Effect of LKB1 deficiency on mitochondrial content, fiber type, and muscle performance in the mouse diaphragm

PubMed Central

Brown, Jacob D.; Hancock, Chad R.; Mongillo, Anthony D.; Barton, J. Benjamin; DiGiovanni, Ryan A.; Parcell, Allen C.; Winder, William W.; Thomson, David M.

2010-01-01

Aim The Liver Kinase B1 (LKB1)/AMP-Activated Protein Kinase (AMPK) signaling pathway is a major regulator of skeletal muscle metabolic processes. During exercise, LKB1-mediated phosphorylation of AMPK leads to its activation, promoting mitochondrial biogenesis and glucose transport, among other effects. The roles of LKB1 and AMPK have not been fully characterized in the diaphragm. Methods Two methods of AMPK activation were used to characterize LKB1/AMPK signaling in diaphragms from muscle-specific LKB1 knockout (KO) and littermate control mice: (1) acute injection of 5-aminoimidazole-4-carboxamide ribonucleoside (AICAR) and (2) 5-min direct electrical stimulation of the diaphragm. Diaphragms were excised 60 minutes post-AICAR injection and immediately after electrical stimulation. Results AMPK phosphorylation increased with AICAR and electrical stimulation in control but not KO mice. Acetyl CoA carboxylase phosphorylation increased with AICAR in control but not KO mice, but increased in both genotypes with electrical stimulation. While the majority of mitochondrial protein levels were lower in KO diaphragms, uncoupling protein 3, complex I, and cytochrome oxidase IV protein levels were not different between genotypes. KO diaphragms have a lower percentage of IIx fibers and an elevated percentage of IIb fibers when compared to control diaphragms. While in vitro peak force generation was similar between genotypes, KO diaphragms fatigued more quickly and had an impaired ability to recover. Conclusion LKB1 regulates AMPK phosphorylation, mitochondrial protein expression, fiber type distribution, as well as recovery of the diaphragm from fatigue. PMID:21073663

LKB1-AMPK signaling in muscle from obese insulin-resistant Zucker rats and effects of training.

PubMed

Sriwijitkamol, Apiradee; Ivy, John L; Christ-Roberts, Christine; DeFronzo, Ralph A; Mandarino, Lawrence J; Musi, Nicolas

2006-05-01

AMPK is a key regulator of fat and carbohydrate metabolism. It has been postulated that defects in AMPK signaling could be responsible for some of the metabolic abnormalities of type 2 diabetes. In this study, we examined whether insulin-resistant obese Zucker rats have abnormalities in the AMPK pathway. We compared AMPK and ACC phosphorylation and the protein content of the upstream AMPK kinase LKB1 and the AMPK-regulated transcriptional coactivator PPARgamma coactivator-1 (PGC-1) in gastrocnemius of sedentary obese Zucker rats and sedentary lean Zucker rats. We also examined whether 7 wk of exercise training on a treadmill reversed abnormalities in the AMPK pathway in obese Zucker rats. In the obese rats, AMPK phosphorylation was reduced by 45% compared with lean rats. Protein expression of the AMPK kinase LKB1 was also reduced in the muscle from obese rats by 43%. In obese rats, phosphorylation of ACC and protein expression of PGC-1alpha, two AMPK-regulated proteins, tended to be reduced by 50 (P = 0.07) and 35% (P = 0.1), respectively. There were no differences in AMPKalpha1, -alpha2, -beta1, -beta2, and -gamma3 protein content between lean and obese rats. Training caused a 1.5-fold increase in AMPKalpha1 protein content in the obese rats, although there was no effect of training on AMPK phosphorylation and the other AMPK isoforms. Furthermore, training also significantly increased LKB1 and PGC-1alpha protein content 2.8- and 2.5-fold, respectively, in the obese rats. LKB1 protein strongly correlated with hexokinase II activity (r = 0.75, P = 0.001), citrate synthase activity (r = 0.54, P = 0.02), and PGC-1alpha protein content (r = 0.81, P < 0.001). In summary, obese insulin-resistant rodents have abnormalities in the LKB1-AMPK-PGC-1 pathway in muscle, and these abnormalities can be restored by training.

3D view to tumor suppression: Lkb1, polarity and the arrest of oncogenic c-Myc.

PubMed

Partanen, Johanna I; Nieminen, Anni I; Klefstrom, Juha

2009-03-01

Machiavelli wrote, in his famous political treatise Il Principe, about disrupting organization by planting seeds of dissension or by eliminating necessary support elements. Tumor cells do exactly that by disrupting the organized architecture of epithelial cell layers during progression from contained benign tumor to full-blown invasive cancer. However, it is still unclear whether tumor cells primarily break free by activating oncogenes powerful enough to cause chaos or by eliminating tumor suppressor genes guarding the order of the epithelial organization. Studies in Drosophila have exposed genes that encode key regulators of the epithelial apicobasal polarity and which, upon inactivation, cause disorganization of the epithelial layers and promote unscheduled cell proliferation. These polarity regulator/tumor suppressor proteins, which include products of neoplastic tumor suppressor genes (nTSGs), are carefully positioned in polarized epithelial cells to maintain the order of epithelial structures and to impose a restraint on cell proliferation. In this review, we have explored the presence and prevalence of somatic mutations in the human counterparts of Drosophila polarity regulator/tumor suppressor genes across the human cancers. The screen points out LKB1, which is a causal genetic lesion in Peutz-Jeghers cancer syndrome, a gene mutated in certain sporadic cancers and a human homologue of the fly polarity gene par-4. We review the evidence linking Lkb1 protein to polarity regulation in the scope of our recent results suggesting a coupled role for Lkb1 as an architect of organized acinar structures and a suppressor of oncogenic c-Myc. We finally present models to explain how Lkb1-dependent formation of epithelial architecture is coupled to suppression of normal and oncogene-induced proliferation.

Adipocyte-specific DKO of Lkb1 and mTOR protects mice against HFD-induced obesity, but results in insulin resistance.

PubMed

Xiong, Yan; Xu, Ziye; Wang, Yizhen; Kuang, Shihuan; Shan, Tizhong

2018-06-01

Liver kinase B1 (Lkb1) and mammalian target of rapamycin (mTOR) are key regulators of energy metabolism and cell growth. We have previously reported that adipocyte-specific KO of Lkb1 or mTOR in mice results in distinct developmental and metabolic phenotypes. Here, we aimed to assess how genetic KO of both Lkb1 and mTOR affects adipose tissue development and function in energy homeostasis. We used Adiponectin-Cre to drive adipocyte-specific double KO (DKO) of Lkb1 and mTOR in mice. We performed indirect calorimetry, glucose and insulin tolerance tests, and gene expression assays on the DKO and WT mice. We found that DKO of Lkb1 and mTOR results in reductions of brown adipose tissue and inguinal white adipose tissue mass, but in increases of liver mass. Notably, the DKO mice developed fatty liver and insulin resistance, but displayed improved glucose tolerance after high-fat diet (HFD)-feeding. Interestingly, the DKO mice were protected from HFD-induced obesity due to their higher energy expenditure and lower expression levels of adipogenic genes (CCAAT/enhancer binding protein α and PPARγ) compared with WT mice. These results together indicate that, compared with Lkb1 or mTOR single KOs, Lkb1/mTOR DKO in adipocytes results in overlapping and distinct metabolic phenotypes, and mTOR KO largely overrides the effect of Lkb1 KO. Copyright © 2018 by the American Society for Biochemistry and Molecular Biology, Inc.

LKB1 loss promotes endometrial cancer progression via CCL2-dependent macrophage recruitment.

PubMed

Peña, Christopher G; Nakada, Yuji; Saatcioglu, Hatice D; Aloisio, Gina M; Cuevas, Ileana; Zhang, Song; Miller, David S; Lea, Jayanthi S; Wong, Kwok-Kin; DeBerardinis, Ralph J; Amelio, Antonio L; Brekken, Rolf A; Castrillon, Diego H

2015-11-02

Endometrial cancer is the most common gynecologic malignancy and the fourth most common malignancy in women. For most patients in whom the disease is confined to the uterus, treatment results in successful remission; however, there are no curative treatments for tumors that have progressed beyond the uterus. The serine/threonine kinase LKB1 has been identified as a potent suppressor of uterine cancer, but the biological modes of action of LKB1 in this context remain incompletely understood. Here, we have shown that LKB1 suppresses tumor progression by altering gene expression in the tumor microenvironment. We determined that LKB1 inactivation results in abnormal, cell-autonomous production of the inflammatory cytokine chemokine (C-C motif) ligand 2 (CCL2) within tumors, which leads to increased recruitment of macrophages with prominent tumor-promoting activities. Inactivation of Ccl2 in an Lkb1-driven mouse model of endometrial cancer slowed tumor progression and increased survival. In human primary endometrial cancers, loss of LKB1 protein was strongly associated with increased CCL2 expression by tumor cells as well as increased macrophage density in the tumor microenvironment. These data demonstrate that CCL2 is a potent effector of LKB1 loss in endometrial cancer, creating potential avenues for therapeutic opportunities.

Par3L enhances colorectal cancer cell survival by inhibiting Lkb1/AMPK signaling pathway

DOE Office of Scientific and Technical Information (OSTI.GOV)

Li, Taiyuan; Liu, Dongning; Lei, Xiong

Partitioning defective 3-like protein (Par3L) is a recently identified cell polarity protein that plays an important role in mammary stem cell maintenance. Previously, we showed that high expression of Par3L is associated with poor survival in malignant colorectal cancer (CRC), but the underlying mechanism remained unknown. To this end, we established a Par3L knockout colorectal cancer cell line using the CRISPR/Cas system. Interestingly, reduced proliferation, enhanced cell death and caspase-3 activation were observed in Par3L knockout (KO) cells as compared with wildtype (WT) cells. Consistent with previous studies, we showed that Par3L interacts with a tumor suppressor protein liver kinasemore » B1 (Lkb1). Moreover, Par3L depletion resulted in abnormal activation of Lkb1/AMPK signaling cascade. Knockdown of Lkb1 in these cells could significantly reduce AMPK activity and partially rescue cell death caused by Par3L knockdown. Furthermore, we showed that Par3L KO cells were more sensitive to chemotherapies and irradiation. Together, these results suggest that Par3L is essential for colorectal cancer cell survival by inhibiting Lkb1/AMPK signaling pathway, and is a putative therapeutic target for CRC. - Highlights: • Par3L knockout using the CRISPR/Cas system induces apoptosis in colorectal cancer cells. • Par3L interacts with Lkb1 and regulates the activity of AMPK signaling cascade. • Par3L knockout cells are more sensitive to treatment of different chemotherapy drugs and irradiation.« less

CPS1 maintains pyrimidine pools and DNA synthesis in KRAS/LKB1-mutant lung cancer cells. | Office of Cancer Genomics

Cancer.gov

Metabolic reprogramming by oncogenic signals promotes cancer initiation and progression. The oncogene KRAS and tumor suppressor STK11, which encodes the kinase LKB1, regulate metabolism and are frequently mutated in non-small-cell lung cancer(NSCLC). Concurrent occurrence of oncogenic KRAS and loss of LKB1 (KL) in cells specifies aggressive oncological behavior. Here we show that human KL cells and tumors share metabolic signatures of perturbed nitrogen handling.

The tumor suppressor gene TUSC2 (FUS1) sensitizes NSCLC to the AKT inhibitor MK2206 in LKB1-dependent manner.

PubMed

Meng, Jieru; Majidi, Mourad; Fang, Bingliang; Ji, Lin; Bekele, B Nebiyou; Minna, John D; Roth, Jack A

2013-01-01

TUSC2-defective gene expression is detected in the majority of lung cancers and is associated with worse overall survival. We analyzed the effects of TUSC2 re-expression on tumor cell sensitivity to the AKT inhibitor, MK2206, and explored their mutual signaling connections, in vitro and in vivo. TUSC2 transient expression in three LKB1-defective non-small cell lung cancer (NSCLC) cell lines combined with MK2206 treatment resulted in increased repression of cell viability and colony formation, and increased apoptotic activity. In contrast, TUSC2 did not affect the response to MK2206 treatment for two LKB1-wild type NSCLC cell lines. In vivo, TUSC2 systemic delivery, by nanoparticle gene transfer, combined with MK2206 treatment markedly inhibited growth of tumors in a human LKB1-defective H322 lung cancer xenograft mouse model. Biochemical analysis showed that TUSC2 transient expression in LKB1-defective NSCLC cells significantly stimulated AMP-activated protein kinase (AMPK) phosphorylation and enzymatic activity. More importantly, AMPK gene knockdown abrogated TUSC2-MK2206 cooperation, as evidenced by reduced sensitivity to the combined treatment. Together, TUSC2 re-expression and MK2206 treatment was more effective in inhibiting the phosphorylation and kinase activities of AKT and mTOR proteins than either single agent alone. In conclusion, these findings support the hypothesis that TUSC2 expression status is a biological variable that potentiates MK2206 sensitivity in LKB1-defective NSCLC cells, and identifies the AMPK/AKT/mTOR signaling axis as an important regulator of this activity.

Methylisoindigo preferentially kills cancer stem cells by interfering cell metabolism via inhibition of LKB1 and activation of AMPK in PDACs.

PubMed

Cheng, Xinlai; Kim, Jee Young; Ghafoory, Shahrouz; Duvaci, Tijen; Rafiee, Roya; Theobald, Jannick; Alborzinia, Hamed; Holenya, Pavlo; Fredebohm, Johannes; Merz, Karl-Heinz; Mehrabi, Arianeb; Hafezi, Mohammadreza; Saffari, Arash; Eisenbrand, Gerhard; Hoheisel, Jörg D; Wölfl, Stefan

2016-06-01

Pancreatic ductal adenocarcinoma (PDAC) clinically has a very poor prognosis. No small molecule is available to reliably achieve cures. Meisoindigo is chemically related to the natural product indirubin and showed substantial efficiency in clinical chemotherapy for CML in China. However, its effect on PDAC is still unknown. Our results showed strong anti-proliferation effect of meisoindigo on gemcitabine-resistant PDACs. Using a recently established primary PDAC cell line, called Jopaca-1 with a larger CSCs population as model, we observed a reduction of CD133+ and ESA+/CD44+/CD24+ populations upon treatment and concomitantly a decreased expression of CSC-associated genes, and reduced cellular mobility and sphere formation. Investigating basic cellular metabolic responses, we detected lower oxygen consumption and glucose uptake, while intracellular ROS levels increased. This was effectively neutralized by the addition of antioxidants, indicating an essential role of the cellular redox balance. Further analysis on energy metabolism related signaling revealed that meisoindigo inhibited LKB1, but activated AMPK. Both of them were involved in cellular apoptosis. Additional in situ hybridization in tissue sections of PDAC patients reproducibly demonstrated co-expression and -localization of LKB1 and CD133 in malignant areas. Finally, we detected that CD133+/CD44+ were more vulnerable to meisoindigo, which could be mimicked by LKB1 siRNAs. Our results provide the first evidence, to our knowledge, that LKB1 sustains the CSC population in PDACs and demonstrate a clear benefit of meisoindigo in treatment of gemcitabine-resistant cells. This novel mechanism may provide a promising new treatment option for PDAC. Copyright © 2016 Federation of European Biochemical Societies. Published by Elsevier B.V. All rights reserved.

LKB1 inactivation dictates therapeutic response of non-small cell lung cancer to the metabolism drug phenformin

PubMed Central

Shackelford, David B.; Abt, Evan; Gerken, Laurie; Vasquez, Debbie S.; Seki, Atsuko; Leblanc, Mathias; Wei, Liu; Fishbein, Michael C.; Czernin, Johannes; Mischel, Paul S.; Shaw, Reuben J.

2013-01-01

SUMMARY The LKB1 (also called STK11) tumor suppressor is mutationally inactivated in ~20% of non-small cell lung cancers (NSCLC). LKB1 is the major upstream kinase activating the energy-sensing kinase AMPK, making LKB1-deficient cells unable to appropriately sense metabolic stress. We tested the therapeutic potential of metabolic drugs in NSCLC and identified phenformin, a mitochondrial inhibitor and analog of the diabetes therapeutic metformin, as selectively inducing apoptosis in LKB1-deficient NSCLC cells. Therapeutic trials in Kras-dependent mouse models of NSCLC revealed that tumors with Kras and Lkb1 mutations, but not those with Kras and p53 mutations showed selective response to phenformin as a single agent, resulting in prolonged survival. This study suggests phenformin as a cancer metabolism-based therapeutic to selectively target LKB1-deficient tumors. PMID:23352126

Ursolic Acid Inhibits Adipogenesis in 3T3-L1 Adipocytes through LKB1/AMPK Pathway

PubMed Central

He, Yonghan; Li, Ying; Zhao, Tiantian; Wang, Yanwen; Sun, Changhao

2013-01-01

Background Ursolic acid (UA) is a triterpenoid compound with multiple biological functions. This compound has recently been reported to possess an anti-obesity effect; however, the mechanisms are less understood. Objective As adipogenesis plays a critical role in obesity, the present study was conducted to investigate the effect of UA on adipogenesis and mechanisms of action in 3T3-L1 preadipocytes. Methods and Results The 3T3-L1 preadipocytes were induced to differentiate in the presence or absence of UA for 6 days. The cells were determined for proliferation, differentiation, fat accumulation as well as the protein expressions of molecular targets that regulate or are involved in fatty acid synthesis and oxidation. The results demonstrated that ursolic acid at concentrations ranging from 2.5 µM to 10 µM dose-dependently attenuated adipogenesis, accompanied by reduced protein expression of CCAAT element binding protein β (C/EBPβ), peroxisome proliferator-activated receptor γ (PPARγ), CCAAT element binding protein α (C/EBPα) and sterol regulatory element binding protein 1c (SREBP-1c), respectively. Ursolic acid increased the phosphorylation of acetyl-CoA carboxylase (ACC) and protein expression of carnitine palmitoyltransferase 1 (CPT1), but decreased protein expression of fatty acid synthase (FAS) and fatty acid-binding protein 4 (FABP4). Ursolic acid increased the phosphorylation of AMP-activated protein kinase (AMPK) and protein expression of (silent mating type information regulation 2, homolog) 1 (Sirt1). Further studies demonstrated that the anti-adipogenic effect of UA was reversed by the AMPK siRNA, but not by the Sirt1 inhibitor nicotinamide. Liver kinase B1 (LKB1), the upstream kinase of AMPK, was upregulated by UA. When LKB1 was silenced with siRNA or the inhibitor radicicol, the effect of UA on AMPK activation was diminished. Conclusions Ursolic acid inhibited 3T3-L1 preadipocyte differentiation and adipogenesis through the LKB1/AMPK pathway

LKB1 inactivation dictates therapeutic response of non-small cell lung cancer to the metabolism drug phenformin.

PubMed

Shackelford, David B; Abt, Evan; Gerken, Laurie; Vasquez, Debbie S; Seki, Atsuko; Leblanc, Mathias; Wei, Liu; Fishbein, Michael C; Czernin, Johannes; Mischel, Paul S; Shaw, Reuben J

2013-02-11

The LKB1 (also called STK11) tumor suppressor is mutationally inactivated in ∼20% of non-small cell lung cancers (NSCLC). LKB1 is the major upstream kinase activating the energy-sensing kinase AMPK, making LKB1-deficient cells unable to appropriately sense metabolic stress. We tested the therapeutic potential of metabolic drugs in NSCLC and identified phenformin, a mitochondrial inhibitor and analog of the diabetes therapeutic metformin, as selectively inducing apoptosis in LKB1-deficient NSCLC cells. Therapeutic trials in Kras-dependent mouse models of NSCLC revealed that tumors with Kras and Lkb1 mutations, but not those with Kras and p53 mutations, showed selective response to phenformin as a single agent, resulting in prolonged survival. This study suggests phenformin as a cancer metabolism-based therapeutic to selectively target LKB1-deficient tumors. Copyright © 2013 Elsevier Inc. All rights reserved.

Cadmium induces autophagy through ROS-dependent activation of the LKB1-AMPK signaling in skin epidermal cells

DOE Office of Scientific and Technical Information (OSTI.GOV)

Son, Young-Ok; Wang Xin; Hitron, John Andrew

2011-09-15

Cadmium is a toxic heavy metal which is environmentally and occupationally relevant. The mechanisms underlying cadmium-induced autophagy are not yet completely understood. The present study shows that cadmium induces autophagy, as demonstrated by the increase of LC3-II formation and the GFP-LC3 puncta cells. The induction of autophagosomes was directly visualized by electron microscopy in cadmium-exposed skin epidermal cells. Blockage of LKB1 or AMPK by siRNA transfection suppressed cadmium-induced autophagy. Cadmium-induced autophagy was inhibited in dominant-negative AMPK-transfected cells, whereas it was accelerated in cells transfected with the constitutively active form of AMPK. mTOR signaling, a negative regulator of autophagy, was downregulatedmore » in cadmium-exposed cells. In addition, cadmium generated reactive oxygen species (ROS) at relatively low levels, and caused poly(ADP-ribose) polymerase-1 (PARP) activation and ATP depletion. Inhibition of PARP by pharmacological inhibitors or its siRNA transfection suppressed ATP reduction and autophagy in cadmium-exposed cells. Furthermore, cadmium-induced autophagy signaling was attenuated by either exogenous addition of catalase and superoxide dismutase, or by overexpression of these enzymes. Consequently, these results suggest that cadmium-mediated ROS generation causes PARP activation and energy depletion, and eventually induces autophagy through the activation of LKB1-AMPK signaling and the down-regulation of mTOR in skin epidermal cells. - Highlights: > Cadmium, a toxic heavy metal, induces autophagic cell death through ROS-dependent activation of the LKB1-AMPK signaling. > Cadmium generates intracellular ROS at low levels and this leads to severe DNA damage and PARP activation, resulting in ATP depletion, which are the upstream events of LKB1-AMPK-mediated autophagy. > This novel finding may contribute to further understanding of cadmium-mediated diseases.« less

Galangin inhibits proliferation of HepG2 cells by activating AMPK via increasing the AMP/TAN ratio in a LKB1-independent manner.

PubMed

Zhang, Haitao; Li, Ning; Wu, Jun; Su, Lijuan; Chen, Xiaoyi; Lin, Biyun; Luo, Hui

2013-10-15

Galangin, a flavonol derived from Alpinia officinarum Hance and used as food additives in southern China, induces apoptosis and autophagy to suppress the proliferation of HepG2 cells. In this study, we demonstrated that galangin induced autophagy by increasing the ratio of AMP/TAN in HepG2 cells. It stimulated the phosphorylation of adenosine monophosphate-activated protein kinase (AMPK) and LKB1, but inhibited the phosphorylation of AKT and mTOR. Inhibition of AMPK activation suppressed the dephosphorylation of mTOR to block galangin-induced autophagy. AMPK activation by galangin appeared to be independent of the LKB1 signaling pathway because the down-regulation of LKB1 by its siRNA failed to affect galangin-induced autophagy. Collectively, the findings demonstrated a novel mechanism of how galangin induces autophagy via activating AMPK in a LKB1- independent manner. The induction of autophagy can thus reflect the anti-proliferation effect of galangin in HCC cells. © 2013 Elsevier B.V. All rights reserved.

Heightening energetic stress selectively targets LKB1-deficient non-small cell lung cancers

PubMed Central

Momcilovic, Milica; McMickle, Robert; Abt, Evan; Seki, Atsuko; Simko, Sarah A.; Magyar, Clara; Stout, David B.; Fishbein, Michael C.; Walser, Tonya C.; Dubinett, Steven M.; Shackelford, David B.

2015-01-01

Inactivation of the LKB1 tumor suppressor is a frequent event in non-small cell lung carcinoma (NSCLC) leading to the activation of mammalian target of rapamycin complex 1 (mTORC1) and sensitivity to the metabolic stress inducer phenformin. In this study, we explored the combinatorial use of phenformin with the mTOR catalytic kinase inhibitor MLN0128 as a treatment strategy for NSCLC bearing co-mutations in the LKB1 and KRAS genes. NSCLC is a genetically and pathologically heterogeneous disease, giving rise to lung tumors of varying histologies that include adenocarcinomas (ADCs) and squamous cell carcinomas (SCCs). We demonstrate that phenformin in combination with MLN0128 induced a significant therapeutic response in KRAS/LKB1 mutant human cell lines and genetically engineered mouse models of NSCLC that develop both ADCs and SCCs. Specifically, we found that KRAS/LKB1 mutant lung ADCs responded strongly to phenformin + MLN0128 treatment, but the response of SCCs to single or combined treatment with MLN0128 was more attenuated due to acquired resistance to mTOR inhibition through modulation of the AKT-GSK signaling axis. Combinatorial use of the mTOR inhibitor and AKT inhibitor MK2206 robustly inhibited the growth and viability of squamous lung tumors thus providing an effective strategy to overcome resistance. Taken together, our findings define new personalized therapeutic strategies that may be rapidly translated into clinical use for the treatment of KRAS/LKB1 mutant adenocarcinomas and squamous cell tumors. PMID:26574479

Heightening Energetic Stress Selectively Targets LKB1-Deficient Non-Small Cell Lung Cancers.

PubMed

Momcilovic, Milica; McMickle, Robert; Abt, Evan; Seki, Atsuko; Simko, Sarah A; Magyar, Clara; Stout, David B; Fishbein, Michael C; Walser, Tonya C; Dubinett, Steven M; Shackelford, David B

2015-11-15

Inactivation of the LKB1 tumor suppressor is a frequent event in non-small cell lung carcinoma (NSCLC) leading to the activation of mTOR complex 1 (mTORC1) and sensitivity to the metabolic stress inducer phenformin. In this study, we explored the combinatorial use of phenformin with the mTOR catalytic kinase inhibitor MLN0128 as a treatment strategy for NSCLC bearing comutations in the LKB1 and KRAS genes. NSCLC is a genetically and pathologically heterogeneous disease, giving rise to lung tumors of varying histologies that include adenocarcinomas and squamous cell carcinomas (SCC). We demonstrate that phenformin in combination with MLN0128 induced a significant therapeutic response in KRAS/LKB1-mutant human cell lines and genetically engineered mouse models of NSCLC that develop both adenocarcinomas and SCCs. Specifically, we found that KRAS/LKB1-mutant lung adenocarcinomas responded strongly to phenformin + MLN0128 treatment, but the response of SCCs to single or combined treatment with MLN0128 was more attenuated due to acquired resistance to mTOR inhibition through modulation of the AKT-GSK signaling axis. Combinatorial use of the mTOR inhibitor and AKT inhibitor MK2206 robustly inhibited the growth and viability of squamous lung tumors, thus providing an effective strategy to overcome resistance. Taken together, our findings define new personalized therapeutic strategies that may be rapidly translated into clinical use for the treatment of KRAS/LKB1-mutant adenocarcinomas and squamous cell tumors. ©2015 American Association for Cancer Research.

Activity of LKB1 and AMPK-related kinases in skeletal muscle: effects of contraction, phenformin, and AICAR.

PubMed

Sakamoto, Kei; Göransson, Olga; Hardie, D Grahame; Alessi, Dario R

2004-08-01

Activation of AMP-activated protein kinase (AMPK) by exercise and metformin is beneficial for the treatment of type 2 diabetes. We recently found that, in cultured cells, the LKB1 tumor suppressor protein kinase activates AMPK in response to the metformin analog phenformin and the AMP mimetic drug 5-aminoimidazole-4-carboxamide-1-beta-D-ribofuranoside (AICAR). We have also reported that LKB1 activates 11 other AMPK-related kinases. The activity of LKB1 or the AMPK-related kinases has not previously been studied in a tissue with physiological relevance to diabetes. In this study, we have investigated whether contraction, phenformin, and AICAR influence LKB1 and AMPK-related kinase activity in rat skeletal muscle. Contraction in situ, induced via sciatic nerve stimulation, significantly increased AMPKalpha2 activity and phosphorylation in multiple muscle fiber types without affecting LKB1 activity. Treatment of isolated skeletal muscle with phenformin or AICAR stimulated the phosphorylation and activation of AMPKalpha1 and AMPKalpha2 without altering LKB1 activity. Contraction, phenformin, or AICAR did not significantly increase activities or expression of the AMPK-related kinases QSK, QIK, MARK2/3, and MARK4 in skeletal muscle. The results of this study suggest that muscle contraction, phenformin, or AICAR activates AMPK by a mechanism that does not involve direct activation of LKB1. They also suggest that the effects of excercise, phenformin, and AICAR on metabolic processes in muscle may be mediated through activation of AMPK rather than activation of LKB1 or the AMPK-related kinases.

LKB1 promotes cell survival by modulating TIF-IA-mediated pre-ribosomal RNA synthesis under uridine downregulated conditions

PubMed Central

Liu, Xiuju; Huang, Henry; Wilkinson, Scott C.; Zhong, Diansheng; Khuri, Fadlo R.; Fu, Haian; Marcus, Adam; He, Yulong; Zhou, Wei

2016-01-01

We analyzed the mechanism underlying 5-aminoimidazole-4-carboxamide riboside (AICAR) mediated apoptosis in LKB1-null non-small cell lung cancer (NSCLC) cells. Metabolic profile analysis revealed depletion of the intracellular pyrimidine pool after AICAR treatment, but uridine was the only nucleotide precursor capable of rescuing this apoptosis, suggesting the involvement of RNA metabolism. Because half of RNA transcription in cancer is for pre-ribosomal RNA (rRNA) synthesis, which is suppressed by over 90% after AICAR treatment, we evaluated the role of TIF-IA-mediated rRNA synthesis. While the depletion of TIF-IA by RNAi alone promoted apoptosis in LKB1-null cells, the overexpression of a wild-type or a S636A TIF-IA mutant, but not a S636D mutant, attenuated AICAR-induced apoptosis. In LKB1-null H157 cells, pre-rRNA synthesis was not suppressed by AICAR when wild-type LKB1 was present, and cellular fractionation analysis indicated that TIF-IA quickly accumulated in the nucleus in the presence of a wild-type LKB1 but not a kinase-dead mutant. Furthermore, ectopic expression of LKB1 was capable of attenuating AICAR-induced death in AMPK-null cells. Because LKB1 promotes cell survival by modulating TIF-IA-mediated pre-rRNA synthesis, this discovery suggested that targeted depletion of uridine related metabolites may be exploited in the clinic to eliminate LKB1-null cancer cells. PMID:26506235

LKB1 promotes cell survival by modulating TIF-IA-mediated pre-ribosomal RNA synthesis under uridine downregulated conditions.

PubMed

Liu, Fakeng; Jin, Rui; Liu, Xiuju; Huang, Henry; Wilkinson, Scott C; Zhong, Diansheng; Khuri, Fadlo R; Fu, Haian; Marcus, Adam; He, Yulong; Zhou, Wei

2016-01-19

We analyzed the mechanism underlying 5-aminoimidazole-4-carboxamide riboside (AICAR) mediated apoptosis in LKB1-null non-small cell lung cancer (NSCLC) cells. Metabolic profile analysis revealed depletion of the intracellular pyrimidine pool after AICAR treatment, but uridine was the only nucleotide precursor capable of rescuing this apoptosis, suggesting the involvement of RNA metabolism. Because half of RNA transcription in cancer is for pre-ribosomal RNA (rRNA) synthesis, which is suppressed by over 90% after AICAR treatment, we evaluated the role of TIF-IA-mediated rRNA synthesis. While the depletion of TIF-IA by RNAi alone promoted apoptosis in LKB1-null cells, the overexpression of a wild-type or a S636A TIF-IA mutant, but not a S636D mutant, attenuated AICAR-induced apoptosis. In LKB1-null H157 cells, pre-rRNA synthesis was not suppressed by AICAR when wild-type LKB1 was present, and cellular fractionation analysis indicated that TIF-IA quickly accumulated in the nucleus in the presence of a wild-type LKB1 but not a kinase-dead mutant. Furthermore, ectopic expression of LKB1 was capable of attenuating AICAR-induced death in AMPK-null cells. Because LKB1 promotes cell survival by modulating TIF-IA-mediated pre-rRNA synthesis, this discovery suggested that targeted depletion of uridine related metabolites may be exploited in the clinic to eliminate LKB1-null cancer cells.

Phenformin enhances the therapeutic effect of selumetinib in KRAS-mutant non-small cell lung cancer irrespective of LKB1 status

PubMed Central

Zhang, Jun; Nannapaneni, Sreenivas; Wang, Dongsheng; Liu, Fakeng; Wang, Xu; Jin, Rui; Liu, Xiuju; Rahman, Mohammad Aminur; Peng, Xianghong; Qian, Guoqing; Chen, Zhuo G.; Wong, Kwok-Kin; Khuri, Fadlo R.; Zhou, Wei; Shin, Dong M.

2017-01-01

MEK inhibition is potentially valuable in targeting KRAS-mutant non-small cell lung cancer (NSCLC). Here, we analyzed whether concomitant LKB1 mutation alters sensitivity to the MEK inhibitor selumetinib, and whether the metabolism drug phenformin can enhance the therapeutic effect of selumetinib in isogenic cell lines with different LKB1 status. Isogenic pairs of KRAS-mutant NSCLC cell lines A549, H460 and H157, each with wild-type and null LKB1, as well as genetically engineered mouse-derived cell lines 634 (krasG12D/wt/p53-/-/lkb1wt/wt) and t2 (krasG12D/wt/p53-/-/lkb1-/-) were used in vitro to analyze the activities of selumetinib, phenformin and their combination. Synergy was measured and potential mechanisms investigated. The in vitro findings were then confirmed in vivo using xenograft models. The re-expression of wild type LKB1 increased phospho-ERK level, suggesting that restored dependency on MEK->ERK->MAPK signaling might have contributed to the enhanced sensitivity to selumetinib. In contrast, the loss of LKB1 sensitized cells to phenformin. At certain combination ratios, phenformin and selumetinib showed synergistic activity regardless of LKB1 status. Their combination reduced phospho-ERK and S6 levels and induced potent apoptosis, but was likely through different mechanisms in cells with different LKB1 status. Finally, in xenograft models bearing isogenic A549 cells, we confirmed that loss of LKB1 confers resistance to selumetinib, and phenformin significantly enhances the therapeutic effect of selumetinib. Irrespective of LKB1 status, phenformin may enhance the anti-tumor effect of selumetinib in KRAS-mutant NSCLC. The dual targeting of MEK and cancer metabolism may provide a useful strategy to treat this subset of lung cancer. PMID:28938614

Phenformin enhances the therapeutic effect of selumetinib in KRAS-mutant non-small cell lung cancer irrespective of LKB1 status.

PubMed

Zhang, Jun; Nannapaneni, Sreenivas; Wang, Dongsheng; Liu, Fakeng; Wang, Xu; Jin, Rui; Liu, Xiuju; Rahman, Mohammad Aminur; Peng, Xianghong; Qian, Guoqing; Chen, Zhuo G; Wong, Kwok-Kin; Khuri, Fadlo R; Zhou, Wei; Shin, Dong M

2017-08-29

MEK inhibition is potentially valuable in targeting KRAS-mutant non-small cell lung cancer (NSCLC). Here, we analyzed whether concomitant LKB1 mutation alters sensitivity to the MEK inhibitor selumetinib, and whether the metabolism drug phenformin can enhance the therapeutic effect of selumetinib in isogenic cell lines with different LKB1 status. Isogenic pairs of KRAS-mutant NSCLC cell lines A549, H460 and H157, each with wild-type and null LKB1, as well as genetically engineered mouse-derived cell lines 634 ( kras G12D/wt /p53 -/- /lkb1 wt/wt ) and t2 ( kras G12D/wt /p53 -/- / lkb1 -/- ) were used in vitro to analyze the activities of selumetinib, phenformin and their combination. Synergy was measured and potential mechanisms investigated. The in vitro findings were then confirmed in vivo using xenograft models. The re-expression of wild type LKB1 increased phospho-ERK level, suggesting that restored dependency on MEK->ERK->MAPK signaling might have contributed to the enhanced sensitivity to selumetinib. In contrast, the loss of LKB1 sensitized cells to phenformin. At certain combination ratios, phenformin and selumetinib showed synergistic activity regardless of LKB1 status. Their combination reduced phospho-ERK and S6 levels and induced potent apoptosis, but was likely through different mechanisms in cells with different LKB1 status. Finally, in xenograft models bearing isogenic A549 cells, we confirmed that loss of LKB1 confers resistance to selumetinib, and phenformin significantly enhances the therapeutic effect of selumetinib. Irrespective of LKB1 status, phenformin may enhance the anti-tumor effect of selumetinib in KRAS-mutant NSCLC. The dual targeting of MEK and cancer metabolism may provide a useful strategy to treat this subset of lung cancer.

Intact LKB1 activity is required for survival of dormant ovarian cancer spheroids

PubMed Central

Peart, Teresa; Valdes, Yudith Ramos; Correa, Rohann J. M.; Fazio, Elena; Bertrand, Monique; McGee, Jacob; Préfontaine, Michel; Sugimoto, Akira; DiMattia, Gabriel E.; Shepherd, Trevor G.

2015-01-01

Metastatic epithelial ovarian cancer (EOC) cells can form multicellular spheroids while in suspension and disperse directly throughout the peritoneum to seed secondary lesions. There is growing evidence that EOC spheroids are key mediators of metastasis, and they use specific intracellular signalling pathways to control cancer cell growth and metabolism for increased survival. Our laboratory discovered that AKT signalling is reduced during spheroid formation leading to cellular quiescence and autophagy, and these may be defining features of tumour cell dormancy. To further define the phenotype of EOC spheroids, we have initiated studies of the Liver kinase B1 (LKB1)-5′-AMP-activated protein kinase (AMPK) pathway as a master controller of the metabolic stress response. We demonstrate that activity of AMPK and its upstream kinase LKB1 are increased in quiescent EOC spheroids as compared with proliferating adherent EOC cells. We also show elevated AMPK activity in spheroids isolated directly from patient ascites. Functional studies reveal that treatment with the AMP mimetic AICAR or allosteric AMPK activator A-769662 led to a cytostatic response in proliferative adherent ovarian cancer cells, but they fail to elicit an effect in spheroids. Targeted knockdown of STK11 by RNAi to reduce LKB1 expression led to reduced viability and increased sensitivity to carboplatin treatment in spheroids only, a phenomenon which was AMPK-independent. Thus, our results demonstrate a direct impact of altered LKB1-AMPK signalling function in EOC. In addition, this is the first evidence in cancer cells demonstrating a pro-survival function for LKB1, a kinase traditionally thought to act as a tumour suppressor. PMID:26068970

Intact LKB1 activity is required for survival of dormant ovarian cancer spheroids.

PubMed

Peart, Teresa; Ramos Valdes, Yudith; Correa, Rohann J M; Fazio, Elena; Bertrand, Monique; McGee, Jacob; Préfontaine, Michel; Sugimoto, Akira; DiMattia, Gabriel E; Shepherd, Trevor G

2015-09-08

Metastatic epithelial ovarian cancer (EOC) cells can form multicellular spheroids while in suspension and disperse directly throughout the peritoneum to seed secondary lesions. There is growing evidence that EOC spheroids are key mediators of metastasis, and they use specific intracellular signalling pathways to control cancer cell growth and metabolism for increased survival. Our laboratory discovered that AKT signalling is reduced during spheroid formation leading to cellular quiescence and autophagy, and these may be defining features of tumour cell dormancy. To further define the phenotype of EOC spheroids, we have initiated studies of the Liver kinase B1 (LKB1)-5'-AMP-activated protein kinase (AMPK) pathway as a master controller of the metabolic stress response. We demonstrate that activity of AMPK and its upstream kinase LKB1 are increased in quiescent EOC spheroids as compared with proliferating adherent EOC cells. We also show elevated AMPK activity in spheroids isolated directly from patient ascites. Functional studies reveal that treatment with the AMP mimetic AICAR or allosteric AMPK activator A-769662 led to a cytostatic response in proliferative adherent ovarian cancer cells, but they fail to elicit an effect in spheroids. Targeted knockdown of STK11 by RNAi to reduce LKB1 expression led to reduced viability and increased sensitivity to carboplatin treatment in spheroids only, a phenomenon which was AMPK-independent. Thus, our results demonstrate a direct impact of altered LKB1-AMPK signalling function in EOC. In addition, this is the first evidence in cancer cells demonstrating a pro-survival function for LKB1, a kinase traditionally thought to act as a tumour suppressor.

Mutations in the LKB1 tumour suppressor are frequently detected in tumours from Caucasian but not Asian lung cancer patients.

PubMed

Koivunen, J P; Kim, J; Lee, J; Rogers, A M; Park, J O; Zhao, X; Naoki, K; Okamoto, I; Nakagawa, K; Yeap, B Y; Meyerson, M; Wong, K-K; Richards, W G; Sugarbaker, D J; Johnson, B E; Jänne, P A

2008-07-22

Somatic mutations of LKB1 tumour suppressor gene have been detected in human cancers including non-small cell lung cancer (NSCLC). The relationship between LKB1 mutations and clinicopathological characteristics and other common oncogene mutations in NSCLC is inadequately described. In this study we evaluated tumour specimens from 310 patients with NSCLC including those with adenocarcinoma, adenosquamous carcinoma, and squamous cell carcinoma histologies. Tumours were obtained from patients of US (n=143) and Korean (n=167) origin and screened for LKB1, KRAS, BRAF, and EGFR mutations using RT-PCR-based SURVEYOR-WAVE method followed by Sanger sequencing. We detected mutations in the LKB1 gene in 34 tumours (11%). LKB1 mutation frequency was higher in NSCLC tumours of US origin (17%) compared with 5% in NSCLCs of Korean origin (P=0.001). They tended to occur more commonly in adenocarcinomas (13%) than in squamous cell carcinomas (5%) (P=0.066). LKB1 mutations associated with smoking history (P=0.007) and KRAS mutations (P=0.042) were almost mutually exclusive with EGFR mutations (P=0.002). The outcome of stages I and II NSCLC patients treated with surgery alone did not significantly differ based on LKB1 mutation status. Our study provides clinical and molecular characteristics of NSCLC, which harbour LKB1 mutations.

Mutations in the LKB1 tumour suppressor are frequently detected in tumours from Caucasian but not Asian lung cancer patients

PubMed Central

Koivunen, J P; Kim, J; Lee, J; Rogers, A M; Park, J O; Zhao, X; Naoki, K; Okamoto, I; Nakagawa, K; Yeap, B Y; Meyerson, M; Wong, K-K; Richards, W G; Sugarbaker, D J; Johnson, B E; Jänne, P A

2008-01-01

Somatic mutations of LKB1 tumour suppressor gene have been detected in human cancers including non-small cell lung cancer (NSCLC). The relationship between LKB1 mutations and clinicopathological characteristics and other common oncogene mutations in NSCLC is inadequately described. In this study we evaluated tumour specimens from 310 patients with NSCLC including those with adenocarcinoma, adenosquamous carcinoma, and squamous cell carcinoma histologies. Tumours were obtained from patients of US (n=143) and Korean (n=167) origin and screened for LKB1, KRAS, BRAF, and EGFR mutations using RT—PCR-based SURVEYOR-WAVE method followed by Sanger sequencing. We detected mutations in the LKB1 gene in 34 tumours (11%). LKB1 mutation frequency was higher in NSCLC tumours of US origin (17%) compared with 5% in NSCLCs of Korean origin (P=0.001). They tended to occur more commonly in adenocarcinomas (13%) than in squamous cell carcinomas (5%) (P=0.066). LKB1 mutations associated with smoking history (P=0.007) and KRAS mutations (P=0.042) were almost mutually exclusive with EGFR mutations (P=0.002). The outcome of stages I and II NSCLC patients treated with surgery alone did not significantly differ based on LKB1 mutation status. Our study provides clinical and molecular characteristics of NSCLC, which harbour LKB1 mutations. PMID:18594528

RUNX1 promote invasiveness in pancreatic ductal adenocarcinoma through regulating miR-93

PubMed Central

Cheng, Yin; Yang, Haiyan; Sun, Yang; Zhang, Hongkai; Yu, Shuangni; Lu, Zhaohui; Chen, Jie

2017-01-01

Runt-related transcription factor 1(RUNX1), a key factor in hematopoiesis that mediates specification and homeostasis of hematopoietic stem and progenitor cells (HSPCs), is also overexpressed in several solid human cancers, and correlated with tumor progression. However, the expression and function of RUNX1 in pancreatic ductal adenocarcinoma were still unclear. Here, we show that RUNX1 is highly expressed in pancreatic adenocarcinoma tissues and knocking down of RUNX1 attenuated aggressiveness in pancreatic cell lines. Moreover, we found that RUNX1 could negatively regulate the expression of miR-93. Bioinformatics method showed that there are two binding sites in the the promotor region of miR-93 precursor and through ChIP-qPCR and firefly luciferase reporter assay, we vertified that these two binding sites each have transcriptive activity in one pancreatic cell lines. This result supported our presumption that RUNX1 regulate miR-93 through binding to the promotor region of miR-93. Besides, the expression and function of miR-93 is quite the opposite, miR-93 overexpression suppresses migration and invasiveness in pancreatic cell lines supporting that RUNX1 negatively regulated miR-93. Our findings provided evidence regarding the role of RUNX1 as an oncogene through the inhibition of miR-93. Targeting RUNX1 can be a potential therapeutic strategy in pancreatic cancer. PMID:29245924

Tanshinone IIA suppresses FcεRI-mediated mast cell signaling and anaphylaxis by activation of the Sirt1/LKB1/AMPK pathway.

PubMed

Li, Xian; Park, Soon Jin; Jin, Fansi; Deng, Yifeng; Yang, Ju Hye; Chang, Jae-Hoon; Kim, Dong-Young; Kim, Jung-Ae; Lee, Youn Ju; Murakami, Makoto; Son, Kun Ho; Chang, Hyeun Wook

2018-06-01

AMP-activated protein kinase (AMPK) and its upstream mediators liver kinase B1 (LKB1) and sirtuin 1 (Sirt1) are generally known as key regulators of metabolism. We have recently reported that the AMPK pathway negatively regulates mast cell activation and anaphylaxis. Tanshinone IIA (Tan IIA), an active component of Salvia miltiorrhiza extract that is currently used for the treatment of cardiovascular and cerebrovascular diseases, shows anti-diabetic activity and improves insulin resistance in db/db mice through activation of AMPK. The aim of this study was to evaluate the anti-allergic activity of Tan IIA in vivo and to investigate the underlying mechanism in vitro in the context of AMPK signaling. The anti-allergic effect of Tan IIA was evaluated using mouse bone marrow-derived mast cells (BMMCs) from AMPKα2 -/- or Sirt1 -/- mice, or BMMCs transfected with siRNAs specific for AMPKα2, LKB1, or Sirt1. AMPKα2 -/- and Sirt1 -/- mice were used to confirm the anti-allergic effect of Tan IIA in anaphylaxis in vivo. Tan IIA dose-dependently inhibited FcεRI-mediated degranulation and production of eicosanoids and cytokines in BMMCs. These inhibitory effects were diminished by siRNA-mediated knockdown or genetic deletion of AMPKα2 or Sirt1. Moreover, Tan IIA inhibited a mast cell-mediated local passive anaphylactic reaction in wild-type mice, but not in AMPKα2 -/- or Sirt1 -/- mice. In conclusion, Tan IIA suppresses FcεRI-mediated mast cell activation and anaphylaxis through activation of the inhibitory Sirt1-LKB1-AMPK pathway. Thus, Tan IIA may be useful as a new therapeutic agent for mast cell-mediated allergic diseases. Copyright © 2018 Elsevier Inc. All rights reserved.

LKB1 promotes radioresistance in esophageal cancer cells exposed to radiation, by suppression of apoptosis and activation of autophagy via the AMPK pathway.

PubMed

He, Qing; Li, Jing; Dong, Feng; Cai, Chuanshu; Zou, Xi

2017-08-01

Liver kinase B (LKB) 1 acts as a tumor suppressor in a broad spectrum of human cancers, and is important in chemoradiotherapy treatment of various tumor types. However, the potential function of LKB1 in esophageal cancer radiotherapy remains to be elucidated. The aim of the present study was to investigate the role of LKB1 in radiosensitivity of esophageal cancer in vivo and in vitro, and to explore its molecular mechanism. Eca‑109 cells transfected with LKB1 overexpression plasmid were xenografted into nude mice and subjected to irradiation and it was observed that the tumor volume was significantly increased in LKB1‑overexpressed tumors compared with that of the control tumors. The in vitro study revealed that LKB1 overexpression led to the radioresistance of Eca‑109 cells, as determined by MTT and colony formation assays. Furthermore, it was demonstrated that LKB1 overexpression inhibited apoptosis and activated autophagy of Eca‑109 cells following radiation treatment, as determined by flow cytometry and western blot analyses. AMP‑activated protein kinase (AMPK) inhibition attenuated LKB1‑induced radioresistance of Eca‑109 cells. To the best of our knowledge, the present study, for the first time, confirmed that LKB1 induces radioresistance of esophageal cancer cells to irradiation via suppression of apoptosis and activation of autophagy, and AMPK mediates this function of LKB1 in esophageal cancer radiotherapy. These findings suggest that LKB1 may act as a novel target in the future, to maximize the efficiency of esophageal cancer radiotherapy.

Honokiol activates the LKB1–AMPK signaling pathway and attenuates the lipid accumulation in hepatocytes

DOE Office of Scientific and Technical Information (OSTI.GOV)

Seo, Min Suk; Kim, Jung Hwan; Kim, Hye Jung

Honokiol is a bioactive neolignan compound isolated from the species of Magnolia. This study was designed to elucidate the cellular mechanism by which honokiol alleviates the development of non-alcoholic steatosis. HepG2 cells were treated with honokiol for 1 h, and then exposed to 1 mM free fatty acid (FFA) for 24 h to simulate non-alcoholic steatosis in vitro. C57BL/6 mice were fed with a high-fat diet for 28 days, and honokiol (10 mg/kg/day) was daily treated. Honokiol concentration-dependently attenuated intracellular fat overloading and triglyceride (TG) accumulation in FFA-exposed HepG2 cells. These effects were blocked by pretreatment with an AMP-activated proteinmore » kinase (AMPK) inhibitor. Honokiol significantly inhibited sterol regulatory element-binding protein-1c (SREBP-1c) maturation and the induction of lipogenic proteins, stearoyl-CoA desaturase-1 (SCD-1) and fatty acid synthase (FAS) in FFA-exposed HepG2 cells, but these effects were blocked by pretreatment of an AMPK inhibitor. Honokiol induced AMPK phosphorylation and subsequent acetyl-CoA carboxylase (ACC) phosphorylation, which were inhibited by genetic deletion of liver kinase B1 (LKB1). Honokiol stimulated LKB1 phosphorylation, and genetic deletion of LKB1 blocked the effect of honokiol on SREBP-1c maturation and the induction of SCD-1 and FAS proteins in FFA-exposed HepG2 cells. Honokiol attenuated the increases in hepatic TG and lipogenic protein levels and fat accumulation in the mice fed with high-fat diet, while significantly induced LKB1 and AMPK phosphorylation. Taken together, our findings suggest that honokiol has an anti-lipogenic effect in hepatocytes, and this effect may be mediated by the LKB1–AMPK signaling pathway, which induces ACC phosphorylation and inhibits SREBP-1c maturation in hepatocytes. - Highlights: • Honokiol attenuates lipid accumulation induced by free fatty acid in hepatocyte. • Honokiol inhibits the increase in lipogenic enzyme levels induced by free

Radiation-induced autophagy promotes esophageal squamous cell carcinoma cell survival via the LKB1 pathway.

PubMed

Lu, Chi; Xie, Conghua

2016-06-01

Radiotherapy is an important treatment modality for esophageal cancer; however, the clinical efficacy of radiotherapy is limited by tumor radioresistance. In the present study, we explored the hypothesis that radiation induces tumor cell autophagy as a cytoprotective adaptive response, which depends on liver kinase B1 (LKB1) also known as serine/threonine kinase 11 (STK11). Radiation-induced Eca-109 cell autophagy was found to be dependent on signaling through the LKB1 pathway, and autophagy inhibitors that disrupted radiation-induced Eca-109 cell autophagy increased cell cycle arrest and cell death in vitro. Inhibition of autophagy also reduced the clonogenic survival of the Eca-109 cells. When treated with radiation alone, human esophageal carcinoma xenografts showed increased LC3B and p-LKB1 expression, which was decreased by the autophagy inhibitor chloroquine. In vivo inhibition of autophagy disrupted tumor growth and increased tumor apoptosis when combined with 6 Gy of ionizing radiation. In summary, our findings elucidate a novel mechanism of resistance to radiotherapy in which radiation-induced autophagy, via the LKB1 pathway, promotes tumor cell survival. This indicates that inhibition of autophagy can serve as an adjuvant treatment to improve the curative effect of radiotherapy.

LKB1 signaling in cephalic neural crest cells is essential for vertebrate head development.

PubMed

Creuzet, Sophie E; Viallet, Jean P; Ghawitian, Maya; Torch, Sakina; Thélu, Jacques; Alrajeh, Moussab; Radu, Anca G; Bouvard, Daniel; Costagliola, Floriane; Borgne, Maïlys Le; Buchet-Poyau, Karine; Aznar, Nicolas; Buschlen, Sylvie; Hosoya, Hiroshi; Thibert, Chantal; Billaud, Marc

2016-10-15

Head development in vertebrates proceeds through a series of elaborate patterning mechanisms and cell-cell interactions involving cephalic neural crest cells (CNCC). These cells undergo extensive migration along stereotypical paths after their separation from the dorsal margins of the neural tube and they give rise to most of the craniofacial skeleton. Here, we report that the silencing of the LKB1 tumor suppressor affects the delamination of pre-migratory CNCC from the neural primordium as well as their polarization and survival, thus resulting in severe facial and brain defects. We further show that LKB1-mediated effects on the development of CNCC involve the sequential activation of the AMP-activated protein kinase (AMPK), the Rho-dependent kinase (ROCK) and the actin-based motor protein myosin II. Collectively, these results establish that the complex morphogenetic processes governing head formation critically depends on the activation of the LKB1 signaling network in CNCC. Copyright © 2016 Elsevier Inc. All rights reserved.

A positive feedback regulation of ISL-1 in DLBCL but not in pancreatic β-cells

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zhang, Qiao, E-mail: zhangqiao200824@126.com; Yang, Zhe, E-mail: zheyang@bjmu.edu.cn; Wang, Weiping, E-mail: wwp@bjmu.edu.cn

2014-07-04

Highlights: • ISL-1 is highly expressed in human pancreatic β-cells and DLBCL. • ISL-1 accelerates the tumorigenesis of DLBCL in vivo. • c-Myc positively regulates ISL-1 expression in DLBCL but not in pancreatic β-cells. • ISL-1 and c-Myc forms an ISL-1/c-Myc transcriptional complex only in DLBCL. • Positive feedback regulation of ISL-1 does not exist in normal pancreatic β-cell. - Abstract: Insulin enhancer binding protein-1 (ISL-1), a LIM-homeodomain transcription factor, has been reported to play essential roles in promoting adult pancreatic β-cells proliferation. Recent studies indicate that ISL-1 may also involve in the occurrence of a variety of tumors. However,more » whether ISL-1 has any functional effect on tumorigenesis, and what are the differences on ISL-1 function in distinct conditions, are completely unknown. In this study, we found that ISL-1 was highly expressed in human pancreatic β-cells, as well as in diffuse large B cell lymphoma (DLBCL), but to a much less extent in other normal tissues or tumor specimens. Further study revealed that ISL-1 promoted the proliferation of pancreatic β-cells and DLBCL cells, and also accelerated the tumorigenesis of DLBCL in vivo. We also found that ISL-1 could activate c-Myc transcription not only in pancreatic β-cells but also in DLBCL cells. However, a cell-specific feedback regulation was detectable only in DLBCL cells. This auto-regulatory loop was established by the interaction of ISL-1 and c-Myc to form an ISL-1/c-Myc transcriptional complex, and synergistically to promote ISL-1 transcription through binding on the ISL-1 promoter. Taken together, our results demonstrate a positive feedback regulation of ISL-1 in DLBCL but not in pancreatic β-cells, which might result in the functional diversities of ISL-1 in different physiological and pathological processes.« less

APPL1 Mediates Adiponectin-Induced LKB1 Cytosolic Localization Through the PP2A-PKCζ Signaling Pathway

PubMed Central

Deepa, Sathyaseelan S.; Zhou, Lijun; Ryu, Jiyoon; Wang, Changhua; Mao, Xuming; Li, Cai; Zhang, Ning; Musi, Nicolas; DeFronzo, Ralph A.; Liu, Feng

2011-01-01

We recently found that the adaptor protein containing pleckstrin homology domain, phosphotyrosine binding domain and leucine zipper motif (APPL)1 is essential for mediating adiponectin signal to induce liver kinase B (LKB)1 cytosloic translocation, an essential step for activation of AMP-activated protein kinase (AMPK) in cells. However, the underlying molecular mechanisms remain unknown. Here, we demonstrate that treating C2C12 myotubes with adiponectin promoted APPL1 interaction with protein phosphatase 2A (PP2A) and protein kinase Cζ (PKCζ), leading to the activation of PP2A and subsequent dephosphorylation and inactivation of PKCζ. The adiponectin-induced inactivation of PKCζ results in dephosphorylation of LKB1 at Ser307 and its subsequent translocation to the cytosol, where it stimulates AMPK activity. Interestingly, we found that metformin also induces LKB1 cytosolic translocation, but the stimulation is independent of APPL1 and the PP2A-PKCζ pathway. Together, our study uncovers a new mechanism underlying adiponectin-stimulated AMPK activation in muscle cells and shed light on potential targets for prevention and treatment of insulin resistance and its associated diseases. PMID:21835890

OCT1-Mediated Metformin Uptake Regulates Pancreatic Stellate Cell Activity.

PubMed

Wu, Chunhua; Qiu, Shanhu; Zhu, Xiangyun; Lin, Hao; Li, Ling

2018-06-27

Metformin treatment is reported to be associated with a lower incidence of and mortality from pancreatic cancer (PC) in type 2 diabetes patients. Activated pancreatic stellate cells (PSCs) are key stroma cells responsible for pancreatic fibrogenesis and PC progression. However, little research is about the influence of metformin on PSCs. Given the potential beneficial effects of metformin on PC, pancreatic tumour stroma is an important target for new therapeutics. We observed the effects of metformin on PSCs. We investigated the effects of metformin on human PSCs proliferation and the production of extracellular matrix (ECM) proteins. Cells were cultured with different concentrations of metformin (0-10 mmol/L). Cell proliferation was determined by immunofluorescence staining for nuclear Ki67 labelling. ECM production was studied by quantitative real-time polymerase chain reaction, immunoblotting and immunofluorescence microscopy. Adenosine monophosphate-activated protein kinase (AMPK), an important regulatory molecule responsible for metformin action, and the organic cation transporter member 1 (OCT1), which is believed to be the most important transporter for the pharmacological action of metformin, were investigated for their possible involvements in metformin-induced proliferation and ECM production. Our results showed that metformin inhibited PSCs proliferation and decreased the production of ECM proteins by activation of AMPK phosphorylation. Silencing of OCT1 expression resulted in a reduction in the effects of metformin on PSCs activity. Collectively, the data indicate that OCT1 may contribute to uptake metformin and regulate PSCs activity. OCT1 is a target of metformin in regulating PSCs activity. © 2018 The Author(s). Published by S. Karger AG, Basel.

Pre-clinical study of drug combinations that reduce breast cancer burden due to aberrant mTOR and metabolism promoted by LKB1 loss

PubMed Central

Andrade-Vieira, Rafaela; Goguen, Donna; Bentley, Heidi A.; Bowen, Chris V.; Marignani, Paola A.

2014-01-01

Cancer therapies that simultaneously target activated mammalian target of rapamycin (mTOR) and cell metabolism are urgently needed. The goal of our study was to identify therapies that effectively inhibited both mTOR activity and cancer cell metabolism in primary tumors in vivo. Using our mouse model of spontaneous breast cancer promoted by loss of LKB1 expression in an ErbB2 activated model; referred to as LKB1−/−NIC mice, we evaluated the effect of novel therapies in vivo on primary tumors. Treatment of LKB1−/−NIC mice with AZD8055 and 2-DG mono-therapies significantly reduced mammary gland tumorigenesis by inhibiting mTOR pathways and glycolytic metabolism; however simultaneous inhibition of these pathways with AZD8055/2-DG combination was significantly more effective at reducing tumor volume and burden. At the molecular level, combination treatment inhibited mTORC1/mTORC2 activity, selectively inhibited mitochondria function and blocked MAPK pro-survival signaling responsible for the ERK-p90RSK feedback loop. Our findings suggest that loss of LKB1 expression be considered a marker for metabolic dysfunction given its role in regulating AMPK and mTOR function. Finally, the outcome of our pre-clinical study confirms therapies that simultaneously target mTORC1/mTORC2 and glycolytic metabolism in cancer produce the best therapeutic outcome for the treatment of patients harboring metabolically active HER2 positive breast cancers. PMID:25436981

Intraventricular Injection of LKB1 Inhibits the Formation of Diet-Induced Obesity in Rats by Activating the AMPK-POMC Neurons-Sympathetic Nervous System Axis.

PubMed

Xi, Pengjiao; Du, Jianying; Liang, Huimin; Han, Jie; Wu, Zhaoxia; Wang, Haomin; He, Lu; Wang, Qiming; Ge, Haize; Li, Yongmei; Xue, Jie; Tian, Derun

2018-01-01

Obesity is increasingly becoming a major public health problem worldwide. Peripheral LKB1 inhibits white fat generation, but the effect of central LKB1 on diet-induced obesity (DIO) is unknown. Therefore, we examined whether LKB1 over-expression in the hypothalamus can inhibit the development of obesity. Adult male Sprague-Dawley rats were anesthetized and placed in a stereotaxic apparatus. LKB1-AAV-EGFP (2.0 × 108 or 2.0 × 1010 vector genomes) or Control-AAV-EGFP (2.0 × 108 vector genomes) was injected into the third ventricle. After administration, the rats were fed a high-fat diet (HFD) for 9 weeks to induce obesity. Rats fed a chow fat diet were used as normal controls. LKB1 delivery decreased body weight, energy intake, fat mass, and serum lipid levels. LKB1 also improved HFD-induced hepatic fatty degeneration. Interestingly, LKB1 over-expression in the hypothalamus activated the AMPK-POMC neurons-sympathetic nervous system (SNS) axis, which can release epinephrine to promote white fat browning. Conversely, the elevated expression of MC3R/MC4R inhibited food intake. These two factors worked together to inhibit the development of obesity. LKB1 in the hypothalamus may have therapeutic potential for DIO through the activation of the AMPK-POMC neurons-SNS axis. © 2018 The Author(s). Published by S. Karger AG, Basel.

Sulforaphane prevents the development of cardiomyopathy in type 2 diabetic mice probably by reversing oxidative stress-induced inhibition of LKB1/AMPK pathway.

PubMed

Zhang, Zhiguo; Wang, Shudong; Zhou, Shanshan; Yan, Xiaoqing; Wang, Yonggang; Chen, Jing; Mellen, Nicholas; Kong, Maiying; Gu, Junlian; Tan, Yi; Zheng, Yang; Cai, Lu

2014-12-01

Type 2 diabetes mellitus (T2DM)-induced cardiomyopathy is associated with cardiac oxidative stress, inflammation, and remodeling. Sulforaphane (SFN), an isothiocyanate naturally presenting in widely consumed vegetables, particularly broccoli, plays an important role in cardiac protection from diabetes. We investigated the effect of SFN on T2DM-induced cardiac lipid accumulation and subsequent cardiomyopathy. Male C57BL/6J mice were fed a high-fat diet for 3months to induce insulin resistance, followed by a treatment with 100mg/kg body-weight streptozotocin to induce hyperglycemia; we referred to it as the T2DM mouse model. Other age-matched mice were fed a normal diet as control. T2DM and control mice were treated with or without 4-month SFN at 0.5mg/kg daily five days a week. At the study's end, cardiac function was assessed. SFN treatment significantly attenuated cardiac remodeling and dysfunction induced by T2DM. SFN treatment also significantly inhibited cardiac lipid accumulation, measured by Oil Red O staining, and improved cardiac inflammation oxidative stress and fibrosis, shown by down-regulating diabetes-induced PAI-1, TNF-α, CTGF, TGF-β, 3-NT, and 4-HNE expression. Elevated 4-HNE resulted in the increase of 4-HNE-LKB1 adducts that should inhibit LKB1 and subsequent AMPK activity. SFN upregulated the expression of Nrf2 and its downstream genes, NQO1 and HO-1, decreased 4-HNE-LKB1 adducts and then reversed diabetes-induced inhibition of LKB1/AMPK and its downstream targets, including sirtuin 1, PGC-1α, phosphorylated acetyl-CoA carboxylase, carnitine palmitoyl transferase-1, ULK1, and light chain-3 II. These results suggest that SFN treatment to T2DM mice may attenuate the cardiac oxidative stress-induced inhibition of LKB1/AMPK signaling pathway, thereby preventing T2DM-induced lipotoxicity and cardiomyopathy. Copyright © 2014 Elsevier Ltd. All rights reserved.

WIPI3 and WIPI4 β-propellers are scaffolds for LKB1-AMPK-TSC signalling circuits in the control of autophagy

PubMed Central

Bakula, Daniela; Müller, Amelie J.; Zuleger, Theresia; Takacs, Zsuzsanna; Franz-Wachtel, Mirita; Thost, Ann-Katrin; Brigger, Daniel; Tschan, Mario P.; Frickey, Tancred; Robenek, Horst; Macek, Boris; Proikas-Cezanne, Tassula

2017-01-01

Autophagy is controlled by AMPK and mTOR, both of which associate with ULK1 and control the production of phosphatidylinositol 3-phosphate (PtdIns3P), a prerequisite for autophagosome formation. Here we report that WIPI3 and WIPI4 scaffold the signal control of autophagy upstream of PtdIns3P production and have a role in the PtdIns3P effector function of WIPI1-WIPI2 at nascent autophagosomes. In response to LKB1-mediated AMPK stimulation, WIPI4-ATG2 is released from a WIPI4-ATG2/AMPK-ULK1 complex and translocates to nascent autophagosomes, controlling their size, to which WIPI3, in complex with FIP200, also contributes. Upstream, WIPI3 associates with AMPK-activated TSC complex at lysosomes, regulating mTOR. Our WIPI interactome analysis reveals the scaffold functions of WIPI proteins interconnecting autophagy signal control and autophagosome formation. Our functional kinase screen uncovers a novel regulatory link between LKB1-mediated AMPK stimulation that produces a direct signal via WIPI4, and we show that the AMPK-related kinases NUAK2 and BRSK2 regulate autophagy through WIPI4. PMID:28561066

Sirtuin-1 regulates acinar-to-ductal metaplasia and supports cancer cell viability in pancreatic cancer.

PubMed

Wauters, Elke; Sanchez-Arévalo Lobo, Victor J; Pinho, Andreia V; Mawson, Amanda; Herranz, Daniel; Wu, Jianmin; Cowley, Mark J; Colvin, Emily K; Njicop, Erna Ngwayi; Sutherland, Rob L; Liu, Tao; Serrano, Manuel; Bouwens, Luc; Real, Francisco X; Biankin, Andrew V; Rooman, Ilse

2013-04-01

The exocrine pancreas can undergo acinar-to-ductal metaplasia (ADM), as in the case of pancreatitis where precursor lesions of pancreatic ductal adenocarcinoma (PDAC) can arise. The NAD(+)-dependent protein deacetylase Sirtuin-1 (Sirt1) has been implicated in carcinogenesis with dual roles depending on its subcellular localization. In this study, we examined the expression and the role of Sirt1 in different stages of pancreatic carcinogenesis, i.e. ADM models and established PDAC. In addition, we analyzed the expression of KIAA1967, a key mediator of Sirt1 function, along with potential Sirt1 downstream targets. Sirt1 was co-expressed with KIAA1967 in the nuclei of normal pancreatic acinar cells. In ADM, Sirt1 underwent a transient nuclear-to-cytoplasmic shuttling. Experiments where during ADM, we enforced repression of Sirt1 shuttling, inhibition of Sirt1 activity or modulation of its expression, all underscore that the temporary decrease of nuclear and increase of cytoplasmic Sirt1 stimulate ADM. Our results further underscore that important transcriptional regulators of acinar differentiation, that is, Pancreatic transcription factor-1a and β-catenin can be deacetylated by Sirt1. Inhibition of Sirt1 is effective in suppression of ADM and in reducing cell viability in established PDAC tumors. KIAA1967 expression is differentially downregulated in PDAC and impacts on the sensitivity of PDAC cells to the Sirt1/2 inhibitor Tenovin-6. In PDAC, acetylation of β-catenin is not affected, unlike p53, a well-characterized Sirt1-regulated protein in tumor cells. Our results reveal that Sirt1 is an important regulator and potential therapeutic target in pancreatic carcinogenesis. ©2012 AACR.

Hydrogen-rich medium protects mouse embryonic fibroblasts from oxidative stress by activating LKB1-AMPK-FoxO1 signal pathway.

PubMed

Lee, Jihyun; Yang, Goowon; Kim, Young-Joo; Tran, Quynh Hoa; Choe, Wonchae; Kang, Insug; Kim, Sung Soo; Ha, Joohun

2017-09-23

Persistent oxidative stress is recognized as a major cause of many pathological conditions as well as ageing. However, most clinical trials of dietary antioxidants have failed to produce successful outcomes in treating oxidative stress-induced diseases. Molecular hydrogen (H 2 ) has recently received considerable attention as a therapeutic agent owing to its novel antioxidant properties, a selective scavenger of hydroxyl and peroxynitrite radicals. Beyond this, numerous reports support that H 2 can modulate the activity of various cellular signal pathways. However, its effect on AMP-activated protein kinase (AMPK) signal pathway, a central regulator of energy hemostasis, has remained almost elusive. Here, we report that hydrogen-rich medium activated LKB1-AMPK signal pathway without ATP depletion, which in turn induced FoxO1-dependent transcription of manganese superoxide dismutase and catalase in mouse embryonic fibroblasts. Moreover, hydrogen-rich media effectively reduced the level of reactive oxygen species in cells treated with hydrogen peroxide and protected these cells from apoptosis in an AMPK-dependent manner. These results suggest that the LKB1-AMPK-FoxO1 signaling pathway is a critical mediator of the antioxidant properties of H 2 , further supporting the idea that H 2 acts as a signaling molecule to serve various physiological functions. Copyright © 2017 Elsevier Inc. All rights reserved.

ADIPOQ/adiponectin induces cytotoxic autophagy in breast cancer cells through STK11/LKB1-mediated activation of the AMPK-ULK1 axis.

PubMed

Chung, Seung J; Nagaraju, Ganji Purnachandra; Nagalingam, Arumugam; Muniraj, Nethaji; Kuppusamy, Panjamurthy; Walker, Alyssa; Woo, Juhyung; Győrffy, Balázs; Gabrielson, Ed; Saxena, Neeraj K; Sharma, Dipali

2017-08-03

ADIPOQ/adiponectin, an adipocytokine secreted by adipocytes in the breast tumor microenvironment, negatively regulates cancer cell growth hence increased levels of ADIPOQ/adiponectin are associated with decreased breast cancer growth. However, its mechanisms of action remain largely elusive. We report that ADIPOQ/adiponectin induces a robust accumulation of autophagosomes, increases MAP1LC3B-II/LC3B-II and decreases SQSTM1/p62 in breast cancer cells. ADIPOQ/adiponectin-treated cells and xenografts exhibit increased expression of autophagy-related proteins. LysoTracker Red-staining and tandem-mCherry-GFP-LC3B assay show that fusion of autophagosomes and lysosomes is augmented upon ADIPOQ/adiponectin treatment. ADIPOQ/adiponectin significantly inhibits breast cancer growth and induces apoptosis both in vitro and in vivo, and these events are preceded by macroautophagy/autophagy, which is integral for ADIPOQ/adiponectin-mediated cell death. Accordingly, blunting autophagosome formation, blocking autophagosome-lysosome fusion or genetic-knockout of BECN1/Beclin1 and ATG7 effectively impedes ADIPOQ/adiponectin induced growth-inhibition and apoptosis-induction. Mechanistic studies show that ADIPOQ/adiponectin reduces intracellular ATP levels and increases PRKAA1 phosphorylation leading to ULK1 activation. AMPK-inhibition abrogates ADIPOQ/adiponectin-induced ULK1-activation, LC3B-turnover and SQSTM1/p62-degradation while AMPK-activation potentiates ADIPOQ/adiponectin's effects. Further, ADIPOQ/adiponectin-mediated AMPK-activation and autophagy-induction are regulated by upstream master-kinase STK11/LKB1, which is a key node in antitumor function of ADIPOQ/adiponectin as STK11/LKB1-knockout abrogates ADIPOQ/adiponectin-mediated inhibition of breast tumorigenesis and molecular analyses of tumors corroborate in vitro mechanistic findings. ADIPOQ/adiponectin increases the efficacy of chemotherapeutic agents. Notably, high expression of ADIPOQ receptor ADIPOR2, ADIPOQ

Peutz-Jeghers families unlinked to STK11/LKB1 gene mutations are highly predisposed to primitive biliary adenocarcinoma

PubMed Central

Olschwang, S.; Boisson, C.; Thomas, G.

2001-01-01

INTRODUCTION—Germline mutations of the STK11/LKB1 tumour suppressor gene (19p13.3) are responsible for Peutz-Jeghers syndrome (PJS), a rare genetic disorder, which is dominantly inherited. In addition to the typical hamartomatous gastrointestinal polyps and perioral pigmented lesions, PJS is also associated with the development of tumours in various sites. No specific follow up has yet been evaluated for gene carriers. Furthermore, genetic heterogeneity has been reported, which makes genetic counselling difficult.
METHODS—We report here the analysis of the STK11/LKB1 locus in a series of 34 PJS families, combining the search for mutations and rearrangements in the coding sequence, allele specific expression tests, and linkage studies.
RESULTS—Germline deleterious mutation of the STK11/LKB1 gene were identified in 70% of cases. The hypothesis of a second PJS locus was reinforced and PJS families could be divided into two groups on the basis of the presence or absence of an identified STK11/LKB1 alteration. Analysis of clinical data indicates that the cancer associated risk is markedly different in the two groups. PJS patients with no identified STK11/LKB1 mutation are at major risk for proximal biliary adenocarcinoma, an infrequent tumour in the general population.
CONCLUSION—Up to 30% of PJS patients are caused by mutation in an unidentified gene that confers high susceptibility to cancer development.


Keywords: Peutz-Jeghers disease; genetic heterogeneity; cancer predisposition; risk estimation PMID:11389158

Critical role for NHE1 in intracellular pH regulation in pancreatic acinar cells.

PubMed

Brown, David A; Melvin, James E; Yule, David I

2003-11-01

The primary function of pancreatic acinar cells is to secrete digestive enzymes together with a NaCl-rich primary fluid which is later greatly supplemented and modified by the pancreatic duct. A Na+/H+ exchanger(s) [NHE(s)] is proposed to be integral in the process of fluid secretion both in terms of the transcellular flux of Na+ and intracellular pH (pHi) regulation. Multiple NHE isoforms have been identified in pancreatic tissue, but little is known about their individual functions in acinar cells. The Na+/H+ exchange inhibitor 5-(N-ethyl-N-isopropyl) amiloride completely blocked pHi recovery after an NH4Cl-induced acid challenge, confirming a general role for NHE in pHi regulation. The targeted disruption of the Nhe1 gene also completely abolished pHi recovery from an acid load in pancreatic acini in both HCO3--containing and HCO3--free solutions. In contrast, the disruption of either Nhe2 or Nhe3 had no effect on pHi recovery. In addition, NHE1 activity was upregulated in response to muscarinic stimulation in wild-type mice but not in NHE1-deficient mice. Fluctuations in pHi could potentially have major effects on Ca2+ signaling following secretagogue stimulation; however, the targeted disruption of Nhe1 was found to have no significant effect on intracellular Ca2+ homeostasis. These data demonstrate that NHE1 is the major regulator of pHi in both resting and muscarinic agonist-stimulated pancreatic acinar cells.

LKB1/KRAS mutant lung cancers constitute a genetic subset of NSCLC with increased sensitivity to MAPK and mTOR signalling inhibition.

PubMed

Mahoney, C L; Choudhury, B; Davies, H; Edkins, S; Greenman, C; Haaften, G van; Mironenko, T; Santarius, T; Stevens, C; Stratton, M R; Futreal, P A

2009-01-27

LKB1/STK11 is a multitasking tumour suppressor kinase. Germline inactivating mutations of the gene are responsible for the Peutz-Jeghers hereditary cancer syndrome. It is also somatically inactivated in approximately 30% of non-small-cell lung cancer (NSCLC). Here, we report that LKB1/KRAS mutant NSCLC cell lines are sensitive to the MEK inhibitor CI-1040 shown by a dose-dependent reduction in proliferation rate, whereas LKB1 and KRAS mutations alone do not confer similar sensitivity. We show that this subset of NSCLC is also sensitised to the mTOR inhibitor rapamycin. Importantly, the data suggest that LKB1/KRAS mutant NSCLCs are a genetically and functionally distinct subset and further suggest that this subset of lung cancers might afford an opportunity for exploitation of anti-MAPK/mTOR-targeted therapies.

LKB1/KRAS mutant lung cancers constitute a genetic subset of NSCLC with increased sensitivity to MAPK and mTOR signalling inhibition

PubMed Central

Mahoney, C L; Choudhury, B; Davies, H; Edkins, S; Greenman, C; Haaften, G van; Mironenko, T; Santarius, T; Stevens, C; Stratton, M R; Futreal, P A

2009-01-01

LKB1/STK11 is a multitasking tumour suppressor kinase. Germline inactivating mutations of the gene are responsible for the Peutz-Jeghers hereditary cancer syndrome. It is also somatically inactivated in approximately 30% of non-small-cell lung cancer (NSCLC). Here, we report that LKB1/KRAS mutant NSCLC cell lines are sensitive to the MEK inhibitor CI-1040 shown by a dose-dependent reduction in proliferation rate, whereas LKB1 and KRAS mutations alone do not confer similar sensitivity. We show that this subset of NSCLC is also sensitised to the mTOR inhibitor rapamycin. Importantly, the data suggest that LKB1/KRAS mutant NSCLCs are a genetically and functionally distinct subset and further suggest that this subset of lung cancers might afford an opportunity for exploitation of anti-MAPK/mTOR-targeted therapies. PMID:19165201

Activation of neurokinin-1 receptors up-regulates substance P and neurokinin-1 receptor expression in murine pancreatic acinar cells

PubMed Central

Koh, Yung-Hua; Moochhala, Shabbir; Bhatia, Madhav

2012-01-01

Abstract Acute pancreatitis (AP) has been associated with an up-regulation of substance P (SP) and neurokinin-1 receptor (NK1R) in the pancreas. Increased SP-NK1R interaction was suggested to be pro-inflammatory during AP. Previously, we showed that caerulein treatment increased SP/NK1R expression in mouse pancreatic acinar cells, but the effect of SP treatment was not evaluated. Pancreatic acinar cells were obtained from pancreas of male swiss mice (25–30 g). We measured mRNA expression of preprotachykinin-A (PPTA) and NK1R following treatment of SP (10−6M). SP treatment increased PPTA and NK1R expression in isolated pancreatic acinar cells, which was abolished by pretreatment of a selective NK1R antagonist, CP96,345. SP also time dependently increased protein expression of NK1R. Treatment of cells with a specific NK1R agonist, GR73,632, up-regulated SP protein levels in the cells. Using previously established concentrations, pre-treatment of pancreatic acinar cells with Gö6976 (10 nM), rottlerin (5 μM), PD98059 (30 μM), SP600125 (30 μM) or Bay11-7082 (30 μM) significantly inhibited up-regulation of SP and NK1R. These observations suggested that the PKC-ERK/JNK-NF-κB pathway is necessary for the modulation of expression levels. In comparison, pre-treatment of CP96,345 reversed gene expression in SP-induced cells, but not in caerulein-treated cells. Overall, the findings in this study suggested a possible auto-regulatory mechanism of SP/NK1R expression in mouse pancreatic acinar cells, via activation of NK1R. Elevated SP levels during AP might increase the occurrence of a positive feedback loop that contributes to abnormally high expression of SP and NK1R. PMID:22040127

Regulation of xenogeneic porcine pancreatic islets.

PubMed

Arcidiacono, Judith A; Evdokimov, Evgenij; Lee, Mark H; Jones, Jeff; Rudenko, Larisa; Schneider, Bruce; Snoy, Phillip J; Wei, Cheng-Hong; Wensky, Allen K; Wonnacott, Keith

2010-01-01

The use of xenogeneic porcine pancreatic islets has been shown to be a potentially promising alternative to using human allogeneic islets to treat insulin-dependent type 1 diabetes (T1D). This article provides an overview of the existing FDA regulatory framework that would be applied to the regulation of clinical trials utilizing xenogeneic porcine pancreatic islets to treat T1D. © 2010 John Wiley & Sons A/S.

The pancreatitis-associated protein VMP1, a key regulator of inducible autophagy, promotes Kras(G12D)-mediated pancreatic cancer initiation.

PubMed

Loncle, C; Molejon, M I; Lac, S; Tellechea, J I; Lomberk, G; Gramatica, L; Fernandez Zapico, M F; Dusetti, N; Urrutia, R; Iovanna, J L

2016-07-14

Both clinical and experimental evidence have firmly established that chronic pancreatitis, in particular in the context of Kras oncogenic mutations, predisposes to pancreatic ductal adenocarcinoma (PDAC). However, the repertoire of molecular mediators of pancreatitis involved in Kras-mediated initiation of pancreatic carcinogenesis remains to be fully defined. In this study we demonstrate a novel role for vacuole membrane protein 1 (VMP1), a pancreatitis-associated protein critical for inducible autophagy, in the regulation of Kras-induced PDAC initiation. Using a newly developed genetically engineered model, we demonstrate that VMP1 increases the ability of Kras to give rise to preneoplastic lesions, pancreatic intraepithelial neoplasias (PanINs). This promoting effect of VMP1 on PanIN formation is due, at least in part, by an increase in cell proliferation combined with a decrease in apoptosis. Using chloroquine, an inhibitor of autophagy, we show that this drug antagonizes the effect of VMP1 on PanIN formation. Thus, we conclude that VMP1-mediated autophagy cooperate with Kras to promote PDAC initiation. These findings are of significant medical relevance, molecules targeting autophagy are currently being tested along chemotherapeutic agents to treat PDAC and other tumors in human trials.

Activation of neurokinin-1 receptors up-regulates substance P and neurokinin-1 receptor expression in murine pancreatic acinar cells.

PubMed

Koh, Yung-Hua; Moochhala, Shabbir; Bhatia, Madhav

2012-07-01

Acute pancreatitis (AP) has been associated with an up-regulation of substance P (SP) and neurokinin-1 receptor (NK1R) in the pancreas. Increased SP-NK1R interaction was suggested to be pro-inflammatory during AP. Previously, we showed that caerulein treatment increased SP/NK1R expression in mouse pancreatic acinar cells, but the effect of SP treatment was not evaluated. Pancreatic acinar cells were obtained from pancreas of male swiss mice (25-30 g). We measured mRNA expression of preprotachykinin-A (PPTA) and NK1R following treatment of SP (10(-6) M). SP treatment increased PPTA and NK1R expression in isolated pancreatic acinar cells, which was abolished by pretreatment of a selective NK1R antagonist, CP96,345. SP also time dependently increased protein expression of NK1R. Treatment of cells with a specific NK1R agonist, GR73,632, up-regulated SP protein levels in the cells. Using previously established concentrations, pre-treatment of pancreatic acinar cells with Gö6976 (10 nM), rottlerin (5 μM), PD98059 (30 μM), SP600125 (30 μM) or Bay11-7082 (30 μM) significantly inhibited up-regulation of SP and NK1R. These observations suggested that the PKC-ERK/JNK-NF-κB pathway is necessary for the modulation of expression levels. In comparison, pre-treatment of CP96,345 reversed gene expression in SP-induced cells, but not in caerulein-treated cells. Overall, the findings in this study suggested a possible auto-regulatory mechanism of SP/NK1R expression in mouse pancreatic acinar cells, via activation of NK1R. Elevated SP levels during AP might increase the occurrence of a positive feedback loop that contributes to abnormally high expression of SP and NK1R. © 2011 The Authors Journal of Cellular and Molecular Medicine © 2011 Foundation for Cellular and Molecular Medicine/Blackwell Publishing Ltd.

β1 integrin is a crucial regulator of pancreatic β-cell expansion

PubMed Central

Diaferia, Giuseppe R.; Jimenez-Caliani, Antonio J.; Ranjitkar, Prerana; Yang, Wendy; Hardiman, Gary; Rhodes, Christopher J.; Crisa, Laura; Cirulli, Vincenzo

2013-01-01

Development of the endocrine compartment of the pancreas, as represented by the islets of Langerhans, occurs through a series of highly regulated events encompassing branching of the pancreatic epithelium, delamination and differentiation of islet progenitors from ductal domains, followed by expansion and three-dimensional organization into islet clusters. Cellular interactions with the extracellular matrix (ECM) mediated by receptors of the integrin family are postulated to regulate key functions in these processes. Yet, specific events regulated by these receptors in the developing pancreas remain unknown. Here, we show that ablation of the β1 integrin gene in developing pancreatic β-cells reduces their ability to expand during embryonic life, during the first week of postnatal life, and thereafter. Mice lacking β1 integrin in insulin-producing cells exhibit a dramatic reduction of the number of β-cells to only ∼18% of wild-type levels. Despite the significant reduction in β-cell mass, these mutant mice are not diabetic. A thorough phenotypic analysis of β-cells lacking β1 integrin revealed a normal expression repertoire of β-cell markers, normal architectural organization within islet clusters, and a normal ultrastructure. Global gene expression analysis revealed that ablation of this ECM receptor in β-cells inhibits the expression of genes regulating cell cycle progression. Collectively, our results demonstrate that β1 integrin receptors function as crucial positive regulators of β-cell expansion. PMID:23863477

Adiponectin attenuates neuronal apoptosis induced by hypoxia-ischemia via the activation of AdipoR1/APPL1/LKB1/AMPK pathway in neonatal rats.

PubMed

Xu, Ningbo; Zhang, Yixin; Doycheva, Desislava Met; Ding, Yan; Zhang, Yiting; Tang, Jiping; Guo, Hongbo; Zhang, John H

2018-05-01

Adiponectin is an important adipocyte-derived plasma protein that has beneficial effects on cardio- and cerebrovascular diseases. A low level of plasma Adiponectin is associated with increased mortality post ischemic stroke; however, little is known about the causal role of Adiponectin as well as its molecular mechanisms in neonatal hypoxia ischemia (HI). In the present study, ten-day-old rat pups were subjected to right common carotid artery ligation followed by 2.5 h hypoxia. Recombinant human Adiponectin (rh-Adiponectin) was administered intranasally 1 h post HI. Adiponectin Receptor 1 (AdipoR1) siRNA, APPL1 siRNA, LKB1 siRNA were administered through intracerebroventricular injection 48 h before HI. Brain infarct area measurement, neurological function test, western blot, Fluoro Jade C (FJC), TUNEL, and immunofluorescence staining were conducted. Results revealed that endogenous Adiponectin, AdipoR1 and APPL1 were increased in a time dependent manner after HI. Administration of rh-Adiponectin reduced brain infarct area, neuronal apoptosis, brain atrophy and improved neurological function at 24 h and 4 weeks post HI. Furthermore, rh-Adiponectin treatment increased Adiponectin, AdipoR1, APPL1, cytosolic LKB1, p-AMPK expression levels and thereby attenuated apoptosis as shown by the decreased expression of the pro-apoptotic marker, Cleaved Caspase 3 (C-Cas3), as well as the number of FJC and TUNEL positively stained neurons. AdipoR1, APPL1 and LKB1 siRNAs abolished the anti-apoptotic effects of rh-Adiponectin at 24 h after HI. Collectively, the data provided evidence that intranasal administration of rh-Adiponectin attenuated neuronal apoptosis at least in part via activating AdipoR1/APPL1/LKB1/AMPK signaling pathway. Adiponectin could represent a therapeutic target for treatment of neonatal hypoxic ischemic encephalopathy. Copyright © 2018 Elsevier Ltd. All rights reserved.

SIRT1 inhibits proliferation of pancreatic cancer cells expressing pancreatic adenocarcinoma up-regulated factor (PAUF), a novel oncogene, by suppression of {beta}-catenin

DOE Office of Scientific and Technical Information (OSTI.GOV)

Cho, Il-Rae; Koh, Sang Seok; Department of Functional Genomics, University of Science and Technology, Daejeon 305-333

2012-06-29

Highlights: Black-Right-Pointing-Pointer SIRT1 inhibits protein levels of {beta}-catenin and its transcriptional activity. Black-Right-Pointing-Pointer Nuclear localization of SIRT1 is not required for the decrease of {beta}-catenin expression. Black-Right-Pointing-Pointer SIRT1-mediated degradation of {beta}-catenin is not required for GSK-3{beta} and Siah-1 but for proteosome. Black-Right-Pointing-Pointer SIRT1 activation inhibits proliferation of pancreatic cancer cells expressing PAUF. -- Abstract: Because we found in a recent study that pancreatic adenocarcinoma up-regulated factor (PAUF), a novel oncogene, induces a rapid proliferation of pancreatic cells by up-regulation of {beta}-catenin, we postulated that {beta}-catenin might be a target molecule for pancreatic cancer treatment. We thus speculated whether SIRT1, knownmore » to target {beta}-catenin in a colon cancer model, suppresses {beta}-catenin in those pancreatic cancer cells that express PAUF (Panc-PAUF). We further evaluated whether such suppression would lead to inhibition of the proliferation of these cells. The ectopic expression of either SIRT1 or resveratrol (an activator of SIRT1) suppressed levels of {beta}-catenin protein and its transcriptional activity in Panc-PAUF cells. Conversely, suppression of SIRT1 expression by siRNA enhanced {beta}-catenin expression and transcriptional activity. SIRT1 mutant analysis showed that nuclear localization of SIRT1 is not required for reduction of {beta}-catenin. Treatment with MG132, a proteasomal inhibitor, restored {beta}-catenin protein levels, suggesting that SIRT1-mediated degradation of {beta}-catenin requires proteasomal activity. It was reported that inhibition of GSK-3{beta} or Siah-1 stabilizes {beta}-catenin in colon cancer cells, but suppression of GSK-3{beta} or Siah-1 using siRNA in the presence of resveratrol instead diminished {beta}-catenin protein levels in Panc-PAUF cells. This suggests that GSK-3{beta} and Siah-1 are not involved

Zanthoxylum ailanthoides Suppresses Oleic Acid-Induced Lipid Accumulation through an Activation of LKB1/AMPK Pathway in HepG2 Cells

PubMed Central

Kwon, Eun-Bin; Kang, Myung-Ji; Kim, Soo-Yeon; Lee, Yong-Moon; Lee, Mi-Kyeong; Yuk, Heung Joo; Ryu, Hyung Won; Lee, Su Ui

2018-01-01

Zanthoxylum ailanthoides (ZA) has been used as folk medicines in East Asian and recently reported to have several bioactivity; however, the studies of ZA on the regulation of triacylglycerol (TG) biosynthesis have not been elucidated yet. In this study, we examined whether the methanol extract of ZA (ZA-M) could reduce oleic acid- (OA-) induced intracellular lipid accumulation and confirmed its mode of action in HepG2 cells. ZA-M was shown to promote the phosphorylation of AMPK and its upstream LKB1, followed by reduction of lipogenic gene expressions. As a result, treatment of ZA-M blocked de novo TG biosynthesis and subsequently mitigated intracellular neutral lipid accumulation in HepG2 cells. ZA-M also inhibited OA-induced production of reactive oxygen species (ROS) and TNF-α, suggesting that ZA-M possess the anti-inflammatory feature in fatty acid over accumulated condition. Taken together, these results suggest that ZA-M attenuates OA-induced lipid accumulation and inflammation through the activation of LKB1/AMPK signaling pathway in HepG2 cells. PMID:29507591

Zanthoxylum ailanthoides Suppresses Oleic Acid-Induced Lipid Accumulation through an Activation of LKB1/AMPK Pathway in HepG2 Cells.

PubMed

Kwon, Eun-Bin; Kang, Myung-Ji; Kim, Soo-Yeon; Lee, Yong-Moon; Lee, Mi-Kyeong; Yuk, Heung Joo; Ryu, Hyung Won; Lee, Su Ui; Oh, Sei-Ryang; Moon, Dong-Oh; Lee, Hyun-Sun; Kim, Mun-Ock

2018-01-01

Zanthoxylum ailanthoides (ZA) has been used as folk medicines in East Asian and recently reported to have several bioactivity; however, the studies of ZA on the regulation of triacylglycerol (TG) biosynthesis have not been elucidated yet. In this study, we examined whether the methanol extract of ZA (ZA-M) could reduce oleic acid- (OA-) induced intracellular lipid accumulation and confirmed its mode of action in HepG2 cells. ZA-M was shown to promote the phosphorylation of AMPK and its upstream LKB1, followed by reduction of lipogenic gene expressions. As a result, treatment of ZA-M blocked de novo TG biosynthesis and subsequently mitigated intracellular neutral lipid accumulation in HepG2 cells. ZA-M also inhibited OA-induced production of reactive oxygen species (ROS) and TNF- α , suggesting that ZA-M possess the anti-inflammatory feature in fatty acid over accumulated condition. Taken together, these results suggest that ZA-M attenuates OA-induced lipid accumulation and inflammation through the activation of LKB1/AMPK signaling pathway in HepG2 cells.

Alterations of LKB1 and KRAS and risk of brain metastasis: comprehensive characterization by mutation analysis, copy number, and gene expression in non-small-cell lung carcinoma.

PubMed

Zhao, Ni; Wilkerson, Matthew D; Shah, Usman; Yin, Xiaoying; Wang, Anyou; Hayward, Michele C; Roberts, Patrick; Lee, Carrie B; Parsons, Alden M; Thorne, Leigh B; Haithcock, Benjamin E; Grilley-Olson, Juneko E; Stinchcombe, Thomas E; Funkhouser, William K; Wong, Kwok-Kin; Sharpless, Norman E; Hayes, D Neil

2014-11-01

Brain metastases are one of the most malignant complications of lung cancer and constitute a significant cause of cancer related morbidity and mortality worldwide. Recent years of investigation suggested a role of LKB1 in NSCLC development and progression, in synergy with KRAS alteration. In this study, we systematically analyzed how LKB1 and KRAS alteration, measured by mutation, gene expression (GE) and copy number (CN), are associated with brain metastasis in NSCLC. Patients treated at University of North Carolina Hospital from 1990 to 2009 with NSCLC provided frozen, surgically extracted tumors for analysis. GE was measured using Agilent 44,000 custom-designed arrays, CN was assessed by Affymetrix GeneChip Human Mapping 250K Sty Array or the Genome-Wide Human SNP Array 6.0 and gene mutation was detected using ABI sequencing. Integrated analysis was conducted to assess the relationship between these genetic markers and brain metastasis. A model was proposed for brain metastasis prediction using these genetic measurements. 17 of the 174 patients developed brain metastasis. LKB1 wild type tumors had significantly higher LKB1 CN (p<0.001) and GE (p=0.002) than the LKB1 mutant group. KRAS wild type tumors had significantly lower KRAS GE (p<0.001) and lower CN, although the latter failed to be significant (p=0.295). Lower LKB1 CN (p=0.039) and KRAS mutation (p=0.007) were significantly associated with more brain metastasis. The predictive model based on nodal (N) stage, patient age, LKB1 CN and KRAS mutation had a good prediction accuracy, with area under the ROC curve of 0.832 (p<0.001). LKB1 CN in combination with KRAS mutation predicted brain metastasis in NSCLC. Copyright © 2014 The Authors. Published by Elsevier Ireland Ltd.. All rights reserved.

Different downstream signalling of CCK1 receptors regulates distinct functions of CCK in pancreatic beta cells.

PubMed

Ning, Shang-lei; Zheng, Wen-shuai; Su, Jing; Liang, Nan; Li, Hui; Zhang, Dao-lai; Liu, Chun-hua; Dong, Jun-hong; Zhang, Zheng-kui; Cui, Min; Hu, Qiao-Xia; Chen, Chao-chao; Liu, Chang-hong; Wang, Chuan; Pang, Qi; Chen, Yu-xin; Yu, Xiao; Sun, Jin-peng

2015-11-01

Cholecystokinin (CCK) is secreted by intestinal I cells and regulates important metabolic functions. In pancreatic islets, CCK controls beta cell functions primarily through CCK1 receptors, but the signalling pathways downstream of these receptors in pancreatic beta cells are not well defined. Apoptosis in pancreatic beta cell apoptosis was evaluated using Hoechst-33342 staining, TUNEL assays and Annexin-V-FITC/PI staining. Insulin secretion and second messenger production were monitored using ELISAs. Protein and phospho-protein levels were determined by Western blotting. A glucose tolerance test was carried out to examine the functions of CCK-8s in streptozotocin-induced diabetic mice. The sulfated carboxy-terminal octapeptide CCK26-33 amide (CCK-8s) activated CCK1 receptors and induced accumulation of both IP3 and cAMP. Whereas Gq -PLC-IP3 signalling was required for the CCK-8s-induced insulin secretion under low-glucose conditions, Gs -PKA/Epac signalling contributed more strongly to the CCK-8s-mediated insulin secretion in high-glucose conditions. CCK-8s also promoted formation of the CCK1 receptor/β-arrestin-1 complex in pancreatic beta cells. Using β-arrestin-1 knockout mice, we demonstrated that β-arrestin-1 is a key mediator of both CCK-8s-mediated insulin secretion and of its the protective effect against apoptosis in pancreatic beta cells. The anti-apoptotic effects of β-arrestin-1 occurred through cytoplasmic late-phase ERK activation, which activates the 90-kDa ribosomal S6 kinase-phospho-Bcl-2-family protein pathway. Knowledge of different CCK1 receptor-activated downstream signalling pathways in the regulation of distinct functions of pancreatic beta cells could be used to identify biased CCK1 receptor ligands for the development of new anti-diabetic drugs. © 2015 The British Pharmacological Society.

Berberine inhibits hepatic gluconeogenesis via the LKB1-AMPK-TORC2 signaling pathway in streptozotocin-induced diabetic rats.

PubMed

Jiang, Shu-Jun; Dong, Hui; Li, Jing-Bin; Xu, Li-Jun; Zou, Xin; Wang, Kai-Fu; Lu, Fu-Er; Yi, Ping

2015-07-07

To investigate the molecular mechanisms of berberine inhibition of hepatic gluconeogenesis in a diabetic rat model. The 40 rats were randomly divided into five groups. One group was selected as the normal group. In the remaining groups (n = 8 each), the rats were fed on a high-fat diet for 1 mo and received intravenous injection of streptozotocin for induction of the diabetic models. Berberine (156 mg/kg per day) (berberine group) or metformin (184 mg/kg per day) (metformin group) was intragastrically administered to the diabetic rats and 5-aminoimidazole-4-carboxamide1-β-D-ribofuranoside (AICAR) (0.5 mg/kg per day) (AICAR group) was subcutaneously injected to the diabetic rats for 12 wk. The remaining eight diabetic rats served as the model group. Fasting plasma glucose and insulin levels as well as lipid profile were tested. The expressions of proteins were examined by western blotting. The nuclear translocation of CREB-regulated transcription co-activator (TORC)2 was observed by immunohistochemical staining. Berberine improved impaired glucose tolerance and decreased plasma hyperlipidemia. Moreover, berberine decreased fasting plasma insulin and homeostasis model assessment of insulin resistance (HOMA-IR). Berberine upregulated protein expression of liver kinase (LK)B1, AMP-activated protein kinase (AMPK) and phosphorylated AMPK (p-AMPK). The level of phophorylated TORC2 (p-TORC2) protein in the cytoplasm was higher in the berberine group than in the model group, and no significant difference in total TORC2 protein level was observed. Immunohistochemical staining revealed that more TORC2 was localized in the cytoplasm of the berberine group than in the model group. Moreover, berberine treatment downregulated protein expression of the key gluconeogenic enzymes (phosphoenolpyruvate carboxykinase and glucose-6-phosphatase) in the liver tissues. Our findings revealed that berberine inhibited hepatic gluconeogenesis via the regulation of the LKB1-AMPK-TORC2

6-Phosphogluconate dehydrogenase links oxidative PPP, lipogenesis and tumour growth by inhibiting LKB1-AMPK signalling.

PubMed

Lin, Ruiting; Elf, Shannon; Shan, Changliang; Kang, Hee-Bum; Ji, Quanjiang; Zhou, Lu; Hitosugi, Taro; Zhang, Liang; Zhang, Shuai; Seo, Jae Ho; Xie, Jianxin; Tucker, Meghan; Gu, Ting-Lei; Sudderth, Jessica; Jiang, Lei; Mitsche, Matthew; DeBerardinis, Ralph J; Wu, Shaoxiong; Li, Yuancheng; Mao, Hui; Chen, Peng R; Wang, Dongsheng; Chen, Georgia Zhuo; Hurwitz, Selwyn J; Lonial, Sagar; Arellano, Martha L; Khoury, Hanna J; Khuri, Fadlo R; Lee, Benjamin H; Lei, Qunying; Brat, Daniel J; Ye, Keqiang; Boggon, Titus J; He, Chuan; Kang, Sumin; Fan, Jun; Chen, Jing

2015-11-01

The oxidative pentose phosphate pathway (PPP) contributes to tumour growth, but the precise contribution of 6-phosphogluconate dehydrogenase (6PGD), the third enzyme in this pathway, to tumorigenesis remains unclear. We found that suppression of 6PGD decreased lipogenesis and RNA biosynthesis and elevated ROS levels in cancer cells, attenuating cell proliferation and tumour growth. 6PGD-mediated production of ribulose-5-phosphate (Ru-5-P) inhibits AMPK activation by disrupting the active LKB1 complex, thereby activating acetyl-CoA carboxylase 1 and lipogenesis. Ru-5-P and NADPH are thought to be precursors in RNA biosynthesis and lipogenesis, respectively; thus, our findings provide an additional link between the oxidative PPP and lipogenesis through Ru-5-P-dependent inhibition of LKB1-AMPK signalling. Moreover, we identified and developed 6PGD inhibitors, physcion and its derivative S3, that effectively inhibited 6PGD, cancer cell proliferation and tumour growth in nude mice xenografts without obvious toxicity, suggesting that 6PGD could be an anticancer target.

ROS mediated EGFR/MEK/ERK/HIF-1α Loop Regulates Glucose metabolism in pancreatic cancer.

PubMed

Wang, Gang; Li, Yifeng; Yang, Zeyu; Xu, Weina; Yang, Yifan; Tan, Xiaodong

2018-06-12

To investigate the glycometabolism associated mechanism in invasion and metastasis of pancreatic cancer, We screened out genes involved in anaerobic glycolysis headed by HIF-1α,using pre-established a pair of pancreatic cancer cell lines. In this study, we further detected the glucose metabolism state not only in the cells but all also in two groups of patients with different SUVmax on 18 F-FDG PET/CT. The data suggests that ROS mediated EGFR/MEK/ERK/HIF-1α loop is activated in high glucose metabolic samples both in vitro and in vivo: The increasing of HIF-1α expression is controlled by activation of EGFR/MEK/ERK pathway in hypoxia condition, HIF-1α inhibits excessive release of ROS, the reduction of ROS further activates EGFR to form a positive feedback loop. This difference is closely related to invasion and metastasis capacity of pancreatic cancer, and can be rescued by separate or combined inhibition of EGFR or HIF-1α in various degree. These results indicate a new clue to develop therapy of pancreatic cancer by regulating the glucose metabolism. Copyright © 2018 Elsevier Inc. All rights reserved.

Chalcones suppress fatty acid-induced lipid accumulation through a LKB1/AMPK signaling pathway in HepG2 cells.

PubMed

Zhang, Tianshun; Yamamoto, Norio; Ashida, Hitoshi

2014-06-01

Excessive lipid accumulation in the liver has been proposed to cause hyperlipidemia, diabetes and fatty liver disease. 4-Hydroxyderricin (4HD), xanthoangelol (XAG), cardamonin (CAR) and flavokawain B (FKB) are chalcones that have exhibited various biological effects against obesity, inflammation, and diabetes; however, little is known about the inhibitory effects of these chalcones on fatty liver disease. In the present study, we investigated the ability of 4HD, XAG, CAR, and FKB to reduce lipid accumulation in hepatocytes. When HepG2 cells were treated with a mixture of fatty acids (FAs; palmitic acid : oleic acid = 1 : 2 ratio), significant lipid accumulation was observed. Under the same experimental conditions, addition of chalcones at 5 μM significantly suppressed the FA-induced lipid accumulation. We found that the expression of sterol regulatory element-binding protein-1 (SREBP-1), a key molecule involved in lipogenesis, was decreased in these chalcone-treated cells. We also found that these chalcones increased the expression of peroxisome proliferator-activated receptor α (PPARα), which is involved in FA oxidation. Moreover, these chalcones increased phosphorylation of AMP-activated protein kinase (AMPK) and liver kinase B1 (LKB1), upstream regulators of SREBP-1 and PPARα. We confirmed that an AMPK inhibitor, compound C, reversed chalcone-induced changes in SREBP-1 and PPARα expression in the HepG2 cells. Collectively, we found that 4HD, XAG, CAR, and XAG attenuated lipid accumulation through activation of the LKB1/AMPK signaling pathway in HepG2 cells.

Somatic alterations of the serine/threonine kinase LKB1 gene in squamous cell (SCC) and large cell (LCC) lung carcinoma.

PubMed

Strazisar, Mojca; Mlakar, Vid; Rott, Tomaz; Glavac, Damjan

2009-05-01

Somatic LKB1 serine/threonine kinase alterations are rare in sporadic cancers, with the exception lung adenocarcinoma, but no mutations in squamous cell or large cell primary carcinoma were discovered. We screened the LKB1 gene in 129 primary nonsmall cell lung carcinomas, adjacent healthy lung tissue, and control blood samples. Forty-five percent of nonsmall cell lung tumors harbored either intron or exon alterations. We identified R86G, F354L, Y272Y and three polymorphisms: 290+36G/T, 386+156G/T, and 862+145C/T (novel). R86G (novel) and F354L mutations were found in six squamous cell carcinomas and three large cell cancer carcinomas, but not in the adjacent healthy tissue or controls samples. The F354L mutation was found in advanced squamous cell carcinomas with elevated COX-2 expression, rare P53, and no K-RAS mutation. Results indicate that the LKB1 gene is changed in a certain proportion of nonsmall cell lung tumors, predominately in advanced squamous lung carcinoma. Inactivation of the gene takes place via the C-terminal domain and could be related to mechanisms influencing tumor initiation, differentiation, and metastasis.

Dosimetric characteristics of LKB:Cu,P solid TL detector

NASA Astrophysics Data System (ADS)

Hashim, S.; Alajerami, Y. S. M.; Ghoshal, S. K.; Saleh, M. A.; Saripan, M. I.; Kadir, A. B. A.; Bradley, D. A.; Alzimami, K.

2014-11-01

The dosimetric characteristics of newly developed borate glass dosimeter modified with lithium and potassium carbonate (LKB) and co-doped with CuO and NH4H2PO4 are reported. Broad peaks in the absence of any sharp peak confirms the amorphous nature of the prepared glass. A simple glow curve of Cu doped sample is observed with a single prominent peak (Tm) at 220 °C. The TL intensity response shows an enhancement of ~100 times due to the addition of CuO (0.1 mol%) to LKB compound. A further enhancement of the intensity by a factor of 3 from the addition of 0.25 mol% NH4H2PO4 as a co-dopant impurity is attributed to the creation of extra electron traps with consequent increase in energy transfer of radiation recombination centers. The TL yield performance of LKB:Cu,P with Zeff ≈8.92 is approximately seventeen times less sensitive compared to LiF:Mg,Ti (TLD-100). The proposed dosimeter shows good linearity up to 103 Gy, minimal fading and photon energy independence. These attractive features offered by our dosimeter is expected to pave the way towards dosimetric applications.

Dexmedetomidine attenuates pancreatic injury and inflammatory response in mice with pancreatitis by possible reduction of NLRP3 activation and up-regulation of NET expression.

PubMed

Li, Yong; Pan, Yiyuan; Gao, Lin; Lu, Guotao; Zhang, Jingzhu; Xie, Xiaochun; Tong, Zhihui; Li, Baiqiang; Li, Gang; Li, Weiqin

2018-01-22

Previous studies have shown that acute inflammation is associated with increased sympathetic activity, which in turn increases the inflammatory response and leads to organ damage. The present study aimed to investigate whether dexmedetomidine administration during acute pancreatitis (AP) lessens pancreatic pathological and functional injury and the inflammatory response, and to explore the underlying mechanisms. Mild pancreatitis was induced in mice with caerulein, and severe pancreatitis was induced with caerulein plus lipopolysaccharide (LPS). After pancreatitis induction, dexmedetomidine at 10 or 20 μg/kg was injected via the tail vein. Pancreatic pathological and functional injury was assessed by histology and serum levels of amylase and lipase, respectively. The inflammatory response was evaluated by determining serum levels of inflammatory factors. The expression of myeloperoxidase (MPO) was examined by immunohistochemistry. The expression of norepinephrine transporter (NET), NLRP3, pro-IL-1β, and interleukin (IL)-1β in pancreatic tissue was detected by Western blot and real-time PCR. Dexmedetomidine at 20 μg/kg significantly attenuated pancreatic pathological injury, reduced serum levels of amylase, lipase, IL-1β, IL-6, and tumor necrosis factor (TNF)-α, and decreased the expression of MPO in pancreatic tissue in both mouse models of pancreatitis. In addition, dexmedetomidine at 20 μg/kg significantly down-regulated the expression of NLRP3, pro-IL-1β, and IL-1β in pancreatic tissue, but up-regulated the expression of NET in both mouse models. Dexmedetomidine attenuates pancreatic injury and inflammatory response in mice with pancreatitis possibly by reducing NLRP3 activation and up-regulating NET expression. Copyright © 2018 Elsevier Inc. All rights reserved.

Complement component 1, q subcomponent binding protein (C1QBP) in lipid rafts mediates hepatic metastasis of pancreatic cancer by regulating IGF-1/IGF-1R signaling.

PubMed

Shi, Haojun; Fang, Winston; Liu, Minda; Fu, Deliang

2017-10-01

Pancreatic cancer shows a remarkable predilection for hepatic metastasis. Complement component 1, q subcomponent binding protein (C1QBP) can mediate growth factor-induced cancer cell chemotaxis and distant metastasis by activation of receptor tyrosine kinases. Coincidentally, insulin-like growth factor-1 (IGF-1) derived from the liver and cancer cells itself has been recognized as a critical inducer of hepatic metastasis. However, the mechanism underlying IGF-1-dependent hepatic metastasis of pancreatic cancer, in which C1QBP may be involved, remains unknown. In the study, we demonstrated a significant association between C1QBP expression and hepatic metastasis in patients with pancreatic cancer. IGF-1 induced the translocation of C1QBP from cytoplasm to lipid rafts and further drove the formation of CD44 variant 6 (CD44v6)/C1QBP complex in pancreatic cancer cells. C1QBP interacting with CD44v6 in lipid rafts promoted phosphorylation of IGF-1R and thus activated downstream PI3K and MAPK signaling pathways which mediated metastatic potential of pancreatic cancer cells including proliferation, apoptosis, invasion, adhesion and energy metabolism. Furthermore, C1QBP knockdown suppressed hepatic metastasis of pancreatic cancer cells in nude mice. We therefore conclude that C1QBP in lipid rafts serves a key regulator of IGF-1/IGF-1R-induced hepatic metastasis from pancreatic cancer. Our findings about C1QBP in lipid rafts provide a novel strategy to block IGF-1/IGF-1R signaling in pancreatic cancer and a reliable premise for more efficient combined modality therapies. © 2017 UICC.

miR-219-1-3p is a negative regulator of the mucin MUC4 expression and is a tumor suppressor in pancreatic cancer.

PubMed

Lahdaoui, F; Delpu, Y; Vincent, A; Renaud, F; Messager, M; Duchêne, B; Leteurtre, E; Mariette, C; Torrisani, J; Jonckheere, N; Van Seuningen, I

2015-02-05

Pancreatic ductal adenocarcinoma (PDAC) is among the most lethal cancers in the world with one of the worst outcome. The oncogenic mucin MUC4 has been identified as an actor of pancreatic carcinogenesis as it is involved in many processes regulating pancreatic cancer cell biology. MUC4 is not expressed in healthy pancreas whereas it is expressed very early in pancreatic carcinogenesis. Targeting MUC4 in these early steps may thus appear as a promising strategy to slow-down pancreatic tumorigenesis. miRNA negative regulation of MUC4 could be one mechanism to efficiently downregulate MUC4 gene expression in early pancreatic neoplastic lesions. Using in silico studies, we found two putative binding sites for miR-219-1-3p in the 3'-UTR of MUC4 and showed that miR-219-1-3p expression is downregulated both in PDAC-derived cell lines and human PDAC tissues compared with their normal counterparts. We then showed that miR-219-1-3p negatively regulates MUC4 mucin expression via its direct binding to MUC4 3'-UTR. MiR-219-1-3p overexpression (transient and stable) in pancreatic cancer cell lines induced a decrease of cell proliferation associated with a decrease of cyclin D1 and a decrease of Akt and Erk pathway activation. MiR-219-1-3p overexpression also decreased cell migration. Furthermore, miR-219-1-3p expression was found to be conversely correlated with Muc4 expression in early pancreatic intraepithelial neoplasia lesions of Pdx1-Cre;LSL-Kras(G12D) mice. Most interestingly, in vivo studies showed that miR-219-1-3p injection in xenografted pancreatic tumors in mice decreased both tumor growth and MUC4 mucin expression. Altogether, these results identify miR-219-1-3p as a new negative regulator of MUC4 oncomucin that possesses tumor-suppressor activity in PDAC.

Folic acid supplementation during high-fat diet feeding restores AMPK activation via an AMP-LKB1-dependent mechanism

PubMed Central

Sid, Victoria; Wu, Nan; Sarna, Lindsei K.; Siow, Yaw L.; House, James D.

2015-01-01

AMPK is an endogenous energy sensor that regulates lipid and carbohydrate metabolism. Nonalcoholic fatty liver disease (NAFLD) is regarded as a hepatic manifestation of metabolic syndrome with impaired lipid and glucose metabolism and increased oxidative stress. Our recent study showed that folic acid supplementation attenuated hepatic oxidative stress and lipid accumulation in high-fat diet-fed mice. The aim of the present study was to investigate the effect of folic acid on hepatic AMPK during high-fat diet feeding and the mechanisms involved. Male C57BL/6J mice were fed a control diet (10% kcal fat), a high-fat diet (60% kcal fat), or a high-fat diet supplemented with folic acid (26 mg/kg diet) for 5 wk. Mice fed a high-fat diet exhibited hyperglycemia, hepatic cholesterol accumulation, and reduced hepatic AMPK phosphorylation. Folic acid supplementation restored AMPK phosphorylation (activation) and reduced blood glucose and hepatic cholesterol levels. Activation of AMPK by folic acid was mediated through an elevation of its allosteric activator AMP and activation of its upstream kinase, namely, liver kinase B1 (LKB1) in the liver. Consistent with in vivo findings, 5-methyltetrahydrofolate (bioactive form of folate) restored phosphorylation (activation) of both AMPK and LKB1 in palmitic acid-treated HepG2 cells. Activation of AMPK by folic acid might be responsible for AMPK-dependent phosphorylation of HMG-CoA reductase, leading to reduced hepatic cholesterol synthesis during high-fat diet feeding. These results suggest that folic acid supplementation may improve cholesterol and glucose metabolism by restoration of AMPK activation in the liver. PMID:26400185

TEAD and YAP regulate the enhancer network of human embryonic pancreatic progenitors.

PubMed

Cebola, Inês; Rodríguez-Seguí, Santiago A; Cho, Candy H-H; Bessa, José; Rovira, Meritxell; Luengo, Mario; Chhatriwala, Mariya; Berry, Andrew; Ponsa-Cobas, Joan; Maestro, Miguel Angel; Jennings, Rachel E; Pasquali, Lorenzo; Morán, Ignasi; Castro, Natalia; Hanley, Neil A; Gomez-Skarmeta, Jose Luis; Vallier, Ludovic; Ferrer, Jorge

2015-05-01

The genomic regulatory programmes that underlie human organogenesis are poorly understood. Pancreas development, in particular, has pivotal implications for pancreatic regeneration, cancer and diabetes. We have now characterized the regulatory landscape of embryonic multipotent progenitor cells that give rise to all pancreatic epithelial lineages. Using human embryonic pancreas and embryonic-stem-cell-derived progenitors we identify stage-specific transcripts and associated enhancers, many of which are co-occupied by transcription factors that are essential for pancreas development. We further show that TEAD1, a Hippo signalling effector, is an integral component of the transcription factor combinatorial code of pancreatic progenitor enhancers. TEAD and its coactivator YAP activate key pancreatic signalling mediators and transcription factors, and regulate the expansion of pancreatic progenitors. This work therefore uncovers a central role for TEAD and YAP as signal-responsive regulators of multipotent pancreatic progenitors, and provides a resource for the study of embryonic development of the human pancreas.

C. elegans STRADalpha and SAD cooperatively regulate neuronal polarity and synaptic organization.

PubMed

Kim, Joanne S M; Hung, Wesley; Narbonne, Patrick; Roy, Richard; Zhen, Mei

2010-01-01

Neurons are polarized cells with morphologically and functionally distinct axons and dendrites. The SAD kinases are crucial for establishing the axon-dendrite identity across species. Previous studies suggest that a tumour suppressor kinase, LKB1, in the presence of a pseudokinase, STRADalpha, initiates axonal differentiation and growth through activating the SAD kinases in vertebrate neurons. STRADalpha was implicated in the localization, stabilization and activation of LKB1 in various cell culture studies. Its in vivo functions, however, have not been examined. In our present study, we analyzed the neuronal phenotypes of the first loss-of-function mutants for STRADalpha and examined their genetic interactions with LKB1 and SAD in C. elegans. Unexpectedly, only the C. elegans STRADalpha, STRD-1, functions exclusively through the SAD kinase, SAD-1, to regulate neuronal polarity and synaptic organization. Moreover, STRD-1 tightly associates with SAD-1 to coordinate its synaptic localizations. By contrast, the C. elegans LKB1, PAR-4, also functions in an additional genetic pathway independently of SAD-1 and STRD-1 to regulate neuronal polarity. We propose that STRD-1 establishes neuronal polarity and organizes synaptic proteins in a complex with the SAD-1 kinase. Our findings suggest that instead of a single, linear genetic pathway, STRADalpha and LKB1 regulate neuronal development through multiple effectors that are shared in some cellular contexts but distinct in others.

Collagen triple helix repeat containing-1 promotes pancreatic cancer progression by regulating migration and adhesion of tumor cells.

PubMed

Park, Eun Hye; Kim, Seokho; Jo, Ji Yoon; Kim, Su Jin; Hwang, Yeonsil; Kim, Jin-Man; Song, Si Young; Lee, Dong-Ki; Koh, Sang Seok

2013-03-01

Collagen triple helix repeat containing-1 (CTHRC1) is a secreted protein involved in vascular remodeling, bone formation and developmental morphogenesis. CTHRC1 has recently been shown to be expressed in human cancers such as breast cancer and melanoma. In this study, we show that CTHRC1 is highly expressed in human pancreatic cancer tissues and plays a role in the progression and metastasis of the disease. CTHRC1 promoted primary tumor growth and metastatic spread of cancer cells to distant organs in orthotopic xenograft tumor mouse models. Overexpression of CTHRC1 in cancer cells resulted in increased motility and adhesiveness, whereas these cellular activities were diminished by down-regulation of the protein. CTHRC1 activated several key signaling molecules, including Src, focal adhesion kinase, paxillin, mitogen-activated protein kinase kinase (MEK), extracellular signal-regulated kinase and Rac1. Treatment with chemical inhibitors of Src, MEK or Rac1 and expression of dominant-negative Rac1 attenuated CTHRC1-induced cell migration and adhesion. Collectively, our results suggest that CTHRC1 has a role in pancreatic cancer progression and metastasis by regulating migration and adhesion activities of cancer cells.

Two chalcones, 4-hydroxyderricin and xanthoangelol, stimulate GLUT4-dependent glucose uptake through the LKB1/AMP-activated protein kinase signaling pathway in 3T3-L1 adipocytes.

PubMed

Ohta, Mitsuhiro; Fujinami, Aya; Kobayashi, Norihiro; Amano, Akiko; Ishigami, Akihito; Tokuda, Harukuni; Suzuki, Nobutaka; Ito, Fumitake; Mori, Taisuke; Sawada, Morio; Iwasa, Koichi; Kitawaki, Jo; Ohnishi, Katsunori; Tsujikawa, Muneo; Obayashi, Hiroshi

2015-07-01

4-Hydroxyderricin (4HD) and xanthoangelol (XAG) are major components of n-hexane/ethyl acetate (5:1) extract of the yellow-colored stem juice of Angelica keiskei. 4-Hydroxyderricin and XAG have been reported to increase glucose transporter 4 (GLUT4)-dependent glucose uptake in 3T3-L1 adipocytes, but the detailed mechanism of this phenomenon remains unknown. This present study was aimed at clarifying the detailed mechanism by which 4HD and XAG increase GLUT4-dependent glucose uptake in 3T3-L1 adipocytes. Both 4HD and XAG increased glucose uptake and GLUT4 translocation to the plasma membrane. 4-Hydroxyderricin and XAG also stimulated the phosphorylation of 5' adenosine monophosphate-activated protein kinase (AMPK) and its downstream target acetyl-CoA carboxylase. In addition, phosphorylation of liver kinase B1 (LKB1), which acts upstream of AMPK, was also increased by 4HD and XAG treatment. Small interfering RNA knockdown of LKB1 attenuated 4HD- and XAG-stimulated AMPK phosphorylation and suppressed glucose uptake. These findings demonstrate that 4HD and XAG can increase GLUT4-dependent glucose uptake through the LKB1/AMPK signaling pathway in 3T3-L1 adipocytes. Copyright © 2015 Elsevier Inc. All rights reserved.

GATA6 Activates Wnt Signaling in Pancreatic Cancer by Negatively Regulating the Wnt Antagonist Dickkopf-1

PubMed Central

Fu, Baojin; Pan, Fan; Yachida, Shinichi; Dhara, Mousumi; Albesiano, Emilia; Li, Li; Naito, Yoshiki; Vilardell, Felip; Cummings, Christopher; Martinelli, Paola; Li, Ang; Yonescu, Raluca; Ma, Qingyong; Griffin, Constance A.; Real, Francisco X.; Iacobuzio-Donahue, Christine A.

2011-01-01

Pancreatic ductal adenocarcinoma (PDAC) is a highly lethal disease characterized by late diagnosis and treatment resistance. Recurrent genetic alterations in defined genes in association with perturbations of developmental cell signaling pathways have been associated with PDAC development and progression. Here, we show that GATA6 contributes to pancreatic carcinogenesis during the temporal progression of pancreatic intraepithelial neoplasia by virtue of Wnt pathway activation. GATA6 is recurrently amplified by both quantitative-PCR and fluorescent in-situ hybridization in human pancreatic intraepithelial neoplasia and in PDAC tissues, and GATA6 copy number is significantly correlated with overall patient survival. Forced overexpression of GATA6 in cancer cell lines enhanced cell proliferation and colony formation in soft agar in vitro and growth in vivo, as well as increased Wnt signaling. By contrast siRNA mediated knockdown of GATA6 led to corresponding decreases in these same parameters. The effects of GATA6 were found to be due to its ability to bind DNA, as forced overexpression of a DNA-binding mutant of GATA6 had no effects on cell growth in vitro or in vivo, nor did they affect Wnt signaling levels in these same cells. A microarray analysis revealed the Wnt antagonist Dickopf-1 (DKK1) as a dysregulated gene in association with GATA6 knockdown, and direct binding of GATA6 to the DKK1 promoter was confirmed by chromatin immunoprecipitation and electrophoretic mobility shift assays. Transient transfection of GATA6, but not mutant GATA6, into cancer cell lines led to decreased DKK1 mRNA expression and secretion of DKK1 protein into culture media. Forced overexpression of DKK1 antagonized the effects of GATA6 on Wnt signaling in pancreatic cancer cells. These findings illustrate that one mechanism by which GATA6 promotes pancreatic carcinogenesis is by virtue of its activation of canonical Wnt signaling via regulation of DKK1. PMID:21811562

TGF-β Signaling Regulates Pancreatic β-Cell Proliferation through Control of Cell Cycle Regulator p27 Expression

PubMed Central

Suzuki, Tomoyuki; Dai, Ping; Hatakeyama, Tomoya; Harada, Yoshinori; Tanaka, Hideo; Yoshimura, Norio; Takamatsu, Tetsuro

2013-01-01

Proliferation of pancreatic β-cells is an important mechanism underlying β-cell mass adaptation to metabolic demands. Increasing β-cell mass by regeneration may ameliorate or correct both type 1 and type 2 diabetes, which both result from inadequate production of insulin by β-cells of the pancreatic islet. Transforming growth factor β (TGF-β) signaling is essential for fetal development and growth of pancreatic islets. In this study, we exposed HIT-T15, a clonal pancreatic β-cell line, to TGF-β signaling. We found that inhibition of TGF-β signaling promotes proliferation of the cells significantly, while TGF-β signaling stimulation inhibits proliferation of the cells remarkably. We confirmed that this proliferative regulation by TGF-β signaling is due to the changed expression of the cell cycle regulator p27. Furthermore, we demonstrated that there is no observed effect on transcriptional activity of p27 by TGF-β signaling. Our data show that TGF-β signaling mediates the cell-cycle progression of pancreatic β-cells by regulating the nuclear localization of CDK inhibitor, p27. Inhibition of TGF-β signaling reduces the nuclear accumulation of p27, and as a result this inhibition promotes proliferation of β-cells. PMID:23720603

Wnt signaling regulates pancreatic β cell proliferation

PubMed Central

Rulifson, Ingrid C.; Karnik, Satyajit K.; Heiser, Patrick W.; ten Berge, Derk; Chen, Hainan; Gu, Xueying; Taketo, Makoto M.; Nusse, Roel; Hebrok, Matthias; Kim, Seung K.

2007-01-01

There is widespread interest in defining factors and mechanisms that stimulate proliferation of pancreatic islet cells. Wnt signaling is an important regulator of organ growth and cell fates, and genes encoding Wnt-signaling factors are expressed in the pancreas. However, it is unclear whether Wnt signaling regulates pancreatic islet proliferation and differentiation. Here we provide evidence that Wnt signaling stimulates islet β cell proliferation. The addition of purified Wnt3a protein to cultured β cells or islets promoted expression of Pitx2, a direct target of Wnt signaling, and Cyclin D2, an essential regulator of β cell cycle progression, and led to increased β cell proliferation in vitro. Conditional pancreatic β cell expression of activated β-catenin, a crucial Wnt signal transduction protein, produced similar phenotypes in vivo, leading to β cell expansion, increased insulin production and serum levels, and enhanced glucose handling. Conditional β cell expression of Axin, a potent negative regulator of Wnt signaling, led to reduced Pitx2 and Cyclin D2 expression by β cells, resulting in reduced neonatal β cell expansion and mass and impaired glucose tolerance. Thus, Wnt signaling is both necessary and sufficient for islet β cell proliferation, and our study provides previously unrecognized evidence of a mechanism governing endocrine pancreas growth and function. PMID:17404238

Sirt1 Regulates Insulin Secretion by Repressing UCP2 in Pancreatic β Cells

PubMed Central

Bordone, Laura; Jhala, Ulupi S; Apfeld, Javier; McDonagh, Thomas; Lemieux, Madeleine; McBurney, Michael; Szilvasi, Akos; Easlon, Erin J; Lin, Su-Ju; Guarente, Leonard

2006-01-01

Sir2 and insulin/IGF-1 are the major pathways that impinge upon aging in lower organisms. In Caenorhabditis elegans a possible genetic link between Sir2 and the insulin/IGF-1 pathway has been reported. Here we investigate such a link in mammals. We show that Sirt1 positively regulates insulin secretion in pancreatic β cells. Sirt1 represses the uncoupling protein (UCP) gene UCP2 by binding directly to the UCP2 promoter. In β cell lines in which Sirt1 is reduced by SiRNA, UCP2 levels are elevated and insulin secretion is blunted. The up-regulation of UCP2 is associated with a failure of cells to increase ATP levels after glucose stimulation. Knockdown of UCP2 restores the ability to secrete insulin in cells with reduced Sirt1, showing that UCP2 causes the defect in glucose-stimulated insulin secretion. Food deprivation induces UCP2 in mouse pancreas, which may occur via a reduction in NAD (a derivative of niacin) levels in the pancreas and down-regulation of Sirt1. Sirt1 knockout mice display constitutively high UCP2 expression. Our findings show that Sirt1 regulates UCP2 in β cells to affect insulin secretion. PMID:16366736

Minireview: Thioredoxin-interacting protein: regulation and function in the pancreatic β-cell.

PubMed

Shalev, Anath

2014-08-01

Pancreatic β-cells are responsible for insulin production, and loss of functional β-cell mass is now recognized as a critical step in the pathogenesis of both type 1 and type 2 diabetes. However, the factors controlling the life and death of the pancreatic β-cell have only started to be elucidated. Discovered as the top glucose-induced gene in a human islet microarray study 12 years ago, thioredoxin-interacting protein (TXNIP) has now emerged as such a key player in pancreatic β-cell biology. Since then, β-cell expression of TXNIP has been found to be tightly regulated by multiple factors and to be dramatically increased in diabetic islets. Elevated TXNIP levels induce β-cell apoptosis, whereas TXNIP deficiency protects against type 1 and type 2 diabetes by promoting β-cell survival. TXNIP interacts with and inhibits thioredoxin and thereby controls the cellular redox state, but it also belongs to the α-arrestin family of proteins and regulates a variety of metabolic processes. Most recently, TXNIP has been discovered to control β-cell microRNA expression, β-cell function, and insulin production. In this review, the current state of knowledge regarding regulation and function of TXNIP in the pancreatic β-cell and the implications for drug development are discussed.

Hedgehog Signaling Regulates Epithelial-Mesenchymal Transition in Pancreatic Cancer Stem-Like Cells

PubMed Central

Wang, Feng; Ma, Ling; Zhang, Zhengkui; Liu, Xiaoran; Gao, Hongqiao; Zhuang, Yan; Yang, Pei; Kornmann, Marko; Tian, Xiaodong; Yang, Yinmo

2016-01-01

Hedgehog (Hh) signaling is crucially involved in tumorigenesis. This study aimed to assess the role of Hh signaling in the regulation of epithelial-mesenchymal transition (EMT), stemness properties and chemoresistance of human pancreatic Panc-1 cancer stem cells (CSCs). Panc-1 cells were transfected with recombinant lentiviral vectors to silence SMO and serum-free floating-culture system was used to isolate Panc-1 tumorspheres. The expression of CSC and EMT markers was detected by flow cytometry, real-time RT-PCR and Western blot analysis. Malignant behaviors of Panc-1 CSC were evaluated by tumorigenicity assays and nude mouse lung metastasis model. We found that tumorspheres derived from pancreatic cancer cell line Panc-1 possessed self-renewal, differentiation and stemness properties. Hh pathway and EMT were active in Panc-1 tumorspheres. Inhibition of Hh signaling by SMO knockdown inhibited self-renewal, EMT, invasion, chemoresistance, pulmonary metastasis, tumorigenesis of pancreatic CSCs. In conclusion, Hh signaling contributes to the maintenance of stem-like properties and chemoresistance of pancreatic CSC and promotes the tumorigenesis and metastasis of pancreatic cancer. Hh pathway is a potential molecular target for the development of therapeutic strategies for pancreatic CSCs. PMID:26918054

Hedgehog Signaling Regulates Epithelial-Mesenchymal Transition in Pancreatic Cancer Stem-Like Cells.

PubMed

Wang, Feng; Ma, Ling; Zhang, Zhengkui; Liu, Xiaoran; Gao, Hongqiao; Zhuang, Yan; Yang, Pei; Kornmann, Marko; Tian, Xiaodong; Yang, Yinmo

2016-01-01

Hedgehog (Hh) signaling is crucially involved in tumorigenesis. This study aimed to assess the role of Hh signaling in the regulation of epithelial-mesenchymal transition (EMT), stemness properties and chemoresistance of human pancreatic Panc-1 cancer stem cells (CSCs). Panc-1 cells were transfected with recombinant lentiviral vectors to silence SMO and serum-free floating-culture system was used to isolate Panc-1 tumorspheres. The expression of CSC and EMT markers was detected by flow cytometry, real-time RT-PCR and Western blot analysis. Malignant behaviors of Panc-1 CSC were evaluated by tumorigenicity assays and nude mouse lung metastasis model. We found that tumorspheres derived from pancreatic cancer cell line Panc-1 possessed self-renewal, differentiation and stemness properties. Hh pathway and EMT were active in Panc-1 tumorspheres. Inhibition of Hh signaling by SMO knockdown inhibited self-renewal, EMT, invasion, chemoresistance, pulmonary metastasis, tumorigenesis of pancreatic CSCs. In conclusion, Hh signaling contributes to the maintenance of stem-like properties and chemoresistance of pancreatic CSC and promotes the tumorigenesis and metastasis of pancreatic cancer. Hh pathway is a potential molecular target for the development of therapeutic strategies for pancreatic CSCs.

Up-regulation of CXCR4 expression contributes to persistent abdominal pain in rats with chronic pancreatitis.

PubMed

Zhu, Hong-Yan; Liu, Xuelian; Miao, Xiuhua; Li, Di; Wang, Shusheng; Xu, Guang-Yin

2017-01-01

Background Pain in patients with chronic pancreatitis is critical hallmark that accompanied inflammation, fibrosis, and destruction of glandular pancreas. Many researchers have demonstrated that stromal cell-derived factor 1 (also named as CXCL12) and its cognate receptor C-X-C chemokine receptor type 4 (CXCR4) involved in mediating neuropathic and bone cancer pain. However, their roles in chronic pancreatic pain remain largely unclear. Methods Chronic pancreatitis was induced by intraductal injection of trinitrobenzene sulfonic acid to the pancreas. Von Frey filament tests were conducted to evaluate pancreas hypersensitivity of rat. Expression of CXCL12, CXCR4, NaV1.8, and pERK in rat dorsal root ganglion was detected by Western blot analyses. Dorsal root ganglion neuronal excitability was assessed by electrophysiological recordings. Results We showed that both CXCL12 and CXCR4 were dramatically up-regulated in the dorsal root ganglion in trinitrobenzene sulfonic acid-induced chronic pancreatitis pain model. Intrathecal application with AMD3100, a potent and selective CXCR4 inhibitor, reversed the hyperexcitability of dorsal root ganglion neurons innervating the pancreas of rats following trinitrobenzene sulfonic acid injection. Furthermore, trinitrobenzene sulfonic acid-induced extracellular signal-regulated kinase activation and Nav1.8 up-regulation in dorsal root ganglias were reversed by intrathecal application with AMD3100 as well as by blockade of extracellular signal-regulated kinase activation by intrathecal U0126. More importantly, the trinitrobenzene sulfonic acid-induced persistent pain was significantly suppressed by CXCR4 and extracellular signal-regulated kinase inhibitors. Conclusions The present results suggest that the activation of CXCL12-CXCR4 signaling might contribute to pancreatic pain and that extracellular signal-regulated kinase-dependent Nav1.8 up-regulation might lead to hyperexcitability of the primary nociceptor neurons in rats with

The Prrx1 homeodomain transcription factor plays a central role in pancreatic regeneration and carcinogenesis

PubMed Central

Reichert, Maximilian; Takano, Shigetsugu; von Burstin, Johannes; Kim, Sang-Bae; Lee, Ju-Seog; Ihida-Stansbury, Kaori; Hahn, Christopher; Heeg, Steffen; Schneider, Günter; Rhim, Andrew D.; Stanger, Ben Z.; Rustgi, Anil K.

2013-01-01

Pancreatic exocrine cell plasticity can be observed during development, pancreatitis with subsequent regeneration, and also transformation. For example, acinar–ductal metaplasia (ADM) occurs during acute pancreatitis and might be viewed as a prelude to pancreatic intraepithelial neoplasia (PanIN) and pancreatic ductal adenocarcinoma (PDAC) development. To elucidate regulatory processes that overlap ductal development, ADM, and the progression of normal cells to PanIN lesions, we undertook a systematic approach to identify the Prrx1 paired homeodomain Prrx1 transcriptional factor as a highly regulated gene in these processes. Prrx1 annotates a subset of pancreatic ductal epithelial cells in Prrx1creERT2-IRES-GFP mice. Furthermore, sorted Prrx1+ cells have the capacity to self-renew and expand during chronic pancreatitis. The two isoforms, Prrx1a and Prrx1b, regulate migration and invasion, respectively, in pancreatic cancer cells. In addition, Prrx1b is enriched in circulating pancreatic cells (Pdx1cre;LSL-KrasG12D/+;p53fl/+;R26YFP). Intriguingly, the Prrx1b isoform, which is also induced in ADM, binds the Sox9 promoter and positively regulates Sox9 expression. This suggests a new hierarchical scheme whereby a Prrx1–Sox9 axis may influence the emergence of acinar–ductal metaplasia and regeneration. Furthermore, our data provide a possible explanation of why pancreatic cancer is skewed toward a ductal fate. PMID:23355395

Macrophage Liver Kinase B1 Inhibits Foam Cell Formation and Atherosclerosis.

PubMed

Liu, Zhaoyu; Zhu, Huaiping; Dai, Xiaoyan; Wang, Cheng; Ding, Ye; Song, Ping; Zou, Ming-Hui

2017-10-13

LKB1 (liver kinase B1) is a serine/threonine kinase and tumor suppressor, which regulates the homeostasis of hematopoietic cells and immune responses. Macrophages transform into foam cells upon taking-in lipids. No role for LKB1 in foam cell formation has previously been reported. We sought to establish the role of LKB1 in atherosclerotic foam cell formation. LKB1 expression was examined in human carotid atherosclerotic plaques and in western diet-fed atherosclerosis-prone Ldlr -/- and ApoE -/- mice. LKB1 expression was markedly reduced in human plaques when compared with nonatherosclerotic vessels. Consistently, time-dependent reduction of LKB1 levels occurred in atherosclerotic lesions in western diet-fed Ldlr -/- and ApoE -/- mice. Exposure of macrophages to oxidized low-density lipoprotein downregulated LKB1 in vitro. Furthermore, LKB1 deficiency in macrophages significantly increased the expression of SRA (scavenger receptor A), modified low-density lipoprotein uptake and foam cell formation, all of which were abolished by blocking SRA. Further, we found LKB1 phosphorylates SRA resulting in its lysosome degradation. To further investigate the role of macrophage LKB1 in vivo, ApoE -/- LKB1 fl/fl LysM cre and ApoE -/- LKB1 fl/fl mice were fed with western diet for 16 weeks. Compared with ApoE -/- LKB1 fl/fl wild-type control, ApoE -/- LKB1 fl/fl LysM cre mice developed more atherosclerotic lesions in whole aorta and aortic root area, with markedly increased SRA expression in aortic root lesions. We conclude that macrophage LKB1 reduction caused by oxidized low-density lipoprotein promotes foam cell formation and the progression of atherosclerosis. © 2017 American Heart Association, Inc.

The voltage-gated proton channel Hv1 is expressed in pancreatic islet β-cells and regulates insulin secretion

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zhao, Qing; Che, Yongzhe; Li, Qiang

The voltage-gated proton channel Hv1 is a potent acid extruder that participates in the extrusion of the intracellular acid. Here, we showed for the first time, Hv1 is highly expressed in mouse and human pancreatic islet β-cells, as well as β-cell lines. Imaging studies demonstrated that Hv1 resides in insulin-containing granules in β-cells. Knockdown of Hv1 with RNA interference significantly reduces glucose- and K{sup +}-induced insulin secretion in isolated islets and INS-1 (832/13) β-cells and has an impairment on glucose- and K{sup +}-induced intracellular Ca{sup 2+} homeostasis. Our data demonstrated that the expression of Hv1 in pancreatic islet β-cells regulatesmore » insulin secretion through regulating Ca{sup 2+} homeostasis.« less

Analysis of Foxo1-regulated genes using Foxo1-deficient pancreatic β cells.

PubMed

Miyazaki, Satsuki; Minamida, Rie; Furuyama, Tatsuo; Tashiro, Fumi; Yamato, Eiji; Inagaki, Shinobu; Miyazaki, Jun-ichi

2012-09-01

Several reports have suggested that Foxo1, a key regulator in differentiation, growth and metabolism, is involved in pancreatic β-cell function. However, detailed analyses have been hampered by a lack of Foxo1-deficient β cells. To elucidate Foxo1's function in β cells, we produced a β-cell line with inducible Foxo1 deletion. We generated a conditional knockout mouse line, in which Cre recombinase deletes the Foxo1 gene. We then established a β-cell line from an insulinoma induced in this knockout mouse by the β-cell-specific expression of simian virus 40 T antigen. In this cell line, designated MIN6-Foxo1flox/flox, adenovirus-mediated Cre expression ablates the Foxo1 gene, generating MIN6-Foxo1-KO cells. Using these knockout and floxed cell lines, we found that Foxo1 ablation enhanced the glucose-stimulated insulin secretion (GSIS) at high glucose concentrations and enhanced β-cell proliferation. We also conducted DNA microarray analyses of MIN6-Foxo1-KO cells infected with either an adenovirus vector expressing a constitutively active FOXO1 or a control vector and identified several Foxo1-regulated genes, including some known to be related to β-cell function. These cells should be useful for further studies on Foxo1's roles in β-cells and may lead to novel strategies for treating the impaired insulin secretion in type 2 diabetes mellitus. © 2012 The Authors Journal compilation © 2012 by the Molecular Biology Society of Japan/Wiley Publishing Ltd.

Minireview: Dopaminergic Regulation of Insulin Secretion from the Pancreatic Islet

PubMed Central

Ustione, Alessandro

2013-01-01

Exogenous dopamine inhibits insulin secretion from pancreatic β-cells, but the lack of dopaminergic neurons in pancreatic islets has led to controversy regarding the importance of this effect. Recent data, however, suggest a plausible physiologic role for dopamine in the regulation of insulin secretion. We review the literature underlying our current understanding of dopaminergic signaling that can down-regulate glucose-stimulated insulin secretion from pancreatic islets. In this negative feedback loop, dopamine is synthesized in the β-cells from circulating l-dopa, serves as an autocrine signal that is cosecreted with insulin, and causes a tonic inhibition on glucose-stimulated insulin secretion. On the whole animal scale, l-dopa is produced by cells in the gastrointestinal tract, and its concentration in the blood plasma increases following a mixed meal. By reviewing the outcome of certain types of bariatric surgery that result in rapid amelioration of glucose tolerance, we hypothesize that dopamine serves as an “antiincretin” signal that counterbalances the stimulatory effect of glucagon-like peptide 1. PMID:23744894

GLI1, a master regulator of the hallmark of pancreatic cancer.

PubMed

Kasai, Kenji

2016-12-01

Hedgehog signaling is highly conserved across species and governs proper embryonic development. Germline gene mutations that reduce this signaling activity cause a variety of developmental abnormalities such as holoprosencephaly, while those that enhance Hedgehog signaling activity induce a tumor-predisposition condition Nevoid basal cell carcinoma syndrome. Furthermore, dysregulated activation of Hedgehog signaling has been recognized in various sporadic malignancies, including pancreatic adenocarcinoma. Pancreatic adenocarcinoma develops through a multistep carcinogenesis starting with oncogenic mutation of the KRAS gene. During this process, precancerous or cancer cells secrete Hedgehog ligand proteins to promote characteristic desmoplastic stroma around the cells, which in turn activates the expression of the downstream transcription factor GLI1 inside the cells. The quantitative and spatiotemporal dysregulation of GLI1 subsequently leads to the expression of transcriptional target genes of GLI1 that govern the hallmark of malignant properties. Here, after a brief introductory outline, a perspective is offered of Hedgehog signaling with a special focus on the role of GLI1 in pancreatic carcinogenesis. © 2016 Japanese Society of Pathology and John Wiley & Sons Australia, Ltd.

CaMKKβ Is Involved in AMP-Activated Protein Kinase Activation by Baicalin in LKB1 Deficient Cell Lines

PubMed Central

Wang, Ying; Du, Zhiyan; Liu, Daihua; Guo, Hongxia; Shen, Jingkang; Peng, Hongli

2012-01-01

AMP-activated protein kinase (AMPK) plays an important role in mediating energy metabolism and is controlled mainly by two upstream kinases, LKB1 or Ca2+/calmodulin-dependent protein kinase kinase-β (CaMKKβ). Previously, we found that baicalin, one of the major flavonoids in a traditional Chinese herb medicine, Scutellaria baicalensis, protects against the development of hepatic steatosis in rats feeding with a high-fat diet by the activation of AMPK, but, the underlying mechanism for AMPK activation is unknown. Here we show that in two LKB1-deficient cells, HeLa and A549 cells, baicalin activates AMPK by α Thr-172 phosphorylation and subsequent phosphorylation of its downstream target, acetyl CoA carboxylase, at Ser-79, to a similar degree as does in HepG2 cells (that express LKB1). Pharmacologic inhibition of CaMKKβ by its selective inhibitor STO-609 markedly inhibits baicalin-induced AMPK activation in both HeLa and HepG2 cells, indicating that CaMKKβ is the responsible AMPK kinase. We also show that treatment of baicalin causes a larger increase in intracellular Ca2+ concentration ([Ca2+]i), although the maximal level of [Ca2+]i is lower in HepG2 cells compared to HeLa cells. Chelation of intracellular free Ca2+ by EDTA and EGTA, or depletion of intracellular Ca2+ stores by the endoplasmic reticulum Ca2+-ATPase inhibitor thapsigargin abrogates baicalin-induced activation of AMPK in HeLa cells. Neither cellular ATP nor the production of reactive oxygen species is altered by baicalin. Finally, in HeLa cells, baicalin treatment no longer decreases intracellular lipid accumulation caused by oleic acid after inhibition of CaMKKβ by STO-609. These results demonstrate that a potential Ca2+/CaMKKβ dependent pathway is involved in the activation of AMPK by baicalin and suggest that CaMKKβ likely acts as an upstream kinase of AMPK in response to baicalin. PMID:23110126

Mutations in the pancreatic secretory enzymes CPA1 and CPB1 are associated with pancreatic cancer.

PubMed

Tamura, Koji; Yu, Jun; Hata, Tatsuo; Suenaga, Masaya; Shindo, Koji; Abe, Toshiya; MacGregor-Das, Anne; Borges, Michael; Wolfgang, Christopher L; Weiss, Matthew J; He, Jin; Canto, Marcia Irene; Petersen, Gloria M; Gallinger, Steven; Syngal, Sapna; Brand, Randall E; Rustgi, Anil; Olson, Sara H; Stoffel, Elena; Cote, Michele L; Zogopoulos, George; Potash, James B; Goes, Fernando S; McCombie, Richard W; Zandi, Peter P; Pirooznia, Mehdi; Kramer, Melissa; Parla, Jennifer; Eshleman, James R; Roberts, Nicholas J; Hruban, Ralph H; Klein, Alison Patricia; Goggins, Michael

2018-05-01

To evaluate whether germline variants in genes encoding pancreatic secretory enzymes contribute to pancreatic cancer susceptibility, we sequenced the coding regions of CPB1 and other genes encoding pancreatic secretory enzymes and known pancreatitis susceptibility genes ( PRSS1 , CPA1 , CTRC , and SPINK1 ) in a hospital series of pancreatic cancer cases and controls. Variants in CPB1 , CPA1 (encoding carboxypeptidase B1 and A1), and CTRC were evaluated in a second set of cases with familial pancreatic cancer and controls. More deleterious CPB1 variants, defined as having impaired protein secretion and induction of endoplasmic reticulum (ER) stress in transfected HEK 293T cells, were found in the hospital series of pancreatic cancer cases (5/986, 0.5%) than in controls (0/1,045, P = 0.027). Among familial pancreatic cancer cases, ER stress-inducing CPB1 variants were found in 4 of 593 (0.67%) vs. 0 of 967 additional controls ( P = 0.020), with a combined prevalence in pancreatic cancer cases of 9/1,579 vs. 0/2,012 controls ( P < 0.01). More ER stress-inducing CPA1 variants were also found in the combined set of hospital and familial cases with pancreatic cancer than in controls [7/1,546 vs. 1/2,012; P = 0.025; odds ratio, 9.36 (95% CI, 1.15-76.02)]. Overall, 16 (1%) of 1,579 pancreatic cancer cases had an ER stress-inducing CPA1 or CPB1 variant, compared with 1 of 2,068 controls ( P < 0.00001). No other candidate genes had statistically significant differences in variant prevalence between cases and controls. Our study indicates ER stress-inducing variants in CPB1 and CPA1 are associated with pancreatic cancer susceptibility and implicate ER stress in pancreatic acinar cells in pancreatic cancer development.

Histamine regulation of pancreatitis and pancreatic cancer: a review of recent findings

PubMed Central

Francis, Taylor; Graf, Allyson; Hodges, Kyle; Kennedy, Lindsey; Hargrove, Laura; Price, Mattie; Kearney, Kate

2013-01-01

The pancreas is a dynamic organ that performs a multitude of functions within the body. Diseases that target the pancreas, like pancreatitis and pancreatic cancer, are devastating and often fatal to the suffering patient. Histamine and histamine receptors (H1-H4HRs) have been found to play a critical role in biliary diseases. Accordingly, the biliary tract and the pancreas share similarities with regards to morphological, phenotypical and functional features and disease progression, studies related the role of H1-H4HRs in pancreatic diseases are important. In this review, we have highlighted the role that histamine, histidine decarboxylase (HDC), histamine receptors and mast cells (the main source of histamine in the body) play during both pancreatitis and pancreatic cancer. The objective of the review is to demonstrate that histamine and histamine signaling may be a potential therapeutic avenue towards treatment strategies for pancreatic diseases. PMID:24570946

Fibulin-3 negatively regulates ALDH1 via c-MET suppression and increases γ-radiation-induced sensitivity in some pancreatic cancer cell lines

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kim, In-Gyu, E-mail: igkim@kaeri.re.kr; Department of Radiation Biotechnology and Applied Radioisotope, Korea University of Science and Technology; Lee, Jae-Ha

2014-11-21

Highlights: • FBLN-3 gene was poorly expressed in some pancreatic cancer lines. • FBLN-3 promoter region was highly methylated in some pancreatic cancer cell lines. • FBLN-3 inhibited c-MET activation and expression and reduced cellular level of ALDH1. • FBLN-3/c-Met/ALDH1 axis modulates stemness and EMT in pancreatic cancer cells. - Abstract: Fibulin-3 (FBLN-3) has been postulated to be either a tumor suppressor or promoter depending on the cell type, and hypermethylation of the FBLN-3 promoter is often associated with human disease, especially cancer. We report that the promoter region of the FBLN-3 was significantly methylated (>95%) in some pancreatic cancermore » cell lines and thus FBLN-3 was poorly expressed in pancreatic cancer cell lines such as AsPC-1 and MiaPaCa-2. FBLN-3 overexpression significantly down-regulated the cellular level of c-MET and inhibited hepatocyte growth factor-induced c-MET activation, which were closely associated with γ-radiation resistance of cancer cells. Moreover, we also showed that c-MET suppression or inactivation decreased the cellular level of ALDH1 isozymes (ALDH1A1 or ALDH1A3), which serve as cancer stem cell markers, and subsequently induced inhibition of cell growth in pancreatic cancer cells. Therefore, forced overexpression of FBLN-3 sensitized cells to cytotoxic agents such as γ-radiation and strongly inhibited the stemness and epithelial to mesenchymal transition (EMT) property of pancreatic cancer cells. On the other hand, if FBLN3 was suppressed in FBLN-3-expressing BxPC3 cells, the results were opposite. This study provides the first demonstration that the FBLN-3/c-MET/ALDH1 axis in pancreatic cancer cells partially modulates stemness and EMT as well as sensitization of cells to the detrimental effects of γ-radiation.« less

[Overexpression of liver kinase B1 inhibits the proliferation of lung cancer cells].

PubMed

Li, Yang; Zhang, Libin; Wang, Ping

2017-01-01

Objective To explore the effect of overexpressed liver kinase B1(LKB1) on the proliferation of lung cancer cell lines. Methods The expression levels of LKB1 and PTEN in A549, NCI-H23, NCI-H157, XWLC-05, NCI-H446 lung cancer cells were detected by immunocytochemistry (ICC) and Western blotting. Plasmid pcDNA3.1 + -LKB1 and empty vector pcDNA3.1 + -null were separately transfected into the above five cell lines, and then the expression of LKB1 mRNA and protein were determined by quantitative real-time PCR and Western blotting, respectively. Finally, CCK-8 assay was used to analyze the proliferation ability of the transfected cells. Results LKB1 and PTEN were positive in NCI-H23 cells; LKB1 was negative while PTEN was positive in A549 and NCI-H446 cells; both LKB1 and PTEN were negative in NCI-H157 and XWLC-05 cells. Quantitative real-time PCR and Western blotting showed that the expression level of LKB1 significantly increased in the above cell lines transfected with plasmid pcDNA3.1 + -LKB1 compared with the ones with empty vector pcDNA3.1 + -null. Besides, CCK-8 assay showed that the overexpression of LKB1 in the lung cancer cells transfected with pcDNA3.1 + -LKB1 had an obvious inhibitory effect on cell proliferation. Conclusion The expression of LKB1 is down-regulated in most of the lung cell lines to different extent and the over-expression of LKB1 can remarkably inhibit the proliferation ability of lung cancer cell lines.

Clock-controlled output gene Dbp is a regulator of Arnt/Hif-1β gene expression in pancreatic islet β-cells

DOE Office of Scientific and Technical Information (OSTI.GOV)

Nakabayashi, Hiroko; Ohta, Yasuharu, E-mail: yohta@yamaguchi-u.ac.jp; Yamamoto, Masayoshi

2013-05-03

Highlights: •Arnt mRNA expressed in a circadian manner in mouse pancreatic islets. •Expressions of Dbp and Arnt damped in the islets of a diabetic model mouse. •DBP and E4BP4 regulate Arnt promoter activity by direct binding. •Arnt may have a role in connecting circadian rhythm and metabolism. -- Abstract: Aryl hydrocarbon receptor nuclear translocator (ARNT)/hypoxia inducible factor-1β (HIF-1β) has emerged as a potential determinant of pancreatic β-cell dysfunction and type 2 diabetes in humans. An 82% reduction in Arnt expression was observed in islets from type 2 diabetic donors as compared to non-diabetic donors. However, few regulators of Arnt expressionmore » have been identified. Meanwhile, disruption of the clock components CLOCK and BMAL1 is known to result in hypoinsulinemia and diabetes, but the molecular details remain unclear. In this study, we identified a novel molecular connection between Arnt and two clock-controlled output genes, albumin D-element binding protein (Dbp) and E4 binding protein 4 (E4bp4). By conducting gene expression studies using the islets of Wfs1{sup −/−} A{sup y}/a mice that develop severe diabetes due to β-cell apoptosis, we demonstrated clock-related gene expressions to be altered in the diabetic mice. Dbp mRNA decreased by 50%, E4bp4 mRNA increased by 50%, and Arnt mRNA decreased by 30% at Zeitgever Time (ZT) 12. Mouse pancreatic islets exhibited oscillations of clock gene expressions. E4BP4, a D-box negative regulator, oscillated anti-phase to DBP, a D-box positive regulator. We also found low-amplitude circadian expression of Arnt mRNA, which peaked at ZT4. Over-expression of DBP raised both mRNA and protein levels of ARNT in HEK293 and MIN6 cell lines. Arnt promoter-driven luciferase reporter assay in MIN6 cells revealed that DBP increased Arnt promoter activity by 2.5-fold and that E4BP4 competitively inhibited its activation. In addition, on ChIP assay, DBP and E4BP4 directly bound to D-box elements

Salmonella Typhimurium disrupts Sirt1/AMPK checkpoint control of mTOR to impair autophagy

PubMed Central

Ganesan, Raja; Hos, Nina Judith; Gutierrez, Saray; Fischer, Julia; Stepek, Joanna Magdalena; Daglidu, Evmorphia; Krönke, Martin

2017-01-01

During intracellular infections, autophagy significantly contributes to the elimination of pathogens, regulation of pro-inflammatory signaling, secretion of immune mediators and in coordinating the adaptive immune system. Intracellular pathogens such as S. Typhimurium have evolved mechanisms to circumvent autophagy. However, the regulatory mechanisms targeted by S. Typhimurium to modulate autophagy have not been fully resolved. Here we report that cytosolic energy loss during S. Typhimurium infection triggers transient activation of AMPK, an important checkpoint of mTOR activity and autophagy. The activation of AMPK is regulated by LKB1 in a cytosolic complex containing Sirt1 and LKB1, where Sirt1 is required for deacetylation and subsequent activation of LKB1. S. Typhimurium infection targets Sirt1, LKB1 and AMPK to lysosomes for rapid degradation resulting in the disruption of the AMPK-mediated regulation of mTOR and autophagy. The degradation of cytosolic Sirt1/LKB1/AMPK complex was not observed with two mutant strains of S. Typhimurium, ΔssrB and ΔssaV, both compromising the pathogenicity island 2 (SPI2). The results highlight virulence factor-dependent degradation of host cell proteins as a previously unrecognized strategy of S. Typhimurium to evade autophagy. PMID:28192515

Stromal liver kinase B1 [STK11] signaling loss induces oviductal adenomas and endometrial cancer by activating mammalian Target of Rapamycin Complex 1.

PubMed

Tanwar, Pradeep S; Kaneko-Tarui, Tomoko; Zhang, Lihua; Tanaka, Yoshihiro; Crum, Christopher P; Teixeira, Jose M

2012-01-01

Germline mutations of the Liver Kinase b1 (LKB1/STK11) tumor suppressor gene have been linked to Peutz-Jeghers Syndrome (PJS), an autosomal-dominant, cancer-prone disorder in which patients develop neoplasms in several organs, including the oviduct, ovary, and cervix. We have conditionally deleted Lkb1 in Müllerian duct mesenchyme-derived cells of the female reproductive tract and observed expansion of the stromal compartment and hyperplasia and/or neoplasia of adjacent epithelial cells throughout the reproductive tract with paratubal cysts and adenomyomas in oviducts and, eventually, endometrial cancer. Examination of the proliferation marker phospho-histone H3 and mammalian Target Of Rapamycin Complex 1 (mTORC1) pathway members revealed increased proliferation and mTORC1 activation in stromal cells of both the oviduct and uterus. Treatment with rapamycin, an inhibitor of mTORC1 activity, decreased tumor burden in adult Lkb1 mutant mice. Deletion of the genes for Tuberous Sclerosis 1 (Tsc1) or Tsc2, regulators of mTORC1 that are downstream of LKB1 signaling, in the oviductal and uterine stroma phenocopies some of the defects observed in Lkb1 mutant mice, confirming that dysregulated mTORC1 activation in the Lkb1-deleted stroma contributes to the phenotype. Loss of PTEN, an upstream regulator of mTORC1 signaling, along with Lkb1 deletion significantly increased tumor burden in uteri and induced tumorigenesis in the cervix and vagina. These studies show that LKB1/TSC1/TSC2/mTORC1 signaling in mesenchymal cells is important for the maintenance of epithelial integrity and suppression of carcinogenesis in adjacent epithelial cells. Because similar changes in the stromal population are also observed in human oviductal/ovarian adenoma and endometrial adenocarcinoma patients, we predict that dysregulated mTORC1 activity by upstream mechanisms similar to those described in these model systems contributes to the pathogenesis of these human diseases.

Stromal Liver Kinase B1 [STK11] Signaling Loss Induces Oviductal Adenomas and Endometrial Cancer by Activating Mammalian Target of Rapamycin Complex 1

PubMed Central

Zhang, LiHua; Tanaka, Yoshihiro; Crum, Christopher P.; Teixeira, Jose M.

2012-01-01

Germline mutations of the Liver Kinase b1 (LKB1/STK11) tumor suppressor gene have been linked to Peutz-Jeghers Syndrome (PJS), an autosomal-dominant, cancer-prone disorder in which patients develop neoplasms in several organs, including the oviduct, ovary, and cervix. We have conditionally deleted Lkb1 in Müllerian duct mesenchyme-derived cells of the female reproductive tract and observed expansion of the stromal compartment and hyperplasia and/or neoplasia of adjacent epithelial cells throughout the reproductive tract with paratubal cysts and adenomyomas in oviducts and, eventually, endometrial cancer. Examination of the proliferation marker phospho-histone H3 and mammalian Target Of Rapamycin Complex 1 (mTORC1) pathway members revealed increased proliferation and mTORC1 activation in stromal cells of both the oviduct and uterus. Treatment with rapamycin, an inhibitor of mTORC1 activity, decreased tumor burden in adult Lkb1 mutant mice. Deletion of the genes for Tuberous Sclerosis 1 (Tsc1) or Tsc2, regulators of mTORC1 that are downstream of LKB1 signaling, in the oviductal and uterine stroma phenocopies some of the defects observed in Lkb1 mutant mice, confirming that dysregulated mTORC1 activation in the Lkb1-deleted stroma contributes to the phenotype. Loss of PTEN, an upstream regulator of mTORC1 signaling, along with Lkb1 deletion significantly increased tumor burden in uteri and induced tumorigenesis in the cervix and vagina. These studies show that LKB1/TSC1/TSC2/mTORC1 signaling in mesenchymal cells is important for the maintenance of epithelial integrity and suppression of carcinogenesis in adjacent epithelial cells. Because similar changes in the stromal population are also observed in human oviductal/ovarian adenoma and endometrial adenocarcinoma patients, we predict that dysregulated mTORC1 activity by upstream mechanisms similar to those described in these model systems contributes to the pathogenesis of these human diseases. PMID:22916036

The transcription factor GLI1 modulates the inflammatory response during pancreatic tissue remodeling.

PubMed

Mathew, Esha; Collins, Meredith A; Fernandez-Barrena, Maite G; Holtz, Alexander M; Yan, Wei; Hogan, James O; Tata, Zachary; Allen, Benjamin L; Fernandez-Zapico, Martin E; di Magliano, Marina Pasca

2014-10-03

Pancreatic cancer, one of the deadliest human malignancies, is almost uniformly associated with a mutant, constitutively active form of the oncogene Kras. Studies in genetically engineered mouse models have defined a requirement for oncogenic KRAS in both the formation of pancreatic intraepithelial neoplasias, the most common precursor lesions to pancreatic cancer, and in the maintenance and progression of these lesions. Previous work using an inducible model allowing tissue-specific and reversible expression of oncogenic Kras in the pancreas indicates that inactivation of this GTPase at the pancreatic intraepithelial neoplasia stage promotes pancreatic tissue repair. Here, we extend these findings to identify GLI1, a transcriptional effector of the Hedgehog pathway, as a central player in pancreatic tissue repair upon Kras inactivation. Deletion of a single allele of Gli1 results in improper stromal remodeling and perdurance of the inflammatory infiltrate characteristic of pancreatic tumorigenesis. Strikingly, this partial loss of Gli1 affects activated fibroblasts in the pancreas and the recruitment of immune cells that are vital for tissue recovery. Analysis of the mechanism using expression and chromatin immunoprecipitation assays identified a subset of cytokines, including IL-6, mIL-8, Mcp-1, and M-csf (Csf1), as direct GLI1 target genes potentially mediating this phenomenon. Finally, we demonstrate that canonical Hedgehog signaling, a known regulator of Gli1 activity, is required for pancreas recovery. Collectively, these data delineate a new pathway controlling tissue repair and highlight the importance of GLI1 in regulation of the pancreatic microenvironment during this cellular process. © 2014 by The American Society for Biochemistry and Molecular Biology, Inc.

miR-1271 inhibits migration, invasion and epithelial-mesenchymal transition by targeting ZEB1 and TWIST1 in pancreatic cancer cells

DOE Office of Scientific and Technical Information (OSTI.GOV)

Liu, Huaize; Wang, Han; Liu, Xiaoxiao

Pancreatic cancer (PC) remains one of the most lethal types of cancer in adults. The purpose of this study was to determine the role of miR-1271 in regulation of epithelial mesenchymal transition (EMT) and metastasis of pancreatic cancer cells. miR-1271 was identified to be significantly down-regulated in PC tissues by miRNA array. Also, an increase of EMT-regulators ZEB1 and TWIST1 expression level is accompanied by a decrease of miR-1271. We showed that expression of miR-1271 was significantly down-regulated in PC tissues as compared with that in normal tissues. In addition, our results showed that miR-1271 expression levels were decreased whilemore » ZEB1 and TWIST1 expression levels were increased in detected PC cell lines. Moreover, ectopic expression of miR-1271 suppressed and antagomiR-1271 promoted proliferation, migration, and invasion in SW1990 and PANC-1 cells. Bioinformatics coupled with luciferase and Western blot assays also revealed that miR-1271 inhibited expression of ZEB1 and TWIST1, which are master regulators of tumor metastasis. Our study first indicates that miR-1271 functions as a suppressor in regulating of pancreatic cancer EMT by targeting ZEB1 and TWIST1, and it promise as a therapeutic target and prognostic marker for metastatic pancreatic cancer. - Highlights: • miR-1271 is downregulated in pancreatic cancer tissues and cell lines. • miR-1271 regulates cell metastasis ability and EMT marker expression. . • miR-1271 directly targets ZEB1 and TWIST1. • ZEB1 and TWIST1 are functionally related to the effects of miR-1271.« less

RAS/ERK modulates TGFbeta-regulated PTEN expression in human pancreatic adenocarcinoma cells.

PubMed

Chow, Jimmy Y C; Quach, Khai T; Cabrera, Betty L; Cabral, Jennifer A; Beck, Stayce E; Carethers, John M

2007-11-01

Phosphatase and tensin homolog deleted on chromosome 10 (PTEN) is rarely mutated in pancreatic cancers, but its regulation by transforming growth factor (TGF)-beta might mediate growth suppression and other oncogenic actions. Here, we examined the role of TGFbeta and the effects of oncogenic K-RAS/ERK upon PTEN expression in the absence of SMAD4. We utilized two SMAD4-null pancreatic cell lines, CAPAN-1 (K-RAS mutant) and BxPc-3 (WT-K-RAS), both of which express TGFbeta surface receptors. Cells were treated with TGFbeta1 and separated into cytosolic/nuclear fractions for western blotting with phospho-SMAD2, SMAD 2, 4 phospho-ATP-dependent tyrosine kinases (Akt), Akt and PTEN antibodies. PTEN mRNA levels were assessed by reverse transcriptase-polymerase chain reaction. The MEK1 inhibitor, PD98059, was used to block the downstream action of oncogenic K-RAS/ERK, as was a dominant-negative (DN) K-RAS construct. TGFbeta increased phospho-SMAD2 in both cytosolic and nuclear fractions. PD98059 treatment further increased phospho-SMAD2 in the nucleus of both pancreatic cell lines, and DN-K-RAS further improved SMAD translocation in K-RAS mutant CAPAN cells. TGFbeta treatment significantly suppressed PTEN protein levels concomitant with activation of Akt by 48 h through transcriptional reduction of PTEN mRNA that was evident by 6 h. TGFbeta-induced PTEN suppression was reversed by PD98059 and DN-K-RAS compared with treatments without TGFbeta. TGFbeta-induced PTEN expression was inversely related to cellular proliferation. Thus, oncogenic K-RAS/ERK in pancreatic adenocarcinoma facilitates TGFbeta-induced transcriptional down-regulation of the tumor suppressor PTEN in a SMAD4-independent manner and could constitute a signaling switch mechanism from growth suppression to growth promotion in pancreatic cancers.

Identification of key regulators of pancreatic cancer progression through multidimensional systems-level analysis.

PubMed

Rajamani, Deepa; Bhasin, Manoj K

2016-05-03

Pancreatic cancer is an aggressive cancer with dismal prognosis, urgently necessitating better biomarkers to improve therapeutic options and early diagnosis. Traditional approaches of biomarker detection that consider only one aspect of the biological continuum like gene expression alone are limited in their scope and lack robustness in identifying the key regulators of the disease. We have adopted a multidimensional approach involving the cross-talk between the omics spaces to identify key regulators of disease progression. Multidimensional domain-specific disease signatures were obtained using rank-based meta-analysis of individual omics profiles (mRNA, miRNA, DNA methylation) related to pancreatic ductal adenocarcinoma (PDAC). These domain-specific PDAC signatures were integrated to identify genes that were affected across multiple dimensions of omics space in PDAC (genes under multiple regulatory controls, GMCs). To further pin down the regulators of PDAC pathophysiology, a systems-level network was generated from knowledge-based interaction information applied to the above identified GMCs. Key regulators were identified from the GMC network based on network statistics and their functional importance was validated using gene set enrichment analysis and survival analysis. Rank-based meta-analysis identified 5391 genes, 109 miRNAs and 2081 methylation-sites significantly differentially expressed in PDAC (false discovery rate ≤ 0.05). Bimodal integration of meta-analysis signatures revealed 1150 and 715 genes regulated by miRNAs and methylation, respectively. Further analysis identified 189 altered genes that are commonly regulated by miRNA and methylation, hence considered GMCs. Systems-level analysis of the scale-free GMCs network identified eight potential key regulator hubs, namely E2F3, HMGA2, RASA1, IRS1, NUAK1, ACTN1, SKI and DLL1, associated with important pathways driving cancer progression. Survival analysis on individual key regulators revealed

Transferrin receptor regulates pancreatic cancer growth by modulating mitochondrial respiration and ROS generation

DOE Office of Scientific and Technical Information (OSTI.GOV)

Jeong, Seung Min, E-mail: smjeong@catholic.ac.kr; Institute for Aging and Metabolic Diseases, College of Medicine, The Catholic University of Korea, Seoul 137-701; Hwang, Sunsook

2016-03-11

The transferrin receptor (TfR1) is upregulated in malignant cells and its expression is associated with cancer progression. Because of its pre-eminent role in cell proliferation, TfR1 has been an important target for the development of cancer therapy. Although TfR1 is highly expressed in pancreatic cancers, what it carries out in these refractory cancers remains poorly understood. Here we report that TfR1 supports mitochondrial respiration and ROS production in human pancreatic ductal adenocarcinoma (PDAC) cells, which is required for their tumorigenic growth. Elevated TfR1 expression in PDAC cells contributes to oxidative phosphorylation, which allows for the generation of ROS. Importantly, mitochondrial-derivedmore » ROS are essential for PDAC growth. However, exogenous iron supplement cannot rescue the defects caused by TfR1 knockdown. Moreover, we found that TfR1 expression determines PDAC cells sensitivity to oxidative stress. Together, our findings reveal that TfR1 can contribute to the mitochondrial respiration and ROS production, which have essential roles in growth and survival of pancreatic cancer. - Highlights: • Pancreatic ductal adenocarcinoma (PDAC) exhibits an elevated transferrin receptor (TfR1) expression in comparison with non-transformed pancreatic cells. • TfR1 is required for PDAC growth by regulating mitochondrial respiration and ROS production. • TfR1 functions as a determinant of cell viability to oxidative stress in PDAC cells.« less

Transforming Growth Factor-β and Bone Morphogenetic Protein 2 Regulation of MicroRNA-200 Family in Chronic Pancreatitis.

PubMed

Yu, Peter; Liu, Ka; Gao, Xuxia; Karmouty-Quintana, Harry; Bailey, Jennifer M; Cao, Yanna; Ko, Tien C

2018-02-01

To investigate regulation of microRNA (miR)-200 family (a, b, c, 141, and 429) in chronic pancreatitis (CP). This was accomplished by examining miR-200 family levels in a mouse model in vivo and their regulation in pancreatic cells in vitro. Chronic pancreatitis was induced by cerulein for 4 weeks (50 μg/kg, 5 hourly intraperitoneal injections/day, and 3 days/week). Control mice received normal saline. The pancreata were harvested for fibrosis assessment by Sirius red staining and for miRNA, collagen, and fibronectin levels by quantitative PCR. In vitro, human primary pancreatic stellate cells and human primary pancreatic fibroblast (hPFBs), and rat pancreatic epithelial AR42J cells were treated with vehicle, transforming growth factor (TGF)-β (1 ng/mL), or BMP2 (50 ng/mL) for 24 hours and then harvested for miRNA analysis. In CP, miR-200s were decreased by 56% to 70% and inversely correlated with pancreatic fibrosis, miR-21, and miR-31 (P < 0.05). In vitro, TGF-β inhibited miR-200b in AR42J cells by 62%, whereas BMP2 increased miR-200b in all 3 cell types in a range of 1.5- to 3.4-fold and inhibited miR-21 in hPFBs by 21% (P < 0.05). Both in vivo and in vitro studies suggest an antifibrogenic function of miR-200s in CP. The TGF-β and BMP2 may function through inverse regulation of miR-200b levels.

Elongation factor-2 kinase regulates TG2/β1 integrin/Src/uPAR pathway and epithelial–mesenchymal transition mediating pancreatic cancer cells invasion

PubMed Central

Ashour, Ahmed A; Gurbuz, Nilgun; Alpay, Sultan Neslihan; Abdel-Aziz, Abdel-Aziz H; Mansour, Ahmed M; Huo, Longfei; Ozpolat, Bulent

2014-01-01

Pancreatic ductal adenocarcinoma is one of the lethal cancers with extensive local tumour invasion, metastasis, early systemic dissemination and poorest prognosis. Thus, understanding the mechanisms regulating invasion/metastasis and epithelial–mesenchymal transition (EMT), is the key for developing effective therapeutic strategies for pancreatic cancer (PaCa). Eukaryotic elongation factor-2 kinase (eEF-2K) is an atypical kinase that we found to be highly up-regulated in PaCa cells. However, its role in PaCa invasion/progression remains unknown. Here, we investigated the role of eEF-2K in cellular invasion, and we found that down-regulation of eEF-2K, by siRNA or rottlerin, displays impairment of PaCa cells invasion/migration, with significant decreases in the expression of tissue transglutaminase (TG2), the multifunctional enzyme implicated in regulation of cell attachment, motility and survival. These events were associated with reductions in β1 integrin/uPAR/MMP-2 expressions as well as decrease in Src activity. Furthermore, inhibition of eEF-2K/TG2 axis suppresses the EMT, as demonstrated by the modulation of the zinc finger transcription factors, ZEB1/Snail, and the tight junction proteins, claudins. Importantly, while eEF-2K silencing recapitulates the rottlerin-induced inhibition of invasion and correlated events, eEF-2K overexpression, by lentivirus-based expression system, suppresses such rottlerin effects and potentiates PaCa cells invasion/migration capability. Collectively, our results show, for the first time, that eEF-2K is involved in regulation of the invasive phenotype of PaCa cells through promoting a new signalling pathway, which is mediated by TG2/β1 integrin/Src/uPAR/MMP-2, and the induction of EMT biomarkers which enhance cancer cell motility and metastatic potential. Thus, eEF-2K could represent a novel potential therapeutic target in pancreatic cancer. PMID:25215932

SOX9 regulates ERBB signalling in pancreatic cancer development.

PubMed

Grimont, Adrien; Pinho, Andreia V; Cowley, Mark J; Augereau, Cécile; Mawson, Amanda; Giry-Laterrière, Marc; Van den Steen, Géraldine; Waddell, Nicola; Pajic, Marina; Sempoux, Christine; Wu, Jianmin; Grimmond, Sean M; Biankin, Andrew V; Lemaigre, Frédéric P; Rooman, Ilse; Jacquemin, Patrick

2015-11-01

The transcription factor SOX9 was recently shown to stimulate ductal gene expression in pancreatic acinar-to-ductal metaplasia and to accelerate development of premalignant lesions preceding pancreatic ductal adenocarcinoma (PDAC). Here, we investigate how SOX9 operates in pancreatic tumourigenesis. We analysed genomic and transcriptomic data from surgically resected PDAC and extended the expression analysis to xenografts from PDAC samples and to PDAC cell lines. SOX9 expression was manipulated in human cell lines and mouse models developing PDAC. We found genetic aberrations in the SOX9 gene in about 15% of patient tumours. Most PDAC samples strongly express SOX9 protein, and SOX9 levels are higher in classical PDAC. This tumour subtype is associated with better patient outcome, and cell lines of this subtype respond to therapy targeting epidermal growth factor receptor (EGFR/ERBB1) signalling, a pathway essential for pancreatic tumourigenesis. In human PDAC, high expression of SOX9 correlates with expression of genes belonging to the ERBB pathway. In particular, ERBB2 expression in PDAC cell lines is stimulated by SOX9. Inactivating Sox9 expression in mice confirmed its role in PDAC initiation; it demonstrated that Sox9 stimulates expression of several members of the ERBB pathway and is required for ERBB signalling activity. By integrating data from patient samples and mouse models, we found that SOX9 regulates the ERBB pathway throughout pancreatic tumourigenesis. Our work opens perspectives for therapy targeting tumourigenic mechanisms. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions.

Apicidin sensitizes pancreatic cancer cells to gemcitabine by epigenetically regulating MUC4 expression.

PubMed

Ansari, Daniel; Urey, Carlos; Hilmersson, Katarzyna Said; Bauden, Monika P; Ek, Fredrik; Olsson, Roger; Andersson, Roland

2014-10-01

Mucin 4 (MUC4) has been linked to resistance to gemcitabine in pancreatic cancer cells. The aim of the present study was to assess whether epigenetic control of MUC4 expression can sensitize pancreatic cancer cells to gemcitabine treatment. A 76-member combined epigenetics and phosphatase small-molecule inhibitor library was screened for anti-proliferative activity against the MUC4(+) gemcitabine-resistant pancreatic cancer cell line Capan-1, followed by high-content screening of protein expression. Apicidin, a histone deacetylase inhibitor, showed the greatest anti-proliferative activity with a lethal dose 50 (LD50) value of 5.17 μM. Apicidin significantly reduced the expression of MUC4 and its transcription factor hepatocyte nuclear factor 4α. Combined treatment with a sub-therapeutic concentration of apicidin and gemcitabine synergistically inhibited growth of Capan-1 cells. Apicidin appears to be a novel anti-proliferative agent against pancreatic cancer cells that may reverse chemoresistance by epigenetically regulating MUC4 expression. Copyright© 2014 International Institute of Anticancer Research (Dr. John G. Delinassios), All rights reserved.

STAT5-glucocorticoid receptor interaction and MTF-1 regulate the expression of ZnT2 (Slc30a2) in pancreatic acinar cells

PubMed Central

Guo, Liang; Lichten, Louis A.; Ryu, Moon-Suhn; Liuzzi, Juan P.; Wang, Fudi; Cousins, Robert J.

2010-01-01

The exocrine pancreas plays an important role in endogenous zinc loss by regulating excretion into the intestinal tract and hence influences the dietary zinc requirement. The present experiments show that the zinc transporter ZnT2 (Slc30a2) is localized to the zymogen granules and that dietary zinc restriction in mice decreased the zinc concentration of zymogen granules and ZnT2 expression. Excess zinc given orally increased ZnT2 expression and was associated with increased pancreatic zinc accumulation. Rat AR42J acinar cells when induced into a secretory phenotype, using the glucocorticoid analog dexamethasone (DEX), exhibited increased ZnT2 expression and labile zinc as measured with a fluorophore. DEX administrated to mice also induced ZnT2 expression that accompanied a reduction of the pancreatic zinc content. ZnT2 promoter analyses identified elements required for responsiveness to zinc and DEX. Zinc regulation was traced to a MRE located downstream from the ZnT2 transcription start site. Responsiveness to DEX is produced by two upstream STAT5 binding sites that require the glucocorticoid receptor for activation. ZnT2 knockdown in the AR42J cells using siRNA resulted in increased cytoplasmic zinc and decreased zymogen granule zinc that further demonstrated that ZnT2 may mediate the sequestration of zinc into zymogen granules. We conclude, based upon experiments with intact mice and pancreatic acinar cells in culture, that ZnT2 participates in zinc transport into pancreatic zymogen granules through a glucocorticoid pathway requiring glucocorticoid receptor and STAT5, and zinc-regulated signaling pathways requiring MTF-1. The ZnT2 transporter appears to function in a physiologically responsive manner involving entero-pancreatic zinc trafficking. PMID:20133611

Drp1 guarding of the mitochondrial network is important for glucose-stimulated insulin secretion in pancreatic beta cells

DOE Office of Scientific and Technical Information (OSTI.GOV)

Reinhardt, Florian; Schultz, Julia; Waterstradt, Rica

Mitochondria form a tubular network in mammalian cells, and the mitochondrial life cycle is determined by fission, fusion and autophagy. Dynamin-related protein 1 (Drp1) has a pivotal role in these processes because it alone is able to constrict mitochondria. However, the regulation and function of Drp1 have been shown to vary between cell types. Mitochondrial morphology affects mitochondrial metabolism and function. In pancreatic beta cells mitochondrial metabolism is a key component of the glucose-induced cascade of insulin secretion. The goal of the present study was to investigate the action of Drp1 in pancreatic beta cells. For this purpose Drp1 wasmore » down-regulated by means of shDrp1 in insulin-secreting INS1 cells and mouse pancreatic islets. In INS1 cells reduced Drp1 expression resulted in diminished expression of proteins regulating mitochondrial fusion, namely mitofusin 1 and 2, and optic atrophy protein 1. Diminished mitochondrial dynamics can therefore be assumed. After down-regulation of Drp1 in INS1 cells and spread mouse islets the initially homogenous mitochondrial network characterised by a moderate level of interconnections shifted towards high heterogeneity with elongated, clustered and looped mitochondria. These morphological changes were found to correlate directly with functional alterations. Mitochondrial membrane potential and ATP generation were significantly reduced in INS1 cells after Drp1down-regulation. Finally, a significant loss of glucose-stimulated insulin secretion was demonstrated in INS1 cells and mouse pancreatic islets. In conclusion, Drp1 expression is important in pancreatic beta cells to maintain the regulation of insulin secretion. -- Highlights: •Down-regulation of Drp1 in INS1 cells reduces mitochondrial fusion protein expression. •Mitochondrial membrane potential in INS1 cells is diminished after Drp1 down-regulation. •Mitochondria become elongated after down-regulation of Drp1 in beta cells. •Down-regulation

Yes-associated protein (YAP) in pancreatic cancer: at the epicenter of a targetable signaling network associated with patient survival.

PubMed

Rozengurt, Enrique; Sinnett-Smith, James; Eibl, Guido

2018-01-01

Pancreatic ductal adenocarcinoma (PDAC) is generally a fatal disease with no efficacious treatment modalities. Elucidation of signaling mechanisms that will lead to the identification of novel targets for therapy and chemoprevention is urgently needed. Here, we review the role of Yes-associated protein (YAP) and WW-domain-containing Transcriptional co-Activator with a PDZ-binding motif (TAZ) in the development of PDAC. These oncogenic proteins are at the center of a signaling network that involves multiple upstream signals and downstream YAP-regulated genes. We also discuss the clinical significance of the YAP signaling network in PDAC using a recently published interactive open-access database (www.proteinatlas.org/pathology) that allows genome-wide exploration of the impact of individual proteins on survival outcomes. Multiple YAP/TEAD-regulated genes, including AJUBA , ANLN , AREG , ARHGAP29 , AURKA , BUB1 , CCND1 , CDK6, CXCL5 , EDN2 , DKK1 , FOSL1,FOXM1 , HBEGF , IGFBP2 , JAG1 , NOTCH2 , RHAMM , RRM2 , SERP1 , and ZWILCH , are associated with unfavorable survival of PDAC patients. Similarly, components of AP-1 that synergize with YAP ( FOSL1 ), growth factors (TGFα, EPEG, and HBEGF), a specific integrin ( ITGA2 ), heptahelical receptors ( P2Y 2 R , GPR87 ) and an inhibitor of the Hippo pathway ( MUC1 ), all of which stimulate YAP activity, are associated with unfavorable survival of PDAC patients. By contrast, YAP inhibitory pathways (STRAD/LKB-1/AMPK, PKA/LATS, and TSC/mTORC1) indicate a favorable prognosis. These associations emphasize that the YAP signaling network correlates with poor survival of pancreatic cancer patients. We conclude that the YAP pathway is a major determinant of clinical aggressiveness in PDAC patients and a target for therapeutic and preventive strategies in this disease.

CIP2A down regulation enhances the sensitivity of pancreatic cancer cells to gemcitabine.

PubMed

Xu, Peng; Yao, Jie; He, Jin; Zhao, Long; Wang, Xiaodong; Li, Zhennan; Qian, Jianjun

2016-03-22

Cancerous inhibitor of protein phosphatase 2A (CIP2A) is an oncoprotein which participates in inhibiting tumor apoptosis in pancreatic cancer cells. Using immunohistochemical staining, we investigated the expression of CIP2A protein in 72 cases of human pancreatic ductal adenocarcinoma (PDAC) tissue and 27 cases of adjacent normal pancreatic tissue. The positive rate of CIP2A protein expression in pancreatic cancer tissue was70.83 %, which was significantly higher than that in adjacent non- cancerous pancreatic tissue (11.11%). The expression of CIP2A was found to be correlated with TNM stage, but not correlated with age, gender, tumor location, smoking status, alcohol consumption, diabetes, high blood pressure, BMI, tumor size, lymph node metastasis or distant metastases. Kaplan- Meier survival analysis showed that patients with positive CIP2A protein expression had a lower overall survival rate than patients without CIP2A expression. COX regression analysis indicated that expression of CIP2A was an independent prognostic factor for pancreatic ductal adenocarcinoma. In addition, down-regulation of CIP2A inhibited cell proliferation and increased sensitivity to gemcitabine in pancreatic cancer cells by decreasing AKT signaling pathway. Our results indicated that down-regulation of CIP2A could be a novel therapeutic strategy for pancreatic cancer.

A Novel Hydroxamate-Based Compound WMJ-J-09 Causes Head and Neck Squamous Cell Carcinoma Cell Death via LKB1-AMPK-p38MAPK-p63-Survivin Cascade.

PubMed

Yen, Chia-Sheng; Choy, Cheuk-Sing; Huang, Wei-Jan; Huang, Shiu-Wen; Lai, Pin-Ye; Yu, Meng-Chieh; Shiue, Ching; Hsu, Ya-Fen; Hsu, Ming-Jen

2018-01-01

Growing evidence shows that hydroxamate-based compounds exhibit broad-spectrum pharmacological properties including anti-tumor activity. However, the precise mechanisms underlying hydroxamate derivative-induced cancer cell death remain incomplete understood. In this study, we explored the anti-tumor mechanisms of a novel aliphatic hydroxamate-based compound, WMJ-J-09, in FaDu head and neck squamous cell carcinoma (HNSCC) cells. WMJ-J-09 induced G2/M cell cycle arrest and apoptosis in FaDu cells. These actions were associated with liver kinase B1 (LKB1), AMP-activated protein kinase (AMPK) and p38 mitogen-activated protein kinase (p38MAPK) activation, transcription factor p63 phosphorylation, as well as modulation of p21 and survivin. LKB1-AMPK-p38MAPK signaling blockade reduced WMJ-J-09's enhancing effects in p63 phosphorylation, p21 elevation and survivin reduction. Moreover, WMJ-J-09 caused an increase in α-tubulin acetylation and interfered with microtubule assembly. Furthermore, WMJ-J-09 suppressed the growth of subcutaneous FaDu xenografts in vivo . Taken together, WMJ-J-09-induced FaDu cell death may involve LKB1-AMPK-p38MAPK-p63-survivin signaling cascade. HDACs inhibition and disruption of microtubule assembly may also contribute to WMJ-J-09's actions in FaDu cells. This study suggests that WMJ-J-09 may be a potential lead compound and warrant the clinical development in the treatment of HNSCC.

Berberine diminishes side population and down-regulates stem cell-associated genes in the pancreatic cancer cell lines PANC-1 and MIA PaCa-2.

PubMed

Park, S H; Sung, J H; Chung, N

2014-09-01

Cancer stem cells play an important role in metastasis and the relapse of drug resistant cancers. Side-population (SP) cells are capable of effluxing Hoechst 33342 dye and are referred to as cancer stem cells. We investigated the effect of berberine on pancreatic cancer stem cells of PANC-1 and MIA PaCa-2. For both cell lines, the proportions of SP cells in the presence of berberine were investigated and compared to the proportions in the presence of gemcitabine, a standard pancreatic anti-cancer drug. The proportions of SP cells in the PANC-1 and MIA PaCa-2 cell lines were about 9 and <0.1%, respectively. After berberine and gemcitabine treatments, the SP cell proportion of PANC-1 decreased to 5.7 ± 2.0 and 6.8 ± 0.8%, respectively, which compares to the control proportion of (9.7 ± 1.7). After berberine and gemcitabine treatment of PANC-1, of the four stem cell-associated genes (SOX2, POU5F1, NANOG, and NOTCH1), all but NOTCH1 were down-regulated. Unfortunately, the effect of berberine and gemcitabine treatments on MIA PaCa-2 SP cells could not be clearly observed because SP cells represented only a very small proportion of MIA PaCa-2 cells. However, SOX2, POU5F1, and NANOG genes were shown to be effectively down-regulated in the MIA PaCa-2 cell line as a whole. Taken together, these results indicate that berberine is as effective at targeting pancreatic cancer cell lines as gemcitabine. Therefore, we believe that POU5F1, SOX2, and NANOG can serve as potential markers, and berberine may be an effective anti-cancer agent when targeting human pancreatic cancer cells and/or their cancer stem cells.

N-n-butyl haloperidol iodide ameliorates hypoxia/reoxygenation injury through modulating the LKB1/AMPK/ROS pathway in cardiac microvascular endothelial cells.

PubMed

Lu, Binger; Wang, Bin; Zhong, Shuping; Zhang, Yanmei; Gao, Fenfei; Chen, Yicun; Zheng, Fuchun; Shi, Ganggang

2016-06-07

Endothelial cells are highly sensitive to hypoxia and contribute to myocardial ischemia/reperfusion injury. We have reported that N-n-butyl haloperidol iodide (F2) can attenuate hypoxia/reoxygenation (H/R) injury in cardiac microvascular endothelial cells (CMECs). However, the molecular mechanisms remain unclear. Neonatal rat CMECs were isolated and subjected to H/R. Pretreatment of F2 leads to a reduction in H/R injury, as evidenced by increased cell viability, decreased lactate dehydrogenase (LDH) leakage and apoptosis, together with enhanced AMP-activated protein kinase (AMPK) and liver kinase B1 (LKB1) phosphorylation in H/R ECs. Blockade of AMPK with compound C reversed F2-induced inhibition of H/R injury, as evidenced by decreased cell viability, increased LDH release and apoptosis. Moreover, compound C also blocked the ability of F2 to reduce H/R-induced reactive oxygen species (ROS) generation. Supplementation with the ROS scavenger N-acetyl-L-cysteine (NAC) reduced ROS levels, increased cell survival rate, and decreased both LDH release and apoptosis after H/R. In conclusion, our data indicate that F2 may mitigate H/R injury by stimulating LKB1/AMPK signaling pathway and subsequent suppression of ROS production in CMECs.

Pancreatic cancer-derived exosomes suppress the production of GIP and GLP-1 from STC-1 cells in vitro by down-regulating the PCSK1/3.

PubMed

Zhang, Yuefeng; Huang, Shifei; Li, Pengping; Chen, Qing; Li, Yongzhou; Zhou, Yizhao; Wang, Lantian; Kang, Muxing; Zhang, Bo; Yang, Bin; Wu, Yulian

2018-05-22

One hallmark of pancreatic cancer (PC) is the high prevalence of pancreatic cancer-associated diabetes mellitus (PC-DM), but the mechanisms remain to be elucidated. Patients with PC who are diagnosed with new-onset diabetes/prediabetes have recently been shown to display significantly lower levels of glucose-dependent insulinotropic peptide (GIP) secreted mainly by enteroendocrine cells. We hypothesized that PC-derived exosomes are responsible for the decreased levels of incretins in patients with PC-DM. In this study, exosomes were successfully isolated from PANC-1, MIA PaCa-2 and SW620 cells and characterized. Only the exosomes from MIA PaCa-2 cells (Exo-Mia) reduce the production of GIP and glucagon-like peptide-1 (GLP-1) from STC-1 cells in vitro in a concentration- and time-dependent manner. Moreover, Exo-Mia increased the levels of the Gip and proglucagon mRNAs and decreased the expression of proprotein convertase subtilisin/kexin type 1/3 (PCSK1/3), which is responsible for the post-translational processing of Gip and proglucagon. Furthermore, differentially expressed exosomal miRNAs (miR-6796-3p, miR-6763-5p, miR-4750-3p and miR-197-3p) were identified and considered to be responsible for the inhibitory effects on GIP and GLP-1 production. To further determine the approach of cancer-derived exosomes reaching enteroendocrine cells, we analyzed the uptake and distribution of exosomes in animal model. It was observed that exosomes infused into the intestinal cavity were more easily internalized by the intestinal epithelium than exosomes injected into blood. In conclusion, pancreatic cancer-derived exosomes (Exo-Mia) suppress the synthesis of GIP and GLP-1 from STC-1 cells in vitro by down-regulating the PCSK1/3. Moreover, it may be the pancreatic juice that transport cancer-derived exosomes to target cells (K and L cells) in the gut. Copyright © 2018 Elsevier B.V. All rights reserved.

Tuft Cell Regulation of miRNAs in Pancreatic Cancer

DTIC Science & Technology

2013-10-01

are involved in chemosensensing of the microenvironment. With the successful deletion of Dclk1 throughout the pancreatic ducts , we can begin...characterization, which extends our understanding of the role tuft cells play within ducts and their broader effects on the overall pancreatic...characterization of Pdx-1-Cre;Dclk1flox/flox was completed which demonstrated the loss of Dclk1 expression within tuft cells in all pancreatic ducts

The pattern of hMENA isoforms is regulated by TGF-β1 in pancreatic cancer and may predict patient outcome

PubMed Central

Melchionna, Roberta; Iapicca, Pierluigi; Di Modugno, Francesca; Trono, Paola; Sperduti, Isabella; Fassan, Matteo; Cataldo, Ivana; Rusev, Borislav C.; Lawlor, Rita T.; Diodoro, Maria Grazia; Milella, Michele; Grazi, Gian Luca; Bissell, Mina J.; Scarpa, Aldo; Nisticò, Paola

2016-01-01

ABSTRACT Pancreatic ductal adenocarcinoma (PDAC) is an aggressive disease in need of prognostic markers to address therapeutic choices. We have previously shown that alternative splicing of the actin regulator, hMENA, generates hMENA11a, and hMENAΔv6 isoforms with opposite roles in cell invasion. We examined the expression pattern of hMENA isoforms by immunohistochemistry, using anti-pan hMENA and specific anti-hMENA11a antibodies, in 285 PDACs, 15 PanINs, 10 pancreatitis, and normal pancreas. Pan hMENA immunostaining, absent in normal pancreas and low-grade PanINs, was weak in PanIN-3 and had higher levels in virtually all PDACs with 64% of cases showing strong staining. Conversely, the anti-invasive hMENA11a isoform only showed strong staining in 26% of PDAC. The absence of hMENA11a in a subset (34%) of pan-hMENA-positive tumors significantly correlated with poor outcome. The functional effects of hMENA isoforms were analyzed by loss and gain of function experiments in TGF-β1-treated PDAC cell lines. hMENA11a knock-down in PDAC cell lines affected cell–cell adhesion but not invasion. TGF-β1 cooperated with β-catenin signaling to upregulate hMENA and hMENAΔv6 expression but not hMENA11a In the absence of hMENA11a, the hMENA/hMENAΔv6 up-regulation is crucial for SMAD2-mediated TGF-β1 signaling and TGF-β1-induced EMT. Since the hMENA isoform expression pattern correlates with patient outcome, the data suggest that hMENA splicing and related pathways are novel key players in pancreatic tumor microenvironment and may represent promising targets for the development of new prognostic and therapeutic tools in PDAC. PMID:28123868

Insulin-like Growth Factor 1 Regulates the Expression of ATP-Binding Cassette Transporter A1 in Pancreatic Beta Cells.

PubMed

Lyu, J; Imachi, H; Iwama, H; Zhang, H; Murao, K

2016-05-01

ATP-binding cassette transporter A1 (ABCA1) in pancreatic beta cells influences insulin secretion and cholesterol homeostasis. The present study investigates whether insulin-like growth factor 1 (IGF-1), which mediates stimulation of ABCA1 gene expression, could also interfere with the phosphatidylinositol 3-kinase (PI3-K) cascade.ABCA1 expression was examined by real-time polymerase chain reaction (PCR), Western blot analysis, and a reporter gene assay in rat insulin-secreting INS-1 cells incubated with IGF-1. The binding of forkhead box O1 (FoxO1) protein to the ABCA1 promoter was assessed by a chromatin immunoprecipitation (ChIP) assay. ABCA1 protein levels increased in response to rising concentrations of IGF-1. Real-time PCR analysis showed a significant increase in ABCA1 mRNA expression. However, both effects were suppressed after silencing the IGF-1 receptor. In parallel with its effect on endogenous ABCA1 mRNA levels, IGF-1 induced the activity of a reporter construct containing the ABCA1 promoter, while it was abrogated by LY294002, a specific inhibitor of PI3-K. Constitutively active Akt stimulated activity of the ABCA1 promoter, and a dominant-negative mutant of Akt or mutagenesis of the FoxO1 response element in the ABCA1 promoter abolished the ability of IGF-1 to stimulate promoter activity. A ChIP assay showed that FoxO1 mediated its transcriptional activity by directly binding to the ABCA1 promoter region. The knockdown of FoxO1 disrupted the effect of IGF-1 on ABCA1 expression. Furthermore, IGF-1 promoted cholesterol efflux and reduced the pancreatic lipotoxicity. These results demonstrate that the PI3-K/Akt/FoxO1 pathway contributes to the regulation of ABCA1 expression in response to IGF-1 stimulation. © Georg Thieme Verlag KG Stuttgart · New York.

TAp63 is a master transcriptional regulator of lipid and glucose metabolism

PubMed Central

Su, Xiaohua; Gi, Young Jin; Chakravarti, Deepavali; Chan, Io Long; Zhang, Aijun; Xia, Xuefeng; Tsai, Kenneth Y.; Flores, Elsa R.

2012-01-01

SUMMARY TAp63 prevents premature aging suggesting a link to genes that regulate longevity. Further characterization of TAp63−/− mice revealed that these mice develop obesity, insulin resistance, and glucose intolerance, similar to those seen in mice lacking two key metabolic regulators, Silent information regulator T1 (Sirt1) and AMPK. While the roles of Sirt1 and AMPK in metabolism have been well studied, their upstream regulators are not well understood. We found that TAp63 is important in regulating energy metabolism by accumulating in response to metabolic stress and transcriptionally activating Sirt1, AMPKα2, and LKB1 resulting in increased fatty acid synthesis and decreased fatty acid oxidation. Moreover, we found that TAp63 lowers blood glucose levels in response to metformin. Restoration of Sirt1, AMPKα2, and LKB1 in TAp63−/− mice rescued some of the metabolic defects of the TAp63−/− mice. Our study defines a role for TAp63 in metabolism and weight control. PMID:23040072

Intracellular and extracellular adenosine triphosphate in regulation of insulin secretion from pancreatic β cells (β).

PubMed

Wang, Chunjiong; Geng, Bin; Cui, Qinghua; Guan, Youfei; Yang, Jichun

2014-03-01

Adenosine triphosphate (ATP) synthesis and release in mitochondria play critical roles in regulating insulin secretion in pancreatic β cells. Mitochondrial dysfunction is mainly characterized by a decrease in ATP production, which is a central event in the progression of pancreatic β cell dysfunction and diabetes. ATP has been demonstrated to regulate insulin secretion via several pathways: (i) Intracellular ATP directly closes ATP-sensitive potassium channel to open L-type calcium channel, leading to an increase in free cytosolic calcium levels and exocytosis of insulin granules; (ii) A decrease in ATP production is always associated with an increase in production of reactive oxygen species, which exerts deleterious effects on pancreatic β cell survival and insulin secretion; and (iii) ATP can be co-secreted with insulin from pancreatic β cells, and the released ATP functions as an autocrine signal to modulate insulin secretory process via P2 receptors on the cell membrane. In this review, the recent findings regarding the role and mechanism of ATP synthesis and release in regulation of insulin secretion from pancreatic β cells will be summarized and discussed. © 2013 Ruijin Hospital, Shanghai Jiaotong University School of Medicine and Wiley Publishing Asia Pty Ltd.

Silencing of the integrin-linked kinase gene suppresses the proliferation, migration and invasion of pancreatic cancer cells (Panc-1).

PubMed

Zhu, Xiang-Yu; Liu, Ning; Liu, Wei; Song, Shao-Wei; Guo, Ke-Jian

2012-04-01

Integrin-linked kinase (ILK) is an ankyrin repeat-containing serine-threonine protein kinase that is involved in the regulation of integrin-mediated processes such as cancer cell proliferation, migration and invasion. In this study, we examined the effect of a lentivirus-mediated knockdown of ILK on the proliferation, migration and invasion of pancreatic cancer (Panc-1) cells. Immunohistochemical staining showed that ILK expression was enhanced in pancreatic cancer tissue. The silencing of ILK in human Panc-1 cells led to cell cycle arrest in the G0/G1 phase and delayed cell proliferation, in addition to down-regulating cell migration and invasion. The latter effects were mediated by up-regulating the expression of E-cadherin, a key protein in cell adhesion. These findings indicate that ILK may be a new diagnostic marker for pancreatic cancer and that silencing ILK could be a potentially useful therapeutic approach for treating pancreatic cancer.

Hyperglycemia regulates TXNIP/TRX/ROS axis via p38 MAPK and ERK pathways in pancreatic cancer.

PubMed

Li, Wei; Wu, Zheng; Ma, Qingyong; Liu, Jiangbo; Xu, Qinhong; Han, Liang; Duan, Wanxing; Lv, Yunfu; Wang, Fengfei; Reindl, Katie M; Wu, Erxi

2014-01-01

Approximately 85% of pancreatic cancer patients suffer from glucose intolerance or even diabetes because high glucose levels can contribute to oxidative stress which promotes tumor development. As one of the reactive oxygen species (ROS)-regulating factors, thioredoxin-interacting protein (TXNIP), is involved in the maintenance of thioredoxin (TRX)-mediated redox regulation. In this study, we demonstrated that high glucose levels increased the expression of TXNIP in time- and concentration-dependent manners and modulated the activity of TRX and ROS production in pancreatic cancer cells, BxPC-3 and Panc-1. We also found that glucose activated both p38 MAPK and ERK pathways and inhibitors of these pathways impaired the TXNIP/TRX/ROS axis. Knockdown of TXNIP restored TRX activity and decreased ROS production under high glucose conditions. Moreover, we observed that the integrated optical density (IOD) of TXNIP staining as well as the protein and mRNA expression levels of TXNIP were higher in the tumor tissues of pancreatic cancer patients with diabetes. Taken together, these results indicate that hyperglycemia-induced TXNIP expression is involved in diabetes-mediated oxidative stress in pancreatic cancer via p38 MAPK and ERK pathways.

Cinnamon Extract Enhances Glucose Uptake in 3T3-L1 Adipocytes and C2C12 Myocytes by Inducing LKB1-AMP-Activated Protein Kinase Signaling

PubMed Central

Shen, Yan; Honma, Natsumi; Kobayashi, Katsuya; Jia, Liu Nan; Hosono, Takashi; Shindo, Kazutoshi; Ariga, Toyohiko; Seki, Taiichiro

2014-01-01

We previously demonstrated that cinnamon extract (CE) ameliorates type 1 diabetes induced by streptozotocin in rats through the up-regulation of glucose transporter 4 (GLUT4) translocation in both muscle and adipose tissues. This present study was aimed at clarifying the detailed mechanism(s) with which CE increases the glucose uptake in vivo and in cell culture systems using 3T3-L1 adipocytes and C2C12 myotubes in vitro. Specific inhibitors of key enzymes in insulin signaling and AMP-activated protein kinase (AMPK) signaling pathways, as well as small interference RNA, were used to examine the role of these kinases in the CE-induced glucose uptake. The results showed that CE stimulated the phosphorylation of AMPK and acetyl-CoA carboxylase. An AMPK inhibitor and LKB1 siRNA blocked the CE-induced glucose uptake. We also found for the first time that insulin suppressed AMPK activation in the adipocyte. To investigate the effect of CE on type 2 diabetes in vivo, we further performed oral glucose tolerance tests and insulin tolerance tests in type 2 diabetes model rats administered with CE. The CE improved glucose tolerance in oral glucose tolerance tests, but not insulin sensitivity in insulin tolerance test. In summary, these results indicate that CE ameliorates type 2 diabetes by inducing GLUT4 translocation via the AMPK signaling pathway. We also found insulin antagonistically regulates the activation of AMPK. PMID:24551069

Cinnamon extract enhances glucose uptake in 3T3-L1 adipocytes and C2C12 myocytes by inducing LKB1-AMP-activated protein kinase signaling.

PubMed

Shen, Yan; Honma, Natsumi; Kobayashi, Katsuya; Jia, Liu Nan; Hosono, Takashi; Shindo, Kazutoshi; Ariga, Toyohiko; Seki, Taiichiro

2014-01-01

We previously demonstrated that cinnamon extract (CE) ameliorates type 1 diabetes induced by streptozotocin in rats through the up-regulation of glucose transporter 4 (GLUT4) translocation in both muscle and adipose tissues. This present study was aimed at clarifying the detailed mechanism(s) with which CE increases the glucose uptake in vivo and in cell culture systems using 3T3-L1 adipocytes and C2C12 myotubes in vitro. Specific inhibitors of key enzymes in insulin signaling and AMP-activated protein kinase (AMPK) signaling pathways, as well as small interference RNA, were used to examine the role of these kinases in the CE-induced glucose uptake. The results showed that CE stimulated the phosphorylation of AMPK and acetyl-CoA carboxylase. An AMPK inhibitor and LKB1 siRNA blocked the CE-induced glucose uptake. We also found for the first time that insulin suppressed AMPK activation in the adipocyte. To investigate the effect of CE on type 2 diabetes in vivo, we further performed oral glucose tolerance tests and insulin tolerance tests in type 2 diabetes model rats administered with CE. The CE improved glucose tolerance in oral glucose tolerance tests, but not insulin sensitivity in insulin tolerance test. In summary, these results indicate that CE ameliorates type 2 diabetes by inducing GLUT4 translocation via the AMPK signaling pathway. We also found insulin antagonistically regulates the activation of AMPK.

Metastatic pancreatic adenocarcinoma associated with chronic calcific pancreatitis and a heterozygous SPINK1 N34S mutation.

PubMed

Moran, Robert A; Klapheke, Robert; Jalaly, Niloofar Y; Makary, Martin A; Hirose, Kenzo; Goggins, Michael; Wood, Laura; Laheru, Daniel A; Lennon, Anne Marie; Khashab, Mouen A; Singh, Vikesh K

2016-01-01

Contrary to patients with a cationic trypsinogen gene (PRSS1) mutations, Serine protease inhibitor Kazal-type 1 (SPINK1) heterozygote gene mutation carriers have a very low penetrance for acute, acute recurrent and/or chronic pancreatitis. Despite this, heterozygote SPINK 1 gene mutation patients have a similar age of onset of pancreatitis as PRSS 1 gene mutation patients. While the substantially elevated risk of pancreatic cancer in patients with PRSS1 gene mutations with chronic pancreatitis has been well established, little is known about the risk of pancreatic cancer in SPINK 1 gene mutation carriers with pancreatitis. We describe a case of malignant pancreatic cancer diagnosed in a young patient with chronic pancreatitis who is a SPINK 1 heterozygote gene mutation carrier. The risk of pancreatic cancer in gene mutation patients with chronic pancreatitis, in addition to screening options and management options for these patients is discussed. Copyright © 2016 IAP and EPC. Published by Elsevier B.V. All rights reserved.

Cholecystokinin regulates the invasiveness of human pancreatic cancer cell lines via protein kinase C pathway.

PubMed

Hirata, M; Tsuchida, A; Iwao, T; Sasaki, T; Matsubara, K; Yamamoto, S; Morinaka, K; Kawasaki, Y; Fujimoto, Y; Inoue, H; Kariya, K; Kajiyama, G

1999-06-01

We have previously reported that cholecystokinin (CCK) plays an important role in the invasiveness and the production of matrix metalloproteinase-9 (MMP-9) in two human pancreatic cancer cell lines. In this study we investigated the pathway of the invasiveness associated with MMP-9 of those lines regulated by CCK. Two human pancreatic cancer cell lines were treated with CCK-8 alone, CCK-8 and staurosporine, or CCK-8 and indomethacine. The invasiveness and the production of MMP-9 were decreased with staurosporine but not indomethacine. These results suggest that CCK may regulate the invasiveness and the production of MMP-9 via protein kinase C in human pancreatic cancer cell lines.

Regulator of calcineurin 1 controls growth plasticity of adult pancreas.

PubMed

Gurda, Grzegorz T; Crozier, Stephen J; Ji, Baoan; Ernst, Stephen A; Logsdon, Craig D; Rothermel, Beverly A; Williams, John A

2010-08-01

Growth of exocrine pancreas is regulated by gastrointestinal hormones, notably cholecystokinin (CCK). CCK-driven pancreatic growth requires calcineurin (CN), which activates Nuclear Factor of Activated T cells (NFATs), but the genetic underpinnings and feedback mechanisms that regulate this response are not known. Pancreatic growth was stimulated by protease inhibitor (PI)-containing chow, which induces secretion of endogenous CCK. Expression profiling of PI stimulation was performed on Affymetrix 430A chips, and CN was inhibited via FK506. Exocrine pancreas-specific overexpression of CN inhibitor Regulator of Calcineurin 1 (Rcan1) was achieved by breeding elastase-Cre(estrogen receptor [ER]) transgenics with "flox-on" Rcan1 mice. CN inhibitor FK506 blocked expression of 38 genes, as confirmed by quantitative polymerase chain reaction. The CN-dependent genes were linked to growth-related processes, whereas their promoters were enriched in NFAT and NFAT/AP1 sites. Multiple NFAT targets, including Rcan1, Rgs2, HB-EGF, Lif, and Gem, were validated by chromatin immunoprecipitation. One of these, a CN feedback inhibitor Rcan1, was induced >50 fold during 1-8 hours course of pancreatic growth and strongly inhibited (>99%) by FK506. To examine its role in pancreatic growth, we overexpressed Rcan1 in an inducible, acinar-specific fashion. Rcan1 overexpression inhibited CN-NFAT signaling, as shown using an NFAT-luciferase reporter and quantitative polymerase chain reaction. Most importantly, the increase in exocrine pancreas size, protein/DNA content, and acinar proliferation were all blocked in Rcan1 overexpressing mice. We profile adaptive pancreatic growth, identify Rcan1 as an important new feedback regulator, and firmly establish that CN-NFAT signaling is required for this response. Copyright (c) 2010 AGA Institute. Published by Elsevier Inc. All rights reserved.

Regulation of Insulin Synthesis and Secretion and Pancreatic Beta-Cell Dysfunction in Diabetes

PubMed Central

Fu, Zhuo; Gilbert, Elizabeth R.; Liu, Dongmin

2014-01-01

Pancreatic β-cell dysfunction plays an important role in the pathogenesis of both type 1 and type 2 diabetes. Insulin, which is produced in β-cells, is a critical regulator of metabolism. Insulin is synthesized as preproinsulin and processed to proinsulin. Proinsulin is then converted to insulin and C-peptide and stored in secretary granules awaiting release on demand. Insulin synthesis is regulated at both the transcriptional and translational level. The cis-acting sequences within the 5′ flanking region and trans-activators including paired box gene 6 (PAX6), pancreatic and duodenal homeobox-1(PDX-1), MafA, and B-2/Neurogenic differentiation 1 (NeuroD1) regulate insulin transcription, while the stability of preproinsulin mRNA and its untranslated regions control protein translation. Insulin secretion involves a sequence of events in β-cells that lead to fusion of secretory granules with the plasma membrane. Insulin is secreted primarily in response to glucose, while other nutrients such as free fatty acids and amino acids can augment glucose-induced insulin secretion. In addition, various hormones, such as melatonin, estrogen, leptin, growth hormone, and glucagon like peptide-1 also regulate insulin secretion. Thus, the β-cell is a metabolic hub in the body, connecting nutrient metabolism and the endocrine system. Although an increase in intracellular [Ca2+] is the primary insulin secretary signal, cAMP signaling-dependent mechanisms are also critical in the regulation of insulin secretion. This article reviews current knowledge on how β-cells synthesize and secrete insulin. In addition, this review presents evidence that genetic and environmental factors can lead to hyperglycemia, dyslipidemia, inflammation, and autoimmunity, resulting in β-cell dysfunction, thereby triggering the pathogenesis of diabetes. PMID:22974359

Gene expression analysis of pancreatic cell lines reveals genes overexpressed in pancreatic cancer.

PubMed

Alldinger, Ingo; Dittert, Dag; Peiper, Matthias; Fusco, Alberto; Chiappetta, Gennaro; Staub, Eike; Lohr, Matthias; Jesnowski, Ralf; Baretton, Gustavo; Ockert, Detlef; Saeger, Hans-Detlev; Grützmann, Robert; Pilarsky, Christian

2005-01-01

Pancreatic cancer is one of the leading causes of cancer-related death. Using DNA gene expression analysis based on a custom made Affymetrix cancer array, we investigated the expression pattern of both primary and established pancreatic carcinoma cell lines. We analyzed the gene expression of 5 established pancreatic cancer cell lines (AsPC-1, BxPC-3, Capan-1, Capan-2 and HPAF II) and 5 primary isolates, 1 of them derived from benign pancreatic duct cells. Out of 1,540 genes which were expressed in at least 3 experiments, we found 122 genes upregulated and 18 downregulated in tumor cell lines compared to benign cells with a fold change >3. Several of the upregulated genes (like Prefoldin 5, ADAM9 and E-cadherin) have been associated with pancreatic cancer before. The other differentially regulated genes, however, play a so far unknown role in the course of human pancreatic carcinoma. By means of immunohistochemistry we could show that thymosin beta-10 (TMSB10), upregulated in tumor cell lines, is expressed in human pancreatic carcinoma, but not in non-neoplastic pancreatic tissue, suggesting a role for TMSB10 in the carcinogenesis of pancreatic carcinoma. Using gene expression profiling of pancreatic cell lines we were able to identify genes differentially expressed in pancreatic adenocarcinoma, which might contribute to pancreatic cancer development. Copyright 2005 S. Karger AG, Basel.

Bmi1 is required for the initiation of pancreatic cancer through an Ink4a-independent mechanism.

PubMed

Bednar, Filip; Schofield, Heather K; Collins, Meredith A; Yan, Wei; Zhang, Yaqing; Shyam, Nikhil; Eberle, Jaime A; Almada, Luciana L; Olive, Kenneth P; Bardeesy, Nabeel; Fernandez-Zapico, Martin E; Nakada, Daisuke; Simeone, Diane M; Morrison, Sean J; Pasca di Magliano, Marina

2015-07-01

Epigenetic dysregulation is involved in the initiation and progression of many epithelial cancers. BMI1, a component of the polycomb protein family, plays a key role in these processes by controlling the histone ubiquitination and long-term repression of multiple genomic loci. BMI1 has previously been implicated in pancreatic homeostasis and the function of pancreatic cancer stem cells. However, no work has yet addressed its role in the early stages of pancreatic cancer development. Here, we show that BMI1 is required for the initiation of murine pancreatic neoplasia using a novel conditional knockout of Bmi1 in combination with a Kras(G12D)-driven pancreatic cancer mouse model. We also demonstrate that the requirement for Bmi1 in pancreatic carcinogenesis is independent of the Ink4a/Arf locus and at least partially mediated by dysregulation of reactive oxygen species. Our data provide new evidence of the importance of this epigenetic regulator in the genesis of pancreatic cancer. © The Author 2015. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Genome-scale analysis identifies GJB2 and ERO1LB as prognosis markers in patients with pancreatic cancer.

PubMed

Zhu, Tao; Gao, Yuan-Feng; Chen, Yi-Xin; Wang, Zhi-Bin; Yin, Ji-Ye; Mao, Xiao-Yuan; Li, Xi; Zhang, Wei; Zhou, Hong-Hao; Liu, Zhao-Qian

2017-03-28

Pancreatic cancer is a complex and heterogeneous disease with the etiology largely unknown. The deadly nature of pancreatic cancer, with an extremely low 5-year survival rate, renders urgent a better understanding of the molecular events underlying it. The aim of this study is to investigate the gene expression module of pancreatic adenocarcinoma and to identify differentially expressed genes (DEGs) with prognostic potentials. Transcriptome microarray data of five GEO datasets (GSE15471, GSE16515, GSE18670, GSE32676, GSE71989), including 117 primary tumor samples and 73 normal pancreatic tissue samples, were utilized to identify DEGs. The five sets of DEGs had an overlapping subset consisting of 98 genes (90 up-regulated and 8 down-regulated), which were probably common to pancreatic cancer. Gene ontology (GO) analysis of the 98 DEGs showed that cell cycle and cell adhesion were the major enriched processes, and extracellular matrix (ECM)-receptor interaction and p53 signaling pathway were the most enriched pathways according to Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis. Elevated expression of gap junction protein beta 2 (GJB2) and reduced endoplasmic reticulum oxidoreductase 1-like beta (ERO1LB) expression were validated in an independent cohort. Kaplan-Meier survival analysis revealed that GJB2 and ERO1LB levels were significantly associated with the overall survival of pancreatic cancer patients. GJB2 and ERO1LB are implicated in pancreatic cancer progression and can be used to predict patient survival. Therapeutic strategies targeting GJB2 and facilitating ERO1LB expression may deserve evaluation to improve prognosis of pancreatic cancer patients.

Involvement of the Clock Gene Rev-erb alpha in the Regulation of Glucagon Secretion in Pancreatic Alpha-Cells

PubMed Central

Vieira, Elaine; Marroquí, Laura; Figueroa, Ana Lucia C.; Merino, Beatriz; Fernandez-Ruiz, Rebeca; Nadal, Angel; Burris, Thomas P.; Gomis, Ramon; Quesada, Ivan

2013-01-01

Disruption of pancreatic clock genes impairs pancreatic beta-cell function, leading to the onset of diabetes. Despite the importance of pancreatic alpha-cells in the regulation of glucose homeostasis and in diabetes pathophysiology, nothing is known about the role of clock genes in these cells. Here, we identify the clock gene Rev-erb alpha as a new intracellular regulator of glucagon secretion. Rev-erb alpha down-regulation by siRNA (60–70% inhibition) in alphaTC1-9 cells inhibited low-glucose induced glucagon secretion (p<0.05) and led to a decrease in key genes of the exocytotic machinery. The Rev-erb alpha agonist GSK4112 increased glucagon secretion (1.6 fold) and intracellular calcium signals in alphaTC1-9 cells and mouse primary alpha-cells, whereas the Rev-erb alpha antagonist SR8278 produced the opposite effect. At 0.5 mM glucose, alphaTC1-9 cells exhibited intrinsic circadian Rev-erb alpha expression oscillations that were inhibited by 11 mM glucose. In mouse primary alpha-cells, glucose induced similar effects (p<0.001). High glucose inhibited key genes controlled by AMPK such as Nampt, Sirt1 and PGC-1 alpha in alphaTC1-9 cells (p<0.05). AMPK activation by metformin completely reversed the inhibitory effect of glucose on Nampt-Sirt1-PGC-1 alpha and Rev-erb alpha. Nampt inhibition decreased Sirt1, PGC-1 alpha and Rev-erb alpha mRNA expression (p<0.01) and glucagon release (p<0.05). These findings identify Rev-erb alpha as a new intracellular regulator of glucagon secretion via AMPK/Nampt/Sirt1 pathway. PMID:23936124

Targeting galectin-1 inhibits pancreatic cancer progression by modulating tumor-stroma crosstalk.

PubMed

Orozco, Carlos A; Martinez-Bosch, Neus; Guerrero, Pedro E; Vinaixa, Judith; Dalotto-Moreno, Tomás; Iglesias, Mar; Moreno, Mireia; Djurec, Magdolna; Poirier, Françoise; Gabius, Hans-Joachim; Fernandez-Zapico, Martin E; Hwang, Rosa F; Guerra, Carmen; Rabinovich, Gabriel A; Navarro, Pilar

2018-04-17

Pancreatic ductal adenocarcinoma (PDA) remains one of the most lethal tumor types, with extremely low survival rates due to late diagnosis and resistance to standard therapies. A more comprehensive understanding of the complexity of PDA pathobiology, and especially of the role of the tumor microenvironment in disease progression, should pave the way for therapies to improve patient response rates. In this study, we identify galectin-1 (Gal1), a glycan-binding protein that is highly overexpressed in PDA stroma, as a major driver of pancreatic cancer progression. Genetic deletion of Gal1 in a Kras -driven mouse model of PDA ( Ela-Kras G12V p53 -/- ) results in a significant increase in survival through mechanisms involving decreased stroma activation, attenuated vascularization, and enhanced T cell infiltration leading to diminished metastasis rates. In a human setting, human pancreatic stellate cells (HPSCs) promote cancer proliferation, migration, and invasion via Gal1-driven pathways. Moreover, in vivo orthotopic coinjection of pancreatic tumor cells with Gal1-depleted HPSCs leads to impaired tumor formation and metastasis in mice. Gene-expression analyses of pancreatic tumor cells exposed to Gal1 reveal modulation of multiple regulatory pathways involved in tumor progression. Thus, Gal1 hierarchically regulates different events implicated in PDA biology including tumor cell proliferation, invasion, angiogenesis, inflammation, and metastasis, highlighting the broad therapeutic potential of Gal1-specific inhibitors, either alone or in combination with other therapeutic modalities.

Long term effects of neonatal hypoglycaemia on pancreatic function.

PubMed

Anju, T R; Paulose, C S

2015-02-01

Low blood glucose in neonates predisposes to long term pancreatic damage. We focused on evaluating long term consequences of neonatal hypoglycaemia in pancreatic functions. Pancreatic function was analysed by measuring DNA/protein synthesis, glucose/ATP uptake in vitro. Gene expression of Pdx1, NeuroD1, Pax4, Bax, caspase 3, Beclin1 were done. Muscarinic receptors were analysed by radio receptor assay. Overall pancreatic efficiency was reduced in one-month-old rats exposed to neonatal hypoglycaemia as indicated by decreased DNA/protein synthesis and glucose/ATP uptake in vitro. Both Pdx1 and Neuro D1 expression were significantly down-regulated whereas Pax4 was up-regulated. Up-regulated Bax, caspase 3 and beclin1 along with reduced muscarinic receptors accounts for activation of cell death pathways. The study revealed a drastic reduction in pancreatic functions along with activation of apoptotic factors in one month old rats exposed to neonatal hypoglycaemia.

Biotin uptake by mouse and human pancreatic beta cells/islets: a regulated, lipopolysaccharide-sensitive carrier-mediated process

PubMed Central

Ghosal, Abhisek; Sekar, Thillai V.

2014-01-01

Biotin is essential for the normal function of pancreatic beta cells. These cells obtain biotin from their surroundings via transport across their cell membrane. Little is known about the uptake mechanism involved, how it is regulated, and how it is affected by internal and external factors. We addressed these issues using the mouse-derived pancreatic beta-TC-6 cells and freshly isolated mouse and human primary pancreatic beta cells as models. The results showed biotin uptake by pancreatic beta-TC-6 cells occurs via a Na+-dependent, carrier-mediated process, that is sensitive to desthiobiotin, as well as to pantothenic acid and lipoate; the process is also saturable as a function of concentration (apparent Km = 22.24 ± 5.5 μM). These cells express the sodium-dependent multivitamin transporter (SMVT), whose knockdown (with doxycycline-inducible shRNA) led to a sever inhibition in biotin uptake. Similarly, uptake of biotin by mouse and human primary pancreatic islets is Na+-dependent and carrier-mediated, and both cell types express SMVT. Biotin uptake by pancreatic beta-TC-6 cells is also adaptively regulated (via transcriptional mechanism) by extracellular substrate level. Chronic treatment of pancreatic beta-TC-6 cells with bacterial lipopolysaccharides (LPS) leads to inhibition in biotin uptake. This inhibition is mediated via a Toll-Like receptor 4-mediated process and involves a decrease in membrane expression of SMVT. These findings show, for the first time, that pancreatic beta cells/islets take up biotin via a specific and regulated carrier-mediated process, and that the process is sensitive to the effect of LPS. PMID:24904078

Ethanol Extract of Pinus koraiensis Leaf Ameliorates Alcoholic Fatty Liver via the Activation of LKB1-AMPK Signaling In Vitro and In Vivo.

PubMed

Hong, Sang-Hyuk; Lee, Hyemin; Lee, Hyo-Jung; Kim, Bonglee; Nam, Min-Ho; Shim, Bum-Sang; Kim, Sung-Hoon

2017-05-01

Although Pinus koraiensis leaf (PKL) was reported for its anti-diabetes, anti-obesity and anticancer effects as a folk remedy, the inhibitory effect of PKL on alcoholic fatty liver has never been elucidated yet. This study investigated the molecular mechanisms of PKL on alcoholic fatty liver in HepG2 cells, Sprague Dawley (SD) rats and Imprinting Control Region (ICR) mice. Pinus koraiensis leaf increased phosphorylation of liver kinase B1 (LKB1)/AMP-activated protein kinase signaling, low-density lipoprotein receptor and decreased fatty acid biosynthesis-related proteins such as sterol regulatory element-binding protein 1c, fatty acid synthase, 3-hydroxy-3-methylglutaryl-CoA reductase in HepG2 cells. In SD rats with 25% alcohol-induced fatty liver, PKL suppressed the levels of aspartate aminotransferase and triglyceride and also enhanced the activities of antioxidant enzymes including superoxide dismutase, glutathione peroxidase and glutathione s-transferase compared with untreated control. Furthermore, PKL increased serum alcohol dehydrogenase and serum aldehyde dehydrogenase, but decreased serum alcohol concentration in ICR mice after alcohol administration. Consistently, histochemical analysis revealed that PKL attenuated alcohol-induced fatty liver in SD rats. Overall, these findings suggest that PKL ameliorates alcohol-induced fatty liver via activation of LKB1-AMP-activated protein kinase and modulation of proteins related to lipogenesis synthesis, cholesterol synthesis and fatty acid oxidation. Copyright © 2017 John Wiley & Sons, Ltd. Copyright © 2017 John Wiley & Sons, Ltd.

Effect of pancreatic proteases on plasma cholecystokinin, secretin, and pancreatic exocrine secretion in response to sodium oleate.

PubMed

Li, P; Lee, K Y; Ren, X S; Chang, T M; Chey, W Y

1990-06-01

The effect of pancreatic proteases or juice on the sodium oleate-stimulated pancreatic secretion and plasma concentrations of secretin and cholecystokinin in anesthetized rats was investigated. Each rat received sodium oleate in a dose of 0.12 mmol.h-1 via a duodenal tube. Sodium oleate infusion significantly increased pancreatic secretion (volume and protein output) compared with the saline given the control group. The increase in pancreatic secretion paralleled significant elevations of plasma concentrations of secretin and cholecystokinin. To determine a possible role of pancreatic proteases on the responses induced by sodium oleate, saline, chymotrypsin, and trypsin, a combination of chymotrypsin and trypsin or pancreatic juice was infused into the duodenum. The pancreatic secretion was significantly reduced by pancreatic proteases or pancreatic juice, and the reduction paralleled the decreases in plasma concentrations of the two hormones. These agents suppressed both pancreatic secretion and plasma hormone levels in the following order of magnitude: (pancreatic juice or chymotrypsin + trypsin) greater than (trypsin) greater than (chymotrypsin). The reduction of pancreatic secretion by pancreatic proteases was reversed by intravenous administration of secretin and cholecystokinin in physiological doses. It is concluded that negative-feedback regulation of pancreatic secretion is operative in the intestinal phase in rats and that both secretin and cholecystokinin are involved in the regulation.

GROWTH OF HUMAN PANCREATIC CANCER IS INHIBITED BY DOWN-REGULATION OF GASTRIN GENE EXPRESSION

PubMed Central

Matters, Gail L.; Harms, John F.; McGovern, Christopher O.; Jayakumar, Calpurnia; Crepin, Keisha; Smith, Zachary P.; Nelson, Melissa C.; Stock, Heather; Fenn, Craig W.; Kaiser, James; Kester, Mark; Smith, Jill P.

2009-01-01

Objectives This study evaluated the effects of gastrin mRNA down-regulation on growth of human pancreatic cancer. Methods Gastrin expression was examined in human pancreatic cancer cell lines by RT-PCR and peptide expression was assessed by immunocytochemistry. Gastrin was down-regulated using either stable transfection of an antisense gastrin cDNA or one of three shRNA (short hairpin RNA) constructs. Tumor formation was evaluated following either subcutaneous or orthotopic injections into nude mice. The effect of nanoliposomes loaded with gastrin siRNA was tested in mice bearing pancreatic tumors. Results Stable transfection of gastrin antisense or shRNAs into BxPC-3 cells resulted in clones with >90% reduction in gastrin mRNA. Tumor growth rate and incidence of metastases in both wild type and transfected pancreatic cancer cells was directly proportional to the degrees of gastrin mRNA expression. Immunofluoresence analysis confirmed that gastrin peptide levels were decreased in antisense and shRNA tumors. Gastrin knockdown clones had lower Ki-67 and increased cleaved caspase-3 staining, consistent with known effects of gastrin on proliferation and apoptosis. Tumors in mice treated with gastrin siRNA were smaller than controls. Conclusions These results suggest that RNAi targeting of gastrin could serve as an effective treatment for pancreatic cancer. PMID:19465883

Decreased expression of MUC1 induces apoptosis and inhibits migration in pancreatic cancer PANC-1 cells via regulation of Slug pathway.

PubMed

Zhao, Ping; Meng, Meng; Xu, Bin; Dong, Aiping; Ni, Guangzhen; Lu, Lianfang

2017-12-06

MUC1, a membrane tethered mucin glycoprotein, is overexpressed in > 60% of human pancreatic cancers (PCs), and is associated with poor prognosis and enhanced metastasis. Here, we report the effect of silencing MUC1 expression on the growth, migration and invasive ability of pancreatic cancer cells, and explored its mechanisms. We observed that siRNA mediated suppression of the MUC1 expression significantly reduced invasive and migrative capability and induced apoptosis of the pancreatic cancer PANC-1 cells. We found that Slug was inhibited in the MUC1 siRNA transfected PANC-1 cells (MUC1 siRNA/PANC-1 cells). Expression of PUMA and E-cadherin was increased in the MUC1 siRNA/PANC-1 cells. PANC-1 cells overexpressing full long Slug gene (when transfected with Slug cDNA plasmid) significantly inhibited PUMA and E-cadherin expression in the MUC1 siRNA/PANC-1 cells. Silencing PUMA expression inhibited apoptosis in the MUC1 siRNA transfected PANC-1 cells (MUC1 siRNA/PANC-1 cells). Silencing E-cadherin expression restored the invasion and migration ability in the MUC1 siRNA/PANC-1 cells. We therefore concluded that silencing MUC1 expression inhibited migration and invasion, and induced apoptosis of PANC-1 cells via downregulation of Slug and upregulation of Slug dependent PUMA and E-cadherin expression. MUC1 could serve as a potential therapeutic target in pancreatic cancer.

Oxidative stress and NO generation in the rat pancreatitis induced by pancreatic duct ligation.

PubMed

Buchwalow, Igor; Schnekenburger, Jürgen; Atiakshin, Dmitri; Samoilova, Vera; Wolf, Eduard; Boecker, Werner; Tiemann, Katharina

2017-04-01

The interaction between nitric oxide (NO) and superoxides is critical in the development of an acute pancreatitis. Previously, we reported that the expression of superoxides and of the NO-generating enzyme (NO synthase, NOS) was up-regulated in the human pancreatitis, especially within the exocrine compartment indicating an exceptional susceptibility of the exocrine parenchyma to oxidative stress. The aim of the present study was to compare the regulation of NO signalling pathways in the human pancreatitis and in an animal model of an acute pancreatitis induced by pancreatic duct ligation (PDL) in rats. In the PDL-induced rat pancreatitis, we revealed a similar pattern of oxidative stress and NOS up-regulation in acinar and in ductal compartments, like in the human pancreatitis. This demonstrates that the PDL-induced rat pancreatitis is a proper model for further studies of acute pancreatitis development in humans. Copyright © 2017 Elsevier GmbH. All rights reserved.

Parp-1 genetic ablation in Ela-myc mice unveils novel roles for Parp-1 in pancreatic cancer.

PubMed

Martínez-Bosch, Neus; Iglesias, Mar; Munné-Collado, Jessica; Martínez-Cáceres, Carlos; Moreno, Mireia; Guerra, Carmen; Yélamos, Jose; Navarro, Pilar

2014-10-01

Pancreatic cancer has a dismal prognosis and is currently the fourth leading cause of cancer-related death in developed countries. The inhibition of poly(ADP-ribose) polymerase-1 (Parp-1), the major protein responsible for poly(ADP-ribosy)lation in response to DNA damage, has emerged as a promising treatment for several tumour types. Here we aimed to elucidate the involvement of Parp-1 in pancreatic tumour progression. We assessed Parp-1 protein expression in normal, preneoplastic and pancreatic tumour samples from humans and from K-Ras- and c-myc-driven mouse models of pancreatic cancer. Parp-1 was highly expressed in acinar cells in normal and cancer tissues. In contrast, ductal cells expressed very low or undetectable levels of this protein, both in a normal and in a tumour context. The Parp-1 expression pattern was similar in human and mouse samples, thereby validating the use of animal models for further studies. To determine the in vivo effects of Parp-1 depletion on pancreatic cancer progression, Ela-myc-driven pancreatic tumour development was analysed in a Parp-1 knock-out background. Loss of Parp-1 resulted in increased tumour necrosis and decreased proliferation, apoptosis and angiogenesis. Interestingly, Ela-myc:Parp-1(-/-) mice displayed fewer ductal tumours than their Ela-myc:Parp-1(+/+) counterparts, suggesting that Parp-1 participates in promoting acinar-to-ductal metaplasia, a key event in pancreatic cancer initiation. Moreover, impaired macrophage recruitment can be responsible for the ADM blockade found in the Ela-myc:Parp-1(-/-) mice. Finally, molecular analysis revealed that Parp-1 modulates ADM downstream of the Stat3-MMP7 axis and is also involved in transcriptional up-regulation of the MDM2, VEGFR1 and MMP28 cancer-related genes. In conclusion, the expression pattern of Parp-1 in normal and cancer tissue and the in vivo functional effects of Parp-1 depletion point to a novel role for this protein in pancreatic carcinogenesis and shed light

Deletion Of XIAP reduces the severity of acute pancreatitis via regulation of cell death and nuclear factor-κB activity

PubMed Central

Liu, Yong; Chen, Xiao-Dong; Yu, Jiang; Chi, Jun-Lin; Long, Fei-Wu; Yang, Hong-Wei; Chen, Ke-Ling; Lv, Zhao-Ying; Zhou, Bin; Peng, Zhi-Hai; Sun, Xiao-Feng; Li, Yuan; Zhou, Zong-Guang

2017-01-01

Severe acute pancreatitis (SAP) still remains a clinical challenge, not only for its high mortality but the uncontrolled inflammatory progression from acute pancreatitis (AP) to SAP. Cell death, including apoptosis and necrosis are critical pathology of AP, since the severity of pancreatitis correlates directly with necrosis and inversely with apoptosis Therefore, regulation of cell death from necrosis to apoptosis may have practicably therapeutic value. X-linked inhibitor of apoptosis protein (XIAP) is the best characterized member of the inhibitor of apoptosis proteins (IAP) family, but its function in AP remains unclear. In the present study, we investigated the potential role of XIAP in regulation of cell death and inflammation during acute pancreatitis. The in vivo pancreatitis model was induced by the administration of cerulein with or without lipopolysaccharide (LPS) or by the administration of l-arginine in wild-type or XIAP-deficient mice, and ex vivo model was induced by the administration of cerulein+LPS in AR42J cell line following XIAP inhibition. The severity of acute pancreatitis was determined by serum amylase activity and histological grading. XIAP deletion on cell apoptosis, necrosis and inflammatory response were examined. Caspases activities, nuclear factor-κB (NF-κB) activation and receptor-interacting protein kinase1 (RIP1) degradation were assessed by western blot. Deletion of XIAP resulted in the reduction of amylase activity, decrease of NF-κB activation and less release of TNF-α and IL-6, together with increased caspases activities and RIP1 degradation, leading to enhanced apoptosis and reduced necrosis in pancreatic acinar cells and ameliorated the severity of acute pancreatitis. Our results indicate that deletion of XIAP switches cell death away from necrosis to apoptosis and decreases the inflammatory response, effectively attenuating the severity of AP/SAP. The critical role of XIAP in cell death and inflammation suggests that

Hereditary chronic pancreatitis

PubMed Central

Rosendahl, Jonas; Bödeker, Hans; Mössner, Joachim; Teich, Niels

2007-01-01

Hereditary chronic pancreatitis (HCP) is a very rare form of early onset chronic pancreatitis. With the exception of the young age at diagnosis and a slower progression, the clinical course, morphological features and laboratory findings of HCP do not differ from those of patients with alcoholic chronic pancreatitis. As well, diagnostic criteria and treatment of HCP resemble that of chronic pancreatitis of other causes. The clinical presentation is highly variable and includes chronic abdominal pain, impairment of endocrine and exocrine pancreatic function, nausea and vomiting, maldigestion, diabetes, pseudocysts, bile duct and duodenal obstruction, and rarely pancreatic cancer. Fortunately, most patients have a mild disease. Mutations in the PRSS1 gene, encoding cationic trypsinogen, play a causative role in chronic pancreatitis. It has been shown that the PRSS1 mutations increase autocatalytic conversion of trypsinogen to active trypsin, and thus probably cause premature, intrapancreatic trypsinogen activation disturbing the intrapancreatic balance of proteases and their inhibitors. Other genes, such as the anionic trypsinogen (PRSS2), the serine protease inhibitor, Kazal type 1 (SPINK1) and the cystic fibrosis transmembrane conductance regulator (CFTR) have been found to be associated with chronic pancreatitis (idiopathic and hereditary) as well. Genetic testing should only be performed in carefully selected patients by direct DNA sequencing and antenatal diagnosis should not be encouraged. Treatment focuses on enzyme and nutritional supplementation, pain management, pancreatic diabetes, and local organ complications, such as pseudocysts, bile duct or duodenal obstruction. The disease course and prognosis of patients with HCP is unpredictable. Pancreatic cancer risk is elevated. Therefore, HCP patients should strongly avoid environmental risk factors for pancreatic cancer. PMID:17204147

Inhibition of NFκB and Pancreatic Cancer Cell and Tumor Growth by Curcumin Is Dependent on Specificity Protein Down-regulation*

PubMed Central

Jutooru, Indira; Chadalapaka, Gayathri; Lei, Ping; Safe, Stephen

2010-01-01

Curcumin activates diverse anticancer activities that lead to inhibition of cancer cell and tumor growth, induction of apoptosis, and antiangiogenic responses. In this study, we observed that curcumin inhibits Panc28 and L3.6pL pancreatic cancer cell and tumor growth in nude mice bearing L3.6pL cells as xenografts. In addition, curcumin decreased expression of p50 and p65 proteins and NFκB-dependent transactivation and also decreased Sp1, Sp3, and Sp4 transcription factors that are overexpressed in pancreatic cancer cells. Because both Sp transcription factors and NFκB regulate several common genes such as cyclin D1, survivin, and vascular endothelial growth factor that contribute to the cancer phenotype, we also investigated interactions between Sp and NFκB transcription factors. Results of Sp1, Sp3, and Sp4 knockdown by RNA interference demonstrate that both p50 and p65 are Sp-regulated genes and that inhibition of constitutive or tumor necrosis factor-induced NFκB by curcumin is dependent on down-regulation of Sp1, Sp3, and Sp4 proteins by this compound. Curcumin also decreased mitochondrial membrane potential and induced reactive oxygen species in pancreatic cancer cells, and this pathway is required for down-regulation of Sp proteins in these cells, demonstrating that the mitochondriotoxic effects of curcumin are important for its anticancer activities. PMID:20538607

Oxymatrine induces human pancreatic cancer PANC-1 cells apoptosis via regulating expression of Bcl-2 and IAP families, and releasing of cytochrome c

PubMed Central

2011-01-01

Background Oxymatrine, an isolated extract from traditional Chinese herb Sophora Flavescens Ait, has been traditionally used for therapy of anti-hepatitis B virus, anti-inflammation and anti-anaphylaxis. The present study was to investigate the anti-cancer effect of oxymatrine on human pancreatic cancer PANC-1 cells, and its possible molecular mechanism. Methods The effect of oxymatrine on the viability and apoptosis was examined by methyl thiazolyl tetrazolium and flow cytometry analysis. The expression of Bax, Bcl-2, Bcl-x (L/S), Bid, Bad, HIAP-1, HIAP-2, XIAP, NAIP, Livin and Survivin genes was accessed by RT-PCR. The levels of cytochrome c and caspase 3 protein were assessed by Western blotting. Results Oxymatrine inhibited cell viability and induced apoptosis of PANC-1 cells in a time- and dose-dependent manner. This was accompanied by down-regulated expression of Livin and Survivin genes while the Bax/Bcl-2 ratio was upregulated. Furthermore, oxymatrine treatment led to the release of cytochrome c and activation of caspase-3 proteins. Conclusion Oxymatrine can induce apoptotic cell death of human pancreatic cancer, which might be attributed to the regulation of Bcl-2 and IAP families, release of mitochondrial cytochrome c and activation of caspase-3. PMID:21714853

MUC1 enhances tumor progression and contributes toward immunosuppression in a mouse model of spontaneous pancreatic adenocarcinoma.

PubMed

Tinder, Teresa L; Subramani, Durai B; Basu, Gargi D; Bradley, Judy M; Schettini, Jorge; Million, Arefayene; Skaar, Todd; Mukherjee, Pinku

2008-09-01

MUC1, a membrane tethered mucin glycoprotein, is overexpressed and aberrantly glycosylated in >80% of human ductal pancreatic adenocarcinoma. However, the role of MUC1 in pancreatic cancer has been elusive, partly due to the lack of an appropriate model. We report the characterization of a novel mouse model that expresses human MUC1 as a self molecule (PDA.MUC1 mice). Pancreatic tumors arise in an appropriate MUC1-tolerant background within an immune-competent host. Significant enhancement in the development of pancreatic intraepithelial preneoplastic lesions and progression to adenocarcinoma is observed in PDA.MUC1 mice, possibly due to increased proliferation. Tumors from PDA.MUC1 mice express higher levels of cyclooxygenase-2 and IDO compared with PDA mice lacking MUC1, especially during early stages of tumor development. The increased proinflammatory milieu correlates with an increased percentage of regulatory T cells and myeloid suppressor cells in the pancreatic tumor and tumor draining lymph nodes. Data shows that during pancreatic cancer progression, MUC1-mediated mechanisms enhance the onset and progression of the disease, which in turn regulate the immune responses. Thus, the mouse model is ideally suited for testing novel chemopreventive and therapeutic strategies against pancreatic cancer.

MUC1 enhances tumor progression and contributes towards immunosuppression in a mouse model of spontaneous pancreatic adenocarcinoma

PubMed Central

Tinder, Teresa L.; Subramani, Durai B.; Basu, Gargi D.; Bradley, Judy M.; Schettini, Jorge; Million, Arefayene; Skaar, Todd

2008-01-01

MUC1, a membrane tethered mucin glycoprotein, is overexpressed and aberrantly glycosylated in >80% of human ductal pancreatic adenocarcinoma. However, the role of MUC1 in pancreatic cancer has been elusive, partly due to the lack of an appropriate model. We report the characterization of a novel mouse model that expresses human MUC1 as a self molecule (PDA.MUC1 mice). Pancreatic tumors arise in an appropriate MUC1-tolerant background within an immune competent host. Significant enhancement in the development of pancreatic intraepithelial pre-neoplastic lesions (PanINs) and progression to adenocarcinoma is observed in PDA.MUC1 mice, possibly due to increased proliferation. Tumors from PDA.MUC1 mice express higher levels of cyclooxygenase-2 and indoleamine 2,3, dioxygenase compared to PDA mice lacking MUC1, especially during early stages of tumor development. The increased pro-inflammatory milieu correlates with an increased percentage of regulatory T cells and myeloid suppressor cells in the pancreatic tumor and tumor draining lymph nodes. Data shows that during pancreatic cancer progression, MUC1-mediated mechanisms enhance the onset and progression of the disease which in turn regulate the immune responses. Thus, the mouse model is ideally-suited for testing novel chemopreventive and therapeutic strategies against pancreatic cancer. PMID:18713982

A decrease in miR-150 regulates the malignancy of pancreatic cancer by targeting c-Myb and MUC4.

PubMed

Yang, Ke; He, Miaoxia; Cai, Zailong; Ni, Canrong; Deng, Jingjing; Ta, Na; Xu, Jingjing; Zheng, Jianming

2015-04-01

Pancreatic cancer is an aggressive cancer with high mortality. Conventional treatments have little impact on its progression. Limited research investigating the role of oncogene miR-150 specifically in pancreatic cancer has been published. The purpose of this study was to determine the tumorigenesis of miR-150 in pancreatic cancer. One hundred six pancreatic ductal adenocarcinomas were analyzed together with their adjacent benign pancreatic tissues. The associations of miR-150, c-Myb, and MUC4 expression with survival rates were determined. Functional studies on miR-150 in pancreatic cancer were used to assess its effect on proliferation and malignancy in several pancreatic cell lines. miR-150 expression was significantly down-regulated in pancreatic ductal adenocarcinoma tissues compared with adjacent benign pancreatic tissues. Patients with low miR-150 expression had significantly higher mortality rates than those with high miR-150 expression. The in vitro and in vivo assays of pancreatic cancer cells showed that miR-150 overexpression leads to reduced cell growth, clonogenicity, migration, invasion, modular cell cycles, and induced apoptosis. Moreover, miR-150 expression was inversely correlated with c-Myb and MUC4 activities in pancreatic tissue, cell lines, and nude mouse model. miR-150 is an important suppressor of pancreatic ductal carcinoma and acts as a regulator of c-Myb and MUC4 in aggressive progress.

Environmental risk factors for chronic pancreatitis and pancreatic cancer.

PubMed

Nitsche, Claudia; Simon, Peter; Weiss, F Ulrich; Fluhr, Gabriele; Weber, Eckhard; Gärtner, Simone; Behn, Claas O; Kraft, Matthias; Ringel, Jörg; Aghdassi, Ali; Mayerle, Julia; Lerch, Markus M

2011-01-01

Chronic pancreatitis has long been thought to be mainly associated with immoderate alcohol consumption. The observation that only ∼10% of heavy drinkers develop chronic pancreatitis not only suggests that other environmental factors, such as tobacco smoke, are potent additional risk factors, but also that the genetic component of pancreatitis is more common than previously presumed. Either disease-causing or protective traits have been indentified for mutations in different trypsinogen genes, the gene for the trypsin inhibitor SPINK1, chymotrypsinogen C, and the cystic fibrosis transmembane conductance regulator (CFTR). Other factors that have been proposed to contribute to pancreatitis are obesity, diets high in animal protein and fat, as well as antioxidant deficiencies. For the development of pancreatic cancer, preexisting chronic pancreatitis, more prominently hereditary pancreatitis, is a risk factor. The data on environmental risk factors for pancreatic cancer are, with the notable exception of tobacco smoke, either sparse, unconfirmed or controversial. Obesity appears to increase the risk of pancreatic cancer in the West but not in Japan. Diets high in processed or red meat, diets low in fruits and vegetables, phytochemicals such as lycopene and flavonols, have been proposed and refuted as risk or protective factors in different trials. The best established and single most important risk factor for cancer as well as pancreatitis and the one to clearly avoid is tobacco smoke. Copyright © 2011 S. Karger AG, Basel.

MiR-338 controls BPA-triggered pancreatic islet insulin secretory dysfunction from compensation to decompensation by targeting Pdx-1.

PubMed

Wei, Jie; Ding, Dongxiao; Wang, Tao; Liu, Qiong; Lin, Yi

2017-12-01

Bisphenol A (BPA) can disrupt glucose homeostasis and impair pancreatic islet function; however, the mechanisms behind these effects are poorly understood. Male mice (4 wk old) were treated with BPA (50 or 500 μg/kg/d) for 8 wk. Whole-body glucose homeostasis, pancreatic islet morphology and function, and miR-338-mediated molecular signal transduction analyses were examined. We showed that BPA treatment led to a disruption of glucose tolerance and a compensatory increase of pancreatic islets insulin secretion and pancreatic and duodenal homeobox 1 ( Pdx1 ) expression in mice. Inhibition of Pdx1 reduced glucose-stimulated insulin secretion and ATP production in the islets of BPA-exposed mice. Based on primary pancreatic islets, we also confirmed that miR-338 regulated Pdx1 and thus contributed to BPA-induced insulin secretory dysfunction from compensation to decompensation. Short-term BPA exposure downregulated miR-338 through activation of G-protein-coupled estrogen receptor 1 (Gpr30), whereas long-term BPA exposure upregulated miR-338 through suppression of glucagon-like peptide 1 receptor (Glp1r). Taken together, our results reveal a molecular mechanism, whereby BPA regulates Gpr30/Glp1r to mediate the expression of miR-338, which acts to control Pdx1-dependent insulin secretion. The Gpr30/Glp1r-miR-338-Pdx1 axis should be represented as a novel mechanism by which BPA induces insulin secretory dysfunction in pancreatic islets.-Wei, J., Ding, D., Wang, T., Liu, Q., Lin, Y. MiR-338 controls BPA-triggered pancreatic islet insulin secretory dysfunction from compensation to decompensation by targeting Pdx-1. © FASEB.

Proteomic differential display analysis for TS-1-resistant and -sensitive pancreatic cancer cells using two-dimensional gel electrophoresis and mass spectrometry.

PubMed

Yoshida, Kanako; Kuramitsu, Yasuhiro; Murakami, Kohei; Ryozawa, Shomei; Taba, Kumiko; Kaino, Seiji; Zhang, Xiulian; Sakaida, Isao; Nakamura, Kazuyuki

2011-06-01

TS-1 is an oral anticancer agent containing two biochemical modulators for 5-fluorouracil (5-FU) and tegafur (FT), a metabolically activated prodrug of 5-FU. TS-1 has been recognized as an effective anticancer drug using standard therapies for patients with advanced pancreatic cancer along with gemcitabine. However, a high level of inherent and acquired tumor resistance to TS-1 induces difficulty in the treatment. To identify proteins linked to the TS-1-resistance of pancreatic cancer, we profiled protein expression levels in samples of TS-1-resistant and -sensitive pancreatic cancer cell lines by using two-dimensional gel electrophoresis (2-DE) and liquid chromatography-tandem mass spectrometry (LC-MS/MS). The cytotoxicity of a 5-FU/5-chloro-2,4-dihydroxypyridine (CDHP) combination towards pancreatic cancer cell lines was evaluated by MTS assay. Panc-1, BxPC-3, MiaPaCa-2 and PK59 showed high sensitivity to the 5-FU/CDHP combination (TS-1-sensitive), whereas PK45p and KLM-1 were much less sensitive (TS-1-resistant). Proteomic analysis showed that eleven spots, including T-complex protein 1 subunit beta, ribonuclease inhibitor, elongation factor 1-delta, peroxiredoxin-2 and superoxide dismutase (Cu-Zn), appeared to be down-regulated, and 29 spots, including hypoxia up-regulated protein 1, lamin-A/C, endoplasmin, fascin and annexin A1, appeared to be up-regulated in TS-1-resistant cells compared with -sensitive cells. These results suggest that the identified proteins showing different expression between TS-1-sensitive and -resistant pancreatic cancer cells possibly relate to TS-1-sensitivity. These findings could be useful to overcome the TS-1-resistance of pancreatic cancer cells.

Active Hexose-correlated Compound Down-regulates Heat Shock Factor 1, a Transcription Factor for HSP27, in Gemcitabine-resistant Human Pancreatic Cancer Cells.

PubMed

Tokunaga, Masayuki; Baron, Byron; Kitagawa, Takao; Tokuda, Kazuhiro; Kuramitsu, Yasuhiro

2015-11-01

Active hexose-correlated compound (AHCC) is an extract of a basidiomycete mushroom that enhances the therapeutic effects and reduces the side-effects of chemotherapy. Our previous studies demonstrated that heat-shock protein 27 (HSP27) was involved in gemcitabine-resistance of pancreatic cancer cells and it was down-regulated by AHCC-treatment. However, how AHCC down-regulated HSP27 is unknown. In the present study, we focused on two transcription factors reported to induce HSP27, heat shock factor 1 (HSF1) and high-mobility group box 1 (HMGB1) and investigated the effect of AHCC on their expression. KLM1-R cells were treated with AHCC and the protein expression of HSF1 and HMGB1 were analyzed by western blotting. The protein expression of HSF1 in KLM1-R was down-regulated by AHCC treatment. On the other hand, the protein expression of HMGB1 was not reduced in KLM1-R cells after AHCC treatment. The possibility that AHCC down-regulated HSP27 through down-regulation of the HSF1, was herein shown. Copyright© 2015 International Institute of Anticancer Research (Dr. John G. Delinassios), All rights reserved.

The role of cholinergic and peptidergic pathways in the regulation of pancreatic exocrine function during postnatal development in pigs.

PubMed

Lesniewska, V; Gregard, A; Weström, B; Hedemann, M S; Laerke, H N; Kruszewska, D; Pierzynowski, S G

2001-05-01

The aim of this study was to investigate the role of the parasympathetic (cholinergic and peptidergic) nervous system in the regulation of exocrine pancreas function in piglets during their early postnatal development. The cholinergic and peptidergic regulatory pathways of exocrine pancreatic function were tested by the specific muscarinic receptor blocker 4-diphenylacetoxy-N-methylpiperidine-methiodide (4-DAMP) and bombesin, respectively. At the age of 2 weeks, piglets were surgically fitted with a chronic pancreatic duct catheter, a duodenal re-entrant cannula and a jugular vein catheter. The experiments comprised a pre-weaning period, and a post-weaning period that commenced at the beginning of the 5th week of age. Intravenous infusion of 4-DAMP (100 pmol x kg(-1) x h(-1)) reduced the outflow of pancreatic juice, the output of total protein and the activity of trypsin, chymotrypsin, carboxyl ester hydrolase and amylase during preprandial and postprandial pancreatic secretion, in both the pre- and post-weaning periods. However, the inhibitory effect of 4-DAMP during postprandial secretion was significantly greater (P < 0.05) in suckling piglets. The infusion of bombesin (10, 100 and 1000 pmol x kg(-1) x h(-1)) stimulated exocrine pancreatic secretion in a dose-dependent manner during both the pre- and post-weaning periods. However, the stimulatory effect of 1000 pmol x kg(-1) x h(-1) bombesin on total protein output and the activities of trypsin, chymotrypsin and amylase were significantly higher (P < 0.05) in suckling piglets. In summary, our study showed that cholinergic and peptidergic mechanisms are involved in the regulation of exocrine pancreas function in piglets in both the pre- and post-weaning stages. 4-DAMP had a greater inhibitory effect on exocrine pancreatic secretion in piglets during the pre-weaning period. Thus, these observations suggest that the parasympathetic nervous system plays a dominant role in the functioning of the exocrine pancreas at

Smad4 inhibits cell migration via suppression of JNK activity in human pancreatic carcinoma PANC-1 cells.

PubMed

Zhang, Xueying; Cao, Junxia; Pei, Yujun; Zhang, Jiyan; Wang, Qingyang

2016-05-01

Smad4 is a common Smad and is a key downstream regulator of the transforming growth factor-β signaling pathway, in which Smad4 often acts as a potent tumor suppressor and functions in a highly context-dependent manner, particularly in pancreatic cancer. However, little is known regarding whether Smad4 regulates other signaling pathways involved in pancreatic cancer. The present study demonstrated that Smad4 downregulates c-Jun N-terminal kinase (JNK) activity using a Smad4 loss-of-function or gain-of-function analysis. Additionally, stable overexpression of Smad4 clearly affected the migration of human pancreatic epithelioid carcinoma PANC-1 cells, but did not affect cell growth. In addition, the present study revealed that upregulation of mitogen-activated protein kinase phosphatase-1 is required for the reduction of JNK activity by Smad4, leading to a decrease in vascular endothelial growth factor expression and inhibiting cell migration. Overall, the present findings indicate that Smad4 may suppress JNK activation and inhibit the tumor characteristics of pancreatic cancer cells.

Chronic pancreatitis associated with the p.G208A variant of PRSS1 gene in a European patient.

PubMed

Hegyi, Eszter; Cierna, Iveta; Vavrova, Ludmila; Ilencikova, Denisa; Konecny, Michal; Kovacs, Laszlo

2014-01-10

The major etiologic factor of chronic pancreatitis in adults is excessive alcohol consumption, whereas among children structural anomalies, systemic and metabolic disorders, and genetic factors are prevalent. Mutations in the cationic trypsinogen gene (PRSS1) cause hereditary pancreatitis, while mutations in serine protease inhibitor Kazal type 1 (SPINK1), cystic fibrosis transmembrane conductance regulator (CFTR) and chymotrypsin C (CTRC) genes have been shown to associate with chronic pancreatitis as independent risk factors. We present a case of 13-year-old boy with idiopathic chronic pancreatitis. Given the unexplained attacks of pancreatitis since early childhood and despite the negative family history, molecular-genetic analysis of four pancreatitis susceptibility genes (PRSS1, SPINK1, CTRC and CFTR) was performed. The boy was found to carry the c.623G>C (p.G208A) mutation of the PRSS1 gene and the c.180C>T (p.G60G) mutation of the CTRC gene, both in heterozygous state. These mutations are considered as contributing risk factors for chronic pancreatitis. In children with idiopathic chronic pancreatitis genetic causes should be considered, even in absence of positive family history. To the best of our knowledge, this is the first description of a European patient with chronic pancreatitis associated with the p.G208A mutation of PRSS1 gene. This mutation was previously reported only in Asian subjects and is thought to be a unique genetic cause of pancreatitis in Asia.

PDX-1 Is a Therapeutic Target for Pancreatic Cancer, Insulinoma and Islet Neoplasia Using a Novel RNA Interference Platform

PubMed Central

Liu, Shi-He; Rao, Donald D.; Nemunaitis, John; Senzer, Neil; Zhou, Guisheng; Dawson, David; Gingras, Marie-Claude; Wang, Zhaohui; Gibbs, Richard; Norman, Michael; Templeton, Nancy S.; DeMayo, Francesco J.; O'Malley, Bert; Sanchez, Robbi; Fisher, William E.; Brunicardi, F. Charles

2012-01-01

Pancreatic and duodenal homeobox-1 (PDX-1) is a transcription factor that regulates insulin expression and islet maintenance in the adult pancreas. Our recent studies demonstrate that PDX-1 is an oncogene for pancreatic cancer and is overexpressed in pancreatic cancer. The purpose of this study was to demonstrate that PDX-1 is a therapeutic target for both hormonal symptoms and tumor volume in mouse models of pancreatic cancer, insulinoma and islet neoplasia. Immunohistochemistry of human pancreatic and islet neoplasia specimens revealed marked PDX-1 overexpression, suggesting PDX-1 as a “drugable” target within these diseases. To do so, a novel RNA interference effector platform, bifunctional shRNAPDX-1, was developed and studied in mouse and human cell lines as well as in mouse models of pancreatic cancer, insulinoma and islet neoplasia. Systemic delivery of bi-shRNAhumanPDX-1 lipoplexes resulted in marked reduction of tumor volume and improved survival in a human pancreatic cancer xenograft mouse model. bi-shRNAmousePDX-1 lipoplexes prevented death from hyperinsulinemia and hypoglycemia in an insulinoma mouse model. shRNAmousePDX-1 lipoplexes reversed hyperinsulinemia and hypoglycemia in an immune-competent mouse model of islet neoplasia. PDX-1 was overexpressed in pancreatic neuroendocrine tumors and nesidioblastosis. These data demonstrate that PDX-1 RNAi therapy controls hormonal symptoms and tumor volume in mouse models of pancreatic cancer, insulinoma and islet neoplasia, therefore, PDX-1 is a potential therapeutic target for these pancreatic diseases. PMID:22905092

Peripancreatic fat necrosis worsens acute pancreatitis independent of pancreatic necrosis via unsaturated fatty acids increased in human pancreatic necrosis collections

PubMed Central

Noel, Pawan; Patel, Krutika; Durgampudi, Chandra; Trivedi, Ram N; de Oliveira, Cristiane; Crowell, Michael D; Pannala, Rahul; Lee, Kenneth; Brand, Randall; Chennat, Jennifer; Slivka, Adam; Papachristou, Georgios I; Khalid, Asif; Whitcomb, David C; DeLany, James P; Cline, Rachel A; Acharya, Chathur; Jaligama, Deepthi; Murad, Faris M; Yadav, Dhiraj; Navina, Sarah; Singh, Vijay P

2016-01-01

Background and aims Peripancreatic fat necrosis occurs frequently in necrotising pancreatitis. Distinguishing markers from mediators of severe acute pancreatitis (SAP) is important since targeting mediators may improve outcomes. We evaluated potential agents in human pancreatic necrotic collections (NCs), pseudocysts (PCs) and pancreatic cystic neoplasms and used pancreatic acini, peripheral blood mononuclear cells (PBMC) and an acute pancreatitis (AP) model to determine SAP mediators. Methods We measured acinar and PBMC injury induced by agents increased in NCs and PCs. Outcomes of caerulein pancreatitis were studied in lean rats coadministered interleukin (IL)-1β and keratinocyte chemoattractant/growth-regulated oncogene, triolein alone or with the lipase inhibitor orlistat. Results NCs had higher fatty acids, IL-8 and IL-1β versus other fluids. Lipolysis of unsaturated triglyceride and resulting unsaturated fatty acids (UFA) oleic and linoleic acids induced necro-apoptosis at less than half the concentration in NCs but other agents did not do so at more than two times these concentrations. Cytokine coadministration resulted in higher pancreatic and lung inflammation than caerulein alone, but only triolein coadministration caused peripancreatic fat stranding, higher cytokines, UFAs, multisystem organ failure (MSOF) and mortality in 97% animals, which were prevented by orlistat. Conclusions UFAs, IL-1β and IL-8 are elevated in NCs. However, UFAs generated via peripancreatic fat lipolysis causes worse inflammation and MSOF, converting mild AP to SAP. PMID:25500204

MUC1 enhances invasiveness of pancreatic cancer cells by inducing epithelial to mesenchymal transition

PubMed Central

Roy, Lopamudra Das; Sahraei, Mahnaz; Subramani, Durai B.; Besmer, Dahlia; Nath, Sritama; Tinder, Teresa L.; Bajaj, Ekta; Shanmugam, Kandavel; Lee, Yong Yook; Hwang, Sun IL; Gendler, Sandra J.; Mukherjee, Pinku

2010-01-01

Increased motility and invasiveness of pancreatic cancer cells are associated with epithelial to mesenchymal transition (EMT). Snai1 and Slug are zinc-finger transcription factors that trigger this process by repressing E-cadherin and enhancing vimentin and N-Cadherin protein expression. However, the mechanisms that regulate this activation in pancreatic tumors remain elusive. MUC1, a transmembrane mucin glycoprotein, is associated with the most invasive forms of pancreatic adenocarcinomas (PDA). In this study, we show that over expression of MUC1 in pancreatic cancer cells triggers the molecular process of EMT which translates to increased invasiveness and metastasis. EMT was significantly reduced when Muc1 was genetically deleted in a mouse model of PDA or when all seven tyrosines in the cytoplasmic tail of MUC1 were mutated to phenylalanine (mutated MUC1 CT). Using proteomics, RT-PCR, and Western blotting, we revealed a significant increase in vimentin, Slug and Snail expression with repression of E-Cadherin in MUC1-expressing cells compared to cells expressing the mutated MUC1 CT. In the cells that carried the mutated MUC1 CT, MUC1 failed to co-immunoprecipitate with β-catenin and translocate to the nucleus thereby blocking transcription of the genes associated with EMT and metastasis. Thus, functional tyrosines are critical in stimulating the interactions between MUC1 and β-catenin and their nuclear translocation to initiate the process of EMT. This study signifies the oncogenic role of MUC1 CT and is the first to identify a direct role of the MUC1 in initiating EMT during pancreatic cancer. The data may have implications in future design of MUC1-targeted therapies for pancreatic cancer. PMID:21102519

MUC1 enhances invasiveness of pancreatic cancer cells by inducing epithelial to mesenchymal transition.

PubMed

Roy, L D; Sahraei, M; Subramani, D B; Besmer, D; Nath, S; Tinder, T L; Bajaj, E; Shanmugam, K; Lee, Y Y; Hwang, S I L; Gendler, S J; Mukherjee, P

2011-03-24

Increased motility and invasiveness of pancreatic cancer cells are associated with epithelial to mesenchymal transition (EMT). Snai1 and Slug are zinc-finger transcription factors that trigger this process by repressing E-cadherin and enhancing vimentin and N-cadherin protein expression. However, the mechanisms that regulate this activation in pancreatic tumors remain elusive. MUC1, a transmembrane mucin glycoprotein, is associated with the most invasive forms of pancreatic ductal adenocarcinomas (PDA). In this study, we show that over expression of MUC1 in pancreatic cancer cells triggers the molecular process of EMT, which translates to increased invasiveness and metastasis. EMT was significantly reduced when MUC1 was genetically deleted in a mouse model of PDA or when all seven tyrosines in the cytoplasmic tail of MUC1 were mutated to phenylalanine (mutated MUC1 CT). Using proteomics, RT-PCR and western blotting, we revealed a significant increase in vimentin, Slug and Snail expression with repression of E-Cadherin in MUC1-expressing cells compared with cells expressing the mutated MUC1 CT. In the cells that carried the mutated MUC1 CT, MUC1 failed to co-immunoprecipitate with β-catenin and translocate to the nucleus, thereby blocking transcription of the genes associated with EMT and metastasis. Thus, functional tyrosines are critical in stimulating the interactions between MUC1 and β-catenin and their nuclear translocation to initiate the process of EMT. This study signifies the oncogenic role of MUC1 CT and is the first to identify a direct role of the MUC1 in initiating EMT during pancreatic cancer. The data may have implications in future design of MUC1-targeted therapies for pancreatic cancer.

(+)-Grandifloracin, an antiausterity agent, induces autophagic PANC-1 pancreatic cancer cell death.

PubMed

Ueda, Jun-ya; Athikomkulchai, Sirivan; Miyatake, Ryuta; Saiki, Ikuo; Esumi, Hiroyasu; Awale, Suresh

2014-01-01

Human pancreatic tumors are known to be highly resistant to nutrient starvation, and this prolongs their survival in the hypovascular (austere) tumor microenvironment. Agents that retard this tolerance to nutrient starvation represent a novel antiausterity strategy in anticancer drug discovery. (+)-Grandifloracin (GF), isolated from Uvaria dac, has shown preferential toxicity to PANC-1 human pancreatic cancer cells under nutrient starvation, with a PC50 value of 14.5 μM. However, the underlying mechanism is not clear. In this study, GF was found to preferentially induce PANC-1 cell death in a nutrient-deprived medium via hyperactivation of autophagy, as evidenced by a dramatic upregulation of microtubule-associated protein 1 light chain 3. No change was observed in expression of the caspase-3 and Bcl-2 apoptosis marker proteins. GF was also found to strongly inhibit the activation of Akt, a key regulator of cancer cell survival and proliferation. Because pancreatic tumors are highly resistant to current therapies that induce apoptosis, the alternative cell death mechanism exhibited by GF provides a novel therapeutic insight into antiausterity drug candidates.

Master Regulators of Oncogenic KRAS Response in Pancreatic Cancer: An Integrative Network Biology Analysis

PubMed Central

2017-01-01

Background KRAS is the most frequently mutated gene in pancreatic ductal adenocarcinoma (PDAC), but the mechanisms underlying the transcriptional response to oncogenic KRAS are still not fully understood. We aimed to uncover transcription factors that regulate the transcriptional response of oncogenic KRAS in pancreatic cancer and to understand their clinical relevance. Methods and Findings We applied a well-established network biology approach (master regulator analysis) to combine a transcriptional signature for oncogenic KRAS derived from a murine isogenic cell line with a coexpression network derived by integrating 560 human pancreatic cancer cases across seven studies. The datasets included the ICGC cohort (n = 242), the TCGA cohort (n = 178), and five smaller studies (n = 17, 25, 26, 36, and 36). 55 transcription factors were coexpressed with a significant number of genes in the transcriptional signature (gene set enrichment analysis [GSEA] p < 0.01). Community detection in the coexpression network identified 27 of the 55 transcription factors contributing to three major biological processes: Notch pathway, down-regulated Hedgehog/Wnt pathway, and cell cycle. The activities of these processes define three distinct subtypes of PDAC, which demonstrate differences in survival and mutational load as well as stromal and immune cell composition. The Hedgehog subgroup showed worst survival (hazard ratio 1.73, 95% CI 1.1 to 2.72, coxPH test p = 0.018) and the Notch subgroup the best (hazard ratio 0.62, 95% CI 0.42 to 0.93, coxPH test p = 0.019). The cell cycle subtype showed highest mutational burden (ANOVA p < 0.01) and the smallest amount of stromal admixture (ANOVA p < 2.2e–16). This study is limited by the information provided in published datasets, not all of which provide mutational profiles, survival data, or the specifics of treatment history. Conclusions Our results characterize the regulatory mechanisms underlying the transcriptional response to oncogenic

Molecular basis of potassium channels in pancreatic duct epithelial cells

PubMed Central

Hayashi, Mikio; Novak, Ivana

2013-01-01

Potassium channels regulate excitability, epithelial ion transport, proliferation, and apoptosis. In pancreatic ducts, K+ channels hyperpolarize the membrane potential and provide the driving force for anion secretion. This review focuses on the molecular candidates of functional K+ channels in pancreatic duct cells, including KCNN4 (KCa3.1), KCNMA1 (KCa1.1), KCNQ1 (Kv7.1), KCNH2 (Kv11.1), KCNH5 (Kv10.2), KCNT1 (KCa4.1), KCNT2 (KCa4.2), and KCNK5 (K2P5.1). We will give an overview of K+ channels with respect to their electrophysiological and pharmacological characteristics and regulation, which we know from other cell types, preferably in epithelia, and, where known, their identification and functions in pancreatic ducts and in adenocarcinoma cells. We conclude by pointing out some outstanding questions and future directions in pancreatic K+ channel research with respect to the physiology of secretion and pancreatic pathologies, including pancreatitis, cystic fibrosis, and cancer, in which the dysregulation or altered expression of K+ channels may be of importance. PMID:23962792

The acinar differentiation determinant PTF1A inhibits initiation of pancreatic ductal adenocarcinoma

PubMed Central

Krah, Nathan M; De La O, Jean-Paul; Swift, Galvin H; Hoang, Chinh Q; Willet, Spencer G; Chen Pan, Fong; Cash, Gabriela M; Bronner, Mary P; Wright, Christopher VE; MacDonald, Raymond J; Murtaugh, L Charles

2015-01-01

Understanding the initiation and progression of pancreatic ductal adenocarcinoma (PDAC) may provide therapeutic strategies for this deadly disease. Recently, we and others made the surprising finding that PDAC and its preinvasive precursors, pancreatic intraepithelial neoplasia (PanIN), arise via reprogramming of mature acinar cells. We therefore hypothesized that the master regulator of acinar differentiation, PTF1A, could play a central role in suppressing PDAC initiation. In this study, we demonstrate that PTF1A expression is lost in both mouse and human PanINs, and that this downregulation is functionally imperative in mice for acinar reprogramming by oncogenic KRAS. Loss of Ptf1a alone is sufficient to induce acinar-to-ductal metaplasia, potentiate inflammation, and induce a KRAS-permissive, PDAC-like gene expression profile. As a result, Ptf1a-deficient acinar cells are dramatically sensitized to KRAS transformation, and reduced Ptf1a greatly accelerates development of invasive PDAC. Together, these data indicate that cell differentiation regulators constitute a new tumor suppressive mechanism in the pancreas. DOI: http://dx.doi.org/10.7554/eLife.07125.001 PMID:26151762

HIF-2α dictates the susceptibility of pancreatic cancer cells to TRAIL by regulating survivin expression

PubMed Central

Harashima, Nanae; Takenaga, Keizo; Akimoto, Miho; Harada, Mamoru

2017-01-01

Cancer cells develop resistance to therapy by adapting to hypoxic microenvironments, and hypoxia-inducible factors (HIFs) play crucial roles in this process. We investigated the roles of HIF-1α and HIF-2α in cancer cell death induced by tumor necrosis factor (TNF)-related apoptosis-inducing ligand (TRAIL) using human pancreatic cancer cell lines. siRNA-mediated knockdown of HIF-2α, but not HIF-1α, increased susceptibility of two pancreatic cancer cell lines, Panc-1 and AsPC-1, to TRAIL in vitro under normoxic and hypoxic conditions. The enhanced sensitivity to TRAIL was also observed in vivo. This in vitro increased TRAIL sensitivity was observed in other three pancreatic cancer cell lines. An array assay of apoptosis-related proteins showed that knockdown of HIF-2α decreased survivin expression. Additionally, survivin promoter activity was decreased in HIF-2α knockdown Panc-1 cells and HIF-2α bound to the hypoxia-responsive element in the survivin promoter region. Conversely, forced expression of the survivin gene in HIF-2α shRNA-expressing Panc-1 cells increased resistance to TRAIL. In a xenograft mouse model, the survivin suppressant YM155 sensitized Panc-1 cells to TRAIL. Collectively, our results indicate that HIF-2α dictates the susceptibility of human pancreatic cancer cell lines, Panc-1 and AsPC-1, to TRAIL by regulating survivin expression transcriptionally, and that survivin could be a promising target to augment the therapeutic efficacy of death receptor-targeting anti-cancer therapy. PMID:28476028

Adenylyl cyclase 3/adenylyl cyclase-associated protein 1 (CAP1) complex mediates the anti-migratory effect of forskolin in pancreatic cancer cells.

PubMed

Quinn, Sierra N; Graves, Sarai H; Dains-McGahee, Clayton; Friedman, Emilee M; Hassan, Humma; Witkowski, Piotr; Sabbatini, Maria E

2017-04-01

Pancreatic cancer is one of the most lethal human malignancies. A better understanding of the intracellular mechanism of migration and invasion is urgently needed to develop treatment that will suppress metastases and improve overall survival. Cyclic adenosine monophosphate (cyclic AMP) is a second messenger that has shown to regulate migration and invasion of pancreatic cancer cells. The rise of cyclic AMP suppressed migration and invasion of pancreatic ductal adenocarcinoma cells. Cyclic AMP is formed from cytosolic ATP by the enzyme adenylyl cyclase (AC). There are ten isoforms of ACs; nine are anchored in the plasma membrane and one is soluble. What remains unknown is the extent to which the expression of transmembrane AC isoforms is both modified in pancreatic cancer and mediates the inhibitory effect of forskolin on cell motility. Using real-time PCR analysis, ADCY3 was found to be highly expressed in pancreatic tumor tissues, resulting in a constitutive increase in cyclic AMP levels. On the other hand, ADCY2 was down-regulated. Migration, invasion, and filopodia formation in two different pancreatic adenocarcinoma cell lines, HPAC and PANC-1 deficient in AC1 or AC3, were studied. We found that AC3, upon stimulation with forskolin, enhanced cyclic AMP levels and inhibited cell migration and invasion. Unlikely to be due to a cytotoxic effect, the inhibitory effects of forskolin involved the quick formation of AC3/adenylyl cyclase-associated protein 1 (CAP1)/G-actin complex, which inhibited filopodia formation and cell motility. Using Western blotting analysis, forskolin, through AC3 activation, caused phosphorylation of CREB, but not ERK. The effect of CREB phosphorylation is likely to be associated with long-term signaling changes. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

Circulating Microvesicles from Pancreatic Cancer Accelerate the Migration and Proliferation of PANC-1 Cells.

PubMed

An, Mingrui; Zhu, Jianhui; Wu, Jing; Cuneo, Kyle C; Lubman, David M

2018-04-06

Circulating microvesicles are able to mediate long-distance cell-cell communications. It is essential to understand how microvesicles from pancreatic cancer act on other cells in the body. In this work, serum-derived microvesicles were isolated from 10 patients with locally advanced pancreatic cancer and healthy controls. Using Cell Transwell and WST-1 reagents, we found that microvesicles from pancreatic cancer accelerated migration and proliferation of PANC-1 cells. Meanwhile, the proliferation of these cancer-microvesicle-treated cells (CMTCs) was affected less by 10 μM of gemcitabine relative to healthy microvesicle-treated cells (HMTCs). Next, we optimized the filter-aided sample preparation method to increase the recovery of protein samples and then applied it to the quantification of the proteome of CMTCs and HMTCs. The peptides were labeled and analyzed by liquid chromatography-tandem mass spectrometry. In total, 4102 proteins were identified, where 35 proteins were up-regulated with 27 down-regulated in CMTCs. We verified the quantitative results of three key proteins CD44, PPP2R1A, and TP53 by Western blot. The Ingenuity Pathway Analysis revealed pathways that cancer microvesicles might participate in to promote cell migration and proliferation. These findings may provide novel clues of treatment for tumorigenesis and metastasis.

Paracrine GABA and insulin regulate pancreatic alpha cell proliferation in a mouse model of type 1 diabetes.

PubMed

Feng, Allen L; Xiang, Yun-Yan; Gui, Le; Kaltsidis, Gesthika; Feng, Qingping; Lu, Wei-Yang

2017-06-01

This study aimed to elucidate the mechanism of increased proliferation of alpha cells in recent-onset type 1 diabetes. Pancreatic beta cells express GAD and produce γ-aminobutyric acid (GABA), which inhibits alpha cell secretion of glucagon. We explored the roles of GABA in alpha cell proliferation in conditions corresponding to type 1 diabetes in a mouse model and in vitro. Type 1 diabetes was induced by injecting the mice with streptozotocin (STZ). Some of the STZ-injected mice were treated with GABA (10 mg/kg daily) for 12 days. Isolated pancreatic islets were treated with STZ or STZ together with GABA for 2 days. The effects of GABA treatment on STZ-induced alpha cell proliferation in vivo and in vitro were assessed. The effect of muscimol, a GABA receptor agonist, on αTC1-6 cell proliferation was also examined. STZ injection substantially decreased levels of GAD, GABA and insulin in pancreatic beta cells 12 h after injection; this was followed by an upsurge of phosphorylated mechanistic target of rapamycin (p-mTOR) in the alpha cells at day 1, and a significant increase in alpha cell mass at day 3. Treating STZ-injected mice with GABA largely restored the immunodetectable levels of insulin and GAD in the beta cells and significantly decreased the number of aldehyde dehydrogenase 1 family, member A3 (ALDH1a3)-positive cells, alpha cell mass and hyperglucagonaemia. STZ treatment also increased alpha cell proliferation in isolated islets, which was reversed by co-treatment with GABA. Muscimol, together with insulin, significantly lowered the level of cytosolic Ca 2+ and p-mTOR, and decreased the proliferation rate of αTC1-6 cells. GABA signalling critically controls the alpha cell population in pancreatic islets. Low intraislet GABA may contribute to alpha cell hyperplasia in early type 1 diabetes.

MUC4-mediated regulation of acute phase protein lipocalin 2 through HER2/AKT/NF-κB signaling in pancreatic cancer.

PubMed

Kaur, Sukhwinder; Sharma, Neil; Krishn, Shiv Ram; Lakshmanan, Imay; Rachagani, Satyanarayana; Baine, Michael J; Smith, Lynette M; Lele, Subodh M; Sasson, Aaron R; Guha, Sushovan; Mallya, Kavita; Anderson, Judy M; Hollingsworth, Michael A; Batra, Surinder K

2014-02-01

MUC4 shows aberrant expression in early pancreatic lesions and a high specificity for pancreatic cancer. It thus has a high potential to be a sensitive and specific biomarker. Unfortunately, its low serum level limits its diagnostic/prognostic potential. We here report that a multifaceted acute phase protein lipocalin 2, regulated by MUC4, could be a potential diagnostic/prognostic marker for pancreatic cancer. Experimental Designs and Overexpression/knockdown, luciferase reporter and molecular inhibition studies revealed that MUC4 regulates lipocalin 2 by stabilizing HER2 and stimulating AKT, which results in the activation of NF-κB. Immunohistochemical analyses of lipocalin 2 and MUC4 showed a significant positive correlation between MUC4 and lipocalin 2 in primary, metastatic tissues (Spearman correlation coefficient 0.71, P = 0.002) from rapid autopsy tissue sample from patients with pancreatic cancer as well as in serum and tissue samples from spontaneous KRASG(12)D mouse pancreatic cancer model (Spearman correlation coefficient 0.98, P < 0.05). Lipocalin 2 levels increased progressively with disease advancement (344.2 ± 22.8 ng/mL for 10 weeks to 3067.2 ± 572.6 for 50 weeks; P < 0.0001). In human pancreatic cancer cases, significantly elevated levels of lipocalin 2 were observed in patients with pancreatic cancer (148 ± 13.18 ng/mL) in comparison with controls (73.27 ± 4.9 ng/mL, P = 0.014). Analyses of pre- and postchemotherapy patients showed higher lipocalin 2 levels in prechemotherapy patients [121.7 ng/mL; 95% confidence interval (CI), 98.1-150.9] in comparison with the postchemotherapy (92.6 ng/mL; 95% CI, 76.7-111.6; P = 0.06) group. This study delineates the association and the downstream mechanisms of MUC4-regulated elevation of lipocalin-2 (via HER2/AKT/NF-κB) and its clinical significance for prognosis of pancreatic cancer. ©2013 AACR.

Clobenpropit enhances anti-tumor effect of gemcitabine in pancreatic cancer

PubMed Central

Paik, Woo Hyun; Ryu, Ji Kon; Jeong, Kyoung-Sin; Park, Jin Myung; Song, Byeong Jun; Lee, Sang Hyub; Kim, Yong-Tae; Yoon, Yong Bum

2014-01-01

AIM: To evaluate the anti-tumor effect of clobenpropit, which is a specific H3 antagonist and H4 agonist, in combination with gemcitabine in a pancreatic cancer cell line. METHODS: Three kinds of human pancreatic cancer cell lines (Panc-1, MiaPaCa-2, and AsPC-1) were used in this study. Expression of H3 and H4 receptors in pancreatic cancer cells was identified with Western blotting. Effects of clobenpropit on cell proliferation, migration and apoptosis were evaluated. Alteration of epithelial and mesenchymal markers after administration of clobenpropit was analyzed. An in vivo study with a Panc-1 xenograft mouse model was also performed. RESULTS: H4 receptors were present as 2 subunits in human pancreatic cancer cells, while there was no expression of H3 receptor. Clobenpropit inhibited cell migration and increased apoptosis of pancreatic cancer cells in combination with gemcitabine. Clobenpropit up-regulated E-cadherin, but down-regulated vimentin and matrix metalloproteinase 9 in real-time polymerase chain reaction. Also, clobenpropit inhibited tumor growth (gemcitabine 294 ± 46 mg vs combination 154 ± 54 mg, P = 0.02) and enhanced apoptosis in combination with gemcitabine (control 2.5%, gemcitabine 25.8%, clobenpropit 9.7% and combination 40.9%, P = 0.001) by up-regulation of E-cadherin and down-regulation of Zeb1 in Panc-1 xenograft mouse. CONCLUSION: Clobenpropit enhanced the anti-tumor effect of gemcitabine in pancreatic cancer cells through inhibition of the epithelial-mesenchymal transition process. PMID:25024609

MicroRNA-100 regulates pancreatic cancer cells growth and sensitivity to chemotherapy through targeting FGFR3.

PubMed

Li, Zhipeng; Li, Xu; Yu, Chao; Wang, Min; Peng, Feng; Xiao, Jie; Tian, Rui; Jiang, Jianxin; Sun, Chengyi

2014-12-01

We intended to investigate the role of microRNA 100 (miR-100) in regulating pancreatic cancer cells' growth in vitro and tumor development in vivo. QTR-PCR was used to examine the expression of miR-100 in pancreatic cancer cell lines and tumor cells from human patients. Lentivirual vector containing miR-100 mimics (lv-miR-100) was used to overexpress miR-100 in MIA PaCa-2 and FCPAC-1 cells. The effects of overexpressing miR-100 on pancreatic cancer cell proliferation and chemosensitivity to cisplatin were examined by cell proliferation essay in vitro. MIA PaCa-2 cells with endogenously overexpressed miR-100 were transplanted into null mice to examine tumor growth in vivo. The predicted target of miR-100, fibroblast growth factor receptor 3 (FGFR3), was downregulated by siRNA to examine its effect on pancreatic cancer cells. We found miR-100 was markedly underexpressed in both pancreatic cancer cell lines and tumor cells from patients. In cancer cells, transfection of lv-miR-100 was able to upregulate endogenous expression of miR-100, inhibited cancer cell proliferation, and increased sensitivities to cisplatin. Overexpressing miR-100 led to significant inhibition on tumor formation in vivo. Luciferase essay showed FGFR3 was direct target of miR-100. FGFR3 was significantly downregulated by overexpressing miR-100 in pancreatic cancer cells and knocking down FGFR3 by siRNA exerted similar effect as miR-100. Our study demonstrated that miR-100 played an important role in pancreatic cancer development, possibly through targeting FGFR3. It may become a new therapeutic target for gene therapy in patients suffered from pancreatic cancer.

miR-146a Suppresses Invasion of Pancreatic Cancer Cells

PubMed Central

Li, Yiwei; VandenBoom, Timothy G.; Wang, Zhiwei; Kong, Dejuan; Ali, Shadan; Philip, Philip A.; Sarkar, Fazlul H.

2010-01-01

The aggressive course of pancreatic cancer is believed to reflect its unusually invasive and metastatic nature, which is associated with epidermal growth factor receptor (EGFR) overexpression and NF-κB activation. MicroRNAs (miRNA) have been implicated in the regulation of various pathobiological processes in cancer, including metastasis in pancreatic cancer and in other human malignancies. In this study, we report lower expression of miR-146a in pancreatic cancer cells compared with normal human pancreatic duct epithelial cells. Reexpression of miR-146a inhibited the invasive capacity of pancreatic cancer cells with concomitant downregulation of EGFR and the NF-κB regulatory kinase interleukin 1 receptor–associated kinase 1 (IRAK-1). Cellular mechanism studies revealed crosstalk between EGFR, IRAK-1, IκBα, NF-κB, and MTA-2, a transcription factor that regulates metastasis. Treatment of pancreatic cancer cells with the natural products 3,3′-diinodolylmethane (DIM) or isoflavone, which increased miR-146a expression, caused a downregulation of EGFR, MTA-2, IRAK-1, and NF-κB, resulting in an inhibition of pancreatic cancer cell invasion. Our findings reveal DIM and isoflavone as nontoxic activators of a miRNA that can block pancreatic cancer cell invasion and metastasis, offering starting points to design novel anticancer agents. PMID:20124483

Toll-like receptor 7 regulates pancreatic carcinogenesis in mice and humans

PubMed Central

Ochi, Atsuo; Graffeo, Christopher S.; Zambirinis, Constantinos P.; Rehman, Adeel; Hackman, Michael; Fallon, Nina; Barilla, Rocky M.; Henning, Justin R.; Jamal, Mohsin; Rao, Raghavendra; Greco, Stephanie; Deutsch, Michael; Medina-Zea, Marco V.; Saeed, Usama Bin; Ego-Osuala, Melvin O.; Hajdu, Cristina; Miller, George

2012-01-01

Pancreatic ductal adenocarcinoma is an aggressive cancer that interacts with stromal cells to produce a highly inflammatory tumor microenvironment that promotes tumor growth and invasiveness. The precise interplay between tumor and stroma remains poorly understood. TLRs mediate interactions between environmental stimuli and innate immunity and trigger proinflammatory signaling cascades. Our finding that TLR7 expression is upregulated in both epithelial and stromal compartments in human and murine pancreatic cancer led us to postulate that carcinogenesis is dependent on TLR7 signaling. In a mouse model of pancreatic cancer, TLR7 ligation vigorously accelerated tumor progression and induced loss of expression of PTEN, p16, and cyclin D1 and upregulation of p21, p27, p53, c-Myc, SHPTP1, TGF-β, PPARγ, and cyclin B1. Furthermore, TLR7 ligation induced STAT3 activation and interfaced with Notch as well as canonical NF-κB and MAP kinase pathways, but downregulated expression of Notch target genes. Moreover, blockade of TLR7 protected against carcinogenesis. Since pancreatic tumorigenesis requires stromal expansion, we proposed that TLR7 ligation modulates pancreatic cancer by driving stromal inflammation. Accordingly, we found that mice lacking TLR7 exclusively within their inflammatory cells were protected from neoplasia. These data suggest that targeting TLR7 holds promise for treatment of human pancreatic cancer. PMID:23023703

Downregulated miR-506 expression facilitates pancreatic cancer progression and chemoresistance via SPHK1/Akt/NF-κB signaling

PubMed Central

Li, J; Wu, H; Li, W; Yin, L; Guo, S; Xu, X; Ouyang, Y; Zhao, Z; Liu, S; Tian, Y; Tian, Z; Ju, J; Ni, B; Wang, H

2016-01-01

The aberrant expression of microRNAs (miRNAs) has emerged as an important hallmark of cancer. However, the molecular mechanisms underlying the changes in miRNA expression remain unclear. In this study, we discovered a novel epigenetic mechanism of miR-506 regulation and investigated its functional significance in pancreatic cancer. Sequencing analysis revealed that the miR-506 promoter is highly methylated in pancreatic cancer tissues compared with non-cancerous tissues. Reduced miR-506 expression was significantly associated with clinical stage, pathologic tumor status, distant metastasis and decreased survival of pancreatic cancer patients. miR-506 inhibited cell proliferation, induced cell cycle arrest at the G1/S transition and enhanced apoptosis and chemosensitivity of pancreatic cancer cells. Furthermore, we identified sphingosine kinase 1 (SPHK1) as a novel target of miR-506, the expression of which inhibited the SPHK1/Akt/NF-κB signaling pathway, which is activated in pancreatic cancer. High SPHK1 expression was significantly associated with poor survival in a large cohort of pancreatic cancer specimens. Our data suggest that miR-506 acts as a tumor suppressor miRNA and is epigenetically silenced in pancreatic cancer. The newly identified miR-506/SPHK1 axis represents a novel therapeutic strategy for future pancreatic cancer treatment. PMID:27065335

JWA gene regulates PANC-1 pancreatic cancer cell behaviors through MEK-ERK1/2 of the MAPK signaling pathway.

PubMed

Wu, Yuan-Yuan; Ma, Tie-Liang; Ge, Zhi-Jun; Lin, Jie; Ding, Wei-Liang; Feng, Jia-Ke; Zhou, Su-Jun; Chen, Guo-Chang; Tan, Yong-Fei; Cui, Guo-Xing

2014-10-01

The present study aimed to investigate the role of JWA gene in the proliferation, apoptosis, invasion and migration of PANC-1 pancreatic cancer cells and the effect on the MAPK signaling pathway. Human PANC-1 pancreatic cancer cells were cultured in vitro , and small interfering RNA (siRNA) was designed for the JWA gene. The siRNA was transfected into PANC-1 cells. Subsequently, the cell proliferation was measured by MTT assay; cell apoptosis was detected by analyzing BAX and Bcl-2 protein expression; cell migration and invasion were measured using Transwell ® chambers; and the protein expression of JWA and ERK1/2, JNK and p38 and their phosphorylated forms were measured by western blotting. By utilizing the MTT assay, the results showed that when JWA protein expression was inhibited, the proliferation of PANC-1 cells was enhanced. In addition, the expression of apoptosis-associated protein (AAP) BAX was substantially decreased, while the expression of the apoptosis inhibitor gene, Bcl-2 , was significantly enhanced. Using Transwell chambers, it was found that the number of penetrating PANC-1 cells was significantly increased after transfection with JWA siRNA, suggesting that the migration and invasion of the cells was substantially increased. By studying the association between JWA and the MAPK pathway in PANC-1 cells, it was found that the expression of p-ERK1/2 of the MAPK pathway was significantly downregulated following JWA siRNA transfection. However, the expression levels of ERK1/2, JNK, p38, p-JNK and p-p38 showed no significant differences. In conclusion, it was shown that JWA affects the proliferation, apoptosis, invasion and migration of PANC-1 pancreatic cancer cells which could be attributed to effects on the expression of ERK1/2 in the MAPK pathway.

Genistein induced anticancer effects on pancreatic cancer cell lines involves mitochondrial apoptosis, G0/G1cell cycle arrest and regulation of STAT3 signalling pathway.

PubMed

Bi, Yi-Liang; Min, Min; Shen, Wei; Liu, Yan

2018-01-15

Genistein is a natural flavonoid that has been reported to exhibit anticancer effects against different types of cancers which include, but are not limited to, breast and oral squamous cell carcinoma. The present study was designed to evaluate the anticancer effects of the natural flavonoid genistein against pancreatic cancer cell lines and to explore the underlying mechanism. Antiproliferative activity was investigated by MTT assay. Apoptosis was detected by DAPI and annexin V/PI staining. DNA damage was assessed by comet assay. Reactive oxygen species (ROS) and reduction of mitochondrial membrane potential (MMP) were determined by flow cytometry. Cell migration was examined by wound healing assay. Protien expressions were determined by western blotting. Antiproliferative assay revealed that genistein reduced the cell viability of pancreatic cancer cells in a dose dependent manner with an IC 50 of 20 and 25 µM against Mia-PaCa2 and PANC-1 cancer cell lines respectively. However, its antiproliferative effects were less pronounced against non-cancerous pancreatic ductal epithelial cell line (H6C7) as evident from the IC 50 of 120 µM. Genistein induced significant morphological changes in pancreatic cancer cells and triggered cell cycle arrest in G 0 /G 1 phase. DAPI staining and flow cytometric analysis revealed that genistein induced apoptosis in a dose dependent manner through generation of substantial amounts of ROS and reduction of MMP. However, treatment of the pancreatic cancer with genistein and ascorbic acid could abrogate the effects of genistein on cell viability. Protien expression analysis revealed that genistein upregulated cytosolic cytochrome c, Bax, cleaved Caspase-3 and cleaved caspase-9 expressions with concomitant downregulation of Bcl-2 expression. Moreover, genistein inhibited the phosphorylation of signal transducer and activator of transcription STAT3 proteins and downregulated the expression of survivin, cyclin D1 and ALDH1A1 in Mia

Basophils activated via TLR signaling may contribute to pathophysiology of type 1 autoimmune pancreatitis.

PubMed

Yanagawa, Masato; Uchida, Kazushige; Ando, Yugo; Tomiyama, Takashi; Yamaguchi, Takashi; Ikeura, Tsukasa; Fukui, Toshiro; Nishio, Akiyoshi; Uemura, Yoshiko; Miyara, Takayuki; Okamoto, Hiroyuki; Satoi, Souhei; Okazaki, Kazuichi

2018-03-01

Pathophysiology of type 1 autoimmune pancreatitis (AIP) is still unclear. We previously reported that M2 macrophages might play an important role in type 1 AIP. Recently, it has been reported that basophils regulate differentiation to M2 macrophages. In this study, we investigated basophils from the pancreatic tissue and peripheral blood of individuals with type 1 AIP. By using immunohistochemistry, we investigated basophils in pancreatic tissue from 13 patients with type 1 AIP and examined expression of toll-like receptors (TLRs) by these cells. Additionally, we obtained peripheral blood samples from 27 healthy subjects, 40 patients with type 1 AIP, 8 patients with alcoholic chronic pancreatitis, 10 patients with bronchial asthma, and 10 patients with atopic dermatitis, and analyzed activation of basophils by stimulating them with ligands of TLR1-9. We also compared TLR expression in basophils from the tissue and blood samples. Basophils were detected in pancreatic tissues from 10 of 13 patients with type 1 AIP. Flow cytometric analysis revealed that the ratios of basophils activated by TLR4 stimulation in type 1 AIP (9.875 ± 1.148%) and atopic dermatitis (11.768 ± 1.899%) were significantly higher than those in healthy subjects (5.051 ± 0.730%; P < 0.05). Levels of basophils activated by TLR2 stimulation were higher in seven type 1 AIP cases. Furthermore, stimulation of TLR2 and/or TLR4, which were expressed by basophils in pancreas, activated basophils in peripheral blood. Basophils activated via TLR signaling may play an important role in the pathophysiology of type 1 AIP.

Hypoxic stellate cells of pancreatic cancer stroma regulate extracellular matrix fiber organization and cancer cell motility.

PubMed

Sada, Masafumi; Ohuchida, Kenoki; Horioka, Kohei; Okumura, Takashi; Moriyama, Taiki; Miyasaka, Yoshihiro; Ohtsuka, Takao; Mizumoto, Kazuhiro; Oda, Yoshinao; Nakamura, Masafumi

2016-03-28

Desmoplasia and hypoxia in pancreatic cancer mutually affect each other and create a tumor-supportive microenvironment. Here, we show that microenvironment remodeling by hypoxic pancreatic stellate cells (PSCs) promotes cancer cell motility through alteration of extracellular matrix (ECM) fiber architecture. Three-dimensional (3-D) matrices derived from PSCs under hypoxia exhibited highly organized parallel-patterned matrix fibers compared with 3-D matrices derived from PSCs under normoxia, and promoted cancer cell motility by inducing directional migration of cancer cells due to the parallel fiber architecture. Microarray analysis revealed that procollagen-lysine, 2-oxoglutarate 5-dioxygenase 2 (PLOD2) in PSCs was the gene that potentially regulates ECM fiber architecture under hypoxia. Stromal PLOD2 expression in surgical specimens of pancreatic cancer was confirmed by immunohistochemistry. RNA interference-mediated knockdown of PLOD2 in PSCs blocked parallel fiber architecture of 3-D matrices, leading to decreased directional migration of cancer cells within the matrices. In conclusion, these findings indicate that hypoxia-induced PLOD2 expression in PSCs creates a permissive microenvironment for migration of cancer cells through architectural regulation of stromal ECM in pancreatic cancer. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

Gastrin regulates ABCG2 to promote the migration, invasion and side populations in pancreatic cancer cells via activation of NF-κB signaling

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wang, Juan; Xin, Beibei; Wang, Hui

Gastrin is absent in most normal adult pancreatic tissues but is highly expressed in pancreatic cancer tissues. Although Gastrin expression was reported to be associated with tumor proliferation in human pancreatic cancer, studies on the relationship between Gastrin and tumor metastasis in pancreatic cancer are rare. In this study, we performed an analysis to determine the effects of Gastrin on modulating the side populations, cell proportion and tumor cell metastatic potential and invasion activity and explored its mechanisms in pancreatic cancer. We indicated that Gastrin and ABCG2 were widely expressed in pancreatic cancer cell lines and overexpressed in cancer tissues.more » Gastrin induced ABCG2 expression, and this effect was mediated by NF-κB activation. Gastrin regulated the SP proportion of BxPC-3 cells via modulating ABCG2 expression. Through the regulation of the functions of NF-κB/ABCG2, Gastrin functionally promoted the migration and invasion in pancreatic cancer cell. The present study indicated that Gastrin induced ABCG2 expression by activating NF-κB and thereby modulated the SP proportion, tumor cell metastatic potential and invasion activity in pancreatic cancer. Gastrin could serve as an effective therapeutic target for the metastasis of pancreatic cancer. - Highlights: • Gastrin induces ABCG2 expression mediated by NF-κB activation. • Gastrin regulates NF-κB's function that binds to the ABCG2 promoter in BxPC-3 cells. • Gastrin promotes the SP proportion in BxPC-3 cells by modulating ABCG2 expression via activation of NF-κB molecule. • Gastrin induces an increase in migration and invasion potential in pancreatic cancer cell by regulating NF-κB/ABCG2 signaling.« less

Diabetes and exocrine pancreatic insufficiency in E2F1/E2F2 double-mutant mice.

PubMed

Iglesias, Ainhoa; Murga, Matilde; Laresgoiti, Usua; Skoudy, Anouchka; Bernales, Irantzu; Fullaondo, Asier; Moreno, Bernardino; Lloreta, José; Field, Seth J; Real, Francisco X; Zubiaga, Ana M

2004-05-01

E2F transcription factors are thought to be key regulators of cell growth control. Here we use mutant mouse strains to investigate the function of E2F1 and E2F2 in vivo. E2F1/E2F2 compound-mutant mice develop nonautoimmune insulin-deficient diabetes and exocrine pancreatic dysfunction characterized by endocrine and exocrine cell dysplasia, a reduction in the number and size of acini and islets, and their replacement by ductal structures and adipose tissue. Mutant pancreatic cells exhibit increased rates of DNA replication but also of apoptosis, resulting in severe pancreatic atrophy. The expression of genes involved in DNA replication and cell cycle control was upregulated in the E2F1/E2F2 compound-mutant pancreas, suggesting that their expression is repressed by E2F1/E2F2 activities and that the inappropriate cell cycle found in the mutant pancreas is likely the result of the deregulated expression of these genes. Interestingly, the expression of ductal cell and adipocyte differentiation marker genes was also upregulated, whereas expression of pancreatic cell marker genes were downregulated. These results suggest that E2F1/E2F2 activity negatively controls growth of mature pancreatic cells and is necessary for the maintenance of differentiated pancreatic phenotypes in the adult.

Pancreatic acini possess endothelin receptors whose internalization is regulated by PLC-activating agents.

PubMed

Hildebrand, P; Mrozinski, J E; Mantey, S A; Patto, R J; Jensen, R T

1993-05-01

Endothelin-1 (ET-1) and ET-3 mRNA have been found in the pancreas. We investigated the ability of ET-1, ET-2, and ET-3 to interact with and alter dispersed rat pancreatic acinar cell function. Radiolabeled ETs bound in a time- and temperature-dependent fashion, which was specific and saturable. Analysis demonstrated two classes of receptors, one class (ETA receptor) had a high affinity for ET-1 but a low affinity for ET-3, and the other class (ETB receptor) had equally high affinities for ET-1 and ET-3. No specific receptor for ET-2 was identified. Pancreatic secretagogues that activate phospholipase C (PLC) inhibited binding of 125I-labeled ET-1 (125I-ET-1) or 125I-ET-3, whereas agents that act through adenosine 3',5'-cyclic monophosphate (cAMP) did not. A23187 had no effect on 125I-ET-1 or 125I-ET-3 binding, whereas the phorbol ester 12-O-tetradecanoylphorbol 13-acetate reduced binding. The effect of cholecystokinin octapeptide (CCK-8) was mediated through its own receptor. Stripping of surface bound ligand studies demonstrated that both 125I-labeled ET-1 and 125I-labeled ET-3 were rapidly internalized. CCK-8 decreased the internalization but did not change the amount of surface bound ligand. Endothelins neither stimulate nor alter changes in enzyme secretion, intracellular calcium, cAMP, or [3H]inositol trisphosphate (IP3). This study demonstrates the presence of ETA and ETB receptors on rat pancreatic acini; occupation of both receptors resulted in rapid internalization, which is regulated by PLC-activating secretagogues. Occupation of either ET receptor did not alter intracellular calcium, cAMP, IP3, or stimulate amylase release.

Role of endogenous cortistatin in the regulation of ghrelin system expression at pancreatic level under normal and obese conditions.

PubMed

Chanclón, Belén; Luque, Raúl M; Córdoba-Chacón, José; Gahete, Manuel D; Pozo-Salas, Ana I; Castaño, Justo P; Gracia-Navarro, Francisco; Martínez-Fuentes, Antonio J

2013-01-01

Ghrelin-system components [native ghrelin, In1-ghrelin, Ghrelin-O-acyltransferase enzyme (GOAT) and receptors (GHS-Rs)] are expressed in a wide variety of tissues, including the pancreas, where they exert different biological actions including regulation of neuroendocrine secretions, food intake and pancreatic function. The expression of ghrelin system is regulated by metabolic conditions (fasting/obesity) and is associated with the progression of obesity and insulin resistance. Cortistatin (CORT), a neuropeptide able to activate GHS-R, has emerged as an additional link in gut-brain interplay. Indeed, we recently reported that male CORT deficient mice (cort-/-) are insulin-resistant and present a clear dysregulation in the stomach ghrelin-system. The present work was focused at analyzing the expression pattern of ghrelin-system components at pancreas level in cort-/- mice and their control littermates (cort +/+) under low- or high-fat diet. Our data reveal that all the ghrelin-system components are expressed at the mouse pancreatic level, where, interestingly, In1-ghrelin was expressed at higher levels than native-ghrelin. Thus, GOAT mRNA levels were significantly lower in cort-/- mice compared with controls while native ghrelin, In1-ghrelin and GHS-R transcript levels remained unaltered under normal metabolic conditions. Moreover, under obese condition, a significant increase in pancreatic expression of native-ghrelin, In1-ghrelin and GHS-R was observed in obese cort+/+ but not in cort-/- mice. Interestingly, insulin expression and release was elevated in obese cort+/+, while these changes were not observed in obese cort-/- mice. Altogether, our results indicate that the ghrelin-system expression is clearly regulated in the pancreas of cort+/+ and cort -/- under normal and/or obesity conditions suggesting that this system may play relevant roles in the endocrine pancreas. Most importantly, our data demonstrate, for the first time, that endogenous CORT is essential

Crystallographic analysis of NHERF1–PLCβ3 interaction provides structural basis for CXCR2 signaling in pancreatic cancer

DOE Office of Scientific and Technical Information (OSTI.GOV)

Jiang, Yuanyuan; Wang, Shuo; Holcomb, Joshua

2014-04-04

Highlights: • CXCR2–NHERF1–PLCβ3 complex regulates CXCR2 signaling in pancreatic cancer. • The crystal structure of the NHERF1 PDZ1 domain in complex with PLCβ3. • The structure reveals specificity determinants of PDZ1–PLCβ3 interaction. • Endogenous PLCβ3 in pancreatic cancer cells interacts with both PDZ1 and PDZ2. • Structural basis of the PDZ1–PLCβ3 interaction is valuable in selective drug design. - Abstract: The formation of CXCR2–NHERF1–PLCβ3 macromolecular complex in pancreatic cancer cells regulates CXCR2 signaling activity and plays an important role in tumor proliferation and invasion. We previously have shown that disruption of the NHERF1-mediated CXCR2–PLCβ3 interaction abolishes the CXCR2 signaling cascademore » and inhibits pancreatic tumor growth in vitro and in vivo. Here we report the crystal structure of the NHERF1 PDZ1 domain in complex with the C-terminal PLCβ3 sequence. The structure reveals that the PDZ1–PLCβ3 binding specificity is achieved by numerous hydrogen bonds and hydrophobic contacts with the last four PLCβ3 residues contributing to specific interactions. We also show that PLCβ3 can bind both NHERF1 PDZ1 and PDZ2 in pancreatic cancer cells, consistent with the observation that the peptide binding pockets of these PDZ domains are highly structurally conserved. This study provides an understanding of the structural basis for the PDZ-mediated NHERF1–PLCβ3 interaction that could prove valuable in selective drug design against CXCR2-related cancers.« less

Polycomb complex protein BMI-1 promotes invasion and metastasis of pancreatic cancer stem cells by activating PI3K/AKT signaling, an ex vivo, in vitro, and in vivo study

PubMed Central

Wang, Min-Cong; Jiao, Min; Wu, Tao; Jing, Li; Cui, Jie; Guo, Hui; Tian, Tao; Ruan, Zhi-ping; Wei, Yong-Chang; Jiang, Li-Li; Sun, Hai-Feng; Huang, Lan-Xuan; Nan, Ke-Jun; Li, Chun-Li

2016-01-01

Cancer stem cell theory indicates cancer stem cells are the key to promote tumor invasion and metastasis. Studies showed that BMI-1 could promote self-renew, differentiation and tumor formation of CSCs and invasion/metastasis of human cancer. However, whether BMI-1 could regulate invasion and metastasis ability of CSCs is still unclear. In our study, we found that up-regulated expression of BMI-1 was associated with tumor invasion, metastasis and poor survival of pancreatic cancer patients. CD133+ cells were obtained by using magnetic cell sorting and identified of CSCs properties such as self-renew, multi-differentiation and tumor formation ability. Then, we found that BMI-1 expression was up-regulated in pancreatic cancer stem cells. Knockdown of BMI-1 expression attenuated invasion ability of pancreatic cancer stem cells in Transwell system and liver metastasis capacity in nude mice which were injected CSCs through the caudal vein. We are the first to reveal that BMI-1 could promote invasion and metastasis ability of pancreatic cancer stem cells. Finally, we identified that BMI-1 expression activating PI3K/AKT singing pathway by negative regulating PTEN was the main mechanism of promoting invasion and metastasis ability of pancreatic CSCs. In summary, our findings indicate that BMI-1 could be used as the therapeutic target to inhibiting CSCs-mediated pancreatic cancer metastasis. PMID:26840020

Translating Discovery in Zebrafish Pancreatic Development to Human Pancreatic Cancer: Biomarkers, Targets, Pathogenesis, and Therapeutics

PubMed Central

Kazi, Abid A.; Yee, Rosemary K.

2013-01-01

Abstract Experimental studies in the zebrafish have greatly facilitated understanding of genetic regulation of the early developmental events in the pancreas. Various approaches using forward and reverse genetics, chemical genetics, and transgenesis in zebrafish have demonstrated generally conserved regulatory roles of mammalian genes and discovered novel genetic pathways in exocrine pancreatic development. Accumulating evidence has supported the use of zebrafish as a model of human malignant diseases, including pancreatic cancer. Studies have shown that the genetic regulators of exocrine pancreatic development in zebrafish can be translated into potential clinical biomarkers and therapeutic targets in human pancreatic adenocarcinoma. Transgenic zebrafish expressing oncogenic K-ras and zebrafish tumor xenograft model have emerged as valuable tools for dissecting the pathogenetic mechanisms of pancreatic cancer and for drug discovery and toxicology. Future analysis of the pancreas in zebrafish will continue to advance understanding of the genetic regulation and biological mechanisms during organogenesis. Results of those studies are expected to provide new insights into how aberrant developmental pathways contribute to formation and growth of pancreatic neoplasia, and hopefully generate valid biomarkers and targets as well as effective and safe therapeutics in pancreatic cancer. PMID:23682805

Translating discovery in zebrafish pancreatic development to human pancreatic cancer: biomarkers, targets, pathogenesis, and therapeutics.

PubMed

Yee, Nelson S; Kazi, Abid A; Yee, Rosemary K

2013-06-01

Abstract Experimental studies in the zebrafish have greatly facilitated understanding of genetic regulation of the early developmental events in the pancreas. Various approaches using forward and reverse genetics, chemical genetics, and transgenesis in zebrafish have demonstrated generally conserved regulatory roles of mammalian genes and discovered novel genetic pathways in exocrine pancreatic development. Accumulating evidence has supported the use of zebrafish as a model of human malignant diseases, including pancreatic cancer. Studies have shown that the genetic regulators of exocrine pancreatic development in zebrafish can be translated into potential clinical biomarkers and therapeutic targets in human pancreatic adenocarcinoma. Transgenic zebrafish expressing oncogenic K-ras and zebrafish tumor xenograft model have emerged as valuable tools for dissecting the pathogenetic mechanisms of pancreatic cancer and for drug discovery and toxicology. Future analysis of the pancreas in zebrafish will continue to advance understanding of the genetic regulation and biological mechanisms during organogenesis. Results of those studies are expected to provide new insights into how aberrant developmental pathways contribute to formation and growth of pancreatic neoplasia, and hopefully generate valid biomarkers and targets as well as effective and safe therapeutics in pancreatic cancer.

Clusterin and Pycr1 alterations associate with strain and model differences in susceptibility to experimental pancreatitis.

PubMed

Iyer, Sapna; Park, Min-Jung; Moons, David; Kwan, Raymond; Liao, Jian; Liu, Li; Omary, M Bishr

2017-01-22

Acute pancreatitis has several underlying etiologies, and results in consequences ranging from mild to complex multi-organ failure. The wide range of pathology suggests a genetic predisposition for progression. We compared the susceptibility to acute pancreatitis in BALB/c and FVB/N mice, coupled with proteomic analysis, in order to identify potential protein associations with pancreatitis progression. Pancreatitis was induced in BALB/c and FVB/N mice by administration of cerulein or feeding a choline-deficient, ethionine-supplemented (CDE) diet. Histology and changes in serum amylase were examined. Proteome profiling in cerulein-treated mice was performed using 2-dimensional differential in gel electrophoresis (2D-DIGE) followed by mass spectrometry analysis and biochemical validation. Male and female FVB/N mice manifested more severe cerulein-induced pancreatitis as compared with BALB/c mice, but both strains were similarly susceptible to CDE-induced pancreatitis. Few of the 2D-DIGE alterations were validated by immunoblotting. Clusterin was markedly up-regulated after cerulein-induced pancreatitis in FVB/N but less-so in BALB/c mice. Pyrroline-5-carboxylate reductase (Pycr1), an enzyme involved in proline biosynthesis, had higher basal levels in FVB/N male and female mouse pancreata compared with BALB/c pancreata, and was relatively more resistant to degradation in FVB/N pancreata. However, serum and pancreas tissue proline levels were similar in the two strains. FVB/N is more susceptible than BALB/c mice to cerulein-induced but not CDE-induced pancreatitis. Most of the 2D-DIGE alterations in the two strains likely relate to posttranslational modifications rather than protein level differences. Clusterin levels increase dramatically in association with pancreatitis severity, while Pycr1 is higher in FVB/N versus BALB/c pancreata basally and after induction of pancreatitis. Changes in proline metabolism may represent a novel potential genetic modifier in the

Scolopendra subspinipes mutilans protected the cerulein-induced acute pancreatitis by inhibiting high-mobility group box protein-1.

PubMed

Jo, Il-Joo; Bae, Gi-Sang; Park, Kyoung-Chel; Choi, Sun Bok; Jung, Won-Seok; Jung, Su-Young; Cho, Jung-Hee; Choi, Mee-Ok; Song, Ho-Joon; Park, Sung-Joo

2013-03-14

To evaluate the inhibitory effects of Scolopendra subspinipes mutilans (SSM) on cerulein-induced acute pancreatitis (AP) in a mouse model. SSM water extract (0.1, 0.5, or 1 g/kg) was administrated intraperitoneally 1 h prior to the first injection of cerulein. Once AP developed, the stable cholecystokinin analogue, cerulein was injected hourly, over a 6 h period. Blood samples were taken 6 h later to determine serum amylase, lipase, and cytokine levels. The pancreas and lungs were rapidly removed for morphological examination, myeloperoxidase assay, and real-time reverse transcription polymerase chain reaction. To specify the role of SSM in pancreatitis, the pancreatic acinar cells were isolated using collagenase method. Then the cells were pre-treated with SSM, then stimulated with cerulein. The cell viability, cytokine productions and high-mobility group box protein-1 (HMGB-1) were measured. Furthermore, the regulating mechanisms of SSM action were evaluated. The administration of SSM significantly attenuated the severity of pancreatitis and pancreatitis associated lung injury, as was shown by the reduction in pancreatic edema, neutrophil infiltration, vacuolization and necrosis. SSM treatment also reduced pancreatic weight/body weight ratio, serum amylase, lipase and cytokine levels, and mRNA expression of multiple inflammatory mediators such as tumor necrosis factor-α and interleukin-1β. In addition, treatment with SSM inhibited HMGB-1 expression in the pancreas during AP. In accordance with in vivo data, SSM inhibited the cerulein-induced acinar cell death, cytokine, and HMGB-1 release. SSM also inhibited the activation of c-Jun NH2-terminal kinase, p38 and nuclear factor (NF)-κB. These results suggest that SSM plays a protective role during the development of AP and pancreatitis associated lung injury via deactivating c-Jun NH2-terminal kinase, p38 and NF-κB.

Scolopendra subspinipes mutilans protected the cerulein-induced acute pancreatitis by inhibiting high-mobility group box protein-1

PubMed Central

Jo, Il-Joo; Bae, Gi-Sang; Park, Kyoung-Chel; Choi, Sun Bok; Jung, Won-Seok; Jung, Su-Young; Cho, Jung-Hee; Choi, Mee-Ok; Song, Ho-Joon; Park, Sung-Joo

2013-01-01

AIM: To evaluate the inhibitory effects of Scolopendra subspinipes mutilans (SSM) on cerulein-induced acute pancreatitis (AP) in a mouse model. METHODS: SSM water extract (0.1, 0.5, or 1 g/kg) was administrated intraperitoneally 1 h prior to the first injection of cerulein. Once AP developed, the stable cholecystokinin analogue, cerulein was injected hourly, over a 6 h period. Blood samples were taken 6 h later to determine serum amylase, lipase, and cytokine levels. The pancreas and lungs were rapidly removed for morphological examination, myeloperoxidase assay, and real-time reverse transcription polymerase chain reaction. To specify the role of SSM in pancreatitis, the pancreatic acinar cells were isolated using collagenase method. Then the cells were pre-treated with SSM, then stimulated with cerulein. The cell viability, cytokine productions and high-mobility group box protein-1 (HMGB-1) were measured. Furthermore, the regulating mechanisms of SSM action were evaluated. RESULTS: The administration of SSM significantly attenuated the severity of pancreatitis and pancreatitis associated lung injury, as was shown by the reduction in pancreatic edema, neutrophil infiltration, vacuolization and necrosis. SSM treatment also reduced pancreatic weight/body weight ratio, serum amylase, lipase and cytokine levels, and mRNA expression of multiple inflammatory mediators such as tumor necrosis factor-α and interleukin-1β. In addition, treatment with SSM inhibited HMGB-1 expression in the pancreas during AP. In accordance with in vivo data, SSM inhibited the cerulein-induced acinar cell death, cytokine, and HMGB-1 release. SSM also inhibited the activation of c-Jun NH2-terminal kinase, p38 and nuclear factor (NF)-κB. CONCLUSION: These results suggest that SSM plays a protective role during the development of AP and pancreatitis associated lung injury via deactivating c-Jun NH2-terminal kinase, p38 and NF-κB. PMID:23539679

Homotypic cell cannibalism, a cell-death process regulated by the nuclear protein 1, opposes to metastasis in pancreatic cancer

PubMed Central

Cano, Carla E; Sandí, María José; Hamidi, Tewfik; Calvo, Ezequiel L; Turrini, Olivier; Bartholin, Laurent; Loncle, Céline; Secq, Véronique; Garcia, Stéphane; Lomberk, Gwen; Kroemer, Guido; Urrutia, Raul; Iovanna, Juan L

2012-01-01

Pancreatic adenocarcinoma (PDAC) is an extremely deadly disease for which all treatments available have failed to improve life expectancy significantly. This may be explained by the high metastatic potential of PDAC cells, which results from their dedifferentiation towards a mesenchymal phenotype. Some PDAC present cell-in-cell structures whose origin and significance are currently unknown. We show here that cell-in-cells form after homotypic cell cannibalism (HoCC). We found PDAC patients whose tumours display HoCC develop less metastasis than those without. In vitro, HoCC was promoted by inactivation of the nuclear protein 1 (Nupr1), and was enhanced by treatment with transforming growth factor β. HoCC ends with death of PDAC cells, consistent with a metastasis suppressor role for this phenomenon. Hence, our data indicates a protective role for HoCC in PDAC and identifies Nupr1 as a molecular regulator of this process. PMID:22821859

Effect of PI3K- and mTOR-specific inhibitors on spontaneous B-cell follicular lymphomas in PTEN/LKB1-deficient mice.

PubMed

García-Martínez, J M; Wullschleger, S; Preston, G; Guichard, S; Fleming, S; Alessi, D R; Duce, S L

2011-03-29

The PI3K-mTOR (phosphoinositide 3-kinase-mammalian target of rapamycin kinase) pathway is activated in the majority of tumours, and there is interest in assessing whether inhibitors of PI3K or mTOR kinase have efficacy in treating cancer. Here, we define the effectiveness of specific mTOR (AZD8055) and PI3K (GDC-0941) inhibitors, currently in clinical trials, in treating spontaneous B-cell follicular lymphoma that develops in PTEN(+/-)LKB1(+/hypo) mice. The PTEN(+/-)LKB1(+/hypo) mice were administered AZD8055 or GDC-0941, and the volumes of B-cell follicular lymphoma were measured by MRI. Tumour samples were analysed by immunohistochemistry, immunoblot and flow cytometry. The AZD8055 or GDC-0941 induced ∼40% reduction in tumour volume within 2 weeks, accompanied by ablation of phosphorylation of AKT, S6K and SGK (serum and glucocorticoid protein kinase) protein kinases. The drugs reduced tumour cell proliferation, promoted apoptosis and suppressed centroblast population. The AZD8055 or GDC-0941 treatment beyond 3 weeks caused a moderate additional decrease in tumour volume, reaching ∼50% of the initial volume after 6 weeks of treatment. Tumours grew back at an increased rate and displayed similar high grade and diffuse morphology as the control untreated tumours upon cessation of drug treatment. These results define the effects that newly designed and specific mTOR and PI3K inhibitors have on a spontaneous tumour model, which may be more representative than xenograft models frequently employed to assess effectiveness of kinase inhibitors. Our data suggest that mTOR and PI3K inhibitors would benefit treatment of cancers in which the PI3K pathway is inappropriately activated; however, when administered alone, may not cause complete regression of such tumours.

Effect of PI3K- and mTOR-specific inhibitors on spontaneous B-cell follicular lymphomas in PTEN/LKB1-deficient mice

PubMed Central

García-Martínez, J M; Wullschleger, S; Preston, G; Guichard, S; Fleming, S; Alessi, D R; Duce, S L

2011-01-01

Background: The PI3K–mTOR (phosphoinositide 3-kinase–mammalian target of rapamycin kinase) pathway is activated in the majority of tumours, and there is interest in assessing whether inhibitors of PI3K or mTOR kinase have efficacy in treating cancer. Here, we define the effectiveness of specific mTOR (AZD8055) and PI3K (GDC-0941) inhibitors, currently in clinical trials, in treating spontaneous B-cell follicular lymphoma that develops in PTEN+/−LKB1+/hypo mice. Methods: The PTEN+/−LKB1+/hypo mice were administered AZD8055 or GDC-0941, and the volumes of B-cell follicular lymphoma were measured by MRI. Tumour samples were analysed by immunohistochemistry, immunoblot and flow cytometry. Results: The AZD8055 or GDC-0941 induced ∼40% reduction in tumour volume within 2 weeks, accompanied by ablation of phosphorylation of AKT, S6K and SGK (serum and glucocorticoid protein kinase) protein kinases. The drugs reduced tumour cell proliferation, promoted apoptosis and suppressed centroblast population. The AZD8055 or GDC-0941 treatment beyond 3 weeks caused a moderate additional decrease in tumour volume, reaching ∼50% of the initial volume after 6 weeks of treatment. Tumours grew back at an increased rate and displayed similar high grade and diffuse morphology as the control untreated tumours upon cessation of drug treatment. Conclusion: These results define the effects that newly designed and specific mTOR and PI3K inhibitors have on a spontaneous tumour model, which may be more representative than xenograft models frequently employed to assess effectiveness of kinase inhibitors. Our data suggest that mTOR and PI3K inhibitors would benefit treatment of cancers in which the PI3K pathway is inappropriately activated; however, when administered alone, may not cause complete regression of such tumours. PMID:21407213

Ellagic acid inhibits the proliferation of human pancreatic carcinoma PANC-1 cells in vitro and in vivo.

PubMed

Cheng, Hao; Lu, Chenglin; Tang, Ribo; Pan, Yiming; Bao, Shanhua; Qiu, Yudong; Xie, Min

2017-02-14

Ellagic aicd (EA), a dietary polyphenolic compound found in plants and fruits, possesses various pharmacological activities. This study investigated the effect of EA on human pancreatic carcinoma PANC-1 cells both in vitro and in vivo; and defined the associated molecular mechanisms. In vitro, the cell growth and repairing ability were assessed by CCK-8 assay and wound healing assay. The cell migration and invasion activity was evaluated by Tanswell assay. In vivo, PANC-1 cell tumor-bearing mice were treated with different concentrations of EA. We found that EA significantly inhibited cell growth, cell repairing activity, and cell migration and invasion in a dose-dependent manner. Treatment of PANC-1 xenografted mice with EA resulted in significant inhibition in tumor growth and prolong mice survival rate. Furthermore, flow cytometric analysis showed that EA increased the percentage of cells in the G1 phase of cell cycle. Western blot analysis revealed that EA inhibited the expression of COX-2 and NF-κB. In addition, EA reversed epithelial to mesenchymal transition by up-regulating E-cadherin and down-regulating Vimentin. In summary, the present study demonstrated that EA inhibited cell growth, cell repairing activity, cell migration and invasion in a dose-dependent manner. EA also effectively inhibit human pancreatic cancer growth in mice. The anti-tumor effect of EA might be related to cell cycle arrest, down-regulating the expression of COX-2 and NF-κB, reversing epithelial to mesenchymal transition by up-regulating E-cadherin and down-regulating Vimentin. Our findings suggest that the use of EA would be beneficial for the management of pancreatic cancer.

Myeloid cells are required for PD-1/PD-L1 checkpoint activation and the establishment of an immunosuppressive environment in pancreatic cancer

PubMed Central

Zhang, Yaqing; Velez-Delgado, Ashley; Mathew, Esha; Li, Dongjun; Mendez, Flor M; Flannagan, Kevin; Rhim, Andrew D; Simeone, Diane M; Beatty, Gregory L; Pasca di Magliano, Marina

2017-01-01

Background Pancreatic cancer is characterised by the accumulation of a fibro-inflammatory stroma. Within this stromal reaction, myeloid cells are a predominant population. Distinct myeloid subsets have been correlated with tumour promotion and unmasking of anti-tumour immunity. Objective The goal of this study was to determine the effect of myeloid cell depletion on the onset and progression of pancreatic cancer and to understand the relationship between myeloid cells and T cell-mediated immunity within the pancreatic cancer microenvironment. Methods Primary mouse pancreatic cancer cells were transplanted into CD11b-diphtheria toxin receptor (DTR) mice. Alternatively, the iKras* mouse model of pancreatic cancer was crossed into CD11b-DTR mice. CD11b+ cells (mostly myeloid cell population) were depleted by diphtheria toxin treatment during tumour initiation or in established tumours. Results Depletion of myeloid cells prevented KrasG12D-driven pancreatic cancer initiation. In pre-established tumours, myeloid cell depletion arrested tumour growth and in some cases, induced tumour regressions that were dependent on CD8+ T cells. We found that myeloid cells inhibited CD8+ T-cell anti-tumour activity by inducing the expression of programmed cell death-ligand 1 (PD-L1) in tumour cells in an epidermal growth factor receptor (EGFR)/mitogen-activated protein kinases (MAPK)-dependent manner. Conclusion Our results show that myeloid cells support immune evasion in pancreatic cancer through EGFR/MAPK-dependent regulation of PD-L1 expression on tumour cells. Derailing this crosstalk between myeloid cells and tumour cells is sufficient to restore anti-tumour immunity mediated by CD8+ T cells, a finding with implications for the design of immune therapies for pancreatic cancer. PMID:27402485

Regulation of muscarinic acetylcholine receptors in cultured guinea pig pancreatic acini

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hootman, S.R.; Brown, M.E.; Williams, J.A.

1986-07-01

Regulation of muscarinic receptors in cultured guinea pig pancreatic acini was investigated by assessing the effects of cholinergic agonists on binding of (N-methyl-TH)scopolamine ((TH)NMS) and on amylase release. Freshly dispersed acini bound (TH)NMS with a K/sub d/ of 74 pM and a maximal binding level (B/sub max/) of 908 fmol/mg DNA. Carbachol (CCh) stimulated amylase secretion and inhibited (TH)NMS binding. Incubation of acini for 30 min with 0.1 mM CCh decreased the subsequent efficacy of CCh in stimulating amylase release by threefold but had no effect on its potency. In contrast, amylase release in response to cholecystokinin octapeptide (CCK-8) wasmore » not altered by CCh preincubation. (TH)NMS binding to acini was decreased only 15-20% after 30-min incubation with CCh. However, culture of acini with 0.1 mM CCh decreased (TH)NMS binding by 50% at 3-4 h and by 85-90% at 24 h. This decrease was attributable primarily to a reduction in B/sub max/ (TH)NMS binding also was decreased to a similar extent by the cholinergic agonists bethanechol and methacholine but not by other secretagogues. The decrease in antagonist binding induced by CCh was dose dependent, with the IC50, 5.8 M, approximating the EC50 for amylase release, 4.3 M. Cultured of acini for 24 h with CCh abolished subsequent amylase release in response to CCh but not to CCK-8. The results indicate that muscarinic receptor turnover in the pancreatic acinus is regulated by receptor activation and that both a decease in receptor numbers and sensitivity to agonists follows prolonged cholinergic agonist exposure.« less

XRCC1 Polymorphisms and Pancreatic Cancer: A Meta-Analysis

PubMed Central

Shen, Wei-dong; Chen, Hong-lin; Liu, Peng-fei

2011-01-01

Objective To assess the association between X-ray repair cross-complementating group 1 (XRCC1) polymorphisms and pancreatic cancer. Methods We searched MEDLINE, Web of Science and HuGE Navigator at June 2010, and then quantitatively summarized associations of the XRCC1 polymorphisms with pancreatic cancer risk using meta-analysis. Results Four studies with 1343 cases and 2302 controls were included. Our analysis found: at codon 194, the Trp allele did not decrease pancreatic cancer risk (Arg/Arg versus Trp/Trp: OR=0.97; 95% CI: 0.48-1.96; P=0.97; Arg/Arg versus Arg/Trp: OR=0.89; 95% CI: 0.70-1.13; P=0.55; Arg/Trp versus Trp/Trp: OR=1.06; 95% CI: 0.52-2.16; P=0.90); at codon 280, only a study showed a nonsignificant association between single nucleotide polymorphism with pancreatic cancer risk; at codon 399, the Gln allele also showed no significant effect on pancreatic cancer compared to Arg allele (Arg/Arg versus Gln/Gln: OR=0.94; 95% CI: 0.74-1.18; Arg/Arg versus Arg/Gln: OR=0.97; 95% CI: 0.83-1.13; Arg/Gln versus Gln/Gln: OR=0.97; 95% CI: 0.77-1.22). The shape of the funnel plot and the Egger’s test did not detect any publication bias. Conclusion There is no evidence that XRCC1 polymorphisms (Arg194Trp, Arg280His, and Arg399Gln) are associated with pancreatic cancer risk. PMID:23467456

The novel mTORC1/2 dual inhibitor INK-128 suppresses survival and proliferation of primary and transformed human pancreatic cancer cells

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lou, Hai-zhou; Weng, Xiao-chuan; Pan, Hong-ming

Highlights: • INK-128 inhibits the survival and growth of human pancreatic cancer cells. • INK-128 induced pancreatic cancer cell apoptosis and necrosis simultaneously. • INK-128 blocks mTORC1/2 activation simultaneously in pancreatic cancer cells. • INK-128 down-regulates cyclin D1 and causes pancreatic cancer cell cycle arrest. • INK-128 significantly increases sensitivity of pancreatic cancer cells to gemcitabine. - Abstract: Pancreatic cancer has one of worst prognosis among all human malignancies around the world, the development of novel and more efficient anti-cancer agents against this disease is urgent. In the current study, we tested the potential effect of INK-128, a novel mammalianmore » target of rapamycin (mTOR) complex 1 and 2 (mTORC1/2) dual inhibitor, against pancreatic cancer cells in vitro. Our results demonstrated that INK-128 concentration- and time-dependently inhibited the survival and growth of pancreatic cancer cells (both primary cells and transformed cells). INK-128 induced pancreatic cancer cell apoptosis and necrosis simultaneously. Further, INK-128 dramatically inhibited phosphorylation of 4E-binding protein 1 (4E-BP1), ribosomal S6 kinase 1 (S6K1) and Akt at Ser 473 in pancreatic cancer cells. Meanwhile, it downregulated cyclin D1 expression and caused cell cycle arrest. Finally, we found that a low concentration of INK-128 significantly increased the sensitivity of pancreatic cancer cells to gemcitabine. Together, our in vitro results suggest that INK-128 might be further investigated as a novel anti-cancer agent or chemo-adjuvant for pancreatic cancer treatment.« less

Celecoxib suppresses fibroblast growth factor-2 expression in pancreatic ductal adenocarcinoma PANC-1 cells.

PubMed

Li, Jing; Luo, Miaosha; Wang, Yan; Shang, Boxin; Dong, Lei

2016-09-01

The inhibition of cyclooxygenase (COX)-2 has been reported to suppress growth and induce apoptosis in human pancreatic cancer cells. Nevertheless, the precise biological mechanism of how celecoxib, a selective COX-2 inhibitor, regulates the growth and invasion of pancreatic tumors is not completely understood. It has been shown that fibroblast growth factor-2 (FGF-2) and its receptor levels correlate with the inhibition of cancer cell proliferation, migration and invasion in pancreatic ductal adenocarcinoma (PDAC). Therefore, the aim of the present study was to examine the hypothesis that the antitumor activity of celecoxib in PDAC may be exerted through modulation of FGF-2 function. In the present study, we evaluated the effects of celecoxib on the proliferation, migration, invasion and apoptosis of the PANC-1 cell line. Western blotting and quantitative real-time polymerase chain reaction (qRT-PCR) were used to examine the expression of FGF-2, FGFR-2, ERK1/2 and MMPs. In the present study, FGF-2 and FGFR-2 were expressed in PANC-1 cells and FGF-2 exerted a stimulatory effect on phosphorylated extracellular signal regulated kinase (p-ERK) expression. Celecoxib treatment suppressed FGF-2 and FGFR-2 expression and decreased MMP-2, MMP-9 and p-ERK expression in the PANC-1 cells. Furthermore, celecoxib treatment caused the resistance of PANC-1 cells to FGF-2 induced proliferation, migration and invasion ability, as well as the increase in their apoptotic rate. Our data provide evidence that targeting FGF-2 with celecoxib may be used as an effective treatment in PDAC.

Converting adult pancreatic islet α-cells into β-cells by targeting both Dnmt1 and Arx

PubMed Central

Chakravarthy, Harini; Gu, Xueying; Enge, Martin; Dai, Xiaoqing; Wang, Yong; Damond, Nicolas; Downie, Carolina; Liu, Kathy; Wang, Jing; Xing, Yuan; Chera, Simona; Thorel, Fabrizio; Quake, Stephen; Oberholzer, Jose; MacDonald, Patrick E.; Herrera, Pedro L.; Kim, Seung K.

2017-01-01

Summary Insulin-producing pancreatic β-cells in mice can slowly regenerate from glucagon-producing α-cells in settings like β-cell loss, but the basis of this conversion is unknown. Moreover it remains unclear if this intra-islet cell conversion is relevant to diseases like type 1 diabetes (T1D). We show that the α-cell regulators Aristaless-related homeobox (Arx) and DNA methyltransferase 1 (Dnmt1) maintain α-cell identity in mice. Within 3 months of Dnmt1 and Arx loss, lineage tracing and single cell RNA sequencing revealed extensive α-cell conversion into progeny resembling native β-cells. Physiological studies demonstrated that converted α-cells acquire hallmark β-cell electrophysiology, and show glucose-stimulated insulin secretion. In T1D patients, subsets of Glucagon-expressing cells show loss of DNMT1 and ARX, and produce Insulin and other β-cell factors, suggesting that DNMT1 and ARX maintain α-cell identity in humans. Our work reveals pathways regulated by Arx and Dnmt1 sufficient for achieving targeted generation of β-cells from adult pancreatic α-cells. PMID:28215845

Inhibitors of ORAI1 Prevent Cytosolic Calcium-Associated Injury of Human Pancreatic Acinar Cells and Acute Pancreatitis in 3 Mouse Models

PubMed Central

Wen, Li; Voronina, Svetlana; Javed, Muhammad A.; Awais, Muhammad; Szatmary, Peter; Latawiec, Diane; Chvanov, Michael; Collier, David; Huang, Wei; Barrett, John; Begg, Malcolm; Stauderman, Ken; Roos, Jack; Grigoryev, Sergey; Ramos, Stephanie; Rogers, Evan; Whitten, Jeff; Velicelebi, Gonul; Dunn, Michael; Tepikin, Alexei V.; Criddle, David N.; Sutton, Robert

2015-01-01

Background & Aims Sustained activation of the cytosolic calcium concentration induces injury to pancreatic acinar cells and necrosis. The calcium release–activated calcium modulator ORAI1 is the most abundant Ca2+ entry channel in pancreatic acinar cells; it sustains calcium overload in mice exposed to toxins that induce pancreatitis. We investigated the roles of ORAI1 in pancreatic acinar cell injury and the development of acute pancreatitis in mice. Methods Mouse and human acinar cells, as well as HEK 293 cells transfected to express human ORAI1 with human stromal interaction molecule 1, were hyperstimulated or incubated with human bile acid, thapsigargin, or cyclopiazonic acid to induce calcium entry. GSK-7975A or CM_128 were added to some cells, which were analyzed by confocal and video microscopy and patch clamp recordings. Acute pancreatitis was induced in C57BL/6J mice by ductal injection of taurolithocholic acid 3-sulfate or intravenous' administration of cerulein or ethanol and palmitoleic acid. Some mice then were given GSK-7975A or CM_128, which inhibit ORAI1, at different time points to assess local and systemic effects. Results GSK-7975A and CM_128 each separately inhibited toxin-induced activation of ORAI1 and/or activation of Ca2+ currents after Ca2+ release, in a concentration-dependent manner, in mouse and human pancreatic acinar cells (inhibition >90% of the levels observed in control cells). The ORAI1 inhibitors also prevented activation of the necrotic cell death pathway in mouse and human pancreatic acinar cells. GSK-7975A and CM_128 each inhibited all local and systemic features of acute pancreatitis in all 3 models, in dose- and time-dependent manners. The agents were significantly more effective, in a range of parameters, when given at 1 vs 6 hours after induction of pancreatitis. Conclusions Cytosolic calcium overload, mediated via ORAI1, contributes to the pathogenesis of acute pancreatitis. ORAI1 inhibitors might be developed

NAD(P)H-dependent quinone oxidoreductase 1 (NQO1) and cytochrome P450 oxidoreductase (CYP450OR) differentially regulate menadione-mediated alterations in redox status, survival and metabolism in pancreatic β-cells.

PubMed

Gray, Joshua P; Karandrea, Shpetim; Burgos, Delaine Zayasbazan; Jaiswal, Anil A; Heart, Emma A

2016-11-16

NQO1 (NAD(P)H-quinone oxidoreductase 1) reduces quinones and xenobiotics to less-reactive compounds via 2-electron reduction, one feature responsible for the role of NQO1 in antioxidant defense in several tissues. In contrast, NADPH cytochrome P450 oxidoreductase (CYP450OR), catalyzes the 1-electron reduction of quinones and xenobiotics, resulting in enhanced superoxide formation. However, to date, the roles of NQO1 and CYP450OR in pancreatic β-cell metabolism under basal conditions and oxidant challenge have not been characterized. Using NQO1 inhibition, over-expression and knock out, we have demonstrated that, in addition to protection of β-cells from toxic concentrations of the redox cycling quinone menadione, NQO1 also regulates the basal level of reduced-to-oxidized nucleotides, suggesting other role(s) beside that of an antioxidant enzyme. In contrast, over-expression of NADPH cytochrome P450 oxidoreductase (CYP450OR) resulted in enhanced redox cycling activity and decreased cellular viability, consistent with the enhanced generation of superoxide and H 2 O 2 . Basal expression of NQO1 and CYP450OR was comparable in isolated islets and liver. However, NQO1, but not CYP450OR, was strongly induced in β-cells exposed to menadione. NQO1 and CYP450OR exhibited a reciprocal preference for reducing equivalents in β-cells: while CYP450OR preferentially utilized NADPH, NQO1 primarily utilized NADH. Together, these results demonstrate that NQO1 and CYP450OR reciprocally regulate oxidant metabolism in pancreatic β-cells. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

NAD(P)H-dependent Quinone Oxidoreductase 1 (NQO1) and Cytochrome P450 Oxidoreductase (CYP450OR) differentially regulate menadione-mediated alterations in redox status, survival and metabolism in pancreatic β-cells

PubMed Central

Gray, Joshua P.; Karandrea, Shpetim; Burgos, Delaine Zayasbazan; Jaiswal, Anil A; Heart, Emma A.

2017-01-01

NQO1 (NAD(P)H-quinone oxidoreductase 1) reduces quinones and xenobiotics to less-reactive compounds via 2-electron reduction, one feature responsible for the role of NQO1 in antioxidant defense in several tissues. In contrast, NADPH cytochrome P450 oxidoreductase (CYP450OR), catalyzes the 1-electron reduction of quinones and xenobiotics, resulting in enhanced superoxide formation. However, to date, the roles of NQO1 and CYP450OR in pancreatic β-cell metabolism under basal conditions and oxidant challenge have not been characterized. Using NQO1 inhibition, over-expression and knock out, we have demonstrated that, in addition to protection of β-cells from toxic concentrations of the redox cycling quinone menadione, NQO1 also regulates the basal level of reduced-to-oxidized nucleotides, suggesting other role(s) beside that of an antioxidant enzyme. In contrast, over-expression of NADPH cytochrome P450 oxidoreductase (CYP450OR) resulted in enhanced redox cycling activity and decreased cellular viability, consistent with the enhanced generation of superoxide and H2O2. Basal expression of NQO1 and CYP450OR was comparable in isolated islets and liver. However, NQO1, but not CYP450OR, was strongly induced in β-cells exposed to menadione. NQO1 and CYP450OR exhibited a reciprocal preference for reducing equivalents in β-cells: while CYP450OR preferentially utilized NADPH, NQO1 primarily utilized NADH. Together, these results demonstrate that NQO1 and CYP450OR reciprocally regulate oxidant metabolism in pancreatic β-cells. PMID:27558805

Variation in the γ-glutamyltransferase 1 gene and risk of chronic pancreatitis.

PubMed

Brand, Harrison; Diergaarde, Brenda; O'Connell, Michael R; Whitcomb, David C; Brand, Randall E

2013-07-01

Individuals with chronic pancreatitis are at increased risk for pancreatic cancer. We hypothesized that genetic variation in the γ-glutamyltransferase 1 (GGT1) gene, which was recently reported associated with pancreatic cancer risk in a genome-wide association study, is also associated with risk of chronic pancreatitis. Associations between common polymorphisms in GGT1 and chronic pancreatitis were evaluated using data and samples from the North American Pancreatitis Study 2. Patients (n = 496) and control subjects (n = 465) were genotyped for 4 single-nucleotide polymorphisms: rs4820599, rs2017869, rs8135987, and rs5751901. Odds ratios (ORs) and corresponding 95% confidence intervals (95% CI) for chronic pancreatitis risk were calculated using multiple logistic regression models. Interactions with cigarette smoking and alcohol use were explored. Single-nucleotide polymorphisms rs8135987 and rs4820599 were both statistically significantly associated with risk of chronic pancreatitis; compared with common allele homozygotes, individuals with at least 1 minor allele were at increased risk (rs8135987: OR, 1.36; 95% CI, 1.03-1.80 [P(trend) = 0.01]; rs4820599: OR, 1.39; 95% CI, 1.04-1.84 [P(trend) = 0.0]; adjusted for age, sex, race, smoking status, and alcohol use). No significant interactions with cigarette smoking and alcohol use were observed. Our results suggest that common variation in the GGT1 gene may also affect risk of chronic pancreatitis.

Up-regulation of miR-146a contributes to the inhibition of invasion of pancreatic cancer cells

PubMed Central

Li, Yiwei; VandenBoom, Timothy G.; Wang, Zhiwei; Kong, Dejuan; Ali, Shadan; Philip, Philip A.; Sarkar, Fazlul H.

2009-01-01

Pancreatic cancer (PC) is an aggressive malignancy with high mortality and is believed to be in part due to its highly invasive and metastatic behavior, which is associated with over-expression of EGFR and activation of NF-κB. Emerging evidence also suggest critical roles of microRNAs (miRNAs) in the regulation of various pathobiological processes including metastasis in PC and in other human malignancies. In the present study, we found lower expression of miR-146a in PC cells compared to normal human pancreatic duct epithelial (HPDE) cells. Interestingly, re-expression of miR-146a inhibited the invasive capacity of Colo357 and Panc-1 PC cells with concomitant down-regulation of EGFR and IRAK-1. Mechanistic studies including miR-146a re-expression, anti-miR-146 transfection, and EGFR knock-down experiment showed that there was a crosstalk between EGFR, MTA-2, IRAK-1, IκBα and NF-κB. Most importantly, we found that the treatment of PC cells with “natural agents” [3,3′-diinodolylmethane (DIM) or isoflavone] led to an increase in the expression of miR-146a and consequently down-regulated the expression of EGFR, MTA-2, IRAK-1 and NF-κB, resulting in the inhibition of invasion of Colo357 and Panc-1 cells. These results provide experimental evidence in support of the role of DIM and isoflavone as potential non-toxic agents as regulators of miRNA, which could be useful for the inhibition of cancer cell invasion and metastasis, and further suggesting that these agents could be important for designing novel targeted strategy for the treatment of PC. PMID:25242818

Profiling CCK-mediated pancreatic growth: the dynamic genetic program and the role of STATs as potential regulators.

PubMed

Gurda, Grzegorz T; Wang, Jackie Y; Guo, LiLi; Ernst, Stephen A; Williams, John A

2012-01-18

Feeding mice with protease inhibitor (PI) leads to increased endogenous cholecystokinin (CCK) release and results in pancreatic growth. This adaptive response requires calcineurin (CN)-NFAT and AKT-mTOR pathways, but the genes involved, the dynamics of their expression, and other regulatory pathways remain unknown. Here, we examined the early (1-8 h) transcriptional program that underlies pancreatic growth. We found 314 upregulated and 219 downregulated genes with diverse temporal and functional profiles. Several new identifications include the following: stress response genes Gdf15 and Txnip, metabolic mediators Pitpnc1 and Hmges2, as well as components of growth factor response Fgf21, Atf3, and Egr1. The genes fell into seven self-organizing clusters, each with a distinct pattern of expression; a representative gene within each of the upregulated clusters (Egr1, Gadd45b, Rgs2, and Serpinb1a) was validated by qRT-PCR. Genes up at any point throughout the time course and CN-dependent genes were subjected to further bioinformatics-based networking and promoter analysis, yielding STATs as potential transcriptional regulators. As shown by PCR, qPCR, and Western blots, the active phospho-form of STAT3 and the Jak-STAT feedback inhibitor Socs2 were both increased throughout early pancreatic growth. Moreover, immunohistochemistry showed a CCK-dependent and acinar cell-specific increase in nuclear localization of p-STAT3, with >75% nuclear occupancy in PI-fed mice vs. <0.1% in controls. Thus, the study identified novel genes likely to be important for CCK-driven pancreatic growth, characterized and biologically validated the dynamic pattern of their expression and investigated STAT-Socs signaling as a new player in this trophic response.

MUC4 down-regulation reverses chemoresistance of pancreatic cancer stem/progenitor cells and their progenies.

PubMed

Mimeault, Murielle; Johansson, Sonny L; Senapati, Shantibhusan; Momi, Navneet; Chakraborty, Subhankar; Batra, Surinder K

2010-09-01

The present study was undertaken to estimate the therapeutic benefit to down-regulate the MUC4 mucin for reversing chemoresistance of pancreatic cancer (PC) stem/progenitor cells and their progenies. The results have revealed that MUC4 mucin is overexpressed in CD133(+) and CD133(-) pancreatic cells (PCs) detected in patient's adenocarcinoma tissues while no significant expression was seen in normal pancreatic tissues. The gain- and loss-of-function analyses have indicated that the overexpression of MUC4 in PC lines is associated with a higher resistance to the anti-proliferative, anti-invasive and apoptotic effects induced by gemcitabine. Importantly, the treatment of the MUC4-overexpressing CD18/HPAF-Src cells with gemcitabine resulted in an enrichment of the side population (SP) cells expressing CD133 while the total PC cells including non-SP cells detected in MUC4 knockdown CD18/HPAF-shMUC4 cells were responsive to the cytotoxic effects induced by gemcitabine. These data suggest that the MUC4 down-regulation may constitute a potential therapeutic strategy for improving the efficacy of gemcitabine to eradicate the total PC cell mass, and thereby preventing disease relapse. Copyright 2010 Elsevier Ireland Ltd. All rights reserved.

[Pancreatic acinar neoplasms : Comparative molecular characterization].

PubMed

Bergmann, F

2016-11-01

Pancreatic acinar cell carcinomas are biologically aggressive neoplasms for which treatment options are very limited. The molecular mechanisms of tumor initiation and progression are largely not understood and precursor lesions have not yet been identified. In this study, pancreatic acinar cell carcinomas were cytogenetically characterized as well as by molecular and immunohistochemical analyses. Corresponding investigations were carried out on pancreatic ductal adenocarcinomas and pancreatic neuroendocrine neoplasms augmented by functional analyses. We show that pancreatic acinar cell carcinomas display a microsatellite stable, chromosomal unstable genotype, characterized by recurrent chromosomal imbalances that clearly discriminate them from pancreatic ductal adenocarcinomas and neuroendocrine neoplasms. Based on findings obtained from comparative genomic hybridization, candidate genes could be identified, such as deleted in colorectal cancer (DCC) and c-MYC. Furthermore, several therapeutic targets were identified in acinar cell carcinomas and other pancreatic neoplasms, including epidermal growth factor receptor (EGFR), L1 cell adhesion molecule (L1CAM) and heat shock protein 90 (HSP90). Moreover, L1CAM was shown to play a significant role in the tumorigenesis of pancreatic ductal adenocarcinoma. Functional analyses in cell lines derived from pancreatic neuroendocrine neoplasms revealed promising anti-tumorigenic effects using EGFR and HSP90 inhibitors affecting the cell cycle and in the case of HSP90, regulating several other oncogenes. Finally, based on mutational analyses of mitochondrial DNA, molecular evidence is provided that acinar cell cystadenomas (or better cystic acinar transformation) represent non-clonal lesions, suggesting an inflammatory reactive non-neoplastic nature.

Morphological and immunohistochemical comparison of intrapancreatic nerves between chronic pancreatitis and type 1 autoimmune pancreatitis.

PubMed

Kato, Kota; Ikeura, Tsukasa; Yanagawa, Masato; Tomiyama, Takashi; Fukui, Toshiro; Uchida, Kazushige; Takaoka, Makoto; Nishio, Akiyoshi; Uemura, Yoshiko; Satoi, Sohei; Yamada, Hisao; Okazaki, Kazuichi

The abdominal pain associated with chronic pancreatitis (CP) may be related to the increased number and size of intrapancreatic nerves. On the other hand, patients with type 1 autoimmune pancreatitis (AIP) rarely suffer from the pain syndrome, and there are no previous studies concerning the histopathological findings of intrapancreatic nerves in patients with type 1 AIP. The current study is aimed at investigating the differences in the histopathological and immunohistochemical findings of intrapancreatic nerves in patients with CP and type 1 AIP. Neuroanatomical differences between CP and type 1 AIP were assessed by immunostaining with a pan-neuronal marker, protein gene product 9.5 (PGP9.5). The number (neural density) and area (neural hypertrophy) of PGP9.5-immunopositive nerves were quantitatively analyzed. Furthermore, the expression of nerve growth factor (NGF), and a high affinity receptor for NGF, tyrosine kinase receptor A (TrkA), was assessed by immunohistochemistry. Both neural density and hypertrophy were significantly greater in pancreatic tissue samples from patients with CP than those with normal pancreas or type 1 AIP. NGF expression was stronger in type 1 AIP than in CP, whereas TrkA expression in type 1 AIP was poorer than in CP. Although CP and type 1 AIP are both characterized by the presence of sustained pancreatic inflammation, they are different in terms of the density and hypertrophy of intrapancreatic nerve fibers. It is possible that this may be related to the difference in the activity of the NGF/TrkA-pathway between the two types of pancreatitis. Copyright © 2017 IAP and EPC. Published by Elsevier B.V. All rights reserved.

Macrophage/epithelium cross-talk regulates cell cycle progression and migration in pancreatic progenitors.

PubMed

Mussar, Kristin; Tucker, Andrew; McLennan, Linsey; Gearhart, Addie; Jimenez-Caliani, Antonio J; Cirulli, Vincenzo; Crisa, Laura

2014-01-01

Macrophages populate the mesenchymal compartment of all organs during embryogenesis and have been shown to support tissue organogenesis and regeneration by regulating remodeling of the extracellular microenvironment. Whether this mesenchymal component can also dictate select developmental decisions in epithelia is unknown. Here, using the embryonic pancreatic epithelium as model system, we show that macrophages drive the epithelium to execute two developmentally important choices, i.e. the exit from cell cycle and the acquisition of a migratory phenotype. We demonstrate that these developmental decisions are effectively imparted by macrophages activated toward an M2 fetal-like functional state, and involve modulation of the adhesion receptor NCAM and an uncommon "paired-less" isoform of the transcription factor PAX6 in the epithelium. Over-expression of this PAX6 variant in pancreatic epithelia controls both cell motility and cell cycle progression in a gene-dosage dependent fashion. Importantly, induction of these phenotypes in embryonic pancreatic transplants by M2 macrophages in vivo is associated with an increased frequency of endocrine-committed cells emerging from ductal progenitor pools. These results identify M2 macrophages as key effectors capable of coordinating epithelial cell cycle withdrawal and cell migration, two events critical to pancreatic progenitors' delamination and progression toward their differentiated fates.

Pancreatic stellate cells and CX3CR1: occurrence in normal pancreas, acute and chronic pancreatitis and effect of their activation by a CX3CR1 agonist

PubMed Central

Uchida, Masahiko; Ito, Tetsuhide; Nakamura, Taichi; Hijioka, Masayuki; Igarashi, Hisato; Oono, Takamasa; Kato, Masaki; Nakamura, Kazuhiko; Suzuki, Koichi; Takayanagi, Ryoichi; Jensen, Robert T.

2014-01-01

Objectives Numerous studies suggest important roles of the chemokine, fractalkine (CX3CL1) in acute/chronic pancreatitis, however the possible mechanisms of the effects are unclear. Pancreatic stellate cells (PSCs) can play important roles in pancreatitis, secreting inflammatory cytokines/chemokines, as well as proliferation. Therefore, we investigated CX3CL1 receptor (CX3CR1) occurrence in normal pancreas and pancreatitis (acute/chronic) tissues, and the effects of CX3CL1 on activated-PSCs. Methods CX3CR1 expression/localization in normal pancreas and pancreatitis (acute/chronic) tissues were evaluated with immunohistochemical analysis. CX3CR1 expression and effects of CX3CL1 on activated-PSCs were examined with realtime-PCR, BrdU assays and Western Blotting. Results In normal pancreas, acinar cells expressed CX3CR1 within granule-like-formations in the cytoplasm, whereas in acute/chronic pancreatitis, acinar, ductal and activated-PSCs expressed CX3CR1 on cell membranes. With activation of normal PSCs, CX3CR1 is increased. CX3CL1 activated multiple signaling cascades in PSCs. CX3CL1, did not induce inflammatory-genes expression in activated-PSCs, but induced proliferation. Conclusions CX3CR1s are expressed in normal pancreas. Expression is increased in acute/chronic pancreatitis and the CX3CR1s are activated. CX3CL1 induces proliferation of activated-PSCs without increasing release of inflammatory-mediators. These results suggest that CX3CR1 activation of PSCs could be important in their effects in pancreatitis, especially to PSCs proliferation in pancreatitis where CX3CL1 levels are elevated. PMID:24681877

Dclk1 Defines Quiescent Pancreatic Progenitors that Promote Injury-Induced Regeneration and Tumorigenesis.

PubMed

Westphalen, C Benedikt; Takemoto, Yoshihiro; Tanaka, Takayuki; Macchini, Marina; Jiang, Zhengyu; Renz, Bernhard W; Chen, Xiaowei; Ormanns, Steffen; Nagar, Karan; Tailor, Yagnesh; May, Randal; Cho, Youngjin; Asfaha, Samuel; Worthley, Daniel L; Hayakawa, Yoku; Urbanska, Aleksandra M; Quante, Michael; Reichert, Maximilian; Broyde, Joshua; Subramaniam, Prem S; Remotti, Helen; Su, Gloria H; Rustgi, Anil K; Friedman, Richard A; Honig, Barry; Califano, Andrea; Houchen, Courtney W; Olive, Kenneth P; Wang, Timothy C

2016-04-07

The existence of adult pancreatic progenitor cells has been debated. While some favor the concept of facultative progenitors involved in homeostasis and repair, neither a location nor markers for such cells have been defined. Using genetic lineage tracing, we show that Doublecortin-like kinase-1 (Dclk1) labels a rare population of long-lived, quiescent pancreatic cells. In vitro, Dclk1+ cells proliferate readily and sustain pancreatic organoid growth. In vivo, Dclk1+ cells are necessary for pancreatic regeneration following injury and chronic inflammation. Accordingly, their loss has detrimental effects after cerulein-induced pancreatitis. Expression of mutant Kras in Dclk1+ cells does not affect their quiescence or longevity. However, experimental pancreatitis converts Kras mutant Dclk1+ cells into potent cancer-initiating cells. As a potential effector of Kras, Dclk1 contributes functionally to the pathogenesis of pancreatic cancer. Taken together, these observations indicate that Dclk1 marks quiescent pancreatic progenitors that are candidates for the origin of pancreatic cancer. Copyright © 2016 Elsevier Inc. All rights reserved.

Genomic analyses identify molecular subtypes of pancreatic cancer.

PubMed

Bailey, Peter; Chang, David K; Nones, Katia; Johns, Amber L; Patch, Ann-Marie; Gingras, Marie-Claude; Miller, David K; Christ, Angelika N; Bruxner, Tim J C; Quinn, Michael C; Nourse, Craig; Murtaugh, L Charles; Harliwong, Ivon; Idrisoglu, Senel; Manning, Suzanne; Nourbakhsh, Ehsan; Wani, Shivangi; Fink, Lynn; Holmes, Oliver; Chin, Venessa; Anderson, Matthew J; Kazakoff, Stephen; Leonard, Conrad; Newell, Felicity; Waddell, Nick; Wood, Scott; Xu, Qinying; Wilson, Peter J; Cloonan, Nicole; Kassahn, Karin S; Taylor, Darrin; Quek, Kelly; Robertson, Alan; Pantano, Lorena; Mincarelli, Laura; Sanchez, Luis N; Evers, Lisa; Wu, Jianmin; Pinese, Mark; Cowley, Mark J; Jones, Marc D; Colvin, Emily K; Nagrial, Adnan M; Humphrey, Emily S; Chantrill, Lorraine A; Mawson, Amanda; Humphris, Jeremy; Chou, Angela; Pajic, Marina; Scarlett, Christopher J; Pinho, Andreia V; Giry-Laterriere, Marc; Rooman, Ilse; Samra, Jaswinder S; Kench, James G; Lovell, Jessica A; Merrett, Neil D; Toon, Christopher W; Epari, Krishna; Nguyen, Nam Q; Barbour, Andrew; Zeps, Nikolajs; Moran-Jones, Kim; Jamieson, Nigel B; Graham, Janet S; Duthie, Fraser; Oien, Karin; Hair, Jane; Grützmann, Robert; Maitra, Anirban; Iacobuzio-Donahue, Christine A; Wolfgang, Christopher L; Morgan, Richard A; Lawlor, Rita T; Corbo, Vincenzo; Bassi, Claudio; Rusev, Borislav; Capelli, Paola; Salvia, Roberto; Tortora, Giampaolo; Mukhopadhyay, Debabrata; Petersen, Gloria M; Munzy, Donna M; Fisher, William E; Karim, Saadia A; Eshleman, James R; Hruban, Ralph H; Pilarsky, Christian; Morton, Jennifer P; Sansom, Owen J; Scarpa, Aldo; Musgrove, Elizabeth A; Bailey, Ulla-Maja Hagbo; Hofmann, Oliver; Sutherland, Robert L; Wheeler, David A; Gill, Anthony J; Gibbs, Richard A; Pearson, John V; Waddell, Nicola; Biankin, Andrew V; Grimmond, Sean M

2016-03-03

Integrated genomic analysis of 456 pancreatic ductal adenocarcinomas identified 32 recurrently mutated genes that aggregate into 10 pathways: KRAS, TGF-β, WNT, NOTCH, ROBO/SLIT signalling, G1/S transition, SWI-SNF, chromatin modification, DNA repair and RNA processing. Expression analysis defined 4 subtypes: (1) squamous; (2) pancreatic progenitor; (3) immunogenic; and (4) aberrantly differentiated endocrine exocrine (ADEX) that correlate with histopathological characteristics. Squamous tumours are enriched for TP53 and KDM6A mutations, upregulation of the TP63∆N transcriptional network, hypermethylation of pancreatic endodermal cell-fate determining genes and have a poor prognosis. Pancreatic progenitor tumours preferentially express genes involved in early pancreatic development (FOXA2/3, PDX1 and MNX1). ADEX tumours displayed upregulation of genes that regulate networks involved in KRAS activation, exocrine (NR5A2 and RBPJL), and endocrine differentiation (NEUROD1 and NKX2-2). Immunogenic tumours contained upregulated immune networks including pathways involved in acquired immune suppression. These data infer differences in the molecular evolution of pancreatic cancer subtypes and identify opportunities for therapeutic development.

Progression of Pancreatic Adenocarcinoma Is Significantly Impeded with a Combination of Vaccine and COX-2 Inhibition1

PubMed Central

Mukherjee, Pinku; Basu, Gargi D.; Tinder, Teresa L.; Subramani, Durai B.; Bradley, Judy M.; Arefayene, Million; Skaar, Todd; De Petris, Giovanni

2013-01-01

With a 5-year survival rate of <5%, pancreatic cancer is one of the most rapidly fatal malignancies. Current protocols for the treatment of pancreas cancer are not as effective as we desire. In this study, we show that a novel Mucin-1 (MUC1)-based vaccine in combination with a cyclooxygenase-2 inhibitor (celecoxib), and low-dose chemotherapy (gemcitabine) was effective in preventing the progression of preneoplastic intraepithelial lesions to invasive pancreatic ductal adenocarcinomas. The study was conducted in an appropriate triple transgenic model of spontaneous pancreatic cancer induced by the KRASG12D mutation and that expresses human MUC1 as a self molecule. The combination treatment elicited robust antitumor cellular and humoral immune responses and was associated with increased apoptosis in the tumor. The mechanism for the increased immune response was attributed to the down-regulation of circulating prostaglandin E2 and indoleamine 2, 3,-dioxygenase enzymatic activity, as well as decreased levels of T regulatory and myeloid suppressor cells within the tumor microenvironment. The preclinical data provide the rationale to design clinical trials with a combination of MUC1-based vaccine, celecoxib, and gemcitabine for the treatment of pancreatic cancer. PMID:19109152

GLUT-1 Expression in Pancreatic Neoplasia

PubMed Central

Basturk, Olca; Singh, Rajendra; Kaygusuz, Ecmel; Balci, Serdar; Dursun, Nevra; Culhaci, Nil; Adsay, N. Volkan

2011-01-01

Objectives GLUT-1 has been found to have an important role in the upregulation of various cellular pathways and implicated in neoplastic transformation correlating with biological behavior in malignancies. However, literature regarding the significance of GLUT-1 expression in pancreatic neoplasia has been limited and controversial. Methods Immunohistochemical expression of GLUT-1 was tested in a variety of pancreatic neoplasia including ductal adenocarcinomas (DAs), pancreatic intraepithelial neoplasms (PanINs), intraductal papillary mucinous neoplasms (IPMNs), and serous cystadenomas. Results There was a progressive increase in the expression of GLUT-1 from low- to higher-grade dysplastic lesions: All higher-grade PanINs/IPMNs (the ones with moderate/high-grade dysplasia) revealed noticeable GLUT-1 expression. Among the 94 DAs analyzed, there were minimal/moderate expression in 46 and significant expression in 24 DAs. However, all 4 clear-cell variants of DAs revealed significant GLUT-1 immunolabeling, as did areas of clear-cell change seen in other DAs. Moreover, all 12 serous cystadenomas expressed significant GLUT-1. GLUT-1 expression was also directly correlated with DA histological grade (P = 0.016) and tumor size (P = 0.03). Conclusions GLUT-1 may give rise to the distinctive clear-cell appearance of these tumors by inducing the accumulation of glycogen in the cytoplasm. Additionally, because GLUT-1 expression was related to histological grade and tumor size of DA, further studies are warranted to investigate the association of GLUT-1 with prognosis and tumor progression. PMID:21206329

Cholecystokinin induces caspase activation and mitochondrial dysfunction in pancreatic acinar cells. Roles in cell injury processes of pancreatitis.

PubMed

Gukovskaya, Anna S; Gukovsky, Ilya; Jung, Yoon; Mouria, Michelle; Pandol, Stephen J

2002-06-21

Apoptosis and necrosis are critical parameters of pancreatitis, the mechanisms of which remain unknown. Many characteristics of pancreatitis can be studied in vitro in pancreatic acini treated with high doses of cholecystokinin (CCK). We show here that CCK stimulates apoptosis and death signaling pathways in rat pancreatic acinar cells, including caspase activation, cytochrome c release, and mitochondrial depolarization. The mitochondrial dysfunction is mediated by upstream caspases (possibly caspase-8) and, in turn, leads to activation of caspase-3. CCK causes mitochondrial alterations through both permeability transition pore-dependent (cytochrome c release) and permeability transition pore-independent (mitochondrial depolarization) mechanisms. Caspase activation and mitochondrial alterations also occur in untreated pancreatic acinar cells; however, the underlying mechanisms are different. In particular, caspases protect untreated acinar cells from mitochondrial damage. We found that caspases not only mediate apoptosis but also regulate other parameters of CCK-induced acinar cell injury that are characteristic of pancreatitis; in particular, caspases negatively regulate necrosis and trypsin activation in acinar cells. The results suggest that the observed signaling pathways regulate parenchymal cell injury and death in CCK-induced pancreatitis. Protection against necrosis and trypsin activation by caspases can explain why the severity of pancreatitis in experimental models correlates inversely with the extent of apoptosis.

The long and the short of SAD-1 kinase.

PubMed

Kim, Joanne S M; Hung, Wesley; Zhen, Mei

2010-05-01

The Ser/Thr SAD kinases are evolutionarily conserved, critical regulators of neural development. Exciting findings in recent years have significantly advanced our understanding of the mechanism through which SAD kinases regulate neural development. Mammalian SAD-A and SAD-B, activated by a master kinase LKB1, regulate microtubule dynamics and polarize neurons. In C. elegans, the sad-1 gene encodes two isoforms, namely the long and the short, which exhibit overlapping and yet distinct functions in neuronal polarity and synaptic organization. Surprisingly, our most recent findings in C. elegans revealed a SAD-1-independent LKB1 activity in neuronal polarity. We also found that the long SAD-1 isoform directly interacts with a STRADalpha pseudokinase, STRD-1, to regulate neuronal polarity and synaptic organization. We elaborate here a working model of SAD-1 in which the two isoforms dimer/oligomerize to form a functional complex, and STRD-1 clusters and localizes the SAD-1 complex to synapses. While the mechanistic difference between the vertebrate and invertebrate SAD kinases may be puzzling, a recent discovery of the functionally distinct SAD-B isoforms predicts that the difference likely arises from our incomplete understanding of the SAD kinase mechanism and may eventually be reconciled as the revelation continues.

Sirtuin 1 stimulates the proliferation and the expression of glycolysis genes in pancreatic neoplastic lesions.

PubMed

Pinho, Andreia V; Mawson, Amanda; Gill, Anthony; Arshi, Mehreen; Warmerdam, Max; Giry-Laterriere, Marc; Eling, Nils; Lie, Triyana; Kuster, Evelyne; Camargo, Simone; Biankin, Andrew V; Wu, Jianmin; Rooman, Ilse

2016-11-15

Metabolic reprogramming is a feature of neoplasia and tumor growth. Sirtuin 1 (SIRT1) is a lysine deacetylase of multiple targets including metabolic regulators such as p53. SIRT1 regulates metaplasia in the pancreas. Nevertheless, it is unclear if SIRT1 affects the development of neoplastic lesions and whether metabolic gene expression is altered.To assess neoplastic lesion development, mice with a pancreas-specific loss of Sirt1 (Pdx1-Cre;Sirt1-lox) were bred into a KrasG12D mutant background (KC) that predisposes to the development of pancreatic intra-epithelial neoplasia (PanIN) and ductal adenocarcinoma (PDAC). Similar grade PanIN lesions developed in KC and KC;Sirt1-lox mice but specifically early mucinous PanINs occupied 40% less area in the KC;Sirt1-lox line, attributed to reduced proliferation. This was accompanied by reduced expression of proteins in the glycolysis pathway, such as GLUT1 and GAPDH.The stimulatory effect of SIRT1 on proliferation and glycolysis gene expression was confirmed in a human PDAC cell line. In resected PDAC samples, higher proliferation and expression of glycolysis genes correlated with poor patient survival. SIRT1 expression per se was not prognostic but low expression of Cell Cycle and Apoptosis Regulator 2 (CCAR2), a reported SIRT1 inhibitor, corresponded to poor patient survival.These findings open perspectives for novel targeted therapies in pancreatic cancer.

Pdx-1 and Ptf1a concurrently determine fate specification of pancreatic multipotent progenitor cells

PubMed Central

Burlison, Jared S.; Long, Qiaoming; Fujitani, Yoshio; Wright, Christopher V.E.; Magnuson, Mark A.

2008-01-01

The pancreas is derived from a pool of multipotent progenitor cells (MPCs) that co-express Pdx-1 and Ptf1a. To more precisely define how the individual and combined loss of Pdx-1 and Ptf1a affects pancreatic MPC specification and differentiation we derived and studied mice bearing a novel Ptf1aYFP allele. While the expression of Pdx-1 and Ptf1a in pancreatic MPCs coincides between E9.5–12.5 the developmental phenotypes of Pdx-1 null and Pdx-1; Ptf1a double null mice are indistinguishable, and an early pancreatic bud is formed in both cases. This finding indicates that Pdx-1 is required in the foregut endoderm prior to Ptf1a for pancreatic MPC specification. We also found that Ptf1a is neither required for specification of Ngn3-positive endocrine progenitors nor differentiation of mature β-cells. In the absence of Pdx-1 Ngn3-positive cells were not observed after E9.5. Thus, in contrast to the deletion of Ptf1a, the loss of Pdx-1 precludes the sustained Ngn3-based derivation of endocrine progenitors from pancreatic MPCs. Taken together, these studies indicate that Pdx-1 and Ptf1a have distinct but interdependent functions during pancreatic MPC specification. PMID:18294628

Pdx-1 and Ptf1a concurrently determine fate specification of pancreatic multipotent progenitor cells.

PubMed

Burlison, Jared S; Long, Qiaoming; Fujitani, Yoshio; Wright, Christopher V E; Magnuson, Mark A

2008-04-01

The pancreas is derived from a pool of multipotent progenitor cells (MPCs) that co-express Pdx-1 and Ptf1a. To more precisely define how the individual and combined loss of Pdx-1 and Ptf1a affects pancreatic MPC specification and differentiation we derived and studied mice bearing a novel Ptf1a(YFP) allele. While the expression of Pdx-1 and Ptf1a in pancreatic MPCs coincides between E9.5 and 12.5 the developmental phenotypes of Pdx-1 null and Pdx-1; Ptf1a double null mice are indistinguishable, and an early pancreatic bud is formed in both cases. This finding indicates that Pdx-1 is required in the foregut endoderm prior to Ptf1a for pancreatic MPC specification. We also found that Ptf1a is neither required for specification of Ngn3-positive endocrine progenitors nor differentiation of mature beta-cells. In the absence of Pdx-1 Ngn3-positive cells were not observed after E9.5. Thus, in contrast to the deletion of Ptf1a, the loss of Pdx-1 precludes the sustained Ngn3-based derivation of endocrine progenitors from pancreatic MPCs. Taken together, these studies indicate that Pdx-1 and Ptf1a have distinct but interdependent functions during pancreatic MPC specification.

HIF-1 maintains a functional relationship between pancreatic cancer cells and stromal fibroblasts by upregulating expression and secretion of Sonic hedgehog

PubMed Central

Katagiri, Tomohiro; Kobayashi, Minoru; Yoshimura, Michio; Morinibu, Akiyo; Itasaka, Satoshi; Hiraoka, Masahiro; Harada, Hiroshi

2018-01-01

Hypoxic and stroma-rich microenvironments, characteristic features of pancreatic cancers, are strongly associated with a poor prognosis. However, whether and how hypoxia increases stromal compartments remain largely unknown. Here, we investigated the potential importance of a master regulator of the cellular adaptive response to hypoxia, hypoxia-inducible factor-1 (HIF-1), in the formation of stroma-rich microenvironments of pancreatic tumors. We found that pancreatic cancer cells secreted more Sonic hedgehog protein (SHH) under hypoxia by upregulating its expression and efficiency of secretion in a HIF-1-dependent manner. Recombinant SHH, which was confirmed to activate the hedgehog signaling pathway, accelerated the growth of fibroblasts in a dose-dependent manner. The SHH protein secreted from pancreatic cancer cells under hypoxic conditions promoted the growth of fibroblasts by stimulating their Sonic hedgehog signaling pathway. These results suggest that the increased secretion of SHH by HIF-1 is potentially responsible for the formation of detrimental and stroma-rich microenvironments in pancreatic cancers, therefore providing a rational basis to target it in cancer therapy. PMID:29535824

Pancreatic stellate cells and CX3CR1: occurrence in normal pancreas and acute and chronic pancreatitis and effect of their activation by a CX3CR1 agonist.

PubMed

Uchida, Masahiko; Ito, Tetsuhide; Nakamura, Taichi; Hijioka, Masayuki; Igarashi, Hisato; Oono, Takamasa; Kato, Masaki; Nakamura, Kazuhiko; Suzuki, Koichi; Takayanagi, Ryoichi; Jensen, Robert T

2014-07-01

Numerous studies suggest important roles of the chemokine, fractalkine (CX3CL1), in acute/chronic pancreatitis; however, the possible mechanisms of the effects are unclear. Pancreatic stellate cells (PSCs) can play important roles in pancreatitis, secreting inflammatory cytokines/chemokines, as well as proliferation. Therefore, we investigated CX3CL1 receptor (CX3CR1) occurrence in normal pancreas and pancreatitis (acute/chronic) tissues and the effects of CX3CL1 on activated PSCs. CX3CR1 expression/localization in normal pancreas and pancreatitis (acute/chronic) tissues was evaluated with immunohistochemical analysis. CX3CR1 expression and effects of CX3CL1 on activated PSCs were examined with real-time polymerase chain reaction, BrdU (5-bromo-2-deoxyuridine) assays, and Western blotting. In normal pancreas, acinar cells expressed CX3CR1 within granule-like formations in the cytoplasm, whereas in acute/chronic pancreatitis, acinar, ductal, and activated PSCs expressed CX3CR1 on cell membranes. With activation of normal PSCs, CX3CR1 is increased. CX3CL1 activated multiple signaling cascades in PSCs. CX3CL1 did not induce inflammatory genes expression in activated PSCs, but induced proliferation. CX3CR1s are expressed in normal pancreas. Expression is increased in acute/chronic pancreatitis, and the CX3CR1s are activated. CX3CL1 induces proliferation of activated PSCs without increasing release of inflammatory mediators. These results suggest that CX3CR1 activation of PSCs could be important in their effects in pancreatitis, especially to PSC proliferation in pancreatitis where CX3CL1 levels are elevated.

[Persistence of chronic inflammatory responses, role in the development of chronic pancreatitis, obesity and pancreatic cancer].

PubMed

Khristich, T N

2014-11-01

The purpose of the review--to analyze the basic data of the role of chronic low-intensity inflammatory response as general biological process in the development and progression of chronic pancreatitis, obesity, and pancreatic cancer. Highlighted evidence from epidemiological studies showing that chronic pancreatitis and obesity are independent risk factors for pancreatic cancer, regardless of diabetes. Studied role of adipokines as Cytokines regulating of immune inflammatory response. Draws attention to the staging of pancreatic cancer in obesity.

Nicotine, IFN-γ and retinoic acid mediated induction of MUC4 in pancreatic cancer requires E2F1 and STAT-1 transcription factors and utilize different signaling cascades.

PubMed

Kunigal, Sateesh; Ponnusamy, Moorthy P; Momi, Navneet; Batra, Surinder K; Chellappan, Srikumar P

2012-04-26

The membrane-bound mucins are thought to play an important biological role in cell-cell and cell-matrix interactions, in cell signaling and in modulating biological properties of cancer cell. MUC4, a transmembrane mucin is overexpressed in pancreatic tumors, while remaining undetectable in the normal pancreas, thus indicating a potential role in pancreatic cancer pathogenesis. The molecular mechanisms involved in the regulation of MUC4 gene are not yet fully understood. Smoking is strongly correlated with pancreatic cancer and in the present study; we elucidate the molecular mechanisms by which nicotine as well as agents like retinoic acid (RA) and interferon-γ (IFN-γ) induce the expression of MUC4 in pancreatic cancer cell lines CD18, CAPAN2, AsPC1 and BxPC3. Chromatin immunoprecipitation assays and real-time PCR showed that transcription factors E2F1 and STAT1 can positively regulate MUC4 expression at the transcriptional level. IFN-γ and RA could collaborate with nicotine in elevating the expression of MUC4, utilizing E2F1 and STAT1 transcription factors. Depletion of STAT1 or E2F1 abrogated the induction of MUC4; nicotine-mediated induction of MUC4 appeared to require α7-nicotinic acetylcholine receptor subunit. Further, Src and ERK family kinases also mediated the induction of MUC4, since inhibiting these signaling molecules prevented the induction of MUC4. MUC4 was also found to be necessary for the nicotine-mediated invasion of pancreatic cancer cells, suggesting that induction of MUC4 by nicotine and other agents might contribute to the genesis and progression of pancreatic cancer. Our studies show that agents that can promote the growth and invasion of pancreatic cancer cells induce the MUC4 gene through multiple pathways and this induction requires the transcriptional activity of E2F1 and STAT1. Further, the Src as well as ERK signaling pathways appear to be involved in the induction of this gene. It appears that targeting these signaling pathways

Nicotine, IFN-γ and retinoic acid mediated induction of MUC4 in pancreatic cancer requires E2F1 and STAT-1 transcription factors and utilize different signaling cascades

PubMed Central

2012-01-01

Background The membrane-bound mucins are thought to play an important biological role in cell–cell and cell–matrix interactions, in cell signaling and in modulating biological properties of cancer cell. MUC4, a transmembrane mucin is overexpressed in pancreatic tumors, while remaining undetectable in the normal pancreas, thus indicating a potential role in pancreatic cancer pathogenesis. The molecular mechanisms involved in the regulation of MUC4 gene are not yet fully understood. Smoking is strongly correlated with pancreatic cancer and in the present study; we elucidate the molecular mechanisms by which nicotine as well as agents like retinoic acid (RA) and interferon-γ (IFN-γ) induce the expression of MUC4 in pancreatic cancer cell lines CD18, CAPAN2, AsPC1 and BxPC3. Results Chromatin immunoprecipitation assays and real-time PCR showed that transcription factors E2F1 and STAT1 can positively regulate MUC4 expression at the transcriptional level. IFN-γ and RA could collaborate with nicotine in elevating the expression of MUC4, utilizing E2F1 and STAT1 transcription factors. Depletion of STAT1 or E2F1 abrogated the induction of MUC4; nicotine-mediated induction of MUC4 appeared to require α7-nicotinic acetylcholine receptor subunit. Further, Src and ERK family kinases also mediated the induction of MUC4, since inhibiting these signaling molecules prevented the induction of MUC4. MUC4 was also found to be necessary for the nicotine-mediated invasion of pancreatic cancer cells, suggesting that induction of MUC4 by nicotine and other agents might contribute to the genesis and progression of pancreatic cancer. Conclusions Our studies show that agents that can promote the growth and invasion of pancreatic cancer cells induce the MUC4 gene through multiple pathways and this induction requires the transcriptional activity of E2F1 and STAT1. Further, the Src as well as ERK signaling pathways appear to be involved in the induction of this gene. It appears that

PRSS1 and SPINK1 mutations in idiopathic chronic and recurrent acute pancreatitis.

PubMed

Pelaez-Luna, Mario; Robles-Diaz, Guillermo; Canizales-Quinteros, Samuel; Tusié-Luna, Maria T

2014-09-07

To identify gene mutations in PRSS1 and SPINK1 in individuals with early onset idiopathic chronic or recurrent acute pancreatitis. The cationic trypsinogen gene (PRSS1; exons 2 and 3) and the serine protease inhibitor Kazal 1 gene (SPINK1; exon 3) were selectively amplified and sequenced from blood samples of 19 patients admitted to the Pancreas Clinic at our institution with chronic pancreatitis and/or idiopathic recurrent acute pancreatitis that were diagnosed or with onset before age 35. Fifty healthy volunteers served as controls. Whole blood samples were collected and gene specific sequences were amplified by polymerase chain reaction (PCR). All PCR products were subsequently sequenced in order to identify the presence of any mutations. Nineteen patients with pancreatitis (14 males; median age 24 years, range 15-48 years) were included in this study, of which five showed the presence of gene mutations. Direct sequencing results indicated the presence of two previously unidentified mutations in exon 2 of PRSS1 (V39E and N42S) in two patients with recurrent acute pancreatitis. Two cases had the N34S SPINK1 mutation. Analysis of the relatives of one patient homozygous for this mutation showed that five of the six family members carried the N34S SPINK1 mutation. Of these members, three were healthy heterozygous carriers and two were homozygotes (one sibling had diabetes, the other was healthy). Another patient was heterozygous for a novel SPINK1 mutation located on exon 3 (V46D). All members from this patient's family had normal genotypes, indicating that it was a de novo mutation. No mutations in either gene were present in the control subjects. Two novel PRSS1 mutations and one novel SPINK1 mutation were identified in Mexican patients with early onset idiopathic recurrent acute pancreatitis.

SEL1L Regulates Adhesion, Proliferation and Secretion of Insulin by Affecting Integrin Signaling

PubMed Central

Diaferia, Giuseppe R.; Cirulli, Vincenzo; Biunno, Ida

2013-01-01

SEL1L, a component of the endoplasmic reticulum associated degradation (ERAD) pathway, has been reported to regulate the (i) differentiation of the pancreatic endocrine and exocrine tissue during the second transition of mouse embryonic development, (ii) neural stem cell self-renewal and lineage commitment and (iii) cell cycle progression through regulation of genes related to cell-matrix interaction. Here we show that in the pancreas the expression of SEL1L is developmentally regulated, such that it is readily detected in developing islet cells and in nascent acinar clusters adjacent to basement membranes, and becomes progressively restricted to the islets of Langherans in post-natal life. This peculiar expression pattern and the presence of two inverse RGD motifs in the fibronectin type II domain of SEL1L protein indicate a possible interaction with cell adhesion molecules to regulate islets architecture. Co-immunoprecipitation studies revealed SEL1L and ß1-integrin interaction and, down-modulation of SEL1L in pancreatic ß-cells, negatively influences both cell adhesion on selected matrix components and cell proliferation likely due to altered ERK signaling. Furthermore, the absence of SEL1L protein strongly inhibits glucose-stimulated insulin secretion in isolated mouse pancreatic islets unveiling an important role of SEL1L in insulin trafficking. This phenotype can be rescued by the ectopic expression of the ß1-integrin subunit confirming the close interaction of these two proteins in regulating the cross-talk between extracellular matrix and insulin signalling to create a favourable micro-environment for ß-cell development and function. PMID:24324549

Nuclear hormone retinoid X receptor (RXR) negatively regulates the glucose-stimulated insulin secretion of pancreatic ß-cells.

PubMed

Miyazaki, Satsuki; Taniguchi, Hidenori; Moritoh, Yusuke; Tashiro, Fumi; Yamamoto, Tsunehiko; Yamato, Eiji; Ikegami, Hiroshi; Ozato, Keiko; Miyazaki, Jun-ichi

2010-11-01

Retinoid X receptors (RXRs) are members of the nuclear hormone receptor superfamily and are thought to be key regulators in differentiation, cellular growth, and gene expression. Although several experiments using pancreatic β-cell lines have shown that the ligands of nuclear hormone receptors modulate insulin secretion, it is not clear whether RXRs have any role in insulin secretion. To elucidate the function of RXRs in pancreatic β-cells, we generated a double-transgenic mouse in which a dominant-negative form of RXRβ was inducibly expressed in pancreatic β-cells using the Tet-On system. We also established a pancreatic β-cell line from an insulinoma caused by the β-cell-specific expression of simian virus 40 T antigen in the above transgenic mouse. In the transgenic mouse, expression of the dominant-negative RXR enhanced the insulin secretion with high glucose stimulation. In the pancreatic β-cell line, the suppression of RXRs also enhanced glucose-stimulated insulin secretion at a high glucose concentration, while 9-cis-retinoic acid, an RXR agonist, repressed it. High-density oligonucleotide microarray analysis showed that expression of the dominant-negative RXR affected the expression levels of a number of genes, some of which have been implicated in the function and/or differentiation of β-cells. These results suggest that endogenous RXR negatively regulates the glucose-stimulated insulin secretion. Given these findings, we propose that the modulation of endogenous RXR in β-cells may be a new therapeutic approach for improving impaired insulin secretion in type 2 diabetes.

Inhibition of Chronic Pancreatitis and Murine Pancreatic Intraepithelial Neoplasia by a Dual Inhibitor of c-RAF and Soluble Epoxide Hydrolase in LSL-KrasG12D/Pdx-1-Cre Mice

PubMed Central

LIAO, JIE; HWANG, SUNG HEE; LI, HAONAN; LIU, JUN-YAN; HAMMOCK, BRUCE D.; YANG, GUANG-YU

2016-01-01

Mutation of Kirsten rat sarcoma viral oncogene homolog (KRAS) and chronic pancreatitis are the most common pathogenic events involved in human pancreatic carcinogenesis. In the process of long-standing chronic inflammation, aberrant metabolites of arachidonic acid play a crucial role in promoting carcinogenesis, in which the soluble epoxide hydrolase (sEH), as a pro-inflammatory enzyme, generally inactivates anti-inflammatory epoxyeicosatrienoic acids (EETs). Herein, we determined the effect of our newly-synthesized novel compound trans-4-{4-[3-(4-chloro-3-trifluoromethyl-phenyl)-ureido]-cyclohexyloxy}-pyridine-2-carboxylic acid methylamide (t-CUPM), a dual inhibitor of sEH and RAF1 proto-oncogene serine/threonine kinase (c-RAF), on inhibiting the development of pancreatitis and pancreatic intraepithelial neoplasia (mPanIN) in LSL-KrasG12D/Pdx1-Cre mice. The results showed that t-CUPM significantly reduced the severity of chronic pancreatitis, as measured by the extent of acini loss, inflammatory cell infiltration and stromal fibrosis. The progression of low-grade mPanIN I to high-grade mPanIN II/III was significantly suppressed. Inhibition of mutant Kras-transmitted phosphorylation of mitogen-activated protein kinase’s kinase/extracellular signal-regulated kinases was demonstrated in pancreatic tissues by western blots. Quantitative real-time polymerase chain reaction analysis revealed that t-CUPM treatment significantly reduced the levels of inflammatory cytokines including tumor necrosis facor-α, monocyte chemoattractant protein-1, as well as vascular adhesion molecule-1, and the levels of Sonic hedgehog and Gli transcription factor (Hedgehog pathway). Analysis of the eicosanoid profile revealed a significant increase of the EETs/dihydroxyeicosatrienoic acids ratio, which further confirmed sEH inhibition by t-CUPM. These results indicate that simultaneous inhibition of sEH and c-RAF by t-CUPM is important in preventing chronic pancreatitis and carcinogenesis

Transient receptor potential ankyrin 1 mediates chronic pancreatitis pain in mice.

PubMed

Cattaruzza, Fiore; Johnson, Cali; Leggit, Alan; Grady, Eileen; Schenk, A Katrin; Cevikbas, Ferda; Cedron, Wendy; Bondada, Sandhya; Kirkwood, Rebekah; Malone, Brian; Steinhoff, Martin; Bunnett, Nigel; Kirkwood, Kimberly S

2013-06-01

Chronic pancreatitis (CP) is a devastating disease characterized by persistent and uncontrolled abdominal pain. Our lack of understanding is partially due to the lack of experimental models that mimic the human disease and also to the lack of validated behavioral measures of visceral pain. The ligand-gated cation channel transient receptor potential ankyrin 1 (TRPA1) mediates inflammation and pain in early experimental pancreatitis. It is unknown if TRPA1 causes fibrosis and sustained pancreatic pain. We induced CP by injecting the chemical agent trinitrobenzene sulfonic acid (TNBS), which causes severe acute pancreatitis, into the pancreatic duct of C57BL/6 trpa1(+/+) and trpa1(-/-) mice. Chronic inflammatory changes and pain behaviors were assessed after 2-3 wk. TNBS injection caused marked pancreatic fibrosis with increased collagen-staining intensity, atrophy, fatty replacement, monocyte infiltration, and pancreatic stellate cell activation, and these changes were reflected by increased histological damage scores. TNBS-injected animals showed mechanical hypersensitivity during von Frey filament probing of the abdomen, decreased daily voluntary wheel-running activity, and increased immobility scores during open-field testing. Pancreatic TNBS also reduced the threshold to hindpaw withdrawal to von Frey filament probing, suggesting central sensitization. Inflammatory changes and pain indexes were significantly reduced in trpa1(-/-) mice. In conclusion, we have characterized in mice a model of CP that resembles the human condition, with marked histological changes and behavioral measures of pain. We have demonstrated, using novel and objective pain measurements, that TRPA1 mediates inflammation and visceral hypersensitivity in CP and could be a therapeutic target for the treatment of sustained inflammatory abdominal pain.

Calcium-Oxidant Signaling Network Regulates AMP-activated Protein Kinase (AMPK) Activation upon Matrix Deprivation*

PubMed Central

Sundararaman, Ananthalakshmy; Amirtham, Usha; Rangarajan, Annapoorni

2016-01-01

The AMP-activated protein kinase (AMPK) has recently been implicated in anoikis resistance. However, the molecular mechanisms that activate AMPK upon matrix detachment remain unexplored. In this study, we show that AMPK activation is a rapid and sustained phenomenon upon matrix deprivation, whereas re-attachment to the matrix leads to its dephosphorylation and inactivation. Because matrix detachment leads to loss of integrin signaling, we investigated whether integrin signaling negatively regulates AMPK activation. However, modulation of focal adhesion kinase or Src, the major downstream components of integrin signaling, failed to cause a corresponding change in AMPK signaling. Further investigations revealed that the upstream AMPK kinases liver kinase B1 (LKB1) and Ca2+/calmodulin-dependent protein kinase kinase β (CaMKKβ) contribute to AMPK activation upon detachment. In LKB1-deficient cells, we found AMPK activation to be predominantly dependent on CaMKKβ. We observed no change in ATP levels under detached conditions at early time points suggesting that rapid AMPK activation upon detachment was not triggered by energy stress. We demonstrate that matrix deprivation leads to a spike in intracellular calcium as well as oxidant signaling, and both these intracellular messengers contribute to rapid AMPK activation upon detachment. We further show that endoplasmic reticulum calcium release-induced store-operated calcium entry contributes to intracellular calcium increase, leading to reactive oxygen species production, and AMPK activation. We additionally show that the LKB1/CaMKK-AMPK axis and intracellular calcium levels play a critical role in anchorage-independent cancer sphere formation. Thus, the Ca2+/reactive oxygen species-triggered LKB1/CaMKK-AMPK signaling cascade may provide a quick, adaptable switch to promote survival of metastasizing cancer cells. PMID:27226623

Pancreas lineage allocation and specification are regulated by sphingosine-1-phosphate signalling.

PubMed

Serafimidis, Ioannis; Rodriguez-Aznar, Eva; Lesche, Mathias; Yoshioka, Kazuaki; Takuwa, Yoh; Dahl, Andreas; Pan, Duojia; Gavalas, Anthony

2017-03-01

During development, progenitor expansion, lineage allocation, and implementation of differentiation programs need to be tightly coordinated so that different cell types are generated in the correct numbers for appropriate tissue size and function. Pancreatic dysfunction results in some of the most debilitating and fatal diseases, including pancreatic cancer and diabetes. Several transcription factors regulating pancreas lineage specification have been identified, and Notch signalling has been implicated in lineage allocation, but it remains unclear how these processes are coordinated. Using a combination of genetic approaches, organotypic cultures of embryonic pancreata, and genomics, we found that sphingosine-1-phosphate (S1p), signalling through the G protein coupled receptor (GPCR) S1pr2, plays a key role in pancreas development linking lineage allocation and specification. S1pr2 signalling promotes progenitor survival as well as acinar and endocrine specification. S1pr2-mediated stabilisation of the yes-associated protein (YAP) is essential for endocrine specification, thus linking a regulator of progenitor growth with specification. YAP stabilisation and endocrine cell specification rely on Gαi subunits, revealing an unexpected specificity of selected GPCR intracellular signalling components. Finally, we found that S1pr2 signalling posttranscriptionally attenuates Notch signalling levels, thus regulating lineage allocation. Both S1pr2-mediated YAP stabilisation and Notch attenuation are necessary for the specification of the endocrine lineage. These findings identify S1p signalling as a novel key pathway coordinating cell survival, lineage allocation, and specification and linking these processes by regulating YAP levels and Notch signalling. Understanding lineage allocation and specification in the pancreas will shed light in the origins of pancreatic diseases and may suggest novel therapeutic approaches.

Pancreas lineage allocation and specification are regulated by sphingosine-1-phosphate signalling

PubMed Central

Serafimidis, Ioannis; Rodriguez-Aznar, Eva; Lesche, Mathias; Yoshioka, Kazuaki; Takuwa, Yoh; Dahl, Andreas; Pan, Duojia; Gavalas, Anthony

2017-01-01

During development, progenitor expansion, lineage allocation, and implementation of differentiation programs need to be tightly coordinated so that different cell types are generated in the correct numbers for appropriate tissue size and function. Pancreatic dysfunction results in some of the most debilitating and fatal diseases, including pancreatic cancer and diabetes. Several transcription factors regulating pancreas lineage specification have been identified, and Notch signalling has been implicated in lineage allocation, but it remains unclear how these processes are coordinated. Using a combination of genetic approaches, organotypic cultures of embryonic pancreata, and genomics, we found that sphingosine-1-phosphate (S1p), signalling through the G protein coupled receptor (GPCR) S1pr2, plays a key role in pancreas development linking lineage allocation and specification. S1pr2 signalling promotes progenitor survival as well as acinar and endocrine specification. S1pr2-mediated stabilisation of the yes-associated protein (YAP) is essential for endocrine specification, thus linking a regulator of progenitor growth with specification. YAP stabilisation and endocrine cell specification rely on Gαi subunits, revealing an unexpected specificity of selected GPCR intracellular signalling components. Finally, we found that S1pr2 signalling posttranscriptionally attenuates Notch signalling levels, thus regulating lineage allocation. Both S1pr2-mediated YAP stabilisation and Notch attenuation are necessary for the specification of the endocrine lineage. These findings identify S1p signalling as a novel key pathway coordinating cell survival, lineage allocation, and specification and linking these processes by regulating YAP levels and Notch signalling. Understanding lineage allocation and specification in the pancreas will shed light in the origins of pancreatic diseases and may suggest novel therapeutic approaches. PMID:28248965

Nicotine/Cigarette-smoke Promotes Metastasis of Pancreatic Cancer Through α7nAChR-mediated MUC4 Up-regulation

PubMed Central

Momi, Navneet; Ponnusamy, Moorthy P.; Kaur, Sukhwinder; Rachagani, Satyanarayana; Kunigal, Sateesh S; Chellappan, Srikumar; Ouellette, Michel M; Batra, Surinder K

2012-01-01

Despite evidence that long-term smoking is the leading risk factor for pancreatic malignancies, the underlying mechanism(s) for cigarette-smoke (CS)-induced pancreatic cancer (PC) pathogenesis has not been well-established. Our previous studies revealed an aberrant expression of the MUC4 mucin in PC as compared to the normal pancreas and its association with cancer progression and metastasis. Interestingly, here we explore a potential link between MUC4 expression and smoking-mediated PC pathogenesis and report that both cigarette-smoke-extract (CSE) and nicotine, which is the major component of CS, significantly up-regulates MUC4 in PC cells. This nicotine-mediated MUC4 overexpression was via α7 subunit of nicotinic acetylcholine receptor (nAChR) stimulation and subsequent activation of the JAK2/STAT3 downstream signaling cascade in cooperation with the MEK/ERK1/2 pathway; this effect was blocked by the α7nAChR antagonists, α-bungarotoxin and mecamylamine, and by specific siRNA-mediated STAT3 inhibition. Additionally, we demonstrated that nicotine-mediated MUC4 up-regulation promotes the PC cell migration through the activation of the downstream effectors such as HER2, c-Src and FAK; this effect was attenuated by shRNA-mediated MUC4 abrogation, further implying that these nicotine-mediated pathological effects on PC cells are MUC4 dependent. Furthermore, the in-vivo studies demonstrated a dramatic increase in the mean pancreatic tumor weight [low-dose (100 mg/m3 TSP), p=0.014; high-dose (247 mg/m3 TSP), p=0.02] and significant tumor metastasis to various distant organs in the CS-exposed-mice, orthotopically implanted with luciferase-transfected PC cells, as compared to the sham-controls. Moreover, the CS-exposed mice had elevated levels of serum cotinine [low-dose, 155.88±35.96 ng/ml; high-dose, 216.25±29.95 ng/ml] and increased MUC4, α7nAChR and pSTAT3 expression in the pancreatic tumor tissues. Altogether, our findings revealed for the first time that CS up-regulates

Elevation of β-galactoside α2,6-sialyltransferase 1 in a fructose-responsive manner promotes pancreatic cancer metastasis

PubMed Central

Hsieh, Chi-Che; Shyr, Yi-Ming; Liao, Wen-Ying; Chen, Tien-Hua; Wang, Shin-E; Lu, Peir-Chuen; Lin, Pei-Yu; Chen, Yan-Bo; Mao, Wan-Yu; Han, Hsin-Ying; Hsiao, Michael; Yang, Wen-Bin; Li, Wen-Shan; Sher, Yuh-Pyng; Shen, Chia-Ning

2017-01-01

Pancreatic ductal adenocarcinoma (PDAC) is an aggressive type of pancreatic cancer with clinical characteristics of local invasion and early metastasis. Recent cohort studies indicate high fructose intake is associated with an increase in pancreatic cancer risk. However, the mechanisms by which fructose promotes pancreatic tumorigenesis remain unclear. Herein, Kras+/LSLG12D mice were crossed with Elas-CreER transgenic mice to determine whether fructose intake directly contributes to tumor formation. Orthotopic tumor-xenograft experiments were performed to determine whether fructose substitution enhances the metastatic potential of PDAC cells. The mechanisms underlying the effects of fructose were explored by RNAseq analysis in combination with high-performance anion exchange chromatography. Dietary fructose was initially found to promote the development of aggressive pancreatic cancer in mice conditionally expressing KrasG12D in the adult pancreas. We further revealed that fructose substitution enhanced the metastatic potential of human PDAC cell via selective outgrowth of aggressive ABCG2-positive subpopulations and elevating N-acetylmannosamine levels that upregulated β-galactoside α2,6-sialyltransferase 1 (ST6Gal1), thereby promoting distant metastasis. Finally, we observed that PDAC patients expressing higher levels of ST6Gal1 and GLUT5 presented poorer prognosis compared to other groups. In conclusion, our findings have elucidated a crucial role of ST6Gal1 in regulating the invasiveness of PDACs in a fructose-responsive manner. PMID:28032597

Rare hereditary cause of chronic pancreatitis in a young male: SPINK1 mutation

PubMed Central

Patel, Janaki; Madan, Arina; Gammon, Amanda; Sossenheimer, Michael; Samadder, Niloy Jewel

2017-01-01

Hereditary chronic pancreatitis associated with a mutation in the serine protease inhibitor, Kazal Type-1 (SPINK-1 gene) is extremely rare. The SPINK1 mutation results in trypsinogen activation which predisposes to chronic pancreatitis predominately when combined with CFTR gene mutations. It presents as either chronic or recurrent acute pancreatitis. Symptom control and management of complications is important. Active surveillance with cross-sectional imaging for pancreatic malignancy in individuals with hereditary pancreatitis is advocated due to individuals being high risk. We present an unusual case of a young male who initially presented with renal colic and was incidentally diagnosed with severe chronic pancreatitis on abdominal imaging, with genetic testing confirming a homozygous SPINK1 mutation. PMID:29515728

Rare hereditary cause of chronic pancreatitis in a young male: SPINK1 mutation.

PubMed

Patel, Janaki; Madan, Arina; Gammon, Amanda; Sossenheimer, Michael; Samadder, Niloy Jewel

2017-01-01

Hereditary chronic pancreatitis associated with a mutation in the serine protease inhibitor, Kazal Type-1 (SPINK-1 gene) is extremely rare. The SPINK1 mutation results in trypsinogen activation which predisposes to chronic pancreatitis predominately when combined with CFTR gene mutations. It presents as either chronic or recurrent acute pancreatitis. Symptom control and management of complications is important. Active surveillance with cross-sectional imaging for pancreatic malignancy in individuals with hereditary pancreatitis is advocated due to individuals being high risk. We present an unusual case of a young male who initially presented with renal colic and was incidentally diagnosed with severe chronic pancreatitis on abdominal imaging, with genetic testing confirming a homozygous SPINK1 mutation.

Ectonucleotidase NTPDase3 is abundant in pancreatic β-cells and regulates glucose-induced insulin secretion.

PubMed

Syed, Samreen K; Kauffman, Audra L; Beavers, Lisa S; Alston, James T; Farb, Thomas B; Ficorilli, James; Marcelo, Marialuisa C; Brenner, Martin B; Bokvist, Krister; Barrett, David G; Efanov, Alexander M

2013-11-15

Extracellular ATP released from pancreatic β-cells acts as a potent insulinotropic agent through activation of P2 purinergic receptors. Ectonucleotidases, a family of membrane-bound nucleotide-metabolizing enzymes, regulate extracellular ATP levels by degrading ATP and related nucleotides. Ectonucleotidase activity affects the relative proportion of ATP and its metabolites, which in turn will impact the level of purinergic receptor stimulation exerted by extracellular ATP. Therefore, we investigated the expression and role of ectonucleotidases in pancreatic β-cells. Of the ectonucleotidases studied, only ENTPD3 (gene encoding the NTPDase3 enzyme) mRNA was detected at fairly abundant levels in human and mouse pancreatic islets as well as in insulin-secreting MIN6 cells. ARL67156, a selective ectonucleotidase inhibitor, blocked degradation of extracellular ATP that was added to MIN6 cells. The compound also decreased degradation of endogenous ATP released from cells. Measurements of insulin secretion in MIN6 cells as well as in mouse and human pancreatic islets demonstrated that ARL67156 potentiated glucose-dependent insulin secretion. Downregulation of NTPDase3 expression in MIN6 cells with the specific siRNA replicated the effects of ARL67156 on extracellular ATP hydrolysis and insulin secretion. Our results demonstrate that NTPDase3 is the major ectonucleotidase in pancreatic β-cells in multiple species and that it modulates insulin secretion by controlling activation of purinergic receptors.

Fisetin Enhances the Cytotoxicity of Gemcitabine by Down-regulating ERK-MYC in MiaPaca-2 Human Pancreatic Cancer Cells.

PubMed

Kim, Nayoung; Kang, Min-Jung; Lee, Sang Hyub; Son, Jun Hyuk; Lee, Ji Eun; Paik, Woo Hyun; Ryu, Ji Kon; Kim, Yong-Tae

2018-06-01

Pancreatic cancer is a highly lethal malignancy with a poor prognosis. This study was set up to investigate the combined effect of gemcitabine and fisetin, a natural flavonoid from plants, on human pancreatic cancer cells. Meterials and Methods: Cytotoxic effect of fisetin in combination with gemcitabine on MiaPaca-2 cells was evaluated by the MTT assay, caspase 3/7 assay and propidium iodide/Annexin V. Extracellular signal-regulated kinase (ERK)-v-myc avian myelocytomatosis viral oncogene homolog (MYC) pathway was investigated by western blotting and quantitative real-time polymerase chain reaction. Combination treatment with fisetin and gemcitabine inhibited the proliferation of pancreatic cancer cells within 72 h and induced apoptosis, as indicated by activation of caspase 3/7. Fisetin down-regulated ERK at the protein and mRNA levels, and reduced ERK-induced MYC instability at the protein level. Fisetin sensitized human pancreatic cancer cells to gemcitabine-induced cytotoxicity through inhibition of ERK-MYC signaling. These results suggest that the combination of fisetin and gemcitabine could be developed as a novel potent therapeutic. Copyright© 2018, International Institute of Anticancer Research (Dr. George J. Delinasios), All rights reserved.

Mechanisms of CFTR Functional Variants That Impair Regulated Bicarbonate Permeation and Increase Risk for Pancreatitis but Not for Cystic Fibrosis

PubMed Central

Lewis, Michele D.; Park, Hyun Woo; Brand, Randall E.; Gelrud, Andres; Anderson, Michelle A.; Banks, Peter A.; Conwell, Darwin; Lawrence, Christopher; Romagnuolo, Joseph; Baillie, John; Alkaade, Samer; Cote, Gregory; Gardner, Timothy B.; Amann, Stephen T.; Slivka, Adam; Sandhu, Bimaljit; Aloe, Amy; Kienholz, Michelle L.; Yadav, Dhiraj; Barmada, M. Michael; Bahar, Ivet; Lee, Min Goo; Whitcomb, David C.

2014-01-01

CFTR is a dynamically regulated anion channel. Intracellular WNK1-SPAK activation causes CFTR to change permeability and conductance characteristics from a chloride-preferring to bicarbonate-preferring channel through unknown mechanisms. Two severe CFTR mutations (CFTRsev) cause complete loss of CFTR function and result in cystic fibrosis (CF), a severe genetic disorder affecting sweat glands, nasal sinuses, lungs, pancreas, liver, intestines, and male reproductive system. We hypothesize that those CFTR mutations that disrupt the WNK1-SPAK activation mechanisms cause a selective, bicarbonate defect in channel function (CFTRBD) affecting organs that utilize CFTR for bicarbonate secretion (e.g. the pancreas, nasal sinus, vas deferens) but do not cause typical CF. To understand the structural and functional requirements of the CFTR bicarbonate-preferring channel, we (a) screened 984 well-phenotyped pancreatitis cases for candidate CFTRBD mutations from among 81 previously described CFTR variants; (b) conducted electrophysiology studies on clones of variants found in pancreatitis but not CF; (c) computationally constructed a new, complete structural model of CFTR for molecular dynamics simulation of wild-type and mutant variants; and (d) tested the newly defined CFTRBD variants for disease in non-pancreas organs utilizing CFTR for bicarbonate secretion. Nine variants (CFTR R74Q, R75Q, R117H, R170H, L967S, L997F, D1152H, S1235R, and D1270N) not associated with typical CF were associated with pancreatitis (OR 1.5, p = 0.002). Clones expressed in HEK 293T cells had normal chloride but not bicarbonate permeability and conductance with WNK1-SPAK activation. Molecular dynamics simulations suggest physical restriction of the CFTR channel and altered dynamic channel regulation. Comparing pancreatitis patients and controls, CFTRBD increased risk for rhinosinusitis (OR 2.3, p<0.005) and male infertility (OR 395, p<<0.0001). WNK1-SPAK pathway-activated increases in CFTR

Mechanisms of CFTR functional variants that impair regulated bicarbonate permeation and increase risk for pancreatitis but not for cystic fibrosis.

PubMed

LaRusch, Jessica; Jung, Jinsei; General, Ignacio J; Lewis, Michele D; Park, Hyun Woo; Brand, Randall E; Gelrud, Andres; Anderson, Michelle A; Banks, Peter A; Conwell, Darwin; Lawrence, Christopher; Romagnuolo, Joseph; Baillie, John; Alkaade, Samer; Cote, Gregory; Gardner, Timothy B; Amann, Stephen T; Slivka, Adam; Sandhu, Bimaljit; Aloe, Amy; Kienholz, Michelle L; Yadav, Dhiraj; Barmada, M Michael; Bahar, Ivet; Lee, Min Goo; Whitcomb, David C

2014-07-01

CFTR is a dynamically regulated anion channel. Intracellular WNK1-SPAK activation causes CFTR to change permeability and conductance characteristics from a chloride-preferring to bicarbonate-preferring channel through unknown mechanisms. Two severe CFTR mutations (CFTRsev) cause complete loss of CFTR function and result in cystic fibrosis (CF), a severe genetic disorder affecting sweat glands, nasal sinuses, lungs, pancreas, liver, intestines, and male reproductive system. We hypothesize that those CFTR mutations that disrupt the WNK1-SPAK activation mechanisms cause a selective, bicarbonate defect in channel function (CFTRBD) affecting organs that utilize CFTR for bicarbonate secretion (e.g. the pancreas, nasal sinus, vas deferens) but do not cause typical CF. To understand the structural and functional requirements of the CFTR bicarbonate-preferring channel, we (a) screened 984 well-phenotyped pancreatitis cases for candidate CFTRBD mutations from among 81 previously described CFTR variants; (b) conducted electrophysiology studies on clones of variants found in pancreatitis but not CF; (c) computationally constructed a new, complete structural model of CFTR for molecular dynamics simulation of wild-type and mutant variants; and (d) tested the newly defined CFTRBD variants for disease in non-pancreas organs utilizing CFTR for bicarbonate secretion. Nine variants (CFTR R74Q, R75Q, R117H, R170H, L967S, L997F, D1152H, S1235R, and D1270N) not associated with typical CF were associated with pancreatitis (OR 1.5, p = 0.002). Clones expressed in HEK 293T cells had normal chloride but not bicarbonate permeability and conductance with WNK1-SPAK activation. Molecular dynamics simulations suggest physical restriction of the CFTR channel and altered dynamic channel regulation. Comparing pancreatitis patients and controls, CFTRBD increased risk for rhinosinusitis (OR 2.3, p<0.005) and male infertility (OR 395, p<0.0001). WNK1-SPAK pathway-activated increases in CFTR

Association between alcohol dehydrogenase 1C gene *1/*2 polymorphism and pancreatitis risk: a meta-analysis.

PubMed

Fang, F; Pan, J; Su, G H; Xu, L X; Li, G; Li, Z H; Zhao, H; Wang, J

2015-11-30

Numerous studies have focused on the relationship be-tween alcohol dehydrogenase 1C gene (ADH1C) *1/*2 polymorphism (Ile350Val, rs698, also known as ADH1C *1/*2) and pancreatitis risk, but the results have been inconsistent. Thus, we conducted a meta-anal-ysis to more precisely estimate this association. Relevant publications were searched in several widely used databases and 9 eligible studies were included in the meta-analysis. Pooled odds ratios (ORs) and 95% confidence intervals (CIs) were calculated to evaluate the strength of the association. Significant associations between ADH1C *1/*2 poly-morphism and pancreatitis risk were observed in both overall meta-analysis for 12 vs 22 (OR = 1.53, 95%CI = 1.12-2.10) and 11 + 12 vs 22 (OR = 1.44, 95%CI = 1.07-1.95), and the chronic alcoholic pancre-atitis subgroup for 12 vs 22 (OR = 1.64, 95%CI = 1.17-2.29) and 11 + 12 vs 22 (OR = 1.53, 95%CI = 1.11-2.11). Significant pancreatitis risk variation was also detected in Caucasians for 11 + 12 vs 22 (OR = 1.45, 95%CI = 1.07-1.98). In conclusion, the ADH1C *1/*2 polymorphism is likely associated with pancreatitis risk, particularly chronic alcoholic pancreatitis risk, with the *1 allele functioning as a risk factor.

Insulin-producing cells could not mimic the physiological regulation of insulin secretion performed by pancreatic beta cells

PubMed Central

2013-01-01

Objective The aim of this study was to compare the difference between insulin-producing cells (IPCs) and normal human pancreatic beta cells both in physiological function and morphological features in cellular level. Methods The levels of insulin secretion were measured by enzyme-linked immunosorbent assay. The insulin gene expression was determined by real-time quantitative polymerase chain reaction. The morphological features were detected by atomic force microscopy (AFM) and laser confocal scanning microscopy. Results IPCs and normal human pancreatic beta cells were similar to each other under the observation in AFM with the porous structure features in the cytoplasm. Both number of membrane particle size and average roughness of normal human beta cells were higher than those of IPCs. Conclusions Our results firstly revealed that the cellular ultrastructure of IPCs was closer to that of normal human pancreatic beta cells, but they still could not mimic the physiological regulation of insulin secretion performed by pancreatic beta cells. PMID:23421382

Carbachol does not down-regulate substance P receptors in pancreatic acini.

PubMed

Patto, R J; Vinayek, R; Jensen, R T; Gardner, J D

1992-01-01

In a previous study, we found that first incubating guinea pig pancreatic acini with carbachol caused desensitization of the enzyme secretory response to cholecystokinin-octapeptide (CCK-8), bombesin, and carbachol but not that to substance P. This carbachol-induced desensitization could be accounted for by carbachol-induced down-regulation of receptors for CCK-8, bombesin, and carbachol. Although carbachol did not desensitize the enzyme secretory response to substance P, an effect of carbachol on substance P receptors was not examined. In the present study, in dispersed acini from guinea pig pancreas, substance P caused a twofold increase in amylase secretion. Stimulation was half-maximal at 0.7 nM and was maximal at 10 nM. Analysis of the ability of substance P to inhibit binding of 125I-substance P to substance P receptors indicated that acini possess a single class of receptors for substance P (Kd = 0.8 +/- 0.1 nM; Bmax = 1,037 +/- 145 fmol/mg of DNA). There was a close correlation between the relative potency with which substance P stimulated amylase secretion (0.7 nM) and the potency for inhibiting binding of 125I-substance P (Kd = 0.8 nM). First incubating pancreatic acini with carbachol did not alter either substance P-stimulated enzyme secretion or binding of 125I-substance P to substance P receptors, whereas in the same experiments, carbachol reduced binding of 125I-CCK-8 to cholecystokinin receptors by 50% and decreased in CCK-8-stimulated enzyme secretion by 50%.(ABSTRACT TRUNCATED AT 250 WORDS)

Expression and clinical significance of glucose transporter-1 in pancreatic cancer

PubMed Central

LU, KAI; YANG, JIAN; LI, DE-CHUN; HE, SONG-BING; ZHU, DONG-MING; ZHANG, LI-FENG; ZHANG, XU; CHEN, XIAO-CHEN; ZHANG, BING; ZHOU, JIAN

2016-01-01

Increasing evidence has demonstrated that malignant cells exhibit increased glucose uptake, which facilitates survival and growth in a hypoxic environment. The glucose transporter-1 (GLUT-1) is overexpressed in a variety of malignant tumors. However, the association between GLUT-1 expression and clinicopathological factors, 18F-fluorodeoxyglucose uptake and tumor proliferation in pancreatic cancer has not been investigated to date. In the present study, the expression of GLUT-1 in 53 pancreatic cancer tissues was analyzed, which revealed that GLUT-1 was overexpressed in pancreatic tissue and correlated with poor prognosis and clinicopathological characteristics, including increased tumor size, clinical stage and lymph node metastasis, maximum standardized uptake value (SUVmax) and Ki-67 expression. The receiver operating characteristic curve analysis indicated that a cut-off SUVmax value of 4.830 was associated with optimal sensitivity (88%) and specificity (71.4%) for the detection of strong positive GLUT-1 expression. In addition, as the expression of GLUT-1 was found to correlate with Ki-67 expression, GLUT-1 may exhibit a significant effect on cell proliferation in pancreatic cancer. Overall, these findings indicate that GLUT-1 may represent a prognostic indicator, and a potential therapeutic target for pancreatic cancer. PMID:27347132

Pancreatic adenocarcinoma upregulated factor (PAUF) confers resistance to pancreatic cancer cells against oncolytic parvovirus H-1 infection through IFNA receptor-mediated signaling

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kaowinn, Sirichat; Cho, Il-Rae; Moon, Jeong

2015-04-03

Pancreatic adenocarcinoma upregulated factor (PAUF), a novel oncogene, plays a crucial role in the development of pancreatic cancer, including its metastasis and proliferation. Therefore, PAUF-expressing pancreatic cancer cells could be important targets for oncolytic virus-mediated treatment. Panc-1 cells expressing PAUF (Panc-PAUF) showed relative resistance to parvovirus H-1 infection compared with Panc-1 cells expressing an empty vector (Panc-Vec). Of interest, expression of type I IFN-α receptor (IFNAR) was higher in Panc-PAUF cells than in Panc-Vec cells. Increased expression of IFNAR in turn increased the activation of Stat1 and Tyk2 in Panc-PAUF cells compared with that in Panc-Vec cells. Suppression of Tyk2more » and Stat1, which are important downstream molecules for IFN-α signaling, sensitized pancreatic cancer cells to parvovirus H-1-mediated apoptosis. Further, constitutive suppression of PAUF sensitized Bxpc3 pancreatic cancer cells to parvovirus H-1 infection. Taken together, these results suggested that PAUF conferred resistance to pancreatic cancer cells against oncolytic parvovirus H-1 infection through IFNAR-mediated signaling. - Highlights: • PAUF confers resistance against oncolytic parvovirus H-1 infection. • PAUF enhances the expression of IFNAR in Panc-1 cells. • Increased activation of Tyk2 or Stat1 by PAUF provides resistance to parvovirus H-1-mediated apoptosis. • Constitutive inhibition of PAUF enhances parvovirus H-1-mediated oncolysis of Bxpc3 pancreatic cancer cells.« less

DOE Office of Scientific and Technical Information (OSTI.GOV)

Mack, Hildegard I.D.; Munger, Karl, E-mail: kmunger@rics.bwh.harvard.edu

Infection with high-risk human papillomaviruses is causally linked to cervical carcinogenesis. However, most lesions caused by high-risk HPV infections do not progress to cancer. Host cell mutations contribute to malignant progression but the molecular nature of such mutations is unknown. Based on a previous study that reported an association between liver kinase B1 (LKB1) tumor suppressor loss and poor outcome in cervical cancer, we sought to determine the molecular basis for this observation. LKB1-negative cervical and lung cancer cells were reconstituted with wild type or kinase defective LKB1 mutants and we examined the importance of LKB1 catalytic activity in knownmore » LKB1-regulated processes including inhibition of cell proliferation and elevated resistance to energy stress. Our studies revealed marked differences in the biological activities of two kinase defective LKB1 mutants in the various cell lines. Thus, our results suggest that LKB1 may be a cell-type specific tumor suppressor. - Highlights: • LKB1 is a tumor suppressor that is linked to Peutz-Jeghers syndrome. • Peutz-Jeghers syndrome patients have a high incidence of cervical cancer. • Cervical cancer is caused by HPV infections. • This study investigates LKB1 tumor suppressor activity in cervical cancer.« less

Targeting Insulin-Like Growth Factor 1 Receptor Inhibits Pancreatic Cancer Growth and Metastasis

PubMed Central

Subramani, Ramadevi; Lopez-Valdez, Rebecca; Arumugam, Arunkumar; Nandy, Sushmita; Boopalan, Thiyagarajan; Lakshmanaswamy, Rajkumar

2014-01-01

Pancreatic cancer is one of the most lethal cancers. Increasing incidence and mortality indicates that there is still much lacking in detection and management of the disease. This is partly due to a lack of specific symptoms during early stages of the disease. Several growth factor receptors have been associated with pancreatic cancer. Here, we have investigated if an RNA interference approach targeted to IGF-IR could be effective and efficient against pancreatic cancer growth and metastasis. For that, we evaluated the effects of IGF-1R inhibition using small interfering RNA (siRNAs) on tumor growth and metastasis in HPAC and PANC-1 pancreatic cancer cell lines. We found that silencing IGF-1R inhibits pancreatic cancer growth and metastasis by blocking key signaling pathways such AKT/PI3K, MAPK, JAK/STAT and EMT. Silencing IGF-1R resulted in an anti-proliferative effect in PANC-1 and HPAC pancreatic cancer cell lines. Matrigel invasion, transwell migration and wound healing assays also revealed a role for IGF-1R in metastatic properties of pancreatic cancer. These results were further confirmed using Western blotting analysis of key intermediates involved in proliferation, epithelial mesenchymal transition, migration, and invasion. In addition, soft agar assays showed that silencing IGF-1R also blocks the colony forming capabilities of pancreatic cancer cells in vitro. Western blots, as well as, flow cytometric analysis revealed the induction of apoptosis in IGF-1R silenced cells. Interestingly, silencing IGF-1R also suppressed the expression of insulin receptor β. All these effects together significantly control pancreatic cancer cell growth and metastasis. To conclude, our results demonstrate the significance of IGF-1R in pancreatic cancer. PMID:24809702

Pancreatic fibrosis correlates with exocrine pancreatic insufficiency after pancreatoduodenectomy.

PubMed

Tran, T C K; van 't Hof, G; Kazemier, G; Hop, W C; Pek, C; van Toorenenbergen, A W; van Dekken, H; van Eijck, C H J

2008-01-01

Obstruction of the pancreatic duct can lead to pancreatic fibrosis. We investigated the correlation between the extent of pancreatic fibrosis and the postoperative exocrine and endocrine pancreatic function. Fifty-five patients who were treated for pancreatic and periampullary carcinoma and 19 patients with chronic pancreatitis were evaluated. Exocrine pancreatic function was evaluated by fecal elastase-1 test, while endocrine pancreatic function was assessed by plasma glucose level. The extent of fibrosis, duct dilation and endocrine tissue loss was examined histopathologically. A strong correlation was found between pancreatic fibrosis and elastase-1 level less than 100 microg/g (p < 0.0001), reflecting severe exocrine pancreatic insufficiency. A strong correlation was found between pancreatic fibrosis and endocrine tissue loss (p < 0.0001). Neither pancreatic fibrosis nor endocrine tissue loss were correlated with the development of postoperative diabetes mellitus. Duct dilation alone was neither correlated with exocrine nor with endocrine function loss. The majority of patients develop severe exocrine pancreatic insufficiency after pancreatoduodenectomy. The extent of exocrine pancreatic insufficiency is strongly correlated with preoperative fibrosis. The loss of endocrine tissue does not correlate with postoperative diabetes mellitus. Preoperative dilation of the pancreatic duct per se does not predict exocrine or endocrine pancreatic insufficiency postoperatively. Copyright 2008 S. Karger AG, Basel.

Liver kinase B1 inhibits the expression of inflammation-related genes postcontraction in skeletal muscle

PubMed Central

Chen, Ting; Moore, Timothy M.; Ebbert, Mark T. W.; McVey, Natalie L.; Madsen, Steven R.; Hallowell, David M.; Harris, Alexander M.; Char, Robin E.; Mackay, Ryan P.; Hancock, Chad R.; Hansen, Jason M.; Kauwe, John S.

2016-01-01

Skeletal muscle-specific liver kinase B1 (LKB1) knockout mice (skmLKB1-KO) exhibit elevated mitogen-activated protein kinase (MAPK) signaling after treadmill running. MAPK activation is also associated with inflammation-related signaling in skeletal muscle. Since exercise can induce muscle damage, and inflammation is a response triggered by damaged tissue, we therefore hypothesized that LKB1 plays an important role in dampening the inflammatory response to muscle contraction, and that this may be due in part to increased susceptibility to muscle damage with contractions in LKB1-deficient muscle. Here we studied the inflammatory response and muscle damage with in situ muscle contraction or downhill running. After in situ muscle contractions, the phosphorylation of both NF-κB and STAT3 was increased more in skmLKB1-KO vs. wild-type (WT) muscles. Analysis of gene expression via microarray and RT-PCR shows that expression of many inflammation-related genes increased after contraction only in skmLKB1-KO muscles. This was associated with mild skeletal muscle fiber membrane damage in skmLKB1-KO muscles. Gene markers of oxidative stress were also elevated in skmLKB1-KO muscles after contraction. Using the downhill running model, we observed significantly more muscle damage after running in skmLKB1-KO mice, and this was associated with greater phosphorylation of both Jnk and STAT3 and increased expression of SOCS3 and Fos. In conclusion, we have shown that the lack of LKB1 in skeletal muscle leads to an increased inflammatory state in skeletal muscle that is exacerbated by muscle contraction. Increased susceptibility of the muscle to damage may underlie part of this response. PMID:26796753

Monocarboxylate Transporters MCT1 and MCT4 Regulate Migration and Invasion of Pancreatic Ductal Adenocarcinoma Cells.

PubMed

Kong, Su Chii; Nøhr-Nielsen, Asbjørn; Zeeberg, Katrine; Reshkin, Stephan Joel; Hoffmann, Else Kay; Novak, Ivana; Pedersen, Stine Falsig

2016-08-01

Novel treatments for pancreatic ductal adenocarcinoma (PDAC) are severely needed. The aim of this work was to explore the roles of H-lactate monocarboxylate transporters 1 and 4 (MCT1 and MCT4) in PDAC cell migration and invasiveness. Monocarboxylate transporter expression, localization, activity, and function were explored in human PDAC cells (MIAPaCa-2, Panc-1, BxPC-3, AsPC-1) and normal human pancreatic ductal epithelial (HPDE) cells, by quantitative polymerase chain reaction, immunoblotting, immunocytochemistry, lactate flux, migration, and invasion assays. MCT1 and MCT4 (messenger RNA, protein) were robustly expressed in all PDAC lines, localizing to the plasma membrane. Lactate influx capacity was highest in AsPC-1 cells and lowest in HPDE cells and was inhibited by the MCT inhibitor α-cyano-4-hydroxycinnamate (4-CIN), MCT1/MCT2 inhibitor AR-C155858, or knockdown of MCT1 or MCT4. PDAC cell migration was largely unaffected by MCT1/MCT2 inhibition or MCT1 knockdown but was reduced by 4-CIN and by MCT4 knockdown (BxPC-3). Invasion measured in Boyden chamber (BxPC-3, Panc-1) and spheroid outgrowth (BxPC-3) assays was attenuated by 4-CIN and AR-C155858 and by MCT1 or MCT4 knockdown. Human PDAC cells exhibit robust MCT1 and MCT4 expression and partially MCT1- and MCT4-dependent lactate flux. PDAC cell migration is partially dependent on MCT4; and invasion, on MCT1 and MCT4. Inhibition of MCT1 and MCT4 may have clinical relevance in PDAC.

Targeting pancreatic expressed PAX genes for the treatment of diabetes mellitus and pancreatic neuroendocrine tumors.

PubMed

Martin-Montalvo, Alejandro; Lorenzo, Petra I; López-Noriega, Livia; Gauthier, Benoit R

2017-01-01

Four members of the PAX family, PAX2, PAX4, PAX6 and PAX8 are known to be expressed in the pancreas. Accumulated evidences indicate that several pancreatic expressed PAX genes play a significant role in pancreatic development/functionality and alterations in these genes are involved in the pathogenesis of pancreatic diseases. Areas covered: In this review, we summarize the ongoing research related to pancreatic PAX genes in diabetes mellitus and pancreatic neuroendocrine tumors. We dissect the current knowledge at different levels; from mechanistic studies in cell lines performed to understand the molecular processes controlled by pancreatic PAX genes, to in vivo studies using rodent models that over-express or lack specific PAX genes. Finally, we describe human studies associating variants on pancreatic-expressed PAX genes with pancreatic diseases. Expert opinion: Based on the current literature, we propose that future interventions to treat pancreatic neuroendocrine tumors and diabetes mellitus could be developed via the modulation of PAX4 and/or PAX6 regulated pathways.

Activator protein 1 promotes gemcitabine-induced apoptosis in pancreatic cancer by upregulating its downstream target Bim.

PubMed

Ren, Xiaoxia; Zhao, Wenjing; Du, Yongxing; Zhang, Taiping; You, Lei; Zhao, Yupei

2016-12-01

Gemcitabine is a commonly used chemotherapy drug in pancreatic cancer. The function of activator protein 1 (AP-1) is cell-specific, and its function depends on the expression of other complex members. In the present study, we added gemcitabine to the media of Panc-1 and SW1990 cells at clinically achieved concentrations (10 µM). Compared with constitutive c-Fos expression, c-Jun expression increased in a dose-dependent manner upon gemcitabine treatment. c-Jun overexpression increased gemcitabine-induced apoptosis through Bim activation, while cell apoptosis and Bim expression decreased following c-Jun knockdown. Furthermore, gemcitabine-induced apoptosis and Bim levels decreased when c-Jun phosphorylation was blocked by SP600125. Our findings suggest that c-Jun, which is a member of the AP-1 complex, functions in gemcitabine-induced apoptosis by regulating its downstream target Bim in pancreatic cancer cells.

Suppression of the epidermal growth factor receptor inhibits epithelial-mesenchymal transition in human pancreatic cancer PANC-1 cells.

PubMed

Chang, Zhi-Gang; Wei, Jun-Min; Qin, Chang-Fu; Hao, Kun; Tian, Xiao-Dong; Xie, Kun; Xie, Xue-Hai; Yang, Yin-Mo

2012-05-01

Aberrant expression of epidermal growth factor receptor (EGFR) has been detected in pancreatic cancer; however, the mechanisms of EGFR in inducing pancreatic cancer development have not been adequately elucidated. The objective of this study was to determine the role of EGFR in mediating epithelial-mesenchymal transition (EMT) in pancreatic cancer cells. Pancreatic cancer cell line PANC-1 was transfected with small interfering RNA of EGFR by use of a lentiviral expression vector to establish an EGFR-knockdown cell line (si-PANC-1). PANC-1 cells transfected with lentiviral vector expressing negative control sequence were used as negative control (NC-PANC-1). Scratch assay and transwell study were used to analyze cell migration and invasion. Real-time PCR and Western blotting were used to detect the expression of EMT markers E-cadherin, N-cadherin, vimentin, and fibronectin and transcription factors snail, slug, twist1, and sip1 in PANC-1, NC-PANC-1, and si-PANC-1 cells. Immunofluorescent staining with these antibodies and confocal microscopy were used to observe their cellular location and morphologic changes. After RNA interference of EGFR, the migration and invasion ability of si-PANC-1 cells decreased significantly. The expression of epithelial phenotype marker E-cadherin increased and the expression of mesenchymal phenotype markers N-cadherin, vimentin, and fibronectin decreased, indicating reversion of EMT. We also observed intracellular translocation of E-cadherin. Expression of transcription factors snail and slug in si-PANC-1 cells decreased significantly. Suppression of EGFR expression can significantly inhibit EMT of pancreatic cancer PANC-1 cells. The mechanism may be related with the down-regulation of the expression of transcription factors snail and slug.

Comparison of fecal elastase-1 and pancreatic function testing in children.

PubMed

Wali, Prateek D; Loveridge-Lenza, Beth; He, Zhaoping; Horvath, Karoly

2012-02-01

The fecal pancreatic elastase-1 (FE-1) test is considered a simple, noninvasive, indirect measure of pancreatic function. We aimed to evaluate the performance of the FE-1 test compared with the direct pancreatic function test (PFT) with secretin stimulation in children. Data of 70 children (6 months-17 years of age) who had both FE-1 test and PFT were analyzed. The average FE-1 concentration was 403 ± 142 μg/g. Eleven children had concentrations below 200  μg/g, 23 between 201 to 500 μg/g, and 36 were above 500 μg/g. The average pancreatic elastase activity measured on direct stimulation was 49.1 ± 38.6  μmol · min (-1)· ml(-1) and 11 children had activity below the established cutoff (10.5 μmol · min(-1) · ml(-1)). Among the 11 children with pathologic PFT, 7 had normal FE-1, 4 were in the intermediate range (201-500 μg/g), and none were in the low range (<200 μg/g). Among the 59 children with normal direct PFT 11 (19%) had pathologic (<200 μg/g) and 19 (32%) had intermediate FE-1 tests. Twenty-nine children had both normal FE-1 concentration and normal PFT, giving a negative predictive value of 80%. The correlation between pancreatic elastase activity and FE-1 concentration was poor (r = 0.190). The sensitivity of the FE-1 test was found to be 41.7%, whereas the specificity was 49.2%. The positive predictive value of the FE-1 test was only 14%. The FE-1 test is a simple, noninvasive, indirect method; however, ordering physicians should be aware of its limitations. It can give false-positive results and has low sensitivity in children with mild pancreatic insufficiency without cystic fibrosis and in those with isolated pancreatic enzyme deficiencies.

Periodontitis aggravated pancreatic β-cell dysfunction in diabetic mice through interleukin-12 regulation on Klotho.

PubMed

Liu, Yihua; Zhang, Qiuli

2016-05-01

Recent studies have shown that periodontitis can contribute to adipose tissue inflammation and subsequent systemic insulin resistance in the obese rat model. However, the related inflammatory mechanism is not yet clear. The present study aims to investigate the effects of periodontitis on the function of pancreatic β-cells with pro-inflammatory cytokines-related immune mechanism in a mouse model. C57BL/6-db/db and inbred C57BL/6 mice were chosen here to establish a mouse model with periodontitis, which was induced by ligatures for 8 weeks. Glucose-stimulated insulin secretion was introduced to evaluate the function of pancreatic islets and β-cells. Serum levels of pro-inflammatory cytokines and Klotho were also measured, and the correlation between immunostimulation and Klotho level was deeply investigated in vitro. Pancreatic β-cell failure, with insulin resistance, was observed in db/db mice, while periodontitis could aggravate β-cell dysfunction-related features. Serum levels of interleukin (IL)-12 and Klotho showed a negatively synergistic change, whereas the expression of Klotho was also inhibited under IL-12 treatment in MIN6 β-cells or isolated islets. Furthermore, IL-12-induced immune stimulation and also decreased insulin secretion were proven to be reversed by Klotho overexpression. Periodontitis aggravated pancreatic β-cell failure in diabetic mice. Further in vitro studies showed IL-12 regulation on Klotho, while Klotho also acted as an inhibitor on IL-12, indicating the potential of Klotho for preserving pancreatic β-cell function in diabetes.

Chaiqinchengqi decoction regulates necrosis-apoptosis via regulating the release of mitochondrial cytochrome c and caspase-3 in rats with acute necrotizing pancreatitis.

PubMed

Lin, Ziqi; Guo, Jia; Xue, Ping; Huang, Lei; Deng, Lihui; Yang, Xiaonan; Xia, Qing

2014-04-01

To explore the effect and the mechanism of Chaiqinchengqi decoction (CQCQD) on the apoptosis-necrosis switch of pancreatic acinar cells in acute necrotizing pancreatitis (ANP) in rats. Sixty Sprague-Dawley rats were randomized into the control group, the ANP group and the CQCQD group. The acute pancreatitis (AP) model was induced by intraperitoneal injections of 4 g/kg 8% L-Arginine (PH 7.0) twice with a 1 h interval. Rats in the CQCQD group were intragastrically administered CQCQD (20 mL/kg every 2 h, 3 times, then 20 mL/kg every 6 h, 3 times). Rats were killed at the 6 and 24 h after the induction of AP. The pancreatic tissues were collected for pathology and to isolate pancreatic acinar cells and mitochondria. CQCQD significantly ameliorated the severity of ANP by reducing the pancreatic histopathology score, indicated by lactate dehydrogenase levels at the 6 and 24 h. The CQCQD group promoted the apoptosis of pancreatic acinar cells by raising the apoptosis index compared with the ANP group and the control group. Mitochondrial cytochrome c at the 6 and 24 h in the ANP group were lower than that in the control group or the CQCQD group (0.67 +/- 0.13 vs 1.54 +/- 0.03 vs 0.81 +/- 0.09; 0.71 +/- 0.08 vs 1.55 +/- 0.09 vs 0.89 +/- 0.16, P < 0.01). The cytochrome c levels in the cytoplasm at the 6 and 2 h in the CQCQD group were higher than in the control group (1.36 +/- 0.15 vs 0.67 +/- 0.04, 1.46 +/- 0.08 vs 0.59 +/- 0.09, P < 0.01), or the ANP group (0.96 +/- 0.13, P > 0.05; 0.97 +/- 0.09, P < 0.05). CQCQD increased caspase-3 activity over the ANP group at the 6 h. CQCQD can induce apoptosis and relieve the necrosis of pancreatic acinar cells via promoting the release of mitochondrial cytochrome c and increasing pancreatic caspase-3 activity in ANP rats.

Protein-bound Polysaccharide-K Inhibits Hedgehog Signaling Through Down-regulation of MAML3 and RBPJ Transcription Under Hypoxia, Suppressing the Malignant Phenotype in Pancreatic Cancer.

PubMed

Yamasaki, Akio; Onishi, Hideya; Imaizumi, Akira; Kawamoto, Makoto; Fujimura, Akiko; Oyama, Yasuhiro; Katano, Mitsuo

2016-08-01

Hedgehog signaling is activated in pancreatic cancer and could be a therapeutic target. We previously demonstrated that recombination signal binding protein for immunoglobulin-kappa-J region (RBPJ) and mastermind-like 3 (MAML3) contribute to the hypoxia-induced up-regulation of Smoothened (SMO) transcription. We have also shown that protein-bound polysaccharide-K (PSK) could be effective for refractory pancreatic cancer that down-regulates SMO transcription under hypoxia. In this study, we evaluated whether the anticancer mechanism of PSK involves inhibiting RBPJ and MAML3 expression under hypoxia. PSK reduced SMO, MAML3 and RBPJ expression in pancreatic cancer cells under hypoxia. PSK also blocked RBPJ-induced invasiveness under hypoxia by inhibiting matrix metalloproteinase expression. Lastly, we showed that PSK attenuated RBPJ-induced proliferation both in vitro and in vivo. These results suggest that PSK suppresses Hedgehog signaling through down-regulation of MAML3 and RBPJ transcription under hypoxia, inhibiting the induction of a malignant phenotype in pancreatic cancer. Our results may lead to development of new treatments for refractory pancreatic cancer using PSK as a Hedgehog inhibitor. Copyright© 2016 International Institute of Anticancer Research (Dr. John G. Delinassios), All rights reserved.

The Epidemiology of Pancreatitis and Pancreatic Cancer

PubMed Central

Yadav, Dhiraj; Lowenfels, Albert B.

2013-01-01

Acute pancreatitis is one of the most frequent gastrointestinal causes for hospital admission in the US. Chronic pancreatitis, although lower in incidence, significantly reduces patients’ quality of life. Pancreatic cancer has high mortality and is 1 of the top 5 causes of death from cancer. The burden of pancreatic disorders is expected to increase over time. The risk and etiology of pancreatitis differ with age and sex, and all pancreatic disorders affect Blacks more than any other race. Gallstones are the most common cause of acute pancreatitis, and early cholecystectomy eliminates the risk of future attacks. Alcohol continues to be the single most important risk factor for chronic pancreatitis. Smoking is an independent risk factor for acute and chronic pancreatitis, and its effects could synergize with those of alcohol. Significant risk factors for pancreatic cancer include smoking and non-O blood groups. Alcohol abstinence and smoking cessation can alter progression of pancreatitis and reduce recurrence; smoking cessation is the most effective strategy to reduce the risk of pancreatic cancer. PMID:23622135

Qingyihuaji Formula Inhibits Pancreatic Cancer and Prolongs Survival by Downregulating Hes-1 and Hey-1.

PubMed

Xu, Yanli; Xu, Shan; Cai, Yueqin; Liu, Luming

2015-01-01

The dire prognosis of pancreatic cancer has not markedly improved during past decades. The present study was carried out to explore the effect of Qingyihuaji formula (QYHJ) on inhibiting pancreatic cancer and prolonging survival in related Notch signaling pathway. Proliferation of pancreatic cancer cells (SW1990 and PANC-1) was detected by MTT assay at 24, 48, and 72 h with exposure to various concentrations (0.08-50 mg/mL) of QYHJ water extract. Pancreatic tumor models of nude mice were divided into three groups randomly (control, QYHJ, and gemcitabine). mRNA and protein expression of Notch target genes (Hes-1, Hey-1, Hey-2, and Hey-L) in dissected tumor tissue were detected. Results showed that proliferation of SW1990 cells and PANC-1 cells was inhibited by QYHJ water extract in a dose-dependent and time-dependent manner. QYHJ effectively inhibited tumor growth and prolonged survival time in nude mice. Expression of both Hes-1 and Hey-1 was decreased significantly in QYHJ group, suggesting that Hes-1 and Hey-1 in Notch signaling pathway might be potential targets for QYHJ treatment. This research could help explain the clinical effectiveness of QYHJ and may provide advanced pancreatic cancer patients with a new therapeutic option.

Reduced STMN1 expression induced by RNA interference inhibits the bioactivity of pancreatic cancer cell line Panc-1.

PubMed

Li, J; Hu, G H; Kong, F J; Wu, K M; He, B; Song, K; Sun, W J

2014-01-01

Increased expression of STMN1 has been observed in many tumor forms, but its expression and potential biological role in pancreatic cancer is still unknown. In this study, we demonstrated that STMN1 was expressed to a large extent in pancreatic cancer tissues and cell lines as compared to normal pancreatic tissues. Suppression of STMN1 expression via transfection with STMN1-specific siRNA could not only significantly inhibit the proliferation, migration and invasion ability of Panc-1 cells, but also enhance the apoptosis of Panc-1 cells. In addition, downregulation of STMN1 obviously enhanced the acetylation level of α-tubulin. All these results indicated that STMN1 plays an important role in pancreatic cancer development, and might serve as a potential therapeutic target for pancreatic cancer.

Deoxypodophyllotoxin suppresses tumor vasculature in HUVECs by promoting cytoskeleton remodeling through LKB1-AMPK dependent Rho A activatio.

PubMed

Wang, Yurong; Wang, Bin; Guerram, Mounia; Sun, Li; Shi, Wei; Tian, Chongchong; Zhu, Xiong; Jiang, Zhenzhou; Zhang, Luyong

2015-10-06

Angiogenesis plays a critical role in the growth and metastasis of tumors, which makes it an attractive target for anti-tumor drug development. Deoxypodophyllotoxin (DPT), a natural product isolated from Anthriscus sylvestris, inhibits cell proliferation and migration in various cancer cell types. Our previous studies indicate that DPT possesses both anti-angiogenic and vascular-disrupting activities. Although the RhoA/ RhoA kinase (ROCK) signaling pathway is implicated in DPT-stimulated cytoskeleton remodeling and tumor vasculature suppressing, the detailed mechanisms by which DPT mediates these effects are poorly understood. In the current study, we found that DPT promotes cytoskeleton remodeling in human umbilical vein endothelial cells (HUVECs) via stimulation of AMP-activated protein kinase (AMPK) and that this effect is abolished by either treatment with a selective AMPK inhibitor or knockdown. Moreover, the cellular levels of LKB1, a kinase upstream of AMPK, were enhanced following DPT exposure. DPT-induced activation of AMPK in tumor vasculature effect was also verified by transgenic zebrafish (VEGFR2:GFP), Matrigel plug assay, and xenograft model in nude mice. The present findings may lay the groundwork for a novel therapeutic approach in treating cancer.

Expression of HOXB2, a retinoic acid signaling target in pancreatic cancer and pancreatic intraepithelial neoplasia.

PubMed

Segara, Davendra; Biankin, Andrew V; Kench, James G; Langusch, Catherine C; Dawson, Amanda C; Skalicky, David A; Gotley, David C; Coleman, Maxwell J; Sutherland, Robert L; Henshall, Susan M

2005-05-01

Despite significant progress in understanding the molecular pathology of pancreatic cancer and its precursor lesion: pancreatic intraepithelial neoplasia (PanIN), there remain no molecules with proven clinical utility as prognostic or therapeutic markers. Here, we used oligonucleotide microarrays to interrogate mRNA expression of pancreatic cancer tissue and normal pancreas to identify novel molecular pathways dysregulated in the development and progression of pancreatic cancer. RNA was hybridized to Affymetrix Genechip HG-U133 oligonucleotide microarrays. A relational database integrating data from publicly available resources was created to identify candidate genes potentially relevant to pancreatic cancer. The protein expression of one candidate, homeobox B2 (HOXB2), in PanIN and pancreatic cancer was assessed using immunohistochemistry. We identified aberrant expression of several components of the retinoic acid (RA) signaling pathway (RARalpha, MUC4, Id-1, MMP9, uPAR, HB-EGF, HOXB6, and HOXB2), many of which are known to be aberrantly expressed in pancreatic cancer and PanIN. HOXB2, a downstream target of RA, was up-regulated 6.7-fold in pancreatic cancer compared with normal pancreas. Immunohistochemistry revealed ectopic expression of HOXB2 in 15% of early PanIN lesions and 48 of 128 (38%) pancreatic cancer specimens. Expression of HOXB2 was associated with nonresectable tumors and was an independent predictor of poor survival in resected tumors. We identified aberrant expression of RA signaling components in pancreatic cancer, including HOXB2, which was expressed in a proportion of PanIN lesions. Ectopic expression of HOXB2 was associated with a poor prognosis for all patients with pancreatic cancer and was an independent predictor of survival in patients who underwent resection.

The role of p21-activated kinases in pancreatic cancer.

PubMed

Yeo, Dannel; He, Hong; Baldwin, Graham S; Nikfarjam, Mehrdad

2015-04-01

Pancreatic cancer is an aggressive cancer with a poor prognosis and an overall 5-year survival rate of less than 5%. Management has not improved significantly over the last 30 years, and a better understanding of the genetic and molecular changes that occur is urgently required. Many of these changes appear to involve the p21-activated kinases (PAKs). The PAK family consists of 6 isoforms, 2 of which, PAK1 and PAK4, are up-regulated and/or hyperactivated in pancreatic cancer. p21-Activated kinases can mediate many different cellular processes especially those contributing to cancer development and progression. These processes include the regulation of cytoskeletal dynamics and cell adhesion, the evasion of apoptosis, and the promotion of cell survival, proliferation, migration, and invasion. p21-Activated kinases may also be involved in characteristics unique to pancreatic tumors, such as interplay with the pancreatic stroma, the re-emergence of embryonic pathways, and the involvement of a subset of microRNAs and heat shock proteins. This review highlights the potential role of PAKs in pancreatic cancer and provides a foundation for more effective therapeutics to improve our current treatment of pancreatic cancer.

Role of Endogenous Cholecystokinin on Growth of Human Pancreatic Cancer

PubMed Central

Matters, Gail L.; McGovern, Christopher; Harms, John F.; Markovic, Kevin; Anson, Krystal; Jayakumar, Calpurnia; Martenis, Melissa; Awad, Christina; Smith, Jill P.

2012-01-01

Cholecystokinin (CCK) and gastrin stimulate growth of pancreatic cancer. Although down regulation of gastrin inhibits growth of pancreatic cancer, the contribution of endogenous CCK to tumor growth is unknown. The purpose of this study was to evaluate the role of endogenous CCK on autocrine growth of pancreatic cancer. Pancreatic cancer cell lines were analyzed for CCK mRNA and peptide expression by real time RT-PCR and radioimmunoassay, respectively. The effect of endogenous CCK on growth was evaluated by treating cancer cells with CCK neutralizing antibodies and by down regulating CCK mRNA by RNAi. Wild type pancreatic cancer cells expressed significantly lower CCK mRNA and peptide levels than gastrin. Neither treatment of pancreatic cancer cells with CCK antibodies nor the down regulation of CCK mRNA and peptide by shRNAs altered growth in vitro or in vivo. Conversely, when gastrin mRNA expression was down regulated, the same cells failed to produce tumors in spite of having sustained levels of endogenous CCK. Pancreatic cancer cells produce CCK and gastrin; however, the autocrine production of gastrin is more important for stimulating tumor growth. PMID:21186400

Expression patterns of epiplakin1 in pancreas, pancreatic cancer and regenerating pancreas.

PubMed

Yoshida, Tetsu; Shiraki, Nobuaki; Baba, Hideo; Goto, Mizuki; Fujiwara, Sakuhei; Kume, Kazuhiko; Kume, Shoen

2008-07-01

Epiplakin1 (Eppk1) is a plakin family gene with its function remains largely unknown, although the plakin genes are known to function in interconnecting cytoskeletal filaments and anchoring them at plasma membrane-associated adhesive junction. Here we analyzed the expression patterns of Eppk1 in the developing and adult pancreas in the mice. In the embryonic pancreas, Eppk1+/Pdx1+ and Eppk1+/Sox9+ pancreatic progenitor cells were observed in early pancreatic epithelium. Since Pdx1 expression overlapped with that of Sox9 at this stage, these multipotent progenitor cells are Eppk1+/Pdx1+/Sox9+ cells. Then Eppk1 expression becomes confined to Ngn3+ or Sox9+ endocrine progenitor cells, and p48+ exocrine progenitor cells, and then restricted to the duct cells and a cells at birth. In the adult pancreas, Eppk1 is expressed in centroacinar cells (CACs) and in duct cells. Eppk1 is observed in pancreatic intraepithelial neoplasia (PanIN), previously identified as pancreatic ductal adenocarcinoma (PDAC) precursor lesions. In addition, the expansion of Eppk1-positive cells occurs in a caerulein-induced acute pancreatitis, an acinar cell regeneration model. Furthermore, in the partial pancreatectomy (Px) regeneration model using mice, Eppk1 is expressed in "ducts in foci", a tubular structure transiently induced. These results suggest that Eppk1 serves as a useful marker for detecting pancreatic progenitor cells in developing and regenerating pancreas.

Somatostatin Receptor-1 Induces Cell Cycle Arrest and Inhibits Tumor Growth in Pancreatic Cancer

PubMed Central

Li, Min; Wang, Xiaochi; Li, Wei; Li, Fei; Yang, Hui; Wang, Hao; Brunicardi, F. Charles; Chen, Changyi; Yao, Qizhi; Fisher, William E.

2010-01-01

Functional somatostatin receptors (SSTRs) are lost in human pancreatic cancer. Transfection of SSTR-1 inhibited pancreatic cancer cell proliferation in vitro. We hypothesize that stable transfection of SSTR-1 may inhibit pancreatic cancer growth in vivo possibly through cell cycle arrest. In this study, we examined the expression of SSTR-1 mRNA in human pancreatic cancer tissue specimens, and investigated the effect of SSTR-1 overexpression on cell proliferation, cell cycle, and tumor growth in in a subcutaneous nude mouse model. We found that SSTR-1 mRNA was downregulated in the majority of pancreatic cancer tissue specimens. Transfection of SSTR-1 caused cell cycle arrest at the G0/G1 growth phase, with a corresponding decline of cells in the S (mitotic) phase. The overexpression of SSTR-1 significantly inhibited subcutaneous tumor size by 71% and 43% (n=5, p<0.05, t-test), and inhibited tumor weight by 69% and 47%, (n=5, p<0.05, t-test), in Panc-SSTR-1 and MIA-SSTR-1 groups, respectively, indicating the potent inhibitory effect of SSTR-1 on pancreatic cancer growth. Our data demonstrate that overexpression of SSTR-1 significantly inhibits pancreatic cancer growth possibly through cell cycle arrest. This study suggests that gene therapy with SSTR-1 may be a potential adjuvant treatment for pancreatic cancer. PMID:18823376

All for one and FOSL1 for all: FOSL1 at the crossroads of lung and pancreatic cancer driven by mutant KRAS.

PubMed

Vallejo, Adrian; Valencia, Karmele; Vicent, Silvestre

2017-01-01

KRAS proto-oncogene, GTPase ( KRAS ) remains refractory to current therapies. We devised an integrative cross-tumor approach to expose common core elements up-regulated in mutant KRAS cancers that could provide new treatment opportunities. This approach identified FOSL1 ( Fos-like antigen 1 ) as a clinically and functionally relevant gene in mutant KRAS -driven lung and pancreatic cancers, and unveiled downstream transcriptional targets amenable to pharmacological inhibition.

High fat diet and GLP-1 drugs induce pancreatic injury in mice

DOE Office of Scientific and Technical Information (OSTI.GOV)

Rouse, Rodney, E-mail: rodney.rouse@fda.hhs.gov; Xu, Lin; Stewart, Sharron

Glucagon Like Peptide-1 (GLP-1) drugs are currently used to treat type-2 diabetes. Safety concerns for increased risk of pancreatitis and pancreatic ductal metaplasia have accompanied these drugs. High fat diet (HFD) is a type-2 diabetes risk factor that may affect the response to GLP-1 drug treatment. The objective of the present study was to investigate the effects of diet and GLP-1 based drugs on the exocrine pancreas in mice. Experiments were designed in a mouse model of insulin resistance created by feeding a HFD or standard diet (STD) for 6 weeks. The GLP-1 drugs, sitagliptin (SIT) and exenatide (EXE) weremore » administered once daily for additional 6 weeks in both mice fed HFD or STD. The results showed that body weight, blood glucose levels, and serum levels of pro-inflammatory cytokines (TNFα, IL-1β, and KC) were significantly greater in HFD mice than in STD mice regardless of GLP-1 drug treatment. The semi-quantitative grading showed that pancreatic changes were significantly greater in EXE and SIT-treated mice compared to control and that HFD exacerbated spontaneous exocrine pancreatic changes seen in saline-treated mice on a standard diet. Exocrine pancreatic changes identified in this study included acinar cell injury (hypertrophy, autophagy, apoptosis, necrosis, and atrophy), vascular injury, interstitial edema and inflammation, fat necrosis, and duct changes. These findings support HFD as a risk factor to increased susceptibility/severity for acute pancreatitis and indicate that GLP-1 drugs cause pancreatic injury that can be exacerbated in a HFD environment.« less

Glutathione S-transferase M1 and glutathione S-transferase T1 genotype in chronic pancreatitis: a meta-analysis.

PubMed

Zhong, Yanjun; Zou, Runmei; Cao, Jie; Peng, Mou

2015-02-01

A meta-analysis to determine the association between chronic pancreatitis and glutathione-S transferase (GST) mu 1 (GSTM1) and theta 1 (GSTT1) deletions. Case-control studies concerning the relationship between chronic pancreatitis and GSTM1 or GSTT1 deletions were identified (up to October 2013). Meta-analyses of the association between GSTM1 and GSTT1 genotype and chronic pancreatitis or alcoholic chronic pancreatitis (ACP) were performed. Seven studies were included in the meta-analysis (650 patients/1382 controls for GSTM1 and 536 patients/1304 controls for GSTT1). There were no significant relationships between GSTM1/GSTT1 and chronic pancreatitis or GSTT1 and ACP. There was a significant association between GSTM1 null genotype and ACP (odds ratio 1.16, 95% confidence intervals 1.03, 1.30). The GSTM1 null genotype was significantly associated with ACP risk. © The Author(s) 2014 Reprints and permissions: sagepub.co.uk/journalsPermissions.nav.

Pancreatic Fibroblasts Stimulate the Motility of Pancreatic Cancer Cells through IGF1/IGF1R Signaling under Hypoxia.

PubMed

Hirakawa, Toshiki; Yashiro, Masakazu; Doi, Yosuke; Kinoshita, Haruhito; Morisaki, Tamami; Fukuoka, Tatsunari; Hasegawa, Tsuyoshi; Kimura, Kenjiro; Amano, Ryosuke; Hirakawa, Kosei

2016-01-01

Pancreatic ductal adenocarcinoma (PDAC) is characterized by its hypovascularity, with an extremely poor prognosis because of its highly invasive nature. PDAC proliferates with abundant stromal cells, suggesting that its invasive activity might be controlled by intercellular interactions between cancer cells and fibroblasts. Using four PDAC cell lines and two pancreas cancer-associated fibroblasts (CAFs), the expression of insulin-like growth factor-1 (IGF1) and IGF1 receptor (IGF1R) was evaluated by RT-PCR, FACScan, western blot, or ELISA. Correlation between IGF1R and the hypoxia marker carbonic anhydrase 9 (CA9) was examined by immunohistochemical staining of 120 pancreatic specimens. The effects of CAFs, IGF1, and IGF1R inhibitors on the motility of cancer cells were examined by wound-healing assay or invasion assay under normoxia (20% O2) and hypoxia (1% O2). IGF1R expression was significantly higher in RWP-1, MiaPaCa-2, and OCUP-AT cells than in Panc-1 cells. Hypoxia increased the expression level of IGF1R in RWP-1, MiaPaCa-2, and OCUP-AT cells. CA9 expression was correlated with IGF1R expression in pancreatic specimens. CAFs produced IGF1 under hypoxia, but PDAC cells did not. A conditioned medium from CAFs, which expressed αSMA, stimulated the migration and invasion ability of MiaPaCa-2, RWP-1, and OCUP-AT cells. The motility of all PDAC cells was greater under hypoxia than under normoxia. The motility-stimulating ability of CAFs was decreased by IGF1R inhibitors. These findings might suggest that pancreas CAFs stimulate the invasion activity of PDAC cells through paracrine IGF1/IGF1R signaling, especially under hypoxia. Therefore the targeting of IGF1R signaling might represent a promising therapeutic approach in IGF1R-dependent PDAC.

Effects of emodin on the demethylation of tumor-suppressor genes in pancreatic cancer PANC-1 cells.

PubMed

Zhang, Hao; Chen, Liang; Bu, He-Qi; Yu, Qing-Jiang; Jiang, Dan-Dan; Pan, Feng-Ping; Wang, Yu; Liu, Dian-Lei; Lin, Sheng-Zhang

2015-06-01

Emodin, a natural anthraquinone derivative isolated from Rheum palmatum, has been reported to inhibit the growth of pancreatic cancer cells through different modes of action; yet, the detailed mechanism remains unclear. In the present study, we hypothesized that emodin exerts its antitumor effect by participating in the regulation of the DNA methylation level. Our research showed that emodin inhibited the growth of pancreatic cancer PANC-1 cells in a dose- and time-dependent manner. Dot-blot results showed that 40 µM emodin significantly inhibited genomic 5 mC expression in the PANC-1 cells, and mRNA-Seq showed that different concentrations of emodin could alter the gene expression profile in the PANC-1 cells. BSP confirmed that the methylation levels of P16, RASSF1A and ppENK were decreased, while concomitantly the unmethylated status was increased. RT-PCR and western blotting results confirmed that the low expression or absence of expression of mRNA and protein in the PANC-1 cells was re-expressed following treatment with emodin. In conclusion, our study for the first time suggests that emodin inhibits pancreatic cancer cell growth, which may be related to the demethylation of tumor-suppressor genes. The related mechanism may be through the inhibition of methyltransferase expression.

Targeted Gene Next-Generation Sequencing in Chinese Children with Chronic Pancreatitis and Acute Recurrent Pancreatitis.

PubMed

Xiao, Yuan; Yuan, Wentao; Yu, Bo; Guo, Yan; Xu, Xu; Wang, Xinqiong; Yu, Yi; Yu, Yi; Gong, Biao; Xu, Chundi

2017-12-01

To identify causal mutations in certain genes in children with acute recurrent pancreatitis (ARP) or chronic pancreatitis (CP). After patients were enrolled (CP, 55; ARP, 14) and their clinical characteristics were investigated, we performed next-generation sequencing to detect nucleotide variations among the following 10 genes: cationic trypsinogen protease serine 1 (PRSS1), serine protease inhibitor, Kazal type 1 (SPINK1), cystic fibrosis transmembrane conductance regulator gene (CFTR), chymotrypsin C (CTRC), calcium-sensing receptor (CASR), cathepsin B (CTSB), keratin 8 (KRT8), CLAUDIN 2 (CLDN2), carboxypeptidase A1 (CPA1), and ATPase type 8B member 1 (ATP8B1). Mutations were searched against online databases to obtain information on the cause of the diseases. Certain novel mutations were analyzed using the SIFT2 and Polyphen-2 to predict the effect on protein function. There were 45 patients with CP and 10 patients with ARP who harbored 1 or more mutations in these genes; 45 patients had at least 1 mutation related to pancreatitis. Mutations were observed in the PRSS1, SPINK1, and CFTR genes in 17 patients, the CASR gene in 5 patients, and the CTSB, CTRC, and KRT8 genes in 1 patient. Mutations were not found in the CLDN, CPA1, or ATP8B1 genes. We found that mutations in SPINK1 may increase the risk of pancreatic duct stones (OR, 11.07; P = .003). The patients with CFTR mutations had a higher level of serum amylase (316.0 U/L vs 92.5 U/L; P = .026). Mutations, especially those in PRSS1, SPINK1, and CFTR, accounted for the major etiologies in Chinese children with CP or ARP. Children presenting mutations in the SPINK1 gene may have a higher risk of developing pancreatic duct stones. Copyright © 2017 Elsevier Inc. All rights reserved.

The JAK/STAT pathway is involved in the upregulation of PD-L1 expression in pancreatic cancer cell lines.

PubMed

Doi, Toshifumi; Ishikawa, Takeshi; Okayama, Tetsuya; Oka, Kaname; Mizushima, Katsura; Yasuda, Tomoyo; Sakamoto, Naoyuki; Katada, Kazuhiro; Kamada, Kazuhiro; Uchiyama, Kazuhiko; Handa, Osamu; Takagi, Tomohisa; Naito, Yuji; Itoh, Yoshito

2017-03-01

Although improvements in the chemotherapy modalities for pancreatic cancer have been realized, pancreatic cancer remains one of the most lethal malignancies. New-generation cancer immunotherapy methods, such as blocking of the PD-1/PD-L1 pathway, are consistently being investigated to improve the survival of pancreatic cancer patients. In the present study, we evaluated the influence of anticancer agents 5-fluorouracil, gemcitabine and paclitaxel on PD-L1 expression in human pancreatic cancer cell lines MIA PaCa-2 and AsPC-1 and in murine pancreatic cancer cell line Pan02. Additionally, we analyzed the molecular mechanisms that facilitated the regulation of PD-L1 expression in these cell lines. We observed that when AsPC-1, MIA PaCa-2 and Pan02 cells were stimulated by 5-fluorouracil, gemcitabine or paclitaxel, PD-L1 surface protein expression was enhanced. Similarly, the mRNA level of PD-L1 was upregulated in the AsPC-1 and Pan02 cells when stimulated by each of the three anticancer agents. The phosphorylation of STAT1 and an increase in total STAT1 were also observed in the AsPC-1 cells when stimulated by each anticancer agent. In response to JAK2 inhibitor treatment, PD-L1 upregulation induced by the anticancer agents was reduced in a dose-dependent manner. These results suggest that i) the JAK2/STAT1 pathway is involved in the anticancer agent-mediated PD-L1 transcription; and ii) the anticancer agents altered the tumor immune response which may induce tumor immune escape. These findings can have an influence on the design of treatments that combine chemotherapy and immunotherapy.

Sox9: A Master Regulator of the Pancreatic Program

PubMed Central

Seymour, Philip A.

2014-01-01

Over the last decade, it has been discovered that the transcription factor Sox9 plays several critical roles in governing the development of the embryonic pancreas and the homeostasis of the mature organ. While analysis of pancreata from patients affected by the Sox9 haploinsufficiency syndrome campomelic dysplasia initially alluded to a functional role of Sox9 in pancreatic morphogenesis, transgenic mouse models have been instrumental in mechanistically dissecting such roles. Although initially defined as a marker and maintenance factor for pancreatic progenitors, Sox9 is now considered to fulfill additional indispensable functions during pancreogenesis and in the postnatal organ through its interactions with other transcription factors and signaling pathways such as Fgf and Notch. In addition to maintaining both multipotent and bipotent pancreatic progenitors, Sox9 is also required for initiating endocrine differentiation and maintaining pancreatic ductal identity, and it has recently been unveiled as a key player in the initiation of pancreatic cancer. These functions of Sox9 are discussed in this article, with special emphasis on the knowledge gained from various loss-of-function and lineage tracing mouse models. Also, current controversies regarding Sox9 function in healthy and injured adult pancreas and unanswered questions and avenues of future study are discussed. PMID:25148367

Diarylheptanoids suppress proliferation of pancreatic cancer PANC-1 cells through modulating shh-Gli-FoxM1 pathway.

PubMed

Dong, Guang-Zhi; Jeong, Ji Hye; Lee, Yu-Ih; Lee, So Yoon; Zhao, Hui-Yuan; Jeon, Raok; Lee, Hwa Jin; Ryu, Jae-Ha

2017-04-01

Pancreatic cancer is one of the leading causes of cancer, and it has the lowest 5-year survival rates. It is necessary to develop more potent anti-pancreatic cancer drugs to overcome the fast metastasis and resistance to surgery, radiotherapy, chemotherapy, and combinations of these. We have identified several diarylheptanoids as anti-pancreatic cancer agents from Alpinia officinarum (lesser galangal) and Alnus japonica. These diarylheptanoids suppressed cell proliferation and induced the cell cycle arrest of pancreatic cancer cells (PANC-1). Among them, the most potent compounds 1 and 7 inhibited the shh-Gli-FoxM1 pathway and their target gene expression in PANC-1 cells. Furthermore, they suppressed the expression of the cell cycle associated genes that were rescued by the overexpression of exogenous FoxM1. Taken together, (E)-7-(4-hydroxy-3-methoxyphenyl)-1-phenylhept-4-en-3-one (1) from Alpinia officinarum (lesser galangal) and platyphyllenone (7) from Alnus japonica inhibit PANC-1 cell proliferation by suppressing the shh-Gli-FoxM1 pathway, and they can be potential candidates for anti-pancreatic cancer drug development.

MUC1-specific CTLs are non-functional within a pancreatic tumor microenvironment.

PubMed

Mukherjee, P; Ginardi, A R; Madsen, C S; Tinder, T L; Jacobs, F; Parker, J; Agrawal, B; Longenecker, B M; Gendler, S J

2001-01-01

Pancreatic cancer is a highly aggressive, treatment refractory disease and is the fourth leading cause of death in the United States. In humans, 90% of pancreatic adenocarcinomas over-express altered forms of a tumor-associated antigen, MUC1 (an epithelial mucin glycoprotein), which is a target for immunotherapy. Using a clinically relevant mouse model of pancreas cancer that demonstrates peripheral and central tolerance to human MUC1 and develops spontaneous tumors of the pancreas, we have previously reported the presence of functionally active, low affinity, MUC1-specific precursor cytotoxic T cells (pCTLs). Hypothesis for this study is that MUC1-based immunization may enhance the low level MUC1-specific immunity that may lead to an effective anti-tumor response. Data demonstrate that MUC1 peptide-based immunization elicits mature MUC1-specific CTLs in the peripheral lymphoid organs. The mature CTLs secrete IFN-gamma and are cytolytic against MUC1-expressing tumor cells in vitro. However, active CTLs that infiltrate the pancreas tumor microenvironment become cytolytically anergic and are tolerized to MUC1 antigen, allowing the tumor to grow. We demonstrate that the CTL tolerance could be reversed at least in vitro with the use of anti-CD40 co-stimulation. The pancreas tumor cells secrete immunosuppressive cytokines, including IL-10 and TGF-beta that are partly responsible for the down-regulation of CTL activity. In addition, they down-regulate their MHC class I molecules to avoid immune recognition. CD4+ CD25+ T regulatory cells, which secrete IL-10, were also found in the tumor environment. Together these data indicate the use of several immune evasion mechanisms by tumor cells to evade CTL killing. Thus altering the tumor microenvironment to make it more conducive to CTL killing may be key in developing a successful anti-cancer immunotherapy.

[Effects of ezrin silencing on pancreatic cancer cell line Panc-1].