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s To investigate the relationship between the expression of VEGF-C, VEGFR-3 and lymph node metastasis (LNM) in the gastric cancer, and explore the role of VEGF-C, VEGFR-3 in the prognosis of gastric cancer.Gastric cancer specimens were selected from gastric cancer database from April, 1994 to December, 2003, which were registered and followed up. The specimens were divided into two groups according to LNM existing or not. Immunohistochemistry staining was performed with anti-VEGF-C, anti-VEGFR-3 monoclonal antibody by DAB method. Their effects on prognosis of gastric cancer patients were analyzed by Kaplan-meier, Logistic and Cox Regression methods.In 188 cases of gastric cancer patients, 97 patients presented with LNM and the rest did not. The positive expression rate of VEGF-C, VEGFR-3 in the group without LNM was lower than those in group with LNM, and there was significant difference between the two groups. There was significant difference in the average lymphatic vessel density between the group with LNM and the group without, and the same results were found between the group with positive VEGF-C expression and the group without.VEGF-C, VEGFR-3 are over-expressed in gastric cancer patients with LNM, and the expression of VEGF-C, VEGFR-3 are important predictors for the prognosis of gastric cancer.

To explore the patterns, intervals, risk factors of recurrent gastric cancer and provide evidences for predicting and prevention of recurrence after curative gastrectomy.Forty-eight patients with recurrent gastric cancer after curative gastrectomy for gastric cancer who were operated on in our department from August 1994 to August 1999 were enrolled in this study. Their recurrent patterns, intervals and clinicopathologic characters of primary tumors were analyzed retrospectively and compared with 48 cases without recurrence, who were treated homeochronously and chosen randomly. Risk factors correlated with tumor recurrence and recurrent intervals were studied by univariate and multivariate analysis.Univariate analysis showed that patients with metastases node in pelvic cavity, cancer invasion to serosa or more, Borrmann III or IV types were more occurred in recurrent group (P0.05). Multivariate analysis showed the depth of cancer invasion and Borrmann types were independently correlated with tumor recurrence after curative gastrectomy. COX regression analysis showed ascites and depth of cancer invasion were parameters dominating recurrent interval.Borrmann type is a risk factor of gastric cancer recurrence, while ascites is a parameter dominating recurrent interval, and the depth of cancer invasion is both risk factor of gastric cancer recurrence and parameter dominating recurrent interval.

To analyze the influence of radical excision combining splenectomy on prognosis of the patients with gastric cancer.Between June 1994 and March 2004, 692 patients were operated on for gastric cancer and registered into gastric cancer database. Radical excision (D2, D3 or D4) combining splenectomy for gastric cancer was performed in 45 cases. 343 cases were selected simultaneously for comparison according to the resembling rules in sex, age, tumor size, location, serosa invasion, Borrmann type and range of lymph node dissection. Clinicopathological factors affecting lymph node metastasis, patterns of lymph node metastasis, 5-year survival rate after radical excision combined with splenectomy for gastric cancer were compared.Lymph node metastasis rate of splenic hilus was 15.6 percent. Among them, upper, middle and lower domain is 11.5 percent, 33.3 percent and zero respectively. It was significantly different between gastric adenocarcinoma in proximal and body of stomach and that in distal stomach, poor differentiation and adenocarcinoma anaplastic and well and moderately differentiation adenocarcinoma, Borrmann III and IV types and Borrmann I and II types, infiltrated depth in T(3) and T(4) and infiltrated depth in T(1) and T(2), clinical stages III and IV and clinical stages I and II. The average and median survival time between radical gastrectomy only and radical gastrectomy combining splenectomy for gastric cancer at stage I and II patients were significantly different, but at stage III and IV patients not significantly different.Spleen should be reserved for patients with gastric cancer at stage I and II, and radical excision combining splenectomy could only be performed at stage III and IV patients with cancer infiltrating body and tail of the pancreas, or lymph nodes metastasis in the splenic hilus. Indication of radical excision combining splenectomy for gastric cancer must be further study to clarify its efficacy.

Activation of hTERT, the human telomerase catalytic subunit, has been implicated as the critical event in triggering telomerase activity of cancer cells. In present research, we investigated whether RNA interference (RNAi) induced by small interference RNA (siRNA) could suppress human telomerase catalytic unit (hTERT) gene expression in gastric SGC7901 cells.As a pilot study, we utilized green fluorescent protein (GFP) plasmid pCX-GFP (5 510 bp) as a reporter system and generated constructs SHi-pU6-GFP expressing small hairpin RNA (shRNA) specific for green fluorescence protein (GFP) in K562 and SGC7901 cell respectively. Furthermore, we constructed pU6-hTERT-siRNAs carried hairpin siRNA for hTERT gene and transfected in SGC7901 by using Lipofectamine trade mark 2000. The expression of hTERT gene was detected by reverse transcription polymerase chain reaction (RT-PCR) and fluorescence quantitative polymerase chain reaction (FQ-PCR) assay.Our pilot study showed the short hairpin RNA (shRNA) expression vector driven by the murine U6 small nuclear RNA promoter can specifically induce potent gene knockdown effect (i.e., inhibit GFP expression specifically) when transfected transiently into SGC7901 cell. The constructed pU6-hTERT-siRNAs carried hairpin siRNA for hTERT gene was proved to be the same as designed by restriction endonuclease analysis. pU6-hTERT-siRNAs were successfully transferred into SGC7901 cell and their stable expression were obtained. The expression of hTERT gene were specific inhibited by pU6-hTERT-siRNAs in SGC7901 cell.Short hairpin RNAs (shRNAs) could induce sequence-specific hTERT gene silencing in SGC7901 cell. Our results prove the feasibility of the U6 promoter-driven shRNA expression technique to be used to cancer gene therapy.

To assess whether any correlation exists between survival and the extent of lymph-node dissection.D(2), D(2)(+) or D(3) radical resection was performed on 158 patients with advanced gastric cancer. Among them, 73 were subjected to para-aortic lymph node dissection, (PALD group), and the other 85 were not subjected to the operation (non-PALD group). There was no significant difference in age, gender, site of tumors, type of Borrmann and histology between the two groups. The PALD group showed more advanced diseases in term of tumor invasion, lymph node metastasis and clinicopathological stage.Average operation time was longer in the PALD group than in the non-PALD group [(280 +/- 93) min VS. (245 +/- 91) min, (P0.01)]. Blood transfusion volume was (693 +/- 324) ml in the PALD group, and (460 +/- 375) ml in the non-PALD group (P0.01). No anastomotic leaks, pancreatic fistula, abdominal abscess and ileus were observed in both groups. No significant complications were found except for a higher incidence of diarrhea in the PALD group. Significant difference was found in survival curve, mean and median survival time between the two groups. The difference in survival was also found between patients with positive and negative lymph node metastasis in the PALD and non-PALD groups. Again, there was significant difference in survival between positive and negative No. 16 lymph node in the PALD group.Para-aortic lymph node dissection offers a significant survival benefit to curable patients with advanced gastric cancer. It is similar to limited lymphadenectomy in morbidity and mortality.

To investigate the clinical importance of palliative gastrectomy for late-staged gastric cancer.From June 1994 to October 2001, 95 patients with late-staged gastric cancer underwent palliative operation. Clinicopathological and prognostic parameters between 64 patients with palliative gastrectomy (PG group) and 31 patients with unresectable operation (UO group) was compared retrospectively.The age and gender ratios were not different between the two groups. The incidence of large volume (diameteror = 8 cm), serosal invasion (T(4)) and late TNM stage (IV stage) were significantly higher in the UO group than that in the PG group. There was no difference in peritoneal dissemination, distant lymph node and hepatic metastasis, and tumor location between the two groups. The one- and two-year survival of the patients in the PG group was 48.1% and 23.1%, and significantly better than 13.5% and 0 in the UO group.Palliative gastrectomy, compared with unresectable operation, can improve the prognosis of the patients with late-staged gastric cancer even with peritoneal dissemination, distant lymph node and hepatic metastasis, and surrounding organ invasion.