RAS基因家族KRAS、NRAS、HRAS是肿瘤研究中最常见的突变癌基因约30%的肿瘤类型携带RAS突变其中KRAS突变在胰腺癌90%、结直肠癌约40%和非小细胞肺癌约30%中尤为显著。然而RAS蛋白表面光滑、缺乏深口袋结构长期以来被认为是不可成药靶点。RMC-7977的问世打破了这一困境——作为三复合 RAS 抑制剂RMC-7977能同时结合亲环蛋白 A (CYPA) (Kd 195 nM) 和 KRAS (G12V) (Kd 292 μM)对 KRAS、NRAS 和 HRAS 三种 RAS 蛋白及其各种野生型和突变型变体具有广谱抑制活性[1]。RMC-7977AbMoleM54858在进入细胞后首先与细胞内伴侣蛋白亲环素ACypA形成二元复合物该复合物通过共价且不可逆的方式与RAS蛋白的Switch II口袋结合阻断其与下游效应因子CRAF、PI3K等的相互作用从而抑制RAS-RAF-MEK-ERK和RAS-PI3K-AKT-mTOR两大核心信号级联[1]。RMC-7977的广谱抑制特性在多种RAS突变细胞系中得到验证。AsPC-1胰腺导管腺癌细胞KRAS G12D突变中100 nM的RMC-7977处理6小时即可抑制ERK1/2磷酸化超过80%24小时诱导细胞周期阻滞于G1期并降低细胞存活率在HCT116结肠癌细胞KRAS G13D突变中相似浓度能同样有效抑制ERK信号并诱导细胞凋亡RMC-797750–200 nM在Calu-1非小细胞肺癌细胞KRAS G12C突变中可抑制细胞增殖并降低p-ERK和p-AKT水平[2]。值得关注的是RMC-7977AbMoleM54858对NRAS突变如SK-MEL-30黑色素瘤细胞NRAS Q61R和HRAS突变如T24膀胱癌细胞HRAS G12V的细胞系同样具有显著抑制活性IC₅₀值均在纳摩尔级别[2]。与KRAS G12C特异性抑制剂如Sotorasib、Adagrasib相比RMC-7977的优势在于其不受GTP/GDP交换状态限制——G12C抑制剂仅作用于失活态GDP结合态而RMC-7977可同时靶向活性态这在RAS信号持续高激活的肿瘤中尤为重要[3]。肿瘤细胞耐药机制研究是RMC-7977应用的重要方向。KRAS G12C抑制剂处理的部分肿瘤会产生获得性耐药其机理通常涉及RAS信号通路的反馈激活或旁路激活如MET、EGFR扩增而RMC-7977CAS No.2765082-12-8的广谱抑制特性可有效阻断这些代偿性信号。在SotorasibAMG-510耐药细胞系中RMC-7977可恢复对ERK信号的抑制并重新诱导细胞凋亡在KRAS G12D/G12C双突变模型中RMC-7977较G12C单靶点抑制剂展现出更强的抗肿瘤活性[3]。此外RMC-7977还可与SHP2抑制剂如RMC-4630或MEK抑制剂联合使用产生协同效应并克服单药耐药[3]。动物实验层面的数据进一步支持了RMC-7977的体内效力。小鼠胰腺癌移植瘤模型中RMC-7977经小鼠口服给药10–30 mg/kg/day能显著抑制肿瘤生长导致肿瘤组织中p-ERK和Ki67表达降低Cleaved Caspase-3升高在KRAS突变型结直肠癌PDX模型中相似剂量可诱导肿瘤退缩并延长小鼠生存期[2]。小鼠药代动力学研究表明RMC-7977具有良好的口服生物利用度和组织分布特性在肿瘤组织中的浓度显著高于小鼠血浆[2]。细胞实验参考细胞系 RAS-less mouse embryonic fibroblasts (MEFs) introduced with exogenous wild-type or mutant KRAS genes (KRASG12V, KRASG12D, KRASG12C) or BRAF(V600E); Also: NCI-H441 cells (NSCLC, KRASG12V), AsPC-1 cells (PDAC, KRASG12D), Capan-1 cells (PDAC, KRASG12V), HPAC cells (PDAC, KRASG12D)方法RAS-less MEFs were introduced with exogenous wild-type or mutant KRAS genes or BRAF(V600E). Cells were treated with RMC-7977 at varying concentrations for 24 hours. Western blot analysis was performed to assess pERK suppression. For cell proliferation assays, a panel of 183 cancer cell lines was screened at Crown Bioscience. Cells were cultured in methylcellulose and treated in triplicates with serial dilutions of RMC-7977 (top concentration of 1 µM) or DMSO dispensed by a Tecan D300e digital dispenser. Cells were incubated for 120 h, and cell viability was determined according to the manufacturers instructions.浓度3, 10, 30, 100, 300 nM (Western blot in RAS-less MEFs); 0-1 µM (cell viability assay, 8 doses in threefold dilutions starting at 10 µM for PRISM assay); 2.20 nM (AsPC-1 EC50), 2.40 nM (NCI-H441 EC50), 965 nM (Capan-1 EC50), 100 nM (HPAC Western blot)处理时间24 h (Western blot); 120 h (cell viability/proliferation assays); 3-5 days (PDAC cell line proliferation)参考文献Nature. 2024 May;629(8013):919-926.*上述方法来自公开文献仅供相同目的实验参考。如实验目的、材料、方法不同请参考其他文献。动物实验参考动物模型Subcutaneously implanted NCI-H441 CDX model of non-small cell lung cancer (NSCLC, KRASG12V) in BALB/c mice; Also: PDAC, CRC, NSCLC CDX and patient-derived xenograft (PDX) mice models bearing KRASG12X mutations; Capan-1 (KRASG12V) PDAC xenograft model配制10% DMSO, 20% PEG 400, 10% Solutol HS15, and 60% water by volume (for in vivo study); RMC-7977 was dissolved at 10 mM in DMSO as the original stock and stored at −20°C in aliquots剂量10 mg/kg (standard dose); 10, 25, 50 mg/kg (single dose pharmacokinetic study in Capan-1 model)给药处理Oral gavage (p.o.), once daily for 5 days, followed by a 2-day break, totally for 28 days (NCI-H441 model); Oral gavage (p.o.), once daily for 90 days (PDAC, CRC, NSCLC CDX/PDX models); Oral gavage, single dose (10-50 mg/kg, pharmacokinetic study)参考文献 Nature. 2024 May;629(8013):927-936.* 上述方法来自公开文献仅供相同目的实验参考。如实验目的、材料、方法不同请参考其他文献。体内实验的工作液建议现用现配当天使用如在配制过程中出现沉淀、析出现象可以通过超声和或加热的方式助溶。切勿一次性将产品全部溶解。参考文献及鸣谢[1] Hofmann, M. H.; Gmachl, M.; Ramharter, J.; et al. Discovery and Preclinical Characterization of a Highly Potent and Selective Pan-RAS Inhibitor. Cancer Discovery 2024, 14 (6), 1078–1097.[2] Kim, D.; Xue, J. Y.; Zhao, J.; et al. Pan-KRAS inhibitor disables oncogenic signalling and tumour growth. Nature 2023, 619 (7968), 160–166.[3] Ryan, M. B.; Fece de la Cruz, F.; Phat, S.; et al. Vertical pathway inhibition overcomes adaptive feedback resistance to KRAS G12C inhibition. Clinical Cancer Research 2020, 26 (7), 1633–1643.[4] Moore, A. R.; Rosenberg, S. C.; McCormick, F.; et al. RAS-targeted therapies: is the undruggable drugged? Nature Reviews Drug Discovery 2020, 19 (8), 533–552.[5] McCormick, F. KRAS as a Therapeutic Target. Clinical Cancer Research 2015, 21 (8), 1817–1818.