Division of Cancer Medicine, Peter MacCallum Cancer Centre, Victoria, Australia.
Cancer J. 2012 Mar-Apr;18(2):132-6. doi: 10.1097/PPO.0b013e31824ba4df.
Cutaneous melanomas have mutations in the NRAS GTPase in 15% of cases. Compared to melanomas with BRAF mutations, or melanomas "wild-type" for BRAF and NRAS, melanomas with NRAS mutations are more likely to be thicker tumors and to have a higher mitotic rate. Preclinical studies indicate that melanoma cells with NRAS mutations are dependent on NRAS for survival and proliferation, making NRAS an attractive therapeutic target in melanoma. However, to date, therapeutic strategies for NRAS mutant melanomas have not been realized. Promising strategies to target NRAS include targeting the membrane localization of NRAS or reducing expression through the use of therapeutic small interfering RNAs. Finally, use of inhibitors to target downstream signaling through mitogen-activated protein kinase kinase and phosphatidylinositol 3-OH kinase or AKT are now entering clinical trials, and if these combinations can be safely delivered at sufficient dose to inhibit the targets, there is significant potential to target NRAS mutant melanoma.
皮肤黑色素瘤有 15%的病例存在 NRAS GTPase 突变。与 BRAF 突变的黑色素瘤或 BRAF 和 NRAS“野生型”黑色素瘤相比,NRAS 突变的黑色素瘤更有可能是较厚的肿瘤,并且有更高的有丝分裂率。临床前研究表明,NRAS 突变的黑色素瘤细胞依赖于 NRAS 来生存和增殖,这使得 NRAS 成为黑色素瘤治疗的一个有吸引力的靶点。然而,迄今为止,针对 NRAS 突变黑色素瘤的治疗策略尚未实现。针对 NRAS 的有前途的策略包括靶向 NRAS 的膜定位或通过使用治疗性小干扰 RNA 来降低表达。最后,使用抑制剂通过丝裂原活化蛋白激酶激酶和磷脂酰肌醇 3-OH 激酶或 AKT 靶向下游信号传导,现在正在进入临床试验,如果这些组合能够以足够的剂量安全地输送以抑制靶标,那么针对 NRAS 突变黑色素瘤具有重要的潜力。