Objective To investigate the expression of transcription factor Oct 4 in gastric carcinoma and its effects on gastric cancer cell proliferation and apoptosis after Oct 4 gene interfered by lentivirus vector.Methods Real time PCR and Western blot were used to observe the expression of Oct 4 in different differentiated gastric cancer cell lines.Gastric cancer cell lines with high expression of Oct 4 was cultured and infected by siRNA-Oct 4-lentivirus vector.Cell proliferation and apoptosis were observed after Oct 4 gene was interfered.Results Oct 4 was highly expressed in poorly and moderately differentiated gastric cancer cells.Gene interfered with siRNA inhibits the expression of Oct 4 in gastric cancer cells and show significant effects on cell proliferation and mobility as well as apoptosis after down-regulation of Oct 4.Condusions Oct 4 expression is in close relationship with gastric cancer cell proliferation and invasive ability.

Objective To evaluate circulating tumor cells (CTC) in prognosis prediction of gastric cancer.Method Peripheral blood samples were obtained from 65 patients with gastric cancer and 20 normal volunteers.CTC were detected by using CellSearch(R) CTC Detecting System.Postoperative progress-free survival (PFIS) and overall survival (OS) were evaluated against CTC status and clinicopathological factors.Result CTC were positive in 35 out of 65 (53％) patients compared to 1 out of 20 (5％) healthy controls,P ＜ 0.05.CTC were not statistically corelated with patients' age,sex and lymph node status or distal metastasis,vascular invasion and tumor markers (all P ＞ 0.05).CTC positive patients had poorer OS (P ＜ 0.05) and PFS (P ＜ 0.05) compared with those with negative CTC.Conclusion Positive CTC in gastric cancer patients predict poor prognosis after radical gastrectomy.