Molecular characterization of carcinosarcomas arising in the uterus and ovaries

Gynaecological carcinosarcomas are rare biphasic tumours which are highly aggressive. We performed molecular investigations on a series of such tumours arising in the uterus ( = 16) and ovaries ( = 10) to gain more information on their mutational landscapes and the expression status of the genes , , , and , the pseudogenes and , and the miRNAs known to influence expression of the above-mentioned genes. In uterine carcinosarcomas (UCS), we identified mutations in , , and with a frequency of 6%, 31%, and 75%, respectively, whereas in ovarian carcinosarcomas (OCS), was the only mutated gene found (30%). An inverse correlation was observed between overexpression of , , and and downregulation of miRNAs such as let-7a, let-7d, miR26a, miR16, miR214, and miR30c in both UCS and OCS. was expressed in its full length in 14 UCS and 9 OCS; in the remaining tumours, it was expressed in its truncated form. Because was normally expressed while miR30c was downregulated, not both downregulated as is the case in several other carcinomas, alterations of the epithelial-mesenchymal transition through an as yet unknown mechanism seems to be a feature of carcinosarcomas.