Down-regulation of matriptase by overexpression of bikunin attenuates cell invasion in prostate carcinoma cells.

The precise mechanisms of metastasis in prostatic cancer are still unknown. A subculture cell line (PC-J) was isolated from the metastasis human prostate cell line PC-3. In vitro cell proliferation, wound healing and invasion assays revealed that tumorigenesis and metastasis differed between PC-3 and PC-J cells. Eight weeks after nude mice were prostate-injected with PC-J and PC-3 cells, the PC-3 group had low tumor volume and exhibited metastasis whereas the PC-J group had high tumor volume and no metastasis. Subsequent RT-PCR and immunoblot assays indicated that matriptase was the putative metastatic gene. Overexpression of bikunin significantly reduced the gene expression of matriptase, which attenuated in vitro cell invasion in the PC-3 cells. In vitro and xenograft animal models indicated different metastatic characteristics between PC-3 and PC-J cells, suggesting that matriptase plays an important role in the metastasis of prostate cancer.