TIP30Inhibits Growth And Metastasis Of Pancreatic Cancer

Objective:The initiation, development and metastasis of pancreatic cancer is a multi-factor,multi-step and multiple genes involved complex process. Gene mutation, activation ofproto-oncogene, inactivation of tumor suppressor gene and the resulting abnormalchanges of signal pathways run throughout the whole process of pancreatic cancer.TIP30is a potential tumor suppressor gene, which is frequently down-regulated in manytumor cells and cancerous tissues. In this study we explore the role of TIP30insuppressing growth and metastasis of pancreatic cancer.Methods:1. TIP30expression of pancreatic cancer samples with adjacent non-tumorpancreatic tissues was detected by IHC assay with anti-TIP30antibody. Andcorrelations between relative expression of TIP30and clinic-pathologic information ofthese pancreatic patients were analyzed by different statistical methods.2. TIP30inhibited growth and metastasis of pancreatic cancer cell lines in Vitro: Weexplored the TIP30expression level of6common pancreatic cancer cell lines.Lenti-virus expressing corresponding plasmids were applied to up-regulate ordown-regulate expression of TIP30by infecting pancreatic cancer cells. We performedMTS, soft-agar colony formation and plate colony formation to study roles of TIP30onthe growth of pancreatic cancer cells in Vitro. Wound-healing assay, transwell cellmigration assay and Matrigel cell invasion assay were applied to study the role of TIP30on metastasis of pancreatic cancer cells in Vitro.3. Tumorigenicity assay on nude mice was applied to explore the role of TIP30ongrowth and metastasis of pancreatic cancer cells in Vivo. MiaPaCa-2cell were infectedwith LV-shTIP30or LV-shNon at MOI20and5×106cells were injected subcutaneouslyinto each mouse (n=6mice/group). The mice were monitored over the course of theexperiment and euthanized for histopathology examination at day45after cellsinoculation. The tumors volume was calculated according to the formula: V=length×width2×0.5. Results:1. TIP30expressed mainly in cytoplasm.TIP30expression was significantly decreasedin cancer tissue compared with peri-tumor tissues.2. TIP30inhibited growth and metastasis of pancreatic cancer cells in Vitro.1)MTSassay revealed that down-regulation of TIP30promoted growth ability of pancreaticcancer cell.Number of clones in soft-agar formed by cells infected with LV-shTIP30increased by53.8%when compared with that of cells infected with LV-shNon(P<0.05).Plate colony formation assay showed that cells with decreased TIP30expression formedmore and larger clones（P<0.05).2) Down-regulation of TIP30enhanced cell migrationability in the wound-healing assay. Transwell assay showed that down-regulation ofTIP30increased number of cells migrated through the membrane by57.1%（P<0.05）.Matrigel cell invasion assay showed that down-regulation of TIP30increased number ofcells invaded through the matrigel by113%（P<0.05）.3. TIP30inhibited growth and metastasis of pancreatic cancer cells in Vivo. Pancreaticcancer cells with decreased TIP30expression formed larger tumors and more metastasisnodes in liver（P<0.05）. Down-regulation of TIP30in pancreatic cancer cells promotedgrowth and metastasis in Vivo.Conclusion:TIP30expression decreased in pancreatic cancer. There wasn’t closely correlationbetween TIP30expression and gender，age，differentiation degree of the tumor.TIP30greatly decreased cell growth and metastasis ability of pancreatic cancer cells in Vitroand in Vivo. Therefore, TIP30may play great role in growth and metastasis ofpancreatic cancer.