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Sample records for acquired radioresistant cells

  1. The acquired radioresistance in HeLa cells under conditions mimicking hypoxia was attenuated by a decreased expression of HIF subunit genes induced by RNA interference

    SciTech Connect

    Doi, Nobutaka; Ogawa, Ryohei; Cui, Zheng-Guo; Morii, Akihiro; Watanabe, Akihiko; Kanayama, Shinji; Yoneda, Yuko; Kondo, Takashi

    2015-05-01

    The cancer cells residing in the hypoxic layer are resistant to radiation and these are ones responsible for cancer recurrence after radiation therapy. One of the reasons why hypoxic cancer cells acquire radioresistance may be attributable to changes in the gene expression profile by the activation of hypoxia inducible factors (HIFs). However, the details underlying this process remain unknown. In this study, we investigated the effects of knockdown of HIF subunit genes to elucidate how HIF subunit genes may be involved in the radioresistance acquired by HeLa cells following exposure to a hypoxia mimic. Interestingly, HIF-1α and HIF-2α seemed mutually complementary for each other when either of them was suppressed. We thus suppressed the expression of both genes simultaneously. To do this, we developed a short hairpin RNA (shRNA) targeting a high homology region between HIF-1α and HIF-2α. It was shown that the expression of the shRNA effectively suppressed the acquisition of radioresistance following the hypoxia mimic. Moreover, it was confirmed that suppression of both subunits resulted in the downregulation of stem cell markers and the suppression of spheroid formation during the hypoxia mimicking-conditions. This shRNA-mediated knockdown method targeting a common region shared by a family of genes may offer a new candidate cancer treatment. - Highlights: • Incubation with CoCl{sub 2} confers radioresistance to HeLa cells. • Both HIF-1α and HIF-2α are involved in the acquisition of radioresistance. • An shRNA to a homology region of HIF-1α and HIF-2α suppressed the radioresistance. • The shRNA decreased cells with stem cell markers and a stem cell phenotype.

  2. DNA-dependent protein kinase catalytic subunit inhibitor reverses acquired radioresistance in lung adenocarcinoma by suppressing DNA repair.

    PubMed

    Li, Yong; Li, Hang; Peng, Wen; He, Xin-Yun; Huang, Min; Qiu, Dong; Xue, Ying-Bo; Lu, Liang

    2015-07-01

    The mechanisms underlying lung cancer radioresistance remain to be fully elucidated. The DNA repair pathway is a predominant target of radiotherapy, which is considered to be involved in the acquired radioresistance of cancer cells. The present study aimed to establish a radioresistant cell model using the A549 human lung cancer cell line, and to further investigate the potential mechanisms underlying the radioresistance. The A549R radioresistant lung cancer cell variant was established by exposing the parental A549 cells to repeated γ-ray irradiation at a total dose of 60 Gy. Colony formation assays were then used to determine cell survival following γ-ray exposure. The established radioresistant cells were subsequently treated with or without the NU7026 DNA-PKcs inhibitor. The levels of DNA damage were determined by counting the number of fluorescent γ-H2AX foci in the cells. The cellular capacity for DNA repair was assessed using antibodies for the detection of various DNA repair pathway proteins. The radioresistant sub-clones exhibited significantly decreased survival following NU7026 treatment, compared with the parental cells, as determined by colony formation assays (P<0.05), and this finding was found to be dose-dependent. Treatment with the DNA-dependent protein kinase (DNA-PK) inhibitor significantly reduced γ-H2AX foci formation (P<0.05) following acute radiation exposure in the radioresistant sub-clones, compared with the parental control cells. The decreased levels of γ-H2AX were accompanied by an increase in the percentage of apoptotic cells in the radioresistant cell line following post-radiation treatment with the DNA-PKcs inhibitor. The expression levels of proteins associated with the DNA repair pathway were altered markedly in the cells treated with NU7026. The results of the present study suggested that radioresistance may be associated with enhanced DNA repair following exposure to radiation, resulting in reduced apoptosis. Therefore, the

  3. Targeting the AKT/GSK3{beta}/Cyclin D1/Cdk4 Survival Signaling Pathway for Eradication of Tumor Radioresistance Acquired by Fractionated Radiotherapy

    SciTech Connect

    Shimura, Tsutomu; Kakuda, Satoshi; Ochiai, Yasushi; Kuwahara, Yoshikazu; Takai, Yoshihiro; Fukumoto, Manabu

    2011-06-01

    Purpose: Radioresistance is a major cause of treatment failure of radiotherapy (RT) in human cancer. We have recently revealed that acquired radioresistance of tumor cells induced by fractionated radiation is attributable to cyclin D1 overexpression as a consequence of the downregulation of GSK3{beta}-dependent cyclin D1 proteolysis mediated by a constitutively activated serine-threonine kinase, AKT. This prompted us to hypothesize that targeting the AKT/GSK3{beta}/cyclin D1 pathway may improve fractionated RT by suppressing acquired radioresistance of tumor cells. Methods and Materials: Two human tumor cell lines with acquired radioresistance were exposed to X-rays after incubation with either an AKT inhibitor, AKT/PKB signaling inhibitor-2 (API-2), or a Cdk4 inhibitor (Cdk4-I). Cells were then subjected to immunoblotting, clonogenic survival assay, cell growth analysis, and cell death analysis with TUNEL and annexin V staining. In vivo radiosensitivity was assessed by growth of human tumors xenografted into nude mice. Results: Treatment with API-2 resulted in downregulation of cyclin D1 expression in cells with acquired radioresistance. Cellular radioresistance disappeared completely both in vitro and in vivo with accompanying apoptosis when treated with API-2. Furthermore, inhibition of cyclin D1/Cdk4 by Cdk4-I was sufficient for abolishing radioresistance. Treatment with either API-2 or Cdk4-I was also effective in suppressing resistance to cis-platinum (II)-diamine-dichloride in the cells with acquired radioresistance. Interestingly, the radiosensitizing effect of API-2 was canceled by overexpression of cyclin D1 whereas Cdk4-I was still able to sensitize cells with cyclin D1 overexpression. Conclusion: Cyclin D1/Cdk4 is a critical target of the AKT survival signaling pathway responsible for tumor radioresistance. Targeting the AKT/GSK3{beta}/cyclin D1/Cdk4 pathway would provide a novel approach to improve fractionated RT and would have an impact on tumor

  4. Cancer stem cells and signaling pathways in radioresistance

    PubMed Central

    Chang, Lei; Graham, Peter; Hao, Jingli; Ni, Jie; Deng, Junli; Bucci, Joseph; Malouf, David; Gillatt, David; Li, Yong

    2016-01-01

    Radiation therapy (RT) is one of the most important strategies in cancer treatment. Radioresistance (the failure to RT) results in locoregional recurrence and metastasis. Therefore, it is critically important to investigate the mechanisms leading to cancer radioresistance to overcome this problem and increase patients' survival. Currently, the majority of the radioresistance-associated researches have focused on preclinical studies. Although the exact mechanisms of cancer radioresistance have not been fully uncovered, accumulating evidence supports that cancer stem cells (CSCs) and different signaling pathways play important roles in regulating radiation response and radioresistance. Therefore, targeting CSCs or signaling pathway proteins may hold promise for developing novel combination modalities and overcoming radioresistance. The present review focuses on the key evidence of CSC markers and several important signaling pathways in cancer radioresistance and explores innovative approaches for future radiation treatment. PMID:26716904

  5. Bmi-1 confers adaptive radioresistance to KYSE-150R esophageal carcinoma cells

    SciTech Connect

    Wang, Guanyu; Liu, Luying; Sharma, Sherven; Liu, Hai; Yang, Weifang; Sun, Xiaonan; Dong, Qinghua

    2012-08-24

    Highlights: Black-Right-Pointing-Pointer Adaptive radioresistant KYSE-150R cells expressed high level of Bmi-1. Black-Right-Pointing-Pointer Bmi-1 depletion sensitized KYSE-150R cells to RT. Black-Right-Pointing-Pointer Bmi-1 depletion increased the generation of ROS in KYSE-150R cells exposed to radiation. Black-Right-Pointing-Pointer Bmi-1 depletion impaired DNA repair capacities in KYSE-150R cells exposed to radiation. -- Abstract: Radiotherapy (RT) is a major modality of cancer treatment. However, tumors often acquire radioresistance, which causes RT to fail. The exact mechanisms by which tumor cells subjected to fractionated irradiation (FIR) develop an adaptive radioresistance are largely unknown. Using the radioresistant KYSE-150R esophageal squamous cell carcinoma (ESCC) model, which was derived from KYSE-150 parental cells using FIR, the role of Bmi-1 in mediating the radioadaptive response of ESCC cells to RT was investigated. The results showed that the level of Bmi-1 expression was significantly higher in KYSE-150R cells than in the KYSE-150 parental cells. Bmi-1 depletion sensitized the KYSE-150R cells to RT mainly through the induction of apoptosis, partly through the induction of senescence. A clonogenic cell survival assay showed that Bmi-1 depletion significantly decreased the radiation survival fraction in KYSE-150R cells. Furthermore, Bmi-1 depletion increased the generation of reactive oxygen species (ROS) and the expression of oxidase genes (Lpo, Noxo1 and Alox15) in KYSE-150R cells exposed to irradiation. DNA repair capacities assessed by {gamma}-H2AX foci formation were also impaired in the Bmi-1 down-regulated KYSE-150R cells. These results suggest that Bmi-1 plays an important role in tumor radioadaptive resistance under FIR and may be a potent molecular target for enhancing the efficacy of fractionated RT.

  6. E-Cadherin loss associated with EMT promotes radioresistance in human tumor cells

    PubMed Central

    Theys, Jan; Jutten, Barry; Habets, Roger; Paesmans, Kim; Groot, Arjan J.; Lambin, Philippe; Wouters, Brad G.

    2016-01-01

    Background and purpose Hypoxia is a hallmark of solid cancers and associated with metastases and treatment failure. During tumor progression epithelial cells often acquire mesenchymal features, a phenomenon known as epithelial-to-mesenchymal transition (EMT). Intratumoral hypoxia has been linked to EMT induction. We hypothesized that signals from the tumor microenvironment such as growth factors and tumor oxygenation collaborate to promote EMT and thereby contribute to radioresistance. Materials and methods Gene expression changes under hypoxia were analyzed using microarray and validated by qRT-PCR. Conversion of epithelial phenotype upon hypoxic exposure, TGFβ addition or oncogene activation was investigated by Western blot and immunofluorescence. Cell survival following ionizing radiation was assayed using clonogenic survival. Results Upon hypoxia, TGFβ addition or EGFRvIII expression, MCF7, A549 and NMuMG epithelial cells acquired a spindle shape and lost cell–cell contacts. Expression of epithelial markers such as E-cadherin decreased, whereas mesenchymal markers such as vimentin and N-cadherin increased. Combining hypoxia with TGFβ or EGFRvIII expression, lead to more rapid and pronounced EMT-like phenotype. Interestingly, E-cadherin expression and the mesenchymal appearance were reversible upon reoxygenation. Mesenchymal conversion and E-cadherin loss were associated with radioresistance. Conclusions Our findings describe a mechanism by which the tumor microenvironment may contribute to tumor radioresistance via E-cadherin loss and EMT. PMID:21680037

  7. Role of Natural Radiosensitizers and Cancer Cell Radioresistance: An Update

    PubMed Central

    Sultana, Misbah; Qazi, Aamer; Qazi, Mahmood Husain; Parveen, Gulshan; Waquar, Sulayman; Ashraf, Abdul Basit; Rasool, Mahmood

    2016-01-01

    Cancer originates from genetic mutations accumulation. Cancer stem cells have been depicted as tumorigenic cells that can differentiate and self-renew. Cancer stem cells are thought to be resistant to conventional therapy like chemotherapy and radiation therapy. Radiation therapy and chemotherapy damage carcinomic DNA cells. Because of the ability of cancer stem cells to self-renew and reproduce malignant tumors, they are the subject of intensive research. In this review, CSCs radioresistant mechanisms which include DNA damage response and natural radiosensitizers have been summed up. Reactive oxygen species play an important role in different physiological processes. ROS scavenging is responsible for regulation of reactive oxygen species generation. A researcher has proved that microRNAs regulate tumor radiation resistance. Ionizing radiation does not kill the cancer cells; rather, IR just slows down the signs and symptoms. Ionizing radiation damages DNA directly/indirectly. IR is given mostly in combination with other chemo/radiotherapies. We briefly described here the behavior of cancer stem cells and radioresistance therapies in cancer treatment. To overcome radioresistance in treatment of cancer, strategies like fractionation modification, treatment in combination, inflammation modification, and overcoming hypoxic tumor have been practiced. Natural radiosensitizers, for example, curcumin, genistein, and quercetin, are more beneficial than synthetic compounds. PMID:26998418

  8. Hypoxia-inducible factor 1–mediated characteristic features of cancer cells for tumor radioresistance

    PubMed Central

    Harada, Hiroshi

    2016-01-01

    Tumor hypoxia has been attracting increasing attention in the fields of radiation biology and oncology since Thomlinson and Gray detected hypoxic cells in malignant solid tumors and showed that they exert a negative impact on the outcome of radiation therapy. This unfavorable influence has, at least partly, been attributed to cancer cells acquiring a radioresistant phenotype through the activation of the transcription factor, hypoxia-inducible factor 1 (HIF-1). On the other hand, accumulating evidence has recently revealed that, even though HIF-1 is recognized as an important regulator of cellular adaptive responses to hypoxia, it may not become active and induce tumor radioresistance under hypoxic conditions only. The mechanisms by which HIF-1 is activated in cancer cells not only under hypoxic conditions, but also under normoxic conditions, through cancer-specific genetic alterations and the resultant imbalance in intermediate metabolites have been summarized herein. The relevance of the HIF-1–mediated characteristic features of cancer cells, such as the production of antioxidants through reprogramming of the glucose metabolic pathway and cell cycle regulation, for tumor radioresistance has also been reviewed. PMID:26983985

  9. Impairing the radioresistance of cancer cells by hydrogenated nanodiamonds.

    PubMed

    Grall, Romain; Girard, Hugues; Saad, Lina; Petit, Tristan; Gesset, Céline; Combis-Schlumberger, Mathilde; Paget, Vincent; Delic, Jozo; Arnault, Jean-Charles; Chevillard, Sylvie

    2015-08-01

    Hydrogenated nanodiamonds (H-NDs) exhibit a negative electron affinity that confers a high reactivity with oxygen species and a positive charge in aqueous solutions. It allows electron emission from H-NDs following irradiation by photons and in consequence may enhance the effects of radiation on cancer cells. By using three human radioresistant cancer cell lines, we showed a potentialization of cytotoxicity after a co-exposure to H-NDs and irradiation; an event occurring through the induction of DNA damage and reactive oxygen species. This occurred together with a decrease in cell impedance, the activation of G1/S, an unlocking of G2 cell cycle check-points and early low cell death rate. At later stage of exposure, persistent increases in heterochromatinization, large γ-H2AX foci and β-galactosidase activity were detected providing evidence of cells' entrance into senescence. Similar potentialization was observed with neocarzinostatin (NCS), a radiomimetic drug. This original finding underlines a wide clinical potential of H-NDs to intensify radiation effects on radio-resistant cancer cells. PMID:26010122

  10. Vitamin K2-derived compounds induce growth inhibition in radioresistant cancer cells.

    PubMed

    Amalia, Helfi; Sasaki, Ryohei; Suzuki, Yoko; Demizu, Yusuke; Bito, Toshinori; Nishimura, Hideki; Okamoto, Yoshiaki; Yoshida, Kenji; Miyawaki, Daisuke; Kawabe, Tetsuya; Mizushina, Yoshiyuki; Sugimura, Kazuro

    2010-01-01

    A strategy to overcome radioresistance in cancer treatment has been expected. To evaluate the strategy, appropriate experimental models are needed. Radioresistant tumour models were originally established from human colon cancer cells, and we evaluated their molecular basis. Next, the growth inhibitory effects of newly synthesized vitamin K2 (VK2)-related compounds were tested. Here, we showed that these novel compounds have growth inhibitory effects not only on cancer cells of various origins, but also on radioresistant cells, through the generation of reactive oxygen species (ROS). Human colon, lung, and breast cancer cell lines were used for testing the growth inhibitory activities of several chemical compounds. Radioresistant tumour models were established by fractionated radiation exposure. Irradiated cells were selected by a single cell cloning method, and their sensitivity to ionizing radiation was evaluated by a colony-forming assay. The VK2 derivatives (named MQ-1, MQ-2, and MQ-3) were chemically synthesized. To evaluate the generation of ROS, flow cytometer analyses were performed. A radioresistant tumour model was established from the HCT116 human colon cancer cell line. The radioresistant cells from HCT116 also showed resistance to cisplatin. In the radioresistant cells, NF-κB was highly activated. MQ-1, MQ-2, and MQ-3 showed greater growth inhibitory activities than VK2 not only in various cancer cells but also in radioresistant cells through the generation of ROS. In conclusion, a radioresistant tumour model was originally established from colon cancer cell lines through NF-κB activation, and it could be a useful tool for evaluating anti-tumour agents. Newly synthesized VK2 derivatives (MQ-1, MQ-2 and MQ-3) seemed to be potential anti-tumour agents in various cancers and radioresistant cancers. The efficacy of those compounds was related to the generation of ROS. These findings together might pave the way for the treatment of radioresistant or

  11. Radiotherapy diagnostic biomarkers in radioresistant human H460 lung cancer stem-like cells

    PubMed Central

    Yun, Hong Shik; Baek, Jeong-Hwa; Yim, Ji-Hye; Um, Hong-Duck; Park, Jong Kuk; Song, Jie-Young; Park, In-Chul; Kim, Jae-Sung; Lee, Su-Jae; Lee, Chang-Woo; Hwang, Sang-Gu

    2016-01-01

    ABSTRACT Tumor cell radioresistance is a major contributor to radiotherapy failure, highlighting the importance of identifying predictive biomarkers for radioresistance. In this work, we established a radioresistant H460 (RR-H460) cell line from parental radiosensitive H460 lung cancer cells by exposure to fractionated radiation. The radiation-resistant, anti-apoptotic phenotype of RR-H460 cell lines was confirmed by their enhanced clonogenic survival and increased expression of the radioresistance genes Hsp90 and Her-3. RR-H460 cells displayed characteristics of cancer stem-like cells (CSCs), including induction of the surface marker CD44 and stem cell markers Nanog, Oct4, and Sox2. RR-H460 cells also exhibited sphere formation and malignant behavior, further supporting a CSC phenotype. Using proteomic analyses, we identified 8 proteins that were up-regulated in RR-H460 CSC lines and therefore potentially involved in radioresistance and CSC-related biological processes. Notably, 4 of these—PAI-2, NOMO2, KLC4, and PLOD3—have not been previously linked to radioresistance. Depletion of these individual genes sensitized RR-H460 cells to radiotoxicity and additively enhancing radiation-induced apoptosis. Our findings suggest the possibility of integrating molecular targeted therapy with radiotherapy as a strategy for resolving the radioresistance of lung tumors. PMID:26901847

  12. Radiotherapy diagnostic biomarkers in radioresistant human H460 lung cancer stem-like cells.

    PubMed

    Yun, Hong Shik; Baek, Jeong-Hwa; Yim, Ji-Hye; Um, Hong-Duck; Park, Jong Kuk; Song, Jie-Young; Park, In-Chul; Kim, Jae-Sung; Lee, Su-Jae; Lee, Chang-Woo; Hwang, Sang-Gu

    2016-02-01

    Tumor cell radioresistance is a major contributor to radiotherapy failure, highlighting the importance of identifying predictive biomarkers for radioresistance. In this work, we established a radioresistant H460 (RR-H460) cell line from parental radiosensitive H460 lung cancer cells by exposure to fractionated radiation. The radiation-resistant, anti-apoptotic phenotype of RR-H460 cell lines was confirmed by their enhanced clonogenic survival and increased expression of the radioresistance genes Hsp90 and Her-3. RR-H460 cells displayed characteristics of cancer stem-like cells (CSCs), including induction of the surface marker CD44 and stem cell markers Nanog, Oct4, and Sox2. RR-H460 cells also exhibited sphere formation and malignant behavior, further supporting a CSC phenotype. Using proteomic analyses, we identified 8 proteins that were up-regulated in RR-H460 CSC lines and therefore potentially involved in radioresistance and CSC-related biological processes. Notably, 4 of these-PAI-2, NOMO2, KLC4, and PLOD3-have not been previously linked to radioresistance. Depletion of these individual genes sensitized RR-H460 cells to radiotoxicity and additively enhancing radiation-induced apoptosis. Our findings suggest the possibility of integrating molecular targeted therapy with radiotherapy as a strategy for resolving the radioresistance of lung tumors. PMID:26901847

  13. Role of glutathione in the intrinsic radioresistance of cell lines from a mouse squamous cell carcinoma

    SciTech Connect

    Miura, M.; Sasaki, T. )

    1991-05-01

    The role of glutathione (GSH) in determining the intrinsic cellular radioresistance under aerobic conditions was studied with the parent cell line MSCC and its radioresistant subclone R1 isolated from a mouse squamous cell carcinoma. The mean inactivation doses (D) of the survival curves were 2.1 and 4.0 Gy for exponentially growing MSCC and R1 cells, respectively. The corresponding GSH content was 22.6 and 13.4 nmol/10(6) cells. There was no significant difference in either the distribution of GSH between nucleus and cytoplasm or the turnover rate of GSH between the two cell lines. Thus it appeared that the radioresistance of R1 cells resulted from mechanisms unrelated to GSH. However, R1 cells became progressively more radiosensitive with a decrease of the GSH content with buthionine sulfoximine (BSO) treatment until about 20 h, and the radiosensitivity showed little change thereafter. The MSCC cells showed little change in the radiosensitivity with the same treatment. In fact, dose-survival curves showed that the enhancement ratio of D with the 24-h BSO treatment was 1.1 for MSCC and 1.4 for R1 cells, although the GSH content was reduced to 1 to 2% of the untreated level for both cell lines. There was no significant difference in the activities of GSH S-transferase and GSH reductase between MSCC and R1 cells before and after BSO treatment, or between BSO-treated and untreated cells of the same cell lines. Although the exact mechanisms of GSH-related radioresistance of R1 cells are unclear, these results suggest that there may exist GSH-related mechanisms in addition to radical scavenging which determine the intrinsic cellular radioresistance under aerobic conditions.

  14. Stathmin1 increases radioresistance by enhancing autophagy in non-small-cell lung cancer cells

    PubMed Central

    Zhang, Xi; Ji, Jingfen; Yang, Yu; Zhang, Juan; Shen, Liangfang

    2016-01-01

    Radioresistance has been demonstrated to be involved in the poor prognosis of patients with non-small-cell lung cancer (NSCLC). However, the underlying mechanism remains largely unclear. Investigation on special therapeutic targets associated with radioresistance shows promises for the enhancement of clinical radiotherapy effect toward NSCLC. This study aimed to reveal the role of Stathmin1 (STMN1) in radioresistance in NSCLC as well as the underlying mechanism. Our data showed that the protein levels of STMN1 were significantly upregulated in NSCLC cells subjected to radiation, accompanied with the activation of autophagy. Knockdown of STMN1 expression enhanced the sensitivity of NSCLC cells to X-ray, and the radiation-induced autophagy was also inhibited. Molecular mechanism investigation showed that knockdown of STMN1 expression upregulated the activity of phosphoinositide 3-kinase (PI3K)/mammalian target of rapamycin (mTOR) signaling pathway in NSCLC cells. Moreover, the activation of PI3K/mTOR signaling showed an inhibitory effect on the autophagy and radioresistance induced by STMN1 in NSCLC cells. In addition, luciferase reporter assay data indicated that STMN1 was a direct target gene of miR-101, which had been reported to be an inhibitor of autophagy. Based on these data, we suggest that as a target gene of miR-101, STMN1 promotes the radioresistance by induction of autophagy through PI3K/mTOR signaling pathway in NSCLC. Therefore, STMN1 may become a potential therapeutic target for NSCLC radiotherapy. PMID:27199567

  15. Stathmin1 increases radioresistance by enhancing autophagy in non-small-cell lung cancer cells.

    PubMed

    Zhang, Xi; Ji, Jingfen; Yang, Yu; Zhang, Juan; Shen, Liangfang

    2016-01-01

    Radioresistance has been demonstrated to be involved in the poor prognosis of patients with non-small-cell lung cancer (NSCLC). However, the underlying mechanism remains largely unclear. Investigation on special therapeutic targets associated with radioresistance shows promises for the enhancement of clinical radiotherapy effect toward NSCLC. This study aimed to reveal the role of Stathmin1 (STMN1) in radioresistance in NSCLC as well as the underlying mechanism. Our data showed that the protein levels of STMN1 were significantly upregulated in NSCLC cells subjected to radiation, accompanied with the activation of autophagy. Knockdown of STMN1 expression enhanced the sensitivity of NSCLC cells to X-ray, and the radiation-induced autophagy was also inhibited. Molecular mechanism investigation showed that knockdown of STMN1 expression upregulated the activity of phosphoinositide 3-kinase (PI3K)/mammalian target of rapamycin (mTOR) signaling pathway in NSCLC cells. Moreover, the activation of PI3K/mTOR signaling showed an inhibitory effect on the autophagy and radioresistance induced by STMN1 in NSCLC cells. In addition, luciferase reporter assay data indicated that STMN1 was a direct target gene of miR-101, which had been reported to be an inhibitor of autophagy. Based on these data, we suggest that as a target gene of miR-101, STMN1 promotes the radioresistance by induction of autophagy through PI3K/mTOR signaling pathway in NSCLC. Therefore, STMN1 may become a potential therapeutic target for NSCLC radiotherapy. PMID:27199567

  16. Increased radioresistance of tumor cells exposed to metallothionein-inducing agents

    SciTech Connect

    Renan, M.J.; Dowman, P.I. )

    1989-12-01

    In this study, we have determined the radiosensitivity parameters of cells exposed in vitro to metallothionein-inducing agents. Three well-characterized tumor cell lines were chosen for investigation: HeLa, B16, and WHFIB. We have shown that exposure of cells in vitro to a heavy metal (cadmium), followed by irradiation, enhances cell survival for two out of three cell lines studied. As measured by the mean inactivation dose, the radioresistance increases by a factor of 1.6 for HeLa cells, 1.4 for WHFIB, and a negligible factor for B16 cells. An additional effect was noted when different classes of metallothionein inducers (such as serum factors, cadmium, and dexamethasone) were allowed to act together. Also, we found that the increase in radioresistance exhibits a peak at exposure times of approximately 10 h; longer exposure to inducing agents results in a reduction in radioresistance.

  17. Fractionated irradiation-induced EMT-like phenotype conferred radioresistance in esophageal squamous cell carcinoma

    PubMed Central

    Zhang, Hongfang; Luo, Honglei; Jiang, Zhenzhen; Yue, Jing; Hou, Qiang; Xie, Ruifei; Wu, Shixiu

    2016-01-01

    The efficacy of radiotherapy, one major treatment modality for esophageal squamous cell carcinoma (ESCC) is severely attenuated by radioresistance. Epithelial-to-mesenchymal transition (EMT) is a cellular process that determines therapy response and tumor progression. However, whether EMT is induced by ionizing radiation and involved in tumor radioresistance has been less studied in ESCC. Using multiple fractionated irradiation, the radioresistant esophageal squamous cancer cell line KYSE-150R had been established from its parental cell line KYSE-150. We found KYSE-150R displayed a significant EMT phenotype with an elongated spindle shape and down-regulated epithelial marker E-cadherin and up-regulated mesenchymal marker N-cadherin in comparison with KYSE-150. Furthermore, KYSE-150R also possessed some stemness-like properties characterized by density-dependent growth promotion and strong capability for sphere formation and tumorigenesis in NOD-SCID mice. Mechanical studies have revealed that WISP1, a secreted matricellular protein, is highly expressed in KYSE-150R and mediates EMT-associated radioresistance both in ESCC cells and in xenograft tumor models. Moreover, WISP1 has been demonstrated to be closely associated with the EMT phenotype observed in ESCC patients and to be an independent prognosis factor of ESCC patients treated with radiotherapy. Our study highlighted WISP1 as an attractive target to reverse EMT-associated radioresistance in ESCC and can be used as an independent prognostic factor of patients treated with radiotherapy. PMID:27125498

  18. Cancer Stem Cells and Radioresistance: Rho/ROCK Pathway Plea Attention.

    PubMed

    Pranatharthi, Annapurna; Ross, Cecil; Srivastava, Sweta

    2016-01-01

    Radiation is the most potent mode of cancer therapy; however, resistance to radiation therapy results in tumor relapse and subsequent fatality. The cancer stem cell (CSC), which has better DNA repair capability, has been shown to contribute to tumor resistance and is an important target for treatment. Signaling molecules such as Notch, Wnt, and DNA repair pathways regulate molecular mechanisms in CSCs; however, none of them have been translated into therapeutic targets. The RhoGTPases and their effector ROCK-signaling pathway, though important for tumor progression, have not been well studied in the context of radioresistance. There are reports that implicate RhoA in radioresistance. ROCK2 has also been shown to interact with BRCA2 in the regulation of cell division. Incidentally, statins (drug for cardiovascular ailment) are functional inhibitors of RhoGTPases. Studies suggest that patients on statins have a better prognosis in cancers. Data from our lab suggest that ROCK signaling regulates radioresistance in cervical cancer cells. Collectively, these findings suggest that Rho/ROCK signaling may be important for radiation resistance. In this review, we enumerate the role of Rho/ROCK signaling in stemness and radioresistance and highlight the need to explore these molecules for a better understanding of radioresistance and development of therapeutics. PMID:27597870

  19. Cancer Stem Cells and Radioresistance: Rho/ROCK Pathway Plea Attention

    PubMed Central

    Pranatharthi, Annapurna; Ross, Cecil

    2016-01-01

    Radiation is the most potent mode of cancer therapy; however, resistance to radiation therapy results in tumor relapse and subsequent fatality. The cancer stem cell (CSC), which has better DNA repair capability, has been shown to contribute to tumor resistance and is an important target for treatment. Signaling molecules such as Notch, Wnt, and DNA repair pathways regulate molecular mechanisms in CSCs; however, none of them have been translated into therapeutic targets. The RhoGTPases and their effector ROCK-signaling pathway, though important for tumor progression, have not been well studied in the context of radioresistance. There are reports that implicate RhoA in radioresistance. ROCK2 has also been shown to interact with BRCA2 in the regulation of cell division. Incidentally, statins (drug for cardiovascular ailment) are functional inhibitors of RhoGTPases. Studies suggest that patients on statins have a better prognosis in cancers. Data from our lab suggest that ROCK signaling regulates radioresistance in cervical cancer cells. Collectively, these findings suggest that Rho/ROCK signaling may be important for radiation resistance. In this review, we enumerate the role of Rho/ROCK signaling in stemness and radioresistance and highlight the need to explore these molecules for a better understanding of radioresistance and development of therapeutics. PMID:27597870

  20. HIF-1 and NDRG2 contribute to hypoxia-induced radioresistance of cervical cancer Hela cells

    SciTech Connect

    Liu, Junye; Zhang, Jing; Wang, Xiaowu; Li, Yan; Chen, Yongbin; Li, Kangchu; Zhang, Jian; Yao, Libo; Guo, Guozhen

    2010-07-15

    Hypoxia inducible factor 1 (HIF-1), the key mediator of hypoxia signaling pathways, has been shown involved in hypoxia-induced radioresistance. However, the underlying mechanisms are unclear. The present study demonstrated that both hypoxia and hypoxia mimetic cobalt chloride could increase the radioresistance of human cervical cancer Hela cells. Meanwhile, ectopic expression of HIF-1 could enhance the resistance of Hela cells to radiation, whereas knocking-down of HIF-1 could increase the sensitivity of Hela cells to radiation in the presence of hypoxia. N-Myc downstream-regulated gene 2 (NDRG2), a new HIF-1 target gene identified in our lab, was found to be upregulated by hypoxia and radiation in a HIF-1-dependent manner. Overexpression of NDRG2 resulted in decreased sensitivity of Hela cells to radiation while silencing NDRG2 led to radiosensitization. Moreover, NDRG2 was proved to protect Hela cells from radiation-induced apoptosis and abolish radiation-induced upregulation of Bax. Taken together, these data suggest that both HIF-1 and NDRG2 contribute to hypoxia-induced tumor radioresistance and that NDRG2 acts downstream of HIF-1 to promote radioresistance through suppressing radiation-induced Bax expression. It would be meaningful to further explore the clinical application potential of HIF-1 and NDRG2 blockade as radiosensitizer for tumor therapy.

  1. Radioresistant human lung adenocarcinoma cells that survived multiple fractions of ionizing radiation are sensitive to HSP90 inhibition.

    PubMed

    Gomez-Casal, Roberto; Epperly, Michael W; Wang, Hong; Proia, David A; Greenberger, Joel S; Levina, Vera

    2015-12-29

    Despite the common usage of radiotherapy for the treatment of NSCLC, outcomes for these cancers when treated with ionizing radiation (IR) are still unsatisfactory. A better understanding of the mechanisms underlying resistance to IR is needed to design approaches to eliminate the radioresistant cells and prevent tumor recurrence and metastases. Using multiple fractions of IR we generated radioresistant cells from T2821 and T2851 human lung adenocarcinoma cells. The radioresistant phenotypes present in T2821/R and T2851/R cells include multiple changes in DNA repair genes and proteins expression, upregulation of EMT markers, alterations of cell cycle distribution, upregulation of PI3K/AKT signaling and elevated production of growth factors, cytokines, important for lung cancer progression, such as IL-6, PDGFB and SDF-1 (CXCL12). In addition to being radioresistant these cells were also found to be resistant to cisplatin.HSP90 is a molecular chaperone involved in stabilization and function of multiple client proteins implicated in NSCLC cell survival and radioresistance. We examined the effect of ganetespib, a novel HSP90 inhibitor, on T2821/R and T2851/R cell survival, migration and radioresistance. Our data indicates that ganetespib has cytotoxic activity against parental T2821 and T2851 cells and radioresistant T2821/R and T2851/R lung tumor cells. Ganetespib does not affect proliferation of normal human lung fibroblasts. Combining IR with ganetespib completely abrogates clonogenic survival of radioresistant cells.Our data show that HSP90 inhibition can potentiate the effect of radiotherapy and eliminate radioresistant and cisplatin -resistant residual cells, thus it may aid in reducing NSCLC tumor recurrence after fractionated radiotherapy. PMID:26517240

  2. Radioresistant human lung adenocarcinoma cells that survived multiple fractions of ionizing radiation are sensitive to HSP90 inhibition

    PubMed Central

    Gomez-Casal, Roberto; Epperly, Michael W.; Wang, Hong; Proia, David A.; Greenberger, Joel S.; Levina, Vera

    2015-01-01

    Despite the common usage of radiotherapy for the treatment of NSCLC, outcomes for these cancers when treated with ionizing radiation (IR) are still unsatisfactory. A better understanding of the mechanisms underlying resistance to IR is needed to design approaches to eliminate the radioresistant cells and prevent tumor recurrence and metastases. Using multiple fractions of IR we generated radioresistant cells from T2821 and T2851 human lung adenocarcinoma cells. The radioresistant phenotypes present in T2821/R and T2851/R cells include multiple changes in DNA repair genes and proteins expression, upregulation of EMT markers, alterations of cell cycle distribution, upregulation of PI3K/AKT signaling and elevated production of growth factors, cytokines, important for lung cancer progression, such as IL-6, PDGFB and SDF-1 (CXCL12). In addition to being radioresistant these cells were also found to be resistant to cisplatin. HSP90 is a molecular chaperone involved in stabilization and function of multiple client proteins implicated in NSCLC cell survival and radioresistance. We examined the effect of ganetespib, a novel HSP90 inhibitor, on T2821/R and T2851/R cell survival, migration and radioresistance. Our data indicates that ganetespib has cytotoxic activity against parental T2821 and T2851 cells and radioresistant T2821/R and T2851/R lung tumor cells. Ganetespib does not affect proliferation of normal human lung fibroblasts. Combining IR with ganetespib completely abrogates clonogenic survival of radioresistant cells. Our data show that HSP90 inhibition can potentiate the effect of radiotherapy and eliminate radioresistant and cisplatin -resistant residual cells, thus it may aid in reducing NSCLC tumor recurrence after fractionated radiotherapy. PMID:26517240

  3. Radio-resistant mesenchymal stem cells: mechanisms of resistance and potential implications for the clinic

    PubMed Central

    Nicolay, Nils H.; Perez, Ramon Lopez; Saffrich, Rainer; Huber, Peter E.

    2015-01-01

    Mesenchymal stem cells (MSCs) comprise a heterogeneous population of multipotent stromal cells and can be isolated from various tissues and organs. Due to their regenerative potential, they have been subject to intense research efforts, and they may provide an efficient means for treating radiation-induced tissue damage. MSCs are relatively resistant to ionizing radiation and retain their stem cell characteristics even after high radiation doses. The underlying mechanisms for the observed MSC radioresistance have been extensively studied and may involve efficient DNA damage recognition, double strand break repair and evasion of apoptosis. Here, we present a concise review of the published scientific data on the radiobiological features of MSCs. The involvement of different DNA damage recognition and repair pathways in the creation of a radioresistant MSC phenotype is outlined, and the roles of apoptosis, senescence and autophagy regarding the reported radioresistance are summarized. Finally, potential influences of the radioresistant MSCs for the clinic are discussed with respect to the repair and radioprotection of irradiated tissues. PMID:26203772

  4. CpG Oligodeoxynucleotide1826 combined with radioresistant cancer cell vaccine confers significant antitumor effects.

    PubMed

    Zhuang, X B; Xing, N; Zhang, Q; Yuan, S J; Chen, W; Qiao, T K

    2015-01-01

    Immunotherapy is a hot issue in cancer research over the years and tumor cell vaccine is one of the increasing number of studies. Although the whole tumor cell vaccine can provide the best source of immunizing antigens, there is still a limitation that most tumors are not naturally immunogenic. CpG Oligodeoxynucleotides (CpG ODNs), synthetic oligonucleotides containing a cytosine-phosphate-guanine(CpG) motif, was shown to enhance immune responses to a wide variety of antigens. In this study, we generated the radioresistant Lewis lung cancer cell by repeated X-ray radiation and inactivated it as a whole tumor cell vaccine to enhance the immunogenicity of tumor cell vaccine. Mice were subcutaneously immunized with this inactivated vaccine combined with CpG ODN1826 and then inoculated with autologous Lewis lung cancer (LLC) to estimate the antitumor efficacy. The results showed that the radioresistant tumor cell vaccine combined with CpG ODN1826 could significantly inhibit tumor growth, increased survival of the mice and with 20% of the mice surviving tumor free in vivo compared with the unimmunized mice bearing LLC tumor. A significant increase of apoptosis was also observed in the tumor prophylactically immunized with vaccine of inactivated radioresistant tumor cell plus CpG ODN1826. The potent antitumor effect correlated with higher secretion levels of tumor necrosis factor-alpha(TNF-α) and lower levels of interleukin-10(IL-10) concentration in serum. Furthermore, the results suggested that the antitumor mechanism was probably depended on the decreased level of programmed death ligand-1(PD-L1) which plays an important role in the negative regulation of immune response by the inhibition of tumor antigen-specific T cell activation. These findings clearly demonstrated that the radioresistant tumor cell vaccine combined with CpG ODN1826 as an appropriate adjuvant could induce effective antitumor immunity in vivo. PMID:26458317

  5. MET inhibitor PHA-665752 suppresses the hepatocyte growth factor-induced cell proliferation and radioresistance in nasopharyngeal carcinoma cells

    SciTech Connect

    Liu, Tongxin; Li, Qi; Sun, Quanquan; Zhang, Yuqin; Yang, Hua; Wang, Rong; Chen, Longhua; Wang, Wei

    2014-06-20

    Highlights: • We demonstrated that irradiation induced MET overexpression and activation. • The aberrant MET signal mediated by HGF induced proliferation and radioresistance of NPC cells. • MET inhibitor PHA-665752 effectively suppressed HGF induced cell proliferation and radioresistance in NPC cells. • PHA-665752 suppressed the three downstream pathway of HGF/MET signal in a dose-dependent manner. - Abstract: Although ionizing radiation (IR) has provided considerable improvements in nasopharyngeal carcinoma (NPC), in subsets of patients, radioresistance is still a major problem in the treatment. In this study, we demonstrated that irradiation induced MET overexpression and activation, and the aberrant MET signal mediated by hepatocyte growth factor (HGF) induced radioresistance. We also found that MET inhibitor PHA-665752 effectively suppressed HGF induced cell proliferation and radioresistance in NPC cells. Further investigation indicated that PHA-665752 suppressed the phosphorylation of the Akt, ERK1/2, and STAT3 proteins in a dose-dependent manner. Our data indicated that the combination of IR with a MET inhibitor, such as PHA-665752, might be a promising therapeutic strategy for NPC.

  6. Lysyl oxidase mediates hypoxia-induced radioresistance in non-small cell lung cancer A549 cells.

    PubMed

    Gong, Chongwen; Gu, Runxia; Jin, Honglin; Sun, Yao; Li, Zhenyu; Chen, Jing; Wu, Gang

    2016-02-01

    Hypoxia-induced radioresistance has been well known as the main obstacle in cancer radiotherapy. Lysyl oxidase (LOX) was previously demonstrated to play an important role in hypoxia-induced biological behaviors, such as metastasis and angiogenesis, through hypoxia-inducible factor-1α (HIF-1α), which is an important contributing factor to radioresistance in tumor cells. However, how LOX plays a role in hypoxia-induced radioresistance has yet to be determined. Here, we found that LOX expression was in accordance with HIF-1α expression, and LOX expression at the mRNA and protein level, and enzymatic activity were remarkably upregulated in the hypoxic A549 cells, compared with normoxic A549 cells. Inhibition of LOX resulted in the reduction of the ability to repair double-stranded breaks (DSBs), promotion of apoptosis, relief of G2/M cycle arrest, and eventually reduction of hypoxia-induced radioresistance in the hypoxic A549 cells. This suggests that LOX may play an important role in hypoxia-induced radioresistance. Together, our results might suggest a novel potential therapeutic target in the management of non-small cell lung cancer (NSCLC). PMID:26515140

  7. The Brain Microenvironment Preferentially Enhances the Radioresistance of CD133+ Glioblastoma Stem-like Cells

    PubMed Central

    Jamal, Muhammad; Rath, Barbara H; Tsang, Patricia S; Camphausen, Kevin; Tofilon, Philip J

    2012-01-01

    Brain tumor xenografts initiated from glioblastoma (GBM) CD133+ tumor stem-like cells (TSCs) are composed of TSC and non-TSC subpopulations, simulating the phenotypic heterogeneity of GBMs in situ. Given that the discrepancies between the radiosensitivity of GBM cells in vitro and the treatment response of patients suggest a role for the microenvironment in GBM radioresistance, we compared the response of TSCs and non-TSCs irradiated under in vitro and orthotopic conditions. As a measure of radioresponse determined at the individual cell level, γH2AX and 53BP1 foci were quantified in CD133+ cells and their differentiated (CD133-) progeny. Under in vitro conditions, no difference was detected between CD133+ and CD133- cells in foci induction or dispersal after irradiation. However, irradiation of orthotopic xenografts initiated from TSCs resulted in the induction of fewer γH2AX and 53BP1 foci in CD133+ cells compared to their CD133- counterparts within the same tumor. Xenograft irradiation resulted in a tumor growth delay of approximately 7 days with a corresponding increase in the percentage of CD133+ cells at 7 days after radiation, which persisted to the onset of neurologic symptoms. These results suggest that, although the radioresponse of TSCs and non-TSCs does not differ under in vitro growth conditions, CD133+ cells are relatively radioresistant under intracerebral growth conditions. Whereas these findings are consistent with the suspected role for TSCs as a determinant of GBM radioresistance, these data also illustrate the dependence of the cellular radioresistance on the brain microenvironment. PMID:22431923

  8. Radiation-induced microrna-622 causes radioresistance in colorectal cancer cells by down-regulating Rb

    PubMed Central

    Liang, Li; Zhang, Yan; Ding, Yi; Lin, Xiaoshan; Li, Guoxin; Ding, Yanqing

    2015-01-01

    The standard treatment for patients with locally advanced rectal cancer is preoperative 5-fluorouracil-based chemoradiotherapy followed by total mesorectal excision. However, tumor response to standard dose radiation varies. In this study, we found that miR-622 was increased significantly in ionizing radiation-treated colorectal cancer (CRC) cells compared to the cells cultured with irradiated medium, and persisted stably in surviving cells treated with continuous low-dose radiation. Overexpression of miR-622 induced the radioresistance in vitro. In addition, miR-622 inhibited Rb expression by directly targeting RB1-3′UTR. Overexpression of Rb reversed miR-622-induced radioresistance in vitro. In response to ionizing radiation, the Rb-E2F1-P/CAF complex activated proapoptotic genes. Importantly, miR-622 was highly expressed in tumors of rectal cancer patients with non-regression after standard dose radiotherapy. In conclusion, miR-622 overexpressing cells are induced or selected by radiotherapy, causing in turn radioresistance and poor response to further therapy. MiR-622 is a potential biomarker of responders for radiotherapy and a potential therapeutic target. PMID:25961730

  9. Conditional Radioresistance of tet-Inducible Manganese Superoxide Dismutase Bone Marrow Stromal Cell Lines

    PubMed Central

    Epperly, Michael W.; Chaillet, J. Richard; Kalash, Ronny; Shaffer, Ben; Goff, Julie; Franicola, Darcy; Zhang, Xichen; Dixon, Tracy; Houghton, Frank; Wang, Hong; Berhane, Hebist; Romero, Cynthia; Kim, Jee-Hong; Greenberger, Joel S.

    2013-01-01

    Mitochondrial targeted manganese superoxide dismutase is a major antioxidant enzyme, the levels of which modulate the response of cells, tissues and organs to ionizing irradiation. We developed a Tet-regulated MnSOD mouse (MnSODtet) to examine the detailed relationship between cellular MnSOD concentration and radioresistance and carried out in vitro studies using bone marrow culture derived stromal cell lines (mesenchymal stem cells). Homozygous MnSODtet/tet cells had low levels of MnSOD, reduced viability and proliferation, increased radiosensitivity, elevated overall antioxidant stores, and defects in cell proliferation and DNA strand-break repair. Doxycycline (doxy) treatment of MnSODtet/tet cells increased MnSOD levels and radioresistance from ñ of 2.79 ± 1.04 to 8.69 ± 1.09 (P = 0.0060) and normalized other biologic parameters. In contrast, MnSODtet/tet cells showed minimal difference in baseline and radiation induced mRNA and protein levels of TGF-β, Nrf2 and NF-κB and radiation induced cell cycle arrest was not dependent upon MnSOD level. These novel MnSODtet/tet mouse derived cells should be valuable for elucidating several parameters of the oxidative stress response to ionizing radiation. PMID:23862693

  10. Conditional radioresistance of Tet-inducible manganese superoxide dismutase bone marrow stromal cell lines.

    PubMed

    Epperly, Michael W; Chaillet, J Richard; Kalash, Ronny; Shaffer, Ben; Goff, Julie; Franicola, Darcy; Zhang, Xichen; Dixon, Tracy; Houghton, Frank; Wang, Hong; Berhane, Hebist; Romero, Cynthia; Kim, Jee-Hong; Greenberger, Joel S

    2013-08-01

    Mitochondrial targeted manganese superoxide dismutase is a major antioxidant enzyme, the levels of which modulate the response of cells, tissues and organs to ionizing irradiation. We developed a Tet-regulated MnSOD mouse (MnSOD(tet)) to examine the detailed relationship between cellular MnSOD concentration and radioresistance and carried out in vitro studies using bone marrow culture derived stromal cell lines (mesenchymal stem cells). Homozygous MnSOD(tet/tet) cells had low levels of MnSOD, reduced viability and proliferation, increased radiosensitivity, elevated overall antioxidant stores, and defects in cell proliferation and DNA strand-break repair. Doxycycline (doxy) treatment of MnSOD(tet/tet) cells increased MnSOD levels and radioresistance from ñ of 2.79 ± 1.04 to 8.69 ± 1.09 (P = 0.0060) and normalized other biologic parameters. In contrast, MnSOD(tet/tet) cells showed minimal difference in baseline and radiation induced mRNA and protein levels of TGF-β, Nrf2 and NF-κB and radiation induced cell cycle arrest was not dependent upon MnSOD level. These novel MnSOD(tet/tet) mouse derived cells should be valuable for elucidating several parameters of the oxidative stress response to ionizing radiation. PMID:23862693

  11. Chinese hamster pleiotropic multidrug-resistant cells are not radioresistant

    SciTech Connect

    Mitchell, J.B.; Gamson, J.; Russo, A.; Friedman, N.; DeGraff, W.; Carmichael, J.; Glatstein, E.

    1988-01-01

    The inherent cellular radiosensitivity of a Chinese hamster ovary pleiotropic cell line that is multidrug resistant (CHRC5) was compared to that of its parental cell line (AuxB1). Radiation survival curve parameters n and D0 were 4.5 and 1.1 Gy, respectively, for the CHRC5 line and 5.0 and 1.2 Gy, respectively, for the parental line. Thus, the inherent radiosensitivity of the two lines was similar even though key intracellular free radical scavenging and detoxifying systems employing glutathione, glutathione transferase, and catalase produced enzyme levels that were 2.0-, 1.9-, and 1.9-fold higher, respectively, in the drug-resistant cell line. Glutathione depletion by buthionine sulfoximine resulted in the same extent of aerobic radiosensitization in both lines (approximately 10%). Incorporation of iododeoxyuridine into cellular DNA sensitized both cell lines to radiation. These studies indicate that pleiotropic drug resistance does not necessarily confer radiation resistance.

  12. A role for chromosomal instability in the development of and selection for radioresistant cell variants

    NASA Technical Reports Server (NTRS)

    Limoli, C. L.; Corcoran, J. J.; Jordan, R.; Morgan, W. F.; Schwartz, J. L.

    2001-01-01

    Chromosome instability is a common occurrence in tumour cells. We examined the hypothesis that the elevated rate of mutation formation in unstable cells can lead to the development of clones of cells that are resistant to the cancer therapy. To test this hypothesis, we compared chromosome instability to radiation sensitivity in 30 independently isolated clones of GM10115 human-hamster hybrid cells. There was a broader distribution of radiosensitivity and a higher mean SF(2)in chromosomally unstable clones. Cytogenetic and DNA double-strand break rejoining assays suggest that sensitivity was a function of DNA repair efficiency. In the unstable population, the more radioresistant clones also had significantly lower plating efficiencies. These observations suggest that chromosome instability in GM10115 cells can lead to the development of cell variants that are more resistant to radiation. In addition, these results suggest that the process of chromosome breakage and recombination that accompanies chromosome instability might provide some selective pressure for more radioresistant variants. Copyright 2001 Cancer Research Campaign.

  13. Radiation-induced Akt activation modulates radioresistance in human glioblastoma cells

    PubMed Central

    Li, Hui-Fang; Kim, Jung-Sik; Waldman, Todd

    2009-01-01

    Background Ionizing radiation (IR) therapy is a primary treatment for glioblastoma multiforme (GBM), a common and devastating brain tumor in humans. IR has been shown to induce PI3K-Akt activation in many cell types, and activation of the PI3K-Akt signaling pathway has been correlated with radioresistance. Methods Initially, the effects of IR on Akt activation were assessed in multiple human GBM cell lines. Next, to evaluate a potential causative role of IR-induced Akt activation on radiosensitivity, Akt activation was inhibited during IR with several complementary genetic and pharmacological approaches, and radiosensitivity measured using clonogenic survival assays. Results Three of the eight cell lines tested demonstrated IR-induced Akt activation. Further studies revealed that IR-induced Akt activation was dependent upon the presence of a serum factor, and could be inhibited by the EGFR inhibitor AG1478. Inhibition of PI3K activation with LY294002, or with inducible wild-type PTEN, inhibition of EGFR, as well as direct inhibition of Akt with two Akt inhibitors during irradiation increased the radiosensitivity of U87MG cells. Conclusion These results suggest that Akt may be a central player in a feedback loop whereby activation of Akt induced by IR increases radioresistance of GBM cells. Targeting the Akt signaling pathway may have important therapeutic implications when used in combination with IR in the treatment of a subset of brain tumor patients. PMID:19828040

  14. ERK/p38 MAPK inhibition reduces radio-resistance to a pulsed proton beam in breast cancer stem cells

    NASA Astrophysics Data System (ADS)

    Jung, Myung-Hwan; Park, Jeong Chan

    2015-10-01

    Recent studies have identified highly tumorigenic cells with stem cell-like characteristics, termed cancer stem cells (CSCs) in human cancers. CSCs are resistant to conventional radiotherapy and chemotherapy owing to their high DNA repair ability and oncogene overexpression. However, the mechanisms regulating CSC radio-resistance, particularly proton beam resistance, remain unclear. We isolated CSCs from the breast cancer cell lines MCF-7 and MDA-MB-231, which expressed the characteristic breast CSC membrane protein markers CD44+/CD24-/ low , and irradiated the CSCs with pulsed proton beams. We confirmed that CSCs were resistant to pulsed proton beams and showed that treatment with p38 and ERK inhibitors reduced CSC radio-resistance. Based on these results, BCSC radio-resistance can be reduced during proton beam therapy by co-treatment with ERK1/2 or p38 inhibitors, a novel approach to breast cancer therapy.

  15. Radioresistance of granulation tissue-derived cells from skin wounds combined with total body irradiation.

    PubMed

    Dai, Tingyu; Chen, Zelin; Tan, Li; Shi, Chunmeng

    2016-04-01

    Combined radiation and wound injury (CRWI) occurs following nuclear explosions and accidents, radiological or nuclear terrorism, and radiation therapy combined with surgery. CRWI is complicated and more difficult to heal than single injuries. Stem cell‑based therapy is a promising treatment strategy for CRWI, however, sourcing stem cells remains a challenge. In the present study, the granulation tissue-derived cells (GTCs) from the skin wounds (SWs) of CRWI mice (C‑GTCs) demonstrated a higher radioresistance to the damage caused by combined injury, and were easier to isolate and harvest when compared with bone marrow‑derived mesenchymal stromal cells (BMSCs). Furthermore, the C-GTCs exhibited similar stem cell-associated properties, such as self-renewal and multilineage differentiation capacity, when compared with neonatal dermal stromal cells (DSCs) and GTCs from unirradiated SWs. Granulation tissue, which is easy to access, may present as an optimal autologous source of stem/progenitor cells for therapeutic applications in CRWI. PMID:26936439

  16. Ionizing radiations sustain glioblastoma cell dedifferentiation to a stem-like phenotype through survivin: possible involvement in radioresistance

    PubMed Central

    Dahan, P; Martinez Gala, J; Delmas, C; Monferran, S; Malric, L; Zentkowski, D; Lubrano, V; Toulas, C; Cohen-Jonathan Moyal, E; Lemarie, A

    2014-01-01

    Glioblastomas (GBM) are some bad prognosis brain tumors despite a conventional treatment associating surgical resection and subsequent radio-chemotherapy. Among these heterogeneous tumors, a subpopulation of chemo- and radioresistant GBM stem-like cells appears to be involved in the systematic GBM recurrence. Moreover, recent studies showed that differentiated tumor cells may have the ability to dedifferentiate and acquire a stem-like phenotype, a phenomenon also called plasticity, in response to microenvironment stresses such as hypoxia. We hypothesized that GBM cells could be subjected to a similar dedifferentiation process after ionizing radiations (IRs), then supporting the GBM rapid recurrence after radiotherapy. In the present study we demonstrated that subtoxic IR exposure of differentiated GBM cells isolated from patient resections potentiated the long-term reacquisition of stem-associated properties such as the ability to generate primary and secondary neurospheres, the expression of stemness markers and an increased tumorigenicity. We also identified during this process an upregulation of the anti-apoptotic protein survivin and we showed that its specific downregulation led to the blockade of the IR-induced plasticity. Altogether, these results demonstrated that irradiation could regulate GBM cell dedifferentiation via a survivin-dependent pathway. Targeting the mechanisms associated with IR-induced plasticity will likely contribute to the development of some innovating pharmacological strategies for an improved radiosensitization of these aggressive brain cancers. PMID:25429620

  17. Involvement of cdc25c in cell cycle alteration of a radioresistant lung cancer cell line established with fractionated ionizing radiation.

    PubMed

    Li, Jie; Yang, Chun-Xu; Mei, Zi-Jie; Chen, Jing; Zhang, Shi-Min; Sun, Shao-Xing; Zhou, Fu-Xiang; Zhou, Yun-Feng; Xie, Cong-Hua

    2013-01-01

    Cancer patients often suffer from local tumor recurrence after radiation therapy. Cell cycling, an intricate sequence of events which guarantees high genomic fidelity, has been suggested to affect DNA damage responses and eventual radioresistant characteristics of cancer cells. Here, we established a radioresistant lung cancer cell line, A549R , by exposing the parental A549 cells to repeated γ-ray irradiation with a total dose of 60 Gy. The radiosensitivity of A549 and A549R was confirmed using colony formation assays. We then focused on examination of the cell cycle distribution between A549 and A549R and found that the proportion of cells in the radioresistant S phase increased, whereas that in the radiosensitive G1 phase decreased. When A549 and A549R cells were exposed to 4 Gy irradiation the total differences in cell cycle redistribution suggested that G2-M cell cycle arrest plays a predominant role in mediating radioresistance. In order to further explore the possible mechanisms behind the cell cycle related radioresistance, we examined the expression of Cdc25 proteins which orchestrate cell cycle transitions. The results showed that expression of Cdc25c increased accompanied by the decrease of Cdc25a and we proposed that the quantity of Cdc25c, rather than activated Cdc25c or Cdc25a, determines the radioresistance of cells. PMID:24289569

  18. 2-Methoxyestradiol, an Endogenous Estrogen Metabolite, Sensitizes Radioresistant MCF-7/FIR Breast Cancer Cells Through Multiple Mechanisms

    SciTech Connect

    Salama, Salama; Diaz-Arrastia, Concepcion; Patel, Deepa; Botting, Shaleen; Hatch, Sandra

    2011-05-01

    Purpose: The requirement for a well-tolerated and highly effective radiosensitizer that preferentially sensitizes tumor cells at multiple levels of radioresistance remains largely unmet. 2-Methoxyestradiol (2ME) has polypharmacological profiles that target multiple signaling pathways involved in the development of radioresistance. In the current study, we investigated the radiosensitizing effect of 2ME on the radioresistant breast cancer MCF-7/FIR cell line and explored the underlying mechanisms. Methods and Materials: The radiosensitizing effect of 2ME was evaluated on the basis of cell death and clonogenic survival. Formation of reactive oxygen species (ROS), apoptosis, and cell cycle progression were assessed by flow cytometry. Radiation-induced DNA damage was evaluated on the basis of histone {gamma}-H2AX phosphorylation and foci formation. Immunoblotting was used to assess the effects of {gamma} radiation and/or 2ME on radioresistance pathways. Results: Our data demonstrate that MCF-7/FIR cells expressed higher levels of Bcl-2 and HIF-1{alpha} and displayed a lower ROS phenotype than the parental MCF-7 cells. Treatment of parental MCF-7 cells with 2ME (0.5 {mu}M) had minimal effect on {gamma} radiation-induced cell proliferation and surviving fractions. On the contrary, in MCF-7/FIR cells, treatment with 2ME significantly enhanced {gamma} radiation-induced reduction in cell proliferation and surviving fraction. This combination was effective in activating apoptosis, arresting the cell cycle at the G{sub 2}/M phase, and increasing the level of {gamma} radiation-induced ROS and the number of {gamma}-H2AX foci. In addition, 2ME significantly ameliorated {gamma} radiation-induced expression of the HIF-1{alpha} transcription factor and its downstream targets AKT/mTOR. Conclusion: 2ME preferentially sensitizes radioresistant MCF-7/FIR cells to {gamma} radiation by targeting multiple signaling pathways involved in the development of radioresistance. This

  19. Investigating the Radioresistant Properties of Lung Cancer Stem Cells in the Context of the Tumor Microenvironment.

    PubMed

    Chan, Ryan; Sethi, Pallavi; Jyoti, Amar; McGarry, Ronald; Upreti, Meenakshi

    2016-02-01

    Lung cancer is the most common cause of cancer-related deaths worldwide and non-small cell lung cancer (NSCLC) accounts for ~85% of all lung cancer. While recent research has shown that cancer stem cells (CSC) exhibit radioresistant and chemoresistant properties, current cancer therapy targets the bulk of the tumor burden without accounting for the CSC and the contribution of the tumor microenvironment. CSC interaction with the stroma enhances NSCLC survival, thus limiting the efficacy of treatment. The aim of this study was to elucidate the role of CSC and the microenvironment in conferring radio- or chemoresistance in an in vitro tumor model for NSCLC. The novel in vitro three-dimensional (3D) NSCLC model of color-coded tumor tissue analogs (TTA) that we have developed is comprised of human lung adenocarcinoma cells, fibroblasts, endothelial cells and NSCLC cancer stem cells maintained in low oxygen conditions (5% O2) to recapitulate the physiologic conditions in tumors. Using this model, we demonstrate that a single 5 Gy radiation dose does not inhibit growth of TTA containing CSC and results in elevated expression of cytokines (TGF-α, RANTES, ENA-78) and factors (vimentin, MMP and TIMP), indicative of an invasive and aggressive phenotype. However, combined treatment of single dose or fractionated doses with cisplatin was found to either attenuate or decrease the proliferative effect that radiation exposure alone had on TTA containing CSC maintained in hypoxic conditions. In summary, we utilized a 3D NSCLC model, which had characteristics of the tumor microenvironment and tumor cell heterogeneity, to elucidate the multifactorial nature of radioresistance in tumors. PMID:26836231

  20. Radioresistance of cancer stem-like cell derived from canine tumours.

    PubMed

    Tanabe, A; Deguchi, T; Sato, T; Nemoto, Y; Maruo, T; Madarame, H; Shida, T; Naya, Y; Ogihara, K; Sahara, H

    2016-09-01

    Cancer stem-like cells (CSCs)/cancer-initiating cells (CICs) are a small subpopulation of cancer cells that are responsible for the initiation, recurrence and metastasis of cancer. We previously demonstrated that, using the Hoechst 33342 dye-based side population technique, CSCs/CICs in canine lung adenocarcinoma cell line exist. In this study, as CSCs/CICs are known to form spheres in anchorage-independent environment in vitro, we evaluated the stemness of spheroid cells derived from canine lung adenocarcinoma and osteosarcoma cells by expression of stemness markers, and investigated radioresistance. Spheroid cells showed greater expression of stemness markers Oct-4 and CD133 gene than those of adherent-cultured cells. In nude mouse xenograft models, spheroid cells showed higher tumourigenic ability than adherent-cultured cells. In addition, spheroid cells showed significantly resistant against radioactivity as compared with adherent-cultured cells. These results suggest that spheroid cells could possess stemness and provide a CSCs/CICs research tool to investigate CSCs/CICs of canine tumour cells. PMID:25070729

  1. Radioresistance of Brain Tumors

    PubMed Central

    Kelley, Kevin; Knisely, Jonathan; Symons, Marc; Ruggieri, Rosamaria

    2016-01-01

    Radiation therapy (RT) is frequently used as part of the standard of care treatment of the majority of brain tumors. The efficacy of RT is limited by radioresistance and by normal tissue radiation tolerance. This is highlighted in pediatric brain tumors where the use of radiation is limited by the excessive toxicity to the developing brain. For these reasons, radiosensitization of tumor cells would be beneficial. In this review, we focus on radioresistance mechanisms intrinsic to tumor cells. We also evaluate existing approaches to induce radiosensitization and explore future avenues of investigation. PMID:27043632

  2. Telomere-Binding Protein TPP1 Modulates Telomere Homeostasis and Confers Radioresistance to Human Colorectal Cancer Cells

    PubMed Central

    Hu, Liu; Yang, Xiaoxi; Zhong, Juan; Li, Zheng; Yang, Hui; Lei, Han; Yu, Haijun; Liao, ZhengKai; Zhou, Fuxiang; Xie, Conghua; Zhou, Yunfeng

    2013-01-01

    Background Radiotherapy is one of the major therapeutic strategies in cancer treatment. The telomere-binding protein TPP1 is an important component of the shelterin complex at mammalian telomeres. Our previous reports showed that TPP1 expression was elevated in radioresistant cells, but the exact effects and mechanisms of TPP1 on radiosensitivity is unclear. Principal Findings In this study, we found that elevated TPP1 expression significantly correlated with radioresistance and longer telomere length in human colorectal cancer cell lines. Moreover, TPP1 overexpression showed lengthened telomere length and a significant decrease of radiosensitivity to X-rays. TPP1 mediated radioresistance was correlated with a decreased apoptosis rate after IR exposure. Furthermore, TPP1 overexpression showed prolonged G2/M arrest mediated by ATM/ATR-Chk1 signal pathway after IR exposure. Moreover, TPP1 overexpression accelerated the repair kinetics of total DNA damage and telomere dysfunction induced by ionizing radiation. Conclusions We demonstrated that elevated expressions of TPP1 in human colorectal cancer cells could protect telomere from DNA damage and confer radioresistance. These results suggested that TPP1 may be a potential target in the radiotherapy of colorectal cancer. PMID:24260532

  3. A calcium-insensitive attenuated nitrosative stress response contributes significantly in the radioresistance of Sf9 insect cells.

    PubMed

    Suman, Shubhankar; Seth, Rakesh Kumar; Chandna, Sudhir

    2011-09-01

    Lepidopteran insects/insect cells display 50-100 times higher radioresistance than humans, and are evolutionarily closest to mammals amongst all radioresistant organisms known. Compared to mammalian cells, Lepidopteran cells (TN-368, Sf9) display more efficient antioxidant system and DNA repair and suffer considerably less radiation-induced DNA/cytogenetic damage and apoptosis. Recent studies indicate that a considerably lower radiation-induced oxidative stress may significantly reduce macromolecular damage in Lepidopteran cells. Since nitrosative stress contributes in radiation-induced cellular damage, we investigated its nature in the γ-irradiated Sf9 cells (derived from Spodoptera frugiperda; order Lepidoptera; family Noctuidae) and compared with BMG-1 human cell line having significant NOS expression. Radiation induced considerably less ROS/RNS in Sf9 cells, which remained unchanged on treatment with NOS inhibitor l-NMMA. Surprisingly, growth of Sf9 cultures or irradiation could not induce NO or its metabolites, indicating negligible basal/radiation-induced NOS activity that remained unchanged even after supplementation with arginine. Cytosolic calcium release following high-dose (1000-2000Gy at 61.1cGys(-1)) γ-irradiation or H(2)O(2) (250μM) treatment also failed to generate NO in Sf9 cells having high constitutive levels of calmodulin, whereas BMG-1 cells displayed considerable calcium-dependent NO generation even following 10Gy dose. These results strongly imply the lack of calcium-mediated NOS activity in Sf9 cells. Addition of exogenous NO from GSH-NO caused considerable increase in radiation-induced apoptosis, indicating significant contribution of constitutively attenuated nitrosative stress response into the radioresistance of Lepidopteran cells. Our study demonstrates for the first time that a calcium-insensitive, attenuated nitrosative stress response may contribute significantly in the unusual radioresistance displayed by Lepidopteran insect cells

  4. mRNA and microRNA expression profiles of radioresistant NCI-H520 non-small cell lung cancer cells

    PubMed Central

    GUO, WEI; XIE, LI; ZHAO, LONG; ZHAO, YUEHUAN

    2015-01-01

    To elucidate the mechanism of radioresistance in non-small cell lung cancer (NSCLC) cells and to identify key molecules conferring radioresistance, the radioresistant subclone NCI-H520/R, derived from the NCI-H520 NSCLC cell line, was established with eight rounds of sublethal irradiation. The radioresistant features were subsequently assessed using a clonogenic assay, analysis of apoptosis and an MTT assay, the gene expression levels were examined using an Agilent Whole Human Genome 4×44 k Oligo microarray and Agilent Human miRCURY™ LNA array, and confirmed by reverse transcription-quantitative polymerase chain reaction. Pathway analysis and Gene Ontology (GO) analysis were performed to determine the biological functions of the subset of differentially expressed genes. miRNA-mRNA correlation analysis between the expression levels of each miRNA and all its predicted target genes was performed to further understand the radioresistance in the NCI-H520 cells. Following eight rounds of sublethal irradiation, a total of 2,862 mRNAs were significantly differentially expressed in the NCI-H520/R cells, including 893 upregulated genes and 1,969 downregulated genes. A total of 162 upregulated miRNAs and 274 downregulated miRNAs were significantly deregulated in the NCI-H520/R cells. Multiple core regulatory processes and signaling pathways were identified as being of likely relevance to radioresistance in NCI-H520/R cells, including the mitogen-activated protein kinase signaling pathway and neurotrophin signaling pathway. The expression of genes associated with radioresistance reflects the complex biological processes involved in clinical cancer cell eradication and requires further investigation for future enhancement of therapy. PMID:25873351

  5. mRNA and microRNA expression profiles of radioresistant NCI-H520 non-small cell lung cancer cells.

    PubMed

    Guo, Wei; Xie, Li; Zhao, Long; Zhao, Yuehuan

    2015-08-01

    To elucidate the mechanism of radioresistance in non-small cell lung cancer (NSCLC) cells and to identify key molecules conferring radioresistance, the radioresistant subclone NCI-H520/R, derived from the NCI-H520 NSCLC cell line, was established with eight rounds of sublethal irradiation. The radioresistant features were subsequently assessed using a clonogenic assay, analysis of apoptosis and an MTT assay, the gene expression levels were examined using an Agilent Whole Human Genome 4 x 44 k Oligo microarray and Agilent Human miRCURY(™) LNA array, and confirmed by reverse transcription-quantitative polymerase chain reaction. Pathway analysis and Gene Ontology (GO) analysis were performed to determine the biological functions of the subset of differentially expressed genes. miRNA-mRNA correlation analysis between the expression levels of each miRNA and all its predicted target genes was performed to further understand the radioresistance in the NCI-H520 cells. Following eight rounds of sublethal irradiation, a total of 2,862 mRNAs were significantly differentially expressed in the NCI-H520/R cells, including 893 upregulated genes and 1,969 downregulated genes. A total of 162 upregulated miRNAs and 274 downregulated miRNAs were significantly deregulated in the NCI-H520/R cells. Multiple core regulatory processes and signaling pathways were identified as being of likely relevance to radioresistance in NCI-H520/R cells, including the mitogen-activated protein kinase signaling pathway and neurotrophin signaling pathway. The expression of genes associated with radioresistance reflects the complex biological processes involved in clinical cancer cell eradication and requires further investigation for future enhancement of therapy. PMID:25873351

  6. Bcl-2 inhibitors potentiate the cytotoxic effects of radiation in Bcl-2 overexpressing radioresistant tumor cells

    SciTech Connect

    Hara, Takamitsu; Omura-Minamisawa, Motoko . E-mail: momuram@med.yokohama-cu.ac.jp; Chao Cheng; Nakagami, Yoshihiro; Ito, Megumi; Inoue, Tomio

    2005-02-01

    Purpose: Bcl-2, an inhibitor of apoptosis frequently shows elevated expression in human tumors, thus resulting in resistance to radiation therapy. Therefore, inhibiting Bcl-2 function may enhance the radiosensitivity of tumor cells. Tetrocarcin A (TC-A) and bcl-2 antisense oligonucleotides exhibit antitumor activity by inhibiting Bcl-2 function and transcription, respectively. We investigated whether these antitumor agents would enhance the cytotoxic effects of radiation in tumor cells overexpressing Bcl-2. Methods and materials: We used HeLa/bcl-2 cells, a stable Bcl-2-expressing cell line derived from wild-type HeLa (HeLa/wt) cells. Cells were incubated with TC-A and bcl-2 antisense oligonucleotides for 24 h after irradiation, and cell viability was then determined. Apoptotic cells were quantified by flow cytometric assay. Results: The HeLa/bcl-2 cells were more resistant to radiation than HeLa/wt cells. At concentrations that are not inherently cytotoxic, both TC-A and bcl-2 antisense oligonucleotides increased the cytotoxic effects of radiation in HeLa/bcl-2 cells, but not in HeLa/wt cells. However, in HeLa/bcl-2 cells, additional treatment with TC-A in combination with radiation did not significantly increase apoptosis. Conclusions: The present results suggest that TC-A and bcl-2 antisense oligonucleotides reduce radioresistance of tumor cells overexpressing Bcl-2. Therefore, a combination of radiotherapy and Bcl-2 inhibitors may prove to be a useful therapeutic approach for treating tumors that overexpress Bcl-2.

  7. Reversal effect of GnT-V on the radioresistance of human nasopharyngeal carcinoma cells by alteration β1, 6-GlcNAc branched N-glycans

    PubMed Central

    Wu, Jun-Bo; Shen, Li; Qiu, Li; Duan, Qi-Wen; Luo, Zhi-Guo; Dong, Xiao-Xia

    2015-01-01

    Radiotherapy is the primary treatment for human nasopharyngeal carcinoma (NPC), yet radioresistance remains a major obstacle to successful treatment in many cases. N-acetylglucosaminyltransferase V (GnT-V), which synthesizes β1, 6-GlcNAc branched N-glycans, is closely related to the radiosensitivity of NPC cells. However, a better understanding of the functional role of GnT-V in NPC radioresistance and the related mechanisms is urgently needed. In the present study, a radioresistant NPC cell line, CNE-2R, was established by repeated γ-irradiation. We found that GnT-V levels, as well as β1, 6-GlcNAc branched N-glycans were significantly increased in the CNE-2R cells as compared with that in the parental cells. Meanwhile, knockdown of GnT-V in the CNE-2R cells enhanced cell radiosensitivity and inhibited the formation of β1, 6-branched N-glycans. In addition, the regulated expression of GnT-V in the CNE-2R cells converted the heterogeneous N-glycosylated forms of CD147. Furthermore, swainsonine, an inhibitor of N-glycan biosynthesis, was also able to reverse the radioresistance of the CNE-2R cells. Taken together, the present study revealed a novel mechanism of GnT-V as a regulator of radioresistance in NPC cells, which may be useful for fully understanding the biological role of N-glycans in NPC radioresistance. PMID:26617699

  8. Alterations in transcription factor binding in radioresistant human melanoma cells after ionizing radiation

    SciTech Connect

    Sahijdak, W.M.; Yang, Chin-Rang; Zuckerman, J.S.; Meyers, M.; Boothman, D.A.

    1994-04-01

    We analyzed alterations in transcription factor binding to specific, known promoter DNA consensus sequences between irradiated and unirradiated radioresistant human melanoma (U1-Mel) cells. The goal of this study was to begin to investigate which transcription factors and DNA-binding sites are responsible for the induction of specific transcripts and proteins after ionizing radiation. Transcription factor binding was observed using DNA band-shift assays and oligonucleotide competition analyses. Confluence-arrested U1-Mel cells were irradiated (4.5 Gy) and harvested at 4 h. Double-stranded oligonucleotides containing known DNA-binding consensus sites for specific transcription factors were used. Increased DNA binding activity after ionizing radiation was noted with oligonucleotides containing the CREB, NF-kB and Sp1 consensus sites. No changes in protein binding to AP-1, AP-2, AP-3, or CTF/NF1, GRE or Oct-1 consensus sequences were noted. X-ray activation of select transcription factors, which bind certain consensus sites in promoters, may cause specific induction or repression of gene transcription. 22 refs., 2 figs.

  9. The radioresistance to killing of A1-5 cells derives from activation of the Chk1 pathway

    NASA Technical Reports Server (NTRS)

    Hu, B.; Zhou, X. Y.; Wang, X.; Zeng, Z. C.; Iliakis, G.; Wang, Y.

    2001-01-01

    Checkpoints respond to DNA damage by arresting the cell cycle to provide time for facilitating repair. In mammalian cells, the G(2) checkpoint prevents the Cdc25C phosphatase from removing inhibitory phosphate groups from the mitosis-promoting kinase Cdc2. Both Chk1 and Chk2, the checkpoint kinases, can phosphorylate Cdc25C and inactivate its in vitro phosphatase activity. Therefore, both Chk1 and Chk2 are thought to regulate the activation of the G(2) checkpoint. Here we report that A1-5, a transformed rat embryo fibroblast cell line, shows much more radioresistance associated with a much stronger G(2) arrest response when compared with its counterpart, B4, although A1-5 and B4 cells have a similar capacity for nonhomologous end-joining DNA repair. These phenotypes of A1-5 cells are accompanied by a higher Chk1 expression and a higher phosphorylation of Cdc2. On the other hand, Chk2 expression increases slightly following radiation; however, it has no difference between A1-5 and B4 cells. Caffeine or UCN-01 abolishes the extreme radioresistance with the strong G(2) arrest and at the same time reduces the phosphorylation of Cdc2 in A1-5 cells. In addition, Chk1 but not Chk2 antisense oligonucleotide sensitizes A1-5 cells to radiation-induced killing and reduces the G(2) arrest of the cells. Taken together these results suggest that the Chk1/Cdc25C/Cdc2 pathway is the major player for the radioresistance with G(2) arrest in A1-5 cells.

  10. Hypoxia-Responsive Mir-301a and Mir-301b Promote Radioresistance of Prostate Cancer Cells via Downregulating NDRG2

    PubMed Central

    Wang, Wei; Liu, Mingbo; Guan, Yawei; Wu, Qingwu

    2016-01-01

    Background MiR-301a and miR-301b are 2 oncomiRs involved in multiple types of cancer. In this study, we explored the expression change of miR-301a and miR-301b in prostate cancer cells in hypoxia and studied their regulation of autophagy and radiosensitivity of prostate cancer cells. Material/Methods QRT-PCR was performed to quantify the expression change of miR-301a and miR-301b in hypoxia. Their effects on autophagy were measured by Western blot analysis, and their effects on radiosensitivity were measured by clonogenic assay and flow cytometry. In addition, the regulation of miR-301a and miR-301b on NDRG2, a tumor-suppressor gene in prostate cancer, was also studied. The effect of miR-301a/b-NDRG2 axis on autophagy and radiosensitivity of prostate cancer cells was further investigated. Results MiR-301a and miR-301b are 2 hypoxia responsive miRNAs that are significantly upregulated in hypoxia in prostate cancer cells. Higher level of miR-301a and miR-301b expression results in elevated autophagy and increased radioresistance in LNCaP cells. MiR-301a and miR-301b simultaneously target NDRG2 and decrease its expression. Knockdown of NDRG2 leads to increased autophagy and radioresistance. Conclusions MiR-301a and miR-301b are 2 hypoxia-responsive miRNAs that decrease autophagy of prostate cancer cells in hypoxia by targeting NDRG2. Through downregulating NDRG2, miR-301a and miR-301b can promote radioresistance of prostate cancer cells. PMID:27327120

  11. Differences in DNA Repair Capacity, Cell Death and Transcriptional Response after Irradiation between a Radiosensitive and a Radioresistant Cell Line.

    PubMed

    Borràs-Fresneda, Mireia; Barquinero, Joan-Francesc; Gomolka, Maria; Hornhardt, Sabine; Rössler, Ute; Armengol, Gemma; Barrios, Leonardo

    2016-01-01

    Normal tissue toxicity after radiotherapy shows variability between patients, indicating inter-individual differences in radiosensitivity. Genetic variation probably contributes to these differences. The aim of the present study was to determine if two cell lines, one radiosensitive (RS) and another radioresistant (RR), showed differences in DNA repair capacity, cell viability, cell cycle progression and, in turn, if this response could be characterised by a differential gene expression profile at different post-irradiation times. After irradiation, the RS cell line showed a slower rate of γ-H2AX foci disappearance, a higher frequency of incomplete chromosomal aberrations, a reduced cell viability and a longer disturbance of the cell cycle when compared to the RR cell line. Moreover, a greater and prolonged transcriptional response after irradiation was induced in the RS cell line. Functional analysis showed that 24 h after irradiation genes involved in "DNA damage response", "direct p53 effectors" and apoptosis were still differentially up-regulated in the RS cell line but not in the RR cell line. The two cell lines showed different response to IR and can be distinguished with cell-based assays and differential gene expression analysis. The results emphasise the importance to identify biomarkers of radiosensitivity for tailoring individualized radiotherapy protocols. PMID:27245205

  12. Differences in DNA Repair Capacity, Cell Death and Transcriptional Response after Irradiation between a Radiosensitive and a Radioresistant Cell Line

    PubMed Central

    Borràs-Fresneda, Mireia; Barquinero, Joan-Francesc; Gomolka, Maria; Hornhardt, Sabine; Rössler, Ute; Armengol, Gemma; Barrios, Leonardo

    2016-01-01

    Normal tissue toxicity after radiotherapy shows variability between patients, indicating inter-individual differences in radiosensitivity. Genetic variation probably contributes to these differences. The aim of the present study was to determine if two cell lines, one radiosensitive (RS) and another radioresistant (RR), showed differences in DNA repair capacity, cell viability, cell cycle progression and, in turn, if this response could be characterised by a differential gene expression profile at different post-irradiation times. After irradiation, the RS cell line showed a slower rate of γ-H2AX foci disappearance, a higher frequency of incomplete chromosomal aberrations, a reduced cell viability and a longer disturbance of the cell cycle when compared to the RR cell line. Moreover, a greater and prolonged transcriptional response after irradiation was induced in the RS cell line. Functional analysis showed that 24 h after irradiation genes involved in “DNA damage response”, “direct p53 effectors” and apoptosis were still differentially up-regulated in the RS cell line but not in the RR cell line. The two cell lines showed different response to IR and can be distinguished with cell-based assays and differential gene expression analysis. The results emphasise the importance to identify biomarkers of radiosensitivity for tailoring individualized radiotherapy protocols. PMID:27245205

  13. Intrathymic radioresistant stem cells follow an IL-2/IL-2R pathway during thymic regeneration after sublethal irradiation

    SciTech Connect

    Zuniga-Pfluecker, J.C.K.; Kruisbeek, A.M. )

    1990-05-15

    Sublethally irradiated mice undergo thymic regeneration which follows a phenotypic pattern of events similar to that observed during normal fetal development. Thymic regeneration after irradiation is the product of a limited pool of intrathymic radioresistant stem cells undergoing simultaneous differentiation. We show that in this model of T cell development, thymic regeneration follows a pathway in which the IL-2R is transiently expressed on CD4-/CD8- cells. IL-2R expression occurred during the exponential growth period of thymic regeneration, and IL-2R blocking prevented this explosive growth. Flow cytometry analysis revealed that the IL-2R blockade affected primarily the development of the immature CD3-/CD4-/CD8- (triple negative) cells and their ability to generate CD3+/CD4+/CD8+ or CD3+/CD4+/CD8- and CD3+/CD4-/CD8+ thymocytes. Thus, our findings demonstrate that blocking of the IL-2R resulted in an arrest in proliferation and differentiation by intrathymic radioresistant stem cells, indicating that the IL-2/IL-2R pathway is necessary for the expansion of immature triple negative T cells.

  14. Inflammation-induced radioresistance is mediated by ROS-dependent inactivation of protein phosphatase 1 in non-small cell lung cancer cells.

    PubMed

    Kim, Wanyeon; Youn, HyeSook; Kang, ChulHee; Youn, BuHyun

    2015-09-01

    Inflammation plays a pivotal role in modulating the radiation responsiveness of tumors. We determined that an inflammation response prior to irradiation contributes to radiotherapy resistance in non-small cell lung cancer (NSCLC) cells. In the clonogenic survival assay, activation of the inflammation response by lipopolysaccharide (LPS) decreased the degree of radiosensitivity in NCI-H460 cells (relatively radiosensitive cells), but had no effect in A549 cells (relatively radioresistant cells). LPS-induced radioresistance of NCI-H460 cells was also confirmed with a xenograft mouse model. The radioresistant effect observed in NCI-H460 cells was correlated with inhibition of apoptotic cell death due to reduced Caspase 3/7 activity. Moreover, we found that the levels of reactive oxygen species (ROS) were synergistically elevated in NCI-H460 cells by treatment with LPS and radiation. Increased ROS generation negatively affected the activity of protein phosphatase 1 (PP1). Decreased PP1 activity did not lead to Bad dephosphorylation, consequently resulting in the inhibition of irradiation-induced mitochondrial membrane potential loss and apoptosis. We confirmed that pre-treatment with a PP1 activator and LPS sensitized NCI-H460 cells to radiation. Taken together, our findings provided evidence that PP1 activity is critical for radiosensitization in NSCLC cells and PP1 activators can serve as promising radiosensitizers to improve therapeutic efficacy. PMID:26033480

  15. PI3K/Akt/mTOR pathway inhibitors enhance radiosensitivity in radioresistant prostate cancer cells through inducing apoptosis, reducing autophagy, suppressing NHEJ and HR repair pathways.

    PubMed

    Chang, L; Graham, P H; Hao, J; Ni, J; Bucci, J; Cozzi, P J; Kearsley, J H; Li, Y

    2014-01-01

    The PI3K/Akt/mTOR pathway has a central role in cancer metastasis and radiotherapy. To develop effective therapeutics to improve radiosensitivity, understanding the possible pathways of radioresistance involved and the effects of a combination of the PI3K/Akt/mTOR inhibitors with radiotherapy on prostate cancer (CaP) radioresistant cells is needed. We found that compared with parent CaP cells, CaP-radioresistant cells demonstrated G0/G1 and S phase arrest, activation of cell cycle check point, autophagy and DNA repair pathway proteins, and inactivation of apoptotic proteins. We also demonstrated that compared with combination of single PI3K or mTOR inhibitors (BKM120 or Rapamycin) and radiation, low-dose of dual PI3K/mTOR inhibitors (BEZ235 or PI103) combined with radiation greatly improved treatment efficacy by repressing colony formation, inducing more apoptosis, leading to the arrest of the G2/M phase, increased double-strand break levels and less inactivation of cell cycle check point, autophagy and non-homologous end joining (NHEJ)/homologous recombination (HR) repair pathway proteins in CaP-radioresistant cells. This study describes the possible pathways associated with CaP radioresistance and demonstrates the putative mechanisms of the radiosensitization effect in CaP-resistant cells in the combination treatment. The findings from this study suggest that the combination of dual PI3K/Akt/mTOR inhibitors (BEZ235 or PI103) with radiotherapy is a promising modality for the treatment of CaP to overcome radioresistance. PMID:25275598

  16. miRNA-148b regulates radioresistance in non-small lung cancer cells via regulation of MutL homologue 1.

    PubMed

    Zhai, Guangsheng; Li, Gaozhong; Xu, Bo; Jia, Tongfu; Sun, Yinping; Zheng, Jianbo; Li, Jianbin

    2016-07-01

    Radioresistance represents a major obstacle in cancer treatment, the underlying mechanism of which is complex and not well understood. miR-148b has been reported to be implicated regulating radioresistance in lymphoma cells. However, this function has not been investigated in lung cancer cells. Microarray analysis was performed in A549 cells 48 h after exposure to 8 Gy of γ-irradiation or sham irradiation to identify differentially expressed miRNAs. miR-148b mimic and inhibitor were transfected, followed by clonogenic survival assay to examine response to irradiation in A549 cells. Western Blot and luciferase assay were performed to investigate the direct target of miR-148b Xenograft mouse models were used to examine in vivo function of miR-148b Our data showed that expression of miR-148b was significantly down-regulated in both serum and cancerous tissues of radioresistant lung cancer patients compared with radiosensitive patients. Overexpression of miR-148b reversed radioresistance in A549 cells. MutL homologue 1 (MLH1) is the direct target of miR-148b which is required for the regulatory role of miR-148b in radioresistance. miR-148b mimic sensitized A549 xenografts to irradiation in vivo Our study demonstrated that miR-148b regulates radioresistance of lung cancer cells by modulating MLH1 expression level. miR-148b may represent a new therapeutic target for the intervention of lung cancer. PMID:26759383

  17. Neuropilin 1 expression correlates with the Radio-resistance of human non-small-cell lung cancer cells.

    PubMed

    Dong, Juan Cong; Gao, Hui; Zuo, Si Yao; Zhang, Hai Qin; Zhao, Gang; Sun, Shi Long; Han, Hai Ling; Jin, Lin Lin; Shao, Li Hong; Wei, Wei; Jin, Shun Zi

    2015-09-01

    The purpose of this study was to determine the correlation between over-expression of the neuropilin 1 (NRP1) gene and growth, survival, and radio-sensitivity of non-small cell lung carcinoma (NSCLC) cells. 3-[4,5-dimethylthylthiazol-2-yl]-2,5 diphenyltetrazolium broide (MTT) and colony assays were then performed to determine the effect of NRP1 inhibition on the in vitro growth of NSCLC cells. The Annexin V-Fluorescein Isothiocyanate (FITC) apoptosis detection assay was performed to analyse the effect of NRP1 enhancement on apoptosis of NSCLC cells. Transwell invasion and migration assays were employed to examine the metastatic ability of A549 cells post X-ray irradiation. In addition, Western blot assays were carried out to detect the protein level of VEGFR2, PI3K and NF-κB. Finally, to examine the effect of shNRP1 on proliferation and radio-sensitivity in vivo, a subcutaneous tumour formation assay in nude mice was performed. Microvessel density in tumour tissues was assessed by immunohistochemistry. The stable transfected cell line (shNRP1-A549) showed a significant reduction in colony-forming ability and proliferation not only in vitro, but also in vivo. Moreover, shRNA-mediated NRP1 inhibition also significantly enhanced the radio-sensitivity of NSCLC cells both in vitro and in vivo. The over-expression of NRP1 was correlated with growth, survival and radio-resistance of NSCLC cells via the VEGF-PI3K- NF-κB pathway, and NRP1 may be a molecular therapeutic target for gene therapy or radio-sensitization of NSCLC. PMID:26147006

  18. Concomitant TLR/RLH signaling of radioresistant and radiosensitive cells is essential for protection against vesicular stomatitis virus infection.

    PubMed

    Spanier, Julia; Lienenklaus, Stefan; Paijo, Jennifer; Kessler, Annett; Borst, Katharina; Heindorf, Sabrina; Baker, Darren P; Kröger, Andrea; Weiss, Siegfried; Detje, Claudia N; Staeheli, Peter; Kalinke, Ulrich

    2014-09-15

    Several studies indicated that TLR as well as retinoic acid-inducible gene I-like helicase (RLH) signaling contribute to vesicular stomatitis virus (VSV)-mediated triggering of type I IFN (IFN-I) responses. Nevertheless, TLR-deficient MyD88(-/-)Trif(-/-) mice and RLH-deficient caspase activation and recruitment domain adaptor inducing IFN-β (Cardif)(-/-) mice showed only marginally enhanced susceptibility to lethal VSV i.v. infection. Therefore, we addressed whether concomitant TLR and RLH signaling, or some other additional mechanism, played a role. To this end, we generated MyD88(-/-)Trif(-/-)Cardif(-/-) (MyTrCa(-/-)) mice that succumbed to low-dose i.v. VSV infection with similar kinetics as IFN-I receptor-deficient mice. Three independent approaches (i.e., analysis of IFN-α/β serum levels, experiments with IFN-β reporter mice, and investigation of local IFN-stimulated gene induction) revealed that MyTrCa(-/-) mice did not mount IFN-I responses following VSV infection. Of note, treatment with rIFN-α protected the animals, qualifying MyTrCa(-/-) mice as a model to study the contribution of different immune cell subsets to the production of antiviral IFN-I. Upon adoptive transfer of wild-type plasmacytoid dendritic cells and subsequent VSV infection, MyTrCa(-/-) mice displayed significantly reduced viral loads in peripheral organs and showed prolonged survival. On the contrary, adoptive transfer of wild-type myeloid dendritic cells did not have such effects. Analysis of bone marrow chimeric mice revealed that TLR and RLH signaling of radioresistant and radiosensitive cells was required for efficient protection. Thus, upon VSV infection, plasmacytoid dendritic cell-derived IFN-I primarily protects peripheral organs, whereas concomitant TLR and RLH signaling of radioresistant stroma cells as well as of radiosensitive immune cells is needed to effectively protect against lethal disease. PMID:25127863

  19. WE-E-BRE-10: Level of Breast Cancer Stem Cell Correlated with Tumor Radioresistence: An Indication for Individualized Breast Cancer Therapy Adapted to Cancer Stem Cell Fractions

    SciTech Connect

    Qi, S; Pajonk, F; McCloskey, S; Low, D; Kupelian, P; Steinberg, M; Sheng, K

    2014-06-15

    Purposes: The presence of cancer stem cells (CSCs) in a solid tumor could result in poor tumor control probability. The purposes are to study CSC radiosensitivity parameters α and β and their correlation to CSC levels to understand the underlying radioresistance mechanisms and enable individualized treatment design. Methods: Four established breast cancer cell lines (MCF-7, T47D, MDA-MB-231, and SUM159PT) were irradiated in vitro using single radiation doses of 0, 2, 4, 6, 8 or 10 Gy. The fractions of CSCs in each cell lines were determined using cancer stem cell markers. Mammosphere assays were also performed to better estimate the number of CSCs and represent the CSC repopulation in a human solid tumor. The measured cell surviving fractions were fitted using the Linear-quadratic (LQ) model with independent fitting parameters: α-TC, β-TC (TCs), α-CSC, β-CSC (CSCs), and fs (the percentage of CSCs in each sample). Results: The measured fs increased following the irradiation by MCF-7 (0.1%), T47D (0.9%), MDA-MB-231 (1.18%) and SUM159T (2.46%), while decreasing surviving curve slopes were observed, indicating greater radioresistance, in the opposite order. The fitting yielded the radiosensitive parameters for the MCF-7: α-TC=0.1±0.2Gy{sup −1}, β-TC= 0.08 ±0.14Gy{sup −2}, α-CSC=0.04±0.07Gy{sup −1}, β-CSC =0.02±0.3Gy{sup −2}; for the SUM159PT, α-TC=0.08±0.25 Gy{sup −1}, β-TC=0.02±0.02Gy{sup −2}, α-CSC=0.04±0.18Gy{sup −1}, β-CSC =0.004±0.24Gy{sup −2}. In the mammosphere assay, where fs were higher than the corresponding cell line assays, there was almost no shoulder found in the surviving curves (more radioresistant in mammosphere assays) yielding β-CSC of approximately 0. Conclusion: Breast cancer stem cells were more radioresistant characterized by smaller α and β values compared to differentiated breast cancer cells. Percentage of breast cancer stem cells strongly correlated to overall tumor radioresistance. This observation

  20. MiR-20a Induces Cell Radioresistance by Activating the PTEN/PI3K/Akt Signaling Pathway in Hepatocellular Carcinoma

    SciTech Connect

    Zhang, Yuqin; Zheng, Lin; Ding, Yi; Li, Qi; Wang, Rong; Liu, Tongxin; Sun, Quanquan; Yang, Hua; Peng, Shunli; Wang, Wei; Chen, Longhua

    2015-08-01

    Purpose: To investigate the role of miR-20a in hepatocellular carcinoma (HCC) cell radioresistance, which may reveal potential strategies to improve treatment. Methods and Materials: The expression of miR-20a and PTEN were detected in HCC cell lines and paired primary tissues by quantitative real-time polymerase chain reaction. Cell radiation combined with colony formation assays was administrated to discover the effect of miR-20a on radiosensitivity. Bioinformatics prediction and luciferase assay were used to identify the target of miR-20a. The phosphatidylinositol 3-kinase inhibitor LY294002 was used to inhibit phosphorylation of Akt, to verify whether miR-20a affects HCC cell radioresistance through activating the PTEN/PI3K/Akt pathway. Results: MiR-20a levels were increased in HCC cell lines and tissues, whereas PTEN was inversely correlated with it. Overexpression of miR-20a in Bel-7402 and SMMC-7721 cells enhances their resistance to the effect of ionizing radiation, and the inhibition of miR-20a in HCCLM3 and QGY-7701 cells sensitizes them to it. PTEN was identified as a direct functional target of miR-20a for the induction of radioresistance. Overexpression of miR-20a activated the PTEN/PI3K/Akt signaling pathway. Additionally, the kinase inhibitor LY294002 could reverse the effect of miR-20a–induced radioresistance. Conclusion: MiR-20a induces HCC cell radioresistance by activating the PTEN/PI3K/Akt pathway, which suggests that miR-20a/PTEN/PI3K/Akt might represent a target of investigation for developing effective therapeutic strategies against HCC.

  1. DANGER is involved in high glucose-induced radioresistance through inhibiting DAPK-mediated anoikis in non-small cell lung cancer

    PubMed Central

    Kim, Daehoon; Seong, Ki Moon; Park, Sungkyun; Kim, Wanyeon; Youn, BuHyun

    2016-01-01

    18F-labeled fluorodeoxyglucose (FDG) uptake during FDG positron emission tomography seems to reflect increased radioresistance. However, the exact molecular mechanism underlying high glucose (HG)-induced radioresistance is unclear. In the current study, we showed that ionizing radiation-induced activation of the MEK-ERK-DAPK-p53 signaling axis is required for anoikis (anchorage-dependent apoptosis) of non-small cell lung cancer (NSCLC) cells in normal glucose media. Phosphorylation of DAPK at Ser734 by ERK was essential for p53 transcriptional activity and radiosensitization. In HG media, overexpressed DANGER directly bound to the death domain of DAPK, thus inhibiting the catalytic activity of DAPK. In addition, inhibition of the DAPK-p53 signaling axis by DANGER promoted anoikis-resistance and epithelial-mesenchymal transition (EMT), resulting in radioresistance of HG-treated NSCLC cells. Notably, knockdown of DANGER enhanced anoikis, EMT inhibition, and radiosensitization in a mouse xenograft model of lung cancer. Taken together, our findings offered evidence that overexpression of DANGER and the subsequent inhibitory effect on DAPK kinase activity are critical responses that account for HG-induced radioresistance of NSCLC. PMID:26769850

  2. Different Mechanisms of Cell Death in Radiosensitive and Radioresistant P53 Mutated Head and Neck Squamous Cell Carcinoma Cell Lines Exposed to Carbon Ions and X-Rays

    SciTech Connect

    Maalouf, Mira; Alphonse, Gersende; Colliaux, Anthony; Beuve, Michael Ph.D.; Trajkovic-Bodennec, Selena; Battiston-Montagne, Priscillia B.Sc.; Testard, Isabelle; Chapet, Olivier; Bajard, Marcel; Taucher-Scholz, Gisela; Fournier, Claudia; Rodriguez-Lafrasse, Claire

    2009-05-01

    Purpose: We initiated studies on the mechanisms of cell death in head and neck squamous cell carcinoma cell lines (HNSCC) since recent clinical trials have shown that local treatment of HNSCC by carbon hadrontherapy is less efficient than it is in other radioresistant cancers. Methods and Materials: Two p53-mutated HNSCC cell lines displaying opposite radiosensitivity were used. Different types of cell death were determined after exposure to carbon ions (33.6 and 184 keV/{mu}m) or X-rays. Results: Exposure to radiation with high linear energy transfer (LET) induced clonogenic cell death for SCC61 (radiosensitive) and SQ20B (radioresistant) cells, the latter systematically showing less sensitivity. Activation of an early p53-independent apoptotic process occurred in SCC61 cells after both types of irradiation, which increased with time, dose and LET. In contrast, SQ20B cells underwent G2/M arrest associated with Chk1 activation and Cdc2 phosphorylation. This inhibition was transient after X-rays, compared with a more prolonged and LET-dependent accumulation after carbon irradiation. After release, a LET-dependent increase of polyploid and multinucleated cells, both typical signs of mitotic catastrophe, was identified. However, a subpopulation of SQ20B cells was able to escape mitotic catastrophe and continue to proliferate. Conclusions: High LET irradiation induced distinct types of cell death in HNSCC cell lines and showed an increased effectiveness compared with X-rays. However, the reproliferation of SQ20B may explain the potential locoregional recurrence observed among some HNSCC patients treated by hadrontherapy. An adjuvant treatment forcing the tumor cells to enter apoptosis may therefore be necessary to improve the outcome of radiotherapy.

  3. Radioresistance secondary to low pH in human glial cells and Chinese hamster ovary cells

    SciTech Connect

    Rottinger, E.M.; Mendonca, M.

    1982-08-01

    The influence of the extracellular pH on the radiosensitivity of human glial cells and Chinese hamster ovary cells was examined. The period of low pH varied from 0 to 96 hours in glial cells and from 0 to 48 hours in Chinese hamster cells. Maintenance of low pH after a dose of 10 Gy for at least 24 hours for glial cells and at least 6 hours for Chinese hamster cells improved survival by more than one order of magnitude at pH 6.4. Cellular inactivation by irradiation may be impaired by an extracellular pH at or below pH 6.7.

  4. Multiple facets of the DNA damage response contribute to the radioresistance of mouse mesenchymal stromal cell lines.

    PubMed

    Sugrue, Tara; Brown, James A L; Lowndes, Noel F; Ceredig, Rhodri

    2013-01-01

    The regeneration of the hematopoietic system following total body irradiation is supported by host-derived mesenchymal stromal cells (MSCs) within the bone marrow. The mechanisms used by MSCs to survive radiation doses that are lethal to the hematopoietic system are poorly understood. The DNA damage response (DDR) represents a cohort of signaling pathways that enable cells to execute biological responses to genotoxic stress. Here, we examine the role of the DDR in mediating the resistance of MSCs to ionizing radiation (IR) treatment using two authentic clonal mouse MSC lines, MS5 and ST2, and primary bulk mouse MSCs. We show that multiple DDR mechanisms contribute to the radio-resistance of MSCs: robust DDR activation via rapid γ-H2AX formation, activation of effective S and G(2)/M DNA damage checkpoints, and efficient repair of IR-induced DNA double-strand breaks. We show that MSCs are intrinsically programmed to maximize survival following IR treatment by expressing high levels of key DDR proteins including ATM, Chk2, and DNA Ligase IV; high levels of the anti-apoptotic, Bcl-2 and Bcl-(XL); and low levels of the pro-apoptotic, Bim and Puma. As a result, we demonstrate that irradiated mouse MSCs withstand IR-induced genotoxic stress, continue to proliferate, and retain their capacity to differentiate long-term along mesenchymal-derived lineages. We have shown, for the first time, that the DDR plays key roles in mediating the radioresistance of mouse MSCs which may have important implications for the study and application of MSCs in allogeneic bone marrow transplantation, graft-versus-host disease, and cancer treatment. PMID:22961695

  5. Downregulation of Ubiquitin-conjugating Enzyme UBE2D3 Promotes Telomere Maintenance and Radioresistance of Eca-109 Human Esophageal Carcinoma Cells

    PubMed Central

    Yang, Hui; Wu, Lin; Ke, Shaobo; Wang, Wenbo; Yang, Lei; Gao, Xiaojia; Fang, Hongyan; Yu, Haijun; Zhong, Yahua; Xie, Conghua; Zhou, Fuxiang; Zhou, Yunfeng

    2016-01-01

    Ubiquitin-conjugating enzyme UBE2D3 is an important member of the ubiquitin-proteasome pathways. Our previous study showed that the expression of UBE2D3 was negatively related to human telomerase reverse transcriptase (hTERT) and radioresistance in human breast cancer cells. However, in esophageal carcinoma, the exact effects and mechanisms of UBE2D3 in radioresistance remain unclear. This study shows that UBE2D3 knockdown was associated with significant increases in radioresistance to X-rays, telomerase activity, telomere length, and telomere shelterins. UBE2D3 knockdown-mediated radioresistance was related to a decrease in the spontaneous and ionizing radiation-induced apoptosis, resulting from a decrease in the Bax/Bcl-2 ratio. Furthermore, UBE2D3 downregulation was associated with increased G1-S phase transition and prolonged IR-induced G2/M arrest through over expression of cyclin D1, decrease of CDC25A expression and promotion of the ATM/ATR-Chk1-CDC25C pathway. Moreover, UBE2D3 downregulation reduced spontaneous DNA double-strand breaks and accelerated the repair of DNA damage induced by IR. The current data thus demonstrate that UBE2D3 downregulation enhances radioresistance by increased telomere homeostasis and prolonged IR-induced G2/M arrest, but decreases the IR-induced apoptosis and the number of DNA damage foci. These results suggest that UBE2D3 might be a potential molecular target to improve radiotherapy effects in esophageal carcinoma. PMID:27326259

  6. Targeting of tumor endothelial cells combining 2 Gy/day of X-ray with Everolimus is the effective modality for overcoming clinically relevant radioresistant tumors.

    PubMed

    Kuwahara, Yoshikazu; Mori, Miyuki; Kitahara, Shuji; Fukumoto, Motoi; Ezaki, Taichi; Mori, Shiro; Echigo, Seishi; Ohkubo, Yasuhito; Fukumoto, Manabu

    2014-04-01

    Radiotherapy is widely used to treat cancer because it has the advantage of physically and functionally conserving the affected organ. To improve radiotherapy and investigate the molecular mechanisms of cellular radioresistance, we established a clinically relevant radioresistant (CRR) cell line, SAS-R, from SAS cells. SAS-R cells continue to proliferate when exposed to fractionated radiation (FR) of 2 Gy/day for more than 30 days in vitro. A xenograft tumor model of SAS-R was also resistant to 2 Gy/day of X-rays for 30 days. The density of blood vessels in SAS-R tumors was higher than in SAS tumors. Everolimus, a mammalian target of rapamycin (mTOR) inhibitor, sensitized microvascular endothelial cells to radiation, but failed to radiosensitize SAS and SAS-R cells in vitro. Everolimus with FR markedly reduced SAS and SAS-R tumor volumes. Additionally, the apoptosis of endothelial cells (ECs) increased in SAS-R tumor tissues when both Everolimus and radiation were administered. Both CD34-positive and tomato lectin-positive blood vessel densities in SAS-R tumor tissues decreased remarkably after the Everolimus and radiation treatment. Everolimus-induced apoptosis of vascular ECs in response to radiation was also followed by thrombus formation that leads to tumor necrosis. We conclude that FR combined with Everolimus may be an effective modality to overcome radioresistant tumors via targeting tumor ECs. PMID:24464839

  7. Differential Gene Expression Profiles of Radioresistant Non-Small-Cell Lung Cancer Cell Lines Established by Fractionated Irradiation: Tumor Protein p53-Inducible Protein 3 Confers Sensitivity to Ionizing Radiation

    SciTech Connect

    Lee, Young Sook; Oh, Jung-Hwa; Yoon, Seokjoo; Kwon, Myung-Sang

    2010-07-01

    Purpose: Despite the widespread use of radiotherapy as a local and regional modality for the treatment of cancer, some non-small-cell lung cancers commonly develop resistance to radiation. We thus sought to clarify the molecular mechanisms underlying resistance to radiation. Methods and Materials: We established the radioresistant cell line H460R from radiosensitive parental H460 cells. To identify the radioresistance-related genes, we performed microarray analysis and selected several candidate genes. Results: Clonogenic and MTT assays showed that H460R was 10-fold more resistant to radiation than H460. Microarray analysis indicated that the expression levels of 1,463 genes were altered more than 1.5-fold in H460R compared with parental H460. To evaluate the putative functional role, we selected one interesting gene tumor protein p53-inducible protein 3 (TP53I3), because that this gene was significantly downregulated in radioresistant H460R cells and that it was predicted to link p53-dependent cell death signaling. Interestingly, messenger ribonucleic acid expression of TP53I3 differed in X-ray-irradiated H460 and H460R cells, and overexpression of TP53I3 significantly affected the cellular radiosensitivity of H460R cells. Conclusions: These results show that H460R may be useful in searching for candidate genes that are responsible for radioresistance and elucidating the molecular mechanism of radioresistance.

  8. Epothilone B Confers Radiation Dose Enhancement in DAB2IP Gene Knock-Down Radioresistant Prostate Cancer Cells

    SciTech Connect

    Kong Zhaolu; Raghavan, Pavithra; Xie Daxing; Boike, Thomas; Burma, Sandeep; Chen, David; Chakraborty, Arup; Hsieh, Jer-Tsong; Saha, Debabrata

    2010-11-15

    Purpose: In metastatic prostate cancer, DOC-2/DAB2 interactive protein (DAB2IP) is often downregulated and has been reported as a possible prognostic marker to predict the risk of aggressive prostate cancer (PCa). Our preliminary results show that DAB2IP-deficient PCa cells are radioresistant. In this study, we investigated the anticancer drug Epothilone B (EpoB) for the modulation of radiosensitivity in DAB2IP-deficient human PCa cells. Methods and Materials: We used a stable DAB2IP-knock down human PCa cell line, PC3 shDAB2IP, treated with EpoB, ionizing radiation (IR), or the combined treatment of EpoB and IR. The modulation of radiosensitivity was determined by surviving fraction, cell cycle distribution, apoptosis, and DNA double-strand break (DSB) repair. For in vivo studies, the PC3shDAB2IP xenograft model was used in athymic nude mice. Results: Treatment with EpoB at IC{sub 50} dose (33.3 nM) increased cellular radiosensitivity in the DAB2IP-deficient cell line with a dose enhancement ratio of 2.36. EpoB delayed the DSB repair kinetics after IR and augmented the induction of apoptosis in irradiated cells after G{sub 2}/M arrest. Combined treatment of EpoB and radiation enhanced tumor growth delay with an enhancement factor of 1.2. Conclusions: We have demonstrated a significant radiation dose enhancement using EpoB in DAB2IP-deficient prostate cancer cells. This radiosensitization can be attributed to delayed DSB repair, prolonged G{sub 2} block, and increased apoptosis in cells entering the cell cycle after G{sub 2}/M arrest.

  9. Daoy medulloblastoma cells that express CD133 are radioresistant relative to CD133- cells, and the CD133+ sector is enlarged by hypoxia

    SciTech Connect

    Blazek, Ed R.

    2007-01-01

    Purpose: Primary medulloblastoma and glioblastoma multiforme tumor cells that express the surface marker CD133 are believed to be enriched for brain tumor stem cells because of their unique ability to initiate or reconstitute tumors in immunodeficient mice. This study sought to characterize the radiobiological properties and marker expression changes of CD133+ vs. CD133- cells of an established medulloblastoma cell line. Methods and Materials: Daoy and D283 Med cell lines were stained with fluorescently labeled anti-CD133 antibody and sorted into CD133+ and CD133- populations. The effect of oxygen (2% vs. 20%) on CD133 expression was measured. Both populations were analyzed for marker stability, cell cycle distribution, and radiosensitivity. Results: CD133+ Daoy cells restored nearly native CD133+ and CD133- populations within 18 days, whereas CD133- cells remained overwhelmingly CD133-. Culturing Daoy cells in 2% oxygen rather than the standard 20% oxygen increased their CD133 expression 1.6-fold. CD133+ Daoy cells were radioresistant via the {beta}-parameter of the linear-quadratic model relative to CD133- Daoy cells, although their {alpha}-parameters and cell cycle distributions were identical. Conclusions: Restoration of the original CD133+ and CD133- populations from CD133+ Daoy cells in serum is further evidence that CD133+ cells are functionally distinct from CD133- cells. The radioresistance of CD133+ compared with CD133- Daoy cells is consistent with better repair of sublethal damage. Enlargement of the CD133+ sector is a new feature of the hypoxic response.

  10. Downregulation of ubiquitin inhibits the proliferation and radioresistance of non-small cell lung cancer cells in vitro and in vivo

    PubMed Central

    Tang, Yiting; Geng, Yangyang; Luo, Judong; Shen, Wenhao; Zhu, Wei; Meng, Cuicui; Li, Ming; Zhou, Xifa; Zhang, Shuyu; Cao, Jianping

    2015-01-01

    Radioresistance has been an important factor in restricting efficacy of radiotherapy for non-small cell lung cancer (NSCLC) patients and new approaches to inhibit cancer growth and sensitize irradiation were warranted. Despite the important role of ubiquitin/proteasome system (UPS) during cancer progression and treatment, the expression and biological role of ubiquitin (Ub) in human NSCLC has not been characterized. In this study, we found that ubiquitin was significantly overexpressed in 75 NSCLC tissues, compared to their respective benign tissues by immunohistochemistry (P < 0.0001). Knock-down of ubiquitin by mixed shRNAs targeting its coding genes ubiquitin B (UBB) and ubiquitin C (UBC) suppressed the growth and increased the radiosensitivity in NSCLC H1299 cells. Apoptosis and γ H2AX foci induced by X-ray irradiation were enhanced by knock-down of ubiquitin. Western blot and immunostaining showed that knock-down of ubiquitin decreased the expression and translocation of NF-κB to the nucleus by reduced phospho-IκBα after irradiation. Suppression of ubiquitin decreased the proliferation and radioresistance of H1299 transplanted xenografts in nude mice by promoting apoptosis. Taken together, our results demonstrate the critical role of ubiquitin in NSCLC proliferation and radiosensitivity. Targeting ubiquitin may serve as a potentially important and novel approach for NSCLC prevention and therapy. PMID:25820571

  11. Radioresistance of Bone Marrow Stromal and Hematopoietic Progenitor Cell Lines Derived from Nrf2−/− Homozygous Deletion Recombinant-Negative Mice

    PubMed Central

    BERHANE, HEBIST; EPPERLY, MICHAEL W.; CAO, SHAONAN; GOFF, JULIE P.; FRANICOLA, DARCY; WANG, HONG; GREENBERGER, JOEL S.

    2014-01-01

    Aim: We determined whether bone marrow from Nrf2−/− compared with Nrf2+/+ mice differed in response to the oxidative stress of continuous marrow culture, and in radiosensitivity of derived stromal and interleukin-3 (IL-3)-dependent hematopoietic progenitor cells. Materials and Methods: Hematopoiesis longevity in Nrf2−/− was compared with Nrf2+/+ mice in long-term bone marrow cultures. Clonogenic irradiation survival curves were performed on derived cell lines. Total antioxidant capacity at baseline in nonirradiated cells and at 24 hours after 5 Gy and 10 Gy irradiation was quantitated using an antioxidant reductive capacity assay. Results: Long-term cultures of bone marrow from Nrf2−/− compared to Nrf2+/+ mice demonstrated equivalent longevity of production of total cells and hematopoietic progenitor cells forming multi-lineage hematopoietic colonies over 26 weeks in culture. Both bone marrow stromal cell lines and Il-3-dependent hematopoietic progenitor cell lines derived from Nrf2−/− mouse marrow cultures were radioresistant compared to Nrf2+/+-derived cell lines. Both DNA repair assay and total antioxidant capacity assay showed no defect in Nrf2−/− compared to Nrf2+/+ stromal cells and IL-3-dependent cells. Conclusion: The absence of a functional Nrf2 gene product does not alter cellular interactions in continuous marrow culture, nor response to dsDNA damage repair and antioxidant response. However, lack of the Nrf2 gene does confer radioresistance on marrow stromal and hematopoietic cells. PMID:23988890

  12. Reciprocal Regulation of Hypoxia-Inducible Factor 2α and GLI1 Expression Associated With the Radioresistance of Renal Cell Carcinoma

    SciTech Connect

    Zhou, Jiancheng; Wu, Kaijie; Gao, Dexuan; Zhu, Guodong; Wu, Dapeng; Wang, Xinyang; Chen, Yule; Du, Yuefeng; Song, Wenbin; Ma, Zhenkun; Authement, Craig; Saha, Debabrata; Hsieh, Jer-Tsong; He, Dalin

    2014-11-15

    Purpose: Renal cell carcinoma (RCC) is often considered a radioresistant tumor, but the molecular mechanism underlying its radioresistance is poorly understood. This study explored the roles of hypoxia-inducible factor 2α (HIF2α) and sonic hedgehog (SHH)-GLI1 signaling in mediating the radioresistance of RCC cells and to unveil the interaction between these 2 signaling pathways. Methods and Materials: The activities of SHH-GLI1 signaling pathway under normoxia and hypoxia in RCC cells were examined by real-time polymerase chain reaction, Western blot, and luciferase reporter assay. The expression of HIF2α and GLI1 in RCC patients was examined by immunohistochemistry, and their correlation was analyzed. Furthermore, RCC cells were treated with HIF2α-specific shRNA (sh-HIF2α), GLI1 inhibitor GANT61, or a combination to determine the effect of ionizing radiation (IR) on RCC cells based on clonogenic assay and double-strand break repair assay. Results: RCC cells exhibited elevated SHH-GLI1 activities under hypoxia, which was mediated by HIF2α. Hypoxia induced GLI1 activation through SMO-independent pathways that could be ablated by PI3K inhibitor or MEK inhibitor. Remarkably, the SHH-GLI1 pathway also upregulated HIF2α expression in normoxia. Apparently, there was a positive correlation between HIF2α and GLI1 expression in RCC patients. The combination of sh-HIF2α and GLI1 inhibitor significantly sensitized RCC cells to IR. Conclusions: Cross-talk between the HIF2α and SHH-GLI1 pathways was demonstrated in RCC. Cotargeting these 2 pathways, significantly sensitizing RCC cells to IR, provides a novel strategy for RCC treatment.

  13. Targeted Inhibition of ATR or CHEK1 Reverses Radioresistance in Oral Squamous Cell Carcinoma Cells with Distal Chromosome Arm 11q Loss

    PubMed Central

    Sankunny, Madhav; Parikh, Rahul A.; Lewis, Dale W.; Gooding, William E.; Saunders, William S.; Gollin, Susanne M.

    2014-01-01

    Oral squamous cell carcinoma (OSCC), a subset of head and neck squamous cell carcinoma (HNSCC), is the eighth most common cancer in the U.S.. Amplification of chromosomal band 11q13 and its association with poor prognosis has been well established in OSCC. The first step in the breakage-fusion-bridge (BFB) cycle leading to 11q13 amplification involves breakage and loss of distal 11q. Distal 11q loss marked by copy number loss of the ATM gene is observed in 25% of all Cancer Genome Atlas (TCGA) tumors, including 48% of HNSCC. We showed previously that copy number loss of distal 11q is associated with decreased sensitivity (increased resistance) to ionizing radiation (IR) in OSCC cell lines. We hypothesized that this radioresistance phenotype associated with ATM copy number loss results from upregulation of the compensatory ATR-CHEK1 pathway, and that knocking down the ATR-CHEK1 pathway increases the sensitivity to IR of OSCC cells with distal 11q loss. Clonogenic survival assays confirmed the association between reduced sensitivity to IR in OSCC cell lines and distal 11q loss. Gene and protein expression studies revealed upregulation of the ATR-CHEK1 pathway and flow cytometry showed G2-M checkpoint arrest after IR treatment of cell lines with distal 11q loss. Targeted knockdown of the ATR-CHEK1 pathway using CHEK1 or ATR siRNA or a CHEK1 small molecule inhibitor (SMI, PF-00477736) resulted in increased sensitivity of the tumor cells to IR. Our results suggest that distal 11q loss is a useful biomarker in OSCC for radioresistance that can be reversed by ATR-CHEK1 pathway inhibition. PMID:24327542

  14. Prognostic significance of survivin expression in renal cell cancer and its correlation with radioresistance.

    PubMed

    Lei, Yu; Geng, Zhang; Guo-Jun, Wu; He, Wang; Jian-Lin, Yuan

    2010-11-01

    Survivin, an important inhibitor of apoptosis, has been found to play an important role in the initiation, progression, and chemoradioresistance of human malignancies. Previously, we have reported that upregulation of survivin in oral squamous cell carcinoma correlates with poor prognosis and chemoresistance. The aim of this study was to assess prognostic significance of survivin protein expression in RCC and analyze its correlation with radiosensitivity of RCC cells. RT-PCR and Western blot assays were performed to detect survivin mRNA and protein expression in normal human kidney epithelial cell line (HKEC) or RCC cell lines. The expression of survivin mRNA in RCC and corresponding nontumor kidney tissues was also detected by RT-PCR. Immunohistochemistry was performed to determine survivin protein expression in 75 cases of RCC tissue samples. Moreover, the association of survivin protein expression with clinicopathogical factors and prognosis of RCC patients was statistically analyzed. Small interfering RNA was used to knockdown the endogenous survivin expression in RCC cell line (ACHN) and evaluate the effects of survivin knockdown on proliferation, apoptosis, and radiosensitivity of RCC cell line. RCC cells showed sufficient expression of survivin mRNA and protein, but the expression of survivin gene was not detected in normal HKEC. Moreover, the expression level of survivin mRNA in RCC tissues was significantly higher than that in corresponding nontumor kidney tissues. The immunostaining of survivin protein was mainly located in cytoplasm of RCC tumor cells. Tumor pathological stage (P = 0.028), grade (P = 0.004), and lymph node metastasis (P = 0.017) of RCC patients were significantly correlated with survivin protein expression. In addition, patients with high survivin levels had a significantly shorter overall survival than those with low levels (P < 0.001), and the expression of survivin protein was an independent prognostic factor for RCC patients (P = 0

  15. APOBEC3G enhances lymphoma cell radioresistance by promoting cytidine deaminase-dependent DNA repair.

    PubMed

    Nowarski, Roni; Wilner, Ofer I; Cheshin, Ori; Shahar, Or D; Kenig, Edan; Baraz, Leah; Britan-Rosich, Elena; Nagler, Arnon; Harris, Reuben S; Goldberg, Michal; Willner, Itamar; Kotler, Moshe

    2012-07-12

    APOBEC3 proteins catalyze deamination of cytidines in single-stranded DNA (ssDNA), providing innate protection against retroviral replication by inducing deleterious dC > dU hypermutation of replication intermediates. APOBEC3G expression is induced in mitogen-activated lymphocytes; however, no physiologic role related to lymphoid cell proliferation has yet to be determined. Moreover, whether APOBEC3G cytidine deaminase activity transcends to processing cellular genomic DNA is unknown. Here we show that lymphoma cells expressing high APOBEC3G levels display efficient repair of genomic DNA double-strand breaks (DSBs) induced by ionizing radiation and enhanced survival of irradiated cells. APOBEC3G transiently accumulated in the nucleus in response to ionizing radiation and was recruited to DSB repair foci. Consistent with a direct role in DSB repair, inhibition of APOBEC3G expression or deaminase activity resulted in deficient DSB repair, whereas reconstitution of APOBEC3G expression in leukemia cells enhanced DSB repair. APOBEC3G activity involved processing of DNA flanking a DSB in an integrated reporter cassette. Atomic force microscopy indicated that APOBEC3G multimers associate with ssDNA termini, triggering multimer disassembly to multiple catalytic units. These results identify APOBEC3G as a prosurvival factor in lymphoma cells, marking APOBEC3G as a potential target for sensitizing lymphoma to radiation therapy. PMID:22645179

  16. Radiation-induced mitotic cell death and glioblastoma radioresistance: a new regulating pathway controlled by integrin-linked kinase, hypoxia-inducible factor 1 alpha and survivin in U87 cells.

    PubMed

    Lanvin, Olivia; Monferran, Sylvie; Delmas, Caroline; Couderc, Bettina; Toulas, Christine; Cohen-Jonathan-Moyal, Elizabeth

    2013-09-01

    We have previously shown that integrin-linked kinase (ILK) regulates U87 glioblastoma cell radioresistance by modulating the main radiation-induced cell death mechanism in solid tumours, the mitotic cell death. To decipher the biological pathways involved in these mechanisms, we constructed a U87 glioblastoma cell model expressing an inducible shRNA directed against ILK (U87shILK). We then demonstrated that silencing ILK enhanced radiation-induced centrosome overduplication, leading to radiation-induced mitotic cell death. In this model, ionising radiations induce hypoxia-inducible factor 1 alpha (HIF-1α) stabilisation which is inhibited by silencing ILK. Moreover, silencing HIF-1α in U87 cells reduced the surviving fraction after 2 Gy irradiation by increasing cell sensitivity to radiation-induced mitotic cell death and centrosome amplification. Because it is known that HIF-1α controls survivin expression, we then looked at the ILK silencing effect on survivin expression. We show that survivin expression is decreased in U87shILK cells. Furthermore, treating U87 cells with the specific survivin suppressor YM155 significantly increased the percentage of giant multinucleated cells, centrosomal overduplication and thus U87 cell radiosensitivity. In consequence, we decipher here a new pathway of glioma radioresistance via the regulation of radiation-induced centrosome duplication and therefore mitotic cell death by ILK, HIF-1α and survivin. This work identifies new targets in glioblastoma with the intention of radiosensitising these highly radioresistant tumours. PMID:23747271

  17. Flavopiridol Potentiates the Cytotoxic Effects of Radiation in Radioresistant Tumor Cells in Which p53 is Mutated or Bcl-2 is Overexpressed

    SciTech Connect

    Hara, Takamitsu; Omura-Minamisawa, Motoko Kang, Yun; Cheng, Chao; Inoue, Tomio

    2008-08-01

    Purpose: Loss of the cell-cycle regulatory protein p53 or overexpression of the antiapoptotic protein Bcl-2 is associated with resistance to radiation in several types of cancer cells. Flavopiridol, a synthetic flavone, inhibits the growth of malignant tumors cells in vitro and in vivo through multiple mechanisms. The purpose of the present study is to clarify whether flavopiridol enhances the cytotoxic effects of radiation in tumor cells that contain dysfunction p53 or that overexpress Bcl-2. Methods and Materials: A human glioma cell line (A172/mp53) stably transfected with a plasmid containing mutated p53 and a human cervical cancer cell line (HeLa/bcl-2) transfected with a bcl-2 expression plasmid were used. Cells were incubated with flavopiridol for 24 h after radiation, and then cell viability was determined by a colony formation assay. Foci of phosphorylated histone H2AX were also evaluated as a sensitive indicator of DNA double-strand breaks. Results: Compared with the parental wild-type cells, both transfected cell lines were more resistant to radiation. Post-treatment with flavopiridol increased the cytotoxic effects of radiation in both transfected cell lines, but not in their parental wild-type cell lines. Post-treatment with flavopiridol inhibited sublethal damage repair as well as the repair of DNA double-strand breaks in response to radiation. Conclusions: Flavopiridol enhanced the cytotoxic effect of radiation in radioresistant tumor cells that harbor p53 dysfunction or Bcl-2 overexpression. A combination treatment of flavopiridol with radiation has the potential to conquer the radioresistance of malignant tumors induced by the genetic alteration of p53 or bcl-2.

  18. Combination of nicotinamide and hyperthermia to eliminate radioresistant chronically and acutely hypoxic tumor cells

    SciTech Connect

    Horsman, M.R.; Chaplin, D.J.; Overgaard, J. )

    1990-12-01

    The interaction among nicotinamide, radiation, and heat was studied in vivo using a C3H mouse mammary carcinoma grown in the feet of CDF1 mice. Response following local tumor treatment was assessed by tumor control and regrowth delay. Nicotinamide (1000 mg/kg i.p.) produced maximal radiosensitization when injected 30 min to 2 h before irradiation (enhancement ratios (ERs), 1.2-1.5). Radiation damage was also increased by heating tumors (43.5 degrees C for 60 min) 4 h after irradiation (ERs = 1.6-2.6). This combined radiation and heat treatment was enhanced by nicotinamide but the effect depended on the assay procedure, such that although a significant increase was observed with the tumor control assay, only a slight increase was seen using regrowth delay as the end point. The development of moist desquamation in normal feet was used to estimate skin damage after irradiation. Nicotinamide and heat both resulted in a small yet significant increase in skin damage (ERs less than 1.2 and 1.1, respectively). A combined treatment resulted in a greater ER of 1.7, but when compared to the tumor response it still gave a therapeutic gain. A histological fluorescent staining technique was used to assess functional tumor vasculature at two periods in time separated by 20 min. Under normal conditions 7.7% of the vessels in this tumor were functional at one time but not the other. This value was reduced to 2.8% after nicotinamide administration. Since these fluctuations in blood flow can result in acute hypoxia we conclude that while heat eliminates chronically hypoxic tumor cells, nicotinamide probably removes the presence of acute hypoxia.

  19. Inhibitory effect of traditional oriental medicine-derived monoamine oxidase B inhibitor on radioresistance of non-small cell lung cancer

    PubMed Central

    Son, Beomseok; Jun, Se Young; Seo, HyunJeong; Youn, HyeSook; Yang, Hee Jung; Kim, Wanyeon; Kim, Hyung Kook; Kang, ChulHee; Youn, BuHyun

    2016-01-01

    Increased survival of cancer cells mediated by high levels of ionizing radiation (IR) reduces the effectiveness of radiation therapy for non-small cell lung cancer (NSCLC). In the present study, danshensu which is a selected component of traditional oriental medicine (TOM) compound was found to reduce the radioresistance of NSCLC by inhibiting the nuclear factor-κB (NF-κB) pathway. Of the various TOM compounds reported to inhibit the IR activation of NF-κB, danshensu was chosen as a final candidate based on the results of structural comparisons with human metabolites and monoamine oxidase B (MAOB) was identified as the putative target enzyme. Danshensu decreased the activation of NF-κB by inhibiting MAOB activity in A549 and NCI-H1299 NSCLC cells. Moreover, it suppressed IR-induced epithelial-to-mesenchymal transition, expressions of NF-κB-regulated prosurvival and proinflammatory genes, and in vivo radioresistance of mouse xenograft models. Taken together, this study shows that danshensu significantly reduces MAOB activity and attenuates NF-κB signaling to elicit the radiosensitization of NSCLC. PMID:26906215

  20. Acquisition of epithelial–mesenchymal transition and cancer stem cell phenotypes is associated with activation of the PI3K/Akt/mTOR pathway in prostate cancer radioresistance

    PubMed Central

    Chang, L; Graham, P H; Hao, J; Ni, J; Bucci, J; Cozzi, P J; Kearsley, J H; Li, Y

    2013-01-01

    Radioresistance is a major challenge in prostate cancer (CaP) radiotherapy (RT). In this study, we investigated the role and association of epithelial–mesenchymal transition (EMT), cancer stem cells (CSCs) and the PI3K/Akt/mTOR signaling pathway in CaP radioresistance. We developed three novel CaP radioresistant (RR) cell lines (PC-3RR, DU145RR and LNCaPRR) by radiation treatment and confirmed their radioresistance using a clonogenic survival assay. Compared with untreated CaP-control cells, the CaP-RR cells had increased colony formation, invasion ability and spheroid formation capability (P<0.05). In addition, enhanced EMT/CSC phenotypes and activation of the checkpoint proteins (Chk1 and Chk2) and the PI3K/Akt/mTOR signaling pathway proteins were also found in CaP-RR cells using immunofluorescence, western blotting and quantitative real-time PCR (qRT-PCR). Furthermore, combination of a dual PI3K/mTOR inhibitor (BEZ235) with RT effectively increased radiosensitivity and induced more apoptosis in CaP-RR cells, concomitantly correlated with the reduced expression of EMT/CSC markers and the PI3K/Akt/mTOR signaling pathway proteins compared with RT alone. Our findings indicate that CaP radioresistance is associated with EMT and enhanced CSC phenotypes via activation of the PI3K/Akt/mTOR signaling pathway, and that the combination of BEZ235 with RT is a promising modality to overcome radioresistance in the treatment of CaP. This combination approach warrants future in vivo animal study and clinical trials. PMID:24157869

  1. Activation of mitochondrial promoter P{sub H}-binding protein in a radio-resistant Chinese hamster cell strain associated with Bcl-2

    SciTech Connect

    Roychoudhury, Paromita; Ghosh, Utpal . E-mail: keyachaudhuri@yahoo.com

    2006-11-17

    The cellular response to ionizing radiation is mediated by a complex interaction of number of proteins involving different pathways. Previously, we have shown that up regulation of mitochondrial genes ND1, ND4, and COX1 transcribed from the heavy strand promoter (P{sub H}) has been increased in a radio-resistant cell strain designated as M5 in comparison with the parental Chinese hamster V79 cells. These genes are also up regulated in Chinese hamster V79 cells VB13 that express exogenous human Bcl2. In the present study, the expression of the gene ND6 that is expressed from the light strand promoter (P{sub L}) was found to be similar in both the cell lines, as determined by RT-PCR. To test the possibility that this differential expression of mitochondrial genes under these two promoters was mediated by differences in proteins' affinity to interact with these promoters, we have carried out electrophoretic mobility shift assay (EMSA) using mitochondrial cell extracts from these two cell lines. Our result of these experiments revealed that two different proteins formed complex with the synthetic promoters and higher amount of protein from M5 cell extracts interacted with the P{sub H} promoter in comparison to that observed with cell extracts from Chinese hamster V79 cells. The promoter-specific differential binding of proteins was also observed in VB13. These results showed that differential mitochondrial gene expression observed earlier in the radio-resistant M5 cells was due to enhanced interaction proteins with the promoters P{sub H} and mediated by the expression of Bcl2.

  2. Erythroleukemia cells acquire an alternative mitophagy capability

    PubMed Central

    Wang, Jian; Fang, Yixuan; Yan, Lili; Yuan, Na; Zhang, Suping; Xu, Li; Nie, Meilan; Zhang, Xiaoying; Wang, Jianrong

    2016-01-01

    Leukemia cells are superior to hematopoietic cells with a normal differentiation potential in buffering cellular stresses, but the underlying mechanisms for this leukemic advantage are not fully understood. Using CRISPR/Cas9 deletion of the canonical autophagy-essential gene Atg7, we found that erythroleukemia K562 cells are armed with two sets of autophagic machinery. Alternative mitophagy is functional regardless of whether the canonical autophagic mechanism is intact or disrupted. Although canonical autophagy defects attenuated cell cycling, proliferation and differentiation potential, the leukemia cells retained their abilities for mitochondrial clearance and for maintaining low levels of reactive oxygen species (ROS) and apoptosis. Treatment with a specific inducer of mitophagy revealed that the canonical autophagy-defective erythroleukemia cells preserved a mitophagic response. Selective induction of mitophagy was associated with the upregulation and localization of RAB9A on the mitochondrial membrane in both wild-type and Atg7−/− leukemia cells. When the leukemia cells were treated with the alternative autophagy inhibitor brefeldin A or when the RAB9A was knocked down, this mitophagy was prohibited. This was accompanied by elevated ROS levels and apoptosis as well as reduced DNA damage repair. Therefore, the results suggest that erythroleukemia K562 cells possess an ATG7-independent alternative mitophagic mechanism that functions even when the canonical autophagic process is impaired, thereby maintaining the ability to respond to stresses such as excessive ROS and DNA damage. PMID:27091640

  3. Enhanced induction of apoptosis in a radio-resistant bladder tumor cell line by combined treatments with X-rays and wortmannin.

    PubMed

    Ortiz, Trinidad; Burguillos, Miguel Angel; López-Lluch, Guillermo; Navas, Plácido; Herrador, Miguel; González, Isabel; Piñero, Joaquín

    2008-11-01

    The radiosensitizing effect of wortmannin (WM) treatment during and after irradiation was studied in radioresistant bladder tumor cell lines with normal (MGH-U1 cells) or defective p53 activity (RT112 cells). WM modulated G(2)/M cell cycle arrest induced by higher X-ray doses (10 Gy) in both cell lines, although the alteration was significant only in RT112 cells. The observation suggests that WM activity is independent of p53. Constitutive expression of DNA-PKcs was found to be higher in RT112 cells than in MGH-U1. Treatment with WM enhanced radiation-induced apoptosis significantly in RT112 cells while it had no effect on MGH-U1 cells. Although a variety of PI3-kinases and PI3-K like kinases (including ATM) could be inhibited by WM, our observation of increased early lethality by WM treatment in RT112 is in agreement with previous results. They suggest that the WM-dependent radiosensitization of RT112 is a direct consequence of the inhibition of DNA-PK, resulting in the inhibition of DSB repair in the fast component. This early effect in the p53 deficient cell line could also indicate that processes other than apoptosis may contribute to the increased radiosensitization. In our opinion, the expression level of DNA-PKcs in human tumor cells may be a good predictor for the success of DNA-PKcs inhibitors when used as radiosensitizers. PMID:18787832

  4. DIFFERENTIAL CONTRIBUTION OF β-ADRENERGIC RECEPTORS EXPRESSED ON RADIOSENSITIVE VERSUS RADIORESISTANT CELLS TO PROTECTION AGAINST INFLAMMATION AND MORTALITY IN MURINE ENDOTOXEMIA

    PubMed Central

    Walker-Brown, Jill; Roberts, Margo R.

    2010-01-01

    The sympathetic nervous system modulates immune responses via the secretion of catecholamines and subsequent activation of adrenergic receptors (ARs), and systemic catecholamine levels increase markedly in the setting of endotoxemia and sepsis. Previous studies have demonstrated that stimulation of β-ARs by pharmacological agonists attenuates the inflammatory response to LPS observed in vitro, and can increase survival in animal models of endotoxemia and sepsis. However, the consequences of β-AR activation by endogenous catecholamines have not been explored in these settings. Furthermore, the relative contribution of β-ARs expressed on immune versus non-immune cells to LPS-mediated inflammation and mortality is not known. Our first goal was therefore to determine the impact of β-AR stimulation by endogenous catecholamines released during endotoxemia on LPS-mediated inflammation and mortality in vivo. To address this question, we examined the LPS response of mice lacking all three known βAR subtypes, β1-, β2- and β3-AR, and demonstrated that these β-less mice exhibited a net increase in inflammation (increased TNF-α levels and decreased IL-10 levels in serum) and a 50% decrease in survival relative to wildtype animals. The second goal of our study was to determine the relative contribution of β-ARs expressed on radiosensitive immune versus radioresistant cells to the protective action of β-ARs in the setting of endotoxemia. We therefore examined the LPS response of bone marrow chimeras generated between β-less and wildtype mice, and concluded that β-ARs expressed on radioresistant cells play the dominant role in protecting against LPS-mediated mortality and attenuating systemic TNF-α responses. Finally, we determined that β3-AR subtype does not play a significant role in regulating LPS-mediated mortality and inflammation, by evaluating mice lacking the β1- and β2-AR subtypes only. PMID:19333138

  5. mir-129-5p Attenuates Irradiation-Induced Autophagy and Decreases Radioresistance of Breast Cancer Cells by Targeting HMGB1

    PubMed Central

    Luo, Jing; Chen, Jie; He, Li

    2015-01-01

    Background This study aimed to determine the role of miR-129-5p in irradiation-induced autophagy in breast cancer cells and to investigate its downstream regulation in autophagy-related radiosensitivity. Material/Methods Relative miR-129-5p expression in breast cancer cell lines MCF-7, MDA-MB-231, BT474, and BT549, and in 1 non-tumorigenic breast epithelial cell line, MCF-10A, was compared. The effect of miR-129-5p on irradiation-induced autophagy and radiosensitivity of the cancer cells was explored. The regulative effect of miR-129-5p on HMGB1 and the functional role of this axis in autophagy and radiosensitivity were also studied. Results Ectopic expression of miR-129-5p sensitized MDA-MD-231 cells to irradiation, while knockdown of miR-129-5p reduced radiosensitivity of MCF-7 cells. MiR-129-5p overexpression inhibited irradiation-induced autophagy. HMGB1 is a direct functional target of miR-129-5p in breast cancer cells. MiR-129-5p may suppress autophagy and decrease radioresistance of breast cancer cells by targeting HMGB1. Conclusions The miR-129-5p/HMGB1 axis can regulate irradiation-induced autophagy in breast cancer and might be an important pathway in regulating radiosensitivity of breast cancer cells. PMID:26720492

  6. Effects of the bifunctional sulfoxide MMS350, a radiation mitigator, on hematopoiesis in long-term bone marrow cultures and on radioresistance of marrow stromal cell lines.

    PubMed

    Shinde, Ashwin; Epperly, Michael W; Cao, Shaonan; Franicola, Darcy; Shields, Donna; Wang, Hong; Wipf, Peter; Sprachman, Melissa M; Greenberger, Joel S

    2014-01-01

    The ionizing irradiation mitigator MMS350 prolongs survival of mice treated with total-body irradiation and prevents radiation-induced pulmonary fibrosis when added to drinking water at day 100 after thoracic irradiation. The effects of MMS350 on hematopoiesis in long-term bone marrow culture and on the radiobiology of derived bone marrow stromal cell lines were tested. Long-term bone marrow cultures were established from C57BL/6NTac mice and maintained in a high-humidity incubator, with 7% CO2 and the addition of 100 μM MMS350 at the weekly media change. Over 10 weeks in culture, MMS350 had no significant effect on maintenance of hematopoietic stem cell production, or on nonadherent cells or colony-forming units of hematopoietic progenitor cells. Stromal cell lines derived from non MMS350-treated long-term cultures or control stromal cells treated with MMS350 were radioresistant in the clonogenic survival curve assay. MMS350 is a non-toxic, highly water-soluble radiation mitigator that exhibits radioprotective effects on bone marrow stromal cells. PMID:24982210

  7. Acquired cancer stem cell phenotypes through Oct4-mediated dedifferentiation

    PubMed Central

    Kumar, Suresh M.; Liu, Shujing; Lu, Hezhe; Zhang, Hongtao; Zhang, Paul J.; Gimotty, Phyllis A.; Guerra, Matthew; Guo, Wei; Xu, Xiaowei

    2012-01-01

    There is enormous interest to target cancer stem cells (CSCs) for clinical treatment because these cells are highly tumorigenic and resistant to chemotherapy. Oct4 is expressed by CSC-like cells in different types of cancer. However, function of Oct4 in tumor cells is unclear. In this study, we showed that expression of Oct4 gene or transmembrane delivery of Oct4 protein promoted dedifferentiation of melanoma cells to CSC-like cells. The dedifferentiated melanoma cells showed significantly decreased expression of melanocytic markers and acquired the ability to form tumor spheroids. They showed markedly increased resistance to chemotherapeutic agents and hypoxic injury. In the subcutaneous xenograft and tail vein injection assays, these cells had significantly increased tumorigenic capacity. The dedifferentiated melanoma cells acquired features associated with CSCs such as multipotent differentiation capacity and expression of melanoma CSC markers such as ABCB5 and CD271. Mechanistically, Oct4 induced dedifferentiation was associated with increased expression of endogenous Oct4, Nanog and Klf4, and global gene expression changes that enriched for transcription factors. RNAi mediated knockdown of Oct4 in dedifferentiated cells led to diminished CSC phenotypes. Oct4 expression in melanoma was regulated by hypoxia and its expression was detected in a subpopulation of melanoma cells in clinical samples. Our data indicate that Oct4 is a positive regulator of tumor dedifferentiation. The results suggest that CSC phenotype is dynamic and may be acquired through dedifferentiation. Oct4 mediated tumor cell dedifferentiation may play an important role during tumor progression. PMID:22286766

  8. Depletion of hepatoma-derived growth factor-related protein-3 induces apoptotic sensitization of radioresistant A549 cells via reactive oxygen species-dependent p53 activation

    SciTech Connect

    Yun, Hong Shik; Hong, Eun-Hee; Lee, Su-Jae; Baek, Jeong-Hwa; Lee, Chang-Woo; Yim, Ji-Hye; Um, Hong-Duck; Hwang, Sang-Gu

    2013-09-27

    Highlights: •HRP-3 is a radiation- and anticancer drug-responsive protein in A549 cells. •Depletion of HRP-3 induces apoptosis of radio- and chemoresistant A549 cells. •Depletion of HRP-3 promotes ROS generation via inhibition of the Nrf2/HO-1 pathway. •Depletion of HRP-3 enhances ROS-dependent p53 activation and PUMA expression. -- Abstract: Biomarkers based on functional signaling have the potential to provide greater insight into the pathogenesis of cancer and may offer additional targets for anticancer therapeutics. Here, we identified hepatoma-derived growth factor-related protein-3 (HRP-3) as a radioresistance-related gene and characterized the molecular mechanism by which its encoded protein regulates the radio- and chemoresistant phenotype of lung cancer-derived A549 cells. Knockdown of HRP-3 promoted apoptosis of A549 cells and potentiated the apoptosis-inducing action of radio- and chemotherapy. This increase in apoptosis was associated with a substantial generation of reactive oxygen species (ROS) that was attributable to inhibition of the Nrf2/HO-1 antioxidant pathway and resulted in enhanced ROS-dependent p53 activation and p53-dependent expression of PUMA (p53 upregulated modulator of apoptosis). Therefore, the HRP-3/Nrf2/HO-1/ROS/p53/PUMA cascade is an essential feature of the A549 cell phenotype and a potential radiotherapy target, extending the range of targets in multimodal therapies against lung cancer.

  9. The radiomimetic enediyne, 20'-deschloro-C-1027 induces inter-strand DNA crosslinks in hypoxic cells and overcomes cytotoxic radioresistance.

    PubMed

    Beerman, Terry A; Gawron, Loretta S; Shen, Ben; Kennedy, Daniel R

    2014-09-01

    The ability of the radiomimetic anti-tumor enediyne C-1027 to induce DNA inter-strand crosslinks (ICLs), in addition to the expected DNA strand breaks, is unique among traditional DNA targeted cancer therapies. Importantly, radiation therapy and most radiomimetic drugs have diminished effect in hypoxic environments due to decreased induction of DNA strand breaks, which is an oxygen requiring process. However, C-1027's induction of ICLs is enhanced under hypoxia and it is actually more potent against hypoxic cells, overcoming this common tumor resistance mechanism. In this study, an analog of C-1027, 20'-deschloro-C-1027 was examined for its ability to induce DNA ICLs under hypoxic conditions. Deschloro-induced ICLs were detected under hypoxic cell-free conditions, with a concomitant reduction in the induction of DNA strand breaks. In cells deschloro behaved similarly, inducing cellular ICLs under hypoxic conditions with a reduction in DNA breaks. The cytotoxicity of deschloro treatment was similar in normoxic and hypoxic cells, suggesting that the ICL induction allows deschloro to retain its cytotoxic activity under hypoxia. It appears that rational engineering of the C-1027 family of radiomimetics holds promise toward overcoming the radioresistance associated with the hypoxic environment associated with solid tumors. PMID:24986640

  10. The radiomimetic enediyne, 20′-deschloro-C-1027 induces inter-strand DNA crosslinks in hypoxic cells and overcomes cytotoxic radioresistance

    PubMed Central

    Beerman, Terry A.; Gawron, Loretta S.; Shen, Ben; Kennedy, Daniel R.

    2014-01-01

    The ability of the radiomimetic anti-tumor enediyne C-1027 to induce DNA inter-strand crosslinks (ICLs), in addition to the expected DNA strand breaks, is unique among traditional DNA targeted cancer therapies. Importantly, radiation therapy and most radiomimetic drugs have diminished effect in hypoxic environments due to decreased induction of DNA strand breaks, which is an oxygen requiring process. However, C-1027’s induction of ICLs is enhanced under hypoxia and it is actually more potent against hypoxic cells, overcoming this common tumor resistance mechanism. In this study, an analog of C-1027, 20′deschloro-C-1027 was examined for its ability to induce DNA ICLs under hypoxic conditions. Deschloro-induced ICLs were detected under hypoxic cell-free conditions, with a concomitant reduction in the induction of DNA strand breaks. In cells deschloro behaved similarly, inducing cellular ICLs under hypoxic conditions with a reduction in DNA breaks. The cytotoxicity of deschloro treatment was similar in normoxic and hypoxic cells, suggesting that the ICL induction allows deschloro to retain its cytotoxic activity under hypoxia. It appears that rational engineering of the C-1027 family of radiomimetics holds promise toward overcoming the radioresistance associated with the hypoxic environment associated with solid tumors. PMID:24986640

  11. MicroRNA-196a promotes an oncogenic effect in head and neck cancer cells by suppressing annexin A1 and enhancing radioresistance.

    PubMed

    Suh, Yae-Eun; Raulf, Nina; Gäken, Joop; Lawler, Katherine; Urbano, Teresa Guerrero; Bullenkamp, Jessica; Gobeil, Stéphane; Huot, Jacques; Odell, Eddy; Tavassoli, Mahvash

    2015-09-01

    Radiotherapy is a major treatment modality for head and neck squamous cell carcinoma (HNSCC). Up to 50% of patients with locally advanced disease relapse after radical treatment and there is therefore a need to develop predictive bomarkers for clinical use that allow the selection of patients who are likely to respond. MicroRNA (miRNA) expression profiling of a panel of HNSCC tumours with and without recurrent disease after surgery and radiotherapy detected miR-196a as one of the highest upregulated miRNAs in the poor prognostic group. To further study the role of miR-196a, its expression was determined in eight head and neck cancer cell lines. Overexpression of miR-196a in HNSCC cells, with low endogenous miR-196a expression, significantly increased cell proliferation, migration and invasion, and induced epithelial to mesenchymal transition. Conversely, miR-196a knockdown in cells with high endogenous expression levels significantly reduced oncogenic behaviour. Importantly, overexpression of miR-196a increased radioresistance of cells as measured by gamma H2AX staining and MTT survival assay. Annexin A1 (ANXA1), a known target of miR-196a, was found to be directly modulated by miR-196a as measured by luciferase assay and confirmed by Western blot analysis. ANXA1 knockdown in HNSCC exhibited similar phenotypic effects to miR-196a overexpression, suggesting the oncogenic effect of miR-196a may at least be partly regulated through suppression of ANXA1. In conclusion, this study identifies miR-196a as a potential important biomarker of prognosis and response of HNSCC to radiotherapy. Furthermore, our data suggest that miR-196a and/or its target gene ANXA1 could represent important therapeutic targets in HNSCC. PMID:25523631

  12. Cancer-associated adipocytes promotes breast tumor radioresistance

    SciTech Connect

    Bochet, Ludivine; Meulle, Aline; Imbert, Sandrine; Salles, Bernard; Valet, Philippe; Muller, Catherine

    2011-07-22

    Highlights: {yields} Tumor-surrounding adipocytes contribute to breast cancer progression. {yields} Breast tumor cells previously co-cultivated with mature adipocytes exhibit radioresistance. {yields} Increased in Chk1 phosphorylation is observed in irradiated co-cultivated tumor cells. {yields} IL-6 is over-expressed in tumor cells co-cultivated with adipocytes. {yields} IL-6 exposure confers increased Chk1 phosphorylation and radioresistance in tumor cells. -- Abstract: Mature adipocytes are excellent candidates to influence tumor behavior through heterotypic signaling processes since these cells produce hormones, growth factors, cytokines and other molecules, a heterogeneous group of molecules named adipokines. Using a 2D coculture system, we demonstrate that breast tumor cells previously co-cultivated with mature adipocytes exhibit radioresistance and an earlier and higher increase in the effector kinase Chk1, a phenotype that was associated with decreased cell death as compared to tumor cells grown alone. Interestingly, the adipocytes-induced tumor changes taking place during the coculture time preceding the exposure to IR were sufficient to confer the radioresistant effect. Notorious among the changes brought by adipocytes was the significant increase of IL-6 expression in tumor cells, whose activity may well account for the observed tumor cell protection from IR toxicity. Indeed, our data confirmed the protective role of this cytokine as tumor cells incubated after irradiation with recombinant IL-6 exhibit an increased in Chk1 phosphorylation and a radioresistant phenotype, thus far recapitulating the effects observed in the presence of adipocytes. Our current study sheds light on a new role of tumor-surrounding adipocytes in fostering a radioresistant phenotype in breast tumors, a finding that might have important clinical implications in obese patients that frequently exhibit aggressive diseases.

  13. Smad2/3-Regulated Expression of DLX2 Is Associated with Radiation-Induced Epithelial-Mesenchymal Transition and Radioresistance of A549 and MDA-MB-231 Human Cancer Cell Lines

    PubMed Central

    Choi, Yeo-Jin; Baek, Ga-Young; Park, Hae-Ran; Jo, Sung-Kee; Jung, Uhee

    2016-01-01

    The control of radioresistance and metastatic potential of surviving cancer cells is important for improving cancer eradication by radiotheraphy. The distal-less homeobox2 (DLX2) gene encodes for a homeobox transcription factor involved in morphogenesis and its deregulation was found in human solid tumors and hematologic malignancies. Here we investigated the role of DLX2 in association with radiation-induced epithelial to mesenchymal transition (EMT) and stem cell-like properties and its regulation by Smad2/3 signaling in irradiated A549 and MDA-MB-231 human cancer cell lines. In irradiated A549 and MDA-MB-231 cells, EMT was induced as demonstrated by EMT marker expression, phosphorylation of Smad2/3, and migratory and invasive ability. Also, irradiated A549 and MDA-MB-231 cells showed increased cancer stem cells (CSCs) marker. Interestingly, DLX2 was overexpressed upon irradiation. Therefore, we examined the role of DLX2 in radiation-induced EMT and radioresistance. The overexpression of DLX2 alone induced EMT, migration and invasion, and CSC marker expression. The reduced colony-forming ability in irradiated cells was partially restored by DLX2 overexpression. On the other hand, the depletion of DLX2 using si-RNA abolished radiation-induced EMT, CSC marker expression, and phosphorylation of Smad2/3 in irradiated A549 and MDA-MB-231 cells. Also, depletion of DLX2 increased the radiation sensitivity in both cell lines. Moreover, knockdown of Smad2/3, a key activator of TGF-β1 pathway, abrogated the radiation-induced DLX2 expression, indicating that radiation-induced DLX2 expression is dependent on Smad2/3 signaling. These results demonstrated that DLX2 plays a crucial role in radioresistance, radiation-induced EMT and CSC marker expression, and the expression of DLX2 is regulated by Smad2/3 signaling in A549 and MDA-MB-231 cell lines. PMID:26799321

  14. Smad2/3-Regulated Expression of DLX2 Is Associated with Radiation-Induced Epithelial-Mesenchymal Transition and Radioresistance of A549 and MDA-MB-231 Human Cancer Cell Lines.

    PubMed

    Choi, Yeo-Jin; Baek, Ga-Young; Park, Hae-Ran; Jo, Sung-Kee; Jung, Uhee

    2016-01-01

    The control of radioresistance and metastatic potential of surviving cancer cells is important for improving cancer eradication by radiotheraphy. The distal-less homeobox2 (DLX2) gene encodes for a homeobox transcription factor involved in morphogenesis and its deregulation was found in human solid tumors and hematologic malignancies. Here we investigated the role of DLX2 in association with radiation-induced epithelial to mesenchymal transition (EMT) and stem cell-like properties and its regulation by Smad2/3 signaling in irradiated A549 and MDA-MB-231 human cancer cell lines. In irradiated A549 and MDA-MB-231 cells, EMT was induced as demonstrated by EMT marker expression, phosphorylation of Smad2/3, and migratory and invasive ability. Also, irradiated A549 and MDA-MB-231 cells showed increased cancer stem cells (CSCs) marker. Interestingly, DLX2 was overexpressed upon irradiation. Therefore, we examined the role of DLX2 in radiation-induced EMT and radioresistance. The overexpression of DLX2 alone induced EMT, migration and invasion, and CSC marker expression. The reduced colony-forming ability in irradiated cells was partially restored by DLX2 overexpression. On the other hand, the depletion of DLX2 using si-RNA abolished radiation-induced EMT, CSC marker expression, and phosphorylation of Smad2/3 in irradiated A549 and MDA-MB-231 cells. Also, depletion of DLX2 increased the radiation sensitivity in both cell lines. Moreover, knockdown of Smad2/3, a key activator of TGF-β1 pathway, abrogated the radiation-induced DLX2 expression, indicating that radiation-induced DLX2 expression is dependent on Smad2/3 signaling. These results demonstrated that DLX2 plays a crucial role in radioresistance, radiation-induced EMT and CSC marker expression, and the expression of DLX2 is regulated by Smad2/3 signaling in A549 and MDA-MB-231 cell lines. PMID:26799321

  15. FoxM1 Promotes Stemness and Radio-Resistance of Glioblastoma by Regulating the Master Stem Cell Regulator Sox2

    PubMed Central

    Kim, Dong Geon; Cho, Hee Jin; Kim, Yeonghwan; Rheey, Jinguen; Shin, Kayoung; Seo, Yun Jee; Choi, Yeon-Sook; Lee, Jung-Il; Lee, Jeongwu; Joo, Kyeung Min; Nam, Do-Hyun

    2015-01-01

    Glioblastoma (GBM) is the most aggressive and most lethal brain tumor. As current standard therapy consisting of surgery and chemo-irradiation provides limited benefit for GBM patients, novel therapeutic options are urgently required. Forkhead box M1 (FoxM1) transcription factor is an oncogenic regulator that promotes the proliferation, survival, and treatment resistance of various human cancers. The roles of FoxM1 in GBM remain incompletely understood, due in part to pleotropic nature of the FoxM1 pathway. Here, we show the roles of FoxM1 in GBM stem cell maintenance and radioresistance. ShRNA-mediated FoxM1 inhibition significantly impeded clonogenic growth and survival of patient-derived primary GBM cells with marked downregulation of Sox2, a master regulator of stem cell phenotype. Ectopic expression of Sox2 partially rescued FoxM1 inhibition-mediated effects. Conversely, FoxM1 overexpression upregulated Sox2 expression and promoted clonogenic growth of GBM cells. These data, with a direct binding of FoxM1 in the Sox2 promoter region in GBM cells, suggest that FoxM1 regulates stemness of primary GBM cells via Sox2. We also found significant increases in FoxM1 and Sox2 expression in GBM cells after irradiation both in vitro and in vivo orthotopic tumor models. Notably, genetic or a small-molecule FoxM1 inhibitor-mediated FoxM1 targeting significantly sensitized GBM cells to irradiation, accompanying with Sox2 downregulation. Finally, FoxM1 inhibition combined with irradiation in a patient GBM-derived orthotopic model significantly impeded tumor growth and prolonged the survival of tumor bearing mice. Taken together, these results indicate that the FoxM1-Sox2 signaling axis promotes clonogenic growth and radiation resistance of GBM, and suggest that FoxM1 targeting combined with irradiation is a potentially effective therapeutic approach for GBM. PMID:26444992

  16. Reduced RKIP enhances nasopharyngeal carcinoma radioresistance by increasing ERK and AKT activity

    PubMed Central

    Yuan, Li; Yi, Hong-Mei; Yi, Hong; Qu, Jia-Quan; Zhu, Jin-Feng; Li, Li-Na; Xiao, Ta; Zheng, Zhen; Lu, Shan-Shan; Xiao, Zhi-Qiang

    2016-01-01

    Raf kinase inhibitory protein (RKIP) functions as a chemo-immunotherapeutic sensitizer of cancers, but regulation of RKIP on tumor radiosensitivity remains largely unexplored. In this study, we investigate the role and mechanism of RKIP in nasopharyngeal carcinoma (NPC) radioresistance. The results showed that RKIP was frequently downregulated in the radioresistant NPC tissues compared with radiosensitive NPC tissues, and its reduction correlated with NPC radioresistance and poor patient survival, and was an independent prognostic factor. In vitro radioresponse assay showed that RKIP overexpression decreased while RKIP knockdown increased NPC cell radioresistance. In the NPC xenografts, RKIP overexpression decreased while RKIP knockdown increased tumor radioresistance. Mechanistically, RKIP reduction promoted NPC cell radioresistance by increasing ERK and AKT activity, and AKT may be a downstream transducer of ERK signaling. Moreover, the levels of phospho-ERK−1/2 and phospho-AKT were increased in the radioresistant NPC tissues compared with radiosensitive ones, and negatively associated with RKIP expression, indicating that RKIP-regulated NPC radioresponse is mediated by ERK and AKT signaling in the clinical samples. Our data demonstrate that RKIP is a critical determinant of NPC radioresponse, and its reduction enhances NPC radioresistance through increasing ERK and AKT signaling activity, highlighting the therapeutic potential of RKIP-ERK-AKT signaling axis in NPC radiosensitization. PMID:26862850

  17. Global whole-cell FTICR mass spectrometric proteomics analysis of the heat shock response in the radioresistant bacterium Deinococcus radiodurans

    SciTech Connect

    Schmid, Amy K.; Lipton, Mary S.; Mottaz, Heather M.; Monroe, Matthew E.; Smith, Richard D.; Lidstrom, Mary E.

    2005-05-01

    Despite intense interest in the response to radiation in D. radiodurans, little is known about how the organism responds to other stress factors. Our previous studies indicated that D. radiodurans mounts a regulated protective response to heat shock, and that expression of the groESL and dnaKJ operons are induced in response to elevated temperature. In order to gain greater insight into the heat shock response of D. radiodurans on a more global scale, we undertook the study reported here. Using whole-cell semiquantitative mass spectrometric proteomics integrated with global transcriptome microarray analyses, we have determined a core set of highly induced heat shock genes whose expression correlates well at the transcriptional and translational levels. In addition, we observed that the higher the absolute expression of a given gene at physiological conditions, the better the quantitative correlation between RNA and protein expression levels.

  18. Progeny from irradiated colorectal cancer cells acquire an EMT-like phenotype and activate Wnt/β-catenin pathway.

    PubMed

    Bastos, Lilian Gonçalves dos Reis; de Marcondes, Priscila Guimarães; de-Freitas-Junior, Julio Cesar Madureira; Leve, Fernanda; Mencalha, André Luiz; de Souza, Waldemir Fernandes; de Araujo, Wallace Martins; Tanaka, Marcelo Neves; Abdelhay, Eliana Saul Furquim Werneck; Morgado-Díaz, José Andrés

    2014-12-01

    Radiotherapy remains a major approach to adjuvant therapy for patients with advanced colorectal cancer, however, the fractionation schedules frequently allow for the repopulation of surviving tumors cells, neoplastic progression, and subsequent metastasis. The aim of the present study was to analyze the transgenerational effects induced by radiation and evaluate whether it could increase the malignant features on the progeny derived from irradiated parental colorectal cancer cells, Caco-2, HT-29, and HCT-116. The progeny of these cells displayed a differential radioresistance as seen by clonogenic and caspase activation assay and had a direct correlation with survivin expression as observed by immunoblotting. Immunofluorescence showed that the most radioresistant progenies had an aberrant morphology, disturbance of the cell-cell adhesion contacts, disorganization of the actin cytoskeleton, and vimentin filaments. Only the progeny derived from intermediary radioresistant cells, HT-29, reduced the E-cadherin expression and overexpressed β-catenin and vimentin with increased cell migration, invasion, and metalloprotease activation as seen by immunoblotting, wound healing, invasion, and metalloprotease activity assay. We also observed that this most aggressive progeny increased the Wnt/β-catenin-dependent TCF/LEF activity and underwent an upregulation of mesenchymal markers and downregulation of E-cadherin, as determined by qRT-PCR. Our results showed that the intermediate radioresistant cells can generate more aggressive cellular progeny with the EMT-like phenotype. The Wnt/β-catenin pathway may constitute an important target for new adjuvant treatment schedules with radiotherapy, with the goal of reducing the migratory and invasive potential of the remaining cells after treatment. PMID:25103643

  19. Acquired Cell-Mediated Immunodepression in Acute Chagas' Disease

    PubMed Central

    Teixeira, Antonio R. L.; Teixeira, Glória; Macêdo, Vanize; Prata, Aluizio

    1978-01-01

    In this study two groups of patients with acute Chagas' disease were identified. Group one consisted of five patients with apparent acute Chagas' disease. These patients showed symptoms and signals of an acute illness, such as high fever and enlarged spleen. One of these patients developed severe myocarditis and heart failure. Group two consisted of seven patients with inapparent acute Chagas' disease. This was a nonclinical entity, not perceived by the patient who did not seek medical care. The diagnosis was made by the shift of a serologic test which indicates the presence of immunoglobulin M antibodies to Trypanosoma cruzi. The patients with apparent acute Chagas' disease showed positive delayed-type skin response to T. cruzi antigen. Also, their leukocytes showed significant inhibition of migration in the presence of this antigen. By contrast, the patients with the inapparent acute Chagas' disease did not show positive delayed-type skin response to T. cruzi antigen and no significant inhibition was observed when their cells migrated in the presence of this antigen. Of interest, none of these patients was capable of developing contact sensitivity to 2,4-dinitrochlorobenzene. However, three out of five patients with the apparent acute disease and all the normal control subjects showed positive contact reaction after sensitization to this drug. The results of these experiments would suggest that the thymus-derived (T)-lymphocyte function is depressed in patients with the clinically inapparent acute Chagas' disease. This immunodepression seems to be acquired in the course of the T. cruzi infection because all patients showed positive delayed-type skin response to at least one ubiquitous microbial extract, thus indicating previously normal T-cell function. We hypothesize that T. cruzi antigens may directly stimulate T cells with the concomitant release of factors that might become supressive for T-cell responses. Furthermore, the suppressive effect might interfere

  20. Radiation-induced radioresistance of mammals and risk assessment

    NASA Astrophysics Data System (ADS)

    Smirnova, O.; Yonezawa, M.

    It is shown experimentally that a preliminary low dose exposure can induce radioresistance in mice in two (early and late) periods after preirradiation. The manifestation of such effects is reduced mortality of pre-exposed specimens after challenge acute irradiation, the reason of the animal death being the hematopoietic subsyndrome of the acute radiation syndrome. Therefore, proceeding from the radiobiological concept of the critical system, the theoretical investigation of the influence of preirradiation on mammalian radiosensitivity is conducted by making use of mathematical models of the vital body system, hematopoiesis. Modeling results make it possible to elucidate the mechanisms of the radioprotection effect of low level priming irradiation on mammals. Specifically, the state of acquired radioresistance in mice is caused by reduced radiosensitivity of lymphopoietic and thrombocytopoietic systems in the early period and by reduced radiosensitivity of granulocytopoietic system in the late period after preirradiation. It is important to emphasize that the evaluations of the duration of the early and late periods of postirradiation radioresistance in mice, carried out on the basis of the modeling and experimental investigations, practically coincide. All this demonstrates the effectiveness of joint modeling and experimental methods in studies and predictions of modification effects of preirradiation on mammalian radiosensitivity. The results obtained show the importance of accounting such effects in radiation risk assessments for cosmonauts and astronauts on long-term missions.

  1. LIG4 mediates Wnt signalling-induced radioresistance.

    PubMed

    Jun, Sohee; Jung, Youn-Sang; Suh, Han Na; Wang, Wenqi; Kim, Moon Jong; Oh, Young Sun; Lien, Esther M; Shen, Xi; Matsumoto, Yoshihisa; McCrea, Pierre D; Li, Lei; Chen, Junjie; Park, Jae-Il

    2016-01-01

    Despite the implication of Wnt signalling in radioresistance, the underlying mechanisms are unknown. Here we find that high Wnt signalling is associated with radioresistance in colorectal cancer (CRC) cells and intestinal stem cells (ISCs). We find that LIG4, a DNA ligase in DNA double-strand break repair, is a direct target of β-catenin. Wnt signalling enhances non-homologous end-joining repair in CRC, which is mediated by LIG4 transactivated by β-catenin. During radiation-induced intestinal regeneration, LIG4 mainly expressed in the crypts is conditionally upregulated in ISCs, accompanied by Wnt/β-catenin signalling activation. Importantly, among the DNA repair genes, LIG4 is highly upregulated in human CRC cells, in correlation with β-catenin hyperactivation. Furthermore, blocking LIG4 sensitizes CRC cells to radiation. Our results reveal the molecular mechanism of Wnt signalling-induced radioresistance in CRC and ISCs, and further unveils the unexpected convergence between Wnt signalling and DNA repair pathways in tumorigenesis and tissue regeneration. PMID:27009971

  2. LIG4 mediates Wnt signalling-induced radioresistance

    PubMed Central

    Jun, Sohee; Jung, Youn-Sang; Suh, Han Na; Wang, Wenqi; Kim, Moon Jong; Oh, Young Sun; Lien, Esther M.; Shen, Xi; Matsumoto, Yoshihisa; McCrea, Pierre D.; Li, Lei; Chen, Junjie; Park, Jae-Il

    2016-01-01

    Despite the implication of Wnt signalling in radioresistance, the underlying mechanisms are unknown. Here we find that high Wnt signalling is associated with radioresistance in colorectal cancer (CRC) cells and intestinal stem cells (ISCs). We find that LIG4, a DNA ligase in DNA double-strand break repair, is a direct target of β-catenin. Wnt signalling enhances non-homologous end-joining repair in CRC, which is mediated by LIG4 transactivated by β-catenin. During radiation-induced intestinal regeneration, LIG4 mainly expressed in the crypts is conditionally upregulated in ISCs, accompanied by Wnt/β-catenin signalling activation. Importantly, among the DNA repair genes, LIG4 is highly upregulated in human CRC cells, in correlation with β-catenin hyperactivation. Furthermore, blocking LIG4 sensitizes CRC cells to radiation. Our results reveal the molecular mechanism of Wnt signalling-induced radioresistance in CRC and ISCs, and further unveils the unexpected convergence between Wnt signalling and DNA repair pathways in tumorigenesis and tissue regeneration. PMID:27009971

  3. Cell-of-Origin-Specific 3D Genome Structure Acquired during Somatic Cell Reprogramming

    PubMed Central

    Krijger, Peter Hugo Lodewijk; Di Stefano, Bruno; de Wit, Elzo; Limone, Francesco; van Oevelen, Chris; de Laat, Wouter; Graf, Thomas

    2016-01-01

    Summary Forced expression of reprogramming factors can convert somatic cells into induced pluripotent stem cells (iPSCs). Here we studied genome topology dynamics during reprogramming of different somatic cell types with highly distinct genome conformations. We find large-scale topologically associated domain (TAD) repositioning and alterations of tissue-restricted genomic neighborhoods and chromatin loops, effectively erasing the somatic-cell-specific genome structures while establishing an embryonic stem-cell-like 3D genome. Yet, early passage iPSCs carry topological hallmarks that enable recognition of their cell of origin. These hallmarks are not remnants of somatic chromosome topologies. Instead, the distinguishing topological features are acquired during reprogramming, as we also find for cell-of-origin-dependent gene expression patterns. PMID:26971819

  4. Leukemia inhibitory factor promotes nasopharyngeal carcinoma progression and radioresistance

    PubMed Central

    Liu, Shu-Chen; Tsang, Ngan-Ming; Chiang, Wen-Che; Chang, Kai-Ping; Hsueh, Chuen; Liang, Ying; Juang, Jyh-Lyh; Chow, Kai-Ping N.; Chang, Yu-Sun

    2013-01-01

    Radioresistance of EBV-associated nasopharyngeal carcinoma (NPC) is associated with poor prognosis for patients with this form of cancer. Here, we found that NPC patients had increased serum levels of leukemia inhibitory factor (LIF) and that higher LIF levels correlated with local tumor recurrence. Furthermore, in vitro studies with NPC cells and in vivo xenograft mouse studies demonstrated that LIF critically contributes to NPC tumor growth and radioresistance. Using these model systems, we found that LIF treatment activated the mTORC1/p70S6K signaling pathway, enhanced tumor growth, inhibited DNA damage responses, and enhanced radioresistance. Treatment with either soluble LIF receptor (sLIFR), a LIF antagonist, or the mTOR inhibitor rapamycin reversed LIF-mediated effects, resulting in growth arrest and increased sensitivity to γ irradiation. Immunohistochemical (IHC) analyses of human NPC biopsies revealed that LIF and LIFR were overexpressed in tumor cells and that LIF expression correlated with the presence of the activated p-p70S6K. Finally, we found that the EBV-encoded protein latent membrane protein 1 (LMP1) enhances LIF production. Together, our findings indicate that LIF promotes NPC tumorigenesis and suggest that serum LIF levels may predict local recurrence and radiosensitivity in NPC patients. PMID:24270418

  5. Small Cell Variant of T-Cell Prolymphocytic Leukemia with Acquired Palmoplantar Keratoderma and Cutaneous Infiltration

    PubMed Central

    Al-Musalhi, Buthaina; Shehata, Nancy; Billick, Robin

    2016-01-01

    T-cell prolymphocytic leukemia (T-PLL) is a rare and aggressive post-thymic malignancy that is characterized by the proliferation of small- to medium- sized prolymphocytes. The classic clinical features of T-PLL are lymphocytosis, lymphadenopathy, hepatosplenomegaly, and skin lesions. Skin involvement varies clinically from diffuse infiltrated erythema. Infiltration is localized to the face and ears, nodules, and erythroderma. We present a case of small cell variant of T-PLL in a patient who presented with unusual cutaneous manifestations of acquired palmoplantar keratoderma (PPK) followed by diffuse erythematous infiltrated papules and plaques involving the trunk. When the etiology of acquired PPK is not clear, the physician should consider the possibility of an underlying malignant disease. In this case, the diagnosis of T-PLL was subsequently confirmed by laboratory and cytological findings, as well as by the immunophenotyping of leukemic cells in skin biopsy. Since paraneoplastic acquired PPK may be the initial evident sign of malignancy, the physician’s awareness of this manifestation may be crucial for early diagnosis and treatment. Our case emphasizes the importance of accurate evaluation of skin lesions and early skin biopsy in the diagnosis of some hematological malignancies. PMID:26813734

  6. Small Cell Variant of T-Cell Prolymphocytic Leukemia with Acquired Palmoplantar Keratoderma and Cutaneous Infiltration.

    PubMed

    Al-Musalhi, Buthaina; Shehata, Nancy; Billick, Robin

    2016-01-01

    T-cell prolymphocytic leukemia (T-PLL) is a rare and aggressive post-thymic malignancy that is characterized by the proliferation of small- to medium- sized prolymphocytes. The classic clinical features of T-PLL are lymphocytosis, lymphadenopathy, hepatosplenomegaly, and skin lesions. Skin involvement varies clinically from diffuse infiltrated erythema. Infiltration is localized to the face and ears, nodules, and erythroderma. We present a case of small cell variant of T-PLL in a patient who presented with unusual cutaneous manifestations of acquired palmoplantar keratoderma (PPK) followed by diffuse erythematous infiltrated papules and plaques involving the trunk. When the etiology of acquired PPK is not clear, the physician should consider the possibility of an underlying malignant disease. In this case, the diagnosis of T-PLL was subsequently confirmed by laboratory and cytological findings, as well as by the immunophenotyping of leukemic cells in skin biopsy. Since paraneoplastic acquired PPK may be the initial evident sign of malignancy, the physician's awareness of this manifestation may be crucial for early diagnosis and treatment. Our case emphasizes the importance of accurate evaluation of skin lesions and early skin biopsy in the diagnosis of some hematological malignancies. PMID:26813734

  7. Extracellular matrix metalloproteinase inducer (CD147/BSG/EMMPRIN)-induced radioresistance in cervical cancer by regulating the percentage of the cells in the G2/m phase of the cell cycle and the repair of DNA Double-strand Breaks (DSBs).

    PubMed

    Ju, Xingzhu; Liang, Shanhui; Zhu, Jun; Ke, Guihao; Wen, Hao; Wu, Xiaohua

    2016-01-01

    Our preliminary study found that CD147 is related to radioresistance and maybe an adverse prognostic factor in cervical cancer. To date, the mechanisms underlying CD147-induced radioresistance in cervical cancer remain unclear. In the present study, we investigated the mechanisms by which CD147 affects radiosensitivity in cervical cancer both in vitro and in vivo. In this study, the clonogenic assay showed that radiosensitivity was significantly higher in the experimental group (the CD147-negative cell lines) than in the control group (the CD147-positive cell lines). After radiotherapy, the residual tumour volume was significantly lower in the experimental group. FCM analysis showed the cells percentage in the G2/M phase of the cell cycle were significantly higher in the CD147-negative group than in the control group. However, there was no significant difference in terms of apoptosis. The expression of gamma-H2A histone family, member X (γH2AX) was dramatically elevated in the CD147-negative cell lines after irradiation, but the expression of ataxia-telangiectasia mutated (ATM) was not different between the two groups. WB analysis did not show any other proteins relating to the expression of CD147. In conclusion, it is likely that CD147 regulates radioresistance by regulating the percentage of the cells in the G2/M phase of the cell cycle and the repair of DNA double-strand breaks (DSBs). Inhibition of CD147 expression enhances the radiosensitivity of cervical cancer cell lines and promotes post-radiotherapy xenograft tumour regression in nude mice. Therefore, CD147 may be used in individualized therapy against cervical cancer and is worth further exploration. PMID:27398135

  8. Extracellular matrix metalloproteinase inducer (CD147/BSG/EMMPRIN)-induced radioresistance in cervical cancer by regulating the percentage of the cells in the G2/m phase of the cell cycle and the repair of DNA Double-strand Breaks (DSBs)

    PubMed Central

    Ju, Xingzhu; Liang, Shanhui; Zhu, Jun; Ke, Guihao; Wen, Hao; Wu, Xiaohua

    2016-01-01

    Our preliminary study found that CD147 is related to radioresistance and maybe an adverse prognostic factor in cervical cancer. To date, the mechanisms underlying CD147-induced radioresistance in cervical cancer remain unclear. In the present study, we investigated the mechanisms by which CD147 affects radiosensitivity in cervical cancer both in vitro and in vivo. In this study, the clonogenic assay showed that radiosensitivity was significantly higher in the experimental group (the CD147-negative cell lines) than in the control group (the CD147-positive cell lines). After radiotherapy, the residual tumour volume was significantly lower in the experimental group. FCM analysis showed the cells percentage in the G2/M phase of the cell cycle were significantly higher in the CD147-negative group than in the control group. However, there was no significant difference in terms of apoptosis. The expression of gamma-H2A histone family, member X (γH2AX) was dramatically elevated in the CD147-negative cell lines after irradiation, but the expression of ataxia-telangiectasia mutated (ATM) was not different between the two groups. WB analysis did not show any other proteins relating to the expression of CD147. In conclusion, it is likely that CD147 regulates radioresistance by regulating the percentage of the cells in the G2/M phase of the cell cycle and the repair of DNA double-strand breaks (DSBs). Inhibition of CD147 expression enhances the radiosensitivity of cervical cancer cell lines and promotes post-radiotherapy xenograft tumour regression in nude mice. Therefore, CD147 may be used in individualized therapy against cervical cancer and is worth further exploration. PMID:27398135

  9. FGFR1 Induces Glioblastoma Radioresistance through the PLCγ/Hif1α Pathway.

    PubMed

    Gouazé-Andersson, Valérie; Delmas, Caroline; Taurand, Marion; Martinez-Gala, Judith; Evrard, Solène; Mazoyer, Sandrine; Toulas, Christine; Cohen-Jonathan-Moyal, Elizabeth

    2016-05-15

    FGF2 signaling in glioblastoma induces resistance to radiotherapy, so targeting FGF2/FGFR pathways might offer a rational strategy for tumor radiosensitization. To investigate this possibility, we evaluated a specific role for FGFR1 in glioblastoma radioresistance as modeled by U87 and LN18 glioblastomas in mouse xenograft models. Silencing FGFR1 decreased radioresistance in a manner associated with radiation-induced centrosome overduplication and mitotic cell death. Inhibiting PLCγ (PLCG1), a downstream effector signaling molecule for FGFR1, was sufficient to produce similar effects, arguing that PLCγ is an essential mediator of FGFR1-induced radioresistance. FGFR1 silencing also reduced expression of HIF1α, which in addition to its roles in hypoxic responses exerts an independent effect on radioresistance. Finally, FGFR1 silencing delayed the growth of irradiated tumor xenografts, in a manner that was associated with reduced HIF1α levels but not blood vessel alterations. Taken together, our results offer a preclinical proof of concept that FGFR1 targeting can degrade radioresistance in glioblastoma, a widespread problem in this tumor, prompting clinical investigations of the use of FGFR1 inhibitors for radiosensitization. Cancer Res; 76(10); 3036-44. ©2016 AACR. PMID:26896280

  10. DNA Repair and Cytokines: TGF-β, IL-6, and Thrombopoietin as Different Biomarkers of Radioresistance.

    PubMed

    Centurione, Lucia; Aiello, Francesca B

    2016-01-01

    Double strand breaks (DSBs) induced by radiotherapy are highly cytotoxic lesions, leading to chromosomal aberrations and cell death. Ataxia-telangiectasia-mutated (ATM)-dependent DNA-damage response, non-homologous end joining, and homologous recombination pathways coordinately contribute to repairing DSBs in higher eukaryotes. It is known that the expression of DSB repair genes is increased in tumors, which is one of the main reasons for radioresistance. The inhibition of DSB repair pathways may be useful to increase tumor cell radiosensitivity and may target stem cell-like cancer cells, known to be the most radioresistant tumor components. Commonly overexpressed in neoplastic cells, cytokines confer radioresistance by promoting proliferation, survival, invasion, and angiogenesis. Unfortunately, tumor irradiation increases the expression of various cytokines displaying these effects, including transforming growth factor-beta and interleukin-6. Recently, the capabilities of these cytokines to support DNA repair pathways and the ATM-dependent DNA response have been demonstrated. Thrombopoietin, essential for megakaryopoiesis and very important for hematopoietic stem cell (HSC) homeostasis, has also been found to promote DNA repair in a highly selective manner. These findings reveal a novel mechanism underlying cytokine-related radioresistance, which may be clinically relevant. Therapies targeting specific cytokines may be used to improve radiosensitivity. Specific inhibitors may be chosen in consideration of different tumor microenvironments. Thrombopoietin may be useful in fending off irradiation-induced loss of HSCs. PMID:27500125

  11. DNA Repair and Cytokines: TGF-β, IL-6, and Thrombopoietin as Different Biomarkers of Radioresistance

    PubMed Central

    Centurione, Lucia; Aiello, Francesca B.

    2016-01-01

    Double strand breaks (DSBs) induced by radiotherapy are highly cytotoxic lesions, leading to chromosomal aberrations and cell death. Ataxia-telangiectasia-mutated (ATM)-dependent DNA-damage response, non-homologous end joining, and homologous recombination pathways coordinately contribute to repairing DSBs in higher eukaryotes. It is known that the expression of DSB repair genes is increased in tumors, which is one of the main reasons for radioresistance. The inhibition of DSB repair pathways may be useful to increase tumor cell radiosensitivity and may target stem cell-like cancer cells, known to be the most radioresistant tumor components. Commonly overexpressed in neoplastic cells, cytokines confer radioresistance by promoting proliferation, survival, invasion, and angiogenesis. Unfortunately, tumor irradiation increases the expression of various cytokines displaying these effects, including transforming growth factor-beta and interleukin-6. Recently, the capabilities of these cytokines to support DNA repair pathways and the ATM-dependent DNA response have been demonstrated. Thrombopoietin, essential for megakaryopoiesis and very important for hematopoietic stem cell (HSC) homeostasis, has also been found to promote DNA repair in a highly selective manner. These findings reveal a novel mechanism underlying cytokine-related radioresistance, which may be clinically relevant. Therapies targeting specific cytokines may be used to improve radiosensitivity. Specific inhibitors may be chosen in consideration of different tumor microenvironments. Thrombopoietin may be useful in fending off irradiation-induced loss of HSCs. PMID:27500125

  12. Critical Role of Aberrant Angiogenesis in the Development of Tumor Hypoxia and Associated Radioresistance

    PubMed Central

    Multhoff, Gabriele; Radons, Jürgen; Vaupel, Peter

    2014-01-01

    Newly formed microvessels in most solid tumors show an abnormal morphology and thus do not fulfil the metabolic demands of the growing tumor mass. Due to the chaotic and heterogeneous tumor microcirculation, a hostile tumor microenvironment develops, that is characterized inter alia by local hypoxia, which in turn can stimulate the HIF-system. The latter can lead to tumor progression and may be involved in hypoxia-mediated radioresistance of tumor cells. Herein, cellular and molecular mechanisms in tumor angiogenesis are discussed that, among others, might impact hypoxia-related radioresistance. PMID:24717239

  13. Radiation-Induced Glycogen Accumulation Detected by Single Cell Raman Spectroscopy Is Associated with Radioresistance that Can Be Reversed by Metformin.

    PubMed

    Matthews, Quinn; Isabelle, Martin; Harder, Samantha J; Smazynski, Julian; Beckham, Wayne; Brolo, Alexandre G; Jirasek, Andrew; Lum, Julian J

    2015-01-01

    Altered cellular metabolism is a hallmark of tumor cells and contributes to a host of properties associated with resistance to radiotherapy. Detection of radiation-induced biochemical changes can reveal unique metabolic pathways affecting radiosensitivity that may serve as attractive therapeutic targets. Using clinically relevant doses of radiation, we performed label-free single cell Raman spectroscopy on a series of human cancer cell lines and detected radiation-induced accumulation of intracellular glycogen. The increase in glycogen post-irradiation was highest in lung (H460) and breast (MCF7) tumor cells compared to prostate (LNCaP) tumor cells. In response to radiation, the appearance of this glycogen signature correlated with radiation resistance. Moreover, the buildup of glycogen was linked to the phosphorylation of GSK-3β, a canonical modulator of cell survival following radiation exposure and a key regulator of glycogen metabolism. When MCF7 cells were irradiated in the presence of the anti-diabetic drug metformin, there was a significant decrease in the amount of radiation-induced glycogen. The suppression of glycogen by metformin following radiation was associated with increased radiosensitivity. In contrast to MCF7 cells, metformin had minimal effects on both the level of glycogen in H460 cells following radiation and radiosensitivity. Our data demonstrate a novel approach of spectral monitoring by Raman spectroscopy to assess changes in the levels of intracellular glycogen as a potential marker and resistance mechanism to radiation therapy. PMID:26280348

  14. Radiation-Induced Glycogen Accumulation Detected by Single Cell Raman Spectroscopy Is Associated with Radioresistance that Can Be Reversed by Metformin

    PubMed Central

    Matthews, Quinn; Isabelle, Martin; Harder, Samantha J.; Smazynski, Julian; Beckham, Wayne; Brolo, Alexandre G.; Jirasek, Andrew; Lum, Julian J.

    2015-01-01

    Altered cellular metabolism is a hallmark of tumor cells and contributes to a host of properties associated with resistance to radiotherapy. Detection of radiation-induced biochemical changes can reveal unique metabolic pathways affecting radiosensitivity that may serve as attractive therapeutic targets. Using clinically relevant doses of radiation, we performed label-free single cell Raman spectroscopy on a series of human cancer cell lines and detected radiation-induced accumulation of intracellular glycogen. The increase in glycogen post-irradiation was highest in lung (H460) and breast (MCF7) tumor cells compared to prostate (LNCaP) tumor cells. In response to radiation, the appearance of this glycogen signature correlated with radiation resistance. Moreover, the buildup of glycogen was linked to the phosphorylation of GSK-3β, a canonical modulator of cell survival following radiation exposure and a key regulator of glycogen metabolism. When MCF7 cells were irradiated in the presence of the anti-diabetic drug metformin, there was a significant decrease in the amount of radiation-induced glycogen. The suppression of glycogen by metformin following radiation was associated with increased radiosensitivity. In contrast to MCF7 cells, metformin had minimal effects on both the level of glycogen in H460 cells following radiation and radiosensitivity. Our data demonstrate a novel approach of spectral monitoring by Raman spectroscopy to assess changes in the levels of intracellular glycogen as a potential marker and resistance mechanism to radiation therapy. PMID:26280348

  15. Human-induced pluripotent stem cells from blood cells of healthy donors and patients with acquired blood disorders

    PubMed Central

    Ye, Zhaohui; Zhan, Huichun; Mali, Prashant; Dowey, Sarah; Williams, Donna M.; Jang, Yoon-Young; Dang, Chi V.; Spivak, Jerry L.; Moliterno, Alison R.

    2009-01-01

    Human induced pluripotent stem (iPS) cells derived from somatic cells hold promise to develop novel patient-specific cell therapies and research models for inherited and acquired diseases. We and others previously reprogrammed human adherent cells, such as postnatal fibroblasts to iPS cells, which resemble adherent embryonic stem cells. Here we report derivation of iPS cells from postnatal human blood cells and the potential of these pluripotent cells for disease modeling. Multiple human iPS cell lines were generated from previously frozen cord blood or adult CD34+ cells of healthy donors, and could be redirected to hematopoietic differentiation. Multiple iPS cell lines were also generated from peripheral blood CD34+ cells of 2 patients with myeloproliferative disorders (MPDs) who acquired the JAK2-V617F somatic mutation in their blood cells. The MPD-derived iPS cells containing the mutation appeared normal in phenotypes, karyotype, and pluripotency. After directed hematopoietic differentiation, the MPD-iPS cell-derived hematopoietic progenitor (CD34+CD45+) cells showed the increased erythropoiesis and gene expression of specific genes, recapitulating features of the primary CD34+ cells of the corresponding patient from whom the iPS cells were derived. These iPS cells provide a renewable cell source and a prospective hematopoiesis model for investigating MPD pathogenesis. PMID:19797525

  16. Inhibition of mitochondrial glutaminase activity reverses acquired erlotinib resistance in non-small cell lung cancer

    PubMed Central

    Xie, Caifeng; Jin, Jiangbo; Bao, Xujie; Zhan, Wei-Hua; Han, Tian-Yu; Gan, Mingxi; Zhang, Chengfu; Wang, Jianbin

    2016-01-01

    The epidermal growth factor receptor (EGFR) tyrosine kinase inhibitor (TKI) erlotinib has been approved based on the clinical benefit in non-small cell lung cancer (NSCLC) patients over the past decade. Unfortunately, cancer cells become resistant to this agent via various mechanisms, and this limits the improvement in patient outcomes. Thus, it is urgent to develop novel agents to overcome erlotinib resistance. Here, we propose a novel strategy to overcome acquired erlotinib resistance in NSCLC by inhibiting glutaminase activity. Compound 968, an inhibitor of the glutaminase C (GAC), when combined with erlotinib potently inhibited the cell proliferation of erlotinib-resistant NSCLC cells HCC827ER and NCI-H1975. The combination of compound 968 and erlotinib not only decreased GAC and EGFR protein expression but also inhibited GAC activity in HCC827ER cells. The growth of erlotinib-resistant cells was glutamine-dependent as proved by GAC gene knocked down and rescue experiment. More importantly, compound 968 combined with erlotinib down-regulated the glutamine and glycolysis metabolism in erlotinib-resistant cells. Taken together, our study provides a valuable approach to overcome acquired erlotinib resistance by blocking glutamine metabolism and suggests that combination of EGFR-TKI and GAC inhibitor maybe a potential treatment strategy for acquired erlotinib-resistant NSCLC. PMID:26575584

  17. MiR-95 induces proliferation and chemo- or radioresistance through directly targeting sorting nexin1 (SNX1) in non-small cell lung cancer.

    PubMed

    Chen, Xiaochun; Chen, Shaomu; Hang, Weijie; Huang, Haitao; Ma, Haitao

    2014-06-01

    MicroRNAs are emerging as a class of small regulatory RNAs whose specific roles and significant functions in the majority of carcinomas have yet to be entirely illustrated. The aim of this study is to explore the effect of miR-95 and determine whether miR-95 could be a potential therapeutic target for human non-small cell lung cancer. First of all, our study showed that miR-95 was highly expressed in both NSCLC cell lines (compared with normal cells) and tumor tissues (compared with corresponding normal tissues), whereas the protein level of SNX1 was downregulated in NSCLC cell lines. Next, we found that ectopic overexpression of miR-95 in A549 or H226 contributed to tumor growth in xenograft mouse models. In addition, the results also indicated that upregulation of miR-95 could significantly enhance the susceptibilities of NSCLC cells to chemo- or radiotherapy. Furthermore, using the luciferase reporter, we demonstrated that SNX1 is a direct target of miR-95. Meanwhile, overexpression of SNX1 could abrogate the growth of NSCLC cells induced by miR-95. Taken together, these results suggest that miR-95 functions as an oncogene role in NSCLC cells by directly targeting SNX1. PMID:24835695

  18. Managing acquired resistance in EGFR-mutated non-small cell lung cancer.

    PubMed

    Forde, Patrick M; Ettinger, David S

    2015-08-01

    Epidermal growth factor receptor (EGFR) tyrosine kinase inhibitors (TKIs) deliver high response rates with relatively modest toxicity in patients with advanced EGFR-mutated non-small cell lung cancer. Despite this, nearly all tumors eventually develop resistance to first-line therapy. At present, the only standard treatment option for patients with acquired resistance is cytotoxic chemotherapy. In this article, we review the latest research into methods of targeting acquired resistance to EGFR TKI therapy, including third-generation EGFR TKIs that target the T790M resistance mutation and other novel agents in development. PMID:26351816

  19. Overexpression of Specific CD44 Isoforms Is Associated with Aggressive Cell Features in Acquired Endocrine Resistance

    PubMed Central

    Bellerby, Rebecca; Smith, Chris; Kyme, Sue; Gee, Julia; Günthert, Ursula; Green, Andy; Rakha, Emad; Barrett-Lee, Peter; Hiscox, Stephen

    2016-01-01

    While endocrine therapy is the mainstay of ER+ breast cancer, the clinical effectiveness of these agents is limited by the phenomenon of acquired resistance that is associated with disease relapse and poor prognosis. Our previous studies revealed that acquired resistance is accompanied by a gain in cellular invasion and migration and also that CD44 family proteins are overexpressed in the resistant phenotype. Given the association of CD44 with tumor progression, we hypothesized that its overexpression may act to promote the aggressive behavior of endocrine-resistant breast cancers. Here, we have investigated further the role of two specific CD44 isoforms, CD44v3 and CD44v6, in the endocrine-resistant phenotype. Our data revealed that overexpression of CD44v6, but not CD44v3, in endocrine-sensitive MCF-7 cells resulted in a gain in EGFR signaling, enhanced their endogenous invasive capacity, and attenuated their response to endocrine treatment. Suppression of CD44v6 in endocrine-resistant cell models was associated with a reduction in their invasive capacity. Our data suggest that upregulation of CD44v6 in acquired resistant breast cancer may contribute to a gain in the aggressive phenotype of these cells and loss of endocrine response through transactivation of the EGFR pathway. Future therapeutic targeting of CD44v6 may prove to be an effective strategy alongside EGFR-targeted agents in delaying/preventing acquired resistance in breast cancer. PMID:27379207

  20. Radiobiological Response of Cervical Cancer Cell Line in Low Dose Region: Evidence of Low Dose Hypersensitivity (HRS) and Induced Radioresistance (IRR)

    PubMed Central

    Singh, Rabiraja; George, Daicy; Vijaykumar, T.S.; John, Subhashini

    2015-01-01

    Background Purpose of the present study was to examine the response of cervical cancer cell line (HeLa cell line) to low dose radiation using clonogenic assay and mathematical modeling of the low dose response by Joiner’s induced repair model. Materials and Methods Survival of HeLa cells following exposure to single and fractionated low doses of γ (gamma)-ray, 6 MV, and 15 MV photon was measured by clonogenic assay. Results HeLa cell line demonstrated marked low dose response consisting of an area of HRS and IRR in the dose region of <1 Gy. The two gradients of the low dose region (αs and αr) were distinctly different with a transition dose (Dc) of 0.28-0.40 cGy. Conclusion HeLa cell line demonstrates marked HRS and IRR with distinct transition dose. This may form the biological basis of the clinical study to investigate the chemo potentiating effect of low dose radiation in cervical cancer. PMID:26266200

  1. miR-185-3p regulates nasopharyngeal carcinoma radioresistance by targeting WNT2B in vitro

    PubMed Central

    Li, Guo; Wang, Yunyun; Liu, Yong; Su, Zhongwu; Liu, Chao; Ren, Shuling; Deng, Tengbo; Huang, Donghai; Tian, Yongquan; Qiu, Yuanzheng

    2014-01-01

    Aberrant microRNA (miRNA) expression contributes to a series of malignant cancer behaviors, including radioresistance. Our previous study showed differential expression of miR-185-3p in post-radiation nasopharyngeal carcinoma (NPC) cells. To investigate the role of miR-185-3p in NPC radioresistance, CNE-2 and 5-8F cells were transfected with miR-185-3p mimic and miR-185-3p inhibitor, respectively. CCK-8 assay and colony formation experiment confirmed that the expression of miR-185-3p affected the radioresistance of NPC cells. A negative correlation between miR-185-3p and WNT2B expression was observed in NPC cells and tissues. Luciferase reporter assays confirmed that miR-185-3p directly targeted the coding region of WNT2B. Furthermore, we found radioresistance decreased in WNT2B-silenced NPC cells. Activation of the WNT2B/β-catenin pathway was accompanied by epithelial–mesenchymal transition biomarker changes in NPC. We concluded that miR-185-3p contributed to the radioresistance of NPC via modulation of WNT2B expression in vitro. PMID:25297925

  2. Acquisition of cancer stem cell-like properties in non-small cell lung cancer with acquired resistance to afatinib

    PubMed Central

    Hashida, Shinsuke; Yamamoto, Hiromasa; Shien, Kazuhiko; Miyoshi, Yuichiro; Ohtsuka, Tomoaki; Suzawa, Ken; Watanabe, Mototsugu; Maki, Yuho; Soh, Junichi; Asano, Hiroaki; Tsukuda, Kazunori; Miyoshi, Shinichiro; Toyooka, Shinichi

    2015-01-01

    Afatinib is an irreversible epidermal growth factor receptor (EGFR)-tyrosine kinase inhibitor (TKI) that is known to be effective against the EGFR T790M variant, which accounts for half of the mechanisms of acquired resistance to reversible EGFR-TKIs. However, acquired resistance to afatinib was also observed in clinical use. Thus, elucidating and overcoming the mechanisms of resistance are important issues in the treatment of non-small cell lung cancer. In this study, we established various afatinib-resistant cell lines and investigated the resistance mechanisms. EGFR T790M mutations were not detected using direct sequencing in established resistant cells. Several afatinib-resistant cell lines displayed MET amplification, and these cells were sensitive to the combination of afatinib plus crizotinib. As a further investigation, a cell line that acquired resistance to afatinib plus crizotinib, HCC827-ACR, was established from one of the MET amplified-cell lines. Several afatinib-resistant cell lines including HCC827-ACR displayed epithelial-to-mesenchymal transition (EMT) features and epigenetic silencing of miR-200c, which is a suppresser of EMT. In addition, these cell lines also exhibited overexpression of ALDH1A1 and ABCB1, which are putative stem cell markers, and resistance to docetaxel. In conclusion, we established afatinib-resistant cells and found that MET amplification, EMT, and stem cell-like features are observed in cells with acquired resistance to EGFR-TKIs. This finding may provide clues to overcoming resistance to EGFR-TKIs. PMID:26202045

  3. Acquisition of cancer stem cell-like properties in non-small cell lung cancer with acquired resistance to afatinib.

    PubMed

    Hashida, Shinsuke; Yamamoto, Hiromasa; Shien, Kazuhiko; Miyoshi, Yuichiro; Ohtsuka, Tomoaki; Suzawa, Ken; Watanabe, Mototsugu; Maki, Yuho; Soh, Junichi; Asano, Hiroaki; Tsukuda, Kazunori; Miyoshi, Shinichiro; Toyooka, Shinichi

    2015-10-01

    Afatinib is an irreversible epidermal growth factor receptor (EGFR)-tyrosine kinase inhibitor (TKI) that is known to be effective against the EGFR T790M variant, which accounts for half of the mechanisms of acquired resistance to reversible EGFR-TKIs. However, acquired resistance to afatinib was also observed in clinical use. Thus, elucidating and overcoming the mechanisms of resistance are important issues in the treatment of non-small cell lung cancer. In this study, we established various afatinib-resistant cell lines and investigated the resistance mechanisms. EGFR T790M mutations were not detected using direct sequencing in established resistant cells. Several afatinib-resistant cell lines displayed MET amplification, and these cells were sensitive to the combination of afatinib plus crizotinib. As a further investigation, a cell line that acquired resistance to afatinib plus crizotinib, HCC827-ACR, was established from one of the MET amplified-cell lines. Several afatinib-resistant cell lines including HCC827-ACR displayed epithelial-to-mesenchymal transition (EMT) features and epigenetic silencing of miR-200c, which is a suppresser of EMT. In addition, these cell lines also exhibited overexpression of ALDH1A1 and ABCB1, which are putative stem cell markers, and resistance to docetaxel. In conclusion, we established afatinib-resistant cells and found that MET amplification, EMT, and stem cell-like features are observed in cells with acquired resistance to EGFR-TKIs. This finding may provide clues to overcoming resistance to EGFR-TKIs. PMID:26202045

  4. Dual role of B cells in mediating innate and acquired immunity to herpes simplex virus infections.

    PubMed

    Deshpande, S P; Kumaraguru, U; Rouse, B T

    2000-06-15

    mu-immunoglobulin chain gene targeted B-cell-deficient mice of susceptible BALB/c strain and resistant C57B1/6 strain are up to 100- to 1000-fold more susceptible to cutaneous infection by herpes simplex virus (HSV) than the respective control wild type mice. The effect of the lack of B cells on immunity to HSV infections was analyzed and B cells were found to play a dual role in affecting both innate and acquired immune responses. Natural antibodies (IgM isotype), reactive with HSV have an anti-viral effect in the innate control of primary cutaneous HSV infection. B cells can also function as antigen-presenting cells for the stimulation of HSV-specific CD4+ T-cell responses. Consequently, CD4+ T cells and interferon-gamma responses were found to be significantly impaired in HSV-infected B-cell-deficient mice compared to that seen in control mice. No significant differences were found in natural-killer-cell- or HSV-specific CD8+ T-cell activity between control and B-cell-deficient mice. Our results imply a role for B cell in mediating innate and CD4+ T-cell-specific immunity in determining susceptibility to primary HSV infections. PMID:10896767

  5. A robust potency assay highlights significant donor variation of human mesenchymal stem/progenitor cell immune modulatory capacity and extended radio-resistance.

    PubMed

    Ketterl, Nina; Brachtl, Gabriele; Schuh, Cornelia; Bieback, Karen; Schallmoser, Katharina; Reinisch, Andreas; Strunk, Dirk

    2015-01-01

    The inherent immunomodulatory capacity of mesenchymal stem/progenitor cells (MSPCs) encouraged initiation of multiple clinical trials. Release criteria for therapeutic MSPCs cover identity, purity and safety but appropriate potency assessment is often missing. Reports on functional heterogeneity of MSPCs created additional uncertainty regarding donor and organ/source selection. We established a robust immunomodulation potency assay based on pooling responder leukocytes to minimize individual immune response variability. Comparing various MSPCs revealed significant potency inconsistency and generally diminished allo-immunosuppression compared to dose-dependent inhibition of mitogenesis. Gamma-irradiation to block unintended MSPC proliferation did not prohibit chondrogenesis and osteogenesis in vivo, indicating the need for alternative safety strategies. PMID:26620155

  6. Acquired resistance to EGFR inhibitors is associated with a manifestation of stem cell-like properties in cancer cells.

    PubMed

    Shien, Kazuhiko; Toyooka, Shinichi; Yamamoto, Hiromasa; Soh, Junichi; Jida, Masaru; Thu, Kelsie L; Hashida, Shinsuke; Maki, Yuho; Ichihara, Eiki; Asano, Hiroaki; Tsukuda, Kazunori; Takigawa, Nagio; Kiura, Katsuyuki; Gazdar, Adi F; Lam, Wan L; Miyoshi, Shinichiro

    2013-05-15

    Acquired resistance to EGF receptor (EGFR) tyrosine kinase inhibitor (TKI) is a critical problem in the treatment of lung cancer. Although several mechanisms have been shown to be responsible for acquired resistance, all mechanisms have not been uncovered. In this study, we investigated the molecular and cellular profiles of the acquired resistant cells to EGFR-TKI in EGFR-mutant lung cancers. Four EGFR-mutant cell lines were exposed to gefitinib by stepwise escalation and high-concentration exposure methods, and resistant sublines to gefitinib were established. The molecular profiles and cellular phenotypes of these resistant sublines were characterized. Although previously reported, alterations including secondary EGFR T790M mutation, MET amplification, and appearance of epithelial-to-mesenchymal transition (EMT) features were observed, these 2 drug-exposure methods revealed different resistance mechanisms. The resistant cells with EMT features exhibited downregulation of miRNA-200c by DNA methylation. Furthermore, the HCC827-derived subline characterized by the high-concentration exposure method exhibited not only EMT features but also stem cell-like properties, including aldehyde dehydrogenase isoform 1 (ALDH1A1) overexpression, increase of side-population, and self-renewal capability. Resistant sublines with stem cell-like properties were resistant to conventional chemotherapeutic agents but equally sensitive to histone deacetylase and proteasome inhibitors, compared with their parental cells. ALDH1A1 was upregulated in clinical samples with acquired resistance to gefitinib. In conclusion, our study indicates that the manner of EGFR-TKI exposure influences the mechanism of acquired resistance and the appearance of stem cell-like property with EGFR-TKI treatment. PMID:23542356

  7. Review of acquired cystic disease-associated renal cell carcinoma with focus on pathobiological aspects.

    PubMed

    Kuroda, Naoto; Ohe, Chisato; Mikami, Shuji; Hes, Ondrej; Michal, Michal; Brunelli, Matteo; Martignoni, Guido; Sato, Yasuharu; Yoshino, Tadashi; Kakehi, Yoshiyuki; Shuin, Taro; Lee, Gang-Hong

    2011-09-01

    Acquired cystic disease (ACD)-associated renal cell carcinoma (RCC) is a recently established entity. In this article, we introduce the general view of this new entity. Macroscopically, the disease exclusively occurs in ACD and may arise as a dominant mass or non-dominant masses. Histologically, the tumor is characterized by a microcystic pattern, neoplastic cells with an eosinophilic or oncocytic cytoplasm and frequent intratumoral oxalate crystal deposition. Prominent nucleoli of tumor cells are often observed. Immunohistochemically, neoplastic cells are generally positive for AMACR but negative for cytokeratin 7. Ultrastructurally, neoplastic cells contain abundant mitochondria in the cytoplasm. Genetically, the gain of chromosomes 3, 7, 17 and abnormality of the sex chromosome were frequently observed in several studies. In conclusion, ACD-associated RCC may be widely recognized as a distinct entity in the near future because this tumor is morphologically and genetically different from other renal tumor entities that have been previously established. PMID:21751153

  8. Esophageal epithelial cells acquire functional characteristics of activated myofibroblasts after undergoing an epithelial to mesenchymal transition

    PubMed Central

    Muir, Amanda B.; Dods, Kara; Noah, Yuli; Toltzis, Sarit; Chandramouleeswaran, Prasanna Modayur; Lee, Anna; Benitez, Alain; Bedenbaugh, Adam; Falk, Gary W.; Wells, Rebecca G.; Nakagawa, Hiroshi; Wang, Mei-Lun

    2015-01-01

    Background and Aims Eosinophilic esophagitis (EoE) is an allergic inflammatory disease that leads to esophageal fibrosis and stricture. We have recently shown that in EoE, esophageal epithelial cells undergo an epithelial to mesenchymal transition (EMT), characterized by gain of mesenchymal markers and loss of epithelial gene expression. Whether epithelial cells exposed to profibrotic cytokines can also acquire the functional characteristics of activated myofibroblasts, including migration, contraction, and extracellular matrix deposition, is relevant to our understanding and treatment of EoE-associated fibrogenesis. In the current study, we characterize cell migration, contraction, and collagen production by esophageal epithelial cells that have undergone cytokine-induced EMT in vitro. Methods and Results Stimulation of human non-transformed immortalized esophageal epithelial cells (EPC2-hTERT) with profibrotic cytokines TNFα, TGFβ, and IL1β for three weeks led to acquisition of mesenchymal αSMA and vimentin, and loss of epithelial E-cadherin expression. Upon removal of the profibrotic stimulus, epithelial characteristics were partially rescued. TGFβ stimulation had a robust effect upon epithelial collagen production. Surprisingly, TNFα stimulation had the most potent effect upon cell migration and contraction, exceeding the effects of the prototypical profibrotic cytokine TGFβ. IL1β stimulation alone had minimal effect upon esophageal epithelial migration, contraction, and collagen production. Conclusions Esophageal epithelial cells that have undergone EMT acquire functional characteristics of activated myofibroblasts in vitro. Profibrotic cytokines exert differential effects upon esophageal epithelial cells, underscoring complexities of fibrogenesis in EoE, and implicating esophageal epithelial cells as effector cells in EoE-associated fibrogenesis. PMID:25183431

  9. Local control rates of metastatic renal cell carcinoma to the bone using stereotactic body radiation therapy: Is RCC truly radioresistant?′

    PubMed Central

    Bourlon, Maria T.; Bedrick, Edward; Bhatia, Shilpa; Kessler, Elizabeth R.; Flaig, Thomas W.; Fisher, Christine M.; Kavanagh, Brian D; Lam, Elaine T.; Karam, Sana D.

    2015-01-01

    Purpose We report the radiographic and clinical response rate of stereotactic body radiation therapy (SBRT) compared with conventional fractionated external beam radiation therapy (CF-EBRT) for renal cell carcinoma (RCC) bone lesions treated at our institution. Methods and materials Forty-six consecutive patients were included in the study, with 95 total lesions treated (50 SBRT, 45 CF-EBRT). We included patients who had histologic confirmation of primary RCC and radiographic evidence of metastatic bone lesions. The most common SBRT regimen used was 27 Gy in 3 fractions. Results Median follow-up was 10 months (range, 1-64 months). Median time to symptom control between SBRT and CF-EBRT were 2 (range, 0-6 weeks) and 4 weeks (range, 0-7 weeks), respectively. Symptom control rates with SBRT and CF-EBRT were significantly different (P = .020) with control rates at 10, 12, and 24 months of 74.9% versus 44.1%, 74.9% versus 39.9%, and 74.9% versus 35.7%, respectively. The median time to radiographic failure and unadjusted pain progression was 7 months in both groups. When controlling for gross tumor volume, dose per fraction, smoking, and the use of systemic therapy, biologically effective dose ≥80 Gy was significant for clinical response (hazard ratio [HR], 0.204; 95% confidence interval [CI], 0.043-0.963; P = .046) and radiographic (HR, 0.075; 95% CI, 0.013-0.430; P = .004). When controlling for gross tumor volume and total dose, biologically effective dose ≥80 Gy was again predictive of clinical local control (HR, 0.140; 95% CI, 0.025-0.787; P = .026). Toxicity rates were low and equivalent in both groups, with no grade 4 or 5 toxicity reported. Conclusions SBRT is both safe and effective for treating RCC bone metastases, with rapid improvement in symptoms after treatment and more durable clinical and radiographic response rate. Future prospective trials are needed to further define efficacy and toxicity of treatment, especially in the setting of targeted agents

  10. CD8 T-cell recognition of acquired alloantigen promotes acute allograft rejection

    PubMed Central

    Harper, Simon J. F.; Ali, Jason M.; Wlodek, Elizabeth; Negus, Marg C.; Harper, Ines G.; Chhabra, Manu; Qureshi, M. Saeed; Mallik, Mekhola; Bolton, Eleanor; Bradley, J. Andrew; Pettigrew, Gavin J.

    2015-01-01

    Adaptive CD8 T-cell immunity is the principal arm of the cellular alloimmune response, but its development requires help. This can be provided by CD4 T cells that recognize alloantigen “indirectly,” as self-restricted allopeptide, but this process remains unexplained, because the target epitopes for CD4 and CD8 T-cell recognition are “unlinked” on different cells (recipient and donor antigen presenting cells (APCs), respectively). Here, we test the hypothesis that the presentation of intact and processed MHC class I alloantigen by recipient dendritic cells (DCs) (the “semidirect” pathway) allows linked help to be delivered by indirect-pathway CD4 T cells for generating destructive cytotoxic CD8 T-cell alloresponses. We show that CD8 T-cell–mediated rejection of murine heart allografts that lack hematopoietic APCs requires host secondary lymphoid tissue (SLT). SLT is necessary because within it, recipient dendritic cells can acquire MHC from graft parenchymal cells and simultaneously present it as intact protein to alloreactive CD8 T cells and as processed peptide alloantigen for recognition by indirect-pathway CD4 T cells. This enables delivery of essential help for generating cytotoxic CD8 T-cell responses that cause rapid allograft rejection. In demonstrating the functional relevance of the semidirect pathway to transplant rejection, our findings provide a solution to a long-standing conundrum as to why SLT is required for CD8 T-cell allorecognition of graft parenchymal cells and suggest a mechanism by which indirect-pathway CD4 T cells provide help for generating effector cytotoxic CD8 T-cell alloresponses at late time points after transplantation. PMID:26420874

  11. Afatinib increases sensitivity to radiation in non-small cell lung cancer cells with acquired EGFR T790M mutation

    PubMed Central

    Huang, Haixiu; Wu, Kan; Wang, Bing; Chen, Xufeng; Ma, Shenglin

    2015-01-01

    Afatinib is a second-generation of epidermal growth factor receptor (EGFR) tyrosine kinase inhibitor and has shown a significant clinical benefit in non-small cell lung cancer (NSCLC) patients with EGFR-activating mutations. However, the potential therapeutic effects of afatinib combining with other modalities, including ionizing radiation (IR), are not well understood. In this study, we developed a gefitinib-resistant cell subline (PC-9-GR) with a secondary EGFR mutation (T790M) from NSCLC PC-9 cells after chronic exposures to increasing doses of gefitinib. The presence of afatinib significantly increases the cell killing effect of radiation in PC-9-GR cells harboring acquired T790M, but not in H1975 cells with de novo T790M or in H460 cells that express wild-type EGFR. In PC-9-GR cells, afatinib remarkable blocks baseline of EGFR and ERK phosphorylations, and causes delay of IR-induced AKT phosphorylation. Afatinib treatment also leads to increased apoptosis and suppressed DNA damage repair in irradiated PC-9-GR cells, and enhanced tumor growth inhibition when combined with IR in PC-9-GR xenografts. Our findings suggest a potential therapeutic impact of afatinib as a radiation sensitizer in lung cancer cells harboring acquired T790M mutation, providing a rationale for a clinical trial with combination of afatinib and radiation in NSCLCs with EGFR T790M mutation. PMID:25714021

  12. Comparative Study of Bone Marrow and Blood B Cells in Infantile and Acquired Agammaglobulinemia

    PubMed Central

    Abdou, Nabih I.; Casella, Salvatore R.; Abdou, Nancy L.; Abrahamsohn, Ises A.

    1973-01-01

    The status of immunoglobulin (Ig) receptors of the bone marrow dependent (B) cells present in either the bone marrow (BM) or peripheral blood (PB) of three patients with infantile agammaglobulinemia (I-AGG), or seven patients with acquired agammaglobulinemia (A-AGG) is compared with those of 12 controls. Quantitative and qualitative changes of the different classes of Ig receptors on B cells were evaluated by their capacity to bind [125I]anti-Ig, to be stained with fluorescinated anti-Ig and their in vitro proliferative capacity upon incubation with the anti-Ig. Patients with I-AGG lacked B cells in both the BM and PB. Whereas BM cells of patients with A-AGG carried receptors similar to control cells, their blood B cells had fewer IgM, IgG, and IgA cells which failed to proliferate in vitro in the presence of the anti-Ig. An anti-IgM of the IgG class was detected in the sera of patients with A-AGG but not in sera of I-AGG. The isolated anti-IgM agglutinated human red cells coated with IgM. The anti-IgM partially blocked the binding of fluorescinated or radiolabeled anti-IgM to IgM peripheral blood lymphocytes of normal controls. The eluted anti-IgM in presence of complement was partially cytotoxic to normal cells. It is concluded that I-AGG-B cell defect is due to failure of B cell development in the bone marrow compartment whereas the peripheral exclusion of IgM cells by an anti-IgM with the subsequent failure of differentiation of both IgG and IgA cells could be an important mechanism in A-AGG-B cell defect. PMID:4580388

  13. A Convenient Cell Culture Model for CML Acquired Resistance Through BCR-ABL Mutations.

    PubMed

    Wang, Zhiqiang; Chen, WenYong

    2016-01-01

    Tyrosine kinase inhibitors (TKIs) are the effective treatments for chronic myeloid leukemia (CML). However, clinical resistance to TKIs that leads to patient relapse remains a challenge. Acquisition of BCR-ABL mutations is crucial in the resistance but the underlying molecular mechanisms are poorly understood. Here we describe a cell culture model for CML acquired resistance in which blast crisis CML cells undergo initial apoptosis upon treatment with therapeutically effective doses of TKIs, but the cells regrow quickly with development of resistance through BCR-ABL mutations. This model mimics the clinical process of acquisition of BCR-ABL mutations and will be an important tool to dissect molecular mechanisms of CML drug resistance and to explore strategies to overcome resistance. PMID:27581146

  14. Characterization of a human colorectal carcinoma cell line with acquired resistance to flavopiridol.

    PubMed

    Smith, V; Raynaud, F; Workman, P; Kelland, L R

    2001-11-01

    Flavopiridol is a broad-spectrum inhibitor of cyclin-dependent kinases (cdks) and represents the first in this anticancer class to enter clinical trials. In anticipation of the likelihood that, as with other cancer drugs, acquired resistance may limit the drug's efficacy, an acquired resistance model has been established by in vitro drug exposure of the human colon carcinoma cell line HCT116. This stably resistant line, possessing 8-fold resistance to flavopiridol, showed a lack of cross-resistance to the anticancer agents etoposide, doxorubicin, paclitaxel, topotecan, and cisplatin, and notably to other chemical classes of cdk inhibitors: the aminopurines roscovitine and purvalanol A, 9-nitropaullone, and hymenialdisine. Resistance did not seem to be related to differences in the levels of multidrug resistance drug efflux proteins, P-glycoprotein, and MRP1. Moreover, there were no changes in overall drug accumulation between the resistant and sensitive cell lines. Flavopiridol induced cell cycle arrest, apoptosis, and inhibition of retinoblastoma gene product phosphorylation on serine 780 in both parental and resistant lines, but the latter required 8-fold higher concentrations to achieve these effects. Cyclin E protein levels and cyclin E-associated kinase activity were increased in the resistant line, suggesting that overexpression of cyclin E may be the mechanism of resistance to flavopiridol. However, transfection of cyclin E to increase expression of this protein did not result in an increase in resistance to flavopiridol. Thus, up-regulation of cyclin E alone does not seem to cause resistance to this cdk inhibitor. PMID:11641415

  15. Deinococcus radiodurans pprI expression enhances the radioresistance of eukaryotes.

    PubMed

    Wen, Ling; Yue, Ling; Shi, Yi; Ren, Lili; Chen, Tingting; Li, Na; Zhang, Shuyu; Yang, Wei; Yang, Zhanshan

    2016-03-29

    PprI accelerates radiation-induced DNA damage repair via regulating the expression of DNA repair genes and enhances antioxidative enzyme activity in Deinococcus radiodurans after radiation. The main aim of our study was to determine whether the expression of pprI gene could fulfil its DNA repair function in eukaryotes and enhance the radioresistance of eukaryotic organism or not. In this study, we constructed pEGFP-c1-pprI eukaryotic expression vector and established a human lung epithelial cell line BEAS-2B with stable integration of pprI gene. We found that pprIexpression enhanced radioresistance of BEAS-2B cells, decreased γ-H2AX foci formation and apoptosis in irradiated BEAS-2B cells and alleviated radiation induced G2/M arrest of BEAS-2B cells. Moreover, we transferred pEGFP-c1-pprI vector into muscle of BALB/c mice by in vivo electroporation and studied the protective effect of prokaryotic pprI gene in irradiated mice. We found that pprI expression alleviated acute radiation induced hematopoietic system, lung, small intestine and testis damage and increased survival rate of irradiated mice via regulating Rad51 expression in different organs. These findings suggest that prokaryotic pprI gene expression in mammalian cells could enhance radioresistance in vitro and in vivo. PMID:26992215

  16. Deinococcus radiodurans pprI expression enhances the radioresistance of eukaryotes

    PubMed Central

    Wen, Ling; Yue, Ling; Shi, Yi; Ren, Lili; Chen, Tingting; Li, Na; Zhang, Shuyu; Yang, Wei; Yang, Zhanshan

    2016-01-01

    PprI accelerates radiation-induced DNA damage repair via regulating the expression of DNA repair genes and enhances antioxidative enzyme activity in Deinococcus radiodurans after radiation. The main aim of our study was to determine whether the expression of pprI gene could fulfil its DNA repair function in eukaryotes and enhance the radioresistance of eukaryotic organism or not. In this study, we constructed pEGFP-c1-pprI eukaryotic expression vector and established a human lung epithelial cell line BEAS-2B with stable integration of pprI gene. We found that pprIexpression enhanced radioresistance of BEAS-2B cells, decreased γ-H2AX foci formation and apoptosis in irradiated BEAS-2B cells and alleviated radiation induced G2/M arrest of BEAS-2B cells. Moreover, we transferred pEGFP-c1-pprI vector into muscle of BALB/c mice by in vivo electroporation and studied the protective effect of prokaryotic pprI gene in irradiated mice. We found that pprI expression alleviated acute radiation induced hematopoietic system, lung, small intestine and testis damage and increased survival rate of irradiated mice via regulating Rad51 expression in different organs. These findings suggest that prokaryotic pprI gene expression in mammalian cells could enhance radioresistance in vitro and in vivo. PMID:26992215

  17. Hypoxia-induced autophagy as an additional mechanism in human osteosarcoma radioresistance.

    PubMed

    Feng, Helin; Wang, Jin; Chen, Wei; Shan, Baoen; Guo, Yin; Xu, Jianfa; Wang, Ling; Guo, Peng; Zhang, Yingze

    2016-06-01

    Osteosarcoma (OS) responds poorly to radiotherapy, but the mechanism is unclear. We found OS tumor tissues expressed high level of protein HIF-1α, a common biological marker indicative of hypoxia. It is known that hypoxic cells are generally radioresistant because of reduced production of irradiation-induced DNA-damaging reactive oxygen species (ROS) in the anaerobic condition. Here we report another mechanism how hypoxia induces radioresistance. In MG-63 human osteosarcoma cells, hypoxic pretreatment increased the cellular survival in irradiation. These hypoxia-exposed cells displayed compartmental recruitment of GFP-tagged LC3 and expression of protein LC3-II, and restored the radiosensitivity upon autophagy inhibition. The following immunohistochemistry of OS tumor tissue sections revealed upregulated LC3 expression in a correlation with HIF-1α protein level, implying the possibly causative link between hypoxia and autophagy. Further studies in MG-63 cells demonstrated hypoxic pretreatment reduced cellular and mitochondrial ROS production during irradiation, while inhibition of autophagy re-elicited them. Taken together, our study suggests hypoxia can confer cells resistance to irradiation through activated autophagy to accelerate the clearance of cellular ROS products. This might exist in human osteosarcoma as an additional mechanism for radioresistance. PMID:27335774

  18. Acquired resistance to 17-allylamino-17-demethoxygeldanamycin (17-AAG, tanespimycin) in glioblastoma cells

    PubMed Central

    Gaspar, Nathalie; Sharp, Swee Y; Pacey, Simon; Jones, Chris; Walton, Michael; Vassal, Gilles; Eccles, Suzanne; Pearson, Andrew; Workman, Paul

    2009-01-01

    HSP90 inhibitors, such as 17-allylamino-17-demethoxygeldanamycin (17-AAG, tanespimycin) which is currently in phase II/III clinical trials, are promising new anticancer agents. Here, we explored acquired resistance to HSP90 inhibitors in glioblastoma, a primary brain tumor with poor prognosis. Glioblastoma cells were exposed continuously to increased 17-AAG concentrations. Four 17-AAG-resistant glioblastoma cell lines were generated. High resistance levels with resistance indices (RI=resistant line IC50/parental line IC50) of 20-137 were obtained rapidly (2-8 weeks). After cessation of 17-AAG exposure, RI decreased and then stabilised. Cross-resistance was found with other ansamycin benzoquinones but not with the structurally unrelated HSP90 inhibitors, radicicol, the purine BIIB021 and the resorcinylic pyrazole/isoxazole amide compounds VER-49009, VER-50589, and NVP-AUY922. An inverse correlation between NQO1 expression/activity and 17-AAG IC50 was observed in the resistant lines. The NQO1 inhibitor ES936 abrogated the differential effects of 17-AAG sensitivity between the parental and resistant lines. NQO1 mRNA levels and NQO1 DNA polymorphism analysis indicated different underlying mechanisms: reduced expression and selection of the inactive NQO1*2 polymorphism. Decreased NQO1 expression was also observed in a melanoma line with acquired resistance to 17-AAG. No resistance was generated with VER-50589 and NVP-AUY922. In conclusion, low NQO1 activity is a likely mechanism of acquired resistance to 17-AAG in glioblastoma, melanoma and possibly other tumor types. Such resistance can be overcome with novel HSP90 inhibitors. PMID:19244114

  19. Non-Small Cell Lung Cancer Cells Acquire Resistance to the ALK Inhibitor Alectinib by Activating Alternative Receptor Tyrosine Kinases.

    PubMed

    Isozaki, Hideko; Ichihara, Eiki; Takigawa, Nagio; Ohashi, Kadoaki; Ochi, Nobuaki; Yasugi, Masayuki; Ninomiya, Takashi; Yamane, Hiromichi; Hotta, Katsuyuki; Sakai, Katsuya; Matsumoto, Kunio; Hosokawa, Shinobu; Bessho, Akihiro; Sendo, Toshiaki; Tanimoto, Mitsune; Kiura, Katsuyuki

    2016-03-15

    Crizotinib is the standard of care for advanced non-small cell lung cancer (NSCLC) patients harboring the anaplastic lymphoma kinase (ALK) fusion gene, but resistance invariably develops. Unlike crizotinib, alectinib is a selective ALK tyrosine kinase inhibitor (TKI) with more potent antitumor effects and a favorable toxicity profile, even in crizotinib-resistant cases. However, acquired resistance to alectinib, as for other TKIs, remains a limitation of its efficacy. Therefore, we investigated the mechanisms by which human NSCLC cells acquire resistance to alectinib. We established two alectinib-resistant cell lines that did not harbor the secondary ALK mutations frequently occurring in crizotinib-resistant cells. One cell line lost the EML4-ALK fusion gene, but exhibited increased activation of insulin-like growth factor-1 receptor (IGF1R) and human epidermal growth factor receptor 3 (HER3), and overexpressed the HER3 ligand neuregulin 1. Accordingly, pharmacologic inhibition of IGF1R and HER3 signaling overcame resistance to alectinib in this cell line. The second alectinib-resistant cell line displayed stimulated HGF autocrine signaling that promoted MET activation and remained sensitive to crizotinib treatment. Taken together, our findings reveal two novel mechanisms underlying alectinib resistance that are caused by the activation of alternative tyrosine kinase receptors rather than by secondary ALK mutations. These studies may guide the development of comprehensive treatment strategies that take into consideration the various approaches ALK-positive lung tumors use to withstand therapeutic insult. PMID:26719536

  20. Fibrocyte-like cells mediate acquired resistance to anti-angiogenic therapy with bevacizumab

    PubMed Central

    Mitsuhashi, Atsushi; Goto, Hisatsugu; Saijo, Atsuro; Trung, Van The; Aono, Yoshinori; Ogino, Hirokazu; Kuramoto, Takuya; Tabata, Sho; Uehara, Hisanori; Izumi, Keisuke; Yoshida, Mitsuteru; Kobayashi, Hiroaki; Takahashi, Hidefusa; Gotoh, Masashi; Kakiuchi, Soji; Hanibuchi, Masaki; Yano, Seiji; Yokomise, Hiroyasu; Sakiyama, Shoji; Nishioka, Yasuhiko

    2015-01-01

    Bevacizumab exerts anti-angiogenic effects in cancer patients by inhibiting vascular endothelial growth factor (VEGF). However, its use is still limited due to the development of resistance to the treatment. Such resistance can be regulated by various factors, although the underlying mechanisms remain incompletely understood. Here we show that bone marrow-derived fibrocyte-like cells, defined as alpha-1 type I collagen-positive and CXCR4-positive cells, contribute to the acquired resistance to bevacizumab. In mouse models of malignant pleural mesothelioma and lung cancer, fibrocyte-like cells mediate the resistance to bevacizumab as the main producer of fibroblast growth factor 2. In clinical specimens of lung cancer, the number of fibrocyte-like cells is significantly increased in bevacizumab-treated tumours, and correlates with the number of treatment cycles, as well as CD31-positive vessels. Our results identify fibrocyte-like cells as a promising cell biomarker and a potential therapeutic target to overcome resistance to anti-VEGF therapy. PMID:26635184

  1. Fibrocyte-like cells mediate acquired resistance to anti-angiogenic therapy with bevacizumab.

    PubMed

    Mitsuhashi, Atsushi; Goto, Hisatsugu; Saijo, Atsuro; Trung, Van The; Aono, Yoshinori; Ogino, Hirokazu; Kuramoto, Takuya; Tabata, Sho; Uehara, Hisanori; Izumi, Keisuke; Yoshida, Mitsuteru; Kobayashi, Hiroaki; Takahashi, Hidefusa; Gotoh, Masashi; Kakiuchi, Soji; Hanibuchi, Masaki; Yano, Seiji; Yokomise, Hiroyasu; Sakiyama, Shoji; Nishioka, Yasuhiko

    2015-01-01

    Bevacizumab exerts anti-angiogenic effects in cancer patients by inhibiting vascular endothelial growth factor (VEGF). However, its use is still limited due to the development of resistance to the treatment. Such resistance can be regulated by various factors, although the underlying mechanisms remain incompletely understood. Here we show that bone marrow-derived fibrocyte-like cells, defined as alpha-1 type I collagen-positive and CXCR4-positive cells, contribute to the acquired resistance to bevacizumab. In mouse models of malignant pleural mesothelioma and lung cancer, fibrocyte-like cells mediate the resistance to bevacizumab as the main producer of fibroblast growth factor 2. In clinical specimens of lung cancer, the number of fibrocyte-like cells is significantly increased in bevacizumab-treated tumours, and correlates with the number of treatment cycles, as well as CD31-positive vessels. Our results identify fibrocyte-like cells as a promising cell biomarker and a potential therapeutic target to overcome resistance to anti-VEGF therapy. PMID:26635184

  2. Treosulfan, cyclophosphamide and antithymocyte globulin for allogeneic hematopoietic cell transplantation in acquired severe aplastic anemia.

    PubMed

    Giebel, Sebastian; Wojnar, Jerzy; Krawczyk-Kulis, Malgorzata; Markiewicz, Miroslaw; Wylezoł, Iwona; Seweryn, Marek; Holowiecka-Goral, Aleksandra; Holowiecki, Jerzy

    2006-01-01

    To reduce the risk of graft rejection after allogeneic hematopoietic cell transplantation (alloHCT) for patients with acquired severe aplastic anemia (SAA), we introduced an intensified preparative regimen consisting of treosulfan 10 g/m2/d on days -7, -6, cyclophosphamide 40 mg/kg/d on days -5, -4, -3, -2 and anti-thymocyte globulin 2 mg/kg/d on days -3, -2, -1. Six patients with the history of multiple transfusions were treated with alloHCT from either HLA-identical sibling (n=3) or an unrelated volunteer (n=3). Each, bone marrow and peripheral blood was used as a source of stem cells in three cases. All patients engrafted and achieved complete donor chimerism. None of the patients experienced severe organ toxicity. No severe acute graft-versus-host-disease (GVHD) was observed; two patients experienced extensive chronic GVHD. At the median follow-up of 14.5 (13-27) months all patients remained alive and disease-free. Our observation indicates that treosulfan + cyclophosphamide + antithymocyte globulin conditioning is well-tolerated and allows stable engraftment in acquired SAA. PMID:17494286

  3. Cyclosporine therapy of aplastic anaemia, congenital and acquired red cell aplasia.

    PubMed

    Leonard, E M; Raefsky, E; Griffith, P; Kimball, J; Nienhuis, A W; Young, N S

    1989-06-01

    We treated 22 patients with severe aplastic anaemia refractory to antithymocyte globulin (ATG) with cyclosporine, alone or in combination with prednisone. Eight patients showed significant clinical improvement, all but one to transfusion-independence. Although cyclosporine alone was effective, the addition of prednisone resulted in prompter and fuller haematologic improvement. No patient with an absolute granulocyte count less than 0.2 x 10(9)/l responded to treatment. Haematologic remissions were sustained beyond the treatment period. Of nine patients with Diamond-Blackfan syndrome, one showed a complete response to two separate courses of cyclosporine and relapse with withdrawal of therapy, and a second achieved significant reduction in corticosteroid dose without relapse; however, seven cases failed to respond. Two of three adults with acquired pure red cell aplasia recovered. A combination of cyclosporine and corticosteroids may be effective therapy in patients with aplastic anaemia who have failed ATG treatment. Occasional cases of congenital and acquired pure red cell aplasia may also respond to cyclosporine. PMID:2503027

  4. A critical role of toll-like receptor 2 (TLR2) and its’ in vivo ligands in radio-resistance

    PubMed Central

    Gao, Fu; Zhang, Chaoxiong; Zhou, Chuanfeng; Sun, Weimin; Liu, Xin; Zhang, Pei; Han, Jiaqi; Xian, Linfeng; Bai, Dongchen; Liu, Hu; Cheng, Ying; Li, Bailong; Cui, Jianguo; Cai, Jianming; Liu, Cong

    2015-01-01

    The role of Toll-like receptor-2 (TLR2) in radio-resistance remained largely unknown. TLR2 knockout (TLR2−/−) mice received radiation of 6.5 Gy, and then were studied. We found that radiation resulted in more severe mortality and morbidity rates in TLR2−/− mice. The cause of death in TLR2−/− mice may be severe and persistent bone marrow cell loss. Injection of the TLR2 agonist Pam3CSK4 into wild type (WT) mice induced radio-resistance. Myd88−/− mice were more susceptible to radiation. In conclusion, our data indicate that, similar to TLR4, TLR2 plays a critical role in radio-resistance. PMID:26268450

  5. A critical role of toll-like receptor 2 (TLR2) and its' in vivo ligands in radio-resistance.

    PubMed

    Gao, Fu; Zhang, Chaoxiong; Zhou, Chuanfeng; Sun, Weimin; Liu, Xin; Zhang, Pei; Han, Jiaqi; Xian, Linfeng; Bai, Dongchen; Liu, Hu; Cheng, Ying; Li, Bailong; Cui, Jianguo; Cai, Jianming; Liu, Cong

    2015-01-01

    The role of Toll-like receptor-2 (TLR2) in radio-resistance remained largely unknown. TLR2 knockout (TLR2(-/-)) mice received radiation of 6.5 Gy, and then were studied. We found that radiation resulted in more severe mortality and morbidity rates in TLR2(-/-) mice. The cause of death in TLR2(-/-) mice may be severe and persistent bone marrow cell loss. Injection of the TLR2 agonist Pam3CSK4 into wild type (WT) mice induced radio-resistance. Myd88(-/-) mice were more susceptible to radiation. In conclusion, our data indicate that, similar to TLR4, TLR2 plays a critical role in radio-resistance. PMID:26268450

  6. Molecular Characterization of Acquired Tolerance of Tumor Cells to Picropodophyllin (PPP)

    PubMed Central

    Hashemi, Jamileh; Worrall, Claire; Vasilcanu, Daiana; Fryknäs, Mårten; Sulaiman, Luqman; Karimi, Mohsen; Weng, Wen-Hui; Lui, Weng-Onn; Rudduck, Christina; Axelson, Magnus; Jernberg-Wiklund, Helena; Girnita, Leonard; Larsson, Olle; Larsson, Catharina

    2011-01-01

    Background Picropodophyllin (PPP) is a promising novel anti-neoplastic agent that efficiently kills tumor cells in vitro and causes tumor regression and increased survival in vivo. We have previously reported that PPP treatment induced moderate tolerance in two out of 10 cell lines only, and here report the acquired genomic and expression alterations associated with PPP selection over 1.5 years of treatment. Methodology/Principal Findings Copy number alterations monitored using metaphase and array-based comparative genomic hybridization analyses revealed largely overlapping alterations in parental and maximally tolerant cells. Gain/ amplification of the MYC and PVT1 loci in 8q24.21 were verified on the chromosome level. Abnormalities observed in connection to PPP treatment included regular gains and losses, as well as homozygous losses in 10q24.1-q24.2 and 12p12.3-p13.2 in one of the lines and amplification at 5q11.2 in the other. Abnormalities observed in both tolerant derivatives include amplification/gain of 5q11.2, gain of 11q12.1-q14.3 and gain of 13q33.3-qter. Using Nexus software analysis we combined the array-CGH data with data from gene expression profilings and identified genes that were altered in both inputs. A subset of genes identified as downregulated (ALDH1A3, ANXA1, TLR4 and RAB5A) or upregulated (COX6A1, NFIX, ME1, MAPK and TAP2) were validated by siRNA in the tolerant or parental cells to alter sensitivity to PPP and confirmed to alter sensitivity to PPP in further cell lines. Conclusions Long-term PPP selection lead to altered gene expression in PPP tolerant cells with increase as well as decrease of genes involved in cell death such as PTEN and BCL2. In addition, acquired genomic copy number alterations were observed that were often reflected by altered mRNA expression levels for genes in the same regions. PMID:21423728

  7. Radiation response mechanisms of the extremely radioresistant bacterium Deinococcus radiodurans.

    PubMed

    Kobayashi, Yasuhiko; Narumi, Issay; Satoh, Katsuya; Funayama, Tomoo; Kikuchi, Masahiro; Kitayama, Shigeru; Watanabe, Hiroshi

    2004-11-01

    Effect of microgravity on recovery of bacterial cells from radiation damage was examined in IML-2, S/MM-4 and S/MM-9 experiments using the extremely radioresistant bacterium Deinococcus radiodurans. The cells were irradiated with gamma rays before the space flight and incubated on board the Space Shuttle. The survival of the wild type cells incubated in space increased compared with the ground controls, suggesting that the recovery of this bacterium from radiation damage was enhanced under the space environment. No difference was observed between the survivals of radiosensitive mutant rec30 cells incubated in space and on the ground. The amount of DNA-repair related RecA protein induced under microgravity was similar to those of ground controls, however, induction of PprA protein, product of a unique radiation-inducible gene (designated pprA) responsible for loss of radiation resistance in repair-deficient mutant, KH311, was enhanced under microgravity compared with ground controls. Recent investigation in vitro showed that PprA preferentially bound to double-stranded DNA carrying strand breaks, inhibited Escherichia coli exonuclease III activity, and stimulated the DNA end-joining reaction catalyzed by DNA ligases. These results suggest that D. radiodurans has a radiation-induced non-homologous end-joining (NHEJ) repair mechanism in which PprA plays a critical role. PMID:15858357

  8. Acquired cystic disease-associated renal cell carcinoma: further characterization of the morphologic and immunopathologic features.

    PubMed

    Ahn, Soomin; Kwon, Ghee Young; Cho, Yong Mee; Jun, Sun-Young; Choi, Chan; Kim, Hyun-Jung; Park, Yong Wook; Park, Weon Seo; Shim, Jung Won

    2013-12-01

    Acquired cystic disease-associated renal cell carcinoma (ACD-RCC) is a subtype of renal cell carcinoma (RCC) with unique morphologic features found exclusively in the background of end-stage renal disease. We analyzed the clinicopathologic features and immumoreactive profiles of 12 cases of ACD-RCC to further characterize this recently recognized entity. Review of histologic slides was performed in conjunction with immunohistochemical staining directed to the contemporary diagnostic antibodies and the putative target therapy-related markers. Histologically, the tumors showed characteristic inter-or intracellular microlumens and eosinophilic tumor cells. Intratumoral hemosiderin deposition and degenerating foamy tumor cells were consistent findings which were not previously described. Immunohistochemically, all the tumors were positive for alpha-methylacyl-CoA-racemase, CD10, pan-cytokeratin, PTEN (phosphatase and tensin homolog deleted on chromosome 10) and c-met, while negative for carbonic anhydrase-9, CD57, CD68, c-kit, pax-2, platelet-derived growth factor receptor (PDGFR)-α or vascular endothelial growth factor receptor (VEGFR)-2. Heterogenous staining was found for CK7 and kidney-specific cadherin. Positive reaction to c-met suggests its utility as a plausible therapeutic target in ACD-RCC. Thus, we present the unique morphologic and immunopathologic features of ACD-RCC, which may be helpful in both diagnostic and therapeutic aspects. PMID:23471757

  9. Pivotal role for skin transendothelial radio-resistant anti-inflammatory macrophages in tissue repair

    PubMed Central

    Barreiro, Olga; Cibrian, Danay; Clemente, Cristina; Alvarez, David; Moreno, Vanessa; Valiente, Íñigo; Bernad, Antonio; Vestweber, Dietmar; Arroyo, Alicia G; Martín, Pilar; von Andrian, Ulrich H; Sánchez Madrid, Francisco

    2016-01-01

    Heterogeneity and functional specialization among skin-resident macrophages are incompletely understood. In this study, we describe a novel subset of murine dermal perivascular macrophages that extend protrusions across the endothelial junctions in steady-state and capture blood-borne macromolecules. Unlike other skin-resident macrophages that are reconstituted by bone marrow-derived progenitors after a genotoxic insult, these cells are replenished by an extramedullary radio-resistant and UV-sensitive Bmi1+ progenitor. Furthermore, they possess a distinctive anti-inflammatory transcriptional profile, which cannot be polarized under inflammatory conditions, and are involved in repair and remodeling functions for which other skin-resident macrophages appear dispensable. Based on all their properties, we define these macrophages as Skin Transendothelial Radio-resistant Anti-inflammatory Macrophages (STREAM) and postulate that their preservation is important for skin homeostasis. DOI: http://dx.doi.org/10.7554/eLife.15251.001 PMID:27304075

  10. Acquired cystic disease-associated renal cell carcinoma: an immunohistochemical and fluorescence in situ hybridization study.

    PubMed

    Kuroda, Naoto; Yamashita, Motoki; Kakehi, Yoshiyuki; Hes, Ondrej; Michal, Michal; Lee, Gang-Hong

    2011-12-01

    Acquired cystic disease (ACD)-associated renal cell carcinoma (RCC) has been recently identified. However, there are only a few genetic studies to date. In this article, we performed an immunohistochemical and fluorescence in situ hybridization (FISH) study for six cases including one case with sarcomatoid change. As a result, we observed frequent immunohistochemical expression of AMACR. FISH of chromosome 3 showed trisomy for three cases, monosomy for two cases, and disomy for one case. Additionally, FISH of chromosome 16 showed trisomy for three cases, monosomy for two cases, and both trisomy and monosomy for one case. Furthermore, both the carcinomatous area and the sarcomatoid area of one ACD-associated RCC with sarcomatoid change revealed monosomy of chromosomes 3, 9, and 16 but showed disomy of chromosome 14. In conclusion, the numerical abnormalities of chromosomes 3 and 16, irrespective of gain or loss, may be characteristic of ACD-associated RCC. PMID:22179186

  11. Duodenal mucosal T cell subpopulation and bacterial cultures in acquired immune deficiency syndrome.

    PubMed

    Budhraja, M; Levendoglu, H; Kocka, F; Mangkornkanok, M; Sherer, R

    1987-05-01

    Enteric infections, chronic diarrhea frequently with no obvious etiology, and weight loss cause major morbidity and mortality in acquired immune deficiency syndrome (AIDS). Alterations in mucosal immunity may explain the increased incidence of enteric infections, and contamination of the upper small intestine with bacteria may be the cause of weight loss observed in these patients. To test this hypothesis we studied the mucosal T lymphocyte subset in duodenal mucosal biopsies in 14 AIDS and seven control patients. Duodenal fluid was also cultured for aerobic and anaerobic bacteria. There was a significant decrease among leu-3a T cells (helper/inducer) subset in AIDS. The proportion of mucosal T cells reacting with leu-2a (cytotoxic/suppressor) was significantly increased in AIDS patients. These patients also had a significant reversal of the normal mucosal helper/suppressor T cell ratio. There was no change in the number of leu-7 cells (cells mediate natural killer and antibody-dependent cellular cytotoxicity) as compared to controls. All patients with diarrhea and three of five patients without diarrhea had bacteria in their duodenal fluid. Mean number of organisms was 4.5 X 10(4)/ml. Cultures were negative in all control subjects. The results reveal that the abnormalities of T cell subpopulation in the blood of AIDS patients also occur in their duodenal mucosa. This immunological abnormality is associated with the bacterial colonization of upper gastrointestinal tract which may explain the diarrhea and weight loss observed in majority of our patients. The results also indicate that increased incidence of enteric infections in AIDS may be explained on the basis of altered mucosal immunity. PMID:2953237

  12. Proteomics of the Radioresistant Phenotype in Head-and-Neck Cancer: Gp96 as a Novel Prediction Marker and Sensitizing Target for Radiotherapy

    SciTech Connect

    Lin, Ting-Yang; Chang, Joseph Tung-Chieh; Wang, Hung-Ming

    2010-09-01

    Purpose: Radiotherapy is an integral part of the treatment modality for head-neck cancer (HNC), but in some cases the disease is radioresistant. We designed this study to identify molecules that may be involved in this resistance. Methods and Materials: Two radioresistant sublines were established by fractionated irradiation of the HNC cell lines, to determine differentially proteins between parental and radioresistant cells. Proteomic analysis and reverse-transcription polymerase chain reaction were used to identify and confirm the differential proteins. The siRNA knockdown experiments were applied to examine cellular functions of a radioresistant gene, with investigation of the alterations in colonogenic survival, cell cycle status, and reactive oxygen species levels. Xenografted mouse tumors were studied to validate the results. Results: IN all, 64 proteins were identified as being potentially associated with radioresistance, which are involved in several cellular pathways, including regulation of stimulus response, cell apoptosis, and glycolysis. Six genes were confirmed to be differentially expressed in both radioresistant sublines, with Gp96, Grp78, HSP60, Rab40B, and GDF-15 upregulated, and annexin V downregulated. Gp96 was further investigated for its functions in response to radiation. Gp96-siRNA transfectants displayed a radiation-induced growth delay, reduction in colonogenic survival, increased cellular reactive oxygen species levels, and increased proportion of the cells in the G2/M phase. Xenograft mice administered Gp96-siRNA showed significantly enhanced growth suppression in comparison with radiation treatment alone (p = 0.009). Conclusions: We identified 64 proteins and verified 6 genes that are potentially involved in the radioresistant phenotype. We further demonstrated that Gp96 knockdown enhances radiosensitivity both in cells and in vivo, which may lead to a better prognosis of HNC treatment.

  13. Acquired color vision loss and a possible mechanism of ganglion cell death in glaucoma.

    PubMed Central

    Nork, T M

    2000-01-01

    PURPOSE: First, to study the cellular mechanisms of acquired color vision loss in retinal detachment and diabetic retinopathy. Second, to learn why, in glaucoma, the type of color vision deficit that is observed is more characteristic of a retinal injury than it is of an optic neuropathy. Third, to test a hypothesis of photoreceptor-induced, ganglion cell death in glaucoma. METHODS: Various histologic techniques were employed to distinguish the L/M-cones (long/medium wavelength-sensitive cones, or red/green sensitive cones) from the S-cones (short wavelength-sensitive cones, or blue sensitive cones) in humans and monkeys with retinal detachment, humans with diabetic retinopathy, and both humans and monkeys with glaucoma. To test if the photoreceptors were contributing to ganglion cell death, laser photocoagulation was used in a experimental model of glaucoma to focally eliminate the photoreceptors. As a control, optic nerve transection was done following retinal laser photocoagulation in one animal. RESULTS: Selective and widespread loss of the S-cones was found in retinal detachment as well as diabetic retinopathy. By contrast, in human as well as experimental glaucoma, marked swelling of the L/M-cones was the predominant histopathologic feature. Retinal laser photocoagulation followed by experimental glaucoma resulted in selective protection of ganglion cells overlying the laser spots. This was not seen with retinal laser photocoagulation by optic nerve transection. CONCLUSIONS: In retinal detachment and diabetic retinopathy, acquired tritan-like color vision loss could be caused, or contributed to, by selective loss of the S-cones. Both L- and M-cones are affected in glaucoma, which is also consistent with a tritan-like deficit. Although not a therapeutic option, protection of ganglion cells by retinal laser in experimental glaucoma is consistent with an hypothesis of anterograde, photoreceptor-induced, ganglion cell death. Images FIGURE 1 FIGURE 2 FIGURE 3

  14. Acquired cystic disease-associated renal cell carcinoma with sarcomatoid change and rhabdoid features.

    PubMed

    Kuroda, Naoto; Tamura, Masato; Hamaguchi, Nobumasa; Mikami, Shuji; Pan, Chin-Chen; Brunelli, Matteo; Martignoni, Guido; Hes, Ondrej; Michal, Michal; Lee, Gang-Hong

    2011-12-01

    Acquired cystic disease (ACD)-associated renal cell carcinoma (RCC) is a recently described entity. To the best of our knowledge, there are no reports of ACD-associated RCC with sarcomatoid and rhabdoid changes. In this article, we present the first case of such a tumor. A 56-year-old Japanese man has received long-term hemodialysis and had a history of right renal cancer. Following the discovery of metastatic cancer in the thoracic wall, detailed imaging studies revealed a mass in the left kidney. The histologic examination of the left renal tumor showed ACD-associated RCC with sarcomatoid change and rhabdoid features. Immunohistochemically, intracytoplasmic globular inclusions in rhabdoid cells were positive for vimentin and cytokeratin CAM5.2. The G-band karyotype showed the following changes: 46, X, +X. -Y[1]/43, idem, add(2)(q31), -6, -9, -14, -15, +16, -22, +mar1[6]/46, XY[2]/abnormal cell[11]. In conclusion, pathologists and urologists should be aware that rhabdoid features may occur in ACD-associated RCC and that the loss of chromosomes 9 and 14 may occur during the process of sarcomatoid change in ACD-associated RCC. PMID:21036640

  15. Acquired Tissue-Specific Promoter Bivalency Is a Basis for PRC2 Necessity in Adult Cells.

    PubMed

    Jadhav, Unmesh; Nalapareddy, Kodandaramireddy; Saxena, Madhurima; O'Neill, Nicholas K; Pinello, Luca; Yuan, Guo-Cheng; Orkin, Stuart H; Shivdasani, Ramesh A

    2016-06-01

    Bivalent promoters in embryonic stem cells (ESCs) carry methylation marks on two lysine residues, K4 and K27, in histone3 (H3). K4me2/3 is generally considered to promote transcription, and Polycomb Repressive Complex 2 (PRC2) places K27me3, which is erased at lineage-restricted genes when ESCs differentiate in culture. Molecular defects in various PRC2 null adult tissues lack a unifying explanation. We found that epigenomes in adult mouse intestine and other self-renewing tissues show fewer and distinct bivalent promoters compared to ESCs. Groups of tissue-specific genes that carry bivalent marks are repressed, despite the presence of promoter H3K4me2/3. These are the predominant genes de-repressed in PRC2-deficient adult cells, where aberrant expression is proportional to the H3K4me2/3 levels observed at their promoters in wild-type cells. Thus, in adult animals, PRC2 specifically represses genes with acquired, tissue-restricted promoter bivalency. These findings provide new insights into specificity in chromatin-based gene regulation. PMID:27212235

  16. The majority of early primordial germ cells acquire pluripotency by AKT activation.

    PubMed

    Matsui, Yasuhisa; Takehara, Asuka; Tokitake, Yuko; Ikeda, Makiko; Obara, Yuka; Morita-Fujimura, Yuiko; Kimura, Tohru; Nakano, Toru

    2014-12-01

    Primordial germ cells (PGCs) are undifferentiated germ cells in embryos, the fate of which is to become gametes; however, mouse PGCs can easily be reprogrammed into pluripotent embryonic germ cells (EGCs) in culture in the presence of particular extracellular factors, such as combinations of Steel factor (KITL), LIF and bFGF (FGF2). Early PGCs form EGCs more readily than do later PGCs, and PGCs lose the ability to form EGCs by embryonic day (E) 15.5. Here, we examined the effects of activation of the serine/threonine kinase AKT in PGCs during EGC formation; notably, AKT activation, in combination with LIF and bFGF, enhanced EGC formation and caused ∼60% of E10.5 PGCs to become EGCs. The results indicate that the majority of PGCs at E10.5 could acquire pluripotency with an activated AKT signaling pathway. Importantly, AKT activation did not fully substitute for bFGF and LIF, and AKT activation without both LIF and bFGF did not result in EGC formation. These findings indicate that AKT signal enhances and/or collaborates with signaling pathways of bFGF and of LIF in PGCs for the acquisition of pluripotency. PMID:25359722

  17. Oligoarray comparative genomic hybridization of renal cell tumors that developed in patients with acquired cystic renal disease.

    PubMed

    Kuntz, Eva; Yusenko, Maria V; Nagy, Anetta; Kovacs, Gyula

    2010-09-01

    Renal cell carcinoma occurs at higher frequency in acquired cystic renal disease than in the general population. We have analyzed 4 tumors obtained from the kidneys of 2 patients with acquired cystic renal disease, including 2 conventional renal cell carcinomas and 2 acquired cystic renal disease-associated tumors, for genetic alterations. DNA changes were established by applying the 44K Agilent Oligonucleotide Array-Based CGH (Agilent Technologies, Waldbronn, Germany), and mutation of VHL gene was detected by direct sequencing of the tumor genome. DNA losses and mutation of the VHL gene, which are characteristic for conventional renal cell carcinomas, were seen in 2 of the tumors. The acquired cystic renal disease-associated eosinophilic-vacuolated cell tumor showed gain of chromosomes 3 and 16. No DNA alterations occurred in the papillary clear cell tumor. We suggest that not only the morphology but also the genetics of renal cell tumors associated with acquired cystic renal disease may differ from those occurring in the general population. PMID:20646738

  18. Protein expression of nucleophosmin, annexin A3 and nm23-H1 correlates with human nasopharyngeal carcinoma radioresistance in vivo

    PubMed Central

    QU, SONG; LI, XIAO-YU; LIANG, ZHONG-GUO; LI, LING; HUANG, SHI-TING; LI, JIA-QUAN; LI, DAN-RONG; ZHU, XIAO-DONG

    2016-01-01

    Radioresistance is a significant obstacle in the treatment of endemic nasopharyngeal carcinoma (NPC). The present study aimed to identify proteins associated with radioresistance in NPC in vitro and in vivo. Proteomics analyses were conducted to screen for differentially-expressed proteins (DEPs) in parental CNE-2 cells and CNE-2R cells. Using proteomics approaches, 16 DEPs were identified. Of these DEPs, nucleophosmin (NPM1), annexin A3 and nm23-H1, were verified using western blot analyses. The tumorigenicity was investigated using mouse xenograft tumorigenicity assays, and tumor growth curves were generated. The protein expression of NPM1, annexin A3 and nm23-H1 was examined by immunohistochemically staining tumor tissues. NPM1 and annexin A3 protein levels were downregulated in the CNE-2R cells, whereas nm23-H1 expression was upregulated. In vivo tests showed that compared with the CNE-2 tumors, CNE-2R tumor growth was significantly retarded (P<0.05). CNE-2 tumor progression was inhibited by irradiation, but CNE-2R tumor progression was not, indicating that the CNE-2R cells were also radioresistant in vivo. NPM1 and annexin A3 expression was significantly lower in non-irradiated (NIR)-CNE-2R tumors compared with NIR-CNE-2 tumors (P<0.01). However, Nm23-H1 protein levels were significantly higher (P<0.05). Overall, the present study established comparable radioresistant and radiosensitive tumor models of human NPC, and identified candidate biomarkers that may correlate with radioresistance. The data showed that dysregulation of NPM1, annexin A3 and nm23-H1 expression correlated with the cellular and tumor radioresponse. These proteins are involved in the regulation of intracellular functions, including stress responses, cell proliferation and DNA repair. However, further clinical evaluations are required. PMID:27347189

  19. Increased Mitochondrial DNA Induces Acquired Docetaxel Resistance in Head and Neck Cancer Cells

    PubMed Central

    Mizumachi, T; Suzuki, S; Naito, A; Carcel-Trullols, J; Evans, TT; Spring, PM; Oridate, N; Furuta, Y; Fukuda, S; Higuchi, M

    2008-01-01

    Docetaxel is one of the most effective chemotherapeutic agents against cancer; nevertheless, some patients develop resistance. Unfortunately, their causes and mechanisms remain unknown. We created docetaxel-resistant DRHEp2 from human laryngeal cancer HEp2 and investigated the roles of mitochondrial DNA (mtDNA) and ROS on docetaxel resistance. DRHEp2 had greatly increased mtDNA content. Reduction of mtDNA content in DRHEp2 by ethidium bromide treatment reduced the resistance. These results indicate the possible roles of mtDNA-coded enzymes in mitochondrial respiratory chain (MRC) in resistant mechanisms. Oligomycin A, an Fo-ATPase inhibitor, eliminated docetaxel resistance in DRHEp2. In contrast, inhibitors of other MRC did not. RNA interference targeted to Fo-ATPase d-subunit restored docetaxel-induced cytotoxicity to DRHEp2. These results indicate the roles of Fo-ATPase for resistant mechanisms. Docetaxel induced ROS generation in HEp2 but not in DRHEp2 and antioxidant pyrrolidine dithiocarbamate eliminated docetaxel-induced cytotoxicity, suggesting roles of ROS in docetaxel-induced cell death. Furthermore, inhibition of Fo-ATPase by Oligomycin A induced docetaxel–mediated ROS generation in DRHEp2. Taken together, DRHEp2 acquired docetaxel resistance through increasing Fo-ATPase, which led to diminish docetaxel-induced ROS generation and subsequently inhibited cell death. In conclusion, mtDNA plays an important role in developing docetaxel resistance through the reduction of ROS generation by regulating Fo-ATPase. PMID:17637738

  20. miR-620 promotes tumor radioresistance by targeting 15-hydroxyprostaglandin dehydrogenase (HPGD)

    PubMed Central

    Huang, Xiaoyong; Taeb, Samira; Jahangiri, Sahar; Korpela, Elina; Cadonic, Ivan; Yu, Nancy; Krylov, Sergey N.; Fokas, Emmanouil; Boutros, Paul C.; Liu, Stanley K.

    2015-01-01

    MicroRNA contribute to tumor radiation resistance, which is an important clinical problem, and thus we are interested in identifying and characterizing their function. We demonstrate that miR-620 contributes to radiation resistance in cancer cells by increasing proliferation, and decreasing the G2/M block. We identify the hydroxyprostaglandin dehydrogenase 15-(nicotinamide adenine dinucleotide) (HPGD/15-PGDH) tumor suppressor gene as a direct miR-620 target, which results in increased prostaglandin E2 (PGE2) levels. Furthermore, we show that siRNA targeting of HPGD or administration of exogenous PGE2 recapitulates radioresistance. Targeting of the EP2 receptor that responds to PGE2 using pharmacological or genetic approaches, abrogates radioresistance. Tumor xenograft experiments confirm that miR-620 increases proliferation and tumor radioresistance in vivo. Regulation of PGE2 levels via targeting of HPGD by miR-620 is an innovative manner by which a microRNA can induce radiation resistance. PMID:26068950

  1. Memory Stem T Cells in Autoimmune Disease: High Frequency of Circulating CD8+ Memory Stem Cells in Acquired Aplastic Anemia.

    PubMed

    Hosokawa, Kohei; Muranski, Pawel; Feng, Xingmin; Townsley, Danielle M; Liu, Baoying; Knickelbein, Jared; Keyvanfar, Keyvan; Dumitriu, Bogdan; Ito, Sawa; Kajigaya, Sachiko; Taylor, James G; Kaplan, Mariana J; Nussenblatt, Robert B; Barrett, A John; O'Shea, John; Young, Neal S

    2016-02-15

    Memory stem T cells (TSCMs) constitute a long-lived, self-renewing lymphocyte population essential for the maintenance of functional immunity. Hallmarks of autoimmune disease pathogenesis are abnormal CD4(+) and CD8(+) T cell activation. We investigated the TSCM subset in 55, 34, 43, and 5 patients with acquired aplastic anemia (AA), autoimmune uveitis, systemic lupus erythematosus, and sickle cell disease, respectively, as well as in 41 age-matched healthy controls. CD8(+) TSCM frequency was significantly increased in AA compared with healthy controls. An increased CD8(+) TSCM frequency at diagnosis was associated with responsiveness to immunosuppressive therapy, and an elevated CD8(+) TSCM population after immunosuppressive therapy correlated with treatment failure or relapse in AA patients. IFN-γ and IL-2 production was significantly increased in various CD8(+) and CD4(+) T cell subsets in AA patients, including CD8(+) and CD4(+) TSCMs. CD8(+) TSCM frequency was also increased in patients with autoimmune uveitis or sickle cell disease. A positive correlation between CD4(+) and CD8(+) TSCM frequencies was found in AA, autoimmune uveitis, and systemic lupus erythematosus. Evaluation of PD-1, CD160, and CD244 expression revealed that TSCMs were less exhausted compared with other types of memory T cells. Our results suggest that the CD8(+) TSCM subset is a novel biomarker and a potential therapeutic target for AA. PMID:26764034

  2. Mitochondrial targeting of a catalase transgene product by plasmid liposomes increases radioresistance in vitro and in vivo.

    PubMed

    Epperly, Michael W; Melendez, J A; Zhang, Xichen; Nie, Suhua; Pearce, Linda; Peterson, James; Franicola, Darcy; Dixon, Tracy; Greenberger, Benjamin A; Komanduri, Paavani; Wang, Hong; Greenberger, Joel S

    2009-05-01

    To determine whether increased mitochondrially localized catalase was radioprotective, a human catalase transgene was cloned into a small pSVZeo plasmid and localized to the mitochondria of 32D cl 3 cells by adding the mitochondrial localization sequence of MnSOD (mt-catalase). The cell lines 32D-Cat and 32D-mt-Cat had increased catalase biochemical activity as confirmed by Western blot analysis compared to the 32D cl 3 parent cells. The MnSOD-overexpressing 32D cl 3 cell line, 2C6, had decreased baseline catalase activity that was increased in 2C6-Cat and 2C6-mt-Cat subclonal cell lines. 32D-mt-Cat cells were more radioresistant than 32D-Cat cells, but both were radioresistant relative to 32D cl 3 cells. 2C6-mt-Cat cells but not 2C6-Cat cells were radioresistant compared to 2C6 cells. Intratracheal injection of the mt-catalase-plasmid liposome complex (mt-Cat-PL) but not the catalase-plasmid liposome complex (Cat-PL) increased the resistance of C57BL/6NHsd female mice to 20 Gy thoracic irradiation compared to MnSOD-plasmid liposomes. Thus mitochondrially targeted overexpression of the catalase transgene is radioprotective in vitro and in vivo. PMID:19580494

  3. Bovine NK cells acquire cytotoxic activity and produce IFN-gamma after stimulation by Mycobacterium bovis BCG- or Babesia bovis-exposed splenic dendritic cells

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Early interactions of innate immune cell populations such as DC, monocytes/macrophages and NK cells, can affect the ability of the acquired immune response to control infection of intracellular microorganisms. In this study, we investigated the activation of bovine NK cells by CD13+ splenic DC or CD...

  4. Distinct mechanisms account for acquired von Willebrand syndrome in plasma cell dyscrasias.

    PubMed

    Dicke, Christina; Schneppenheim, Sonja; Holstein, Katharina; Spath, Brigitte; Bokemeyer, Carsten; Dittmer, Rita; Budde, Ulrich; Langer, Florian

    2016-05-01

    Acquired von Willebrand syndrome (AVWS) is a rare bleeding disorder that may cause life-threatening hemorrhages in patients with plasma cell dyscrasias (PCDs). Early diagnosis and treatment require a thorough understanding of its underlying pathophysiology. Two patients with IgG MGUS presented with dramatically decreased plasma von Willebrand factor (VWF) and a severe type-1 pattern on multimer analysis. A prompt response to intravenous immunoglobulins (IVIG), but not to VWF/FVIII, was consistent with accelerated immunologic clearance of plasma VWF. Another IgG MGUS patient showed a type-2 pattern and a less pronounced response to IVIG, suggesting that additional mechanism(s) contributed to AVWS evolution. In a patient with Waldenström's macroglobulinemia and severe depletion of plasma VWF, multimer analysis indicated association of the IgM paraprotein with VWF before, but not after plasmapheresis, resulting in destruction of the agarose gel and a characteristically distorted band structure of VWF multimers. A type-2 pattern with highly abnormal VWF triplets and laboratory evidence of excessive fibrinolytic activity suggested that plasmin-mediated VWF degradation contributed to AVWS in a patient with multiple myeloma (MM) and AL amyloidosis. Finally, in a patient with IgG MM, maximally prolonged PFA-100® closure times and a specific defect in ristocetin-induced platelet agglutination, both of which resolved after remission induction, indicated interference of the paraprotein with VWF binding to platelet GPIb. Importantly, in none of the six patients, circulating autoantibodies to VWF were detected by a specific in-house ELISA. In summary, when evaluating PCD patients with severe bleeding symptoms, AVWS due to various pathogenic mechanisms should be considered. PMID:27040683

  5. Identification of Martian biota using their radioresistance ability and specific isotopic composition

    NASA Astrophysics Data System (ADS)

    Pavlov, A. K.; Kalinin, V.; Konstantinov, A.; Shelegedin, V.; Pavlov, A. A.

    2003-04-01

    Because of a thin atmosphere and weak magnetic field, Martian surface is a subject to high levels of ionizing radiation. On the other hand, variations in Martian obliquity produce the global climate oscillations (with the main period ~120000 years) of the great magnitude. Martian biota would accumulate large radiation dosage during the periods of cold climate, when it would be in the dormant state and would rebuild its population during the periods of warm climate. Therefore, all types of hypothetical Martian microorganisms living in subsurface layers of soil have to posses very high radiation tolerance. In our experiments, we find that "ordinary" bacteria (Escherichia coli and two species of Bacillus ) can develop radioresistance ability after a number of cycles of exposure to the high (almost lethal) radiation dosages, followed by recovery of the bacterial population. We show that natural cycles of this kind could take place only on Mars. On the other hand, high radiation tolerance is hardly necessary for the survival in any natural environment on Earth. A few number of terrestrial microorganisms (radioresistant bacteria) posses this peculiar ability (Deinococus radiodurance , Rubrobacter radiotolerance, Rubrobacter xylanophilus ). The radiation background on Earth, including vicinity of natural nuclear reactor Oklo is many orders of magnitude lower than the lethal dose for these microorganisms. We show that such radioresistance can be "trained" only in the Martian conditions. Therefore, we propose that Earth has been infected several times by the Martian biota on Martian meteorites. We propose that high radioresistance could be a strong sign of the Martian origin for potential microorganisms acquired in the sample return missions. Another way to identify "Martian" microorganisms and exclude contamination in returned samples involves analysis of the radionuclides abundance (being produced by the high energy cosmic rays in the Martian soil). We show that these

  6. Increased interleukin-6 expression is associated with poor prognosis and acquired cisplatin resistance in head and neck squamous cell carcinoma.

    PubMed

    Gao, Jian; Zhao, Sen; Halstensen, Trond S

    2016-06-01

    Increased expression of interleukin 6 (IL-6) is associated with poor prognosis and chemoresistance in many different carcinomas, but its role in head and neck squamous cell carcinoma (HNSCC) is still unsettled. Analyzing tumorous mRNA expression data from 399 HNSCC patients revealed that high IL-6 expression predicted poor prognosis. Similar tendency was observed in platinum treated patients, suggesting an IL-6 associated cisplatin resistance. IL-6 increase was also found in two in-house acquired cisplatin‑resistant HNSCC cell lines (both basaloid and conventional squamous cell carcinoma) by using microarray analysis. However, although the in-house acquired cisplatin-resistant cell lines had higher basal and markedly increased cisplatin-induced IL-6 expression, IL-6 did not mediate the cisplatin resistance as neither exogenous IL-6 nor IL-6R/gp130 inhibitors affected cisplatin sensitivity. Moreover, the IL-6/STAT3 pathway was impaired in the resistant cell lines, partly due to decreased IL-6R expression. Thus, high IL-6 expression correlated to poor prognosis and acquired cisplatin resistance, but it did not mediate cisplatin resistance in the HNSCC cell lines. PMID:27108527

  7. Increased interleukin-6 expression is associated with poor prognosis and acquired cisplatin resistance in head and neck squamous cell carcinoma

    PubMed Central

    GAO, JIAN; ZHAO, SEN; HALSTENSEN, TROND S.

    2016-01-01

    Increased expression of interleukin 6 (IL-6) is associated with poor prognosis and chemoresistance in many different carcinomas, but its role in head and neck squamous cell carcinoma (HNSCC) is still unsettled. Analyzing tumorous mRNA expression data from 399 HNSCC patients revealed that high IL-6 expression predicted poor prognosis. Similar tendency was observed in platinum treated patients, suggesting an IL-6 associated cisplatin resistance. IL-6 increase was also found in two in-house acquired cisplatin-resistant HNSCC cell lines (both basaloid and conventional squamous cell carcinoma) by using microarray analysis. However, although the in-house acquired cisplatin-resistant cell lines had higher basal and markedly increased cisplatin-induced IL-6 expression, IL-6 did not mediate the cisplatin resistance as neither exogenous IL-6 nor IL-6R/gp130 inhibitors affected cisplatin sensitivity. Moreover, the IL-6/STAT3 pathway was impaired in the resistant cell lines, partly due to decreased IL-6R expression. Thus, high IL-6 expression correlated to poor prognosis and acquired cisplatin resistance, but it did not mediate cisplatin resistance in the HNSCC cell lines. PMID:27108527

  8. CD4 memory T cells develop and acquire functional competence by sequential cognate interactions and stepwise gene regulation.

    PubMed

    Kaji, Tomohiro; Hijikata, Atsushi; Ishige, Akiko; Kitami, Toshimori; Watanabe, Takashi; Ohara, Osamu; Yanaka, Noriyuki; Okada, Mariko; Shimoda, Michiko; Taniguchi, Masaru; Takemori, Toshitada

    2016-06-01

    Memory CD4(+) T cells promote protective humoral immunity; however, how memory T cells acquire this activity remains unclear. This study demonstrates that CD4(+) T cells develop into antigen-specific memory T cells that can promote the terminal differentiation of memory B cells far more effectively than their naive T-cell counterparts. Memory T cell development requires the transcription factor B-cell lymphoma 6 (Bcl6), which is known to direct T-follicular helper (Tfh) cell differentiation. However, unlike Tfh cells, memory T cell development did not require germinal center B cells. Curiously, memory T cells that develop in the absence of cognate B cells cannot promote memory B-cell recall responses and this defect was accompanied by down-regulation of genes associated with homeostasis and activation and up-regulation of genes inhibitory for T-cell responses. Although memory T cells display phenotypic and genetic signatures distinct from Tfh cells, both had in common the expression of a group of genes associated with metabolic pathways. This gene expression profile was not shared to any great extent with naive T cells and was not influenced by the absence of cognate B cells during memory T cell development. These results suggest that memory T cell development is programmed by stepwise expression of gatekeeper genes through serial interactions with different types of antigen-presenting cells, first licensing the memory lineage pathway and subsequently facilitating the functional development of memory T cells. Finally, we identified Gdpd3 as a candidate genetic marker for memory T cells. PMID:26714588

  9. Acquired Resistance to EGFR Inhibitors Is Associated with a Manifestation of Stem cell–like Properties in Cancer Cells

    PubMed Central

    Shien, Kazuhiko; Toyooka, Shinichi; Yamamoto, Hiromasa; Soh, Junichi; Jida, Masaru; Thu, Kelsie L.; Hashida, Shinsuke; Maki, Yuho; Ichihara, Eiki; Asano, Hiroaki; Tsukuda, Kazunori; Takigawa, Nagio; Kiura, Katsuyuki; Gazdar, Adi F.; Lam, Wan L.; Miyoshi, Shinichiro

    2015-01-01

    Acquired resistance to EGF receptor (EGFR) tyrosine kinase inhibitor (TKI) is a critical problem in the treatment of lung cancer. Although several mechanisms have been shown to be responsible for acquired resistance, all mechanisms have not been uncovered. In this study, we investigated the molecular and cellular profiles of the acquired resistant cells to EGFR-TKI in EGFR-mutant lung cancers. Four EGFR-mutant cell lines were exposed to gefitinib by stepwise escalation and high-concentration exposure methods, and resistant sublines to gefitinib were established. The molecular profiles and cellular phenotypes of these resistant sublines were characterized. Although previously reported, alterations including secondary EGFR T790M mutation, MET amplification, and appearance of epithelial-to-mesenchymal transition (EMT) features were observed, these 2 drug-exposure methods revealed different resistance mechanisms. The resistant cells with EMT features exhibited downregulation of miRNA-200c by DNA methylation. Furthermore, the HCC827-derived subline characterized by the high-concentration exposure method exhibited not only EMT features but also stem cell–like properties, including aldehyde dehydrogenase isoform 1 (ALDH1A1) overexpression, increase of side-population, and self-renewal capability. Resistant sublines with stem cell–like properties were resistant to conventional chemotherapeutic agents but equally sensitive to histone deacetylase and proteasome inhibitors, compared with their parental cells. ALDH1A1 was upregulated in clinical samples with acquired resistance to gefitinib. In conclusion, our study indicates that the manner of EGFR-TKI exposure influences the mechanism of acquired resistance and the appearance of stem cell–like property with EGFR-TKI treatment. PMID:23542356

  10. Long-term persistence of acquired resistance to 5-fluorouracil in the colon cancer cell line SW620

    SciTech Connect

    Tentes, I.K.; Schmidt, W.M.; Krupitza, G.; Steger, G.G.; Mikulits, W.; Kortsaris, A.; Mader, R.M.

    2010-11-15

    Treatment resistance to antineoplastic drugs represents a major clinical problem. Here, we investigated the long-term stability of acquired resistance to 5-fluorouracil (FU) in an in vitro colon cancer model, using four sub-clones characterised by increasing FU-resistance derived from the cell line SW620. The resistance phenotype was preserved after FU withdrawal for 15 weeks ({approx} 100 cell divisions) independent of the established level of drug resistance and of epigenetic silencing. Remarkably, resistant clones tolerated serum deprivation, adopted a CD133{sup +} CD44{sup -} phenotype, and further exhibited loss of membrane-bound E-cadherin together with predominant nuclear {beta}-catenin localisation. Thus, we provide evidence for a long-term memory of acquired drug resistance, driven by multiple cellular strategies (epithelial-mesenchymal transition and selective propagation of CD133{sup +} cells). These resistance phenomena, in turn, accentuate the malignant phenotype.

  11. Axl mediates acquired resistance of head and neck cancer cells to the epidermal growth factor receptor inhibitor erlotinib.

    PubMed

    Giles, Keith M; Kalinowski, Felicity C; Candy, Patrick A; Epis, Michael R; Zhang, Priscilla M; Redfern, Andrew D; Stuart, Lisa M; Goodall, Gregory J; Leedman, Peter J

    2013-11-01

    Elevated expression and activity of the epidermal growth factor receptor (EGFR) is associated with development and progression of head and neck cancer (HNC) and a poor prognosis. Clinical trials with EGFR tyrosine kinase inhibitors (e.g., erlotinib) have been disappointing in HNC. To investigate the mechanisms mediating resistance to these agents, we developed an HNC cell line (HN5-ER) with acquired erlotinib resistance. In contrast to parental HN5 HNC cells, HN5-ER cells exhibited an epithelial-mesenchymal (EMT) phenotype with increased migratory potential, reduced E-cadherin and epithelial-associated microRNAs (miRNA), and elevated vimentin expression. Phosphorylated receptor tyrosine kinase profiling identified Axl activation in HN5-ER cells. Growth and migration of HN5-ER cells were blocked with a specific Axl inhibitor, R428, and R428 resensitized HN5-ER cells to erlotinib. Microarray analysis of HN5-ER cells confirmed the EMT phenotype associated with acquired erlotinib resistance, and identified activation of gene expression associated with cell migration and inflammation pathways. Moreover, increased expression and secretion of interleukin (IL)-6 and IL-8 in HN5-ER cells suggested a role for inflammatory cytokine signaling in EMT and erlotinib resistance. Expression of the tumor suppressor miR-34a was reduced in HN5-ER cells and increasing its expression abrogated Axl expression and reversed erlotinib resistance. Finally, analysis of 302 HNC patients revealed that high tumor Axl mRNA expression was associated with poorer survival (HR = 1.66, P = 0.007). In summary, our results identify Axl as a key mediator of acquired erlotinib resistance in HNC and suggest that therapeutic inhibition of Axl by small molecule drugs or specific miRNAs might overcome anti-EGFR therapy resistance. PMID:24026012

  12. Treatment of Acquired von Willebrand Syndrome and Prevention of Bleeding Postautologous Stem Cell Transplant during Severe Pancytopenia with IVIG

    PubMed Central

    Zoghi, Behyar; Shaughnessy, Paul; Lyons, Roger M.; Helmer, Richard; Bachier, Carlos; LeMaistre, C. Frederick

    2015-01-01

    The use of high dose chemotherapy followed by autologous hematopoietic stem cell transplantation for remission consolidation after initial induction represents standard of care for patients with multiple myeloma. Patients with myeloma and Acquired von Willebrand Syndrome (AVWS) undergoing autologous stem cell transplant (ASCT) are at significant risk of bleeding due to the profound thrombocytopenia, low Factor VIII levels, fever, and toxicities associated with the preparative regimen. We report a patient with AVWS associated with multiple myeloma who underwent autologous stem cell transplants as consolidation after initial induction and again at relapse. He was successfully treated with high dose intravenous immunoglobulin (IVIG) prior to each transplant with rapid resolution of AVWS. PMID:25922770

  13. The ability of inner cell mass cells to self-renew as embryonic stem cells is acquired upon epiblast specification

    PubMed Central

    Boroviak, Thorsten; Loos, Remco; Bertone, Paul; Smith, Austin; Nichols, Jennifer

    2016-01-01

    The precise relationship of embryonic stem cells (ESC) to cells in the mouse embryo remains controversial. We present transcriptional and functional data to identify the embryonic counterpart of ESC. Marker profiling shows that ESC are distinct from early inner cell mass (ICM) and closely resemble preimplantation epiblast. A characteristic feature of mouse ESC is propagation without ERK signalling. Single-cell culture reveals that cell autonomous capacity to thrive when the ERK pathway is inhibited arises late during blastocyst development and is lost after implantation. The frequency of deriving clonal ESC lines suggests that all E4.5 epiblast cells can become ESC. We further show that ICM cells from early blastocysts can progress to ERK-independence if provided with a specific laminin substrate. These findings suggest that formation of the epiblast coincides with competence for ERK-independent self-renewal in vitro and consequent propagation as ESC lines. PMID:24859004

  14. Evidence for the role of microRNA 374b in acquired cisplatin resistance in pancreatic cancer cells

    PubMed Central

    Schreiber, R; Mezencev, R; Matyunina, L V; McDonald, J F

    2016-01-01

    Recent evidence has implicated microRNAs (miRNAs) as potentially significant players in the acquisition of cancer-drug resistance in pancreatic and other cancers. To evaluate the potential contribution of miRNAs in acquired resistance to cisplatin in pancreatic cancer, we compared levels of more than 2000 human miRNAs in a cisplatin-resistant cell line (BxPC3-R) derived from parental (BxPC3) cells by step-wise exposure to increasing concentrations of the drug over more than 20 passages. The acquired drug resistance was accompanied by significant changes in the expression of 57 miRNAs, of which 23 were downregulated and 34 were upregulated. Employing a hidden Markov model (HMM) algorithm, we identified downregulation of miR-374b as likely being directly involved in acquisition of the drug-resistant phenotype. Consistent with this prediction, ectopic overexpression of miR-374b in the resistant BxPC3-R cells restored cisplatin sensitivity to levels approaching those displayed by the BxPC3 parental cells. The results are consistent with a growing body of evidence implicating miRNAs in acquired cancer-drug resistance and with the potential therapeutic value of these small regulatory RNAs in blocking and/or reversing the process. PMID:27229158

  15. Evidence for the role of microRNA 374b in acquired cisplatin resistance in pancreatic cancer cells.

    PubMed

    Schreiber, R; Mezencev, R; Matyunina, L V; McDonald, J F

    2016-08-01

    Recent evidence has implicated microRNAs (miRNAs) as potentially significant players in the acquisition of cancer-drug resistance in pancreatic and other cancers. To evaluate the potential contribution of miRNAs in acquired resistance to cisplatin in pancreatic cancer, we compared levels of more than 2000 human miRNAs in a cisplatin-resistant cell line (BxPC3-R) derived from parental (BxPC3) cells by step-wise exposure to increasing concentrations of the drug over more than 20 passages. The acquired drug resistance was accompanied by significant changes in the expression of 57 miRNAs, of which 23 were downregulated and 34 were upregulated. Employing a hidden Markov model (HMM) algorithm, we identified downregulation of miR-374b as likely being directly involved in acquisition of the drug-resistant phenotype. Consistent with this prediction, ectopic overexpression of miR-374b in the resistant BxPC3-R cells restored cisplatin sensitivity to levels approaching those displayed by the BxPC3 parental cells. The results are consistent with a growing body of evidence implicating miRNAs in acquired cancer-drug resistance and with the potential therapeutic value of these small regulatory RNAs in blocking and/or reversing the process. PMID:27229158

  16. Forced expression of PDX-1 gene makes hepatoma cells to acquire glucose-responsive insulin secretion while maintaining hepatic characteristic.

    PubMed

    Hashimoto, H; Higuchi, Y; Kawai, K

    2015-01-01

    Evidence shows that forced expression of the PDX1 gene converts hepatoma cells, mouse liver epithelial cells (MLECs) and HepaRG cells, into insulin—producing cells, β—cells, or islets of Langerhans. However, no reports have investigated the characteristics of mouse or human hepatocytes introduced with the PDX1 gene over prolonged observation periods. In this study, we immunohistologically and molecularly investigated the alternative processes induced by PDX1 gene introduction in mouse and human hepatocytes over prolonged observation periods using immunocytochemistry, immunofluorescence, polymerase chain reaction (PCR), Western blotting, and flow cytometry (FCM) analysis. Immunocytochemical and immunofluorescent observations showed that MLECs and HepaRG cells on 2 and 21 days after introduction of the PDX1 gene comprised cells double—positive for insulin and albumin. Additionally, they showed MAFA expression and glucose—responsive insulin secretion with glucokinase expression. However mouse embryonic fibroblasts introduced with PDX1—GFP could not acquire glucose—responsive insulin secretion and glucokinase expression. Subsequently, we hypothesized that the number of albumin—positive MLECs and HepaRG cells would decrease after introduction of PDX1 due to the conversion of MLECs and HepaRG cells into insulin—producing cells. However, FCM analysis indicated that the number of albumin—positive MLECs and HepaRG cells was not altered by the introduction of PDX1. We thought that MLECs and HepaRG cells introduced with the PDX1 gene could acquire a functional insulin secretory capacity without conversion to β—cells, or islets of Langerhans, and the acquisition could need glucokinase expression. PMID:25817342

  17. Collateral Chemoresistance to Anti-Microtubule Agents in a Lung Cancer Cell Line with Acquired Resistance to Erlotinib

    PubMed Central

    Mizuuchi, Hiroshi; Suda, Kenichi; Sato, Katsuaki; Tomida, Shuta; Fujita, Yoshihiko; Kobayashi, Yoshihisa; Maehara, Yoshihiko; Sekido, Yoshitaka; Nishio, Kazuto; Mitsudomi, Tetsuya

    2015-01-01

    Various alterations underlying acquired resistance to epidermal growth factor receptor-tyrosine kinase inhibitors (EGFR-TKIs) have been described. Although treatment strategies specific for these mechanisms are under development, cytotoxic agents are currently employed to treat many patients following failure of EGFR-TKIs. However, the effect of TKI resistance on sensitivity to these cytotoxic agents is mostly unclear. This study investigated the sensitivity of erlotinib-resistant tumor cells to five cytotoxic agents using an in vitro EGFR-TKI-resistant model. Four erlotinib-sensitive lung adenocarcinoma cell lines and their resistant derivatives were tested. Of the resistant cell lines, all but one showed a similar sensitivity to the tested drugs as their parental cells. HCC4006ER cells with epithelial mesenchymal transition features acquired resistance to the three microtubule-targeting agents, docetaxel, paclitaxel and vinorelbine, but not to cisplatin and gemcitabine. Gene expression array and immunoblotting demonstrated that ATP-binding cassette subfamily B, member 1 (ABCB1) was up-regulated in HCC4006ER cells. ABCB1 knockdown by siRNA partially restored sensitivity to the anti-microtubule agents but not to erlotinib. Moreover, the histone deacetylase inhibitor entinostat sensitized HCC4006ER cells to anti-microtubule agents through ABCB1 suppression. Our study indicates that sensitivity of tumor cells to cytotoxic agents in general does not change before and after failure of EGFR-TKIs. However, we describe that two different molecular alterations confer acquired resistance to EGFR-TKIs and cytotoxic agents, respectively. This phenomenon should be kept in mind in selection of subsequent therapy after failure of EGFR-TKIs. PMID:25875914

  18. Collateral chemoresistance to anti-microtubule agents in a lung cancer cell line with acquired resistance to erlotinib.

    PubMed

    Mizuuchi, Hiroshi; Suda, Kenichi; Sato, Katsuaki; Tomida, Shuta; Fujita, Yoshihiko; Kobayashi, Yoshihisa; Maehara, Yoshihiko; Sekido, Yoshitaka; Nishio, Kazuto; Mitsudomi, Tetsuya

    2015-01-01

    Various alterations underlying acquired resistance to epidermal growth factor receptor-tyrosine kinase inhibitors (EGFR-TKIs) have been described. Although treatment strategies specific for these mechanisms are under development, cytotoxic agents are currently employed to treat many patients following failure of EGFR-TKIs. However, the effect of TKI resistance on sensitivity to these cytotoxic agents is mostly unclear. This study investigated the sensitivity of erlotinib-resistant tumor cells to five cytotoxic agents using an in vitro EGFR-TKI-resistant model. Four erlotinib-sensitive lung adenocarcinoma cell lines and their resistant derivatives were tested. Of the resistant cell lines, all but one showed a similar sensitivity to the tested drugs as their parental cells. HCC4006ER cells with epithelial mesenchymal transition features acquired resistance to the three microtubule-targeting agents, docetaxel, paclitaxel and vinorelbine, but not to cisplatin and gemcitabine. Gene expression array and immunoblotting demonstrated that ATP-binding cassette subfamily B, member 1 (ABCB1) was up-regulated in HCC4006ER cells. ABCB1 knockdown by siRNA partially restored sensitivity to the anti-microtubule agents but not to erlotinib. Moreover, the histone deacetylase inhibitor entinostat sensitized HCC4006ER cells to anti-microtubule agents through ABCB1 suppression. Our study indicates that sensitivity of tumor cells to cytotoxic agents in general does not change before and after failure of EGFR-TKIs. However, we describe that two different molecular alterations confer acquired resistance to EGFR-TKIs and cytotoxic agents, respectively. This phenomenon should be kept in mind in selection of subsequent therapy after failure of EGFR-TKIs. PMID:25875914

  19. Characteristics and response of mouse bone marrow derived novel low adherent mesenchymal stem cells acquired by quantification of extracellular matrix

    PubMed Central

    Zheng, Ri-Cheng; Heo, Seong-Joo; Koak, Jai-Young; Lee, Joo-Hee; Park, Ji-Man

    2014-01-01

    PURPOSE The aim of present study was to identify characteristic and response of mouse bone marrow (BM) derived low-adherent bone marrow mesenchymal stem cells (BMMSCs) obtained by quantification of extracellular matrix (ECM). MATERIALS AND METHODS Non-adherent cells acquired by ECM coated dishes were termed low-adherent BMMSCs and these cells were analyzed by in vitro and in vivo methods, including colony forming unit fibroblast (CFU-f), bromodeoxyuridine (BrdU), multi-potential differentiation, flow cytometry and transplantation into nude mouse to measure the bone formation ability of these low-adherent BMMSCs. Titanium (Ti) discs with machined and anodized surfaces were prepared. Adherent and low-adherent BMMSCs were cultured on the Ti discs for testing their proliferation. RESULTS The amount of CFU-f cells was significantly higher when non-adherent cells were cultured on ECM coated dishes, which was made by 7 days culturing of adherent BMMSCs. Low-adherent BMMSCs had proliferation and differentiation potential as adherent BMMSCs in vitro. The mean amount bone formation of adherent and low-adherent BMMSCs was also investigated in vivo. There was higher cell proliferation appearance in adherent and low-adherent BMMSCs seeded on anodized Ti discs than machined Ti discs by time. CONCLUSION Low-adherent BMMSCs acquired by ECM from non-adherent cell populations maintained potential characteristic similar to those of the adherent BMMSCs and therefore could be used effectively as adherent BMMSCs in clinic. PMID:25352957

  20. Targeting glucosylceramide synthase induction of cell surface globotriaosylceramide (Gb3) in acquired cisplatin-resistance of lung cancer and malignant pleural mesothelioma cells

    SciTech Connect

    Tyler, Andreas; Johansson, Anders; Karlsson, Terese; Gudey, Shyam Kumar; Brännström, Thomas; Grankvist, Kjell; Behnam-Motlagh, Parviz

    2015-08-01

    Background: Acquired resistance to cisplatin treatment is a caveat when treating patients with non-small cell lung cancer (NSCLC) and malignant pleural mesothelioma (MPM). Ceramide increases in response to chemotherapy, leading to proliferation arrest and apoptosis. However, a tumour stress activation of glucosylceramide synthase (GCS) follows to eliminate ceramide by formation of glycosphingolipids (GSLs) such as globotriaosylceramide (Gb3), the functional receptor of verotoxin-1. Ceramide elimination enhances cell proliferation and apoptosis blockade, thus stimulating tumor progression. GSLs transactivate multidrug resistance 1/P-glycoprotein (MDR1) and multidrug resistance-associated protein 1 (MRP1) expression which further prevents ceramide accumulation and stimulates drug efflux. We investigated the expression of Gb3, MDR1 and MRP1 in NSCLC and MPM cells with acquired cisplatin resistance, and if GCS activity or MDR1 pump inhibitors would reduce their expression and reverse cisplatin-resistance. Methods: Cell surface expression of Gb3, MDR1 and MRP1 and intracellular expression of MDR1 and MRP1 was analyzed by flow cytometry and confocal microscopy on P31 MPM and H1299 NSCLC cells and subline cells with acquired cisplatin resistance. The effect of GCS inhibitor PPMP and MDR1 pump inhibitor cyclosporin A for 72 h on expression and cisplatin cytotoxicity was tested. Results: The cisplatin-resistant cells expressed increased cell surface Gb3. Cell surface Gb3 expression of resistant cells was annihilated by PPMP whereas cyclosporin A decreased Gb3 and MDR1 expression in H1299 cells. No decrease of MDR1 by PPMP was noted in using flow cytometry, whereas a decrease of MDR1 in H1299 and H1299res was indicated with confocal microscopy. No certain co-localization of Gb3 and MDR1 was noted. PPMP, but not cyclosporin A, potentiated cisplatin cytotoxicity in all cells. Conclusions: Cell surface Gb3 expression is a likely tumour biomarker for acquired cisplatin

  1. Patterns and frequencies of acquired and constitutional uniparental isodisomies in pediatric and adult B-cell precursor acute lymphoblastic leukemia.

    PubMed

    Lundin, Kristina B; Olsson, Linda; Safavi, Setareh; Biloglav, Andrea; Paulsson, Kajsa; Johansson, Bertil

    2016-05-01

    Single nucleotide polymorphism (SNP) arrays are increasingly being used in clinical routine for genetic analysis of pediatric B-cell precursor acute lymphoblastic leukemias (BCP ALL). Because constitutional DNA is not readily available as a control at the time of diagnosis, it is important to be able to distinguish between acquired and constitutional aberrations in a diagnostic setting. In the present study we focused on uniparental isodisomies (UPIDs). SNP array analyses of 143 pediatric and 38 adult B-cell precursor acute lymphoblastic leukemias and matched remission samples revealed acquired whole chromosome or segmental UPIDs (wUPIDs, sUPIDs) in 32 cases (18%), without any age- or gender-related frequency differences. Acquired sUPIDs were larger than the constitutional ones (mean 35.3 Mb vs. 10.7 Mb; P < 0.0001) and were more often terminally located in the chromosomes (69% vs. 4.5%; P < 0.0001). Chromosomes 3, 5, and 9 were most often involved in acquired wUPIDs, whilst recurrent acquired sUPIDs targeted 6p, 9p, 9q, and 14q. The majority (56%) of sUPID9p was associated with homozygous CDKN2A deletions. In pediatric ALL, all wUPIDs were found in high hyperdiploid (51-67 chromosomes) cases and an extended analysis, also including unmatched diagnostic samples, revealed a higher frequency of wUPID-positivity in higher modal number (56-67 chromosomes) than in lower modal number (51-55 chromosomes) high hyperdiploid cases (34% vs. 11%; P = 0.04), suggesting different underlying mechanisms of formation of these subtypes of high hyperdiploidy. © 2016 Wiley Periodicals, Inc. PMID:26773847

  2. Characterization of naturally acquired multiple-drug resistance of Yoshida rat ascites hepatoma AH66 cell line.

    PubMed

    Miyamoto, K; Wakabayashi, D; Minamino, T; Nomura, M; Wakusawa, S; Nakamura, S

    1996-01-01

    Characteristics of multiple-drug resistance of rat ascites hepatoma AH66, a cell line induced by dimethylaminoazobenzene and established as a transplantable tumor, were compared with those of AH66F, a drug sensitive line obtained from AH66. The AH66 cell line was resistant to vinblastine, adriamycin, SN-38 an active form of camptothesine, etoposide, and clorambucil by 10-fold or more than the AH66F cell line. The resistance of AH66 cells to vinblastine, adriamycin, and SN-38 was closely related to P-glycoprotein overexpression in the plasma membrane, because the resistance was significantly inhibited by verapamil. AH66 cells contained much glutahione and had a high activity of glutathione S-transferase P-form (GST-P), compared with AH66F cells, and resistance to clorambucil was decreased by treatment with buthionine sulfoximine, an inhibitor of glutathione synthesis. AH66 cells have a similar topoisomerase I activity, but about 6 times lower topoisomerase II activity than AH66F cells. Therefore, the resistance to etoposide and a part of the resistance to adriamycin of AH66 cells seems to depend upon this low topoisomerase II activity. These results, show that the AH66 cell line has high multiple-drug resistance compared with the AH66F cell line, by several mechanisms. Consequently, the AH66 and AH66F cell lines are useful to study naturally acquired multiple-drug resistance of hepatomas. PMID:8702243

  3. Consequences of cell-to-cell P-glycoprotein transfer on acquired multidrug resistance in breast cancer: a cell population dynamics model

    PubMed Central

    2011-01-01

    Background Cancer is a proliferation disease affecting a genetically unstable cell population, in which molecular alterations can be somatically inherited by genetic, epigenetic or extragenetic transmission processes, leading to a cooperation of neoplastic cells within tumoural tissue. The efflux protein P-glycoprotein (P-gp) is overexpressed in many cancer cells and has known capacity to confer multidrug resistance to cytotoxic therapies. Recently, cell-to-cell P-gp transfers have been shown. Herein, we combine experimental evidence and a mathematical model to examine the consequences of an intercellular P-gp trafficking in the extragenetic transfer of multidrug resistance from resistant to sensitive cell subpopulations. Methodology and Principal Findings We report cell-to-cell transfers of functional P-gp in co-cultures of a P-gp overexpressing human breast cancer MCF-7 cell variant, selected for its resistance towards doxorubicin, with the parental sensitive cell line. We found that P-gp as well as efflux activity distribution are progressively reorganized over time in co-cultures analyzed by flow cytometry. A mathematical model based on a Boltzmann type integro-partial differential equation structured by a continuum variable corresponding to P-gp activity describes the cell populations in co-culture. The mathematical model elucidates the population elements in the experimental data, specifically, the initial proportions, the proliferative growth rates, and the transfer rates of P-gp in the sensitive and resistant subpopulations. Conclusions We confirmed cell-to-cell transfer of functional P-gp. The transfer process depends on the gradient of P-gp expression in the donor-recipient cell interactions, as they evolve over time. Extragenetically acquired drug resistance is an additional aptitude of neoplastic cells which has implications in the diagnostic value of P-gp expression and in the design of chemotherapy regimens. Reviewers This article was reviewed by

  4. MicroRNA142-3p promotes tumor-initiating and radioresistant properties in malignant pediatric brain tumors.

    PubMed

    Lee, Yi-Yen; Yang, Yi-Ping; Huang, Ming-Chao; Wang, Mong-Lien; Yen, Sang-Hue; Huang, Pin-I; Chen, Yi-Wei; Chiou, Shih-Hwa; Lan, Yuan-Tzu; Ma, Hsin-I; Shih, Yang-Hsin; Chen, Ming-Teh

    2014-01-01

    Primary central nervous system (CNS) atypical teratoid/rhabdoid tumor (ATRT) is an extremely malignant pediatric brain tumor observed in infancy and childhood. It has been reported that a subpopulation of CD133(+) cells isolated from ATRT tumors present with cancer stem-like and radioresistant properties. However, the exact biomolecular mechanisms of ATRT or CD133-positive ATRT (ATRT-CD133(+)) cells are still unclear. We have previously shown that ATRT-CD133(+) cells have pluripotent differentiation ability and the capability of malignant cells to be highly resistant to ionizing radiation (IR). By using microRNA array and quantitative RT-PCR in this study, we showed that expression of miR142-3p was lower in ATRT-CD133(+) cells than in ATRT-CD133(-) cells. miR142-3p overexpression significantly inhibited the self-renewal and tumorigenicity of ATRT-CD133(+) cells. On the contrary, silencing of endogenous miR142-3p dramatically increased the tumor-initiating and stem-like cell capacities in ATRT cells or ATRT-CD133(-) cells and further promoted the mesenchymal transitional and radioresistant properties of ATRT cells. Most importantly, therapeutic delivery of miR142-3p in ATRT cells effectively reduced its lethality by blocking tumor growth, repressing invasiveness, increasing radiosensitivity, and prolonging survival time in orthotropic-transplanted immunocompromised mice. These results demonstrate the prospect of developing novel miRNA-based strategies to block the stem-like and radioresistant properties of malignant pediatric brain cancer stem cells. PMID:24816458

  5. Virus-triggered acquired immunodeficiency by cytotoxic T-cell-dependent destruction of antigen-presenting cells and lymph follicle structure.

    PubMed Central

    Odermatt, B; Eppler, M; Leist, T P; Hengartner, H; Zinkernagel, R M

    1991-01-01

    Virus-induced acquired immune suppression in mice infected with lymphocytic choriomeningitis virus is shown here to be caused by the CD8+-T-cell-dependent elimination of macrophages/antigen-presenting cells. Surprisingly, this is associated with severe destruction of the follicular organization of lymphoid organs, indicating a crucial role for dendritic cells and marginal zone macrophages in maintaining follicular structure. Once established, this immunopathology cannot be readily reversed by the elimination of CD8+ effector cells. Such a T-cell-mediated pathogenesis may play a pivotal role in acquired virus-induced immunosuppression and may represent one strategy by which virus escapes immune surveillance and establishes persistent infections in initially immunocompetent hosts. Images PMID:1910175

  6. Acquired factor V inhibitor in a patient with mantle cell lymphoma presenting with hematuria followed by thrombosis: a case report

    PubMed Central

    AlJohani, Naif I; Matthews, John H

    2014-01-01

    Acquired factor V inhibitor is a rare hemostatic disorder that presents with hemorrhagic manifestations in the vast majority of patients. Factor V inhibitor may develop through a variety of mechanisms involving development of alloantibodies or autoantibodies specific to Factor V. Autoantibodies, in particular, have been reported in a number of conditions. In this report, we describe a case of acquired factor V inhibitor in a patient with mantle cell lymphoma who presented with hematuria. Seven weeks after diagnosis and successful management, the patient developed deep vein thrombosis in the right lower extremity. The patient’s factor V levels were normalized, and the inhibitor was successfully eradicated using corticosteroids. Here, we discuss this rare disorder, its unusual manifestation, and provide a mini-review of the current literature regarding factor V inhibitors. PMID:24591851

  7. Combine therapy of gefitinib and fulvestrant enhances antitumor effects on NSCLC cell lines with acquired resistance to gefitinib.

    PubMed

    Xu, Ruitong; Shen, Hua; Guo, Renhua; Sun, Jing; Gao, Wen; Shu, Yongqian

    2012-07-01

    Gefitinib, an EGFR receptor tyrosine kinase inhibitor, is approved for clinical use in the treatment of non-small cell lung cancer (NSCLC), but the emergence of mutations resistant to these inhibitors, such as T790M, has become a clinical problem. According to statistics, female patients, the presence of adenocarcinoma or non-smokers experienced a higher response rate. This may be involved in interaction between the estrogen receptor (ER) and the epidermal growth factor receptor (EGFR). To test whether inhibition of the ER signaling pathway affects the antitumor effect of gefitinib, gefitinib and an ER antagonist, fulvestrant, were administered to NSCLC cell lines with acquired resistance to gefitinib. Compared with treatment of either fulvestrant or gefitinib alone, drug combination obviously decreased proliferation of H1976, H1650 and PC-9 cells coming from adenocarcinoma. Rapid activations of EGFR pathway by E2β were observed in H1975 cells with T790M mutation. Additionally, EGFR and ERs expression were down-regulated respectively in response to estrogen and EGF but up-regulated in response to fulvestrant and gefitinib in vitro. These results suggest that there is a functional cross-signaling between the EGFR/ER pathways in NSCLC with acquired resistance to gefitinib, possibly providing rationale for combining gefitinib with anti-estrogen therapy for advanced NSCLC treatment. PMID:22560634

  8. HLA class I downregulation is associated with enhanced NK-cell killing of melanoma cells with acquired drug resistance to BRAF inhibitors.

    PubMed

    Sottile, Rosa; Pangigadde, Pradeepa N; Tan, Thomas; Anichini, Andrea; Sabbatino, Francesco; Trecroci, Francesca; Favoino, Elvira; Orgiano, Laura; Roberts, James; Ferrone, Soldano; Kärre, Klas; Colucci, Francesco; Carbone, Ennio

    2016-02-01

    The frequent development of drug resistance to targeted therapies in cancer patients has stimulated interest in strategies counteracting resistance. Combining immunotherapies with targeted therapies is one such strategy. In this context, we asked whether human NK cells can target melanoma cells that have acquired resistance to selective inhibitors targeting activating mutants of the B-Raf kinase (BRAF inhibitors, BRAFi). We generated drug-resistant cell variants in vitro from human BRAF-mutant melanoma cell lines MEL-HO, COLO-38, SK-MEL-37, 1520 and from primary melanoma cells freshly isolated from two patients. All drug-resistant cell variants remained susceptible to lysis by IL-2-activated NK cells; and two BRAFi-resistant lines (BRAFi-R) became significantly more susceptible to NK-cell lysis than their parental lines. This was associated with significant HLA class I antigen downregulation and PD-L1 upregulation on the drug-resistant lines. Although blocking HLA class I enhanced the extent of lysis of both BRAFi-R and parental cells to NK-cell-mediated lysis, antibody-mediated inhibition of PD1-PD-L1 interactions had no detectable effect. HLA class I antigen expression on BRAFi-R melanoma variants thus appears to play a major role in their susceptibility to NK-cell cytotoxicity. These findings suggest that NK-cell-based immunotherapy may be a viable approach to treat melanoma patients with acquired resistance to BRAF inhibitors. PMID:26564811

  9. 2,3,7,8-Tetrachlorodibenzo-p-dioxin induced cell-specific drug transporters with acquired cisplatin resistance in cisplatin sensitive cancer cells.

    PubMed

    Gotovdorj, Tuvshinjargal; Lee, Eunil; Lim, Yongchul; Cha, Eun Jeong; Kwon, Daeho; Hong, Eunyoung; Kim, YunJeong; Oh, Min-Yeong

    2014-09-01

    2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) can induce drug transporter genes such as the ATP-binding cassette G member 2 (ABCG2), which contributes to multidrug resistance. We investigated the effect of TCDD pretreatment on drug transporters induction from cancer cells of various origins. Cell viabilities after treatment of cisplatin were measured to evaluate acquiring cisplatin resistance by TCDD. Acquring cisplatin resistance was found only in cisplatin senstivie cancer cells including gastric SNU601, colon LS180, brain CRT-MG and lymphoma Jurkat cells which showed a significant increase in cell viability after combined treatment with TCDD and cisplatin. High increase of ABCG2 gene expression was found in SNU601 and LS180 cells with a mild increase in the expression of the ABCC3, ABCC5,and SLC29A2 genes in SNU601 cells, and of major vault protein (MVP) in LS180 cells. The AhR inhibitor kaempferol suppressed the upregulation of ABCG2 expression and reversed the TCDD-induced increase in cell viability in LS180 cells. However, in CRT-MG cells, other transporter genes including ABCC1, ABCC5, ABCA3, ABCA2, ABCB4, ABCG1, and SLC29A1 were up-regulated. These findings suggested the acquiring cisplatin resistance by TCDD associated with cancer cell-type-specific induction of drug transporters. PMID:25246735

  10. Homeostasis or channelopathy? Acquired cell type-specific ion channel changes in temporal lobe epilepsy and their antiepileptic potential

    PubMed Central

    Wolfart, Jakob; Laker, Debora

    2015-01-01

    Neurons continuously adapt the expression and functionality of their ion channels. For example, exposed to chronic excitotoxicity, neurons homeostatically downscale their intrinsic excitability. In contrast, the “acquired channelopathy” hypothesis suggests that proepileptic channel characteristics develop during epilepsy. We review cell type-specific channel alterations under different epileptic conditions and discuss the potential of channels that undergo homeostatic adaptations, as targets for antiepileptic drugs (AEDs). Most of the relevant studies have been performed on temporal lobe epilepsy (TLE), a widespread AED-refractory, focal epilepsy. The TLE patients, who undergo epilepsy surgery, frequently display hippocampal sclerosis (HS), which is associated with degeneration of cornu ammonis subfield 1 pyramidal cells (CA1 PCs). Although the resected human tissue offers insights, controlled data largely stem from animal models simulating different aspects of TLE and other epilepsies. Most of the cell type-specific information is available for CA1 PCs and dentate gyrus granule cells (DG GCs). Between these two cell types, a dichotomy can be observed: while DG GCs acquire properties decreasing the intrinsic excitability (in TLE models and patients with HS), CA1 PCs develop channel characteristics increasing intrinsic excitability (in TLE models without HS only). However, thorough examination of data on these and other cell types reveals the coexistence of protective and permissive intrinsic plasticity within neurons. These mechanisms appear differentially regulated, depending on the cell type and seizure condition. Interestingly, the same channel molecules that are upregulated in DG GCs during HS-related TLE, appear as promising targets for future AEDs and gene therapies. Hence, GCs provide an example of homeostatic ion channel adaptation which can serve as a primer when designing novel anti-epileptic strategies. PMID:26124723

  11. Dendritic cells, indoleamine 2,3 dioxygenase and acquired immune privilege

    PubMed Central

    Huang, Lei; Baban, Babak; Johnson, Burles A; Mellor, Andrew L.

    2013-01-01

    Dendritic cells (DCs) are specialized to stimulate T cell immunity. Paradoxically some DCs suppress T cell responses, and activate regulatory T cells. In this review we focus on a potent counter-regulatory pathway mediated by plasmacytoid DCs (pDCs) expressing the immunosuppressive enzyme indoleamine 2,3 dioxygenase (IDO). IDO-expressing pDCs inhibit effector T cell responses, activate regulatory T cells, and attenuate pro-inflammatory responses in settings of chronic inflammation that manifest in clinical syndromes such as infectious, allergic and autoimmune diseases, cancer, and transplantation. Thus IDO-expressing pDCs create immune privilege, and provide novel opportunities to improve immunotherapy in multiple disease syndromes. PMID:20367139

  12. [Radioresistance parameters in head and neck cancers and methods to radiosensitize].

    PubMed

    Biau, J; Chautard, E; Miroir, J; Lapeyre, M

    2015-08-01

    Head and neck cancers have been widely studied concerning their sensitivity to radiation therapy. Several parameters affect tumour response to radiation therapy. Some parameters are linked to the tumour. Large or invasive tumours, localization, such as oral cavity or adenopathy, are factors of radioresistance. Others parameters are linked to the patients themselves. Tobacco intoxication during radiotherapy and a low hemoglobin level contribute to radioresistance. More recently, a positive human papilloma virus (HPV) status has been reported to positively affect radiosensitivity. Finally, other parameters are related to tumour biology. Hypoxia, intrinsic radiosensitivity of tumour cells, tumour differentiation and repopulation (provided by Ki-67 index or EGFR level) are components of radiosensitivity. Currently, concurrent chemoradiotherapy is one of the gold standard treatments to overcome clinical outcome of locally advanced head and neck cancer. This combination increases locoregional control and survival. Taxane-based induction chemotherapy can also be an alternative. Another validated approach is the association of radiotherapy with cetuximab (EGFR targeting) but only one randomized study has been published. Fractionation modifications, especially hyperfractionation, have given positive results on both tumour control and survival. Strategies targeting hypoxia improve locoregional control but have less clinical impact. PMID:26119219

  13. Acquired resistance to ABT-737 in lymphoma cells that up-regulate MCL-1 and BFL-1

    PubMed Central

    Yecies, Derek; Carlson, Nicole E.; Deng, Jing

    2010-01-01

    ABT-737 is a small-molecule antagonist of BCL-2 currently under evaluation in clinical trials in the oral form of ABT-263. We anticipate that acquired resistance to this promising drug will inevitably arise. To study potential mechanisms of resistance to ABT-737, we derived resistant lines from initially sensitive OCI-Ly1 and SU-DHL-4 lymphoma cell lines via long-term exposure. Resistance was based in the mitochondria and not due to an inability of the drug to bind BCL-2. Resistant cells had increased levels of BFL-1 and/or MCL-1 proteins, which are not targeted by ABT-737. Proapoptotic BIM was displaced from BCL-2 by ABT-737 in both parental and resistant cells, but in resistant cells, BIM was sequestered by the additional BFL-1 and/or MCL-1. Decreasing MCL-1 levels with flavopiridol, PHA 767491, or shRNA restored sensitivity to ABT-737 resistant cells. MCL-1 was up-regulated not by protein stabilization but rather by increased transcript levels. Surprisingly, in addition to stable increases in MCL-1 transcript and protein in resistant cells, there was a dynamic increase within hours after ABT-737 treatment. BFL-1 protein and transcript levels in resistant cells were similarly dynamically up-regulated. This dynamic increase suggests a novel mechanism whereby modulation of antiapoptotic protein function communicates with nuclear transcriptional machinery. PMID:20197552

  14. HLA class I downregulation is associated with enhanced NK‐cell killing of melanoma cells with acquired drug resistance to BRAF inhibitors

    PubMed Central

    Sottile, Rosa; Pangigadde, Pradeepa N.; Tan, Thomas; Anichini, Andrea; Sabbatino, Francesco; Trecroci, Francesca; Favoino, Elvira; Orgiano, Laura; Roberts, James; Ferrone, Soldano; Kärre, Klas; Colucci, Francesco

    2015-01-01

    The frequent development of drug resistance to targeted therapies in cancer patients has stimulated interest in strategies counteracting resistance. Combining immunotherapies with targeted therapies is one such strategy. In this context, we asked whether human NK cells can target melanoma cells that have acquired resistance to selective inhibitors targeting activating mutants of the B‐Raf kinase (BRAF inhibitors, BRAFi). We generated drug‐resistant cell variants in vitro from human BRAF‐mutant melanoma cell lines MEL‐HO, COLO‐38, SK‐MEL‐37, 1520 and from primary melanoma cells freshly isolated from two patients. All drug‐resistant cell variants remained susceptible to lysis by IL‐2‐activated NK cells; and two BRAFi‐resistant lines (BRAFi‐R) became significantly more susceptible to NK‐cell lysis than their parental lines. This was associated with significant HLA class I antigen downregulation and PD‐L1 upregulation on the drug‐resistant lines. Although blocking HLA class I enhanced the extent of lysis of both BRAFi‐R and parental cells to NK‐cell‐mediated lysis, antibody‐mediated inhibition of PD1–PD‐L1 interactions had no detectable effect. HLA class I antigen expression on BRAFi‐R melanoma variants thus appears to play a major role in their susceptibility to NK‐cell cytotoxicity. These findings suggest that NK‐cell‐based immunotherapy may be a viable approach to treat melanoma patients with acquired resistance to BRAF inhibitors. PMID:26564811

  15. Parasitophorous vacuoles of Leishmania mexicana acquire macromolecules from the host cell cytosol via two independent routes.

    PubMed

    Schaible, U E; Schlesinger, P H; Steinberg, T H; Mangel, W F; Kobayashi, T; Russell, D G

    1999-03-01

    The intracellular parasite Leishmania survives and proliferates in host macrophages. In this study we show that parasitophorous vacuoles of L. mexicana gain access to cytosolic material via two different routes. (1) Small anionic molecules such as Lucifer Yellow are rapidly transported into the vacuoles by an active transport mechanism that is sensitive to inhibitors of the host cell's organic anion transporter. (2) Larger molecules such as fluorescent dextrans introduced into the host cell cytosol are also delivered to parasitophorous vacuoles. This transport is slower and sensitive to modulators of autophagy. Infected macrophages were examined by two novel assays to visualize and quantify this process. Immunoelectron microscopy of cells loaded with digoxigenin-dextran revealed label in multivesicular endosomes, which appeared to fuse with parasitophorous vacuoles. The inner membranes of the multivesicular vesicles label strongly with antibodies against lysobisphosphatidic acid, suggesting that they represent a point of confluence between the endosomal and autophagosomal pathways. Although the rate of autophagous transfer was comparable in infected and uninfected cells, infected cells retained hydrolyzed cysteine proteinase substrate to a greater degree. These data suggest that L. mexicana-containing vacuoles have access to potential nutrients in the host cell cytosol via at least two independent mechanisms. PMID:9973603

  16. Cyclosporine restores hematopoietic function by compensating for decreased Tregs in patients with pure red cell aplasia and acquired aplastic anemia.

    PubMed

    Dao, An T T; Yamazaki, Hirohito; Takamatsu, Hiroyuki; Sugimori, Chiharu; Katagiri, Takamasa; Maruyama, Hiroyuki; Zaimoku, Yoshitaka; Maruyama, Kana; Ly, Trung Q; Espinoza, Luis; Nakao, Shinji

    2016-04-01

    Most patients with acquired pure red cell aplasia (PRCA) and some with acquired aplastic anemia (AA) respond well to cyclosporine (CsA), but thereafter often show CsA dependency. The mechanism underlying this dependency remains unknown. We established a reliable method for measuring the regulatory T cell (Treg) count using FoxP3 and Helios expression as markers and determined the balance between Tregs and other helper T cell subsets in 16 PRCA and 29 AA patients. The ratios of interferon-γ-producing CD4(+) (Th1) T cells to Tregs in untreated patients and CsA-dependent patients were significantly higher (PRCA 5.77 ± 1.47 and 7.38 ± 2.58; AA 6.18 ± 2.35 and 8.94 ± 4.06) than in healthy volunteers (HVs; 3.33 ± 0.90) due to the profound decrease in the percentage of Tregs. In contrast, the ratios were comparable to HVs in convalescent CsA-treated AA patients (4.74 ± 2.10) and AA patients in remission after the cessation of CsA treatment (4.24 ± 1.67). Low-dose CsA (100 ng/ml) inhibited the proliferation of conventional T cells (Tconv) to a similar degree to the inhibition by Tregs in a co-culture with a 1:1 Treg/Tconv ratio. The data suggest that CsA may reverse the hematopoietic suppression in PRCA and AA patients by compensating for the inadequate immune regulatory function that occurs due to a profound decrease in the Treg count. PMID:26968551

  17. Proteomic Signatures of Acquired Letrozole Resistance in Breast Cancer: Suppressed Estrogen Signaling and Increased Cell Motility and Invasiveness*

    PubMed Central

    Tilghman, Syreeta L.; Townley, Ian; Zhong, Qiu; Carriere, Patrick P.; Zou, Jin; Llopis, Shawn D.; Preyan, Lynez C.; Williams, Christopher C.; Skripnikova, Elena; Bratton, Melyssa R.; Zhang, Qiang; Wang, Guangdi

    2013-01-01

    Aromatase inhibitors, such as letrozole, have become the first-line treatment for postmenopausal women with estrogen-dependent breast cancer. However, acquired resistance remains a major clinical obstacle. Previous studies demonstrated constitutive activation of the MAPK signaling, overexpression of HER2, and down-regulation of aromatase and ERα in letrozole-resistant breast cancer cells. Given the complex signaling network involved in letrozole-refractory breast cancer and the lack of effective treatment for hormone resistance, further investigation of aromatase inhibitor resistance by a novel systems biology approach may reveal previously unconsidered molecular changes that could be utilized as therapeutic targets. This study was undertaken to characterize for the first time global proteomic alterations occurring in a letrozole-resistant cell line. A quantitative proteomic analysis of the whole cell lysates of LTLT-Ca (resistant) versus AC-1 cells (sensitive) was performed to identify significant protein expression changes. A total of 1743 proteins were identified and quantified, of which 411 were significantly up-regulated and 452 significantly down-regulated (p < 0.05, fold change > 1.20). Bioinformatics analysis revealed that acquired letrozole resistance is associated with a hormone-independent, more aggressive phenotype. LTLT-Ca cells exhibited 84% and 138% increase in migration and invasion compared with the control cells. The ROCK inhibitor partially abrogated the enhanced migration and invasion of the letrozole-resistant cells. Flow cytometric analyses also demonstrated an increase in vimentin and twist expression in letrozole-resistance cells, suggesting an onset of epithelial to mesenchymal transition (EMT). Moreover, targeted gene expression arrays confirmed a 28-fold and sixfold up-regulation of EGFR and HER2, respectively, whereas ERα and pS2 were dramatically reduced by 28-fold and 1100-fold, respectively. Taken together, our study revealed global

  18. Engraftment of Human Glioblastoma Cells in Immunocompetent Rats through Acquired Immunosuppression

    PubMed Central

    Huszthy, Peter C.; Sakariassen, Per Ø.; Espedal, Heidi; Brokstad, Karl A.; Bjerkvig, Rolf; Miletic, Hrvoje

    2015-01-01

    Transplantation of glioblastoma patient biopsy spheroids to the brain of T cell-compromised Rowett (nude) rats has been established as a representative animal model for human GBMs, with a tumor take rate close to 100%. In immunocompetent littermates however, primary human GBM tissue is invariably rejected. Here we show that after repeated passaging cycles in nude rats, human GBM spheroids are enabled to grow in the brain of immunocompetent rats. In case of engraftment, xenografts in immunocompetent rats grow progressively and host leukocytes fail to enter the tumor bed, similar to what is seen in nude animals. In contrast, rejection is associated with massive infiltration of the tumor bed by leukocytes, predominantly ED1+ microglia/macrophages, CD4+ T helper cells and CD8+ effector cells, and correlates with elevated serum levels of pro-inflammatory cytokines IL-1β, IL-18 and TNF-α. We observed that in nude rat brains, an adaptation to the host occurs after several in vivo passaging cycles, characterized by striking attenuation of microglial infiltration. Furthermore, tumor-derived chemokines that promote leukocyte migration and their entry into the CNS such as CXCL-10 and CXCL-12 are down-regulated, and the levels of TGF-β2 increase. We propose that through serial in vivo passaging in nude rats, human GBM cells learn to avoid and or/ suppress host immunity. Such adapted GBM cells are in turn able to engraft in immunocompetent rats without signs of an inflammatory response. PMID:26291724

  19. Ligand associated ERBB2/3 activation confers acquired resistance to FGFR inhibition in FGFR3 dependent cancer cells

    PubMed Central

    Wang, Jun; Mikse, Oliver; Liao, Rachel G.; Li, Yvonne; Tan, Li; Janne, Pasi A.; Gray, Nathanael S.; Wong, Kwok-kin; Hammerman, Peter S.

    2014-01-01

    Somatic alterations of Fibroblast Growth Factor Receptors (FGFRs) have been described in a wide range of malignancies. A number of anti-FGFR therapies are currently under investigation in clinical trials for subjects with FGFR gene amplifications, mutations and translocations. Here, we develop cell line models of acquired resistance to FGFR inhibition by exposure of cell lines harboring FGFR3 gene amplification and translocation to the selective FGFR inhibitor BGJ398 and multi-targeted FGFR inhibitor ponatinib. We show that the acquisition of resistance is rapid, reversible and characterized by an epithelial to mesenchymal transition (EMT) and a switch from dependency on FGFR3 to ERBB family members. Acquired resistance was associated with demonstrable changes in gene expression including increased production of ERBB2/3 ligands which were sufficient to drive resistance in the setting of FGFR3 dependency but not dependency on other FGFR family members. These data support the concept that activation of ERBB family members is sufficient to bypass dependency on FGFR3 and suggest that concurrent inhibition of these two pathways may be desirable when targeting FGFR3 dependent cancers. PMID:24909170

  20. Ligand-associated ERBB2/3 activation confers acquired resistance to FGFR inhibition in FGFR3-dependent cancer cells.

    PubMed

    Wang, J; Mikse, O; Liao, R G; Li, Y; Tan, L; Janne, P A; Gray, N S; Wong, K-k; Hammerman, P S

    2015-04-23

    Somatic alterations of fibroblast growth factor receptors (FGFRs) have been described in a wide range of malignancies. A number of anti-FGFR therapies are currently under investigation in clinical trials for subjects with FGFR gene amplifications, mutations and translocations. Here, we develop cell line models of acquired resistance to FGFR inhibition by exposure of cell lines harboring FGFR3 gene amplification and translocation to the selective FGFR inhibitor BGJ398 and multitargeted FGFR inhibitor ponatinib. We show that the acquisition of resistance is rapid, reversible and characterized by an epithelial to mesenchymal transition and a switch from dependency on FGFR3 to ERBB family members. Acquired resistance was associated with demonstrable changes in gene expression including increased production of ERBB2/3 ligands, which were sufficient to drive resistance in the setting of FGFR3 dependency but not dependency on other FGFR family members. These data support the concept that activation of ERBB family members is sufficient to bypass dependency on FGFR3 and suggest that concurrent inhibition of these two pathways may be desirable when targeting FGFR3-dependent cancers. PMID:24909170

  1. Persistent linear bands in infancy acquired after local pressure: a consequence of mast cell activation?

    PubMed

    Ford, Lara S; Rogers, Maureen; Kemp, Andrew S; Campbell, Dianne E

    2007-01-01

    A 10-month-old girl with marked symptomatic dermographism presented with linear bands at the sock line noted to have developed following an episode of localized urticaria and angioedema at the sock line. We speculate that release of mast cell mediators associated with the dermographism may have triggered the development of the linear bands. PMID:17845163

  2. Acquiring Chondrocyte Phenotype from Human Mesenchymal Stem Cells under Inflammatory Conditions

    PubMed Central

    Kondo, Masahiro; Yamaoka, Kunihiro; Tanaka, Yoshiya

    2014-01-01

    An inflammatory milieu breaks down the cartilage matrix and induces chondrocyte apoptosis, resulting in cartilage destruction in patients with cartilage degenerative diseases, such as rheumatoid arthritis or osteoarthritis. Because of the limited regenerative ability of chondrocytes, defects in cartilage are irreversible and difficult to repair. Mesenchymal stem cells (MSCs) are expected to be a new tool for cartilage repair because they are present in the cartilage and are able to differentiate into multiple lineages of cells, including chondrocytes. Although clinical trials using MSCs for patients with cartilage defects have already begun, its efficacy and repair mechanisms remain unknown. A PubMed search conducted in October 2014 using the following medical subject headings (MeSH) terms: mesenchymal stromal cells, chondrogenesis, and cytokines resulted in 204 articles. The titles and abstracts were screened and nine articles relevant to “inflammatory” cytokines and “human” MSCs were identified. Herein, we review the cell biology and mechanisms of chondrocyte phenotype acquisition from human MSCs in an inflammatory milieu and discuss the clinical potential of MSCs for cartilage repair. PMID:25407530

  3. Normal human mammary epithelial cells spontaneously escape senescence and acquire genomic changes

    NASA Technical Reports Server (NTRS)

    Romanov, S. R.; Kozakiewicz, B. K.; Holst, C. R.; Stampfer, M. R.; Haupt, L. M.; Tlsty, T. D.

    2001-01-01

    Senescence and genomic integrity are thought to be important barriers in the development of malignant lesions. Human fibroblasts undergo a limited number of cell divisions before entering an irreversible arrest, called senescence. Here we show that human mammary epithelial cells (HMECs) do not conform to this paradigm of senescence. In contrast to fibroblasts, HMECs exhibit an initial growth phase that is followed by a transient growth plateau (termed selection or M0; refs 3-5), from which proliferative cells emerge to undergo further population doublings (approximately 20-70), before entering a second growth plateau (previously termed senescence or M1; refs 4-6). We find that the first growth plateau exhibits characteristics of senescence but is not an insurmountable barrier to further growth. HMECs emerge from senescence, exhibit eroding telomeric sequences and ultimately enter telomere-based crisis to generate the types of chromosomal abnormalities seen in the earliest lesions of breast cancer. Growth past senescent barriers may be a pivotal event in the earliest steps of carcinogenesis, providing many genetic changes that predicate oncogenic evolution. The differences between epithelial cells and fibroblasts provide new insights into the mechanistic basis of neoplastic transformation.

  4. Dynamics of cell and tissue growth acquired by means of extended field of view lensfree microscopy.

    PubMed

    Momey, F; Coutard, J-G; Bordy, T; Navarro, F; Menneteau, M; Dinten, J-M; Allier, C

    2016-02-01

    In this paper, we discuss a new methodology based on lensfree imaging to perform wound healing assay with unprecedented statistics. Our video lensfree microscopy setup is a simple device featuring only a CMOS sensor and a semi coherent illumination system. Yet it is a powerful mean for the real-time monitoring of cultivated cells. It presents several key advantages, e.g. integration into standard incubator, compatibility with standard cell culture protocol, simplicity and ease of use. It can perform the follow-up in a large field of view (25 mm(2)) of several crucial parameters during the culture of cells i.e. their motility, their proliferation rate or their death. Consequently the setup can gather large statistics both in space and time. Here we uses this facility in the context of wound healing assay to perform label-free measurements of the velocities of the fronts of proliferation of the cell layer as a function of time by means of particle image velocimetry (PIV) processing. However, for such tissue growth experiments, the field of view of 25 mm(2) remains not sufficient and results can be biased depending on the position of the device with respect to the recipient of the cell culture. Hence, to conduct exhaustive wound healing assays, we propose to enlarge the field of view up to 10 cm(2) through a raster scan, by moving the source/sensor with respect to the Petri dish. We have performed acquisitions of wound healing assay (keratinocytes HaCaT) both in real-time (25 mm(2)) and in final point (10 cm(2)) to assess the combination of velocimetry measurements and final point wide field imaging. In the future, we aim at combining directly our extended field of view acquisitions (>10 cm(2)) with real time ability inside the incubator. PMID:26977359

  5. Dynamics of cell and tissue growth acquired by means of extended field of view lensfree microscopy

    PubMed Central

    Momey, F.; Coutard, J.-G.; Bordy, T.; Navarro, F.; Menneteau, M.; Dinten, J.-M.; Allier, C.

    2016-01-01

    In this paper, we discuss a new methodology based on lensfree imaging to perform wound healing assay with unprecedented statistics. Our video lensfree microscopy setup is a simple device featuring only a CMOS sensor and a semi coherent illumination system. Yet it is a powerful mean for the real-time monitoring of cultivated cells. It presents several key advantages, e.g. integration into standard incubator, compatibility with standard cell culture protocol, simplicity and ease of use. It can perform the follow-up in a large field of view (25 mm2) of several crucial parameters during the culture of cells i.e. their motility, their proliferation rate or their death. Consequently the setup can gather large statistics both in space and time. Here we uses this facility in the context of wound healing assay to perform label-free measurements of the velocities of the fronts of proliferation of the cell layer as a function of time by means of particle image velocimetry (PIV) processing. However, for such tissue growth experiments, the field of view of 25 mm2 remains not sufficient and results can be biased depending on the position of the device with respect to the recipient of the cell culture. Hence, to conduct exhaustive wound healing assays, we propose to enlarge the field of view up to 10 cm2 through a raster scan, by moving the source/sensor with respect to the Petri dish. We have performed acquisitions of wound healing assay (keratinocytes HaCaT) both in real-time (25 mm2) and in final point (10 cm2) to assess the combination of velocimetry measurements and final point wide field imaging. In the future, we aim at combining directly our extended field of view acquisitions (>10 cm2) with real time ability inside the incubator. PMID:26977359

  6. Mechanisms of resistance to etoposide and teniposide in acquired resistant human colon and lung carcinoma cell lines.

    PubMed

    Long, B H; Wang, L; Lorico, A; Wang, R C; Brattain, M G; Casazza, A M

    1991-10-01

    Stable acquired resistance to etoposide (VP-16) or teniposide (VM-26) in HCT116 human colon carcinoma cells and A549 human lung adenocarcinoma cells, was previously obtained by weekly 1-h exposures to either drug (B. H. Long, Natl. Cancer Inst. Monogr., 4: 123-127, 1987). The purpose of this study was to identify possible mechanisms of resistance present in these cells by using human mdr1 and topoisomerase II DNA probes, antibodies to these gene products, and P4 phage unknotting assay for topoisomerase II activities. HCT116(VP)35 cells were 9-, 7-, and 6-fold resistant to VP-16, VM-26, and Adriamycin, respectively, and showed no cross-resistance to colchicine and actinomycin D. These cells had no differences in mdr1 gene, mdr1 mRNA, or P-glycoprotein levels but displayed decreased levels of topoisomerase II mRNA and enzyme activity without any alteration of drug sensitivity displayed by the enzyme. HCT116(VM)34 cells were 5-, 7-, and 21-fold resistant to VP-16, VM-26, and Adriamycin; were cross-resistant to colchicine (7-fold) and actinomycin D (18-fold); and possessed a 9-fold increase in mdr1 mRNA and increased P-glycoprotein without evidence of mdr1 gene amplification. No alterations in topoisomerase II gene or mRNA levels, enzyme activity, or drug sensitivity were observed. A549(VP)28 and A549(VM)28 cells were 8-fold resistant to VP-16 and VM-26 and 3-fold resistant to Adriamycin. Both lines were not cross-resistant to colchicine or actinomycin D but were hypersensitive to cis-platinum. No alterations in mdr1 gene, mdr1 mRNA, or P-glycoprotein levels, but lower topoisomerase II mRNA levels and decreased enzyme activities, were observed. Of the four acquired resistant cell lines, resistance is likely related to elevated mdr1 expression in one line and to decreased topoisomerase II expression in the other three lines. PMID:1717144

  7. Nuclear AURKA acquires kinase-independent transactivating function to enhance breast cancer stem cell phenotype

    PubMed Central

    Zheng, Feimeng; Yue, Caifeng; Li, Guohui; He, Bin; Cheng, Wei; Wang, Xi; Yan, Min; Long, Zijie; Qiu, Wanshou; Yuan, Zhongyu; Xu, Jie; Liu, Bing; Shi, Qian; Lam, Eric W.-F.; Hung, Mien-Chie; Liu, Quentin

    2016-01-01

    Centrosome-localized mitotic Aurora kinase A (AURKA) facilitates G2/M events. Here we show that AURKA translocates to the nucleus and causes distinct oncogenic properties in malignant cells by enhancing breast cancer stem cell (BCSC) phenotype. Unexpectedly, this function is independent of its kinase activity. Instead, AURKA preferentially interacts with heterogeneous nuclear ribonucleoprotein K (hnRNP K) in the nucleus and acts as a transcription factor in a complex that induces a shift in MYC promoter usage and activates the MYC promoter. Blocking AURKA nuclear localization inhibits this newly discovered transactivating function of AURKA, sensitizing resistant BCSC to kinase inhibition. These findings identify a previously unknown oncogenic property of the spatially deregulated AURKA in tumorigenesis and provide a potential therapeutic opportunity to overcome kinase inhibitor resistance. PMID:26782714

  8. Resistance to caspase-8 and -9 fragments in a malignant pleural mesothelioma cell line with acquired cisplatin-resistance

    PubMed Central

    Janson, V; Johansson, A; Grankvist, K

    2010-01-01

    Apoptotic cysteine–aspartate proteases (caspases) are essential for the progression and execution of apoptosis, and detection of caspase fragmentation or activity is often used as markers of apoptosis. Cisplatin (cis-diamminedichloroplatinum (II)) is a chemotherapeutic drug that is clinically used for the treatment of solid tumours. We compared a cisplatin-resistant pleural malignant mesothelioma cell line (P31res1.2) with its parental cell line (P31) regarding the consequences of in vitro acquired cisplatin-resistance on basal and cisplatin-induced (equitoxic and equiapoptotic cisplatin concentrations) caspase-3, -8 and -9 fragmentation and proteolytic activity. Acquisition of cisplatin-resistance resulted in basal fragmentation of caspase-8 and -9 without a concomitant increase in proteolytic activity, and there was an increased basal caspase-3/7 activity. Similarly, cisplatin-resistant non-small-cell lung cancer cells, H1299res, had increased caspase-3 and -9 content compared with the parental H1299 cells. In P31 cells, cisplatin exposure resulted in caspase-9-mediated caspase-3/7 activation, but in P31res1.2 cells the cisplatin-induced caspase-3/7 activation occurred before caspase-8 or -9 activation. We therefore concluded that in vitro acquisition of cisplatin-resistance rendered P31res1.2 cells resistant to caspase-8 and caspase-9 fragments and that cisplatin-induced, initiator-caspase independent caspase-3/7 activation was necessary to overcome this resistance. Finally, the results demonstrated that detection of cleaved caspase fragments alone might be insufficient as a marker of caspase activity and ensuing apoptosis induction. PMID:21364680

  9. Tissue myeloid cells in SIV-infected primates acquire viral DNA through phagocytosis of infected T cells.

    PubMed

    Calantone, Nina; Wu, Fan; Klase, Zachary; Deleage, Claire; Perkins, Molly; Matsuda, Kenta; Thompson, Elizabeth A; Ortiz, Alexandra M; Vinton, Carol L; Ourmanov, Ilnour; Loré, Karin; Douek, Daniel C; Estes, Jacob D; Hirsch, Vanessa M; Brenchley, Jason M

    2014-09-18

    The viral accessory protein Vpx, expressed by certain simian and human immunodeficiency viruses (SIVs and HIVs), is thought to improve viral infectivity of myeloid cells. We infected 35 Asian macaques and African green monkeys with viruses that do or do not express Vpx and examined viral targeting of cells in vivo. While lack of Vpx expression affected viral dynamics in vivo, with decreased viral loads and infection of CD4⁺ T cells, Vpx expression had no detectable effect on infectivity of myeloid cells. Moreover, viral DNA was observed only within myeloid cells in tissues not massively depleted of CD4⁺ T cells. Myeloid cells containing viral DNA also showed evidence of T cell phagocytosis in vivo, suggesting that their viral DNA may be attributed to phagocytosis of SIV-infected T cells. These data suggest that myeloid cells are not a major source of SIV in vivo, irrespective of Vpx expression. PMID:25238099

  10. Acquired hyperpigmentations*

    PubMed Central

    Cestari, Tania Ferreira; Dantas, Lia Pinheiro; Boza, Juliana Catucci

    2014-01-01

    Cutaneous hyperpigmentations are frequent complaints, motivating around 8.5% of all dermatological consultations in our country. They can be congenital, with different patterns of inheritance, or acquired in consequence of skin problems, systemic diseases or secondary to environmental factors. The vast majority of them are linked to alterations on the pigment melanin, induced by different mechanisms. This review will focus on the major acquired hyperpigmentations associated with increased melanin, reviewing their mechanisms of action and possible preventive measures. Particularly prominent aspects of diagnosis and therapy will be emphasized, with focus on melasma, post-inflammatory hyperpigmentation, periorbital pigmentation, dermatosis papulosa nigra, phytophotodermatoses, flagellate dermatosis, erythema dyschromicum perstans, cervical poikiloderma (Poikiloderma of Civatte), acanthosis nigricans, cutaneous amyloidosis and reticulated confluent dermatitis PMID:24626644

  11. Hematopoietic Stem Cell Regulation by Type I and II Interferons in the Pathogenesis of Acquired Aplastic Anemia

    PubMed Central

    Smith, Julianne N. P.; Kanwar, Vikramjit S.; MacNamara, Katherine C.

    2016-01-01

    Aplastic anemia (AA) occurs when the bone marrow fails to support production of all three lineages of blood cells, which are necessary for tissue oxygenation, infection control, and hemostasis. The etiology of acquired AA is elusive in the vast majority of cases but involves exhaustion of hematopoietic stem cells (HSC), which are usually present in the bone marrow in a dormant state, and are responsible for lifelong production of all cells within the hematopoietic system. This destruction is immune mediated and the role of interferons remains incompletely characterized. Interferon gamma (IFNγ) has been associated with AA and type I IFNs (alpha and beta) are well documented to cause bone marrow aplasia during viral infection. In models of infection and inflammation, IFNγ activates HSCs to differentiate and impairs their ability to self-renew, ultimately leading to HSC exhaustion. Recent evidence demonstrating that IFNγ also impacts the HSC microenvironment or niche, raises new questions regarding how IFNγ impairs HSC function in AA. Immune activation can also elicit type I interferons, which may exert effects both distinct from and overlapping with IFNγ on HSCs. IFNα/β increase HSC proliferation in models of sterile inflammation induced by polyinosinic:polycytidylic acid and lead to BM aplasia during viral infection. Moreover, patients being treated with IFNα exhibit cytopenias, in part due to BM suppression. Herein, we review the current understanding of how interferons contribute to the pathogenesis of acquired AA, and we explore additional potential mechanisms by which interferons directly and indirectly impair HSCs. A comprehensive understanding of how interferons impact hematopoiesis is necessary in order to identify novel therapeutic approaches for treating AA patients. PMID:27621733

  12. Hematopoietic Stem Cell Regulation by Type I and II Interferons in the Pathogenesis of Acquired Aplastic Anemia.

    PubMed

    Smith, Julianne N P; Kanwar, Vikramjit S; MacNamara, Katherine C

    2016-01-01

    Aplastic anemia (AA) occurs when the bone marrow fails to support production of all three lineages of blood cells, which are necessary for tissue oxygenation, infection control, and hemostasis. The etiology of acquired AA is elusive in the vast majority of cases but involves exhaustion of hematopoietic stem cells (HSC), which are usually present in the bone marrow in a dormant state, and are responsible for lifelong production of all cells within the hematopoietic system. This destruction is immune mediated and the role of interferons remains incompletely characterized. Interferon gamma (IFNγ) has been associated with AA and type I IFNs (alpha and beta) are well documented to cause bone marrow aplasia during viral infection. In models of infection and inflammation, IFNγ activates HSCs to differentiate and impairs their ability to self-renew, ultimately leading to HSC exhaustion. Recent evidence demonstrating that IFNγ also impacts the HSC microenvironment or niche, raises new questions regarding how IFNγ impairs HSC function in AA. Immune activation can also elicit type I interferons, which may exert effects both distinct from and overlapping with IFNγ on HSCs. IFNα/β increase HSC proliferation in models of sterile inflammation induced by polyinosinic:polycytidylic acid and lead to BM aplasia during viral infection. Moreover, patients being treated with IFNα exhibit cytopenias, in part due to BM suppression. Herein, we review the current understanding of how interferons contribute to the pathogenesis of acquired AA, and we explore additional potential mechanisms by which interferons directly and indirectly impair HSCs. A comprehensive understanding of how interferons impact hematopoiesis is necessary in order to identify novel therapeutic approaches for treating AA patients. PMID:27621733

  13. Comparison of protein patterns of xrs-5, a radiosensitive Chinese hamster ovary cell line, and CHO-K1, its radioresistant parent, using two-dimensional gel-electrophoresis

    SciTech Connect

    Kramer, J.M. . Dept. of Zoology)

    1991-01-01

    X-ray sensitive strains of Chinese hamster ovary cell lines have been used to analyze radiation repair mechanisms. One cell line, xrs-5, has been shown to be very sensitive to ionizing radiation and radical forming chemical mutagens. This sensitivity is thought to be a result a mutation in the DNA double strand break (DSB) repair mechanism, and its characterization has been a goal of several repair mechanism studies. Using two-dimensional gel electrophoresis, we have detected a protein (MW approximately 55KD) in the DNA/Nuclear Matrix (nucleoid) cell fraction of CHO-Kl cells that is absent in the nucleoid fraction of xrs-5. This protein is present, however, in both CHO-Kl and xrs-5 whole cell protein maps. To determine whether the 55KD protein is responsible for the radiosensitive and defective DSB repair phenotype of xrs-5 cells, studies are now underway to analyze revertants of xrs-5 that are proficient in DSB repair. Furthermore, an effort to sequence the protein in question is planned. 23 refs., 2 figs.

  14. Microbial radio-resistance of Salmonella Typhimurium in egg increases due to repetitive irradiation with electron beam

    NASA Astrophysics Data System (ADS)

    Tesfai, Adiam T.; Beamer, Sarah K.; Matak, Kristen E.; Jaczynski, Jacek

    2011-04-01

    Ionizing radiation improves food safety. However, foodborne pathogens develop increased resistance in response to sub-lethal stresses such as heat, pH, antibiotics, etc. Therefore, it is hypothesized that foodborne pathogens may develop increased radio-resistance to electron beam (e-beam) radiation. The objective was to determine if D10-value for Salmonella Typhimurium in de-shelled raw egg (egg white and yolk mixed together) increases due to repetitive processing with e-beam at sub-lethal doses. Survivors were enumerated on non-selective (TSA) and selective (XLD) media. Survivors from the highest dose were isolated and used in subsequent e-beam cycle. This process was repeated four times for a total of five e-beam cycles. D10-values for S. Typhimurium enumerated on TSA and XLD following each e-beam cycle were calculated as inverse reciprocal of the slope of survivor curves. D10-values for the ATCC strain were 0.59±0.031 and 0.46±0.022 kGy on TSA and XLD, respectively. However, following the fifth e-beam cycle, the respective D10-values increased (P<0.05) to 0.69±0.026 and 0.61±0.029 kGy, respectively. S. Typhimurium showed a trend (P>0.05) to develop radio-resistance faster on selective media, likely due to facilitated selection of radio-resistant cells within microbial population following each e-beam cycle. For all five e-beam cycles, S. Typhimurium had higher (P<0.05) D10-values on non-selective media, indicating that sub-lethal injury followed by cellular repair and recovery are important for radio-resistance and inactivation of this microorganism. This study demonstrated that e-beam efficiently inactivates S. Typhimurium in raw egg; however, similar to other inactivation techniques and factors affecting microbial growth, S. Typhimurium develops increased radio-resistance if repetitively processed with e-beam at sub-lethal doses.

  15. ZEB1 Mediates Acquired Resistance to the Epidermal Growth Factor Receptor-Tyrosine Kinase Inhibitors in Non-Small Cell Lung Cancer

    PubMed Central

    Yoshida, Takeshi; Song, Lanxi; Bai, Yun; Kinose, Fumi; Li, Jiannong; Ohaegbulam, Kim C.; Muñoz-Antonia, Teresita; Qu, Xiaotao; Eschrich, Steven; Uramoto, Hidetaka; Tanaka, Fumihiro; Nasarre, Patrick; Gemmill, Robert M.; Roche, Joëlle; Drabkin, Harry A.; Haura, Eric B.

    2016-01-01

    Epithelial-mesenchymal transition (EMT) is one mechanism of acquired resistance to inhibitors of the epidermal growth factor receptor-tyrosine kinases (EGFR-TKIs) in non-small cell lung cancer (NSCLC). The precise mechanisms of EMT-related acquired resistance to EGFR-TKIs in NSCLC remain unclear. We generated erlotinib-resistant HCC4006 cells (HCC4006ER) by chronic exposure of EGFR-mutant HCC4006 cells to increasing concentrations of erlotinib. HCC4006ER cells acquired an EMT phenotype and activation of the TGF-β/SMAD pathway, while lacking both T790M secondary EGFR mutation and MET gene amplification. We employed gene expression microarrays in HCC4006 and HCC4006ER cells to better understand the mechanism of acquired EGFR-TKI resistance with EMT. At the mRNA level, ZEB1 (TCF8), a known regulator of EMT, was >20-fold higher in HCC4006ER cells than in HCC4006 cells, and increased ZEB1 protein level was also detected. Furthermore, numerous ZEB1 responsive genes, such as CDH1 (E-cadherin), ST14, and vimentin, were coordinately regulated along with increased ZEB1 in HCC4006ER cells. We also identified ZEB1 overexpression and an EMT phenotype in several NSCLC cells and human NSCLC samples with acquired EGFR-TKI resistance. Short-interfering RNA against ZEB1 reversed the EMT phenotype and, importantly, restored erlotinib sensitivity in HCC4006ER cells. The level of micro-RNA-200c, which can negatively regulate ZEB1, was significantly reduced in HCC4006ER cells. Our results suggest that increased ZEB1 can drive EMT-related acquired resistance to EGFR-TKIs in NSCLC. Attempts should be made to explore targeting ZEB1 to resensitize TKI-resistant tumors. PMID:26789630

  16. [Radiosensitivity and/or radioresistance of head and neck cancers: Biological angle].

    PubMed

    Guy, Jean-Baptiste; Rancoule, Chloé; Méry, Benoîte; Espenel, Sophie; Wozny, Anne-Sophie; Simonet, Stéphanie; Vallard, Alexis; Alphonse, Gersende; Ardail, Dominique; Rodriguez-Lafrasse, Claire; Magné, Nicolas

    2016-01-01

    Radiation therapy is a cornerstone of head and neck cancer management. Technological improvements in recent years in radiation therapy, with intensity-modulated techniques, reinforce even more its role. However, both local and locoregional relapses are still observed. Understanding biological mechanisms of treatment resistance is a topic of major interest. From the cancer cell itself, its ability to repair and proliferate, its microenvironment and oxygenation conditions, migratory and invasive capacity, to biological parameters related to the patient, there are many mechanisms involving radiosensitivity and/or radioresistance of head and neck cancer. The present study explores the main biological mechanisms involved in radiation resistance of head and neck cancer, and describes promising therapeutic approaches. PMID:26702507

  17. Benefit of Carbon Ion Radiotherapy in the Treatment of Radio-resistant Tumors

    NASA Astrophysics Data System (ADS)

    Kamada, Tadashi; Tsujii, Hirohiko; Tsuji, Hiroshi; Yanagi, Tsuyoshi; Imai, Reiko; Mizoe, Jun-etsu; Miyamoto, Tadaaki; Kato, Hirotoshi; Yamada, Shigeru; Kato, Shingo; Yoshikawa, Kyousan; Kandatsu, Susumu

    2003-08-01

    The Heavy Ion Medical Accelerator in Chiba (HIMAC) is the world's first heavy ion accelerator complex dedicated to medical use in a hospital environment. Heavy ions have superior depth-dose distribution and greater cell-killing ability. In June 1994, clinical research for the treatment of cancer was begun using carbon ions generated by HIMAC. Until August 2002, a total of 1,297 patients were enrolled in clinical trials. Most of the patients had locally advanced and/or medically inoperable tumors. Tumors radio-resistant and/or located near critical organs were also included. The clinical trials revealed that carbon ion radiotherapy provided definite local control and offered a survival advantage without unacceptable morbidity in a variety of tumors that were hard to cure by other modalities.

  18. Benefit of Carbon Ion Radiotherapy in the Treatment of Radio-resistant Tumors

    SciTech Connect

    Kamada, Tadashi; Tsujii, Hirohiko; Tsuji, Hiroshi; Yanagi, Tsuyoshi; Imai, Reiko; Mizoe, Jun-etsu; Miyamoto, Tadaaki; Kato, Hirotoshi; Yamada, Shigeru; Kato, Shingo; Yoshikawa, Kyousan; Kandatsu, Susumu

    2003-08-26

    The Heavy Ion Medical Accelerator in Chiba (HIMAC) is the world's first heavy ion accelerator complex dedicated to medical use in a hospital environment. Heavy ions have superior depth-dose distribution and greater cell-killing ability. In June 1994, clinical research for the treatment of cancer was begun using carbon ions generated by HIMAC. Until August 2002, a total of 1,297 patients were enrolled in clinical trials. Most of the patients had locally advanced and/or medically inoperable tumors. Tumors radio-resistant and/or located near critical organs were also included. The clinical trials revealed that carbon ion radiotherapy provided definite local control and offered a survival advantage without unacceptable morbidity in a variety of tumors that were hard to cure by other modalities.

  19. Somatically Acquired LINE-1 Insertions in Normal Esophagus Undergo Clonal Expansion in Esophageal Squamous Cell Carcinoma.

    PubMed

    Doucet-O'Hare, Tara T; Sharma, Reema; Rodić, Nemanja; Anders, Robert A; Burns, Kathleen H; Kazazian, Haig H

    2016-09-01

    Squamous cell carcinoma of the esophagus (SCC) is the most common form of esophageal cancer in the world and is typically diagnosed at an advanced stage when successful treatment is challenging. Understanding the mutational profile of this cancer may identify new treatment strategies. Because somatic retrotransposition has been shown in tumors of the gastrointestinal system, we focused on LINE-1 (L1) mobilization as a source of genetic instability in this cancer. We hypothesized that retrotransposition is ongoing in SCC patients. The expression of L1 encoded proteins is necessary for retrotransposition to occur; therefore, we evaluated the expression of L1 open reading frame 1 protein (ORF1p). Using immunohistochemistry, we detected ORF1p expression in all four SCC cases evaluated. Using L1-seq, we identified and validated 74 somatic insertions in eight tumors of the nine evaluated. Of these, 12 insertions appeared to be somatic, not genetically inherited, and sub-clonal (i.e., present in less than one copy per genome equivalent) in the adjacent normal esophagus (NE), while clonal in the tumor. Our results indicate that L1 retrotransposition is active in SCC of the esophagus and that insertion events are present in histologically NE that expands clonally in the subsequent tumor. PMID:27319353

  20. Coherent nonlinear optical microscopy for acquiring structural information of cell cytoskeleton

    NASA Astrophysics Data System (ADS)

    Sharoukhov, D.; Lim, H.

    2015-05-01

    Second-harmonic generation (SHG) is a coherent nonlinear optical process occurring in non-centrosymmetric molecules, including microtubule (MT). MT is a cytoskeleton playing many important roles in a variety of cellular processes depending on the cell type, and the conformation is crucial for the function. Here we present the use of SHG process to probe MT cytoskeleton in living neuronal tissue. Polarization-resolved SHG (p-SHG) imaging and the second-order tensor analysis were performed on the retinal nerve fibers in order to probe the structure of MTs in axon. The polar anisotropy of tubulins was determined at the molecular level. The effect of MT-stabilizing drug Taxol was also examined and the induced changes were not detectable by p-SHG. Our results demonstrate SHG as a novel optical method to measure conformational changes of MTs in the native cellular context. The technique could be employed in conjunction with existing atomic-resolution methods of structural biology to improve our understanding of cytoskeleton dynamics in vivo.

  1. Draft Genome Sequence of the Radioresistant Bacterium Deinococcus grandis, Isolated from Freshwater Fish in Japan

    PubMed Central

    Onodera, Takefumi; Omoso, Kota; Takeda-Yano, Kiyoko; Katayama, Takeshi; Oono, Yutaka; Narumi, Issay

    2016-01-01

    Deinococcus grandis is a radioresistant bacterium isolated from freshwater fish in Japan. Here we reported the draft genome sequence of D. grandis (4.1 Mb), which will be useful for elucidating the common principles of radioresistance in Deinococcus species through the comparative analysis of genomic sequences. PMID:26868384

  2. CAVEOLIN-1 expression in brain metastasis from lung cancer predicts worse outcome and radioresistance, irrespective of tumor histotype

    PubMed Central

    Pittaro, Alessandra; Verdun di Cantogno, Ludovica; Stella, Giulia; De Blasi, Pierpaolo; Zorzetto, Michele; Mantovani, Cristina; Papotti, Mauro; Cassoni, Paola

    2015-01-01

    Brain metastases develop in one-third of patients with non-small-cell lung cancer and are associated with a dismal prognosis, irrespective of surgery or chemo-radiotherapy. Pathological markers for predicting outcomes after surgical resection and radiotherapy responsiveness are still lacking. Caveolin 1 has been associated with chemo- and radioresistance in various tumors, including non-small-cell lung cancer. Here, caveolin 1 expression was assessed in a series of 69 brain metastases from non-small-cell lung cancer and matched primary tumors to determine its role in predicting survival and radiotherapy responsiveness. Only caveolin 1 expression in brain metastasis was associated with poor prognosis and an increased risk of death (log rank test, p = 0.015). Moreover, in the younger patients (median age of <54 years), caveolin 1 expression neutralized the favorable effect of young age on survival compared with the older patients. Among the radiotherapy-treated patients, an increased risk of death was detected in the group with caveolin 1-positive brain metastasis (14 out of 22 patients, HR=6.839, 95% CI 1.849 to 25.301, Wald test p = 0.004). Overall, caveolin 1 expression in brain metastasis from non-small-cell lung cancer is independently predictive of worse outcome and radioresistance and could become an additional tool for personalized therapy in the critical subset of brain-metastatic non-small-cell lung cancer patients. PMID:26315660

  3. Elevated Cellular PD1/PD-L1 Expression Confers Acquired Resistance to Cisplatin in Small Cell Lung Cancer Cells.

    PubMed

    Yan, Fei; Pang, Jiuxia; Peng, Yong; Molina, Julian R; Yang, Ping; Liu, Shujun

    2016-01-01

    Although small cell lung cancer (SCLC) is highly responsive to chemotherapies (e.g., cisplatin-etoposide doublet), virtually almost all responsive SCLC patients experience disease recurrence characterized by drug resistance. The mechanisms underlying cisplatin resistance remain elusive. Here we report that cell-intrinsic expression of PD1 and PD-L1, two immune checkpoints, is required for sustained expansion of SCLC cells under cisplatin selection. Indeed, PD1 and PD-L1 were expressed at a higher level in lung cancer cell lines, tumor tissues, and importantly, in SCLC cells resistant to cisplatin (H69R, H82R), when compared to respective controls. Genetic abrogation of PD1 and PD-L1 in H69R and H82R cells decreased their proliferation rate, and restored their sensitivity to cisplatin. Mechanistically, PD-L1 upregulation in H69R and H82R cells was attributed to the overexpression of DNA methyltransferase 1 (DNMT1) or receptor tyrosine kinase KIT, as knockdown of DNMT1 or KIT in H69R and H82R cells led to PD-L1 downregulation. Consequently, combined knockdown of PD-L1 with KIT or DNMT1 resulted in more pronounced inhibition of H69R and H82R cell growth. Thus, cell intrinsic PD1/PD-L1 signaling may be a predictor for poor efficacy of cisplatin treatment, and targeting the cellular PD1/PD-L1 axis may improve chemosensitization of aggressive SCLC. PMID:27610620

  4. Adipose tissue-deprived stem cells acquire cementoblast features treated with dental follicle cell conditioned medium containing dentin non-collagenous proteins in vitro

    SciTech Connect

    Wen, Xiujie; Nie, Xin; Zhang, Li; Liu, Luchuan; Deng, Manjing

    2011-06-10

    Highlights: {yields} In this study we examine the effects of dental follicle cell conditioned medium (DFCCM) containing dentin non-collagenous proteins (dNCPs) on differentiation of ADSCs. {yields} We examined that ADSCs treated with dNCPs/DFCCM underwent morphological changes and significantly lost their proliferative capacity. {yields} dNCPs/DFCCM enhanced the mineralization behaviour and mineralization-related marker expression of ADSCs. {yields} ADSCs acquired cementoblast features in vitro with dNCPs/DFCCM treatment. -- Abstract: Adipose tissue-derived stem cells (ADSCs), which are easily harvested and show excellent pluripotency potential, have generated considerable interest in regenerative medicine. In this study, the differentiation of ADSCs was assessed after treatment with dental follicle cell conditioned medium (DFCCM) containing dentin non-collagenous proteins (dNCPs). ADSCs exhibited a fibroblast-like morphology and high proliferative capacity. However, after treatment with dNCPs/DFCCM, ADSCs changed from a fibroblast-like to cementoblast-like morphology and significantly lost their proliferative capacity. Alkaline phosphatase activity and in vitro mineralization behaviour of ADSCs were significantly enhanced. Mineralization-related markers including cementum attachment protein, bone sialoprotein, osteocalcin, osteopontin and osteonectin were detected at mRNA or protein levels, whereas dentin sialophosphoprotein and dentin sialoprotein were not detected, implying a cementoblast-like phenotype. These results demonstrate that ADSCs acquired cementoblast features in vitro with dNCPs/DFCCM treatment and could be a potential source of cementogenic cells for periodontal regeneration.

  5. Targeting AKT with the allosteric AKT inhibitor MK-2206 in non-small cell lung cancer cells with acquired resistance to cetuximab.

    PubMed

    Iida, Mari; Brand, Toni M; Campbell, David A; Starr, Megan M; Luthar, Neha; Traynor, Anne M; Wheeler, Deric L

    2013-06-01

    The epidermal growth factor receptor (EGFR) is a central regulator of tumor progression in human cancers. Cetuximab is an anti-EGFR monoclonal antibody that has been approved for use in oncology. Despite clinical success the majority of patients do not respond to cetuximab and those who initially respond frequently acquire resistance. To understand how tumor cells acquire resistance to cetuximab we developed a model of resistance using the non-small cell lung cancer line NCI-H226. We found that cetuximab-resistant (Ctx (R) ) clones manifested strong activation of EGFR, PI3K/AKT and MAPK. To investigate the role of AKT signaling in cetuximab resistance we analyzed the activation of the AKT pathway effector molecules using a human AKT phospho-antibody array. Strong activation was observed in Ctx (R) clones for several key AKT substrates including c-jun, GSK3β, eIF4E, rpS6, IKKα, IRS-1 and Raf1. Inhibition of AKT signaling by siAKT1/2 or by the allosteric AKT inhibitor MK-2206 resulted in robust inhibition of cell proliferation in all Ctx (R) clones. Moreover, the combinational treatment of cetuximab and MK-2206 resulted in further decreases in proliferation than either drug alone. This combinatorial treatment resulted in decreased activity of both AKT and MAPK thus highlighting the importance of simultaneous pathway inhibition to maximally affect the growth of Ctx (R) cells. Collectively, our findings demonstrate that AKT activation is an important pathway in acquired resistance to cetuximab and suggests that combinatorial therapy directed at both the AKT and EGFR/MAPK pathways may be beneficial in this setting. PMID:23760490

  6. Targeting AKT with the allosteric AKT inhibitor MK-2206 in non-small cell lung cancer cells with acquired resistance to cetuximab

    PubMed Central

    Iida, Mari; Brand, Toni M.; Campbell, David A.; Starr, Megan M.; Luthar, Neha; Traynor, Anne M.; Wheeler, Deric L.

    2013-01-01

    The epidermal growth factor receptor (EGFR) is a central regulator of tumor progression in human cancers. Cetuximab is an anti-EGFR monoclonal antibody that has been approved for use in oncology. Despite clinical success the majority of patients do not respond to cetuximab and those who initially respond frequently acquire resistance. To understand how tumor cells acquire resistance to cetuximab we developed a model of resistance using the non-small cell lung cancer line NCI-H226. We found that cetuximab-resistant (CtxR) clones manifested strong activation of EGFR, PI3K/AKT and MAPK. To investigate the role of AKT signaling in cetuximab resistance we analyzed the activation of the AKT pathway effector molecules using a human AKT phospho-antibody array. Strong activation was observed in CtxR clones for several key AKT substrates including c-jun, GSK3β, eIF4E, rpS6, IKKα, IRS-1 and Raf1. Inhibition of AKT signaling by siAKT1/2 or by the allosteric AKT inhibitor MK-2206 resulted in robust inhibition of cell proliferation in all CtxR clones. Moreover, the combinational treatment of cetuximab and MK-2206 resulted in further decreases in proliferation than either drug alone. This combinatorial treatment resulted in decreased activity of both AKT and MAPK thus highlighting the importance of simultaneous pathway inhibition to maximally affect the growth of CtxR cells. Collectively, our findings demonstrate that AKT activation is an important pathway in acquired resistance to cetuximab and suggests that combinatorial therapy directed at both the AKT and EGFR/MAPK pathways may be beneficial in this setting. PMID:23760490

  7. miR-504 mediated down-regulation of nuclear respiratory factor 1 leads to radio-resistance in nasopharyngeal carcinoma

    PubMed Central

    Zhao, Luqing; Tang, Min; Hu, Zheyu; Yan, Bin; Pi, Weiwei; Li, Zhi; Zhang, Jing; Zhang, Liqin; Jiang, Wuzhong; Li, Guo; Qiu, Yuanzheng; Hu, Fang; Liu, Feng; Lu, Jingchen; Chen, Xue; Xiao, Lanbo; Xu, Zhijie; Tao, Yongguang; Yang, Lifang; Bode, Ann M.; Dong, Zigang; Zhou, Jian; Fan, Jia; Sun, Lunquan; Cao, Ya

    2015-01-01

    microRNAs (miRNAs) are involved in the various processes of DNA damage repair and play crucial roles in regulating response of tumors to radiation therapy. Here, we used nasopharyngeal carcinoma (NPC) radio-resistant cell lines as models and found that the expression of miR-504 was significantly up-regulated. In contrast, the expression of nuclear respiratory factor 1 (NRF1) and other mitochondrial metabolism factors, including mitochondrial transcription factor A (TFAM) and oxidative phosphorylation (OXPHOS) complex III were down-regulated in these cell lines. At the same time, the Seahorse cell mitochondrial stress test results indicated that the mitochondrial respiratory capacity was impaired in NPC radio-resistant cell lines and in a miR-504 over-expressing cell line. We also conducted dual luciferase reporter assays and verified that miR-504 could directly target NRF1. Additionally, miR-504 could down-regulate the expression of TFAM and OXPHOS complexes I, III, and IV and impaired the mitochondrial respiratory function of NPC cells. Furthermore, serum from NPC patients showed that miR-504 was up-regulated during different weeks of radiotherapy and correlated with tumor, lymph nodes and metastasis (TNM) stages and total tumor volume. The radio-therapeutic effect at three months after radiotherapy was evaluated. Results indicated that patients with high expression of miR-504 exhibited a relatively lower therapeutic effect ratio of complete response (CR), but a higher ratio of partial response (PR), compared to patients with low expression of miR-504. Taken together, these results demonstrated that miR-504 affected the radio-resistance of NPC by down-regulating the expression of NRF1 and disturbing mitochondrial respiratory function. Thus, miR-504 might become a promising biomarker of NPC radio-resistance and targeting miR-504 might improve tumor radiation response. PMID:26201446

  8. Association of ATM activation and DNA repair with induced radioresistance after low-dose irradiation.

    PubMed

    Enns, L; Rasouli-Nia, A; Hendzel, M; Marples, B; Weinfeld, M

    2015-09-01

    Mammalian cells often exhibit a hyper-radiosensitivity (HRS) to radiation doses <20 cGy, followed by increased radioresistance (IRR) at slightly higher doses (∼20-30 cGy). Here, the influence of DNA double-strand break repair (DSBR) on IRR was examined. The failure of Ataxia telangiectasia (AT) cells to undergo IRR reported by others was confirmed. Flow cytometric analysis indicated that normal cells fail to show a measurable increase in serine 1981 phosphorylated AT-mutated (ATM) protein after 10 cGy up to 4 h post irradiation, but a two- to fourfold increase after 25 cGy. Similarly, more proficient reduction of phosphorylated histone H2AX was observed 24 h after 25 cGy than after 10 cGy, suggesting that DSBR is more efficient during IRR than HRS. A direct examination of the consequences of inefficient DNA repair per se (as opposed to ATM-mediated signal transduction/cell cycle responses), by determining the clonogenic survival of cells lacking the DNA repair enzyme polynucleotide kinase/phosphatase, indicated that these cells have a response similar to AT cells, i.e. HRS but no IRR, strongly linking IRR to DSBR. PMID:25904696

  9. Dose Escalation for Metastatic Spinal Cord Compression in Patients With Relatively Radioresistant Tumors

    SciTech Connect

    Rades, Dirk; Freundt, Katja; Meyners, Thekla; Bajrovic, Amira; Basic, Hiba; Karstens, Johann H.; Adamietz, Irenaeus A.; Wildfang, Ingeborg; Rudat, Volker; Schild, Steven E.; Dunst, Juergen

    2011-08-01

    Purpose: Radiotherapy alone is the most common treatment for metastatic spinal cord compression (MSCC) from relatively radioresistant tumors such as renal cell carcinoma, colorectal cancer, and malignant melanoma. However, the results of the 'standard' regimen 30 Gy/10 fractions need to be improved with respect to functional outcome. This study investigated whether a dose escalation beyond 30 Gy can improve treatment outcomes. Methods and Materials: A total of 91 patients receiving 30 Gy/10 fractions were retrospectively compared to 115 patients receiving higher doses (37.5 Gy/15 fractions, 40 Gy/20 fractions) for motor function and local control of MSCC. Ten further potential prognostic factors were evaluated: age, gender, tumor type, performance status, number of involved vertebrae, visceral or other bone metastases, interval from tumor diagnosis to radiotherapy, pretreatment ambulatory status, and time developing motor deficits before radiotherapy. Results: Motor function improved in 18% of patients after 30 Gy and in 22% after higher doses (p = 0.81). On multivariate analysis, functional outcome was associated with visceral metastases (p = 0.030), interval from tumor diagnosis to radiotherapy (p = 0.010), and time developing motor deficits (p < 0.001). The 1-year local control rates were 76% after 30 Gy and 80% after higher doses, respectively (p = 0.64). On multivariate analysis, local control was significantly associated with visceral metastases (p = 0.029) and number of involved vertebrae (p = 0.043). Conclusions: Given the limitations of a retrospective study, escalation of the radiation dose beyond 30 Gy/10 fractions did not significantly improve motor function and local control of MSCC in patients with relatively radioresistant tumors.

  10. Methemoglobinemia - acquired

    MedlinePlus

    ... blood disorder in which the body cannot reuse hemoglobin because it is damaged. Hemoglobin is the oxygen-carrying molecule found in red blood cells. In some cases of methemoglobinemia, the hemoglobin is unable to carry enough oxygen to body ...

  11. Modulation of Cell Metabolic Pathways and Oxidative Stress Signaling Contribute to Acquired Melphalan Resistance in Multiple Myeloma Cells

    PubMed Central

    Zub, Kamila Anna; de Sousa, Mirta Mittelstedt Leal; Sarno, Antonio; Sharma, Animesh; Demirovic, Aida; Rao, Shalini; Young, Clifford; Aas, Per Arne; Ericsson, Ida; Sundan, Anders; Jensen, Ole Nørregaard; Slupphaug, Geir

    2015-01-01

    Alkylating agents are widely used chemotherapeutics in the treatment of many cancers, including leukemia, lymphoma, multiple myeloma, sarcoma, lung, breast and ovarian cancer. Melphalan is the most commonly used chemotherapeutic agent against multiple myeloma. However, despite a 70–80% initial response rate, virtually all patients eventually relapse due to the emergence of drug-resistant tumour cells. By using global proteomic and transcriptomic profiling on melphalan sensitive and resistant RPMI8226 cell lines followed by functional assays, we discovered changes in cellular processes and pathways not previously associated with melphalan resistance in multiple myeloma cells, including a metabolic switch conforming to the Warburg effect (aerobic glycolysis), and an elevated oxidative stress response mediated by VEGF/IL8-signaling. In addition, up-regulated aldo-keto reductase levels of the AKR1C family involved in prostaglandin synthesis contribute to the resistant phenotype. Finally, selected metabolic and oxidative stress response enzymes were targeted by inhibitors, several of which displayed a selective cytotoxicity against the melphalan-resistant cells and should be further explored to elucidate their potential to overcome melphalan resistance. PMID:25769101

  12. Sci—Fri AM: Mountain — 04: Label-free Raman spectroscopy of single tumour cells detects early radiation-induced glycogen synthesis associated with increased radiation resistance

    SciTech Connect

    Matthews, Q; Lum, JJ; Isabelle, M; Harder, S; Jirasek, A; Brolo, AG

    2014-08-15

    Purpose: To use label-free Raman spectroscopy (RS) for early treatment monitoring of tumour cell radioresistance. Methods: Three human tumour cell lines, two radioresistant (H460, SF{sub 2} = 0.57 and MCF7, SF{sub 2} = 0.70) and one radiosensitive (LNCaP, SF{sub 2} = 0.36), were irradiated with single fractions of 2, 4, 6, 8 or 10 Gy. In additional experiments, H460 and MCF7 cells were irradiated under co-treatment with the anti-diabetic drug metformin, a known radiosensitizing agent. Treated and control cultures were analyzed with RS daily for 3 days post-treatment. Single-cell Raman spectra were acquired from 20 live cells per sample, and experiments were repeated in triplicate. The combined data sets were analyzed with principal component analysis using standard algorithms. Cells from each culture were also subjected to standard assays for viability, proliferation, cell cycle, and radiation clonogenic survival. Results: The radioresistant cells (H460, MCF7) exhibited a RS molecular radiation response signature, detectable as early as 1 day post-treatment, of which radiation-induced glycogen synthesis is a significant contributor. The radiosensitive cells (LNCaP) exhibited negligible glycogen synthesis. Co-treatment with metformin in MCF7 cells blocked glycogen synthesis, reduced viability and proliferation, and increased radiosensitivity. Conversely, metformin co-treatment in H460 cells did not produce these same effects; importantly, both radiation-induced synthesis of glycogen and radiosensitivity were unaffected. Conclusions: Label-free RS can detect early glycogen synthesis post-irradiation, a previously undocumented metabolic mechanism associated with tumour cell radioresistance that can be targeted to increase radiosensitivity. RS monitoring of intratumoral glycogen may provide new opportunities for personalized combined modality radiotherapy treatments.

  13. The phenomenon of acquired resistance to metformin in breast cancer cells: The interaction of growth pathways and estrogen receptor signaling.

    PubMed

    Scherbakov, Alexander M; Sorokin, Danila V; Tatarskiy, Victor V; Prokhorov, Nikolay S; Semina, Svetlana E; Berstein, Lev M; Krasil'nikov, Mikhail A

    2016-04-01

    Metformin, a biguanide antidiabetic drug, is used to decrease hyperglycemia in patients with type 2 diabetes. Recently, the epidemiological studies revealed the potential of metformin as an anti-tumor drug for several types of cancer, including breast cancer. Anti-tumor metformin action was found to be mediated, at least in part, via activation of adenosine monophosphate-activated protein kinase (AMPK)-intracellular energy sensor, which inhibits the mammalian target of rapamycin (mTOR) and some other signaling pathways. Nevertheless, some patients can be non-sensitive or resistant to metformin action. Here we analyzed the mechanism of the formation of metformin-resistant phenotype in breast cancer cells and its role in estrogen receptor (ER) regulation. The experiments were performed on the ER-positive MCF-7 breast cancer cells and metformin-resistant MCF-7 subline (MCF-7/M) developed due to long-term metformin treatment. The transcriptional activity of NF-κB and ER was measured by the luciferase reporter gene analysis. The protein expression was determined by immunoblotting (Snail1, (phospho)AMPK, (phospho)IκBα, (phospho)mTOR, cyclin D1, (phospho)Akt and ERα) and immunohistochemical analysis (E-cadherin). We have found that: 1) metformin treatment of MCF-7 cells is accompanied with the stimulation of AMPK and inhibition of growth-related proteins including IκBα, NF-κB, cyclin D1 and ERα; 2) long-term metformin treatment lead to the appearance and progression of cross-resistance to metformin and tamoxifen; the resistant cells are characterized with the unaffected AMPK activity, but the irreversible ER suppression and constitutive activation of Akt/Snail1 signaling; 3) Akt/Snail1 signaling is involved into progression of metformin resistance. The results presented may be considered as the first evidence of the progression of cross-resistance to metformin and tamoxifen in breast cancer cells. Importantly, the acquired resistance to both drugs is based on the

  14. Atypical Cell Populations Associated with Acquired Resistance to Cytostatics and Cancer Stem Cell Features: The Role of Mitochondria in Nuclear Encapsulation

    PubMed Central

    Gustmann, Sebastian; Jastrow, Holger; Acikelli, Ali Haydar; Dammann, Philip; Klein, Jacqueline; Dembinski, Ulrike; Bardenheuer, Walter; Malak, Sascha; Araúzo-Bravo, Marcos J.; Schultheis, Beate; Aldinger, Constanze; Strumberg, Dirk

    2014-01-01

    Until recently, acquired resistance to cytostatics had mostly been attributed to biochemical mechanisms such as decreased intake and/or increased efflux of therapeutics, enhanced DNA repair, and altered activity or deregulation of target proteins. Although these mechanisms have been widely investigated, little is known about membrane barriers responsible for the chemical imperviousness of cell compartments and cellular segregation in cytostatic-treated tumors. In highly heterogeneous cross-resistant and radiorefractory cell populations selected by exposure to anticancer agents, we found a number of atypical recurrent cell types in (1) tumor cell cultures of different embryonic origins, (2) mouse xenografts, and (3) paraffin sections from patient tumors. Alongside morphologic peculiarities, these populations presented cancer stem cell markers, aberrant signaling pathways, and a set of deregulated miRNAs known to confer both stem-cell phenotypes and highly aggressive tumor behavior. The first type, named spiral cells, is marked by a spiral arrangement of nuclei. The second type, monastery cells, is characterized by prominent walls inside which daughter cells can be seen maturing amid a rich mitochondrial environment. The third type, called pregnant cells, is a giant cell with a syncytium-like morphology, a main nucleus, and many endoreplicative functional progeny cells. A rare fourth cell type identified in leukemia was christened shepherd cells, as it was always associated with clusters of smaller cells. Furthermore, a portion of resistant tumor cells displayed nuclear encapsulation via mitochondrial aggregation in the nuclear perimeter in response to cytostatic insults, probably conferring imperviousness to drugs and long periods of dormancy until nuclear eclosion takes place. This phenomenon was correlated with an increase in both intracellular and intercellular mitochondrial traffic as well as with the uptake of free extracellular mitochondria. All these cellular

  15. Elevated Plasma Stromal-Cell-Derived Factor-1 Protein Levels Correlate with Severity in Patients with Community-Acquired Pneumonia

    PubMed Central

    Tsai, Ping-Kun; Hsieh, Ming-Ju; Wang, Hsiang-Ling; Chou, Ming-Chih; Yang, Shun-Fa

    2014-01-01

    Background. The aim of this study was to investigate differential changes in plasma levels of stromal-cell-derived factor-1 (SDF-1) before and after antibiotic treatment in patients with community-acquired pneumonia (CAP) and observe the association between the severity of CAP and the plasma SDF-1 level. Methods. We gathered blood specimens from 61 adult CAP patients before and after antibiotic treatment and from 60 healthy controls to measure the plasma concentrations of SDF-1 by using an enzyme-linked immunosorbent assay. Results. The plasma SDF-1 concentration was elevated significantly in patients with CAP before receiving treatment compared with the controls and decreased significantly after the patients received treatment. Leukocyte (WBC) and neutrophil counts and C-reactive protein (CRP) levels decreased significantly after antibiotic treatment. Moreover, differences in the plasma concentration of SDF-1 were significantly correlated with PSI, CURB-65, and APACHE II scores (r = 0.389, P = 0.002, and n = 61; r = 0.449, P < 0.001, and n = 61; and r = 0.363, P = 0.004, and n = 61, resp.). Conclusions. An elevated plasma SDF-1 concentration can be used as a biological marker for the early diagnosis of CAP and for the early detection of its severity. PMID:25371597

  16. C9orf72 promoter hypermethylation is reduced while hydroxymethylation is acquired during reprogramming of ALS patient cells.

    PubMed

    Esanov, Rustam; Belle, Kinsley C; van Blitterswijk, Marka; Belzil, Veronique V; Rademakers, Rosa; Dickson, Dennis W; Petrucelli, Leonard; Boylan, Kevin B; Dykxhoorn, Derek M; Wuu, Joanne; Benatar, Michael; Wahlestedt, Claes; Zeier, Zane

    2016-03-01

    Among several genetic mutations known to cause amyotrophic lateral sclerosis (ALS), a hexanucleotide repeat expansion in the C9orf72 gene is the most common. In approximately 30% of C9orf72-ALS cases, 5-methylcytosine (5mC) levels within the C9orf72 promoter are increased, resulting in a modestly attenuated phenotype. The developmental timing of C9orf72 promoter hypermethylation and the reason why it occurs in only a subset of patients remain unknown. In order to model the acquisition of C9orf72 hypermethylation and examine the potential role of 5-hydroxymethylcytosine (5hmC), we generated induced pluripotent stem cells (iPSCs) from an ALS patient with C9orf72 promoter hypermethylation. Our data show that 5mC levels are reduced by reprogramming and then re-acquired upon neuronal specification, while 5hmC levels increase following reprogramming and are highest in iPSCs and motor neurons. We confirmed the presence of 5hmC within the C9orf72 promoter in post-mortem brain tissues of hypermethylated patients. These findings show that iPSCs are a valuable model system for examining epigenetic perturbations caused by the C9orf72 mutation and reveal a potential role for cytosine demethylation. PMID:26746986

  17. Overcoming acquired drug resistance in colorectal cancer cells by targeted delivery of 5-FU with EGF grafted hollow mesoporous silica nanoparticles

    NASA Astrophysics Data System (ADS)

    Chen, Lijue; She, Xiaodong; Wang, Tao; He, Li; Shigdar, Sarah; Duan, Wei; Kong, Lingxue

    2015-08-01

    Acquired drug resistance (ADR) can be developed in colorectal cancer cells after 5-fluorouracil (5-FU) treatment and diminish the effectiveness of chemotherapy. In this work, acquired 5-FU resistance in the colorectal cancer cell line SW480 was obtained with the up-regulation of dihydropyrimidine dehydrogenase (DPYD) gene expression which can convert 5-FU to its inactive metabolite. To overcome ADR in colorectal cancer, hollow mesoporous silica nanoparticles (HMSNs) grafted with epidermal growth factor (EGF) were used as nanocarriers to deliver 5-FU to colorectal cancer cells with acquired drug resistance. The effect and mechanism of 5-FU loaded EGF grafted HMSNs (EGF-HMSNs-5-FU) in overcoming acquired drug resistance in SW480/ADR cells were studied. The EGF-HMSNs were demonstrated to be specifically internalized in EGFR overexpressed SW480/ADR cells via a receptor-mediated endocytosis and can escape from endo-lysosomes. The EGF-HMSNs-5-FU exhibited much higher cytotoxicity on SW480/ADR cells than HMSNs-5-FU and free 5-FU while the plain HMSNs did not show significant cytotoxicity. The mechanism of EGF-HMSNs-5-FU in overcoming drug resistance in SW480/ADR cells could be attributed to the specific internalization of EGF-HMSNs-5-FU in EGFR overexpressed cells which can lead to high intracellular drug accumulation and cause cell death through S phase arrest.Acquired drug resistance (ADR) can be developed in colorectal cancer cells after 5-fluorouracil (5-FU) treatment and diminish the effectiveness of chemotherapy. In this work, acquired 5-FU resistance in the colorectal cancer cell line SW480 was obtained with the up-regulation of dihydropyrimidine dehydrogenase (DPYD) gene expression which can convert 5-FU to its inactive metabolite. To overcome ADR in colorectal cancer, hollow mesoporous silica nanoparticles (HMSNs) grafted with epidermal growth factor (EGF) were used as nanocarriers to deliver 5-FU to colorectal cancer cells with acquired drug resistance. The

  18. Clear cell papillary renal cell carcinoma and clear cell renal cell carcinoma arising in acquired cystic disease of the kidney: an immunohistochemical and genetic study.

    PubMed

    Kuroda, Naoto; Shiotsu, Tomoyuki; Kawada, Chiaki; Shuin, Taro; Hes, Ondrej; Michal, Michal; Ohe, Chisato; Mikami, Shuji; Pan, Chin-Chen

    2011-08-01

    Clear cell papillary renal cell carcinoma (RCC) is a recently established disease entity. However, there are few reports on genetic study of this entity. We report such a case with focus on genetic study. A 57-year-old Japanese man was found to have 3 renal tumors. Histologically, two tumors showed findings of clear cell RCC; and the other tumor showed findings of clear cell papillary RCC that was characterized by papillary growth pattern of neoplastic cells in cystic space with purely clear cell cytology. Immunohistochemically, tumor cells of clear cell papillary RCC were diffusely positive for PAX2 and cytokeratin 7, but negative for CD10, RCC Ma, and AMACR. In fluorescence in situ hybridization study for one clear cell papillary RCC, we detected polysomy for chromosome 7 and monosomy for chromosomes 17, 16, and 20. In addition, we detected mutation of VHL gene in clear cell RCC, but found no VHL gene mutation in clear cell papillary RCC. Finally, our results provide further evidence that clear cell papillary RCC may be both morphologically and genetically distinct entity from clear cell RCC and papillary RCC. PMID:20952286

  19. [The role of genetic factors in human radioresistance].

    PubMed

    Tel'nov, V I

    2005-01-01

    The role of genetic factors in the development of chronic radiation disease (CRD), mostly caused by occupational external gamma-exposure, was evaluated. The data of molecular genetic survey of a cohort of 985 workers at the nuclear power plant, the Mayak PA, were analyzed. Among the genetic markers tested, an association between the haptoglobin (Hp) genetic system and the development of CRD was established. It was demonstrated that the contribution of genetic factors to the CRD onset was realized not within the whole, but in a relatively narrow dose interval (70 to 400 cGy), i.e., was relative. Furthermore, at equal irradiation doses, relatively higher risk of CRD was observed among the Hp 2-2 phenotype carriers (1.96) compared to lower risk among the Hp 1-1 and Hp 2-1 phenotype carriers (0.64). It was shown that with the increase of the irradiation dose, genotypic differences in the CRD frequency decreased to the point of their complete disappearance. Comparison of the roles of the genetic factors in the onset of such deterministic irradiation effect as CRD, with their roles in the onset of lung cancer in tobacco smokers revealed similar patterns. A scheme of the relationships between the effector intensity and the differences in the genetically determined radioresistance is presented. The data obtained do not support the idea that the survivals of the atomic bombing of Hiroshima and Nagasaki were the most radioresistant individuals, who are not representative for evaluating the radiation risk. PMID:15771255

  20. Induction of acquired resistance to anti estrogen by reversible mitochondrial DNA depletion in breast cancer cell line

    PubMed Central

    Naito, Akihiro; Carcel-Trullols, Jaime; Xie, Cheng-hui; Evans, Teresa T; Mizumachi, Takatsugu; Higuchi, Masahiro

    2008-01-01

    Although the net benefits of tamoxifen in adjuvant breast cancer therapy have been proven, the recurrence of the cancer in an aggressive and hormone independent form has been highly problematic. We previously demonstrated the important role mitochondrial DNA (mtDNA) plays in hormone-independence in prostate cancer. Here, the role of mtDNA in breast cancer progression was investigated. We established hydroxytamoxifen (4-OHT) resistant HTRMCF by growing MCF-7, a human breast adenocarcinoma cells, in the presence of 4-OHT. HTRMCF was cross-resistant to 4-OHT and ICI182,780 concurrent with the depletion of mtDNA. To further investigate the role of mtDNA depletion, MCF-7 was depleted of mtDNA by treatment with ethidium bromide. MCFρ0 was resistant to both 4-OHT and ICI182,780. Furthermore, cybrid (MCFcyb) prepared by fusion MCFρ0 with platelet to transfer mtDNA showed susceptibility to anti-estrogen. Surprisingly, after withdrawal of 4-OHT for 8 weeks, HTRMCF and their clones became susceptible to both drugs concurrent with a recovery of mtDNA. Herein, our results substantiated the first evidence that the depletion of mtDNA induced by hormone therapy triggers a shift to acquired resistance to hormone therapy in breast cancer. In addition, we showed that mtDNA depletion can be reversed, rendering the cancer cells susceptible to anti-estrogen. The hormone independent phenotype can be reversed should be a step toward more effective treatments for estrogen-responsive breast cancer. PMID:17990320

  1. Allogeneic hematopoietic stem cell transplantation for acquired aplastic anemia using cyclophosphamide and antithymocyte globulin: a single center experience.

    PubMed

    Ladeb, S; Abdelkefi, A; Torjman, L; Ben Neji, H; Lakhal, A; Kaabi, H; Ben Hamed, L; Ennigrou, S; Hmida, S; Ben Othman, T; Ben Abdeladhim, A

    2009-07-27

    Between February 1998 and October 2007, 97 (69 male, 28 female) patients with acquired aplastic anemia and a median age of 18 years (range, 2-39) received related allogeneic hematopoietic stem cell transplantation. Ninety-five patients received bone marrow grafts and two patients G-CSF primed peripheral blood stem cell transplantation. The donors were genotypically HLA-identical siblings in 94 cases, HLA-matched parents in 2 cases and a syngeneic twin in 1 case. Median time from diagnosis to transplantation was 2 months (range, 1-15). Conditioning regimen consisted of cyclophosphamide combined with antithymocyte globulin in all patients. For graft versus host disease (GVHD) prophylaxis, all patients received methotrexate and cyclosporine. Eighty-six patients showed evidence of hematopoietic engraftment. Eight patients died before engraftment. Rejection rate was 14.8% with three primary graft failures and eight secondary graft rejections occurring between 2 and 27 months post transplantation. Of the 11 rejecting patients, 3 died from infection and 8 proceeded to a second transplantation. Among the eight patients re-transplanted, seven are alive with successful second engraftments and one died from acute grade III GVHD. Acute GVHD occurred in 15.5% and extensive chronic GVHD in only 5.3% of patients. The 4-year overall probability of survival was 76.8%. Infection was the cause of 81.1% of deaths. The major factor affecting survival was onset of infection before transplantation. Major ABO donor-recipient incompatibility, disease severity and acute GVHD had also negative impact on survival. These results could be improved by reducing the time to transplant and by a more efficient supportive care policy.Bone Marrow Transplantation advance online publication, 27 July 2009; doi:10.1038/bmt.2009.175. PMID:19633695

  2. First-Line Matched Related Donor Hematopoietic Stem Cell Transplantation Compared to Immunosuppressive Therapy in Acquired Severe Aplastic Anemia

    PubMed Central

    Peinemann, Frank; Grouven, Ulrich; Kröger, Nicolaus; Bartel, Carmen; Pittler, Max H.; Lange, Stefan

    2011-01-01

    Introduction Acquired severe aplastic anemia (SAA) is a rare and progressive disease characterized by an immune-mediated functional impairment of hematopoietic stem cells. Transplantation of these cells is a first-line treatment option if HLA-matched related donors are available. First-line immunosuppressive therapy may be offered as alternative. The aim was to compare the outcome of these patients in controlled trials. Methods A systematic search was performed in the bibliographic databases MEDLINE, EMBASE, and The Cochrane Library. To show an overview of various outcomes by treatment group we conducted a meta-analysis on overall survival. We evaluated whether studies reported statistically significant factors for improved survival. Results 26 non-randomized controlled trials (7,955 patients enrolled from 1970 to 2001) were identified. We did not identify any RCTs. Risk of bias was high except in 4 studies. Young age and recent year of treatment were identified as factors for improved survival in the HSCT group. Advanced age, SAA without very severe aplastic anemia, and combination of anti-lymphocyte globulin with cyclosporine A were factors for improved survival in the IST group. In 19 studies (4,855 patients), summary statistics were sufficient to be included in meta-analysis. Considerable heterogeneity did not justify a pooled estimate. Adverse events were inconsistently reported and varied significantly across studies. Conclusions Young age and recent year of treatment were identified as factors for improved survival in the transplant group. Advanced age, SAA without very severe aplastic anemia, and combination of anti-lymphocyte globulin with cyclosporine A were factors for improved survival in the immunosuppressive group. Considerable heterogeneity of non-randomized controlled studies did not justify a pooled estimate. Adverse events were inconsistently reported and varied significantly across studies. PMID:21541024

  3. S1 nuclease analysis of alpha-globin gene expression in preleukemic patients with acquired hemoglobin H disease after transfer to mouse erythroleukemia cells.

    PubMed

    Helder, J; Deisseroth, A

    1987-04-01

    The loss of alpha-globin gene transcriptional activity rarely occurs as an acquired abnormality during the evolution of myeloproliferative disease or preleukemia. To test whether the mutation responsible for the loss of alpha-globin gene expression (hemoglobin H disease) in these patients is linked with the alpha-globin genes on chromosome 16, we transferred chromosome 16 from preleukemic patients with acquired hemoglobin H disease to mouse erythroleukemia cells and measured the transcriptional activity of the human alpha-globin genes. After transfer to mouse erythroleukemia cells, the expression of human alpha-globin genes from the peripheral blood or marrow cells of preleukemic patients with acquired hemoglobin H disease was similar to that of human alpha-globin genes transferred to mouse erythroleukemia cells from normal donors. These data showed that factor(s) in the mouse erythroleukemia cell can genetically complement the alpha-globin gene defect in these preleukemia patients with acquired hemoglobin H disease and suggest that altered expression of a gene in trans to the alpha-globin gene may be responsible for the acquisition of hemoglobin H disease in these patients. PMID:3031681

  4. JAK2-related pathway induces acquired erlotinib resistance in lung cancer cells harboring an epidermal growth factor receptor-activating mutation.

    PubMed

    Harada, Daijiro; Takigawa, Nagio; Ochi, Nobuaki; Ninomiya, Takashi; Yasugi, Masayuki; Kubo, Toshio; Takeda, Hiromasa; Ichihara, Eiki; Ohashi, Kadoaki; Takata, Saburo; Tanimoto, Mitsune; Kiura, Katsuyuki

    2012-10-01

    Epidermal growth factor receptor (EGFR) tyrosine kinase inhibitors, such as gefitinib and erlotinib, are effective for non-small cell lung cancer with activating EGFR mutations. However, even in patients with an initial dramatic response to such a drug, acquired resistance develops after 6-12 months. A secondary mutation of T790M in EGFR and amplification of the MET gene account for this resistance; however, the mechanism(s) of approximately 30% of acquired resistance cases remain unknown. We established an erlotinib-resistant lung cancer cell line named PC-9/ER3 that harbors an EGFR mutation after continuously exposing PC-9 cells to erlotinib. PC-9/ER3 cells were 136-fold more resistant to erlotinib than the parental cells. Although the PC-9/ER3 cells did not carry the T790M mutation or MET amplification and had similar levels of phosphorylated (p) STAT3, pJAK2 increased in the resistant cells. It was found in the present study that 3-12 h of exposure to erlotinib in both cell lines did not affect pJAK2 expression, but did result in increased pSTAT3 expression. pAkt in PC-9/ER3 cells was less suppressed than in PC-9 cells, although pEGFR and pMAPK were markedly suppressed in both cell lines. The combined treatment of erlotinib plus a JAK2 inhibitor (JSI-124) suppressed pAkt in PC-9/ER3 cells. Similarly, the combination of erlotinib plus JSI-124 or siRNA against JAK2 restored sensitivity to erlotinib in PC-9/ER3 cells. The combination of erlotinib plus JSI-124 was also effective for reducing PC-9/ER3 tumors in a murine xenograft model. Our results suggest that the activation of JAK2 partially accounts for acquired erlotinib resistance. PMID:22712764

  5. Inhibition of Casein Kinase 1 Alpha Prevents Acquired Drug Resistance to Erlotinib in EGFR-Mutant Non-Small Cell Lung Cancer.

    PubMed

    Lantermann, Alexandra B; Chen, Dongshu; McCutcheon, Kaitlin; Hoffman, Greg; Frias, Elizabeth; Ruddy, David; Rakiec, Daniel; Korn, Joshua; McAllister, Gregory; Stegmeier, Frank; Meyer, Matthew J; Sharma, Sreenath V

    2015-11-15

    Patients with lung tumors harboring activating mutations in the EGF receptor (EGFR) show good initial treatment responses to the EGFR tyrosine kinase inhibitors (TKI) erlotinib or gefitinib. However, acquired resistance invariably develops. Applying a focused shRNA screening approach to identify genes whose knockdown can prevent and/or overcome acquired resistance to erlotinib in several EGFR-mutant non-small cell lung cancer (NSCLC) cell lines, we identified casein kinase 1 α (CSNK1A1, CK1α). We found that CK1α suppression inhibits the NF-κB prosurvival signaling pathway. Furthermore, downregulation of NF-κB signaling by approaches independent of CK1α knockdown can also attenuate acquired erlotinib resistance, supporting a role for activated NF-κB signaling in conferring acquired drug resistance. Importantly, CK1α suppression prevented erlotinib resistance in an HCC827 xenograft model in vivo. Our findings suggest that patients with EGFR-mutant NSCLC might benefit from a combination of EGFR TKIs and CK1α inhibition to prevent acquired drug resistance and to prolong disease-free survival. PMID:26490646

  6. Atypical variant of acquired von Willebrand syndrome in Wilms tumor: is hyaluronic acid secreted by nephroblastoma cells the cause?

    PubMed

    Michiels, J; Schroyens, W; Berneman, Z; van der Planken, M

    2001-04-01

    Acquired von Willebrand syndrome (AvWS) has been reported in eight children with Wilms tumor (nephroblastoma in four boys and four girls) at a mean age of 3.3 years (range, 0.33-9 years). Only three of eight patients with AvWS in Wilms tumor presented with mild mucocutaneous bleeding symptoms. The AvWS in seven children with Wilms tumor featured either undetectable or very low von Willebrand factor antigen (vWF.Ag) levels (mean, 3%) and decreased values for vWF ristocetin cofactor (RCF) activity (mean, 20%) and factor VIII coagulant (VIIIc) activity (mean, 16%). The response to 1-desamino-8-arginine vasopressin (DDAVP) was good in two and poor in one patient. Multimeric analysis of the vWF showed a normal pattern of type I von Willebrand disease (vWD) in three patients and an absence of multimers consistent with type III vWD in two patients. The higher functional levels, as compared with antigen levels, with increased ratios for factor VIIIc/vWFAg (mean, 5.3) and vWF.RCF/vWF.Ag (mean, 6.6) in seven patients with Wilms tumor are unexplained physiologically and are not consistent with type I vWF deficiency. The absence of vWD in the patient's family, and the return of factor VIII-vWF parameters to normal after chemotherapy or surgical removal of the Wilms tumor, support the diagnosis of AvWS causally related to the Wilms tumor. The causative agent is thought to be hyaluronic acid secreted by nephroblastoma cells of the Wilms tumor. Prospective studies to determine the nature of AvWS in children with Wilms tumor are warranted. PMID:11292185

  7. Abnormal pattern of post-gamma-ray DNA replication in radioresistant fibroblast strains from affected members of a cancer-prone family with Li-Fraumeni syndrome.

    PubMed Central

    Mirzayans, R.; Aubin, R. A.; Bosnich, W.; Blattner, W. A.; Paterson, M. C.

    1995-01-01

    Non-malignant dermal fibroblast strains, cultured from affected members of a Li-Fraumeni syndrome (LFS) family with diverse neoplasms associated with radiation exposure, display a unique increased resistance to the lethal effects of gamma-radiation. In the studies reported here, this radioresistance (RR) trait has been found to correlate strongly with an abnormal pattern of post-gamma-ray DNA replicative synthesis, as monitored by radiolabelled thymidine incorporation and S-phase cell autoradiography. In particular, the time interval between the gamma-ray-induced shutdown of DNA synthesis and its subsequent recovery was greater in all four RR strains examined and the post-recovery replication rate was much higher and was maintained longer than in normal and spousal controls. Alkaline sucrose sedimentation profiles of pulse-labelled cellular DNA indicated that the unusual pattern of DNA replication in irradiated RR strains may be ascribed to anomalies in both replicon initiation and DNA chain elongation processes. Moreover, the RR strain which had previously displayed the highest post-gamma-ray clonogenic survival was found to harbour a somatic (codon 234) mutation (presumably acquired during culture in vitro) in the same conserved region of the p53 tumour-suppressor gene as the germline (codon 245) mutation in the remaining three RR strains from other family members, thus coupling the RR phenotype and abnormal post-gamma-ray DNA synthesis pattern with faulty p53 expression. Significantly, these two aberrant radioresponse end points, along with documented anomalies in c-myc and c-raf-1 proto-oncogenes, are unprecedented among other LFS families carrying p53 germline mutations. We thus speculate that this peculiar cancer-prone family may possess in its germ line a second, as yet unidentified, genetic defect in addition to the p53 mutation. Images Figure 8 PMID:7779715

  8. KNK437, abrogates hypoxia-induced radioresistance by dual targeting of the AKT and HIF-1{alpha} survival pathways

    SciTech Connect

    Oommen, Deepu; Prise, Kevin M.

    2012-05-11

    Highlights: Black-Right-Pointing-Pointer KNK437, a benzylidene lactam compound, is a novel radiosensitizer. Black-Right-Pointing-Pointer KNK437 inhibits AKT signaling and abrogates the accumulation of HIF-1{alpha} under hypoxia. Black-Right-Pointing-Pointer KNK437 abrogates hypoxia induced resistance to radiation. -- Abstract: KNK437 is a benzylidene lactam compound known to inhibit stress-induced synthesis of heat shock proteins (HSPs). HSPs promote radioresistance and play a major role in stabilizing hypoxia inducible factor-1{alpha} (HIF-1{alpha}). HIF-1{alpha} is widely responsible for tumor resistance to radiation under hypoxic conditions. We hypothesized that KNK437 sensitizes cancer cells to radiation and overrides hypoxia-induced radioresistance via destabilizing HIF-1{alpha}. Treatment of human cancer cells MDA-MB-231 and T98G with KNK437 sensitized them to ionizing radiation (IR). Surprisingly, IR did not induce HSPs in these cell lines. As hypothesized, KNK437 abrogated the accumulation of HIF-1{alpha} in hypoxic cells. However, there was no induction of HSPs under hypoxic conditions. Moreover, the proteosome inhibitor MG132 did not restore HIF-1{alpha} levels in KNK437-treated cells. This suggested that the absence of HIF-1{alpha} in hypoxic cells was not due to the enhanced protein degradation. HIF-1{alpha} is mainly regulated at the level of post-transcription and AKT is known to modulate the translation of HIF-1{alpha} mRNA. Interestingly, pre-treatment of cells with KNK437 inhibited AKT signaling. Furthermore, down regulation of AKT by siRNA abrogated HIF-1{alpha} levels under hypoxia. Interestingly, KNK437 reduced cell survival in hypoxic conditions and inhibited hypoxia-induced resistance to radiation. Taken together, these data suggest that KNK437 is an effective radiosensitizer that targets multiple pro-survival stress response pathways.

  9. The insulin-like growth factor 1 receptor causes acquired resistance to erlotinib in lung cancer cells with the wild-type epidermal growth factor receptor.

    PubMed

    Suda, Kenichi; Mizuuchi, Hiroshi; Sato, Katsuaki; Takemoto, Toshiki; Iwasaki, Takuya; Mitsudomi, Tetsuya

    2014-08-15

    Epidermal growth factor receptor (EGFR)-tyrosine kinase inhibitor (TKI) therapy often provides a dramatic response in lung cancer patients with EGFR mutations. In addition, moderate clinical efficacy of the EGFR-TKI, erlotinib, has been shown in lung cancer patients with the wild-type EGFR. Numerous molecular mechanisms that cause acquired resistance to EGFR-TKIs have been identified in lung cancers with the EGFR mutations; however, few have been reported in lung cancers with the wild-type EGFR. We used H358 lung adenocarcinoma cells lacking EGFR mutations that showed modest sensitivity to erlotinib. The H358 cells acquired resistance to erlotinib via chronic exposure to the drug. The H358 erlotinib-resistant (ER) cells do not have a secondary EGFR mutation, neither MET gene amplification nor PTEN downregulation; these have been identified in lung cancers with the EGFR mutations. From comprehensive screening of receptor tyrosine kinase phosphorylation, we observed increased phosphorylation of insulin-like growth factor 1 receptor (IGF1R) in H358ER cells compared with parental H358 cells. H358ER cells responded to combined therapy with erlotinib and NVP-AEW541, an IGF1R-TKI. Our results indicate that IGF1R activation is a molecular mechanism that confers acquired resistance to erlotinib in lung cancers with the wild-type EGFR. PMID:24458568

  10. Integrin β1-mediated acquired gefitinib resistance in non-small cell lung cancer cells occurs via the phosphoinositide 3-kinase-dependent pathway

    PubMed Central

    DENG, QIN-FANG; SU, BO; ZHAO, YIN-MIN; TANG, LIANG; ZHANG, JIE; ZHOU, CAI-CUN

    2016-01-01

    The present study aimed to explore the role of integrin β1 and the relevant signaling pathways in acquired gefitinib resistance in non-small cell lung cancer (NSCLC). The inhibitory effects of gefitinib, with or without LY294002, on cellular proliferation were evaluated by 3-(4,5-dimethylthiazol-2-yl) 2,5-diphenyltetrazolium bromide assay. Cell cycle progression and apoptosis were analyzed by flow cytometry, while western blotting was used to evaluate the expression of EGFR, phosphorylated (phospho)-EGFR, protein kinase B (Akt), phospho-Akt, extracellular signal-regulated kinase (Erk) and phospho-Erk. The gene expression profiles of PC9 and PC9/G cells were determined by DNA microarray. Integrin β1 was knocked down in PC9/G cells by transiently transfected short interfering RNA (siRNA). A scrambled siRNA sequence was used as a control. Apoptosis of transfected cells was determined by Annexin V-phycoerythrin-Cy5/propidium iodide staining. Sequencing products were amplified by nested PCR. The resistant index of PC9/G cells to gefitinib was ~138- to 256-fold higher than that of PC9 cells, and this resistance was accompanied by significant increase in integrin β1 expression in PC9/G cells. Knockdown of integrin β1 with short hairpin RNA in PC9/G cells markedly inhibited proliferation and enhanced apoptosis in response to gefitinib, restoring the sensitivity of PC9/G cells gefitinib. Phosphoinositide 3-kinase (PI3K)/Akt activation was observed in PC9/G cells in the presence of gefitinib and the sensitivity of PC9/G cells to gefitinib was also able to be restored by PI3K/Akt pathway inhibitor LY294002. Finally, knockdown of integrin β1 significantly reduced the levels of phospho-Akt. These findings suggest that integrin β1 signaling via the PI3K/Akt pathway may be a significant mechanism underlying gefitinib resistance, and may potentially present an alternative therapeutic target for the treatment of NSCLC unresponsive to EGFR inhibitors. PMID:26870244

  11. Human B-cell interleukin-10: B-cell lines derived from patients with acquired immunodeficiency syndrome and Burkitt's lymphoma constitutively secrete large quantities of interleukin-10.

    PubMed

    Benjamin, D; Knobloch, T J; Dayton, M A

    1992-09-01

    A recent addition to the lymphokine network is human IL-10 (hIL-10). This novel lymphokine has striking homology to BCRF1 protein, the product of a previously uncharacterized open-reading frame in the Epstein-Barr virus (EBV) genome. To date, IL-10 expression has been described in several T clones induced with anti-CD3 and phorbol myristate acetate (PMA), in monocytes stimulated with lipopolysaccharide (LPS), and in murine B-cell lymphomas. We sought to determine whether human B cells express hIL-10 and, if so, its relationship to EBV and to other B-cell lymphokines. We studied 21 EBV-positive B-cell lines derived from patients with acquired immunodeficiency syndrome (AIDS) and Burkitt's lymphoma (n = 6), American Burkitt's (n = 3), African Burkitt's (n = 5), and normal lymphoblastoid cell lines (n = 7), in comparison with seven EBV-negative cell lines. All cell lines were activated with the tumor promoters PMA and teleocidin and were studied by Northern blot analysis, reverse transcription-polymerase chain reaction (RT-PCR), and enzyme-linked immunoadsorbent assay (ELISA). We demonstrated that EBV-positive cell lines derived from patients with American Burkitt's lymphoma, and especially those from patients with AIDS, constitutively express large quantities of hIL-10 by Northern blot analysis and ELISA (range, 3,101 to 25,915 pg/mL), and that both teleocidin and PMA induce hIL-10 in these cell lines. In contrast, six of seven EBV-negative cell lines did not express hIL-10 even by RT-PCR, and hIL-10 was not triggered by PMA or teleocidin. To assure that the 350 bp amplified by PCR was hIL-10 and not BCRF1, we used PCR primers, which do not amplify a fragment from plasmid templates containing BCRF1. Cloning and sequencing of the 350 bp product also demonstrated that B-cell IL-10 is identical to hIL-10 from the T-cell clone B21. Correlation of hIL-10 with other B-cell lymphokines secreted by these B-cell lines demonstrated that hIL-10 secretor cell lines also

  12. Acquired resistance to rechallenge injury in rats recovered from subclinical renal damage with uranyl acetate-Importance of proliferative activity of tubular cells

    SciTech Connect

    Sun, Yuan; Fujigaki, Yoshihide; Sakakima, Masanori; Hishida, Akira

    2010-02-15

    Animals recovered from acute renal failure are resistant to subsequent insult. We investigated whether rats recovered from mild proximal tubule (PT) injury without renal dysfunction (subclinical renal damage) acquire the same resistance. Rats 14 days after recovering from subclinical renal damage, which was induced by 0.2 mg/kg of uranyl acetate (UA) (sub-toxic dose), were rechallenged with 4 mg/kg of UA (nephrotoxic dose). Fate of PT cells and renal function were examined in response to nephrotoxic dose of UA. All divided cells after sub-toxic dose of UA insult were labeled with bromodeoxyuridine (BrdU) for 14 days then the number of PT cells with or without BrdU-labeling was counted following nephrotoxic dose of UA insult. Rats recovered from subclinical renal damage gained resistance to nephrotoxic dose of UA with reduced renal dysfunction, less severity of peak damage (necrotic and TUNEL+ apoptotic cells) and accelerated PT cell proliferation, but with earlier peak of PT damage. The decrease in number of PT cells in the early phase of rechallenge injury with nephrotoxic UA was more in rats pretreated with sub-toxic dose of UA than vehicle pretreated rats. The exaggerated loss of PT cells was mainly caused by the exaggerated loss of BrdU+ divided cells. In contrast, accelerated cell proliferation in rats recovered from sub-toxic dose of UA was observed mainly in BrdU- non-divided cells. The findings suggest that rats recovered from subclinical renal damage showed partial acquired resistance to nephrotoxic insult. Accelerated recovery with increased proliferative activity of non-divided PT cells after subclinical renal damage may mainly contribute to acquired resistance.

  13. Characterization of monofunctional catalase KatA from radioresistant bacterium Deinococcus radiodurans.

    PubMed

    Kobayashi, Issei; Tamura, Takashi; Sghaier, Haitham; Narumi, Issay; Yamaguchi, Shotaro; Umeda, Koichi; Inagaki, Kenji

    2006-04-01

    Catalase plays a key role in protecting cells against toxic reactive oxygen species. Here we report on the cloning, purification and characterization of a catalase (KatA, DR1998) from the extremely radioresistant bacterium Deinococcus radiodurans. The size of purified D. radiodurans KatA monomer was 65 kDa while gel filtration revealed that the size of the enzyme was 240 kDa, suggesting that KatA formed a homotetramer in solution. Purified KatA displayed a final specific activity of 68,800 U/mg of protein. The catalase activity of KatA was inhibited by sodium azide, sodium cyanide and 3-amino-1,2,4-triazole. The absorption spectrum of KatA exhibited a Soret band at 408 nm. The position of the spectral peak remained unchanged following reduction of KatA with dithionite. No peroxidase activity was found for KatA. These results demonstrate that D. radiodurans KatA is a typical monofunctional heme-containing catalase. The stability of KatA with respect to H2O2 stress was superior to that of commercially available Aspergillus niger and bovine liver catalases. The relative abundance of KatA in cells in addition to the H2O2 resistance property may play a role in the survival strategy of D. radiodurans against oxidative damage. PMID:16716939

  14. Acquired resistance to HSP90 inhibitor 17-AAG and increased metastatic potential are associated with MUC1 expression in colon carcinoma cells.

    PubMed

    Liu, Xin; Ban, Li-Li; Luo, Gang; Li, Zhi-Yao; Li, Yun-Feng; Zhou, Yong-Chun; Wang, Xi-Cai; Jin, Cong-Guo; Ye, Jia-Gui; Ma, Ding-Ding; Xie, Qing; Huang, You-Guang

    2016-06-01

    Heat shock protein 90 (HSP90) is a molecular chaperone required for the stability and function of many proteins. The chaperoning of oncoproteins by HSP90 enhances the survival, growth, and invasive potential of cancer cells. HSP90 inhibitors are promising new anticancer agents, in which the benzoquinone ansamycin 17-allylamino-17-demethoxygeldanamycin (17-AAG) is currently in clinical evaluation. However, the implications of acquired resistance to this class of drug remain largely unexplored. In the present study, we have generated isogenic human colon cancer cell lines that are resistant to 17-AAG by continued culturing in the compound. Cross-resistance was found with another HSP90 inhibitor 17-dimethylaminoethylamino-17-demethoxygeldanamycin. The resistant cells showed obvious morphology changes with a metastatic phenotype and significant increases in migration and adhesion to collagens. Western blotting analysis of epithelial-mesenchymal transition molecular markers found that expression of E-cadherin downregulated, whereas expression of N-cadherin and β-catenin upregulated in the resistant cells. Mucin 1 (MUC1) has been reported to mediate metastasis as well as chemical resistance in many cancers. Here, we found that MUC1 expression was significantly elevated in the acquired drug resistance cells. 17-AAG treatment could decrease MUC1 more in parental cells than in acquired 17-AAG-resistant cells. Further study found that knockdown of MUC1 expression by small interfering RNA could obviously re-sensitize the resistant cells to 17-AAG treatment, and decrease the cell migration and adhesion. These were coupled with a downregulation in N-cadherin and β-catenin. The results indicate that HSP90 inhibitor therapies in colon carcinomas could generate resistance and increase metastatic potential that might mediated by upregulation of MUC1 expression. Findings from this study further our understanding of the potential clinical effects of HSP90-directed therapies in

  15. IKK phosphorylation of NF-κB at serine 536 contributes to acquired cisplatin resistance in head and neck squamous cell cancer

    PubMed Central

    Li, Zhipeng; Yang, Zejia; Lapidus, Rena G; Liu, Xuefeng; Cullen, Kevin J; Dan, Han C

    2015-01-01

    Current treatment methods for advanced head and neck squamous cell carcinoma (HNSCC) include surgery, radiation therapy and chemotherapy. For recurrent and metastatic HNSCC, cisplatin is the most common treatment option, but most of patients will eventually develop cisplatin resistance. Therefore, it is imperative to define the mechanisms involved in cisplatin resistance and find novel therapeutic strategies to overcome this deadly disease. In order to determine the role of nuclear factor-kappa B (NF-κB) in contributing to acquired cisplatin resistance in HNSCC, the expression and activity of NF-κB and its upstream kinases, IKKα and IKKβ, were evaluated and compared in three pairs of cisplatin sensitive and resistant HNSCC cell lines, including a pair of patient derived HNSCC cell line. The experiments revealed that NF-κB p65 activity was elevated in cisplatin resistant HNSCC cells compared to that in their parent cells. Importantly, the phosphorylation of NF-κB p65 at serine 536 and the phosphorylation of IKKα and IKKβ at their activation loops were dramatically elevated in the resistant cell lines. Furthermore, knockdown of NF-κB or overexpression of p65-S536 alanine (p65-S536A) mutant sensitizes resistant cells to cisplatin. Additionally, the novel IKKβ inhibitor CmpdA has been shown to consistently block the phosphorylation of NF-κB at serine 536 while also dramatically improving the efficacy of cisplatin in inhibition of cell proliferation and induction of apoptosis in the cisplatin resistant cancer cells. These results indicated that IKK/NF-κB plays a pivotal role in controlling acquired cisplatin resistance and that targeting the IKK/NF-κB signaling pathway may provide a possible therapeutic method to overcome the acquired resistance to cisplatin in HNSCC. PMID:26693062

  16. Acquired EGFR C797S mutation mediates resistance to AZD9291 in non-small cell lung cancer harboring EGFR T790M.

    PubMed

    Thress, Kenneth S; Paweletz, Cloud P; Felip, Enriqueta; Cho, Byoung Chul; Stetson, Daniel; Dougherty, Brian; Lai, Zhongwu; Markovets, Aleksandra; Vivancos, Ana; Kuang, Yanan; Ercan, Dalia; Matthews, Sarah E; Cantarini, Mireille; Barrett, J Carl; Jänne, Pasi A; Oxnard, Geoffrey R

    2015-06-01

    Here we studied cell-free plasma DNA (cfDNA) collected from subjects with advanced lung cancer whose tumors had developed resistance to the epidermal growth factor receptor (EGFR) tyrosine kinase inhibitor (TKI) AZD9291. We first performed next-generation sequencing of cfDNA from seven subjects and detected an acquired EGFR C797S mutation in one; expression of this mutant EGFR construct in a cell line rendered it resistant to AZD9291. We then performed droplet digital PCR on serial cfDNA specimens collected from 15 AZD9291-treated subjects. All were positive for the T790M mutation before treatment, but upon developing AZD9291 resistance three molecular subtypes emerged: six cases acquired the C797S mutation, five cases maintained the T790M mutation but did not acquire the C797S mutation and four cases lost the T790M mutation despite the presence of the underlying EGFR activating mutation. Our findings provide insight into the diversity of mechanisms through which tumors acquire resistance to AZD9291 and highlight the need for therapies that are able to overcome resistance mediated by the EGFR C797S mutation. PMID:25939061

  17. Acquired EGFR C797S mediates resistance to AZD9291 in advanced non-small cell lung cancer harboring EGFR T790M

    PubMed Central

    Thress, Kenneth S.; Paweletz, Cloud P.; Felip, Enriqueta; Cho, Byoung Chul; Stetson, Daniel; Dougherty, Brian; Lai, Zhongwu; Markovets, Aleksandra; Vivancos, Ana; Kuang, Yanan; Ercan, Dalia; Matthews, Sarah; Cantarini, Mireille; Barrett, J. Carl; Jänne, Pasi A.; Oxnard, Geoffrey R.

    2015-01-01

    Here we studied cell-free plasma DNA (cfDNA) collected from subjects with advanced lung cancer whose tumors had developed resistance to the epidermal growth factor receptor (EGFR) tyrosine kinase inhibitor (TKI) AZD9291. We first performed next-generation sequencing of cfDNA from seven subjects and detected an acquired EGFR C797S mutation in one; expression of this mutant EGFR construct in a cell line rendered it resistant to AZD9291. We then performed droplet digital PCR on serial cfDNA specimens collected from 15 AZD9291-treated subjects. All were positive for T790M prior to treatment, but at resistance three molecular subtypes emerged: 6 cases acquired the C797S mutation, 5 cases maintained the T790M mutation but did not acquire the C797S mutation, and 4 cases lost the T790M mutation despite detecting of the underlying EGFR activating mutation. Our findings provide insight into the diversity of mechanisms through which tumors acquire resistance to AZD9291 and highlight the need for therapies able to overcome resistance mediated by EGFR C797S. PMID:25939061

  18. Promotion of radioresistance by metallothionein induction prior to irradiation

    SciTech Connect

    Matsubara, J.; Tajima, Y.; Karasawa, M.

    1987-06-01

    A striking radioresistance has been found in mice which were subjected to various pretreatments to induce metallothionein synthesis in the liver prior to irradiation. The tolerance to lethal damage from an LD50 level of radiation during a 30-day postirradiation period was demonstrated by a highly significant difference (P less than 0.01) in mortality rate between mice given subcutaneously manganese, cadmium, or zinc injection or surgical skin excision of mice and the control mice (no pretreatment). A typical loss in body weight that generally reached a peak 2 weeks after irradiation was observed in the control mice, but mice given a dose of 10 mg manganese per kilogram body weight showed a steady weight increase even a few days after irradiation. The normal level of metallothionein in mouse liver is 20 micrograms/g tissue. This level increased up to 70 micrograms/g tissue following irradiation at 6.3 Gy. Among irradiated mice, metallothionein levels in the liver increased approximately 200-800% after cadmium, manganese, or zinc injection compared to levels of irradiated mice without pretreatment. Mice undergoing 2 X 2-cm/sup 2/ dermal excision also demonstrated a similar reduction of mortality and high metallothionein contents in liver, i.e., 150-400 micrograms/g. The present results, together with our previous findings suggest that the body's protective mechanism against radiation strongly correlates with the biosynthesis of metallothionein or metallothionein itself acting as a scavenger of radiation-induced peroxides.

  19. Valproic acid, an inhibitor of class I histone deacetylases, reverses acquired Erlotinib-resistance of lung adenocarcinoma cells: a Connectivity Mapping analysis and an experimental study.

    PubMed

    Zhuo, Wenlei; Zhang, Liang; Zhu, Yi; Xie, Qichao; Zhu, Bo; Chen, Zhengtang

    2015-01-01

    Epidermal growth factor receptor (EGFR) tyrosine kinase inhibitors (TKI) have been used as a powerful targeting therapeutic agent for treatment of lung adenocarcinoma for years. Nevertheless, the efficacy of TKI was hampered by the appearance of acquired TKI-resistance. In the present study, we aimed to search, predict, and screen the agents that can overcome the acquired TKI-resistance of lung adenocarcinoma by using the expression profiles of differentially expressed genes (DEGs) and Connectivity map (CMAP). The profiles of DEGs were obtained by searching GEO microarray database, and then, they were submitted to CMAP for analysis in order to predict and screen the agent that might reverse the TKI-resistance of lung cancer cells. Next, the effects of the selected agent on TKI-resistant cancer cells were tested and the possible signaling pathways were also evaluated. As a result, valproic acid (VPA) was selected. Then, we used a low-concentration of VPA that has little effect on the cell growth for analysis. Interestingly, the results showed that treatment with a combination of VPA and Erlotinib significantly led to a decrease in cell viability and an increase in cell apoptosis for TKI-resistant HCC827-ER cells, relative to those treated with VPA or Erlotinib alone. Further experiments confirmed that inhibition of MAPK and AKT might be involved in this process. Analyzing the DEGs through the CMAP is a good strategy for exploitation of anti-tumor agents. VPA might markedly increase the sensitivity of TKI-resistant lung adenocarcinoma cells to Erlotinib, thus reversing the acquired TKI-resistance of cancer cells and raising VPA as a potential agent for TKI-resistant lung cancer therapy. PMID:26328250

  20. Protein N-arginine methyltransferase 5 promotes the tumor progression and radioresistance of nasopharyngeal carcinoma.

    PubMed

    Yang, Daoke; Liang, Tiansong; Gu, Yue; Zhao, Yulin; Shi, Yonggang; Zuo, Xiaoxiao; Cao, Qinchen; Yang, Ya; Kan, Quancheng

    2016-03-01

    Radiotherapy resistance is the main cause of the the poor prognosis of some nasopharyngeal carcinoma (NPC) patients. Yet, the exact mechanism is still elusive. In the present study, we explored the clinical and biological role of protein arginine methyltransferase 5 (PRMT5) in NPC. Our results revealed that PRMT5 was overexpressed in NPC tissues when compared with that in adjacent non-tumor tissues by quantitative RT-PCR and immunoblotting. High expression of PRMT5 was correlated with adverse outcomes of NPC patients as determined by the scoring of a tissue microarray. Silencing of PRMT5 promoted the radiosensitivity of 5-8F and CNE2 cells as determined by cell proliferation and colony formation assays. Furthermore, fibroblast growth factor receptor 3 (FGFR3) was identified as one of the downstream targets of PRMT5, and the silencing of PRMT5 decreased the mRNA and protein levels of FGFR3 in the 5-8F and CNE2 cells. Silencing of FGFR3 induced similar phenotypes as the inhibition of PRMT5, and re-expression of FGFR3 in 5-8F/shPRMT5 and CNE2/shPRMT5 cells restored the proliferation and colony formation ability induced by irradiation exposure. Our results indicate that PRMT5 is a marker of poor prognosis in NPC patients. PRMT5 promoted the radioresistance of NPC cells via targeting FGFR3, at least partly if not totally. PRMT5 and its downstream effector FGFR3 may be potential targets for anticancer strategy. PMID:26708443

  1. Promotion of radioresistance by metallothionein induction prior to irradiation.

    PubMed

    Matsubara, J; Tajima, Y; Karasawa, M

    1987-06-01

    A striking radioresistance has been found in mice which were subjected to various pretreatments to induce metallothionein synthesis in the liver prior to irradiation. The tolerance to lethal damage from an LD50 level of radiation during a 30-day postirradiation period was demonstrated by a highly significant difference (P less than 0.01) in mortality rate between mice given subcutaneously manganese, cadmium, or zinc injection or surgical skin excision of mice and the control mice (no pretreatment). A typical loss in body weight that generally reached a peak 2 weeks after irradiation was observed in the control mice, but mice given a dose of 10 mg manganese per kilogram body weight showed a steady weight increase even a few days after irradiation. The normal level of metallothionein in mouse liver is 20 micrograms/g tissue. This level increased up to 70 micrograms/g tissue following irradiation at 6.3 Gy. Among irradiated mice, metallothionein levels in the liver increased approximately 200-800% after cadmium, manganese, or zinc injection compared to levels of irradiated mice without pretreatment. Mice undergoing 2 X 2-cm2 dermal excision also demonstrated a similar reduction of mortality and high metallothionein contents in liver, i.e., 150-400 micrograms/g. The present results, together with our previous findings (Matsubara et al., 1982, 1983, 1984; Matsubara, 1986), suggest that the body's protective mechanism against radiation strongly correlates with the biosynthesis of metallothionein or metallothionein itself acting as a scavenger of radiation-induced peroxides. PMID:3556159

  2. β-Catenin Signaling Biases Multipotent Lingual Epithelial Progenitors to Differentiate and Acquire Specific Taste Cell Fates

    PubMed Central

    Gaillard, Dany; Xu, Mingang; Liu, Fei; Millar, Sarah E.; Barlow, Linda A.

    2015-01-01

    Continuous taste bud cell renewal is essential to maintain taste function in adults; however, the molecular mechanisms that regulate taste cell turnover are unknown. Using inducible Cre-lox technology, we show that activation of β-catenin signaling in multipotent lingual epithelial progenitors outside of taste buds diverts daughter cells from a general epithelial to a taste bud fate. Moreover, while taste buds comprise 3 morphological types, β-catenin activation drives overproduction of primarily glial-like Type I taste cells in both anterior fungiform (FF) and posterior circumvallate (CV) taste buds, with a small increase in Type II receptor cells for sweet, bitter and umami, but does not alter Type III sour detector cells. Beta-catenin activation in post-mitotic taste bud precursors likewise regulates cell differentiation; forced activation of β-catenin in these Shh+ cells promotes Type I cell fate in both FF and CV taste buds, but likely does so non-cell autonomously. Our data are consistent with a model where β-catenin signaling levels within lingual epithelial progenitors dictate cell fate prior to or during entry of new cells into taste buds; high signaling induces Type I cells, intermediate levels drive Type II cell differentiation, while low levels may drive differentiation of Type III cells. PMID:26020789

  3. Immunophenotypic characterization of the cutaneous exanthem of SIV-infected rhesus monkeys. Apposition of degenerative Langerhans cells and cytotoxic lymphocytes during the development of acquired immunodeficiency syndrome.

    PubMed Central

    Ringler, D. J.; Hancock, W. W.; King, N. W.; Letvin, N. L.; Daniel, M. D.; Desrosiers, R. C.; Murphy, G. F.

    1987-01-01

    A T-cell tropic retrovirus, simian immunodeficiency virus (SIV), has recently been isolated from immunodeficient rhesus monkeys. This virus has remarkable similarities to human immunodeficiency virus (HIV), the etiologic agent of acquired immunodeficiency syndrome. Subsequent studies of simian infection with SIV have shown it to be a relevant animal model for studying the pathogenesis of AIDS in man. In both HIV-infected humans and SIV-infected monkeys, a cutaneous maculopapular eruption has been described. To date, the pathogenesis and possible relationship of these exanthema to the evolution of systemic immunosuppression have remained obscure. In this study, the mononuclear cell infiltrates that characterize skin rashes of SIV-infected rhesus monkeys were found to be composed predominantly of cells with phenotypic characteristics of cytotoxic/suppressor (T8+) lymphocytes and natural killer cells. Many of these cells expressed membrane-bound interleukin-2 receptor molecules. Double labeling and immunoelectron microscopy revealed these cells in direct contact with degenerative Langerhans cells within the epidermis and dermis. These observations suggest that the cutaneous rash associated with SIV infection may be the consequence of target cell injury of Langerhans cells by effector cells with cytotoxic potential. Images Figure 1 Figure 2 Figure 3 PMID:3030113

  4. Immunoregulation of genetically controlled acquired responses to Leishmania donovani infection in mice: demonstration and characterization of suppressor T cells in noncure mice.

    PubMed Central

    Blackwell, J M; Ulczak, O M

    1984-01-01

    On a B10 genetic background, genes in the I region of H-2 influence the development of acquired T-cell mediated immunity to Leishmania donovani infection in mice. In previous studies, noncure in H-2d mice could be abrogated by pretreatments with cyclophosphamide or sublethal irradiation. The prophylactic effect of these pretreatments was consistent with deletion of the precursors of suppressor T cells suppressing T-cell-mediated immune responses. In this study, cell transfer experiments provide direct evidence for the role of suppressor T cells in the noncure response. T-cell-enriched populations isolated from the spleens of B10.D2/n mice infected 30, 61, or 85 days previously reversed the prophylactic effect of sublethal irradiation when injected before infection into B10.D2/n mice that had received 550 rads. B-cell-enriched populations failed to transfer suppression in this manner, and T-cell-enriched populations from the spleens of normal B10.D2/n mice had only a transient effect on liver parasite loads. Transfer of suppression with the T-cell-enriched populations from infected donors was abrogated by pretreatment with anti-Thy-1.2 and anti-Lyt-1.2 antisera plus complement but not by pretreatment with anti-Lyt-2.2 plus complement, indicating that the suppressor T cell involved has an Lyt-1+2- surface phenotype. Results are discussed in relation to the possible mechanism of H-2-linked control. PMID:6231248

  5. Acquired von Willebrand disease.

    PubMed

    Kumar, Shaji; Pruthi, Rajiv K; Nichols, William L

    2002-02-01

    Acquired von Willebrand disease (AvWD) is a relatively rare acquired bleeding disorder that usually occurs in elderly patients, in whom its recognition may be delayed. Patients usually present predominantly with mucocutaneous bleeding, with no previous history of bleeding abnormalities and no clinically meaningful family history. Various underlying diseases have been associated with AvWD, most commonly hematoproliferative disorders, including monoclonal gammopathies, lymphoproliferative disorders, and myeloproliferative disorders. The pathogenesis of AvWD remains incompletely understood but includes autoantibodies directed against the von Willebrand factor (vWF), leading to a more rapid clearance from the circulation or interference with its function, adsorption of vWF by tumor cells, and nonimmunologic mechanisms of destruction. Laboratory evaluation usually reveals a pattern of prolonged bleeding time and decreased levels of vWF antigen, ristocetin cofactor activity, and factor VIII coagulant activity consistent with a diagnosis of vWD. Acquired vWD is distinguished from the congenital form by age at presentation, absence of a personal and family history of bleeding disorders, and, often, presence of a hematoproliferative or autoimmune disorder. The severity of the bleeding varies considerably among patients. Therapeutic options include desmopressin and certain factor VIII concentrates that also contain vWF. Successful treatment of the associated illness can reverse the clinical and laboratory manifestations. Intravenous immunoglobulins have also shown some efficacy in the management of AvWD, especially cases associated with monoclonal gammopathies. Awareness of AvWD is essential for diagnosis and appropriate management. PMID:11838652

  6. Imaging of acquired cystic disease-associated renal cell carcinoma by contrast-enhanced ultrasonography with perflubutane microbubbles and positron emission tomography-computed tomography.

    PubMed

    Ishikawa, Isao; Morita, Kyoko; Hayama, Satoshi; Nakazawa, Tetsuya; Araki, Ichiro; Higashi, Kotaro; Miyazawa, Katsuhito; Suzuki, Koji; Nojima, Takayuki

    2011-02-01

    The preoperative assessment of renal cell carcinoma (RCC) complicated with acquired renal cystic disease in a 63-year-old male patient on long-term hemodialysis (30 years and 8 months) that was difficult because of no or poor contrast enhancement by dynamic CT scan is reported. Contrast-enhanced ultrasonography with perflubutane microbubbles and positron emission tomography-computed tomography (PET-CT) with 18F-fluorodeoxy glucose (FDG) in addition to dynamic CT were effective and useful for preoperative assessment of this patient. The pathological subtype of RCC in this patient was acquired cystic disease-associated RCC (ACD-associated RCC), which has been newly defined by Tickoo et al. (Am J Surg Pathol 30:141-153, 2006). PMID:20824295

  7. Overexpression of CD44 accompanies acquired tamoxifen resistance in MCF7 cells and augments their sensitivity to the stromal factors, heregulin and hyaluronan

    PubMed Central

    2012-01-01

    Background Acquired resistance to endocrine therapy in breast cancer is a significant problem with relapse being associated with local and/or regional recurrence and frequent distant metastases. Breast cancer cell models reveal that endocrine resistance is accompanied by a gain in aggressive behaviour driven in part through altered growth factor receptor signalling, particularly involving erbB family receptors. Recently we identified that CD44, a transmembrane cell adhesion receptor known to interact with growth factor receptors, is upregulated in tamoxifen-resistant (TamR) MCF7 breast cancer cells. The purpose of this study was to explore the consequences of CD44 upregulation in an MCF7 cell model of acquired tamoxifen resistance, specifically with respect to the hypothesis that CD44 may influence erbB activity to promote an adverse phenotype. Methods CD44 expression in MCF7 and TamR cells was assessed by RT-PCR, Western blotting and immunocytochemistry. Immunofluorescence and immunoprecipitation studies revealed CD44-erbB associations. TamR cells (± siRNA-mediated CD44 suppression) or MCF7 cells (± transfection with the CD44 gene) were treated with the CD44 ligand, hyaluronon (HA), or heregulin and their in vitro growth (MTT), migration (Boyden chamber and wound healing) and invasion (Matrigel transwell migration) determined. erbB signalling was assessed using Western blotting. The effect of HA on erbB family dimerisation in TamR cells was determined by immunoprecipitation in the presence or absence of CD44 siRNA. Results TamR cells overexpressed CD44 where it was seen to associate with erbB2 at the cell surface. siRNA-mediated suppression of CD44 in TamR cells significantly attenuated their response to heregulin, inhibiting heregulin-induced cell migration and invasion. Furthermore, TamR cells exhibited enhanced sensitivity to HA, with HA treatment resulting in modulation of erbB dimerisation, ligand-independent activation of erbB2 and EGFR and induction

  8. Molecularly targeted radiosensitization chances towards gene aberration-due organ confined/regionally advanced prostate cancer radioresistance

    PubMed Central

    ALBERTI, C.

    2015-01-01

    Considering that the prostate cancer radioresistance occurs in a significant percentage – as 20–40% of prostate cancer (PCa) patients undergone external beam radiation therapy developing, within ten years, recurrent and more aggressive tumor – the resort to customized radiosensitizer measures, focusly targeting PCa radioresistance-linked individual molecular aberrations, can increase the successful outcomes of PCa radiotherapy. PMID:26188759

  9. MC32 tumor cells acquire Ag-specific CTL resistance through the loss of CEA in a colon cancer model

    PubMed Central

    Lee, Sang-Yeul; Sin, Jeong-Im

    2015-01-01

    We previously reported that MC32 cells resist carcinoembryonic antigen (CEA) DNA vaccination by losing their antigen presentation to Ag-specific CTLs in the context of MHC class I antigens in a colon cancer therapeutic model. In this study, we selected 2 tumor cells, MC32-S2–2 and MC32-S4–2, which have the ability to form tumors in CEA DNA vaccine-immunized mice. Wild type MC32 cells grew significantly less in CEA-immunized mice (with Ag-specific CTL lytic activity) than in control mice (with no Ag-specific CTL lytic activity). However, MC32-S2–2 and MC32-S4–2 cells grew at a similar rate in both control and CEA-immunized mice, confirming their resistant status against CEA DNA vaccination. MC32-S2–2 and MC32-S4–2 cells were not susceptible to lysis by CEA-specific CD8+ T cells. Moreover, when MC32-S2–2 and MC32-S4–2 cells were used as stimulating agents of CEA-specific immune cells for IFN-γ production, these cells failed to stimulate the induction of Ag-specific IFN-γ, suggesting a loss of tumor cell recognition by Ag-specific immune cells. However, MC32-S2–2 and MC32-S4–2 cells expressed MHC class I antigens in a manner similar to that of wild type MC32 cells. Finally, Western blot assay confirmed that in MC32-S2–2 and MC32-S4–2 cells, CEA expression remained absent but mouse CEA was expressed. Taken together, these data show that MC32 cells may also be able to achieve resistance to CEA-specific CTLs by antigen loss in this model. PMID:25902414

  10. EGFR-Mediated Reactivation of MAPK Signaling Induces Acquired Resistance to GSK2118436 in BRAF V600E-Mutant NSCLC Cell Lines.

    PubMed

    Kim, Sung-Moo; Kim, Hwan; Jang, Kang Won; Kim, Min Hwan; Sohn, Jinyoung; Yun, Mi Ran; Kang, Han Na; Kang, Chan Woo; Kim, Hye Ryun; Lim, Sun Min; Moon, Yong Wha; Kim, Joo Hang; Paik, Soonmyung; Cho, Byoung Chul

    2016-07-01

    Although treatment of BRAF V600E-mutant non-small cell lung cancer (NSCLC(V600E)) with GSK2118436 has shown an encouraging efficacy, most patients develop resistance. To investigate the mechanisms of acquired resistance to GSK2118436 in NSCLC(V600E), we established GSK2118436-resistant (GSR) cells by exposing MV522 NSCLC(V600E) to increasing GSK2118436 concentrations. GSR cells displayed activated EGFR-RAS-CRAF signaling with upregulated EGFR ligands and sustained activation of ERK1/2, but not MEK1/2, in the presence of GSK2118436. Treatment of GSR cells with GSK2118436 enhanced EGFR-mediated RAS activity, leading to the formation of BRAF-CRAF dimers and transactivation of CRAF. Interestingly, sustained activation of ERK1/2 was partly dependent on receptor-interacting protein kinase-2 (RIP2) activity, but not on MEK1/2 activity. Combined BRAF and EGFR inhibition blocked reactivation of ERK signaling and improved efficacy in vitro and in vivo Our findings support the evaluation of combined BRAF and EGFR inhibition in NSCLC(V600E) with acquired resistance to BRAF inhibitors. Mol Cancer Ther; 15(7); 1627-36. ©2016 AACR. PMID:27196768

  11. Identification of a homozygous JAK3 V674A mutation caused by acquired uniparental disomy in a relapsed early T-cell precursor ALL patient.

    PubMed

    Kawashima-Goto, Sachiko; Imamura, Toshihiko; Seki, Masafumi; Kato, Motohiro; Yoshida, Kenichi; Sugimoto, Atsuya; Kaneda, Daisuke; Fujiki, Atsushi; Miyachi, Mitsuru; Nakatani, Takuya; Osone, Shinya; Ishida, Hiroyuki; Taki, Tomohiko; Takita, Junko; Shiraishi, Yuichi; Chiba, Kenichi; Tanaka, Hiroko; Miyano, Satoru; Ogawa, Seishi; Hosoi, Hajime

    2015-04-01

    Investigation of genetic alterations associated with relapse in acute lymphoblastic leukemia (ALL) may help to identify druggable targets for specific therapies. Early T-cell precursor ALL (ETP-ALL) is a subtype of T-ALL with poor prognosis. Although the genetic landscape of ETP-ALL has been determined, genetic alterations related to the relapse of ETP-ALL have not been fully investigated. Here, we report the first patient with relapsed pediatric ETP-ALL to exhibit a homozygous JAK3 activating mutation, V674A, caused by acquired uniparental disomy (UPD). Single nucleotide polymorphism array analysis revealed acquired UPD (aUPD) at the 19p13.3-p12 locus only in leukemic cells at relapse. Sanger sequence of the JAK3 gene, which was located at 19p13.1 and frequently mutated in ETP-ALL, was performed in paired leukemic samples to determine homozygous JAK3 V674A mutation only in relapsed leukemic cells. In contrast, leukemic cells at initial diagnosis harbored hemizygous JAK3 V674A mutation. Further, whole-exome sequencing revealed mutations in 18 genes only in relapsed samples, although none of these was recurrent in T-ALL. These findings suggest that aUPD at 19p13.1 is partly associated with relapse in this patient. Pharmacological inhibition of JAK3 may be therapeutic in such cases. PMID:25430085

  12. Curcumin mediates oxaliplatin-acquired resistance reversion in colorectal cancer cell lines through modulation of CXC-Chemokine/NF-κB signalling pathway

    PubMed Central

    Ruiz de Porras, Vicenç; Bystrup, Sara; Martínez-Cardús, Anna; Pluvinet, Raquel; Sumoy, Lauro; Howells, Lynne; James, Mark I.; Iwuji, Chinenye; Manzano, José Luis; Layos, Laura; Bugés, Cristina; Abad, Albert; Martínez-Balibrea, Eva

    2016-01-01

    Resistance to oxaliplatin (OXA) is a complex process affecting the outcomes of metastatic colorectal cancer (CRC) patients treated with this drug. De-regulation of the NF-κB signalling pathway has been proposed as an important mechanism involved in this phenomenon. Here, we show that NF-κB was hyperactivated in in vitro models of OXA-acquired resistance but was attenuated by the addition of Curcumin, a non-toxic NF-κB inhibitor. The concomitant combination of Curcumin + OXA was more effective and synergistic in cell lines with acquired resistance to OXA, leading to the reversion of their resistant phenotype, through the inhibition of the NF-κB signalling cascade. Transcriptomic profiling revealed the up-regulation of three NF-κB-regulated CXC-chemokines, CXCL8, CXCL1 and CXCL2, in the resistant cells that were more efficiently down-regulated after OXA + Curcumin treatment as compared to the sensitive cells. Moreover, CXCL8 and CXCL1 gene silencing made resistant cells more sensitive to OXA through the inhibition of the Akt/NF-κB pathway. High expression of CXCL1 in FFPE samples from explant cultures of CRC patients-derived liver metastases was associated with response to OXA + Curcumin. In conclusion, we suggest that combination of OXA + Curcumin could be an effective treatment, for which CXCL1 could be used as a predictive marker, in CRC patients. PMID:27091625

  13. Low inducible expression of p21Cip1 confers resistance to paclitaxel in BRAF mutant melanoma cells with acquired resistance to BRAF inhibitor.

    PubMed

    Jang, Gun-Hee; Kim, Na-Yeon; Lee, Michael

    2015-08-01

    The therapeutic efficacy of oncogenic BRAF inhibitor is limited by the onset of acquired resistance. In this study, we investigated the potential therapeutic effects of the mitotic inhibitor paclitaxel on three melanoma cell lines with differing sensitivity to the BRAF inhibitor. Of the two BRAF inhibitor-resistant cell lines, A375P/Mdr cells harboring the BRAF V600E mutant were resistant and the wild-type BRAF SK-MEL-2 cells were sensitive to paclitaxel. In particular, paclitaxel caused the growth inhibition of SK-MEL-2 cells to a much greater extent than it caused growth inhibition of A375P cells. Paclitaxel exhibited no significant effect on the phosphorylation of MEK-ERK in any cell lines tested, regardless of both the BRAF mutation and the drug resistance, implying that paclitaxel activity is independent of MEK-ERK inhibition. In A375P cells, paclitaxel treatment resulted in a marked emergence of apoptotic cells after mitotic arrest, concomitant with a remarkable induction of p21(Cip1). However, paclitaxel only moderately increased the levels of p21(Cip1) in A375P/Mdr cells, which exhibited a strong resistance to paclitaxel. The p21(Cip1) overexpression partially conferred paclitaxel sensitivity to A375P/Mdr cells. Interestingly, we found an extremely low background expression level of p21(Cip1) in SK-MEL-2 cells lacking normal p53 function, which caused much greater G2/M arrest than that seen in A375P cells. Taken together, these results suggest that paclitaxel may be an effective anticancer agent through regulating the expression of p21(Cip1) for the treatment of BRAF mutant melanoma cells resistant to BRAF inhibitors. PMID:25912549

  14. Use of V(D)J recombination excision circles to identify T- and B-cell defects and to monitor the treatment in primary and acquired immunodeficiencies

    PubMed Central

    2013-01-01

    T-cell receptor excision circles (TRECs) and kappa-deleting recombination excision circles (KRECs) are circular DNA segments generated in T and B cells during their maturation in the thymus and bone marrow. These circularized DNA elements persist in the cells, are unable to replicate, and are diluted as a result of cell division, thus are considered markers of new lymphocyte output. The quantification of TRECs and KRECs, which can be reliably performed using singleplex or duplex real-time quantitative PCR, provides novel information in the management of T- and B-cell immunity-related diseases. In primary immunodeficiencies, when combined with flow cytometric analysis of T- and B-cell subpopulations, the measure of TRECs and KRECs has contributed to an improved characterization of the diseases, to the identification of patients’ subgroups, and to the monitoring of stem cell transplantation and enzyme replacement therapy. For the same diseases, the TREC and KREC assays, introduced in the newborn screening program, allow early disease identification and may lead to discovery of new genetic defects. TREC and KREC levels can also been used as a surrogate marker of lymphocyte output in acquired immunodeficiencies. The low number of TRECs, which has in fact been extensively documented in untreated HIV-infected subjects, has been shown to increase following antiretroviral therapy. Differently, KREC number, which is in the normal range in these patients, has been shown to decrease following long-lasting therapy. Whether changes of KREC levels have relevance in the biology and in the clinical aspects of primary and acquired immunodeficiencies remains to be firmly established. PMID:23656963

  15. Therapeutic targeting of Neu1 sialidase with oseltamivir phosphate (Tamiflu®) disables cancer cell survival in human pancreatic cancer with acquired chemoresistance

    PubMed Central

    O’Shea, Leah K; Abdulkhalek, Samar; Allison, Stephanie; Neufeld, Ronald J; Szewczuk, Myron R

    2014-01-01

    Background Resistance to drug therapy, along with high rates of metastasis, contributes to the low survival rate in patients diagnosed with pancreatic cancer. An alternate treatment for human pancreatic cancer involving targeting of Neu1 sialidase with oseltamivir phosphate (Tamiflu®) was investigated in human pancreatic cancer (PANC1) cells with acquired resistance to cisplatin and gemcitabine. Its efficacy in overcoming the intrinsic resistance of the cell to chemotherapeutics and metastasis was evaluated. Methods Microscopic imaging, immunocytochemistry, immunohistochemistry, and WST-1 cell viability assays were used to evaluate cell survival, morphologic changes, and expression levels of E-cadherin, N-cadherin, and VE-cadherin before and after treatment with oseltamivir phosphate in PANC1 cells with established resistance to cisplatin, gemcitabine, or a combination of the two agents, and in archived paraffin-embedded PANC1 tumors grown in RAGxCγ double mutant mice. Results Oseltamivir phosphate overcame the chemoresistance of PANC1 to cisplatin and gemcitabine alone or in combination in a dose-dependent manner, and disabled the cancer cell survival mechanism(s). Oseltamivir phosphate also reversed the epithelial-mesenchymal transition characteristic of the phenotypic E-cadherin to N-cadherin changes associated with resistance to drug therapy. Low-dose oseltamivir phosphate alone or in combination with gemcitabine in heterotopic xenografts of PANC1 tumors growing in RAGxCγ double mutant mice did not prevent metastatic spread to the liver and lung. Conclusion Therapeutic targeting of Neu1 sialidase with oseltamivir phosphate at the growth factor receptor level disables the intrinsic signaling platform for cancer cell survival in human pancreatic cancer with acquired chemoresistance. These findings provide evidence for oseltamivir phosphate (Tamiflu) as a potential therapeutic agent for pancreatic cancer resistant to drug therapy. PMID:24470763

  16. IL-17 induces radiation resistance of B lymphoma cells by suppressing p53 expression and thereby inhibiting irradiation-triggered apoptosis

    PubMed Central

    Li, Qingshan; Xu, Xin; Zhong, Weijie; Du, Qinghua; Yu, Bizhen; Xiong, Huabao

    2015-01-01

    p53 is a well-known tumor suppressor. However, the regulatory mechanism(s) for p53 expression in B lymphoma cells, and the possible role of p53 in the development of the radioresistance in tumor cells are largely unknown. A human B lymphoma cell line, Karpas1106 (k1106), was used as a model of radioresistance. Apoptosis of k1106 cells was determined using flow cytometry. Expression of p53 was assessed using real time RT-PCR and western blotting. The results showed that irradiation at 8 Gy induced apoptosis in up to 40% of k1106 cells. At the same time, the irradiation markedly increased IL-6 production of the k1106 cells. When k1106 cells were cocultured with regulatory T cells (Tregs) and irradiated, the rate of apoptotic k1106 cells was significantly reduced, indicating an acquired resistance to irradiation. IL-6 derived from the irradiation-treated k1106 cells induced IL-17 expression in Tregs. The IL-17+Foxp3+ T cells suppressed p53 expression in k1106 cells. Collectively, irradiated k1106 cells induce the expression of IL-17 in Tregs, which interferes with the expression of p53 protein in k1106 cells and thereby represses irradiation-triggered apoptosis in k1106 cells. PMID:25544504

  17. Genomic profiling of acquired resistance to apoptosis in cells derived from human atherosclerotic lesions: potential role of STATs, cyclinD1, BAD, and Bcl-XL.

    PubMed

    Gagarin, Dmitry; Yang, Zhaoqing; Butler, Jason; Wimmer, Monika; Du, Baoheng; Cahan, Patrick; McCaffrey, Timothy A

    2005-09-01

    Current theories suggest that atherosclerosis, plaque rupture, stroke, and restenosis after angioplasty may involve defective apoptotic mechanisms in vascular cells. Prior work has demonstrated that cells from human atherosclerotic lesions, and cells from the aorta of aged rats, exhibit functional resistance to apoptosis induced by TGF-beta and glucocorticoids. The present studies demonstrate that human lesion-derived cells (LDC) are also resistant to apoptosis induced by fas ligation compared to cells derived from the adjacent media, and that in vitro expansion of LDC causes acquired resistance to apoptosis. Microarray profiling of fas-resistant versus sensitive cells identified a set of genes including STATs, caspase 1, cyclin D1, Bcl-xL, VDAC2, and BAD. The STAT proteins have been implicated in resistance to apoptosis, potentially via their ability to modulate caspase 1 (ICE), Bcl-xL, and cyclin D1 expression. Western blot analysis of sensitive and resistant LDC clonal lines confirmed increases in cyclin D1, STAT6, Bcl-xL, and BAD, with decreased expression of caspase 1. Thus, transcript profiling has identified a potential pathway of apoptotic regulation in subsets of lesion cells. The resistant phenotype may contribute to plaque stability and excessive vascular repair, while sensitive cells may be involved in plaque rupture and infarction. The data suggests both genetic interventions and novel small-molecule inhibitors that may be effective modulators of apoptosis in atherosclerosis, angina, and in-stent restenosis. PMID:16005468

  18. Monocytes That Have Ingested Yersinia enterocolitica Serotype O:3 Acquire Enhanced Capacity To Bind to Nonstimulated Vascular Endothelial Cells via P-Selectin

    PubMed Central

    Wuorela, Maarit; Tohka, Sami; Granfors, Kaisa; Jalkanen, Sirpa

    1999-01-01

    Reactive arthritis is usually a self-limiting polyarthritis which develops after certain gastrointestinal or urogenital infections. Microbial antigens found in the inflamed joints are thought to play a key role in the development of this disease. It is not known how antigens of the pathogenic organisms migrate from the mucosal tissues into the joints. The data presented here show that mononuclear phagocytes which mediate the dissemination of several intracellular pathogens acquire an enhanced capacity to bind to nonstimulated vascular endothelial cells after phagocytosis of Yersinia enterocolitica O:3, one of the causative organisms of reactive arthritis. The increased binding to previously nonstimulated endothelial cells was mediated by P-selectin, whose translocation to the endothelial cell surface was induced by monocytes with intracellular Yersinia bacteria. These results suggest that mononuclear phagocytes may be responsible for the dissemination of bacterial antigens and the initiation of the joint inflammation in reactive arthritis. PMID:9916083

  19. Small cell lung cancer transformation and T790M mutation: complimentary roles in acquired resistance to kinase inhibitors in lung cancer

    PubMed Central

    Suda, Kenichi; Murakami, Isao; Sakai, Kazuko; Mizuuchi, Hiroshi; Shimizu, Shigeki; Sato, Katsuaki; Tomizawa, Kenji; Tomida, Shuta; Yatabe, Yasushi; Nishio, Kazuto; Mitsudomi, Tetsuya

    2015-01-01

    Lung cancers often harbour a mutation in the epidermal growth factor receptor (EGFR) gene. Because proliferation and survival of lung cancers with EGFR mutation solely depend on aberrant signalling from the mutated EGFR, these tumours often show dramatic responses to EGFR tyrosine kinase inhibitors (TKIs). However, acquiring resistance to these drugs is almost inevitable, thus a better understanding of the underlying resistance mechanisms is critical. Small cell lung cancer (SCLC) transformation is a relatively rare acquired resistance mechanism that has lately attracted considerable attention. In the present study, through an in-depth analysis of multiple EGFR-TKI refractory lesions obtained from an autopsy case, we observed a complementary relationship between SCLC transformation and EGFR T790M secondary mutation (resistance mutation). We also identified analogies and differences in genetic aberration between a TKI-refractory lesion with SCLC transformation and one with EGFR T790M mutation. In particular, target sequencing revealed a TP53 P151S mutation in all pre- and post-treatment lesions. PTEN M264I mutation was identified only in a TKI-refractory lesion with SCLC transformation, while PIK3CA and RB1 mutations were identified only in pre-treatment primary tumour samples. These results provide the groundwork for understanding acquired resistance to EGFR-TKIs via SCLC transformation. PMID:26400668

  20. Small cell lung cancer transformation and T790M mutation: complimentary roles in acquired resistance to kinase inhibitors in lung cancer.

    PubMed

    Suda, Kenichi; Murakami, Isao; Sakai, Kazuko; Mizuuchi, Hiroshi; Shimizu, Shigeki; Sato, Katsuaki; Tomizawa, Kenji; Tomida, Shuta; Yatabe, Yasushi; Nishio, Kazuto; Mitsudomi, Tetsuya

    2015-01-01

    Lung cancers often harbour a mutation in the epidermal growth factor receptor (EGFR) gene. Because proliferation and survival of lung cancers with EGFR mutation solely depend on aberrant signalling from the mutated EGFR, these tumours often show dramatic responses to EGFR tyrosine kinase inhibitors (TKIs). However, acquiring resistance to these drugs is almost inevitable, thus a better understanding of the underlying resistance mechanisms is critical. Small cell lung cancer (SCLC) transformation is a relatively rare acquired resistance mechanism that has lately attracted considerable attention. In the present study, through an in-depth analysis of multiple EGFR-TKI refractory lesions obtained from an autopsy case, we observed a complementary relationship between SCLC transformation and EGFR T790M secondary mutation (resistance mutation). We also identified analogies and differences in genetic aberration between a TKI-refractory lesion with SCLC transformation and one with EGFR T790M mutation. In particular, target sequencing revealed a TP53 P151S mutation in all pre- and post-treatment lesions. PTEN M264I mutation was identified only in a TKI-refractory lesion with SCLC transformation, while PIK3CA and RB1 mutations were identified only in pre-treatment primary tumour samples. These results provide the groundwork for understanding acquired resistance to EGFR-TKIs via SCLC transformation. PMID:26400668

  1. LPS/TLR4-mediated stromal cells acquire an invasive phenotype and are implicated in the pathogenesis of adenomyosis

    PubMed Central

    Guo, Jing; Chen, Li; Luo, Ning; Li, Caixia; Chen, Rong; Qu, Xiaoyan; Liu, Mingmin; Kang, Le; Cheng, Zhongping

    2016-01-01

    The present study tested whether the LPS/TLR4 signal pathway in endometrial stromal cells is essential for the pathogenesis of adenomyosis. We tested the expression of TLR4, MD2 in the endometrium without adenomyosis (CE), the eutopic endometrium with adenomyosis (EuE) and the ectopic endometrium with adenomyosis (EE). We isolated the stromal cells from CE, EuE and EE (CESC, EuESC, EESC), treated with lipopolysaccharide (LPS) and TLR4 antagonist and detected the cell viability. And we also measured the key protein of the TLR4 signal pathway and inflammatory proliferation and invasive growth of experimental cells. We found that the viability of experimental cells treated with LPS was significantly greater than that of the non-treated cells, blocked by the TLR4 antagonist VIPER. TLR4 signal pathway and inflammatory proliferation and invasive growth of experimental cells stimulated by LPS, and it was inhibited by VIPER. This study suggested that stromal cells were activated by the TLR4 signalling pathway, which processed the cellular inflammatory proliferation and invasive growth involved in the pathogenesis of adenomyosis. PMID:26898650

  2. LPS/TLR4-mediated stromal cells acquire an invasive phenotype and are implicated in the pathogenesis of adenomyosis.

    PubMed

    Guo, Jing; Chen, Li; Luo, Ning; Li, Caixia; Chen, Rong; Qu, Xiaoyan; Liu, Mingmin; Kang, Le; Cheng, Zhongping

    2016-01-01

    The present study tested whether the LPS/TLR4 signal pathway in endometrial stromal cells is essential for the pathogenesis of adenomyosis. We tested the expression of TLR4, MD2 in the endometrium without adenomyosis (CE), the eutopic endometrium with adenomyosis (EuE) and the ectopic endometrium with adenomyosis (EE). We isolated the stromal cells from CE, EuE and EE (CESC, EuESC, EESC), treated with lipopolysaccharide (LPS) and TLR4 antagonist and detected the cell viability. And we also measured the key protein of the TLR4 signal pathway and inflammatory proliferation and invasive growth of experimental cells. We found that the viability of experimental cells treated with LPS was significantly greater than that of the non-treated cells, blocked by the TLR4 antagonist VIPER. TLR4 signal pathway and inflammatory proliferation and invasive growth of experimental cells stimulated by LPS, and it was inhibited by VIPER. This study suggested that stromal cells were activated by the TLR4 signalling pathway, which processed the cellular inflammatory proliferation and invasive growth involved in the pathogenesis of adenomyosis. PMID:26898650

  3. Reciprocal positive regulation between Cx26 and PI3K/Akt pathway confers acquired gefitinib resistance in NSCLC cells via GJIC-independent induction of EMT

    PubMed Central

    Yang, J; Qin, G; Luo, M; Chen, J; Zhang, Q; Li, L; Pan, L; Qin, S

    2015-01-01

    Gefitinib efficiency in non-small-cell lung cancer (NSCLC) therapy is limited due to development of drug resistance. The molecular mechanisms of gefitinib resistance remain still unclear. In this study, we first found that connexin 26 (Cx26) is the predominant Cx isoform expressed in various NSCLC cell lines. Then, two gefitinib-resistant (GR) NSCLC cell lines, HCC827 GR and PC9 GR, from their parental cells were established. In these GR cells, the results showed that gefitinib resistance correlated with changes in cellular EMT phenotypes and upregulation of Cx26. Cx26 was detected to be accumulated in the cytoplasm and failed to establish functional gap-junctional intercellular communication (GJIC) either in GR cells or their parental cells. Ectopic expression of GJIC-deficient chimeric Cx26 was sufficient to induce EMT and gefitinib insensitivity in HCC827 and PC9 cells, while knockdown of Cx26 reversed EMT and gefitinib resistance in their GR cells both in vitro and in vivo. Furthermore, Cx26 overexpression could activate PI3K/Akt signaling in these cells. Cx26-mediated EMT and gefitinib resistance were significantly blocked by inhibition of PI3K/Akt pathway. Specifically, inhibition of the constitutive activation of PI3K/Akt pathway substantially suppressed Cx26 expression, and Cx26 was confirmed to functionally interplay with PI3K/Akt signaling to promote EMT and gefitinib resistance in NSCLC cells. In conclusion, the reciprocal positive regulation between Cx26 and PI3K/Akt signaling contributes to acquired gefitinib resistance in NSCLC cells by promoting EMT via a GJIC-independent manner. PMID:26203858

  4. Mesenchymal stromal cells from bone marrow treated with bovine tendon extract acquire the phenotype of mature tenocytes☆

    PubMed Central

    Augusto, Lívia Maria Mendonça; Aguiar, Diego Pinheiro; Bonfim, Danielle Cabral; dos Santos Cavalcanti, Amanda; Casado, Priscila Ladeira; Duarte, Maria Eugênia Leite

    2016-01-01

    Objective This study evaluated in vitro differentiation of mesenchymal stromal cells isolated from bone marrow, in tenocytes after treatment with bovine tendon extract. Methods Bovine tendons were used for preparation of the extract and were stored at −80 °C. Mesenchymal stromal cells from the bone marrow of three donors were used for cytotoxicity tests by means of MTT and cell differentiation by means of qPCR. Results The data showed that mesenchymal stromal cells from bone marrow treated for up to 21 days in the presence of bovine tendon extract diluted at diminishing concentrations (1:10, 1:50 and 1:250) promoted activation of biglycan, collagen type I and fibromodulin expression. Conclusion Our results show that bovine tendon extract is capable of promoting differentiation of bone marrow stromal cells in tenocytes. PMID:26962503

  5. Increased CD271 expression by the NF-kB pathway promotes melanoma cell survival and drives acquired resistance to BRAF inhibitor vemurafenib

    PubMed Central

    Lehraiki, Abdelali; Cerezo, Michael; Rouaud, Florian; Abbe, Patricia; Allegra, Marilyne; Kluza, Jerome; Marchetti, Philippe; Imbert, Veronique; Cheli, Yann; Bertolotto, Corine; Ballotti, Robert; Rocchi, Stéphane

    2015-01-01

    Specific BRAFV600E inhibitors (BRAFi) are highly effective in the treatment of melanoma. However, acquired drug resistances invariably develop after the initial response. Therefore, the identification of new mechanisms of acquired resistance gives important clues towards the development of therapies that could elicit long lasting responses. Here we report that CD271 confers resistance to BRAFi in melanoma cells. The expression of CD271 is increased by BRAFi through a stimulation of tumor necrosis factor-alpha (TNFα) secretion that leads to NF-κB signaling pathway activation. CD271 is upregulated in a subset of BRAFi-resistant melanoma cells. The inhibition of TNFα/NF-κB pathway and CD271 silencing restore the BRAFi sensitivity of resistant melanoma cells. Finally, increase of CD271 expression is validated in BRAFi-resistant xenografts tumors and also in tumors from the patients who relapsed under BRAFi. In summary, these results reveal a novel TNFα/NF-κB/CD271 axis whose activation contributes to the acquisition of resistance to BRAFi and therefore may represent a novel therapeutic target to improve the efficacy of therapy in melanoma.

  6. Exome Sequencing in Classic Hairy Cell Leukaemia Reveals Widespread Variation in Acquired Somatic Mutations between Individual Tumours Apart from the Signature BRAF V(600)E Lesion

    PubMed Central

    Weston-Bell, Nicola J.; Tapper, Will; Gibson, Jane; Bryant, Dean; Moreno, Yurany; John, Melford; Ennis, Sarah; Kluin-Nelemans, Hanneke C.; Collins, Andrew R.; Sahota, Surinder S.

    2016-01-01

    In classic Hairy cell leukaemia (HCLc), a single case has thus far been interrogated by whole exome sequencing (WES) in a treatment naive patient, in which BRAF V(600)E was identified as an acquired somatic mutation and confirmed as occurring near-universally in this form of disease by conventional PCR-based cohort screens. It left open however the question whether other genome-wide mutations may also commonly occur at high frequency in presentation HCLc disease. To address this, we have carried out WES of 5 such typical HCLc cases, using highly purified splenic tumour cells paired with autologous T cells for germline. Apart from BRAF V(600)E, no other recurrent somatic mutation was identified in these HCLc exomes, thereby excluding additional acquired mutations as also prevalent at a near-universal frequency in this form of the disease. These data then place mutant BRAF at the centre of the neoplastic drive in HCLc. A comparison of our exome data with emerging genetic findings in HCL indicates that additional somatic mutations may however occur recurrently in smaller subsets of disease. As mutant BRAF alone is insufficient to drive malignant transformation in other histological cancers, it suggests that individual tumours utilise largely differing patterns of genetic somatic mutations to coalesce with BRAF V(600)E to drive pathogenesis of malignant HCLc disease. PMID:26871591

  7. Hypermorphic mutation of phospholipase C, γ2 acquired in ibrutinib-resistant CLL confers BTK independency upon B-cell receptor activation

    PubMed Central

    Liu, Ta-Ming; Woyach, Jennifer A.; Zhong, Yiming; Lozanski, Arletta; Lozanski, Gerard; Dong, Shuai; Strattan, Ethan; Lehman, Amy; Zhang, Xiaoli; Jones, Jeffrey A.; Flynn, Joseph; Andritsos, Leslie A.; Maddocks, Kami; Jaglowski, Samantha M.; Blum, Kristie A.; Byrd, John C.; Dubovsky, Jason A.

    2015-01-01

    Ibrutinib has significantly improved the outcome of patients with relapsed chronic lymphocytic leukemia (CLL). Recent reports attribute ibrutinib resistance to acquired mutations in Bruton agammaglobulinemia tyrosine kinase (BTK), the target of ibrutinib, as well as the immediate downstream effector phospholipase C, γ2 (PLCG2). Although the C481S mutation found in BTK has been shown to disable ibrutinib’s capacity to irreversibly bind this primary target, the detailed mechanisms of mutations in PLCG2 have yet to be established. Herein, we characterize the enhanced signaling competence, BTK independence, and surface immunoglobulin dependence of the PLCG2 mutation at R665W, which has been documented in ibrutinib-resistant CLL. Our data demonstrate that this missense alteration elicits BTK-independent activation after B-cell receptor engagement, implying the formation of a novel BTK-bypass pathway. Consistent with previous results, PLCG2R665W confers hypermorphic induction of downstream signaling events. Our studies reveal that proximal kinases SYK and LYN are critical for the activation of mutant PLCG2 and that therapeutics targeting SYK and LYN can combat molecular resistance in cell line models and primary CLL cells from ibrutinib-resistant patients. Altogether, our results engender a molecular understanding of the identified aberration at PLCG2 and explore its functional dependency on BTK, SYK, and LYN, suggesting alternative strategies to combat acquired ibrutinib resistance. PMID:25972157

  8. ROBO1, a tumor suppressor and critical molecular barrier for localized tumor cells to acquire invasive phenotype: Study in African-American and Caucasian prostate cancer models

    PubMed Central

    Parray, Aijaz; Siddique, Hifzur R.; Kuriger, Jacquelyn K.; Mishra, Shrawan K.; Rhim, Johng S.; Nelson, Heather H.; Aburatani, Hiroyuki; Konety, Badrinath R.; Koochekpour, Shahriar; Saleem, Mohammad

    2015-01-01

    High-risk populations exhibit early transformation of localized prostate cancer (CaP) disease to metastasis which results in the mortality of such patients. The paucity of knowledge about the molecular mechanism involved in acquiring of metastatic behavior by primary tumor cells and non-availability of reliable phenotype-discriminating biomarkers are stumbling blocks in the management of CaP disease. Here, we determine the role and translational relevance of ROBO1 (an organogenesis-associated gene) in human CaP. Employing CaP-progression models and prostatic tissues of Caucasian and African-American patients, we show that ROBO1 expression is localized to cell-membrane and significantly lost in primary and metastatic tumors. While Caucasians exhibited similar ROBO1 levels in primary and metastatic phenotype, a significant difference was observed between tumor phenotypes in African-Americans. Epigenetic assays identified promoter methylation of ROBO1 specific to African-American metastatic CaP cells. Using African-American CaP models for further studies, we show that ROBO1 negatively regulates motility and invasiveness of primary CaP cells, and its loss causes these cells to acquire invasive trait. To understand the underlying mechanism, we employed ROBO1-expressing/ROBO1-C2C3-mutant constructs, immunoprecipitation, confocal-microscopy and luciferase-reporter techniques. We show that ROBO1 through its interaction with DOCK1 (at SH3-SH2-domain) controls the Rac-activation. However, loss of ROBO1 results in Rac1-activation which in turn causes E-Cadherin/β-catenin cytoskeleton destabilization and induction of cell migration. We suggest that ROBO1 is a predictive biomarker that has potential to discriminate among CaP types, and could be exploited as a molecular target to inhibit the progression of disease as well as treat metastasis in high-risk populations such as African-Americans. PMID:24752651

  9. Clinical approaches to treat patients with non-small cell lung cancer and epidermal growth factor receptor tyrosine kinase inhibitor acquired resistance.

    PubMed

    Tartarone, Alfredo; Lerose, Rosa

    2015-10-01

    The discovery of epidermal growth factor receptor activating mutations (EGFR Mut+) has determined a paradigm shift in the treatment of non-small cell lung cancer (NSCLC). In several phase III studies, patients with NSCLC EGFR Mut+ achieved a significantly better progression-free survival when treated with a first- (gefitinib, erlotinib) or second-generation (afatinib) EGFR tyrosine kinase inhibitor (TKI) compared with standard chemotherapy. However, despite these impressive results, most patients with NSCLC EGFR Mut+ develop acquired resistance to TKIs. This review will discuss both the mechanisms of resistance to TKIs and the therapeutic strategies to overcome resistance, including emerging data on third-generation TKIs. PMID:26016841

  10. Prenatal cadmium exposure produces persistent changes to thymus and spleen cell phenotypic repertoire as well as the acquired immune response

    SciTech Connect

    Holásková, Ida; Elliott, Meenal; Hanson, Miranda L.; Schafer, Rosana; Barnett, John B.

    2012-12-01

    Cadmium (Cd) is a common environmental contaminant. Adult exposure to Cd alters the immune system, however, there are limited studies on the effects of prenatal exposure to Cd. Pregnant C57Bl/6 mice were exposed to an environmentally relevant dose of CdCl{sub 2} (10 ppm) and the effects on the immune system of the offspring were assessed at 20 weeks of age. Prenatal Cd exposure caused an increase in the percent of CD4{sup −}CD8{sup −}CD44{sup +}CD25{sup −} (DN1) thymocytes in both sexes and a decrease in the percent of CD4{sup −}CD8{sup −}CD44{sup −}CD25{sup +} (DN3) thymocytes in females. Females had an increase in the percent of splenic CD4{sup +} T cells, CD8{sup +} T cells, and CD45R/B220{sup +} B cells and a decrease in the percent of NK cells and granulocytes (Gr-1{sup +}). Males had an increase in the percent of splenic CD4{sup +} T cells and CD45R/B220{sup +} B cells and a decrease in the percent of CD8{sup +} T cells, NK cells, and granulocytes. The percentage of neutrophils and myeloid-derived suppressor cells were reduced in both sexes. The percent of splenic nTreg cells was decreased in all Cd-exposed offspring. Cd-exposed offspring were immunized with a streptococcal vaccine and the antibody response was determined. PC-specific serum antibody titers were decreased in Cd exposed female offspring but increased in the males. PspA-specific serum IgG titers were increased in both females and males compared to control animals. Females had a decrease in PspA-specific serum IgM antibody titers. Females and males had a decrease in the number of splenic anti-PspA antibody-secreting cells when standardized to the number of B cells. These findings demonstrate that very low levels of Cd exposure during gestation can result in long term sex-specific alterations on the immune system of the offspring. -- Highlights: ► Prenatal exposure to cadmium alters the immune system of 20 week old offspring. ► The percentage of DN1 and DN3 thymocytes was changed

  11. Cytokeratin-19 positivity is acquired along cancer progression and does not predict cell origin in rat hepatocarcinogenesis

    PubMed Central

    Kowalik, Marta Anna; Sulas, Pia; Ledda-Columbano, Giovanna Maria; Giordano, Silvia; Columbano, Amedeo; Perra, Andrea

    2015-01-01

    Although the expression of the stem/progenitor cell marker cytokeratin-19 (CK-19) has been associated with the worst clinical prognosis among all HCC subclasses, it is yet unknown whether its presence in HCC is the result of clonal expansion of hepatic progenitor cells (HPCs) or of de-differentiation of mature hepatocytes towards a progenitor-like cell phenotype. We addressed this question by using two rat models of hepatocarcinogenesis: the Resistant-Hepatocyte (R-H) and the Choline-methionine deficient (CMD) models. Our data indicate that the expression of CK-19 is not the result of a clonal expansion of HPCs (oval cells in rodents), but rather of a further step of preneoplastic hepatocytes towards a less differentiated phenotype and a more aggressive behavior. Indeed, although HCCs were positive for CK-19, very early preneoplastic foci (EPFs) were completely negative for this marker. While a few weeks later the vast majority of preneoplastic nodules remained CK-19 negative, a minority became positive, suggesting that CK-19 expression is the result of de-differentiation of a subset of EPFs, rather than a marker of stem/progenitor cells. Moreover, the gene expression profile of CK-19-negative EPFs clustered together with CK-19-positive nodules, but was clearly distinct from CK-19 negative nodules and oval cells. Conclusion i) CK-19-positive cells are not involved in the early clonal expansion observed in rat hepatocarcinogenesis; ii) CK-19 expression arises in preneoplastic hepatocyte lesions undergoing malignant transformation; iii) CK-19 positivity in HCCs does not necessarily reflect the cell of origin of the tumor, but rather the plasticity of preneoplastic cells during the tumorigenic process. PMID:26452031

  12. CD10-Equipped Melanoma Cells Acquire Highly Potent Tumorigenic Activity: A Plausible Explanation of Their Significance for a Poor Prognosis

    PubMed Central

    Hashimoto-Hachiya, Akiko; Liu, Min; Abe, Takeru; Hagihara, Akihito; Yokomizo, Takehiko; Furue, Masutaka

    2016-01-01

    CD10 has been widely used in cancer diagnosis. We previously demonstrated that its expression in melanoma increased with tumor progression and predicted poor patient survival. However, the mechanism by which CD10 promotes melanoma progression remains unclear. In order to elucidate the role of CD10 in melanoma, we established CD10-overexpressing A375 melanoma cells and performed DNA microarray and qRT–PCR analyses to identify changes in the gene expression profile. The microarray analysis revealed that up-regulated genes in CD10-A375 were mostly involved in cell proliferation, angiogenesis, and resistance to apoptosis; down-regulated genes mostly belonged to the categories associated with cell adhesion and migration. Accordingly, in functional experiments, CD10-A375 showed significantly greater cell proliferation in vitro and higher tumorigenicity in vivo; CD10 enzymatic inhibitors, thiorphan and phosphoramidon, significantly blocked the tumor growth of CD10-A375 in mice. In migration and invasion assays, CD10-A375 displayed lower migratory and invasive capacity than mock-A375. CD10 augmented melanoma cell resistance to apoptosis mediated by etoposide and gemcitabine. These findings indicate that CD10 may promote tumor progression by regulating the expression profiles of genes related to cell proliferation, angiogenesis, and resistance to apoptosis. PMID:26881775

  13. Helicobacter pylori-infected MSCs acquire a pro-inflammatory phenotype and induce human gastric cancer migration by promoting EMT in gastric cancer cells

    PubMed Central

    ZHANG, QIANG; DING, JUAN; LIU, JINJUN; WANG, WEI; ZHANG, FENG; WANG, JUNHE; LI, YUYUN

    2016-01-01

    Accumulating clinical and experimental evidence has suggested that Helicobacter pylori (H. pylori) infection-associated gastric cancer (GC) is associated with high rates of mortality and serious health effects. The majority of patients succumb to H. pylori infection-associated GC due to metastasis. Mesenchymal stem cells (MSCs), which have multipotent differentiation potential, may be recruited into the tumor-associated stroma. MSCs are crucial components of the H. pylori infection-associated GC microenvironment, and may be critical for GC cell migration. In this study, an MSCs/H. pylori co-culture model was designed, and the effect of H. pylori-infected MSCs on the migration of GC cells was evaluated using a Transwell migration assay. H. pylori-infected MSC cytokine expression was evaluated using Luminex/ELISA. The expression of epithelial-mesenchymal transition (EMT) markers in the GC cells treated with supernatants from H. pylori-infected MSCs were detected by western blot analysis. The results demonstrated that the interaction between MSCs and H. pylori may induce GC cell migration, through secretion of a combination of cytokines that promote EMT in GC cells. The expression of phosphorylated forms of nuclear factor-κB (NF-κB) was observed to be increased in MSCs by H. pylori. Inhibition of NF-κB activation by pyrrolidine dithiocarbamate blocked the effects of H. pylori-infected MSCs on SGC-7901 human stomach adenocarcinoma cell migration. Overall, the results of the present study suggest that H. pylori-infected MSCs acquire a pro-inflammatory phenotype through secretion of a combination of multiple cytokines, a number of which are NF-κB-dependent. These cytokines enhance H. pylori infection-associated GC cell migration by promoting EMT in GC cells. The results of the present study provide novel evidence for the modulatory effect of MSCs in the tumor microenvironment and provide insight into the significance of stromal cell involvement in GC progression

  14. Acquired resistance to EGFR tyrosine kinase inhibitors alters the metabolism of human head and neck squamous carcinoma cells and xenograft tumours

    PubMed Central

    Beloueche-Babari, M; Box, C; Arunan, V; Parkes, H G; Valenti, M; De Haven Brandon, A; Jackson, L E; Eccles, S A; Leach, M O

    2015-01-01

    Background: Acquired resistance to molecularly targeted therapeutics is a key challenge in personalised cancer medicine, highlighting the need for identifying the underlying mechanisms and early biomarkers of relapse, in order to guide subsequent patient management. Methods: Here we use human head and neck squamous cell carcinoma (HNSCC) models and nuclear magnetic resonance (NMR) spectroscopy to assess the metabolic changes that follow acquired resistance to EGFR tyrosine kinase inhibitors (TKIs), and which could serve as potential metabolic biomarkers of drug resistance. Results: Comparison of NMR metabolite profiles obtained from control (CALS) and EGFR TKI-resistant (CALR) cells grown as 2D monolayers, 3D spheroids or xenograft tumours in athymic mice revealed a number of differences between the sensitive and drug-resistant models. In particular, we observed elevated levels of glycerophosphocholine (GPC) in CALR relative to CALS monolayers, spheroids and tumours, independent of the growth rate or environment. In addition, there was an increase in alanine, aspartate and creatine+phosphocreatine in resistant spheroids and xenografts, and increased levels of lactate, branched-chain amino acids and a fall in phosphoethanolamine only in xenografts. The xenograft lactate build-up was associated with an increased expression of the glucose transporter GLUT-1, whereas the rise in GPC was attributed to inhibition of GPC phosphodiesterase. Reduced glycerophosphocholine (GPC) and phosphocholine were observed in a second HNSCC model probably indicative of a different drug resistance mechanism. Conclusions: Our studies reveal metabolic signatures associated not only with acquired EGFR TKI resistance but also growth pattern, microenvironment and contributing mechanisms in HNSCC models. These findings warrant further investigation as metabolic biomarkers of disease relapse in the clinic. PMID:25742484

  15. Anhydrobiosis-Associated Nuclear DNA Damage and Repair in the Sleeping Chironomid: Linkage with Radioresistance

    PubMed Central

    Vanyagina, Veronica; Malutina, Ludmila; Cornette, Richard; Sakashita, Tetsuya; Hamada, Nobuyuki; Kikawada, Takahiro; Kobayashi, Yasuhiko; Okuda, Takashi

    2010-01-01

    Anhydrobiotic chironomid larvae can withstand prolonged complete desiccation as well as other external stresses including ionizing radiation. To understand the cross-tolerance mechanism, we have analyzed the structural changes in the nuclear DNA using transmission electron microscopy and DNA comet assays in relation to anhydrobiosis and radiation. We found that dehydration causes alterations in chromatin structure and a severe fragmentation of nuclear DNA in the cells of the larvae despite successful anhydrobiosis. Furthermore, while the larvae had restored physiological activity within an hour following rehydration, nuclear DNA restoration typically took 72 to 96 h. The DNA fragmentation level and the recovery of DNA integrity in the rehydrated larvae after anhydrobiosis were similar to those of hydrated larvae irradiated with 70 Gy of high-linear energy transfer (LET) ions (4He). In contrast, low-LET radiation (gamma-rays) of the same dose caused less initial damage to the larvae, and DNA was completely repaired within within 24 h. The expression of genes encoding the DNA repair enzymes occurred upon entering anhydrobiosis and exposure to high- and low-LET radiations, indicative of DNA damage that includes double-strand breaks and their subsequent repair. The expression of antioxidant enzymes-coding genes was also elevated in the anhydrobiotic and the gamma-ray-irradiated larvae that probably functions to reduce the negative effect of reactive oxygen species upon exposure to these stresses. Indeed the mature antioxidant proteins accumulated in the dry larvae and the total activity of antioxidants increased by a 3–4 fold in association with anhydrobiosis. We conclude that one of the factors explaining the relationship between radioresistance and the ability to undergo anhydrobiosis in the sleeping chironomid could be an adaptation to desiccation-inflicted nuclear DNA damage. There were also similarities in the molecular response of the larvae to damage caused by

  16. Therapeutic Efficacy of Astatine-211-Labeled Trastuzumab on Radioresistant SKOV-3 Tumors in Nude Mice

    SciTech Connect

    Palm, Stig Baeck, Tom; Claesson, Ingela; Danielsson, Anna; Elgqvist, Joergen; Frost, Sofia; Hultborn, Ragnar; Jensen, Holger; Lindegren, Sture; Jacobsson, Lars

    2007-10-01

    Purpose: To investigate the potential use of astatine-211 ({sup 211}At)-labeled trastuzumab for the treatment of HER-2-positive, radioresistant ovarian carcinoma. Methods and Materials: Four-week-old nude mice were inoculated intraperitoneally with 5 . 10{sup 6} SKOV-3 cells in 0.4 mL saline on Day 0. The endpoint was the total tumor weight in each mouse on Day 63. Three experiments were performed in which the response to single-dose and fractionated treatment with unlabeled and {sup 211}At-labeled antibody was evaluated. Results: Experiment 1 showed, for the same total amount of trastuzumab, a dose-response relationship between {sup 211}At activity (0-400 kBq on Day 7) and therapeutic efficacy (p = 0.001). The effect of varying the amount of unlabeled trastuzumab was studied in Experiment 2. All mice, except for the controls, received 400 kBq {sup 211}At-trastuzumab, and different groups received 5, 50, or 500 {mu}g trastuzumab on Day 7. The increase from 5 to 50 {mu}g trastuzumab reduced the tumors by 78% in weight. No tumors were present in mice given 500 {mu}g trastuzumab. In Experiment 3, the effect of a fractionated treatment regimen was studied. Mice that received 100 kBq {sup 211}At-trastuzumab on Days 7 and 8 had a 42% smaller tumor burden than did controls. Groups of mice injected with 200 + 100 kBq on Days 7 and 21 and mice injected with 100 kBq on Days 7, 8, and 21 both had 24% less tumor weight than the corresponding controls. Conclusion: The combination of 500 {mu}g trastuzumab and 400 kBq {sup 211}At-trastuzumab had the greatest effect, with complete eradication of the tumors in this nude mouse model.

  17. Anhydrobiosis-associated nuclear DNA damage and repair in the sleeping chironomid: linkage with radioresistance.

    PubMed

    Gusev, Oleg; Nakahara, Yuichi; Vanyagina, Veronica; Malutina, Ludmila; Cornette, Richard; Sakashita, Tetsuya; Hamada, Nobuyuki; Kikawada, Takahiro; Kobayashi, Yasuhiko; Okuda, Takashi

    2010-01-01

    Anhydrobiotic chironomid larvae can withstand prolonged complete desiccation as well as other external stresses including ionizing radiation. To understand the cross-tolerance mechanism, we have analyzed the structural changes in the nuclear DNA using transmission electron microscopy and DNA comet assays in relation to anhydrobiosis and radiation. We found that dehydration causes alterations in chromatin structure and a severe fragmentation of nuclear DNA in the cells of the larvae despite successful anhydrobiosis. Furthermore, while the larvae had restored physiological activity within an hour following rehydration, nuclear DNA restoration typically took 72 to 96 h. The DNA fragmentation level and the recovery of DNA integrity in the rehydrated larvae after anhydrobiosis were similar to those of hydrated larvae irradiated with 70 Gy of high-linear energy transfer (LET) ions ((4)He). In contrast, low-LET radiation (gamma-rays) of the same dose caused less initial damage to the larvae, and DNA was completely repaired within within 24 h. The expression of genes encoding the DNA repair enzymes occurred upon entering anhydrobiosis and exposure to high- and low-LET radiations, indicative of DNA damage that includes double-strand breaks and their subsequent repair. The expression of antioxidant enzymes-coding genes was also elevated in the anhydrobiotic and the gamma-ray-irradiated larvae that probably functions to reduce the negative effect of reactive oxygen species upon exposure to these stresses. Indeed the mature antioxidant proteins accumulated in the dry larvae and the total activity of antioxidants increased by a 3-4 fold in association with anhydrobiosis. We conclude that one of the factors explaining the relationship between radioresistance and the ability to undergo anhydrobiosis in the sleeping chironomid could be an adaptation to desiccation-inflicted nuclear DNA damage. There were also similarities in the molecular response of the larvae to damage caused by

  18. Acquired Tumor Cell Radiation Resistance at the Treatment Site Is Mediated Through Radiation-Orchestrated Intercellular Communication

    SciTech Connect

    Aravindan, Natarajan; Aravindan, Sheeja; Pandian, Vijayabaskar; Khan, Faizan H.; Ramraj, Satish Kumar; Natt, Praveen; Natarajan, Mohan

    2014-03-01

    Purpose: Radiation resistance induced in cancer cells that survive after radiation therapy (RT) could be associated with increased radiation protection, limiting the therapeutic benefit of radiation. Herein we investigated the sequential mechanistic molecular orchestration involved in radiation-induced radiation protection in tumor cells. Results: Radiation, both in the low-dose irradiation (LDIR) range (10, 50, or 100 cGy) or at a higher, challenge dose IR (CDIR), 4 Gy, induced dose-dependent and sustained NFκB-DNA binding activity. However, a robust and consistent increase was seen in CDIR-induced NFκB activity, decreased DNA fragmentation, apoptosis, and cytotoxicity and attenuation of CDIR-inhibited clonal expansion when the cells were primed with LDIR prior to challenge dose. Furthermore, NFκB manipulation studies with small interfering RNA (siRNA) silencing or p50/p65 overexpression unveiled the influence of LDIR-activated NFκB in regulating CDIR-induced DNA fragmentation and apoptosis. LDIR significantly increased the transactivation/translation of the radiation-responsive factors tumor necrosis factor-α (TNF-α), interleukin-1α (IL-1α), cMYC, and SOD2. Coculture experiments exhibit LDIR-influenced radiation protection and increases in cellular expression, secretion, and activation of radiation-responsive molecules in bystander cells. Individual gene-silencing approach with siRNAs coupled with coculture studies showed the influence of LDIR-modulated TNF-α, IL-1α, cMYC, and SOD2 in induced radiation protection in bystander cells. NFκB inhibition/overexpression studies coupled with coculture experiments demonstrated that TNF-α, IL-1α, cMYC, and SOD2 are selectively regulated by LDIR-induced NFκB. Conclusions: Together, these data strongly suggest that scattered LDIR-induced NFκB-dependent TNF-α, IL-1α, cMYC, and SOD2 mediate radiation protection to the subsequent challenge dose in tumor cells.

  19. Successful treatment with autologous peripheral blood stem cell transplantation for acquired immunodeficiency syndrome (AIDS)-related malignant lymphoma.

    PubMed

    NAGAI, Yuya; MORI, Minako; INOUE, Daichi; KIMURA, Takaharu; SHIMOJI, Sonoko; TOGAMI, Katsuhiro; TABATA, Sumie; MATSUSHITA, Akiko; NAGAI, Kenichi; Imai, Yukihiro; Takafuta, Toshiro; Takahashi, Takayuki

    2009-11-01

    A 62-year-old man was diagnosed with human immunodeficiency virus (HIV) infection while suffering from recurrent herpes zoster infection. Laboratory examination revealed CD4(+) lymphocyte count 16 cells/mul and HIV loading 150,000 copies/ml at presentation. In addition, he had multiple lymph node swelling. Histologic diagnosis of a biopsied lymph node was diffuse, large, B cell-type malignant lymphoma. The karyotype of the lymphoma cells was t(8;14)(q24;q32), which was confirmed by G-banding and fluorescent in situ hybridization. Positron emission tomography (PET)-combined CT scanning revealed systemic extranodal tumors involving the gastrointestinal tract, pancreas, and bone marrow. The clinical stage of the lymphoma was IVB and the international prognosis index was categorized as high. Complete remission (CR) of the lymphoma was obtained after 2 courses of CHOP (cyclophosphamide, adriamycin, vincristine, prednisolone) chemotherapy and 4 subsequent courses of rituximab-combined CHOP (R-CHOP). Highly active antiretroviral therapy (HAART) was started at the initiation of CHOP. Because of the poor prognosis of AIDS-related lymphoma, he received autologous peripheral blood stem cell transplantation with the MEAM protocol (ranimustine, etoposide, cytarabine, melphalan) as a conditioning procedure without a severe infectious episode. He remains in CR 24 months after the transplantation. PMID:20009441

  20. Allergen-Experienced Group 2 Innate Lymphoid Cells Acquire Memory-like Properties and Enhance Allergic Lung Inflammation.

    PubMed

    Martinez-Gonzalez, Itziar; Mathä, Laura; Steer, Catherine A; Ghaedi, Maryam; Poon, Grace F T; Takei, Fumio

    2016-07-19

    Group 2 innate lymphoid cells (ILC2s) in the lung are stimulated by inhaled allergens. ILC2s do not directly recognize allergens but they are stimulated by cytokines including interleukin (IL)-33 released by damaged epithelium. In response to allergens, lung ILC2s produce T helper 2 cell type cytokines inducing T cell-independent allergic lung inflammation. Here we examined the fate of lung ILC2s upon allergen challenges. ILC2s proliferated and secreted cytokines upon initial stimulation with allergen or IL-33, and this phase was followed by a contraction phase as cytokine production ceased. Some ILC2s persisted long after the resolution of the inflammation as allergen-experienced ILC2s and responded to unrelated allergens more potently than naive ILC2s, mediating severe allergic inflammation. The allergen-experienced ILC2s exhibited a gene expression profile similar to that of memory T cells. The memory-like properties of allergen-experienced ILC2s may explain why asthma patients are often sensitized to multiple allergens. PMID:27421705

  1. Natural cytotoxicity in immunodeficiency diseases: preservation of natural killer activity and the in vivo appearance of radioresistant killing

    SciTech Connect

    Pierce, G.F.; Polmar, S.H.; Schacter, B.Z.; Brovall, C.; Hornick, D.L.; Sorensen, R.U.

    1986-01-01

    We studied spontaneous natural killer (NK) cell activity and radiation-resistant NK mediated cytotoxicity in four patients with clinically documented severe combined immune deficiency disease (SCID), and in one subject each with intestinal lymphangiectasia and cartilage-hair hypoplasia. We observed the preservation of spontaneous NK activity in all patients despite the presence of profound B- and T-lymphocytopenia and clinical immunodeficiency. NK activity was associated with relatively normal circulating numbers of OKM1+ lymphocytes, a population known to contain NK effectors. Spontaneous NK activity resistant to 3000 rad was increased in all patients, indicating the presence of activated natural killer cells in vivo. The concept of a chronically activated immune system in these patients was further supported by the presence of increased Ia positive T cells in all subjects tested, suggesting that radioresistant NK activity may be a useful parameter to measure when assessing in vivo immune activation. Our data, as well as that of others, supports the hypothesis that at least one population of NK cells is a distinct lineage arising at the differentiation level of myeloid and lymphoid stem cells in the bone marrow.

  2. Hospital-acquired pneumonia

    MedlinePlus

    ... this page: //medlineplus.gov/ency/article/000146.htm Hospital-acquired pneumonia To use the sharing features on this page, please enable JavaScript. Hospital-acquired pneumonia is an infection of the lungs ...

  3. l-carnosine dipeptide overcomes acquired resistance to 5-fluorouracil in HT29 human colon cancer cells via downregulation of HIF1-alpha and induction of apoptosis.

    PubMed

    Iovine, Barbara; Guardia, Francesca; Irace, Carlo; Bevilacqua, Maria Assunta

    2016-08-01

    Hypoxia-inducible factor (HIF-1α) protein is over-expressed in many human cancers and is a major cause of resistance to drugs. HIF-1α up-regulation decreases the effectiveness of several anticancer agents, including 5-fluorouracil (5-FU), because it induces the expression of drug efflux transporters, alters DNA repair mechanisms and modifies the balance between pro- and antiapoptotic factors. These findings suggest that inhibition of HIF-1α activity may sensitize cancer cells to cytotoxic drugs. We previously reported that l-carnosine reduces HIF-1α expression by inhibiting the proliferation of colon cancer cells. In the present study we investigated the effect of l-carnosine on HT29 colon cancer cells with acquired resistance to 5-FU. We found that l-carnosine reduces colon cancer cell viability, decreases HIF-1α and multi-drug resistant protein MDR1-pg expression, and induces apoptosis. Moreover, the l-carnosine/5-FU combination lowers the expression of some chemoresistance markers. The combination index evaluated in vitro on the HT29-5FU cell line by median drug effect analysis reveals a significant synergistic effect. PMID:27234614

  4. Acquired resistance of pancreatic cancer cells to treatment with gemcitabine and HER-inhibitors is accompanied by increased sensitivity to STAT3 inhibition

    PubMed Central

    IOANNOU, NIKOLAOS; SEDDON, ALAN M.; DALGLEISH, ANGUS; MACKINTOSH, DAVID; SOLCA, FLAVIO; MODJTAHEDI, HELMOUT

    2016-01-01

    Drug-resistance is a major contributing factor for the poor prognosis in patients with pancreatic cancer. We have shown previously that the irreversible ErbB family blocker afatinib, is more effective than the reversible EGFR tyrosine kinase inhibitor erlotinib in inhibiting the growth of human pancreatic cancer cells. The aim of this study was to develop human pancreatic cancer cell (BxPc3) variants with acquired resistance to treatment with gemcitabine, afatinib, or erlotinib, and to investigate the molecular changes that accompany the acquisition of a drug-resistant phenotype. We also investigated the therapeutic potential of various agents in the treatment of such drug-resistant variants. Three variant forms of BxPc3 cells with acquired resistance to gemcitabine (BxPc3GEM), afatinib (BxPc3AFR) or erlotinib (BxPc3OSIR) were developed following treatment with increasing doses of such drugs. The expression level, mutational and phosphorylation status of various growth factor receptors and downstream cell signaling molecules were determined by FACS, human phopsho-RTK array, and western blot analysis while the sulforhodamine B assay was used for determining the effect of various agents on the growth of such tumours. We found that all three BxPc3 variants with acquired resistance to gemcitabine (BxPc3GEM), afatinib (BxPc3AFR) or erlotinib (BxPc3OSIR) also become less sensitive to treatment with the two other agents. Acquisition of resistance to these agents was accompanied by upregulation of p-c-MET, p-STAT3, CD44, increased autocrine production of EGFR ligand amphiregulin and differential activation status of EGFR tyrosine residues as well as downregulation of total and p-SRC. Of all therapeutic interventions examined, including the addition of an anti-EGFR antibody ICR62, an anti-CD44 monoclonal antibody, and of STAT3 or c-MET inhibitors, only treatment with the STAT3 inhibitor Stattic produced a higher growth inhibitory effect in all three drug-resistant variants

  5. Renal-cell carcinomas in end-stage kidneys: a clinicopathological study with emphasis on clear-cell papillary renal-cell carcinoma and acquired cystic kidney disease-associated carcinoma.

    PubMed

    Bhatnagar, Ramneesh; Alexiev, Borislav A

    2012-02-01

    Clear-cell papillary renal-cell carcinoma (CCPC) and acquired cystic kidney disease-associated carcinoma (ACDAC) are neoplasms with distinct morphological characteristics that behave less aggressively than conventional renal-cell carcinomas. End-stage kidney specimens from 61 patients (47 males and 14 females) with 109 renal-cell carcinomas were selected. Papillary renal-cell carcinoma was the most common malignancy (61/109, 56%), followed by CCPC (20/109, 18%). The CCPC showed a papillary or tubular/solid architecture, clear cytoplasm, low nuclear grade, and a distinct immunohistochemical profile (RCC-, vimentin+, CK7+, p504S-). ACDAC displayed a variety of architectural patterns, eosinophilic cytoplasm, high nuclear grade, intratumoral calcium oxalate deposits, and an immunohistochemical profile similar to type 2 papillary renal-cell carcinoma (RCC+, vimentin+, CK7-/+, p504S+). Less than 5% (3/69) of pathologically staged renal-cell carcinomas in end-stage kidneys presented with lymphogenous and/or hematogenous metastases. PMID:21791489

  6. Retinal Ganglion Cell Atrophy in Homonymous Hemianopia due to Acquired Occipital Lesions Observed Using Cirrus High-Definition-OCT

    PubMed Central

    Yamashita, Tsutomu; Miki, Atsushi; Goto, Katsutoshi; Araki, Syunsuke; Takizawa, Go; Ieki, Yoshiaki; Kiryu, Junichi; Tabuchi, Akio; Iguchi, Yasuyuki; Kimura, Kazumi; Yagita, Yoshiki

    2016-01-01

    Purpose. To report a reduction in macular ganglion cell layer and inner plexiform layer (GCL+IPL) thickness and circumpapillary retinal nerve fiber layer (cpRNFL) thickness using spectral-domain optical coherence tomography in patients with homonymous hemianopia due to posterior cerebral artery (PCA) stroke. Methods. Seven patients with PCA stroke were examined using Cirrus high-definition-OCT. The GCL+IPL thicknesses were divided into the hemianopic and unaffected sides. The relationship between the time after stroke and the GCL+IPL thicknesses in the hemianopic side was evaluated. Results. The average thicknesses of the GCL+IPL were 64.6 and 82.0 μm on the hemianopic and unaffected sides, respectively, and the measurement was significantly thinner on the former side (p = 0.018). A regression analysis revealed a negative linear relationship (R2 = 0.574, p = 0.049) between the time after stoke and the GCL+IPL thicknesses on the hemianopic side. The supratemporal and inferotemporal cpRNFL thicknesses in the eyes ipsilateral to the stroke showed a significant reduction. Conclusion. Our findings confirmed our previous observations that the degeneration of retinal ganglion cells can occur after PCA stroke. GCL+IPL thinning was demonstrated in the hemiretinae corresponding to the affected hemifields. Also, it is suggested that the retinal changes observed are progressive. PMID:27274865

  7. Identification of New Genes Contributing to the Extreme Radioresistance of Deinococcus radiodurans Using a Tn5-Based Transposon Mutant Library

    PubMed Central

    Passot, Fanny; Dutertre, Murielle; Porteron, Martine; Confalonieri, Fabrice; Sommer, Suzanne; Pasternak, Cécile

    2015-01-01

    Here, we have developed an extremely efficient in vivo Tn5-based mutagenesis procedure to construct a Deinococcus radiodurans insertion mutant library subsequently screened for sensitivity to genotoxic agents such as γ and UV radiations or mitomycin C. The genes inactivated in radiosensitive mutants belong to various functional categories, including DNA repair functions, stress responses, signal transduction, membrane transport, several metabolic pathways, and genes of unknown function. Interestingly, preliminary characterization of previously undescribed radiosensitive mutants suggests the contribution of cyclic di-AMP signaling in the recovery of D. radiodurans cells from genotoxic stresses, probably by modulating several pathways involved in the overall cell response. Our analyses also point out a new transcriptional regulator belonging to the GntR family, encoded by DR0265, and a predicted RNase belonging to the newly described Y family, both contributing to the extreme radioresistance of D. radiodurans. Altogether, this work has revealed new cell responses involved either directly or indirectly in repair of various cell damage and confirmed that D. radiodurans extreme radiation resistance is determined by a multiplicity of pathways acting as a complex network. PMID:25884619

  8. Integrated genomic approaches identify upregulation of SCRN1 as a novel mechanism associated with acquired resistance to erlotinib in PC9 cells harboring oncogenic EGFR mutation

    PubMed Central

    Kim, Nayoung; Cho, Ahye; Watanabe, Hideo; Choi, Yoon-La; Aziz, Meraj; Kassner, Michelle; Joung, Je-Gun; Park, Angela KJ; Francis, Joshua M.; Bae, Joon Seol; Ahn, Soo-min; Kim, Kyoung-Mee; Park, Joon Oh; Park, Woong-Yang; Ahn, Myung-Ju; Park, Keunchil; Koo, Jaehyung; Yin, Hongwei Holly; Cho, Jeonghee

    2016-01-01

    Therapies targeting the tyrosine kinase activity of Epidermal Growth Factor Receptor (EGFR) have been proven to be effective in treating a subset of non-small cell lung cancer (NSCLC) patients harboring activating EGFR mutations. Inevitably these patients develop resistance to the EGFR-targeted tyrosine kinase inhibitors (TKIs). Here, we performed integrated genomic analyses using an in vitro system to uncover alternative genomic mechanisms responsible for acquired resistance to EGFR-TKIs. Specifically, we identified 80 genes whose expression is significantly increased in the erlotinib-resistant clones. RNAi-based systematic synthetic lethal screening of these candidate genes revealed that suppression of one upregulated transcript, SCRN1, a secernin family member, restores sensitivity to erlotinib by enhancing inhibition of PI3K/AKT signaling pathway. Furthermore, immunohistochemical analysis revealed increased levels of SCRN1 in 5 of 11 lung tumor specimens from EGFR-TKIs resistant patients. Taken together, we propose that upregulation of SCRN1 is an additional mechanism associated with acquired resistance to EGFR-TKIs and that its suppression serves as a novel therapeutic strategy to overcome drug resistance in these patients. PMID:26883194

  9. RORγt⁺ innate lymphoid cells acquire a proinflammatory program upon engagement of the activating receptor NKp44.

    PubMed

    Glatzer, Timor; Killig, Monica; Meisig, Johannes; Ommert, Isabelle; Luetke-Eversloh, Merlin; Babic, Marina; Paclik, Daniela; Blüthgen, Nils; Seidl, Rainer; Seifarth, Claudia; Gröne, Jörn; Lenarz, Minoo; Stölzel, Katharina; Fugmann, Dominik; Porgador, Angel; Hauser, Anja; Karlas, Alexander; Romagnani, Chiara

    2013-06-27

    RORγt⁺ innate lymphoid cells (ILCs) are crucial players of innate immune responses and represent a major source of interleukin-22 (IL-22), which has an important role in mucosal homeostasis. The signals required by RORγt⁺ ILCs to express IL-22 and other cytokines have been elucidated only partially. Here we showed that RORγt⁺ ILCs can directly sense the environment by the engagement of the activating receptor NKp44. NKp44 triggering in RORγt⁺ ILCs selectively activated a coordinated proinflammatory program, including tumor necrosis factor (TNF), whereas cytokine stimulation preferentially induced IL-22 expression. However, combined engagement of NKp44 and cytokine receptors resulted in a strong synergistic effect. These data support the concept that NKp44⁺ RORγt⁺ ILCs can be activated without cytokines and are able to switch between IL-22 or TNF production, depending on the triggering stimulus. PMID:23791642

  10. [Acquired angioedema with C1-INH deficiency and accompanying chronic spontaneous urticaria in a patient with chronic lymphatic B cell leukemia].

    PubMed

    Klossowski, N; Braun, S A; von Gruben, V; Losem, C; Plewe, D; Homey, B; Meller, S

    2015-10-01

    Acquired angioedema due to C1 inhibitor deficiency (C1-INH-AAE) is characterized by recurrent edema of the subcutaneous and/or submucosal tissue without wheals and negative family history of angioedema. Here, we present the case of a patient with a chronic lymphatic B cell leukemia who suffered from both C1-INH-AAE and chronic spontaneous urticaria. Oral corticosteroids, antihistamines, and the anti-IgE antibody omalizumab were applied to treat the chronic urticaria in combination with the plasma-derived C1 esterase inhibitor concentrate Berinert® and the bradykinin B2 receptor antagonist icatibant, but the symptoms did not improved significantly. Thus, polychemotherapy targeting the slow-growing lymphoproliferative disease including rituximab was initiated, which resulted in remission of both the urticaria and the angioedema. PMID:26335859

  11. [3rd generation's TKI in lung cancer non-small cell EGFR-mutated having acquired a secondary T790M resistance].

    PubMed

    Brosseau, Solenn; Viala, Marie; Varga, Andréa; Planchard, David; Besse, Benjamin; Soria, Jean-Charles

    2015-09-01

    Activating EGFR mutations discovery and efficacy of 1st generation tyrosine kinase inhibitors (TKI), such as erlotinib or gefitinib, inaugurated the beginning of personalized medicine in the treatment of EGFR-mutated non-small cell lung cancer (NSCLC). However, all patients showed a tumor progression of 10 to 16 months after the onset of TKI therapy related to molecular resistance mechanisms as T790M mutation. Till now, patients suffering from EGFR-mutated NSCLC with acquired resistance have conventional treatment options. Two new 3rd generations' TKI, AZD9291 and rociletinib, are currently being studied in phases 1-3 studies. Preliminary results show relevant therapeutic properties in patients with T790M mutated-EGFR NSCLC. This review aims to highlight these new molecules, their effectiveness and their clinical toxicities in the treatment of advanced stages of NSCLC expressing the T790M mutation. PMID:26235419

  12. Elevated hepatocyte growth factor expression as an autocrine c-Met activation mechanism in acquired resistance to sorafenib in hepatocellular carcinoma cells.

    PubMed

    Firtina Karagonlar, Zeynep; Koc, Dogukan; Iscan, Evin; Erdal, Esra; Atabey, Neşe

    2016-04-01

    Hepatocellular carcinoma (HCC) is the most common type of primary liver cancer and the third leading cause of cancer-related deaths worldwide. Limitations in HCC treatment result due to poor prognosis and resistance against traditional radiotherapy and chemotherapies. The multikinase inhibitor sorafenib is the only FDA approved drug available for advanced HCC patients, and development of second-line treatment options for patients who cannot tolerate or develop resistance to sorafenib is an urgent medical need. In this study, we established sorafenib-resistant cells from Huh7 and Mahlavu cell lines by long-term sorafenib exposure. Sorafenib-resistant HCC cells acquired spindle-shape morphology, upregulated mesenchymal markers, and showed significant increase in both migration and invasion abilities compared to their parental counterparts. Moreover, after long-term sorafenib treatment, HCC cells showed induction of hepatocyte growth factor (HGF) synthesis and secretion along with increased levels of c-Met kinase and its active phosphorylated form, indicating autocrine activation of HGF/c-Met signaling. Importantly, the combined treatment of the resistant cells with c-Met kinase inhibitor SU11274 and HGF neutralizing antibody significantly reversed the increased invasion ability of the cells. The combined treatment also significantly augmented sorafenib-induced apoptosis, suggesting restoration of sorafenib sensitivity. These results describe, for the first time, compensatory upregulation of HGF synthesis leading to autocrine activation of HGF/c-Met signaling as a novel cellular strategy in the acquisition of sorafenib resistance. Therefore, we suggest that combinatorial therapeutic strategies with HGF and c-Met inhibitors comprise promising candidates for overcoming sorafenib resistance. PMID:26790028

  13. Increased thymidylate synthase in L1210 cells possessing acquired resistance to N10-propargyl-5,8-dideazafolic acid (CB3717): development, characterization, and cross-resistance studies

    SciTech Connect

    Jackman, A.L.; Alison, D.L.; Calvert, A.H.; Harrap, K.R.

    1986-06-01

    The properties are described of a mutant L1210 cell line (L1210:C15) with acquired resistance (greater than 200-fold) to the thymidylate synthase (TS) inhibitor N10-propargyl-5,8-dideazafolic acid. TS was overproduced 45-fold and was accompanied by a small increase in the activity of dihydrofolate reductase (2.6-fold). Both the level of resistance and enzyme activities were maintained in drug-free medium (greater than 300 generations). Failure of N10-propargyl-5,8-dideazafolic acid to suppress the (/sup 3/H)-2'-deoxyuridine incorporation into the acid-precipitable material of the resistant line supported the evidence that TS overproduction was the mechanism of resistance; consequently the L1210:C15 cells were largely cross-resistant to another (but weaker) TS inhibitor, 5,8-dideazafolic acid. Minimal cross-resistance was observed to the dihydrofolate reductase inhibitors methotrexate and 5-methyl-5,8-dideazaaminopterin (5- and 2-fold, respectively). L1210 and L1210:C15 cells were, however, equally sensitive to 5-fluorodeoxyuridine (FdUrd), an unexpected finding since a metabolite, 5-fluorodeoxyuridine monophosphate, is a potent TS inhibitor; however, this cytotoxicity against the L1210:C15 cells was antagonized by coincubation with 5 microM folinic acid although folinic acid potentiated the cytotoxicity of FdUrd to the N10-propargyl-5,8-dideazafolic acid-sensitive L1210 line. Thymidine was much less effective as a FdUrd protecting agent in the L1210:C15 when compared with the L1210 cells; however, a combination of thymidine plus hypoxanthine was without any additional effect (compared with thymidine alone) against the sensitive line but effectively protected L1210:C15 cells.

  14. Ex vivo generated natural killer cells acquire typical natural killer receptors and display a cytotoxic gene expression profile similar to peripheral blood natural killer cells.

    PubMed

    Lehmann, Dorit; Spanholtz, Jan; Osl, Markus; Tordoir, Marleen; Lipnik, Karoline; Bilban, Martin; Schlechta, Bernhard; Dolstra, Harry; Hofer, Erhard

    2012-11-01

    Ex vivo differentiation systems of natural killer (NK) cells from CD34+ hematopoietic stem cells are of potential importance for adjuvant immunotherapy of cancer. Here, we analyzed ex vivo differentiation of NK cells from cord blood-derived CD34+ stem cells by gene expression profiling, real-time RT-PCR, flow cytometry, and functional analysis. Additionally, we compared the identified characteristics to peripheral blood (PB) CD56(bright) and CD56(dim) NK cells. The data show sequential expression of CD56 and the CD94 and NKG2 receptor chains during ex vivo NK cell development, resulting finally in the expression of a range of genes with partial characteristics of CD56(bright) and CD56(dim) NK cells from PB. Expression of characteristic NK cell receptors and cytotoxic genes was mainly found within the predominant ex vivo generated population of NKG2A+ NK cells, indicating the importance of NKG2A expression during NK cell differentiation and maturation. Furthermore, despite distinct phenotypic characteristics, the detailed analysis of cytolytic genes expressed within the ex vivo differentiated NK cells revealed a pattern close to CD56(dim) NK cells. In line with this finding, ex vivo generated NK cells displayed potent cytotoxicity. This supports that the ex vivo differentiation system faithfully reproduces major steps of the differentiation of NK cells from their progenitors, constitutes an excellent model to study NK cell differentiation, and is valuable to generate large-scale NK cells appropriate for immunotherapy. PMID:22571679

  15. Characteristics of malignant melanoma cells in the treatment with fast neutrons

    SciTech Connect

    Tsunemoto, H.; Morita, S.; Mori, S. )

    1989-07-01

    The radioresistance of malignant melanoma cells has been explained by the wide shoulder of the dose-cell-survival curve of the cells exposed to photon beams. Fast neutrons, 30 MeV d-Be, were used to treat patients who had malignant melanoma in order to confirm the biological effects of high linear energy transfer (LET) radiation for tumor control. Seventy-two patients suffering from malignant melanoma participated in the clinical trials with fast neutrons between November 1975 and December 1986. Of 72 patients, 45 had melanoma of the skin, 20 had melanoma of the head and neck, and seven had choroidal melanoma. Five-year survival rate of the patients who had previously untreated melanoma of the skin was 61% and for patients who received postoperative irradiation, it was 35.7% whereas no patients who had recurrent tumor survived over 4 years. Of 22 patients who had melanoma of the skin, stage I, local control in four cases was achieved by irradiation alone, whereas local control was achieved in 17 of 18 patients who required salvage surgery after fast-neutron therapy. The results of pathological studies performed with specimens obtained from salvage surgery have shown that melanoma cells growing in intradermal tissue are radioresistant, compared with cells growing in intraepidermal tissue. This might suggest that melanoma cells acquire radioresistance when the connective tissue is involved. Five-year survival rate of the patients who had locally advanced melanoma of the head and neck, previously untreated, was 15.4%. Radiation therapy with accelerated protons was suitable for patients suffering from choroidal melanoma.

  16. Recursion-based depletion of human immunodeficiency virus-specific naive CD4(+) T cells may facilitate persistent viral replication and chronic viraemia leading to acquired immunodeficiency syndrome.

    PubMed

    Tsukamoto, Tetsuo; Yamamoto, Hiroyuki; Okada, Seiji; Matano, Tetsuro

    2016-09-01

    Although antiretroviral therapy has made human immunodeficiency virus (HIV) infection a controllable disease, it is still unclear how viral replication persists in untreated patients and causes CD4(+) T-cell depletion leading to acquired immunodeficiency syndrome (AIDS) in several years. Theorists tried to explain it with the diversity threshold theory in which accumulated mutations in the HIV genome make the virus so diverse that the immune system will no longer be able to recognize all the variants and fail to control the viraemia. Although the theory could apply to a number of cases, macaque AIDS models using simian immunodeficiency virus (SIV) have shown that failed viral control at the set point is not always associated with T-cell escape mutations. Moreover, even monkeys without a protective major histocompatibility complex (MHC) allele can contain replication of a super infected SIV following immunization with a live-attenuated SIV vaccine, while those animals are not capable of fighting primary SIV infection. Here we propose a recursion-based virus-specific naive CD4(+) T-cell depletion hypothesis through thinking on what may happen in individuals experiencing primary immunodeficiency virus infection. This could explain the mechanism for impairment of virus-specific immune response in the course of HIV infection. PMID:27515208

  17. Acquired resistance to metformin in breast cancer cells triggers transcriptome reprogramming toward a degradome-related metastatic stem-like profile.

    PubMed

    Oliveras-Ferraros, Cristina; Vazquez-Martin, Alejandro; Cuyàs, Elisabet; Corominas-Faja, Bruna; Rodríguez-Gallego, Esther; Fernández-Arroyo, Salvador; Martin-Castillo, Begoña; Joven, Jorge; Menendez, Javier A

    2014-01-01

    Therapeutic interventions based on metabolic inhibitor-based therapies are expected to be less prone to acquired resistance. However, there has not been any study assessing the possibility that the targeting of the tumor cell metabolism may result in unforeseeable resistance. We recently established a pre-clinical model of estrogen-dependent MCF-7 breast cancer cells that were chronically adapted to grow (> 10 months) in the presence of graded, millimolar concentrations of the anti-diabetic biguanide metformin, an AMPK agonist/mTOR inhibitor that has been evaluated in multiple in vitro and in vivo cancer studies and is now being tested in clinical trials. To assess what impact the phenomenon of resistance might have on the metformin-like "dirty" drugs that are able to simultaneously hit several metabolic pathways, we employed the ingenuity pathway analysis (IPA) software to functionally interpret the data from Agilent whole-human genome arrays in the context of biological processes, networks, and pathways. Our findings establish, for the first time, that a "global" targeting of metabolic reprogramming using metformin certainly imposes a great selective pressure for the emergence of new breast cancer cellular states. Intriguingly, acquired resistance to metformin appears to trigger a transcriptome reprogramming toward a metastatic stem-like profile, as many genes encoding the components of the degradome (KLK11, CTSF, FREM1, BACE-2, CASP, TMPRSS4, MMP16, HTRA1), cancer cell migration and invasion factors (TP63, WISP2, GAS3, DKK1, BCAR3, PABPC1, MUC1, SPARCL1, SEMA3B, SEMA6A), stem cell markers (DCLK1, FAK), and key pro-metastatic lipases (MAGL and Cpla2) were included in the signature. Because this convergent activation of pathways underlying tumor microenvironment interactions occurred in low-proliferative cancer cells exhibiting a notable downregulation of the G 2/M DNA damage checkpoint regulators that maintain genome stability (CCNB1, CCNB2, CDC20, CDC25C, AURKA

  18. K-RAS(V12) Induces Autocrine Production of EGFR Ligands and Mediates Radioresistance Through EGFR-Dependent Akt Signaling and Activation of DNA-PKcs

    SciTech Connect

    Minjgee, Minjmaa; Toulany, Mahmoud; Kehlbach, Rainer; Giehl, Klaudia; Rodemann, H. Peter

    2011-12-01

    Purpose: It is known that postirradiation survival of tumor cells presenting mutated K-RAS is mediated through autocrine activation of epidermal growth factor receptor (EGFR). In this study the molecular mechanism of radioresistance of cells overexpressing mutated K-RAS(V12) was investigated. Methods and Materials: Head-and-neck cancer cells (FaDu) presenting wild-type K-RAS were transfected with empty vector or vector expressing mutated K-RAS(V12). The effect of K-RAS(V12) on autocrine production of EGFR ligands, activation of EGFR downstream pathways, DNA damage repair, and postirradiation survival was analyzed. Results: Conditioned medium collected from K-RAS(V12)-transfected cells enhanced activation of the phosphatidylinositol-3-kinase-Akt pathway and increased postirradiation survival of wild-type K-RAS parental cells when compared with controls. These effects were reversed by amphiregulin (AREG)-neutralizing antibody. In addition, secretion of the EGFR ligands AREG and transforming growth factor {alpha} was significantly increased upon overexpression of K-RAS(V12). Expression of mutated K-RAS(V12) resulted in an increase in radiation-induced DNA-dependent protein kinase catalytic subunit (DNA-PKcs) phosphorylation at S2056. This increase was accompanied by increased repair of DNA double-strand breaks. Abrogation of DNA-PKcs phosphorylation by serum depletion or AREG-neutralizing antibody underscored the role of autocrine production of EGFR ligands, namely, AREG, in regulating DNA-PKcs activation in K-RAS mutated cells. Conclusions: These data indicate that radioresistance of K-RAS mutated tumor cells is at least in part due to constitutive production of EGFR ligands, which mediate enhanced repair of DNA double-strand breaks through the EGFR-phosphatidylinositol-3-kinase-Akt cascade.

  19. Transition in Survival From Low-Dose Hyper-Radiosensitivity to Increased Radioresistance Is Independent of Activation of ATM SER1981 Activity

    SciTech Connect

    Krueger, Sarah A.; Collis, Spencer J.; Joiner, Michael C.; Wilson, George D.; Marples, Brian

    2007-11-15

    Purpose: The molecular basis of low-dose hyper-radiosensitivity (HRS) is only partially understood. The aim of this study was to define the roles of ataxia telangiectasia mutated (ATM) activity and the downstream ATM-dependent G{sub 2}-phase cell cycle checkpoint in overcoming HRS and triggering radiation resistance. Methods and Materials: Survival was measured using a high-resolution clonogenic assay. ATM Ser1981 activation was measured by Western blotting. The role of ATM was determined in survival experiments after molecular (siRNA) and chemical (0.4 mM caffeine) inhibition and chemical (20 {mu}g/mL chloroquine, 15 {mu}M genistein) activation 4-6 h before irradiation. Checkpoint responsiveness was assessed in eight cell lines of differing HRS status using flow cytometry to quantify the progression of irradiated (0-2 Gy) G{sub 2}-phase cells entering mitosis, using histone H3 phosphorylation analysis. Results: The dose-response pattern of ATM activation was concordant with the transition from HRS to radioresistance. However, ATM activation did not play a primary role in initiating increased radioresistance. Rather, a relationship was discovered between the function of the downstream ATM-dependent early G{sub 2}-phase checkpoint and the prevalence and overcoming of HRS. Four cell lines that exhibited HRS failed to show low-dose (<0.3-Gy) checkpoint function. In contrast, four HRS-negative cell lines exhibited immediate cell cycle arrest for the entire 0-2-Gy dose range. Conclusion: Overcoming HRS is reliant on the function of the early G{sub 2}-phase checkpoint. These data suggest that clinical exploitation of HRS could be achieved by combining radiotherapy with chemotherapeutic agents that modulate this cell cycle checkpoint.

  20. Acquired resistance to anti-EGFR mAb ICR62 in cancer cells is accompanied by an increased EGFR expression, HER-2/HER-3 signalling and sensitivity to pan HER blockers

    PubMed Central

    Khelwatty, Said A; Essapen, Sharadah; Seddon, Alan M; Fan, Zhen; Modjtahedi, Helmout

    2015-01-01

    Background: The human epidermal growth factor receptor (EGFR) is an important target for cancer treatment. Currently, only the EGFR antibodies cetuximab and panitumumab are approved for the treatment of patients with colorectal cancer. However, a major clinical challenge is a short-term response owing to development of acquired resistance during the course of the treatment. Methods: In this study, we investigated the molecular mechanisms underlying development of acquired resistance in DiFi colorectal cancer cells to the anti-EGFR mAb ICR62 (termed DiFi62) and to the small molecule tyrosine kinase inhibitor (TKI) gefitinib (termed DiFiG) using a range of techniques. Results: Compared with the findings from parental DiFi and DiFiG cells, development of acquired resistance to anti-EGFR mAb ICR62 in DiFi62 cells was accompanied by an increase in cell surface EGFR and increased phosphorylation of HER-2 and HER-3. Interestingly, DiFi62 cells also acquired resistance to treatment with anti-EGFR mAbs cetuximab and ICR61, which bind to other distinct epitopes on the extracellular domain of EGFR, but these cells remained equally sensitive as the parental cells to treatment with pan-HER inhibitors such as afatinib. Conclusions: Our results provide a novel mechanistic insight into the development of acquired resistance to EGFR antibody-based therapy in colorectal cancer cells and justify further investigations on the therapeutic benefits of pan-HER family inhibitors in the treatment of colorectal cancer patients once acquired resistance to EGFR antibody-based therapy is developed. PMID:26372697

  1. Acquired cystic disease-associated renal cell carcinoma with gain of chromosomes 3, 7, and 16, gain of chromosome X, and loss of chromosome Y.

    PubMed

    Kuroda, Naoto; Shiotsu, Tomoyuki; Hes, Ondrej; Michal, Michal; Shuin, Taro; Lee, Gang-Hong

    2010-12-01

    Acquired cystic disease (ACD)-associated renal cell carcinoma (RCC) has been recently described. To date, there are no reports on genetic findings of G-band karyotype of ACD-associated RCC. In this article, we report the first report of G-band karyotype of ACD-associated RCC. A 66-year-old Japanese man was found to have a left renal tumor during the follow-up of hemodialysis consequent to chronic renal failure. Left nephrectomy was performed. Histological examination of three tumors in the left kidney showed the cribriform or microcystic growth pattern of neoplastic cells with eosinophilic cytoplasm, and many oxalate crystals were observed. The G-band karyotype of ACD-associated RCC showed 49, X, +X, -Y, +3, +7, +16. These chromosomal abnormalities resemble those of sporadic papillary RCC that has been previously reported. Finally, we suggest that this tumor may show a close relationship between ACD-associated RCC and papillary RCC, but a large-scale study will be needed to clarify the relationship between ACD-associated RCC and papillary RCC. PMID:21267700

  2. Clonal analysis of T lymphocytes in the acquired immunodeficiency syndrome. Evidence for an abnormality affecting individual helper and suppressor T cells.

    PubMed Central

    Margolick, J B; Volkman, D J; Lane, H C; Fauci, A S

    1985-01-01

    Purified helper-inducer (T4+) and suppressor-cytotoxic (T8+) lymphocytes from eight patients with acquired immunodeficiency syndrome (AIDS) and eight healthy heterosexual donors were examined by limiting dilution analysis for their ability to be clonally expanded. It was demonstrated that viable T4+ and T8+ lymphocytes from patients with AIDS had markedly reduced proportions of clonable cells compared to the healthy donors (T4 = 1:255 vs. 1:34, P = 0.06; T8 = 1:355 vs. 1:55, P = 0.01). However, the cloned T cells that were obtained from the patients with AIDS demonstrated normal proliferation in response to phytohemagglutinin and alloantigen, and normal ability to help or suppress pokeweed mitogen-driven IgG synthesis. These results strongly suggest that, in addition to a quantitative diminution of T4+ lymphocytes in AIDS, there is an intrinsic functional defect in the surviving T4+ and T8+ lymphocytes, which is reflected by a severe decrease in their potential for clonal expansion. PMID:3161909

  3. Acquired reactive perforating collagenosis.

    PubMed

    Basak, P Y; Turkmen, C

    2001-01-01

    Acquired perforating disorder has been recognized as an uncommon distinct dermatosis in which altered collagen is eliminated through the epidermis. Several disorders accompanied by itching and scratching were reported to be associated with reactive perforating collagenosis. A 67-year-old white woman diagnosed as acquired reactive perforating collagenosis with poorly controlled diabetes mellitus and congestive cardiac failure is presented. PMID:11525959

  4. Human dendritic cells acquire a semimature phenotype and lymph node homing potential through interaction with CD4+CD25+ regulatory T cells.

    PubMed

    Bayry, Jagadeesh; Triebel, Frédéric; Kaveri, Srini V; Tough, David F

    2007-04-01

    Interactions between dendritic cells (DC) and T cells are known to involve the delivery of signals in both directions. We sought to characterize the effects on human DC of contact with different subsets of activated CD4+ T cells. The results showed that interaction with CD25(high)CD4+ regulatory T cells (Tregs) caused DC to take on very different properties than contact with naive or memory phenotype T cells. Whereas non-Tregs stimulated DC maturation, culture with Tregs produced DC with a mixed phenotype. By many criteria, Tregs inhibited DC maturation, inducing down-regulation of costimulatory molecules and T cell stimulatory activity. However, DC exposed to Tregs also showed some changes typically associated with DC maturation, namely, increased expression of CCR7 and MHC class II molecules, and gained the ability to migrate in response to the CCR7 ligand CCL19. Both soluble factors and cell-associated molecules were shown to be involved in Treg modulation of DC, with lymphocyte activation gene 3 (LAG-3) playing a predominant role in driving maturation-associated changes. The data show that Tregs induce the generation of semimature DC with the potential to migrate into lymphoid organs, suggesting a possible mechanism by which Tregs down-modulate immune responses. PMID:17371975

  5. Annexin A1 is involved in the acquisition and maintenance of a stem cell-like/aggressive phenotype in prostate cancer cells with acquired resistance to zoledronic acid

    PubMed Central

    Bizzarro, Valentina; Belvedere, Raffaella; Milone, Maria Rita; Pucci, Biagio; Lombardi, Rita; Bruzzese, Francesca; Popolo, Ada; Parente, Luca; Budillon, Alfredo; Petrella, Antonello

    2015-01-01

    In this study, we have characterized the role of annexin A1 (ANXA1) in the acquisition and maintenance of stem-like/aggressive features in prostate cancer (PCa) cells comparing zoledronic acid (ZA)-resistant DU145R80 with their parental DU145 cells. ANXA1 is over-expressed in DU145R80 cells and its down-regulation abolishes their resistance to ZA. Moreover, ANXA1 induces DU145 and DU145R80 invasiveness acting through formyl peptide receptors (FPRs). Also, ANXA1 knockdown is able to inhibit epithelial to mesenchymal transition (EMT) and to reduce focal adhesion kinase (FAK) and metalloproteases (MMP)-2/9 expression in PCa cells. DU145R80 show a cancer stem cell (CSC)-like signature with a high expression of CSC markers including CD44, CD133, NANOG, Snail, Oct4 and ALDH7A1 and CSC-related genes as STAT3. Interestingly, ANXA1 knockdown induces these cells to revert from a putative prostate CSC to a more differentiated phenotype resembling DU145 PCa cell signature. Similar results are obtained concerning some drug resistance-related genes such as ATP Binding Cassette G2 (ABCG2) and Lung Resistant Protein (LRP). Our study provides new insights on the role of ANXA1 protein in PCa onset and progression.

  6. Annexin A1 is involved in the acquisition and maintenance of a stem cell-like/aggressive phenotype in prostate cancer cells with acquired resistance to zoledronic acid.

    PubMed

    Bizzarro, Valentina; Belvedere, Raffaella; Milone, Maria Rita; Pucci, Biagio; Lombardi, Rita; Bruzzese, Francesca; Popolo, Ada; Parente, Luca; Budillon, Alfredo; Petrella, Antonello

    2015-09-22

    In this study, we have characterized the role of annexin A1 (ANXA1) in the acquisition and maintenance of stem-like/aggressive features in prostate cancer (PCa) cells comparing zoledronic acid (ZA)-resistant DU145R80 with their parental DU145 cells. ANXA1 is over-expressed in DU145R80 cells and its down-regulation abolishes their resistance to ZA. Moreover, ANXA1 induces DU145 and DU145R80 invasiveness acting through formyl peptide receptors (FPRs). Also, ANXA1 knockdown is able to inhibit epithelial to mesenchymal transition (EMT) and to reduce focal adhesion kinase (FAK) and metalloproteases (MMP)-2/9 expression in PCa cells. DU145R80 show a cancer stem cell (CSC)-like signature with a high expression of CSC markers including CD44, CD133, NANOG, Snail, Oct4 and ALDH7A1 and CSC-related genes as STAT3. Interestingly, ANXA1 knockdown induces these cells to revert from a putative prostate CSC to a more differentiated phenotype resembling DU145 PCa cell signature. Similar results are obtained concerning some drug resistance-related genes such as ATP Binding Cassette G2 (ABCG2) and Lung Resistant Protein (LRP). Our study provides new insights on the role of ANXA1 protein in PCa onset and progression. PMID:26312765

  7. HIV-specific CD8+ T cell function in children with vertically acquired HIV-1 infection is critically influenced by age and the state of the CD4+ T cell compartment.

    PubMed

    Sandberg, Johan K; Fast, Noam M; Jordan, Kimberly A; Furlan, Scott N; Barbour, Jason D; Fennelly, Glenn; Dobroszycki, Joanna; Spiegel, Hans M L; Wiznia, Andrew; Rosenberg, Michael G; Nixon, Douglas F

    2003-04-15

    The immunology of vertical HIV transmission differs from that of adult infection in that the immune system of the infant is not fully matured, and the factors that influence the functionality of CD8(+) T cell responses against HIV in children remain largely undefined. We have investigated CD8(+) T cell responses in 65 pediatric subjects with vertically acquired HIV-1 infection. Vigorous, broad, and Ag dose-driven CD8(+) T cell responses against HIV Ags were frequently observed in children who were older than 3 years of age and maintained CD4(+) T cell counts >400 cells/ micro l. In contrast, younger age or a CD4(+) T cell count <400 cells/ micro l was associated with poor CD8(+) T cell responses and high HIV loads. Furthermore, subjects with a severely depleted and phenotypically altered CD4(+) T cell compartment had circulating Gag-specific CD8(+) T cells with impaired IFN-gamma production. When viral load was not suppressed by antiviral treatment, subjects that fell below the putative age and CD4(+) T cell count thresholds had significantly reduced CD8(+) T cell responses and significantly higher viral loads. Thus, the data suggest that fully effective HIV-specific CD8(+) T cell responses take years to develop despite an abundance of Ag in early life, and responses are further severely impaired, independent of age, in children who have a depleted or skewed CD4(+) T cell compartment. The results are discussed in relation to differences between the neonatal and adult immune systems in the ability to respond to HIV infection. PMID:12682278

  8. Radio-resistance in psychrotrophic Kocuria sp. ASB 107 isolated from Ab-e-Siah radioactive spring.

    PubMed

    Asgarani, Ezat; Soudi, Mohammad Reza; Borzooee, Faezeh; Dabbagh, Reza

    2012-11-01

    A new isolate, Kocuria sp. ASB 107 from the Ab-e-Siah mineral radioactive spring (Ramsar, Mazandaran Province, Iran) was characterized on the basis of morphological and biochemical characteristics plus 16S rRNA gene sequencing. The isolate is most closely related to Kocuria rosea DSM 20447(T) (99.7% sequence similarity) and Kocuria polaris DSM 14382(T) (99.5%). This strain has some resistance to various genotoxic stresses, such as ionizing radiation, ultraviolet (256 nm- UV) and corona discharge. The 90% lethal doses (D(10)) for gamma-rays and 256 nm-UV are 2 kGy and 400 J m(-2), respectively, in definite cell concentration. Moreover, the resistance for a definite energy of corona discharge is 10 s, about 10 times greater than that of Escherichia coli. The growth temperature of the strain ASB 107 is 0-37 °C in TSB (tryptic soy broth). This study is the first report on the psychrotrophic radio-resistant bacteria belonging to the Kocuria genus isolated from Ab-e-Siah spring. PMID:22809716

  9. Acquired Cystic Kidney Disease

    MedlinePlus

    ... a kidney transplant or blood-filtering treatments called dialysis. The cysts are more likely to develop in people who are on kidney dialysis. The chance of developing acquired cystic kidney disease ...

  10. Hospital-acquired pneumonia

    MedlinePlus

    ... tends to be more serious than other lung infections because: People in the hospital are often very sick and cannot fight off ... prevent pneumonia. Most hospitals have programs to prevent hospital-acquired infections.

  11. Partial hypoxia as a cause of radioresistance in a human tumor xenograft: its influence illustrated by the sensitizing effect of misonidazole and hyperbaric oxygen

    SciTech Connect

    Reynaud-Bougnoux, A.; Lespinasse, F.; Malaise, E.P.; Guichard, M.

    1986-08-01

    While previous studies with three human tumor xenografts suggest that contact-resistance plays a major role in the response of these tumors to radiation, it remains possible that partial hypoxia may provide an alternate explanation. The present study was carried out to check this possibility by investigating the influence of misonidazole (MISO) and hyperbaric oxygen (HBO) on both the initial and distal components of the survival curves of HRT18 tumor cells. The effect of a challenge dose of radiation on the initial radioresistance of this tumor was also studied. To assess the effects of MISO and HBO, tumor cell survival was determined by excision assay in two groups of tumor-bearing mice, one given MISO (1 mg/g body weight, i.p.) 45 min before irradiation and the other exposed to HBO (3.5 bars). MISO treatment caused greater sensitization than HBO. The enhancement ratios at the 5.10(-1) level were 1.7 (MISO) and 1.7 (HBO); at the 10(-1) level, they were 1.6 (MISO) and 1.4 (HBO); while at 10(-2), they were 1.6 (MISO) and 1.4 (HBO). These two sensitizing effects favor the hypothesis that solid tumors contain a compartment of partially hypoxic cells. To study the effect of a challenge radiation dose on initial radioresistance, tumors were given a challenge dose of 8 Gy, followed 24-48 hr later by doses ranging from 2-12 Gy. The challenge dose did not modify the shape of the survival curve.

  12. Protein Oxidation Implicated as the Primary Determinant of Bacterial Radioresistance

    PubMed Central

    Daly, Michael J; Gaidamakova, Elena K; Matrosova, Vera Y; Vasilenko, Alexander; Zhai, Min; Leapman, Richard D; Lai, Barry; Ravel, Bruce; Li, Shu-Mei W; Kemner, Kenneth M; Fredrickson, James K

    2007-01-01

    In the hierarchy of cellular targets damaged by ionizing radiation (IR), classical models of radiation toxicity place DNA at the top. Yet, many prokaryotes are killed by doses of IR that cause little DNA damage. Here we have probed the nature of Mn-facilitated IR resistance in Deinococcus radiodurans, which together with other extremely IR-resistant bacteria have high intracellular Mn/Fe concentration ratios compared to IR-sensitive bacteria. For in vitro and in vivo irradiation, we demonstrate a mechanistic link between Mn(II) ions and protection of proteins from oxidative modifications that introduce carbonyl groups. Conditions that inhibited Mn accumulation or Mn redox cycling rendered D. radiodurans radiation sensitive and highly susceptible to protein oxidation. X-ray fluorescence microprobe analysis showed that Mn is globally distributed in D. radiodurans, but Fe is sequestered in a region between dividing cells. For a group of phylogenetically diverse IR-resistant and IR-sensitive wild-type bacteria, our findings support the idea that the degree of resistance is determined by the level of oxidative protein damage caused during irradiation. We present the case that protein, rather than DNA, is the principal target of the biological action of IR in sensitive bacteria, and extreme resistance in Mn-accumulating bacteria is based on protein protection. PMID:17373858

  13. Protein oxidation implicated as the primary determinant of bacterial radioresistance.

    PubMed

    Daly, Michael J; Gaidamakova, Elena K; Matrosova, Vera Y; Vasilenko, Alexander; Zhai, Min; Leapman, Richard D; Lai, Barry; Ravel, Bruce; Li, Shu-Mei W; Kemner, Kenneth M; Fredrickson, James K

    2007-04-01

    In the hierarchy of cellular targets damaged by ionizing radiation (IR), classical models of radiation toxicity place DNA at the top. Yet, many prokaryotes are killed by doses of IR that cause little DNA damage. Here we have probed the nature of Mn-facilitated IR resistance in Deinococcus radiodurans, which together with other extremely IR-resistant bacteria have high intracellular Mn/Fe concentration ratios compared to IR-sensitive bacteria. For in vitro and in vivo irradiation, we demonstrate a mechanistic link between Mn(II) ions and protection of proteins from oxidative modifications that introduce carbonyl groups. Conditions that inhibited Mn accumulation or Mn redox cycling rendered D. radiodurans radiation sensitive and highly susceptible to protein oxidation. X-ray fluorescence microprobe analysis showed that Mn is globally distributed in D. radiodurans, but Fe is sequestered in a region between dividing cells. For a group of phylogenetically diverse IR-resistant and IR-sensitive wild-type bacteria, our findings support the idea that the degree of resistance is determined by the level of oxidative protein damage caused during irradiation. We present the case that protein, rather than DNA, is the principal target of the biological action of IR in sensitive bacteria, and extreme resistance in Mn-accumulating bacteria is based on protein protection. PMID:17373858

  14. Protein Oxidation Implicated as the Primary Determinant of Bacterial Radioresistance

    SciTech Connect

    Daly, Michael J.; Gaidamakova, E.; Matrosova, V.; Vasilenko, A.; Zhai, M.; leapman, Richard D.; Lai, Barry; Ravel, Bruce; Li, Shu-Mei W.; Kemner, Kenneth M.; Fredrickson, Jim K.

    2007-04-02

    In the hierarchy of cellular targets damaged by ionizing radiation (IR), classical models of radiation toxicity place DNA at the top. Yet, many prokaryotes are killed by doses of IR that cause little DNA damage. Here we have probed the nature of manganese-facilitated IR resistance in Deinococcus radiodurans, which together with other extremely IR resistant bacteria have high intracellular Mn/Fe concentration ratios compared to IR sensitive bacteria. For in vitro and in vivo irradiation, we demonstrate a mechanistic link between Mn(II) ions and protection of proteins from oxidative modifications which introduce carbonyl groups. Conditions which inhibited Mn-accumulation or Mn redox-cycling rendered D. radiodurans radiation sensitive and highly susceptible to protein oxidation. X-ray fluorescence (XRF) microprobe analysis showed that Mn is globally distributed in D. radiodurans, but Fe is sequestered in a region between dividing cells. For a group of phylogenetically diverse IR resistant and sensitive bacteria, our findings support that the degree of resistance is determined by the level of oxidative protein damage caused during irradiation. We present the case that protein, rather than DNA, is the principal target of the biological action of IR in sensitive bacteria, and extreme resistance in Mn-accumulating bacteria is based on protein protection.

  15. [Principles of therapy with fission neutrons and boron neutron capture therapy for radioresistant head-neck malignancies].

    PubMed

    Clasen, B

    1990-08-01

    Neutron therapy has proven to be clinically useful in cases of advanced, slow-growing radioresistant head and neck carcinoma. Therapeutic effects might be based on direct DNA damaging and thus immediate cell-killing, on the generation of free oxygen radicals and, among others, on the fact that heavy particle radiation is said to be less dependent on the presence of oxygen than gamma rays, i.e. on a lower oxygen enhancement ratio (OER). The smaller difference in reaction between oxygenated and nonoxygenated cells could entail advantages as well as disadvantages, depending on the characteristics of the tumor cell population and of the normal tissue. It is therefore essential to select patients and tumours with an expectedly high therapeutic gain factor. Fission neutrons for tumour therapy: As evaluated by several in vitro and in vivo studies (11/13) the biological efficiency (RBE) of the RENT (Reactor Neutron Therapy) beam in Munich seems to be among the highest of all clinically used neutron beams. For a single dose range between 2 and 8 Gy the RBE for chronic radiation damage is relatively small (2). Consequently, patients with recurrent or metastatic carcinomas of the head and neck are treated with a single dose of 200-250 cGy after previous surgery and/or combined radiochemotherapy. The main limitation of fission neutrons is the small penetration depth. Possibilities of clinical implementation of boron neutron capture therapy (BNCT) in otorhinolaryngology: In near surface tumours it is possible to administer high doses of 10boron not selectively, i.e. no selective tumour-seeking compound is needed. Animal experiments with intratumoural injection of 10boron glycine have shown a strong effect on tumour growth delay (18).(ABSTRACT TRUNCATED AT 250 WORDS) PMID:2222692

  16. Th1/Th2 cell dichotomy in acquired immunity to Bordetella pertussis: variables in the in vivo priming and in vitro cytokine detection techniques affect the classification of T-cell subsets as Th1, Th2 or Th0.

    PubMed Central

    Barnard, A; Mahon, B P; Watkins, J; Redhead, K; Mills, K H

    1996-01-01

    In studies of the mechanism of immunity to Bordetella pertussis in a murine respiratory infection model, we have previously demonstrated that natural infection of immunization with a whole cell vaccine induces a potent protective immune response, which is mediated by T-helper type-1 (Th1) cells. In contrast an acellular vaccine generates Th2 cells and is associated with delayed bacterial clearance following respiratory challenge. In the present study we have investigated the apparent Th1/Th2 cell dichotomy in acquired immunity and have examined the factors that affect their induction or detection. The cytokine profiles of B. pertussis-specific T cells in immune animals were determined using antigen-stimulated ex vivo spleen cells or CD4+ T-cell lines and clones established in the presence of interleukin-2 (IL-2) or IL-4. Antigen-specific T cells derived from mice immunized with the acellular vaccine were almost exclusively of the Th2 cell type. In contrast, T-cell lines and clones established following respiratory infection or immunization with the whole cell vaccine were predominantly of the Th1 type. However, a proportion of T cells from convalescent mice, especially when cultured in the presence of IL-4, secreted IL-4 and IL-5 with or without detectable IL-2 and interferon-gamma (IFN-gamma), suggesting that Th0 or Th2 cells were also primed during natural infection in vivo. Furthermore, when mice were assessed 6 months after infection, spleen cells produced significant levels of IL-4 and IL-5, which were not evident at 6 weeks. The route of immunization and the genetic background of the mice were also found to influence the preferential priming of Th1 cells, and this was directly related to the level of protection against respiratory or intracerebral (i.c.) challenge. Our findings underline the critical role of CD4+ Th1 cells in immunity to B. pertussis, but also demonstrate that a number of factors in the in vivo priming and in vitro restimulation can skew the

  17. Fast Neutron Irradiation of the Highly Radioresistant Bacterium Deinococcus Radiodurans

    NASA Astrophysics Data System (ADS)

    Case, Diane Louise

    Fast neutron dose survival curves were generated for the bacterium Deinococcus radiodurans, which is renowned for its unusually high resistance to gamma, x-ray, and ultraviolet radiation, but for which fast neutron response was unknown. The fast neutrons were produced by the University of Massachusetts Lowell 5.5-MV, type CN Van de Graaff accelerator through the ^7Li(p,n)^7 Be reaction by bombarding a thick metallic lithium target with a 4-MeV proton beam. The bacteria were uniformly distributed on 150-mm agar plates and were exposed to the fast neutron beam under conditions of charged particle equilibrium. The plates were subdivided into concentric rings of increasing diameter from the center to the periphery of the plate, within which the average neutron dose was calculated as the product of the precisely known neutron fluence at the average radius of the ring and the neutron energy dependent kerma factor. The neutron fluence and dose ranged from approximately 3 times 1013 n cm^ {-2} to 1 times 1012 n cm^ {-2}, and 200 kilorad to 5 kilorad, respectively, from the center to the periphery of the plate. Percent survival for Deinococcus radiodurans as a function of fast neutron dose was derived from the ability of the irradiated cells to produce visible colonies within each ring compared to that of a nonirradiated control population. The bacterium Escherichia coli B/r (CSH) was irradiated under identical conditions for comparative purposes. The survival response of Deinococcus radiodurans as a result of cumulative fast neutron exposures was also investigated. The quantification of the ability of Deinococcus radiodurans to survive cellular insult from secondary charged particles, which are produced by fast neutron interactions in biological materials, will provide valuable information about damage and repair mechanisms under extreme cellular stress, and may provide new insight into the origin of this bacterium's unprecedented radiation resistance.

  18. Murine Bone Marrow-Derived Dendritic Cells Transduced by Light-Helper-Dependent Herpes Simplex Virus-1 Amplicon Vector Acquire a Mature Dendritic Cell Phenotype.

    PubMed

    Oz-Arslan, Devrim; Tsitoura, Eliza; Kazazi, Dorothea; Kouvatsis, Vlasis; Epstein, Alberto L; Mavromara, Penelope

    2015-06-01

    Dendritic cells (DCs) turn into the most potent antigen-presenting cells following a complex transforming process, which leads to their maturation. Herpes simplex virus-1 (HSV-1) amplicon vectors represent highly versatile viral vector platforms with the ability to transduce immature DCs at exceedingly high efficiencies, while the efficiency of infection of mature DCs is significantly low. However, the bacterial artificial chromosome (BAC)-dependent (BD) amplicon vectors tested so far do not result in the maturation of mouse bone marrow-derived DCs (BMDCs) in vitro. In this study we investigated the effects of light-helper-dependent (LHD) amplicon vectors produced with the replication-defective HSV-1 LaLΔJ helper virus system. First, we observed that transgene expression in BMDC cultures was equally potent between the LHD and the BD amplicon vectors. We determined that the percentage of transduced cells and the duration of transgene expression were negatively influenced by the presence of increasing levels of helper virus. Second, infection by the LHD amplicon vector as well as the helper HSV-1 LaLΔJ virus alone resulted in the phenotypic maturation of BMDCs and the expression of both interferon-stimulated genes and proinflammatory cytokines. Further comparisons of the gene expression of infected DCs showed that while interferon-stimulated genes such as Ifit1, Ifit3, Mx2, Isg15, and Cxcl10 were induced by both BD and LHD amplicon vectors, early proinflammatory cytokine gene expression (Tnfa, Il1a, Il1b, Il6, Il10, Il12b, Cxcl1, and Cxcl16) and DC maturation were mediated only by the LHD amplicons. PMID:26046494

  19. Community-acquired pneumonia.

    PubMed

    Falguera, M; Ramírez, M F

    2015-11-01

    This article not only reviews the essential aspects of community-acquired pneumonia for daily clinical practice, but also highlights the controversial issues and provides the newest available information. Community-acquired pneumonia is considered in a broad sense, without excluding certain variants that, in recent years, a number of authors have managed to delineate, such as healthcare-associated pneumonia. The latter form is nothing more than the same disease that affects more frail patients, with a greater number of risk factors, both sharing an overall common approach. PMID:26186969

  20. Transcription Factor HBP1 Enhances Radiosensitivity by Inducing Apoptosis in Prostate Cancer Cell Lines

    PubMed Central

    Chen, Yicheng; Wang, Yueping; Yu, Yanlan; Xu, Liwei; Zhang, Youyun; Yu, Shicheng; Li, Gonghui; Zhang, Zhigeng

    2016-01-01

    Radiotherapy for prostate cancer has been gradually carried out in recent years; however, acquired radioresistance often occurred in some patients after radiotherapy. HBP1 (HMG-box transcription factor 1) is a transcriptional inhibitor which could inhibit the expression of dozens of oncogenes. In our previous study, we showed that the expression level of HBP1 was closely related to prostate cancer metastasis and prognosis, but the relationship between HBP1 and radioresistance for prostate cancer is largely unknown. In this study, the clinical data of patients with prostate cancer was compared, and the positive correlation was revealed between prostate cancer brachytherapy efficacy and the expression level of HBP1 gene. Through research on prostate cancer cells in vitro, we found that HBP1 expression levels were negatively correlated with oncogene expression levels. Furthermore, HBP1 overexpression could sensitize prostate cancer cells to radiation and increase apoptosis in prostate cancer cells. In addition, animal model was employed to analyze the relationship between HBP1 gene and prostate cancer radiosensitivity in vivo; the result showed that knockdown of HBP1 gene could decrease the sensitivity to radiation of xenograft. These studies identified a specific molecular mechanism underlying prostate cancer radiosensitivity, which suggested HBP1 as a novel target in prostate cancer radiotherapy. PMID:26942107

  1. Acquired Brain Injury Program.

    ERIC Educational Resources Information Center

    Schwartz, Stacey Hunter

    This paper reviews the Acquired Brain Injury (ABI) Program at Coastline Community College (California). The ABI Program is a two-year, for-credit educational curriculum designed to provide structured cognitive retraining for adults who have sustained an ABI due to traumatic (such as motor vehicle accident or fall) or non-traumatic(such as…

  2. Acquired von Willebrand disease.

    PubMed

    Petrini, P

    1999-05-01

    Acquired von Willebrand disease (AvWD) is a syndrome that has clinical and laboratory features similar to hereditary vWD. In contrast to the latter it occurs in patients without a family history of previous bleeding tendency. PMID:23401904

  3. Long non-coding RNA UCA1 induces non-T790M acquired resistance to EGFR-TKIs by activating the AKT/mTOR pathway in EGFR-mutant non-small cell lung cancer

    PubMed Central

    Ren, Shengxiang; Li, Xuefei; Wang, Qi; Pan, Hui; Zhao, Mingchuan; Li, Jiayu; Zhang, Yishi; Zhao, Chao; Chen, Xiaoxia; Fei, Ke; Zhou, Caicun; Hirsch, Fred R.

    2015-01-01

    The aim of this study was to explore the role of long non-coding RNA UCA1 (urothelial cancer-associated 1) in acquired resistance to epidermal growth factor receptor tyrosine kinase inhibitors (EGFR-TKIs) in EGFR-mutant non-small cell lung cancer (NSCLC). In our study, UCA1 expression was significantly increased in lung cancer cells and patients with acquired resistance to EGFR-TKIs. Over-expression of UCA1 was significantly associated with a shorter progression-free survival (PFS) [13.0 vs. 8.5 months, P < 0.01] in tumors with respond to EGFR-TKIs. The significant relationship was not observed in patients with T790M mutation (10.5 vs. 12.0 months, P = 0.778), but in patients with non-T790M (19.0 vs. 9.0 months, P = 0.023). UCA1 knockdown restored gefitinib sensitivity in acquired resistant cells with non-T790M and inhibited the activation of the AKT/mTOR pathway and epithelial-mesenchymal transition (EMT). The mTOR inhibitor was effective in UCA1-expressing cell PC9/R. Inhibiting mTOR could change the expression of UCA1, although there was no significant difference. In conclusion, the influence of over-expression of UCA1 on PFS for patients with acquired resistance to EGFR-TKIs was from the subgroup with non-T790M mutation. UCA1 may induce non-T790M acquired resistance to EGFR-TKIs by activating the AKT/mTOR pathway and EMT. PMID:26160838

  4. Activation of the IGF1R pathway potentially mediates acquired resistance to mutant-selective 3rd-generation EGF receptor tyrosine kinase inhibitors in advanced non-small cell lung cancer.

    PubMed

    Park, Ji Hyun; Choi, Yun Jung; Kim, Seon Ye; Lee, Jung-Eun; Sung, Ki Jung; Park, Sojung; Kim, Woo Sung; Song, Joon Seon; Choi, Chang-Min; Sung, Young Hoon; Rho, Jin Kyung; Lee, Jae Cheol

    2016-04-19

    Mutant-selective, 3rd-generation EGFR-TKIs were recently developed to control lung cancer cells harboring T790M-mediated resistance. However, the development of resistance to these novel drugs seems inevitable. Thus, we investigated the mechanism of acquired resistance to the mutant-selective EGFR-TKI WZ4002. We established five WZ4002-resistant cells, derived from cells harboring both EGFR and T790M mutations by long-term exposure to increasing doses of WZ4002. Compared with the parental cells, all resistant cells showed 10-100-folds higher resistance to WZ4002, as well as cross-resistance to other mutant-selective inhibitors. Among them, three resistant cells (HCC827/WR, PC-9/WR and H1975/WR) showed dependency on EGFR signaling, but two other cells (PC-9/GR/WR and PC-9/ER/WR) were not. Notably, insulin-like growth factor-1 receptor (IGF1R) was aberrantly activated in PC-9/GR/WR cells in phospho-receptor tyrosine kinase array, consistently accompanied by loss of IGF binding protein-3 (IGFBP3). Down-regulation of IGF1R by shRNA, as well as inhibition of IGF1R activity either by AG-1024 (a small molecule IGF1R inhibitor) or BI 836845 (a monoclonal anti-IGF1/2 blocking antibody), restored the sensitivity to WZ4002 both in vitro and xenograft. Taken together, these results suggest that activation of the IGF1R pathway associated with IGFBP3 loss can induce an acquired resistance to the mutant-selective EGFR-TKI, WZ4002. Therefore, a combined therapy of IGF1R inhibitors and mutant-selective EGFR-TKIs might be a viable treatment strategy for overcoming acquired resistance. PMID:26980747

  5. Activation of the IGF1R pathway potentially mediates acquired resistance to mutant-selective 3rd-generation EGF receptor tyrosine kinase inhibitors in advanced non-small cell lung cancer

    PubMed Central

    Park, Ji Hyun; Choi, Yun Jung; Kim, Seon Ye; Lee, Jung-Eun; Sung, Ki Jung; Park, Sojung; Kim, Woo Sung; Song, Joon Seon; Choi, Chang-Min; Sung, Young Hoon; Rho, Jin Kyung; Lee, Jae Cheol

    2016-01-01

    Mutant-selective, 3rd-generation EGFR-TKIs were recently developed to control lung cancer cells harboring T790M-mediated resistance. However, the development of resistance to these novel drugs seems inevitable. Thus, we investigated the mechanism of acquired resistance to the mutant-selective EGFR-TKI WZ4002. We established five WZ4002-resistant cells, derived from cells harboring both EGFR and T790M mutations by long-term exposure to increasing doses of WZ4002. Compared with the parental cells, all resistant cells showed 10–100-folds higher resistance to WZ4002, as well as cross-resistance to other mutant-selective inhibitors. Among them, three resistant cells (HCC827/WR, PC-9/WR and H1975/WR) showed dependency on EGFR signaling, but two other cells (PC-9/GR/WR and PC-9/ER/WR) were not. Notably, insulin-like growth factor-1 receptor (IGF1R) was aberrantly activated in PC-9/GR/WR cells in phospho-receptor tyrosine kinase array, consistently accompanied by loss of IGF binding protein-3 (IGFBP3). Down-regulation of IGF1R by shRNA, as well as inhibition of IGF1R activity either by AG-1024 (a small molecule IGF1R inhibitor) or BI 836845 (a monoclonal anti-IGF1/2 blocking antibody), restored the sensitivity to WZ4002 both in vitro and xenograft. Taken together, these results suggest that activation of the IGF1R pathway associated with IGFBP3 loss can induce an acquired resistance to the mutant-selective EGFR-TKI, WZ4002. Therefore, a combined therapy of IGF1R inhibitors and mutant-selective EGFR-TKIs might be a viable treatment strategy for overcoming acquired resistance. PMID:26980747

  6. Curcumin Modulates the Radiosensitivity of Colorectal Cancer Cells by Suppressing Constitutive and Inducible NF-{kappa}B Activity

    SciTech Connect

    Sandur, Santosh K.; Deorukhkar, Amit; Pandey, Manoj K.; Pabon, Ana Maria B.S.; Shentu, Shujun; Guha, Sushovan; Aggarwal, Bharat B.; Krishnan, Sunil

    2009-10-01

    Purpose: Radiation therapy is an integral part of the preoperative treatment of rectal cancers. However, only a minority of patients achieve a complete pathologic response to therapy because of resistance of these tumors to radiation therapy. This resistance may be mediated by constitutively active pro-survival signaling pathways or by inducible/acquired mechanisms in response to radiation therapy. Simultaneous inhibition of these pathways can sensitize these tumors to radiation therapy. Methods and Materials: Human colorectal cancer cells were exposed to clinically relevant doses of gamma rays, and the mechanism of their radioresistance was investigated. We characterized the transcription factor nuclear factor-{kappa}B (NF-{kappa}B) activation as a mechanism of inducible radioresistance in colorectal cancer and used curcumin, the active ingredient in the yellow spice turmeric, to overcome this resistance. Results: Curcumin inhibited the proliferation and the post-irradiation clonogenic survival of multiple colorectal cancer cell lines. Radiation stimulated NF-{kappa}B activity in a dose- and time-dependent manner, whereas curcumin suppressed this radiation-induced NF-{kappa}B activation via inhibition of radiation-induced phosphorylation and degradation of inhibitor of {kappa}B alpha, inhibition of inhibitor of {kappa}B kinase activity, and inhibition of Akt phosphorylation. Curcumin also suppressed NF-{kappa}B-regulated gene products (Bcl-2, Bcl-x{sub L}, inhibitor of apoptosis protein-2, cyclooxygenase-2, and cyclin D1). Conclusions: Our results suggest that transient inducible NF-{kappa}B activation provides a prosurvival response to radiation that may account for development of radioresistance. Curcumin blocks this signaling pathway and potentiates the antitumor effects of radiation therapy.

  7. Prognostic factors for outcomes after whole-brain irradiation of brain metastases from relatively radioresistant tumors: a retrospective analysis

    PubMed Central

    2010-01-01

    Background This study investigated potential prognostic factors in patients treated with whole-brain irradiation (WBI) alone for brain metastases from relatively radioresistant tumors such as malignant melanoma, renal cell carcinoma, and colorectal cancer. Additionally, a potential benefit from escalating the radiation dose was investigated. Methods Data from 220 patients were retrospectively analyzed for overall survival and local control. Nine potential prognostic factors were evaluated: tumor type, WBI schedule, age, gender, Karnofsky performance score, number of brain metastases, extracerebral metastases, interval from diagnosis of cancer to WBI, and recursive partitioning analysis (RPA) class. Results Survival rates at 6 and 12 months were 32% and 19%, respectively. In the multivariate analysis, WBI doses >30 Gy (p = 0.038), KPS ≥70 (p < 0.001), only 1-3 brain metastases (p = 0.007), no extracerebral metastases (p < 0.001), and RPA class 1 (p < 0.001) were associated with improved survival. Local control rates at 6 and 12 months were 37% and 15%, respectively. In the multivariate analyses, KPS ≥70 (p < 0.001), only 1-3 brain metastases (p < 0.001), and RPA class 1 (p < 0.001) were associated with improved local control. In RPA class 3 patients, survival rates at 6 months were 10% (35 of 39 patients) after 10 × 3 Gy and 9% (2 of 23 patients) after greater doses, respectively (p = 0.98). Conclusions Improved outcomes were associated with WBI doses >30 Gy, better performance status, fewer brain metastases, lack of extracerebral metastases, and lower RPA class. Patients receiving WBI alone appear to benefit from WBI doses >30 Gy. However, such a benefit is limited to RPA class 1 or 2 patients. PMID:20977700

  8. Lymphoma in acquired generalized lipodystrophy.

    PubMed

    Brown, Rebecca J; Chan, Jean L; Jaffe, Elaine S; Cochran, Elaine; DePaoli, Alex M; Gautier, Jean-Francois; Goujard, Cecile; Vigouroux, Corinne; Gorden, Phillip

    2016-01-01

    Acquired generalized lipodystrophy (AGL) is a rare disease thought to result from autoimmune destruction of adipose tissue. Peripheral T-cell lymphoma (PTCL) has been reported in two AGL patients. We report five additional cases of lymphoma in AGL, and analyze the role of underlying autoimmunity and recombinant human leptin (metreleptin) replacement in lymphoma development. Three patients developed lymphoma during metreleptin treatment (two PTCL and one ALK-positive anaplastic large cell lymphoma), and two developed lymphomas (mycosis fungoides and Burkitt lymphoma) without metreleptin. AGL is associated with high risk for lymphoma, especially PTCL. Autoimmunity likely contributes to this risk. Lymphoma developed with or without metreleptin, suggesting metreleptin does not directly cause lymphoma development; a theoretical role of metreleptin in lymphoma progression remains possible. For most patients with AGL and severe metabolic complications, the proven benefits of metreleptin on metabolic disease will likely outweigh theoretical risks of metreleptin in lymphoma development or progression. PMID:25864863

  9. [Acquired von Willebrand syndrome].

    PubMed

    Franchini, Massimo

    2006-01-01

    Acquired von Willebrand syndrome (aVWS) is a rare, but probably underestimated, bleeding disorder that mimics the congenital form of von Willebrand disease (VWD) in terms of laboratory findings and clinical presentation. However, unlike congenital VWD, it arises in individuals with no personal or family history of bleeding. AVWS occurs in association with a variety of underlying disorders, including lymphoproliferative disorders, myeloproliferative disorders and cardiovascular diseases. The main pathogenic, clinical, laboratory and therapeutic aspects of this syndrome are concisely reported in this review. PMID:16913181

  10. Rational design of cancer-targeted BSA protein nanoparticles as radiosensitizer to overcome cancer radioresistance.

    PubMed

    Huang, Yanyu; Luo, Yi; Zheng, Wenjie; Chen, Tianfeng

    2014-01-01

    Radiotherapy displays curative potential for cervical cancer management, but radioresistance occurs during long-term therapy. To overcome this limitation, tumor-targeted nanotechnology has been proposed to enhance the radiosensitivity of solid tumors. Herein, we used biocompatible bovine serum albumin nanoparticles (BSANPs) as carriers of organic selenocompound (PSeD) with folate (FA) as the targeting ligand to fabricate a cancer-targeted nanosystem. The combination of PSeD and BSANPs endowed the nanosystem with higher light absorption and reactive oxygen species (ROS) generation owing to their properties of surface plasmon resonance (SPR) effect, heavy metal effect, high refractive index and nanoparticulate interfacial effect. The combined treatment drastically increased the ROS overproduction, VEGF/VEGFR2 inactivation and inhibition of XRCC-1-mediated repair of DNA damage, thus triggering G2/M phase arrest and apoptosis. Taken together, our findings demonstrate the utility of FA-BSANPs as a promising radiosensitizer to improve cancer radiotherapy. PMID:25314331

  11. Naturally acquired microchimerism

    PubMed Central

    Eikmans, Michael; van Halteren, Astrid GS; van Besien, Koen; van Rood, Jon J; Drabbels, Jos JM; Claas, Frans HJ

    2014-01-01

    Microchimerism represents a condition where one individual harbors genetically distinct cell populations, and the chimeric population constitutes <1% of the total number of cells. The most common natural source of microchimerism is pregnancy. The reciprocal cell exchange between a mother and her child often leads to the stable engraftment of hematopoietic and non-hematopoietic stem cells in both parties. Interaction between cells from the mother and those from the child may result in maternal immune cells becoming sensitized to inherited paternal alloantigens of the child, which are not expressed by the mother herself. Vice versa, immune cells of the child may become sensitized toward the non-inherited maternal alloantigens of the mother. The extent of microchimerism, its anatomical location, and the sensitivity of the techniques used for detecting its presence collectively determine whether microchimerism can be detected in an individual. In this review, we focus on the clinical consequences of microchimerism in solid organ and hematopoietic stem cell transplantation, and propose concepts derived from data of epidemiologic studies. Next, we elaborate on the latest molecular methodology, including digital PCR, for determining in a reliable and sensitive way the extent of microchimerism. For the first time, tools have become available to isolate viable chimeric cells from a host background, so that the challenges of establishing the biologic mechanisms and function of these cells may finally be tackled. PMID:24762743

  12. AIDS: acquired immunodeficiency syndrome *

    PubMed Central

    Gilmore, N.J.; Beaulieu, R.; Steben, M.; Laverdière, M.

    1992-01-01

    Acquired immunodeficiency syndrome, or AIDS, is a new illness that occurs in previously healthy individuals. It is characterized by immunodeficiency, opportunistic infections and unusual malignant diseases. Life-threatening single or multiple infections with viruses, mycobacteria, fungi or protozoa are common. A rare neoplasm, Kaposi's sarcoma, has developed in approximately one third of patients with AIDS. More than 800 cases of AIDS have been reported in North America, over 24 of them in Canada. The majority of patients are male homosexuals, although AIDS has also developed in abusers of intravenously administered drugs, Haitian immigrants, individuals with hemophilia, recipients of blood transfusions, prostitutes, and infants, spouses and partners of patients with AIDS. The cause of AIDS is unknown, but the features are consistent with an infectious process. Early diagnosis can be difficult owing to the nonspecific symptoms and signs of the infections and malignant diseases. Therefore, vigilance by physicians is of the utmost importance. PMID:1544049

  13. Community-acquired pneumonia.

    PubMed

    Polverino, E; Torres Marti, A

    2011-02-01

    Despite the remarkable advances in antibiotic therapies, diagnostic tools, prevention campaigns and intensive care, community-acquired pneumonia (CAP) is still among the primary causes of death worldwide, and there have been no significant changes in mortality in the last decades. The clinical and economic burden of CAP makes it a major public health problem, particularly for children and the elderly. This issue provides a clinical overview of CAP, focusing on epidemiology, economic burden, diagnosis, risk stratification, treatment, clinical management, and prevention. Particular attention is given to some aspects related to the clinical management of CAP, such as the microbial etiology and the available tools to achieve it, the usefulness of new and old biomarkers, and antimicrobial and other non-antibiotic adjunctive therapies. Possible scenarios in which pneumonia does not respond to treatment are also analyzed to improve clinical outcomes of CAP. PMID:21242952

  14. Acquired Porphyria Cutanea Tarda

    PubMed Central

    Koval, Andrew; Danby, C. W. E.; Petermann, H.

    1965-01-01

    Currently, the porphyrias are classified in four main groups: congenital porphyria, acute intermittent porphyria, porphyria cutanea tarda hereditaria, and porphyria cutanea tarda symptomatica. The acquired form of porphyria (porphyria cutanea tarda symptomatica) occurs in older males and is nearly always associated with chronic alcoholism and hepatic cirrhosis. The main clinical changes are dermatological, with excessive skin fragility and photosensitivity resulting in erosions and bullae. Biochemically, high levels of uroporphyrin are found in the urine and stools. Treatment to date has been symptomatic and usually unsuccessful. A case of porphyria cutanea tarda symptomatica is presented showing dramatic improvement of both the skin lesions and porphyrin levels in urine and blood following repeated phlebotomy. Possible mechanisms of action of phlebotomy on porphyria cutanea tarda symptomatica are discussed. ImagesFig. 1Fig. 2 PMID:14341652

  15. [ICU acquired neuromyopathy].

    PubMed

    Gueret, G; Guillouet, M; Vermeersch, V; Guillard, E; Talarmin, H; Nguyen, B-V; Rannou, F; Giroux-Metges, M-A; Pennec, J-P; Ozier, Y

    2013-09-01

    ICU acquired neuromyopathy (IANM) is the most frequent neurological pathology observed in ICU. Nerve and muscle defects are merged with neuromuscular junction abnormalities. Its physiopathology is complex. The aim is probably the redistribution of nutriments and metabolism towards defense against sepsis. The main risk factors are sepsis, its severity and its duration of evolution. IANM is usually diagnosed in view of difficulties in weaning from mechanical ventilation, but electrophysiology may allow an earlier diagnosis. There is no curative therapy, but early treatment of sepsis, glycemic control as well as early physiotherapy may decrease its incidence. The outcomes of IANM are an increase in morbi-mortality and possibly long-lasting neuromuscular abnormalities as far as tetraplegia. PMID:23958176

  16. Targeting the PI3K/AKT/mTOR pathway overcomes the stimulating effect of dabrafenib on the invasive behavior of melanoma cells with acquired resistance to the BRAF inhibitor.

    PubMed

    Caporali, Simona; Alvino, Ester; Lacal, Pedro Miguel; Levati, Lauretta; Giurato, Giorgio; Memoli, Domenico; Caprini, Elisabetta; Antonini Cappellini, Gian Carlo; D'Atri, Stefania

    2016-09-01

    BRAF inhibitors (BRAFi) have proven clinical benefits in patients with BRAF-mutant melanoma. However, acquired resistance eventually arises. The effects of BRAFi on melanoma cell proliferation and survival have been extensively studied, and several mechanisms involved in acquired resistance to the growth suppressive activity of these drugs have been identified. Much less is known about the impact of BRAFi, and in particular of dabrafenib, on the invasive potential of melanoma cells. In the present study, the BRAF-mutant human melanoma cell line A375 and its dabrafenib-resistant subline A375R were analyzed for invasive capacity, expression of vascular endothelial growth factor receptor (VEGFR)-2, and secretion of VEGF-A and matrix metalloproteinase (MMP)-9, under basal conditions or in response to dabrafenib. The consequences of inhibiting the PI3K/AKT/mTOR pathway on A375R cell responses to dabrafenib were also evaluated. We found that A375R cells were more invasive and secreted higher levels of VEGF-A and MMP-9 as compared with A375 cells. Dabrafenib reduced invasiveness, VEGFR-2 expression and VEGF-A secretion in A375 cells, whereas it increased invasiveness, VEGF-A and MMP-9 release in A375R cells. In these latter cells, the stimulating effects of dabrafenib on the invasive capacity were markedly impaired by the anti-VEGF‑A antibody bevacizumab, or by AKT1 silencing. A375R cells were not cross-resistant to the PI3K/mTOR inhibitor GSK2126458A. Moreover, this inhibitor given in combination with dabrafenib efficiently counteracted the stimulating effects of the BRAFi on invasiveness and VEGF-A and MMP-9 secretion. Our data demonstrate that melanoma cells with acquired resistance to dabrafenib possess a more invasive phenotype which is further stimulated by exposure to the drug. Substantial evidence indicates that continuing BRAFi therapy beyond progression produces a clinical benefit. Our results suggest that after the development of resistance, a regimen

  17. Chk1 phosphorylated at serine345 is a predictor of early local recurrence and radio-resistance in breast cancer.

    PubMed

    Alsubhi, Nouf; Middleton, Fiona; Abdel-Fatah, Tarek M A; Stephens, Peter; Doherty, Rachel; Arora, Arvind; Moseley, Paul M; Chan, Stephen Y T; Aleskandarany, Mohammed A; Green, Andrew R; Rakha, Emad A; Ellis, Ian O; Martin, Stewart G; Curtin, Nicola J; Madhusudan, Srinivasan

    2016-02-01

    Radiation-induced DNA damage activates the DNA damage response (DDR). DDR up-regulation may predict radio-resistance and increase the risk of early local recurrence despite radiotherapy in early stage breast cancers. In 1755 early stage breast cancers, DDR signalling [ATM, ATR, total Ckh1, Chk1 phosphorylated at serine(345) (pChk1), Chk2, p53], base excision repair [PARP1, POLβ, XRCC1, FEN1, SMUG1], non-homologous end joining (Ku70/Ku80, DNA-PKcs) and homologous recombination [RAD51, BRCA1, γH2AX, BLM, WRN, RECQL5, PTEN] protein expression was correlated to time to early local recurrence. Pre-clinically, radio-sensitization by inhibition of Chk1 activation by ATR inhibitor (VE-821) and inhibition of Chk1 (V158411) were investigated in MDA-MB-231 (p53 mutant) and MCF-7 (p53 wild-type) breast cancer cells. In the whole cohort, 208/1755 patients (11.9%) developed local recurrence of which 126 (61%) developed local recurrence within 5 years of initiation of primary therapy. Of the 20 markers tested, only pChk1 and p53 significantly associated with early local recurrence (p value = 0.015 and 0.010, respectively). When analysed together, high cytoplasmic pChk1-nuclear pChk1 (p = 0.039), high cytoplasmic pChk1-p53 (p = 0.004) and high nuclear pChk1-p53 (p = 0.029) co-expression remain significantly linked to early local recurrence. In multivariate analysis, cytoplasmic pChk1 level independently predicted early local recurrence (p = 0.025). In patients who received adjuvant local radiotherapy (n = 949), p53 (p = 0.014) and high cytoplasmic pChk1-p53 (p = 0.017) remain associated with early local recurrence. Pre-clinically, radio-sensitisation by VE-821 or V158411 was observed in both MCF-7 and MDA-MB-231 cells and was more pronounced in MCF-7 cells. We conclude that pChk1 is a predictive biomarker of radiotherapy resistance and early local recurrence. PMID:26459098

  18. Th cells promote CTL survival and memory via acquired pMHC-I and endogenous IL-2 and CD40L signaling and by modulating apoptosis-controlling pathways.

    PubMed

    Umeshappa, Channakeshava Sokke; Xie, Yufeng; Xu, Shulin; Nanjundappa, Roopa Hebbandi; Freywald, Andrew; Deng, Yulin; Ma, Hong; Xiang, Jim

    2013-01-01

    Involvement of CD4(+) helper T (Th) cells is crucial for CD8(+) cytotoxic T lymphocyte (CTL)-mediated immunity. However, CD4(+) Th's signals that govern CTL survival and functional memory are still not completely understood. In this study, we assessed the role of CD4(+) Th cells with acquired antigen-presenting machineries in determining CTL fates. We utilized an adoptive co-transfer into CD4(+) T cell-sufficient or -deficient mice of OTI CTLs and OTII Th cells or Th cells with various gene deficiencies pre-stimulated in vitro by ovalbumin (OVA)-pulsed dendritic cell (DCova). CTL survival was kinetically assessed in these mice using FITC-anti-CD8 and PE-H-2K(b)/OVA257-264 tetramer staining by flow cytometry. We show that by acting via endogenous CD40L and IL-2, and acquired peptide-MHC-I (pMHC-I) complex signaling, CD4(+) Th cells enhance survival of transferred effector CTLs and their differentiation into the functional memory CTLs capable of protecting against highly-metastasizing tumor challenge. Moreover, RT-PCR, flow cytometry and Western blot analysis demonstrate that increased survival of CD4(+) Th cell-helped CTLs is matched with enhanced Akt1/NF-κB activation, down-regulation of TRAIL, and altered expression profiles with up-regulation of prosurvival (Bcl-2) and down-regulation of proapoptotic (Bcl-10, Casp-3, Casp-4, Casp-7) molecules. Taken together, our results reveal a previously unexplored mechanistic role for CD4(+) Th cells in programming CTL survival and memory recall responses. This knowledge could also aid in the development of efficient adoptive CTL cancer therapy. PMID:23785406

  19. Acquired C797S Mutation upon Treatment with a T790M-Specific Third-Generation EGFR Inhibitor (HM61713) in Non-Small Cell Lung Cancer.

    PubMed

    Song, Haa-Na; Jung, Ki Sun; Yoo, Kwai Han; Cho, Jinhyun; Lee, Ji Yun; Lim, Sung Hee; Kim, Hae Su; Sun, Jong-Mu; Lee, Se-Hoon; Ahn, Jin Seok; Park, Keunchil; Choi, Yoon-La; Park, Woongyang; Ahn, Myung-Ju

    2016-04-01

    T790M mutation is most common resistant mechanism to epidermal growth factor receptor gene (EGFR) tyrosin kinase inhibitor (TKI). Several third-generation EGFR-mutant selective TKI, such as AZD9291 (AstraZeneca), Rociletinib (Clovis), or HM61713 (Hanmi) have been developed. Acquired resistant C797S mutation was known to be one of the resistance mechanisms of AZD9291, which has not been reported for HM61713 yet. This is the first case report of C797S mutation as resistance mechanism of HM61713. PMID:26749488

  20. Small noncleaved B cell Burkitt-like lymphoma with chromosome t(8;14) translocation and Epstein-Barr virus nuclear-associated antigen in a homosexual man with acquired immune deficiency syndrome.

    PubMed

    Petersen, J M; Tubbs, R R; Savage, R A; Calabrese, L C; Proffitt, M R; Manolova, Y; Manolov, G; Shumaker, A; Tatsumi, E; McClain, K

    1985-01-01

    This case report describes new manifestations of the acquired immune deficiency syndrome (AIDS) in a promiscuous homosexual man. Investigation of upper gastrointestinal bleeding in the patient lead to discovery of a high-grade, small, noncleaved cell (Burkitt-like) gastroduodenal lymphoma with visceral and extralymphatic extension. Specific phenotyping of the lymphoma revealed that it was a monoclonal B cell lymphoma of mu kappa isotype. An in vitro cell line was established that was Epstein-Barr virus nuclear-associated antigen-positive. The lymphoma cells displayed a t(8;14) translocation similar to endemic African Burkitt lymphoma. Epstein-Barr virus genomes were identified in the lymphoma and an axillary lymph node biopsy specimen by molecular hybridization. These data strongly suggest that Epstein-Barr virus actively infected this patient. However, he showed normal Epstein-Barr virus-specific serologic responses, indicating an immune defect against the virus. PMID:2981469

  1. Comprehensive analysis of a multidimensional liquid chromatography mass spectrometry dataset acquired on a quadrupole selecting, quadrupole collision cell, time-of-flight mass spectrometer: I. How much of the data is theoretically interpretable by search engines?

    PubMed

    Chalkley, Robert J; Baker, Peter R; Hansen, Kirk C; Medzihradszky, Katalin F; Allen, Nadia P; Rexach, Michael; Burlingame, Alma L

    2005-08-01

    An in-depth analysis of a multidimensional chromatography-mass spectrometry dataset acquired on a quadrupole selecting, quadrupole collision cell, time-of-flight (QqTOF) geometry instrument was carried out. A total of 3269 CID spectra were acquired. Through manual verification of database search results and de novo interpretation of spectra 2368 spectra could be confidently determined as predicted tryptic peptides. A detailed analysis of the non-matching spectra was also carried out, highlighting what the non-matching spectra in a database search typically are composed of. The results of this comprehensive dataset study demonstrate that QqTOF instruments produce information-rich data of which a high percentage of the data is readily interpretable. PMID:15923566

  2. The combination of irreversible EGFR TKIs and SAHA induces apoptosis and autophagy-mediated cell death to overcome acquired resistance in EGFR T790M-mutated lung cancer.

    PubMed

    Lee, Tae-Gul; Jeong, Eun-Hui; Kim, Seo Yun; Kim, Hye-Ryoun; Kim, Cheol Hyeon

    2015-06-01

    To overcome T790M-mediated acquired resistance of lung cancer cells to epidermal growth factor receptor tyrosine kinase inhibitors (EGFR TKIs), second generation TKIs such as BIBW2992 (afatinib) and third generation TKIs including WZ4002 have been developed. However, clinical data on their efficacy in treating T790M mutant tumors are lacking. Histone deacetylase (HDAC) inhibitors have been reported to arrest cell growth and to lead to differentiation and apoptosis of various cancer cells, both in vitro and in vivo. In the present study, we assessed whether the combination of suberoylanilide hydroxamic acid (SAHA, vorinostat), a potent HDAC inhibitor, and BIBW2992 or WZ4002 could overcome EGFR TKI resistance associated with T790M mutation in lung cancer cells. While treatment with BIBW2992 or WZ4002 alone slightly reduced the viability of PC-9G and H1975 cells, which possess T790M mutation, combining them with SAHA resulted in significantly decreased cell viability through the activation of the apoptotic pathway. This combination also enhanced autophagy occurrence and inhibition of autophagy significantly reduced the apoptosis induced by the combination treatment, showing that autophagy is required for the enhanced apoptosis. Caspase-independent autophagic cell death was also induced by the combination treatment with SAHA and either BIBW2992 or WZ4002. Finally, the combined treatment with SAHA and either BIBW2992 or WZ4002 showed an enhanced anti-tumor effect on xenografts of H1975 cells in vivo. In conclusion, the combination of new generation EGFR TKIs and SAHA may be a new strategy to overcome the acquired resistance to EGFR TKIs in T790M mutant lung cancer. PMID:25382705

  3. Neuronal generation from somatic stem cells: current knowledge and perspectives on the treatment of acquired and degenerative central nervous system disorders.

    PubMed

    Corti, S; Locatelli, F; Strazzer, S; Guglieri, M; Comi, G P

    2003-06-01

    Stem cell transplantation through cell replacement or as vector for gene delivery is a potential strategy for the treatment of neurodegenerative diseases. Several studies have reported the transdifferentiation of different somatic stem cells into neurons in vitro or after transplantation into animal models. This observation has pointed out the perspective of using an ethical and accessible cell source to "replace" damaged neurons or provide support to brain tissue. However, recent findings such as the cell fusion phenomenon have raised some doubts about the real existence of somatic stem cell plasticity. In this review, we will discuss current evidence and controversial issues about the neuroneogenesis from various sources of somatic cells focusing on the techniques of isolation, expansion in vitro as well as the inductive factors that lead to transdifferentiation in order to identify the factors peculiar to this process. The morphological, immunochemical, and physiological criteria to correctly judge whether the neuronal transdifferentation occurred are critically presented. We will also discuss the transplantation experiments that were done in view of a possible clinical therapeutic application. Animal models of stroke, spinal cord and brain trauma have improved with Mesenchymal Stem Cells or Bone Marrow transplantation. This improvement does not seem to depend on the replacement of the lost neurons but may be due to increased expression levels of neurotrophic factors, thus suggesting a beneficial effect of somatic cells regardless of transdifferentiation. Critical understanding of available data on the mechanisms governing the cell fate reprogramming is a necessary achievement toward an effective cell therapy. PMID:12762483

  4. Myc induced miR-144/451 contributes to the acquired imatinib resistance in chronic myelogenous leukemia cell K562

    SciTech Connect

    Liu, Li; Wang, Sitao; Chen, Renan; Wu, Yanlan; Zhang, Bei; Huang, Siyong; Zhang, Jingyi; Xiao, Fang; Wang, Meng; Liang, Yingmin

    2012-08-24

    Highlights: Black-Right-Pointing-Pointer Increased c-myc expression in imatinib resistant CML cells. Black-Right-Pointing-Pointer c-myc contributes the imatinib resistance in CML cells. Black-Right-Pointing-Pointer c-myc transcriptionally reduces the expression of miR-144/451 in K562R cells. Black-Right-Pointing-Pointer Restoration of miR-144/451 reverses the resistance of K562R cells to imatinib. -- Abstract: Imatinib resistance remains the big hurdle for CML therapy. Previous study reveals that c-myc is important for bcr-abl CML cell proliferation, while its role in imatinib resistance is largely unknown. In this study, we first found that c-myc expression is upregulated in imatinib resistant K562R cells, which in turn enhances the expression of miR-144/451. Knockdown of c-myc or restoration of miR-144/451 in the K562R cells sensitizes K562R cells to imatinib therapy. Our study here reveals an regulatory pathway between myc and miR-144/451 and highlights that targeting either myc or miR-144/451 might be valuable for eliminating the imatinib resistant CML cells.

  5. Acute Acquired Concomitant Esotropia

    PubMed Central

    Chen, Jingchang; Deng, Daming; Sun, Yuan; Shen, Tao; Cao, Guobin; Yan, Jianhua; Chen, Qiwen; Ye, Xuelian

    2015-01-01

    Abstract Acute acquired concomitant esotropia (AACE) is a rare, distinct subtype of esotropia. The purpose of this retrospective study was to describe the clinical characteristics and discuss the classification and etiology of AACE. Charts from 47 patients with AACE referred to our institute between October 2010 and November 2014 were reviewed. All participants underwent a complete medical history, ophthalmologic and orthoptic examinations, and brain and orbital imaging. Mean age at onset was 26.6 ± 12.2 years. Of the 18 cases with deviations ≤ 20 PD, 16 presented with diplopia at distance and fusion at near vision at the onset of deviation; differences between distance and near deviations were < 8 PD; all cases except one were treated with prism and diplopia resolved. Of the 29 cases with deviations > 20 PD, 5 were mild hypermetropic with age at onset between 5 and 19 years, 16 were myopic, and 8 were emmetropic with age at onset > 12 years; 24 were surgically treated and 5 cases remained under observation; all 24 cases achieved normal retinal correspondence or fusion or stereopsis on postoperative day 1 in synoptophore; in 23 cases diplopia or visual confusion resolved postoperatively. Of the 47 cases, brain and orbital imaging in 2 cases revealed a tumor in the cerebellopontine angle and 1 case involved spinocerebellar ataxia as revealed by genetic testing. AACE in this study was characterized by a sudden onset of concomitant nonaccommodative esotropia with diplopia or visual confusion at 5 years of age or older and the potential for normal binocular vision. We suggest that AACE can be divided into 2 subgroups consisting of patients with relatively small versus large angle deviations. Coexisting or underlying neurological diseases were infrequent in AACE. PMID:26705210

  6. 16 CFR 801.2 - Acquiring and acquired persons.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... confer control of X and therefore will file as an acquiring person. Because A held the plant prior to the... within two persons, “A” and “B.” Under this section, if V is to acquire corporation X, both “A” and “B... person. Examples: 1. Assume that person “Q” will acquire voting securities of corporation X held by...

  7. 16 CFR 801.2 - Acquiring and acquired persons.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... confer control of X and therefore will file as an acquiring person. Because A held the plant prior to the... within two persons, “A” and “B.” Under this section, if V is to acquire corporation X, both “A” and “B... person. Examples: 1. Assume that person “Q” will acquire voting securities of corporation X held by...

  8. Spatio-temporal changes in glutathione and thioredoxin redox couples during ionizing radiation-induced oxidative stress regulate tumor radio-resistance.

    PubMed

    Patwardhan, R S; Sharma, D; Checker, R; Thoh, M; Sandur, S K

    2015-10-01

    Ionizing radiation (IR)-induced oxidative stress in tumor cells is effectively managed by constitutive and inducible antioxidant defense systems. This study was initiated to understand the relative contribution of different redox regulatory systems in determining the tumor radio-resistance. In this study, human T-cell lymphoma (Jurkat) cells were exposed to IR (4 Gy) and monitored for the spatio-temporal changes in cellular redox regulatory parameters. We monitored the changes in the levels of reactive oxygen species (ROS) (total, mitochondrial, primary, and secondary), thiols (total, surface, and intracellular), GSH/GSSG ratio, antioxidant enzyme activity viz. thioredoxin (Trx), Trx reductase (TrxR), glutathione peroxidase, and glutathione reductase with respect to time. We have also measured protein glutathionylation. We observed that tumor cells mount a biphasic response after IR exposure which can be divided into early (0-6 h) and late (16-48 h) responses in terms of changes in cellular redox parameters. During early response, constitutively active GSH and Trx systems respond to restore cellular redox balance to pre-exposure levels and help in activation of redox-sensitive transcription factor Nrf-2. During late response, increase in the levels of antioxidants GSH and Trx rescue cells against IR-mediated damage. We observed that disruption of either glutathione or thioredoxin metabolism led to partial impairment of ability of cells to survive against IR-induced damage. But simultaneous disruption of both the pathways significantly increased radio sensitivity of Jurkat cells. This highlighted the importance of these two antioxidant pathways in regulating redox homeostasis under conditions of IR-induced oxidative stress. PMID:26021764

  9. A faster, high resolution, mtPA-GFP-based mitochondrial fusion assay acquiring kinetic data of multiple cells in parallel using confocal microscopy.

    PubMed

    Lovy, Alenka; Molina, Anthony J A; Cerqueira, Fernanda M; Trudeau, Kyle; Shirihai, Orian S

    2012-01-01

    Mitochondrial fusion plays an essential role in mitochondrial calcium homeostasis, bioenergetics, autophagy and quality control. Fusion is quantified in living cells by photo-conversion of matrix targeted photoactivatable GFP (mtPAGFP) in a subset of mitochondria. The rate at which the photoconverted molecules equilibrate across the entire mitochondrial population is used as a measure of fusion activity. Thus far measurements were performed using a single cell time lapse approach, quantifying the equilibration in one cell over an hour. Here, we scale up and automate a previously published live cell method based on using mtPAGFP and a low concentration of TMRE (15 nm). This method involves photoactivating a small portion of the mitochondrial network, collecting highly resolved stacks of confocal sections every 15 min for 1 hour, and quantifying the change in signal intensity. Depending on several factors such as ease of finding PAGFP expressing cells, and the signal of the photoactivated regions, it is possible to collect around 10 cells within the 15 min intervals. This provides a significant improvement in the time efficiency of this assay while maintaining the highly resolved subcellular quantification as well as the kinetic parameters necessary to capture the detail of mitochondrial behavior in its native cytoarchitectural environment. Mitochondrial dynamics play a role in many cellular processes including respiration, calcium regulation, and apoptosis. The structure of the mitochondrial network affects the function of mitochondria, and the way they interact with the rest of the cell. Undergoing constant division and fusion, mitochondrial networks attain various shapes ranging from highly fused networks, to being more fragmented. Interestingly, Alzheimer's disease, Parkinson's disease, Charcot Marie Tooth 2A, and dominant optic atrophy have been correlated with altered mitochondrial morphology, namely fragmented networks. Often times, upon fragmentation

  10. [Acquired aplastic anemia].

    PubMed

    Yamazaki, Hirohito

    2016-02-01

    Idiopathic aplastic anemia (AA) is an autoimmune disease caused by T cells. An increase in the percentage of glycosylphosphatidylinositol-anchored protein-deficient cells and the presence of HLA allele-lacking leukocytes due to 6pUPD provide indirect evidence that T cells contribute to the pathophysiology of AA. Recent studies have revealed the presence of somatic mutations in MDS and/or AML candidate genes in one third of AA patients. Current treatment topics include the efficacy of eltrombopag for AA found to be refractory to immunosuppressive therapy as well as for newly diagnosed AA when administered in combination with ATG and cyclosporine. Furthermore, improved outcomes of allogeneic bone marrow transplantation from unrelated donors using reduced-intensity conditioning regimens have been obtained with eltrombopag. Fludarabine-based regimens are now the mainstream approach for preconditioning and have lowered the transplant-related mortality rate. However, new problems such as mixed chimerism and secondary graft failure have arisen. Attempts to prevent GVHD more efficiently by including ATG and alemtuzumab in the preconditioning regimen are being investigated. PMID:26935624

  11. Induction of Human Immunodeficiency Virus Type 1 (HIV-1)-Specific T-Cell Responses in HIV Vaccine Trial Participants Who Subsequently Acquire HIV-1 Infection

    PubMed Central

    Horton, Helen; Havenar-Daughton, Colin; Lee, Deborah; Moore, Erin; Cao, Jianhong; McNevin, John; Andrus, Thomas; Zhu, Haiying; Rubin, Abbe; Zhu, Tuofu; Celum, Connie; McElrath, M. Juliana

    2006-01-01

    Candidate human immunodeficiency virus type 1 (HIV-1) vaccines designed to elicit T-cell immunity in HIV-1-uninfected persons are under investigation in phase I to III clinical trials. Little is known about how these vaccines impact the immunologic response postinfection in persons who break through despite vaccination. Here, we describe the first comprehensive characterization of HIV-specific T-cell immunity in vaccine study participants following breakthrough HIV-1 infection in comparison to 16 nonvaccinated subjects with primary HIV-1 infection. Whereas none of the 16 breakthrough infections possessed vaccine-induced HIV-1-specific T-cell responses preinfection, 85% of vaccinees and 86% of nonvaccinees with primary HIV-1 infection developed HIV-specific T-cell responses postinfection. Breakthrough subjects' T cells recognized 43 unique HIV-1 T-cell epitopes, of which 8 are newly described, and 25% were present in the vaccine. The frequencies of gamma interferon (IFN-γ)-secreting cells recognizing epitopes within gene products that were and were not encoded by the vaccine were not different (P = 0.64), which suggests that responses were not anamnestic. Epitopes within Nef and Gag proteins were the most commonly recognized in both vaccinated and nonvaccinated infected subjects. One individual controlled viral replication without antiretroviral therapy and, notably, mounted a novel HIV-specific HLA-C14-restricted Gag LYNTVATL-specific T-cell response. Longitudinally, HIV-specific T cells in this individual were able to secrete IFN-γ and tumor necrosis factor alpha, as well as proliferate and degranulate in response to their cognate antigenic peptides up to 5 years postinfection. In conclusion, a vaccinee's ability to mount an HIV-specific T-cell response postinfection is not compromised by previous immunization, since the CD8+ T-cell responses postinfection are similar to those seen in vaccine-naïve individuals. Finding an individual who is controlling infection

  12. Acquired resistance to zoledronic acid and the parallel acquisition of an aggressive phenotype are mediated by p38-MAP kinase activation in prostate cancer cells

    PubMed Central

    Milone, M R; Pucci, B; Bruzzese, F; Carbone, C; Piro, G; Costantini, S; Capone, F; Leone, A; Di Gennaro, E; Caraglia, M; Budillon, A

    2013-01-01

    The nitrogen-containing bisphosphonates (N-BP) zoledronic acid (ZOL) inhibits osteoclast-mediated bone resorption, and it is used to prevent skeletal complications from bone metastases. ZOL has also demonstrated anticancer activities in preclinical models and, recently, in cancer patients, highlighting the interest in determining eventual mechanisms of resistance against this agent. In our study, we selected and characterised a resistant subline of prostate cancer (PCa) cells to better understand the mechanisms, by which tumour cells can escape the antitumour effect of ZOL. DU145R80-resistant cells were selected in about 5 months using stepwise increasing concentrations of ZOL from DU145 parental cells. DU145R80 cells showed a resistance index value of 5.5 and cross-resistance to another N-BP, pamidronate, but not to the non-nitrogen containing BP clodronate. Notably, compared with DU145 parental cells, DU145R80 developed resistance to apoptosis and anoikis, as well as overexpressed the anti-apoptotic protein Bcl-2 and oncoprotein c-Myc. Moreover, DU145R80 cells underwent epithelial to mesenchymal transition (EMT) and showed increased expression of the metalloproteases MMP-2/9, as well as increased invading capability. Interestingly, compared with DU145, DU145R80 cells also increased the gene expression and protein secretion of VEGF and the cytokines Eotaxin-1 and IL-12. At the molecular level, DU145R80 cells showed strong activation of the p38-MAPK-dependent survival pathway compared with parental sensitive cells. Moreover, using the p38-inhibitor SB203580, we completely reversed the resistance to ZOL, as well as EMT marker expression and invasion. Furthermore, SB203580 treatment reduced the expression of VEGF, Eotaxin-1, IL-12, MMP-9, Bcl-2 and c-Myc. Thus, for the first time, we demonstrate that the p38-MAPK pathway can be activated under continuous extensive exposure to ZOL in PCa cells and that the p38-MAPK pathway has a critical role in the induction of

  13. Acquired resistance to decitabine and cross-resistance to gemcitabine during the long-term treatment of human HCT116 colorectal cancer cells with decitabine

    PubMed Central

    HOSOKAWA, MIKA; SAITO, MAI; NAKANO, AIKO; IWASHITA, SAKURA; ISHIZAKA, AYANO; UEDA, KUMIKO; IWAKAWA, SEIGO

    2015-01-01

    The aim of the present study was to determine the effects of long-term exposure of decitabine (DAC) to HCT116 colorectal cancer (CRC) cells on the acquisition of resistance to DAC as well as cross-resistance to anticancer drugs used for CRC or other epigenetic modifiers. In the present study, DAC-resistant HCT116 CRC cells were established through long-term treatment with increasing concentrations of DAC (10 to 540 nM); and the cross-resistance to other drugs was subsequently examined. DAC-resistant HCT116 cells were obtained following a 104-day treatment with DAC, including DAC-free intervals. The results demonstrated that the IC50 value of DAC was increased ~100-fold in DAC-resistant HCT116 cells. Messenger (m)RNA expression of secreted frizzed-related protein 1 (SFRP1), which is regulated by DNA methylation, was not detected in DAC-resistant cells; however, SFRP1 mRNA was present in HCT116 cells treated with DAC for 52 days. DNA methyltransferase 1 (DNMT1) protein levels were slightly decreased until day 81 and then returned to control levels in DAC-resistant cells. Further experiments using DAC-resistant HCT116 cells revealed that these cells exhibited cross-resistance to gemcitabine (Gem); however, cross-resistance was not observed for other DNMT inhibitors (azacitidine and zebularine), histone deacetylase inhibitors (trichostatin A, vorinostat and valproic acid) or anticancer drugs for CRC (5-fluorouracil, irinotecan and oxaliplatin). Furthermore, the protein expression levels of cytidine deaminase (CDA) were increased, while those of deoxycytidine kinase (dCK) were decreased in DAC-resistant HCT116 cells; by contrast, the mRNA expression levels for these proteins were not significantly altered. In conclusion, the results of the present study indicated that the long-term treatment of HCT116 cells with DAC led to the acquisition of resistance to both DAC and Gem. In addition, these results may be partly attributed to changes in CDA and/or dCK, which are

  14. Phosphorylation of Deinococcus radiodurans RecA Regulates Its Activity and May Contribute to Radioresistance.

    PubMed

    Rajpurohit, Yogendra S; Bihani, Subhash C; Waldor, Matthew K; Misra, Hari S

    2016-08-01

    Deinococcus radiodurans has a remarkable capacity to survive exposure to extreme levels of radiation that cause hundreds of DNA double strand breaks (DSBs). DSB repair in this bacterium depends on its recombinase A protein (DrRecA). DrRecA plays a pivotal role in both extended synthesis-dependent strand annealing and slow crossover events of DSB repair during the organism's recovery from DNA damage. The mechanisms that control DrRecA activity during the D. radiodurans response to γ radiation exposure are unknown. Here, we show that DrRecA undergoes phosphorylation at Tyr-77 and Thr-318 by a DNA damage-responsive serine threonine/tyrosine protein kinase (RqkA). Phosphorylation modifies the activity of DrRecA in several ways, including increasing its affinity for dsDNA and its preference for dATP over ATP. Strand exchange reactions catalyzed by phosphorylated versus unphosphorylated DrRecA also differ. In silico analysis of DrRecA structure support the idea that phosphorylation can modulate crucial functions of this protein. Collectively, our findings suggest that phosphorylation of DrRecA enables the recombinase to selectively use abundant dsDNA substrate present during post-irradiation recovery for efficient DSB repair, thereby promoting the extraordinary radioresistance of D. radiodurans. PMID:27255712

  15. Mutations in the tyrosine kinase domain of FLT3 define a new molecular mechanism of acquired drug resistance to PTK inhibitors in FLT3-ITD-transformed hematopoietic cells.

    PubMed

    Bagrintseva, Ksenia; Schwab, Ruth; Kohl, Tobias M; Schnittger, Susanne; Eichenlaub, Sabine; Ellwart, Joachim W; Hiddemann, Wolfgang; Spiekermann, Karsten

    2004-03-15

    Activating mutations in the juxtamembrane domain (FLT3-length mutations, FLT3-LM) and in the protein tyrosine kinase domain (TKD) of FLT3 (FLT3-TKD) represent the most frequent genetic alterations in acute myeloid leukemia (AML) and define a molecular target for therapeutic interventions by protein tyrosine kinase (PTK) inhibitors. We could show that distinct activating FLT3-TKD mutations at position D835 mediate primary resistance to FLT3 PTK inhibitors in FLT3-transformed cell lines. In the presence of increasing concentrations of the FLT3 PTK inhibitor SU5614, we generated inhibitor resistant Ba/F3 FLT3-internal tandem duplication (ITD) cell lines (Ba/F3 FLT3-ITD-R1-R4) that were characterized by a 7- to 26-fold higher IC50 (concentration that inhibits 50%) to SU5614 compared with the parental ITD cells. The molecular characterization of ITD-R1-4 cells demonstrated that specific TKD mutations (D835N and Y842H) on the ITD background were acquired during selection with SU5614. Introduction of these dual ITD-TKD, but not single D835N or Y842H FLT3 mutants, in Ba/F3 cells restored the FLT3 inhibitor resistant phenotype. Our data show that preexisting or acquired mutations in the PTK domain of FLT3 can induce drug resistance to FLT3 PTK inhibitors in vitro. These findings provide a molecular basis for the evaluation of clinical resistance to FLT3 PTK inhibitors in patients with AML. PMID:14604974

  16. Effects of CDK4/6 Inhibition in Hormone Receptor-Positive/Human Epidermal Growth Factor Receptor 2-Negative Breast Cancer Cells with Acquired Resistance to Paclitaxel

    PubMed Central

    Trapé, Adriana Priscila; Liu, Shuying; Cortes, Andrea Carolina; Ueno, Naoto T.; Gonzalez-Angulo, Ana Maria

    2016-01-01

    Among patients with hormone receptor (HR)-positive breast cancer, those with residual disease after neoadjuvant chemotherapy have a higher risk of relapse and poorer survival than those with a complete response. Previous studies have revealed a correlation between activation of cell cycle-regulating pathways in HR-positive breast cancer, particularly cyclin-dependent kinase (CDK) 4 and 6/cyclin D1 signaling, and resistance to standard therapies. Although CDK4/6 inhibition by palbociclib in combination with endocrine therapy has shown potent antiproliferative effects in HR-positive/human epidermal growth factor receptor 2 (HER2)-negative breast cancer, the potential role of palbociclib in re-sensitizing chemotherapy-resistant HR-positive breast cancer is not well defined. We hypothesized that CDK4/6 inhibition by palbociclib re-sensitizes HR-positive/HER2-negative residual breast cancer to taxane-based adjuvant therapy. Using cell counting, flow cytometry, and western blotting, we evaluated the efficacy of palbociclib alone and in concurrent or sequential combination with paclitaxel in parental and paclitaxel-resistant T47D HR-positive/HER2-negative breast cancer cells. The CDK4/6 pathway was constitutively active in both parental and paclitaxel-resistant T47D cells; thus, both cell types were highly sensitive to the inhibitory effects of single-agent palbociclib on cell growth and cell cycle progression. However, palbociclib did not re-sensitize resistant cells to paclitaxel-induced G2/M arrest and cell death in any of the combinations tested. Our results suggest that CDK4/6 inhibition by palbociclib does not re-sensitize HR-positive/HER2-negative residual breast cancer to chemotherapy. Nevertheless, the fact that CDK4/6 activation remained intact in paclitaxel-resistant cells indicates that patients who have HR-positive/HER2-negative residual disease after taxane-based neoadjuvant chemotherapy may still benefit from palbociclib in combination with other regimens

  17. 16 CFR 801.2 - Acquiring and acquired persons.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... acquired person is the pre-acquisition ultimate parent entity of the entity. (ii) The value of an... directors of B. A is deemed to be acquiring all of the assets of B as a result. (g) Transfers of patent... transfer of patent rights covered by this paragraph constitutes an asset acquisition; and (3) Patent...

  18. Decreased DAB2IP gene expression, which could be induced by fractionated irradiation, is associated with resistance to γ‑rays and α‑particles in prostate cancer cells.

    PubMed

    Yang, Chen; He, Hui; Zhang, Tingting; Chen, Ying; Kong, Zhaolu

    2016-07-01

    External beam radiation therapy, alone or combined with androgen deprivation, is a well‑established treatment for prostate cancer (PCa). However, not all patients benefit from radiotherapy due to congenital or acquired radioresistance. The preliminary results of the present study indicated that the loss of disabled homolog 2 interactive protein (DAB2IP) expression in PCa and normal prostate epithelia results in the resistance to γ‑rays. To further explore the association between DAB2IP and ionizing radiation (IR), PCa cells were fractionally irradiated 12 times with 2 Gy of γ‑rays and the change in DAB2IP mRNA expression was monitored. Notably, along with a continuous reduction of DAB2IP expression levels, increased expression levels of ataxia‑telangiectasia mutated (ATM) was observed in IR‑treated cells. In order to improve the sensitivity of DAB2IP‑deficient cells to IR, α‑particles, a type of high linear energy transfer radiation and KU55933, an ATM inhibitor, were used in the current study. It was determined that α‑particle irradiations were more effective than γ‑rays on cells expressing expected and decreased levels of DAB2IP. However, cells with a dysfunctional DAB2IP gene were resistant to α‑particle irradiation. Treatment with KU55933 did not enhance cell sensitivity to α‑irradiation. Therefore, this suggested that DAB2IP downregulation induced by radiotherapy may be associated with acquired radioresistance in patients with PCa. PMID:27177018

  19. The chemotherapeutic drug boanmycin induces cell senescence and senescence-associated secretory phenotype factors, thus acquiring the potential to remodel the tumor microenvironment.

    PubMed

    Chen, Peng; Guo, Hua; Chen, Jinliang; Fu, Yujie

    2016-02-01

    Boanmycin hydrochloride, a new antitumor agent, functions similarly to bleomycin, but has a shorter half-life and faster clearance in vivo. Therefore, it is used in clinical studies for lung squamous cell cancer. However, previous studies have shown that besides its antitumor effect, bleomycin also induces the generation of senescence fibroblasts, which secrete senescence-associated secretory phenotype factors that have protumorigenic potential, consequently altering the tumor microenvironment. Hence, it is critical to clarify boanmycin potential in remodeling the tumor microenvironment after the chemotherapy treatment of tumors. Bone is the favorite organ for lung cancer metastasis. Thus, in this study, lung fibroblasts and bone osteoblasts (OBs) were used to reflect the resident stromal cells in the primary lung and bone metastatic microenvironment, respectively. Lung fibroblasts (IMR90) and primary OBs were treated with 6.7 μl/ml boanmycin or bleomycin for 24 h and MTT was monitored from day 1 to day 9; senescence-associated β-galactosidase staining, which indicated the cell senescence, was performed on day 7; and well-established senescence-associated secretory phenotype factor interleukin-6 expression was detected on day 9. MTT data showed that boanmycin inhibited cell proliferation in both IMR90 and OBs. Moreover, senescence-associated β-galactosidase staining showed that in response to boanmycin, there were 90% senescence cells in IMR90 and 95% in OBs. However, in vehicle, there were only 40 or 30% senescence cells, respectively. Furthermore, quantitative PCR data also showed that the interleukin-6 expression was highly induced by boanmycin to six-fold in OBs. Boanmycin treatment for cancer chemotherapy has the remodeling ability to alter the tumor microenvironment and might contribute toward lung cancer relapse and metastasis on long-term treatment. PMID:26460847

  20. Mechanisms of acquired resistance to the quinazoline thymidylate synthase inhibitor ZD1694 (Tomudex) in one mouse and three human cell lines.

    PubMed Central

    Jackman, A. L.; Kelland, L. R.; Kimbell, R.; Brown, M.; Gibson, W.; Aherne, G. W.; Hardcastle, A.; Boyle, F. T.

    1995-01-01

    Four cell lines, the mouse L1210 leukaemia, the human W1L2 lymphoblastoid and two human ovarian (CH1 and 41M) cell lines, were made resistant to ZD1694 (Tomudex) by continual exposure to incremental doses of the drug. A 500-fold increase in thymidylate synthase (TS) activity is the primary mechanism of resistance to ZD1694 in the W1L2:RD1694 cell line, which is consequently highly cross-resistant to other folate-based TS inhibitors, including BW1843U89, LY231514 and AG337, but sensitive to antifolates with other enzyme targets. The CH1:RD1694 cell line is 14-fold resistant to ZD1694, largely accounted for by the 4.2-fold increase in TS activity. Cross-resistance was observed to other TS inhibitors, including 5-fluorodeoxyuridine (FdUrd). 41M:RD1694 cells, when exposed to 0.1 microM [3H]ZD1694, accumulated approximately 20-fold less 3H-labelled material over 24 h than the parental line. Data are consistent with this being the result of impaired transport of the drug via the reduced folate/methotrexate carrier. Resistance was therefore observed to methotrexate but not to CB3717, a compound known to use this transport mechanism poorly. The mouse L1210:RD1694 cell line does not accumulate ZD1694 or Methotrexate (MTX) polyglutamates. Folylpolyglutamate synthetase substrate activity (using ZD1694 as the substrate) was decreased to approximately 13% of that observed in the parental line. Cross-resistance was found to those compounds known to be active through polyglutamation. PMID:7537518

  1. Dynamics of cell and tissue growth acquired by means of 25 mm2 to 10 cm2 lens-free imaging

    NASA Astrophysics Data System (ADS)

    Momey, F.; Coutard, J.-G.; Bordy, T.; Navarro, F.; Menneteau, M.; Dinten, J.-M.; Allier, C.

    2015-03-01

    In this paper, we discuss a new methodology based on lens-free imaging to perform wound healing assay with unprecedented statistics. Our video lens-free microscopy setup is a simple optical system featuring only a CMOS sensor and a semi coherent illumination system. Yet it is a powerful means for the real-time monitoring of cultivated cells. It presents several key advantages, e.g., integration into standard incubator, compatibility with standard cell culture protocol, simplicity and ease of use. It can perform the follow-up in a large field of view (25 mm2) of several crucial parameters during the culture of cells i.e. their motility, their proliferation rate or their death. Consequently the setup can gather large statistics both in space and time. But in the case of tissue growth experiments, the field of view of 25 mm2 remains not sufficient and results can be biased depending on the position of the device with respect to the recipient of the cell culture. Hence, to conduct exhaustive wound healing assay, here we propose to enlarge the field of view up to 10 cm2 through two different approaches. The first method consists in performing a scan of the cell culture by moving the source/sensor couple and then stitch the stack of images. The second is to make an acquisition by scanning with a line scan camera. The two approaches are compared in term of resolution, complexity and acquisition time. Next we have performed acquisitions of wound healing assay (keratinocytes HaCaT) both in real-time (25 mm2) and in final point (10 cm2) to assess the combination of these two complementary modalities. In the future, we aim at combining directly super wide field of view acquisitions (>10 cm2) with real time ability inside the incubator.

  2. Resistance of colorectal cancer cells to radiation and 5-FU is associated with MELK expression

    SciTech Connect

    Choi, Seungho; Ku, Ja-Lok

    2011-08-26

    Highlights: {yields} MELK expression significantly increased when the cells are exposed to radiation or 5-FU. {yields} Suppression of MELK caused cell cycle changes and decrease in proliferation. {yields} Radiation or 5-FU treatment after MELK suppression by siRNA induced growth inhibition. -- Abstract: It was reported that the local recurrence would be caused by cancer stem cells acquiring chemo- and radio-resistance. Recently, one of the potential therapeutic targets for colorectal and other cancers has been identified, which is maternal embryonic leucine zipper kinase (MELK). MELK is known as an embryonic and neural stem cell marker, and associated with the cell survival, cell proliferation, and apoptosis. In this study, SNU-503, which is a rectal cancer cell line, was treated with radiation or 5-fluorouracil (5-FU), and elevation of the MELK expression level was observed. Furthermore, the cell line was pre-treated with small interfering RNA (siRNA) against MELK mRNA before treatment of radiation or 5-FU and its effects on cell cycle and proliferation were observed. We demonstrated that knockdown of MELK reduced the proliferation of cells with radiation or 5-FU treatment. In addition, MELK suppression caused changes in cell cycle. In conclusion, MELK could be associated with increased resistance of colorectal cancer cells against radiation and 5-FU.

  3. Children Acquire Emotion Categories Gradually

    ERIC Educational Resources Information Center

    Widen, Sherri C.; Russell, James A.

    2008-01-01

    Some accounts imply that basic-level emotion categories are acquired early and quickly, whereas others imply that they are acquired later and more gradually. Our study examined this question for fear, happiness, sadness, and anger in the context of children's categorization of emotional facial expressions. Children (N=168, 2-5 years) first labeled…

  4. The fast milk acidifying phenotype of Streptococcus thermophilus can be acquired by natural transformation of the genomic island encoding the cell-envelope proteinase PrtS

    PubMed Central

    2011-01-01

    Background In industrial fermentation processes, the rate of milk acidification by Streptococcus thermophilus is of major technological importance. The cell-envelope proteinase PrtS was previously shown to be a key determinant of the milk acidification activity in this species. The PrtS enzyme is tightly anchored to the cell wall via a mechanism involving the typical sortase A (SrtA) and initiates the breakdown of milk casein into small oligopeptides. The presence or absence of PrtS divides the S. thermophilus strains into two phenotypic groups i.e. the slow and the fast acidifying strains. The aim of this study was to improve the milk acidification rate of slow S. thermophilus strains, and hence optimise the fermentation process of dairy products. Results In the present work, we developed for the first time a strategy based on natural transformation to confer the rapid acidification phenotype to slow acidifying starter strains of S. thermophilus. First, we established by gene disruption that (i) prtS, encoding the cell-envelope proteinase, is a key factor responsible for rapid milk acidification in fast acidifying strains, and that (ii) srtA, encoding sortase A, is not absolutely required to express the PrtS activity. Second, a 15-kb PCR product encompassing the prtS genomic island was transfered by natural transformation using the competence-inducing peptide in three distinct prtS-defective genetic backgrounds having or not a truncated sortase A gene. We showed that in all cases the milk acidification rate of transformants was significantly increased, reaching a level similar to that of wild-type fast acidifying strains. Furthermore, it appeared that the prtS-encoded activity does not depend on the prtS copy number or on its chromosomal integration locus. Conclusion We have successfully used natural competence to transfer the prtS locus encoding the cell-envelope proteinase in three slow acidifying strains of S. thermophilus, allowing their conversion into fast

  5. Current and temperature distributions in-situ acquired by electrode-segmentation along a microtubular solid oxide fuel cell operating with syngas

    NASA Astrophysics Data System (ADS)

    Aydın, Özgür; Nakajima, Hironori; Kitahara, Tatsumi

    2015-10-01

    Addressing the fuel distribution and endothermic cooling by the internal reforming, we have measured longitudinal current/temperature variations by "Electrode-segmentation" in a microtubular solid oxide fuel cell operated with syngas (50% pre-reformed methane) and equivalent H2/N2 (100% conversion of syngas to H2) at three different flow rates. Regardless of the syngas flow rates, currents and temperatures show irregular fluctuations with varying amplitudes from upstream to downstream segment. Analysis of the fluctuations suggests that the methane steam reforming reaction is highly affected by the H2 partial pressure. Current-voltage curves plotted for the syngas and equivalent H2/N2 flow rates reveal that the fuel depletion is enhanced toward the downstream during the syngas operation, resulting in a larger performance degradation. All the segments exhibit temperature drops with the syngas flow compared with the equivalent H2/N2 flow due to the endothermic cooling by the methane steam reforming reaction. Despite the drops, the segment temperatures remain above the furnace temperature; besides, the maximum temperature difference along the cell diminishes. The MSR reaction rate does not consistently increase with the decreasing gas inlet velocity (increasing residence time on the catalyst); which we ascribe to the dominating impact of the local temperatures.

  6. Differential T-cell responses to a chimeric Plasmodium falciparum antigen; UB05-09, correlates with acquired immunity to malaria.

    PubMed

    Dinga, J N; Njimoh, D L; Kiawa, B; Djikeng, A; Nyasa, R B; Nkuo-Akenji, T; Pellé, R; Titanji, V P K

    2016-05-01

    The development of a sterilizing and cost-effective vaccine against malaria remains a major problem despite recent advances. In this study, it is demonstrated that two antigens of P. falciparum UB05, UB09 and their chimera UB05-09 can serve as protective immunity markers by eliciting higher T-cell responses in malaria semi-immune subjects (SIS) than in frequently sick subjects (FSS) and could be used to distinguish these two groups. UB05, UB09 and UB05-09 were cloned, expressed in E. coli, purified and used to stimulate PBMCs isolated from 63 subjects in a malaria endemic area, for IFN-γ production, which was measured by the ELISpot assay. The polymorphism of UB09 gene in the malaria infected population was also studied by PCR/sequencing of the gene in P. falciparum field isolates. All three antigens were preferentially recognized by PBMCs from SIS. IFN-γ production induced by these antigens correlated with the absence of fever and parasitaemia. UB09 was shown to be relatively well-conserved in nature. It is concluded that UB05, UB09 and the chimera UB05-09 posses T-cell epitopes that are associated with protection against malaria and could thus be used to distinguish SIS from FSS eventhough acute infection with malaria has been shown to reduce cytokine production in some studies. Further investigations of these antigens as potential diagnostic and/or vaccine candidates for malaria are indicated. PMID:27012849

  7. Clinicopathological associations of acquired erythroblastopenia

    PubMed Central

    Gunes, Gursel; Malkan, Umit Yavuz; Yasar, Hatime Arzu; Eliacik, Eylem; Haznedaroglu, Ibrahim Celalettin; Demiroglu, Haluk; Sayinalp, Nilgun; Aksu, Salih; Etgul, Sezgin; Aslan, Tuncay; Goker, Hakan; Ozcebe, Osman Ilhami; Buyukasik, Yahya

    2015-01-01

    Introduction: Acquired erythroblastopenia (AE) is a rare clinical situation. It is characterized by the reduction of erythroid precursors in the bone marrow together with the low reticulocyte counts in the peripheral blood. Background: Main secondary causes of AE are drugs, Parvovirus B19 and other infectious reasons, lymphoid and myeloid neoplasia, autoimmune diseases, thymoma and pregnancy. The aim of this study is to assess the frequencies and clinical associations of AE via analyzing 12340 bone marrow samples in a retrospective manner. Material and method: Bone marrow aspirations which were obtained from patients who applied to Hacettepe University Hematology Clinic between 2002 and 2013, were analyzed retrospectively. Results: Thirty four erythroblastopenia cases were found. Patients ranged in age from 16 to 80 years with a median of 38 years. Fifteen patients were men (44%) and nineteen were women (56%). In these patients, detected causes of erythroblastopenia were MDS, idiopathic pure red cell aplasia (PRCA), parvovirus infection, post chemotherapy aplasia, plasma proliferative diseases, copper deficiency due to secondary amyloidosis, fever of unknown origin, hemophagocytic syndrome, enteric fever and legionella pneumonia. We found that between those reasons the most common causes of erythroblastopenia are MDS (17.7%) and idiopathic PRCA (17.7%). Discussion: As a result, erythroblastopenia in the bone marrow may be an early sign of MDS. In those AE cases possibility of being MDS must be kept in mind as it can be mistaken for PRCA. Conclusion: To conclude, in adults MDS without excess blast is one of the most common causes of erythroblastopenia in clinical practice and in case of erythroblastopenia the presence of MDS should be investigated. PMID:26885236

  8. Targeting WISP1 to sensitize esophageal squamous cell carcinoma to irradiation

    PubMed Central

    Peng, Jin; Jiang, Zhenzhen; Song, Tao; Wu, Bo; Yue, Jing; Zhou, Rongjing; Xie, Ruifei; Chen, Tian; Wu, Shixiu

    2015-01-01

    Radiotherapy is a primary treatment modality for esophageal squamous cell carcinoma (ESCC). However, most of patients benefited little from radiotherapy due to refractory radioresistance. We found that WISP1, a downstream target gene of Wnt/β-catenin pathway, was re-expressed in 67.3 % of ESCC patients as an oncofetal gene. Expression of WISP1 predicted prognosis of ESCC patients treated with radiotherapy. Overall survival in WISP1-positive patients was significantly poorer than in WISP1-negative patients. Serum concentration of WISP1 after radiotherapy reversely correlated with relapse-free survival. Gain and loss of function studies confirmed that WISP1 mediated radioresistance both in esophageal squamous cancer cells and in xenograft tumor models. Further studies revealed that WISP1 contributed to radioresistance primarily by repressing irradiation-induced DNA damage and activating PI3K kinase. LncRNA BOKAS was up-regulated following radiation and promoted WISP1 expression and resultant radioresistance. Furthermore, WISP1 facilitated its own expression in response to radiation, creating a positive feedback loop and increased radioresistance. Our study revealed WISP1 as a potential target to overcome radioresistance in ESCC.  PMID:25749038

  9. T cell reactivity against antigen 85 but not against the 18- and 65-kD heat shock proteins in the early stages of acquired immunity against Mycobacterium leprae.

    PubMed

    Launois, P; Niang N'Diaye, M; Sarthou, J L; Drowart, A; Van Vooren, J P; Cartel, J L; Huygen, K

    1994-04-01

    T cell proliferation and interferon-gamma (IFN-gamma) production of peripheral blood mononuclear cells (PBMC) from 20 household contacts were tested against the 18- and 65-kD heat shock proteins from Mycobacterium leprae (ML18 and ML65 respectively) and antigen 85 from Myco. bovis bacille Calmette-Guérin (BCG) (Ag 85) during a 12-months follow-up study. Among the eight contacts that became positive, eight showed positive reactivity against Ag 85, 5/8 against ML65 and 4/8 against ML18 at the end of the study. Of the 16 contacts who were lepromin-positive either at first or second testing, all responded to Ag 85, 11 to ML 65, but only eight reacted to ML18 antigen. Contacts who were lepromin-positive at first testing developed responses to ML18 only at second testing. In contrast, among the four contacts that remained lepromin-negative during the follow up, three proliferated to Ag 85 either at first or second testing, but only one produced IFN-gamma against Ag 85 at the end of the study. These results demonstrated that T cell reactivity and particularly IFN-gamma secretion against Ag 85, but not against ML18 and ML65, might be a predominant mechanism in the early stages of acquired protective immunity against Myco. leprae. PMID:8149672

  10. In vitro expanded bone marrow-derived murine (C57Bl/KaLwRij) mesenchymal stem cells can acquire CD34 expression and induce sarcoma formation in vivo

    SciTech Connect

    Xu, Song; De Becker, Ann; De Raeve, Hendrik; Van Camp, Ben; Vanderkerken, Karin; Van Riet, Ivan

    2012-08-03

    Highlights: Black-Right-Pointing-Pointer Murine MSCs can undergo spontaneously malignant transformation and form sarcoma. Black-Right-Pointing-Pointer Acquisition of CD34 is a transformation type for MSCs into sarcoma. Black-Right-Pointing-Pointer Notch/Hh/Wnt pathways are related to the malignant phenotype of transformed MSCs. -- Abstract: Mesenchymal stem cells (MSCs) have currently generated numerous interests in pre-clinical and clinical applications due to their multiple lineages differentiation potential and immunomodulary effects. However, accumulating evidence indicates that MSCs, especially murine MSCs (mMSCs), can undergo spontaneous transformation after long-term in vitro culturing, which might reduce the therapeutic application possibilities of these stem cells. In the present study, we observed that in vitro expanded bone marrow (BM) derived mMSCs from the C57Bl/KaLwRij mouse strain can lose their specific stem cells markers (CD90 and CD105) and acquire CD34 expression, accompanied with an altered morphology and an impaired tri-lineages differentiation capacity. Compared to normal mMSCs, these transformed mMSCs exhibited an increased proliferation rate, an enhanced colony formation and migration ability as well as a higher sensitivity to anti-tumor drugs. Transformed mMSCs were highly tumorigenic in vivo, resulting in aggressive sarcoma formation when transplanted in non-immunocompromised mice. Furthermore, we found that Notch signaling downstream genes (hey1, hey2 and heyL) were significantly upregulated in transformed mMSCs, while Hedgehog signaling downstream genes Gli1 and Ptch1 and the Wnt signaling downstream gene beta-catenin were all decreased. Taken together, we observed that murine in vitro expanded BM-MSCs can transform into CD34 expressing cells that induce sarcoma formation in vivo. We assume that dysregulation of the Notch(+)/Hh(-)/Wnt(-) signaling pathway is associated with the malignant phenotype of the transformed mMSCs.

  11. Acquired cystic disease-associated renal cell carcinoma with a focal sarcomatoid component: Report of a case showing more pronounced polysomy of chromosomes 3 and 16 in the sarcomatoid component.

    PubMed

    Tajima, Shogo; Waki, Michihiko; Doi, Wataru; Hayashi, Kazumasa; Takenaka, Syunsuke; Fukaya, Yoshie; Kimura, Ryosuke

    2015-02-01

    Acquired cystic disease (ACD)-associated renal cell carcinoma (RCC) has recently been established. Herein we report the sixth case of ACD-associated RCC with a sarcomatoid change. The patient was a 77-year-old man who regularly underwent hemodialysis for 14 years due to chronic renal failure resulting from IgA nephropathy. On computed tomography, a large right RCC was observed with contrast enhancement in the arterial phase. A nodular protrusion into the perirenal fat was detected. Right nephrectomy was performed under laparoscopy. Surgically resected specimens revealed a tan-to-yellow tumor (95 × 75 × 55 mm) with a whitish nodule (20 × 15 × 15 mm) invading into the perirenal fat. Histopathologically, the large carcinoma component of the tumor displayed a cribriform or microcystic growth pattern with deposition of oxalate crystals. The whitish nodule corresponded to the sarcomatoid component, and the spindled and pleomorphic tumor cells showed diffuse positivity of p53 on immunohistochemistry. Fluorescence in situ hybridization revealed trisomy of chromosomes 3 and 16 in the carcinoma component, as was expected from the literature. In addition, increased polysomy of these chromosomes was also observed in the sarcomatoid component. This finding may be related to the development of the sarcomatoid component along with the TP53 mutation. PMID:25424516

  12. Sensitivity of light-grown and dark-grown Euglena cells to gamma-irradiation.

    PubMed

    Nair, K A; Netrawali, M S

    1979-09-01

    Light-grown cells which contain fully developed chloroplasts were found to be more resistant to gamma-irradiation than dark-grown cells which are devoid of chloroplasts. The radio-resistance of dark-grown cells progressively increased during light-induced development of chloroplasts and, conversely, radio-resistance of light-grown cells decreased progressively with chloroplast de-development during growth in the dark. The presence of chloroplasts seemed to play a major role in the capacity of cells to recover from radiation damage, the efficiency of cellular recovery being correlatable with the degree of chloroplast development. PMID:315395

  13. Acquired Equivalence Changes Stimulus Representations

    ERIC Educational Resources Information Center

    Meeter, M.; Shohamy, D.; Myers, C. E.

    2009-01-01

    Acquired equivalence is a paradigm in which generalization is increased between two superficially dissimilar stimuli (or antecedents) that have previously been associated with similar outcomes (or consequents). Several possible mechanisms have been proposed, including changes in stimulus representations, either in the form of added associations or…

  14. Extracting the normal lung dose-response curve from clinical DVH data: a possible role for low dose hyper-radiosensitivity, increased radioresistance

    NASA Astrophysics Data System (ADS)

    Gordon, J. J.; Snyder, K.; Zhong, H.; Barton, K.; Sun, Z.; Chetty, I. J.; Matuszak, M.; Ten Haken, R. K.

    2015-09-01

    In conventionally fractionated radiation therapy for lung cancer, radiation pneumonitis’ (RP) dependence on the normal lung dose-volume histogram (DVH) is not well understood. Complication models alternatively make RP a function of a summary statistic, such as mean lung dose (MLD). This work searches over damage profiles, which quantify sub-volume damage as a function of dose. Profiles that achieve best RP predictive accuracy on a clinical dataset are hypothesized to approximate DVH dependence. Step function damage rate profiles R(D) are generated, having discrete steps at several dose points. A range of profiles is sampled by varying the step heights and dose point locations. Normal lung damage is the integral of R(D) with the cumulative DVH. Each profile is used in conjunction with a damage cutoff to predict grade 2 plus (G2+) RP for DVHs from a University of Michigan clinical trial dataset consisting of 89 CFRT patients, of which 17 were diagnosed with G2+ RP. Optimal profiles achieve a modest increase in predictive accuracy—erroneous RP predictions are reduced from 11 (using MLD) to 8. A novel result is that optimal profiles have a similar distinctive shape: enhanced damage contribution from low doses (<20 Gy), a flat contribution from doses in the range ~20-40 Gy, then a further enhanced contribution from doses above 40 Gy. These features resemble the hyper-radiosensitivity / increased radioresistance (HRS/IRR) observed in some cell survival curves, which can be modeled using Joiner’s induced repair model. A novel search strategy is employed, which has the potential to estimate RP dependence on the normal lung DVH. When applied to a clinical dataset, identified profiles share a characteristic shape, which resembles HRS/IRR. This suggests that normal lung may have enhanced sensitivity to low doses, and that this sensitivity can affect RP risk.

  15. Genome-wide study predicts promoter-G4 DNA motifs regulate selective functions in bacteria: radioresistance of D. radiodurans involves G4 DNA-mediated regulation

    PubMed Central

    Beaume, Nicolas; Pathak, Rajiv; Yadav, Vinod Kumar; Kota, Swathi; Misra, Hari S.; Gautam, Hemant K.; Chowdhury, Shantanu

    2013-01-01

    A remarkable number of guanine-rich sequences with potential to adopt non-canonical secondary structures called G-quadruplexes (or G4 DNA) are found within gene promoters. Despite growing interest, regulatory role of quadruplex DNA motifs in intrinsic cellular function remains poorly understood. Herein, we asked whether occurrence of potential G4 (PG4) DNA in promoters is associated with specific function(s) in bacteria. Using a normalized promoter-PG4-content (PG4P) index we analysed >60 000 promoters in 19 well-annotated species for (a) function class(es) and (b) gene(s) with enriched PG4P. Unexpectedly, PG4-associated functional classes were organism specific, suggesting that PG4 motifs may impart specific function to organisms. As a case study, we analysed radioresistance. Interestingly, unsupervised clustering using PG4P of 21 genes, crucial for radioresistance, grouped three radioresistant microorganisms including Deinococcus radiodurans. Based on these predictions we tested and found that in presence of nanomolar amounts of the intracellular quadruplex-binding ligand N-methyl mesoporphyrin (NMM), radioresistance of D. radiodurans was attenuated by ∼60%. In addition, important components of the RecF recombinational repair pathway recA, recF, recO, recR and recQ genes were found to harbour promoter-PG4 motifs and were also down-regulated in presence of NMM. Together these results provide first evidence that radioresistance may involve G4 DNA-mediated regulation and support the rationale that promoter-PG4s influence selective functions. PMID:23161683

  16. An enhanced and sensitive autocrine stimulation by transforming growth factor-alpha is acquired in the brain metastatic variant of a human non-small-cell lung cancer cell line.

    PubMed

    Fang, K

    1996-12-01

    Transforming growth factor-alpha (TGF-alpha)-mediated autocrine regulation in human non-small-cell lung cancer (NSCLC) cells NCI-H226 and its brain metastatic variant H226Br were compared. An enhanced TGF-alpha-induced dose-dependent mitogenic responsiveness in H226Br cells was observed. Neutralising antibody that binds TGF-alpha inhibits H226Br cell growth more effectively than NCI-H226 cell growth. Binding assay with 125I-labelled epidermal growth factor (EGF) revealed that H226Br has two types of EGF receptors (EGFRs), whereas the parental cell line, NCI-H226, has only one. H226Br cells contain twice as many EGFRs as H226 cells, as proved by Scatchard analysis and immune kinase assay. Northern analysis indicated that there is more EGFR transcript in H226Br than in NCI-H226, indicating a transcriptional EGFR gene elevation during metastasis progression. The level of accumulated immunoactive TGF-alpha is lower in the conditioned medium of H226Br than in that of NCI-H226. demonstrating down-regulation of TGF-alpha transcript. The accumulated data suggest an elevated and sensitive autocrine modulation by TGF-alpha and EGFR in immortalising the brain metastatic variant cells that were derived from a human NSCLC squamous cell line. PMID:8956792

  17. Acquired causes of intestinal malabsorption.

    PubMed

    van der Heide, F

    2016-04-01

    This review focuses on the acquired causes, diagnosis, and treatment of intestinal malabsorption. Intestinal absorption is a complex process that depends on many variables, including the digestion of nutrients within the intestinal lumen, the absorptive surface of the small intestine, the membrane transport systems, and the epithelial absorptive enzymes. Acquired causes of malabsorption are classified by focussing on the three phases of digestion and absorption: 1) luminal/digestive phase, 2) mucosal/absorptive phase, and 3) transport phase. Most acquired diseases affect the luminal/digestive phase. These include short bowel syndrome, extensive small bowel inflammation, motility disorders, and deficiencies of digestive enzymes or bile salts. Diagnosis depends on symptoms, physical examination, and blood and stool tests. There is no gold standard for the diagnosis of malabsorption. Further testing should be based on the specific clinical context and the suspected underlying disease. Therapy is directed at nutritional support by enteral or parenteral feeding and screening for and supplementation of deficiencies in vitamins and minerals. Early enteral feeding is important for intestinal adaptation in short bowel syndrome. Medicinal treatment options for diarrhoea in malabsorption include loperamide, codeine, cholestyramine, or antibiotics. PMID:27086886

  18. Single Strand Annealing Plays a Major Role in RecA-Independent Recombination between Repeated Sequences in the Radioresistant Deinococcus radiodurans Bacterium

    PubMed Central

    Ithurbide, Solenne; Bentchikou, Esma; Coste, Geneviève; Bost, Bruno; Servant, Pascale; Sommer, Suzanne

    2015-01-01

    The bacterium Deinococcus radiodurans is one of the most radioresistant organisms known. It is able to reconstruct a functional genome from hundreds of radiation-induced chromosomal fragments. Our work aims to highlight the genes involved in recombination between 438 bp direct repeats separated by intervening sequences of various lengths ranging from 1,479 bp to 10,500 bp to restore a functional tetA gene in the presence or absence of radiation-induced DNA double strand breaks. The frequency of spontaneous deletion events between the chromosomal direct repeats were the same in recA+ and in ΔrecA, ΔrecF, and ΔrecO bacteria, whereas recombination between chromosomal and plasmid DNA was shown to be strictly dependent on the RecA and RecF proteins. The presence of mutations in one of the repeated sequence reduced, in a MutS-dependent manner, the frequency of the deletion events. The distance between the repeats did not influence the frequencies of deletion events in recA + as well in ΔrecA bacteria. The absence of the UvrD protein stimulated the recombination between the direct repeats whereas the absence of the DdrB protein, previously shown to be involved in DNA double strand break repair through a single strand annealing (SSA) pathway, strongly reduces the frequency of RecA- (and RecO-) independent deletions events. The absence of the DdrB protein also increased the lethal sectoring of cells devoid of RecA or RecO protein. γ-irradiation of recA + cells increased about 10-fold the frequencies of the deletion events, but at a lesser extend in cells devoid of the DdrB protein. Altogether, our results suggest a major role of single strand annealing in DNA repeat deletion events in bacteria devoid of the RecA protein, and also in recA + bacteria exposed to ionizing radiation. PMID:26517555

  19. Single Strand Annealing Plays a Major Role in RecA-Independent Recombination between Repeated Sequences in the Radioresistant Deinococcus radiodurans Bacterium.

    PubMed

    Ithurbide, Solenne; Bentchikou, Esma; Coste, Geneviève; Bost, Bruno; Servant, Pascale; Sommer, Suzanne

    2015-10-01

    The bacterium Deinococcus radiodurans is one of the most radioresistant organisms known. It is able to reconstruct a functional genome from hundreds of radiation-induced chromosomal fragments. Our work aims to highlight the genes involved in recombination between 438 bp direct repeats separated by intervening sequences of various lengths ranging from 1,479 bp to 10,500 bp to restore a functional tetA gene in the presence or absence of radiation-induced DNA double strand breaks. The frequency of spontaneous deletion events between the chromosomal direct repeats were the same in recA+ and in ΔrecA, ΔrecF, and ΔrecO bacteria, whereas recombination between chromosomal and plasmid DNA was shown to be strictly dependent on the RecA and RecF proteins. The presence of mutations in one of the repeated sequence reduced, in a MutS-dependent manner, the frequency of the deletion events. The distance between the repeats did not influence the frequencies of deletion events in recA+ as well in ΔrecA bacteria. The absence of the UvrD protein stimulated the recombination between the direct repeats whereas the absence of the DdrB protein, previously shown to be involved in DNA double strand break repair through a single strand annealing (SSA) pathway, strongly reduces the frequency of RecA- (and RecO-) independent deletions events. The absence of the DdrB protein also increased the lethal sectoring of cells devoid of RecA or RecO protein. γ-irradiation of recA+ cells increased about 10-fold the frequencies of the deletion events, but at a lesser extend in cells devoid of the DdrB protein. Altogether, our results suggest a major role of single strand annealing in DNA repeat deletion events in bacteria devoid of the RecA protein, and also in recA+ bacteria exposed to ionizing radiation. PMID:26517555

  20. Perioperatively acquired disorders of coagulation

    PubMed Central

    Grottke, Oliver; Fries, Dietmar; Nascimento, Bartolomeu

    2015-01-01

    Purpose of review To provide an overview of acquired coagulopathies that can occur in various perioperative clinical settings. Also described are coagulation disturbances linked to antithrombotic medications and currently available strategies to reverse their antithrombotic effects in situations of severe hemorrhage. Recent findings Recent studies highlight the link between low fibrinogen and decreased fibrin polymerization in the development of acquired coagulopathy. Particularly, fibrin(ogen) deficits are observable after cardiopulmonary bypass in cardiac surgery, on arrival at the emergency room in trauma patients, and with ongoing bleeding after child birth. Regarding antithrombotic therapy, although new oral anticoagulants offer the possibility of efficacy and relative safety compared with vitamin K antagonists, reversal of their anticoagulant effect with nonspecific agents, including prothrombin complex concentrate, has provided conflicting results. Specific antidotes, currently being developed, are not yet licensed for clinical use, but initial results are promising. Summary Targeted hemostatic therapy aims to correct coagulopathies in specific clinical settings, and reduce the need for allogeneic transfusions, thus preventing massive transfusion and its deleterious outcomes. Although there are specific guidelines for reversing anticoagulation in patients treated with antiplatelet agents or warfarin, there is currently little evidence to advocate comprehensive recommendations to treat drug-induced coagulopathy associated with new oral anticoagulants. PMID:25734869

  1. Foodborne listeriosis acquired in hospitals.

    PubMed

    Silk, Benjamin J; McCoy, Morgan H; Iwamoto, Martha; Griffin, Patricia M

    2014-08-15

    Listeriosis is characterized by bacteremia or meningitis. We searched for listeriosis case series and outbreak investigations published in English by 2013, and assessed the strength of evidence for foodborne acquisition among patients who ate hospital food. We identified 30 reports from 13 countries. Among the case series, the median proportion of cases considered to be hospital-acquired was 25% (range, 9%-67%). The median number of outbreak-related illnesses considered to be hospital-acquired was 4.0 (range, 2-16). All patients were immunosuppressed in 18 of 24 (75%) reports with available data. Eight outbreak reports with strong evidence for foodborne acquisition in a hospital implicated sandwiches (3 reports), butter, precut celery, Camembert cheese, sausage, and tuna salad (1 report each). Foodborne acquisition of listeriosis among hospitalized patients is well documented internationally. The number of listeriosis cases could be reduced substantially by establishing hospital policies for safe food preparation for immunocompromised patients and by not serving them higher-risk foods. PMID:24846635

  2. Inhibition of HAS2 induction enhances the radiosensitivity of cancer cells via persistent DNA damage

    SciTech Connect

    Shen, Yan Nan; Shin, Hyun-Jin; Joo, Hyun-Yoo; Park, Eun-Ran; Kim, Su-Hyeon; Hwang, Sang-Gu; Park, Sang Jun; Kim, Chun-Ho; Lee, Kee-Ho

    2014-01-17

    Highlights: •HAS2 may be a promising target for the radiosensitization of human cancer. •HAS2 is elevated (up to ∼10-fold) in irradiated radioresistant and -sensitive cancer cells. •HAS2 knockdown sensitizes cancer cells to radiation. •HAS2 knockdown potentiates irradiation-induced DNA damage and apoptotic death. •Thus, the irradiation-induced up-regulation of HAS2 contributes to the radioresistance of cancer cells. -- Abstract: Hyaluronan synthase 2 (HAS2), a synthetic enzyme for hyaluronan, regulates various aspects of cancer progression, including migration, invasion and angiogenesis. However, the possible association of HAS2 with the response of cancer cells to anticancer radiotherapy, has not yet been elucidated. Here, we show that HAS2 knockdown potentiates irradiation-induced DNA damage and apoptosis in cancer cells. Upon exposure to radiation, all of the tested human cancer cell lines exhibited marked (up to 10-fold) up-regulation of HAS2 within 24 h. Inhibition of HAS2 induction significantly reduced the survival of irradiated radioresistant and -sensitive cells. Interestingly, HAS2 depletion rendered the cells to sustain irradiation-induced DNA damage, thereby leading to an increase of apoptotic death. These findings indicate that HAS2 knockdown sensitizes cancer cells to radiation via persistent DNA damage, further suggesting that the irradiation-induced up-regulation of HAS2 contributes to the radioresistance of cancer cells. Thus, HAS2 could potentially be targeted for therapeutic interventions aimed at radiosensitizing cancer cells.

  3. Acquired immunodeficiency syndrome: neuroradiologic findings.

    PubMed

    Kelly, W M; Brant-Zawadzki, M

    1983-11-01

    Central nervous system complications depicted by CT in ten patients with acquired immunodeficiency syndrome are described. Three patients had multifocal intra-axial enhancing lesions representing atypical brain abscesses (two with toxoplasmosis, one with candidiasis). A fourth patient with multifocal "ring" lesions whose biopsy was interpreted as suggestive of toxoplasmosis responded poorly to treatment. Following his death three months later of Pneumocystis carinii pneumonia, autopsy revealed primary intracerebral immunoblastic lymphoma. One patient had Kaposi sarcoma involving the right frontal lobe (seen as an enhancing mass on the CT scan). CT findings in the remaining five patients revealed mild to moderate enlargement of cerebrospinal fluid spaces (including ventricles and basal cisternae) as a result of cryptococcal meningitis in three patients and "aseptic" meningitis in two. The two patients in whom early biopsy confirmed toxoplasmosis responded well to anti-infective therapy, resulting in dramatic clinical recoveries. PMID:6622693

  4. Bejel: acquirable only in childhood?

    PubMed

    Rothschild, Bruce M; Rothschild, Christine; Naples, Virginia; Billard, Michel; Panero, Barbara

    2006-10-01

    Bejel clearly has a long history in the Middle East and the Sudan, but was it transmitted to Europe? As the major manifestation of bejel is presence of periosteal reaction in 20-40% of afflicted populations, absence of significant population frequency of periosteal reaction in Europe would exclude that diagnosis. Examination of skeletal populations from continental Europe revealed no significant periosteal reaction at the time of and immediately subsequent to the Crusades. Thus, there is no evidence for bejel in Europe, in spite of clear contact (the mechanism of bejel transmission in children) between warring groups, at least during the Crusades. This supports the hypothesis that bejel is a childhood-acquired disease and apparently cannot be contracted in adulthood. PMID:17049474

  5. Loss of Raf Kinase Inhibitory Protein Induces Radioresistance in Prostate Cancer

    SciTech Connect

    Woods Ignatoski, Kathleen M.; Grewal, Navdeep K.; Markwart, Sonja M.; Vellaichamy, Adaikkalam; Chinnaiyan, Arul M.; Yeung, Kam; Ray, Michael E.; Keller, Evan T.

    2008-09-01

    Purpose: External beam radiotherapy (RT) is often used in an attempt to cure localized prostate cancer (PCa), but it is only palliative against disseminated disease. Raf kinase inhibitory protein (RKIP) is a metastasis suppressor whose expression is reduced in approximately 50% of localized PCa tissues and is absent in metastases. Chemotherapeutic agents have been shown to induce tumor apoptosis through induction of RKIP expression. Our goal was to test whether RT similarly induces apoptosis through induction of RKIP expression. Methods and Materials: The C4-2B PCa cell line was engineered to overexpress or underexpress RKIP. The engineered cells were tested for apoptosis in cell culture and tumor regression in mice after RT. Results: RT induced both RKIP expression and apoptosis of PCa cells. Overexpression of RKIP sensitized PCa cells to radiation-induced apoptosis. In contrast, short-hairpin targeting of RKIP, so that RT could not induce RKIP expression, protected cells from radiation-induced apoptosis. In a murine model, knockdown of RKIP in PCa cells diminished radiation-induced apoptosis. Molecular concept mapping of genes altered on manipulation of RKIP expression revealed an inverse correlation with the concept of genes altered by RT. Conclusion: The data presented in this report indicate that the loss of RKIP, as seen in primary PCa tumors and metastases, confers protection against radiation-induced apoptosis. Therefore, it is conceivable that the loss of RKIP confers a growth advantage on PCa cells at distant sites, because the loss of RKIP would decrease apoptosis, favoring proliferation.

  6. Treatment of the acquired von Willebrand syndrome.

    PubMed

    Budde, Ulrich; Scheppenheim, Sonja; Dittmer, Rita

    2015-12-01

    Acquired von Willebrand syndrome (aVWS) accounts for 22% of patients with abnormal von Willebrand factor. Most patients with known pathophysiological mechanisms suffer from cardiovascular, myeloproliferative and lymphoproliferative disorders. Less frequent associations are of autoimmune origin, due to hyperfibrinolysis, adsorption to tumor cells, reduced synthesis and prolonged circulation. The mechanisms leading to aVWS is hitherto not known in patients with liver and kidney diseases, drug use, glycogen storage disease, virus infections and at least 18 other disease entities. Diagnosis is complicated by the battery of tests needed, and their inherent rather low sensitivity and specificity for aVWS. Thus, even in acute bleeding situations it may take days until a firm diagnosis is settled and specific therapies can be initiated. The main aim is to shed more light onto this, compared with inherited von Willebrand disease, rare disease which affects at least 2-3% of the older population. PMID:26577336

  7. Processed pseudogenes acquired somatically during cancer development.

    PubMed

    Cooke, Susanna L; Shlien, Adam; Marshall, John; Pipinikas, Christodoulos P; Martincorena, Inigo; Tubio, Jose M C; Li, Yilong; Menzies, Andrew; Mudie, Laura; Ramakrishna, Manasa; Yates, Lucy; Davies, Helen; Bolli, Niccolo; Bignell, Graham R; Tarpey, Patrick S; Behjati, Sam; Nik-Zainal, Serena; Papaemmanuil, Elli; Teixeira, Vitor H; Raine, Keiran; O'Meara, Sarah; Dodoran, Maryam S; Teague, Jon W; Butler, Adam P; Iacobuzio-Donahue, Christine; Santarius, Thomas; Grundy, Richard G; Malkin, David; Greaves, Mel; Munshi, Nikhil; Flanagan, Adrienne M; Bowtell, David; Martin, Sancha; Larsimont, Denis; Reis-Filho, Jorge S; Boussioutas, Alex; Taylor, Jack A; Hayes, Neil D; Janes, Sam M; Futreal, P Andrew; Stratton, Michael R; McDermott, Ultan; Campbell, Peter J

    2014-01-01

    Cancer evolves by mutation, with somatic reactivation of retrotransposons being one such mutational process. Germline retrotransposition can cause processed pseudogenes, but whether this occurs somatically has not been evaluated. Here we screen sequencing data from 660 cancer samples for somatically acquired pseudogenes. We find 42 events in 17 samples, especially non-small cell lung cancer (5/27) and colorectal cancer (2/11). Genomic features mirror those of germline LINE element retrotranspositions, with frequent target-site duplications (67%), consensus TTTTAA sites at insertion points, inverted rearrangements (21%), 5' truncation (74%) and polyA tails (88%). Transcriptional consequences include expression of pseudogenes from UTRs or introns of target genes. In addition, a somatic pseudogene that integrated into the promoter and first exon of the tumour suppressor gene, MGA, abrogated expression from that allele. Thus, formation of processed pseudogenes represents a new class of mutation occurring during cancer development, with potentially diverse functional consequences depending on genomic context. PMID:24714652

  8. Processed pseudogenes acquired somatically during cancer development

    PubMed Central

    Cooke, Susanna L.; Shlien, Adam; Marshall, John; Pipinikas, Christodoulos P.; Martincorena, Inigo; Tubio, Jose M.C.; Li, Yilong; Menzies, Andrew; Mudie, Laura; Ramakrishna, Manasa; Yates, Lucy; Davies, Helen; Bolli, Niccolo; Bignell, Graham R.; Tarpey, Patrick S.; Behjati, Sam; Nik-Zainal, Serena; Papaemmanuil, Elli; Teixeira, Vitor H.; Raine, Keiran; O’Meara, Sarah; Dodoran, Maryam S.; Teague, Jon W.; Butler, Adam P.; Iacobuzio-Donahue, Christine; Santarius, Thomas; Grundy, Richard G.; Malkin, David; Greaves, Mel; Munshi, Nikhil; Flanagan, Adrienne M.; Bowtell, David; Martin, Sancha; Larsimont, Denis; Reis-Filho, Jorge S.; Boussioutas, Alex; Taylor, Jack A.; Hayes, Neil D.; Janes, Sam M.; Futreal, P. Andrew; Stratton, Michael R.; McDermott, Ultan; Campbell, Peter J.; Provenzano, Elena; van de Vijver, Marc; Richardson, Andrea L.; Purdie, Colin; Pinder, Sarah; Mac Grogan, Gaetan; Vincent-Salomon, Anne; Larsimont, Denis; Grabau, Dorthe; Sauer, Torill; Garred, Øystein; Ehinger, Anna; Van den Eynden, Gert G.; van Deurzen, C.H.M; Salgado, Roberto; Brock, Jane E.; Lakhani, Sunil R.; Giri, Dilip D.; Arnould, Laurent; Jacquemier, Jocelyne; Treilleux, Isabelle; Caldas, Carlos; Chin, Suet-Feung; Fatima, Aquila; Thompson, Alastair M.; Stenhouse, Alasdair; Foekens, John; Martens, John; Sieuwerts, Anieta; Brinkman, Arjen; Stunnenberg, Henk; Span, Paul N.; Sweep, Fred; Desmedt, Christine; Sotiriou, Christos; Thomas, Gilles; Broeks, Annegein; Langerod, Anita; Aparicio, Samuel; Simpson, Peter T.; van ’t Veer, Laura; Erla Eyfjörd, Jórunn; Hilmarsdottir, Holmfridur; Jonasson, Jon G.; Børresen-Dale, Anne-Lise; Lee, Ming Ta Michael; Wong, Bernice Huimin; Tan, Benita Kiat Tee; Hooijer, Gerrit K.J.

    2014-01-01

    Cancer evolves by mutation, with somatic reactivation of retrotransposons being one such mutational process. Germline retrotransposition can cause processed pseudogenes, but whether this occurs somatically has not been evaluated. Here we screen sequencing data from 660 cancer samples for somatically acquired pseudogenes. We find 42 events in 17 samples, especially non-small cell lung cancer (5/27) and colorectal cancer (2/11). Genomic features mirror those of germline LINE element retrotranspositions, with frequent target-site duplications (67%), consensus TTTTAA sites at insertion points, inverted rearrangements (21%), 5′ truncation (74%) and polyA tails (88%). Transcriptional consequences include expression of pseudogenes from UTRs or introns of target genes. In addition, a somatic pseudogene that integrated into the promoter and first exon of the tumour suppressor gene, MGA, abrogated expression from that allele. Thus, formation of processed pseudogenes represents a new class of mutation occurring during cancer development, with potentially diverse functional consequences depending on genomic context. PMID:24714652

  9. 7 CFR 926.10 - Acquire.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... REQUIREMENTS APPLICABLE TO CRANBERRIES NOT SUBJECT TO THE CRANBERRY MARKETING ORDER § 926.10 Acquire. Acquire means to obtain cranberries by any means whatsoever for the purpose of handling cranberries....

  10. 7 CFR 926.10 - Acquire.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... REQUIREMENTS APPLICABLE TO CRANBERRIES NOT SUBJECT TO THE CRANBERRY MARKETING ORDER § 926.10 Acquire. Acquire means to obtain cranberries by any means whatsoever for the purpose of handling cranberries....

  11. 7 CFR 926.10 - Acquire.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... REQUIREMENTS APPLICABLE TO CRANBERRIES NOT SUBJECT TO THE CRANBERRY MARKETING ORDER § 926.10 Acquire. Acquire means to obtain cranberries by any means whatsoever for the purpose of handling cranberries....

  12. 7 CFR 926.10 - Acquire.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... REQUIREMENTS APPLICABLE TO CRANBERRIES NOT SUBJECT TO THE CRANBERRY MARKETING ORDER § 926.10 Acquire. Acquire means to obtain cranberries by any means whatsoever for the purpose of handling cranberries....

  13. Identification of inositol polyphosphate 4-phosphatase type II as a novel tumor resistance biomarker in human laryngeal cancer HEp-2 cells

    PubMed Central

    Kim, Jae-Sung; Yun, Hong Shik; Um, Hong-Duck; Park, Jong Kuk; Lee, Kee-Ho; Kang, Chang-Mo; Lee, Su-Jae; Hwang, Sang-Gu

    2012-01-01

    Although tumor resistance remains a significant impediment to successful radiotherapy, associated regulatory markers and detailed molecular mechanisms underlying this phenomenon are not well defined. In this study, we identified inositol polyphosphate 4-phosphatase type II (INPP4B) as a novel marker of radioresistance by systematically analyzing Unigene libraries of laryngeal cancer. INPP4B was highly expressed in radioresistant laryngeal cancer cells and was induced by treatment with either radiation or anticancer drugs in various types of cancer cells. Ectopic INPP4B overexpression increased radioresistance and anticancer drug resistance by suppressing apoptosis in HEp-2 cells. Conversely, INPP4B depletion with small interfering RNA resensitized HEp-2 as well as A549 and H1299 cells to radiation- and anticancer drug-induced apoptosis. Furthermore, radiation-induced INPP4B expression was blocked by inhibition of extracellular signal-regulated kinase (ERK). INPP4B depletion significantly attenuated radiation-induced increases in Akt phosphorylation, indicating an association of INPP4B-mediated radioresistance with Akt survival signaling. Taken together, our data suggest that ERK-dependent induction of INPP4B triggers the development of a tumor-resistance phenotype via Akt signaling and identify INPP4B as a potentially important target molecule for resolving the radioresistance of cancer cells. PMID:22895072

  14. Mathematical Modeling of the Role of Survivin on Dedifferentiation and Radioresistance in Cancer.

    PubMed

    Rhodes, Adam; Hillen, Thomas

    2016-06-01

    We use a mathematical model to investigate cancer resistance to radiation, based on dedifferentiation of non-stem cancer cells into cancer stem cells. Experimental studies by Iwasa 2008, using human non-small cell lung cancer (NSCLC) cell lines in mice, have implicated the inhibitor of apoptosis protein survivin in cancer resistance to radiation. A marked increase in radio-sensitivity was observed, after inhibiting survivin expression with a specific survivin inhibitor YM155 (sepantronium bromide). It was suggested that these observations are due to survivin-dependent dedifferentiation of non-stem cancer cells into cancer stem cells. Here, we confirm this hypothesis with a mathematical model, which we fit to Iwasa's data on NSCLC in mice. We investigate the timing of combination therapies of YM155 administration and radiation. We find an interesting dichotomy. Sometimes it is best to hit a cancer with a large radiation dose right at the beginning of the YM155 treatment, while in other cases, it appears advantageous to wait a few days until most cancer cells are sensitized and then radiate. The optimal strategy depends on the nature of the cancer and the dose of radiation administered. PMID:27271121

  15. Evolution of acquired resistance to anti-cancer therapy

    PubMed Central

    Foo, Jasmine; Michor, Franziska

    2014-01-01

    Acquired drug resistance is a major limitation for the successful treatment of cancer. Resistance can emerge due to a variety of reasons including host environmental factors as well as genetic or epigenetic alterations in the cancer cells. Evolutionary theory has contributed to the understanding of the dynamics of resistance mutations in a cancer cell population, the risk of resistance pre-existing before the initiation of therapy, the composition of drug cocktails necessary to prevent the emergence of resistance, and optimum drug administration schedules for patient populations at risk of evolving acquired resistance. Here we review recent advances towards elucidating the evolutionary dynamics of acquired drug resistance and outline how evolutionary thinking can contribute to outstanding questions in the field. PMID:24681298

  16. Acquired immune deficiency syndrome (AIDS).

    PubMed

    1987-02-01

    The International Planned Parenthood Medical Advisory Panel has developed recommendations to assist family planning associations in playing a more active role in the prevention and control of acquired immunodeficiency syndrome (AIDS). Of primary importance is an effective program of information and education aimed at communicating the following facts: AIDS is a fatal disease for which there is no cure; AIDS is spread by sexual intercourse, contaminated blood, and contaminated needles; an infected woman can transmit AIDS to her fetus during pregnancy; a monogamous sexual relationship is the surest way to avoid AIDS infection; condom use is good protection; an infected person can look and feel well, yet still be able to transmit the AIDS virus; and AIDS is not spread by ordinary contact with an infected person. Family planning associations should include information on AIDS in all existing IEC projects, as well as develop new materials. Among the target audiences for IEC activities are family planning workers, family planning clients, and the general public including youth, teachers, parents, employers, and national leaders. Special attention should be given to high-risk groups such as homosexual and bisexual men, hemophiliacs, male and female prostitutes, clients of sexually transmitted disease clinics, people with many sexual partners, illegal users of intravenous drugs, and the sexual partners of those in any of these groups. Wide promotion of condom use is a priority activity for family planning organizations. PMID:12340977

  17. Infections Acquired in the Garden.

    PubMed

    Cunha, Cheston B; Cunha, Burke A

    2015-10-01

    Gardening is a wonderful pastime, and the garden is a very peaceful place to enjoy one's vacation. However, the garden may be a treacherous place for very young or compromised hosts when one takes into account the infectious potential residing in the soil, as well as the insect vectors on plants and animals. Even normal hosts may acquire a variety of infections from the soil, animals, or animal-related insect bites. The location of the garden, its natural animal and insect inhabitants, and the characteristics of the soil play a part in determining its infectious potential. The most important factor making the garden an infectious and dangerous place is the number and interaction of animals, whether they are pets or wild, that temporarily use the garden for part of their daily activities. The clinician should always ask about garden exposure, which will help in eliminating the diagnostic possibilities for the patient. The diagnostic approach is to use epidemiological principles in concert with clinical clues, which together should suggest a reasonable list of diagnostic possibilities. Organ involvement and specific laboratory tests help further narrow the differential diagnosis and determine the specific tests necessary to make a definitive diagnosis. PMID:26542044

  18. Associative Learning Through Acquired Salience

    PubMed Central

    Treviño, Mario

    2016-01-01

    Most associative learning studies describe the salience of stimuli as a fixed learning-rate parameter. Presumptive saliency signals, however, have also been linked to motivational and attentional processes. An interesting possibility, therefore, is that discriminative stimuli could also acquire salience as they become powerful predictors of outcomes. To explore this idea, we first characterized and extracted the learning curves from mice trained with discriminative images offering varying degrees of structural similarity. Next, we fitted a linear model of associative learning coupled to a series of mathematical representations for stimulus salience. We found that the best prediction, from the set of tested models, was one in which the visual salience depended on stimulus similarity and a non-linear function of the associative strength. Therefore, these analytic results support the idea that the net salience of a stimulus depends both on the items' effective salience and the motivational state of the subject that learns about it. Moreover, this dual salience model can explain why learning about a stimulus not only depends on the effective salience during acquisition but also on the specific learning trajectory that was used to reach this state. Our mathematical description could be instrumental for understanding aberrant salience acquisition under stressful situations and in neuropsychiatric disorders like schizophrenia, obsessive-compulsive disorder, and addiction. PMID:26793078

  19. Associative Learning Through Acquired Salience.

    PubMed

    Treviño, Mario

    2015-01-01

    Most associative learning studies describe the salience of stimuli as a fixed learning-rate parameter. Presumptive saliency signals, however, have also been linked to motivational and attentional processes. An interesting possibility, therefore, is that discriminative stimuli could also acquire salience as they become powerful predictors of outcomes. To explore this idea, we first characterized and extracted the learning curves from mice trained with discriminative images offering varying degrees of structural similarity. Next, we fitted a linear model of associative learning coupled to a series of mathematical representations for stimulus salience. We found that the best prediction, from the set of tested models, was one in which the visual salience depended on stimulus similarity and a non-linear function of the associative strength. Therefore, these analytic results support the idea that the net salience of a stimulus depends both on the items' effective salience and the motivational state of the subject that learns about it. Moreover, this dual salience model can explain why learning about a stimulus not only depends on the effective salience during acquisition but also on the specific learning trajectory that was used to reach this state. Our mathematical description could be instrumental for understanding aberrant salience acquisition under stressful situations and in neuropsychiatric disorders like schizophrenia, obsessive-compulsive disorder, and addiction. PMID:26793078

  20. [Acquired agammaglobulinaemia with predominantly intestinal symptoms (author's transl)].

    PubMed

    Goldach, R; Wittwer, J

    1977-11-01

    In a 45-year-old female patient primary acquired agammaglobulinaemia was diagnosed. Intestinal symptoms predominated. The disease was characterized by a B-cell defect. Substitution with gamma-globulin (Beriglobin) practically cured the symptoms. The pathogenesis of the disease remains unexplained. PMID:72639

  1. Bleomycin Containing Chemotherapeutic Regimen Induced Acquired Partial Lipodystrophy

    PubMed Central

    Tandon, Vishal R; Gupte, Novy; Mahajan, Vivek; Sharma, Rahul; Langer, Cheena; Khajuria, Vijay; Mahajan, Annil

    2016-01-01

    Bleomycin toxicity predominantly affects the skin and lungs. Cutaneous toxicity classically known to present with bleomycin are flagellate erythema and drug rash. We hereby report an isolated case of (bleomyicn)-induced acquired partial (lipodytrophy) having potential cosmetic implications in a young women prescribed postoperatively following a case of germ cell carcinoma of ovary (endodermal sinus tumor). PMID:26955139

  2. Overexpression of IGF-I receptor in HeLa cells enhances in vivo radioresponse

    SciTech Connect

    Kaneko, Haruna; Yu, Dong; Miura, Masahiko

    2007-11-30

    Insulin-like growth factor I receptor (IGF-IR) is a transmembrane receptor tyrosine kinase whose activation strongly promotes cell growth and survival. We previously reported that IGF-IR activity confers intrinsic radioresistance in mouse embryo fibroblasts in vitro. However, it is still unclear whether tumor cells overexpressing IGF-IR exhibit radioresistance in vivo. For this purpose, we established HeLa cells that overexpress IGF-IR (HeLa-R), subcutaneously transplanted these cells into nude mice, and examined radioresponse in the resulting solid tumors. HeLa-R cells exhibited typical in vitro phenotypes generally observed in IGF-IR-overexpressing cells, as well as significant intrinsic radioresistance in vitro compared with parent cells. As expected, the transplanted HeLa-R tumors grew at a remarkably higher rate than parent tumors. Histological analysis revealed that HeLa-R tumors expressed more VEGF and had a higher density of tumor vessels. Unexpectedly, a marked growth delay was observed in HeLa-R tumors following 10 Gy of X-irradiation. Immunostaining of HeLa-R tumors for the hypoxia marker pimonidazole revealed a significantly lower level of hypoxic cells. Moreover, clamp hypoxia significantly increased radioresistance in HeLa-R tumors. Tumor microenvironments in vivo generated by the IGF-IR expression thus could be a major factor in determining the tumor radioresponse in vivo.

  3. Surface Sampler Arm Acquiring Sample

    NASA Technical Reports Server (NTRS)

    1976-01-01

    Operation of the surface sampler in obtaining Martian soil for Viking 2's molecular analysis experiment last Saturday (September 25) was closely monitored by one of the Lander cameras because of the precision required in trenching the small area--8 by 9 inches-surrounded by rocks. Dubbed 'Bonneville Salt Flats,' the exposure of thin crust appeared unique in contrast with surrounding materials and became a prime target for organic analysis in spite of potential hazards. Large rock in foreground is 8 inches high. At left, the sampler scoop has touched the surface, missing the rock at upper left by a comfortable 6 inches, and the backhoe has penetrated the surface about one-half inch. The scoop was then pulled back to sample the desired point and (second photo) the backhoe furrowed the surface pulling a piece of thin crust toward the spacecraft. The initial touchdown and retraction sequence was used to avoid a collision between a rock in the shadow of the arm and a plate joining the arm and scoop. The rock was cleared by 2 to 3 inches. The third picture was taken 8 minutes after the scoop touched the surface and shows that the collector head has acquired a quantity of soil. With surface sampler withdrawn (right), the foot-long trench is seen between the rocks. The trench is three inches wide and about 1 1/2 to 2 inches deep. The scoop reached to within 3 inches of the rock at far end of trench. Penetration appears to have left a cavernous opening roofed by the crust and only about one inch of undisturbed crust separates the deformed surface and the rock.

  4. Natural and acquired macrolide resistance in mycobacteria.

    PubMed

    Doucet-Populaire, F; Buriánková, K; Weiser, J; Pernodet, J-L

    2002-12-01

    The genus Mycobacterium contains two of the most important human pathogens, Mycobacterium tuberculosis and Mycobacterium leprae, the etiologic agents of tuberculosis and leprosy, respectively. Other mycobacteria are mostly saprophytic organisms, living in soil and water, but some of them can cause opportunistic infections. The increasing incidence of tuberculosis as well as infections with non-tuberculous mycobacteria (NTM) in AIDS patients has renewed interest in molecular mechanisms of drug resistance in these pathogens. Mycobacteria show a high degree of intrinsic resistance to most common antibiotics. For instance, species from the M. tuberculosis complex (MTC) are intrinsically resistant to macrolides. Nevertheless, some semi-synthetic macrolides as the erythromycin derivatives clarithromycin, azithromycin and most recently the ketolides, are active against NTM, particularly Mycobacterium avium, and some of them are widely used for infection treatment. However, shortly after the introduction of these new drugs, resistant strains appeared due to mutations in the macrolide target, the ribosome. The mycobacterial cell wall with its specific composition and structure is considered to be a major factor in promoting the natural resistance of mycobacteria to various antibiotics. However, to explain the difference in macrolide sensitivity between the MTC and NTM, the synergistic contribution of a specific resistance mechanism might be required, in addition to possible differences in cell wall permeability. This mini-review summarizes the current knowledge on the natural and acquired macrolide resistance in mycobacteria, gives an overview of potential mechanisms implicated in the intrinsic resistance and brings recent data concerning a macrolide resistance determinant in the MTC. PMID:12570741

  5. 17 CFR 210.8-06 - Real estate operations acquired or to be acquired.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 17 Commodity and Securities Exchanges 2 2011-04-01 2011-04-01 false Real estate operations acquired or to be acquired. 210.8-06 Section 210.8-06 Commodity and Securities Exchanges SECURITIES AND... Statements of Smaller Reporting Companies § 210.8-06 Real estate operations acquired or to be acquired....

  6. 17 CFR 210.8-06 - Real estate operations acquired or to be acquired.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 17 Commodity and Securities Exchanges 2 2013-04-01 2013-04-01 false Real estate operations acquired or to be acquired. 210.8-06 Section 210.8-06 Commodity and Securities Exchanges SECURITIES AND...-06 Real estate operations acquired or to be acquired. If, during the period for which...

  7. 17 CFR 210.8-06 - Real estate operations acquired or to be acquired.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 17 Commodity and Securities Exchanges 3 2014-04-01 2014-04-01 false Real estate operations acquired or to be acquired. 210.8-06 Section 210.8-06 Commodity and Securities Exchanges SECURITIES AND...-06 Real estate operations acquired or to be acquired. If, during the period for which...

  8. 17 CFR 210.8-06 - Real estate operations acquired or to be acquired.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 17 Commodity and Securities Exchanges 2 2012-04-01 2012-04-01 false Real estate operations acquired or to be acquired. 210.8-06 Section 210.8-06 Commodity and Securities Exchanges SECURITIES AND...-06 Real estate operations acquired or to be acquired. If, during the period for which...

  9. 17 CFR 210.8-06 - Real estate operations acquired or to be acquired.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 17 Commodity and Securities Exchanges 2 2010-04-01 2010-04-01 false Real estate operations acquired or to be acquired. 210.8-06 Section 210.8-06 Commodity and Securities Exchanges SECURITIES AND... Statements of Smaller Reporting Companies § 210.8-06 Real estate operations acquired or to be acquired....

  10. Human cytotrophoblasts acquire aneuploidies as they differentiateto an invasive phenotype

    SciTech Connect

    Weier, Jingly F.; Weier, Heinz-Ulrich G.; Jung, Christine J.; Gormley, Matthew; Zhou, Yuan; Chu, Lisa W.; Genbacev, Olga; Wright, AlexiA.; Fisher, Susan J.

    2004-12-15

    Through an unusual differentiation process, human trophoblast progenitors (cytotrophoblasts) give rise to tumor-like cells that invade the uterus. By an unknown mechanism, invasive cytotrophoblasts exhibit permanent cell cycle withdrawal. Here we report molecular cytogenetic data showing that {approx} 20 to 60 percent of these interphase cells had acquired aneusomies involving chromosomes X, Y, o r16. The incidence positively correlated with gestational age and differentiation to an invasive phenotype. Scoring 12 chromosomes in flow-sorted cytotrophoblasts showed that more than 95 percent of the cells were hyperdiploid. Thus, aneuploidy appears to be an important component of normal placentation, perhaps limiting the proliferative and invasive potential of cytotrophoblasts within the uterus.

  11. p53 Loss in MYC-Driven Neuroblastoma Leads to Metabolic Adaptations Supporting Radioresistance.

    PubMed

    Yogev, Orli; Barker, Karen; Sikka, Arti; Almeida, Gilberto S; Hallsworth, Albert; Smith, Laura M; Jamin, Yann; Ruddle, Ruth; Koers, Alexander; Webber, Hannah T; Raynaud, Florence I; Popov, Sergey; Jones, Chris; Petrie, Kevin; Robinson, Simon P; Keun, Hector C; Chesler, Louis

    2016-05-15

    Neuroblastoma is the most common childhood extracranial solid tumor. In high-risk cases, many of which are characterized by amplification of MYCN, outcome remains poor. Mutations in the p53 (TP53) tumor suppressor are rare at diagnosis, but evidence suggests that p53 function is often impaired in relapsed, treatment-resistant disease. To address the role of p53 loss of function in the development and pathogenesis of high-risk neuroblastoma, we generated a MYCN-driven genetically engineered mouse model in which the tamoxifen-inducible p53ER(TAM) fusion protein was expressed from a knock-in allele (Th-MYCN/Trp53(KI)). We observed no significant differences in tumor-free survival between Th-MYCN mice heterozygous for Trp53(KI) (n = 188) and Th-MYCN mice with wild-type p53 (n = 101). Conversely, the survival of Th-MYCN/Trp53(KI/KI) mice lacking functional p53 (n = 60) was greatly reduced. We found that Th-MYCN/Trp53(KI/KI) tumors were resistant to ionizing radiation (IR), as expected. However, restoration of functional p53ER(TAM) reinstated sensitivity to IR in only 50% of Th-MYCN/Trp53(KI/KI) tumors, indicating the acquisition of additional resistance mechanisms. Gene expression and metabolic analyses indicated that the principal acquired mechanism of resistance to IR in the absence of functional p53 was metabolic adaptation in response to chronic oxidative stress. Tumors exhibited increased antioxidant metabolites and upregulation of glutathione S-transferase pathway genes, including Gstp1 and Gstz1, which are associated with poor outcome in human neuroblastoma. Accordingly, glutathione depletion by buthionine sulfoximine together with restoration of p53 activity resensitized tumors to IR. Our findings highlight the complex pathways operating in relapsed neuroblastomas and the need for combination therapies that target the diverse resistance mechanisms at play. Cancer Res; 76(10); 3025-35. ©2016 AACR. PMID:27197232

  12. Acquired coagulation factor XIII deficiency: a case report.

    PubMed

    Jia, Yongqing; Hu, Huixian; Wei, Bin

    2016-06-01

    The main objective of the study is to summarize the clinical characteristics of acquired factor XIII (FXIII) deficiency caused by a spontaneous FXIII inhibitor. Here we report a new case of acquired FXIII deficiency caused by FXIII inhibitor and review the medical literature regarding the characteristics and treatment of this disorder. FXIII deficiency caused by FXIII inhibitors is rare and of uncertain pathogenesis. Experience with therapeutic measures is limited to data from case reports. Immunosuppressive drugs may reduce autoantibodies or inhibit the cell clone generating the antibodies and may have been of benefit in our patient. The impact of such therapy on patient prognosis is incompletely known. PMID:26588447

  13. Increased Artemis levels confer radioresistance to both high and low LET radiation exposures

    PubMed Central

    2012-01-01

    Background Artemis has a defined role in V(D)J recombination and has been implicated in the repair of radiation induced double-strand breaks. However the exact function(s) of Artemis in DNA repair and its preferred substrate(s) in vivo remain undefined. Our previous work suggests that Artemis is important for the repair of complex DNA damage like that inflicted by high Linear Energy Transfer (LET) radiation. To establish the contribution of Artemis in repairing DNA damage caused by various radiation qualities, we evaluated the effect of over-expressing Artemis on cell survival, DNA repair, and cell cycle arrest after exposure to high and low LET radiation. Results Our data reveal that Artemis over-expression confers marked radioprotection against both types of radiation, although the radioprotective effect was greater following high LET radiation. Inhibitor studies reveal that the radioprotection imparted by Artemis is primarily dependent on DNA-PK activity, and to a lesser extent on ATM kinase activity. Together, these data suggest a DNA-PK dependent role for Artemis in the repair of complex DNA damage. Conclusions These findings indicate that Artemis levels significantly influence radiation toxicity in human cells and suggest that Artemis inhibition could be a practical target for adjuvant cancer therapies. PMID:22713703

  14. Biochemical mechanisms underlying the development of radioresistance by cultured peritoneal exudate macrophages

    SciTech Connect

    Lin, H.S.; Hsu, S.

    1989-01-01

    We investigated changes in radiosensitivity of peritoneal exudate macrophage colony-forming cells (PE-CFC) when exudative peritoneal macrophages were cultured in vitro. The change in the shape of the dose-response curve of PE-CFC to ionizing irradiation was partly dependent on the concentration of oxygen in the gas phase of the incubators. When cells were incubated in an environment containing 20% oxygen, the value of both Dq and D0 for PE-CFC increased. The dose-response curve of PE-CFC cultured for 3 days resembled that of alveolar macrophage colony-forming cells (AL-CFC). The changes in radiosensitivity were accompanied by an increase in the level of three antioxidant enzymes: superoxide dismutase, catalase, and glutathione peroxidase. However, when they were cultured in a 6% oxygen environment, only the value of Dq increased. When alveolar macrophages were incubated in vitro, no significant change in the shape of the dose-response curve of AL-CFC was noted whether they were cultured in gas phase containing either 20 or 6% oxygen. It is concluded that the radiosensitivity of PE-CFC changes when they are cultured in vitro. The increase in D0 appears to be related to the intracellular level of antioxidant enzymes.

  15. A major role for nonenzymatic antioxidant processes in the radioresistance of Halobacterium salinarum.

    PubMed

    Robinson, Courtney K; Webb, Kim; Kaur, Amardeep; Jaruga, Pawel; Dizdaroglu, Miral; Baliga, Nitin S; Place, Allen; Diruggiero, Jocelyne

    2011-04-01

    Oxidative stress occurs when the generation of reactive oxygen species (ROS) exceeds the capacity of the cell's endogenous systems to neutralize them. Our analyses of the cellular damage and oxidative stress responses of the archaeon Halobacterium salinarum exposed to ionizing radiation (IR) revealed a critical role played by nonenzymatic antioxidant processes in the resistance of H. salinarum to IR. ROS-scavenging enzymes were essential for resistance to chemical oxidants, yet those enzymes were not necessary for H. salinarum's resistance to IR. We found that protein-free cell extracts from H. salinarum provided a high level of protection for protein activity against IR in vitro but did not protect DNA significantly. Compared with cell extracts of radiation-sensitive bacteria, H. salinarum extracts were enriched in manganese, amino acids, and peptides, supporting an essential role in ROS scavenging for those small molecules in vivo. With regard to chemical oxidants, we showed that the damage caused by gamma irradiation was mechanistically different than that produced by hydrogen peroxide or by the superoxide-generating redox-cycling drug paraquat. The data presented support the idea that IR resistance is most likely achieved by a "metabolic route," with a combination of tightly coordinated physiological processes. PMID:21278285

  16. Musashi1 Impacts Radio-Resistance in Glioblastoma by Controlling DNA-Protein Kinase Catalytic Subunit.

    PubMed

    de Araujo, Patricia Rosa; Gorthi, Aparna; da Silva, Acarizia E; Tonapi, Sonal S; Vo, Dat T; Burns, Suzanne C; Qiao, Mei; Uren, Philip J; Yuan, Zhi-Min; Bishop, Alexander J R; Penalva, Luiz O F

    2016-09-01

    The conserved RNA-binding protein Musashi1 (MSI1) has been characterized as a stem cell marker, controlling the balance between self-renewal and differentiation and as a key oncogenic factor in numerous solid tumors, including glioblastoma. To explore the potential use of MSI1 targeting in therapy, we studied MSI1 in the context of radiation sensitivity. Knockdown of MSI1 led to a decrease in cell survival and an increase in DNA damage compared to control in cells treated with ionizing radiation. We subsequently examined mechanisms of double-strand break repair and found that loss of MSI1 reduces the frequency of nonhomologous end-joining. This phenomenon could be attributed to the decreased expression of DNA-protein kinase catalytic subunit, which we have previously identified as a target of MSI1. Collectively, our results suggest a role for MSI1 in double-strand break repair and that its inhibition may enhance the effect of radiotherapy. PMID:27470713

  17. Acquired tracheoesophageal fistula in infancy and childhood.

    PubMed

    Szold, A; Udassin, R; Seror, D; Mogle, P; Godfrey, S

    1991-06-01

    Acquired tracheoesophageal fistula (TEF) is a rare entity in the pediatric age group. We report two pediatric patients with acquired TEF caused by shells of pistachio nuts. In both patients the primary operation did not resolve the problem and a second intervention for recurrent fistula was needed. The special nature of acquired TEF, particularly the one described herein, requires delayed surgical intervention and meticulous separation of the respiratory and alimentary tracts by an intercostal muscle flap. PMID:1941455

  18. Acquired stuttering due to recurrent anaplastic astrocytoma

    PubMed Central

    Peters, Katherine B; Turner, Scott

    2013-01-01

    Acquired (neurogenic) stuttering is a rare phenomenon seen after cerebral infarction or brain injury. Aetiology of this symptom is unclear, but recent evidence supports that it is a disturbance in the left hemispheric neural network involving the interplay between the cortex and basal ganglia. We present the case of a patient who develops acquired stuttering after a recurrence of a right temporoparietal anaplastic astrocytoma (WHO grade III). We also review other cases of acquired stuttering and known anatomical correlates. PMID:24252834

  19. Breast Cancer as an Acquired Thrombophilic State

    PubMed Central

    2012-01-01

    Cancer is an acquired thrombophilic condition manifested by increased incidence of venous and arterial thromboembolic complications. Despite progress that has been achieved in treatments over the recent years, thromboembolism remains a major complication in patients with breast cancer; it is accompanied by significant morbidity and mortality. Approximately, 1% of breast cancer patients develop venous thromboembolism within 2 years with the highest incidence occurring in the 6 months post diagnosis. Metastatic disease and their comorbidities are the strongest predictors of the development of thrombotic event. The diagnosis of venous thromboembolism is associated with a higher risk of death within 2 years of diagnosis. Thromboembolic events in cancer patients range from abnormal laboratory coagulation tests without specific symptoms to massive thomboembolism and disseminated intravascular coagulation. The underlying pathophysiology is complex and includes the prothrombotic properties of cancer cells, which can be enhanced by anticancer treatment modalities, such as surgery, hormonal agents, and chemotherapy. Primary thromboprophylaxis in cancer patients should be individualized according to risk. For secondary prevention, several clinical studies have shown that low molecular weight heparin has improved patients' compliance, cancer outcomes and overall survival. This review summarizes the available data on the pathogenesis and clinical approach of hemostatic changes in breast cancer. PMID:22807931

  20. The acquired immunodeficiency syndrome: an ultrastructural study.

    PubMed

    Sidhu, G S; Stahl, R E; el-Sadr, W; Cassai, N D; Forrester, E M; Zolla-Pazner, S

    1985-04-01

    Blood and a variety of tissues from 97 patients with the acquired immunodeficiency syndrome (AIDS) and 25 with the AIDS prodrome were studied ultrastructurally. Tubuloreticular structures (TRS) were found in 85 per cent of the patients with AIDS and in 92 per cent of those with the prodrome. Test tube and ring-shaped forms (TRF), found in 41 per cent of the patients with AIDS and in 8 per cent of those with the prodrome, increased with disease progression. Among the patients with AIDS, as the number of sites examined per case increased, the incidence of TRS and TRF tended to approach 100 per cent, suggesting that they are present in all patients with AIDS. Other changes seen frequently were immunologic capping of blood lymphocytes, intramitochondrial iron in blood reticulocytes and marrow normoblasts, megakaryocytic immaturity and platelet phagocytosis, collections of membranous rings in hepatocytic cytoplasm, suggestive of non-A, non-B hepatitis, and proliferations and engorgement of hepatic Ito cells with lipid. The data suggest that TRS and TRF can be used as diagnostic and prognostic markers. PMID:3872253

  1. Gastrointestinal Manifestations of the Acquired Immunodeficiency Syndrome

    PubMed Central

    Rodgers, Vance D.; Kagnoff, Martin F.

    1987-01-01

    In addition to abnormalities in systemic immune function, patients with the acquired immunodeficiency syndrome (AIDS) and the pre-AIDS syndromes have significant abnormalities in the distribution of T-cell subsets in the intestinal tract. Such immune deficits predispose such patients to opportunistic infections and tumors, many of which involve the gastrointestinal tract. For example, Candida albicans often causes stomatitis and esophagitis. Intestinal infections with parasites (Cryptosporidium, Isospora belli, Microsporidia) or bacteria (Mycobacterium avium-intracellulare) are associated with severe diarrhea and malabsorption, whereas viruses like cytomegalovirus and herpes simplex virus cause mucosal ulcerations. Clinically debilitating chronic diarrhea develops in many AIDS patients for which no clear cause can be identified. Enteric pathogens like Salmonella and Campylobacter can be associated with bacteremias. Kaposi's sarcoma and lymphoma involving the intestinal tract are now well-recognized complications of AIDS. Although AIDS is not associated with a pathognomonic liver lesion, opportunistic infections and Kaposi's sarcoma or lymphoma may involve the liver. ImagesFigure 3.Figure 4.Figure 5.Figure 6.Figure 7. PMID:3825111

  2. Acquired Surface Dyslexia: The Evidence from Hebrew.

    ERIC Educational Resources Information Center

    Birnboim, Smadar

    1995-01-01

    Investigates the symptoms of acquired surface dyslexia in Hebrew. Four acquired surface dyslexic adults were compared with eight normal second graders in terms of reading strategy. Homophones and homographs were a major source of difficulty for native Hebrew surface dyslexic readers; the normal second graders used a non-lexical strategy. (45…

  3. Acquiring and Managing Electronic Journals. ERIC Digest.

    ERIC Educational Resources Information Center

    Curtis, Donnelyn; Yue, Paoshan

    Electronic journals are both a blessing and a curse for libraries. To be meaningful in the current information environment--to meet users' ever-increasing demands--libraries must acquire as many appropriate full text resources as possible, as quickly as possible, and make them easy to use. This Digest provides tips for acquiring and providing…

  4. Acquired Zinc Deficiency in an Adult Female

    PubMed Central

    Saritha, Mohanan; Gupta, Divya; Chandrashekar, Laxmisha; Thappa, Devinder M; Rajesh, Nachiappa G

    2012-01-01

    Acrodermatitis enteropathica is an autosomal recessive inherited disorder of zinc absorption. Acquired cases are reported occasionally in patients with eating disorders or Crohn's disease. We report a 24-year-old housewife with acquired isolated severe zinc deficiency with no other comorbidities to highlight the rare occurrence of isolated nutritional zinc deficiency in an otherwise normal patient. PMID:23248371

  5. Intrinsic resistance to the lethal effects of x-irradiation in insect and arachnid cells

    PubMed Central

    Koval, Thomas M.

    1983-01-01

    Twelve cell lines representing 10 genera of three orders (Diptera, Lepidoptera, and Orthoptera) of the class Insecta and one cell line (Acarina) from the class Arachnida were examined to discern their sensitivity to the lethal effects of x-irradiation. Radiosensitivity was measured by a combination of colony formation and population growth curve techniques. Each of these arthropod cell lines is significantly more radioresistant than mammalian cells, though the degree of resistance varies greatly with order. Dipteran cells are 3 to 9 times and lepidopteran cells 52 to 104 times more radioresistant than mammalian cells. Orthopteran and acarine cells are intermediate in radiosensitivity between dipteran and lepidopteran cells. These cells, especially the lepidopteran, should be valuable in determining the molecular nature of repair mechanisms that result in resistance to ionizing radiation. PMID:16593348

  6. Acquired inducible antimicrobial resistance in Gram-positive bacteria

    PubMed Central

    Chancey, Scott T; Zähner, Dorothea; Stephens, David S

    2012-01-01

    A major contributor to the emergence of antibiotic resistance in Gram-positive bacterial pathogens is the expansion of acquired, inducible genetic elements. Although acquired, inducible antibiotic resistance is not new, the interest in its molecular basis has been accelerated by the widening distribution and often ‘silent’ spread of the elements responsible, the diagnostic challenges of such resistance and the mounting limitations of available agents to treat Gram-positive infections. Acquired, inducible antibiotic resistance elements belong to the accessory genome of a species and are horizontally