Study of G9a methyl transferase expression pattern in tumoral and marginal tissues of breast cancer

Abstract

Breast cancer (BC) is one of the most common malignanciesand leading cause of cancer related death in women.A number of 2.26 000 000fresh cases for BC is identified in women by 2020. Several Environmental, genetic and epigenetic factors are arerelated with enlarged risk of BC. The (G9a) (HMT) is a nuclear histone lysne methyltransferase engaged in chromatin remodeling and differential methylation of key cancer related proteins such as P53. MicroRNAs (miRNAs) are RNA molecules that have controlling roles in severalpaths such as development, progression, and response to treatment. Dysregulated expression of numerous miRNAs has been reported in cancer. One of the greatestprojectingtranscription factorrelatives in BC is the sign transdeucers and transcription an activators (STATs). STAT3 is an example of these proteinswhich plays central roles in the progression of BC. The current study was devoted to the expression profiling of the mentioned genes and miRNAs in BC tissues and the adjacent non cancerous tissues. Material and Methods: RNA extraction was performed from 50 paired tumor/margin samples and utilized for cDNA synthesis. qRT-PCR quantitativ Real Time PCR was employed to assess the probable difference in the expression of the target genes including G9a, STAT3, miR-1 and miR-122. Then the potential of these genes as tumor markers or therapeutic targets was evaluated by ROC curve analysis. Results: According to the results of qRT-PCR, G9a (p< 0.0001) miR-1 (p<0.05) were significantly upregulated in cancerous tissues whereas miR-122 and STAT3 did not show significant changes. ROC curve analysis also revealed that STAT3 had an Area Under Curve (AUC) of 0.6 (p=0.06). AUC value for miR-1 and miR-122 was 0.6 (p=0.008) and 0.65 (p= 0.07), respective. Surprisingly, G9a had an AUC of 1, (p<0.0001).