Liensinine Induces S-phase Arrest And Apoptosis In Human Pancreatic Cancer Cells And Its Possible Mechanisms

Objective:Pancreatic cancer is still considered as one of the most lethal cancers.The incidence of pancreatic cancer has continued increasing over the recent years while current treatment options remains inadequate.For the major part of the patients with either locally advanced or metastatic disease,the standard chemotherapy regimens could not prolong the prognosis significantly and these chemotherapy drugs have serious toxic effects on the human body.Therefore,effective and relatively safe therapies and drugs are urgently needed.Liensinine,an isoquinoline alkaloid,is isolated from the embryo of the mature lotus seed.Studies in recent years started to pay increasing attention to its antitumor effects,and it has been demonstrated that liensinine possess the properties of inhibiting cancer cell growth and proliferation in various human cancers.But the effects of liensinine on pancreatic cancer remain explored.The current study investigated the effects of liensinine on pancreatic cancer in vitro and in vivo and then explored the molecular mechanisms underlying liensinine-inductive effects on cell cycle arrest and apoptosis of pancreatic cancer.Methods:CCK-8 assays and colony forming assays were performed to quantitatively analyze the cell proliferation of MIA PaCa-2 and PANC-1 cells and assess the colony formation ability of these cells after treatment with different doses of liensinine,respectively.Flow cytometric assays and Hoechst33342 staining assays were performed to explore the effects of liensinine on cell cycle distribution and apoptosis of MIA PaCa-2 and PANC-1 cells.Western blot assays were performed to test the expression of cell cycle related proteins(CDK 2,cyclin A)and apoptosis related proteins(cleaved caspase 3,cleaved caspase 9,cleaved PARP,Bcl-2,Bax).Xenografts models in nude mice were built to test the effects of liensinine on tumor-forming ability of human pancreatic cancer cells.Results:Liensinine suppressed the proliferation of MIA PaCa-2 and PANC-1 cells in a timeand dose-dependent manner.Further animal experiments showed the similar results.Consistently,both in MIA PaCa-2 and PANC-1 cell lines,the number of colonies formed in the liensinine-treated groups was significantly less than that formed in the control groups.Liensinine also induced S-phase arrest and apoptosis in these cells.Western blot showed that in liensinine-treated cells,the expression of cleaved caspase 9,cleaved caspase 3,cleaved PARP,Bax was upregulated while the expression of Bcl-2 was downregulated,thus the ratio of Bcl-2 to Bax decreased.Conclusion:Liensinine inhibits cells proliferation,and induces S-phase arrest and apoptosis in MIA PaCa-2 and PANC-1 cells by regulating the expression of cell cycle related proteins and influencing the mitochondria-mediated apoptosis pathway.