Decreasing the ratio of matriptase/HAI-1 by downregulation of matriptase as a potential adjuvant therapy in ovarian cancer

Tumor invasion and metastasis are complex biological processes. Matriptase and its endogenous inhibitor, hepatocyte growth factor activator inhibitor-1 (HAI-1) are involved in invasion and metastasis. To evaluate the ratio of matriptase/HAI-1 and their potential therapeutic value in ovarian cancer, HO-8910 human ovarian cancer cells and the homologous high-metastatic HO-8910PM cells were used as in vitro cellular models ovarian cancer. The invasive and metastatic abilities, and the expression of matriptase and HAI-1 in these cells were detected using scratch assays, Transwell chamber assays, reverse transcription-quantitative polymerase chain reaction, western blotting and fluorescent immunocytochemistry. Following infection with lentivirus-mediated matriptase-targeting small interfering RNA (siRNA), cell cycle progression and apoptosis were also analyzed. The migration distance and number of invading HO-8910PM cells were significantly increased compared with HO-8910 cells. HO-8910PM cells exhibited a significantly higher ratio of matriptase/HAI-1 mRNA levels compared with HO-8910 cells (0.51 vs. 0.24, ~2.2 fold increase). Compared with HO-8910 cells, the matriptase mRNA level was increased by ~3.6 fold in HO-8910PM cells, whereas the HAI-1 mRNA level was increased by ~1.7 fold. Similar increases in protein expression levels were also observed in HO-8910PM cells compared with HO-8910 cells. Migration and invasiveness were positively correlated with matriptase expression level (r=0.994, P<0.01) and the ratio of matriptase/HAI-1 (r=0.929, P<0.01). Downregulation of matriptase using siRNA resulted in inhibition of the invasive and metastatic abilities of HO-8910PM cells, cell cycle arrest in the G(0)/G(1) phase and increased apoptosis. The present study demonstrated that ovarian cancer cell metastasis and invasion were more dependent on upregulation of matriptase levels than downregulation of HAI-1. Matriptase may be a potential adjuvant therapeutic target for inhibiting ovarian cancer invasion and metastasis.