MYC Amplification as a Potential Mechanism of Primary Resistance to Crizotinib in ALK-Rearranged Non-Small Cell Lung Cancer: A Brief Report

Mechanisms of Resistance to ALK Inhibitors and Corresponding Treatment Strategies in Lung Cancer

Lung cancer continues to be a leading cause of cancer-related mortality and morbidity worldwide. The echinoderm microtubule-associated protein-like 4-anaplastic lymphoma kinase (EML4-ALK) fusion gene accounts for approximately 3%-5% of gene mutation types. Targeted therapies for ALK mutations have made significant advancements in recent decades, enabling a considerable number of patients to achieve the goal of five-year survival benefits. However, overcoming the drug resistance that arises with current ALK tyrosine kinase inhibitors (TKIs) remain a major challenge in ALK-targeted therapies. In this review, we briefly discuss the primary and secondary mechanisms of resistance to ALK-TKIs, and explore treatment strategies based on progressive resistance models. Meanwhile, novel drugs and combination therapies are being actively researched and developed to address these challenges. The aim is to offer new insights into the mechanisms of resistance and the corresponding treatment strategies to ALK inhibitors.

A Poor Prognostic ALK Phenotype: A Review of Molecular Markers of Poor Prognosis in ALK Rearranged Nonsmall Cell Lung Cancer

BACKGROUND

Patients with nonsmall cell lung cancer with anaplastic lymphoma kinase (ALK) rearrangements derive a significant and durable clinical benefit from tyrosine kinase inhibitors (TKIs). However, early progression/death on treatment occurs in a subset of patients, which we term the poor prognostic ALK phenotype. This review aims to summarize the known molecular mechanisms that underlie this phenotype with a focus on variant 3 and TP53 mutations.

METHODS

A scoping review was performed using scientific databases such as Ovid Medline, Ovid Embase, and Cochrane Central Register of Controlled Trials. Studies included molecular markers of poor prognosis, with a focus on TP53 mutations, variant 3 re-arrangements, and poor clinical response to TKIs.

RESULTS

Of 4371 studies screened, 108 were included. Numerous studies implicated a negative prognostic role of variant 3, likely mediated through the acquisition of on-target resistance mutations and TP53 mutations which are associated with greater chromosomal instability and mutational burden. Co-occurring variant 3 and TP53 mutations were associated with even worse survival. Other mediators of early resistance development include aberrations in cell cycle regulators and mutations in cell signaling pathways. Comprehensive genomic analysis from first-line TKI clinical trial data was unable to identify a singular genomic signature that underlies the poor prognostic phenotype but implicated a combination of pathways.

CONCLUSIONS

This scoping review highlights that the poor prognostic ALK phenotype is likely composed of a heterogeneous variety of genomic factors. There remains an unmet need for a genomic assay to integrate these various molecular markers to predict this ALK phenotype.

The Use of Anaplastic Lymphoma Kinase Inhibitors in Non-Small-Cell Lung Cancer Treatment-Literature Review

Lung cancer is the leading cause of cancer-related morbidity and mortality. The median survival time for patients with advanced non-small-cell lung cancer before the era of molecular-based personalized treatment was 7.9 months. The discovery of predictive factors and the introduction of molecular diagnostics into daily practice made a breakthrough, enabling several years of survival in patients with advanced disease. The discovery of rearrangements in the ALK gene and ALK tyrosine kinase inhibitors has resulted in a dramatic improvement in the prognosis of patients with this subtype of cancer. Currently, three generations of ALK inhibitors differing in activity, toxicity and degree of penetration into the central nervous system are available in clinical practice. The current state of knowledge on ALK inhibitors used in clinical practice is summarised in this research paper. Methods of diagnosis of abnormalities in ALK have been shown, and the review of research that contributed to the development of the next generation of ALK inhibitors has been presented.

Clinical difference on the variants and co-mutation in a Chinese cohort with ALK-positive advanced non-small cell lung cancer

PURPOSE

Despite the generally favourable prognoses observed in patients with ALK-positive non-small cell lung cancer (NSCLC), there remains significant variability in clinical outcomes. The objective of this study is to enhance patient stratification by examining both the specific sites of gene fusion and the presence of co-occurring mutations.

METHODS

We collected retrospective clinical and pathological data on ALK-positive patients with locally advanced or metastatic disease. ALK fusion variants and concomitant mutations were identified through next-generation sequencing technology. We then assessed treatment efficacy via tumor response and survival metrics.

RESULTS

This study included a total of 59 patients, with 49 harboring echinoderm microtubule-associated protein-like 4 (EML4)-ALK fusions and 10 presenting with rare fusions. The median follow-up period was 33 months. Clinical outcomes between non-EML4-ALK and EML4-ALK patients were comparable. Among the EML4-ALK cohort, patients with longer variants (v1, v2, v8) demonstrated superior progression-free survival (PFS) (median PFS: 34 months vs. 11 months; hazard ratio [HR]: 2.28; P = 0.05) compared to those with shorter variants (v3, v5). Furthermore, patients treated with second-generation ALK inhibitors (ALKi) displayed a progression-free survival advantage (median PFS: not reached [NR] vs. 9 months; HR: 5.37; P = 0.013). Baseline TP53 co-mutation were linked with a substantially shorter OS (median OS,37 months vs. NR; HR 2.74; P = 0.047).

CONCLUSIONS

In ALK+ NSCLC, longer EML4-ALK variants correlate with improved prognosis and enhanced response to second-generation ALKi, while TP53 co-mutations indicate a negative prognosis.

ALK-tyrosine kinase inhibitor intrinsic resistance due to de novo MET-amplification in metastatic ALK-rearranged non-small cell lung cancer effectively treated by alectinib-crizotinib combination-case report

Background

Most patients with advanced anaplastic lymphoma kinase (ALK)-rearranged (ALK+) non-small cell lung cancer (NSCLC) experience prolonged response to second-generation (2G) ALK-tyrosine kinase inhibitors (TKIs). Herein, we present a case of metastatic ALK+ NSCLC rapidly progressing on first-line treatment due to de novo amplification of the mesenchymal-epithelial transition factor (MET) gene, which is a still elusive and underrecognized mechanism of primary resistance to ALK-TKIs.

Case Description

A 43-year-old, female diagnosed with T4N3M1c NSCLC harboring the echinoderm microtubule-associated protein-like 4 (EML4)-ALK fusion variant 1 (EML4-ALK v.1) and TP53 co-mutation, displayed only mixed response after three months and highly symptomatic progression after 6 months of first-line brigatinib treatment. Immunohistochemistry (IHC) and fluorescence in situ hybridization (FISH) analysis on re-biopsies from a new liver metastasis revealed overexpression of MET receptor (3+ in 80% of tumor cells) and heterogeneously increased MET gene copy number (CN) in tumor cells, including 20% with MET clusters (corresponds to ≥15 gene copies, thus exact CN uncountable by FISH) and the other 80% with median MET CN of 8.3, both changes indicating high-level MET-amplification. DNA and RNA next-generation sequencing (NGS) displayed preserved ALK fusion and TP53 co-mutation, but no additional genomic alterations, nor MET-amplification. Therefore, we retrospectively investigated the diagnostic biopsy from the primary tumor in the left lung with IHC and FISH revealing the presence of increased MET receptor expression (2+ in 100% of tumor cells) and MET-amplification (median MET CN of 6.1), which otherwise was not detected by NGS. Thus, given the well-documented efficacy of alectinib towards EML4-ALK v.1, combined second-line treatment with alectinib and the MET-TKI, crizotinib, was implemented resulting in very pronounced objective response, significantly improved quality of life, and no adverse events so far during the ongoing treatment (6 months).

Conclusions

The combination of alectinib and crizotinib may be a feasible and effective treatment for ALK+ NSCLC with de novo MET-amplification. The latter may represent a mechanism of intrinsic ALK-TKI resistance and its recognition by FISH, in NGS-negative cases, may be considered before initiating first-line treatment. This recognition is clinically important as combined therapy with ALK-TKI and MET-inhibitor should be the preferred first-line treatment.

ALK inhibitors in cancer: mechanisms of resistance and therapeutic management strategies

Anaplastic lymphoma kinase (ALK) gene rearrangements have been identified as potent oncogenic drivers in several malignancies, including non-small cell lung cancer (NSCLC). The discovery of ALK inhibition using a tyrosine kinase inhibitor (TKI) has dramatically improved the outcomes of patients with ALK-mutated NSCLC. However, the emergence of intrinsic and acquired resistance inevitably occurs with ALK TKI use. This review describes the molecular mechanisms of ALK TKI resistance and discusses management strategies to overcome therapeutic resistance.

Recurrent mutations in tumor suppressor FBXW7 bypass Wnt/β-catenin addiction in cancer

Pathologic Wnt/β-catenin signaling drives various cancers, leading to multiple approaches to drug this pathway. Appropriate patient selection can maximize success of these interventions. Wnt ligand addiction is a druggable vulnerability in RNF43-mutant/RSPO-fusion cancers. However, pharmacologically targeting the biogenesis of Wnt ligands, e.g., with PORCN inhibitors, has shown mixed therapeutic responses, possibly due to tumor heterogeneity. Here, we show that the tumor suppressor FBXW7 is frequently mutated in RNF43-mutant/RSPO-fusion tumors, and FBXW7 mutations cause intrinsic resistance to anti-Wnt therapies. Mechanistically, FBXW7 inactivation stabilizes multiple oncoproteins including Cyclin E and MYC and antagonizes the cytostatic effect of Wnt inhibitors. Moreover, although FBXW7 mutations do not mitigate β-catenin degradation upon Wnt inhibition, FBXW7-mutant RNF43-mutant/RSPO-fusion cancers instead lose dependence on β-catenin signaling, accompanied by dedifferentiation and loss of lineage specificity. These FBXW7-mutant Wnt/β-catenin-independent tumors are susceptible to multi-cyclin-dependent kinase inhibition. An in-depth understanding of primary resistance to anti-Wnt/β-catenin therapies allows for more appropriate patient selection and use of alternative mechanism-based therapies.

A Phase II Exploratory Study to Identify Biomarkers Predictive of Clinical Response to Regorafenib in Patients with Metastatic Colorectal Cancer Who Have Failed First-Line Therapy

Single-agent regorafenib is approved in Canada for metastatic colorectal cancer (mCRC) patients who have failed previous lines of therapy. Identifying prognostic biomarkers is key to optimizing therapeutic strategies for these patients. In this clinical study (NCT01949194), we evaluated the safety and efficacy of single-agent regorafenib as a second-line therapy for mCRC patients who received it after failing first-line therapy with an oxaliplatin or irinotecan regimen with or without bevacizumab. Using various omics approaches, we also investigated putative biomarkers of response and resistance to regorafenib in metastatic lesions and blood samples in the same cohort. Overall, the safety profile of regorafenib seemed similar to the CORRECT trial, where regorafenib was administered as ≥ 2 lines of therapy. While the mutational landscape showed typical mutation rates for the top five driver genes (APC, KRAS, BRAF, PIK3CA, and TP53), KRAS mutations were enriched in intrinsically resistant lesions. Additional exploration of genomic-phenotype associations revealed several biomarker candidates linked to unfavorable prognoses in patients with mCRC using various approaches, including pathway analysis, cfDNA profiling, and copy number analysis. However, further research endeavors are necessary to validate the potential utility of these promising genes in understanding patients' responses to regorafenib treatment.

Molecular pathways, resistance mechanisms and targeted interventions in non-small-cell lung cancer

Lung cancer is the leading cause of cancer-related mortality worldwide. The discovery of tyrosine kinase inhibitors effectively targeting EGFR mutations in lung cancer patients in 2004 represented the beginning of the precision medicine era for this refractory disease. This great progress benefits from the identification of driver gene mutations, and after that, conventional and new technologies such as NGS further illustrated part of the complex molecular pathways of NSCLC. More targetable driver gene mutation identification in NSCLC patients greatly promoted the development of targeted therapy and provided great help for patient outcomes including significantly improved survival time and quality of life. Herein, we review the literature and ongoing clinical trials of NSCLC targeted therapy to address the molecular pathways and targeted intervention progress in NSCLC. In addition, the mutations in EGFR gene, ALK rearrangements, and KRAS mutations in the main sections, and the less common molecular alterations in MET, HER2, BRAF, ROS1, RET, and NTRK are discussed. The main resistance mechanisms of each targeted oncogene are highlighted to demonstrate the current dilemma of targeted therapy in NSCLC. Moreover, we discuss potential therapies to overcome the challenges of drug resistance. In this review, we manage to display the current landscape of targetable therapeutic patterns in NSCLC in this era of precision medicine.

Alternative Treatment Options to ALK Inhibitor Monotherapy for EML4-ALK-Driven Lung Cancer

EML4-ALK is an oncogenic fusion protein that accounts for approximately 5% of NSCLC cases. Targeted inhibitors of ALK are the standard of care treatment, often leading to a good initial response. Sadly, some patients do not respond well, and most will develop resistance over time, emphasizing the need for alternative treatments. This review discusses recent advances in our understanding of the mechanisms behind EML4-ALK-driven NSCLC progression and the opportunities they present for alternative treatment options to ALK inhibitor monotherapy. Targeting ALK-dependent signalling pathways can overcome resistance that has developed due to mutations in the ALK catalytic domain, as well as through activation of bypass mechanisms that utilise the same pathways. We also consider evidence for polytherapy approaches that combine targeted inhibition of these pathways with ALK inhibitors. Lastly, we review combination approaches that use targeted inhibitors of ALK together with chemotherapy, radiotherapy or immunotherapy. Throughout this article, we highlight the importance of alternative breakpoints in the EML4 gene that result in the generation of distinct EML4-ALK variants with different biological and pathological properties and consider monotherapy and polytherapy approaches that may be selective to particular variants.

Characteristics of MYC Amplification and Their Association with Clinicopathological and Molecular Factors in Patients with Breast Cancer

MYC amplification is detected in ∼15% of breast tumors and is associated with poor prognosis by mediating acquired resistance to anticancer therapies. This study aimed to determine the prevalence of MYC amplifications in Chinese women with breast cancer (BRCA) and investigate the correlation between MYC amplification and clinicopathological and molecular characteristics and its clinical implications. We analyzed MYC alterations in tissue specimens from 410 women diagnosed with BRCA in our hospital from June 1, 2017 to September 27, 2018. We compared our results with publicly available data from The Cancer Genome Atlas (TCGA) BRCA cohort (n = 1079). MYC amplification was identified in 12.4% (51/410) of our cohort, with mean copy number (CN) of 4.42 (range: 2.84-11.27). In TCGA cohort, MYC amplification was identified in 21.2% (229/1079) and was associated with age, estrogen receptor status, progesterone receptor status, human epidermal growth factor receptor 2 (HER2) status, and molecular subtype, whereas in our cohort, MYC amplification was associated with smaller tumor size (T1-2, p = 0.023) and higher Ki-67 levels (≥20%; p = 0.031). Analysis of molecular profiles revealed that MYC-amplified breast tumors had significantly more concurrent CN variations compared with MYC nonamplified BRCA in both Guangdong Provincial People's Hospital (GDPH) and TCGA cohorts (p < 0.001). Pathway mapping analysis demonstrated that MYC-amplified tumors had more mutations involved in 15 different but interrelated pathways critical in DNA repair, cell cycle, and cell proliferation. Patients in TCGA cohort with MYC-amplified hormone receptor (HR)-positive/HER2-positive BRCA (p = 0.038) and MYC nonamplified triple-negative BRCA (p = 0.027) had significantly shorter overall survival. In conclusion, this study contributes to a better understanding that MYC-amplified breast tumors had distinct clinicopathological and molecular features compared with MYC nonamplified breast tumors. Further research with a larger sample size is necessary to further elucidate the clinical and survival implications of MYC amplifications.

Enhancer RNA AL928768.3 from the IGH Locus Regulates MYC Expression and Controls the Proliferation and Chemoresistance of Burkitt Lymphoma Cells with IGH/MYC Translocation

Chromosomal rearrangements leading to the relocation of proto-oncogenes into transcription-active regions are found in various types of tumors. In particular, the transfer of proto-oncogenes to the locus of heavy chains of immunoglobulins (IGH) is frequently observed in B-lymphomas. The increased expression of the MYC proto-oncogene due to IGH/MYC translocation is detected in approximately 85% of Burkitt lymphoma cases. The regulatory mechanisms affecting the oncogenes upon translocation include non-coding enhancer RNAs (eRNAs). We conducted a search for the eRNAs that may affect MYC transcription in the case of IGH/MYC translocation in Burkitt lymphoma, looking for potentially oncogenic eRNAs located at the IGH locus and predominantly expressed in B cells. Overexpression and knockdown of our primary candidate eRNA AL928768.3 led to the corresponding changes in the expression of MYC proto-oncogene in Burkitt lymphoma cells. Furthermore, we demonstrated that AL928768.3 knockdown decreased lymphoma cell proliferation and resistance to chemotherapy. Significant effects were observed only in cell lines bearing IGH/MYC abnormality but not in B-cell lines without this translocation nor primary B-cells. Our results indicate that AL928768.3 plays an important role in the development of Burkitt’s lymphoma and suggest it and similar, yet undiscovered eRNAs as potential tissue-specific targets for cancer treatment.

Clinical Applications of Circulating Tumour Cells and Circulating Tumour DNA in Non-Small Cell Lung Cancer-An Update

Despite efforts to improve earlier diagnosis of non-small cell lung cancer (NSCLC), most patients present with advanced stage disease, which is often associated with poor survival outcomes with only 15% surviving for 5 years from their diagnosis. Tumour tissue biopsy is the current mainstream for cancer diagnosis and prognosis in many parts of the world. However, due to tumour heterogeneity and accessibility issues, liquid biopsy is emerging as a game changer for both cancer diagnosis and prognosis. Liquid biopsy is the analysis of tumour-derived biomarkers in body fluids, which has remarkable advantages over the use of traditional tumour biopsy. Circulating tumour cells (CTCs) and circulating tumour DNA (ctDNA) are two main derivatives of liquid biopsy. CTC enumeration and molecular analysis enable monitoring of cancer progression, recurrence, and treatment response earlier than traditional biopsy through a minimally invasive liquid biopsy approach. CTC-derived ex-vivo cultures are essential to understanding CTC biology and their role in metastasis, provide a means for personalized drug testing, and guide treatment selection. Just like CTCs, ctDNA provides opportunity for screening, monitoring, treatment evaluation, and disease surveillance. We present an updated review highlighting the prognostic and therapeutic significance of CTCs and ctDNA in NSCLC.

Review of Therapeutic Strategies for Anaplastic Lymphoma Kinase-Rearranged Non-Small Cell Lung Cancer

Simple Summary

Anaplastic lymphoma kinase (ALK)-rearranged non-small cell lung cancer (NSCLC) was first reported in 2007. Following the development of crizotinib as a tyrosine kinase inhibitor (TKI) targeting ALK, the treatment of advanced NSCLC with ALK-rearrangements has made remarkable progress. Currently, there are five ALK-TKIs approved by the FDA, and the development of new agents, including fourth-generation TKI, is ongoing. Clinical trials with angiogenesis inhibitors and immune checkpoint inhibitors are also underway, and further progress in the treatment of ALK-rearranged advanced NSCLC is expected. The purpose of this manuscript is to provide information on the recent clinical trials of ALK-TKIs, angiogenesis inhibitors, immune checkpoint inhibitors, and chemotherapy, to describe tissue and liquid biopsy as a method to investigate the mechanisms of resistance against ALK-TKIs and suggest a proposed treatment algorithm.

Abstract

Non-small cell lung cancer (NSCLC) with anaplastic lymphoma kinase rearrangement (ALK) was first reported in 2007. ALK-rearranged NSCLC accounts for about 3–8% of NSCLC. The first-line therapy for ALK-rearranged advanced NSCLC is tyrosine kinase inhibitors (TKI) targeting ALK. Following the development of crizotinib, the first ALK-TKI, patient prognosis has been greatly improved. Currently, five TKIs are approved by the FDA. In addition, clinical trials of the novel TKI, ensartinib, and fourth-generation ALK-TKI for compound ALK mutation are ongoing. Treatment with angiogenesis inhibitors and immune checkpoint inhibitors is also being studied. However, as the disease progresses, cancers tend to develop resistance mechanisms. In addition to ALK mutations, other mechanisms, including the activation of bypass signaling pathways and histological transformation, cause resistance, and the identification of these mechanisms is important in selecting subsequent therapy. Studies on tissue and liquid biopsy have been reported and are expected to be useful tools for identifying resistance mechanisms. The purpose of this manuscript is to provide information on the recent clinical trials of ALK-TKIs, angiogenesis inhibitors, immune checkpoint inhibitors, and chemotherapy to describe tissue and liquid biopsy as a method to investigate the mechanisms of resistance against ALK-TKIs and suggest a proposed treatment algorithm.

MYC promotes tyrosine kinase inhibitor resistance in ROS1 fusion-positive lung cancer

Targeted therapy of ROS1 fusion-driven non-small cell lung cancer (NSCLC) has achieved notable clinical success. Despite this, resistance to therapy inevitably poses a significant challenge. MYC amplification was present in ~19% of lorlatinib-resistant ROS1-driven NSCLC. We hypothesized that MYC overexpression drives ROS1-TKI resistance. Using complementary approaches in multiple models, including a MYC-amplified patient-derived cell line and xenograft (LUAD-0006), we established that MYC overexpression induces broad ROS1 TKI resistance. Pharmacological inhibition of ROS1 combined with MYC knockdown were essential to completely suppress LUAD-0006 cell proliferation compared to either treatment alone. We interrogated cellular signaling in ROS1-TKI resistant LUAD-0006 and discovered significant differential regulation of targets associated with cell cycle, apoptosis, and mitochondrial function. Combinatorial treatment of mitochondrial inhibitors with crizotinib revealed inhibitory synergism, suggesting increased reliance on glutamine metabolism and fatty-acid synthesis in chronic ROS1-TKI treated LUAD-0006 cells. In vitro experiments further revealed that CDK4/6 and BET bromodomain inhibitors effectively mitigate ROS1 TKI resistance in MYC-overexpressing cells. Notably, in vivo studies demonstrate that tumor control may be regained by combining ROS1 TKI and CDK4/6 inhibition. Our results contribute to the broader understanding of ROS1-TKI resistance in NSCLC. Implications: This study functionally characterizes MYC overexpression as a novel form of therapeutic resistance to ROS1 tyrosine kinase inhibitors in non-small-cell lung cancer and proposes rational combination treatment strategies.

Real-world circulating tumor DNA analysis depicts resistance mechanism and clonal evolution in ALK inhibitor-treated lung adenocarcinoma patients

Background

Sequential treatment with different generations of anaplastic lymphoma kinase (ALK) inhibitors have been widely applied to ALK-positive lung cancer; however, resistance mutations inevitably developed. Further characterization of ALK resistance mutations may provide key guidance to subsequent therapies. Here we explored the emergence of secondary ALK mutations during sequential ALK tyrosine kinase inhibitor (TKI) treatment in a real-world study of Chinese lung adenocarcinoma (ADC) patients.

Methods

A clinical-genomic database was queried for lung ADC patients with at least one ALK inhibitor treatment and at least one plasma sample collected following ALK inhibitor treatment. Targeted genome profiling was performed with a 139-gene panel in baseline tumor tissue and serial plasma samples of patients.

Results

A total of 116 patients met inclusion criteria. ALK G1202R was more common in patients with echinoderm microtubule-associated protein-like 4 (EML4)-ALK v3 fusion, whereas ALK L1196M was more common in v1. TP53 mutant patients were significantly associated with harboring multiple ALK resistance mutations (P = 0.03) and v3+/TP53 mutant patients had the highest rate of multiple ALK resistance mutations. The sequential use of ALK TKI led to an increased incidence of concurrent ALK mutations along the lines of therapies. Alectinib had a lower rate (9%) harboring ALK resistance mutation as first-line ALK TKI compared with crizotinib (36%). ALK compound mutations identified included ALK D1203N/L1196M, ALK G1202R/L1196M, and ALK G1202R/F1174C, which may be lorlatinib resistant. Using paired pretreatment and post-treatment samples, we identified several ALK-independent resistance-related genetic alterations, including PTPRD and CNKN2A/B loss, MYC, MYCN and KRAS amplification, and EGFR^19del.

Conclusions

Sequential postprogression plasma profiling revealed that increased lines of ALK inhibitors can accelerate the accumulation of ALK resistance mutations and may lead to treatment-refractory compound ALK mutations. The selection for optimal first-line TKI is very important to achieve a more efficacious long-term strategy and prevent the emergence of on-target resistance, which may provide guidance for clinical decision making.

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ALK resistance mutations were differentially enriched in the setting of EML4-ALK v1/v3 and TP53 status.

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Serial liquid biopsies NGS depicted accumulation of multiple ALK secondary mutations during sequential ALK treatments.

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Several lorlatinib-resistant ALK compound mutations and ALK-independent resistance genetic alterations were identified.

YES1 and MYC Amplifications as Synergistic Resistance Mechanisms to Different Generation ALK Tyrosine Kinase Inhibitors in Advanced NSCLC: Brief Report of Clinical and Preclinical Proofs

INTRODUCTION

ALK tyrosine kinase inhibitors (TKIs) are the standard treatment for advanced ALK-positive NSCLC. Nevertheless, drug resistance inevitably occurs. Here, we report a case of a patient with metastatic ALK-positive lung adenocarcinoma with an impressive resistance to sequential treatment with ALK TKIs mediated by YES1 and MYC amplification in a contest of epithelial-to-mesenchymal transition and high progressive chromosomal instability.

METHODS

The patient received, after chemotherapy and 7 months of crizotinib, brigatinib and lorlatinib with no clinical benefit to both treatments. A study of resistance mechanisms was performed with whole exome sequencing on different biological samples; primary cell lines were established from pleural effusion after lorlatinib progression.

RESULTS

At whole exome sequencing analysis, YES1 and MYC amplifications were observed both in the pericardial biopsy and the pleural effusion samples collected at brigatinib and lorlatinib progression, respectively. Increasing chromosomal instability from diagnostic biopsy to pleural effusion was also observed. The addition of dasatinib to brigatinib or lorlatinib restored the sensitivity in primary cell lines; data were confirmed also in H3122_ALK-positive model overexpressing both YES1 and MYC.

CONCLUSIONS

In conclusion, YES1 and MYC amplifications are candidates to justify a rapid acquired resistance to crizotinib entailing primary brigatinib and lorlatinib resistance. In this context, a combination strategy of ALK TKI with dasatinib could be effective to overcome a rapid resistance.

A Large Real-World Study on the Effectiveness of the Combined Inhibition of EGFR and MET in EGFR-Mutant Non-Small-Cell Lung Cancer After Development of EGFR-TKI Resistance

Background

MET proto-oncogene amplification (amp) is an important mechanism underlying acquired resistance to epidermal growth factor receptor (EGFR) tyrosine kinase inhibitors (TKIs). However, the optimal treatment strategy after acquiring MET-amp-mediated EGFR-TKI resistance remains controversial. Our study compared three treatment strategies for patients with EGFR-mutant non-small-cell lung cancer (NSCLC) who were detected with MET-amp at EGFR-TKI progression using next-generation sequencing.

Methods

Of the 70 patients included in the study, 38 received EGFR-TKI + crizotinib, 10 received crizotinib monotherapy, and 22 received chemotherapy. Clinical outcomes and molecular profiles were analyzed.

Results

The objective response rate was 48.6% for EGFR-TKI + crizotinib group, 40.0% for crizotinib monotherapy group, and 18.2% for chemotherapy group. Patients who received EGFR-TKI + crizotinib had significantly longer progression-free survival than those who received crizotinib or chemotherapy (5.0 vs. 2.3 vs. 2.9 months, p = 0.010), but overall survival was comparable (10.0 vs. 4.1 vs. 8.5 months, p = 0.088). TP53 mutation (58.5%) and EGFR-amp (42.9%) were frequent concurrent mutations of the cohort. Progression-free survival was significantly longer for patients with either concurrent TP53 mutation (n = 17) (6.0 vs. 2.3 vs. 2.9 months, p = 0.009) or EGFR-amp (n = 13) (5.0 vs. 1.2 vs. 2.4 months, p = 0.016) in the EGFR-TKI + crizotinib group than the other two regimen. Potential acquired resistance mechanisms to EGFR-TKI + crizotinib included EGFR-T790M (n = 2), EGFR-L718Q (n = 1), EGFR-S645C (n = 1), MET-D1228H (n = 1), BRAF-V600E (n = 1), NRAS-Q61H (n = 1), KRAS-amp (n = 1), ERBB2-amp (n = 1), CDK4-amp (n = 1), and MYC-amp (n = 1).

Conclusion

Our study provides real-world clinical evidence from a large cohort that simultaneous inhibition of EGFR and MET could be a more effective therapeutic strategy for patients with MET-amp acquired from EGFR-TKI therapy.

The Resistance Mechanisms and Treatment Strategies for ALK-Rearranged Non-Small Cell Lung Cancer

Anaplastic lymphoma kinase (ALK) is a validated molecular target for non-small-cell lung cancer (NSCLC). The use of tyrosine kinase inhibitors (TKIs) has led to significantly improved survival benefits. However, the clinical benefits of targeting ALK using TKIs are limited due to the emergence of drug resistance. The landscape of resistance mechanisms and treatment decisions has become increasingly complex. Therefore, continued research into new drugs and combinatorial therapies is required to improve outcomes in NSCLC. In this review, we explore the resistance mechanisms of ALK TKIs in advanced NSCLC in order to provide a theoretical basis and research ideas for solving the problem of ALK drug resistance.

LINC01001 Promotes Progression of Crizotinib-Resistant NSCLC by Modulating IGF2BP2/MYC Axis

Background: Crizotinib is a microtubule-related protein-4-anaplastic lymphoma kinase (EML4-ALK) multi-target tyrosine kinase inhibitor applied in the treatment of ALK-rearranged NSCLC. However, the specific molecular mechanism underlying its therapeutic effect remains unclear. Therefore, the purpose of this research is to explore the mechanism by which crizotinib targets NSCLC with ALK-rearrangement, mainly whether it is related to LINC01001 in regulating NSCLC progression via IGF2BP2/MYC axis.

Methods: RT-qPCR is conducted to evaluate the mRNA levels of LINC01001, IGF2BP2 and MYC in A549/R and H1299/R cells. CCK-8 and EdU assays are performed to assess the viability and proliferation of A549/R and H1299/R cells. Western blot is conducted to measure the levels of PCNA and Ki-67 proteins in A549/R and H1299/R cells. FACs and TUNEL are performed to detect apoptosis of A549/R and H1299/R cells. Immunohistochemical staining is performed to assess the levels of Ki67 in crizotinib-resistant NSCLC tissue. Bioinformatics analysis of multiple CLIP (crosslinking-immunoprecipitation) data found potential binding sites between LINC01001 and IGF2BP2, IGF2BP2 and MYC, that are confirmed by RIP assay and RNA pulldown assay.

Results: Our findings illustrated that LINC01001 is highly expressed in crizotinib-resistant NSCLC cells and associated with poor overall survival of NSCLC patients. Inhibition of LINC01001 depresses crizotinib resistance of NSCLC cells. LINC01001 interacts with IGF2BP2, and inhibition of IGF2BP2 depresses crizotinib resistance of NSCLC cells. IGF2BP2 interacts with the mRNA of MYC, and LINC01001 overexpression increases crizotinib resistance of NSCLC via MYC.

Conclusion: LINC01001 promotes the progression of crizotinib-resistant NSCLC by modulating the IGF2BP2/MYC axis. Our research clarifies the specific mechanism of crizotinib-resistance in NSCLC treatment.

Comprehensive Molecular Analysis of Inflammatory Myofibroblastic Tumors Reveals Diverse Genomic Landscape and Potential Predictive Markers for Response to Crizotinib

PURPOSE

The European Organization for Research and Treatment of Cancer (EORTC) clinical phase II trial 90101 "CREATE" showed high antitumor activity of crizotinib, an inhibitor of anaplastic lymphoma kinase (ALK)/ROS1, in patients with advanced inflammatory myofibroblastic tumor (IMFT). However, recent findings suggested that other molecular targets in addition to ALK/ROS1 might also contribute to the sensitivity of this kinase inhibitor. We therefore performed an in-depth molecular characterization of archival IMFT tissue, collected from patients enrolled in this trial, with the aim to identify other molecular alterations that could play a role in the response to crizotinib.

EXPERIMENTAL DESIGN

Twenty-four archival IMFT samples were used for histopathological assessment and DNA/RNA evaluation to identify gene fusions, copy-number alterations (CNA), and mutations in the tumor tissue. Results were correlated with clinical parameters to assess a potential association between molecular findings and clinical outcomes.

RESULTS

We found 12 ALK fusions with 11 different partners in ALK-positive IMFT cases by Archer analysis whereas we did not identify any ROS1-rearranged tumor. One ALK-negative patient responding to crizotinib was found to have an ETV6-NTRK fusion in the tumor specimen. The CNA profile and mutational landscape of IMFT revealed extensive molecular heterogeneity. Loss of chromosome 19 (25% of cases) and PIK3CA mutations (9% of cases) were associated with shorter progression-free survival in patients receiving crizotinib.

CONCLUSIONS

We identified multiple genetic alterations in archival IMFT material and provide further insight into the molecular profile of this ultra-rare, heterogeneous malignancy, which may potentially translate into novel treatment approaches for this orphan disease.

MYC: a multipurpose oncogene with prognostic and therapeutic implications in blood malignancies

MYC oncogene is a transcription factor with a wide array of functions affecting cellular activities such as cell cycle, apoptosis, DNA damage response, and hematopoiesis. Due to the multi-functionality of MYC, its expression is regulated at multiple levels. Deregulation of this oncogene can give rise to a variety of cancers. In this review, MYC regulation and the mechanisms by which MYC adjusts cellular functions and its implication in hematologic malignancies are summarized. Further, we also discuss potential inhibitors of MYC that could be beneficial for treating hematologic malignancies.

Research progress on the drug resistance of ALK kinase inhibitors

BACKGROUND

The fusion and rearrangement of the ALK gene of anaplastic lymphoma kinase is an important cause of a variety of cancers, including non-small cell lung cancer (NSCLC) and anaplastic large cell lymphoma (ALCL). Since crizotinib first came out, many ALK inhibitors have come out one after another, but the fatal flaw in each generation of ALK inhibitors is the body's resistance to drugs. Therefore, how to solve the problem of drug resistance has become an important bottleneck in the application and development of ALK inhibitors. This article briefly introduces the drug resistance of ALK inhibitors and the modified forms of ALK inhibitors, which provide a theoretical basis for solving the drug resistance of ALK inhibitors and the development of a new generation of ALK kinase inhibitors.

METHOD

We use relevant databases to query relevant literature, and then screen and select based on the relevance and cutting edge of the content. We then summarize and analyze appropriate articles, integrate and classify relevant studies, and finally write articles based on topics.

RESULT

This article starts with the problem of ALK resistance, first introduces the composition of ALK kinase, and then introduces the problem of resistance of ALK kinase inhibitors. Later, the structural modification to overcome ALK resistance was introduced, and finally, the method to overcome ALK resistance was introduced.

CONCLUSION

This article summarizes the resistance pathways of ALK kinase inhibitors, and integrates the efforts made to overcome the structural modification of ALK resistance problems, and hopes to provide some inspiration for the development of the next generation of ALK kinase inhibitors.

NGS-based liquid biopsy profiling identifies mechanisms of resistance to ALK inhibitors: a step toward personalized NSCLC treatment

Despite impressive and durable responses, nonsmall cell lung cancer (NSCLC) patients treated with anaplastic lymphoma kinase (ALK) inhibitors (ALK-Is) ultimately progress due to development of resistance. Here, we have evaluated the clinical utility of circulating tumor DNA (ctDNA) profiling by next-generation sequencing (NGS) upon disease progression. We collected 26 plasma and two cerebrospinal fluid samples from 24 advanced ALK-positive NSCLC patients at disease progression to an ALK-I. These samples were analyzed by NGS and digital PCR. A tool to retrieve variants at the ALK locus was developed (VALK tool). We identified at least one resistance mutation in the ALK locus in ten (38.5%) plasma samples; the G1269A and G1202R mutations were the most prevalent among patients progressing to first- and second-generation ALK-Is, respectively. Overall, 61 somatic mutations were detected in 14 genes: TP53, ALK, PIK3CA, SMAD4, MAP2K1 (MEK1), FGFR2, FGFR3, BRAF, EGFR, IDH2, MYC, MET, CCND3, and CCND1. Specifically, a deletion in exon 19 in EGFR, a non-V600 BRAF mutation (G466V), and the F129L mutation in MAP2K1 were identified in four patients who showed no objective survival benefit from ALK-Is. Potential ALK-I-resistance mutations were also found in PIK3CA and IDH2. Finally, a c-MYC gain, along with a loss of CCND1 and FGFR3, was detected in a patient progressing on a first-line treatment with crizotinib. We conclude that NGS analysis of liquid biopsies upon disease progression identified different putative ALK-I-resistance mutations in most cases and could be a valuable approach for therapy decision making.

Circulating tumor cell profiling for precision oncology

Analysis of circulating tumor cells (CTCs) collected from patient's blood offers a broad range of opportunities in the field of precision oncology. With new advances in profiling technology, it is now possible to demonstrate an association between the molecular profiles of CTCs and tumor response to therapy. In this Review, we discuss mechanisms of tumor resistance to therapy and their link to phenotypic and genotypic properties of CTCs. We summarize key technologies used to isolate and analyze CTCs and discuss recent clinical studies that examined CTCs for genomic and proteomic predictors of responsiveness to therapy. We also point out current limitations that still hamper the implementation of CTCs into clinical practice. We finally reflect on how these shortcomings can be addressed with the likely contribution of multiparametric approaches and advanced data analytics.

Knockdown of c-MYC Controls the Proliferation of Oral Squamous Cell Carcinoma Cells in vitro via Dynamic Regulation of Key Apoptotic Marker Genes

Oral squamous cell carcinoma (OSCC) is the most common malignant epithelial cancer occurring in the oral cavity, where it accounts for nearly 90% of all oral cavity neoplasms. The c-MYC transcription factor plays an important role in the control of programmed cell death, normal-to-malignant cellular transformation, and progression of the cell cycle. However, the role of c-MYC in controlling the proliferation of OSCC cells is not well known. In this study, c-MYC gene was silenced in OSCC cells (ORL-136T), and molecular and cellular responses were screened. To identify the pathway through which cell death occurred, cytotoxicity, colony formation, western blotting, caspase-3, and RT-qPCR analyzes were performed. Results indicated that knockdown of c-MYC has resulted in a significant decrease in the cell viability and c-MYC protein synthesis. Furthermore, caspase-3 was shown to be upregulated leading to apoptosis via the intrinsic pathway. In response to c-MYC knockdown, eight cell proliferation-associated genes showed variable expression profiles: c-MYC (-21.2), p21 (-2.5), CCNA1(1.8), BCL2 (-1.4), p53(-3.7), BAX(1.1), and CYCS (19.3). p27 expression was dramatically decreased in c-MYC-silenced cells in comparison with control, and this might indicate that the relative absence of c-MYC triggered intrinsic apoptosis in OSCC cells via p27 and CYCS.

Combining Radiation Therapy with ALK Inhibitors in Anaplastic Lymphoma Kinase-Positive Non-Small Cell Lung Cancer (NSCLC): A Clinical and Preclinical Overview

Over the past years, the identification of genetic alterations in oncogenic drivers in non-small cell lung cancer (NSCLC) has significantly and favorably transformed the outcome of patients who can benefit from targeted therapies such as tyrosine kinase inhibitors. Among these genetic alterations, anaplastic lymphoma kinase (ALK) rearrangements were discovered in 2007 and are present in 3-5% of patients with NSCLC. In addition, radiotherapy remains one of the cornerstones of NSCLC treatment. Moreover, improvements in the field of radiotherapy with the use of hypofractionated or ablative stereotactic radiotherapy have led to a better outcome for localized or oligometastatic NSCLC. To date, the effects of the combination of ALK inhibitors and radiotherapy are unclear in terms of safety and efficacy but could potently improve treatment. In this manuscript, we provide a clinical and preclinical overview of combining radiation therapy with ALK inhibitors in anaplastic lymphoma kinase-positive non-small cell lung cancer.

Resistance to anaplastic lymphoma kinase inhibitors: knowing the enemy is half the battle won

Anaplastic lymphoma kinase (ALK) translocations are responsible of neoplastic transformation in a limited subset of non-small cell lung cancer (NSCLC) patients. In recent years outcomes of these patients improved due to the development and clinical availability of specific and extremely active targeted therapies [i.e., next-generation Tyrosine Kinase Inhibitors (TKI)]: ALK+ patients are now reaching impressive results when treated with more potent inhibitors upfront with an average median progression-free survival (mPFS) around 35 months. However, under drug pressure, cancer cells develop resistance and patients eventually progress. Multiple mechanisms of intrinsic or acquired resistance have been extensively characterized. Less potent ALK inhibitors (ALKi)—like crizotinib—usually tend to induce a large spectrum of secondary intra-kinase mutations; however, these alterations may be observed also after sequential administration of multiple ALKi. Noteworthy, neoplastic cells may evade ALK targeting through a myriad of different mechanisms involving cell-stroma interaction, activation of parallel signaling pathways, intracellular downstream adaptation and histological reshaping, as relevant molecular events. Often these phenomena are restricted to a limited number of cases or even can be patient-specific, thus hindering the development of therapeutic strategies largely applicable. Consequently, the recognition of specific resistance mechanisms seldom translates in clinical opportunities. Management of ALK+ patients is drastically changed and deciphering the molecular biology underlying this disease during treatment is of paramount relevance. The bedrock of resistance to TKI is that, after the diagnosis, we face with a different disease that needs to be re-characterized through tissue or/and liquid biopsies. Understanding molecular pathways driving the resistant phenotype will give us the chance to know what we are dealing with and, rather than choose an empirical approach, will help us to properly define the best targeted treatment for these patients.

[Advances in Drug Resistance Mechanisms and Prognostic Markers of Targeted Therapy in ALK-positive Non-small Cell Lung Cancer]

棘皮动物微管相关类蛋白4-间变性淋巴瘤激酶(echinoderm microtubule-associated protein like 4-anaplastic lymphoma kinase, EML4-ALK)融合占非小细胞肺癌(non-small cell lung cancer, NSCLC)患者的3%-5%。随着对该驱动基因的深入研究，以Crizotinib为代表的ALK抑制剂逐渐被开发并应用于临床。然而，不同患者对ALK靶向治疗的反应存在差异，且多数ALK靶向治疗患者最终会不可避免地出现耐药，导致肿瘤进展。利用预后标志物监测患者疗效及时改变治疗方案，以及根据耐药机制选择个体化的后续治疗，可以有效地改善患者的预后。本文将对ALK抑制剂的耐药机制以及相关的预后标志物展开综述，探讨ALK靶向治疗疗效预测以及耐药患者后续治疗方案的选择。

An okadaic acid fragment analogue prevents nicotine-induced resistance to cisplatin by recovering PP2A activity in non-small cell lung cancer cells

We herein report the design, synthesis, and functional impact of an okadaic acid (OA) small analogue, ITH12680, which restores the activity of phosphoprotein phosphatase 2A (PP2A), whose deficient activity has been implicated in nicotine-mediated tumor progression and chemoresistance in non-small cell lung cancer (NSCLC). For its design, we paid attention to the structure of the PP2A-OA complex, where the C16-C38 OA fragment confers PP2A affinity and selectivity, but it is not involved in the inhibitory effect. Confirming this hypothesis, PP2A activity was not inhibited by ITH12680. By contrast, the compound partially restored OA-exerted PP2A inhibition in vitro. Moreover, flow cytometry and immunoblotting experiments revealed that ITH12680 reversed nicotine-induced cisplatin resistance in NSCLC cells, as it prevented nicotine-induced reduction of Bax expression and inhibited nicotine-mediated activation of cell survival and proliferation kinases, Akt and ERK1/2. Our findings suggest that the rescue of nicotine-inhibited PP2A activity could diminish the resistance to cisplatin treatment observed in NSCLC patients who continue smoking.

DEPArray™ system: An automatic image-based sorter for isolation of pure circulating tumor cells

Circulating tumor cells (CTCs) are rare cells shed into the bloodstream by invasive tumors and their analysis offers a promising noninvasive tool to predict and monitor therapeutic responses. CTCs can be isolated from patient blood and their characterization at single‐cell level can inform on the genomic landscape of a tumor. All CTC enrichment methods bear a burden of contaminating normal cells, which mandate a further step of purification to enable reliable downstream genetic analysis. Here, we describe the DEPArray™ technology, a microchip‐based digital sorter, which combines precise microfluidic and microelectronic enabling precise, image‐based isolation of single CTCs, which can then be analyzed by Next Generation Sequencing (NGS) methods. © 2018 The Authors. Cytometry Part A published by Wiley Periodicals, Inc. on behalf of International Society for Advancement of Cytometry.

Unravelling tumour heterogeneity by single-cell profiling of circulating tumour cells

Single-cell technologies have contributed to unravelling tumour heterogeneity, now considered a hallmark of cancer and one of the main causes of tumour resistance to cancer therapies. Liquid biopsy (LB), defined as the detection and analysis of cells or cell products released by tumours into the blood, offers an appealing minimally invasive approach that allows the characterization and monitoring of tumour heterogeneity in individual patients. Here, we will review and discuss how circulating tumour cell (CTC) analysis at single-cell resolution provides unique insights into tumour heterogeneity that are not revealed by analysis of circulating tumour DNA (ctDNA) derived from LBs. The molecular analysis of CTCs provides complementary information to that of genomic aberrations determined using ctDNA to fully describe many different cellular components (for example, DNA, RNA, proteins and metabolites) that can influence tumour heterogeneity.

Clinical features and outcomes of ALK rearranged non-small cell lung cancer with primary resistance to crizotinib

Background

Crizotinib is associated with a favorable survival benefit in patients with ALK‐positive non‐small cell lung cancer (NSCLC); however, a subset of patients harboring ALK rearrangement shows a poor response.

Methods

We collected the clinical features and survival outcomes of 28 primary‐resistant responders (PRR) with progression‐free survival (PFS) of < 3 months on crizotinib and compared these with 78 long‐term responders (LTR) that achieved > 24 months PFS (control).

Results

Primary resistance was observed in 6.5% of the patients. The median PFS of the PRR and LTR groups was 1.2 months (95% confidence interval [CI] 0.70–1.73) and 47.0 months (95% CI 34.39–59.64), respectively. A better Eastern Cooperative Oncology Group performance status score was significantly associated with longer PFS (odds ratio 0.06, 95% CI 0.01–0.33; P = 0.001). The median overall survival (OS) of the PRR group was 8.4 months (95% CI 3.47–13.42) and crizotinib as first‐line treatment was an independent predictive factor for survival outcome (P = 0.005). Patients administered ALK‐tyrosine kinase inhibitors after crizotinib progression had significantly longer survival than the PRR group treated with best supportive care (P = 0.007), but no significant difference was found between ALK‐tyrosine kinase inhibitor treatment and single chemotherapy (P = 0.944).

Conclusion

Patients with primary resistance to crizotinib displayed unfavorable survival outcomes and the underlying mechanism cannot be identified in clinical features. Nevertheless, next‐generation ALK inhibitors and chemotherapy after crizotinib progression could confer a therapeutic and survival benefit in this population.