黑色素瘤具有恶性程度高、转移早、死亡率高等特点, 而且对常规放射治疗不敏感, 因此, 提高黑色素瘤细胞的辐射敏感性对于此种疾病的治疗具有重要意义。本研究中构建了辐射诱导型过表达Ras相关的C3肉毒素底物2(RAC2)和敲低RAC2的黑色素瘤细胞系, 通过测定其辐照后的克隆存活率、γH2AX foci水平、ROS产额以及NADPH氧化酶活性研究了RAC2基因对于黑色素瘤细胞辐射敏感性的影响及可能的作用机制, 发现RAC2能通过增强NADPH氧化酶活性和提高ROS产额显著增强黑色素瘤细胞的辐射敏感性。

Malignant melanoma is characterized by high degree of malignancy, early metastasis and high mortality. However, it is indicated by clinical experience that malignant melanoma is resistant to conventional radiotherapy. Therefore, it is of great significance to radio-sensitize melanoma cells in the treatment of this kind of malignancy. In the present study, the melanoma cell lines with inducible RAC2 over-expression or RAC2 knockdown were established. The effect of RAC2 on radiosensitivity of melanoma cells were evaluated by colony formation assay and γH2AX assay. Meanwhile, the ROS yield and the NADPH oxidase activity were analyzed in the irradiated melanoma cells. We find that RAC2 over-expression sensitizes the melanoma cells by enhancing the NADPH oxidase activity and the subsequent ROS production.