Role of TAp73 in the Transformation of Mouse Ovarian Surface Epithelium

Tumour suppressor 73 (Trp73) gene shares structural and functional homology with p53. Trp73 encodes multiple isoforms with opposing effects. The TAp73 isoform is a transcription factor and is classified as a tumour suppressor where as the DNp73 isoform is a putative oncogene. Imbalance of the two opposing isoforms has been reported in human malignancies including ovarian cancer. TAp73 deficiency results in a dramatic increase in the DNp73 isoform, mimicking the altered isoform balance observed in human ovarian cancer. The effects of TAp73 deficiency in mouse OSE cells were assessed. TAp73 deficiency is not sufficient to induce ovarian cancer in mice. However, TAp73 deficiency compromises cellular proliferation in OSE cell lines. Furthermore, expression of p73 isoforms and epithelial markers is altered in TAp73 deficient cell line. Further studies are needed to determine if TAp73 deficiency in conjunction with other molecular alterations can mediate transformation of OSE cells leading to ovarian cancer.MAS