OBJECTIVEThe purpose of this study was to investigate the effect and mechanism of Vav3 gene on the proliferation of human gastric cancer cell line SGC7901.

METHODSThe expressions of Vav3 proten in gastric cancer tissue, tumor-adjacent tissue, human gastric cancer cell line SGC7901 and gastric epithelial cell line GES-1 cells were tested by Western blot. Vav3-siRNA was transfected into the SGC7901 cells. The proliferation of SGC7901 cells in vitro was measured by MTT assay. Cell cycle of SGC7901 cells was determined by flow cytometry.The expressions of proliferation-related genes PCNA, p16, cyclin D1, Rb were determined by qPCR and Western blot assay. Orthotopic transplantation nude mouse models of gastric cancer were prepared, and the tumor growth and expressions of PCNA, P16, cyclin D1, and Rb proteins were examined.

RESULTSThe relative expressions of Vav3 in the gastric cancer and peritumoral tissue were 0.910±0.242 and 0.243±0.045, respectively; the relative expressions of Vav3 in SGC7901 and GSE-1 cells were 0.925±0.127 and 0.277±0.038, respevtively (both P<0.05). The expression of Vav3 protein in SGC7901 cells was effectively inhibited by Vav3-siRNA. Proliferation of SGC7901 cells was inhibited by (83.43±10.17)% after 80 nmol/L Vav3-siRNA transfection (P<0.05). The ratio of SGC7901 cells in G0/G1 phase was increased, and in S phase decreased after Vav3-siRNA transfection (both P<0.05). The expressions of PCNA and cyclin D1 were decreased in cells after Vav3-siRNA transfection, and expressions of p16 and Rb were increased after Vav3-siRNA transfection (P<0.05 for all). The tumor growth in the Vav3-siRNA group was much slower than that in the other 2 control groups of nude mouse models. Compared with the two control groups, expressions of PCNA and cyclin D1 were significantly lower in the Vav3-siRNA group, while expressions of p16 and Rb were increased (P<0.05 for all).

CONCLUSIONVav3 can promote the proliferation of gastric cancer cells by regulating proliferation-related genes.

Animals ; Cell Cycle ; Cell Line, Tumor ; Cell Proliferation ; Cyclin D1 ; metabolism ; Humans ; Mice ; Mice, Nude ; Proto-Oncogene Proteins c-vav ; metabolism ; RNA, Small Interfering ; Stomach Neoplasms ; metabolism ; Transfection

OBJECTIVEThe purpose of this study was to investigate the efficacy and mechanism of oxaliplatin in combination with capecitabine (XELOX) regimen as neoadjuvant chemotherapy in the treatment of patients with advanced gastric cancer.

METHODSEighty-five patients with advanced gastric cancer (stage IIB and IIIC) were randomly divided into two groups: neoadjuvant chemotherapy group (40 cases) and surgery alone group (45 cases). In the neoadjuvant chemotherapy group, patients received oral administration of Xeloda 1000 mg/m(2) twice a day on days 1-14 and intravenous infusion of oxaliplatin 130 mg/m(2) on day 1 (XELOX regimen). The regimen was repeated every 21 days. In the surgery alone group, patients directly received radical resection of gastric cancer. The R0 resection rate, overall survival and disease free survival (DFS) were observed in all cases. The cycles and apoptosis rate of the gastric cancer cells were detected by flow cytometry. The expression of proliferating cell nuclear antigen (PCNA), p21, p53 and survivin was detected by Western blot.

RESULTSIn the neoadjuvant chemotherapy group, the total effective rate was 32.5% (13/40), and the tumor control rate was 90% (36/40), with few side effects. Compared with the surgery alone group, R0 resection rate was significantly higher in the neoadjuvant chemotherapy group (P < 0.05). The survival analysis indicated that both the overall survival and DFS were longer in the neoadjuvant chemotherapy group in comparison with those in the surgery alone group, but no significant differences were found (P > 0.05). In the neoadjuvant chemotherapy group, both the apoptosis rate and the ratio of cells in stage G0 and G1 were significantly higher than those in the surgery alone group (P < 0.05). The expression of PCNA and survivin was lower in the neoadjuvant chemotherapy group, while the expression of p21 and p53 was higher.

CONCLUSIONSXELOX regimen as neoadjuvant chemotherapy in the treatment of patients with advanced gastric cancer can effectively improve the R0 resection rate and prolong the survival time of the patients. Its mechanism is probably that the neoadjuvant chemotherapy can markedly enhance apoptosis in gastric cancer cells and inhibit their proliferation.

Adult ; Aged ; Antineoplastic Combined Chemotherapy Protocols ; therapeutic use ; Apoptosis ; drug effects ; Cell Cycle ; drug effects ; Chemotherapy, Adjuvant ; Deoxycytidine ; analogs & derivatives ; therapeutic use ; Disease-Free Survival ; Female ; Fluorouracil ; analogs & derivatives ; therapeutic use ; Follow-Up Studies ; Gastrectomy ; methods ; Humans ; Inhibitor of Apoptosis Proteins ; metabolism ; Male ; Middle Aged ; Neoadjuvant Therapy ; Neoplasm Staging ; Proliferating Cell Nuclear Antigen ; metabolism ; Proto-Oncogene Proteins p21(ras) ; metabolism ; Remission Induction ; Stomach Neoplasms ; drug therapy ; metabolism ; pathology ; surgery ; Survival Rate ; Tumor Suppressor Protein p53 ; metabolism