[Pseudogene PTENP1 5'-region methylation in endometrial cancer and hyperplasias]

Genetic mutations in tumor suppressor gene PTEN are often detected in malignant human cells and these genomic changes are especially characteristic ofendometrial cancer. In our previous researches we assumed that alternative epigenetic mechanism of PTEN inactivation trough promoter methylation may exist in endometrial cancer. Moreover, PTENP1 pseudogene has recently been shown to play a role in positive regulation of PTENgene expression. Taking into account these facts, we analyzed PTEN and PTENP1 methylation status in endometrial hyperplasia and cancer. It was demonstrated that PTENgene promoter was not methylated but PTENP1 was methylated in 11 of 18 endometrial cancers and in 5 of9 endometrial hyperplasias. We can assume that PTENP1 methylation may inhibit transcription of this gene and also PTEN gene transcription trough RNA interference in accordance with ceRNA theory. Thus, aberrant suppression of PTENP1 transcription can play a role in endometrial cancer pathogenesis.