Sensitivity of gastric cancer cells to chemotherapy drugs in elderly patients and its correlation with cyclooxygenase-2 expression.
OBJECTIVE
To explore the sensitivity of gastric cancer cells to chemotherapy drugs in elderly patients and its correlation with cyclooxygenase-2 (COX-2) expression in cancer tissue.


METHODS
Forty-three elderly patients with gastric cancer (observation group) and 31 young patients with gastrointestinal tumors (control group) who were all diagnosed by pathology and underwent surgery in the 89th Hospital of Chinese People's Liberation Army were selected. Drug sensitivity testing of tumor cells in primary culture was carried out in both groups using a methyl thiazolyl tetrazolium (MTT) method, and the expression of COX-2 and the factors related to multi-drug resistance (MDR) in cancer tissue were assessed by immunohistochemistry.


RESULTS
The inhibition rates (IR) of vincristine (VCR), 5-fluorouracil (5-FU), oxaliplatin (L-OHP), mitomycin (MMC) and epirubicin (eADM) on tumor cells in the observation group were dramatically lower than in the control group, with statistical significance (P<0.05 or P<0.01). The positive rates of COX-2, glutathione s-transferase-π (GST-π) and P glycoprotein (P-gp) expression in cancer tissue in the observation group were all higher than in control group (P<0.05), while that of DNA topoisomerase IIα (TopoIIα) expression lower than in the control group (P<0.01). In the observation group, COX-2 expression in cancer tissue had a significantly-positive correlation with GST-π and P-gp (r=0.855, P=0.000; r=0.240, P=0.026), but a negative correlation with TopoIIα (r=-0.328, P=0.002). In the control group, COX-2 expression in cancer tissue was only correlated with P-gp positively (r=0.320, P=0.011). Bivariate correlation analysis displayed that COX-2 expression in cancer tissue in the observation group had a significantly-negative correlation with the IRs of 5-FU, L-OHP, paclitaxel (PTX) and eADM in tumor cells (r=-0.723, P=0.000; r=-0.570, P=0.000; r=-0.919, P=0.000; r=-0.781, P=0.000), but with hydroxycamptothecine (HCPT), VCR and 5-FU in the control group (r=-0.915, P=0.000; r=-0.890, P=0.000; r=-0.949, P=0.000).


CONCLUSIONS
Gastric cancer cells in elderly patients feature stronger MDR, which may be related to high COX-2 expression.
Unified Supply Center, The 89th Hospital of Chinese People's Liberation Army, Weifang, China E-mail : qzqsxg@163.com.
Zhen-Qin
ZQ
Qiu
Zhen-Rong
ZR
Qiu
D020168:ATP Binding Cassette Transporter, Subfamily B, Member 1 / Q000378:metabolism; D000328:Adult; D000368:Aged; D000951:Antigens, Neoplasm / Q000378:metabolism; D000970:Antineoplastic Agents; D002166:Camptothecin / Q000031:analogs & derivatives; D016022:Case-Control Studies; D051546:Cyclooxygenase 2 / Q000378:metabolism*; D004250:DNA Topoisomerases, Type II / Q000378:metabolism; D004268:DNA-Binding Proteins / Q000378:metabolism; D018432:Drug Resistance, Multiple; D019008:Drug Resistance, Neoplasm; D004354:Drug Screening Assays, Antitumor; D015251:Epirubicin; D005260:Female; D005472:Fluorouracil; D051549:Glutathione S-Transferase pi / Q000378:metabolism; D006801:Humans; D007150:Immunohistochemistry; D008297:Male; D008875:Middle Aged; D009944:Organoplatinum Compounds; D000077150:Oxaliplatin; D017239:Paclitaxel; D013274:Stomach Neoplasms / Q000188:drug therapy / Q000378:metabolism*; D014407:Tumor Cells, Cultured; D014750:Vincristine
D020168:ATP Binding Cassette Transporter, Subfamily B, Member 1; D000951:Antigens, Neoplasm; D000970:Antineoplastic Agents; D004268:DNA-Binding Proteins; D009944:Organoplatinum Compounds; C527042:hydroxycamptothecinum; D000077150:Oxaliplatin; D015251:Epirubicin; D014750:Vincristine; D051546:Cyclooxygenase 2; C496540:PTGS2 protein, human; D051549:Glutathione S-Transferase pi; D004250:DNA Topoisomerases, Type II; D017239:Paclitaxel; D005472:Fluorouracil; D002166:Camptothecin