对于KRAS突变的转移性结直肠癌（mCRC）患者，发现新的治疗策略是一个未能满足的临床需求。本研究旨在阐明P21激活激?（Paks）在KRAS突变CRC的治疗靶点中的作用。我们通过免疫组织化学法评估一组KRAS-WT或突变CRC患者中Paks的表达和活化水平。通过RNAi和三种广谱Paks抑制剂（PF-3758309，FRAX1036，GNE-2861）评估CRC细胞、球体和肿瘤异种移植物的生长，以测定Paks抑制对肿瘤细胞增殖和信号转导的影响。Paks的活化与患者和细胞系中的KRAS突变状态呈正相关。此外，对于KRAS突变的CRC细胞，遗传调控或药物抑制Paks均导致细胞增殖的显著受损。然而，Paks的持续阻断通过mTOR/p70S6K通路的过度激活引发了快速的肿瘤适应。添加永久霉素（mTOR抑制剂）可以在体外和体内阻止KRAS突变CRC肿瘤的生长，逆转对Paks靶向的肿瘤适应性抗性。总之，我们的结果表明，同时阻断mTOR和Pak通路作为一种有前途的替代治疗策略，适用于KRAS突变的结直肠癌患者。©2023年。作者（们），在Springer Nature Limited的专属许可下发表。

The identification of novel therapeutic strategies for metastatic colorectal cancer (mCRC) patients harbouring KRAS mutations represents an unmet clinical need. In this study, we aimed to clarify the role of p21-activated kinases (Paks) as therapeutic target for KRAS-mutated CRC.Paks expression and activation levels were evaluated in a cohort of KRAS-WT or -mutated CRC patients by immunohistochemistry. The effects of Paks inhibition on tumour cell proliferation and signal transduction were assayed by RNAi and by the use of three pan-Paks inhibitors (PF-3758309, FRAX1036, GNE-2861), evaluating CRC cells, spheroids and tumour xenografts' growth.Paks activation positively correlated with KRAS mutational status in both patients and cell lines. Moreover, genetic modulation or pharmacological inhibition of Paks led to a robust impairment of KRAS-mut CRC cell proliferation. However, Paks prolonged blockade induced a rapid tumour adaptation through the hyper-activation of the mTOR/p70S6K pathway. The addition of everolimus (mTOR inhibitor) prevented the growth of KRAS-mut CRC tumours in vitro and in vivo, reverting the adaptive tumour resistance to Paks targeting.In conclusion, our results suggest the simultaneous blockade of mTOR and Pak pathways as a promising alternative therapeutic strategy for patients affected by KRAS-mut colorectal cancer.© 2023. The Author(s), under exclusive licence to Springer Nature Limited.