Expression of the MDR1 gene and P-glycoprotein in canine mast cell tumor cell lines
Expression of the MDR1 gene and P-glycoprotein in canine mast cell tumor cell lines
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DOI：
10.1292/jvms.69.111
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发表时间：
2007-02-01
影响因子：
1.2
通讯作者：
Taura, Yasuho
中科院分区：
文献类型：
--
作者：
Nakaichi, Munekazu;Takeshita, Yoko;Taura, Yasuho
细胞对化疗药物的耐药性通常是由于药物外排泵的存在，该泵降低了细胞内药物积聚和化疗敏感性。由MDR 1基因编码的P-糖蛋白（P-gp）被认为是ATP驱动的膜药物外排泵，在肿瘤细胞耐药中起重要作用。在本报告中，我们评估了MDR 1的表达在三个犬肥大细胞肿瘤细胞系，TiMC，CoMS和LuMC，分别来自皮肤肿瘤，口腔粘膜肿瘤和胃肠道肿瘤，通过RT-PCR。P-gp表达也通过Western印迹分析进行了检查，而P-gp的功能活性通过流式细胞术分析细胞内罗丹明-123（Rhd-123）摄取进行了评估。结果表明，CoMS和LuMC细胞中MDR 1基因和P-gp均表达，而TiMC细胞中MDR 1基因和P-gp均不表达。在CoMS和LuMC细胞中，在存在维拉帕米（一种P-gp的功能调节剂）的情况下，Rhd-123的细胞内摄取增加。相比之下，TiMC细胞在添加维拉帕米后未显示Rhd-123的细胞内积累的任何变化。结果提示，MDR 1基因和P-gp的表达可能与犬肥大细胞瘤的耐药性有关。
Cellular drug resistance to antineoplastic drugs is often due to the presence of a drug efflux pump that reduces intracellular drug accumulation and chemosensitivity. P-glycoprotein (P-gp), which is encoded by the MDR1 gene, is considered to function as an ATP-driven membrane drug efflux pump and appears to play an important role in tumor cell resistance. In the present report, we assessed the expression of MDR1 by RT-PCR in three canine mast cell tumor cell lines, TiMC, CoMS and LuMC, originating from a cutaneous tumor, an oral-mucosal tumor and a gastrointestinal tumor, respectively. P-gp expression was also examined by Western blot analysis, while the functional activity of P-gp was assessed by flowcytometric analysis of intracellular rhodamine-123 (Rhd-123) uptake. The results revealed that MDR1 gene and P-gp were both expressed in CoMS and LuMC cells, whereas neither was present in TiMC cells. In CoMS and LuMC cells, intracellular uptake of Rhd-123 increased in the presence of verapamil, a functional modulator of P-gp. In contrast, TiMC cells did not show any changes in the intracellular accumulation of Rhd-123 after the veraparnil addition. These findings suggest that the expressions of MDR1 gene and P-gp probably contribute to cellular drug resistance in canine mast cell tumors.