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

Author(s):  
Misha Mao ◽  
Dengdi Hu ◽  
Jingjing Yang ◽  
Yongxia Chen ◽  
Xun Zhang ◽  
...  

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.

2020 ◽  
Vol 38 (15_suppl) ◽  
pp. e13061-e13061
Author(s):  
Minsun Chang ◽  
Sujeong Park ◽  
Byung Ha An

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.


2020 ◽  
Vol 9 ◽  
pp. 1812
Author(s):  
Solmaz Rahmani Barouji ◽  
Arman Shahabi ◽  
Mohammadali Torbati ◽  
Seyyed Mohammad Bagher Fazljou ◽  
Ahmad Yari Khosroushahi

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]


Cancers ◽  
2020 ◽  
Vol 12 (9) ◽  
pp. 2482
Author(s):  
Samson Mathews Samuel ◽  
Elizabeth Varghese ◽  
Lenka Koklesová ◽  
Alena Líšková ◽  
Peter Kubatka ◽  
...  

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.


2021 ◽  
Vol 7 (1) ◽  
Author(s):  
Suganthi Muralidharan ◽  
Adaikkalam Vellaichamy

Abstract Background Epithelial-mesenchymal transition (EMT) helps solid tumors to lose their intercellular adhesive property and drives metastasis. As mangosteen fruit is known for many beneficial effects including antimicrobial, antioxidant, and anti-tumorigenic properties and has been used widely in traditional medicine, we interrogated its possible anti-metastatic effect on MCF-7 breast cancer cells. Results We found that aqueous mangosteen rind extract (MRE) inhibited growth of MCF-7 and altered the transcript levels of ERα, ERβ, and EGFR genes. Additionally, the MRE changed the expression of important markers of EMT, E-Cadherin, N-Cadherin, Snail, and MMP-9. Moreover, MRE inhibited migration of MCF-7 cells. Conclusion The results suggest that MRE suppresses growth and inhibits epithelial-mesenchymal transition in MCF-7 cells.


2020 ◽  
Author(s):  
Zhe Zhang ◽  
Qing Lian Zheng ◽  
Yong Hui Liu ◽  
Lian Qing Sun ◽  
Ping Ping Han ◽  
...  

Abstract BackgroundHuman CD133+ hematopoietic progenitor cells (HPCs) are a specific subset of cells that can regulate tumor malignancy. However, the mechanism by which CD133+ HPCs affect the malignancy of human breast cancer has not been reported.MethodsCD133+ HPCs were isolated and purified from human umbilical cord blood (UCB) .We used in vitro culture of MCF-7 and MDA-MB-231 cell lines, and MCF-7 and MDA-MB-231 cells in nude mice to evaluate whether CD133+ HPCs affected the apoptosis, proliferation, invasion and epithelial mesenchymal transition EMT of breast cancer cells.ResultsCo-culture with CD133+ HPCs, but not UCB CD133- cells, promoted the proliferation of human breast cancer MCF-7 and MDA-MB-231 cells, accompanied by reducing in vitro spontaneous apoptosis. Co-administration of these two lines with CD133+ HPCs significantly enhanced the growth of implanted breast cancer in vivo . Furthermore, co-culture with CD133+ HPCs, enhanced the invasion of breast cancer cells, N-cadherin and Vimentin expression, but reduced E-cadherin expression in breast cancer cells.ConclusionsOur study demonstrated that CD133+ HPCs enhance the malignancy of breast cancer cells by attenuating spontaneous apoptosis and promoting the process of epithelial mesenchymal transition. These findings may provide new insights into the role of human CD133+ HPCs in breast cancer pathogenesis. Therefore, CD133+ HPCs may be a new therapeutic target for inhibiting the progression of breast cancer.


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