Circadian Rhythm and Breast Cancer Susceptibility - A study on PERIODIC3 Gene Polymorphisms in Breast Cancer

It is a disease of significant morbidity and mortality among adult females and research is ongoing on its genetic association and newer therapeutic possibilities. Several of the body's physiological functions are regulated by the biological clock or the circadian rhythm. This has its master control in the suprachiasmatic nucleus in the hypothalamus and synchronised peripheral oscillators in various other tissues. These oscillators are controlled by a group of clock genes namely Period 1,2,3 and cryptochrome 1,2 which function in association with each other based on multiple complex transcription- translational feedback loops. These genes have been shown to regulate directly and indirectly cell cycle genes and thereby control cell proliferation, apoptosis and tumor suppression. As the period genes control several complex downstream regulators of the cell cycle and mediators of tumour suppression, a possible correlation between their mutation and breast cancer could throw open avenues to determine therapies to counteract or supplement the necessary downstream regulators in breast cancer patients[2]