Tissue-Specific Effects of Loss of Estrogen during Menopause and Aging

The roles of estrogens have been best studied in the breast, breast cancers, and in the female reproductive tract. However, estrogens have important functions in almost every tissue in the body. Recent clinical trials such as the Women’s Health Initiative have highlighted both the importance of estrogens and how little we know about the molecular mechanism of estrogens in these other tissues. In this review, we illustrate the diverse functions of estrogens in the bone, adipose tissue, skin, hair, brain, skeletal muscle and cardiovascular system, and how the loss of estrogens during aging affects these tissues. Early transcriptional targets of estrogen are reviewed in each tissue. We also describe the tissue-specific effects of selective estrogen receptor modulators (SERMs) used for the treatment of breast cancers and postmenopausal symptoms

WNT10B/β-catenin signalling induces HMGA2 and proliferation in metastatic triple-negative breast cancer

Wnt/β-catenin signalling has been suggested to be active in basal-like breast cancer. However, in highly aggressive metastatic triple-negative breast cancers (TNBC) the role of β-catenin and the underlying mechanism(s) for the aggressiveness of TNBC remain unknown. We illustrate that WNT10B induces transcriptionally active β-catenin in human TNBC and predicts survival-outcome of patients with both TNBC and basal-like tumours. We provide evidence that transgenic murine Wnt10b-driven tumours are devoid of ERα, PR and HER2 expression and can model human TNBC. Importantly, HMGA2 is specifically expressed during early stages of embryonic mammogenesis and absent when WNT10B expression is lost, suggesting a developmentally conserved mode of action. Mechanistically, ChIP analysis uncovered that WNT10B activates canonical β-catenin signalling leading to up-regulation of HMGA2. Treatment of mouse and human triple-negative tumour cells with two Wnt/β-catenin pathway modulators or siRNA to HMGA2 decreases HMGA2 levels and proliferation. We demonstrate that WNT10B has epistatic activity on HMGA2, which is necessary and sufficient for proliferation of TNBC cells. Furthermore, HMGA2 expression predicts relapse-free-survival and metastasis in TNBC patients

BRCA1 Forms a Functional Complex with γ-H2AX as a Late Response to Genotoxic Stress

Following genotoxic stress, the histone H2AX becomes phosphorylated at serine 139 by the ATM/ATR family of kinases. The tumor suppressor BRCA1, also phosphorylated by ATM/ATR kinases, is one of several proteins that colocalize with phospho-H2AX (γ-H2AX) at sites of active DNA repair. Both the precise mechanism and the purpose of BRCA1 recruitment to sites of DNA damage are unknown. Here we show that BRCA1 and γ-H2AX form an acid-stable biochemical complex on chromatin after DNA damage. Maximal association of BRCA1 with γ-H2AX correlates with reduced global γ-H2AX levels on chromatin late in the repair process. Since BRCA1 is known to have E3 ubiquitin ligase activity in vitro, we examined H2AX for evidence of ubiquitination. We found that H2AX is ubiquitinated at lysines 119 and 119 in vivo and that blockage of 26S proteasome function stabilizes γ-H2AX levels within cells. When BRCA1 levels were reduced, ubiquitination of H2AX was also reduced, and the cells retained higher levels of phosphorylated H2AX. These results indicate that BRCA1 is recruited into stable complexes with γ-H2AX and that the complex is involved in attenuation of the γ-H2AX repair signal after DNA damage

Evaluation of an In-vehicle Monitoring System Among an Oil and Gas Well Servicing Fleet

A pilot study of an in-vehicle monitoring system (IVMS) was conducted among a fleet of oil and gas well servicing vehicles. Data collected from the fleet were handled anonymously across 21 IVMS-instrumented light vehicle pickup trucks. Data were also collected on a sample of four participating drivers, one manager and three site workers, whose vehicles were instrumented with an IVMS and a miniature data acquisition system (MiniDAS). Among the 21 IVMS-instrumented trucks, there was a 60% reduction in speeding events and a 50% reduction in aggressive driving events. Questionnaires on the IVMS showed that drivers remained neutral to positive after the study was completed and rated the functionality of the IVMS positively. Analysis of the driving patterns of the four participants with MiniDAS-equipped vehicles showed long hours (average daily on-duty and commute time of 15.4 hours for the three site workers) and significant driving time on unimproved roads, which offer their own sets of hazards distinct from highway driving

WNT5B in Physiology and Disease

WNT5B, a member of the WNT family of proteins that is closely related to WNT5A, is required for cell migration, cell proliferation, or cell differentiation in many cell types. WNT5B signals through the non-canonical β-catenin-independent signaling pathway and often functions as an antagonist of canonical WNT signaling. Although WNT5B has a high amino acid identity with WNT5A and is often assumed to have similar activities, WNT5B often exhibits unique expression patterns and functions. Here, we describe the distinct effects and mechanisms of WNT5B on development, bone, adipose tissue, cardiac tissue, the nervous system, the mammary gland, the lung and hematopoietic cells, compared to WNT5A. We also highlight aberrances in non-canonical WNT5B signaling contributing to diseases such as osteoarthritis, osteoporosis, obesity, type 2 diabetes mellitus, neuropathology, and chronic diseases associated with aging, as well as various cancers

Abstract 3894: WNT5B in osteosarcoma stem cells

Abstract Osteosarcoma is a rare but deadly pediatric bone cancer. As it stands, there is no targeted therapy available for osteosarcoma. Therefore, patients are left with chemotherapy and surgical resection as their only treatment options. Further, osteosarcoma frequently metastasizes to the lungs and patients with metastatic disease have a dismal overall survival rate of 20% due to the lack of targeted therapy. Therefore, the goal of this study is to understand the role of the WNT5B signaling pathway in osteosarcoma, as it could be a potential therapeutic target. Using RNA sequencing from publicly available data sets and immunohistochemistry on tumor microarrays, we show that WNT5B is overexpressed in a subset of osteosarcoma patients. In these high expressing patients, WNT5B’s overexpression correlates to metastasis and worse overall survival. Due to the significant increase in WNT5B expression between primary tumors and metastasis, we began looking at the stem cell population of osteosarcoma cells. By selecting for the osteosarcoma stem cells using spheroid assays, we show that both protein and mRNA levels of WNT5B are enhanced in the stem cell population compared to the standard adherent cell population. Then, we looked at stemness markers and we show that WNT5B regulates the stemness gene SOX2. We then performed limiting dilution sphere assays to assess the role of WNT5B in sphere forming. We reveal that WNT5B is directly responsible for the sphere forming efficiency, as evidenced by a 50% reduction in spheres formed between 143B control and 143B WNT5B knockdown cells. Additionally, WNT5B drives proliferation and migration of osteosarcoma cancer stem cells as there is significantly decreased sphere size and migratory distance in WNT5B knockdown cells compared to control cells, and there is significantly increased sphere size and migration with the addition of recombinant WNT5B. Through revealing a novel role for WNT5B in osteosarcoma cancer stem cells, we present the WNT5B pathway as a candidate for therapeutically targeting the clinical implications of cancer stem cells, that is, the development of chemoresistance, metastasis and relapse. Citation Format: Rachel S. Perkins, Sarocha Suthon, Gustavo A. Miranda-Carboni, Susan A. Krum. WNT5B in osteosarcoma stem cells [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 3894.</jats:p