Afatinib restrains K-RAS–driven lung tumorigenesis
Menée à l'aide de lignées cellulaires, de xénogreffes et de modèles murins modifiés génétiquement, cette étude montre que l'afatinib réfrène la tumorigenèse pulmonaire liée à l'oncogène KRAS
The K-RAS oncogene is frequently mutated in a variety of cancer types, including lung cancer. Lung cancers with K-RAS mutations are usually difficult to target, and conventional thinking dictates that these tumors are resistant to receptor tyrosine kinase inhibitors because those act upstream of the constitutively active K-RAS protein. However, it appears that receptor tyrosine kinase signaling may have an effect on K-RAS–driven lung tumors after all, by amplifying their growth beyond the effects of K-RAS alone. Kruspig et al. and Moll et al. independently reached this conclusion and identified approved multikinase inhibitors that are effective in the setting of K-RAS–mutant lung cancer in multiple mouse models, suggesting that this may be a potential treatment strategy for human patients as well.On the basis of clinical trials using first-generation epidermal growth factor receptor (EGFR) tyrosine kinase inhibitors (TKIs), it became a doctrine that V-Ki-ras2 Kirsten rat sarcoma viral oncogene homolog (K-RAS) mutations drive resistance to EGFR inhibition in non–small cell lung cancer (NSCLC). Conversely, we provide evidence that EGFR signaling is engaged in K-RAS–driven lung tumorigenesis in humans and in mice. Specifically, genetic mouse models revealed that deletion of Egfr quenches mutant K-RAS activity and transiently reduces tumor growth. However, EGFR inhibition initiates a rapid resistance mechanism involving non-EGFR ERBB family members. This tumor escape mechanism clarifies the disappointing outcome of first-generation TKIs and suggests high therapeutic potential of pan-ERBB inhibitors. On the basis of various experimental models including genetically engineered mouse models, patient-derived and cell line–derived xenografts, and in vitro experiments, we demonstrate that the U.S. Food and Drug Administration–approved pan-ERBB inhibitor afatinib effectively impairs K-RAS–driven lung tumorigenesis. Our data support reconsidering the use of pan-ERBB inhibition in clinical trials to treat K-RAS–mutated NSCLC.