Abstract 2890: Paternal pre-conception stress as a potential risk factor for neuroblastoma
Authors: Hong Sung-Hyeok , Galli Susana , Cruz Raquel Santana da , Jin Lu , Wetlisbach Larissa , Zhu Shiya , Malik Abir , Tilan Jason , Assis Sonia de , Kitlinska Joanna B. 
Published: August 2019

Abstract
Neuroblastomas (NBs) are pediatric tumors that lack adequate treatment for their aggressive form, despite many efforts focusing on novel therapies. Although the disease is known to have a genetic background, its etiology cannot be explained solely by genetics. Yet, the role of environment in NB development is understudied. Thus, there are no established risk factors for NB aside from rare genetic predispositions and therefore no preventative measures. NBs arise due to defects in sympathetic neuron (SN) differentiation, which occurs in the fetus. Thus, we hypothesize that prenatal or pre-conception exposures may interfere with this process and promote NB. Maternal stress during pregnancy and paternal pre-conception stress induce neurodevelopmental defects in offspring by direct effects on fetal development or epigenetic changes, respectively. Indeed, we have previously shown that in a mouse model of NB prenatal stress interferes with SN differentiation in offspring, accelerating NB development and leading to its increased frequency and malignancy. The goal of the current study was to determine if a similar increase in risk of NB development can result from paternal pre-conception stress. To test the effect of paternal stress on NB, we subjected TH-MYCN males to 6 weeks of chronic unpredictable stress (CUS) prior to mating with wild type females and assessed the impact of stress on 1) miRNA content in the germline (RNAseq); 2) fertility and fetal survival; 3) NB frequency, latency, growth and metastasis in their hemizygous TH-MYCN offspring (periodic MRI, histological analyses). CUS resulted in significant changes in non-coding RNA content of the germline, including miRNAs and tsRNAs. Of particular interest was a stress-induced down-regulation of sperm miRNAs, including miR-200b and miR-128, which are involved in neuroblast differentiation, inhibit NB invasiveness and are inactivated in NB tumors. Paternal stress decreased the rate of successful pregnancies from 75% in controls to 37.5% and increased frequency of death in utero from 5.5% to 29.2% (p=0.02). Moreover, offspring of stressed fathers exhibited accelerated NB development (60% vs 0% of mice with tumors at 6 weeks of age for CUS and control groups, respectively; p=0.03) and growth (p=0.3), higher tumor frequency (60% vs 25% at 14 weeks of age, p=0.03), as well as a trend toward a more metastatic phenotype. However, these effects on NB formation and phenotype were observed solely in male offspring. In summary, our data provide the first evidence for the role of paternal preconception stress in NB development. If confirmed, our findings may open new avenues for NB prevention and identifying biomarkers of increased NB risk.
Citation Format: Sung-Hyeok Hong, Susana Galli, Raquel Santana da Cruz, Lu Jin, Larissa Wetlisbach, Shiya Zhu, Abir Malik, Jason Tilan, Sonia de Assis, Joanna B. Kitlinska. Paternal pre-conception stress as a potential risk factor for neuroblastoma [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 2890.