BH3-mimetic类药物是一种抗癌疗法，通过直接结合和抑制BCL-2家族的促存活蛋白，在恶性细胞中诱导凋亡。针对BCL-2的BH3-mimetic药物Venetoclax已被世界各地的监管机构批准用于慢性淋巴细胞白血病和急性髓细胞白血病的治疗。然而，尽管大多数患者最初反应良好，但使用该药物后的耐药性和复发问题正在临床上显现并引起关注 。虽然一些研究已经开始揭示与BCL-2靶向的BH3-mimetic药物耐药性有关的因素，但很少有人关注针对MCL-1靶向的下一代BH3-mimetic药物的预防性耐药性策略，而这些药物正在为多种血液恶性肿瘤进行临床试验。因此，我们利用侵袭性淋巴瘤小鼠和人类模型，试图预测可能导致患者在接受MCL-1靶向BH3-mimetic药物治疗时产生耐药性的因素。首先，我们进行了多个整个基因组CRISPR / Cas9 KO筛选，并确定失去促凋亡效应蛋白BAX而不是其近亲BAK可能在短期和长期治疗方案中赋予淋巴瘤治疗MCL-1靶向的BH3-mimetic药物耐药性，即使在缺乏肿瘤抑制基因TRP53的淋巴瘤细胞中也是如此。此外，我们发现，小鼠Eµ-Myc淋巴瘤细胞因耐受MCL-1抑制剂而在不断增加药物剂量的培养条件下失去BAX和上调未靶向的促存活BCL-2家族蛋白BCL-XL和A1时，便会自然地耐药。最后，我们确定了可以克服这两种耐药方法的治疗方法：分别采用化疗药物或联合BH3-mimetic治疗。总的来说，这些结果揭示了在临床上引起MCL-1抑制的耐药性的一些关键因素，并暗示了理性的治疗策略，以克服这种耐药性，还需要进一步研究。 ©2023年作者。

BH3-mimetic drugs are an anti-cancer therapy that can induce apoptosis in malignant cells by directly binding and inhibiting pro-survival proteins of the BCL-2 family. The BH3-mimetic drug venetoclax, which targets BCL-2, has been approved for the treatment of chronic lymphocytic leukaemia and acute myeloid leukaemia by regulatory authorities worldwide. However, while most patients initially respond well, resistance and relapse while on this drug is an emerging and critical issue in the clinic. Though some studies have begun uncovering the factors involved in resistance to BCL-2-targeting BH3-mimetic drugs, little focus has been applied to pre-emptively tackle resistance for the next generation of BH3-mimetic drugs targeting MCL-1, which are now in clinical trials for diverse blood cancers. Therefore, using pre-clinical mouse and human models of aggressive lymphoma, we sought to predict factors likely to contribute to the development of resistance in patients receiving MCL-1-targeting BH3-mimetic drugs. First, we performed multiple whole genome CRISPR/Cas9 KO screens and identified that loss of the pro-apoptotic effector protein BAX, but not its close relative BAK, could confer resistance to MCL-1-targeting BH3-mimetic drugs in both short-term and long-term treatment regimens, even in lymphoma cells lacking the tumour suppressor TRP53. Furthermore, we found that mouse Eµ-Myc lymphoma cells selected for loss of BAX, as well as upregulation of the untargeted pro-survival BCL-2 family proteins BCL-XL and A1, when made naturally resistant to MCL-1 inhibitors by culturing them in increasing doses of drug over time, a situation mimicking the clinical application of these drugs. Finally, we identified therapeutic approaches which could overcome these two methods of resistance: the use of chemotherapeutic drugs or combined BH3-mimetic treatment, respectively. Collectively, these results uncover some key factors likely to cause resistance to MCL-1 inhibition in the clinic and suggest rational therapeutic strategies to overcome resistance that should be investigated further.© 2023. The Author(s).