Thirdhand tobacco smoke exposure increases the genetic background-dependent risk of pan-tumor development in Collaborative Cross mice.

Increasing evidence has shown that thirdhand smoke (THS) exposure is likely to induce adverse health effects. An important knowledge gap remains in our understanding of THS exposure related to cancer risk in the human population. Population-based animal models are useful and powerful in investigating the interplay between host genetics and THS exposure on cancer risk. Here, we used the Collaborative Cross (CC) mouse population-based model system, which recapitulates the genetic and phenotypic diversity observed in the human population, to assess cancer risk after a short period of exposure, between 4 and 9 weeks of age. Eight CC strains (CC001, CC019, CC026, CC036, CC037, CC041, CC042 and CC051) were included in our study. We quantified pan-tumor incidence, tumor burden per mouse, organ tumor spectrum and tumor-free survival until 18 months of age. At the population level, we observed a significantly increased pan-tumor incidence and tumor burden per mouse in THS-treated mice as compared to the control (p = 3.04E-06). Lung and liver tissues exhibited the largest risk of undergoing tumorigenesis after THS exposure. Tumor-free survival was significantly reduced in THS-treated mice compared to control (p = 0.044). At the individual strain level, we observed a large variation in tumor incidence across the 8 CC strains. CC036 and CC041 exhibited a significant increase in pan-tumor incidence (p = 0.0084 and p = 0.000066, respectively) after THS exposure compared to control. We conclude that early-life THS exposure increases tumor development in CC mice and that host genetic background plays an important role in individual susceptibility to THS-induced tumorigenesis. Genetic background is an important factor that should be taken into account when determining human cancer risk of THS exposure.

Tabagismo passivo: implicações genéticas em gerações / Secondhand smoke: genetics implicatons in future generations

Estudos divulgados recentemente, alguns com até 5 décadas de observações, concluíram com alto grau de evidências, que a exposição involuntária e sistemática à fumaça do cigarro tem implicações genéticas em gerações. Vai muito além do risco do "exposto primário". Ficaram evidentes riscos de doenças tabaco relacionadas em descendentes até a 3ª. geração, isto é, de avós para netos, mesmo que estes não sejam expostos à Poluição Tabagística Ambiental (PTA). As leis que controlam o tabagismo em locais públicos ou privados com circulação de pessoas trouxeram grandes benefícios para toda a coletividade, porém, no ambiente domiciliar, no interior do carro ou a exposição de "gestante/feto" a realidade é outra

Recently published studies, some with up to five decades of observations, have concluded with a high degree of evidence that involuntary and systematic exposure to cigarette smoke has genetic implications in generations. It goes far beyond the risk of the "primary exposed". There have been evident risks of tobacco-related diseases in descendants to the third generation, even if they had never been exposed to "Environmental Tobacco Pollution". Laws that control smoking in public or private places, with circulation of people, have brought great benefits to the whole community, However, regarding places such as the home environment, in the car or the exposure of fetus during pregnancy, have shown different results