학술논문
Altered splicing of ATG16‐L1 mediates acquired resistance to tyrosine kinase inhibitors of EGFR by blocking autophagy in non‐small cell lung cancer
Document Type
Academic Journal
Author
Source
Molecular Oncology. October 2022, Vol. 16 Issue 19, p3490, 19 p.
Subject
Language
English
ISSN
1574-7891
Abstract
Abbreviations Introduction In the past decade, the epidermal growth factor receptor (EGFR) has become an important therapeutic target for patients with lung cancer [1]. EGFR tyrosine kinase inhibitors (TKIs) have [...]
Despite the initial efficacy of using tyrosine kinase inhibitors of epidermal growth factor receptors (EGFR‐TKIs) for treating patients with non‐small cell lung cancer (NSCLC), resistance inevitably develops. Recent studies highlight a link between alternative splicing and cancer drug response. Therefore, we aimed to identify deregulated splicing events that play a role in resistance to EGFR‐TKI. By using RNA sequencing, reverse‐transcription PCR (RT‐PCR), and RNA interference, we showed that overexpression of a splice variant of the autophagic gene ATG16‐L1 that retains exon 8 and encodes the β‐isoform of autophagy‐related protein 16‐1 (ATG16‐L1 β) concurs acquired resistance to EGFR‐TKI in NSCLC cells. Using matched biopsies, we found increased levels of ATG16‐L1 β at the time of progression in 3 of 11 NSCLC patients treated with EGFR‐TKI. Mechanistically, gefitinib‐induced autophagy was impaired in resistant cells that accumulated ATG16‐L1 β. Neutralization of ATG16‐L1 β restored autophagy in response to gefitinib, induced apoptosis, and inhibited the growth of in ovo tumor xenografts. Conversely, overexpression of ATG16‐L1 β in parental sensitive cells prevented gefitinib‐induced autophagy and increased cell survival. These results support a role of defective autophagy in acquired resistance to EGFR‐TKIs and identify splicing regulation of ATG16‐L1 as a therapeutic vulnerability that could be explored for improving EGFR‐targeted cancer therapy.
Despite the initial efficacy of using tyrosine kinase inhibitors of epidermal growth factor receptors (EGFR‐TKIs) for treating patients with non‐small cell lung cancer (NSCLC), resistance inevitably develops. Recent studies highlight a link between alternative splicing and cancer drug response. Therefore, we aimed to identify deregulated splicing events that play a role in resistance to EGFR‐TKI. By using RNA sequencing, reverse‐transcription PCR (RT‐PCR), and RNA interference, we showed that overexpression of a splice variant of the autophagic gene ATG16‐L1 that retains exon 8 and encodes the β‐isoform of autophagy‐related protein 16‐1 (ATG16‐L1 β) concurs acquired resistance to EGFR‐TKI in NSCLC cells. Using matched biopsies, we found increased levels of ATG16‐L1 β at the time of progression in 3 of 11 NSCLC patients treated with EGFR‐TKI. Mechanistically, gefitinib‐induced autophagy was impaired in resistant cells that accumulated ATG16‐L1 β. Neutralization of ATG16‐L1 β restored autophagy in response to gefitinib, induced apoptosis, and inhibited the growth of in ovo tumor xenografts. Conversely, overexpression of ATG16‐L1 β in parental sensitive cells prevented gefitinib‐induced autophagy and increased cell survival. These results support a role of defective autophagy in acquired resistance to EGFR‐TKIs and identify splicing regulation of ATG16‐L1 as a therapeutic vulnerability that could be explored for improving EGFR‐targeted cancer therapy.