Prognostic significance of expression of thymidine phosphorylase and vascular endothelial growth factor in human gastric carcinoma

Effect of Chinese medicine Weikangning on expression of VEGF and its receptors Flt and KDR in gastric carcinoma cells

AIM: To study effect of traditional Chinese medicine Weikangning (WKN) on the expression of VEGF and its receptors Flt and KDR in gastric carcinoma cells.

METHODS: We used different dosage of WKN on rats to prepare serum containing WKN.The gastric carcinoma cells were cultured in the RPMI1640 media with serum containing WKN for 48 h. The expression of VEGF, Flt-1 and KDR was determined by reverse transcription-polymerase chain reaction (RT-PCR) and immunohistochemistry in gastric cancer cell lines respectively.

RESULTS: All gastric cancer cell lines analyzed expressed VEGF Flt-1 and KDR. But the expression of fVEGF (186.82±0.22, 195.35±0.45, 172.62±0.52), Flt-1 (198.44±0.44, 188.66±0.46, 197.01±0.91) in cells cultured in serum containing WKN decreased in a dose-dependent manner as compared with control (VEGF162. 78±0.58, Flt: 172.65±0.65)(P < 0.05).

CONCLUSION: VEGF and its receptors KDR and Flt-1 are expressed widely in gastric carcinoma cells and WKN can inhibit their expression.

Relationship between the expression of iNOS, VEGF, tumor angiogenesis and gastric cancer

AIM: To investigate the relationship between the expression of inducible nitric oxide synthase (iNOS), vascular endothelial growth factor (VEGF), the microvascular density (MVD) and the pathological features and clinical staging of gastric cancer.

METHODS: Immunohistochemical staining was used for detecting the expression of iNOS and VEGF in 46 resected specimens of gastric carcinoma; the monoclonal antibody against CD34 was used for displaying vascular endothelial cells, and MVD was detected by counting of CD34-positive vascular endothelial cells.

RESULTS: Of 46 resected specimens of gastric carcinoma, the rates of expressions of iNOS and VEGF were 58.70% and 76.09%, respectively, and MVD averaged 55.59 ± 19.39. Judged by the standard TNM criteria, the rate of expression of iNOS in stage IV (84.46%) was higher than those in stage I, II, III (Fish exact probabilities test, P = 0.019, 0.023 and 0.033, respectively); the rates of expression of VEGF in stage III, IV (76.0%, 92.31%, respectively) were higher than those in stage I, II (Fish exact probabilities test, P = 0.031, 0.017, 0.022 and 0.019). MVDs in stage III, IV (64.72 ± 14.96, 67.09 ± 18.29, respectively) were higher than those in stage I, II (t = 2.378, 4.015, 2.503 and 2.450, P < 0.05, P < 0.001, P < 0.001, P < 0.05, respectively). In 37 gastric carcinoma specimens with lymph node metastasis, MVD (68.69 ± 18.07) and the rates of expression of iNOS and VEGF (70.27%, 83.78%, respectively) were higher than those in the specimens with absence of metastasis (t = 2.205, χ² = 6.3587, χ² = 6.2584, P < 0.01, P < 0.05, P < 0.05, respectively). MVD and the expressions of iNOS and VEGF were not correlated to the location, size or grade of tumor, nor with the depth of invasion of tumor; MVDs in the positive iNOS and VEGF specimens (59.88 ± 18.02, 58.39 ± 17.73, respectively) were higher than those in the negative iNOS and VEGF specimens (χ² = 6.3587 and 6.1574, P < 0.05, P < 0.05, respectively); thus the expressions of iNOS and VEGF was correlated to MVD, but the expression of iNOS was not correlated to that of VEGF. In addition, of the 46 surviving patients, the 5-year survival rate of patients with positive iNOS or VEGF tumors was significantly less than that of patients with negative iNOS-or VEGF tumors (χ² = 4.3842 and 5.4073, P < 0.05, P < 0.05, respectively).

CONCLUSION: The expressions of iNOS and VEGF are closely related to tumor angiogenesis, and are involved in the advancement and the lymph node metastasis; thus MVD and the expressions of iNOS and VEGF may serve indexes for evaluating staging of gastric carcinoma and forecasting its risk of metastasis, which will help establish a comprehensive therapeutical measure of post-operative patients and provide a new approach to tumor therapy.