Inhibition of c-Jun N-terminal kinase signaling increased apoptosis and prevented the emergence of ALK-TKI-tolerant cells in ALK-rearranged non-small cell lung cancer.

Anaplastic lymphoma kinase-tyrosine kinase inhibitors (ALK-TKIs) have improved clinical outcomes in non-small cell lung cancer (NSCLC) harboring ALK- rearrangements. However, a small population of tumor cells survives due to adaptive resistance under drug pressure and ultimately acquires drug resistance. Thus, it is necessary to elucidate the mechanisms underlying the prevention of drug resistance to improve the prognosis of patients with ALK-rearranged NSCLC. We identified novel adaptive resistance, generated through c-Jun N-terminal kinase (JNK)/c-Jun signaling, to initial ALK-TKIs-alectinib and brigatinib-in ALK-rearranged NSCLC. Inhibition of JNK/c-Jun axis showed suppression of growth and promotion of apoptosis induced by ALK-TKIs in drug-tolerant cells. JNK inhibition, in combination with the use of ALK-TKIs, increased cell apoptosis through repression of the Bcl-xL proteins, compared with ALK-TKI monotherapy. Importantly, combination therapy targeting JNK and ALK significantly delayed the regrowth following cessation of these treatments. Together, our results demonstrated that JNK pathway activation plays a pivotal role in the intrinsic resistance to ALK-TKIs and the emergence of ALK-TKI-tolerant cells in ALK-rearranged NSCLC, thus indicating that optimal inhibition of tolerant signals combined with ALK-TKIs may potentially improve the outcome of ALK-rearranged NSCLC.

Tanimura K ，Yamada T ，Horinaka M ，Katayama Y ，Fukui S ，Morimoto K ，Nakano T ，Tokuda S ，Morimoto Y ，Iwasaku M ，Kaneko Y ，Uchino J ，Yoneda K ，Yano S ，Sakai T ，Takayama K ... -  《-》

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

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.

Tanimoto A ，Matsumoto S ，Takeuchi S ，Arai S ，Fukuda K ，Nishiyama A ，Yoh K ，Ikeda T ，Furuya N ，Nishino K ，Ohe Y ，Goto K ，Yano S ... -  《-》

Inflammation-related molecular signatures involved in the anticancer activities of brigatinib as well as the prognosis of EML4-ALK lung adenocarcinoma patient.

Although ALK tyrosine kinase inhibitors (ALK-TKIs) have shown remarkable benefits in EML4-ALK positive NSCLC patients compared to conventional chemotherapy, the optimal sequence of ALK-TKIs treatment remains unclear due to the emergence of primary and acquired resistance and the lack of potential prognostic biomarkers. In this study, we systematically explored the validity of sequential ALK inhibitors (alectinib, lorlatinib, crizotinib, ceritinib and brigatinib) for a heavy-treated patient with EML4-ALK fusion via developing an in vitro and in vivo drug testing system based on patient-derived models. Based on the patient-derived models and clinical responses of the patient, we found that crizotinib might inhibit proliferation of EML4-ALK positive tumors resistant to alectinib and lorlatinib. In addition, NSCLC patients harboring the G1269A mutation, which was identified in alectinib, lorlatinib and crizotinib-resistant NSCLC, showed responsiveness to brigatinib and ceritinib. Transcriptomic analysis revealed that brigatinib suppressed the activation of multiple inflammatory signaling pathways, potentially contributing to its anti-tumor activity. Moreover, we constructed a prognostic model based on the expression of IL6, CXCL1, and CXCL5, providing novel perspectives for predicting prognosis in EML4-ALK positive NSCLC patients. In summary, our results delineate clinical responses of sequential ALK-TKIs treatments and provide insights into the mechanisms underlying the superior effects of brigatinib in patients harboring ALKG1269A mutation and resistant towards alectinib, lorlatinib and crizotinib. The molecular signatures model based on the combination of IL6, CXCL1 and CXCL5 has the potential to predict prognosis of EML4-ALK positive NSCLC patients.

Ge FJ ，Dai XY ，Qiu Y ，Liu XN ，Zeng CM ，Xu XY ，Chen YD ，Zhu H ，He QJ ，Gai RH ，Ma SL ，Chen XQ ，Yang B ... -  《-》

ALTA-2: Phase II study of brigatinib in patients with ALK-positive, advanced non-small-cell lung cancer who progressed on alectinib or ceritinib.

Kim ES ，Barlesi F ，Mok T ，Ahn MJ ，Shen J ，Zhang P ，Ou SI ... -  《-》

ALK Inhibitor and Chemotherapy Combinations in Models of ALK-Translocated NSCLC.

Randomized trials have shown the benefit of combining tyrosine kinase inhibitors (TKI) and chemotherapy in the treatment of epidermal growth factor receptor-mutant non-small-cell lung cancer (NSCLC). For anaplastic lymphoma kinase-rearranged (ALK+) NSCLC, prospective trial results of the combination are not available and have not even been thoroughly investigated in vitro. In this study, we investigated combinations of TKI and chemotherapy using in vitro models of ALK+ NSCLC. ALK+ cell line models H3122, H2228, and DFCI032 with differing primary resistance to ALK receptor TKIs were used. We investigated short-(viability assay) and long-term (colony-formation assay) cytotoxicity, apoptosis, and cell signaling in response to the combinations of agents. We selected the most commonly used agents, alectinib, cisplatin, and pemetrexed, to investigate the combination effects. In the combination experiments with short-term exposure, synergism between TKI and pemetrexed was observed, while cisplatin had antagonistic effects. In the long-term experiments, the combination of cisplatin and TKI was synergistic in all lines, while no synergism was observed with pemetrexed. Among the chemotherapy and TKI sequences, cisplatin followed by TKI was more cytotoxic than the opposite in two out of the three models. In the TKI-sensitive H3122 cell line, the combination of chemotherapy and TKI combination increased apoptosis. Interestingly, pemetrexed treatment resulted in the activation of ALK, which was abolished with TKI. Combining TKI and chemotherapy in ALK+ models has some synergistic effects that overcome primary TKI resistance. However, the synergy varies depending on the chemotherapeutic agent, cytotoxic assay, and the cell line used. Prospective clinical trials are warranted to fully characterize the potential of combination chemotherapy with TKIs in ALK+ NSCLC.

Luukkainen MEK ，Koivunen JP 《-》