scholarly journals STAT3 in Breast Cancer Onset and Progression: A Matter of Time and Context

2018 ◽  
Vol 19 (9) ◽  
pp. 2818 ◽  
Author(s):  
Ilenia Segatto ◽  
Gustavo Baldassarre ◽  
Barbara Belletti

Signal transducer and activator of transcription 3 (STAT3) is responsible for mediating the transcriptional programs downstream of several cytokine, growth factor, and oncogenic stimuli. Its expression and activity are consistently linked to cellular transformation, as well as tumor initiation and progression. Due to this central role, STAT3 is widely considered a good target for anti-cancer therapy; however, the success of these approaches has been, so far, very limited. Notably, on one side, STAT3 is aberrantly active in many breast cancers, on the other, at the physiological level, it is the main mediator of epithelial cell death during post-lactation mammary-gland involution, thus strongly suggesting that its biological functions are highly context-specific. One of the most peculiar features of STAT3 is that it can act both in cell-autonomous and non-cell-autonomous manners, simultaneously modulating the phenotypes of the tumor cells and their microenvironment. Here, we focus on the role of STAT3 in breast cancer progression, discussing the potential contrasting roles of STAT3 activation in the establishment of locally recurrent and distant metastatic disease. Based on the most recent literature, depending on the tumor cell type, the local microenvironment status, and the stage of the disease, either STAT3 activation or inactivation can support disease progression. Accordingly, cancer cells dynamically exploit STAT3 activity to carry out transcriptional programs somehow contrasting and complementary, such as supporting survival and growth, dormancy and awakening, stem cell-like features, and inflammation, immune response, and immune evasion. As a consequence, to achieve clinical efficacy, the conception and testing of anti-STAT3 targeted therapies will need a very careful evaluation of these opposing roles and of the most appropriate tumor context, disease stage and patient population to treat.

2021 ◽  
Vol 22 (5) ◽  
pp. 2267
Author(s):  
Roni H. G. Wright ◽  
Miguel Beato

Despite global research efforts, breast cancer remains the leading cause of cancer death in women worldwide. The majority of these deaths are due to metastasis occurring years after the initial treatment of the primary tumor and occurs at a higher frequency in hormone receptor-positive (Estrogen and Progesterone; HR+) breast cancers. We have previously described the role of NUDT5 (Nudix-linked to moiety X-5) in HR+ breast cancer progression, specifically with regards to the growth of breast cancer stem cells (BCSCs). BCSCs are known to be the initiators of epithelial-to-mesenchyme transition (EMT), metastatic colonization, and growth. Therefore, a greater understanding of the proteins and signaling pathways involved in the metastatic process may open the door for therapeutic opportunities. In this review, we discuss the role of NUDT5 and other members of the NUDT family of enzymes in breast and other cancer types. We highlight the use of global omics data based on our recent phosphoproteomic analysis of progestin signaling pathways in breast cancer cells and how this experimental approach provides insight into novel crosstalk mechanisms for stratification and drug discovery projects aiming to treat patients with aggressive cancer.


Cancers ◽  
2020 ◽  
Vol 12 (7) ◽  
pp. 1918
Author(s):  
Yanyuan Wu ◽  
Marianna Sarkissyan ◽  
Ochanya Ogah ◽  
Juri Kim ◽  
Jaydutt V. Vadgama

Background: Metastasis-associated lung adenocarcinoma transcript 1 (MALAT1) is associated with cancer progression. Our study examined the role of MALAT1 in breast cancer and the mechanisms involved in the regulation of MALAT1. Methods: In vitro cell and in vivo animal models were used to examine the role of MALAT1 in breast cancer. The interaction of FOXO1 (Forkhead Box O1) at the promoter region of MALAT1 was investigated by chromatin immunoprecipitation (ChIP) assay. Results: The data shows an elevated expression of MALAT1 in breast cancer tissues and cells compared to non-cancer tissues and cells. The highest level of MALAT1 was observed in metastatic triple-negative breast cancer and trastuzumab-resistant HER2 (human epidermal growth factor receptor 2) overexpressing (HER2+) cells. Knockdown of MALAT1 in trastuzumab-resistant HER2+ cells reversed epithelial to mesenchymal transition-like phenotype and cell invasiveness. It improved the sensitivity of the cell’s response to trastuzumab. Furthermore, activation of Akt by phosphorylation was associated with the upregulation of MALAT1. The transcription factor FOXO1 regulates the expression of MALAT1 via the PI3/Akt pathway. Conclusions: We show that MALAT1 contributes to HER2+ cell resistance to trastuzumab. Targeting the PI3/Akt pathway and stabilizing FOXO1 translocation could inhibit the upregulation of MALAT1.


2017 ◽  
Vol 14 (133) ◽  
pp. 20170313 ◽  
Author(s):  
Silvia Ferrati ◽  
Avinash K. Gadok ◽  
Ashlee D. Brunaugh ◽  
Chi Zhao ◽  
Lara A. Heersema ◽  
...  

Gap junction (GJ) channels facilitate cell–cell communication through the exchange of chemical and mechanical signals, ensuring proper tissue development and homeostasis. The complex, disease stage-dependent role of connexins in breast cancer progression has been extensively studied over the past two decades. In the early stages of breast cancer, substantial evidence supports the role of GJ channels, formed by connexins at the interfaces between neighbouring cells, as suppressors of cell migration and proliferation. These findings suggest that materials that reintroduce connexins into the tumour cell environment have the potential to inhibit cell migration. Here, we report that exposure of highly metastatic MDA-MB-231 breast tumour cells to connexin-rich biovesicle materials potently suppresses cell migration. Specifically, these biovesicles, which can form GJ interfaces with cells, were extracted from the plasma membrane of donor cells engineered to express a high concentration of functional connexin 43 channels. These connexin-rich membrane materials dramatically reduced cell migration in both a transwell migration assay and a scratch closure assay. Collectively, these results suggest that using membrane materials to reintroduce connexins into the tumour cell environment provides a novel approach for combating cell migration and invasion.


2020 ◽  
Vol 22 (1) ◽  
pp. 98
Author(s):  
Adele Vivacqua

Breast cancer is the main cause of morbidity and mortality in women worldwide. However, the molecular pathogenesis of breast cancer remains poorly defined due to its heterogeneity. Several studies have reported that G Protein-Coupled Estrogen Receptor 1 (GPER1) plays a crucial role in breast cancer progression, by binding to estrogens or synthetic agonists, like G-1, thus modulating genes involved in diverse biological events, such as cell proliferation, migration, apoptosis, and metastasis. In addition, it has been established that the dysregulation of short sequences of non-coding RNA, named microRNAs (miRNAs), is involved in various pathophysiological conditions, including breast cancer. Recent evidence has indicated that estrogens may regulate miRNA expression and therefore modulate the levels of their target genes, not only through the classical estrogen receptors (ERs), but also activating GPER1 signalling, hence suggesting an alternative molecular pathway involved in breast tumor progression. Here, the current knowledge about GPER1 and miRNA action in breast cancer is recapitulated, reporting recent evidence on the liaison of these two players in triggering breast tumorogenic effects. Elucidating the role of GPER1 and miRNAs in breast cancer might provide new tools for innovative approaches in anti-cancer therapy.


Metabolites ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 180
Author(s):  
Christina Mertens ◽  
Matthias Schnetz ◽  
Claudia Rehwald ◽  
Stephan Grein ◽  
Eiman Elwakeel ◽  
...  

Macrophages supply iron to the breast tumor microenvironment by enforced secretion of lipocalin-2 (Lcn-2)-bound iron as well as the increased expression of the iron exporter ferroportin (FPN). We aimed at identifying the contribution of each pathway in supplying iron for the growing tumor, thereby fostering tumor progression. Analyzing the expression profiles of Lcn-2 and FPN using the spontaneous polyoma-middle-T oncogene (PyMT) breast cancer model as well as mining publicly available TCGA (The Cancer Genome Atlas) and GEO Series(GSE) datasets from the Gene Expression Omnibus database (GEO), we found no association between tumor parameters and Lcn-2 or FPN. However, stromal/macrophage-expression of Lcn-2 correlated with tumor onset, lung metastases, and recurrence, whereas FPN did not. While the total iron amount in wildtype and Lcn-2−/− PyMT tumors showed no difference, we observed that tumor-associated macrophages from Lcn-2−/− compared to wildtype tumors stored more iron. In contrast, Lcn-2−/− tumor cells accumulated less iron than their wildtype counterparts, translating into a low migratory and proliferative capacity of Lcn-2−/− tumor cells in a 3D tumor spheroid model in vitro. Our data suggest a pivotal role of Lcn-2 in tumor iron-management, affecting tumor growth. This study underscores the role of iron for tumor progression and the need for a better understanding of iron-targeted therapy approaches.


2021 ◽  
pp. 107815522110293
Author(s):  
Amanda V Pirolli ◽  
Tatiana Brusamarello ◽  
Stella S Everton ◽  
Vânia M S Andrzejevski

Breast cancer is the most prevalent type of cancer among women, affecting about 2.1 million worldwide and is responsible for the highest number of cancer-related deaths among women. Approximately 80% of breast cancers express on the surface of hormone receptor cells, such as progesterone and estrogen. In these cases, Adjuvant Hormonal Therapy (AHT) is indicated for a period of five to ten years and consists of taking a daily oral pill. The two most used drugs in AHT are tamoxifen and Aromatase Inhibitors. One of the issues most faced by individuals who are subjected to long periods of treatment is the lack of medication adherence and, consequently, therapeutic inefficiency. It is believed that the monitoring by the pharmacist can contribute to the reduction of errors inherent to the medication, making the treatment more effective and improving the patient's quality of life. The present study aimed to know the perception of patients who live with breast cancer and who do AHT in relation to the educational performance of the clinical pharmacist. This is a qualitative, descriptive and exploratory study, carried out from March to October 2020, with 15 women undergoing treatment at the oncology unit of a tertiary-care hospital in south of Brazil. The data were obtained through a semi-structured interview using an instrument composed of two parts, one referring to the characterization of the participants and the other with the guiding question of the research: "How do you perceive the role of the pharmacist in relation to the guidelines for the use of adjuvant hormonal therapy?". The method of theoretical saturation was used to perform the sample closure and the thematic analysis was used to analyze the data. The participants were between 32 and 74 years old, seven were on tamoxifen therapy and eight on anastrozole, ten were on the first year of treatment, two on the second and three on the third year. The themes that emerged were: pharmacist-patient interaction as a safety factor in hormone therapy; role of the pharmacist in the development of strategies for self-management of the patients during hormone therapy; and, challenges for the pharmacist in relation to hormone therapy through continued guidance. It was evident that the pharmacist's educational action encouraged the participants to carry out the treatment in a more confident and assertive manner according to their particularities and beliefs.


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