Savenkov, O. | Search bioRxiv

bioRxiv2022

Obesity promotes breast epithelium DNA damage in BRCA mutation carriers

Obesity is an established risk factor for breast cancer among women in the general population after menopause. Whether elevated bodyweight is a risk factor for women with a germline mutation in BRCA1 or BRCA2 is less clear due to inconsistent findings from epidemiological studies and lack of mechanistic studies in this population. Here, we show that DNA damage in normal breast epithelium of BRCA mutation carriers is positively correlated with body mass index and with biomarkers of metabolic dysfunction. Additionally, RNA-sequencing reveals significant obesity-associated alterations to the breast adipose microenvironment of BRCA mutation carriers, including activation of estrogen biosynthesis, which impacts neighboring breast epithelial cells. We found that blockade of estrogen biosynthesis or estrogen receptor activity decreases DNA damage, whereas treatment with leptin or insulin increases DNA damage in BRCA heterozygous epithelial cells. Furthermore, we show that increased adiposity is associated with mammary gland DNA damage and increased penetrance of mammary tumors in Brca1+/- mice. Overall, our results provide mechanistic evidence in support of a link between bodyweight and breast cancer development in BRCA mutation carriers and suggests that maintaining a healthy bodyweight or pharmacologically targeting estrogen or metabolic dysfunction may reduce the risk of breast cancer in this population. One Sentence SummaryElevated bodyweight is positively associated with DNA damage in breast epithelium of BRCA mutation carriers

cancer biology↗

bioRxiv2017

Somatic Mutations Predict Acute Myeloid Leukemia Years Before Diagnosis

BackgroundSomatic mutations observed in clonal hematopoiesis are associated with increased age and risk of hematological malignancies. However, the limited number of acute myeloid leukemia (AML) patients in studies of clonal hematopoiesis thus far has precluded determination of the spectrum of mutations leading to AML and their impact on risk and time to diagnosis.\n\nMethodsThe relationship between baseline mutations and subsequent AML was determined in a case-control study design. 212 women eventually diagnosed with AML (median time: 9.8 years) were identified from the Womens Health Initiative cohort alongside 212 matched AML-free controls. Deep sequencing of 67 genes was performed on DNA isolated from peripheral blood to detect subclonal mutations.\n\nResultsThe presence of any mutation was associated with increased odds of eventual AML (odds ratio [OR] 4.0; 95% confidence interval [CI], 2.5-6.3). These odds were further elevated with mutations in IDH1/2 (OR 8.4; 95% CI, 1.4-51.9), TP53 (OR 54.2; 95% CI, 2.9-1017.7), or spliceosome genes (OR 5.6; 95% CI, 1.5-20.6). Eventual AML diagnosis occurred in all or most participants with mutations in TP53 (N=23/23) or IDH1/2 (N=15/16). Mutations indicated sooner AML diagnosis (median 8.0 vs. 11.9 years; P < 0.001) with TP53 mutations demonstrating increased odds of AML within 5 years (OR 3.6; 95% CI, 1.4-9.1).\n\nConclusionsMutations are present in peripheral blood of AML patients a decade prior to AML diagnosis with mutations in TP53 producing especially rapid presentation. Strategies for monitoring of high-risk populations are needed and clinical trials of potential early interventions can be considered.

cancer biology↗