Expression and Association of MTNR1A Gene and Circadian Clock Genes in Different Stages of Breast Cancer in MCF - 7 Breast Cancer Line

Background: MTNR1A and MTNR1B are the essential receptors for melatonin physiological activity. Circadian genes expression disrupted can alter breast biology and may promote cancer. Aim: In this study, we investigated the expression of MTNR1A in association to circadian clock genes (Period 1, Period 2, and Cry 1) in the different stages of breast cancer according to AJCC staging system classification. Methods: Cell viability (MCF - 7) breast cancer line and normal breast cell were studied through Real - Time Polymerase Chain Reaction (RT - PCR) to evaluate gene expression of melatonin receptor (MTNR1A) and circadian clock genes Per1, Per2, and Cry1. Results: Our results revealed that MTNR1A gene was significantly up - regulated in normal breast compared to the MCF - 7 breast cancer and significantly down - regulated in stage IV compared to other stages. Both Per1 and Per2 genes were significantly down - regulated in MCF - 7 breast cancer line compared to the normal breast cell. Cry1 gene was up - regulated in stage 1 breast cancer and down - regulated in stage IV breast cancer cell. In addition, our data demonstrate a strong association between MTNR1A expression and circadian genes (Per1, Per2 and Cry1) expression in different stages of breast cancer. Conclusion: Our data indicate that altered gene expression of MTNR1A and circadian genes in breast cancer tissue. In addition, confirmation of association between MTNR1A and circadian genes expression may point to future use of melatonin and circadian clock as molecular basis treatment of breast cancer.