Melanoma cells expressing mutant B-RAF V600E are susceptible to treatment with the combination of a B-RAF inhibitor and a MEK1/2 inhibitor. We investigated the impact of the ERBB family and MAP4K inhibitor neratinib on the biology of PDX isolates of cutaneous melanoma expressing B-RAF V600E. Neratinib synergized with HDAC inhibitors to kill melanoma cells at their physiologic concentrations. Neratinib activated ATM, AMPK, ULK1, and PERK and inactivated mTORC1/2, ERK1/2, eIF2 alpha, and STAT3. Neratinib increased expression of Beclin1, ATG5, CD95, and FAS-L and decreased levels of multiple toxic BH3 domain proteins, MCL1, BCL-XL, FLIP-s, and ERBB1/2/4. ATG13 S318 phosphorylation and autophagosome formation was dependent upon ATM, and activation of ATM was dependent on reactive oxygen species. Reduced expression of ERBB1/2/4 required autophagosome formation and reduced MCL1/BCL-XL levels required eIF2 alpha phosphorylation. Maximal levels of eIF2 alpha phosphorylation required signaling by ATM-AMPK and autophagosome formation. Knock down of eIF2 alpha, CD95, FAS-L, Beclin1, and ATG5 or over-expression of FLIP-s significantly reduced killing. Combined knock down of Beclin1 and CD95 abolished cell death. Our data demonstrate that PDX melanoma cells expressing B-RAF V600E are susceptible to being killed by neratinib and more so when combined with HDACi.

中文翻译：

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Neratinib 通过 ROS 依赖性自噬体形成和死亡受体信号传导杀死 B-RAF V600E 黑色素瘤


表达突变体 B-RAF V600E 的黑色素瘤细胞对 B-RAF 抑制剂和 MEK1/2 抑制剂的组合治疗敏感。我们研究了 ERBB 家族和 MAP4K 抑制剂 neratinib 对表达 B-RAF V600E 的皮肤黑色素瘤 PDX 分离株生物学的影响。 Neratinib 与 HDAC 抑制剂协同作用，在生理浓度下杀死黑色素瘤细胞。 Neratinib 激活 ATM、AMPK、ULK1 和 PERK，并灭活 mTORC1/2、ERK1/2、eIF2 α 和 STAT3。 Neratinib 增加 Beclin1、ATG5、CD95 和 FAS-L 的表达，并降低多种有毒 BH3 结构域蛋白、MCL1、BCL-XL、FLIP-s 和 ERBB1/2/4 的水平。 ATG13 S318 磷酸化和自噬体形成取决于 ATM，而 ATM 的激活取决于活性氧。 ERBB1/2/4 表达减少需要自噬体形成，而 MCL1/BCL-XL 水平降低需要 eIF2 α 磷酸化。 eIF2 α 磷酸化的最高水平需要 ATM-AMPK 信号传导和自噬体形成。 eIF2 α、CD95、FAS-L、Beclin1 和 ATG5 的敲低或 FLIP-s 的过表达显着减少了杀伤作用。联合敲除 Beclin1 和 CD95 可消除细胞死亡。我们的数据表明，表达 B-RAF V600E 的 PDX 黑色素瘤细胞容易被 neratinib 杀死，与 HDACi 联合使用时更是如此。