Inhibitory effect of recombinant human semaphorin 3A on angiogenesis of gastric cancer and the associated mechanisms / 解剖学报

Objective To investigate the expression of semaphorin 3A (Sema3A) and its receptor neuropilin-1 (NRP-1) in gastric cancer and its correlation with microvessel density (MVD), and then to explore the effect of recombinant human Sema3A on angiogenesis of gastric cancer and the associated mechanisms. Methods Forty cases of gastric cancer tissues and its corresponding adjacent normal tissues were used to detecte the expression of Sema3A, NRP-1 and MVD in tissues by immunohistochemistry method . The expression level of Sema3A in serum of gastric cancer patient group and normal control group were measured by Enzyme-linked immuno-sorbent assay (ELISA). Western blotting was used to detect the expression of Sema3A and NRP-1 in five gastric cancer cell lines (MGC-803,HGC-27,MKN-28,SGC-7901,MKN-45) and human gastric mucosal epithelial cell (GES-1). Transwell chamber was used to construct non-contact in vitro co-culture system, in which the effects of different concentrations of recombinant human Sema3A on angiogenesis in gastric cancer were analyzed by tube formation assay preliminarily. The expression levels of vascular endothelial growth factor receptor 2 (VEGFR2) and NRP-1 in co-culture system were detected by Western blotting. Results The expression levels of Sema3A in gastric cancer tissues, cell lines and patient serum were significantly lower than that in the control group(P<0. 05), while the expression of NRP-1 in gastric cancer tissues and MKN-28 cells was significantly increased, and both of them were associated with TNM staging of gastric cancer (P < 0. 05) . In vitro co-culture system, The tube forming abilities of human umbilical vein endothelial cell (HUVEC) were decreased in recombinant human Sema3A treated group, and this phenomenon was concentration dependent. The expression of VEGFR2 protein was down-regulated by recombinant human Sema3A. Conclusion The expression of Sema3A was decreased in gastric cancer tissues, cell lines and patient serum, and negatively correlated with microvessel density. The recombinant human Sema3A could inhibit the angiogenesis of gastric cancer in vitro, which may be related to down-regulation of VEGFR2 protein expression.

Expression of ATP-binding cassette transporter ABCG2 in gastric carcinoma and its significance / 中华胃肠外科杂志

<p><b>OBJECTIVE</b>To investigate the expression of ATP-binding cassette transporter (ABCG2) in gastric carcinoma and its clinical significance.</p><p><b>METHODS</b>Expression of ABCG2 protein was examined by immunohistochemical technique in specimens from 45 gastric carcinoma tissues and 30 surrounding normal tissues. The expression of ABCG2 mRNA was measured by RT-PCR and real-time quantitative PCR in specimens from 30 gastric carcinoma tissues and 30 surrounding normal gastric mucosa respectively.</p><p><b>RESULTS</b>ABCG2 protein expression was observed in 28 of 45 (62.2%) cases by immunohistochemical analysis, while in 2 of 30 (6.7%) normal tissues (P< 0.05). In ABCG2-positive tumors, adjacent non-neoplastic tissue was similarly analyzed and revealed that ABCG2 was up-regulated in gastric carcinoma. The positive rates of ABCG2 expression in poorly differentiated and/or undifferentiated carcinoma were significantly higher than those in well and/or moderately-differentiated carcinoma (P< 0.05). The mRNA expression of ABCG2 was significantly higher in gastric carcinoma tissue than that in normal gastric mucosa (P< 0.05).</p><p><b>CONCLUSIONS</b>ABCG2 expression is up-regulated in gastric carcinoma. ABCG2 may be an important factor in the research of gastric cancer stem cell.</p>

Surgical treatment for patients with gastric cancer: report of 2335 cases / 中华胃肠外科杂志

<p><b>OBJECTIVE</b>To clarify the important factors affecting the prognosis of patient with gastric carcinoma.</p><p><b>METHODS</b>The data of 2335 cases of resected gastric carcinoma from Jan. 1996 to Dec. 2005 were studied by using univariate analysis and multivariate regression analysis.</p><p><b>RESULTS</b>Male patients accounted for 81.0% and female patients 19.0%. The ratio of male to female was 4.2: 1.0. Patients under 50 years old accounted for 77.2%. Two hundred and seventy-five cases were early gastric cancer, accounting for 11.8%, and another 2060 cases were advanced gastric cancer, accounting for 88.2%. Tumor diameter of 72.8% patients was more than 4 cm and 69.6% cases suffered with low differentiated cancer. Curative resections were performed in 1690 patients (72.4%) and palliative operation in other patients. After operation, 1538 cases (65.9%) received comprehensive treatment. For all cases, the 1-, 3- and 5-year survival rates were 71.9%, 45.3% and 40.1% respectively. The independent risk factors influencing prognosis of these patients were Borrmann classification,TNM staging, curative resection and multidisciplinary treatment through univariate and multivariate analyses.</p><p><b>CONCLUSION</b>The factors influencing prognosis of patient with gastric carcinoma after resection are Borrmann classification,TNM staging, curative resection and multidisciplinary treatment. Early and curative resection is the most important management to improve therapeutic efficacy of stomach cancer.</p>

Expression of Plexin A1 in gastric carcinoma and its relationship with tumor angiogenesis and proliferation / 中华胃肠外科杂志

<p><b>OBJECTIVE</b>To investigate the expression of Plexin A1 in gastric cancer(GC) and its relationship with angiogenesis and proliferation of GC.</p><p><b>METHODS</b>Plexin A1 mRNA expression in 20 cases of GC specimens and matched resected normal gastric tissue were examined by RT-PCR. Plexin A1, Ki-67, vascular endothelial growth factor(VEGF) protein expression and microvessel density (MVD) in 50 cases of GC specimens and 20 cases of normal gastric mucosa were detected by immunohistochemistry.</p><p><b>RESULTS</b>RT-PCR showed that the expression of Plexin A1 in GC was significantly higher than that in normal gastric mucosa(0.71 +/- 0.37 vs 0.60 +/- 0.25, P < 0.05). MVD within tumor tissue increased significantly with Plexin A1 mRNA expression(r=0.8736, P < 0.01) and Plexin A1 protein expression (P < 0.01). The Plexin A1 expression was positively correlated with the proliferation index (Ki-67) of cancer cells (r=0.4851, P < 0.01). However, the Plexin A1 expression level had no relationship with the VEGF expression level.</p><p><b>CONCLUSION</b>Plexin A1 plays an important role in the occurrence and development of GC. Plexin A1 may regulate angiogenesis, and promote the proliferation of GC cells.</p>