HER2 missense mutations have distinct effects on oncogenic signaling and migration.
Recurrent human epidermal growth factor receptor 2 (HER2) missense mutations have been reported in human cancers. These mutations occur primarily in the absence of HER2 gene amplification such that most HER2-mutant tumors are classified as "negative" by FISH or immunohistochemistry assays. It remains unclear whether nonamplified HER2 missense mutations are oncogenic and whether they are targets for HER2-directed therapies that are currently approved for the treatment of HER2 gene-amplified breast cancers. Here we functionally characterize HER2 kinase and extracellular domain mutations through gene editing of the endogenous loci in HER2 nonamplified human breast epithelial cells. In in vitro and in vivo assays, the majority of HER2 missense mutations do not impart detectable oncogenic changes. However, the HER2 V777L mutation increased biochemical pathway activation and, in the context of a PIK3CA mutation, enhanced migratory features in vitro. However, the V777L mutation did not alter in vivo tumorigenicity or sensitivity to HER2-directed therapies in proliferation assays. Our results suggest the oncogenicity and potential targeting of HER2 missense mutations should be considered in the context of cooperating genetic alterations and provide previously unidentified insights into functional analysis of HER2 mutations and strategies to target them.
Sidney Kimmel Comprehensive Cancer Center, The Johns Hopkins University School of Medicine, Baltimore, MD 21287;
Daniel J
DJ
Zabransky
Department of Chemical and Biomolecular Engineering, Johns Hopkins University, Baltimore, MD 21218;
Christopher L
CL
Yankaskas
Sidney Kimmel Comprehensive Cancer Center, The Johns Hopkins University School of Medicine, Baltimore, MD 21287;
Rory L
RL
Cochran
Sidney Kimmel Comprehensive Cancer Center, The Johns Hopkins University School of Medicine, Baltimore, MD 21287;
Hong Yuen
HY
Wong
Sidney Kimmel Comprehensive Cancer Center, The Johns Hopkins University School of Medicine, Baltimore, MD 21287;
Sarah
S
Croessmann
Sidney Kimmel Comprehensive Cancer Center, The Johns Hopkins University School of Medicine, Baltimore, MD 21287;
David
D
Chu
Division of Oncology, Department of Medicine, Washington University School of Medicine, St. Louis, MO 63110;
Shyam M
SM
Kavuri
Department of Medicine: Breast Cancer Research Program, Vanderbilt-Ingram Cancer Center, Vanderbilt University, Nashville, TN 37232;
Monica
M
Red Brewer
Sidney Kimmel Comprehensive Cancer Center, The Johns Hopkins University School of Medicine, Baltimore, MD 21287;
D Marc
DM
Rosen
Sidney Kimmel Comprehensive Cancer Center, The Johns Hopkins University School of Medicine, Baltimore, MD 21287;
W Brian
WB
Dalton
Sidney Kimmel Comprehensive Cancer Center, The Johns Hopkins University School of Medicine, Baltimore, MD 21287; Department of Pathology, The Johns Hopkins Hospital and School of Medicine, Baltimore, MD 21287;
Ashley
A
Cimino-Mathews
Sidney Kimmel Comprehensive Cancer Center, The Johns Hopkins University School of Medicine, Baltimore, MD 21287;
Karen
K
Cravero
Sidney Kimmel Comprehensive Cancer Center, The Johns Hopkins University School of Medicine, Baltimore, MD 21287;
Berry
B
Button
Sidney Kimmel Comprehensive Cancer Center, The Johns Hopkins University School of Medicine, Baltimore, MD 21287;
Kelly
K
Kyker-Snowman
Sidney Kimmel Comprehensive Cancer Center, The Johns Hopkins University School of Medicine, Baltimore, MD 21287;
Justin
J
Cidado
Sidney Kimmel Comprehensive Cancer Center, The Johns Hopkins University School of Medicine, Baltimore, MD 21287;
Bracha
B
Erlanger
Sidney Kimmel Comprehensive Cancer Center, The Johns Hopkins University School of Medicine, Baltimore, MD 21287;
Heather A
HA
Parsons
Department of Chemical and Biomolecular Engineering, Johns Hopkins University, Baltimore, MD 21218;
Kristen M
KM
Manto
Division of Oncology, Department of Medicine, Washington University School of Medicine, St. Louis, MO 63110; Siteman Cancer Center, Washington University School of Medicine, St. Louis, MO 63141;
Ron
R
Bose
Sidney Kimmel Comprehensive Cancer Center, The Johns Hopkins University School of Medicine, Baltimore, MD 21287;
Josh
J
Lauring
Department of Medicine: Breast Cancer Research Program, Vanderbilt-Ingram Cancer Center, Vanderbilt University, Nashville, TN 37232;
Carlos L
CL
Arteaga
Department of Chemical and Biomolecular Engineering, Johns Hopkins University, Baltimore, MD 21218; Johns Hopkins Institute for NanoBioTechnology, Johns Hopkins University, Baltimore, MD 21218.
Konstantinos
K
Konstantopoulos
Sidney Kimmel Comprehensive Cancer Center, The Johns Hopkins University School of Medicine, Baltimore, MD 21287; Department of Chemical and Biomolecular Engineering, Johns Hopkins University, Baltimore, MD 21218; bpark2@jhmi.edu.
Ben Ho
BH
Park
D015153:Blotting, Western; D045744:Cell Line, Tumor; D002465:Cell Movement / Q000235:genetics*; D049109:Cell Proliferation / Q000502:physiology; D003114:Colony-Forming Units Assay; D005434:Flow Cytometry; D018390:Gene Targeting; D057809:HEK293 Cells; D006801:Humans; D015151:Immunoblotting; D000077341:Lapatinib; D020125:Mutation, Missense / Q000235:genetics*; D009369:Neoplasms / Q000235:genetics*; D011799:Quinazolines; D011804:Quinolines; D018719:Erb-b2 Receptor Tyrosine Kinases / Q000235:genetics*; D015398:Signal Transduction / Q000235:genetics*; D013844:Thiazoles
D000077341:Lapatinib; D011799:Quinazolines; D011804:Quinolines; D018719:Erb-b2 Receptor Tyrosine Kinases; D013844:Thiazoles; C585539:Alpelisib; C508053:ERBB2 protein, human; C487932:neratinib
HER2 missense mutations; breast cancer; mutant oncogenes; targeted therapies