Human Bone Marrow Mesenchymal Stem Cells Regulating Proliferation, Invasion, Angiogenesis And Epithelial-mesenchymal Transition In Pancreatic Cancer And Its Molecular Mechanisms

ObjectiveCell therapy is an emerging therapeutic therapy and brings hopes to many a disease. Thus, cell therapy still has an important potential in treating tumors. Stem cells, especially mesenchymal stem cells (MSCs) have been proven the ability of carrying therapeutic genes. However, in some newly researches, human MSCs (hMSCs) are found affecting and involving in the genesis and development of tumors, and hMSCs play different roles in different tumor tissues, which gives a great challenge to use MSCs as carriers of cell therapy in clinic. Pancreatic cancer is a solid tumor in digestive system and is highly grade malignancy. Early diagnosis is difficult and effective treat and satisfying therapeutic effects are lack for a late stage pancreatic cancer. Therefore, how MSCs affect during the genesis and development of a pancreatic cancer will offer theoretical foundation for using MSCs as carriers of tumor cell therapy.MSCs are found involving in multiple pathological processes of a tumor including genesis, development, invasion and metastasis. But, the functions of MSCs have a significant otherness in different tumor tissues. For instance, in breast cancer, lung cancer and colon cancer, MSCs facilitate the development and metastasis of the tumors, while, in Kaposi’s sarcoma, hepatocellular carcinoma and melanoma, MSCs restrain the development of tumors. Because MSCs paly a contradictory role in different tumor tissues and MSCs also have an incomparable value as cell therapy carrier, it is of great value to study what role MSCs play in pancreatic cancer. Thus, the focuses of the dissertation are to probe what roles MSCs play during the proliferation, apoptosis, invasion and metastasis and angiogenesis, and it also try to probe the probable mechanism of its in pancreatic cancer.MethodsPANC-1and AsPC-1in pancreatic cancer cell line and human bone marrow mesenchymal stem cells (hBMSCs) were planted into nude mice subcutaneously at some ratios, and the growth situation of nude mice transplanted subcutaneous sarcoma was observed to study how hBMSCs affect the tumor capacity of pancreatic cancer cells. The expressional situations of molecules such as CD31and Ki67in transplanted sarcoma tissues were detected by immunohistochemical technique. The diversities of transplanted sarcoma tissues apoptosis ability were detected by TUNEL.Pancreatic cancer cells (PANC-1and AsPC-1) and hBMSCs were indirectly co-cultured at10:1ratios. The changes of pancreatic cancer cells (PANC-1and AsPC-1) cycle, proliferation and apoptosis capacities were detected by flow cytometry. The effects of invasion ability of hBMSCs on pancreatic cancer cells were detected by transwell technique. The changes of critical molecules (Akt, P-Akt) in the PI3K-Akt cell signal path, epithelial-mesenchymal transition (EMT)(Snail, E-cadherin) and matrix metalloproteinase (MMP-2and MMP-9) were detected by western blot technique.ResultsHBMSCs in nude mice affect the tumor capacity of PANC-1and AsPC-1in pancreatic cancer cell line, and hBMSCs may facilitate the genesis and metastasis of PANC-1and AsPC-1. By immunohistochemical analysis, the amounts of CD31and Ki67expressions are notable increased in transplanted sarcoma tissue that PANC-1and BMSCs were co-injected and the apoptosis rate is notable decreased in the co-injected group by TUNEL detection.HBMSCs may enhance the invasion ability of pancreatic cancer cells (PANC-1and AsPC-1) by in vitro co-culture. The proliferation abilities of pancreatic cancer cells (PANC-1and AsPC-1) are enhanced after they are indirectly co-cultured with hBMSCs by BrdU flow cytometry. The apoptosis rates of pancreatic cancer cells (PANC-1and AsPC-1) are decreased after they are co-cultured by flow cytometry detection technique, while the cell cycles have no obvious change. After pancreatic cancer cells (PANC-1and AsPC-1) were co-cultured with hBMSCs, the expressions of MMP-2and MMP-9in pancreatic cancer cells (PANC-1and AsPC-1) are increased, the expression of EMT Snail increased, the expression of EMT E-cadherin decreased, and the expressions of critical molecules (Akt, P-Akt) in the PI3K-Akt cell signal path are notable increased by western blot detection technique.ConclusionsHBMSCs involve in the proliferation, apoptosis, invasion, metastasis, angiogenesis and EMT of pancreatic cancer. In vivo experiments, hBMSCs may facilitate the proliferation, invasion, metastasis and angiogenesis of pancreatic cancer cell PANC-1and AsPC-1but restrain the apoptosis of pancreatic cancer cell PANC-1and AsPC-1; In vitro experiments, hBMSCs facilitate the genesis and development of pancreatic cancer cells (PNAC-1and AsPC-1) and play a role by epithelial-mesenchymal transition and PI3K-Akt cell signal path, while hBMSCs have no obvious influence on pancreatic cancer cell cycle. The conclusion is that it has some risk to use hBMSCs as the carrier of pancreatic cancer cell therapy.