American Association for Cancer Research
10780432ccr202853-sup-247837_2_supp_6752783_qkgmhg.pptx (72.61 kB)

Supplementary Fig. S5 from Proteasome Inhibition Overcomes ALK-TKI Resistance in ALK-Rearranged/TP53-Mutant NSCLC via Noxa Expression

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posted on 2023-03-31, 22:20 authored by Azusa Tanimoto, Shingo Matsumoto, Shinji Takeuchi, Sachiko Arai, Koji Fukuda, Akihiro Nishiyama, Kiyotaka Yoh, Takaya Ikeda, Naoki Furuya, Kazumi Nishino, Yuichiro Ohe, Koichi Goto, Seiji Yano

Kaplan-Meier curves for PFS according to ALK fusion variants in patients who received alectinib as the first TKI treatment. Kaplan-Meier curves for PFS stratified by EML4-ALK variant 1 (v1), variant 3 (v3), variant 2 (v2) and other ALK fusion variants (A) or by variant 1 and non-variant 1 (non-v1) (B).






In ALK-rearranged non–small cell lung cancer (NSCLC), impacts of concomitant genetic alterations on targeted therapies with ALK-tyrosine kinase inhibitors (ALK-TKI) are not yet well understood. Here, we investigated genetic alterations related to ALK-TKI resistance using clinico-genomic data and explored effective therapies to overcome the resistance in preclinical models through the identification of underlying molecular mechanisms. We used integrated clinical and next-generation sequencing data generated in a nationwide lung cancer genome screening project (LC-SCRUM-Japan). ALK-rearranged NSCLC cell lines expressing wild-type or mutant TP53 were used to evaluate cellular apoptosis induced by ALK-TKIs. In 90 patients with ALK-rearranged NSCLC who were treated with a selective ALK-TKI, alectinib, TP53 comutated patients showed significantly worse progression-free survival (PFS) than TP53 wild-type patients [median PFS, 11.7 months (95% confidence interval, CI, 6.3–not reached, NR) vs. NR (23.6–NR); P = 0.0008; HR, 0.33 (95% CI, 0.17–0.65)]. ALK-rearranged NSCLC cell lines that lost p53 function were resistant to alectinib-induced apoptosis, but a proteasome inhibitior, ixazomib, markedly induced apoptosis in the alectinib-treated cells by increasing the expression of a proapoptotic protein, Noxa, which bound to an antiapoptotic protein, Mcl-1. In subcutaneous tumor models, combination of ixazomib and alectinib prominently induced tumor regression and apoptosis even though the tumors were generated from ALK-rearranged NSCLC cells with nonfunctional p53. These clinical and preclinical results indicate concomitant TP53 mutations reduce the efficacy of alectinib for ALK-rearranged NSCLC and the combined use of a proteasome inhibitor with alectinib is a promising therapy for ALK-rearranged/TP53-mutated NSCLC.