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 ... -  《-》

Concomitant TP53 mutations with response to crizotinib treatment in patients with ALK-rearranged non-small-cell lung cancer.

TP53 mutations are the most prevalent mutations detected in non-small-cell lung cancer (NSCLC) and have been revealed as a negative prognostic biomarker of outcome. The impact of concomitant TP53 mutations in ALK-rearranged NSCLC remains uncertain. Tumor samples from 64 ALK-rearranged NSCLC patients receiving crizotinib treatment were subjected to next-generation sequencing (NGS) to identify TP53 mutational status. The clinicopathologic features of the TP53 mutations and its impact on the effect of crizotinib treatment were analyzed. Among the 64 ALK-rearranged patients, 15 (23.4%) patients showed a TP53 mutation. Of these, six cases had disruptive mutations and nine with nondisruptive mutations. The objective response rate (ORR) and disease control rate (DCR) for TP53 mutated patients were both significantly lower compared with those for TP53 wild-type patients (p = 0.003 and 0.023, respectively). A significantly shorter progression-free survival (PFS) was found in TP53 mutated patients compared with TP53 wild-type patients (p = 0.045). Nondisruptive TP53 mutations were associated with a shorter PFS in comparison with disruptive TP53 mutations in ALK-rearranged patients (p = 0.069). When nondisruptive TP53 mutated patients were in comparison with TP53 wild-type patients, nondisruptive TP53 mutations were associated with a significant reduced PFS (p = 0.003). TP53 mutations, especially nondisruptive mutations, negatively affected the response to crizotinib and correlated with shorter PFS in ALK-rearranged NSCLC patients.

Song P ，Zhang F ，Li Y ，Yang G ，Li W ，Ying J ，Gao S ... -  《Cancer Medicine》

Acquired Resistance to Alectinib in ALK-Rearranged Lung Cancer due to ABCC11/MRP8 Overexpression in a Clinically Paired Resistance Model.

Alectinib is used as a first-line treatment for anaplastic lymphoma kinase (ALK)-rearranged non-small cell lung cancer (NSCLC). Whereas other ALK inhibitors have been reported to be involved in resistance to ATP-binding cassette (ABC) transporters, no data are available regarding the association between resistance to alectinib and ABC-transporters. To investigate whether ABC-transporters contribute to alectinib resistance, ABC-transporter expression in alectinib-resistant cell lines derived from a patient with ALK-rearranged NSCLC and from H2228 lung cancer cells was evaluated and compared with that in each parent cell type. ATP-binding cassette subfamily C member 11 (ABCC11) expression was significantly increased in alectinib-resistant cell lines compared with that in alectinib-sensitive lines. ABCC11 inhibition increased sensitivity to alectinib in vitro ABCC11-overexpressing cells were established by transfection of an ABCC11 expression vector into H2228 cells, while control cells were established by transfecting H2228 cells with an empty vector. ABCC11-overexpressing cells exhibited decreased sensitivity to alectinib compared with that of control cells in vitro Moreover, the tumor growth rate following alectinib treatment was higher in ABCC11-overexpressing cells than that in control cells in vivo In addition, the intracellular alectinib concentration following exposure to 100 nmol/L alectinib was significantly lower in the ABCC11-overexpressing cell line compared with that in control cells. This is the first preclinical evidence showing that ABCC11 expression may be involved in acquired resistance to alectinib.

Funazo T ，Tsuji T ，Ozasa H ，Furugaki K ，Yoshimura Y ，Oguri T ，Ajimizu H ，Yasuda Y ，Nomizo T ，Sakamori Y ，Yoshida H ，Kim YH ，Hirai T ... -  《-》

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 ... -  《-》

Clinical Management of Non-Small Cell Lung Cancer with Concomitant EGFR Mutations and ALK Rearrangements: Efficacy of EGFR Tyrosine Kinase Inhibitors and Crizotinib.

Zhao Y ，Wang S ，Zhang B ，Qiao R ，Xu J ，Zhang L ，Zhang Y ，Han B ... -  《-》