title: Kinase-driven pathways of EGFR in lung carcinomas: perspectives on targeting therapy.
abstract: Despite remarkable advances in oncology medicine, the prognosis of lung cancer patients has not greatly improved over the past few decades. To overcome the current limit, new classes of agents that specifically target particular cascades have been developed. Gefitinib and erlotinib, which are tyrosine kinase inhibitors specific for the epidermal growth factor receptor (EGFR), have provided hope for better survival. The relationship between the sensitivity to gefitinib and the tumors' EGFR mutations have allowed the selective and accelerated use of these therapies. However, their efficacy is still limited, predominantly due to side effects and drug resistance. Further development of rational clinical strategies will require greater clarification of the key signaling factors downstream of EGFR which are potential targets for cancer therapies. In this review, we describe the various observed abnormalities in EGFR, the mechanisms of activation of several critical signaling cascades in lung cancer. Summarizing the data gleaned from preclinical, and clinicopathological aspects, we discuss the molecular mechanisms that may underlie a possible successful response to the blockade of EGFR and/or its downstream signaling.
authors.affiliation: Department of Pathology, Saitama Medical Center, Jichi Medical University, Saitama, Japan.
authors.forename: Yoh
authors.initials: Y
authors.lastname: Dobashi
authors.forename: Shinichiro
authors.initials: S
authors.lastname: Koyama
authors.forename: Yoshihiko
authors.initials: Y
authors.lastname: Kanai
authors.forename: Kenji
authors.initials: K
authors.lastname: Tetsuka
mesh_terms: D000230:Adenocarcinoma / Q000188:drug therapy / Q000503:physiopathology; D000077192:Adenocarcinoma of Lung; D002289:Carcinoma, Non-Small-Cell Lung / Q000188:drug therapy / Q000235:genetics* / Q000503:physiopathology; D019008:Drug Resistance, Neoplasm / Q000235:genetics; D066246:ErbB Receptors / Q000037:antagonists & inhibitors* / Q000235:genetics / Q000378:metabolism; D000077156:Gefitinib; D006801:Humans; D008175:Lung Neoplasms / Q000188:drug therapy* / Q000503:physiopathology; D058990:Molecular Targeted Therapy; D047428:Protein Kinase Inhibitors / Q000627:therapeutic use; D011505:Protein-Tyrosine Kinases / Q000037:antagonists & inhibitors; D051057:Proto-Oncogene Proteins c-akt / Q000378:metabolism; D011799:Quinazolines / Q000627:therapeutic use; D050796:STAT3 Transcription Factor / Q000378:metabolism; D015398:Signal Transduction / Q000187:drug effects; D058570:TOR Serine-Threonine Kinases / Q000378:metabolism
chemical_list: D047428:Protein Kinase Inhibitors; D011799:Quinazolines; D050796:STAT3 Transcription Factor; C546842:MTOR protein, human; D066246:ErbB Receptors; D011505:Protein-Tyrosine Kinases; D051057:Proto-Oncogene Proteins c-akt; D058570:TOR Serine-Threonine Kinases; D000077156:Gefitinib