The Impact of DTYMK as a Prognostic Marker in Colorectal Cancer

Background: Overexpression of deoxythymidylate kinase (DTYMK) has been associated with more aggressiveness and pathological behav-iors in hepatocellular carcinoma (HCC) and non-small cell lung can-cer (NSCLC). However, the expression of DTYMK and its prognostic significance in colorectal cancer (CRC) patients are yet unknown. The goal of this study was to investigate the DTYMK immunohistochemis-try reactivity in CRC tissues and to see how it correlated with various histological and clinical features as well as survival.Methods: Several bioinformatics databases and two tissue microar-rays (TMAs) of 227 cases were used in this study. Immunohistochem-istry assay was used to study the protein expression of DTYMK.Results: Based on the GEPIA, UALCAN, and Oncomine databases, DTYMK expression has increased in tumor tissues at both RNA and protein levels in colorectal adenocarcinoma (COAD) compared to normal tissues. A high DTYMK H-score was found in 122/227 (53%) of the cases, whereas a low DTYMK H-score was found in 105/227. The age at diagnosis (P = 0.036), stage of the disease (P = 0.038), and site of origin (P = 0.032) were all linked to a high DTYMK H-score. Patients with high level of DTYMK had bad overall survival. Inter-estingly, high DTYMK protein level was associated with PSM2 (P = 0.002) and MSH2 (P = 0.003), but not with MLH2 or MSH6.Conclusion: This is the first study to cover the expression and prog-nostic significance of DTYMK in CRC. DTYMK was upregulated in CRC and could be considered as a prognostic biomarker.