Influence of Deleted in Colorectal Carcinoma Gene on Proliferation of Ovarian Cancer Cell Line SKOV-3 In Vivo and In Vitro

Abstract

To elucidate the effects of the deleted in colorectal carcinoma (DCC) gene on proliferation of ovarian cancer cell line SKOV-3. An exogenous recombinant eukaryotic expression vector pcDNA3.1(+)-DCC, containing human DCC cDNA coding sequences, was constructed and transfected into SKOV-3 cells (SKOV-3/DCC). The pcDNA3.1 (+) transfected cells (SKOV-3/Neo) and SKOV-3 cells were used as the positive and negative controls, respectively. Expressions of DCC mRNA and protein were analyzed by RT-PCR and immunocytochemical analysis, respectively. Cell growth was detected by soft agar colony formation assay and MTT assay. Flow cytometry and transmission electron microscopy were used to assess the effects of DCC on cell cycle distribution and ultrastructure, respectively. BALB/c mice were used to evaluate the effects of DCC on tumorigenicity in vivo. RT-PCR and immunocytochemical analysis revealed the exogenous DCC gene was successfully transfected into SKOV-3 cell lines and obtained permanent expression. The half maximal inhibitory concentration (IC50) of SKOV-3/DCC cells was significantly lower than that of SKOV-3 or SKOV-3/Neo cells (all P<0.05). DCC expression caused SKOV-3 cells to be arrested in G1 phase (78.0%), and electron microscopic analysis showed SKOV-3/DCC cells displayed typical morphological changes of apoptosis. Two mice xenografted with SKOV-3/DCC cells showed no tumor tumorigenecity. The tumor volume of BALB/c mice bearing SKOV-3/DCC cells (3.403 mm(3)) was smaller than that of SKOV-3 cells (9.206 mm(3)). DCC gene may play an important role in suppressing the growth of SKOV-3 cell line and inducing apoptosis.