Methylation status of KLF4 and HS3ST2 genes as predictors of endometrial cancer and hyperplastic endometrial lesions.

Endometrial carcinoma is one of the most common tumours in developed countries. In addition to the active role of genetic factors, epigenetic changes also have an important effect. The present study analysed the methylation status of kruppel like factor 4 (KLF4) and heparan sulfate­glucosamine 3­sulfotransferase 2 (HS3ST2) genes in three endometrial tissue types for carcinoma prediction. The sample comprised 91 women with histologically­confirmed endometrial carcinoma (64.16±9.64 years old), 36 women with hyperplasia (53.39±9.64 years old) and 45 with no signs or symptoms of malignancy (48.53±11.11 years old). The CpG dinucleotide methylation levels were examined by quantitative pyrosequencing, and the discrimination accuracy of the model was calculated using the Random Forest classification algorithm of the area under the ROC curve (AUC). The mean values of KLF4 and HS3ST2 methylation indices were 23.83±11.39 and 8.52±2.57 in the control samples; 30.40±8.52 and 33.76±20.66 in hyperplasia and 34.72±10.79 and 34.49±18.39 in the cancerous tissues. Multinomial logistic regression indicated that the HS3ST2 CpG1 methylation status is a predictor of hyperplasia (P<0.05) and that the KLF4 CpG2 dinucleotide can predict carcinoma formation (P<0.001). The AUC value of 0.95 indicates high discrimination accuracy of the CpG nucleotides methylation status model between the controls and the two other diagnoses. The results of the present study establish the likelihood that aberrations in KLF4 and HS3ST2 gene methylation levels are important in the development of endometrial hyperplasia and carcinoma, with hyperplasia an intermediate step between healthy and tumour tissues.

Promoter hypermethylation of the tumor-suppressor genes RASSF1A, GSTP1 and CDH1 in endometrial cancer.

Endometrial cancer is a common gynecological malignancy with a good prognosis in early stages of the disease. The CpG island in the promoter region of tumor-suppressor genes are frequently methylated in various types of human cancers. In the present study, we examined the methylation status of the GSTP1, CDH1 and RASSF1A genes in endometrioid endometrial cancer (EEC), endometrial complex hyperplasia (EHP) and healthy endometrium with the aim to identify correlations between promoter hypermethylation, disease risk and clinicopathological parameters. A nested two-stage methylation-specific PCR (MSP) was performed to analyze the promoter CpG methylation status of GSTP1, CDH1 and RASSF1A genes in the population studied. A total of 92 subjects were initially included in the study of which 41 EEC, 19 EHP and 20 controls were processed for final analyses. A significant difference was found between the study groups and the presence of promoter CpG hypermethylation status in the GSTP1 (p<0.05) and RASSF1A (p<0.0001) genes. RASSF1A, GSTP1 and CDH1 gene promoter methylation was present in 85.4, 68.3 and 31.4% of EEC samples when compared to that in the controls with 30.0, 35.0 and 20.0%, respectively. CpG methylation of all three investigated tumor-suppressor genes was found in 12.2% of EEC patients, in 4.2% of EHP patients and in 3.7% of the controls, respectively. Positive findings for the promoter methylation of two investigated genes were found in 48.7% of EEC patients, 26.0% of EHP patients and in 18.5% of the controls. With regard to histopathological variables and CpG methylation, we found significant correlations between the RASSF1A and GSTP1 genes and higher tumor grade, deeper myometrial invasion and positive metastatic involvement of pelvic lymph nodes. No associations were noted between promoter hypermethylation of the CDH1 gene and biological features of the endometrial cancer cases. The results indicate that aberrant CpG methylation of the promoter region in the GSTP1 and RASSF1A tumor-suppressor genes is an important event in carcinogenesis of endometrial cancer and may have an impact on tumor aggressiveness. Finally, the present study suggests that epigenetic alterations may be of diagnostic value for the better clinical management of premalignant endometrial lesions.

Hypermethylation of selected genes in endometrial carcinogenesis.

OBJECTIVES: Endometrial cancer is one of the most common malignancies in women. The prevention has failed so far to develop an effective screening program and its incidence is rising in proportion to the incidence of cervical cancer. In recent years the investigation of malignancy genomics (genetic and epigenetic changes) has become the main focus of scientists because of its high sensitivity and specificity. MATERIAL AND METHODS: We conducted a prospective longitudinal study at the Dpt. of Gynaecology and Obstetrics of the Jessenius Faculty of Medicine in Martin from 2010 to 2012, in collaboration with the Institute of Pathology of the University Hospital in Martin. We analysed paraffin blocks of endometrial tissue from 123 women with endometrial cancer, hyperplasia and normal endometrial findings. By the use of bisulphidic modification technique and nested methylation-specific PCR (MSP), we analysed the methylation patterns of three genes: GSTP1, E-cad, RASSF1. RESULTS: We found a statistically significant increase of methylation of the RASSF1 gene in endometrial cancer compared to simplex hyperplasia and intact endometrial tissue (p<0.001). GSTP1 and E-cad did not show any relevant methylation pattern in various endometrial lesions. CONCLUSION: According to the results of our study, RASSF1 gene methylation could serve as a prognostic factor of endometrial carcinogenesis and could help to predict the behaviour of endometrial hyperplasia.