Disclosed are methods of attenuating activity of the PME-1 gene. siRNAs or shRNAs are used to target against PME-1, thereby reducing the PME-1 mRNA. It is disclosed that the siRNAs or shRNAs targeted against PME-1 attenuate the epithelial to mesenchymal transition, thereby inhibit endometrial cancer and triple negative breast cancer development. A kit containing siRNA or shRNA reagents for attenuating the PME-1 gene expression is also disclosed.