Study on the mechanism of the cis-platin resistance of the oral squamous cell carcinoma

本研究旨在分析口腔鳞癌顺铂(CDDP)耐药的机制。口腔鳞癌顺铂耐药细胞系的建立。我们从KB细胞中建立了耐CDDP的KB-CDDPr细胞系，并逐渐提高了培养液中CDDP的浓度。KB-CDDPr对MMC、CBDDCA、5-FU和BLM表现交叉耐药。KB-CDDPr与亲本KB细胞内铂含量、P-糖蛋白、谷胱甘肽、谷胱甘肽-S转移酶、热休克蛋白和金属硫蛋白含量的比较1)KB-CDDPr和KB细胞内铂含量呈剂量和时间依赖性增加。而Kb-CDDPr细胞的铂含量仅为KB细胞的1/3。2)P-糖蛋白免疫组织化学染色均为阴性。3)无论CDDP处理与否，Kb-CDDPr和KB-CDDPr细胞的GSH体积无显著差异。4)无论CDDP处理与否，Kb-CDDPr细胞的GST-2pi蛋白和GST-2pi表达水平均无显著差异。HSP50在两种细胞系中均呈强阳性表达。6)无论用不同浓度的CDDP处理KB-CDDPr细胞，其MT免疫组化染色结果均无显著差异，提示细胞内铂含量和HSP27、HSP70参与了KB-CDDPr对CDDP的耐药。

This study was designed to analyze the mechanism of cis-platin (CDDP) resistance of the oral squamous cell carcinoma.1. The establishment of CDDP resistant oral squamous cell carcinoma cell line. We established the CDDP resistant KB-CDDPr cell line from KB cells, gradually increasing CDDP concentration in medium. KB-CDDPr showed cross-resistant to MMC, CBDDCA, 5-FU and BLM.2. The comparison between KB-CDDPr and parental KB concerning intracellular Pt content, P-glycoprotein, glutathIone (GSH), glutathione S-transferase ( GST )-pi, heat shock protein (HSP) and metallothionein (MT).1)The intracelluler Pt content of KB-CDDPr and KB increased dose-and time-dependently, and the Pt content of KB-CDDPr was as 1/3 as that of KB.2)The both cell lines were negative in the staining of imrnunohistocemlstry of P-glycoprotein.3)There was no significant difference between both cells of the volumes of GSH irrespective of CDDP treatment.4)There was no significant difference between both cells in the immunohIstochemical staining, the levels of protein nor the levels of mRNA of GST-2pi Irrespective of CDDP treatment.5)The immunohistochemical staining of HSP27 showed more positive in KB-CDDPr, treated with CDDP furthermore. That of HSP50 showed strongly positive In both cell lines. That of HSP7O showed the same as that of HSP27.6)There was no significant difference between both cells in the staining ofthe imunohlstochemistry of MT irrespective of CDDP treatment.From these findings, it was indicated that intracellular Pt content and HSP27 and HSP7O were involved in the resistance of CDDP of KB-CDDPr.