Shibuya K, Satoh M, Muraoka M, Watanabe Y, Oida M, Shimizu H
Department of Pharmacy, Kitasato Institute Medical Center Hospital, Saitama, Japan.
Radiat Res. 1995 Jul;143(1):54-7.
Although recent studies have shown that radiation can induce metallothionein (MT) synthesis in normal tissues, the induction of tumor MT synthesis by irradiation has not been reported. We examined the accumulation of MT in the Meth-A tumor (mouse fibrosarcoma cells) transplanted into mice exposed to whole-body X irradiation. In the present study, the MT content in the tumor cells was increased by X irradiation in a dose-dependent manner. The MT level induced in the tumor cells by X irradiation was elevated not only after a single exposure but also after repeated exposures. Several studies have shown that MT is one of the important cellular factors in resistance to various anticancer drugs and ionizing radiation. Thus our results suggest that the radiation-induced MT in the tumor cells may have to be taken into consideration when designing protocols for radio- and chemotherapy.
尽管最近的研究表明辐射可诱导正常组织中金属硫蛋白（MT）的合成，但尚未见关于照射诱导肿瘤MT合成的报道。我们研究了移植到全身X线照射小鼠体内的Meth-A肿瘤（小鼠纤维肉瘤细胞）中MT的蓄积情况。在本研究中，肿瘤细胞中的MT含量随X线照射剂量的增加而呈剂量依赖性增加。X线照射诱导肿瘤细胞中的MT水平不仅在单次照射后升高，在重复照射后也升高。多项研究表明MT是细胞对各种抗癌药物和电离辐射产生抗性的重要因素之一。因此，我们的结果提示，在设计放疗和化疗方案时，可能必须考虑肿瘤细胞中辐射诱导产生的MT。
