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Objective To explore the role of p170, MRP, bcl-2 in clinical drug- resistance and their correlation. Methods There are 44 acute leukemia(AL) patients, among them ANLL is 29, ALL is 15.The expression of p170, MRP, bcl-2 were detected. At last, the patients were divided into two groups: CR and NR according to efficacy after two periods standard chemotherapy. Results Overexpression of p170, MRP,bcl-2 were found in AL (P ＜0.05). The expression of p170 and MRP were lower in CR group than that in NR groups in AML and ALL; there were 22 of 24 patients expressed one or two proteins in NR groups and the expression of p170 in patients was concordant with that of MRP to certain extent (P ＜0.01). The overexpression of bcl-2 was related with the worse prognosis. The expression of bcl-2 was lower significantly in CR group than in CR and NR (P＜0.05). Conclusion p170, bcl-2, MRP are all associated with clinical MDR. High expression of these proteins is an unfavorable factor to prognosis. The expression of MRP and p170 showed coincidence, but showed no significance with expression of bcl-2 in untreated patients, it indicated that the drug-resistance mediated by p170 was different from bcl-2.
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OBJECTIVE:To investigate the effect and clinical significance of radiotherapy on the expression of multidrug resistance-associated protein(MRP) in advanced cervical cancer.METHODS:The immunohistochemistry method was applied to detect the expression of lung resistance protein(LRRP),glutathione-S-transferases-?(GST-?),thymidylate synthetase(TS) and type Ⅱ topoisomerase(TopoⅡ) in 23 patients with advanced cervical cancer before radiotherapy and after receiving 30 Gy dose radiation.RESULTS:The positive expression rates of LRRP,GST-?,TS and TopoⅡ before radiotherapy were 47.8%,56.5%,30.4% and 60.9%,respectively.The positive expression rates of LRRP,GST-? and TS in patients after 30 Gy dose radiation were 69.6%,73.9% and 73.9%,respectively,which were signficantly higher as compared before radiotherapy(P
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PURPOSE: Gastric cancer cells may show resistance to various chemotherapeutic agents. The ability of cancer cells to become drug resistant is thought to be a cause of chemotherapy failure. Recent studies showed that multidrug resistance-associated protein (MRP) might confer resistance to a wide spectrum of natural product drugs. However, the clinical relevance of MRP-mediated multidrug resistance in human gastric cancer remains unknown. To determine the significance of MRP expression in gastric cancer, we investigated the relationship between MRP expression and chemosensitivity in gastric cancer cell lines. METHODS: In 8 gastric cancer cell lines (SNU-1, 5, 16, 484, 601, 620, 638 and 668), the expression of MRP and MRP mRNA was detected by using Western blot and reverse transcription-polymerase chain reaction (RT-PCR) analyses, respectively. Sensitivity to the anticancer agents (cisplatin, doxorubicin, 5-fluorouracil, camptothecin, epirubicin, and vincristine) was examined using a dimethylthiazole- diphenyltetrazolium-bromide (MTT) assay. RESULTS: All 8 cell lines expressed MRP and MRP mRNA in various degrees. There was no significant correlation between the expression of MRP and MRP mRNA. Sensitivity to anticancer agents had no significant correlation with the level of MRP expression. CONCLUSION: There was no general correlation between the expression of MRP and chemosensitivity in the various gastric cancer cell lines used in this study. In addition to MRP, another mechanism might be involved in the chemosensitivity of gastric cancer cell lines.