Identification of a High-Level MET Amplification in CTCs and cfTNA of an ALK-Positive NSCLC Patient Developing Evasive Resistance to Crizotinib

We report the case of a 47-year-old female patient with stage IV NSCLC harboring an echinoderm microtubule associated protein like 4 (EML4)-ALK E20;A20 fusion who was initially treated with four cycles of platinum/pemetrexed until progressive disease. Thereafter, she was treated with crizotinib for 9 months until development of evasive resistance. Subsequently, the patient was primarily resistant to alectinib and ceritinib.
We obtained low-pass copy number profiles of single isolated CTCs after the patient had experienced development of evasive resistance to crizotinib and shown primary resistance to alectinib. Furthermore, we generated additional copy number profiles of CTCs upon development of primary resistance to ceritinib. These analyses revealed the presence of an approximately eightfold MNNG HOS Transforming gene (MET) amplification in all evaluable CTCs at both time points. MET amplification (∼sevenfold) could also be detected in the cfTNA at comparable time points.
This study ..... READ ARTICLE

Journal of Thoracic Oncology
DOI:10.1016/j.jtho.2018.08.2025

Authors: Lars-Arne Berger, Melanie Janning, Janna-Lisa Velthaus, Isabel Ben-Batalla, Stefanie Schatz, Markus Falk, Peter Iglauer, Ronald Simon, Ru Cao, Claudio Forcato, Nicolò Manaresi, Kelli Bramlett, Genny Buson, Annkathrin Hanssen, Markus Tiemann, Guido Sauter, Carsten Bokemeyer, Sabine Riethdorf, Martin Reck, Klaus Pantel, Harriet Wikman, and Sonja Loges

Case Study, group2Kirk SmithNovember 29, 2021Crizotinib, Resistance, MET amplification

Comparative efficacy and safety of first-line treatments for advanced non-small cell lung cancer with ALK-rearranged: a meta-analysis of clinical trials

Background
Whereas there are many pharmacological interventions prescribed for patients with advanced anaplastic lymphoma kinase (ALK)- rearranged non-small cell lung cancer (NSCLC), comparative data between novel generation ALK-tyrosine kinase inhibitors (TKIs) remain scant. Here, we indirectly compared the efficacy and safety of first-line systemic therapeutic options used for the treatment of ALK-rearranged NSCLC.

Methods
We included all phase 2 and 3 randomised controlled trials (RCTs) comparing any two or three treatment options. Eligible studies reported at least one of the following outcomes: progression free survival (PFS), overall survival (OS), objective response rate (ORR), or adverse events of grade 3 or higher (Grade ≥ 3 AEs). Subgroup analysis was conducted according to central nervous system (CNS) metastases.

Results
A total of 9 RCTs consisting of 2484 patients with 8 treatment options were included in the systematic review. Our analysis showed that alectinib (300 mg an..... READ ARTICLE

BMC Cancer DOI:10.1186/s12885-021-08977-0

Authors: Ma HC, Liu YH, Ding KL, Liu YF, Zhao WJ, Zhu YJ, Chang XS, Chen YD, Xiao ZZ, Yu YY, Zhou R, Zhang HB.

Review Paper, group2Kirk SmithNovember 25, 2021ALK, NSCLC, First-line treatment, clinical trial meta-analysis

Structural basis for ligand reception by anaplastic lymphoma kinase

The proto-oncogene ALK encodes anaplastic lymphoma kinase, a receptor tyrosine kinase that is expressed primarily in the developing nervous system. After development, ALK activity is associated with learning and memory1 and controls energy expenditure, and inhibition of ALK can prevent diet-induced obesity2. Aberrant ALK signalling causes numerous cancers3. In particular, full-length ALK is an important driver in paediatric neuroblastoma4,5, in which it is either mutated6 or activated by ligand7. Here we report crystal structures of the extracellular glycine-rich domain (GRD) of ALK, which regulates receptor activity by binding to activating peptides8,9. Fusing the ALK GRD to its ligand enabled us to capture a dimeric receptor complex that reveals how ALK responds to its regulatory ligands. We show that repetitive glycines in the GRD form rigid helices that separate the major ligand-binding site from a distal polyglycine extension loop (PXL) that mediates ALK dimerization. The PXL of o..... READ ARTICLE

Nature DOI:10.1038/s41586-021-04141-7

Authors: Tongqing Li, Steven E. Stayrook, Yuko Tsutsui, Jianan Zhang, Yueyue Wang, Hengyi Li, Andrew Proffitt, Stefan G. Krimmer, Mansoor Ahmed, Olivia Belliveau, Ian X. Walker, Krishna C. Mudumbi, Yoshihisa Suzuki, Irit Lax, Diego Alvarado, Mark A. Lemmon, Joseph Schlessinger & Daryl E. Klein

Pre-Clinical, group2Kirk SmithNovember 24, 2021Antibody therapy, CNS cancer, Kinases, X-ray crystallography

Prognostic Markers of Survival among Japanese Patients with Anaplastic Lymphoma Kinase-Positive Non-Small-Cell Lung Cancer Receiving First-Line Alectinib.

The prognoses of patients with non-small-cell lung cancer (NSCLC) harboring anaplastic lymphoma kinase (ALK) gene rearrangement have dramatically improved with the use of ALK tyrosine kinase inhibitors. Although immunological and nutritional markers have been investigated to predict outcomes in patients with several cancers, their usefulness in targeted therapies is scarce, and their significance has never been reported in patients receiving first-line treatment with alectinib. Mean-while, neutrophil-to-lymphocyte ratio and platelet-to-lymphocyte ratio (PLR) has been investigated during crizotinib treatment. This multicenter retrospective study evaluated 42 consecutive Japanese patients with ALK-positive NSCLC who received first-line treatment with alectinib. Immunological and nutritional markers were evaluated at baseline and 3 weeks after alectinib introduction, and their significance in predicting progression-free survival (PFS) was explored. PFS duration was significantly associat..... READ ARTICLE

Diagnostics DOI:10.3390/diagnostics11122170

Authors: Takeda T, Yamada T, Tanimura K, Nakano T, Ishida M, Tachibana Y, Shiotsu S, Horiuchi S, Hibino M, Okada A, Chihara Y, Takayama K.

ALKtALK with Dr Schurgin: Coping Through the Holidays

Battling cancer and simultaneously celebrating the holidays can be tricky waters to navigate. While feeling grateful to continue traditions with family and friends many also experience being overwhelmed, anxious or depressed. This ALKtALK not only validates these feelings, but provides coping skills to help survive and thrive during this upcoming holiday season. WATCH VIDEO

ALK Positive Inc.

AUTHOR: Dr. Schurgin

Video, group2Kirk SmithNovember 23, 2021

Genetic landscape of patients with ALK-rearranged non-small-cell lung cancer (NSCLC) and response to ceritinib in ASCEND-1 study

Objectives: To better understand genetic determinants of response to ceritinib, an exploratory analysis was conducted using tumor biopsies from anaplastic lymphoma kinase (ALK)-rearranged (ALK+) non-small-cell lung cancer (NSCLC) patients treated with ceritinib at doses of ≥ 300 mg in the ASCEND-1 study. Conclusions: This exploratory analysis highlights the potential role of NGS in improving our understanding of response and resistance to ceritinib. It also illustrates that ceritinib is active against almost all ALK resistance mutations found in ALKi-pretreated patients. READ ARTICLE

Lung Cancer DOI:10.1016/j.lungcan.2021.11.007

Authors: D S-W Tan, M Thomas, D-W Kim, S Szpakowski, P Urban, R Mehra, L Q M Chow, S Sharma, B J Solomon, E Felip, D R Camidge, J Vansteenkiste, L Petruzzelli, S Pantano, A T Shaw

P8-133: Clinical course of the patients who survived more than five-years in patients with EGFR mutated OR ALK rearranged advanced non-small cell lung cancer (NSCLC)

Background and Aims: The discovery of driver oncogenes like EGFR mutation and ALK fusion gene, and the development of their specific inhibitors have improved prognosis of NSCLC patients. Because the patients had been followed up to about 5 years in most of the clinical trials, the long-term clinical course especially after 5 years has been undefined. The object is to know clinical course after 5 years from the first chemotherapy, and to investigate factors that lead to long-term survival.
Methods: One hundred seventy-seven patients with EGFR mutated or ALK rearranged advanced NSCLC who received the first chemotherapy between December 2008 and September 2015 were included. Kaplan Meier curves were drawn for the total cohort and for the subgroups of characteristics and metastases.
Results: Median OS in the total cohort was 40.6 months, the 1-year survival rate was 89 %, the 3-year survival rate was 54 %, and the 5-year survival rate was 28 %. “Long tail” in OS curve existed, but most of ..... READ ARTICLE

Respirology DOI:10.1111/resp.14150_645

Authors: Shoko Shimamura, Takehito Shukuya, Tetsuhiko Asao, Daisuke Hayakawa, Kana Kurokawa, Shiting Xu, Yoichiro Mitsuishi, Ken Tajima, Rina Shibayama, Naoko Shimada, Fumiyuki Takahashi, Kazuhisa Takahashi

Conference PaperKirk SmithNovember 19, 2021EGFR, ALK, 5 years+

P8-170: A patient with ALK translocation-positive lung adenocarcinoma in whom an EGFR mutation developed during the treatment with ALK inhibitors

Background: Generally, ALK gene translocation and EGFR gene mutation are mutually exclusive in non-small cell lung cancer (NSCLC). We present a patient with ALK translocation-positive lung adenocarcinoma in whom an EGFR mutation developed during the treatment with an ALK inhibitors.

Case Presentation: A 70-year-old man was diagnosed with Stage IVb (cT2N3M1c) adenocarcinoma of the lung in July 20XX-8. Initial chemotherapy with CDDP+PEM was started in August, and 6 courses were performed with best response of PR. Maintenance therapy was performed for 26 courses. In May 20XX-5, multiple bone metastases emerged and 5 courses of DTX was given as the 2nd-line chemotherapy from July 20XX-5 to May 20XX-4 with the best response of SD until bone metastases developed. A trans-bronchial re-biopsy of the primary tumor in the upper lobe of the right lung revealed the translocation of ALK gene. Crizotinib was started in June as the 3rd-line chemotherapy. In August 20XX-3, multiple brain metastases de..... READ ARTICLE

Respirology DOI:10.1111/resp.14150_682

Authors: Misaki Morishita, Yoshiki Negi, Taiichiro Otsuki, Koji Mikami, Eisuke Shibata, Daisuke Horio, Maiko Niki, Akio Tada, Mayuko Tokuda, Jotaro Kiyota, Toshiyuki Minami, Ryo Takahashi, Takashi Yokoi, Kozo Kuribayashi, Takashi Kijima

Conference PaperKirk SmithNovember 19, 2021ALK and EGFR co-mutation, ALK, EGFR, Co-mutation

The impact of the ALK fusion variant on clinical outcomes in EML4-ALK patients with NSCLC: a systematic review and meta-analysis

Background: Recent studies showed that ALK-fusion variants are associated with heterogeneous clinical outcomes. However, contradictory conclusions have been drawn in other studies showing no correlation between ALK variants and prognoses. Methods: A systematic review and meta-analysis was performed to evaluate the prognostic value of EML4-ALK fusion variants for patient outcomes. Results: 28 studies were included in the analysis. According to the pooled results, patients harboring variant 1 showed equivalent progression-free survival (PFS) and overall survival (OS) with non-v1 patients (hazard ratio [HR] for PFS: 0.91 [0.68–1.21]; p = 0.499; OS: 1.12 [0.73–1.72]; p = 0.610). Similarly, patients with v3 showed the same disease progress as non-v3 patients (pooled HR for PFS = 1.07 [0.72–1.58]; p = 0.741). However, pooled results for OS suggested that patients with v3 had worse survival than non-v3 patients (HR = 3.44 [1.42–8.35]; p = 0.006). Conclusion: Results suggest that patients with..... READ ARTICLE

Future Oncology DOI:10.2217/fon-2021-0945

Authors: Wang S, Luo R, Shi Y, Han X.

Review Paper, group2Kirk SmithNovember 16, 2021ALK fusion, ALK rearrangement, ALK variant, NSCLC, prognosis

Prevalence and Clinicopathologic Risk Factors for Epidermal Growth Factor Receptor, Anaplastic Lymphoma Kinase, and ROS-1 Fusion in Metastatic Non-small Cell Lung Carcinoma

The purpose of he study was to evaluate the prevalence of epidermal growth factor receptor (EGFR) mutations, anaplastic lymphoma kinase (ALK), and ROS-1 fusions in the patients with metastatic nonsquamous nonsmall cell lung carcinoma (NSCLC) and their relation with different demographic and clinical variables. Methods: A cross-sectional study was carried out on 87 adult patients >18 years of age with a confirmed diagnosis of Stage IV metastatic NSCLC. All the patients were studied for EGFR mutations, ALK, and ROS-1 fusions. The outcome measures were the presence of EGFR, ALK, and ROS-1 fusions among the patients with NSCLC and the risk association with age, gender, smoking, and tumor differentiation. Results: Out of 87 patients, 26 (29.89%) patients tested positive for EGFR mutations, 4 (4.6%) for ALK, and a single case for ROS-1 fusion. The mean age of the patients who were EGFR positive was significantly younger than the mean age of those without EGFR mutation (56.77 ± 12.01 vs. 66.6..... READ ARTICLE

Journal of Radiation and Cancer Research DOI:10.4103/jrcr.jrcr_43_21

Authors: Raghav Kesri, Hari Goyal, Geetanjali Gupta, Deepak Bharti and Richu Sharma

Discovery of 2,4-pyrimidinediamine derivatives as potent dual inhibitors of ALK and HDAC

Combination of anaplastic lymphoma kinase (ALK) inhibitor with histone deacetylases (HDAC) inhibitor could exert synergistically anti-proliferative effects on ALK positive non-small cell lung cancer (NSCLC) naïve or resistant cells. In this work, we designed and synthesized a series of 2,4-pyrimidinediamine derivatives as dual ALK and HDAC inhibitors based on pharmacophore merged strategy. Among which, compound 10f displayed the most potent and balanced inhibitory activity against ALK (IC50 = 2.1 nM) and HDAC1 (IC50 = 7.9 nM), respectively. In particular, 10f was also potent against the frequently observed Crizotinib-resistant ALKL1196M (IC50 = 1.7 nM) as well as the Ceritinib-resistant ALKG1202R (IC50 = 0.4 nM) mutants. In antiproliferative activity assay, 10f exhibited impressive activity on ALK-addicted cancer cell lines at low micromole concentrations, which was comparable to that of Crizotinib and Ceritinib. Further flow cytometric analysis indicated that 10f could effectively ind..... READ ARTICLE

European Journal of Medicinal Chemistry DOI:10.1016/j.ejmech.2021.113672

Authors: Tao Pan, Yanrong Dan, Dafeng Guo, Junhao Jiang, Dongzhi Ran, Lin Zhang, Binghua Tian, Jianyong Yuan, Yu Yu, Zongjie Gan

Pre-Clinical, group2Kirk SmithNovember 15, 2021ALK/HDAC dual Inhibitors, Pharmacophore merged strategy, NSCLC

Multiscale profiling of enzyme activity in cancer

Diverse processes in cancer are mediated by enzymes, which most proximally exert their function through their activity. Methods to quantify enzyme activity, rather than just expression, are therefore critical to our ability to understand the pathological roles of enzymes in cancer and to harness this class of biomolecules as diagnostic and therapeutic targets. Here we present an integrated set of methods for measuring specific enzyme activities across the organism, tissue, and cellular levels, which we unify into a methodological hierarchy to facilitate biological discovery. We focus on proteases for method development and validate our approach through the study of tumor progression and treatment response in an autochthonous model of Alk-mutant lung cancer. To quantitatively measure activity dynamics over time, we engineered multiplexed, peptide-based nanosensors to query protease activity in vivo. Machine learning analysis of sensor measurements revealed dramatic protease dysregulatio..... READ ARTICLE

BioRxiv DOI:10.1101/2021.11.11.468288

Authors: Ava P. Soleimany, Jesse D. Kirkpatrick, Cathy S. Wang, Alex M. Jaeger, Susan Su, Santiago Naranjo, Qian Zhong, Christina M. Cabana, Tyler Jacks, Sangeeta N. Bhatia

Review Paper, group2Kirk SmithNovember 12, 2021Multiscale profiling, enzyme activity, cancer

Anaplastic lymphoma kinase rearrangement prevalence in patients with advanced non-small cell lung cancer in the United States: retrospective real world data

This study assessed the prevalence of anaplastic lymphoma kinase (ALK) rearrangements in US oncology practices. The cohort included 19,895 eligible patients with a mean age 68.5 years, majority ever-smokers (85.5%) and from community centers (92.2%). The overall ALK rearrangement prevalence was 2.6%. Positivity rate varied by histology and smoking status; it was the highest among non-smoking patients with non-squamous histology (9.3%). Differences in ALK status also varied by age and race, with young patients (18–39 years) having a higher prevalence (21.6%) vs. older patients (age ≥55 = 2.2%); Asian patients had a prevalence of 6.3%. Patients that were positive for other mutations or rearrangements had a lower ALK positivity rate (0.5%) and patients positive for PD-L1 had a rate of 3.0%. Conclusion: The likelihood of finding an ALK translocation was highest in younger patients and nonsmokers; however, age and smoking history were not discriminative enough to exclude testing based on cl..... READ ARTICLE

Oncotarget DOI:10.18632/oncotarget.28114

Authors: Allen T. Craig, Xiao Y., Yang B., Croix D., Abraham A., Redpath S., Engstrom-Melynk J., Shah R., Madala J., Bernicker E. H.

Real-World OutcomesKirk SmithNovember 9, 2021lorlatinib, NSCLC, post-progression treatment, RECIST 1.1

Efficacy and Safety of First-Line Treatment Strategies for Anaplastic Lymphoma Kinase-Positive Non-Small Cell Lung Cancer: A Bayesian Network Meta-Analysis

Background: Targeted therapies have led to significant improvement in the management and prognosis of anaplastic lymphoma kinase (ALK)-positive non-small cell lung cancer (NSCLC). We performed a network meta-analysis of frontline treatment options of ALK-positive NSCLC to provide clinical guidance.
Conclusions: Lorlatinib is associated with the highest PFS benefit and lowest risk of CNS progression benefits for patients with advanced ALK-positive NSCLC, compared with other first-line treatments, but with higher toxicity. The implementation of a newer generation of ALK-TKIs in the first-line treatment of ALK-positive NSCLC into current clinical practice is evolving rapidly. READ ARTICLE

Frontiers in Oncology DOI:10.3389/fonc.2021.754768

Authors: Ling Peng, Dafeng Lu2, Yang Xia, Shaodong Hong, Giovanni Selvaggi, Justin Stebbing, Yilan Sun, Fei Liang

Epithelioid inflammatory myofibroblastic sarcoma with VCL-ALK fusion of central nervous system: case report and brief review of the literature

Epithelioid inflammatory myofibroblastic sarcomas are an aggressive variant of inflammatory myofibroblastic tumor described primarily in the abdomen and less commonly in pulmonary location. The anaplastic lymphoma kinase (ALK) fusion partners described in this tumor include RANB2, RRBP1 and EML4. While rare examples of inflammatory myofibroblastic tumors have been described in the central nervous system, the epithelioid variant has never been described. The ALK-VCL fusion has been described in renal cell carcinoma, high-grade glioma and epithelioid fibrous histiocytoma but has not been described in epithelioid inflammatory myofibroblastic sarcoma or even inflammatory myofibroblastic tumor. Herein, we report the first case of epithelioid inflammatory myofibroblastic sarcoma in the central nervous system as well as the first case with VCL as the fusion partner for ALK. READ ARTICLE

Brain Tumor Pathology DOI:10.1007/s10014-021-00416-z

Authors: Shefali Chopra, Nolan Maloney & Wei Lien Wang

Hexokinases II-mediated glycolysis governs susceptibility to crizotinib in ALK-positive non-small cell lung cancer

Background

Activation of ALK leads to a high level of aerobic glycolysis related to crizotinib insensitivity in anaplastic lymphoma kinase-positive non-small cell lung cancer (ALK+ NSCLC). The strategy and mechanism of glycolysis inhibition in sensitizing ALK+ NSCLC cells to crizotinib requires further investigation.
Methods

The levels of glycolysis in H3122 and H2228 cells were evaluated through detection of glucose consumption and lactate production. MTT assay was used to explore the effects of glycolytic inhibitors on crizotinib sensitivity, and the potential mechanism of action were detected by colony formation, Ki67 incorporation assay, transwell assay, small interfering RNA technology and western blot analysis.
Results

ALK+ NSCLC cells exhibited significantly higher levels of glycolysis compared to ALK− NSCLC cells. Long-term exposure to crizotinib could decrease the sensitivity of ALK+ NSCLC cells to crizotinib via increasing the levels of glycolysis related to hexokinases I..... READ ARTICLE

Thoracic Cancer DOI:10.1111/1759-7714.14184

Authors: Caiyu Lin, Hengyi Chen, Rui Han, Li Li, Conghua Lu, Shuai Hao, Yubo Wang, Yong He

Pre-Clinical, group2Kirk SmithNovember 2, 20212DG, glycolysis, anaplastic lymphoma kinase (ALK), crizotinib

A Case of Small Cell Lung Carcinoma Harboring an EML4–ALK Fusion with Partial Response to Crizotinib

Clinical Practice Points: •A patient with metastatic small cell lung cancer (SCLC) had an echinoderm microtubule-associated protein-like 4 (EML4)–anaplastic lymphoma kinase (ALK) fusion.
•He had a partial response to crizotinib in the primary lesions.
•ALK tyrosine kinase inhibitors should be considered in SCLC patients with EML4–ALK fusions.
•Gene testing should be performed in young SCLC patients with a limited smoking history. READ ARTICLE

Clinical Lung Cancer DOI:10.1016/j.cllc.2021.03.012

Authors: Qian Shen, Farhin Shaheed Kalyani, Jingjing Qu, Zhen Chen, Jing Zhang, Jianying Zhou

Case StudyKirk SmithNovember 1, 2021SCLC, EML4-ALK, Crizotinib, Partial response, Gene testing

Novel treatment of endobronchial inflammatory myofibroblastic tumor in a child

Isolated endobronchial inflammatory myofibroblatic tumors (IMT) are rare, accounting for about 1% of primary endobronchial tumors in children. The mainstay of treatment for this tumor has been surgical resection. Recently, the identification of anaplastic lymphoma kinase (ALK) gene mutations in half of the IMTs and promising results of treatment with ALK inhibitors in other ALK-positive tumors have opened the possibility of alternative approaches. We present a 4-year-old child with an ALK-positive endobronchial IMT, treated with endoscopic resection and neoadjuvant therapy with Crizotinib, without evidence of tumor recurrence 2 years after the initial resection. READ ARTICLE

Pediatric Pulmonology DOI:10.1097/CAD.0000000000001224

Authors: Jessica Reyes-Angel, Louis B. Rapkin, Jeffrey P. Simons and Hiren Muzumdar

A focal adhesion kinase-YAP signaling axis drives drug tolerant persister cells and residual disease in lung cancer

Targeted therapy is effective in many tumor types including lung cancer, the leading cause of cancer mortality. Paradigm defining examples are targeted therapies directed against non-small cell lung cancer (NSCLC) subtypes with oncogenic alterations in EGFR, ALK and KRAS. The success of targeted therapy is limited by drug-tolerant tumor cells which withstand and adapt to treatment and comprise the residual disease state that is typical during treatment with clinical targeted therapies. Here, we integrate studies in patient-derived and immunocompetent lung cancer models and clinical specimens obtained from patients on targeted therapy to uncover a focal adhesion kinase (FAK)-YAP signaling axis that promotes residual disease during oncogenic EGFR-, ALK-, and KRAS-targeted therapies. FAK-YAP signaling inhibition combined with the primary targeted therapy suppressed residual drug-tolerant cells and enhanced tumor responses. This study unveils a FAK-YAP signaling module that promotes residu..... READ ARTICLE

BioRxiv DOI:10.1101/2021.10.23.465573

Authors: Franziska Haderk, Celia Fernández-Méndez, Lauren Čech, Johnny Yu, Ismail M. Meraz, Victor Olivas, Dora Barbosa Rabago, D. Lucas Kerr, Carlos Gomez, David V. Allegakoen, Juan Guan, Khyati N. Shah, Kari A. Herrington, Oghenekevwe M. Gbenedio, Shigeki Nanjo, Mourad Majidi, Whitney Tamaki, Julia K. Rotow, Caroline E. McCoach, Jonathan W. Riess, J. Silvio Gutkind, Tracy T. Tang, Leonard Post, Bo Huang, Pilar Santisteban, Hani Goodarzi, Sourav Bandyopadhyay, Calvin J. Kuo, Jeroen P. Roose, Wei Wu, Collin M. Blakely, Jack A. Roth, Trever G. Bivona

Phase-separated foci of EML4-ALK facilitate signalling and depend upon an active kinase conformation

Variants of the oncogenic EML4-ALK fusion protein contain a similar region of ALK encompassing the kinase domain, but different portions of EML4. Here, we show that EML4-ALK V1 and V3 proteins form cytoplasmic foci that contain components of the MAPK, PLCγ and PI3K signalling pathways. The ALK inhibitors ceritinib and lorlatinib dissolve these foci and EML4-ALK V3 but not V1 protein re-localises to microtubules, an effect recapitulated in a catalytically inactive EML4-ALK mutant. Mutations that promote a constitutively active ALK stabilise the cytoplasmic foci even in the presence of these inhibitors. In contrast, the inhibitor alectinib increases foci formation of both wild-type and catalytically inactive EML4-ALK V3 proteins, but not a Lys-Glu salt bridge mutant. We propose that EML4-ALK foci formation occurs as a result of transient association of stable EML4-ALK trimers mediated through an active conformation of the ALK kinase domain. Our results demonstrate the formation of EML4-A..... READ ARTICLE

EMBO Reports DOI:10.15252/embr.202153693

Authors: Josephina Sampson, Mark W Richards, Jene Choi, Andrew M Fry, Richard Bayliss

Pre-Clinical, group2Kirk SmithOctober 18, 2021EML4-ALK fusion protein, variants, inhibitors, cytoplasmic foci