Targeting HGF/MET and CXCL1/CXCR2 axes bypasses resistance to KRAS inhibitors in NSCLC.

[BACKGROUND] Resistance to KRAS inhibitors sotorasib and adagrasib, approved for KRAS-mutant advanced Non-Small Cell Lung Cancer (NSCLC), involves multiple subclonal events, raising significant concerns about overcoming the resistant phenotype. Cytokines, chemokines, and growth factors are key mediators of drug resistance and targeting their signaling pathways is an emerging strategy in cancer therapy.

[METHODS] We generated cell clones from KRAS-mutated NSCLC cells treated with KRAS inhibitors and cell cultures from a sotorasib-resistant patient-derived xenograft (PDX). Gene mutations and changes in gene expression were evaluated using NGS, RNAseq. The mRNA and protein levels encoded by the Hepatocyte Growth Factor (HGF) and CXCL1 genes were quantified using RT-PCR and ELISA assay. The effect of drug combination was obtained by the Sulforhodamine-B assay and analyzed by Combenefit Software. Cell death was detected by Annexin-V assay. Cell signaling and epithelial-to-mesenchymal transition were evaluated by Western blotting.

[RESULTS] NSCLC cell clones and PDX cell cultures with acquired and intrinsic resistance to KRAS inhibitors exhibited elevated levels of CXCL1 and HGF expression and secretion, with activation of CXCR2 and c-MET signalling pathways. The combination of CXCR2 and c-MET inhibitors led to synergistic inhibition of cell growth and reduced cell viability by inhibiting the ERK1/2 and AKT signalling pathways. This combination also reversed EMT and induced apoptosis in sotorasib- and adagrasib-resistant clones, regardless of the genetic alterations responsible for resistance.

[CONCLUSIONS] CXCL1/CXCR2 and HGF/c-MET may represent compensatory pathways that sustain proliferation and survival in resistance to KRAS inhibitors. The simultaneous blockade of these signals may offer a novel strategy for bypassing resistance.