MKK4/7 are kinases that phosphorylate JNKs and regulate the MAPK signaling pathway. Their overexpression has been associated with tumorigenesis and aggressiveness in cancers such as breast, prostate, non-small cell lung, and pediatric leukemia, making them a potential target for inhibitor development. Here, we report the discovery, development, and validation of a dual MKK4/7 inhibitor, BSJ-04-122, that covalently targets a conserved cysteine located before the DFG motif and displays excellent kinome selectivity. BSJ-04-122 exhibits potent cellular target engagement and induces robust target-specific downstream effects. The combination of the dual MKK4/7 inhibitor with a selective, covalent JNK inhibitor demonstrated an enhanced antiproliferative activity against triple-negative breast cancer cells. Taken together, the results show that BSJ-04-122 represents a pharmacological probe for MKK4/7 and credential covalent targeting as a way to explore the therapeutic potential of these kinases.

MKK4 / 7是使JNK磷酸化并调节MAPK信号通路的激酶。在乳腺癌，前列腺癌，非小细胞肺癌和小儿白血病等癌症中，它们的过表达与肿瘤的发生和侵袭性相关，使其成为抑制剂开发的潜在靶标。在这里，我们报告发现，开发和验证双重MKK4 / 7抑制剂BSJ-04-122，该抑制剂共价靶向位于DFG基序之前的保守半胱氨酸并显示出优异的kinome选择性。BSJ-04-122表现出强大的细胞靶标接合能力，并诱导强大的靶标特异性下游效应。双重MKK4 / 7抑制剂与选择性共价JNK抑制剂的组合显示出对三阴性乳腺癌细胞增强的抗增殖活性。在一起