scholarly journals Obesity-Altered Adipose Stem Cells Promote ER+ Breast Cancer Metastasis through Estrogen Independent Pathways

2019 ◽  
Vol 20 (6) ◽  
pp. 1419 ◽  
Author(s):  
Rachel A. Sabol ◽  
Adam Beighley ◽  
Paulina Giacomelli ◽  
Rachel M. Wise ◽  
Mark A. A. Harrison ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Stem Cells ◽  
Estrogen Receptor ◽  
Tumor Growth ◽  
Estrogen Receptor Alpha ◽  
Cancer Metastasis ◽  
Breast Cancer Metastasis ◽  
Adipose Stem Cells ◽  
Estrogen Signaling ◽  
Promote Tumor Growth

Adipose stem cells (ASCs) play an essential role in tumor microenvironments. These cells are altered by obesity (obASCs) and previous studies have shown that obASCs secrete higher levels of leptin. Increased leptin, which upregulates estrogen receptor alpha (ERα) and aromatase, enhances estrogen bioavailability and signaling in estrogen receptor positive (ER+) breast cancer (BC) tumor growth and metastasis. In this study, we evaluate the effect of obASCs on ER+BC outside of the ERα signaling axis using breast cancer models with constitutively active ERα resulting from clinically relevant mutations (Y537S and D538G). We found that while obASCs promote tumor growth and proliferation, it occurs mostly through abrogated estrogen signaling when BC has constitutive ER activity. However, obASCs have a similar promotion of metastasis irrespective of ER status, demonstrating that obASC promotion of metastasis may not be completely estrogen dependent. We found that obASCs upregulate two genes in both ER wild type (WT) and ER mutant (MUT) BC: SERPINE1 and ABCB1. This study demonstrates that obASCs promote metastasis in ER WT and MUT xenografts and an ER MUT patient derived xenograft (PDX) model. However, obASCs promote tumor growth only in ER WT xenografts.

scholarly journals Regulatory Interplay between miR-181a-5p and Estrogen Receptor Signaling Cascade in Breast Cancer

Cancers ◽  
2021 ◽  
Vol 13 (3) ◽  
pp. 543
Author(s):  
Rosaria Benedetti ◽  
Chiara Papulino ◽  
Giulia Sgueglia ◽  
Ugo Chianese ◽  
Tommaso De Marchi ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Estrogen Receptor ◽  
Endocrine Therapy ◽  
Mirna Expression ◽  
Estrogen Receptor Alpha ◽  
Estrogen Signaling ◽  
Integrated Analysis ◽  
Tumor Resistance ◽  
Estrogen Receptor Signaling

The efficacy and side effects of endocrine therapy in breast cancer (BC) depend largely on estrogen receptor alpha (ERα) expression, the specific drug administered, and treatment scheduling. Although the benefits of endocrine therapy outweigh any adverse effects in the initial stages of BC, later- or advanced-stage tumors acquire resistance to treatments. The mechanisms underlying tumor resistance to therapy are still not well understood, posing a major challenge for BC patient care. Epigenetic regulation and miRNA expression may be involved in the switch from a treatment-sensitive to a treatment-resistant state and could provide a valid therapeutic strategy for ERα negative BC. Here, a hybrid lysine-specific histone demethylase inhibitor, MC3324, displaying selective estrogen receptor down-regulator-like activities in BC, was used to highlight the interplay between epigenetic and ERα signaling. MC3324 anticancer action is mediated by microRNA (miRNA) expression regulation, indicating an innovative function for this molecule. Integrated analysis suggests a crosstalk between estrogen signaling, ERα interactors, miRNAs, and their putative targets. Specifically, miR-181a-5p expression is regulated by MC3324 and has an impact on cellular levels of ERα. A comparison of breast tumor versus healthy mammary tissues confirmed the important role of miR-181a-5p in ERα regulation and points to its putative predictive function in BC therapy.

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