Calreticulin Overexpression Suppresses Cell Proliferation and Enhances Apoptosis on Human MCF-7 Breast Cancer Cells

2004 ◽  
Vol 32 (3) ◽  
pp. 793-810 ◽  
Author(s):  
MA Greeve ◽  
RK Allan ◽  
JM Harvey ◽  
JM Bentel

Androgens inhibit the growth of breast cancer cells in vitro and in vivo by mechanisms that remain poorly defined. In this study, treatment of asynchronously growing MCF-7 breast cancer cells with the androgen, 5alpha-dihydrotestosterone (DHT), was shown to inhibit cell proliferation and induce moderate increases in the proportion of G1 phase cells. Consistent with targeting the G1-S phase transition, DHT pretreatment of MCF-7 cultures impeded the serum-induced progression of G1-arrested cells into S phase and reduced the kinase activities of cyclin-dependent kinase (Cdk)4 and Cdk2 to less than 50% of controls within 3 days. DHT treatment was associated with greater than twofold increases in the levels of the Cdk inhibitor, p27(Kip1), while p21(Cip1/Waf1) protein levels remained unchanged. During the first 24 h of DHT treatment, levels of Cdk4-associated p21(Cip1/Waf1) and p27(Kip1) were reduced coinciding with decreased levels of Cdk4-associated cyclin D3. In contrast, DHT treatment caused increased accumulation of Cdk2-associated p21(Cip1/Waf1), with no significant alterations in levels of p27(Kip1) bound to Cdk2 complexes. These findings suggest that DHT reverses the Cdk4-mediated titration of p21(Cip1/Waf1) and p27(Kip1) away from Cdk2 complexes, and that the increased association of p21(Cip1/Waf1) with Cdk2 complexes in part mediates the androgen-induced growth inhibition of breast cancer cells.


Biomolecules ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 743
Author(s):  
Oluwaseun Akinyele ◽  
Heather M. Wallace

Breast cancer is a complex heterogeneous disease with multiple underlying causes. The polyamines putrescine, spermidine, and spermine are polycationic molecules essential for cell proliferation. Their biosynthesis is upregulated in breast cancer and they contribute to disease progression. While elevated polyamines are linked to breast cancer cell proliferation, there is little evidence to suggest breast cancer cells of different hormone receptor status are equally dependent on polyamines. In this study, we characterized the responses of two breast cancer cells, ER+ (oestrogen receptor positive) MCF-7 and ER- MDA-MB-231 cell lines, to polyamine modulation and determined the requirement of each polyamine for cancer cell growth. The cells were exposed to DFMO (a polyamine pathway inhibitor) at various concentrations under different conditions, after which several growth parameters were determined. Exposure of both cell lines to DFMO induced differential growth responses, MCF-7 cells showed greater sensitivity to polyamine pathway inhibition at various DFMO concentrations than the MDA-MB-231 cells. Analysis of intracellular DFMO after withdrawal from growth medium showed residual DFMO in the cells with concomitant decreases in polyamine content, ODC protein level, and cell growth. Addition of exogenous polyamines reversed the cell growth inhibition, and this growth recovery appears to be partly dependent on the spermidine content of the cell. Similarly, DFMO exposure inhibits the global translation state of the cells, with spermidine addition reversing the inhibition of translation in the breast cancer cells. Taken together, these data suggest that breast cancer cells are differentially sensitive to the antitumour effects of polyamine depletion, thus, targeting polyamine metabolism might be therapeutically beneficial in breast cancer management based on their subtype.


2015 ◽  
Vol 2015 ◽  
pp. 1-10 ◽  
Author(s):  
Meng-Wong Taing ◽  
Jean-Thomas Pierson ◽  
Paul N. Shaw ◽  
Ralf G. Dietzgen ◽  
Sarah J. Roberts-Thomson ◽  
...  

The assessment of human cancer cell proliferation is a common approach in identifying plant extracts that have potential bioactive effects. In this study, we tested the hypothesis that methanolic extracts of peel and flesh from three archetypal mango cultivars, Irwin (IW), Nam Doc Mai (NDM), and Kensington Pride (KP), differentially affect proliferation, extracellular signal-regulated kinase (ERK) activity, and intracellular calcium ([Ca2+]I) signalling in MCF-7 human breast cancer cells. Mango flesh extracts from all three cultivars did not inhibit cell growth, and of the peel extracts only NDM reduced MCF-7 cell proliferation. Mango cultivar peel and flesh extracts did not significantly change ERK phosphorylation compared to controls; however, some reduced relative maximal peak[Ca2+]Iafter adenosine triphosphate stimulation, with NDM peel extract having the greatest effect among the treatments. Our results identify mango interfruit and intrafruit (peel and flesh) extract variability in antiproliferative effects and[Ca2+]Isignalling in MCF-7 breast cancer cells and highlight that parts of the fruit (such as peel and flesh) and cultivar differences are important factors to consider when assessing potential chemopreventive bioactive compounds in plants extracts.


Endocrinology ◽  
2008 ◽  
Vol 150 (4) ◽  
pp. 1588-1596 ◽  
Author(s):  
Sudipan Karmakar ◽  
Estrella A. Foster ◽  
Carolyn L. Smith

Each of the three members of the p160 steroid receptor coactivator (SRC) family of coactivators (SRC-1, SRC-2 and SRC-3) stimulates estrogen receptor (ER)-α function in trans-activation assays. Consequently, we sought to elucidate their contributions to the ER-regulated processes of cell proliferation, apoptosis, and the expression of ERα target genes in MCF-7 breast cancer cells. The small interfering RNA depletion of SRC-2 or SRC-3 but not SRC-1 inhibited growth of MCF-7 cells, and this was reflected in decreased cell cycle progression and increased apoptosis in SRC-2- or SRC-3-depleted cells as well as a reduction in ERα transcriptional activity measured on a synthetic reporter gene. However, only SRC-3 depletion blocked estradiol stimulated cell proliferation. Depletion of SRC-1 did not affect these events, and together this reveals functional differences between each of the three SRC family coactivators. Regulation of the endogenous ERα target gene, c-myc was not affected by depletion of any of the p160 coactivators although depletion of each of them decreased pS2 mRNA expression in estradiol-treated MCF-7 cells. Moreover, progesterone receptor and cyclin D1 gene expression were decreased in SRC-3 small interfering RNA-treated cells. Expression of mRNA and protein levels for the antiapoptotic gene, Bcl-2 was dependent on SRC-3 expression, whereas Bcl-2 protein but not mRNA expression also was sensitive to SRC-1 depletion. Together these data indicate that the closely related p160 coactivators are not functionally redundant in breast cancer cells because they play gene-specific roles in regulating mRNA and protein expression, and they therefore are likely to make unique contributions to breast tumorigenesis.


2017 ◽  
Vol 17 (2) ◽  
pp. 542-550 ◽  
Author(s):  
Nariman K. Badr El-Din ◽  
Ashraf Z. Mahmoud ◽  
Tahia Ali Hassan ◽  
Mamdooh Ghoneum

Our earlier studies have demonstrated that phagocytosis of baker’s yeast ( Saccharomyces cerevisiae) induces apoptosis in different cancer cell lines in vitro and in vivo. This study aimed to examine how baker’s yeast sensitizes murine and human breast cancer cells (BCC) to paclitaxel in vitro. This sensitizing effect makes lower concentrations of chemotherapy more effective at killing cancer cells, thereby enhancing the capacity of treatment. Three BCC lines were used: the metastatic murine 4T1 line, the murine Ehrlich ascites carcinoma (EAC) line, and the human breast cancer MCF-7 line. Cells were cultured with different concentrations of paclitaxel in the presence or absence of baker’s yeast. Cell survival and the IC50 values were determined by MTT assay and trypan blue exclusion method. Percent of DNA damage, apoptosis, and cell proliferation were examined by flow cytometry. Yeast alone and paclitaxel alone significantly decreased 4T1 cell viability postculture (24 and 48 hours), caused DNA damage, increased apoptosis, and suppressed cell proliferation. Baker’s yeast in the presence of paclitaxel increased the sensitivity of 4T1 cells to chemotherapy and caused effects that were greater than either treatment alone. The chemosensitizing effect of yeast was also observed with murine EAC cells and human MCF-7 cells, but to a lesser extent. These data suggest that dietary baker’s yeast is an effective chemosensitizer and can enhance the apoptotic capacity of paclitaxel against breast cancer cells in vitro. Baker’s yeast may represent a novel adjuvant for chemotherapy treatment.


2019 ◽  
Vol 19 (6) ◽  
pp. 760-771 ◽  
Author(s):  
Oscar J. Zacarías-Lara ◽  
David Méndez-Luna ◽  
Gustavo Martínez-Ruíz ◽  
José R. García-Sanchéz ◽  
Manuel J. Fragoso-Vázquez ◽  
...  

Background: Some reports have demonstrated the role of the G Protein-coupled Estrogen Receptor (GPER) in growth and proliferation of breast cancer cells. Objective: In an effort to develop new therapeutic strategies against breast cancer, we employed an in silico study to explore the binding modes of tetrahydroquinoline 2 and 4 to be compared with the reported ligands G1 and G1PABA. Methods: This study aimed to design and filter ligands by in silico studies determining their Lipinski's rule, toxicity and binding properties with GPER to achieve experimental assays as anti-proliferative compounds of breast cancer cell lines. Results: In silico studies suggest as promissory two tetrahydroquinoline 2 and 4 which contain a carboxyl group instead of the acetyl group (as is needed for G1 synthesis), which add low (2) and high hindrance (4) chemical moieties to explore the polar, hydrophobic and hindrance effects. Docking and molecular dynamics simulations of the target compounds were performed with GPER to explore their binding mode and free energy values. In addition, the target small molecules were synthesized and assayed in vitro using breast cancer cells (MCF-7 and MDA-MB-231). Experimental assays showed that compound 2 decreased cell proliferation, showing IC50 values of 50µM and 25µM after 72h of treatment of MCF-7 and MDA-MB-231 cell lines, respectively. Importantly, compound 2 showed a similar inhibitory effect on proliferation as G1 compound in MDA-MB-231 cells, suggesting that both ligands reach the GPER-binding site in a similar way, as was demonstrated through in silico studies. Conclusion: A concentration-dependent inhibition of cell proliferation occurred with compound 2 in the two cell lines regardless of GPER.


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