Relationship between expression of cydooxygenase-2, Bcl-2 and chemosensitivities in lymph node metastases of gastric carcinoma

Abstract

Objective To investigate the relationship between expression of cyclooxygenase-2 (COX-2), Bcl-2 and chemosensitivities in lymph node metastases (LNMs) of gastric carcinoma. Methods The chemosenisitivities to 9 drugs were measured by MTT assay, and the expression of COX-2, Bcl-2 was determined immunohistochemically in 40 paired primary tumor (PT) and lymph node metastases(LNMs)of gastric carcinoma. Results The positive rate of COX-2 and Bcl-2 in PT were 52.5%, 45.0% respectively, and in LNMs, the positive rate were 72.5% and 60.0%. The expression of COX-2 was higher in LNMs than in PT(χ~2=4, P 0.05). There was positive correlation of COX-2, Bcl-2 between PT and LNMs(r=0.3403, 0.4560, beth P<0.05). There was positive correlation between COX-2 and Bcl-2 in PT and LNMs (r=0.6014, 0.5330, both P<0.01). In PT the inhibition rate for 5-FU, VCR and eADM in COX-2 high expression group were lower than those in low expression group (t=2.29, 2.18, 2.41, all P< 0.05). The inhibition rate to 5-FU, PTX and eADM was significantly lower for the Bcl-2 high expression group in PT (t=2.46, 2.23, 2.22, all P<0.05). In LNMs, there were lower inhibition rates for VCR and MTX in COX-2 strong expression group (t=2.17, 2.35, both P<0.05); the inhibition rates to 5-FU, VP-16, PTX and MTX were significantly lower for the Bcl-2 strong expression group in LNMs (t=2.32, 2.29, 2.50, 2.25, all P<0.05). Conclusions COX-2 and Bcl-2 are involved in MDR of gastric carcinoma. The LNMs of gastric carcinoma are heterogeneous with respect to expression of COX-2, Bcl-2 and response to chemosensitivities. Effective adjuvant chemotherapy in gastric carcinoma depends on targeting the metastatic component of the tumor. Key words: Stomach neoplasms; Neoplasm metastasis; Cyclooxygenase-2 ; Proto-oncogene proteins c-bcl-2; Chemosensitivities