this effect is constriction of capacitance vessels. The current study was performed to determine whether S6c hypertension is caused by increased generation of reactive oxygen species (ROS) and/or activation of the sympathetic nervous system. The model used was continuous 5-day infusion of S6c into male Sprague-Dawley rats. No changes in superoxide anion levels in arteries and veins were found in hypertensive S6c-treated rats. However, superoxide levels were increased in sympathetic ganglia from S6c-treated rats. In addition, superoxide levels in ganglia increased progressively the longer the animals received S6c. Treatment with the antioxidant tempol impaired S6c-induced hypertension and decreased superoxide levels in ganglia. Acute ganglion blockade lowered blood pressure more in S6c-treated rats than in vehicle-treated rats. Although plasma norepinephrine levels were not increased in S6c hypertension, surgical ablation of the celiac ganglion plexus, which provides most of the sympathetic innervation to the splanchnic organs, significantly attenuated hypertension development. The results suggest that S6c-induced hypertension is partially mediated by sympathoexcitation to the splanchnic organs driven by increased oxidative stress in prevertebral sympathetic ganglia.

  8. Investigation of Efficacy of Mitomycin-C, Sodium Hyaluronate and Human Amniotic Fluid in Preventing Epidural Fibrosis and Adhesion Using a Rat Laminectomy Model

    PubMed Central

    Bolat, Elif; Kocamaz, Erdoğan; Kulahcilar, Zeki; Yilmaz, Ali; Topcu, Abdullah; Coskun, Mehmet Erdal

    2013-01-01

    Study Design A retrospective study. Purpose The aim of this study was to evalute the effects of mitomycin-C, sodium hyaluronate and human amniotic fluid on preventing spinal epidural fibrosis. Overview of Literature The role of scar tissue in pain formation is not exactly known, but it is reported that scar tissue causes adhesions between anatomic structures. Intensive fibrotic tissue compresses on anatomic structures and increases the sensitivity of the nerve root for recurrent herniation and lateral spinal stenosis via limiting movements of the root. Also, neuronal atrophy and axonal degeneration occur under scar tissue. Methods The study design included 4 groups of rats: group 1 was the control group, groups 2, 3, and 4 receieved antifibrotic agents, mitomycin-C (group 2), sodium hyaluronate (group 3), and human amniotic fluid (group 4). Midline incision for all animals were done on L5 for total laminectomy. Four weeks after the surgery, the rats were sacrificed and specimens were stained with hematoxylin-eosin and photos of the slides were taken for quantitive assesment of the scar tissue. Results There was no significant scar tissue in the experimental animals of groups 2, 3, and 4. It was found that there was no significant difference between drug groups, but there was a statistically significant difference between the drug groups and the control group. Conclusions This experimental study shows that implantation of mitomycin-C, sodium hyaluronate and human amniotic fluid reduces epidural fibrosis and adhesions after spinal laminectomy in rat models. Further studies in humans are needed to determine the complications of the agents researched. PMID:24353840

  9. O{sup 6}-methylguanine DNA-methyltransferase (MGMT) overexpression in melanoma cells induces resistance to nitrosoureas and temozolomide but sensitizes to mitomycin C

    SciTech Connect

    Passagne, Isabelle; Evrard, Alexandre . E-mail: alexandre.evrard@univ-montp1.fr; Depeille, Philippe; Cuq, Pierre; Cupissol, Didier; Vian, Laurence

    2006-03-01

    Alkylating agents play an important role in the chemotherapy of malignant melanomas. The activity of alkylating agents depends on their capacity to form alkyl adducts with DNA, in some cases causing cross-linking of DNA strands. However, the use of these agents is limited by cellular resistance induced by the DNA repair enzyme O{sup 6}-methylguanine DNA-methyltransferase (MGMT) which removes alkyl groups from alkylated DNA strands. To determine to what extent the expression of MGMT in melanoma cells induces resistance to alkylating agents, the human cell line CAL77 Mer- (i.e., MGMT deficient) were transfected with pcMGMT vector containing human MGMT cDNA. Several clones expressing MGMT at a high level were selected to determine their sensitivity to chemotherapeutic drugs. Melanoma-transfected cells were found to be significantly less sensitive to nitrosoureas (carmustine, fotemustine, streptozotocin) and temozolomide with an increase of IC{sub 5} values between 3 and 14 when compared to parent cells. No difference in cell survival rates between MGMT-proficient and -deficient cells was observed for melphalan, chlorambucil, busulphan, thiotepa and cisplatin which preferentially induce N{sup 7} guanine lesions. Surprisingly, MGMT overexpression increased the sensitivity of CAL77 cells to mitomycin C by approximately 10-fold. Treatment of clonal cell lines with buthionine-[S,R]-sulfoximine (BSO), an inhibitor of {gamma}-glutamylcysteine synthetase which depletes cellular glutathione, completely reversed this unexpected increase in sensitivity to mitomycin C. This observation suggests that glutathione is involved in the sensitivity of MGMT-transfected cells to mitomycin C and may act synergistically with MGMT via an unknown mechanism.

  10. Stage-specific DNA synthesis of rat spermatogenesis as an indicator of genotoxic effects of vinblastine, mitomycin C and ionizing radiation on rat spermatogonia and spermatocytes.

    PubMed

    Sjöblom, T; Parvinen, M; Lähdetie, J

    1995-10-01

    We have studied the effects of three known mutagens: vinblastine sulphate, mitomycin C and local irradiation of testes on the stage-specific DNA synthesis in the rat testis by using transillumination assisted microdissection of rat seminiferous tubules. It enables us to investigate the sensitivity of different types of spermatogonia and preleptotene spermatocytes to the genotoxic effects of these agents. According to our results, spermatogonia and preleptotene spermatocytes are quite resistant to the action of vinblastine at the treatment times and the doses used. After treatment with mitomycin C, type A2, A3 and A4 spermatogonia seem to be the first cell types affected, which shows itself as a reduction in the DNA synthesis at stages I, II-III, XIII-XIV of the epithelial cycle two and/or three days after the treatment. It also seems that they are mostly affected during the S-phase of their cell cycles. In addition, preleptotene spermatocytes are also sensitive to the action of mitomycin C when they are treated in the G1 phase of the cell cycle. The local irradiation of 3 Gy has severe effects on the spermatogonia of rat testis which can be seen already 18 h after the treatment and becomes more evident 42 and 66 h after the treatment as a reduction of DNA synthesis at stages XII-V. Type A spermatogonia (A1-A4) seem to be the most sensitive cell types to the action of irradiation. This study indicates that the novel method of stage-specific DNA synthesis in rat spermatogenesis allows detailed studies of sensitivities in differentiating spermatogonia to genotoxic agents.

  11. Concomitant Chemoradiotherapy With Mitomycin C and Cisplatin in Advanced Unresectable Carcinoma of the Head and Neck: Phase I-II Clinical Study

    SciTech Connect

    Strojan, Primoz Karner, Katarina; Smid, Lojze; Soba, Erika; Fajdiga, Igor; Jancar, Boris; Anicin, Aleksandar; Budihna, Marjan; Zakotnik, Branko

    2008-10-01

    Purpose: To evaluate the toxicity and efficacy of concomitant chemoradiotherapy with mitomycin C and cisplatin in the treatment of advanced unresectable squamous cell carcinoma of the head and neck. Patients and Methods: Treatment consisted of conventional radiotherapy (70 Gy in 35 fractions), mitomycin C 15 mg/m{sup 2} IV, applied after the delivery of 10 Gy, and cisplatin at an initial dose of 10 mg/m{sup 2}/d IV, applied during the last 10 fractions of irradiation ('chemoboost'). The cisplatin dose was escalated with respect to the toxic side effects by 2 mg/m{sup 2}/d up to the maximum tolerated dose (MTD) or at the most 14 mg/m{sup 2}/d (Phase I study), which was tested in the subsequent Phase II study. Results: All 36 patients had Stage T4 and/or N3 disease, and the majority had oropharyngeal (50%) or hypopharyngeal (39%) primary tumors. Six patients were treated at each of the three cisplatin dose levels tested (Phase I study). Dose-limiting toxicity was not reached even at 14 mg/m{sup 2}/d of cisplatin, which was determined as the MTD and tested in an additional 18 patients (Phase II study). After a median follow-up time of 48 months, 4-year locoregional control, failure-free, and overall survival rates were 30%, 14%, and 20%, respectively. In 24 patients treated at the cisplatin dose level of 14 mg/m{sup 2}/d, the corresponding rates were 40%, 20%, and 22%, respectively. Conclusion: Concomitant chemoradiotherapy with mitomycin C and cisplatin 'chemoboost' at 14 mg/m{sup 2}/d is feasible, with encouraging survival results if the extremely poor disease profile of the treated patients is considered.

  12. Effects of laser photobiomodulation on cutaneous wounds treated with mitomycin C: a histomorphometric and histological study in a rodent model.

    PubMed

    Santos, Nicole R Silva; dos Santos, Jean N; Sobrinho, João B Macedo; Ramalho, Luciana M P; Carvalho, Carolina M; Soares, Luiz G P; Pinheiro, Antônio L B

    2010-02-01

    The aim of the present study was to assess histologically the effect of Laser Photobiomodulation (LPBM) on skin wounds treated with Mitomycin C (MMC). Wound healing occurs because of a competitive mechanism between the synthesis and lyses of collagen. Therefore, any factor that increases the lyses or reduces the synthesis of collagen may result in changes in the healing process. MMC is an antineoplastic drug that inhibits fibroblast proliferation, collagen synthesis, and neoangiogenesis. LPBM has been shown to stimulate wound healing, increasing the production of collagen, fibroblastic proliferation, and angiogenesis. Forty-eight Wistar rats were randomly distributed into 4 main groups (n = 12): G1--control (G1a--7 d and G1b--14 d); G2--MMC (G2a--7 d and G2b--14 d); G3--MMC + lambda660 nm laser (G3a--7 d and G3b--14 d); and G4--MMC + lambda790 nm laser (G4a--7 d and G4b--14 d). Under general anesthesia, one excisional wound was created on the dorsum of each animal. Two ml of MMC solution was applied to the wound 4 h after surgery for 5 min. LPBM was performed on groups G3 (lambda690 nm; 20 J/cm(2); 30 mW; Phi = 2 mm) and G4 (lambda790 nm; 20 J/cm(2); 40 mW; Phi = 2 mm), starting immediately after the application of the MMC and repeated every other day during the experimental period. Laser light was applied transcutaneously at 4 equidistant points on the wound margin (4 x 5 J/cm(2), 20 J/cm(2)/session). The specimens were routinely cut and processed to wax. The slides were stained with HE and Sirius red. Computerized hystomorphometry was performed. LPBM resulted in reduced inflammation and an increase in both fibroblast proliferation and collagen deposition. The use of LPBM improves wound healing in subjects treated with MMC.

  13. Hydroxyurea induces chromosomal damage in G2 and enhances the clastogenic effect of mitomycin C in Fanconi anemia cells.

    PubMed

    Molina, Bertha; Marchetti, Francesco; Gómez, Laura; Ramos, Sandra; Torres, Leda; Ortiz, Rocio; Altamirano-Lozano, Mario; Carnevale, Alessandra; Frias, Sara

    2015-06-01

    Fanconi's anemia (FA) is a recessive disease; 16 genes are currently recognized in FA. FA proteins participate in the FA/BRCA pathway that plays a crucial role in the repair of DNA damage induced by crosslinking compounds. Hydroxyurea (HU) is an agent that induces replicative stress by inhibiting ribonucleotide reductase (RNR), which synthesizes deoxyribonucleotide triphosphates (dNTPs) necessary for DNA replication and repair. HU is known to activate the FA pathway; however, its clastogenic effects are not well characterized. We have investigated the effects of HU treatment alone or in sequential combination with mitomycin-C (MMC) on FA patient-derived lymphoblastoid cell lines from groups FA-A, B, C, D1/BRCA2, and E and on lymphocytes from two unclassified FA patients. All FA cells showed a significant increase (P < 0.05) in chromosomal aberrations following treatment with HU during the last 3 h before mitosis. Furthermore, when FA cells previously exposed to MMC were treated with HU, we observed an increase of MMC-induced DNA damage that was characterized by high occurrence of DNA breaks and a reduction in rejoined chromosomal aberrations. These findings show that exposure to HU during G2 induces chromosomal aberrations by a mechanism that is independent of its well-known role in replication fork stalling during S-phase and that HU interfered mainly with the rejoining process of DNA damage. We suggest that impaired oxidative stress response, lack of an adequate amount of dNTPs for DNA repair due to RNR inhibition, and interference with cell cycle control checkpoints underlie the clastogenic activity of HU in FA cells. Environ. Mol. Mutagen. 56:457-467, 2015. © 2015 Wiley Periodicals, Inc.

  14. Loading mitomycin C inside long circulating hyaluronan targeted nano-liposomes increases its antitumor activity in three mice tumor models.

    PubMed

    Peer, Dan; Margalit, Rimona

    2004-02-20

    The frequent overexpression of the hyaluronan receptors CD44 and RHAMM in cancer cells opens the door for targeting by the naturally-occurring high-M(r) hyaluronan. This is the first time effective in vivo tumor targeting is reported for mitomycin C (MMC) loaded inside nano-sized hyaluronan-liposomes (denoted tHA-LIP). The severe adverse effects of free MMC made it a rational candidate for an effective targeted carrier. In vitro, loading MMC inside tHA-LIP increased drug potency 100-fold, in cells overexpressing, but not in cells underexpressing, hyaluronan receptors. Both types of liposomes were non-toxic and reduced MMC-related toxicity in healthy C57BL/6 mice. In 3 tumor models, BALB/c bearing C-26 solid tumors; C57BL/6 bearing B16F10.9 or (separately) D122 lung metastasis, tHA-LIP were long-circulating, 7-fold and 70-fold longer than nt-LIP and free MMC, respectively. tHA-LIP-mediated MMC accumulation in tumor-bearing lungs was 20% of injected dose, compared to 0.6% and 4% with free drug and nt-LIP, respectively. Tumor-free lungs showed low accumulation, irrespective of drug formulation. Key indicators of therapeutic responses, tumor progression, metastatic burden and survival, were superior (p < 0.001) in animals receiving MMC-loaded tHA-LIP, no treatment, MMC-loaded nt-LIP and free drug. In conclusion, tHA-LIP perform as tumor-targeted carriers, with promising prospects for treatment of tumors overexpressing hyaluronan receptors.

  15. Experimental research on the effect of mitomycin C fibrin gel on spinal peridural scar tissue in rats.

    PubMed

    Liu, Wenping

    2014-09-01

    This paper aimed to study the best working concentration of mitomycin C (MMC) fibrin gel on spinal peridural scar tissue in rats and the sustained release function of peridural adhesion after laminectomy of rats. 96 SD rats were divided into four groups. They were conducted L1 laminectomy and sprayed FG-MMC. The concentration of MMC was detected and the best working concentration of MMC was selected. Then other 48 SD rats were divided into four groups to construct L1 vertebral plate excision model. Materials were drawn 4 weeks after the operation for Rydell grading. In addition, we observed HE staining and fibroblast proliferation and collagen distribution situation after Masson staining. And concentration of hydroxyproline was also detected. The best working concentration of MMC experiment showed that except experimental group C, the other groups all appeared drug release peak in the 4th week after the operation. MMC concentration of group C appeared drug release peak in the 5th week besides the 2nd week. Moreover, adhesion of endorhachis and peripheral tissue in group A was the most obvious while the group C was the weakest. Experiment on the slow-release effect of different adhesion materials on peridural adhesion showed that compared to the contrast group and group F, Rydell grading in group E and G was Level 0 and with low adhesion degree, little fibroblast and fibrocyte, low collagen content, regular collagen fibers arrangement and no inflammatory cells after HE staning and Masson staining. In addition, content of hydroxyproline(HOP) decreased significantly especially the group of FG-MMC mixture. It was concluded that MMC fibrin gel mixture had a good slow-release effect on adhesion of spinal peridural scar tissue in rats and the best working concentration was 0.5 mg FG-MMC/ml.

  16. Sustained Release of Mitomycin C from Its Conjugate with Single-Walled Carbon Nanotubes Associated by Pegylated Peptide.

    PubMed

    Ohta, Takahisa; Hashida, Yasuhiko; Yamashita, Fumiyoshi; Hashida, Mitsuru

    2016-01-01

    A novel sustained release formulation of mitomycin C (MMC) was developed by employing single-walled carbon nanotubes (SWCNTs) wrapped by designed peptide with polyethylene glycol (PEG) modification (pegylation) as a nano-scale molecular platform. The amino groups of polycationic and amphiphilic H-(-Cys-Trp-Lys-Gly-)(-Lys-Trp-Lys-Gly-)6-OH [CWKG(KWKG)6] peptide associated with SWCNTs were modified using PEG with 12 units (PEG12) to improve the dispersion stability of the composite. Then thiol groups of peptide were conjugated with MMC using N-ε-maleimidocaproic acid (EMCA) as a linker via transformation of aziridine group of MMC. The obtained SWCNTs-CWKG(KWKG)6-(PEG)12-C6-MMC composites particularly that with 13.6% PEG modification extent of amino groups, showed good dispersion stability both in water and in a cell culture medium for 24 h. The release of MMC from SWCNTs-CWKG(KWKG)6-(PEG)12-C6-MMC was confirmed to follow first-order kinetics being accelerated by the pH increase in good agreement with the results observed for MMC-dextran conjugate with the same conjugation structure. The SWCNTs-CWKG(KWKG)6-(PEG)12 composite exhibited a considerably low cytotoxicity against cultured human lung adenocarcinoma epithelial cell line (A549). In contrast, SWCNTs-CWKG(KWKG)6-(PEG)12-C6-MMC demonstrated delayed but relatively corresponding antitumor activity with free MMC at the same concentration. The results suggested the potential role of SWCNTs-CWKG(KWKG)6-(PEG)12 as a carrier for a controlled release drug delivery system (DDS).

  17. Conjugation of glutathione and other thiols with bioreductively activated mitomycin C. Effect of thiols on the reductive activation rate.

    PubMed

    Sharma, M; Tomasz, M

    1994-01-01

    Mitomycin C (MC), a clinically used natural antitumor agent, was shown to form three monoconjugates (11a-13a) and two bisconjugates (14a, 15a) with GSH upon reductive activation by rat liver microsomes, purified NADPH-cytochrome c reductase, or NADH-cytochrome c reductase or chemical reduction using H2/PtO2. Rat liver cytosol/NADH activated MC only at acidic pH (5.8), resulting in the formation of a single GSH-MC monoconjugate, 13a. The reductase responsible for cytosolic activation of MC to form this conjugate was DT-diaphorase. GSH itself did not reduce MC, and unreduced MC did not form conjugates with GSH. A moderate catalytic effect by glutathione S-transferase was demonstrated on the cytosol-activated reaction. Mercaptoethanol and N-acetylcysteine gave analogous sets of five MC-thiol conjugates under cytochrome c reductase or H2/PtO2 activation conditions. The structures of all 15 MC-thiol conjugates (five each with GSH, mercaptoethanol, and N-acetylcysteine, respectively) were determined, using 1H-NMR, UV, and mass spectroscopies, combined with analytical chemical and radiolabeling methods. The mechanism of formation of the conjugates features SN2 displacement of the carbamate of the reduced MC by GS-. The MC-GSH conjugates were noncytotoxic to the tumor cells tested. The conjugation of GSH with activated MC is likely to represent detoxication in mammalian cells. As another effect, GSH accelerates the rate of reduction of MC by "slow" reducing agents such as cytochrome c reductases and H2/PtO2. A mechanism is proposed to explain this effect, which involves further reduction of the initially formed MC semiquinone free radical by GSH.

  18. Quantitation of mitomycin C in human ocular tissues by high-performance liquid chromatography-photo-diode array detection.

    PubMed

    Xiong, X; Lim, B A; Lat-Luna, M; Chew, P; Tan, D

    2001-05-05

    A chromatographic method, which can quantitate mitomycin C (MMC) along with two antiglaucoma drugs, is described. The separation of MMC, alphagan and timolol was performed on a reversed-phase C18 column with water-methanol-trifluoroacetic acid (65:35:0.01, v/v) as the mobile phase. By monitoring at 360, 248 and 296 nm, the lower limits of detection for MMC, alphagan and timolol are, respectively, 1.0, 2.0 and 5.0 ng (injection amount) at three-time S/N ratio. The dynamic ranges of quantitation for the three drugs are, respectively, 1.0 ng-10.0 microg, 2.0 ng-10.0 microg and 5.0 ng-10.0 microg with linearity being larger than 0.9960. This method was applied to the determination of MMC levels in Tenon's and trabeculum tissues of 10 glaucoma patients. MMC levels in these tissues, which were obtained from glaucoma filtering surgery, were determined following a multiple extraction with methanol. The recovery of MMC for a two-batch extraction was better than 91.2%. The reproducibility of measurement for the MMC levels in these tissues is 2.5-6.0% RSD for triplicate injections. The intra-day variation of retention times for the MMC peaks was less than 1.6% RSD (n=3). The inter-day variation of retention times for the MMC peaks was less than 4.8% RSD (n=3). MMC was detectable in three trabeculum tissues out of 10 cases (ranging from 0.8 to 25.5 ng/mg specimen), while MMC was detected in nine Tenon's tissues out of 10 cases (ranging from 0.3 to 21.1 ng/mg specimen). The results obtained show that the method is sensitive and selective for the quantitation of MMC.

  19. In vitro diffusion of mitomycin-C into human sclera after episcleral application: impact of diffusion time.

    PubMed

    Georgopoulos, M; Vass, C; El Menyawi, I; Radda, S; Graninger, W; Menapace, R

    2000-11-01

    The purpose of this study was to investigate the impact of different diffusion times of mitomycin-C (MMC) on the intrascleral concentration vs depth profile of MMC in an experimental model. Scleral quadrants of eight human donor eyes were exposed to sponges soaked with MMC for an application time of 1 min. After irrigation with 40 ml saline, we allowed further diffusion of MMC in the sclera for 1, 5, 14 and 29 min until the specimens were further processed. A central 8 mm diameter scleral disk was horizontally dissected with a kryotome at -20 degrees C. MMC concentrations of six layers of 140 microm thickness were analysed by means of high-performance liquid chromatography. The MMC concentrations (microg g(-1)) of layer 1 were: 13.45+/- 5.9 (mean +/- S.D. at 2 min diffusion time), 7.6+/-2.5 (6 min diffusion), 5.6+/-3.1 (15 min diffusion) and 3.6+/-1.7 (30 min diffusion). The corresponding MMC concentrations of layer 6 were: 0.61+/-0.48, 1.47 +/-0.66, 1.83+/-0.42 and 2.98+/-0.97 microg g(-1). The superficial concentration of intrascleral MMC decreased with increasing diffusion time, the deep concentrations increased. After 30 min of diffusion time, equal concentrations of MMC were found in all layers. Even with current low-dose application regimens of MMC the concentrations in the inner side of the sclera rapidly increase beyond the limits of the therapeutic range. Owing to this fast diffusion of MMC, the only means of reducing ciliary body concentrations of MMC is to reduce the dose.

  20. Preoperative subconjunctival combined injection of bevacizumab and mitomycin C before the surgical excision of primary pterygium: clinical and histological results

    PubMed Central

    Alsmman, Alahmady Hamad; Radwan, Gamal; Abozaid, Mortada Ahmed; Mohammed, Usama Ali; Abd Elhaleim, Nesreen Gamal

    2017-01-01

    Purpose The aim of this study was to detect the clinical and histological effects of preoperative subconjunctival injection of both bevacizumab and mitomycin C (MMC) 1 month before the surgical excision of primary pterygium using a bare sclera technique. Patients and methods A total of 20 patients with primary pterygium underwent subconjunctival combined injection of 0.1 mL of MMC (0.1 mg/mL) and 0.1 mL of bevacizumab (1.25 mg/0.1 mL) 1 month before bare sclera excision of the pterygium. The excised pterygium tissues were examined histologically and immunohistologically by CD31 staining, and the patients were followed up clinically for at least 2 years. The excised pterygia of two patients without preoperative injection were used for histological comparison. Results Clinically, there were no intraoperative or postoperative complications. No recurrence was noted during the follow-up period. Histologically, the previously injected pterygia showed a decreased number of epithelial cells and stromal fibroblasts. The latter were rounded or oval and swollen rather than spindle shaped, and some were degenerating or apoptotic. Collagen and elastic fibers were degenerated, distorted, and decreased in density, while blood capillaries were obliterated. There was a significant decrease in CD31-positive cells in previously injected pterygia. Conclusion Preoperative subpterygium combined injection of bevacizumab and MMC is safe and effective in reducing the postoperative recurrence of primary pterygium. Histological and immunohistological changes in the form of decreased fibrovascular activity and degeneration of the extracellular matrix and nerve axons were noted. PMID:28331283

  1. Development of both methotrexate and mitomycin C loaded PEGylated chitosan nanoparticles for targeted drug codelivery and synergistic anticancer effect.

    PubMed

    Jia, Mengmeng; Li, Yang; Yang, Xiangrui; Huang, Yuancan; Wu, Hongjie; Huang, Yu; Lin, Jinyan; Li, Yanxiu; Hou, Zhenqing; Zhang, Qiqing

    2014-07-23

    Codelivery of multiple drugs with one kind of drug carriers provided a promising strategy to suppress the drug resistance and achieve the synergistic therapeutic effect in cancer treatment. In this paper, we successfully developed both methotrexate (MTX) and mitomycin C (MMC) loaded PEGylated chitosan nanoparticles (CS-NPs) as drug delivery systems, in which MTX, as a folic acid analogue, was also employed as a tumor-targeting ligand. The new drug delivery systems can coordinate the early phase targeting effect with the late-phase anticancer effect. The (MTX+MMC)-PEG-CS-NPs possessed nanoscaled particle size, narrow particle size distribution, and appropriate multiple drug loading content and simultaneously sustained drug release. In vitro cell viability tests indicated that the (MTX+MMC)-PEG-CS-NPs exhibited concentration- and time-dependent cytotoxicity. Moreover, in vitro cellular uptake suggested that the (MTX+MMC)-PEG-CS-NPs could be efficiently taken up by cancer cells by FA receptor-mediated endocytosis. On the other hand, the (MTX+MMC)-PEG-CS-NPs can codelivery MTX and MMC to not only achieve the high accumulation at the tumor site but also more efficiently suppress the tumor cells growth than the delivery of either drug alone, indicating a synergistic effect. In fact, the codelivery of two anticancer drugs with distinct functions and different anticancer mechanisms was key to opening the door to their targeted drug delivery and synergistic anticancer effect. Therefore, the (MTX+MMC)-PEG-CS-NPs as targeted drug codelivery systems might have important potential in clinical implications for combination cancer chemotherapy.

  2. Comparison of EX-PRESS Shunt and Trabeculectomy With Mitomycin-C in Congenital and Juvenile Glaucoma.

    PubMed

    Nash, David L; Crouch, Eric R; Crouch, Earl R

    2017-02-01

    To compare efficacy and safety of EX-PRESS mini glaucoma shunt (Alcon) and trabeculectomy with mitomycin-C (MMC) in the management of pediatric glaucoma. The authors retrospectively reviewed patients from a single pediatric ophthalmology practice with either congenital or juvenile glaucoma who underwent surgical treatment with either trabeculectomy or EX-PRESS shunt insertion with MMC. Postoperative intraocular pressure at 6, 18, and 36 months, medication requirements, visual acuities, postoperative interventions, complications, and noncompliance with medications or follow-up was reviewed. A total of 42 cases of glaucoma with either trabeculectomy or EX-PRESS shunt were identified for review (n trabeculectomy=25, n EX-PRESS=17). At 6 months, 62.5% of trabeculectomies and 94.1% of EX-PRESS shunts met criteria for success (P=0.0281). At 18 months, 38.1% of trabeculectomies and 81.3% of EX-PRESS shunts met criteria for success (P=0.0178). At 36 months, trabeculectomies had a success rate of 33.3% versus 66.7% for EX-PRESS shunts (P=0.321). The average decrease in medications postoperatively was 0.375 and 1.63 for trabeculectomy and EX-PRESS shunt, respectively (P=0.06). Preoperative visual acuities compared with postoperative best-corrected visual acuities before additional surgery demonstrated a slight average worsening of 0.11 logMAR in trabeculectomy patients and an average improvement of 0.56 logMAR in EX-PRESS shunt patients (P=0.0037). In this review, patients with pediatric glaucoma managed with EX-PRESS shunt with MMC compared with trabeculectomy with MMC appear to have better intraocular pressure control, better visual acuities, and fewer complications and reoperations.

  3. Comparison of Subconjunctival Mitomycin C and 5-Fluorouracil Injection for Needle Revision of Early Failed Trabeculectomy Blebs

    PubMed Central

    Liu, Wei; Wang, Jianrong; Zhang, Miaomiao; Tao, Yuan; Sun, Yan

    2016-01-01

    Background. To compare the efficacy of needle revision with 5-fluorouracil (5-FU) and mitomycin C (MMC) on dysfunctional filtration blebs shortly after trabeculectomy. Methods. It is a prospective randomized study comparing needle revision augmented with MMC or 5-FU for failed trabeculectomy blebs. Results. To date 71 patients (75 eyes) have been enrolled, 40 eyes in the MMC group and 35 in the 5-FU group. 68 patients (72 eyes) have completed 12-month follow-up, 38 eyes in the MMC group and 34 in the 5-FU group. The mean IOP before and that after needle revision in the MMC group were 26.5 ± 4.3 mmHg and 11.3 ± 3.4 mmHg, respectively (P < 0.05), and in the 5-FU group were 27.1 ± 3.8 mmHg and 10.9 ± 3.4 mmHg, respectively (P < 0.05). At 12-month follow-up, complete success rates were 57.5% for MMC group and 34.3% for 5-FU group (P = 0.042; log-rank test) and 75% and 60% (P = 0.145; log-rank test), respectively, for the qualified success. Complication rates between the two groups were not statistically different (P > 0.05). Conclusions. Needle revision and subconjunctival MMC injection were more effective than needling and subconjunctival 5-FU injection for early dysfunctional filtration blebs after trabeculectomies. PMID:26989499

  4. Engraftment of Syngeneic and Allogeneic Endothelial Cells, Hepatocytes and Cholangiocytes into Partially Hepatectomized Rats Previously Treated with Mitomycin C1

    PubMed Central

    Brilliant, Kate E.; Mills, David R.; Callanan, Helen M.; Hixson, Douglas C.

    2009-01-01

    Background Pretreatment with retrorsine crosslinks host hepatocyte DNA and prevents proliferation after partial hepatectomy (PH), allowing selective expansion of transplanted progenitors. Shortcomings are length of protocol and carcinogenicity of retrorsine. Methods This report describes a rapid liver repopulation protocol using mitomycin C (MMC) to block proliferation of rat hepatocytes in response to PH. One week post-MMC treatment, dipeptidyl peptidase IV negative (DPPIV−) host rats were given a PH followed by injection of late gestation, newborn or adult total liver isolates from DPPIV+ rats. For allogeneic transplantation, host rats received injections of anti-CD3 antibody before and after PH. Results Host liver staining 2–9 weeks post-transplantation revealed well-defined donor hepatocyte colonies with strong canalicular DPPIV activity. At the same cell dose, fetal and newborn isolates produced more colonies than adult liver isolates. Hepatocyte colonies also co-expressed marker proteins characteristic of adult hepatocytes and showed polarized localization of plasma membrane proteins. Host livers contained large clusters of sinusoids lined by DPPIV+ endothelial cells co-expressing the endothelial cell marker, RECA-1 but lacked the canalicular marker leucine aminopeptidase. Colonies containing donor hepatocytes, endothelial cells and bile ducts, were also observed. Similar levels of engraftment and expansion were achieved with allogeneic liver cell isolates by using anti-CD3 antibody treatment. Conclusions The MMC transplantation model provides a rapid method for engraftment and expansion of hepatocytes, endothelial cells and cholangiocytes and should be applicable to investigations centering on the role of endothelial cells in liver regeneration and the identification and characterization of putative endothelial, hepatocyte and cholangiocyte progenitors. PMID:19696631

  5. Preoperative concurrent 5-Fluorouracil infusion, Mitomycin C and pelvic radiation therapy in tethered and fixed rectal carcinoma

    SciTech Connect

    Chan, A.; Wong, A.; Langevin, J.; Khoo, R. )

    1993-04-02

    This is a Phase 1/2 study of preoperative concurrent radiation and chemotherapy in tethered and fixed rectal carcinoma. This study examined the curative resectability, the acute toxicities during chemo-radiation and the surgical complications. Between 1986 and 1990, 46 patients were treated with preoperative pelvic radiation (4,000 cGy in 20 fractions in 4 weeks), 5-Fluorouracil infusion (20 mg/m[sup 2], days 1--4 and 15--18) and Mitomycin C (8 mg/m[sup 2], day 1). This was followed by surgery 6 to 8 weeks later. 30 patients had tethered tumors and 16 patients had fixed tumors. After preoperative chemo-radiation, 41 patients (89%) underwent curative resection. Two patients (4%) had no residual tumor found (T0N0M0). Seven patients (15%) had nodal metastases. Two patients developed grade 3 neutropenia (WBC = 1--2 [times] 10[sup 9]/L) during chemo-radiation. Five patients had delay in perineal wound healing. One patient had an anastomotic leak. Four patients developed stomal stenosis which required surgical revision. The 2-year actuarial survival was 73%. The 2-year local relapse rate was 16%. Patients with fixed carcinoma had a higher incidence of local failure (28% vs. 10%) and the difference was statistically significant (p = 0.0036). The 2-year distant failure rate was 41%, and the rates were similar for both tethered and fixed carcinomas. Preoperative pelvic radiation, chemotherapy and surgery could achieve a curative resection rate of 89% in tethered and fixed rectal carcinomas. However, distant metastases remained the major cause of failure. 42 refs., 6 figs., 4 tabs.

  6. Radiosensitizing and cytotoxic properties of mitomycin C in a C3H mouse mammary carcinoma in vivo

    SciTech Connect

    Grau, C.; Overgaard, J. )

    1991-02-01

    The radiosensitizing and cytotoxic properties of Mitomycin C (MMC) was investigated in vivo using regrowth delay and tumor control assays. MMC significantly enhanced the radiation-induced growth delay when administered 15 min before irradiation; the slope of the dose response curve significantly increased and corresponded to a Dose Modifying Factor (DMF) of 1.9 (1.5-2.3; p less than 0.001). When MMC was given 4 hr after irradiation, the additional regrowth delay resulted in a parallel shift of the dose response curve, and MMC was not significantly dose modifying (DMF 1.3 (0.9-1.3); p less than 0.05). From isobologram analysis it was found that the preirradiation MMC schedule resulted in supra-additive responses, whereas MMC given after irradiation had an additive effect. The enhancement of radiation-induced tumor control was similarly found to peak when MMC was given 6 hr to 15 min prior to irradiation. At these intervals, the observed TCD50 for the combined treatments relative to radiation alone corresponded to Enhancement Ratios of 1.27 and 1.29, respectively (p less than 0.001). Longer intervals between the modalities reduced the enhancement, but the combined treatments were still significantly better than radiation alone (ER 1.12, 1.16 and 1.17; p less than 0.001). The significant enhancement of tumor control correlated with a substantial drug-induced cytotoxic effect toward hypoxic tumor cells, as determined by clamped TCD50 experiments. A single dose of MMC (3 mg/kg) was found to kill up to 97% of all hypoxic tumor cells.

  7. One compared with two cycles of mitomycin C in chemoradiotherapy for anal cancer: analysis of outcomes and toxicity

    PubMed Central

    Yeung, R.; McConnell, Y.; Roxin, G.; Banerjee, R.; Urgoiti, G.B. Roldán; MacLean, A.R.; Buie, W.D.; Mulder, K.E.; Vickers, M.M.; Joseph, K.J.; Doll, C.M.

    2014-01-01

    Background Concurrent chemoradiation with fluorouracil (5fu) and mitomycin C (mmc) is standard treatment for anal canal carcinoma (acc). The current protocol in Alberta is administration of 5fu and mmc during weeks 1 and 5 of radiation. However, administration of the second bolus of mmc has been based largely on centre preference. Given limited published data on outcomes with different mmc regimens, our objective was to compare the efficacy and toxicity of 1 compared with 2 cycles of mmc in acc treatment. Methods Our retrospective study evaluated 169 acc patients treated with radical chemoradiotherapy between 2000 and 2010 at two tertiary cancer centres. All patients were treated with 2 cycles of 5fu and with 1 cycle (mmc1) or 2 cycles (mmc2) of mmc. Acute toxicities, disease-free (dfs) and overall survival (os) were analyzed. Results Baseline demographics, performance status, and stage were similar in the groups of patients who received mmc1 (52%) and mmc2 (48%). Before treatment, median hematologic parameters were comparable, except for white blood cell count, which was higher in the mmc2 group, but within normal range. The 5-year os and dfs were similar (75.1% and 54.2% for mmc1 vs. 70.7% and 44.2% for mmc2, p = 0.98 and p = 0.63 respectively). On multivariate analysis, mmc2 was the factor most strongly associated with specific acute toxicities: grade 3+ leukopenia (hazard ratio: 4.82; p < 0.01), grade 3+ skin toxicity (hazard ratio: 4.76; p < 0.001), and hospitalizations secondary to febrile neutropenia (hazard ratio: 9.91; p = 0.001). Conclusions In definitive chemoradiotherapy for acc, 1 cycle of mmc appears to offer outcomes similar to those achieved with 2 cycles, with significantly less acute toxicity. PMID:24940105

  8. Mitomycin-C in corneal surface excimer laser ablation techniques: a report by the American Academy of Ophthalmology.

    PubMed

    Majmudar, Parag A; Schallhorn, Steven C; Cason, John B; Donaldson, Kendall E; Kymionis, George D; Shtein, Roni M; Verity, Steven M; Farjo, Ayad A

    2015-06-01

    To review the published literature assessing the efficacy and safety of mitomycin-C (MMC) as an adjunctive treatment in corneal surface excimer laser ablation procedures. Literature searches of the PubMed and Cochrane Library databases were last conducted on August 19, 2014, without language or date limitations. The searches retrieved a total of 239 references. Of these, members of the Ophthalmic Technology Assessment Committee Refractive Management/Intervention Panel selected 26 articles that were considered to be of high or medium clinical relevance, and the panel methodologist rated each article according to the strength of evidence. Ten studies were rated as level I evidence, 5 studies were rated as level II evidence, and the remaining 11 studies were rated as level III evidence. The majority of the articles surveyed in this report support the role of MMC as an adjunctive treatment in surface ablation procedures. When MMC is applied in the appropriate concentration and confined to the central cornea, the incidence of post-surface ablation haze is decreased. Although a minority of studies that evaluated endothelial cell density (ECD) reported an MMC-related decrease in ECD, no clinical adverse outcomes were reported. Over the past 15 years, the use of MMC during surgery in surface ablation has become widespread. There is good evidence of the effectiveness of MMC when used intraoperatively as prophylaxis against haze in higher myopic ablations. Although there are reports of decreased endothelial counts after the administration of MMC during surgery, the clinical significance of this finding remains uncertain, because no adverse outcomes were reported with as much as 5 years of follow-up. Optimal dosage, effectiveness as prophylaxis in lower myopic and hyperopic ablations, and long-term safety, particularly in eyes with reduced corneal endothelial cell counts from prior intraocular surgery, have yet to be established. Copyright © 2015 American Academy of

  9. Effect of mitomycin-C on contraction and migration of human nasal mucosa fibroblasts: implications in dacryocystorhinostomy.

    PubMed

    Kumar, Vinay; Ali, Mohammad Javed; Ramachandran, Charanya

    2015-09-01

    To determine the effect of mitomycin-C (MMC) on the contraction and migration of human nasal mucosal fibroblasts (HNMFs) in vitro in order to identify the least concentration of MMC required to prevent cicatrix development following dacryocystorhinostomy (DCR). Primary cultures of HNMFs were established from nasal mucosal tissues of patients undergoing DCR. Myofibroblast transformation of HNMFs was induced using transforming growth factor-β (TGF-β1) and confirmed by immunostaining for α-smooth muscle actin (α-SMA). Collagen gel contraction assay was employed to study contraction in the presence or absence of TGF-β1 (5 and 10 ng/mL) and MMC (0.2 and 0.4 mg/mL). Scratch wound assay was employed to determine the influence of MMC treatment on cell migration. Quantification of gel contraction and wound closure was done using Image J software. α-SMA expression increased with TGF-β1 treatment in a time- and dose-dependent manner indicating myofibroblast transformation of HNMFs. MMC inhibited TGF-β1- induced collagen gel contraction in a dose-dependent manner (0.4 mg/mL>0.2 mg/mL). Further, there was a decrease in the migration of MMC-treated HNMFs, resulting in delayed wound closure that corroborated with the loss of actin stress fibres. MMC successfully inhibited TGF-β1-induced myofibroblast transformation, collagen gel contraction and significantly reduced the migration of HNMFs to cover the wound even at a low concentration of 0.2 mg/mL. This study provides evidence that low concentration and short duration of MMC treatment is efficient in reducing increased contraction and migration of HMNFs in response to injury. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions.

  10. Office-based Slit-lamp Needle Revision with Adjunctive Mitomycin-C for Late Failed or Encapsulated Filtering Blebs

    PubMed Central

    Amini, Heidar; Esmaili, Alireza; Zarei, Reza; Amini, Nima; Daneshvar, Ramin

    2012-01-01

    Purpose: The purpose of this study was to assess the results of bleb needling in glaucomatous patients with late failed filtering blebs. Materials and Methods: A retrospective case series of 27 eyes of 27 patients was considered. All patients underwent needle bleb revision with adjuvant mitomycin-C performed at the slit lamp, during an office visit. Complete success was defined as postneedling intraocular pressure (IOP) ≤ 21 mmHg without any antiglaucoma medications and qualified success was IOP ≤ 21 mmHg with topical antiglaucoma medications. Results: There were 12 eyes with encapsulated blebs and 15 eyes with flat blebs. The mean interval between index filtering surgery and bleb revision was 32.74 ± 15.36 months. Mean IOP was 25.07 ± 4.80 mmHg before surgery and 19.66 ± 4.97 mmHg at last postoperative follow-up. The mean follow-up was 20.31 ± 15.63 months. Complete and qualified successes were 7.4% and 51.9%, respectively. Cumulative rates of success at 1, 2, 3, and 4 years were 76%, 65%, 49%, and 37%, respectively. The mean number of antiglaucoma medications was reduced from 3.15 ± 0.36 preoperatively to 2.33 ± 1.21 postoperatively (P<0.001). Conclusion: Slit-lamp needle revision in office is a simple and effective method for treating late encapsulated or flat filtering blebs without significant complications even for late bleb failure. PMID:22623862

  11. Pathophysiological Significance of Hepatic Apoptosis

    PubMed Central

    Wang, Kewei; Lin, Bingliang

    2013-01-01

    Apoptosis is a classical pathological feature in liver diseases caused by various etiological factors such as drugs, viruses, alcohol, and cholestasis. Hepatic apoptosis and its deleterious effects exacerbate liver function as well as involvement in fibrosis/cirrhosis and carcinogenesis. An imbalance between apoptotic and antiapoptotic capabilities is a prominent characteristic of liver injury. The regulation of apoptosis and antiapoptosis can be a pivotal step in the treatment of liver diseases. PMID:27335822

  12. Label-free structural characterization of mitomycin C-modulated wound healing after photorefractive keratectomy by the use of multiphoton microscopy

    NASA Astrophysics Data System (ADS)

    Lo, Wen; Wang, Tsung-Jen; Chen, Wei-Liang; Hsueh, Chiu-Mei; Chen, Shean-Jen; Chen, Yang-Fang; Chou, Hsiu-Chu; Lin, Pi-Jung; Hu, Fung-Rong; Dong, Chen-Yuan

    2010-05-01

    We applied multiphoton autofluorescence (MAF) and second-harmonic generation (SHG) microscopy to monitor corneal wound healing after photorefractive keratectomy (PRK). Our results show that keratocyte activation can be observed by an increase in its MAF, while SHG imaging of corneal stroma can show the depletion of Bowman's layer after PRK and the reticular collagen deposition in the wound healing stage. Furthermore, quantification of the keratocyte activation and collagen deposition in conjunction with immunohistochemistry and histological images demonstrate the effectiveness of mitomycin C (MMC) in suppressing myofibroblast proliferation and collagen regeneration in the post-PRK wound healing process.

  13. [Bronchoscopic dilation techniques and topical application of mitomycin-C in the treatment of tracheal stenosis post intubation - two case reports].

    PubMed

    Ferreira, Susana; Nogueira, Carla; Oliveira, Ana; Neves, Sofia; Almeida, José; Moura e Sá, João

    2010-01-01

    Tracheal stenosis follows any injury to the airway mucosa, such as ischaemic, traumatic and other injuries. The treatment of tracheal stenosis remains a challenging problem despite all the advances in endoscopic and surgical techniques. Scar formation and reestenosis are the main causes of treatment failure. The authors present two cases of successful treatment of a tracheal stenosis after tracheal injury from prolonged oro -tracheal intubation / tracheostomy following dilatation with rigid broncoscope and laser therapy, associated with topical application of mitomycin C as an adjuvant treatment.

  14. Determination of mitomycin C in plasma, serum and urine by high-performance liquid chromatography with ultra-violet and electrochemical detection.

    PubMed

    Tjaden, U R; Langenberg, J P; Ensing, K; van Bennekom, W P; de Bruijn, E A; van Oosterom, A T

    1982-11-12

    The performance of a number of normal phase and reversed-phase systems, with ultraviolet detection at 360 nm, has been investigated with respect to their applicability to pharmacokinetic studies of mitomycin C (MMC). The reversed-phase system developed was also combined with a polarographic detector in order to compare the sensitivity and selectivity of ultraviolet and electrochemical detection. A simple isolation procedure, based on the adsorption of MMC on a non-ionogenic resin, has been developed. The developed assay is applied to a pharmacokinetic study from which some examples are given.

  15. Smac mimetic primes apoptosis-resistant acute myeloid leukaemia cells for cytarabine-induced cell death by triggering necroptosis.

    PubMed

    Chromik, Joerg; Safferthal, Charlotta; Serve, Hubert; Fulda, Simone

    2014-03-01

    The prognosis for patients with acute myeloid leukaemia (AML) is still poor, thus calling for novel treatment strategies. Here, we report that the small-molecule Smac mimetic BV6, which antagonizes Inhibitor of Apoptosis (IAP) proteins, acts in concert with cytarabine (AraC) to trigger cell death in AML cells in a highly synergistic manner (combination index 0.02-0.27). Similarly, BV6 cooperates with AraC to trigger cell death in primary AML samples, underscoring the clinical relevance of our findings. Molecular studies reveal that the TNFα-blocking antibody Enbrel significantly reduces BV6/AraC-induced cell death, demonstrating that an autocrine/paracrine TNFα loop mediates cell death. Furthermore, BV6 and AraC synergize to induce loss of mitochondrial membrane potential, caspase activation and DNA fragmentation, consistent with apoptotic cell death. Nevertheless, the caspase inhibitor zVAD.fmk fails to protect against BV6/AraC-induced cell death. Intriguingly, this cell death upon caspase inhibition is significantly reduced by pharmacological inhibition of two key components of necroptosis signaling, i.e. by RIP1 kinase inhibitor Necrostatin-1 or MLKL inhibitor NSA. Thus, BV6 sensitizes AML cells to AraC-induced cell death and overcomes apoptosis resistance by triggering necroptosis as alternative form of cell death. These findings have important implications for Smac mimetic-based strategies to bypass apoptosis resistance of AML. Copyright © 2013 Elsevier Ireland Ltd. All rights reserved.

  16. Apoptosis Resistance in Endometriosis

    PubMed Central

    Salmassi, Ali; Acar-Perk, Bengi; Schmutzler, Andreas G.; Koch, Kerstin; Püngel, Frank; Jonat, Walter; Mettler, Liselotte

    2011-01-01

    Introduction In a cytological analysis of endometriotic lesions neither granulocytes nor cytotoxic T-cells appear in an appreciable number. Based on this observation we aimed to know, whether programmed cell death plays an essential role in the destruction of dystopic endometrium. Disturbances of the physiological mechanisms of apoptosis, a persistence of endometrial tissue could explain the disease. Another aspect of this consideration is the proliferation competence of the dystopic mucous membrane. Methods Endometriotic lesions of 15 patients were examined through a combined measurement of apoptosis activity with the TUNEL technique (terminal deoxyribosyltransferase mediated dUTP Nick End Labeling) and the proliferation activity (with the help of the Ki-67-Antigens using the monoclonal antibody Ki-S5). Results Twelve out of 15 women studied showed a positive apoptotic activity of 3-47% with a proliferation activity of 2-25% of epithelial cells. Therefore we concluded that the persistence of dystopic endometrium requires proliferative epithelial cells from middle to lower endometrial layers. Conclusion A dystopia misalignment of the epithelia of the upper layers of the functionalism can be rapidly eliminated by apoptotic procedures. PMID:23678417

  17. Cl(-) channels in apoptosis.

    PubMed

    Wanitchakool, Podchanart; Ousingsawat, Jiraporn; Sirianant, Lalida; MacAulay, Nanna; Schreiber, Rainer; Kunzelmann, Karl

    2016-10-01

    A remarkable feature of apoptosis is the initial massive cell shrinkage, which requires opening of ion channels to allow release of K(+), Cl(-), and organic osmolytes to drive osmotic water movement and cell shrinkage. This article focuses on the role of the Cl(-) channels LRRC8, TMEM16/anoctamin, and cystic fibrosis transmembrane conductance regulator (CFTR) in cellular apoptosis. LRRC8A-E has been identified as a volume-regulated anion channel expressed in many cell types. It was shown to be required for regulatory and apoptotic volume decrease (RVD, AVD) in cultured cell lines. Its presence also determines sensitivity towards cytostatic drugs such as cisplatin. Recent data point to a molecular and functional relationship of LRRC8A and anoctamins (ANOs). ANO6, 9, and 10 (TMEM16F, J, and K) augment apoptotic Cl(-) currents and AVD, but it remains unclear whether these anoctamins operate as Cl(-) channels or as regulators of other apoptotic Cl(-) channels, such as LRRC8. CFTR has been known for its proapoptotic effects for some time, and this effect may be based on glutathione release from the cell and increase in cytosolic reactive oxygen species (ROS). Although we find that CFTR is activated by cell swelling, it is possible that CFTR serves RVD/AVD through accumulation of ROS and activation of independent membrane channels such as ANO6. Thus activation of ANO6 will support cell shrinkage and induce additional apoptotic events, such as membrane phospholipid scrambling.

  18. Lovastatin induces platelet apoptosis.

    PubMed

    Zhao, Qing; Li, Ming; Chen, Mengxing; Zhou, Ling; Zhao, Lili; Hu, Renping; Yan, Rong; Dai, Kesheng

    2016-03-01

    Statins are widely used in the prevention of atherosclerosis and treatment of coronary artery disease because of pleiotropic effects on thrombosis. Thrombocytopenia and hemorrhage occurred in some statin-treated patients, but the reason remains unclear. In the current study, we show that lovastatin dose-dependently induces depolarization of mitochondrial inner transmembrane potential, leading to up-regulation of Bak, down-regulation of Bcl-XL, and activation of caspase-3/8/9. Lovastatin treatment did not increase the surface expression of P-selectin or PAC-1 binding but led to strongly reduced collagen- and thrombin-induced platelet aggregation. The integrin αIIbβ3 antagonist, RGDS, inhibited lovastatin-induced apoptosis in both human platelets and Chinese hamster ovary (CHO) cells stably expressing integrin αIIbβ3. The number of circulating platelets in mice was significantly reduced after intraperitoneal injections with lovastatin. Taken together, these data indicate that lovastatin induced caspase-dependent platelet apoptosis. Lovastatin does not incur platelet activation, whereas impairs platelet function and reduces circulating platelets in vivo, suggesting the possible pathogenesis of thrombocytopenia and hemorrhage in patients treated with statins. Copyright © 2016 Elsevier B.V. All rights reserved.

  19. TGEV nucleocapsid protein induces cell cycle arrest and apoptosis through activation of p53 signaling

    SciTech Connect

    Ding, Li; Huang, Yong; Du, Qian; Dong, Feng; Zhao, Xiaomin; Zhang, Wenlong; Xu, Xingang; Tong, Dewen

    2014-03-07

    Highlights: • TGEV N protein reduces cell viability by inducing cell cycle arrest and apoptosis. • TGEV N protein induces cell cycle arrest and apoptosis by regulating p53 signaling. • TGEV N protein plays important roles in TGEV-induced cell cycle arrest and apoptosis. - Abstract: Our previous studies showed that TGEV infection could induce cell cycle arrest and apoptosis via activation of p53 signaling in cultured host cells. However, it is unclear which viral gene causes these effects. In this study, we investigated the effects of TGEV nucleocapsid (N) protein on PK-15 cells. We found that TGEV N protein suppressed cell proliferation by causing cell cycle arrest at the S and G2/M phases and apoptosis. Characterization of various cellular proteins that are involved in regulating cell cycle progression demonstrated that the expression of N gene resulted in an accumulation of p53 and p21, which suppressed cyclin B1, cdc2 and cdk2 expression. Moreover, the expression of TGEV N gene promoted translocation of Bax to mitochondria, which in turn caused the release of cytochrome c, followed by activation of caspase-3, resulting in cell apoptosis in the transfected PK-15 cells following cell cycle arrest. Further studies showed that p53 inhibitor attenuated TGEV N protein induced cell cycle arrest at S and G2/M phases and apoptosis through reversing the expression changes of cdc2, cdk2 and cyclin B1 and the translocation changes of Bax and cytochrome c induced by TGEV N protein. Taken together, these results demonstrated that TGEV N protein might play an important role in TGEV infection-induced p53 activation and cell cycle arrest at the S and G2/M phases and apoptosis occurrence.

  20. Synthetic ciguatoxin CTX 3C induces a rapid imbalance in neuronal excitability.

    PubMed

    Martín, Victor; Vale, Carmen; Hirama, Masahiro; Yamashita, Shuji; Rubiolo, Juan Andrés; Vieytes, Mercedes R; Botana, Luis M

    2015-06-15

    Ciguatera is a human global disease caused by the consumption of contaminated fish that have accumulated ciguatoxins (CTXs), sodium channel activator toxins. Symptoms of ciguatera include neurological alterations such as paraesthesiae, dysaesthesiae, depression, and heightened nociperception, among others. An important issue to understand these long-term neurological alterations is to establish the role that changes in activity produced by CTX 3C represent to neurons. Here, the effects of synthetic ciguatoxin CTX 3C on membrane potential, spontaneous spiking, and properties of synaptic transmission in cultured cortical neurons of 11-18 days in vitro (DIV) were evaluated using electrophysiological approaches. CTX 3C induced a large depolarization that decreased neuronal firing and caused a rapid inward tonic current that was primarily GABAergic. Moreover, the toxin enhanced the amplitude of miniature postsynaptic inhibitory currents (mIPSCs), whereas it decreased the amplitude of miniature postsynaptic excitatory currents (mEPSCs). The frequency of mIPSCs increased, whereas the frequency of mEPSCs remained unaltered. We describe, for the first time, that a rapid membrane depolarization caused by CTX 3C in cortical neurons activates mechanisms that tend to suppress electrical activity by shifting the balance between excitatory and inhibitory synaptic transmission toward inhibition. Indeed, these results suggest that the acute effects of CTX on synaptic transmission could underlie some of the neurological symptoms caused by ciguatera in humans.

  1. Qualitative and quantitative proteomic analysis of Vitamin C induced changes in Mycobacterium smegmatis

    PubMed Central

    Mishra, Abhishek; Sarkar, Dhiman

    2015-01-01

    Vitamin C is a critical dietary nutrient in human which has a wide range of regulatory effects on gene expression and physiology of Mycobacterium tuberculosis that leads to a dormant drug-tolerant phenotype. In the presence of iron, vitamin C shows a high bactericidal activity even in the drug resistant phenotype of M. tuberculosis. The regulatory mechanisms underlying vitamin C induced adaptations are largely unknown due to lack of functional genomics data in this field. In this study, we attempt to characterize the direct effect of vitamin C treatment on the physiology of actively growing Mycobacterium smegmatis. The study chose M. smegmatis as it is a fast-growing bacterium and a non-pathogenic model system which shares many physiological features with the pathogenic M. tuberculosis including dormancy and its regulation. The proteomic adaptation of M. smegmatis on vitamin C treatment demonstrates the important changes in cellular and metabolic process such as reversal of tricarboxylic acid cycle, decrease in ATP synthesis, decrease in iron acquisition and storage, and induction of dormancy regulators WhiB3, PhoP, and Lsr2. PMID:26042100

  2. BARC: A Novel Apoptosis Regulator

    DTIC Science & Technology

    2004-07-01

    turnover is normally achieved through programmed cell death , also known as apoptosis. Effects in apoptosis occur in breast cancers and other types of...malignancies, making tumor cells difficult to kill by chemotherapy, hormonal therapy, and radiation. Restoring function of cell death pathways is a strategy...These findings provide new insights into cell death regulation in breast cancer.

  3. Visante anterior segment optical coherence tomography analysis of morphologic changes after deep sclerectomy with intraoperative mitomycin-C and no implant use.

    PubMed

    Pérez-Rico, Consuelo; Gutiérrez-Ortíz, Consuelo; Moreno-Salgueiro, Agustín; González-Mesa, Ana; Teus, Miguel A

    2014-01-01

    To assess long-term intrascleral space maintenance after nonpenetrating deep sclerectomy (NPDS) without implant placement and with application of intraoperative mitomycin-C, using Visante anterior segment optical coherence tomography (AS-OCT). This cross-sectional, observational, case series study examined 47 eyes from 47 consecutive patients who had undergone NPDS 58.34±23.77 months earlier. All participants underwent a complete ophthalmologic examination. The presence of intrascleral space and its maximum anteroposterior and transverse lengths, maximum height, and volume were evaluated. The thickness of the trabeculo-Descemet membrane, presence and type of any subconjunctival filtering bleb, as well as scleral and suprachoroidal hyporeflectivity were analyzed. Relationships between intraocular pressure (IOP) levels and AS-OCT parameters were established. AS-OCT examinations revealed an open intrascleral space in all cases. The IOP was negatively correlated with the maximum anteroposterior length, maximum height, and volume of intrascleral space. Significant differences in IOP were found between eyes with low-reflective blebs and eyes with other subconjunctival bleb types. The overall surgical success rate was 89.4%. NPDS without implant placement and with intraoperative mitomycin C application seems to be an effective and well-tolerated method to reduce IOP with long-term effectiveness, casting doubt on the mandatory use of intrascleral implants in nonpenetrating glaucoma surgery.

  4. Isolation of Shiga toxin-producing Escherichia coli from fresh produce using STEC heart infusion washed blood agar with mitomycin-C.

    PubMed

    Lin, Andrew; Nguyen, Lam; Clotilde, Laurie M; Kase, Julie A; Son, Insook; Lauzon, Carol R

    2012-11-01

    The ability to detect and isolate Shiga toxin-producing Escherichia coli (STEC) remains a major challenge for food microbiologists. Although methods based on nucleic acids and antibodies have improved detection of STECs in foods, isolation of these bacteria remains arduous. STEC isolation is necessary for matching food, environmental, and clinical isolates during outbreak investigations and for distinguishing between pathogenic and nonpathogenic organisms. STEC heart infusion washed blood agar with mitomycin-C (SHIBAM) is a modification of washed sheep blood agar prepared by adding mitomycin-C and optimizing both the washed blood and base agar to better isolate STECs. Most STEC isolates produce a zone of hemolysis on SHIBAM plates and are easily distinguishable from background microbiota. Here, we present data supporting the use of SHIBAM to isolate STECs from fresh produce. SHIBAM was tested for accuracy in identifying STECs (365 of 410 STEC strains were hemolytic, and 63 of 73 E. coli strains that did not produce Shiga toxin were not hemolytic) and for recovery from artificially inoculated fresh produce (11 of 24 romaine lettuce samples and 6 of 24 tomato samples). STEC recovery with SHIBAM agar was greatly improved when compared with recovery on Levine's eosin-methylene blue agar as a reference method.

  5. Apoptosis and the Airway Epithelium

    PubMed Central

    White, Steven R.

    2011-01-01

    The airway epithelium functions as a barrier and front line of host defense in the lung. Apoptosis or programmed cell death can be elicited in the epithelium as a response to viral infection, exposure to allergen or to environmental toxins, or to drugs. While apoptosis can be induced via activation of death receptors on the cell surface or by disruption of mitochondrial polarity, epithelial cells compared to inflammatory cells are more resistant to apoptotic stimuli. This paper focuses on the response of airway epithelium to apoptosis in the normal state, apoptosis as a potential regulator of the number and types of epithelial cells in the airway, and the contribution of epithelial cell apoptosis in important airways diseases. PMID:22203854

  6. Apoptosis Evaluation by Electrochemical Techniques.

    PubMed

    Yin, Jian; Miao, Peng

    2016-03-04

    Apoptosis has close relevance to pathology, pharmacology, and toxicology. Accurate and convenient detection of apoptosis would be beneficial for biological study, clinical diagnosis, and drug development. Based on distinct features of apoptotic cells, a diversity of analytical techniques have been exploited for sensitive analysis of apoptosis, such as surface plasmon resonance, electrochemical methods, flow cytometry, and some imaging assays. Among them, the features of simplicity, easy operation, low cost, and high sensitivity make electrochemical techniques powerful tools to investigate electron-transfer processes of in vitro biological systems. In this contribution, a general overview of current knowledge on various technical approaches for apoptosis evaluation is provided. Furthermore, recently developed electrochemical biosensors for detecting apoptotic cells and their advantages over traditional methods are summarized. One of the main considerations focuses on designing the recognition elements based on various biochemical events during apoptosis.

  7. Liver cancer cells are sensitive to Lanatoside C induced cell death independent of their PTEN status.

    PubMed

    Durmaz, Irem; Guven, Ebru Bilget; Ersahin, Tulin; Ozturk, Mehmet; Calis, Ihsan; Cetin-Atalay, Rengul

    2016-01-15

    Hepatocellular carcinoma is the second deadliest cancer with limited treatment options. Loss of PTEN causes the P13K/Akt pathway to be hyperactive which contributes to cell survival and resistance to therapeutics in various cancers, including the liver cancer. Hence molecules targeting this pathway present good therapeutic strategies for liver cancer. It was previously reported that Cardiac glycosides possessed antitumor activity by inducing apoptosis of multiple cancer cells through oxidative stress. However, whether Cardiac glycoside Lanatoside C can induce oxidative stress in liver cancer cells and induce cell death both in vitro and in vivo remains unknown. Cell viability was measured by SRB assay. Cell death analysis was investigated by propidium iodide staining with flow cytometry and PARP cleavage. DCFH-DA staining and cytometry were used for intracellular ROS measurement. Protein levels were analyzed by western blot analysis. Antitumor activity was investigated on mice xenografts in vivo. In this study, we found that Cardiac glycosides, particularly Lanatoside C from Digitalis ferruginea could significantly inhibit PTEN protein adequate Huh7 and PTEN deficient Mahlavu human liver cancer cell proliferation by the induction of apoptosis and G2/M arrest in the cells. Lanatoside C was further shown to induce oxidative stress and alter ERK and Akt pathways. Consequently, JNK1 activation resulted in extrinsic apoptotic pathway stimulation in both cells while JNK2 activation involved in the inhibition of cell survival only in PTEN deficient cells. Furthermore, nude mice xenografts followed by MRI showed that Lanatoside C caused a significant decrease in the tumor size. In this study apoptosis induction by Lanatoside C was characterized through ROS altered ERK and Akt pathways in both PTEN adequate epithelial and deficient mesenchymal liver cancer cells. The results indicated that Lanatoside C could be contemplated in liver cancer therapeutics, particularly in PTEN

  8. Apoptosis in Primary Hyperparathyroidism.

    PubMed

    Segiet, Oliwia Anna; Mielańczyk, Łukasz; Piecuch, Adam; Michalski, Marek; Tyczyński, Szczepan; Brzozowa-Zasada, Marlena; Deska, Mariusz; Wojnicz, Romuald

    2017-03-31

    Primary hyperparathyroidism (PHPT) is defined by inappropriate elevation of parathormone, caused by parathyroid hyperplasia, also known as multi-gland disease (MGD), parathyroid adenoma (PA), or parathyroid carcinoma (PC). Although several studies have already been conducted, there is a lack of a definite diagnostic marker, which could unambiguously distinguish MGD from PA or PC. The accurate and prompt diagnosis has the key meaning for effective treatment and follow-up. This review paper presents the role of apoptosis in PHPT. The comparison of the expression of Fas, TRAIL, BCL-2 family members, p53 in MGD, PA, and PC, among others, was described. The expression of described factors varies among proliferative lesions of parathyroid gland; therefore, these could serve as additional markers to assist in the diagnosis.

  9. Inhibitory effect of Paeonia lactiflora Pallas extract (PE) on poly (I:C)-induced immune response of epidermal keratinocytes.

    PubMed

    Choi, Mi-Ra; Choi, Dae-Kyoung; Sohn, Kyung-Cheol; Lim, Seul Ki; Kim, Dong-Il; Lee, Young Ho; Im, Myung; Lee, Young; Seo, Young-Joon; Kim, Chang Deok; Lee, Jeung-Hoon

    2015-01-01

    Epidermal keratinocytes provide protective role against external stimuli by barrier formation. In addition, kertinocytes exerts their role as the defense cells via activation of innate immunity. Disturbance of keratinocyte functions is related with skin disorders. Psoriasis is a common skin disease related with inflammatory reaction in epidermal cells. We attempted to find therapeutics for psoriasis, and found that Paeonia lactiflora Pallas extract (PE) has an inhibitory potential on poly (I:C)-induced inflammation of keratinocytes. PE significantly inhibited poly (I:C)-induced expression of crucial psoriatic cytokines, such as IL-6, IL-8, CCL20 and TNF-α, via down-regulation of NF-κB signaling pathway in human keratinocytes. In addition, PE significantly inhibited poly (I:C)-induced inflammasome activation, in terms of IL-1β and caspase-1 secretion. Finally, PE markedly inhibited poly (I:C)-increased NLRP3, an important component of inflammasome. These results indicate that PE has an inhibitory effect on poly (I:C)-induced inflammatory reaction of keratinocytes, suggesting that PE can be developed for the treatment of psoriasis.

  10. Targeting of pegylated liposomal mitomycin-C prodrug to the folate receptor of cancer cells: Intracellular activation and enhanced cytotoxicity.

    PubMed

    Patil, Yogita; Amitay, Yasmine; Ohana, Patricia; Shmeeda, Hilary; Gabizon, Alberto

    2016-03-10

    Mitomycin C (MMC) is a powerful anti-bacterial, anti-fungal and anti-tumor antibiotic, often active against multidrug resistant cells. Despite a broad spectrum of antitumor activity, MMC clinical use is relatively limited due to its fast clearance and dose-limiting toxicity. To exploit the potential antitumor activity of MMC and reduce its toxicity we have previously developed a formulation of pegylated liposomes with a lipophilic prodrug of MMC (PL-MLP), activated by endogenous reducing agents which are abundant in the tumor cell environment in the form of different thiols. PL-MLP has minimal in vitro cytotoxicity unless reducing agents are added to the cell culture to activate the prodrug. In the present study, we hypothesized that targeting PL-MLP via folate receptors will facilitate intracellular activation of prodrug and enhance cytotoxic activity without added reducing agents. We grafted a lipophilic folate conjugate (folate-PEG(5000)-DSPE) to formulate folate targeted liposomes (FT-PL-MLP) and examined in vitro cell uptake and cytotoxic activity in cancer cell lines with high folate receptors (HiFR). 3H-cholesterol-hexadecyl ether (3H-Chol)-radiolabeled liposomes were prepared to study liposome-cell binding in parallel to cellular uptake of prodrug MLP. 3H-Chol and MLP cell uptake levels were 4-fold and 9-fold greater in KB HiFR cells when FT-PL-MLP is compared to non-targeted PL-MLP liposomes. The cytotoxic activity of FT-PL-MLP liposomes was significantly increased up to ~5-fold compared with PL-MLP liposomes in all tested HiFR expressing cell lines. The enhanced uptake and intracytoplasmic liposome delivery was confirmed by confocal fluorescence studies with Rhodamine-labeled liposomes. In vivo, no significant differences in pharmacokinetics and biodistribution were observed when PL-MLP was compared to FT-PL-MLP by the intravenous route. However, when liposomes were directly injected into the peritoneal cavity of mice with malignant ascites of J6456 Hi

  11. Different repair kinetic of DSBs induced by mitomycin C in peripheral lymphocytes of obese and normal weight adolescents.

    PubMed

    Azzarà, Alessia; Pirillo, Chiara; Giovannini, Caterina; Federico, Giovanni; Scarpato, Roberto

    2016-07-01

    In 2013, 42 million children under the age of 5 years were overweight or obese. In the context of obesity, we recently showed that (1) peripheral lymphocytes of obese children/adolescents had an 8-fold increase in double strand breaks (DSBs), expressed as g-H2AX foci, than normal weight adolescents, and (2) 30% of the damage was retained into chromosome mutations. Thus, we investigated DSBs repair efficiency in a group of obese adolescents assessing the kinetic of H2AX phosphorylation in mitomycin C (MMC)-treated lymphocytes harvested 2 h- or 4 h-post mutagen treatment. According to our previous studies, these harvesting times represent the peak of DSBs induction and the time in which an appreciable DSBs reduction was observed. In addition, we evaluated the expression of the high mobility group box-1 protein (HMGB1), a chromatin remodelling protein involved in DSBs repair and obesity. Compared to normal weight adolescents, obese subjects 1) showed higher levels of g-H2AX foci at either 2 h- (0.239±0.041 vs. 0.473±0.048, P=0.0016) or 4 h- (0.150±0.026 vs. 0.255±0.030, P=0.0198) post mutagen treatment, and 2) have repaired a greater amount of the initial lesions (0.088±0.033 vs. 0.218±0.045, P=0.0408). Concordantly, 1) HMGB1 levels of obese individuals increased and decreased at 2h- or 4 h-post mutagen treatment, respectively, and 2) the opposite occurred for the normal weight adolescents where the protein was down-expressed at 2h and over-expressed at 4h. In conclusion, lymphocytes of obese and normal weight adolescents showed a distinct temporal kinetic of repairing MMC-induced DSBs, together with a different expression of HMGB1. The finding that obesity may modulate the repair of DNA damage induced in lymphocytes by genotoxic agents should be confirmed by further experiments.

  12. Trabeculectomy with mitomycin C combined with direct cauterization of peripheral iris in the management of neovascular glaucoma.

    PubMed

    Elgin, Ufuk; Berker, Nilufer; Batman, Aygen; Simsek, Tulay; Cankaya, Bulent

    2006-10-01

    To determine the outcomes of trabeculectomy with mitomycin C (MMC) combined with direct cauterization of peripheral iris before iridectomy in the management of neovascular glaucoma (NVG), and to demonstrate the effect of this surgical technique on decreasing the incidence of intraoperative bleeding and early postoperative hyphema. This prospective study was based on 72 eyes of 72 patients with NVG who underwent primary trabeculectomy with MMC combined with direct cauterization of peripheral iris before iridectomy. The patients were evaluated for intraoperative and early postoperative complications such as hyphema, and operative success rates. Operative success was defined as an intraocular pressure (IOP) < or =22 mm Hg (+/-medical therapy) in the absence of phthisis. The mean IOP and the mean number of antiglaucomatous medications at baseline and at the posttrabeculectomy sixth month were compared by paired Student t test. The mean preoperative IOP was 39.3+/-5.6 mm Hg (range, 29 to 60 mm Hg) whereas it was 20.02+/-4.3 mm Hg (range, 14 to 38 mm Hg) at the postoperative sixth month. The mean preoperative number of antiglaucoma medications was 3.2+/-0.4 (range, 2 to 4) but it reduced to 1.8+/-0.6 (range, 1 to 4) at the postoperative sixth month. These differences were statistically significant (P<0.00001). The IOP was < or =22 mm Hg (+/-medical therapy) in 69 eyes (95.8%) at the postoperative first week, in 62 eyes (86.1%) at the postoperative first month, in 60 eyes (83.3%) at the postoperative third month and in 48 eyes (66%) at the postoperative sixth month. Hyphema occurred in 15 eyes (20.8%) within the first week of the surgery. In 12 eyes it was transient; however, in 3 eyes irrigation of anterior chamber was required. Trabeculectomy with MMC combined with direct cauterization of peripheral iris decreases the incidence of both intraoperative bleeding, and early postoperative hyphema, and provides reduction of IOP and the number of antiglaucomatous medications

  13. Comparison of TGF-β1 in tears and corneal haze following Epi-LASIK with and without mitomycin C

    PubMed Central

    Chen, Jing; Chen, Yi; Han, Su-Ning

    2013-01-01

    AIM To compare transforming growth factor-β1 (TGF-β1) levels in tears and the degree of corneal haze formation following epithelial laser in situ keratomileusis (Epi-LASIK) with and without the use of mitomycin C (MMC) and to investigate the effect of MMC on corneal wound healing. METHODS Thirty-two patients (64 eyes) with high myopia underwent Epi-LASIK surgery, and MMC was randomly used in one eye in each patient. The epithelialization process was observed, and the TGF-β1 level in tears was measured at 1 day, 3, and 7 days postoperatively for comparison with baseline. Corneal haze was graded at 1 month, 3, and 6 months after surgery. RESULTS Mean preoperative spherical equivalent refraction was -8.24±2.18D (range -6.00 to -10.50D) in the MMC group and -7.82±1.55D (range -6.00 to -9.75D) in the non-MMC group. There was no significant difference between the two groups (P=0.38). Mean epithelialization time was (5.02±0.68) days in the MMC group and (4.86±0.57) days in the non-MMC group (P=0.31). Tear fluid TGF-β1 levels were similar before surgery (P=0.34), but were significantly higher in the non-MMC group at 1 day, 3, and 7 days postoperatively (P=0.004, 0.008, and 0.012, respectively). Corneal haze scores 1 month after surgery were significantly higher in the non-MMC group (P=0.03), and similar at 3 and 6 months after surgery (P=0.28 and 0.62, respectively). CONCLUSION MMC did not delay epithelialization. In early postoperative period, lower TGF-β1 levels in tears and a lower grade of corneal haze were observed in the MMC group. Our findings suggest that the ability of MMC to inhibit Epi-LASIK-induced haze might be mediated through TGF-β1 suppression. PMID:23826524

  14. Predictability and stability of laser-assisted subepithelial keratectomy with mitomycin C for the correction of high myopia.

    PubMed

    Iu, Lawrence P L; Fan, Michelle C Y; Chen, Ivan N; Lai, Jimmy S M

    2017-06-01

    The purpose of this study was to evaluate the predictability and stability of laser-assisted subepithelial keratectomy (LASEK) with mitomycin C (MMC) in correction of high myopia (≤-6.0 diopters [D]) as compared to low-to-moderate myopia (>-6.0 D).This is a retrospective, comparative, cohort study which included 43 eyes of 43 consecutive patients who underwent LASEK with MMC in a private hospital in Hong Kong by a single surgeon. Twenty-five eyes had high myopia (mean spherical equivalent [SE] = -8.53 ± 1.82 D) and 18 eyes had low-to-moderate myopia (mean SE = -3.99 ± 1.37 D) before surgery.In terms of refractive predictability, mean SE was significantly better in eyes with preoperative low-to-moderate myopia than high myopia at 6 months (0.04 ± 0.23 vs 0.31 ± 0.52 D, P = .035). In terms of refractive stability, between 1 and 3 months, both groups had mean absolute change of SE of around 0.25 D. Between 3 and 6 months, preoperative low-to-moderate myopia group had significantly less absolute change of SE compared to high myopia group (0.07 vs 0.23 D, P = .003). More eyes with preoperative high myopia changed SE by more than 0.25 D than those with low-to-moderate myopia between 3 and 6 months (32.0% vs 5.6%, P = .057).In conclusion, LASEK with MMC is more unpredictable and unstable in correction of high myopia than low-to-moderate myopia. The refractive outcome of most low-to-moderate myopia correction stabilizes at 3 months. Stability is not achieved until after 6 months in high myopia correction.

  15. [Induction of robust senescence-associated secretory phenotype in mouse NIH-3T3 cells by mitomycin C].

    PubMed

    Huang, Wei-Xing; Guo, Xiao-Xuan; Peng, Zhong-Zhi; Weng, Chun-Liang; Huang, Chun-Yan; Shi, Ben-Yan; Yang, Jie; Liao, Xiao-Xin; Li, Xiao-Yi; Zheng, Hui-Ling; Liu, Xin-Guang; Sun, Xue-Rong

    2017-02-25

    Senescence-associated secretory phenotype (SASP) is often a concomitant result of cell senescence, embodied by the enhanced function of secretion. The SASP factors secreted by senescent cells include cytokines, proteases and chemokines, etc, which can exert great influence on local as well as systemic environment and participate in the process of cell senescence, immunoregulation, angiogenesis, cell proliferation and tumor invasion, etc. Relative to the abundance of SASP models in human cells, the in vitro SASP model derived from mouse cells is scarce at present. Therefore, the study aimed to establish a mouse SASP model to facilitate the research in the field. With this objective, we treated the INK4a-deficient mouse NIH-3T3 cells and the wildtype mouse embryonic fibroblasts (MEF) respectively with mitomycin C (MMC), an anticarcinoma drug which could induce DNA damage. The occurring of cell senescence was evaluated by cell morphology, β-gal staining, integration ratio of EdU and Western blot. Quantitative RT-PCR and ELISA were used to detect the expression and secretion of SASP factors, respectively. The results showed that, 8 days after the treatment of NIH-3T3 cells with MMC (1 μg/mL) for 12 h or 24 h, the cells became enlarged and the ratios of β-gal-positive (blue-stained) cells significantly increased, up to 77.4% and 90.4%, respectively. Meanwhile, the expression of P21 protein increased and the integration ratios of EdU significantly decreased (P < 0.01). Quantitative RT-PCR detection showed that the mRNA levels of several SASP genes, including IL-6, TNF-α, IL-1α and IL-1β increased evidently. ELISA detection further observed an enhanced secretion of IL-6 (P < 0.01). On the contrary, although wildtype MEF could also be induced into senescence by MMC treatment for 12 h or 24 h, embodied by the enlarged cell volume, increased ratios of β-gal-positive cells (up to 71.7% and 80.2%, respectively) and enhanced expression of P21 protein, the secretion of IL

  16. Lanatoside C, a cardiac glycoside, acts through protein kinase Cδ to cause apoptosis of human hepatocellular carcinoma cells

    PubMed Central

    Chao, Min-Wu; Chen, Tzu-Hsuan; Huang, Han-Li; Chang, Yu-Wei; HuangFu, Wei-Chun; Lee, Yu-Ching; Teng, Che-Ming; Pan, Shiow-Lin

    2017-01-01

    Recent studies have revealed that cardiac glycosides, such as digitalis and digoxin, have anticancer activity and may serve as lead compounds for the development of cancer treatments. The poor prognosis of hepatocellular carcinoma (HCC) patients reflects the development of resistance to current chemotherapeutic agents, highlighting the need for discovering new small-molecule therapeutics. Here, we found that lanatoside C, an anti-arrhythmic agent extracted from Digitalis lanata, inhibited the growth of HCC cells and dramatically decreased tumor volume as well as delayed tumor growth without obvious body weight loss. Moreover, lanatoside C triggered mitochondrial membrane potential (MMP) loss, activation of caspases and translocation of apoptosis-inducing factor (AIF) into the nucleus, which suggests that lanatoside C induced apoptosis through both caspase-dependent and -independent pathways. Furthermore, we discovered that lanatoside C activated protein kinase delta (PKCδ) via Thr505 phosphorylation and subsequent membrane translocation. Inhibition of PKCδ reversed lanatoside C-induced MMP loss and apoptosis, confirming that lanatoside C caused apoptosis through PKCδ activation. We also found that the AKT/mTOR pathway was negatively regulated by lanatoside C through PKCδ activation. In conclusion, we provide the first demonstration that the anticancer effects of lanatoside C are mainly attributable to PKCδ activation. PMID:28387249

  17. Effect of modeled microgravity on UV-C-induced interplant communication of Arabidopsis thaliana.

    PubMed

    Wang, Ting; Xu, Wei; Li, Huasheng; Deng, Chenguang; Zhao, Hui; Wu, Yuejin; Liu, Min; Wu, Lijun; Lu, Jinying; Bian, Po

    2017-09-06

    Controlled ecological life support systems (CELSS) will be an important feature of long-duration space missions of which higher plants are one of the indispensable components. Because of its pivotal role in enabling plants to cope with environmental stress, interplant communication might have important implications for the ecological stability of such CELSS. However, the manifestations of interplant communication in microgravity conditions have yet to be fully elucidated. To address this, a well-established Arabidopsis thaliana co-culture experimental system, in which UV-C-induced airborne interplant communication is evaluated by the alleviation of transcriptional gene silencing (TGS) in bystander plants, was placed in microgravity modeled by a two-dimensional rotating clinostat. Compared with plants under normal gravity, TGS alleviation in bystander plants was inhibited in microgravity. Moreover, TGS alleviation was also prevented when plants of the pgm-1 line, which are impaired in gravity sensing, were used in either the UV-C-irradiated or bystander group. In addition to the specific TGS-loci, interplant communication-shaped genome-wide DNA methylation in bystander plants was altered under microgravity conditions. These results indicate that interplant communications might be modified in microgravity. Time course analysis showed that microgravity interfered with both the production of communicative signals in UV-C-irradiated plants and the induction of epigenetic responses in bystander plants. This was further confirmed by the experimental finding that microgravity also prevented the response of bystander plants to exogenous methyl jasmonate (JA) and methyl salicylate (SA), two well-known airborne signaling molecules, and down-regulated JA and SA biosynthesis in UV-C-irradiated plants. Copyright © 2017 Elsevier B.V. All rights reserved.

  18. Apoptosis in Gingival Overgrowth Tissues

    PubMed Central

    Kantarci, A.; Augustin, P.; Firatli, E.; Sheff, M.C.; Hasturk, H.; Graves, D.T.; Trackman, P.C.

    2010-01-01

    Variations in the balance between cell proliferation and apoptosis could contribute to the etiology of gingival overgrowth. The aim of this study was to test the hypothesis that, in fibrotic gingival lesions, fibroblast proliferation is stimulated and apoptosis is decreased. Apoptotic index, caspase 3 expression, the proliferative index, FOXO1 expression, and histological inflammation were measured in situ. Analysis of data showed that apoptosis decreased in all forms of gingival overgrowth examined (p < 0.05), and inflammation caused a small but significant increase compared with non-inflamed tissues (p < 0.05). The greatest decrease of apoptosis occurred in the most fibrotic tissues. Cell proliferation was elevated in all forms of gingival overgrowth tested, independent of inflammation (p < 0.05). To identify potential mechanisms of transcriptional regulation of apoptosis, we assessed FOXO1 and caspase 3 expression levels and found them to correlate well with diminished apoptosis. Analysis of data suggests that increased fibroblast proliferation and a simultaneous decrease in apoptosis contribute to gingival overgrowth. PMID:17720861

  19. Regulation of Apoptosis by Inhibitors of Apoptosis (IAPs)

    PubMed Central

    Berthelet, Jean; Dubrez, Laurence

    2013-01-01

    Abstract Inhibitors of Apoptosis (IAPs) are a family of proteins with various biological functions including regulation of innate immunity and inflammation, cell proliferation, cell migration and apoptosis. They are characterized by the presence of at least one N-terminal baculoviral IAP repeat (BIR) domain involved in protein-protein interaction. Most of them also contain a C-terminal RING domain conferring an E3-ubiquitin ligase activity. In drosophila, IAPs are essential to ensure cell survival, preventing the uncontrolled activation of the apoptotic protease caspases. In mammals, IAPs can also regulate apoptosis through controlling caspase activity and caspase-activating platform formation. Mammalian IAPs, mainly X-linked IAP (XIAP) and cellular IAPs (cIAPs) appeared to be important determinants of the response of cells to endogenous or exogenous cellular injuries, able to convert the survival signal into a cell death-inducing signal. This review highlights the role of IAP in regulating apoptosis in Drosophila and Mammals. PMID:24709650

  20. Simultaneous Integrated Boost–Intensity Modulated Radiation Therapy With Concomitant Capecitabine and Mitomycin C for Locally Advanced Anal Carcinoma: A Phase 1 Study

    SciTech Connect

    Deenen, Maarten J.; Dewit, Luc; Boot, Henk; Beijnen, Jos H.; Schellens, Jan H.M.; Cats, Annemieke

    2013-04-01

    Purpose: Newer radiation techniques, and the application of continuous 5-FU exposure during radiation therapy using oral capecitabine may improve the treatment of anal cancer. This phase 1, dose-finding study assessed the feasibility and efficacy of simultaneous integrated boost–intensity modulated radiation therapy (SIB-IMRT) with concomitant capecitabine and mitomycin C in locally advanced anal cancer, including pharmacokinetic and pharmacogenetic analyses. Methods and Materials: Patients with locally advanced anal carcinoma were treated with SIB-IMRT in 33 daily fractions of 1.8 Gy to the primary tumor and macroscopically involved lymph nodes and 33 fractions of 1.5 Gy electively to the bilateral iliac and inguinal lymph node areas. Patients received a sequential radiation boost dose of 3 × 1.8 Gy on macroscopic residual tumor if this was still present in week 5 of treatment. Mitomycin C 10 mg/m{sup 2} (maximum 15 mg) was administered intravenously on day 1, and capecitabine was given orally in a dose-escalated fashion (500-825 mg/m{sup 2} b.i.d.) on irradiation days, until dose-limiting toxicity emerged in ≥2 of maximally 6 patients. An additional 8 patients were treated at the maximum tolerated dose (MTD). Results: A total of 18 patients were included. The MTD of capecitabine was determined to be 825 mg/m{sup 2} b.i.d. The predominant acute grade ≥3 toxicities included radiation dermatitis (50%), fatigue (22%), and pain (6%). Fifteen patients (83% [95%-CI: 66%-101%]) achieved a complete response, and 3 (17%) patients a partial response. With a median follow-up of 28 months, none of the complete responders, and 2 partial responders had relapsed. Conclusions: SIB-IMRT with concomitant single dose mitomycin C and capecitabine 825 mg/m{sup 2} b.i.d. on irradiation days resulted in an acceptable safety profile, and proved to be a tolerable and effective treatment regimen for locally advanced anal cancer.

  1. Eradication of Biofilm-Like Microcolony Structures of Borrelia burgdorferi by Daunomycin and Daptomycin but not Mitomycin C in Combination with Doxycycline and Cefuroxime

    PubMed Central

    Feng, Jie; Weitner, Megan; Shi, Wanliang; Zhang, Shuo; Zhang, Ying

    2016-01-01

    Lyme disease, caused by Borrelia burgdorferi, is the most common vector-borne disease in the United States and Europe. While the majority of Lyme disease patients can resolve their symptoms if treated promptly, 10–20% of patients suffer from prolonged symptoms called post-treatment Lyme disease syndrome (PTLDS). Although the cause for PTLDS is unclear, one possibility is the presence of bacterial persisters not effectively cleared by the current Lyme antibiotics. Recent studies identified several drug candidates including daptomycin, daunomycin, doxorubicin, and mitomycin C that had good activity against B. burgdorferi persisters. However, their relative activities against B. burgdorferi persisters have not been evaluated under the same conditions. In this study, we tested the anti-persister activities of these drugs against both 7-day and 15-day old stationary phase cultures of B. burgdorferi individually as well as in combination with Lyme antibiotics doxycycline and cefuroxime (Ceftin). Our findings demonstrate daunomycin and daptomycin were more active than mitomycin C in single drug comparison at 10 and 20 μM, as well as in drug combinations with doxycycline and cefuroxime. In addition, daunomycin was more active than doxorubicin which correlated with their ability to stain and accumulate in B. burgdorferi. The two drug combination of doxycycline and cefuroxime was unable to eradicate biofilm-like microcolonies of B. burgdorferi persisters. However, the addition of either daunomycin or daptomycin to the doxycycline + cefuroxime combination completely eradicated the biofilm-like structures and produced no visible bacterial regrowth after 7 and 21 days, while the addition of doxorubicin was unable to prevent regrowth at either 7 or 21 day subculture. Mitomycin C in combination with doxycycline and cefuroxime caused no regrowth at 7 days but visible spirochetal regrowth occurred after 21 day subculture. Furthermore, we found that cefuroxime (Ceftin), the third

  2. Eradication of Biofilm-Like Microcolony Structures of Borrelia burgdorferi by Daunomycin and Daptomycin but not Mitomycin C in Combination with Doxycycline and Cefuroxime.

    PubMed

    Feng, Jie; Weitner, Megan; Shi, Wanliang; Zhang, Shuo; Zhang, Ying

    2016-01-01

    Lyme disease, caused by Borrelia burgdorferi, is the most common vector-borne disease in the United States and Europe. While the majority of Lyme disease patients can resolve their symptoms if treated promptly, 10-20% of patients suffer from prolonged symptoms called post-treatment Lyme disease syndrome (PTLDS). Although the cause for PTLDS is unclear, one possibility is the presence of bacterial persisters not effectively cleared by the current Lyme antibiotics. Recent studies identified several drug candidates including daptomycin, daunomycin, doxorubicin, and mitomycin C that had good activity against B. burgdorferi persisters. However, their relative activities against B. burgdorferi persisters have not been evaluated under the same conditions. In this study, we tested the anti-persister activities of these drugs against both 7-day and 15-day old stationary phase cultures of B. burgdorferi individually as well as in combination with Lyme antibiotics doxycycline and cefuroxime (Ceftin). Our findings demonstrate daunomycin and daptomycin were more active than mitomycin C in single drug comparison at 10 and 20 μM, as well as in drug combinations with doxycycline and cefuroxime. In addition, daunomycin was more active than doxorubicin which correlated with their ability to stain and accumulate in B. burgdorferi. The two drug combination of doxycycline and cefuroxime was unable to eradicate biofilm-like microcolonies of B. burgdorferi persisters. However, the addition of either daunomycin or daptomycin to the doxycycline + cefuroxime combination completely eradicated the biofilm-like structures and produced no visible bacterial regrowth after 7 and 21 days, while the addition of doxorubicin was unable to prevent regrowth at either 7 or 21 day subculture. Mitomycin C in combination with doxycycline and cefuroxime caused no regrowth at 7 days but visible spirochetal regrowth occurred after 21 day subculture. Furthermore, we found that cefuroxime (Ceftin), the third

  3. Synthesis and in vitro antitumor evaluation of betulin acid ester derivatives as novel apoptosis inducers.

    PubMed

    Yang, Sheng-Jie; Liu, Ming-Chuan; Xiang, Hong-Mei; Zhao, Qi; Xue, Wei; Yang, Song

    2015-09-18

    Nineteen betulin derivatives modified at the C-3 and C-28 positions were synthesized and assessed for antitumor activities against the MGC-803, PC3, Bcap-37, A375, and MCF-7 human cancer cell lines in vitro by MTT assay. Some derivatives (compounds 3a-3d and 5) displayed strong antitumor properties, with IC50 values between 4 and 18 μM. Compound 3c, containing piperidine group at C-28 position, had IC50 values of 4.3, 4.5, 5.2, 7.5, and 5.2 μM on the five cancer cell lines, respectively. Subsequent fluorescence staining and flow cytometric analysis indicated that compound 3c induced apoptosis in MGC-803 cell line, with an apoptosis ratio of 31.11% after 36 h of treatment at 10 μM 3c.

  4. Methylselenium and Prostate Cancer Apoptosis

    DTIC Science & Technology

    2005-02-01

    15. NUMBER OF PAGES Selenium, methylselenol , prostate cancer chemoprevention, apoptosis 15 16. PRICE CODE 17. SECURITY CLASSIFICATION 18. SECURITY...that Methylselenol has been implicated as an active metabolite inhibit one or more steps in the natural history of prostate for the anticancer effect of...in PCa chemoprevention and therapy activity) for their apoptosis responses to the methylselenol by selenium compounds (8). Methylselenol has been impli

  5. Overexpression of immunoglobulin G prompts cell proliferation and inhibits cell apoptosis in human urothelial carcinoma.

    PubMed

    Liang, Pei-Yu; Li, Hao-Yong; Zhou, Zhi-Yan; Jin, Ying-Xia; Wang, Sheng-Xing; Peng, Xiao-Hui; Ou, Shan-Ji

    2013-06-01

    Only B lymphocytes can express immunoglobulins according to the traditional immunological theories, and the expression of immunoglobulin G (IgG) messenger RNA (mRNA) and protein was found in certain human cancer cells recently. However, the expression pattern of IgG and its possible role in human urothelial carcinoma are still elusive. In this study, we investigated the expression of IgG in two human urothelial carcinoma cell lines, T24 and BIU-87, and in 56 cases of clinical urothelial carcinoma tissues. The mRNA of IgG was positively detected by in situ hybridization and reverse transcription PCR; furthermore, IgG protein was also positively detected by immunohistochemistry and Western blot. Moreover, blockade of tumor-derived IgG by either antihuman IgG antibody or antisense oligonucleotides increased cell apoptosis and inhibited cell growth in bladder cancer cell lines in vitro, and antihuman IgG antibody could suppress the growth of xenotransplant tumor in vivo. In addition, either antihuman IgG antibody or antisense oligonucleotides enhanced the sensitivity to mitomycin C in bladder cancer cell line T24. Furthermore, blockade of IgG in bladder cancer cell T24 resulted in upregulation of cleaved caspase-3 and cleaved poly(ADP-ribose) polymerase. Our results indicated that bladder cancer cells were capable of expressing IgG, and blockade of IgG expression induced cell apoptosis through activation of caspase-dependent pathway. A novel potential targeted therapy for bladder cancer will be possibly developed based on these data.

  6. [Apoptosis: cellular and clinical aspects].

    PubMed

    Løvschall, H; Mosekilde, L

    1997-04-01

    Removal of damaged cells is essential for the maintenance of life in multicellular organisms. The process of self destruction, apoptosis, eliminates surplus or damaged cells as part of the pathophysiological defence system. Apoptosis is essential in structural and functional organogenesis during embryological development. The physiological regulation of tissue kinetics is a product of both cell proliferation and cell death. Internal and external regulatory stimuli regulate the balance between apoptosis and mitosis by genetic interaction. Apoptosis is characterized by condensation of chromatine as a result of DNA degradation, formation of blebs in the plasma and nuclear membranes, condensation of cytoplasma, formation of vesicular apoptotic bodies, and phagocytosis by neighbouring cells without inflammatory response. A number of observations indicate that programmed cell death plays an important role in the regulation of cytofunctional homeostasis and defense against accumulation of damaged cells, eg with DNA alterations. Dysregulation of the apoptotic gene program, eg by mutations, may not only lead to loss or degeneration of tissue, but also to hyperproliferative and tumorigenic disorders. New evidence indicates that apoptosis regulation is important both in aging processes and diseases such as: neuropathies, immunopathies, viral infections, cancer, etc. Pharmacological intervention designed to modulate apoptosis seems to raise new possibilities in the treatment of disease.

  7. RNA-binding protein RBM3 prevents NO-induced apoptosis in human neuroblastoma cells by modulating p38 signaling and miR-143

    PubMed Central

    Yang, Hai-Jie; Ju, Fei; Guo, Xin-Xin; Ma, Shuang-Ping; Wang, Lei; Cheng, Bin-Feng; Zhuang, Rui-Juan; Zhang, Bin-Bin; Shi, Xiang; Feng, Zhi-Wei; Wang, Mian

    2017-01-01

    Nitric oxide (NO)-induced apoptosis in neurons is an important cause of neurodegenerative disease in humans. The cold-inducible protein RBM3 mediates the protective effects of cooling on apoptosis induced by various insults. However, whether RBM3 protects neural cells from NO-induced apoptosis is unclear. This study aimed to investigate the neuroprotective effect of RBM3 on NO-induced apoptosis in human SH-SY5Y neuroblastoma cells. Firstly, we demonstrated that mild hypothermia (32 °C) induces RBM3 expression and confers a potent neuroprotective effect on NO-induced apoptosis, which was substantially diminished when RBM3 was silenced by siRNA. Moreover, overexpression of RBM3 exhibited a strong protective effect against NO-induced apoptosis. Signaling pathway screening demonstrated that only p38 inhibition by RBM3 provided neuroprotective effect, although RBM3 overexpression could affect the activation of p38, JNK, ERK, and AKT signaling in response to NO stimuli. Notably, RBM3 overexpression also blocked the activation of p38 signaling induced by transforming growth factor-β1. Furthermore, both RBM3 overexpression and mild hypothermia abolished the induction of miR-143 by NO, which was shown to mediate the cytotoxicity of NO in a p38-dependent way. These findings suggest that RBM3 protects neuroblastoma cells from NO-induced apoptosis by suppressing p38 signaling, which mediates apoptosis through miR-143 induction. PMID:28134320

  8. RNA-binding protein RBM3 prevents NO-induced apoptosis in human neuroblastoma cells by modulating p38 signaling and miR-143.

    PubMed

    Yang, Hai-Jie; Ju, Fei; Guo, Xin-Xin; Ma, Shuang-Ping; Wang, Lei; Cheng, Bin-Feng; Zhuang, Rui-Juan; Zhang, Bin-Bin; Shi, Xiang; Feng, Zhi-Wei; Wang, Mian

    2017-01-30

    Nitric oxide (NO)-induced apoptosis in neurons is an important cause of neurodegenerative disease in humans. The cold-inducible protein RBM3 mediates the protective effects of cooling on apoptosis induced by various insults. However, whether RBM3 protects neural cells from NO-induced apoptosis is unclear. This study aimed to investigate the neuroprotective effect of RBM3 on NO-induced apoptosis in human SH-SY5Y neuroblastoma cells. Firstly, we demonstrated that mild hypothermia (32 °C) induces RBM3 expression and confers a potent neuroprotective effect on NO-induced apoptosis, which was substantially diminished when RBM3 was silenced by siRNA. Moreover, overexpression of RBM3 exhibited a strong protective effect against NO-induced apoptosis. Signaling pathway screening demonstrated that only p38 inhibition by RBM3 provided neuroprotective effect, although RBM3 overexpression could affect the activation of p38, JNK, ERK, and AKT signaling in response to NO stimuli. Notably, RBM3 overexpression also blocked the activation of p38 signaling induced by transforming growth factor-β1. Furthermore, both RBM3 overexpression and mild hypothermia abolished the induction of miR-143 by NO, which was shown to mediate the cytotoxicity of NO in a p38-dependent way. These findings suggest that RBM3 protects neuroblastoma cells from NO-induced apoptosis by suppressing p38 signaling, which mediates apoptosis through miR-143 induction.

  9. Transfer of IP3 through gap junctions is critical, but not sufficient, for the spread of apoptosis

    PubMed Central

    Decrock, E; Krysko, D V; Vinken, M; Kaczmarek, A; Crispino, G; Bol, M; Wang, N; De Bock, M; De Vuyst, E; Naus, C C; Rogiers, V; Vandenabeele, P; Erneux, C; Mammano, F; Bultynck, G; Leybaert, L

    2012-01-01

    Decades of research have indicated that gap junction channels contribute to the propagation of apoptosis between neighboring cells. Inositol 1,4,5-trisphosphate (IP3) has been proposed as the responsible molecule conveying the apoptotic message, although conclusive results are still missing. We investigated the role of IP3 in a model of gap junction-mediated spreading of cytochrome C-induced apoptosis. We used targeted loading of high-molecular-weight agents interfering with the IP3 signaling cascade in the apoptosis trigger zone and cell death communication zone of C6-glioma cells heterologously expressing connexin (Cx)43 or Cx26. Blocking IP3 receptors or stimulating IP3 degradation both diminished the propagation of apoptosis. Apoptosis spread was also reduced in cells expressing mutant Cx26, which forms gap junctions with an impaired IP3 permeability. However, IP3 by itself was not able to induce cell death, but only potentiated cell death propagation when the apoptosis trigger was applied. We conclude that IP3 is a key necessary messenger for communicating apoptotic cell death via gap junctions, but needs to team up with other factors to become a fully pro-apoptotic messenger. PMID:22117194

  10. One-electron oxidation of mitomycin C and its corresponding peroxyl radicals. A steady-state and pulse radiolysis study

    NASA Astrophysics Data System (ADS)

    Getoff, Nikola; Solar, Sonja; Quint, Ruth M.

    1997-12-01

    The one-electron oxidation of Mitomycin C (MMC) as well as the formation of the corresponding peroxyl radicals were investigated by both steady-state and pulse radiolysis. The steady-state MMC-radiolysis by OH-attack followed at both absorption bands showed different yields: at 218 nm G i (-MMC) = 3.0 and at 364 nm G i (-MMC) = 3.9, indicating the formation of various not yet identified products, among which ammonia was determined, G(NH 3) = 0.81. By means of pulse radiolysis it was established a total κ (OH + MMC) = (5.8 ± 0.2) × 10 9 dm 3 mol -1 s -1. The transient absorption spectrum from the one-electron oxidized MMC showed absorption maxima at 295 nm ( ɛ = 9950 dm 3 mol -1 cm t-1 ), 410 nm ( ɛ = 1450 dm 3 mol -1 cm -1) and 505 nm ( ɛ = 5420 dm 3 mol -1 cm -1). At 280-320 and 505 nm and above they exhibit in the first 150 μs a first order decay, κ1 = (0.85 ± 0.1) × 10 3 s -1, and followed upto ms time range, by a second order decay, 2 κ = (1.3 ± 0.3) × 10 8 dm 3 mol -1 s -1. Around 410 nm the kinetics are rather mixed and could not be resolved. The steady-state MMC-radiolysis in the presence of oxygen featured a proportionality towards the absorbed dose for both MMC-absorption bands, resulting in a G i (-MMC) = 1.5. Among several products ammonia-yield was determined G(NH 3) = 0.52. The formation of MMC-peroxyl radicals was studied by pulse radiolysis, likewise in neutral aqueous solution, but saturated with a gas mixture of 80% N 2O and 20% O 2. The maxima of the observed transient spectrum are slightly shifted compared to that of the one-electron oxidized MMC-species, namely: 290 nm ( ɛ = 10100 dm 3 mol -1 cm -1), 410 nm ( ɛ = 2900 dm 3 mol -1 cm -1) and 520 nm ( ɛ = 5500 dm 3 mol -1 cm -1). The O 2-addition to the MMC-one-electron oxidized transients was found to be at 290 to 410 nm gk(MMC·OH + O 2) = 5 × 10 7 dm 3 mol -1 s -1, around 480 nm κ = 1.6 × 10 8 dm 3 mol -1 s -1 and at 510 nm and above, κ = 3 × 10 8 dm 3 mol -1 s -1. The

  11. Pharmacologic Studies of a Prodrug of Mitomycin C in Pegylated Liposomes (Promitil(®)): High Stability in Plasma and Rapid Thiolytic Prodrug Activation in Tissues.

    PubMed

    Amitay, Yasmine; Shmeeda, Hilary; Patil, Yogita; Gorin, Jenny; Tzemach, Dina; Mak, Lidia; Ohana, Patricia; Gabizon, Alberto

    2016-03-01

    Pegylated liposomal (PL) mitomycin C lipid-based prodrug (MLP) has recently entered clinical testing. We studied here the preclinical pharmacology of PL-MLP. The stability, pharmacokinetics, biodistribution, and other pharmacologic parameters of PL-MLP were examined. Thiolytic cleavage of MLP and release of active mitomycin C (MMC) were studied using dithiothreitol (DTT), and by incubation with tissue homogenates. MLP was incorporated in the bilayer at 10% molar ratio with nearly 100% entrapment efficiency, resulting in a formulation with high plasma stability. In vitro, DTT induced cleavage of MLP with predictable kinetics, generating MMC and enhancing pharmacological activity. A long circulation half-life of MLP (10-15 h) was observed in rodents and minipigs. Free MMC is either extremely low or undetectable in plasma. However, urine from PL-MLP injected rats revealed delayed but significant excretion of MMC indicating in vivo activation of MLP. Studies in mice injected with H3-cholesterol radiolabeled PL-MLP demonstrated relatively greater tissue levels of H3-cholesterol than MLP. MLP levels were highest in tumor and spleen, and very low or undetectable in liver and lung. Rapid cleavage of MLP in various tissues, particularly in liver, was shown in ex-vivo experiments of PL-MLP with tissue homogenates. PL-MLP was less toxic in vivo than equivalent doses of MMC. Therapeutic studies in C26 mouse tumor models demonstrated dose-dependent improved efficacy of PL-MLP over MMC. Thiolytic activation of PL-MLP occurs in tissues but not in plasma. Liposomal delivery of MLP confers a favorable pharmacological profile and greater therapeutic index than MMC.

  12. Hepatic arterial infusion chemotherapy using fluorouracil, epirubicin, and mitomycin C for patients with liver metastases from gastric cancer after treatment failure of systemic S-1 plus cisplatin.

    PubMed

    Seki, Hiroshi; Ohi, Hiroyuki; Ozaki, Toshirou; Yabusaki, Hiroshi

    2016-07-01

    For patients with liver metastases from gastric cancer (LMGC), combination chemotherapy with fluoropyrimidines and platinum agents has been recognized as standard treatment. However, the prognosis of hepatic progression after first-line treatment failure remains poor. When hepatic progression occurs, hepatic arterial infusion (HAI) chemotherapy may be helpful for preventing disease progression. To retrospectively assess the feasibility and efficacy of HAI chemotherapy using 5-fluorouracil, epirubicin, and mitomycin C (FEM) for patients with LMGC after failure of systemic S-1 plus cisplatin. We reviewed the records of patients who received HAI chemotherapy using FEM for LMGC that progressed during systemic S-1 plus cisplatin treatment while extrahepatic disease was decreased or did not appear. HAI chemotherapy was given as second-line therapy using 5-fluorouracil (330 mg/m(2) weekly), epirubicin (30 or 40 mg/m(2) every 4 weeks), and mitomycin C (2.7 mg/m(2) biweekly). Fourteen patients were analyzed. Toxicity of HAI chemotherapy was generally mild. The objective response rate was 42.9%, including a complete response rate of 14.3%. Median times to hepatic and extrahepatic progression were 9.2 and 7.4 months, respectively. Of 12 patients with documented progression after HAI chemotherapy, 10 patients (83.3%) received additional treatment, including irinotecan or taxanes. Overall, median survival was 12.7 months. Our findings suggest that HAI chemotherapy using FEM is a feasible and effective treatment for patients with LMGC after failure of systemic S-1 plus cisplatin. HAI chemotherapy employed in the second-line setting is useful for achieving long-term disease control of LMGC. © The Foundation Acta Radiologica 2015.

  13. Prospective randomized trial comparing mitomycin, cisplatin, and protracted venous-infusion fluorouracil (PVI 5-FU) With epirubicin, cisplatin, and PVI 5-FU in advanced esophagogastric cancer.

    PubMed

    Ross, P; Nicolson, M; Cunningham, D; Valle, J; Seymour, M; Harper, P; Price, T; Anderson, H; Iveson, T; Hickish, T; Lofts, F; Norman, A

    2002-04-15

    We report the results of a prospectively randomized study that compared the combination of epirubicin, cisplatin, and protracted venous-infusion fluorouracil (PVI 5-FU) (ECF) with the combination of mitomycin, cisplatin, and PVI 5-FU (MCF) in previously untreated patients with advanced esophagogastric cancer. Five hundred eighty patients with adenocarcinoma, squamous carcinoma, or undifferentiated carcinoma were randomized to receive either ECF (epirubicin 50 mg/m(2) every 3 weeks, cisplatin 60 mg/m(2) every 3 weeks and PVI 5-FU 200 mg/m(2)/d) or MCF (mitomycin 7 mg/m(2) every 6 weeks, cisplatin 60 mg/m(2) every 3 weeks, and PVI 5-FU 300 mg/m(2)/d) and analyzed for survival, response, toxicity, and quality of life (QOL). The overall response rate was 42.4% (95% confidence interval [CI], 37% to 48%) with ECF and 44.1% (95% CI, 38% to 50%) with MCF (P =.692). Toxicity was tolerable, and there were only two toxic deaths. ECF resulted in more grade 3/4 neutropenia and grade 2 alopecia, but MCF caused more thrombocytopenia and plantar-palmar erythema. Median survival was 9.4 months with ECF and 8.7 months with MCF (P =.315); at 1 year, 40.2% (95% CI, 34% to 46%) of ECF and 32.7% (95% CI, 27% to 38%) of MCF patients were alive. Median failure-free survival was 7 months with both regimens. Global QOL scores were better with ECF at 3 and 6 months. This study confirms response, survival, and QOL benefits of ECF observed in a previous randomized study. The equivalent efficacy of MCF was demonstrated, but QOL was superior with ECF. ECF remains one of the reference treatments for advanced esophagogastric cancer.

  14. Patterns of failure in patients with locally advanced head and neck cancer treated postoperatively with irradiation or concomitant irradiation with Mitomycin C and Bleomycin

    SciTech Connect

    Zakotnik, Branko . E-mail: bzakotnik@onko-i.si; Budihna, Marjan; Smid, Lojze; Soba, Erika; Strojan, Primoz; Fajdiga, Igor; Zargi, Miha; Oblak, Irena; Lesnicar, Hotimir

    2007-03-01

    Purpose: The long term results and patterns of failure in patients with squamous cell head and neck carcinoma (SCHNC) treated in a prospective randomized trial in which concomitant postoperative radiochemotherapy with Mitomycin C and Bleomycin (CRT) was compared with radiotherapy only (RT), were analyzed. Patients and Methods: Between March 1997 and December 2001, 114 eligible patients with Stage III or IV SCHNC were randomized. Primary surgical treatment was performed with curative intent in all patients. Patients in both groups were postoperatively irradiated to the total dose of 56-70 Gy. Chemotherapy included Mitomycin C 15 mg/m{sup 2} after 10 Gy and 5 mg of Bleomycin twice weekly during irradiation. Median follow-up was 76 months (48-103 months). Results: At 5 years in the RT and CRT arms, the locoregional control was 65% and 88% (p = 0.026), disease-free survival 33% and 53% (p = 0.035), and overall survival 37% and 55% (p = 0.091) respectively. Patients who benefited from chemotherapy were those with high-risk factors. The probability of distant metastases was 22% in RT and 20% in CRT arm (p = 0.913), of grade III or higher late toxicity 19% in RT and 26% in CRT arm (p = 0.52) and of thyroid dysfunction 36% in RT and 56% in CRT arm (p = 0.24). The probability to develop a second primary malignancy (SPM) was 34% in the RT and 8% in the CRT arm (p = 0.023). One third of deaths were due to infection, but there was no difference between the 2 groups. Conclusion: With concomitant radiochemotherapy, locoregional control and disease free survival were significantly improved. Second primary malignancies in the CRT arm compared to RT arm were significantly less frequent. The high probability of post treatment hypothyroidism in both arms warrants regular laboratory evaluation.

  15. Spontaneous apoptosis of blood dendritic cells in patients with breast cancer.

    PubMed

    Pinzon-Charry, Alberto; Maxwell, Tammy; McGuckin, Michael A; Schmidt, Chris; Furnival, Colin; López, J Alejandro

    2006-01-01

    Dendritic cells (DCs) are key antigen-presenting cells that play an essential role in initiating and directing cellular and humoral immunity, including anti-tumor responses. Due to their critical role in cancer, induction of DC apoptosis may be one of the central mechanisms used by tumors to evade immune recognition. Spontaneous apoptosis of blood DCs (lineage negative HLA-DR positive cells) was assessed in peripheral blood mononuclear cells (PBMCs) using Annexin-V and TUNEL assays immediately after blood collection. The role of tumor products was assessed by culturing cells with supernatants derived from breast cancer cell lines (TDSN) or PBMCs (PBMC-SN, as a control). The capacity of DC stimulation to prevent apoptosis was assessed by incubating DC with inflammatory cytokines, poly I:C, IL-12 or CD40 ligand (CD40L) prior to culture with TDSN. Apoptosis was determined by flow cytometry and microscopy, and Bcl-2 expression determined by intracellular staining. In this study we document the presence of a significantly higher proportion of apoptotic (Annexin-V+ and TUNEL+) blood DCs in patients with early stage breast cancer (stage I to II; n = 13) compared to healthy volunteers (n = 15). We examined the role of tumor products in this phenomenon and show that supernatants derived from breast cancer lines induce apoptosis of blood DCs in PBMC cultures. Aiming to identify factors that protect blood DC from apoptosis, we compared a range of clinically available maturation stimuli, including inflammatory cytokines (tumor necrosis factor-alpha, IL-1beta, IL-6 and prostaglandin (PG)E2 as a cytokine cocktail), synthetic double-stranded RNA (poly I:C) and soluble CD40 ligand. Although inflammatory cytokines and poly I:C induced robust phenotypic maturation, they failed to protect blood DCs from apoptosis. In contrast, CD40 stimulation induced strong antigen uptake, secretion of IL-12 and protected blood DCs from apoptosis through sustained expression of Bcl-2. Exogenous IL

  16. NMR and computational characterization of mitomycin cross-linked to adjacent deoxyguanosines in the minor groove of the d(T-A-C-G-T-A)ter dot d(T-A-C-G-T-A) duplex

    SciTech Connect

    Norman, D.; Sastry, M.; Patel, D.J. ); Live, D. ); Lipman, R.; Tomasz, M. ); Hingerty, B.E. ); Broyde, S. )

    1990-03-20

    Two-dimensional homonuclear and heteronuclear NMR and minimized potential energy calculations have been combined to define the structure of the antitumor agent mitomycin C (MC) cross-linked to deoxyguanosines on adjacent base pairs in the d(T1-A2-C3-G4-T5-A6){center dot}d(T7-A8-C9-G10-T11-A12) duplex. The majority of the mitomycin and nucleic acid protons in the MC-X 6-mer complex have been assigned from through-bond and through-space two-dimensional proton NMR studies in aqueous solution at 5 and 20{degree}C. The C3{center dot}G10 and G4{center dot}C9 base pairs are intact at the cross-link site and stack on each other in the complex. The amino protons of G4 and G10 resonate at 9.36 and 8.87 ppm and exhibit slow exchange with solvent H{sub 2}O. The NMR experimental data establish that the mitomycin is cross-linked to the DNA through the amino groups of G4 and G10 and is positioned in the minor groove. The proton chemical shifts and NOEs establish fraying at the ends of the d(T-A-C-G-T-A) duplex, and this feature is retained on mitomycin cross-linked formation. The NMR distance constraints have been included in minimized potential energy computations on the MC-X 6-mer complex. These computations were undertaken with the nonplanar five-membered ring of mitomycin in each of two pucker orientation. The resulting low-energy structures MX1 and MX2 have the mitomycin cross-linked in a widened minor groove with the chromophore ring system in the vicinity of the G10-T11 step on one of the two strands in the duplex. The experimental evidence supports this model since the H1{prime} of G10 is shifted dramatically upfield and the H1{prime} proton of T11 is shifted dramatically downfield on complex formation.

  17. Placental apoptosis in recurrent miscarriage.

    PubMed

    Atia, Tarek A

    2017-09-01

    Apoptosis is an interactive and dynamic biological process involved in all phases of embryogenesis. We aimed to study the effect of placental apoptosis on recurrent miscarriage (RM). Placental tissue samples were collected from 40 women with RM (study group) and 30 women with sporadic spontaneous abortion (control group). Samples were prepared and stained immunohistochemically with markers for both the apoptotic protein (p53) and anti-apoptotic Bcl-2 antibodies. Our results showed that expression of the apoptotic (p53) protein was significantly increased in the placental tissues of the RM group (p = 0.003). By contrast, the expression of anti-apoptotic (Bcl-2) antibodies was significantly increased in the placental tissues of the control group (p = 0.025). We concluded that placental apoptosis plays a crucial role in pregnancy continuation. However, increased p53 expression in placental tissue in early pregnancy could negatively affect pregnancy continuation. Copyright © 2017. Published by Elsevier Taiwan.

  18. The mechanism of PDT-induced apoptosis

    NASA Astrophysics Data System (ADS)

    Cai, Xiongwei; Liu, Timon C.; Ding, Xin-Min; Gu, Ying; Liu, Fan-Guang; Liu, Song-Hao

    2003-12-01

    Photodynamic therapy (PDT) can induce apoptosis in many cancer cells in vitro and in tumors in vivo. Cells become more oxidation with PDT, and maintain differentiation and proliferation, go apoptosis and necrosis with the increase of reactive oxygen species (ROS) concentration. ROS can induce apoptosis through mitochondria by inhibiting respiration chain or oxidative phosphorylation or damaging mitochondrial membrane. ROS can initiate apoptosis through endoplamic reticulum(ER) by opening Ca2+ channel or starting unfold protein response (UPR). ROS can also induce apoptosis through Golgi by producing ganglioside GD3 by use of ceramide, which induces apoptosis by activating caspase-3, JNK and p38 MAPK. It can also induce apoptosis by activating Bip (mitochondria-dependant) or preocaspase-12 (mitochondria- independent) or inhibiting protein synthesizing. There are so complicated cross-talking among different signal pathways or organnells that we think PDT-induced apoptosis is mediated by multiplex pathways and excessive levels in a refined network.

  19. Irinotecan (CPT-11) and mitomycin-C (MMC) as second-line therapy in advanced gastric cancer: a phase II study of the Gruppo Oncologico dell' Italia Meridionale (prot. 2106).

    PubMed

    Giuliani, Francesco; Molica, Stefano; Maiello, Evaristo; Battaglia, C; Gebbia, Vittorio; Di Bisceglie, Maurizio; Vinciarelli, Gianluca; Gebbia, Nicola; Colucci, Giuseppe

    2005-12-01

    The aim of this study was to evaluate the activity and toxicity of a combination regimen of CPT-11 and mitomycin-c as second-line chemotherapy for pretreated patients with advanced, metastatic, or both, gastric adenocarcinoma. Patients with pretreated metastatic disease or early relapsed after adjuvant chemotherapy were enrolled. Entry criteria included histologic/cytologic diagnosis of gastric adenocarcinoma, age 18 to 75 years, performance status > or =70 (Karnofsky scale), bi-dimensionally measurable disease. Patients received CPT-11 and mitomycin-c at the dosage of 150 mg/m2 on days 1 and 15, and 8 mg/m2 on day 1, respectively, every 4 weeks. The disease evaluation was done every 3 cycles. Among the 38 patients we observed, 1 (3%) complete response and 11 (29%) partial responses for an overall response rate of 32% according to an intent-to-treat analysis. The median duration of response was 6.5 months. The median time to progression was 4 months with a median overall survival 8 months. All patients were evaluable for toxicity and the only grade 3-4 observed toxicities were leukopenia (8%), neutropenia (21%), and anemia (5%). The combination of CPT-11 and mitomycin-c is an active and well tolerated second-line treatment in pretreated gastric cancer patients. Further studies are needed to test its role in first-line treatment.

  20. Photorefractive Keratectomy with Adjunctive Mitomycin C for Residual Error after Laser-Assisted In Situ Keratomileusis Using the Pulzar 213 nm Solid-State Laser: Early Results.

    PubMed

    Ng-Darjuan, Maya Fe; Evangelista, Raymond P; Agahan, Archimedes Lee D

    2013-01-01

    Purpose. To evaluate the accuracy, efficacy, stability, and safety of photorefractive keratectomy (PRK) enhancement using the Pulzar 213 nm solid-state laser (SSL) with adjunctive Mitomycin C in eyes previously treated with laser assisted in situ keratomileusis (LASIK) with residual error of refraction. Methods. This is a prospective noncomparative case series of 16 eyes of 12 patients who underwent PRK for residual refractive error after primary LASIK. Mitomycin C 0.02% was used after the PRK to prevent haze formation. Outcomes measured were pre- and postoperative manifest refraction spherical equivalent (MRSE), uncorrected (UDVA) and best-corrected distance visual acuity (CDVA), and slit lamp evidence of corneal complications. Results. The mean UDVA improved from 20/70 preoperatively to 20/30 postoperatively. The average gain in lines for the UDVA was 2.38. After six months of followup, the postoperative MRSE within 0.50 D in 56% (9) of eyes and 94% (15) eyes were within 1.0 diopters of the intended correction. No eyes developed haze all throughout the study. Conclusion. PRK enhancement with adjunctive use of Mitomycin C for the correction of residual error of refraction after LASIK using the Pulzar 213 nm solid-state laser is an accurate, effective, and safe procedure.

  1. Photorefractive Keratectomy with Adjunctive Mitomycin C for Residual Error after Laser-Assisted In Situ Keratomileusis Using the Pulzar 213 nm Solid-State Laser: Early Results

    PubMed Central

    Ng-Darjuan, Maya Fe; Evangelista, Raymond P.; Agahan, Archimedes Lee D.

    2013-01-01

    Purpose. To evaluate the accuracy, efficacy, stability, and safety of photorefractive keratectomy (PRK) enhancement using the Pulzar 213 nm solid-state laser (SSL) with adjunctive Mitomycin C in eyes previously treated with laser assisted in situ keratomileusis (LASIK) with residual error of refraction. Methods. This is a prospective noncomparative case series of 16 eyes of 12 patients who underwent PRK for residual refractive error after primary LASIK. Mitomycin C 0.02% was used after the PRK to prevent haze formation. Outcomes measured were pre- and postoperative manifest refraction spherical equivalent (MRSE), uncorrected (UDVA) and best-corrected distance visual acuity (CDVA), and slit lamp evidence of corneal complications. Results. The mean UDVA improved from 20/70 preoperatively to 20/30 postoperatively. The average gain in lines for the UDVA was 2.38. After six months of followup, the postoperative MRSE within 0.50 D in 56% (9) of eyes and 94% (15) eyes were within 1.0 diopters of the intended correction. No eyes developed haze all throughout the study. Conclusion. PRK enhancement with adjunctive use of Mitomycin C for the correction of residual error of refraction after LASIK using the Pulzar 213 nm solid-state laser is an accurate, effective, and safe procedure. PMID:24555132

  2. APOPTOSIS IN WHOLE MOUSE OVARIES

    EPA Science Inventory

    Apoptosis in Whole Mouse Ovaries
    Robert M. Zucker Susan C. Jeffay and Sally D. Perreault
    Reproductive Toxicology Division, National Health and Environmental Effects Research Laboratory, U.S. Environmental Protection Agency, Research Triangle Park, North Carolina, 27711.

  3. Methylselenium and Prostate Cancer Apoptosis

    DTIC Science & Technology

    2003-02-01

    dependent apoptosis execution in PCa cells. We have in the reporting period refined a methylselenol generation system based on methioninase with... methylselenol , methylselenium 16. PRICE CODE 17. SECURITY CLASSIFICATION 18. SECURITY CLASSIFICATION 19. SECURITY CLASSIFICATION 20. LIMITATION OF... methylselenol generation system based on methioninase with selenomethionine as substrate (Wang et al, Mol. Carcinogenesis, 2002, appendix 1) and

  4. Methylselenium and Prostate Cancer Apoptosis

    DTIC Science & Technology

    2008-02-01

    methylselenol , prostate cancer chemoprevention, apoptosis 16. SECURITY CLASSIFICATION OF: 17. LIMITATION OF ABSTRACT 18. NUMBER OF PAGES 19a. NAME OF...considered an immediate precursor to the in vivo active anticancer selenium metabolite methylselenol , greatly sensitized HRPCa cells to undergo

  5. Methylselenium and Prostate Cancer Apoptosis

    DTIC Science & Technology

    2006-02-01

    will lay ground work for future validation studies in vivo and translation from the bench to the bedside. 15. SUBJECT TERMS Selenium, methylselenol ...Results: The methylselenol precursor methylseleninic acid (MSeA) increased the apoptosis potency of SN38, etoposide or paclitaxel by several folds

  6. Pancreatic carcinogenesis: apoptosis and angiogenesis.

    PubMed

    Onizuka, Shinya; Kawakami, Shunsuke; Taniguchi, Ken; Fujioka, Hikaru; Miyashita, Kosei

    2004-04-01

    Apoptosis and angiogenesis are critical biologic processes that are altered during carcinogenesis. Both apoptosis and angiogenesis may play an important role in pancreatic carcinogenesis. Despite numerous advances in the diagnosis and treatment of pancreatic cancer, its prognosis remains dismal and a new therapeutic approach is much needed. Recent research has revealed that apoptosis and angiogenesis are closely interrelated. Several reports show that a tumor suppresser gene that is expressed in pancreatic carcinoma and related to malignant potential can induce apoptosis and also inhibit angiogenesis. At present, it is generally accepted that tumor growth in cancers, including pancreatic cancer, depends on angiogenesis. We have identified 2 new angiogenesis inhibitors from a conditioned medium of human pancreatic carcinoma cell line (BxPC-3): antiangiogenic antithrombin III (aaAT-III) and vitamin D binding protein-macrophage activating factor (DBP-maf). These molecules were able to regress tumors in severe combined immunodeficiency disease (SCID) mice, demonstrating potent inhibition of endothelial cell proliferation. Moreover, the angiogenesis inhibitors induced tumor dormancy in the animal model. These results suggest that antiangiogenic therapy using angiogenesis inhibitors may become a new strategy for treatment of pancreatic cancer in the near future.

  7. [Apoptosis in chronic lymphocytic leukemia].

    PubMed

    Giordano, M

    2000-01-01

    Chronic lymphocytic leukemia of B cells (B-CLL) is the most prevalent leukemia in the Occidental Hemisphere. It is characterized by a progressive accumulation of monoclonal CD5+ B lymphocytes, with low amounts of surface Ig. Most B-CLL cells are arrested in the G0 phase of the cell cycle; therefore their accumulation in vivo appears to result from the inhibition of apoptosis which has been attributed to over-expression of the anti-apoptotic protein Bcl-2. When cultured in vitro, spontaneous apoptosis occurs, suggesting the existence in vivo of survival-promoting factors. We here show that non-malignant leukocytes, particularly monocytes and NK cells, are able to inhibit B-CLL cells apoptosis, at least in part, through the release of soluble factors. Neutralizing antibodies directed to interferon-gamma or IL-4 only partially abolish the protecting effects of accessory cells suggesting that they are not the main cytokines involved. Increased apoptosis of B-CLL cells is not associated with modifications in the expression of Bcl-2, Fas or Fas ligand. Considering that B-CLL is associated to autoimmune phenomena and recurrent infections due to hypogammaglobulinemia, it should be interesting to correlate the activation of immune responses with disease progression.

  8. APOPTOSIS IN WHOLE MOUSE OVARIES

    EPA Science Inventory

    Apoptosis in Whole Mouse Ovaries
    Robert M. Zucker Susan C. Jeffay and Sally D. Perreault
    Reproductive Toxicology Division, National Health and Environmental Effects Research Laboratory, U.S. Environmental Protection Agency, Research Triangle Park, North Carolina, 27711.

  9. Methods for determining Myc-induced apoptosis.

    PubMed

    Lu, Dan; Littlewood, Trevor D

    2013-01-01

    Although many oncoproteins promote cell growth and proliferation, some also possess the potential to induce cell death by apoptosis. Deregulated expression of the myc oncogene promotes apoptosis in both cultured cells and in some tissues in vivo. Here we describe techniques to detect Myc-induced apoptosis in vitro using flow cytometry and microscopy and in vivo using immunohistochemical staining.

  10. Regulation of apoptosis and innate immune stimuli in inflammation-induced preterm labor.

    PubMed

    Jaiswal, Mukesh K; Agrawal, Varkha; Mallers, Timothy; Gilman-Sachs, Alice; Hirsch, Emmet; Beaman, Kenneth D

    2013-12-01

    An innate immune response is required for successful implantation and placentation. This is regulated, in part, by the a2 isoform of V-ATPase (a2V) and the concurrent infiltration of M1 (inflammatory) and M2 (anti-inflammatory) macrophages to the uterus and placenta. The objective of the present study was to identify the role of a2V during inflammation-induced preterm labor in mice and its relationship to the regulation of apoptosis and innate immune responses. Using a mouse model of infection-induced preterm delivery, gestational tissues were collected 8 h after intrauterine inoculation on day 14.5 of pregnancy with either saline or peptidoglycan (PGN; a TLR 2 agonist) and polyinosinic-polycytidylic acid [poly(I:C); a TLR3 agonist], modeling Gram-positive bacterial and viral infections, respectively. Expression of a2V decreased significantly in the placenta, uterus, and fetal membranes during PGN+poly(I:C)-induced preterm labor. Expression of inducible NO synthase was significantly upregulated in PGN+poly(I:C)-treated placenta and uterus. PGN+poly(I:C) treatment disturbed adherens junction proteins and increased apoptotic cell death via an extrinsic pathway of apoptosis among uterine decidual cells and spongiotrophoblasts. F4/80(+) macrophages were increased and polarization was skewed in PGN+poly(I:C)-treated uterus toward double-positive CD11c(+) (M1) and CD206(+) (M2) cells, which are critical for the clearance of dying cells and rapid resolution of inflammation. Expression of Nlrp3 and activation of caspase-1 were increased in PGN+poly(I:C)-treated uterus, which could induce pyroptosis. These results suggest that the double hit of PGN+poly(I:C) induces preterm labor via reduction of a2V expression and simultaneous activation of apoptosis and inflammatory processes.

  11. Regulation of Apoptosis and Innate Immune Stimuli in Inflammation Induced Preterm labor

    PubMed Central

    Jaiswal, Mukesh K.; Agrawal, Varkha; Mallers, Timothy; Gilman-Sachs, Alice; Hirsch, Emmet; Beaman, Kenneth D.

    2013-01-01

    An innate immune response is required for successful implantation and placentation. This is regulated in part by a2 isoform of V-ATPase (a2V) and the concurrent infiltration of M1 (inflammatory) and M2 (anti-inflammatory) macrophages to the uterus and placenta. The objective of present study was to identify the role of a2V during inflammation-induced preterm labor in mice and its relationship to the regulation of apoptosis and innate immune responses. Using a mouse model of infection-induced preterm delivery, gestational tissues were collected 8 hrs after intrauterine inoculation on day 14.5 of pregnancy with either saline or peptidoglycan (PGN, a toll-like receptor (TLR) 2 agonist) and polyinosinic:cytidylic acid (poly(I:C), a TLR3 agonist), modeling Gram positive bacterial and viral infections, respectively. Expression of a2V decreased significantly in the placenta, uterus, and fetal membranes during PGN+poly(I:C) induced preterm labor. Expression of iNOS was significantly upregulated in PGN+poly(I:C) treated placenta and uterus. PGN+poly(I:C) treatment disturbed adherens junction proteins and increased apoptotic cell death via extrinsic pathway of apoptosis among uterine decidual cells and spongiotrophoblast. F4/80+ macrophages were increased and polarization was skewed in PGN+poly(I:C) treated uterus toward double positive CD11c+ (M1) and CD206+ (M2) cells, which are critical for the clearance of dying cells and rapid resolution of inflammation. Expression of Nlrp3 and activation of caspase-1 was increased in PGN+poly(I:C) treated uterus which could induce pyroptosis. These results suggest that double hit of PGN+poly(I:C) induces preterm labor via reduction of a2V expression and simultaneous activation of apoptosis and inflammatory processes. PMID:24163412

  12. Therapeutic efficacy of a lipid-based prodrug of mitomycin C in pegylated liposomes: studies with human gastro-entero-pancreatic ectopic tumor models.

    PubMed

    Gabizon, Alberto; Amitay, Yasmine; Tzemach, Dina; Gorin, Jenny; Shmeeda, Hilary; Zalipsky, Samuel

    2012-06-10

    A mitomycin-C lipid-based prodrug (MLP) formulated in pegylated liposomes (PL-MLP) was previously reported to have significant antitumor activity and reduced toxicity in mouse tumor models (Clin Cancer Res 12:1913-20, 2006). MLP is activated by thiolysis releasing mitomycin-C (MMC) which rapidly dissociates from liposomes. The purpose of this study was to examine the plasma stability, pharmacokinetics, and antitumor activity of PL-MLP in mouse models of human gastroentero-pancreatic tumors. MLP was incorporated with almost 100% efficiency in pegylated liposomes composed of hydrogenated phosphatidylcholine, with or without cholesterol (Chol). Mean vesicle size was 45-65 nm for liposome preparations downsized by homogenization, and 80-100 nm when downsized by extrusion, the latter displaying narrower polydispersity. MLP to phospholipid mole ratio was 5% (~20 μg MMC-equivalents/μmol). Therapeutic studies were carried out in the N87 gastric carcinoma (Ca), HCT15 colon Ca, and Panc-1 pancreatic Ca models implanted s.c. in CD1 nude mice. Treatment was administered i.v. in mice with established tumors. PL-MLP was very stable when incubated in plasma, and whole blood with a maximum of 5% release and activation to free MMC after 24 h. In the presence of a strong reducing agent (dithiotreitol), MLP was almost entirely activated to free MMC. Pharmacokinetic studies revealed major differences in plasma clearance between free MMC and PL-MLP. The longest half-lives were observed for extruded and Chol-containing preparations. Using a liposome radiolabel, it was found that the plasma levels of liposomes and prodrug were nearly superimposable confirming the absence of drug leakage in circulation. In vivo prodrug activation was significantly increased by co-injection of a large dose of a biocompatible reducing agent, N-acetylcysteine. PL-MLP was significantly more effective in delaying tumor growth and resulted in more tumor regressions than irinotecan in the N87 and HCT15 models

  13. Somatic Crossing over in GLYCINE MAX (L.) Merrill: Mutagenicity of Sodium Azide and Lack of Synergistic Effect with Caffeine and Mitomycin C

    PubMed Central

    Vig, B. K.

    1973-01-01

    Glycine max (soybean) is one angiosperm which lends itself to the study of somatic crossing over. This is made possible because some varieties have gene combinations Y11Y11, Y11y11 and y11y11 in the segregating populations from Y11y11 plants. The gene in question is responsible for chlorophyll synthesis. The Y11Y11 plants have dark green leaves, Y11y11 are light green and y11y11 plants are golden yellow. The heterozygous plants have dark green, yellow and dark green-yellow (double) spots on the leaves of the untreated control material, whereas the two homozygotes are almost always devoid of somatic sectoring. Application of caffeine, or mitomycin C, to the seeds increased the frequency of double, dark green and yellow spots on the Y11y11 background. Possibly, some dark green or yellow spots originate by failure of one of the two components of what might start as a double spot due to somatic crossing over. The application of NaN3 increases the frequency of dark green or yellow spots, almost exclusively. The two spots increase in equal frequency. The y11y11 plants so treated do not have any light green sectors, but dark green, Y11Y11, plants do develop a few light green or very dark green spots. The data indicate that NaN3 is capable of inducing nondisjunction, but does not cause mutations (at this locus), chromosome fragmentations (segmental losses) or somatic crossing over to an appreciable degree. It has previously been shown that caffeine-induced chromosome rejoining in Vicia faba can be inhibited by treating the roots with NaN3. In the present experiments NaN3 did not affect the processes of somatic crossing over as induced by caffeine or mitomycin C. The effect was additive. This system offers advantages for studying chemical mutagens in that somatic crossing over, point mutations, segmental losses through chromosome breakage and nondisjunction can all be studied in a single treatment to the seeds. PMID:4797661

  14. Somatic crossing over in Glycine max (L.) Merrill: mutagenicity of sodium azide and lack of synergistic effect with caffeine and mitomycin C.

    PubMed

    Vig, B K

    1973-10-01

    Glycine max (soybean) is one angiosperm which lends itself to the study of somatic crossing over. This is made possible because some varieties have gene combinations Y(11)Y(11), Y(11)y(11) and y(11)y(11) in the segregating populations from Y(11)y(11) plants. The gene in question is responsible for chlorophyll synthesis. The Y(11)Y(11) plants have dark green leaves, Y(11)y(11) are light green and y(11)y(11) plants are golden yellow. The heterozygous plants have dark green, yellow and dark green-yellow (double) spots on the leaves of the untreated control material, whereas the two homozygotes are almost always devoid of somatic sectoring. Application of caffeine, or mitomycin C, to the seeds increased the frequency of double, dark green and yellow spots on the Y(11)y(11) background. Possibly, some dark green or yellow spots originate by failure of one of the two components of what might start as a double spot due to somatic crossing over. The application of NaN(3) increases the frequency of dark green or yellow spots, almost exclusively. The two spots increase in equal frequency. The y(11)y(11) plants so treated do not have any light green sectors, but dark green, Y(11)Y(11), plants do develop a few light green or very dark green spots. The data indicate that NaN(3) is capable of inducing nondisjunction, but does not cause mutations (at this locus), chromosome fragmentations (segmental losses) or somatic crossing over to an appreciable degree. It has previously been shown that caffeine-induced chromosome rejoining in Vicia faba can be inhibited by treating the roots with NaN(3). In the present experiments NaN(3) did not affect the processes of somatic crossing over as induced by caffeine or mitomycin C. The effect was additive. This system offers advantages for studying chemical mutagens in that somatic crossing over, point mutations, segmental losses through chromosome breakage and nondisjunction can all be studied in a single treatment to the seeds.

  15. Apoptosis in virus infection dynamics models

    PubMed Central

    Fan, Ruili; Dong, Yueping; Huang, Gang; Takeuchi, Yasuhiro

    2014-01-01

    In this paper, on the basis of the simplified two-dimensional virus infection dynamics model, we propose two extended models that aim at incorporating the influence of activation-induced apoptosis which directly affects the population of uninfected cells. The theoretical analysis shows that increasing apoptosis plays a positive role in control of virus infection. However, after being included the third population of cytotoxic T lymphocytes immune response in HIV-infected patients, it shows that depending on intensity of the apoptosis of healthy cells, the apoptosis can either promote or comfort the long-term evolution of HIV infection. Further, the discrete-time delay of apoptosis is incorporated into the pervious model. Stability switching occurs as the time delay in apoptosis increases. Numerical simulations are performed to illustrate the theoretical results and display the different impacts of a delay in apoptosis. PMID:24963975

  16. [Apoptosis modulation by human papillomavirus].

    PubMed

    Jave-Suárez, Luis Felipe; Ratkovich-González, Sarah; Olimón-Andalón, Vicente; Aguilar-Lemarroy, Adriana

    2015-01-01

    One of the most important processes to keep the homeostasis in organisms is the apoptosis, also called programmed cell death. This mechanism works through two pathways: The intrinsic or mitochondrial, which responds to DNA damage and extern agents like UV radiation; and the extrinsic or receptor-mediated, which binds to their ligands to initiate the apoptotic trail. The evasion of apoptosis is one of the main causes of cellular transformation to malignity. Many viruses had shown capacity to modify the apoptotic process; among them is the human papillomavirus, which, by means of its oncoproteins, interferes in pathways, reacting with the receptors and molecules and participating in the death mechanism. This creates ideal conditions for cancer development.

  17. Apoptosis in Cryopreserved Eukaryotic Cells.

    PubMed

    Savitskaya, M A; Onishchenko, G E

    2016-05-01

    This review considers apoptosis mechanisms that have been revealed in cryopreserved cells and which can be controlled using different chemical agents, thereby improving the viability of cells after their return to normal conditions. The role of oxidative stress as of the most significant damaging factor is discussed, as well as the reasonability of including antioxidants into cryopreservation/thawing protocols as independent agents or in combination with other compounds.

  18. Combination Chemotherapy of Mitomycin C and Methotrexate Was Effective on Metastatic Breast Cancer Resistant to Eribulin, Vinorelbine, and Bevacizumab after Anthracycline, Taxane, and Capecitabine

    PubMed Central

    Tanabe, Masahiko

    2016-01-01

    Complete cure of metastatic breast cancer (MBC) is still considered difficult even after the development of new drugs. While new drugs have been continuously developed, conventional drugs such as mitomycin C (MMC) and methotrexate (MTX) have become less used. Combination chemotherapy with MMC and MTX (MMC/MTX) was reported to be effective for 9.7–19.4% of 31 patients with human epidermal growth factor receptor type 2 (HER2)-negative MBC who were aggressively treated with anthracycline, taxane, capecitabine, and vinorelbine. However, its efficacy, when it is used after newly developed drugs such as eribulin and bevacizumab, is yet to be evaluated. We here introduce one case in which MMC/MTX was effective for MBC that was resistant to chemotherapy with eribulin, vinorelbine, and bevacizumab with paclitaxel after sequential treatment with anthracycline, taxane, capecitabine, and several hormonal therapies. Lung metastasis was newly observed after sequential treatment of MBC for 6 years. Although the disease was resistant to chemotherapy of eribulin, vinorelbine, and bevacizumab with paclitaxel, it responded well to the treatment of MMC/MTX, which continued for 7 months. This case suggests that MMC/MTX could be an effective treatment for MBC patients when the disease progressively develops even after aggressive treatment with multiple regimens. PMID:27721762

  19. Comparison of methods for detecting mitomycin C- and ethyl nitrosourea-induced germ cell damage in mice: sperm enzyme activities, sperm motility, and testis weight

    SciTech Connect

    Ficsor, G.; Oldford, G.M.; Loughlin, K.R.; Panda, B.B.; Dubien, J.L.; Ginsberg, L.C.

    1984-01-01

    Testes weights, sperm motility and enzyme activities in single sperm were compared with respect to their ability to detect either developmental or mutational damage to germ cells. Male mice were injected i.p. with 2.5 mg/kg mitomycin C (MC) or 50 or 100 mg/kg ethylnitrosourea (ENU) or saline and were then killed at times such that sperm derived from treated vas sperm (SZ), spermatids (ST), preleptotene-late-spermatogonial cells (PLSG), spermatogonial cells (SG), or spermatogonial stem cells (SGS) could be evaluated. The authors conclude that testis weight, which is easily obtained, is a sensitive indicator of germ cell damage by these agents. Sperm from each animal were evaluated for sperm motility, acrosin activity, succinic dehydrogenase (SDH) activity with or without the competitive inhibitor malonate or after exposure to 60/sup 8/C for 10 min. The latter two assays were to detect sperm enzymes resistant to the inhibitor or heat. The presence of the acrosin protein was also detected immunologically. Of the sperm assays, acrosin activity proved to be the most sensitive indicator of germ cell damage and was the simplest to measure.

  20. Mitomycin C-treated antigen-presenting cells as a tool for control of allograft rejection and autoimmunity: from bench to bedside.

    PubMed

    Terness, Peter; Kleist, Christian; Simon, Helmut; Sandra-Petrescu, Flavius; Ehser, Sandra; Chuang, Jing-Jing; Mohr, Elisabeth; Jiga, Lucian; Greil, Johann; Opelz, Gerhard

    2009-07-01

    Cells have been previously used in experimental models for tolerance induction in organ transplantation and autoimmune diseases. One problem with the therapeutic use of cells is standardization of their preparation. We discuss an immunosuppressive strategy relying on cells irreversibly transformed by a chemotherapeutic drug. Dendritic cells (DCs) of transplant donors pretreated with mitomycin C (MMC) strongly prolonged rat heart allograft survival when injected into recipients before transplantation. Likewise, MMC-DCs loaded with myelin basic protein suppressed autoreactive T cells of MS patients in vitro and prevented experimental autoimmune encephalitis in mice. Comprehensive gene microarray analysis identified genes that possibly make up the suppressive phenotype, comprising glucocorticoid leucine zipper, immunoglobulin-like transcript 3, CD80, CD83, CD86, and apoptotic genes. Based on these findings, a hypothetical model of tolerance induction by MMC-treated DCs is delineated. Finally, we describe the first clinical application of MMC-treated monocyte-enriched donor cells in an attempt to control the rejection of a haploidentical stem cell transplant in a sensitized recipient and discuss the pros and cons of using MMC-treated antigen-presenting cells for tolerance induction. Although many questions remain, MMC-treated cells are a promising clinical tool for controlling allograft rejection and deleterious immune responses in autoimmune diseases.

  1. Studies on the in vitro interaction of mitomycin C, nitrofurantoin and paraquat with pulmonary microsomes. Stimulation of reactive oxygen-dependent lipid peroxidation.

    PubMed

    Trush, M A; Mimnaugh, E G; Ginsburg, E; Gram, T E

    1982-03-01

    In vitro experiments were performed to evaluate the capacity of the redox cycling compounds mitomycin C (MC), nitrofurantoin (NF) and paraquat (PQ) to stimulate pulmonary microsomal lipid peroxidation. It was observed that the interaction of MC, NF or PQ with rat or mouse lung microsomes in the presence of an NADPH-generating system and an O2 atmosphere resulted in significant lipid peroxidation. All three compounds demonstrated similar concentration dependency, similar time courses and the ability to generate lipid peroxidation-associated chemiluminescence. The stimulation of lipid peroxidation by MC, NF or PQ was inhibited significantly by superoxide dismutase, glutathione, ascorbic acid, catalase and EDTA, agents which either scavenge reactive oxygen and/or prevent the generation of secondary reactive oxygen metabolites. In addition, the ability of MC or NF, but not PQ, to stimulate lipid peroxidation was reduced significantly following preincubation with microsomes and NADPH under N2 (15-20 min) prior to incubation under O2. During this period under N2. MC and NF underwent reductive metabolism of their quinone and nitro moieties respectively. Thus, it appears that under aerobic conditions the pulmonary microsomal-mediated redox cycling of MC, NF and PQ is accompanied by the stimulation of reactive oxygen-dependent lipid peroxidation.

  2. Identification of Escherichia coli ygaQ and rpmG as novel mitomycin C resistance factors implicated in DNA repair

    PubMed Central

    Bolt, Edward L.; Jenkins, Tabitha; Russo, Valeria Moreira; Ahmed, Sharlene; Cavey, James; Cass, Simon D.

    2015-01-01

    Using the ASKA (A Complete Set of Escherichia coli K-12 ORF Archive) library for genome-wide screening of E. coli proteins we identified that expression of ygaQ and rpmG promotes mitomycin C resistance (MMCR). YgaQ mediated MMCR was independent of homologous recombination involving RecA or RuvABC, but required UvrD. YgaQ is an uncharacterized protein homologous with α-amylases that we identified to have nuclease activity directed to ssDNA of 5′ flaps. Nuclease activity was inactivated by mutation of two amino acid motifs, which also abolished MMCR. RpmG is frequently annotated as a bacterial ribosomal protein, although forms an operon with MutM glycosylase and a putative deubiquitinating (DUB) enzyme, YicR. RpmG associated MMCR was dependent on MutM. MMCR from RpmG resembles DNA repair phenotypes reported for ‘idiosyncratic ribosomal proteins’ in eukaryotes. PMID:26704888

  3. Prolonged rest period enables the detection of micronucleated hepatocytes in the liver of young adult rats after a single dose of diethylnitrosamine or mitomycin C.

    PubMed

    Shimada, Keisuke; Yamamoto, Mika; Takashima, Miyuki; Seki, Jiro; Miyamae, Yoichi; Wakata, Akihiro

    2015-09-01

    A repeated-dose micronucleus assay utilizing young adult rat hepatocytes was recently developed to evaluate the genotoxicity. In this assay, accumulation of micronucleated hepatocytes (MNHEPs) induced by repeated dosing of genotoxic chemicals is considered to be a key factor in the detection of micronuclei induction. Then, we hypothesized that the period following chemical exposure enable the detection of MNHEP induction in young adult rats, namely that MNHEPs can be generated from chromosomally damaged cells and accumulate following initiation of chemical exposure until sampling. We therefore measured MNHEP induction at 2 or 4 weeks after a single oral administration of 12.5, 50, or 100mg/kg of diethylnitrosamine (DEN) or an intraperitoneal administration of 0.5, 1.0, or 2.0mg/kg of mitomycin C (MMC) to young adult rats. Results showed a statistically significant, dose-dependent increase in the numbers of MNHEPs in DEN- or MMC-treated rats, indicating that prolonged rest period following a single dose of a genotoxic chemical enables the detection of MNHEP induction in the liver of young adult rats. From these results, a single oral administration of 50mg/kg of DEN with a 2- or 4- week rest period can be used as a positive control in repeated-dose liver micronucleus assays. This procedure is superior in terms of labor saving and animal welfare to repeated dosing of DEN.

  4. Identification of Escherichia coli ygaQ and rpmG as novel mitomycin C resistance factors implicated in DNA repair.

    PubMed

    Bolt, Edward L; Jenkins, Tabitha; Russo, Valeria Moreira; Ahmed, Sharlene; Cavey, James; Cass, Simon D

    2015-12-24

    Using the ASKA (A Complete Set of Escherichia coli K-12 ORF Archive) library for genome-wide screening of E. coli proteins we identified that expression of ygaQ and rpmG promotes mitomycin C resistance (MMC(R)). YgaQ mediated MMC(R) was independent of homologous recombination involving RecA or RuvABC, but required UvrD. YgaQ is an uncharacterized protein homologous with α-amylases that we identified to have nuclease activity directed to ssDNA of 5' flaps. Nuclease activity was inactivated by mutation of two amino acid motifs, which also abolished MMC(R). RpmG is frequently annotated as a bacterial ribosomal protein, although forms an operon with MutM glycosylase and a putative deubiquitinating (DUB) enzyme, YicR. RpmG associated MMC(R) was dependent on MutM. MMC(R) from RpmG resembles DNA repair phenotypes reported for 'idiosyncratic ribosomal proteins' in eukaryotes.

  5. Structure of adduct X, the last unknown of the six major DNA adducts of mitomycin C formed in EMT6 mouse mammary tumor cells.

    PubMed

    Palom, Y; Belcourt, M F; Musser, S M; Sartorelli, A C; Rockwell, S; Tomasz, M

    2000-06-01

    Treatment of EMT6 mouse mammary tumor cells with mitomycin C (MC) results in the formation of six major MC-DNA adducts. We identified the last unknown of these ("adduct X") as a guanine N(2) adduct of 2, 7-diaminomitosene (2,7-DAM), in which the mitosene is linked at its C-10 position to guanine N(2). The assigned structure is based on UV and mass spectra of adduct X isolated directly from the cells, as well as on its difference UV, second-derivative UV, and circular dichroism spectra, synthesis from [8-(3)H]deoxyguanosine, and observation of its heat stability. These tests were carried out using 17 microg of synthetic material altogether. The mechanism of formation of adduct X involves reductive metabolism of MC to 2,7-DAM, which undergoes a second round of reductive activation to alkylate DNA, yielding adduct X and another 2,7-DAM-guanine adduct (adduct Y), which is linked at guanine N7 to the mitosene. Adduct Y has been described previously. Adduct X is formed preferentially at GpC, while adduct Y favors the GpG sequence. In contrast to MC-DNA adducts, the 2,7-DAM-DNA adducts are not cytotoxic.

  6. Conversion of mitomycin C to 2,7-diaminomitosene and 10-decarbamoyl 2,7-diaminomitosene in tumour tissue in vivo.

    PubMed

    Chirrey, L; Cummings, J; Halbert, G W; Smyth, J F

    1995-01-01

    The progress of mitomycin C (MMC) bioreduction was studied in vivo in the rat Sp 107 mammary carcinoma after intra-tumoural injection of either 100 micrograms or 1 mg. 2,7-Diaminomitosene (2,7-DM) was utilised as a primary bioreductive metabolite and 10-decarbamoyl 2,7-diaminomitosene (DC 2,7-DM) served as a secondary bioreductive metabolite, both of which were measured by high-performance liquid chromatography. 2,7-DM and DC 2,7-DM were produced rapidly, achieving close to their maximal concentrations at the earliest time point studied [5 min]. 2,7-DM was cleared rapidly from the tumour with apparent half-lives of 5 and 35 min after the low and high drug doses, respectively. DC 2,7-DM had a longer apparent half-life of 130 min at the higher dose but, as compared with 2,7-DM, was only a minor metabolite [the area under the curve (AUC) of 2,7-DM was 5.6-fold that of DC 2,7-DM]. At the lower drug dose, DC 2,7-DM was not detectable. Rapid formation and disappearance of bioreductive metabolites of MMC may account for the failure of previous studies to detect these products in vivo.

  7. Effects of radiofrequency radiation and simultaneous exposure with mitomycin C on the frequency of sister chromatid exchanges in Chinese hamster ovary cells

    SciTech Connect

    Ciaravino, V.; Meltz, M.L.; Erwin, D.N.

    1987-01-01

    Chinese hamster ovary (CHO) cells were exposed for 2 hr with and without mitomycin C (MMC) to pulsed wave radiofrequency radiation (RFR) at 2450 MHz. The repetition rate of 25,000 pulses per sec (pps), and exposure geometry used, resulted in a specific absorption rate (SAR) of 33.8 W/kg. The following exposure regimens were used: 1) a 37 C water bath control; 2) a water bath temperature control (TC) in which the continuously monitored medium temperature closely followed teh temperature rise in the RFR-exposed flasks; and 3) the RFR-exposed cells in a water bath set at 37 C prior to exposure. RFR exposure resulted in a maximum cell culture medium temperature of 39.2 C. In the absence of MMC, there was no significant increase in sister chromatid exchange (SCE) in the RFR-exposed or TC groups over that of teh 37 C control. When a simultaneous treatment of RFR and MMC occurred there was no statistical difference in SCE frequency from that caused by chemical treatment alone.

  8. Effects of radiofrequency radiation and simultaneous exposure with mitomycin C on the frequency of sister chromatid exchanges in Chinese hamster ovary cells

    SciTech Connect

    Ciaravino, V.; Meltz, M.L.; Erwin, D.N.

    1987-01-01

    Chinese hamster ovary (CHO) cells were exposed for 2 hr with and without mitomycin C (MMC) (1 X 10(-8)M) to pulsed wave radiofrequency radiation (RFR) at 2450 MHz. The repetition rate of 25,000 pulses per sec (pps), pulse width of 10 microseconds, and exposure geometry used, resulted in a specific absorption rate (SAR) of 33.8 W/kg. The following exposure regimens were used: a 37 degrees C water bath control; a water bath temperature control (TC) in which the continuously monitored medium temperature closely followed the temperature rise in the RFR-exposed flasks; and the RFR-exposed cells in a water bath set at 37 degrees C prior to exposure. RFR exposure resulted in a maximum cell culture medium temperature of 39.2 degrees C. In the absence of MMC, there was no significant increase in sister chromatid exchange (SCE) in the RFR-exposed or TC groups over that of the 37 degrees C control. When a simultaneous treatment of RFR and MMC occurred there was no statistical difference in SCE frequency from that caused by chemical treatment alone.

  9. Controlled release of 5-fluorouracil or mitomycin-c from polymer matrix: Preparation by radiation polymerization and in vivo evaluation of the anticancer drug/polymer composites

    NASA Astrophysics Data System (ADS)

    Li, Ximing; Shen, Weiming; Liu, Chengjie; Nishimoto, Sei-Ichi; Kagiya, Tsutomu

    Polymer tablets containing anticancer drugs such as 5-fluorouracil (5-FU) and mitomycin-C (MMC) have been prepared to evaluate the drug-release characteristics in vitro and the effect on local control of mouse solid tumors in vivo. Radiation-induced polymerization of hydrophilic monomers (2-hydroxyethyl methacrylate and related monomers) at low temperature (-80°C) was performed to immobilize 5-FU or MMC in the polymer matrix. The drug was dispersed as microcrystallines within the polymer matrix. The rate of drug release in vitro in buffer solution (pH7.0, 37°C) increased with increase in hydrophilicity of polymer matrix. Appropriate amount of crosslinks within the polymer matrix, as formed by ethylene glycol dimethacrylate (2G) added in the polymerization system, was effective to control the rate of drug release. The drug release became faster upon the addition of increasing amount of water in the radiation-induced polymerization. The tablet consisting of drug/polymer was buried surgically near solid tumors of striate muscle sarcoma (S180) transplanted to Kunming mice and the therapeutic effect of slow releasing drugs was evaluated in vivo by reference to intraperitoneal (i.p.) injection of the corresponding drugs. The slow releasing drugs led to high chemotherapeutic gain for local control of solid tumors with remarkable reduction of toxic side effect of the drugs.

  10. Apoptosis in human retinal degenerations.

    PubMed

    Xu, G Z; Li, W W; Tso, M O

    1996-01-01

    This paper examined the role of apoptosis in human retinal degenerations including pathologic myopia, age-related macular degeneration, serous retinal detachment, retinal lattice, and paving stone degenerations. Thirty-seven enucleated human eyes with 1 of the above-mentioned retinal degenerations were studied by histopathology and by TdT-mediated biotin-dUTP nicked-end labelling (TUNEL) technique. Tunnel labelling characteristic DNA fragmentation of apoptosis was observed in photoreceptor cells in 2 of the 4 eyes with pathologic myopia and in 4 of 16 eyes with age-related macular degeneration, 2 of which were exudative and 2 of which were atrophic. However, only a few scattered photoreceptor cells were labelled in 4 of 8 eyes with serous retinal detachment secondary to malignant melanoma of the choroid. Moreover, none of the photoreceptors cells in the 4 eyes with retinal lattice degeneration and 6 eyes with retinal paving stone degeneration were labelled. Apoptosis is 1 of the important pathways of photoreceptor cell degeneration in pathologic myopia and age-related macular degeneration.

  11. Cytochrome c induces lipid demixing in weakly charged phosphatidylcholine/phosphatidylglycerol model membranes as evidenced by resonance energy transfer.

    PubMed

    Gorbenko, Galyna P; Trusova, Valeriya M; Molotkovsky, Julian G; Kinnunen, Paavo K J

    2009-06-01

    Resonance energy transfer (RET) between anthrylvinyl-labeled phosphatidylcholine (AV-PC) or phosphatidylglycerol (AV-PG) as donors and the heme groups of cytochrome c (cyt c) as acceptors was examined in PC/PG model membranes containing 10, 20 or 40 mol% PG with an emphasis on evaluating lipid demixing caused by this protein. The differences between AV-PC and AV-PG RET profiles observed at PG content 10 mol% were attributed to cyt c ability to produce segregation of acidic lipids into lateral domains. The radius of lipid domains recovered using Monte-Carlo simulation approach was found not to exceed 4 nm pointing to the local character of cyt c-induced lipid demixing. Increase of the membrane PG content to 20 or 40 mol% resulted in domain dissipation as evidenced by the absence of any RET enhancement while recruiting AV-PG instead of AV-PC.

  12. The hormone response element mimic sequence of GAS5 lncRNA is sufficient to induce apoptosis in breast cancer cells

    PubMed Central

    Pickard, Mark R.; Williams, Gwyn T.

    2016-01-01

    Growth arrest-specific 5 (GAS5) lncRNA promotes apoptosis, and its expression is down-regulated in breast cancer. GAS5 lncRNA is a decoy of glucocorticoid/related receptors; a stem-loop sequence constitutes the GAS5 hormone response element mimic (HREM), which is essential for the regulation of breast cancer cell apoptosis. This preclinical study aimed to determine if the GAS5 HREM sequence alone promotes the apoptosis of breast cancer cells. Nucleofection of hormone-sensitive and –insensitive breast cancer cell lines with a GAS5 HREM DNA oligonucleotide increased both basal and ultraviolet-C-induced apoptosis, and decreased culture viability and clonogenic growth, similar to GAS5 lncRNA. The HREM oligonucleotide demonstrated similar sequence specificity to the native HREM for its functional activity and had no effect on endogenous GAS5 lncRNA levels. Certain chemically modified HREM oligonucleotides, notably DNA and RNA phosphorothioates, retained pro-apoptotic. activity. Crucially the HREM oligonucleotide could overcome apoptosis resistance secondary to deficient endogenous GAS5 lncRNA levels. Thus, the GAS5 lncRNA HREM sequence alone is sufficient to induce apoptosis in breast cancer cells, including triple-negative breast cancer cells. These findings further suggest that emerging knowledge of structure/function relationships in the field of lncRNA biology can be exploited for the development of entirely novel, oligonucleotide mimic-based, cancer therapies. PMID:26862727

  13. Human papillomavirus oncoproteins and apoptosis (Review)

    PubMed Central

    JIANG, PEIYUE; YUE, YING

    2014-01-01

    The aim of this study was to review the literature and identify the association between human papillomavirus (HPV) oncoproteins and apoptosis. HPV-associated apoptosis may be primarily blocked by a number of oncoproteins, including E5, E6 and E7. E5 protein protects cells from tumor necrosis factor-associated apoptosis; the oncoprotein E6 predominantly inhibits apoptosis through the p53 pathway; and oncoprotein E7 is involved in apoptosis activation and inhibition. In addition, HPV oncoproteins are involved in activating or repressing the transcription of E6/E7. In conclusion, HPV oncoproteins, including E5, E6 and E7 protein, may interfere with apoptosis via certain regulatory principles. PMID:24348754

  14. Proteome Differences between Hepatitis B Virus Genotype-B- and Genotype-C-Induced Hepatocellular Carcinoma Revealed by iTRAQ-Based Quantitative Proteomics.

    PubMed

    Wei, Dahai; Zeng, Yongyi; Xing, Xiaohua; Liu, Hongzhi; Lin, Minjie; Han, Xiao; Liu, Xiaolong; Liu, Jingfeng

    2016-02-05

    Hepatitis B virus (HBV) is the main cause of hepatocellular carcinoma (HCC) in southeast Asia where HBV genotype B and genotype C are the most prevalent. Viral genotypes have been reported to significantly affect the clinical outcomes of HCC. However, the underlying molecular differences among different genotypes of HBV virus infected HCC have not been revealed. Here, we applied isobaric tags for relative and absolute quantitation (iTRAQ) technology integrated with liquid chromatography-tandem mass spectrometry (LC-MS/MS) analysis to identify the proteome differences between the HBV genotypes B- and C-induced HCC. In brief, a total of 83 proteins in the surrounding noncancerous tissues and 136 proteins in the cancerous tissues between HBV genotype-B- and genotype-C-induced HCC were identified, respectively. This information revealed that there might be different molecular mechanisms of the tumorigenesis and development of HBV genotypes B- and C-induced HCC. Furthermore, our results indicate that the two proteins ARFIP2 and ANXA1 might be potential biomarkers for distinguishing the HBV genotypes B- and C-induced HCC. Thus, the quantitative proteomic analysis revealed molecular differences between the HBV genotypes B- and C-induced HCC, and might provide fundamental information for further deep study.

  15. Differential expression of TP53 associated genes in Fanconi anemia cells after mitomycin C and hydroxyurea treatment.

    PubMed

    Martinez, Angélica; Hinz, John M; Gómez, Laura; Molina, Bertha; Acuña, Hilda; Jones, Irene M; Frias, Sara; Coleman, Matthew A

    2008-10-30

    Fanconi anemia (FA) is a rare, heritable chromosomal instability disease characterized by several congenital defects and cancer predisposition. Functional interactions between specific FA proteins and DNA damage response and repair activities have been reported, but the interplay between these mechanisms for maintaining genomic stability are not well understood. Many DNA damage response proteins are transcriptionally regulated by the tumor suppressor protein p53 (TP53), suggesting an important regulatory role for the DNA damage and stress response pathway. To better understand the association between FA and the DNA damage stress response we analyzed the levels of chromosomal damage and damage mediated gene transcription responses in lymphoblastoid cells derived from normal individuals and patients carrying the most common FA complementation group (FA-A). Chromosomal aberrations were first measured after exposure to mitomicyn C (MMC) or hydroxyurea (HU). Aliquots of the same cell were than assayed for the transcriptional response of 21 DNA damage and stress response genes using quantitative real-time PCR. The FA-A lymphoblastoid cells showed significant increases in the frequency of chromosome aberrations relative to non-FA-A lymphoblastoid lines after MMC treatment. The MMC induced damage was correlated with a general increase in expression of TP53-modulated DNA damage stress response genes involved in processes such as DNA repair, cell cycle progression, and apoptosis. Following HU treatment FA cells showed a decreased induction of CAs with much less transcriptional differences between targeted genes. Overall, the differences between the normal and FA-A cells after genotoxic treatments imply an increased activation and reliance of FA cells on the down-stream activities of TP53 for prevention of cell killing and chromosome damage from interstrand crosslinks but not for general replication arrest and double strand breaks. Furthermore, these results imply a

  16. Autophagy and apoptosis in planarians.

    PubMed

    González-Estévez, Cristina; Saló, Emili

    2010-03-01

    Adult planarians are capable of undergoing regeneration and body remodelling in order to adapt to physical damage or extreme environmental conditions. Moreover, most planarians can tolerate long periods of starvation and during this time, they shrink from an adult size to, and sometimes beyond, the initial size at hatching. Indeed, these properties have made them a classic model to study stem cells and regeneration. Under such stressful conditions, food reserves from the gastrodermis and parenchyma are first used up and later the testes, copulatory organs and ovaries are digested. More surprisingly, when food is again made available to shrunken individuals, they grow back to adult size and all their reproductive structures reappear. These cycles of growth and shrinkage may occur over long periods without any apparent impairment to the individual, or to its future maturation and breeding capacities. This plasticity resides in a mesoderm tissue known as the parenchyma, which is formed by several differentiated non-proliferating cell types and only one mitotically active cell type, the neoblasts, which represent approximately 20-30% of the cells in the parenchyma. Neoblasts are generally thought to be somatic stem-cells that participate in the normal continuous turnover of all cell types in planarians. Hence, planarians are organisms that continuously adapt their bodies (morphallaxis) to different environmental stresses (i.e.: injury or starvation). This adaptation involves a variety of processes including proliferation, differentiation, apoptosis and autophagy, all of which are perfectly orchestrated and tightly regulated to remodel or restore the body pattern. While neoblast biology and body re-patterning are currently the subject of intense research, apoptosis and autophagy remain much less studied. In this review we will summarize our current understanding and hypotheses regarding where and when apoptosis and autophagy occur and fulfil an essential role in

  17. Mycobacterium tuberculosis effectors interfering host apoptosis signaling.

    PubMed

    Liu, Minqiang; Li, Wu; Xiang, Xiaohong; Xie, Jianping

    2015-07-01

    Tuberculosis remains a serious human public health concern. The coevolution between its pathogen Mycobacterium tuberculosis and human host complicated the way to prevent and cure TB. Apoptosis plays subtle role in this interaction. The pathogen endeavors to manipulate the apoptosis via diverse effectors targeting key signaling nodes. In this paper, we summarized the effectors pathogen used to subvert the apoptosis, such as LpqH, ESAT-6/CFP-10, LAMs. The interplay between different forms of cell deaths, such as apoptosis, autophagy, necrosis, is also discussed with a focus on the modes of action of effectors, and implications for better TB control.

  18. Apoptosis and Molecular Targeting Therapy in Cancer

    PubMed Central

    Hassan, Mohamed; Watari, Hidemichi; AbuAlmaaty, Ali; Ohba, Yusuke; Sakuragi, Noriaki

    2014-01-01

    Apoptosis is the programmed cell death which maintains the healthy survival/death balance in metazoan cells. Defect in apoptosis can cause cancer or autoimmunity, while enhanced apoptosis may cause degenerative diseases. The apoptotic signals contribute into safeguarding the genomic integrity while defective apoptosis may promote carcinogenesis. The apoptotic signals are complicated and they are regulated at several levels. The signals of carcinogenesis modulate the central control points of the apoptotic pathways, including inhibitor of apoptosis (IAP) proteins and FLICE-inhibitory protein (c-FLIP). The tumor cells may use some of several molecular mechanisms to suppress apoptosis and acquire resistance to apoptotic agents, for example, by the expression of antiapoptotic proteins such as Bcl-2 or by the downregulation or mutation of proapoptotic proteins such as BAX. In this review, we provide the main regulatory molecules that govern the main basic mechanisms, extrinsic and intrinsic, of apoptosis in normal cells. We discuss how carcinogenesis could be developed via defective apoptotic pathways or their convergence. We listed some molecules which could be targeted to stimulate apoptosis in different cancers. Together, we briefly discuss the development of some promising cancer treatment strategies which target apoptotic inhibitors including Bcl-2 family proteins, IAPs, and c-FLIP for apoptosis induction. PMID:25013758

  19. Apoptosis in cancer: from pathogenesis to treatment

    PubMed Central

    2011-01-01

    Apoptosis is an ordered and orchestrated cellular process that occurs in physiological and pathological conditions. It is also one of the most studied topics among cell biologists. An understanding of the underlying mechanism of apoptosis is important as it plays a pivotal role in the pathogenesis of many diseases. In some, the problem is due to too much apoptosis, such as in the case of degenerative diseases while in others, too little apoptosis is the culprit. Cancer is one of the scenarios where too little apoptosis occurs, resulting in malignant cells that will not die. The mechanism of apoptosis is complex and involves many pathways. Defects can occur at any point along these pathways, leading to malignant transformation of the affected cells, tumour metastasis and resistance to anticancer drugs. Despite being the cause of problem, apoptosis plays an important role in the treatment of cancer as it is a popular target of many treatment strategies. The abundance of literature suggests that targeting apoptosis in cancer is feasible. However, many troubling questions arise with the use of new drugs or treatment strategies that are designed to enhance apoptosis and critical tests must be passed before they can be used safely in human subjects. PMID:21943236

  20. Apoptosis-Dependent and Apoptosis-Independent Functions Bim in Prostate Cancer Cells

    DTIC Science & Technology

    2004-03-01

    AD_ Award Number: DAMD17-03-1-0146 TITLE: Apoptosis-Dependent and Apoptosis-Independent Functions of Bim in Prostate Cancer Cells PRINCIPAL...FUNDING NUMBERS Apoptosis-Dependent and Apoptosis-Independent Functions of DAMD17-03-1-0146 Bim in Prostate Cancer Cells 6. A UTHORs) Junwei Liu, M.D...extended cell survival have been implicated in prostate cancer (PCa) development and progression. We recently found that Bim , a BH3-only pro

  1. Efficacy of holmium laser urethrotomy and intralesional injection of Santosh PGI tetra-inject (Triamcinolone, Mitomycin C, Hyaluronidase and N-acetyl cysteine) on the outcome of urethral strictures

    PubMed Central

    Kishore, Lalit; Sharma, Aditya Prakash; Garg, Nitin; Singh, Shrawan Kumar

    2015-01-01

    Introduction To study the efficacy of holmium laser urethrotomy with intralesional injection of Santosh PGI tetra-inject (Triamcinolone, Mitomycin C, Hyaluronidase and N-acetyl cysteine) in the treatment of urethral strictures. Material and methods A total of 50 patients with symptomatic urethral stricture were evaluated by clinical history, physical examination, uroflowmetry and retrograde urethrogram preoperatively. All patients were treated with holmium laser urethrotomy, followed by injection of tetra-inject at the urethrotomy site. Tetra-inject was prepared by diluting acombination of 40 mg Triamcinolone, 2 mg Mitomycin, 3000 UHyaluronidase and 600 mg N-acetyl cysteine in 5–10 ml of saline, according to the stricture length. An indwelling 18 Fr silicone catheter was left in place for 7–10 days.All patients were followed-up for 6-18 months postoperatively by history, uroflowmetry, and if required, retrograde urethrogram and micturating urethrogram every 3 months. Results 41 (82%) patients had asuccessful outcome,whereas 9 (18%) had recurrences during a follow-up ranging from 6–18 months. In <1 cm length strictures, the success rate was 100%, while in 1–3 cm and >3 cm lengthsthe success rates were 81.2% and 66.7% respectively. This modality, thus, has an encouraging success rate, especially in those with short segment urethral strictures (<3 cm). Conclusions Holmium laser urethrotomy with intralesional injection ofSantosh PGI tetra-inject (Triamcinolone, Mitomycin C, Hyaluronidase, N-acetyl cysteine) is a safe and effective minimally-invasive therapeutic modality for short segment urethral strictures. PMID:26855803

  2. Bare sclera resection followed by mitomycin C and/or autograft limbus conjunctiva in the surgery for pterygium: a Meta-analysis

    PubMed Central

    Long, Tan; Li, Zhi

    2015-01-01

    AIM To evaluate the recurrence and complications after bare sclera resection (BSR) combined with mitomycin C (MMC) treatment and/or autograft limbus conjunctiva (ALC) in the surgery for pterygium. METHODS Meta-analysis was used to evaluate the differences in patient outcomes between BSR of pterygium with or without MMC and/or ALC. All included studies were randomized trials of patients with pterygium who received BSR followed by MMC and/or ALC in the surgery. The recurrence of pterygium and other complications resulting from different treatments were extracted for analysis. RESULTS Thirteen studies met the inclusion criteria. The recurrence of pterygium with intraoperative (IO) MMC was higher than that with ALC (OR=2.38, 95% confidence interval 1.45-3.91, I2=29%). Postoperative MMC resulted in an incidence of recurrence similar to that of ALC (OR=0.66, 95% confidence interval 0.30-1.42, I2=0%), and IO MMC treatment in combination with ALC produced similar patient outcomes to ALC alone (OR=0.41, 95% confidence interval 0.16-1.01, I2=16%). Other complications such as punctate epitheliopathy, scleral thinning and ischemia, irritation and persistent epithelium defect, were more common in patients in the MMC group as compared to those treated with ALC. CONCLUSION The recurrence of pterygium with BSR followed by ALC is lower than that of BSR followed by MMC, and the incidence of other complications is lower. While ALC is a more effective strategy for treating pterygium, the quality of the ALC transplant should be considered when the patient has a history of glaucoma. PMID:26558227

  3. Collagen type I and III synthesis by Tenon's capsule fibroblasts in culture: individual patient characteristics and response to mitomycin C, 5-fluorouracil, and ascorbic acid.

    PubMed Central

    Gross, R L

    1999-01-01

    PURPOSE: This study was performed to better understand the differences between patients in specific components of wound healing as it may pertain to glaucoma filtration surgery, including the use of antimetabolites. METHODS: Human Tenon's capsule fibroblasts were obtained at the time of glaucoma filtering surgery and established in individual cell cultures from 35 glaucoma patients. The dose-response to 5-fluorouracil (5FU) and mitomycin C (MMC) was determined. The individual cell lines were exposed to the antimetabolites and ascorbic acid with measurement of collagen type I and III production by an ELISA-type dot blot assay. These results were then statistically compared to the individual patient characteristics including age, race, previous surgery and medications, and type of glaucoma. RESULTS: 5-FU had little effect on collagen type I and III production or protein synthesis. MMC had an inhibitory effect on collagen secretion and total protein synthesis with increasing concentration. Photomicrographs of the cells after each treatment condition revealed characteristic morphologic changes when compared to controls. There was a large range of collagen type I and III production with correlation between the amounts of each collagen type secreted in response to the antimetabolites. However, there was no correlation with accepted risk factors for filtration failure. CONCLUSION: These antimetabolites act similarly on different cell lines in a nonspecific manner. The results suggest that the increased risk of filtration failure due to age, race, diagnosis, and previous conjunctival surgery is not due to differences in secretion of collagen types I and III by Tenon's capsule fibroblasts. Images FIGURE 3 PMID:10703140

  4. A randomised trial comparing combination chemotherapy using mitomycin C, mitozantrone and methotrexate (3M) with vincristine, anthracycline and cyclophosphamide (VAC) in advanced breast cancer.

    PubMed Central

    Powles, T. J.; Jones, A. L.; Judson, I. R.; Hardy, J. R.; Ashley, S. E.

    1991-01-01

    This paper describes a randomised clinical trial in patients with advanced breast cancer, comparing the regimen 3M, mitomycin C 7-8 mg m-2 (day 1), mitozantrone 7-8 mg m-2 (day 1 and 21), methotrexate 35 mg m-2 (day 1 and 21) given on a 42 day cycle with a standard anthracycline containing regimen, VAC, vincristine 1.4 mg m-2 (day 1), anthracycline (adriamycin or epirubicin) 30 mg m-2 (day 1), cyclophosphamide 400 mg m-2 (day 1) given on a 21 day cycle. Of a total of 217 patients, 107 were randomised to 3M and 110 to VAC and a mean of 5.5 courses was given per patient. The overall response rate (complete and partial) was 53% (95% Confidence Limits (CL): 43-62%) for 3M and 49% (CL; 39-58%) for VAC. The response according to sites of metastases was the same for both treatment groups. Symptomatic toxicity including alopecia, neuropathy, vomiting (P less than 0.001) and nausea (P less than 0.01) were significantly less for 3M. Myelosuppression including leucopenia (P less than 0.001) and thrombocytopenia (P less than 0.001) was significantly greater with 3M at day 21, although there was no difference in nadir counts in patients at special risk of myelosuppression and there was no evidence of an increase in infective or bleeding complications. There was no significant difference in the duration of response to 3M (10 months, CL 6-15) and VAC (11 months, CL 7-12), nor in survival (3M, 8 months, CL 6-12; VAC, 10 months, CL 8-12). These results indicate that 3M is as effective as, but has significantly less symptomatic toxicity than, an anthracycline containing regimen for the treatment of advanced breast cancer. PMID:1892775

  5. Mitomycin C-activity effected by vitamins B1, C, E and beta-carotene under irradiation with gamma-rays.

    PubMed

    Heinrich, Edith; Getoff, Nikola

    2003-01-01

    Vitamin B1 (thiamine) can essentially effect the activity of mitomycin C (MMC), added individually or in combination with antioxidant vitamins (C, E-acetate, beta-carotene) as found in experiments in vitro (Escherichia coli bacteria, AB 1157) under irradiation with gamma-rays. The environment plays a crucial role. In airfree media vitamin B1 leads to a 2-fold increase of the MMC-efficiency, but adding vitamin C it decreases. In the presence of all vitamins (B1, C, E-ac., and beta-carotene) the MMC-action increases about 1.8-fold. In aerated media vitamin B1 causes an about 4-times increase of the MMC-efficiency, but by adding vitamin B1 and C the MMC-activity decreases by a factor of two, whereas in the presence of B1, C, E-ac., and beta-carotene it rises again to 2.6-fold. In environment saturated with N2O (conversion of e(-)aq into OH radicals) a different picture is observed. The presence of vitamin B1 or vitamin B1 + C causes a strong decrease of the MMC-efficiency, but the addition of all vitamins (B1, C, E-ac., and beta-car.) leads to a small increase of the cytostatic action. The results demonstrate the influence of vitamin B1 used individually or in combination with other antioxidants on the MMC-efficiency and the strong effect of the environment. The results are of interest for the application of MMC in radiotherapy.

  6. Detection of Corneal Fibrosis by Imaging Second Harmonic–Generated Signals in Rabbit Corneas Treated with Mitomycin C after Excimer Laser Surface Ablation

    PubMed Central

    Farid, Marjan; Morishige, Naoyuki; Lam, Larry; Wahlert, Andrew; Steinert, Roger F.; Jester, James V.

    2015-01-01

    Purpose Recent studies have shown that confocal imaging of second harmonic–generated (SHG) signals can detect corneal collagen organization. The purpose of this study was to assess whether SHG signals can detect differences in corneal fibrosis after excimer laser surface ablation (photorefractive keratectomy [PRK]). Methods Rabbits received 9-D PRK in one eye followed by treatment with either mitomycin C (MMC) or vehicle. Corneal haze was measured by in vivo confocal microscopy before and 2, 4, 8, and 12 weeks after surgery. Animals were then killed and corneas were evaluated by visible and nonlinear confocal microscopy. Results PRK induced significant haze in vehicle-treated corneas that peaked at 2 weeks and remained elevated at 12 weeks after surgery. MMC treatment significantly (P = 0.05) reduced corneal haze at 2 weeks and was essentially normal by 12 weeks. Imaging of SHG signals in vehicle-treated eyes showed an anterior layer of collagen forming a honeycomb network blending into a dense mat of irregularly arranged collagen fibers that overlaid normal orthogonally arranged collagen lamellae. MMC treatment showed normal collagen organization at the surface. Fibrotic tissue was associated with a high cell density and alignment of intracellular actin filaments with collagen fiber bundles. In MMC-treated eyes, an anterior acellular zone overlaid a sparsely populated stroma containing isolated and enlarged keratocytes. Conclusions Imaging of SHG signals provides a sensitive means for detection of corneal fibrosis after surface ablation and can be used to assess the effects of antifibrotic therapy on corneal healing after refractive surgery. PMID:18502995

  7. Trace levels of mitomycin C disrupt genomic integrity and lead to DNA damage response defect in long-term-cultured human embryonic stem cells.

    PubMed

    Zhou, Di; Lin, Ge; Zeng, Si-Cong; Xiong, Bo; Xie, Ping-Yuan; Cheng, De-Hua; Zheng, Qing; Ouyang, Qi; Zhou, Xiao-Ying; Tang, Wei-Ling; Sun, Yi; Lu, Guang-Ying; Lu, Guang-Xiu

    2015-01-01

    How to maintain the genetic integrity of cultured human embryonic stem (hES) cells is raising crucial concerns for future clinical use in regenerative medicine. Mitomycin C(MMC), a DNA damage agent, is widely used for preparation of feeder cells in many laboratories. However, to what extent MMC affects the karyotypic stability of hES cells is not clear. Here, we measured residual MMC using High Performance Liquid Chromatography-Mass Spectrometry/Mass Spectrometry following each step of feeder preparation and found that 2.26 ± 0.77 and 3.50 ± 0.92 ng/ml remained in mouse feeder cells and human feeder cells, respectively. In addition, different amounts of MMC caused different chromosomal aberrations in hES cells. In particular, one abnormality, dup(1)(p32p36), was the same identical to one we previously reported in another hES cell line. Using Affymetrix SNP 6.0 arrays, the copy number variation changes of the hES cells maintained on MMC-inactivated feeders (MMC-feeder) were significantly more than those cultured on γ-inactivated feeder (IR-feeder) cells. Furthermore, DNA damage response (DDR) genes were down-regulated during long-term culture in the MMC-containing system, leading to DDR defect and shortened telomeres of hES cells, a sign of genomic instability. Therefore, MMC-feeder and MMC-induced genomic variation present an important safety problem that would limit such hES from being applied for future clinic use and drug screening.

  8. Mitomycin C-augmented deep sclerectomy in primary open-angle glaucoma and exfoliation glaucoma: a three-year prospective study.

    PubMed

    Ollikainen, Minna L; Puustjärvi, Tuomo J; Rekonen, Petri K; Uusitalo, Hannu M; Teräsvirta, Markku E

    2011-09-01

    To investigate the efficacy and safety of mitomycin C (MMC)-augmented deep sclerectomy with implant (DSCI) in primary open-angle glaucoma (POAG) and exfoliation glaucoma (ExG) patients. A total of 68 eyes of 68 patients with POAG and ExG were enrolled consecutively to undergo DSCI with MMC (0.4 mg/ml for 2 min). The intraocular pressure (IOP), number of antiglaucoma medications, neodymium:yttrium-aluminum-garnet (Nd:YAG) laser goniopuncture treatments and complications were compared postoperatively after 36- month follow-up. Surgery was considered as a complete success when IOP was <18 mmHg without antiglaucoma medication. Preoperatively the mean IOPs were 23 ± 6 mmHg and 25 ± 8 mmHg, and 13 ± 4 mmHg and 11 ± 4 mmHg in the POAG and ExG groups, respectively, at 36 months. At 36 months, 74% and 73% of surgeries were a complete success in the POAG and ExG group, respectively [not significant (NS)]. Two patients (8%) of the POAG group and one of the ExG group (3%) were receiving antiglaucoma medication at 36 months (NS). Nd:YAG laser goniopuncture was performed more often in the ExG group (87%) than in the POAG group (61%, p = 0.024). Postoperatively choroidal detachment occurred in 16% of eyes in the POAG group and in 11% of eyes in the ExG group (NS). DSCI with MMC augmentation appears to be as effective in patients with ExG and POAG in lowering IOP to target levels at medium term with few immediate postoperative complications. © 2009 The Authors. Journal compilation © 2009 Acta Ophthalmol.

  9. Mitomycin-C-augmented deep sclerectomy in patients with primary open-angle glaucoma and exfoliation glaucoma: a 1-year prospective study.

    PubMed

    Ollikainen, Minna; Puustjärvi, Tuomo; Rekonen, Petri; Uusitalo, Hannu; Teräsvirta, Markku

    2010-02-01

    To investigate the efficacy and safety of mitomycin C (MMC)-augmented deep sclerectomy with implant (DSCI) in patients with primary open-angle glaucoma (POAG) and exfoliation glaucoma (ExG). A total of 68 eyes of 68 patients with POAG and ExG were enrolled consecutively to undergo DSCI with MMC (0.4 mg/ml for 2 min). The intraocular pressure (IOP), number of antiglaucoma medications, neodymium:yttrium-aluminum-garnet (Nd:YAG) laser goniopunctures and complications were compared postoperatively. Surgery was considered as a complete success when IOP was < 18 mmHg without antiglaucoma medication. Preoperatively, the mean IOPs were 23.1 +/- 5.8 and 25.4 +/- 8.3 mmHg, and 13.8 +/- 6.1 and 11.2 +/- 5.6 mmHg in the POAG and ExG groups, respectively, at 12 months. 77.4% and 75.7% of surgeries were a complete success in the POAG and ExG groups, respectively [not significant (NS)]. Five patients (16.1%) in the POAG group but none in the ExG group (0%) were receiving antiglaucoma medication at 12 months (NS). Nd:YAG laser goniopuncture was performed in 29.0% of eyes in the POAG group and in 55.6% of eyes in the ExG group (p = 0.047). Postoperatively, choroidal detachment occurred in 16.1% of eyes in the POAG group and in 10.8% of eyes in the ExG group (NS). We encountered no serious complications related to MMC use. DS with MMC augmentation appears to be equally effective in ExG and POAG patients in lowering IOP to target levels, at least in the short term, with few immediate postoperative complications.

  10. EXTRA-A Multicenter Phase II Study of Chemoradiation Using a 5 Day per Week Oral Regimen of Capecitabine and Intravenous Mitomycin C in Anal Cancer

    SciTech Connect

    Glynne-Jones, Rob Meadows, Helen; Wan, Susan; Gollins, Simon; Leslie, Martin; Levine, Ed; McDonald, Alec C.; Myint, Sun; Samuel, Les; Sebag-Montefiore, David

    2008-09-01

    Purpose: 5-Fluorouracil (5-FU) + mitomycin C (MMC)-based chemoradiotherapy is standard treatment for patients with epidermoid anal carcinoma. Clinical trials in other cancers have confirmed 5-FU can successfully be replaced by the oral fluoropyrimidine capecitabine. This phase II trial aimed to determine the feasibility, toxicity, and efficacy of capecitabine, MMC and radiotherapy (RT) in anal cancer patients. Methods and Materials: Radiotherapy comprised the schedule of the UK Anal Cancer Trial (ACT) II trial (50.4 Gy in 28 fractions of 1.8 Gy). With MMC (12 mg/m{sup 2}) on Day 1 and capecitabine on each RT treatment day in two divided doses (825 mg/m{sup 2} b.i.d). The endpoints were complete response at 4 weeks, local control at 6 months and toxicity. Results: Thirty-one patients entered the trial. The median age was 61 years (range 45-86) with 14 males and 17 females. Compliance with chemotherapy with no dose interruptions or delays was 68%, and with RT was 81%. Eighteen (58%) patients completed both modalities of treatment as planned. Dose-limiting Grade 3 or 4 diarrhea was seen in 1 of 31 patients. Three patients experienced Grade 3 neutropenia. There were no treatment-related deaths. Four weeks following completion of chemoradiation, 24 patients (77%) had a complete clinical response, and 4 (16%) a partial response. With a median follow-up of 14 months, three locoregional relapses occurred. Conclusions: Capecitabine with MMC and RT in with patients anal carcinoma is well tolerated, with minimal toxicity and acceptable compliance. We recommend testing this schedule in future national Phase III studies in anal cancer.

  11. Enhanced mutagenesis of UV-irradiated simian virus 40 occurs in mitomycin C-treated host cells only at a low multiplicity of infection

    SciTech Connect

    Sarasin, A.; Benoit, A.

    1986-04-01

    Treatment of monkey kidney cells with mitomycin C (MMC) 24 h prior to infection with UV-irradiated simian virus 40 (SV40) enhanced both virus survival and virus mutagenesis. The use of SV40 as a biological probe has been taken as an easy method to analyse SOS response of mammalian cells to the stress caused by DNA damage or inhibition of DNA replication. The mutation assay we used was based on the reversion from a temperature-sensitive phenotype (tsA58 mutant) to a wild-type phenotype. The optimal conditions for producing enhanced survival and mutagenesis in the virus progeny were determined with regard to the multiplicity of infection (MOI). Results showed that the level of enhanced mutagenesis observed for UV-irradiated virus grown in MMC-treated cells was an inverse function of the MOI, while enhanced survival was observed at nearly the same level regardless of the MOI. For the unirradiated virus, almost no increase in the mutation of virus progeny issued from MMC-treated cells was observed, while a small amount of enhanced virus survival was obtained. These results show that enhanced virus mutagenesis and enhanced virus survival can be dissociated under some experimental conditions. Enhanced virus mutagenesis, analogous to the error-prone replication of phages in SOS-induced bacteria, was observed, at least for SV40, only when DNA of both virus and host cells was damaged and when infection occurred with a small number of viral particles. We therefore hypothesize that an error-prone replication mode of UV-damaged templates is observed in induced monkey kidney cells.

  12. Multicenter randomized phase III trial comparing protracted venous infusion (PVI) fluorouracil (5-FU) with PVI 5-FU plus mitomycin in inoperable pancreatic cancer.

    PubMed

    Maisey, Nick; Chau, Ian; Cunningham, David; Norman, Andrew; Seymour, Matt; Hickish, Tamas; Iveson, Tim; O'Brien, Mary; Tebbutt, Niall; Harrington, Angela; Hill, Mark

    2002-07-15

    To compare protracted venous infusion (PVI) fluorouracil (5-FU) with PVI 5-FU plus mitomycin (MMC) in patients with advanced pancreatic cancer in a multicenter, prospectively randomized study. Two hundred eight patients were randomized to PVI 5-FU (300 mg/m(2)/d for a maximum of 24 weeks) or PVI 5-FU plus MMC (7 mg/m(2) every 6 weeks for four courses). The major end points were tumor response, survival, toxicity, and quality of life (QOL). The two treatment groups were balanced for baseline demographic factors, and 62% had metastatic disease. The overall response rate was 8.4% (95% confidence interval [CI]) 3.2% to 13.7% for patients treated with PVI 5-FU alone compared with 17.6%; 95% CI 10.3% to 25.1% for PVI 5-FU plus MMC (P =.04). Median failure-free survival was 2.8 months for PVI 5-FU and 3.8 months for PVI 5-FU plus MMC (P =.14). Median survival was 5.1 months for PVI 5-FU and 6.5 months for PVI 5-FU plus MMC (P =.34). Toxicities in both arms were mild. There was an increased incidence of neutropenia in the 5-FU plus MMC arm (P <.01), although no differences in infection were seen. No patients developed hemolytic uremic syndrome. Global QOL improved significantly after 24 weeks of treatment compared with baseline for patients receiving 5-FU plus MMC, although there was no statistically significant difference in QOL between arms. PVI 5-FU plus MMC resulted in a superior response rate in comparison with PVI 5-FU alone in advanced pancreatic cancer, but this did not translate into a survival advantage. These results emphasize the importance of chemotherapy in this setting and the continuing value of the fluoropyrimidines in pancreatic cancer.

  13. Characterization of a quinone reductase activity for the mitomycin C binding protein (MRD): Functional switching from a drug-activating enzyme to a drug-binding protein

    PubMed Central

    He, Min; Sheldon, Paul J.; Sherman, David H.

    2001-01-01

    Self-protection in the mitomycin C (MC)-producing microorganism Streptomyces lavendulae includes MRD, a protein that binds MC in the presence of NADH and functions as a component of a unique drug binding-export system. Characterization of MRD revealed that it reductively transforms MC into 1,2-cis-1-hydroxy-2,7-diaminomitosene, a compound that is produced in the reductive MC activation cascade. However, the reductive reaction catalyzed by native MRD is slow, and both MC and the reduced product are bound to MRD for a relatively prolonged period. Gene shuffling experiments generated a mutant protein (MRDE55G) that conferred a 2-fold increase in MC resistance when expressed in Escherichia coli. Purified MRDE55G reduces MC twice as fast as native MRD, generating three compounds that are identical to those produced in the reductive activation of MC. Detailed amino acid sequence analysis revealed that the region around E55 in MRD strongly resembles the second active site of prokaryotic catalase-peroxidases. However, native MRD has an aspartic acid (D52) and a glutamic acid (E55) residue at the positions corresponding to the catalytic histidine and a nearby glycine residue in the catalase-peroxidases. Mutational analysis demonstrated that MRDD52H and MRDD52H/E55G conferred only marginal resistance to MC in E. coli. These findings suggest that MRD has descended from a previously unidentified quinone reductase, and mutations at the active site of MRD have greatly attenuated its catalytic activity while preserving substrate-binding capability. This presumed evolutionary process might have switched MRD from a potential drug-activating enzyme into the drug-binding component of the MC export system. PMID:11158572

  14. Variability in cytogenetic adaptive response of cultured human lymphocytes to mitomycin C, bleomycin, quinacrine dihydrochloride, Co60 gamma-rays and hyperthermia.

    PubMed

    Krishnaja, A P; Sharma, N K

    2008-03-01

    Adaptive response (AR) is a well-documented phenomenon by which cells or organisms exposed to low dose of a genotoxicant become less sensitive to subsequent high-dose exposure to the same or another genotoxicant. AR, if induced can modify the efficacy leading to drug or radio-resistance, during anti-neoplastic drug or radiation treatment. Contradictions exist in AR induction by different genotoxicants with respect to the biomarkers, time schedules, and inter-individual variability, reflecting the complexity of AR in eukaryotic cells. In order to further ascertain these factors, AR induced by anti-neoplastic agents mitomycin C (MMC), bleomycin (BLM) and chemosterilant quinacrine dihydrochloride was examined in different donors and time schedules using cytogenetic biomarkers chromosome aberrations, sister chromatid exchanges and micronuclei (MN). BLM- and hyperthermia (HT)-induced cross-resistance to gamma rays and MMC/BLM, respectively, was also studied. Difference between MMC- and BLM-induced protective effects in biomarkers examined in the same donors was noticed. Adaptation to BLM and HT showed cross-resistance to chromosome damage induction by gamma rays and BLM/MMC, respectively. Cell cycle analysis indicated that adaptation is not caused by change in the rate of cell proliferation after challenge dose. MN as a chromosomal biomarker in large-scale population studies on AR is advocated, based on similar AR induced in all donors by MMC/BLM and rapid assessment in binucleated cells. Influence of certain genotypes on chromosomal biomarkers used in AR studies and role of AR in radiation and chemotherapy need to be further deciphered.

  15. Phase II study of the oxygen saturation curve left shifting agent BW12C in combination with the hypoxia activated drug mitomycin C in advanced colorectal cancer

    PubMed Central

    Propper, D J; Levitt, N C; O'Byrne, K; Braybrooke, J P; Talbot, D C; Ganesan, T S; Thompson, C H; Rajagopalan, B; Littlewood, T J; Dixon, R M; Harris, A L

    2000-01-01

    BW12C (5-[2-formyl-3-hydroxypenoxyl] pentanoic acid) stabilizes oxyhaemoglobin, causing a reversible left-shift of the oxygen saturation curve (OSC) and tissue hypoxia. The activity of mitomycin C (MMC) is enhanced by hypoxia. In this phase II study, 17 patients with metastatic colorectal cancer resistant to 5-fluorouracil (5-FU) received BW12C and MMC. BW12C was given as a bolus loading dose of 45 mg kg−1over 1 h, followed by a maintenance infusion of 4 mg kg−1h−1for 5 h. MMC 6 mg m−2was administered over 15 min immediately after the BW12C bolus. The 15 evaluable patients had progressive disease after a median of 2 (range 1–4) cycles of chemotherapy. Haemoglobin electrophoresis 3 and 5 h after the BW12C bolus dose showed a fast moving band consistent with the BW12C-oxyhaemoglobin complex, accounting for approximately 50% of total haemoglobin. The predominant toxicities – nausea/vomiting and vein pain – were mild and did not exceed CTC grade 2. Liver31P magnetic resonance spectroscopy of patients with hepatic metastases showed no changes consistent with tissue hypoxia. The principle of combining a hypoxically activated drug with an agent that increases tissue hypoxia is clinically feasible, producing an effect equivalent to reducing tumour oxygen delivery by at least 50%. However, BW12C in combination with MMC for 5-FU-resistant colorectal cancer is not an effective regimen. This could be related to drug resistance rather than a failure to enhance cytotoxicity. © 2000 Cancer Research Campaign PMID:10839290

  16. Arsenite pretreatment enhances the cytotoxicity of mitomycin C in human cancer cell lines via increased NAD(P)H quinone oxidoreductase 1 expression

    SciTech Connect

    Lin Yiling; Ho, I-C.; Su, P.-F.; Lee, T.-C. . E-mail: bmtcl@ibms.sinica.edu.tw

    2006-08-01

    Arsenic is an effective therapeutic agent for the treatment of patients with refractory or relapsed acute promyelocytic leukemia. The use of arsenic for treating solid tumors, particularly in combination with other chemotherapeutic agents, has been extensively studied. Here, we report that arsenite-resistant human lung cancer CL3R15 cells constitutively overexpress NAD(P)H quinone oxidoreductase 1 (NQO1), an enzyme responsible for activation of mitomycin C (MMC), and are more susceptible to MMC cytotoxicity than parental CL3 cells. The effects of arsenite pretreatment on NQO1 induction were examined in CL3, H1299, H460, and MC-T2 cells. Arsenite pretreatment significantly enhanced the expression of NQO1 and susceptibility to MMC in CL3, H1299, and MC-T2 cells, but not in H460 cells that express high endogenous levels of NQO1. Alternatively, arsenic pretreatment reduced adriamycin sensitivity of CL3 cells. Arsenite-mediated MMC susceptibility was abrogated by dicumarol (DIC), an NQO1 inhibitor, indicating that NQO1 is one of the key regulators of arsenite-mediated MMC susceptibility. Various cancer cell lines showed different basal levels of NQO1 activity and a different capacity for NQO1 induction in response to arsenite treatment. However, overall, there was a positive correlation between induced NQO1 activity and MMC susceptibility in cells pretreated with various doses of arsenite. These results suggest that arsenite may increase NQO1 activity and thus enhance the antineoplastic activity of MMC. In addition, our results also showed that inhibition of NQO1 activity by DIC reversed the arsenite resistance of CL3R15 cells.

  17. Evaluation of Filtering Bleb Function after Trabeculectomy with Mitomycin C Using Biomicroscopy, Anterior Segment Optical Coherence Tomography and In Vivo Confocal Microscopy

    PubMed Central

    Güven Yılmaz, Suzan; Değirmenci, Cumali; Palamar, Melis; Yağcı, Ayşe

    2015-01-01

    Objectives: To analyze and assess compatibility of trabeculectomy filtering bleb characteristics and appearances using biomicroscopy, anterior segment optical coherence tomography (AS-OCT) and in vivo confocal microscopy (IVCM). Materials and Methods: Twenty-eight eyes of 28 patients who underwent glaucoma filtering surgery with mitomycin C in our clinic between 2009 and 2013 were evaluated. Morphological appearances of the blebs on slit-lamp biomicroscopy were defined according to the Moorfields bleb classification system. For the internal tissue assessment of blebs, AS-OCT and IVCM were performed. Bleb biometric parameters such as length, height and bleb wall thickness were assessed by AS-OCT; conjunctival epithelial-stromal cyst, structural network of conjunctival stroma and vascularisation were examined with IVCM. The relation between biomicroscopic morphological staging and bleb characteristics detected on AS-OCT and IVCM were assessed. Results: The mean age of the 28 patients (16 male, 12 female) was 57.2±15.9 (19 to 79) years. The mean time elapsed between surgery and examination was 29.2±19.2 (6 to 68) months. According to biomicroscopic appearance, 17 (60.7%) blebs were functional (13 diffuse, 4 microcystic), whereas 11 (39.3%) blebs were non-functional (9 flat, 2 encapsulated). In the comparison of non-functional and functional blebs, functional blebs were found to be superior in terms of biometric parameters on AS-OCT assessment (p<0.05). Higher number of epithelial and stromal cysts and less vascularisation were detected by IVCM in functional blebs when compared with non-functional blebs (p<0.05). Conclusion: Biomicroscopic appearances and characteristics on AS-OCT and IVCM of filtration blebs are consistent with each other. Besides biomicroscopic examination, which is an easy and practical method for determining bleb morphology, cross-sectional images obtained by AS-OCT and IVCM provide objective data regarding internal structure and functional

  18. Concurrent radiation, mitomycin C and 5-fluorouracil in poor prognosis carcinoma of cervix: preliminary results of a Phase I-II study

    SciTech Connect

    Thomas, G.; Dembo, A.; Beale, F.; Bean, H.; Bush, R.; Herman, J.; Pringle, J.; Rawlings, G.; Sturgeon, J.; Fine, S.

    1984-09-01

    Between July 1981 and June 1983, 27 patients with advanced primary squamous cell carcinoma (SCC) of cervix and 8 with recurrent disease were treated using a pilot regimen of combination chemotherapy (CT): Mitomycin C (MIT), 5 Fluorouracil (5 FU), and radiation therapy (RT). CT and RT doses on this Phase I-II Study were escalated to the current regimen. A split course of RT was used, either pelvic RT alone or the same pelvic RT plus para-aortic RT. CT was given by continuous IV infusion days 1 through 4 of each half-course of RT. This was followed by one application of intrauterine /sup 137/Cs when possible. Three of the 8 patients with recurrence in the pelvis or para-aortic nodes had a complete response (CR) to CT-RT and are alive without disease at 19, 19 and 22 months after treatment, respectively. Twenty of the 27 (74%) primary patients had a CR. With a median duration of follow-up of 6 months 4/20 have relapsed, 1 in RT field, 2 at distant sites, and 1 in both. The acute toxicity of this regimen was tolerable: 2/35 developed transient leukopenia with one febrile episode, 9/35 developed transient thrombocytopenia without bleeding. Symptomatic sigmoid strictures developed in two patients, one requiring surgical intervention. Typically, near complete regression of tumor is noted on completion of the external RT, reproducing the dramatic responses that have been observed in SCC of the anal canal, esophagus and head and neck, with this CT-RT regimen.

  19. A retrospective comparison of surgical removal and subsequent CO2 laser ablation versus topical administration of mitomycin C as therapy for equine corneolimbal squamous cell carcinoma.

    PubMed

    Clode, Alison B; Miller, Chelsey; McMullen, Richard J; Gilger, Brian C

    2012-07-01

      To compare the complications and nonrecurrence rate following topical mitomycin C (MMC) therapy vs. CO(2) laser ablation for treating equine corneolimbal squamous cell carcinoma (SCC).   Retrospective study.   Twenty-five horses with corneolimbal SCC.   Medical records of horses undergoing surgical tumor resection followed by either topical MMC therapy (0.04%) or CO(2) laser ablation between the years of 2004 and 2010 were reviewed. Recurrence and complications were compared between groups and within MMC subgroups defined by the time at which treatment was initiated relative to surgery.   Therapy with topical MMC resulted in a nonrecurrence rate comparable to that achieved with CO(2) laser ablation (82.4% vs. 85.7%, respectively). Initiation of MMC following epithelialization of the surgical site a mean of 15 days postoperatively did not result in increased recurrence rates relative to treatment in the immediate postoperative period. Vision- or globe-threatening complications tended to occur with greater frequency in horses receiving topical MMC in the immediate postoperative period (5 of 6 major complications) relative to following epithelialization of the surgical site (1 of 6 major complications).   Horses receiving adjunctive topical MMC therapy were no more likely to experience tumor recurrence than were horses undergoing CO(2) laser ablation in the horses in this study. Initiation of two to three rounds of MMC following epithelialization of the surgical site results in fewer major complications and achieves comparable disease resolution relative to treatment in the immediate postoperative period. © 2011 American College of Veterinary Ophthalmologists.

  20. Heterogeneity of equilibrium molten globule state of cytochrome c induced by weak salt denaturants under physiological condition.

    PubMed

    Rahaman, Hamidur; Alam Khan, Md Khurshid; Hassan, Md Imtaiyaz; Islam, Asimul; Moosavi-Movahedi, Ali Akbar; Ahmad, Faizan

    2015-01-01

    While many proteins are recognized to undergo folding via intermediate(s), the heterogeneity of equilibrium folding intermediate(s) along the folding pathway is less understood. In our present study, FTIR spectroscopy, far- and near-UV circular dichroism (CD), ANS and tryptophan fluorescence, near IR absorbance spectroscopy and dynamic light scattering (DLS) were used to study the structural and thermodynamic characteristics of the native (N), denatured (D) and intermediate state (X) of goat cytochorme c (cyt-c) induced by weak salt denaturants (LiBr, LiCl and LiClO4) at pH 6.0 and 25°C. The LiBr-induced denaturation of cyt-c measured by Soret absorption (Δε400) and CD ([θ]409), is a three-step process, N ↔ X ↔ D. It is observed that the X state obtained along the denaturation pathway of cyt-c possesses common structural and thermodynamic characteristics of the molten globule (MG) state. The MG state of cyt-c induced by LiBr is compared for its structural and thermodynamic parameters with those found in other solvent conditions such as LiCl, LiClO4 and acidic pH. Our observations suggest: (1) that the LiBr-induced MG state of cyt-c retains the native Met80-Fe(III) axial bond and Trp59-propionate interactions; (2) that LiBr-induced MG state of cyt-c is more compact retaining the hydrophobic interactions in comparison to the MG states induced by LiCl, LiClO4 and 0.5 M NaCl at pH 2.0; and (3) that there exists heterogeneity of equilibrium intermediates along the unfolding pathway of cyt-c as highly ordered (X1), classical (X2) and disordered (X3), i.e., D ↔ X3 ↔ X2 ↔ X1 ↔ N.

  1. Apoptosis in oral lichen planus.

    PubMed

    Neppelberg, E; Johannessen, A C; Jonsson, R

    2001-10-01

    Apoptotic cell death may be a contributory cause of basal cell destruction in oral lichen planus (OLP). Therefore. the purpose of this study was to investigate the rate of apoptosis in OLP and the expression of two proteins (FasR and FasL) regulating this process. Biopsies from 18 patients with histologically diagnosed OLP were investigated, with comparison to normal oral mucosa of healthy persons. For visualisation of DNA fragmentation, the TUNEL method was used. In order to characterise the infiltrating cell population (CD3. CD4, CD8) and expression of FasR and FasL, we used an immunohistochemical technique. The results showed that T cells dominated in the subepithelial cell infiltrate. Within the epithelium the apoptotic cells were confined to the basal cell layer, and more apoptotic cells were seen in areas with basal cell degeneration and atrophic epithelium. There was a prominent expression of FasR/FasL in OLP. with a rather uniform distribution throughout the inflammatory cell infiltrate. In the epithelium, the FasR/FasL expression was more abundant in the basal cell area compared to the suprabasal cell layer. In conclusion, apoptosis within the epithelium is significantly increased in situ in OLP compared to normal oral mucosa, and seems to be related to the epithelial thickness.

  2. Differentiation and apoptosis in pilomatrixoma.

    PubMed

    Ishige, Toshiyuki; Kikuchi, Kentaro; Miyazaki, Yuji; Hara, Hiroyuki; Yoshino, Atsuo; Terui, Tadashi; Katayama, Yoichi; Kusama, Kaoru; Nemoto, Norimichi

    2011-02-01

    We carried out a histopathologic study of pilomatrixoma, a benign skin tumor, and also examined apoptosis and hair differentiation with the aim to understand the presence of amorphous debris and cyst formation in the tumor. Among 16 cases of pilomatrixoma examined, 11 were at the early regressive stage and 5 were at the late regressive stage according to the classification by Kaddu et al. In the former cases, tumor nests were basically composed of basophilic, transitional, and shadow cells. Cyst formation was evident in all cases and squamoid epithelium was observed in 4 cases at the early regressive stage. Amorphous debris was found in all cases including those at the late regressive stage. Immunohistochemical analysis revealed positive reaction products for β-catenin and Lef-1 in basophilic and transitional cells, although their distribution differed. Immunoreactivity for β-catenin was observed in the lower transitional cells, whereas immunoreactivity for Lef-1 was also evident in the upper transitional cells. Positive reactions for hair keratins were found in the cytoplasm of transitional and shadow cells, but not in the amorphous debris. Examination by the terminal deoxynucleotidyl transferase-mediated dUTP-biotin nick end-labeling (TUNEL) method revealed positive reactions in transitional and some shadow cells. These results suggest that in pilomatrixoma, production of hair keratin and induction of apoptosis may occur at the same time, and that unlike the normal hair follicle irregular expression of β-catenin and Lef-1 results in the appearance of amorphous debris and cyst formation.

  3. Toxoplasma gondii inhibits cytochrome c-induced caspase activation in its host cell by interference with holo-apoptosome assembly

    PubMed Central

    Graumann, Kristin; Schaumburg, Frieder; Reubold, Thomas F.; Hippe, Diana; Eschenburg, Susanne; Lüder, Carsten G. K.

    2015-01-01

    Inhibition of programmed cell death pathways of mammalian cells often facilitates the sustained survival of intracellular microorganisms. The apicomplexan parasite Toxoplasma gondii is a master regulator of host cell apoptotic pathways. Here, we have characterized a novel anti-apoptotic activity of T. gondii. Using a cell-free cytosolic extract model, we show that T. gondii interferes with the activities of caspase 9 and caspase 3/7 which have been induced by exogenous cytochrome c and dATP. Proteolytic cleavage of caspases 9 and 3 is also diminished suggesting inhibition of holo-apoptosome function. Parasite infection of Jurkat T cells and subsequent triggering of apoptosome formation by exogenous cytochrome c in vitro and in vivo indicated that T. gondii also interferes with caspase activation in infected cells. Importantly, parasite inhibition of cytochrome c-induced caspase activation considerably contributes to the overall anti-apoptotic activity of T. gondii as observed in staurosporine-treated cells. Co-immunoprecipitation showed that T. gondii abolishes binding of caspase 9 to Apaf-1 whereas the interaction of cytochrome c with Apaf-1 remains unchanged. Finally, T. gondii lysate mimics the effect of viable parasites and prevents holo-apoptosome functionality in a reconstituted in vitro system comprising recombinant Apaf-1 and caspase 9. Beside inhibition of cytochrome c release from host cell mitochondria, T. gondii thus also targets the holo-apoptosome assembly as a second mean to efficiently inhibit the caspase-dependent intrinsic cell death pathway. PMID:28357287

  4. Apoptosis in mammalian oocytes: a review.

    PubMed

    Tiwari, Meenakshi; Prasad, Shilpa; Tripathi, Anima; Pandey, Ashutosh N; Ali, Irfan; Singh, Arvind K; Shrivastav, Tulsidas G; Chaube, Shail K

    2015-08-01

    Apoptosis causes elimination of more than 99% of germ cells from cohort of ovary through follicular atresia. Less than 1% of germ cells, which are culminated in oocytes further undergo apoptosis during last phases of oogenesis and depletes ovarian reserve in most of the mammalian species including human. There are several players that induce apoptosis directly or indirectly in oocytes at various stages of meiotic cell cycle. Premature removal of encircling granulosa cells from immature oocytes, reduced levels of adenosine 3',5'-cyclic monophosphate and guanosine 3',5'-cyclic monophosphate, increased levels of calcium (Ca(2+)) and oxidants, sustained reduced level of maturation promoting factor, depletion of survival factors, nutrients and cell cycle proteins, reduced meiotic competency, increased levels of proapoptotic as well as apoptotic factors lead to oocyte apoptosis. The BH3-only proteins also act as key regulators of apoptosis in oocyte within the ovary. Both intrinsic (mitochondria-mediated) as well as extrinsic (cell surface death receptor-mediated) pathways are involved in oocyte apoptosis. BID, a BH3-only protein act as a bridge between both apoptotic pathways and its cleavage activates cell death machinery of both the pathways inside the follicular microenvironment. Oocyte apoptosis leads to the depletion of ovarian reserve that directly affects reproductive outcome of various mammals including human. In this review article, we highlight some of the important players and describe the pathways involved during oocyte apoptosis in mammals.

  5. Apoptosis in chronic tonsillitis and tonsillar hypertrophy.

    PubMed

    Önal, Merih; Yılmaz, Taner; Bilgiç, Elif; Müftüoğlu, Sevda Fatma; Kuşçu, Oğuz; Günaydın, Rıza Önder

    2015-02-01

    Chronic tonsillitis is the persistent inflammation of the tonsillar tissue that occurs due to recurrent, acute or subclinical infection. The recurrent and chronic inflammation of palatine tonsils sometimes results in hypertrophy. Apoptosis provides an important balance between lymphocytes in tonsillar lymphoid tissue. The aim of this study is to investigate the apoptosis in tonsillar diseases. 43 patients with chronic tonsilitis and tonsillar hypertrophy underwent tonsillectomy. The specimens were examined immunohistochemically for apoptosis. Tonsils were assembled into groups according to their size. Specimens were compared for their apoptotic cell count. The apoptosis difference between the tonsil size groups is not statistically significant (p>0.05). However, when the study group was divided into two at age 6, the difference was not statistically significant for patients at and below 6 years of age; but, the difference was statistically significant for patients above 6 years of age (p<0.05). The comparison of apoptosis in microcompartments of tonsil tissue (intrafollicular, interfollicular, subepithelial and intraepithelial) between tonsil size stages and between chronic tonsillitis and tonsillar hypertrophy groups revealed no statistical significance (p>0.05). There was a statistically significant positive correlation between intrafollicular and interfollicular, interfollicular and intraepithelial & subepithelial and intraepithelial areas (p<0.05). In the light of these findings, it was concluded that apoptosis played a role in the tonsillar hypertrophy and atrophy. Apoptosis functioned to balance lymphocyte proliferation in tonsil tissue. The association of apoptosis with tonsillar hypertrophy seemed to be age-dependent. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

  6. Apoptosis in immune-mediated diseases

    PubMed Central

    Sankari, S. Leena; Babu, N. Aravindha; Rajesh, E.; Kasthuri, M.

    2015-01-01

    Apoptosis plays a significant role in both the physiological and pathological process. A dysfunctional apoptotic system can lead to either excessive removal or prolonged survival of cells. Therefore, dysregulation is involved in the pathogenesis of a variety of immunological diseases. The present review aims to provide an overview regarding role of apoptosis in immune-mediated disease. PMID:26015710

  7. Proteases in Fas-mediated apoptosis.

    PubMed

    Zhivotovsky, B; Burgess, D H; Schlegel, J; Pörn, M I; Vanags, D; Orrenius, S

    1997-01-01

    Involvement of a unique family of cysteine proteases in the multistep apoptotic process has been documented. Cloning of several mammalian genes identifies some components of this cellular response. However, it is currently unclear which protease plays a role as a signal and/or effector of apoptosis. We summarize contributions to the data concerning proteases in Fas-mediated apoptosis.

  8. THE ROLE OF APOPTOSIS IN NEUROTOXICOLOGY.

    EPA Science Inventory

    The role of apoptosis in neurodegeneration in developing animals and in adults has become increasingly apparent in the past ten years. Normal apoptosis occurs in the CNS from the embryonic stage through senescence, with different cells in each region of the nervous system having ...

  9. Local anesthetics induce human renal cell apoptosis.

    PubMed

    Lee, H Thomas; Xu, Hua; Siegel, Cory D; Krichevsky, Igor E

    2003-01-01

    Renal cell apoptosis contributes significantly to the pathogenesis of acute renal failure. Local anesthetics induce apoptosis in neuronal and lymphocytic cell lines. We examined the effects of chronic (48 h) local anesthetic treatment (lidocaine, bupivacaine and tetracaine) on human proximal tubular (HK-2) cells. Apoptosis induction was assessed by detecting poly(ADP)-ribose polymerase fragmentation, caspase activation, terminal deoxynucleotidyl transferase biotin-dUTP nick end labeling (TUNEL) staining, DNA laddering and by cellular morphology. Cell death was quantified by measuring neutral red dye uptake and lactate dehydrogenase released into the cell culture medium. All 3 local anesthetics caused concentration-dependent cell death, induced HK-2 cell apoptosis and potentiated TNF-alpha induced apoptosis. Local anesthetics induced HK-2 cell apoptosis by activation of caspases 3, 6, 7, 8 and 9. ZVAD-fmk, a pan-caspase inhibitor, blocked the local anesthetic induced HK-2 cell apoptosis. Local anesthetics also inhibited the activities of anti-apoptotic kinases protein kinase B (Akt) and extracellular signal regulated mitrogen-activated protein kinase. Local anesthetic's pro-apoptotic effects are independent of sodium channel inhibition as tetrodotoxin, a selective voltage-gated sodium channel blocker, failed to mimic local anesthetic-mediated induction or potentiation of HK-2 cell apoptosis. We conclude that local anesthetics induce human renal cell apoptotic signaling by caspase activation and via inhibition of pro-survival signaling pathways.

  10. Apoptosis in acquired and genetic hearing impairment

    PubMed Central

    de Beeck, Ken Op; Schacht, Jochen; Van Camp, Guy

    2012-01-01

    Apoptosis is an important physiological process. Normally, a healthy cell maintains a delicate balance between pro- and anti-apoptotic factors, allowing it to live and proliferate. It is thus not surprising that disturbance of this delicate balance may result in disease. It is a well known fact that apoptosis also contributes to several acquired forms of hearing impairment. Noise-induced hearing loss is the result of prolonged exposure to excessive noise, triggering apoptosis in terminally differentiated sensory hair cells. Moreover, hearing loss caused by the use of therapeutic drugs such as aminoglycoside antibiotics and cisplatin potentially may result in the activation of apoptosis in sensory hair cells leading to hearing loss due to the “ototoxicity” of the drugs. Finally, apoptosis is a key contributor to the development of presbycusis, age-related hearing loss. Recently, several mutations in apoptosis genes were identified as the cause of monogenic hearing impairment. These genes are TJP2, DFNA5 and MSRB3. This implies that apoptosis not only contributes to the pathology of acquired forms of hearing impairment, but also to genetic hearing impairment as well. We believe that these genes constitute a new functional class within the hearing loss field. Here, the contribution of apoptosis in the pathology of both acquired and genetic hearing impairment is reviewed. PMID:21782914

  11. THE ROLE OF APOPTOSIS IN NEUROTOXICOLOGY.

    EPA Science Inventory

    The role of apoptosis in neurodegeneration in developing animals and in adults has become increasingly apparent in the past ten years. Normal apoptosis occurs in the CNS from the embryonic stage through senescence, with different cells in each region of the nervous system having ...

  12. Proapoptotic signalling through Toll-like receptor-3 involves TRIF-dependent activation of caspase-8 and is under the control of inhibitor of apoptosis proteins in melanoma cells.

    PubMed

    Weber, A; Kirejczyk, Z; Besch, R; Potthoff, S; Leverkus, M; Häcker, G

    2010-06-01

    Toll-like receptor-3 (TLR3), a member of an immune recognition receptor family, is widely expressed in tumour cells and has been shown previously to have the capacity to not only activate immune signalling pathways, but also to exert proapoptotic activity in some cells. We show here that HaCaT human keratinocytes are susceptible to apoptosis induction by the TLR3 ligand poly I:C, and use these cells as a model to analyse the apoptotic signalling pathway. Although the BH3-only protein Noxa was transcriptionally induced by poly I:C and translocated to mitochondria, RNAi experiments showed that the BH3-only proteins Noxa, Bim and Puma were individually dispensable for poly I:C-induced apoptosis. Instead, poly I:C-induced activation of caspase-8 via TLR3 and its adapter TRIF was required for apoptosis. In human melanoma cell lines poly I:C failed to induce apoptosis unless protein synthesis was blocked. Significantly, sensitisation towards poly I:C-dependent caspase-8 activation and apoptosis in melanoma cells was also achieved by the synthetic Smac mimetic/inhibitor of apoptosis protein (IAP) antagonist, LBW242, or by specific downregulation of cIAP1 by siRNA. Inactivation of caspase-8 by CrmA overexpression reduced poly I:C/LBW242-induced apoptosis. These results indicate that the proapoptotic activity of TLR3/TRIF/caspase-8 in melanoma cells is under the control of IAPs, and the use of novel Smac mimetics might be a feasible approach to target melanoma.

  13. Regulation of apoptosis by heat shock proteins.

    PubMed

    Kennedy, Donna; Jäger, Richard; Mosser, Dick D; Samali, Afshin

    2014-05-01

    Thermotolerance, the acquired resistance of cells to stress, is a well-established phenomenon. Studies of the key mediators of this response, the heat shock proteins (HSPs), have led to the discovery of the important roles played by these proteins in the regulation of apoptotic cell death. Apoptosis is critical for normal tissue homeostasis and is involved in diverse processes including development and immune clearance. Apoptosis is tightly regulated by both proapoptotic and antiapoptotic factors, and dysregulation of apoptosis plays a significant role in the pathophysiology of many diseases. In the recent years, HSPs have been identified as key determinants of cell survival, which can modulate apoptosis by directly interacting with components of the apoptotic machinery. Therefore, manipulation of the HSPs could represent a viable strategy for the treatment of diseases. Here, we review the current knowledge with regard to the mechanisms of HSP-mediated regulation of apoptosis. © 2014 International Union of Biochemistry and Molecular Biology.

  14. Cancer Therapy Due to Apoptosis: Galectin-9

    PubMed Central

    Fujita, Koji; Iwama, Hisakazu; Oura, Kyoko; Tadokoro, Tomoko; Samukawa, Eri; Sakamoto, Teppei; Nomura, Takako; Tani, Joji; Yoneyama, Hirohito; Morishita, Asahiro; Himoto, Takashi; Hirashima, Mitsuomi; Masaki, Tsutomu

    2017-01-01

    Dysregulation of apoptosis is a major hallmark in cancer biology that might equip tumors with a higher malignant potential and chemoresistance. The anti-cancer activities of lectin, defined as a carbohydrate-binding protein that is not an enzyme or antibody, have been investigated for over a century. Recently, galectin-9, which has two distinct carbohydrate recognition domains connected by a linker peptide, was noted to induce apoptosis in thymocytes and immune cells. The apoptosis of these cells contributes to the development and regulation of acquired immunity. Furthermore, human recombinant galectin-9, hG9NC (null), which lacks an entire region of the linker peptide, was designed to resist proteolysis. The hG9NC (null) has demonstrated anti-cancer activities, including inducing apoptosis in hematological, dermatological and gastrointestinal malignancies. In this review, the molecular characteristics, history and apoptosis-inducing potential of galectin-9 are described. PMID:28045432

  15. Cancer Therapy Due to Apoptosis: Galectin-9.

    PubMed

    Fujita, Koji; Iwama, Hisakazu; Oura, Kyoko; Tadokoro, Tomoko; Samukawa, Eri; Sakamoto, Teppei; Nomura, Takako; Tani, Joji; Yoneyama, Hirohito; Morishita, Asahiro; Himoto, Takashi; Hirashima, Mitsuomi; Masaki, Tsutomu

    2017-01-01

    Dysregulation of apoptosis is a major hallmark in cancer biology that might equip tumors with a higher malignant potential and chemoresistance. The anti-cancer activities of lectin, defined as a carbohydrate-binding protein that is not an enzyme or antibody, have been investigated for over a century. Recently, galectin-9, which has two distinct carbohydrate recognition domains connected by a linker peptide, was noted to induce apoptosis in thymocytes and immune cells. The apoptosis of these cells contributes to the development and regulation of acquired immunity. Furthermore, human recombinant galectin-9, hG9NC (null), which lacks an entire region of the linker peptide, was designed to resist proteolysis. The hG9NC (null) has demonstrated anti-cancer activities, including inducing apoptosis in hematological, dermatological and gastrointestinal m