INTRODUCTIONDevelopment of drug-resistance to chemotherapyand subsequent metastasis of tumor are primarilyresponsible for treatment failure and the death fromcancer. There have been many previous studies onthe relatio...INTRODUCTIONDevelopment of drug-resistance to chemotherapyand subsequent metastasis of tumor are primarilyresponsible for treatment failure and the death fromcancer. There have been many previous studies onthe relationship between expression of multidrugresistance (MDR) phenotype P-glycoprotein (P-gp)and the malignant properties of tumors, but theresults are often conflicting[1-8]. The difference intumor types or MDR phenotype induced by specificagents might account for this discrepancy. Taxotere(TXT), a member of the family of taxanes, hasantitumor activity through its effect of promotingthe polymerization of tubulin[9,10].展开更多
AIM: To investigate the specific mechanisms of intrinsic and acquired resistance to taxotere (TXT) in pancreatic adenocarcinoma (PAC). METHODS: MTT assay was used to detect the sensitivity of PAC cell line SUIT-2 and ...AIM: To investigate the specific mechanisms of intrinsic and acquired resistance to taxotere (TXT) in pancreatic adenocarcinoma (PAC). METHODS: MTT assay was used to detect the sensitivity of PAC cell line SUIT-2 and its sublines (S-007, S-013, S-020, S-028 and TXT selected SUIT-2 cell line, S2/TXT) to TXT. Mdr1 (P-gp), multidrug resistance associated protein (MRP), lung resistance protein (LRP) and beta-tubulin isotype gene expressions were detected by RT-PCR. The functionality of P-gp and MRP was tested using their specific blocker verapamil (Ver) and indomethacin (IMC), respectively. The transporter activity of P-gp was also confirmed by Rhodamine 123 accumulation assay. RESULTS: S-020 and S2/TXT were found to be significantly resistant to TXT(19 and 9.5-fold to their parental cell line SUIT-2, respectively). RT-PCR demonstrated strong expression of Mdr1 in these two cell lines, but weaker expression or no expression in other cells lines. MRP and LRP expressions were found in most of these cell lines. The TXT-resistance in S2-020 and S2/TXT could be reversed almost completely by Ver, but not by IMC. Flow cytometry showed that Ver increased the accumulation of Rhodamine-123 in these two cell lines. Compared with S-020 and SUIT-2, the levels of beta-tubulin isotype II, III expressions in S-2/TXT were increased remarkably. CONCLUSION: The both intrinsic and acquired TXT-related drug resistance in these PAC cell lines is mainly mediated by P-gp, but had no relationship to MRP and LRP expressions. The increases of beta-tubulin isotype II, III might be collateral changes that occur when the SUIT-2 cells are treated with TXT.展开更多
目的应用基因芯片技术筛选人子宫内膜癌细胞株中获得性紫杉醇(TAX)耐药相关基因。方法采用大剂量间歇诱导法,用TAX反复冲击诱导培养人子宫内膜癌Ishikawa细胞株,建成Ishikawa/TAX耐药株。应用Affymetrix Human Genome U133 Plus2.0表达...目的应用基因芯片技术筛选人子宫内膜癌细胞株中获得性紫杉醇(TAX)耐药相关基因。方法采用大剂量间歇诱导法,用TAX反复冲击诱导培养人子宫内膜癌Ishikawa细胞株,建成Ishikawa/TAX耐药株。应用Affymetrix Human Genome U133 Plus2.0表达谱芯片检测Ishikawa/TAX与Ishikawa细胞株基因。通过Gene Ontology(GO)聚类分析对差异表达的基因予以分类。采用qRT-PCR对部分差异表达的基因进行验证。结果与Ishikawa细胞相比,Ishikawa/TAX细胞中有110条基因表达有显著性差异(ratio比值>3),包括87个上调基因、23个下调基因,GO分类涉及细胞信号传导和调控、细胞黏附分子、细胞代谢及转录调控等;其中上调最明显的基因为S100A12,其次有CYP1B1、FUBP1、CEACAM6,下调基因有TNFAIP3、CD44、DKK1等。qRT-PCR检测S100A12、CYP1B1在耐药细胞中高表达,TNFAIP3、CD44在耐药细胞中低表达,与基因芯片结果一致。结论采用基因芯片技术筛选出的人子宫内膜癌获得性TAX耐药相关基因的上调基因有S100A12、CYP1B1、FUBP1、CEACAM6,下调基因有TNFAIP3、CD44、DKK1。展开更多
基金Supported in part by phone-Poulenc Rorer Pharmaceuticals INC
文摘INTRODUCTIONDevelopment of drug-resistance to chemotherapyand subsequent metastasis of tumor are primarilyresponsible for treatment failure and the death fromcancer. There have been many previous studies onthe relationship between expression of multidrugresistance (MDR) phenotype P-glycoprotein (P-gp)and the malignant properties of tumors, but theresults are often conflicting[1-8]. The difference intumor types or MDR phenotype induced by specificagents might account for this discrepancy. Taxotere(TXT), a member of the family of taxanes, hasantitumor activity through its effect of promotingthe polymerization of tubulin[9,10].
基金Supported in part by Phne-Poulenc Rorer Pharmaceuticals INC.
文摘AIM: To investigate the specific mechanisms of intrinsic and acquired resistance to taxotere (TXT) in pancreatic adenocarcinoma (PAC). METHODS: MTT assay was used to detect the sensitivity of PAC cell line SUIT-2 and its sublines (S-007, S-013, S-020, S-028 and TXT selected SUIT-2 cell line, S2/TXT) to TXT. Mdr1 (P-gp), multidrug resistance associated protein (MRP), lung resistance protein (LRP) and beta-tubulin isotype gene expressions were detected by RT-PCR. The functionality of P-gp and MRP was tested using their specific blocker verapamil (Ver) and indomethacin (IMC), respectively. The transporter activity of P-gp was also confirmed by Rhodamine 123 accumulation assay. RESULTS: S-020 and S2/TXT were found to be significantly resistant to TXT(19 and 9.5-fold to their parental cell line SUIT-2, respectively). RT-PCR demonstrated strong expression of Mdr1 in these two cell lines, but weaker expression or no expression in other cells lines. MRP and LRP expressions were found in most of these cell lines. The TXT-resistance in S2-020 and S2/TXT could be reversed almost completely by Ver, but not by IMC. Flow cytometry showed that Ver increased the accumulation of Rhodamine-123 in these two cell lines. Compared with S-020 and SUIT-2, the levels of beta-tubulin isotype II, III expressions in S-2/TXT were increased remarkably. CONCLUSION: The both intrinsic and acquired TXT-related drug resistance in these PAC cell lines is mainly mediated by P-gp, but had no relationship to MRP and LRP expressions. The increases of beta-tubulin isotype II, III might be collateral changes that occur when the SUIT-2 cells are treated with TXT.
