KRAS mutation coupled with p53 loss is sufficient to induce ovarian carcinosarcomas in mice.

Ovarian carcinosarcoma cancer is the most lethal form of gynecological malignancy, but the pathogenesis and biological function for this ovarian cancer remain unknown. We establishment the transgenic mouse model of K-ras p53 and found that K-ras mutation and p53 deletion within the ovarian surface epithelium gave rise to ovarian lesions with a hyperproliferation and endometrioid glandular morphology. Furthermore, double mutant ovaries formed ovarian carcinosarcomas that were high grade and poorly differentiated. Induction was widely metastatic and spread to abdominal organs including liver, spleen, and kidney at 4 wk. We also confirmed the role of K-ras in ovarian cancer cell lines MCAS and PA-1 and showed that K-ras overexpression strongly induced cell proliferation, migration, and invasion. The ovarian cancer model we developed recapitulates the specific tumor histomorphology and the probable mechanism of malignant transformation in endometriosis.