<scp>PRKD3</scp> Overexpression May Improve Survival and Suppresses Proliferation in Colorectal Cancer

OBJECTIVE: The study aimed to explore PRKD3 protein expression in colorectal cancer and its clinical implications. METHODS: PRKD3 expression was assessed in 189 paired colorectal cancer tissues and their corresponding adjacent non-cancerous counterparts using tissue microarray-based immunohistochemistry. The associations of PRKD3 expression with clinicopathological parameters and patient prognosis were analyzed. PRKD3 mRNA levels were quantified by quantitative real-time polymerase chain reaction (qPCR), and its protein expression in colorectal cancer cell lines was detected by Western blot analysis. To investigate the functional role of PRKD3 in cell proliferation, its expression was knocked down using siRNA transfection, followed by proliferation assays. RESULTS: Immunohistochemical analysis revealed that PRKD3 protein was predominantly localized in the cytoplasm of both colorectal cancer and adjacent normal epithelial cells (sampled from > 5 cm beyond the tumor margin). The positive expression rate was 51.8% (72/139) in adjacent normal tissues and 68.7% (114/166) in colorectal cancer tissues, showing a statistically significant increase in cancer tissues (p < 0.05). PRKD3 expression was significantly associated with the clinical diagnosis (colon vs. rectal cancer) (p < 0.05). Kaplan-Meier survival analysis demonstrated that patients with high PRKD3 expression had a significantly longer postoperative survival than those with low expression (p < 0.05). Furthermore, cell proliferation assays showed that knockdown of PRKD3 significantly enhanced proliferation ability compared with the control group. CONCLUSION: Taken together, the positive expression of PRKD3 may be associated with better prognosis. These findings suggest that PRKD3 may be involved in the development and progression of colorectal cancer and could represent a potential prognostic biomarker and therapeutic target for this disease.