Phenformin enhances the therapeutic benefit of BRAFV600E inhibition in melanoma
Phenformin enhances the therapeutic benefit of BRAFV600E inhibition in melanoma
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DOI：
10.1073/pnas.1317577110
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发表时间：
2013-11-05
影响因子：
11.1
通讯作者：
Zheng, Bin
中科院分区：
文献类型：
--
作者：
Yuan, Ping;Ito, Koichi;Zheng, Bin
双胍类化合物，如糖尿病治疗药物二甲双胍和苯福明，在体外和体内都表现出抗肿瘤活性。能量敏感的AMP激活的蛋白激酶(AMPK)是双胍类化合物的主要细胞靶点。基于我们发现AMPK和v-Raf小鼠肉瘤病毒癌基因同源B1(BRAF)信号通路之间的相互作用，我们研究了苯福明与BRAF抑制剂PLX4720联合使用对BRAF突变黑色素瘤细胞的体外抗肿瘤作用和对BRAF诱导的肿瘤生长的抑制作用。与单独用药相比，苯福明和PLX4720联合处理BRAF突变黑色素瘤细胞系可协同抑制细胞活力。此外，在培养的黑色素瘤细胞中，苯福明治疗显著延缓了对PLX4720的耐药性的发展。生化分析表明，苯福明和PLX4720在抑制mTOR信号转导和诱导细胞凋亡方面具有协同作用。值得注意的是，苯福明选择性地针对表达JARID1B的细胞亚群，而PLX4720选择性地针对JARID1B阴性的细胞。JARID1B是黑色素瘤细胞慢周期的标志。最后，与作为单一药物使用相比，苯福明和PLX4720的联合使用在荷有黑色素瘤的裸鼠和基因工程BRAF(V600E)/PTEN驱动的黑色素瘤小鼠模型中均可诱导肿瘤消退。这些结果有力地表明，AMPK激动剂如苯福明与BRAF抑制剂联合治疗黑色素瘤可能获得显著的治疗优势。
Biguanides, such as the diabetes therapeutics metformin and phenformin, have demonstrated antitumor activity both in vitro and in vivo. The energy-sensing AMP-activated protein kinase (AMPK) is known to be a major cellular target of biguanides. Based on our discovery of cross-talk between the AMPK and v-Raf murine sarcoma viral oncogene homolog B1 (BRAF) signaling pathways, we investigated the antitumor effects of combining phenformin with a BRAF inhibitor PLX4720 on the proliferation of BRAF-mutated melanoma cells in vitro and on BRAF-driven tumor growth in vivo. Cotreatment of BRAF-mutated melanoma cell lines with phenformin and PLX4720 resulted in synergistic inhibition of cell viability, compared with the effects of the single agent alone. Moreover, treatment with phenformin significantly delayed the development of resistance to PLX4720 in cultured melanoma cells. Biochemical analyses showed that phenformin and PLX4720 exerted cooperative effects on inhibiting mTOR signaling and inducing apoptosis. Noticeably, phenformin selectively targeted subpopulations of cells expressing JARID1B, a marker for slow cycling melanoma cells, whereas PLX4720 selectively targeted JARID1B-negative cells. Finally, in contrast to their use as single agents, the combination of phenformin and PLX4720 induced tumor regression in both nude mice bearing melanoma xenografts and in a genetically engineered BRAF(V600E)/PTENnull-driven mouse model of melanoma. These results strongly suggest that significant therapeutic advantage may be achieved by combining AMPK activators such as phenformin with BRAF inhbitors for the treatment of melanoma.