AURKA/PHB2 signaling drives acquired resistance to KRAS G12C inhibitors in KRAS G12C -mutant NSCLC
Patients with non-small cell lung cancer (NSCLC) who initially respond to Sotorasib, a drug targeting the KRAS G12C mutation, eventually develop acquired resistance. However, the mechanisms driving this acquired resistance remain largely unclear. This study explored the role of AURKA in mediating resistance to Sotorasib in NSCLC. The expression levels of AURKA mRNA and protein in NSCLC cell lines (H358 and Calu-1) were assessed using qPCR and Western blot. To further elucidate the role of AURKA in the biological alterations of Sotorasib-resistant cells and its association with the PI3K/AKT signaling pathway, a comprehensive set of assays were conducted, including MTS, colony formation, Transwell migration, luciferase reporter assays, fluorescent in situ hybridization (FISH), molecular docking analyses, and immunoprecipitation. The key findings include: (1) Long-term Sotorasib treatment led to upregulation of AURKA; (2) Overexpression of AURKA induced Sotorasib resistance, suppressed apoptosis and promoted migratory potential in Calu-1 and H358 cells, while AURKA knockdown increased the sensitivity, enhanced apoptosis and inhibited migratory capacity of H358-SR and Calu-1-SR cells to Sotorasib; (3) Immunoprecipitation and luciferase reporter assays demonstrated a physical interaction between AURKA and PHB2, establishing a positive feedback loop that sustained malignant behaviors, potentially explaining how Sotorasib-resistant cells survived despite KRAS pathway inhibition; (4) AURKA stabilizes PHB2, activating the PI3K/AKT pathway and allowing cancer cells to bypass the KRAS blockade, thus restoring malignant behavior. (5) The combination of AURKA inhibitor and Sotorasib alleviates the acquired drug resistance in vitro and in vivo. These data suggest that resistance to Sotorasib in NSCLC is associated with a positive feedback loop involving AURKA, PHB2, and PI3K/AKT signaling. AURKA may serve as a biomarker for predicting the therapeutic efficacy of Sotorasib in KRAS G12C-targeted therapies and as a potential therapeutic target to overcome Sotorasib resistance in NSCLC. Overall design: AURKA knockdown cell lines were generated using a lentiviral transduction approach. Cells were adjusted to a final concentration of 1 × 106 cells/mL. Total RNA was extracted and assessed for quality and quantity by agarose gel electrophoresis and NanoDrop spectrophotometry. Poly(A)+ mRNA was enriched using oligo(dT) magnetic beads; for degraded RNA samples or prokaryotic samples, rRNA depletion kits were used instead. RNA sequencing libraries were constructed using commercial kits. Briefly, RNA was fragmented and reverse-transcribed into first-strand cDNA using random primers, followed by second-strand cDNA synthesis incorporating dUTP. The resulting double-stranded cDNA underwent end repair, A-tailing, and ligation with Illumina-compatible adapters, followed by PCR amplification to generate the final libraries. The constructed libraries were quality-checked using an Agilent 2100 Bioanalyzer, quantified by qPCR, and subsequently sequenced on an Illumina NovaSeq 6000 platform.