The Expression And Clinical Significance Of Cyclooxygenase-2 In Non-small Cell Lung Cancer

Background and Objective Cyclooxygenase-2 (COX-2) gene may not only participate in cell proliferation and differentition, but also play important role in tumor invasion,metastasis,angiogenesis , thus promote the occurrence and development of tumor. COX-2 have been an important target in prevention and therapy of tumor. In our study, we examined the expression of COX-2 mRNA in NSCLC tissues and anlalyzed the relationship between its expression and NSCLC invasion, metastasis development. Methods The RNA was extracted from the cancerous tissues and adjacent lung tissues of 48 NSCLC patients. The expression of COX-2 mRNA was examined by reverse transcription-polymerse chain reaction (RT-PCR). Results Expression of COX-2 mRNA was observed in 75% of cancerous tissues and 6% of adjacent tissues(P<0.05). The positive expression rates in adenocarcinoma (94%) was significantly higher than in the squamous cell carcinoma (60%)(P<0.05). Expression rate of COX-2 mRNA was related to TNM staging , but not to patients′age and gender, differentiation grade of tumor cells, size of primary tumor and lymph nodes metastasis(P<0.05). The expression intensity of COX-2 mRNA was related to primary tumor size, lymph node metastasis and TNM staging ,but not to patients′age and sex,pathologic classification and differentiation grade of tumor cells(P<0.05). Conclusion The overexpression of COX-2 may be seen in NSCLC ,especially in adenocarcinoma. The overexpression of COX-2 may be closely related to invasion, metastasis,and development of NSCLC. Part ⅡEffects of cyclooxygenase-2 antisense vector on proliferation and sensitivity to cisplatin of H1299 cells Background and Objective COX-2 plays a crucial role in invasion, development and metastasis of non-small cell lung cancer (NSCLC). To inhibit the expression of COX-2 may prevent the occurrence and development of NSCLC. We transfected antisense vector for human cyclooxygenase-2 (COX-2) into human NSCLC cell line H1299 ,which highly expresses COX-2 and explored its effects on cell proliferation and sensitivity to cisplatin. Methods H1299 cells were transfected with antisense vector of human COX-2 gene with LipoVecTM liposome. Transfected cells were selected with G418. The COX-2 mRNA level was examined by reverse polymerase chain reaction (RT-PCR).The COX-2 protein level was detected by Western Blot. The cell proliferation and the sensitivity to cisplatin were measured by methabenzthiazuron (MTT) assay. Results RT-PCR showed a lower COX-2 mRNA level in transfected cells compared with untransfected cells.The level of COX-2 protein was decreased apparently. The proliferative index of the transfected cells decreased significantly(P<0.05).The IC50 value of cisplatin decreased remarkably in transfected cells (1.8μg/L) compared with that in H1299 cells without transfection (3.8μg/L) (P<0.05). Conclusion Transfection with antisense vector of human COX-2 gene can not only inhibit the H1299 cells ′proliferation ,but also increase the sensitivity to cisplatin .