Expression and mechanistic role of cyclooxygenase-2 in colorectal cancer

ZHANG Hong; YU Chang-fa; YE Li-jun; CAI Sha-sha; LIAO Nan-sheng; FANG Han

doi:10.13820/j.cnki.gdyx.20243455

Abstract：Objective To investigate the differential expression of cyclooxygenase-2(COX-2)in colorectal cancer(CRC)and adjacent non-cancerous tissues,and to explore its correlation with clinicopathological features and potential role in CRC progression.Methods Immunohistochemistry(S-P method)and Western blotting were used to detect COX-2 protein expression in CRC and adjacent tissues.Quantitative real-time PCR was applied to assess COX-2 expression in human colorectal cancer cell lines.CCK-8 assay was used to evaluate changes in cell viability following COX-2 modulation.Kaplan-Meier survival analysis was performed to evaluate cumulative survival rates,and Cox pro-portional hazards model was employed to identify independent prognostic factors.Results The positive expression rate of COX-2 was significantly higher in CRC tissues than in adjacent non-cancerous tissues(61.5％vs.21.8％,P＜0.05).COX-2 expression was positively correlated with TNM stage,poor differentiation,and lymph node metastasis(x2=16.385,5.970,6.307,P＜0.05).Kaplan-Meier analysis showed that patients with low COX-2 expression had significantly better survival than those with high expression(x2=5.774,P＜0.05).Cox regression analysis revealed that TNM stage,differentiation,lymph node metastasis,and COX-2 expression were independent prognostic factors for CRC(x2=7.382,10.241,4.132,7.728,P＜0.05).Knockdown of COX-2 in SW480 cells significantly reduced cell via-bility and upregulated the expression of apoptosis-related protein PARP1 and autophagy marker LC3II,whereas COX-2 overexpression had the opposite effects(P＜0.05).Conclusion COX-2 is overexpressed in colorectal cancer and may regulate tumor cell proliferation via the autophagy signaling pathway.It is an independent prognostic factor affecting the clinical outcome of CRC patients.