title: Role of ERK-BIM and STAT3-survivin signaling pathways in ALK inhibitor-induced apoptosis in EML4-ALK-positive lung cancer.
abstract: OBJECTIVE
  EML4-ALK (echinoderm microtubule-associated protein-like 4 anaplastic lymphoma kinase) was recently identified as a transforming fusion gene in non-small cell lung cancer. The purpose of the present study was to characterize the mechanism of malignant transformation by EML4-ALK.
  
  
  METHODS
  We established NIH 3T3 cells that stably express variant 1 or 3 of EML4-ALK and examined the signaling molecules that function downstream of EML4-ALK.
  
  
  RESULTS
  Forced expression of EML4-ALK induced marked activation of extracellular signal-regulated kinase (ERK) and STAT3, but not that of AKT. Inhibition of ERK or STAT3 signaling resulted in substantial attenuation of the proliferation of cells expressing either variant of EML4-ALK, suggesting that these signaling pathways function downstream of EML4-ALK in lung cancer cells. The specific ALK inhibitor TAE684 induced apoptosis that was accompanied both by upregulation of BIM, a proapoptotic member of the Bcl-2 family, and by downregulation of survivin, a member of the inhibitor of apoptosis protein (IAP) family, in EML4-ALK-expressing NIH 3T3 cells as well as in H3122 human lung cancer cells harboring endogenous EML4-ALK. Depletion of BIM and overexpression of survivin each inhibited TAE684-induced apoptosis, suggesting that both upregulation of BIM and downregulation of survivin contribute to TAE684-induced apoptosis in EML4-ALK-positive lung cancer cells. Furthermore, BIM and survivin expression was found to be independently regulated by ERK and STAT3 signaling pathways, respectively.
  
  
  CONCLUSIONS
  ALK inhibitor-induced apoptosis is mediated both by BIM upregulation resulting from inhibition of ERK signaling as well as by survivin downregulation resulting from inhibition of STAT3 signaling in EML4-ALK-positive lung cancer cells.
authors.affiliation: Department of Medical Oncology, Kinki University Faculty of Medicine, Osaka, Japan.
authors.forename: Ken
authors.initials: K
authors.lastname: Takezawa
authors.forename: Isamu
authors.initials: I
authors.lastname: Okamoto
authors.forename: Kazuto
authors.initials: K
authors.lastname: Nishio
authors.forename: Pasi A
authors.initials: PA
authors.lastname: Jänne
authors.forename: Kazuhiko
authors.initials: K
authors.lastname: Nakagawa
mesh_terms: D000077548:Anaplastic Lymphoma Kinase; D000818:Animals; D017209:Apoptosis / Q000187:drug effects; D051017:Apoptosis Regulatory Proteins / Q000235:genetics / Q000378:metabolism*; D000072224:Bcl-2-Like Protein 11; D045744:Cell Line, Tumor; D049109:Cell Proliferation; D002471:Cell Transformation, Neoplastic / Q000235:genetics; D005260:Female; D006801:Humans; D015151:Immunoblotting; D051034:Inhibitor of Apoptosis Proteins / Q000235:genetics / Q000378:metabolism*; D008175:Lung Neoplasms / Q000235:genetics / Q000378:metabolism / Q000473:pathology; D008565:Membrane Proteins / Q000235:genetics / Q000378:metabolism*; D051379:Mice; D008819:Mice, Nude; D019950:Mitogen-Activated Protein Kinase 1 / Q000235:genetics / Q000378:metabolism*; D041681:NIH 3T3 Cells; D009374:Neoplasms, Experimental / Q000235:genetics / Q000378:metabolism / Q000473:pathology; D015514:Oncogene Proteins, Fusion / Q000235:genetics / Q000378:metabolism*; D011505:Protein-Tyrosine Kinases / Q000235:genetics / Q000378:metabolism; D011518:Proto-Oncogene Proteins / Q000235:genetics / Q000378:metabolism*; D051057:Proto-Oncogene Proteins c-akt / Q000235:genetics / Q000378:metabolism; D011743:Pyrimidines / Q000494:pharmacology; D034622:RNA Interference; D020794:Receptor Protein-Tyrosine Kinases / Q000037:antagonists & inhibitors / Q000378:metabolism; D050796:STAT3 Transcription Factor / Q000235:genetics / Q000378:metabolism*; D015398:Signal Transduction / Q000187:drug effects; D000077022:Survivin; D014162:Transfection
chemical_list: D051017:Apoptosis Regulatory Proteins; C000606775:BCL2L11 protein, human; C107489:BIRC5 protein, human; D000072224:Bcl-2-Like Protein 11; C000606776:Bcl2l11 protein, mouse; C522504:EML4-ALK fusion protein, human; D051034:Inhibitor of Apoptosis Proteins; D008565:Membrane Proteins; C516714:NVP-TAE684; D015514:Oncogene Proteins, Fusion; D011518:Proto-Oncogene Proteins; D011743:Pyrimidines; D050796:STAT3 Transcription Factor; D000077022:Survivin; C107023:p80(NPM-ALK) protein; C000626173:ALK protein, human; C000626174:Alk protein, mouse; D000077548:Anaplastic Lymphoma Kinase; D011505:Protein-Tyrosine Kinases; D020794:Receptor Protein-Tyrosine Kinases; D051057:Proto-Oncogene Proteins c-akt; C535150:MAPK1 protein, human; D019950:Mitogen-Activated Protein Kinase 1