Up-Regulation of Carbonyl Reductase 1 Renders Development of Doxorubicin Resistance in Human Gastrointestinal Cancers
Up-Regulation of Carbonyl Reductase 1 Renders Development of Doxorubicin Resistance in Human Gastrointestinal Cancers
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DOI：
10.1248/bpb.b15-00176
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发表时间：
2015-09-01
影响因子：
2
通讯作者：
Ikari, Akira
中科院分区：
文献类型：
--
作者：
Matsunaga, Toshiyuki;Kezuka, Chihiro;Ikari, Akira
多柔比星（DOX）广泛用于治疗多种癌症，例如乳腺癌和肺癌以及恶性淋巴瘤，但通常在胃肠道癌症中不太有效。DOX不应性的最被接受的解释是其耐药性的发展。在这里，我们通过连续暴露于递增浓度的药物，建立了人胃MKN 45和结肠LoVo细胞的DOX耐药表型。虽然亲本MKN 45和LoVo细胞分别高度和中度表达羰基还原酶1（CBR 1），但DOX抗性的获得进一步提高了CBR 1的表达。此外，通过CBR 1的过表达降低了DOX引起的细胞毒性，并且通过使用小干扰RNA敲低酶或用特异性抑制剂槲皮素预处理而反向增强，这也降低了两种耐药细胞的DOX抗性。提示CBR 1是胃肠道癌细胞对DOX耐药的关键酶，其抑制剂可用于辅助治疗。尽管已知CBR 1将DOX代谢为毒性较小的抗癌代谢物多柔比星，但其在亲本细胞中的过表达对于低浓度的DOX几乎没有显示出显著的还原酶活性。相反，CBR 1的过表达增加了还原酶对氧化应激衍生的细胞毒性醛4-氧代-2-壬烯醛的活性。DOX抗性细胞对4-氧代-2-壬烯醛的敏感性低于亲本细胞，并且通过添加CBR 1抑制剂几乎完全改善了抗性引起的低敏感性。因此，CBR 1可能通过细胞毒性醛的解毒而不是药物的代谢来促进DOX抗性的发展。
Doxorubicin (DOX) is widely used for the treatment of a wide range of cancers such as breast and lung cancers, and malignant lymphomas, but is generally less efficacious in gastrointestinal cancers. The most accepted explanation for the DOX refractoriness is its resistance development. Here, we established DOX-resistant phenotypes of human gastric MKN45 and colon LoVo cells by continuous exposure to incremental concentrations of the drug. While the parental MKN45 and LoVo cells expressed carbonyl reductase 1 (CBR1) highly and moderately, respectively, the gain of DOX resistance further elevated the CBR1 expression. Additionally, the DOX-elicited cytotoxicity was lowered by overexpression of CBR1 and inversely strengthened by knockdown of the enzyme using small interfering RNA or pretreating with the specific inhibitor quercetin, which also reduced the DOX refractoriness of the two resistant cells. These suggest that CBR1 is a key enzyme responsible for the DOX resistance of gastrointestinal cancer cells and that its inhibitor is useful in the adjuvant therapy. Although CBR1 is known to metabolize DOX to a less toxic anticancer metabolite doxorubicinol, its overexpression in the parental cells hardly show significant reductase activity toward low concentration of DOX. In contrast, the overexpression of CBR1 increased the reductase activity toward an oxidative stress-derived cytotoxic aldehyde 4-oxo-2-nonenal. The sensitivity of the DOX-resistant cells to 4-oxo-2-nonenal was lower than that of the parental cells, and the resistance-elicited hyposensitivity was almost completely ameliorated by addition of the CBR1 inhibitor. Thus, CBR1 may promote development of DOX resistance through detoxification of cytotoxic aldehydes, rather than the drug's metabolism.