Research Division, Chugai Pharmaceutical Co., Ltd., 200 Kajiwara, Kamakura, Kanagawa 247-8530, Japan.
Research Division, Chugai Pharmaceutical Co., Ltd., 200 Kajiwara, Kamakura, Kanagawa 247-8530, Japan.
Cancer Lett. 2017 Nov 28;409:116-124. doi: 10.1016/j.canlet.2017.09.008. Epub 2017 Sep 18.
Microphthalmia-associated transcription factor (MITF) is expressed in melanomas and has a critical role in melanocyte development and transformation. Because inhibition of MITF inhibits cell growth in melanoma, MITF is a potential therapeutic target molecule. Here, we report the identification of CH6868398, which has a novel chemical structure and suppresses MITF expression at the protein level in melanoma cells. CH6868398 showed cell growth inhibition activity against MITF-dependent melanoma cells both with and without BRAF mutation and also exhibited anti-tumor efficacy in a melanoma xenograft model. Because selective BRAF inhibitors are standard therapeutics for BRAF-mutated melanoma, we investigated the effect of CH6868398 with a BRAF inhibitor, PLX4720, on cell growth inhibition. The addition of CH6868398 enhanced the cell growth inhibition activity of PLX4720 in melanoma cell lines. Furthermore, combination of CH6868398 and PLX4720 efficiently suppressed MITF protein and enhanced cleavage of Caspase3 and poly (ADP-ribose) polymerase (PARP) in melanoma cell lines. These data support the therapeutic potential of CH6868398 as an anti-melanoma agent that reduces MITF protein levels in combination with BRAF inhibitors.
小眼畸形相关转录因子(MITF)在黑色素瘤中表达,并在黑素细胞发育和转化中具有关键作用。由于抑制 MITF 抑制黑色素瘤中的细胞生长,因此 MITF 是一个潜在的治疗靶标分子。在这里,我们报告了 CH6868398 的鉴定,它具有新颖的化学结构,并在黑色素瘤细胞中抑制 MITF 表达的蛋白质水平。CH6868398 对 MITF 依赖性黑色素瘤细胞具有细胞生长抑制活性,无论是否存在 BRAF 突变,并且在黑色素瘤异种移植模型中也表现出抗肿瘤功效。由于选择性 BRAF 抑制剂是 BRAF 突变型黑色素瘤的标准治疗方法,我们研究了 CH6868398 与 BRAF 抑制剂 PLX4720 对细胞生长抑制的影响。添加 CH6868398 增强了 PLX4720 在黑色素瘤细胞系中的细胞生长抑制活性。此外,CH6868398 和 PLX4720 的组合有效地抑制了黑色素瘤细胞系中的 MITF 蛋白,并增强了 Caspase3 和聚(ADP-核糖)聚合酶(PARP)的裂解。这些数据支持 CH6868398 作为一种抗黑色素瘤药物的治疗潜力,该药物与 BRAF 抑制剂联合降低 MITF 蛋白水平。