Mutational, epigenetic and expressional analyses of caveolin-1 gene in cervical cancers

Caveolin-1 (CAV-1) protein, an integral membrane protein of caveolae membranes, is highly expressed in terminally differentiated cells and down-regulated in cells transformed by human papilloma virus infection. It may also be involved in the tumorigenesis of cervical cancer. CAV-1 gene is regarded as a candidate for the tumor suppressor gene and it can be inactivated in several ways, including point mutations, chromosomal deletions and promoter methylation. We used direct sequencing, methylation specific PCR, and immunohistochemical staining methods to explore the role of CAV-1 gene in the development of cervical cancer. Our results showed that 4 of 72 cases (6%) had methylated CpG-island on the CAV-1 promoter, 17 of 72 cases (26.1%) having no methylation on the promoter showed no expression of CAV-1 protein, and 2 of 72 cases had a GAC right curved arrow GAT transition polymorphism at codon 82. Three types of CAV-1 expression patterns were observed in cervical cancer tissues, and the expression pattern had no relationship with mutation status. From these results, we suggest that CAV-1 gene can be inactivated through mutations, and does not play a role, through methylation of promoter, or an unknown mechanism which may play a role, in the development of cervical cancer.