title: Tobacco Use Increases Oxidative DNA Damage in Sperm - Possible Etiology of Childhood Cancer.
abstract: BACKGROUND
  Cigarette smoking and tobacco chewing are common modes of consuming tobacco all over the world. Parents need to be aware that germ cell integrity is vital for birth of healthy offspring as biological parenting begins much before birth of a child and even before conception. The present study was conducted to determine the etiology of non-familial sporadic heritable retinoblastoma (NFSHRb), by evaluating oxidative sperm DNA damage in fathers due to use of tobacco (smoking and chewing).
  
  
  METHODS
  We recruited 145 fathers of NFSHRb children and 53 fathers of healthy children (controls) in the study. Tobacco history was obtained by personal interview. Seminal reactive oxygen species (ROS) in semen, sperm DNA fragmentation index (DFI) and 8 hydroxy 2' deoxyguanosine (8-OHdG) levels in sperm were evaluated. The RB1 gene was screened in genomic blood DNA of parents of children with NFSHRb and controls. Odds ratios (ORs) derived from conditional logistic regression models.
  
  
  RESULTS
  There was significant difference in the levels of ROS (p<0.05), DFI (p<0.05) and 8-OHdG (p<0.05) between tobacco users and non-users. The OR of NFSHRb for smokers was 7.29 (95%CI 2.9-34.5, p<0.01), for tobacco chewers 4.75 (2.07-10.9, p<0.05) and for both 9.11 (3.79-39.2; p<0.01).
  
  
  CONCLUSIONS
  This study emphasizes the adverse effect of tobacco on the paternal genome and how accumulation of oxidative damage in sperm DNA may contribute to the etiology of NFSHRb. In an ongoing parallel study in our laboratory, 11 of fathers who smoked underwent. Meditation and yoga interventions, showed significant decline in levels of highly mutagenic oxidised DNA adducts after 6 months. Thus our lifestyle and social habits impact sperm DNA integrity and simple interventions like yoga and meditation are therapeutic for oxidative damage to sperm DNA.
authors.affiliation: Laboratory for Molecular Reproduction and Genetics, Department of Anatomy, All India Institute of Medical Sciences, New Delhi, India E-mail : rima_dada@rediffmail.com.
authors.forename: Shiv Basant
authors.initials: SB
authors.lastname: Kumar
authors.forename: Bhavna
authors.initials: B
authors.lastname: Chawla
authors.forename: Shilpa
authors.initials: S
authors.lastname: Bisht
authors.forename: Raj Kumar
authors.initials: RK
authors.lastname: Yadav
authors.forename: Rima
authors.initials: R
authors.lastname: Dada
mesh_terms: D000080242:8-Hydroxy-2'-Deoxyguanosine; D000328:Adult; D016022:Case-Control Studies; D004247:DNA / Q000097:blood; D053938:DNA Fragmentation; D003849:Deoxyguanosine / Q000031:analogs & derivatives / Q000378:metabolism; D006801:Humans; D007223:Infant; D008297:Male; D018384:Oxidative Stress; D018812:Paternal Exposure / Q000009:adverse effects*; D017382:Reactive Oxygen Species / Q000378:metabolism; D019572:Retinal Neoplasms / Q000453:epidemiology / Q000209:etiology*; D012175:Retinoblastoma / Q000453:epidemiology / Q000209:etiology*; D016160:Retinoblastoma Protein / Q000235:genetics*; D013094:Spermatozoa / Q000378:metabolism*; D064424:Tobacco Use / Q000009:adverse effects*; D055815:Young Adult
chemical_list: D017382:Reactive Oxygen Species; D016160:Retinoblastoma Protein; D000080242:8-Hydroxy-2'-Deoxyguanosine; D004247:DNA; D003849:Deoxyguanosine