title: Genomic instability causes HGF gene activation in colon cancer cells, promoting their resistance to necroptosis.
abstract: OBJECTIVE
  Genomic instability promotes colon carcinogenesis by inducing genetic mutations, but not all genes affected by this process have been identified. We investigated whether genomic instability in human colorectal cancer (CRC) cells produces mutations in the hepatocyte growth factor (HGF) gene.
  
  
  METHODS
  We genotyped human colon tumor tissues and adjacent nontumor tissues collected from 78 patients University of Pittsburgh Health Sciences and Veterans Hospital, along with 40 human CRC and adjacent nontumor tissues in a commercial microarray. We used cellular, biochemical, and molecular biological techniques to investigate the factors that alter HGF signaling in colon cancer cells and its effects on cell proliferation and survival.
  
  
  RESULTS
  All tested human CRC tissues and cell lines that had microsatellite instability contained truncations in the regulatory deoxyadenosine tract element (DATE) of the HGF gene promoter. The DATE was unstable in 14% (11 of 78) of CRC samples; DATE truncation was also polymorphic and detected in 18% (13 of 78) of CRC tissues without microsatellite instability. In CRC cell lines, truncation of DATE activated expression of HGF, resulting in its autocrine signaling via MET. This promoted cell proliferation and resistance to necroptosis. HGF signaling via MET reduced levels of the receptor-interacting serine-threonine kinase 1, a mediator of necroptosis, in CRC cells. High levels of HGF protein in tumor tissues correlated with lower levels of receptor-interacting serine-threonine kinase 1 and shorter survival times of patients.
  
  
  CONCLUSIONS
  Thirty-one percent of CRC samples contain alterations in the DATE of the HGF promoter. Disruption of the DATE increased HGF signaling via MET and reduced levels of receptor-interacting serine-threonine kinase 1 and CRC cell necroptosis. DATE alteration might be used as a prognostic factor or to select patients for therapies that target HGF-MET signaling.
authors.affiliation: Department of Pathology, School of Medicine, University of Pittsburgh, Pittsburgh, Pennsylvania.
authors.forename: Danushka
authors.initials: D
authors.lastname: Seneviratne
authors.affiliation: Department of Pathology, School of Medicine, University of Pittsburgh, Pittsburgh, Pennsylvania.
authors.forename: Jihong
authors.initials: J
authors.lastname: Ma
authors.affiliation: Department of Pathology, School of Medicine, University of Pittsburgh, Pittsburgh, Pennsylvania.
authors.forename: Xinping
authors.initials: X
authors.lastname: Tan
authors.affiliation: Department of Pathology, School of Medicine, University of Pittsburgh, Pittsburgh, Pennsylvania.
authors.forename: Yong-Kook
authors.initials: YK
authors.lastname: Kwon
authors.affiliation: Department of Pathology, School of Medicine, University of Pittsburgh, Pittsburgh, Pennsylvania.
authors.forename: Eman
authors.initials: E
authors.lastname: Muhammad
authors.affiliation: Department of Pathology, School of Medicine, University of Pittsburgh, Pittsburgh, Pennsylvania.
authors.forename: Mona
authors.initials: M
authors.lastname: Melhem
authors.affiliation: Department of Pathology, School of Medicine, University of Pittsburgh, Pittsburgh, Pennsylvania.
authors.forename: Marie C
authors.initials: MC
authors.lastname: DeFrances
authors.affiliation: Department of Pathology, School of Medicine, University of Pittsburgh, Pittsburgh, Pennsylvania. Electronic address: rezazar@pitt.edu.
authors.forename: Reza
authors.initials: R
authors.lastname: Zarnegar
mesh_terms: D000230:Adenocarcinoma / Q000235:genetics* / Q000378:metabolism / Q000401:mortality / Q000473:pathology; D000368:Aged; D000369:Aged, 80 and over; D017209:Apoptosis; D019898:Autocrine Communication; D049109:Cell Proliferation; D002470:Cell Survival; D003110:Colonic Neoplasms / Q000235:genetics* / Q000378:metabolism / Q000401:mortality / Q000473:pathology; D053843:DNA Mismatch Repair; D005260:Female; D020869:Gene Expression Profiling / Q000379:methods; D015972:Gene Expression Regulation, Neoplastic; D020022:Genetic Predisposition to Disease; D042822:Genomic Instability; D045325:HCT116 Cells; D019073:HT29 Cells; D017228:Hepatocyte Growth Factor / Q000235:genetics* / Q000378:metabolism; D006801:Humans; D008297:Male; D053842:Microsatellite Instability; D008875:Middle Aged; D009336:Necrosis; D020411:Oligonucleotide Array Sequence Analysis; D010641:Phenotype; D011379:Prognosis; D011401:Promoter Regions, Genetic; D019859:Proto-Oncogene Proteins c-met / Q000378:metabolism; D053422:Receptor-Interacting Protein Serine-Threonine Kinases / Q000378:metabolism; D015398:Signal Transduction; D013997:Time Factors; D015533:Transcriptional Activation; D014162:Transfection
chemical_list: C066855:HGF protein, human; D017228:Hepatocyte Growth Factor; C491743:MET protein, human; D019859:Proto-Oncogene Proteins c-met; C506249:RIPK1 protein, human; D053422:Receptor-Interacting Protein Serine-Threonine Kinases
keywords: Gene Regulation; Oncogene; Receptor Tyrosine Kinase; Signal Transduction