PI6 gene expression was measured by immnohistochemical method in poor differentiated serous cystadenocarcinoma cell line, xenograft of highly metastasizing human ovarian carcinoma in nude mice and paraffin embedded tissues from 69 patients with ovarian carcinoma. The result showed that PI6 gene was positive expression in HO-8910 cell of mother line, HO- 8910PM cell line and xenograft of highly mcatstasizing human ovarian carcinoma in nude mice. However, PI6 gene in the metastatic cell had a weaker expression. PI6 gene positive expression were also found in 51 cases of 69 cases (73.9%) in the ovarian epithelial carcinoma paraffin embedded tissues. Comparative studies showed that the positive rate of PI6 gene expression markedly reduced with the increase of pathologic grade and clinical stage, metastasis in the lymph node and decrease of 5-year survival (P<0.05, P<0.01).



PI6 gene is not only a controller of cytokerastic cycle, but also a key member of tumorigenic suppresser; its absence and expression degree are also correlated with the ovarian carcinoma genesis and development, especially with the metastasis of the ovarian cancer.