Abstract
Anaplastic lymphoma kinase (ALK) translocation is an actionable mutation in lung adenocarcinoma. Nonetheless tumour consists of heterogeneous cell subpopulations with diverse phenotypes and genotypes, and cancer cells can actively release extracellular vesicles (EVs) to modulate the phenotype of other cells in the tumour microenvironment. We hypothesized that EVs derived from a drug-resistant subpopulation of cells could induce drug resistance in recipient cells. We have established ALK-translocated lung adenocarcinoma cell lines and subclones. The subclones have been characterized and the expression of EV-RNAs determined by quantitative polymerase chain reaction. The effects of EV transfer on drug resistance were examined in vitro. Serum EV-RNA was assayed serially in two patients prescribed ALK-tyrosine kinase inhibitor (ALK-TKI) treatment. We demonstrated that the EVs from an ALK-TKI-resistant subclone could induce drug resistance in the originally sensitive subclone. EV-RNA profiling revealed that miRNAs miR-21-5p and miR-486-3p, and lncRNAs MEG3 and XIST were differentially expressed in the EVs secreted by the resistant subclones. These circulating EV-RNA levels have been found to correlate with disease progression of EML4-ALK-translocated lung adenocarcinoma in patients prescribed ALK-TKI treatment. The results from this study suggest that EVs released by a drug-resistant subpopulation can induce drug resistance in other subpopulations and may sustain intratumoural heterogeneity.
Highlights
Rearrangement of chromosome 2 leads to fusion of the echinoderm microtubule-associated protein-like 4 (EML4) and anaplastic lymphoma kinase (ALK) gene to form the constitutively activeEML4-ALK oncoprotein
The aims of this study were: (1) To establish subclones of ALK-translocated non-small cell lung cancer (NSCLC) cell lines with known drug sensitivity and resistance to crizotinib or ceritinib; (2) To identify the extracellular vesicles (EVs)-associated RNAs involved in transmission of drug resistance and migration capability from ALK-tyrosine kinase inhibitor (ALK-tyrosine kinase inhibitor (TKI))-resistant subclones to drug-sensitive subclones; (3) To determine whether these EV-associated RNAs involved in drug resistance correlate with treatment response in patients with ALK–translocated lung adenocarcinoma
PCR products with size 1055 bp were obtained from all the cell lines and subclones (Figure 1E); this confirmed that all has variant 2 of EML4-ALK rearrangement
Summary
Rearrangement of chromosome 2 leads to fusion of the echinoderm microtubule-associated protein-like 4 (EML4) and anaplastic lymphoma kinase (ALK) gene to form the constitutively active. EML4-ALK fusion occurs in only 3–5% of lung adenocarcinomas [1], it is a therapeutic target in non-small cell lung cancer (NSCLC). The first-generation ALK-tyrosine kinase inhibitor (TKI) crizotinib is a small molecule TKI of ALK, MET and ROS1 kinases. Crizotinib was previously the recommended first-line treatment for ALK-translocated NSCLC. Most cases of ALK-translocated NSCLC respond initially to crizotinib, disease progression occurs approximately one year after treatment.
Sign-in/Register to view highlights & summary 
Published Version (
Free)
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call