Up-regulation of p53 by antisense expression of HPV18 E6 oncogene does not influence the level of MN/CA IX tumor-associated protein in HeLa cervical carcinoma cells.

Oncogenic potential of human papillomaviruses is related to capacity of HPV-encoded oncoproteins to bind and inactivate tumor suppressor proteins. Interaction of p53 with HPV E6 results in aberrant regulation of various cellular genes. We evaluated the possible involvement of MN/CA9 gene, whose expression is closely associated with cervical carcinomas, in regulatory pathways driven by p53 and E6. We demonstrated that one of the two p53 consensus sequences present in MN/CA9 promoter participates in DNA-protein interaction but it does not bind p53. Tetracycline-inducible antisense expression of HPV18 E6 in human cervical carcinoma HeLa cells resulted in increased level of p53 but did not affect expression of MN/CA IX protein. Therefore we conclude that at least in HeLa cells there is no direct relationship between expression of MN/CA IX and expression of E6 or p53.