==== Front Innov Aging Innov Aging innovateage Innovation in Aging 2399-5300 Oxford University Press US 10.1093/geroni/igaa057.2656 igaa057.2656 Abstracts Session 6540 (Symposium) AcademicSubjects/SOC02600 Uncovering the Molecular Underpinnings of Oxidative Stress-Induced Senescence Carpenter Melissa Pomatto Laura Corrales-Diaz Kato Jonathan Wong Sarah Bosompra Oye Bernier Michel de Cabo Rafael National Institute on Aging, Bethesda, Maryland, United States 2020 16 12 2020 16 12 2020 4 Suppl 1 Program Abstracts from The GSA 2020 Annual Scientific Meeting “Turning 75: Why Age Matters”742 742 © The Author(s) 2020. Published by Oxford University Press on behalf of The Gerontological Society of America.2020This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted reuse, distribution, and reproduction in any medium, provided the original work is properly cited.Abstract The aging process is sexually dimorphic, with males having higher occurrence rates of cancer and facing a greater risk of mortality. Sexual dimorphism in the response to cellular damage may account for distinct phenotypic changes with age as they relate to the accumulation of cellular damage leading to cancer. Cellular senescence triggers permanent cell cycle arrest in order to protect against malignant growth. However, organismal senescence increases with age and is associated with the release of pro-inflammatory signals (cytokines, chemokines, and proteases) known as the ‘senescence-associated-secretory-phenotype’ (SASP) that, if unchecked, accelerates tissue damage and creates a microenvironment ripe for cancer development. In this study, we hypothesized that sexual disparities in mortality and cancer prevalence stems from differences in the rate of accumulation of senescent cells in mice. Male and female C57BL/6J mice were fed ad libitum or subjected to 30% calorie restriction, a nutritional intervention known to delay the onset of various cancers and prevent senescent cell accumulation. Primary skin fibroblasts were collected longitudinally to allow measurement of cell proliferation, wound healing and the release of SASP factors. The results indicate that when compared to males, fibroblasts of CR-fed females showed significant improvements in cell growth rate, wound healing and SASP markers vs. AL controls. Work is underway to determine how sex influences cellular protective pathways. Thus, like other cell processes, cellular senescence is unequal between males and females and CR delays the emergence of the senescence phenotype.