title: Resveratrol selectively induces DNA Damage, independent of Smad4 expression, in its efficacy against human head and neck squamous cell carcinoma.
abstract: OBJECTIVE
  Alterations in Smad4 signaling and its loss cause genomic instability and head and neck squamous cell carcinoma (HNSCC), suggesting that agents that target both Smad4-dependent and -independent pathways could control HNSCC.
  
  
  METHODS
  Resveratrol efficacy was evaluated against the HNSCC cells FaDu, Cal27, Det562, and Cal27-Smad4 for viability, DNA damage, cell-cycle progression, and apoptosis, as well as γ-H2AX expression, and focus formation (γ-H2AX and Brca1). Resveratrol efficacy was also examined in nude mice for FaDu xenograft growth. Xenografts were analyzed for γ-H2AX and cleaved caspase-3.
  
  
  RESULTS
  Resveratrol (5-50 μmol/L) suppressed viability and induced DNA damage in FaDu and Cal27 cells but not in normal human epidermal keratinocytes and human foreskin fibroblasts, showing its selectivity toward HNSCC cells; however, Det562 cells were resistant to resveratrol even at 100 μmol/L. Cal27 cells stably transfected with Smad4 showed similar resveratrol effects as parental Cal27, indicating that a lack of resveratrol effect in Det562 cells was independent of Smad4 status in these cells. Furthermore, resveratrol caused S-phase arrest and apoptotic death of FaDu and Cal27 cells together with induction of Brca1 and γ-H2AX foci. Resveratrol (50 mg/kg body weight) treatment also inhibited FaDu tumor growth in nude mice, and γ-H2AX and cleaved caspase-3 were strongly increased in xenografts from resveratrol-treated mice compared with controls.
  
  
  CONCLUSIONS
  Our findings for the first time showed antiproliferative, DNA damaging, and apoptotic effects of resveratrol in HNSCC cells independent of Smad4 status, both in vitro and in vivo, suggesting that more studies are needed to establish its potential usefulness against HNSCC.
authors.affiliation: Department of Pharmaceutical Sciences, University of Colorado Denver, Aurora, Colorado 80045, USA.
authors.forename: Alpna
authors.initials: A
authors.lastname: Tyagi
authors.forename: Mallikarjuna
authors.initials: M
authors.lastname: Gu
authors.forename: Takenori
authors.initials: T
authors.lastname: Takahata
authors.forename: Barbara
authors.initials: B
authors.lastname: Frederick
authors.forename: Chapla
authors.initials: C
authors.lastname: Agarwal
authors.forename: Sunitha
authors.initials: S
authors.lastname: Siriwardana
authors.forename: Rajesh
authors.initials: R
authors.lastname: Agarwal
authors.forename: Robert A
authors.initials: RA
authors.lastname: Sclafani
mesh_terms: D000818:Animals; D000972:Antineoplastic Agents, Phytogenic / Q000494:pharmacology; D017209:Apoptosis / Q000187:drug effects; D019313:BRCA1 Protein / Q000378:metabolism; D002294:Carcinoma, Squamous Cell / Q000188:drug therapy* / Q000378:metabolism / Q000473:pathology; D002453:Cell Cycle / Q000187:drug effects; D045744:Cell Line, Tumor; D002470:Cell Survival / Q000187:drug effects; D002478:Cells, Cultured; D020552:Comet Assay; D004249:DNA Damage; D006258:Head and Neck Neoplasms / Q000188:drug therapy* / Q000378:metabolism / Q000473:pathology; D006657:Histones / Q000378:metabolism; D006801:Humans; D015151:Immunoblotting; D007150:Immunohistochemistry; D008297:Male; D051379:Mice; D008819:Mice, Nude; D009154:Mutation; D000077185:Resveratrol; D051901:Smad4 Protein / Q000235:genetics / Q000378:metabolism*; D013267:Stilbenes / Q000494:pharmacology*; D014162:Transfection; D023041:Xenograft Model Antitumor Assays
chemical_list: D000972:Antineoplastic Agents, Phytogenic; D019313:BRCA1 Protein; C492913:BRCA1 protein, human; C468783:H2AX protein, human; D006657:Histones; C497796:SMAD4 protein, human; D051901:Smad4 Protein; D013267:Stilbenes; D000077185:Resveratrol