Ras association domain-containing protein 1 is a protein that in humans is encoded by the RASSF1gene.
Function
This gene encodes a protein similar to the RAS effector proteins. Loss or altered expression of this gene has been associated with the pathogenesis of a variety of cancers, which suggests the tumor suppressor function of this gene. The inactivation of this gene was found to be correlated with the hypermethylation of its CpG-island promoter region. The encoded protein was found to interact with DNA repair protein XPA. The protein was also shown to inhibit the accumulation of cyclin D1, and thus induce cell cycle arrest. Seven alternatively splicedtranscript variants of this gene encoding distinct isoforms have been reported.
Cervical cancer is known to be one of the most severe forms of cancer and is frequently associated with human papilloma virus. A few studies have been done to investigate the relationship between cervical cancers and RASSF1A, an isoform of RASSF1 that has been shown to suppress the proliferation in tumor cells. Through these studies, it was found that RASSF1A is commonly inactivated in adenocarcinomas due to hypermethylation of the promoter region. However, this is not observed in squamous cell carcinomas of the cervix, though they can be associated with HPV as well. It was found that RASSF1A was silenced in cancer cells when the promoter region was hypermethylated. It is speculated that cancer subtypes may develop due to the inverse relationship of RASSF1A and HPV. RASSF1A promoter hypermethylation and oncogenic HPV were detected in ACs, but SCCs displayed a high level of HPV DNA and no RASSF1A promoter methylation. Another study used Hela cells to study the potential therapeutic effects of RASSF1A. Hela cells are a line of cells that are derived from cervical cancer cells and are used in scientific research. When Hela cells were generated with RASSF1A expression, the growth of these cells decreased when compared to cells without RASSF1A expression. The rate of apoptosis in those cells had also increased with RASSF1A expression. Through these studies, it was indicated that RASSF1A expression could induce apoptosis and regulate proliferation to suppress tumors, making it a potential therapeutic mechanism for cervical cancers.
