[Expression of RASSF1A and RASSF1C transcripts in human primary ovarian cancers].

Abstract

To investigate the expression of two major alternative transcripts of RASSF1 gene (RASSF1A and RASSF1C) in human primary ovarian cancers and their biological implication as a new tumor suppressor gene. Reverse transcription-polymerase chain reaction (RT-PCR) and laser capture microdissection (LCM) were used to determine mRNA expression of the two major alternative transcripts of RASSF1 gene (RASSF1A and RASSF1C) in 3 ovarian cancer cell lines and 80 cases of primary ovarian cancers. RASSF1A mRNA was undetectable in SK-OV-3 cell line. Expression of RASSF1A and RASSF1C in 80 primary ovarian cancers were 40.0% (32/80) and 91.3% (73/80) respectively. RASSF1A mRNA expression was detectable more frequently in stage I and II (71.4%, 10/14; 75.0%, 9/12) than in stage III and IV ovarian cancers (26.7%, 12/45; 14.1%, 1/9) (P < 0.05). The expression level was also higher in well and moderately differentiated tumor groups (58.6%, 17/29; 50.0%, 10/20) than in poorly differentiated tumor group (16.1%, 5/31) (P < 0.05). There is a preferential loss of RASSF1A expression in human ovarian cancers and its expression is correlated with the tumor stage and the degree of histological differentiation which, as a tumor suppressor gene, might play an important role in the tumorigenesis of human primary ovarian cancer.