RAS proteins are key regulators of cell signalling and control different cell functions including cell proliferation, differentiation, and cell death. Point mutations in the genes of this family are common, particularly inKRAS. These mutations were thought to cause the constitutive activation of KRAS, but recent findings showed that some mutants can cycle between active and inactive states. This observation, together with the development of covalent KRASG12C inhibitors, has led to the arrival of KRAS inhibitors in the clinic. However, most patients develop resistance to these targeted therapies, and we lack effective treatments for other KRAS mutants. To accelerate the development of RAS targeting therapies, we need to fully characterise the molecular mechanisms governing KRAS signalling networks and determine what differentiates the signalling downstream of the KRAS mutants. Here we have used affinity purification mass-spectrometry proteomics to characterise the interactome of KRAS wild-type and three KRAS mutants. Bioinformatic analysis associated with experimental validation allows us to map the signalling network mediated by the different KRAS proteins. Using this approach, we characterised how the interactome of KRAS wild-type and mutants is regulated by the clinically approved KRASG12C inhibitor Sotorasib. In addition, we identified novel crosstalks between KRAS and its effector pathways including the AKT and JAK-STAT signalling modules.
RAS蛋白是细胞信号传导的关键调控因子，调控包括细胞增殖、分化与死亡在内的多种细胞功能。该蛋白家族基因的点突变较为常见，其中KRAS基因突变尤为突出。传统观点认为这些突变会导致KRAS的持续性激活，但最新研究发现部分突变体可在激活与非激活状态间循环切换。这一发现与共价KRASG12C抑制剂的研发进展共同推动了KRAS抑制剂进入临床阶段。然而多数患者会对这些靶向治疗产生耐药性，且针对其他KRAS突变体仍缺乏有效疗法。为加速RAS靶向治疗的发展，需要全面解析调控KRAS信号网络的分子机制，并明确不同KRAS突变体下游信号传导的差异性特征。本研究采用亲和纯化质谱蛋白质组学技术，系统表征了KRAS野生型及三种突变体的相互作用组。通过生物信息学分析与实验验证相结合的方法，我们绘制了不同KRAS蛋白介导的信号网络图谱。运用该技术体系，我们揭示了临床获批的KRASG12C抑制剂Sotorasib对KRAS野生型及突变体相互作用组的调控机制。此外，本研究还发现了KRAS与其效应通路（包括AKT和JAK-STAT信号模块）之间新型的交叉对话机制。
肿瘤(癌症)患者之家