EML4-ALK G1202R mutation induces EMT and confers resistance to ceritinib in NSCLC cells via activation of STAT3/Slug signaling

The echinoderm microtubule-associated protein-like 4 (EML4)-anaplastic lymphoma kinase (ALK) fusion gene occurs in approximately 5% of non-small-cell lung cancers (NSCLCs). The development of ALK tyrosine kinase inhibitors (ALK-TKIs) is a major advance in treating NSCLC with the ALK fusion gene. Nevertheless, acquired resistance to ALK-TKIs ultimately limits their use. A prevalent mechanism of drug resistance in kinases occurs through the mutation of G1202R in ALK. However, the mechanisms underlying G1202R resistance to ceritinib are not fully understood. Here, we demonstrated that the expression of EML4-ALK G1202R mutation in A549 cells induced an epithelial-mesenchymal transition (EMT) phenotype and significantly increased the migration and invasion abilities. These phenomena may be due to the upregulation of signal transducer and activator of transcription 3 (STAT3), accompanied by the elevated expression of Slug in EML4-ALK G1202R mutant cells. Furthermore, the combination of ALK and STAT3 inhibitors restored the sensitivity of EML4-ALK G1202R mutant cells to ceritinib. In conclusion, these data indicate that the EML4-ALK G1202R mutation mediates the EMT phenotype by activating the STAT3/Slug signaling pathway, resulting in resistance to ceritinib, and that the combination of STAT3 and ALK inhibitors may overcome ALK mutation-driven drug resistance in the clinic. READ ARTICLE

Cellular Signalling DOI:10.1016/j.cellsig.2022.110264

Authors: Jiwei Shen, Yuting Meng, Kunlun Wang, Minghuan Gao, Jianan Du, Junfang Wang, Zengqiang Li, Daiying Zuo, Yingliang Wu

Case StudyKirk SmithApril 1, 2022EML4-ALK G1202R mutation, EMT, STAT3, Slug, Resistance, Ceritinib

Phase separation of EML4–ALK in firing downstream signaling and promoting lung tumorigenesis

Using two genetically engineered mouse models (GEMMs), we find that EML4–ALK variant 1 can drive lung tumorigenesis and these murine tumors, as well as primary tumor-derived organoids, clearly show the condensates of EML4–ALK protein, further supporting the findings from in vitro study. Mutation of multiple aromatic residues in EML4 region significantly impairs the phase separation of EML4–ALK and dampens the activation of the downstream signaling pathways, especially the STAT3 phosphorylation. Importantly, it also significantly decreases cancer malignant transformation and tumor formation. These data together highlight an important role of phase separation in orchestrating EML4–ALK signaling and promoting tumorigenesis, which might provide new clues for the development of clinical therapeutic strategies in treating lung cancer patients with the EML4–ALK fusion. READ ARTICLE

Cell Discovery DOI: 10.1038/s41421-021-00270-5

Authors: Zhen Qin, Honghua Sun, Meiting Yue, Xinwen Pan, Liang Chen, Xinhua Feng, Xiumin Yan, Xueliang Zhu, Hongbin Ji

Pre-ClinicalKirk SmithMay 5, 2021EML4-ALK fusion, variant 1, STAT3

A novel model of controlling PD-L1 expression in ALK+ anaplastic large cell lymphoma revealed by CRISPR screening

The success of programmed cell death protein 1 (PD-1)/PD-L1-based immunotherapy highlights the critical role played by PD-L1 in cancer progression and reveals an urgent need to develop new approaches to attenuate PD-L1 function by gaining insight into how its expression is controlled. Anaplastic lymphoma kinase (ALK)-positive anaplastic large-cell lymphoma (ALK+ ALCL) expresses a high level of PD-L1 as a result of the constitutive activation of multiple oncogenic signaling pathways downstream of ALK activity, making it an excellent model in which to define the signaling processes responsible for PD-L1 upregulation in tumor cells. Here, using clustered regularly interspaced short palindromic repeats (CRISPR)/Cas9 library screening, we sought a comprehensive understanding of the molecular effectors required for PD-L1 regulation in ALK+ ALCL. Indeed, we determined that PD-L1 induction is dependent on the nucleophosmin-ALK oncoprotein activation of STAT3, as well as a signalosome containin..... READ ARTICLE

Blood DOI:10.1182/blood.2019001043

Authors: Jing-Ping Zhang, Zhihui Song, Hong-Bo Wang, Lang Lang, Yuan-Zhong Yang, Wenming Xiao, Daniel E. Webster, Wei Wei, Stefan K. Barta, Marshall E. Kadin, Louis M. Staudt, Masao Nakagawa,Yibin Yang