APPROARCH AT MOLECULAR LEVEL FOR MECHANISMS OF MULTIDRUG-RESISTANCE AND ENHANCEMENT OF ANTICANCER DRUGS WITH HYPERTHERMIA

分子水平的多药耐药机制和热疗增强抗癌药物的研究

• 批准号: 11670890
• 负责人: KAWASAKI Shoji
• 金额: $ 2.05万
• 依托单位: OKAYAMA UNIVERSITY
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (C)
• 财政年份: 1999
• 资助国家: 日本
• 起止时间: 1999 至 2001
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-11670890/
• 关键词: adriamycin; multidrug resistance; hyperthermia; Ehrlich ascites tumor cells; anticancer drugs; ion channel; MGMT; alkylating agent; WAF1; wortmannin; 分化度; 喉頭癌; アントシアニジン; Caイオン; Calcein

It is an important problem that tumor cells treated with anticancer drugs expressed multidrug resistance. Therfore, resistant mechanisms of varius mammalian cells were studied, MDR1 gene concerning resistance to adriamycin were appeared in our established cells of Ehrlich ascites tumor. Its resistance related to eflux pump of p-gp which is in cellular membrane, and the penetration of adriamycin into cells was affected by both of ion channels of Na^+/H^+ and Cl^-/HCO_3. Heating showed marked enhancement of cell killing effects of adriamycin. Abtitumor effects of adriamycin were tested on in vivo with or without treatment of mild hyperthermia. However, antitumor effects were shown not so much. On the other hand, efflux of adriamycin was inhibited with cepharanthine, that is, cepharanthine enhanced a killing effect of adriamycin. Antitumor effects of adriamycin were affected with intraa- and extracellure pH. Intracellular accumulation of adriamycin was small amount at acidic condition. It was depended to slow infflux of adriamycin. It is concluded that antitumor effects of adriamycin were not so large enhancement with hyperthermia as it is low pH condition in tumor and hyperthermia induced low pH more than without treatment. On the othe hand, those cells showed the other unknown resistant mechanisims to adriamycin. It is indicated that adriamysin-resistant cells of Ehrlich ascites tumor have at least two expression processes of resistance to adriamycin. There are many mechanisms on resistant to anticancer drugs. Hyperthermia enhanced markedly killing effects of alkylating agents in vitro and in vivo. The sensitivity to alkylating agents related to 06-methylguanine-DNA methyltransferase(MGMT). As MGMT expression was depressed by methylation, it is investigated that relationship between level of methylation and killing effect of alkylating agent in several human squarmous carcinoma cells. Methylation of MGMT is closely related to the sennsitivity for alkylating agents.

抗肿瘤药物处理的肿瘤细胞表现出多药耐药是一个重要的问题。因此，我们对多种哺乳动物细胞的耐药机制进行了研究，在我们建立的艾氏腹水瘤细胞中发现了与阿霉素耐药相关的mdr1基因。阿霉素的耐受性与细胞膜上p-gp的渗透泵有关，而阿霉素对细胞的渗透受Na+/H+和Cl+/HCO3两种离子通道的影响。加热可明显增强阿霉素对细胞的杀伤作用。在有或无亚高温治疗的情况下，在体内检测阿霉素的抗肿瘤作用。然而，抗肿瘤作用并不是很明显。而三尖杉碱能抑制阿霉素的外排，即增强了阿霉素的杀伤作用。阿霉素的抗肿瘤作用受细胞内外pH的影响。在酸性条件下，细胞内阿霉素积累量很小。其作用依赖于延缓阿霉素的转运。结论：热疗对阿霉素的抗肿瘤作用的增强作用不是很大，而是肿瘤内的低pH条件，热疗引起的低pH比未热疗更明显。另一方面，这些细胞表现出其他未知的阿霉素耐药机制。提示艾氏腹水瘤中的阿霉素耐药细胞至少存在两个阿霉素耐药的表达过程。抗癌药物耐药的机制很多。体内外加温可明显增强烷化剂的杀伤作用。对烷基化药物的敏感性与06-甲基鸟嘌呤-DNA甲基转移酶(MGMT)有关。由于甲基化抑制了MGMT的表达，我们研究了几种人鳞癌细胞中甲基化水平与烷化剂杀伤效应的关系。MGMT的甲基化与烷基化试剂的敏感性密切相关。

项目成果

Asaumi J, Matsuzaki H, Kawasaki S, Kuroda M, Takeda Y, Kishi K, and Hiraki Y: "Influence of bovine calf serum on the intracellular accumulation and retention of adriamycin"Anticancer Research. 20 (2A). 769-772 (2000)

Asaumi J、Matsuzaki H、Kawasaki S、Kuroda M、Takeda Y、Kishi K 和 Hiraki Y：“小牛血清对阿霉素细胞内积累和保留的影响”抗癌研究。

Asaumi J, Higuchi Y, Matsuzaki H, Murakami J, Kawasaki S, Kuroda M, Shibuya K, Konouchi H, Hisatomi M, Wakasa T, Kishi K, and Hiraki Y: "Thermochemotherapy of a human sailvary adenocarcmoma cell line."Oncol Rep.. 9 (2). 365-369 (2002)

Asaumi J、Higuchi Y、Matsuzaki H、Murakami J、Kawasaki S、Kuroda M、Shibuya K、Konouchi H、Hisatomi M、Wakasa T、Kishi K 和 Hiraki Y：“人帆腺癌细胞系的热化疗。”Oncol Rep