The circadian clock is a transcriptional cycle found in all cells of the body that synchronizes 40-80% of human gene expression to daily 24-hour timing. As such, the circadian clock is the regulator of circadian rhythm-controlled processes, such as body temperature, hormone secretion, metabolic processes, and the sleep-wake cycle. Dysregulation of the circadian rhythm has been previously associated with the development and proliferation of gastrointestinal pathologies such as Colorectal Cancer and Inflammatory Bowel Disease (IBD). One aspect of the pathology associated with these illnesses is the effect of the circadian clock on intestinal tissue composition: loss of circadian clock function is known to disrupt regenerative healing in mouse models of disease, and this impacts disease etiology. However, the 24-hour timing of clock function remains to be fully elicited in human tissue and cancer cells. To address this, human intestinal biopsies from Colorectal Cancer patients will be examined histologically to test whether morphological changes are correlated to the aberrant expression of circadian clock genes. This information will connect circadian gene expression with the regulation of disease mechanisms.

Understanding the circadian clock control of regeneration in the intestinal epithelium will raise the possibility of using light-based therapy to increase healing to treat or prevent gastrointestinal illnesses. Further, it will inform physicians about the timing of regeneration withthe goal of optimizing the timing of diagnostics and/or therapy. This information could benefit a wide variety of patients includingColorectal Cancer patients, Inflammatory Bowel Disease (IBD) patients, infants suffering from necrotizing enterocolitis, and cancerpatients following radiation syndrome and surgery.