Paper

Germline ERBB3 mutation in familial non-small cell lung carcinoma: expanding ErbB’s role in oncogenesis

Okano, Satomi, Po-Ling Inglis, Shaw, Janet G, Fong, Kwun M, Gattas, Michael, Hassall, Tim, Simpson, Fiona, Leo, Paul J, Marshall, Mhairi S, Harris, Jessica E, Mcinerney-Leo, Aideen M, Wheeler, Lawrie, Yang, Ian A, Bowman, Rayleen V, Duncan, Emma L, Hui Yi Chew, Anderson, Lisa, Brown, Matthew A, Joseph, Shannon R, Cooper, Caroline L

2021

Overview

ABSTRACT Background Lung cancer is the commonest cause of cancer deaths worldwide. Although strongly associated with smoking, predisposition to lung cancer is also heritable with multiple common risk variants identified. Rarely, dominantly inherited non-small-cell lung cancer (NSCLC) has been reported due to somatic mutations in EGFR/ErbB1 and ERBB2. Methods Germline exome sequencing was performed in a multi-generation family with autosomal dominant NSCLC, including an affected child. Tumour samples were also sequenced. Full-length wild-type (wtErbB3) and mutant ERBB3 (mutErbB3) constructs were transfected into HeLa cells. Protein expression, stability, and sub-cellular localisation were assessed; and cellular proliferation, pAkt/Akt, and pERK levels were determined. Results A novel germline variant in ERBB3 (c.1946T>G: p.Iso649Arg), coding for receptor tyrosineprotein kinase erbB-3 (ErbB3), was identified, with appropriate segregation. There was no loss-of-heterozygosity in tumour samples. Both wtErbB3 and mutErbB3 were stably expressed. MutErbB3-transfected cells demonstrated an increased ratio of the 80kD form (which enhances proliferation) compared to the full-length (180kD) form. MutErbB3 and wtErbB3 had similar punctate cytoplasmic localisation pre- and post-EGF stimulation; however, EGFR levels decreased faster post-stimulation in mutErbB3-transfected cells, suggesting more rapid processing of the mutErbB3/EGFR heterodimer. Cellular proliferation was increased in mutErbB3-transfected cells compared to wtErbB3 transfection. MutErbB3-transfected cells also showed decreased pAkt/tAkt ratios and increased pERK/tERK 30 minutes post-stimulation compared to wtErbB3 transfection, demonstrating altered signalling pathway activation by mutErbB3. Cumulatively, these results support this mutation as tumorogenic. Conclusions This is the first reported family with a germline ERBB3 mutation causing heritable NSCLC, furthering understanding of the ErbB family pathway in oncogenesis. Competing Interest Statement The authors have declared no competing interest. Footnotes * ↵* Joint senior authors * Disclaimers: The authors declare no competing financial interests. * Abbreviations CNV copy number variation; EGFR Epidermal Growth Factor Receptor; GWAS genome-wide association studies; MAF minor allele frequency; NSCLC non-smallcell lung cancer; TKIs tyrosine kinase inhibitors.

• Publisher: Cold Spring Harbor Laboratory Press,Cold Spring Harbor Laboratory
• Subject: AKT protein / Cell proliferation / Epidermal growth factor / Epidermal growth factor receptors / ErbB protein / ErbB-1 protein / ErbB-2 protein / ErbB-3 protein / Genomics / Heterozygosity / Kinases / Localization / Lung cancer / Lung carcinoma / Mutation / Non-small cell lung carcinoma / Protein kinase / Signal transduction / Small cell lung carcinoma / Tumorigenesis / Tumors