Xiangui Hu

MicroRNA 483-3p suppresses the expression of DPC4/Smad4 in pancreatic cancer

Both deregulation of tumor‐suppressor genes and misexpression of microRNAs (miRNAs) have been implicated in the development of pancreatic cancer, but their relationship during this process remains less clear. Here, we report that the expression of miR‐483‐3p is strongly enhanced in pancreatic cancer tissues compared to side normal tissues using a miRNA‐array differential analysis. Furthermore, DPC4/Smad4 is identified as a target of miR‐483‐3p and their expression levels are inversely correlated in human clinical specimens. Ectopic expression of miR‐483‐3p significantly represses DPC4/Smad4 protein levels in pancreatic cancer cell lines, and simultaneously promotes cell proliferation and colony formation in vitro. Our findings identify miR‐483‐3p as a potent regulator of DPC4/Smad4, which may provide a novel therapeutic strategy for the treatment of DPC4/Smad4‐driven pancreatic cancer.

MicroRNA 421 suppresses DPC4/Smad4 in pancreatic cancer

MicroRNAs (miRNAs) have emerged as important regulators in the development of pancreatic cancer and may be a valuable therapeutic application. DPC4/Smad4 is a critical tumor suppressor involved in the progression of pancreatic cancer, but few studies have been conducted to determine its relationship with miRNAs. In this study, we identify miR-421 as a potential regulator of DPC4/Smad4. We find that in human clinical specimens of pancreatic cancer miR-421 is aberrantly upregulated while DPC4/Smad4 is strongly repressed, and their levels of expression are inversely correlated. Moreover, ectopic expression of miR-421 significantly decreases DPC4/Smad4 protein level in pancreatic cancer cell lines and simultaneously promotes cell proliferation and colony formation in vitro. Our findings identify miR-421 as a potent regulator of DPC4/Smad4, which may provide a novel therapeutic strategy for treatment of DPC4/Smad4-driven pancreatic cancer.

Diabetes mellitus and increased risk of cholangiocarcinoma: a meta-analysis.

Diabetes mellitus (DM) has been reported to be associated with an increased risk of several types of cancers. However, its relationship with cholangiocarcinoma (CC), which includes intrahepatic cholangiocarcinoma (ICC) and extrahepatic cholangiocarcinoma (ECC), remains unclear. We conducted a meta-analysis to assess the association between diabetes and the risk of CC (including ICC and ECC). We identified studies by a literature search of Medline (from 1 January 1966) and Embase (from 1 January 1974), through 30 November 2010, and by searching the reference lists of pertinent articles. Summary relative risks (RRs) with corresponding 95% confidence intervals (CIs) were calculated with a random-effects model. A total of 15 articles (10 case–control and five cohort studies) were included in this study. The number of reports on DM and risk of specific cancer were as follows: CC (n=5), ECC (n=9), and ICC (n=9). Compared with those without diabetes, individuals with diabetes had an increased risk of CC (summary RRs, 1.60; 95% CI, 1.38–1.87; P=0.992 for heterogeneity), ECC (summary RRs, 1.63; 95% CIs, 1.29–2.05; P=0.005 for heterogeneity), and ICC (summary RRs, 1.97; 95% CIs, 1.57–2.46; P=0.025 for heterogeneity). The funnel plot revealed no evidence for publication bias concerning diabetes and the risk of CC (including ICC and ECC). These findings strongly support the positive link between DM and the increased risk of CC (including ICC and ECC).

Human Umbilical Cord Blood–Derived Mesenchymal Stem Cells Producing IL15 Eradicate Established Pancreatic Tumor in Syngeneic Mice

Mesenchymal stem cells (MSC) represent a new tool for delivery of therapeutic agents to cancer sites because of their strong tropism toward tumors. IL15 has demonstrated a potent antitumor activity in various animal models as well as clinical trials. However, because of its short half-life, effective therapeutic effects usually require a high dose, which often results in undesired side effects; thus, new strategies for overcoming this disadvantage are needed. In this study, human MSCs were isolated from umbilical cord blood as delivery vehicles and transduced with lentivirus vector expressing murine IL15 (MSC-IL15). In vitro assays of lymphocyte activation and proliferation demonstrated that IL15 produced by MSCs was biofunctional. In syngeneic mice bearing Pan02 pancreatic tumors, systemic administration of MSC-IL15 significantly inhibited tumor growth and prolonged the survival of tumor-bearing mice, which were associated with tumor cell apoptosis, and natural killer (NK)– and T-cell accumulation. Furthermore, we confirmed that MSC-IL15 could migrate toward tumor and secreted IL15 in tumor-specific sites. Depletion of NK and CD8+ T cells abolished the antitumor activity of MSC-IL15, suggesting that NK and CD8+ T cells play a key role for MSC-IL15–mediated effect. Interestingly, cured mice after MSC-IL15 treatment were resistant to Pan02 pancreatic tumor rechallenge, and adoptive transfer of lymphocytes from cured mice also could cause rejection of Pan02 tumor inoculation in naïve mice, indicating that MSC-IL15 induced tumor-specific T-cell immune memory response. Overall, these data support that MSCs producing IL15 might represent an innovative strategy for therapy of pancreatic tumor. Mol Cancer Ther; 13(8); 2127–37. ©2014 AACR.

miR-208-Induced Epithelial to Mesenchymal Transition of Pancreatic Cancer Cells Promotes Cell Metastasis and Invasion

The aim of this study was to investigate the role of miR-208 in the invasion and metastasis of pancreatic cancer cells and the underlying molecular mechanism. miR-208 mimic, miR-208 inhibitor and NC were transfected into pancreatic cancer cell line Bxpc3 using liposome. Transwell invasion and scratch assays were used to test cell migratory and invasive abilities. Western blotting and quantitative PCR methods were used to detect E-cadherin, fibronectin and vimentin protein and mRNA expression in pancreatic cancer cell line BxPC3 after transfection by miR-208 mimic, miR-208 inhibitor and NC. Transwell invasion and scratch assays showed that after overexpressing miR-208, pancreatic cancer cell line BxPC3 exhibited enhanced in vitro migratory and invasive abilities, while after downregulating miR-208 expression, cell migratory and invasive abilities were decreased. Western blotting and quantitative PCR showed that after overexpressing miR-208, expression of E-cadherin, an epithelial cell marker, was decreased and expression of fibronectin and vimentin, interstitial cell markers, was increased in pancreatic cancer cell line BxPC3; however, after inhibiting miR-208, increased E-cadherin expression and decreased fibronectin and vimentin expression were observed in pancreatic cancer cell line BxPC3. After overexpressing miR-208, p-AKT and p-GSK-3β expression was altered by activating AKT/GSK-3β/snail signaling pathway. miR-208 induces epithelial to mesenchymal transition of pancreatic cancer cell line BxPC3 by activating AKT/GSK-3β/snail signaling pathway and thereby promotes cell metastasis and invasion.

Interplay between menin and Dnmt1 reversibly regulates pancreatic cancer cell growth downstream of the Hedgehog signaling pathway.

Menin, the product of the Men1 gene, which is frequently mutated in pancreatic neuroendocrine tumors, acts as a chromatin-remodeling factor to modulate the transcription of cell cycle regulators by interacting with histone modification factors. However, the function of menin and its underlying mechanisms in pancreatic ductal adenocarcinoma remain unknown. Here, we found that menin inhibited pancreatic cancer cell growth in vitro and in vivo and that its expression was gradually lost during pancreatic carcinogenesis. Menin overexpression significantly activated the expression of the cyclin-dependent kinase (CDK) inhibitors p18 and p27, accompanied with a decrease in DNA methylation levels of p18 and p27 promoters. Mechanistically, we found that interaction of menin with DNA methyltransferase 1 (Dnmt1) competitively pulled down Dnmt1 from p18 and p27 promoters, leading to the downregulation of DNA methylation levels. Moreover, menin expression was suppressed by Dnmt1 downstream of the Hedgehog signaling pathway, and menin overexpression strongly antagonized the promotion effect of hedgehog signaling on pancreatic cancer cell proliferation. Taken together, the interaction between menin and Dnmt1 reversibly regulates pancreatic cancer cell growth downstream of Hedgehog pathways with complex mutual modulation networks, suggesting that the Hedgehog/Dnmt1/menin axis is a potential molecular target for pancreatic cancer therapy.

The role of fast-track surgery in pancreaticoduodenectomy: A retrospective cohort study of 635 consecutive resections

BACKGROUND Pancreaticoduodenectomy (PD) is one of the most difficult and dangerous operations in general surgery. This study used the concept of fast-track surgery (FTS) technique, which involves pain control, early enteral nutrition and other measures during the preoperative period, to evaluate the rate of complications and shorter hospitalization. METHODS This retrospective, observational study was conducted between January 2009 and January 2013. A total of 635 patients underwent PD in the Department of Pancreatic Surgery at ChangHai Hospital (Shanghai, China). 325 patients had FTS and 310 patients received the traditional pathway of treatment. The incidence of postoperative complications, the serum albumin level, expenses, postoperative hospitalization, and readmission rates were compared. RESULTS There were no significant differences in the blood transfusion volume, nasogastric intubation, and readmission rates (p > 0.05). However, the FTS group had less postoperative hospitalization, fewer expenses and a lower incidence of postoperative complications compared with the control group (p<0.05). CONCLUSION Pancreaticoduodenectomy can be further optimized by the use of FTS methods, which can reduce the incidence of in hospital postoperative complications and expenses without increasing the risk of readmission.

Analysis of tumor-induced lymphangiogenesis and lymphatic vessel invasion of pancreatic carcinoma in the peripheral nerve plexus

Cancer cells can metastasize throughout the body by various mechanisms, including the lymphatic system, resulting in tumor‐induced lymphangiogenesis that can profoundly affect patient survival. The aim of the present study was to examine the role of lymphangiogenesis in the metastasis of pancreatic cancer to the peripheral nerve plexus. Immunohistochemistry was performed to analyze specimens obtained from 70 ductal adenocarcinoma patients. The markers used included lymphangiogenic factor vascular endothelial growth factor (VEGF)‐C, the lymphatic‐specific marker D2‐40, and cytokeratin 19, an independent prognostic factor for pancreatic tumors. The relationship between survival rate and invasion of both the lymphatic vessels and peripancreatic nerve plexus (PNP) was evaluated, with clearly elevated lymphatic vessel density (LVD) in tissues adjacent to the cancer tissues. In fact, LVD levels were higher in adjacent tissues than in localized cancer tissues, and lymphatic vessel invasion into tissues adjacent to the tumor was significantly correlated with both PNP invasion (P = 0.005) and lymph node metastasis (P = 0.010). Correspondingly, LVD in tissues adjacent to the tumor was correlated with both invasion of lymphatic vessels surrounding the tumor (P = 0.024) and VEGF‐C expression (P = 0.031); in addition, VEGF‐C expression was correlated with invasion of lymphatic vessels around the tumor (P = 0.004). Survival rates were significantly lower in patients in whom there was peritumor lymphatic vessel invasion (P < 0.001), extrapancreatic nerve plexus invasion (P = 0.001), and/or lymph node metastasis (P < 0.001). Based on these results, lymphatic invasion associated with adjacent tumor growth likely contributes to the development of metastatic tumors that invade the PNP.

Downregulation of ASPP2 in pancreatic cancer cells contributes to increased resistance to gemcitabine through autophagy activation.

BackgroundApoptosis-stimulating of p53 protein 2 (ASPP2) is one of the ASPP family members and it has been reported to be associated with human cancer. However, the role of it in pancreatic cancer is still not clear.MethodsWe analyzed the expression level of ASPP2 in cancer tissue samples with RT-qPCR, Western Blotting assay and immunohistochemistry staining. We studied the biological function of ASPP2 and its mechanism with gene overexpression and gene silencing technologies. We determined the sensitivity of pancreatic cells with differential ASPP2 level to gemcitabine and whether autophagy inhibition affected the gemcitabine resistance, both in vitro and in vivo.ResultsExpression of ASPP2 was downregulated in cancerous tissues in comparison with para-cancerous tissues. ASPP2 expression was linked to clinical outcomes in patients and down-regulation of ASPP2 increased cell proliferation, autophagic flux, the activity of AMP Kinase of pancreatic cancer cells and vice versa. Knockdown of ASPP2 results in increased resistance to gemcitabine, which was attributed to the enhanced autophagy.ConclusionsASSP2 expression is lower in cancerous tissues and decreased ASPP2 lead to higher cancer cells proliferation and autophagic flux, which contribute to the gemcitabine resistance.

Ulinastatin reduces the resistance of liver cancer cells to epirubicin by inhibiting autophagy.

During chemotherapy, drug resistance caused by autophagy remains a major challenge to successful treatment of cancer patients. The purpose of this study is to show that ulinastatin (UTI), a trypsin inhibitor, could reduce the resistance of liver cancer cells to chemotherapeutic agent epirubicin (EPI). We achieved this conclusion by analyzing the effect of EPI alone or UTI plus EPI on SMMC-7721 and MHCC-LM3 liver cancer cells. We also generated an EPI-resistant liver cancer cell line (MHCC-LM3er cells), and found that UTI could sensitize the LM3er cells to EPI. Autophagy usually functions to protect cancer cells during chemotherapy. Our study showed that UTI inhibited the autophagy induced by EPI in liver cancer cells, which promoted apoptosis, and therefore, reduced the resistance of the cancer cells to EPI. Further studies showed that the UTI-mediated inhibition on autophagy was achieved by inhibiting transcriptional factor nuclear factor-κB (NF-κB) signaling pathway. To verify our results in vivo, we injected MHCC-LM3 liver cancer cells or EPI-resistant LM3er cells into mice, and found that EPI could only effectively inhibit the growth of tumor in MHCC-LM3 cell-injected mice, but not in LM3er cell-injected mice. However, when UTI was also administered, the growth of tumor was inhibited in the MHCC-LM3er cell-injected mice as well. Our results suggest that UTI may be used in combination with anti-cancer drugs, such as EPI, to improve the outcome of cancer therapy.