Tobacco Use Increases Oxidative DNA Damage in Sperm - Possible Etiology of Childhood Cancer.

Shiv Basant Kumar,Rima Dada,Shilpa Bisht,Bhavna Chawla,Raj Kumar Yadav

doi:10.7314/apjcp.2015.16.16.6967

Abstract

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). 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. 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). 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.

Highlights

In the recent years, there has been a decline in male reproductive health and standard semen parameters
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 non-familial sporadic heritable retinoblastoma (NFSHRb)
Oxidative stress is known to up regulate levels of DNA methyltransferases (DNMT) and seminal oxidative stress may lead to epigenetic alterations and a recent study has reported that paternal sperm DNA methylation is associated with early signs of autism (Feinberg et al, 2015)

Summary

Introduction

There has been a decline in male reproductive health and standard semen parameters (sperm count, morphology and motility). Oxidative stress is known to up regulate levels of DNA methyltransferases (DNMT) and seminal oxidative stress may lead to epigenetic alterations and a recent study has reported that paternal sperm DNA methylation is associated with early signs of autism (Feinberg et al, 2015). The current study aimed to assess the effect of use of tobacco by father’s in the etiology of oxidative sperm DNA damage which may lead to NFSHRb in the offspring. In this study we highlight the deterioration in sperm quality and accumulation of mutagenic bases which we believe may be the cause of childhood cancer and the significant decline in oxidative damage to Sperm genome following meditation and yoga intervention

Materials and Methods

Statistical analysis Statistical analysis was performed using the SPSS

Findings

Discussion