OBJECTIVETo investigate the effects of silencing heparanase (HPA) on growth, angiogenesis and metastasis of human gastric carcinoma transplanted in nude mice.

METHODSHuman gastric carcinoma SGC-7901 cells and those cells with silenced HPA (gastric carcinoma SGC-7901-HPA(-)) were separately transplanted subcutaneously in 6 nude mice. The time, size and speed of tumor growth were recorded. RT-PCR and Western-blot were used to detect the expression of HPA mRNA and protein in the subcutaneous tumors of the two groups. Immunohistochemical staining was used to detect microvessel density (MVD) in the subcutaneous tumors of the two groups. Cells of the subcutaneous transplanted tumors of the two groups were separately injected into the peritoneal cavity of nude mice, 6 mice each. The growth of metastatic tumors in nude mice was observed.

RESULTSHuman gastric carcinoma SGC-7901 cells and SGC-7901-HPA(-) cells were subcutaneously inoculated in nude mice, and tumors appeared at 4 days and 7 days after inoculation, respectively. The MVD was (20.69 ± 1.20)/HP and (11.35 ± 1.94)/HP, respectively (P < 0.05). The expressions of HPA mRNA and protein of the subcutaneously transplanted SGC-7901-HPA(-) tumor were decreased. Four voluminous metastatic tumors caused by SGC-7901 cells occurred in 3 mice in the liver, right kidney, omentum and intestine. Two smaller abdominal metastatic tumors of SGC-7901-HPA(-) cells were found in the liver and right kidney.

CONCLUSIONSilencing HPA can inhibit the tumor growth, angiogenesis and metastasis of human gastric cancer in nude mice. It suggests that HPA might become a new target for prevention and treatment of gastric cancer.