scholarly journals The Missing Lnc: The Potential of Targeting Triple-Negative Breast Cancer and Cancer Stem Cells by Inhibiting Long Non-Coding RNAs

Cells ◽  
2020 ◽  
Vol 9 (3) ◽  
pp. 763 ◽  
Author(s):  
Justin M Brown ◽  
Marie-Claire D Wasson ◽  
Paola Marcato
Keyword(s):  
Breast Cancer ◽  
Stem Cells ◽  
Cancer Stem Cells ◽  
Cancer Progression ◽  
Triple Negative ◽  
Gene Expression Regulation ◽  
Receptor Expression ◽  
Breast Cancers ◽  
Targeting Therapy ◽  
Non Coding Rnas

Treatment decisions for breast cancer are based on staging and hormone receptor expression and include chemotherapies and endocrine therapy. While effective in many cases, some breast cancers are resistant to therapy, metastasize and recur, leading to eventual death. Higher percentages of tumor-initiating cancer stem cells (CSCs) may contribute to the increased aggressiveness, chemoresistance, and worse outcomes among breast cancer. This may be particularly true in triple-negative breast cancers (TNBCs) which have higher percentages of CSCs and are associated with worse outcomes. In recent years, increasing numbers of long non-coding RNAs (lncRNAs) have been identified as playing an important role in breast cancer progression and some of these have been specifically associated within the CSC populations of breast cancers. LncRNAs are non-protein-coding transcripts greater than 200 nucleotides which can have critical functions in gene expression regulation. The preclinical evidence regarding lncRNA antagonists for the treatment of cancer is promising and therefore, presents a potential novel approach for treating breast cancer and targeting therapy-resistant CSCs within these tumors. Herein, we summarize the lncRNAs that have been identified as functionally relevant in breast CSCs. Furthermore, our review of the literature and analysis of patient datasets has revealed that many of these breast CSC-associated lncRNAs are also enriched in TNBC. Together, this suggests that these lncRNAs may be playing a particularly important role in TNBC. Thus, certain breast cancer-promoting/CSC-associated lncRNAs could be targeted in the treatment of TNBCs and the CSCs within these tumors should be susceptible to anti-lncRNA therapy.

scholarly journals TrkA Interacts with and Phosphorylates STAT3 to Enhance Gene Transcription and Promote Breast Cancer Stem Cells in Triple-Negative and HER2-Enriched Breast Cancers

Cancers ◽  
2021 ◽  
Vol 13 (10) ◽  
pp. 2340
Author(s):  
Angelina T. Regua ◽  
Noah R. Aguayo ◽  
Sara Abu Jalboush ◽  
Daniel L. Doheny ◽  
Sara G. Manore ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Stem Cells ◽  
Cancer Stem Cells ◽  
Gene Transcription ◽  
Target Genes ◽  
Triple Negative ◽  
Breast Cancer Stem Cells ◽  
Breast Cancers ◽  
Co Activation ◽  
Stat3 Phosphorylation

JAK2–STAT3 and TrkA signaling pathways have been separately implicated in aggressive breast cancers; however, whether they are co-activated or undergo functional interaction has not been thoroughly investigated. Herein we report, for the first time that STAT3 and TrkA are significantly co-overexpressed and co-activated in triple-negative breast cancer (TNBC) and HER2-enriched breast cancer, as shown by immunohistochemical staining and data mining. Through immunofluorescence staining–confocal microscopy and immunoprecipitation–Western blotting, we found that TrkA and STAT3 co-localize and physically interact in the cytoplasm, and the interaction is dependent on STAT3-Y705 phosphorylation. TrkA–STAT3 interaction leads to STAT3 phosphorylation at Y705 by TrkA in breast cancer cells and cell-free kinase assays, indicating that STAT3 is a novel substrate of TrkA. β-NGF-mediated TrkA activation induces TrkA–STAT3 interaction, STAT3 nuclear transport and transcriptional activity, and the expression of STAT3 target genes, SOX2 and MYC. The co-activation of both pathways promotes breast cancer stem cells. Finally, we found that TNBC and HER2-enriched breast cancer with JAK2–STAT3 and TrkA co-activation are positively associated with poor overall metastasis-free and organ-specific metastasis-free survival. Collectively, our study uncovered that TrkA is a novel activating kinase of STAT3, and their co-activation enhances gene transcription and promotes breast cancer stem cells in TNBC and HER2-enriched breast cancer.

scholarly journals LncRNA PART1 Promotes Proliferation and Migration, Is Associated with Cancer Stem Cells, and Alters the miRNA Landscape in Triple-Negative Breast Cancer

Cancers ◽  
2021 ◽  
Vol 13 (11) ◽  
pp. 2644
Author(s):  
Brianne M. Cruickshank ◽  
Marie-Claire D. Wasson ◽  
Justin M. Brown ◽  
Wasundara Fernando ◽  
Jaganathan Venkatesh ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Stem Cells ◽  
Gene Regulation ◽  
Cancer Stem Cells ◽  
Triple Negative ◽  
Breast Cancers ◽  
Breast Cancer Patients ◽  
Mammosphere Formation ◽  
Basal Like Breast Cancer ◽  
Myosin Va

Triple-negative breast cancers (TNBCs) are aggressive, lack targeted therapies and are enriched in cancer stem cells (CSCs). Novel therapies which target CSCs within these tumors would likely lead to improved outcomes for TNBC patients. Long non-coding RNAs (lncRNAs) are potential therapeutic targets for TNBC and CSCs. We demonstrate that lncRNA prostate androgen regulated transcript 1 (PART1) is enriched in TNBCs and in Aldefluorhigh CSCs, and is associated with worse outcomes among basal-like breast cancer patients. Although PART1 is androgen inducible in breast cancer cells, analysis of patient tumors indicates its androgen regulation has minimal clinical impact. Knockdown of PART1 in TNBC cell lines and a patient-derived xenograft decreased cell proliferation, migration, tumor growth, and mammosphere formation potential. Transcriptome analyses revealed that the lncRNA affects expression of hundreds of genes (e.g., myosin-Va, MYO5A; zinc fingers and homeoboxes protein 2, ZHX2). MiRNA 4.0 GeneChip and TaqMan assays identified multiple miRNAs that are regulated by cytoplasmic PART1, including miR-190a-3p, miR-937-5p, miR-22-5p, miR-30b-3p, and miR-6870-5p. We confirmed the novel interaction between PART1 and miR-937-5p. In general, miRNAs altered by PART1 were less abundant than PART1, potentially leading to cell line-specific effects in terms miRNA-PART1 interactions and gene regulation. Together, the altered miRNA landscape induced by PART1 explains most of the protein-coding gene regulation changes (e.g., MYO5A) induced by PART1 in TNBC.

scholarly journals Targeting Brain-Adaptive Cancer Stem Cells Prohibits Brain Metastatic Colonization of Triple-Negative Breast Cancer

2018 ◽  
Vol 78 (8) ◽  
pp. 2052-2064 ◽  
Author(s):  
Ding Ren ◽  
Xiaoping Zhu ◽  
Ren Kong ◽  
Zhen Zhao ◽  
Jianting Sheng ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Stem Cells ◽  
Cancer Stem Cells ◽  
Triple Negative Breast Cancer ◽  
Triple Negative ◽  
Metastatic Colonization

scholarly journals Counteracting Chemoresistance with Metformin in Breast Cancers: Targeting Cancer Stem Cells

Cancers ◽  
2020 ◽  
Vol 12 (9) ◽  
pp. 2482
Author(s):  
Samson Mathews Samuel ◽  
Elizabeth Varghese ◽  
Lenka Koklesová ◽  
Alena Líšková ◽  
Peter Kubatka ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Stem Cells ◽  
Cancer Stem Cells ◽  
Molecular Mechanisms ◽  
Epithelial Mesenchymal Transition ◽  
Acquired Resistance ◽  
Breast Cancers ◽  
Intrinsic Resistance ◽  
Mesenchymal Transition ◽  
Cancer Breast

Despite the leaps and bounds in achieving success in the management and treatment of breast cancers through surgery, chemotherapy, and radiotherapy, breast cancer remains the most frequently occurring cancer in women and the most common cause of cancer-related deaths among women. Systemic therapeutic approaches, such as chemotherapy, although beneficial in treating and curing breast cancer subjects with localized breast tumors, tend to fail in metastatic cases of the disease due to (a) an acquired resistance to the chemotherapeutic drug and (b) the development of intrinsic resistance to therapy. The existence of cancer stem cells (CSCs) plays a crucial role in both acquired and intrinsic chemoresistance. CSCs are less abundant than terminally differentiated cancer cells and confer chemoresistance through a unique altered metabolism and capability to evade the immune response system. Furthermore, CSCs possess active DNA repair systems, transporters that support multidrug resistance (MDR), advanced detoxification processes, and the ability to self-renew and differentiate into tumor progenitor cells, thereby supporting cancer invasion, metastasis, and recurrence/relapse. Hence, current research is focusing on targeting CSCs to overcome resistance and improve the efficacy of the treatment and management of breast cancer. Studies revealed that metformin (1, 1-dimethylbiguanide), a widely used anti-hyperglycemic agent, sensitizes tumor response to various chemotherapeutic drugs. Metformin selectively targets CSCs and improves the hypoxic microenvironment, suppresses the tumor metastasis and inflammation, as well as regulates the metabolic programming, induces apoptosis, and reverses epithelial–mesenchymal transition and MDR. Here, we discuss cancer (breast cancer) and chemoresistance, the molecular mechanisms of chemoresistance in breast cancers, and metformin as a chemo-sensitizing/re-sensitizing agent, with a particular focus on breast CSCs as a critical contributing factor to acquired and intrinsic chemoresistance. The review outlines the prospects and directions for a better understanding and re-purposing of metformin as an anti-cancer/chemo-sensitizing drug in the treatment of breast cancer. It intends to provide a rationale for the use of metformin as a combinatory therapy in a clinical setting.

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