Multitargeted kinase inhibitor LCI139 overcomes chemotherapy resistance in patient-derived non small cell lung cancer organoids by harnessing intrinsic and extrinsic apoptosis

Introduction: In-silico designed multitarget inhibitor LCI139 (PI3K-CDK4/6-CDK9-AURKA/B) was engineered to overcome resistance inherent to single-target agents by simultaneously targeting tumor metabolism and inducing robust apoptosis. This compound demonstrated nanomolar potency against NSCLC in vitro. We evaluated efficacy in NSCLC cell lines and patient-derived tumor organoids (PTOs)-biofabricated spherical constructs recapitulating cellular matrix of native tumor tissue. Methods: NSCLC cell lines (NCI-H1703, NCI-H1781) and PTOs generated from unsorted lung tumor suspensions in PEPGEL matrix (n=7) were utilized under IRB-approved protocol. Treatments included LCI139 (0.25-1μM), chemotherapeutics (carboplatin, gemcitabine, pemetrexed, cisplatin), and single-agent inhibitors: PI3K (Buparlisib), CDK4/6 (Ribociclib), CDK9 (AZD4573), AURKA (Barasertib), AURKB (Alisertib). Cell lines were co-treated with inhibitors of (carbenoxolone), Caspase (Casp)-8 (Z-IETD-FMK), Casp-9 (Z-LEHD-FMK), or AMPK activator (PF-06409577). Viability (propidium iodide, CellTiter-Glo), cell cycle (DNA dye) and apoptosis (Annexin-V/7-AAD, Casp-3/7/8/9 activity) were measured. Target inhibition was evaluated immunoblotting for pAkt, pRb, pRNA Pol II, MCL-1, pAMPK, pFOXO3, and p53. Results: LCI139 achieved nanomolar IC 50 against H1703 cells (48hr) and demonstrated dose-dependent PTO cytotoxicity: 49% reduction at 0.25μM, 62% at 0.5μM, 78.4% at 1μM (all p<0.0001). By comparison, 1 μM single-agent inhibitors reduced PTO viability by: AURKA (34%), AURKB (24%), PI3K (29%), CDK9 (50.9%) all p<0.0001; CDK4/6 (6.9%, p=0.43). LCI139 overcame significant carboplatin resistance (IC 50 : 10.25-11.69μM) and outperformed standard chemotherapeutics: gemcitabine (29.2%), cisplatin (28.2%), pemetrexed (no activity). LCI139 activated caspases 8, 9, 3/7 in cells and PTOs. Selective Casp-8 or Casp-9 inhibition diminished but didn't abrogate cytotoxicity. Western blotting confirmed dose-dependent target inhibition: decreased pAKT, pRb, MCL-1, pRNAPol II, and p53 modulation. LCI139 induced metabolic stress via pAMPK-pFoxO3 activation. FoxO3 inhibition diminished LCI139 potency against sensitive H1703 cells. AMPK activation enhanced potency in p53-proficient H1703 and sensitized p53-deficient H1781 cells. Conclusions: LCI139 demonstrates superior anti-tumor activity versus standard chemotherapeutics in resistant NSCLC through dual activation of intrinsic (cell cycle arrest-induced) and extrinsic (metabolic stress-induced) apoptotic pathways. Efficacy in both cell lines and PTOs validates this micro-physiological platform for drug development, supporting translational potential of multitargeted kinase inhibition for overcoming therapeutic resistance, as aligned with FDA guidance.