Proteomic analysis of mesenchymal stem-like cells derived from ovarian teratoma: potential role of glutathione S-transferase M2 in ovarian teratoma.

Ovarian teratoma is a dermoid cyst in the ovary that contains mature tissues such as hair, teeth, bone, thyroid, etc. To understand the molecular mechanisms of ovarian teratoma growth, a comparative proteomic analysis was undertaken using mesenchymal stem cell-like cells (MSCLCs) isolated from normal human ovarian or teratoma tissues. Both normal ovarian and teratoma MSCLCs expressed stem cell markers OCT4 and NANOG, and were negatively staining with the senescence-associated (SA) β-galactosidase. Furthermore, teratoma MSCLCs had higher proliferation and colony formation rates, with more angiogenic property than that of normal MSCLCs. Proteomic study revealed that 17 proteins had the expression changes over eightfold in ovarian teratoma MSCLCs compared with normal control. Interestingly, among them, GSTM2 was strongly expressed in teratoma MSCLCs. Moreover, overexpressed GSTM2 in the teratoma was associated with downregulation of p38 MAPK and activation of AKT and survivin. Taken together, these findings suggest that that ovarian teratoma MSCLCs have a higher potency for proliferation and angiogenesis and GSTM2 appears to be involved in the regulation of other survival genes.