METALLOTHIONEIN GENE-EXPRESSION AND RESISTANCE TO CISPLATIN IN HUMAN OVARIAN-CANCER
METALLOTHIONEIN GENE-EXPRESSION AND RESISTANCE TO CISPLATIN IN HUMAN OVARIAN-CANCER
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DOI：
10.1002/ijc.2910450306
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发表时间：
1990-03-15
影响因子：
6.4
通讯作者：
HAMILTON, TC
中科院分区：
文献类型：
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作者：
SCHILDER, RJ;HALL, L;HAMILTON, TC
细胞内硫代已被提议作为对烷化剂和顺铂的抗性的介质。由于金属硫蛋白是主要的巯基蛋白，我们研究了它与人卵巢癌细胞系顺铂耐药的关系。人卵巢癌细胞系，A2780，来自未经治疗的患者，用顺铂以几种方式处理，诱导的顺铂耐药性范围从13到68倍。抗性程度取决于选择方法。耐药细胞系也对镉产生了低水平的交叉耐药性。研究了从未经治疗的患者或对含顺铂和/或卡铂的联合化疗难治的卵巢癌患者建立的其他细胞系。最耐顺铂的细胞系OVCAR-8和OVCAR-10来自既往接受过强化化疗的患者。OVCAR-8对镉的交互抗性相对较强，而OVCAR-10对镉的交互抗性相对较弱。检测细胞系金属硫蛋白mRNA的表达，以评估顺铂耐药、镉交叉耐药与金属硫蛋白表达之间的关系。只有两个体外诱导的顺铂耐药的细胞系，2780 E80和2780 CP 7083，有可检测到的金属硫蛋白mRNA。体外选择的其他顺铂耐药细胞系以及亲本A2780卵巢癌细胞系在我们的检测水平下未显示表达。金属硫蛋白在OVCAR细胞系中的表达是可变的。来自未治疗患者的细胞系OVCAR-5和-7确实表达金属硫蛋白，而大多数顺铂耐药细胞系OVCAR-8和-10则不表达。我们还研究了顺铂诱导的细胞系中的金属硫蛋白mRNA。在体外诱导顺铂耐药的细胞系中，只有2780 CP 7083在短期暴露于顺铂后表达增加。暴露于顺铂后，OVCAR-4的表达也略有增加。用牛乳头瘤病毒-金属硫蛋白基因构建体转染的小鼠C127细胞与仅用牛乳头瘤病毒转染的相同细胞类型的顺铂敏感性进行比较。在该模型系统中，金属硫蛋白表达不影响顺铂的细胞毒性。在这些研究的基础上，我们得出结论，金属硫蛋白的表达和顺铂耐药之间没有因果关系。
Intracellular thiois have been proposed as mediators of resistance to alkylating agents and cisplatin. As metallothionein is the predominant protein thiol, we examined its relationship to cisplatin resistance in human ovarian cancer cell lines. A human ovarian carcinoma cell line, A2780, derived from an untreated patient, was treated with cisplatin in several ways and the induced resistance to cisplatin ranged from 13- to 68-fold. The degree of resistance was dependent upon the method of selection. The drug-resistant cell lines also developed low levels of cross-resistance to cadmium. Additional cell lines established from untreated patients or ovarian cancer patients refractory to cisplatin- and/or carboplatin-containing combination chemotherapy were studied. The most cisplatin-resistant cell lines, OVCAR-8 and -10, were from patients previously treated with intensive chemotherapy. OVCAR-8 was relatively cross-resistant to cadmium while OVCAR-10 appeared relatively sensitive. Cell lines were examined for expression of metallothionein mRNA to evaluate the relationship between cisplatin resistance, cadmium cross-resistance and metallothionein expression. Only two of the cell lines with in vitro-induced resistance to cisplatin, 2780E80 and 2780CP7083, had detectable metallothionein mRNA. The other cell lines selected in vitro for cisplatin resistance, as well as the parental A2780 ovarian cancer cell line, showed no expression at our level of detection. There was variable expression of metallothionein among the OVCAR cell lines. Cell lines from untreated patients, OVCAR-5 and -7, did express metallothionein, while the most cisplatin-resistant cell lines, OVCAR-8 and -10, did not. We also examined cisplatin induction of metallothionein mRNA in the cell lines. Only 2780CP7083 among the cell lines with in vitro-induced cisplatin resistance showed increased expression after short-term exposure to cisplatin. OVCAR-4 also had a slight increase in expression after exposure to cisplatin. Mouse C127 cells transfected with a bovine papilloma virus-metallothionein gene construct were compared for cisplatin sensitivity to the same cell type transfected with bovine papilloma virus alone. In this model system, metallothionein expression did not influence cisplatin cytotoxicity. On the basis of these studies, we conclude that there is no causal relationship between metallothionein expression and cisplatin resistance.