title: Fhit loss-associated initiation and progression of neoplasia in vitro.
abstract: The FHIT gene, encompassing an active common fragile site, FRA3B, is frequently silenced in preneoplasia and cancer, through gene rearrangement or methylation of regulatory sequences. Silencing of Fhit protein expression causes thymidine kinase 1 downregulation, resulting in dNTP imbalance, and spontaneous replication stress that leads to chromosomal aberrations, allele copy number variations, insertions/deletions, and single-base substitutions. Thus, Fhit, which is reduced in expression in the majority of human cancers, is a genome "caretaker" whose loss initiates genome instability in preneoplastic lesions. To follow the early genetic alterations and functional changes induced by Fhit loss that may recapitulate the neoplastic process in vitro, we established epithelial cell lines from kidney tissues of Fhit-/- and +/+ mouse pups early after weaning, and subjected cell cultures to nutritional and carcinogen stress, which +/+ cells did not survive. Through transcriptome profiling and protein expression analysis, we observed changes in the Trp53/p21 and survivin apoptotic pathways in -/- cells, and in expression of proteins involved in epithelial-mesenchymal transition. Some Fhit-deficient cell lines showed anchorage-independent colony formation and increased invasive capacity in vitro. Furthermore, cells of stressed Fhit-/- cell lines formed s.c. and metastatic tumors in nude mice. Collectively, we show that Fhit loss and subsequent thymidine kinase 1 inactivation, combined with selective pressures, leads to neoplasia-associated alterations in genes and gene expression patterns in vitro and in vivo.
authors: Department of Cancer Biology and Genetics, Ohio State University Wexner Medical Center, Columbus, Ohio, USA.
authors: Jenna R
authors: JR
authors: Karras
authors: Department of Cancer Biology and Genetics, Ohio State University Wexner Medical Center, Columbus, Ohio, USA.
authors: Morgan S
authors: MS
authors: Schrock
authors: Department of Cancer Biology and Genetics, Ohio State University Wexner Medical Center, Columbus, Ohio, USA.
authors: Bahadir
authors: B
authors: Batar
authors: Department of Biomedical Informatics, Ohio State University Wexner Medical Center, Columbus, Ohio, USA.
authors: Jie
authors: J
authors: Zhang
authors: Department of Veterinary Biosciences, College of Veterinary Medicine, Ohio State University, Columbus, Ohio, USA.
authors: Krista
authors: K
authors: La Perle
authors: Department of Cancer Biology and Genetics, Ohio State University Wexner Medical Center, Columbus, Ohio, USA.
authors: Teresa
authors: T
authors: Druck
authors: Department of Cancer Biology and Genetics, Ohio State University Wexner Medical Center, Columbus, Ohio, USA.
authors: Kay
authors: K
authors: Huebner
mesh_terms: D017766:Acid Anhydride Hydrolases / Q000172:deficiency* / Q000235:genetics / Q000378:metabolism; D000818:Animals; D017209:Apoptosis / Q000235:genetics; D002465:Cell Movement / Q000235:genetics; D002471:Cell Transformation, Neoplastic / Q000235:genetics* / Q000473:pathology*; D002478:Cells, Cultured; D018450:Disease Progression; D058750:Epithelial-Mesenchymal Transition / Q000235:genetics; D005260:Female; D015972:Gene Expression Regulation, Neoplastic; D007668:Kidney / Q000378:metabolism / Q000473:pathology; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D009362:Neoplasm Metastasis / Q000235:genetics; D009363:Neoplasm Proteins / Q000172:deficiency* / Q000235:genetics / Q000378:metabolism; D015398:Signal Transduction / Q000235:genetics; D013937:Thymidine Kinase / Q000235:genetics; D013997:Time Factors; D014158:Transcription, Genetic; D000099170:Bis(5'-adenosyl)triphosphatase
chemical_list: D017766:Acid Anhydride Hydrolases; D009363:Neoplasm Proteins; D013937:Thymidine Kinase; D000099170:Bis(5'-adenosyl)triphosphatase; C092717:thymidine kinase 1
keywords: Cell transformation; common fragile site; genome instability; kidney cell lines; tumorigenicity