title: STAT3 and HIF1α Signaling Drives Oncogenic Cellular Phenotypes in Malignant Peripheral Nerve Sheath Tumors.
abstract: Therapeutic options are limited for neurofibromatosis type 1 (NF1)-associated malignant peripheral nerve sheath tumors (MPNST) and clinical trials using drug agents have so far been unsuccessful. This lack of clinical success is likely attributed to high levels of intratumoral molecular heterogeneity and variations in signal transduction within MPNSTs. To better explore the variance of malignant signaling properties within heterogeneous MPNSTs, four MPNST cell lines (ST8814, S462, S1844.1, and S1507.2) were used. The data demonstrate that small-molecule inhibition of the MET proto-oncogene and mTOR had variable outcome when preventing wound healing, cell migration, and invasion, with the S462 cells being highly resistant to both. Of interest, targeted inhibition of the STAT3 transcription factor suppressed wound healing, cell migration, invasion, and tumor formation in all four MPNST lines, which demonstrates that unlike MET and mTOR, STAT3 functions as a common driver of tumorigenesis in NF1-MPNSTs. Of clinical importance, STAT3 knockdown was sufficient to block the expression of hypoxia-inducible factor (HIF)1α, HIF2α, and VEGF-A in all four MPNST lines. Finally, the data demonstrate that wound healing, cell migration, invasion, and tumor formation through STAT3 are highly dependent on HIF signaling, where knockdown of HIF1α ablated these oncogenic facets of STAT3.
  
  
  CONCLUSIONS
  This research reveals that aberrant STAT3 and HIF1a activity drives tumor progression in MPNSTs, indicating that inhibition of the STAT3/HIF1α/VEGF-A signaling axis is a viable treatment strategy.
authors.affiliation: Institute of Cancer and Genetics, Cardiff University, Heath Park, Cardiff, Wales, United Kingdom.
authors.forename: Ellie
authors.initials: E
authors.lastname: Rad
authors.affiliation: Institute of Cancer and Genetics, Cardiff University, Heath Park, Cardiff, Wales, United Kingdom.
authors.forename: Kayleigh
authors.initials: K
authors.lastname: Dodd
authors.affiliation: Institute of Cancer and Genetics, Cardiff University, Heath Park, Cardiff, Wales, United Kingdom.
authors.forename: Laura
authors.initials: L
authors.lastname: Thomas
authors.affiliation: Institute of Cancer and Genetics, Cardiff University, Heath Park, Cardiff, Wales, United Kingdom.
authors.forename: Meena
authors.initials: M
authors.lastname: Upadhyaya
authors.affiliation: Institute of Cancer and Genetics, Cardiff University, Heath Park, Cardiff, Wales, United Kingdom. teea@cardiff.ac.uk.
authors.forename: Andrew
authors.initials: A
authors.lastname: Tee
mesh_terms: D045744:Cell Line, Tumor; D002465:Cell Movement; D055785:Gene Knockdown Techniques; D017228:Hepatocyte Growth Factor / Q000378:metabolism; D006801:Humans; D051795:Hypoxia-Inducible Factor 1, alpha Subunit / Q000235:genetics / Q000378:metabolism*; D000076222:Mechanistic Target of Rapamycin Complex 1; D046912:Multiprotein Complexes / Q000037:antagonists & inhibitors / Q000378:metabolism; D009361:Neoplasm Invasiveness; D009442:Neurilemmoma / Q000378:metabolism*; D025542:Neurofibromin 1 / Q000378:metabolism; D010641:Phenotype; D000090063:Proto-Oncogene Mas; D050796:STAT3 Transcription Factor / Q000235:genetics / Q000378:metabolism*; D015398:Signal Transduction; D058570:TOR Serine-Threonine Kinases / Q000037:antagonists & inhibitors / Q000378:metabolism; D042461:Vascular Endothelial Growth Factor A / Q000378:metabolism; D014945:Wound Healing
chemical_list: C066855:HGF protein, human; C497442:HIF1A protein, human; D051795:Hypoxia-Inducible Factor 1, alpha Subunit; C000715470:MAS1 protein, human; D046912:Multiprotein Complexes; D025542:Neurofibromin 1; D000090063:Proto-Oncogene Mas; D050796:STAT3 Transcription Factor; C494086:STAT3 protein, human; C467484:VEGFA protein, human; D042461:Vascular Endothelial Growth Factor A; D017228:Hepatocyte Growth Factor; D000076222:Mechanistic Target of Rapamycin Complex 1; D058570:TOR Serine-Threonine Kinases