Resensitization of palbociclib-resistant MCF-7 cells by inhibiting TGF-β-induced epithelial-mesenchymal transition.

e13061 Background: Inhibition of cyclin-dependent kinases 4 and 6 (CDK4/6) is the most recent therapeutic method to treat estrogen receptor (ER)-positive breast cancer. Three CDK4/6 inhibitors have been approved by the FDA. The acquired resistance to CDK4/6 inhibitors are expected to have a negative impact on success of breast cancer therapy. It is critical to understand the molecular mechanisms underlying drug resistances to devise a better regimen or overcome drug resistance. Methods: The derivative MCF-7 (MCF-7:PR) cells which exert acquired resistance to palbociclib (PCB), one of the FDA-approved CDK4/6 inhibitors, are recently established. The EMT characteristics, major mechanisms for the EMT, and inhibition of TGF-β signaling pathways are studied in MCF-7:PR cells. Results: The mesenchymal markers are increased and the epithelial ones are decreased at both mRNA and protein levels in our cell line model. Transwell migration and would healing assays also demonstrated that MCF-7:PR cells exert EMT properties. Hyperactivation of TGF-β/Smad signaling was observed in MCF-7:PR cells. Chemical inhibition of TGF-β signaling lead to diminished cell migration and resistance to PCB. Conclusions: Resistance to PCB in MCF-7 cells resulted in significant changes in cell motility and molecular markers associated with EMT. In particular, TGF-β signaling is closely related to EMT and its inhibition reversed the EMT and cellular response to PCT. Our findings suggest that the modulation of EMT via inhibition of TGF-β signaling can be one of strategies to bypass PCB resistance in ER-positive breast cancer.

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

Cancers ◽

10.3390/cancers12092482 ◽

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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13P Molecular mechanisms involved in Interleukin-6-induced epithelial-mesenchymal transition in MCF-7 breast cancer cells

Annals of Oncology ◽

10.1093/annonc/mdv517.13 ◽

2015 ◽

Vol 26 ◽

pp. ix1

Author(s):

Y.-F. Hsu ◽

M.-J. Hsu

Keyword(s):

Breast Cancer ◽

Cancer Cells ◽

Interleukin 6 ◽

Breast Cancer Cells ◽

Molecular Mechanisms ◽

Epithelial Mesenchymal Transition ◽

Mesenchymal Transition ◽

Mcf 7

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Regulation of tamoxifen sensitivity by the PLAC8/MAPK pathway axis is antagonized by curcumin-induced protein stability change

Journal of Molecular Medicine ◽

10.1007/s00109-021-02047-5 ◽

2021 ◽

Author(s):

Misha Mao ◽

Dengdi Hu ◽

Jingjing Yang ◽

Yongxia Chen ◽

Xun Zhang ◽

...

Keyword(s):

Breast Cancer ◽

Molecular Mechanisms ◽

Epithelial Mesenchymal Transition ◽

Mapk Pathway ◽

Curcuma Longa ◽

Tamoxifen Resistance ◽

Mesenchymal Transition ◽

Beneficial Effects ◽

Estrogen Receptor Positive ◽

Mcf 7

AbstractTamoxifen resistance remains the major obstacle to the estrogen receptor positive breast cancer endocrine therapy. Placenta-specific 8 (PLAC8) has been implicated in epithelial-mesenchymal transition and tumorigenesis. However, the molecular mechanisms underlying PLAC8 function in the context of tamoxifen resistance are unclear. Curcumin has attracted considerable attention in the last decades. It is isolated from Curcuma longa and has beneficial effects in cancer therapy. We studied this property by using MCF-7 and tamoxifen-resistant breast cancer cells (MCF-7/TAM) cell lines. PLAC8 can regulate MCF-7/TAM cell drug sensitivity through the MAPK/ERK pathway and shows the potential effects of curcumin or as a possible druggable target against tamoxifen failure.

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Estrogen Receptor α Mediates Doxorubicin Sensitivity in Breast Cancer Cells by Regulating E-Cadherin

Frontiers in Cell and Developmental Biology ◽

10.3389/fcell.2021.583572 ◽

2021 ◽

Vol 9 ◽

Author(s):

Xiaoqing Wan ◽

Jiaxin Hou ◽

Shurong Liu ◽

Yanli Zhang ◽

Wenqing Li ◽

...

Keyword(s):

Breast Cancer ◽

Estrogen Receptor ◽

Cell Lines ◽

Epithelial Mesenchymal Transition ◽

Estrogen Receptor Α ◽

Mesenchymal Transition ◽

Mouse Breast Cancer ◽

Mcf 7 ◽

Positive Breast Cancer ◽

E Cadherin

Anthracyclines resistance is commonly seen in patients with estrogen receptor α (ERα) positive breast cancer. Epithelial-mesenchymal transition (EMT), which is characterized with the loss of epithelial cell polarity, cell adhesion and acquisition of new invasive property, is considered as one of the mechanisms of chemotherapy-induced drug resistance. In order to identify factors that associated with doxorubicin resistance, we performed in vitro and in vivo experiments using human and mouse breast cancer cell lines with different ERα status. Cell survival experiments revealed that ERα-positive cells (MCF-7 and MCF-7/ADR cell lines), were less sensitive to doxorubicin than ERα-negative (MDA-MB-231, MDA-MB-468) cells, and mouse mammary carcinoma cells (4T-1). The expression of E-cadherin reduced in low-invasive ERα-positive MCF-7 cells after treatment with doxorubicin, indicating epithelial mesenchymal transition. In contrast, the expression of E-cadherin was upregulated in high-invasive ERα-negative cells, showing mesenchymal-epithelial transition (MET). Moreover, it was found that the growth inhibition of 4T-1 cells by doxorubicin was positively correlated with the expression of E-cadherin. In a mouse breast cancer xenograft model, E-cadherin was overexpressed in the primary tumor tissues of the doxorubicin-treated mice. In ERα-positive MCF-7 cells, doxorubicin treatment upregulated the expression of EMT-related transcription factors Snail and Twist, that regulate the expression of E-cadherin. Following overexpression of ERα in ERα-negative cells (MDA-MB-231 and MDA-MB-468), doxorubicin enhanced the upregulation of Snail and Twist, decreased expression of E-cadherin, and decreased the sensitivity of cells to doxorubicin. In contrast, inhibition of ERα activity increased the sensitivity to doxorubicin in ERα-positive MCF-7 cells. These data suggest that the regulation of Snail and/or Twist varies depends on different ERα status. Therefore, doxorubicin combined with anti-estrogen receptor α therapy could improve the treatment efficacy of doxorubicin in ERα-positive breast cancer.

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Effect of Wnt5a on drug resistance in estrogen receptor-positive breast cancer

10.21203/rs.3.rs-96339/v1 ◽

2020 ◽

Author(s):

Ai Amioka ◽

Takayuki Kadoya ◽

Satoshi Sueoka ◽

Yoshie Kobayashi ◽

Shinsuke Sasada ◽

...

Keyword(s):

Breast Cancer ◽

Poor Prognosis ◽

Breast Cancer Tissue ◽

Cancer Tissue ◽

Breast Cancer Patients ◽

Mtor Signaling Pathway ◽

The Poor ◽

Er Positive ◽

Mcf 7 ◽

Positive Breast Cancer

Abstract BackgroundIt was previously reported by us that Wnt5a-positive breast cancer can be classified as estrogen receptor (ER)-positive breast cancer and its prognosis is worse than that of Wnt5a-negative breast cancer. Herein, the molecular mechanisms underlying the poor prognosis of Wnt5a-positive breast cancer patients were examined. MethodsA total of 151 consecutive ER-positive breast cancer patients who underwent resection between January 2011 and February 2014 were enrolled. DNA microarray and pathway analyses were performed conducted using MCF-7 cells stably expressing Wnt5a (MCF-7/Wnt5a(+)). Based on the results, cell viability and drug sensitivity assays as well as mutation analysis , were performed using culture cells and breast cancer tissue. The relationship between Wnt5a and the PI3K–AKT–mTOR signaling pathway was examined.ResultsThe relapse-free survival rate in patients with Wnt5a-positive breast cancer was significantly lower than that in patients with Wnt5a-negative breast cancer ( P = 0.047). DNA microarray data indicated that only the cytochrome P450 (CYP) pathway was significantly upregulated in MCF-7/Wnt5a(+) cells ( P = 0.0440). MCF-7/Wnt5a(+) cells showed reduced sensitivity to the metabolic substrates of CYP, tamoxifen ( P < 0.001), and paclitaxel ( P < 0.001). PIK3CA mutations were unrelated to Wnt5a expression in breast cancer tissue and culture cells.ConclusionsIn ER-positive breast cancer, Wnt5a upregulated the CYP metabolic pathway; additionally, it inhibited the sensitivity to tamoxifen and paclitaxel, which constitute the standard treatment options for ER-positive breast cancer. Wnt5a could be involved in the poor prognosis of ER-positive breast cancer independently of the PI3K–AKT–mTOR signaling pathway.

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Mummy Induces Apoptosis Through Inhibiting of Epithelial-Mesenchymal Transition (EMT) in Human Breast Cancer Cells

Galen Medical Journal ◽

10.31661/gmj.v9i0.1812 ◽

2020 ◽

Vol 9 ◽

pp. 1812

Author(s):

Solmaz Rahmani Barouji ◽

Arman Shahabi ◽

Mohammadali Torbati ◽

Seyyed Mohammad Bagher Fazljou ◽

Ahmad Yari Khosroushahi

Keyword(s):

Breast Cancer ◽

Gene Expression ◽

Anticancer Activity ◽

Cancer Cells ◽

Breast Cancer Cells ◽

Epithelial Mesenchymal Transition ◽

Control Group ◽

Mrna Levels ◽

Mesenchymal Transition ◽

Mcf 7

Background: Mummy (Iranian pure shilajit) is a remedy with possessing anti-inflammatory, antioxidant and anticancer activities. This study aimed to examine mummy effects on epithelial-mesenchymal transition (EMT) and invasiveness of MCF-7 and MDA-MB-231 breast cancer (BC) cell lines with underlying its mechanism. Materials and Methods: The dose-dependent inhibitory effect of the mummy on cell proliferation in vitro was determined using the MTT assay. Flow cytometry and 4’,6-diamidino-2-phenylindole dihydrochloride staining were respectively used for quantitative and qualitative analysis of cellular apoptosis, and gene expression analysis was conducted using real-time PCR. Results: MDA-MB-231 showed more sensitivity than the MCF-7 cell line to the anticancer activity of mummy, while mummy did not exhibit significant cell cytotoxicity against human normal cells (MCF-10A). The gene expression profile demonstrated a significant decrease in TGF-β1, TGF-βR1, TWIST1, NOTCH1, CTNNB1, SRC along with an increase in E-cadherin mRNA levels in mummy treated cells compared to the untreated control group (P≤0.05). Conclusion: Mummy triggers inhibition of EMT and metastasis in breast cancer cells mainly through the downregulation of TGFβ1 activity, and more studies required to find its specific anticancer activity with details. [GMJ.2020;9:e1812]

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SGK3 Is an Estrogen-Inducible Kinase Promoting Estrogen-Mediated Survival of Breast Cancer Cells

Molecular Endocrinology ◽

10.1210/me.2010-0294 ◽

2011 ◽

Vol 25 (1) ◽

pp. 72-82 ◽

Cited By ~ 35

Author(s):

Yuanzhong Wang ◽

Dujin Zhou ◽

Sheryl Phung ◽

Selma Masri ◽

David Smith ◽

...

Keyword(s):

Breast Cancer ◽

Protein Kinase ◽

Cell Survival ◽

Cancer Cells ◽

Breast Cancer Cells ◽

Dependent Manner ◽

Binding Regions ◽

Er Positive ◽

Mcf 7 ◽

Positive Breast Cancer

Serum- and glucocorticoid-inducible kinase 3 (SGK3) is a protein kinase of the AGC family of protein kinase A, protein kinase G, and protein kinase C and functions downstream of phosphatidylinositol 3-kinase (PI3K). Recent study revealed that SGK3 plays a pivotal role in Akt/protein kinase B independent signaling downstream of oncogenic PI3KCA mutations in breast cancer. Here we report that SGK3 is an estrogen receptor (ER) transcriptional target and promotes estrogen-mediated cell survival of ER-positive breast cancer cells. Through a meta-analysis on 22 microarray studies of breast cancer in the Oncomine database, we found that the expression of SGK3 is significantly higher (5.7-fold, P < 0.001) in ER-positive tumors than in ER-negative tumors. In ER-positive breast cancer cells, SGK3 expression was found to be induced by 17β-estradiol (E2) in a dose- and time-dependent manner, and the induction of SGK3 mRNA by E2 is independent of newly synthesized proteins. We identified two ERα-binding regions at the sgk3 locus through chromatin immunoprecipitation with massively parallel DNA sequencing. Promoter analysis revealed that ERα stimulates the activity of sgk3 promoters by interaction with these two ERα-binding regions on E2 treatment. Loss-of-function analysis indicated that SGK3 is required for E2-mediated cell survival of MCF-7 breast carcinoma cells. Moreover, overexpression of SGK3 could partially protect MCF-7 cells against apoptosis caused by antiestrogen ICI 182,780. Together, our study defines the molecular mechanism of regulation of SGK3 by estrogen/ER and provides a new link between the PI3K pathway and ER signaling as well as a new estrogen-mediated cell survival mechanism mediated by SGK3 in breast cancer cells.

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