Role of the Circadian Clock Gene in Chemosensitivity and Apoptosis in Colorectal Cancer.

Background/aim: Disruptions in the circadian rhythm are linked to various diseases. The clock gene is related to the progression and recurrence of various types of cancer; however, its role in colorectal cancer has not been determined. Therefore, we aimed to evaluate the significance of DEC1 expression level in colorectal cancer and its relationship with prognosis.

Materials And Methods: Using quantitative reverse transcription-polymerase chain reaction and immunohistochemistry, we compared DEC1 mRNA and protein expression in clinical samples. We compared colorectal cancer cell lines and organoids using cell proliferation, wound healing, chemosensitivity, and apoptosis assays. We also performed RNA sequencing to investigate whether changes in DEC1 expression influence the expression of other genes, thereby affecting drug sensitivity and apoptosis.

Results: Based on data obtained from The Cancer Genome Atlas database and clinical samples, high DEC1 expression was associated with a poor prognosis. However, and experiments revealed that DEC1 knockdown in colorectal cancer cell lines does not significantly affect cell proliferation or migration. Modulating DEC1 expression levels altered the sensitivity of cells to 5-fluorouracil, indicating that DEC1 plays a role in treatment response. The suppression of DEC1 expression led to an increase in cell apoptosis. RNA sequencing, analyses of data from The Cancer Genome Atlas database, and Metascape analysis revealed seven genes related to DEC1 associated with apoptosis.

Conclusion: DEC1 expression is related to the circadian rhythm in colorectal cancer cells, and several other genes contribute to this relationship. Overall, DEC1 may function beyond circadian rhythm regulation, potentially affecting the development and progression of colorectal cancer.