The underlying mechanism contributing to P-gp over-expression and drug resistance in the MCF-7 breast cancer cells induced by adriamycin.

2017 ◽  
Vol 35 (15_suppl) ◽  
pp. e12028-e12028
Author(s):  
Guangji Wang ◽  
Jiye Aa ◽  
Chun Ge
Keyword(s):  
Breast Cancer ◽  
Drug Resistance ◽  
Cancer Cells ◽  
Breast Cancer Cells ◽  
Underlying Mechanism ◽  
Ros Generation ◽  
Down Regulation ◽  
Over Expression ◽  
And Function ◽  
Mcf 7

e12028 Background: Continuous exposure of breast cancer cells to adriamycin (ADR) induces the over-expression of P-glycoprotein (P-gp) and multiple drug resistance. However, the biochemical process and underlying mechanisms are not clear. Our previous study revealed that ADR increased reactive oxygen species (ROS) generation and reduced glutathione (GSH) biosynthesis, while N-acetylcysteine, the ROS scavenger, reversed the over-expressed P-gp induced by ADR. Methods: Based on MCF-7 breast cancer cells and the adriamycin-resistant MCF-7 subline (MCF-7R), we investigated the P-gp expression on mRNA, protein and function level by qPCR, western blotting, flow cytometry and laser scanning confocal and so on, under SLC7A11 down-regulation/over-expression, cystine depletion/supplement, increased ROS generation and combined factors. Results: The present study showed that ADR inhibited cystine influx (source material of GSH) and SLC7A11 transporter (in charge of cystine uptake) in MCF-7 cells. For the first time, we showed that a down-regulation/silence of SLC7A11, or cystine deprivation, or an enhanced exposure of ROS agents directly and significantly increased P-gp expression; yet, a combination of either an inhibited/silenced SLC7A11 or cystine deprivation and an increased ROS dramatically promoted the P-gp expression in MCF-7 cells. On the contrary, an over-expression of SLC7A11, or sufficiently supplementary cystine, or scavenger of ROS significantly depressed P-gp expression and activity. Moreover, the down-regulation of SLC7A11 and cystine deprivation induced an elevation of ROS and P-gp that could be reversed by N-acetylcysteine. It was suggested that ROS and SLC7A11/cystine were the two relevant factors responsible for the upregulated expression and function of P-gp. Conclusions: This study provided the direct evidences suggesting that ROS triggered over-expression of P-gp and demonstrated that the combination of either an inhibition of SLC7A11 or cystine influx and elevated ROS was the underlying mechanism contributing to P-gp over-expression induced by ADR. It was indicated that the SLC7A11 might be a potential target modulating ADR resistance.

scholarly journals Proline oxidase silencing inhibits p53-dependent apoptosis in MCF-7 breast cancer cells

Amino Acids ◽  
2021 ◽  
Author(s):  
Ilona Oscilowska ◽  
Thi Y. L. Huynh ◽  
Weronika Baszanowska ◽  
Izabela Prokop ◽  
Arkadiusz Surazynski ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Cancer Cells ◽  
Breast Cancer Cells ◽  
Survival Function ◽  
Underlying Mechanism ◽  
Proline Oxidase ◽  
Down Regulation ◽  
P53 Expression ◽  
Proline Concentration ◽  
Mcf 7

AbstractProline oxidase (POX) is mitochondrial proline-degrading enzyme of dual apoptosis/survival function. POX expression and proline availability are considered an underlying mechanism for differential POX functions. The mechanism for POX-dependent regulation of cell death/survival was studied in wild-type (MCF-7WT) and shRNA POX-silenced breast cancer cells (MCF-7iPOX). Proline concentration and proteomic analyses were determined by LC/MS/QTOF and LC/MS/ORBITRA, respectively. Inhibition of collagen biosynthesis (proline utilizing process) by 2-methoxyestradiol (2ME) contributed to induction of apoptosis in MCF-7WT cells, as detected by increase in the expression of active caspase-3, -9 and p53. The process was not shown in MCF-7iPOX. In MCF-7iPOX cells prolidase activity and expression as well as proline concentration were drastically increased, compared to MCF-7WT cells. Down-regulation of p53 in MCF-7iPOX cells was corroborated by proteomic analysis showing decrease in the expression of p53-related proteins. The mechanism for down-regulation of p53 expression in MCF-7iPOX cells was found at the level of p53–PEPD complex formation that was counteracted by hydrogen peroxide treatment. In this study, we found that silencing POX modulate pro-survival phenotype of MCF-7 cells and suggest that the mechanism of this process undergoes through down-regulation of p53-dependent signaling.

scholarly journals ARTEMISININ MODULATING EFFECT ON HUMAN BREAST CANCER CELL LINES WITH DIFFERENT SENSITIVITY TO CYTOSTATICS

2017 ◽  
Vol 39 (1) ◽  
pp. 25-29 ◽  
Author(s):  
V F Chekhun ◽  
N Yu Lukianova ◽  
T Borikun ◽  
T Zadvornyi ◽  
A Mokhir
Keyword(s):  
Breast Cancer ◽  
Drug Resistance ◽  
Cancer Cells ◽  
Breast Cancer Cells ◽  
Iron Homeostasis ◽  
Chemotherapeutic Agents ◽  
Fold Change ◽  
Breast Cancer Cell Lines ◽  
Cellular Iron ◽  
Mcf 7

Aim: To explore effects of Artemisinin on a series of breast cancer cells with different sensitivity to typical cytotoxic drugs (doxorubicin — Dox; cisplatin — DDP) and to investigate possible artemisinin-induced modification of the mechanisms of drug resistance. Materials and Methods: The study was performed on wild-type breast cancer MCF-7 cell line (MCF-7/S) and its two sublines MCF-7/Dox and MCF-7/DDP resistant to Dox and DDP, respectively. The cells were treated with artemisinin and iron-containing magnetic fluid. The latter was added to modulate iron levels in the cells and explore its role in artemisinin-induced effects. The MTT assay was used to monitor cell viability, whereas changes of expression of selected proteins participating in regulation of cellular iron homeostasis were estimated using immunocytochemical methods. Finally, relative expression levels of miRNA-200b, -320a, and -34a were examined by using qRT-PCR. Results: Artemisinin affects mechanisms of the resistance of breast cancer cells towards both Dox and DDP at sub-toxic doses. The former drug induces changes of expression of iron-regulating proteins via different mechanisms, including epigenetic regulation. Particularly, the disturbances in ferritin heavy chain 1, lactoferrin, hepcidin (decrease) and ferroportin (increase) expression (р ≤ 0.05) were established. The most enhanced increase of miRNA expression under artemisinin influence were found for miRNA-200b in MCF-7/DDP cells (7.1 ± 0.98 fold change), miRNA-320a in MCF-7/Dox cells (2.9 ± 0.45 fold change) and miRNA-34a (1.7 ± 0.15 fold change) in MCF-7/S cells. It was observed that the sensitivity to artemisinin can be influenced by changing iron levels in cells. Conclusions: Artemisinin can modify iron metabolism of breast cancer cells by its cytotoxic effect, but also by inducing changes in expression of iron-regulating proteins and microRNAs (miRNAs), involved in their regulation. This modification affects the mechanisms that are implicated in drug-resistance, that makes artemisinin a perspective modulator of cell sensitivity towards chemotherapeutic agents in cancer treatment.

scholarly journals Oncogenic miR-20b-5p contributes to malignant behaviors of breast cancer stem cells by bidirectionally regulating CCND1 and E2F1

BMC Cancer ◽  
2020 ◽  
Vol 20 (1) ◽  
Author(s):  
Liqin Xia ◽  
Feng Li ◽  
Jun Qiu ◽  
Zhongming Feng ◽  
Zihan Xu ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Stem Cells ◽  
Wound Healing ◽  
Cancer Cells ◽  
Breast Cancer Cells ◽  
Underlying Mechanism ◽  
Luciferase Assay ◽  
Breast Cancer Stem Cells ◽  
Xenograft Growth ◽  
Mcf 7

Abstract Background Breast cancer is the leading cause of cancer mortality in women worldwide. Therefore, it is of great significance to identify the biological mechanism of tumorigenesis and explore the development of breast cancer to achieve a better prognosis for individuals suffering from breast cancer. MicroRNAs (miRNAs) have become a hot topic in cancer research, but the underlying mechanism of its involvement in cancer remains unclear. Methods The miRNA profile between breast cancer stem cells (BCSCs, CD44+CD24−/low) and control MCF-7 breast cancer cells was obtained in a previous study. Based on biological analysis, miR-20b-5p was hypothesized to be a key factor due to the malignant behavior of BCSCs. Then, agomir-20b-5p and antagomir-20b-5p were transfected into MCF-7 and T47D breast cancer cells to detect cell migration, wound healing and proliferation, and lentivirus vectors silencing or overexpressing miR-20b-5p were transfected into T47D-CSCs to detect proliferation and apoptosis. The effect of miR-20b-5p on xenograft growth was investigated in vivo by transfection of a lentivirus-overexpression vector into T47D cells. The target genes were predicted by the online programs picTar, miRanda and TargetScan and verified by dual luciferase assay, and changes in protein expression were detected by western blot. Results MiR-20b-5p had the highest degree in both the miRNA-gene network and miRNA-GO network to regulate BCSCs. Overexpression of miR-20b-5p significantly promoted the migration and wound healing ability of MCF-7 cells and T47D cells compared with the control (P < 0.05). In addition, miR-20b-5p facilitated the proliferation of MCF-7 cells and T47D-CSCs (P < 0.05) and inhibited the apoptosis of T47D-CSCs (P < 0.05). Moreover, miR-20b-5p promoted xenograft growth compared with the control group (P < 0.05). Accordingly, potential targets of both CCND1 and E2F1 were predicted by bioinformatics analysis. MiR-20b-5p directly targeted both CCND1 and E2F1 in a dual luciferase assay, while antagomir-20b-5p downregulated the protein levels of CCND1 and E2F1. Conclusions Oncogenic miR-20b-5p was confirmed to promote the malignant behaviors of breast cancer cells and BCSCs. The underlying mechanism lies in that miR-20b-5p overall enhanced both CCND1 and E2F1 targets via bidirectional regulation probably involving direct downregulation and indirect upregulation.

scholarly journals A polysaccharide from Huaier induced apoptosis in MCF-7 breast cancer cells via down-regulation of MTDH protein

2016 ◽  
Vol 151 ◽  
pp. 1027-1033 ◽  
Author(s):  
Zhiyong Luo ◽  
Xiaopeng Hu ◽  
Hua Xiong ◽  
Hong Qiu ◽  
Xianglin Yuan ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Cancer Cells ◽  
Breast Cancer Cells ◽  
Down Regulation ◽  
Induced Apoptosis ◽  
Mcf 7

Delivery of siRNA by MRI-visible nanovehicles to overcome drug resistance in MCF-7/ADR human breast cancer cells

Biomaterials ◽  
2014 ◽  
Vol 35 (35) ◽  
pp. 9495-9507 ◽  
Author(s):  
Gan Lin ◽  
Wencheng Zhu ◽  
Li Yang ◽  
Jun Wu ◽  
Bingbing Lin ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Drug Resistance ◽  
Cancer Cells ◽  
Human Breast Cancer ◽  
Breast Cancer Cells ◽  
Human Breast Cancer Cells ◽  
Human Breast ◽  
Mcf 7

scholarly journals Oncogenic miR-20b-5p contributes to malignant behaviors of breast cancer stem cells by bidirectionally regulating CCND1 and E2F1

2020 ◽  
Author(s):  
Liqin Xia ◽  
Feng Li ◽  
Jun Qiu ◽  
Zhongming Feng ◽  
Zihan Xu ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Stem Cells ◽  
Wound Healing ◽  
Cancer Cells ◽  
Breast Cancer Cells ◽  
Underlying Mechanism ◽  
Luciferase Assay ◽  
Breast Cancer Stem Cells ◽  
Xenograft Growth ◽  
Mcf 7

Abstract BackgroundBreast cancer is the leading cause of cancer mortality in women worldwide. Therefore, it is of great significance to identify the biological mechanism of tumorigenesis and explore the development of breast cancer to achieve a better prognosis for individuals suffering from breast cancer. MicroRNAs (miRNAs) have become a hot topic in cancer research, but the underlying mechanism of its involvement in cancer remains unclear.MethodsThe miRNA profile between breast cancer stem cells(BCSCs, CD44+CD24-/low) and control MCF-7 breast cancer cells was obtained in a previous study. Based on biological analysis, miR-20b-5p was hypothesized to be a key factor due to the malignant behavior of BCSCs. Then, agomir-20b-5p and antagomir-20b-5p were transfected into MCF-7 and T47D breast cancer cells to detect cell migration, wound healing and proliferation, and lentivirus vectors silencing or overexpressing miR-20b-5p were transfected into T47D-CSCs to detect proliferation and apoptosis. The effect of miR-20b-5p on xenograft growth was investigated in vivo by transfection of a lentivirus-overexpression vector into T47D cells. The target genes were predicted by the online programs picTar, miRanda and TargetScan and verified by dual luciferase assay, and changes in protein expression were detected by western blot.ResultsMiR-20b-5p had the highest degree in both the miRNA-gene network and miRNA-GO network to regulate BCSCs. Overexpression of miR-20b-5p significantly promoted the migration and wound healing ability of MCF-7 cells and T47D cells compared with the control (P < 0.05). In addition, miR-20b-5p facilitated the proliferation of MCF-7 cells and T47D-CSCs (P < 0.05) and inhibited the apoptosis of T47D-CSCs (P < 0.05). Moreover, miR-20b-5p promoted xenograft growth compared with the control group (P < 0.05). Accordingly, potential targets of both CCND1 and E2F1 were predicted by bioinformatics analysis. MiR-20b-5p directly targeted both CCND1 and E2F1 in a dual luciferase assay, while antagomir-20b-5p downregulated the protein levels of CCND1 and E2F1.ConclusionsOncogenic miR-20b-5p was confirmed to promote the malignant behaviors of breast cancer cells and BCSCs. The underlying mechanism lies in that miR-20b-5p overall enhanced both CCND1 and E2F1 targets via bidirectional regulation probably involving direct downregulation and indirect upregulation.

scholarly journals Rab31-dependent regulation of transforming growth factor ß expression in breast cancer cells

2021 ◽  
Vol 27 (1) ◽  
Author(s):  
Susanne Soelch ◽  
Nathalie Beaufort ◽  
Daniela Loessner ◽  
Matthias Kotzsch ◽  
Ute Reuning ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Cancer Cells ◽  
Breast Cancer Cells ◽  
Epithelial To Mesenchymal Transition ◽  
Transforming Growth Factor ◽  
Cancer Cell Line ◽  
Underlying Mechanism ◽  
Mrna Levels ◽  
Down Regulation ◽  
Mesenchymal Transition

Abstract Background The small GTP-binding protein Rab31 plays an important role in the modulation of tumor biological-relevant processes, including cell proliferation, adhesion, and invasion. As an underlying mechanism, Rab31 is presumed to act as a molecular switch between a more proliferative and an invasive phenotype. This prompted us to analyze whether Rab31 overexpression in breast cancer cells affects expression of genes involved in epithelial-to-mesenchymal transition (EMT)-like processes when compared to Rab31 low-expressing cells. Methods Commercially available profiler PCR arrays were applied to search for differentially expressed genes in Rab31 high- and low-expressing CAMA-1 breast cancer cells. Differential expression of selected candidate genes in response to Rab31 overexpression in CAMA-1 cells was validated by independent qPCR and protein assays. Results Gene expression profiling of key genes involved in EMT, or its reciprocal process MET, identified 9 genes being significantly up- or down-regulated in Rab31 overexpressing CAMA-1 cells, with the strongest effects seen for TGFB1, encoding TGF-ß1 (> 25-fold down-regulation in Rab31 overexpressing cells). Subsequent validation analyses by qPCR revealed a strong down-regulation of TGFB1 mRNA levels in response to increased Rab31 expression not only in CAMA-1 cells, but also in another breast cancer cell line, MDA-MB-231. Using ELISA and Western blot analysis, a considerable reduction of both intracellular and secreted TGF-ß1 antigen levels was determined in Rab31 overexpressing cells compared to vector control cells. Furthermore, reduced TGF-ß activity was observed upon Rab31 overexpression in CAMA-1 cells using a sensitive TGF-ß bioassay. Finally, the relationship between Rab31 expression and the TGF-ß axis was analyzed by another profiler PCR array focusing on genes involved in TGF-ß signaling. We found 12 out of 84 mRNAs significantly reduced and 7 mRNAs significantly increased upon Rab31 overexpression. Conclusions Our results demonstrate that Rab31 is a potent modulator of the expression of TGF-ß and other components of the TGF-ß signaling pathway in breast cancer cells.

scholarly journals Oncogenic miR-20b-5p contributes to malignant behaviors of breast cancer stem cells by bidirectionally regulating CCND1 and E2F1

2020 ◽  
Author(s):  
liqin xia ◽  
feng li ◽  
jun qiu ◽  
zhongming feng ◽  
zihan xu ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Stem Cells ◽  
Wound Healing ◽  
Cancer Cells ◽  
Breast Cancer Cells ◽  
Underlying Mechanism ◽  
Luciferase Assay ◽  
Breast Cancer Stem Cells ◽  
Xenograft Growth ◽  
Mcf 7

Abstract Background: Breast cancer is the leading cause of cancer mortality in women worldwide. Therefore, it is of great significance to identify the biological mechanism of tumorigenesis and explore the development of breast cancer to achieve a better prognosis for individuals suffering from breast cancer. MicroRNAs (miRNAs) have become a hot topic in cancer research, but the underlying mechanism of its involvement in cancer remains unclear. Methods: The miRNA profile between breast cancer stem cells (BCSCs, CD44+CD24-/low) and control MCF-7 breast cancer cells was obtained in a previous study. Based on biological analysis, miR-20b-5p was hypothesized to be a key factor due to the malignant behavior of BCSCs. Then, agomir-20b-5p and antagomir-20b-5p were transfected into MCF-7 and T47D breast cancer cells to detect cell migration, wound healing and proliferation, and lentivirus vectors silencing or overexpressing miR-20b-5p were transfected into T47D-CSCs to detect proliferation and apoptosis. The effect of miR-20b-5p on xenograft growth was investigated in vivo by transfection of a lentivirus-overexpression vector into T47D cells. The target genes were predicted by the online programs picTar, miRanda and TargetScan and verified by dual luciferase assay, and changes in protein expression were detected by western blot. Results: MiR-20b-5p had the highest degree in both the miRNA-gene network and miRNA-GO network to regulate BCSCs. Overexpression of miR-20b-5p significantly promoted the migration and wound healing ability of MCF-7 cells and T47D cells compared with the control (P < 0.05). In addition, miR-20b-5p facilitated the proliferation of MCF-7 cells and T47D-CSCs (P < 0.05) and inhibited the apoptosis of T47D-CSCs (P < 0.05). Moreover, miR-20b-5p promoted xenograft growth compared with the control group (P < 0.05). Accordingly, potential targets of both CCND1 and E2F1 were predicted by bioinformatics analysis. MiR-20b-5p directly targeted both CCND1 and E2F1 in a dual luciferase assay, while antagomir-20b-5p downregulated the protein levels of CCND1 and E2F1.Conclusions: Oncogenic miR-20b-5p was confirmed to promote the malignant behaviors of breast cancer cells and BCSCs. The underlying mechanism lies in that miR-20b-5p overall enhanced both CCND1 and E2F1 targets via bidirectional regulation probably involving direct downregulation and indirect upregulation.

The enrichment of CD44 in exosomes from breast cancer cells treated with doxorubicin promotes chemoresistance

2020 ◽  
Author(s):  
xiaohong wang ◽  
kai cheng ◽  
guoqiang zhang ◽  
yue yu ◽  
song liu ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Cancer Cells ◽  
Breast Cancer Cells ◽  
Chemotherapy Resistance ◽  
Clinical Samples ◽  
Cd44 Expression ◽  
Candidate Target ◽  
And Function ◽  
Cancer Chemoresistance ◽  
Mcf 7

Abstract Background: Exosomes have been shown to be associated with chemotherapy resistance transmission between cancer cells. However, the cargo and function of exosomes changed in response to doxorubicin remains unclear. Methods: We compared proteome profiles of exosomes extracted from the supernatant of MCF-7(S/Exo) and MCF-7/ADR(A/Exo) cells. We confirmed the differential expression of the candidate target-exosomic-CD44 by immune gold staining and western blot. We further studied the changes of chemosensitivity and CD44 expression in MCF-7 cells co-incubated with A/Exo. We analyzed the levels of exosomal CD44 from patient plasma, and compared the sensitivity and specificity of exosomic CD44 and plasma CD44 on diagnosis of chemoresistance. We modified the MCF-7-derived exosomes loaded with siRNA against CD44 to observe the effects of targeting reduced CD44 expression in lumimal A breast cancer cells. Results: DOX increased the exosomes release from MCF-7/ADR cells and the exosomes mediated proteins intercellular transfer in breast cancer chemoresistance regulation. The candidate target of CD44 in A/Exo was much higher than in S/Exo and the increase levels of exosomic CD44 (21.65-fold) was much higher than cellular CD44 (6.55-fold). The same results were obtained in clinical samples. Exosome-siRNA targeted CD44 (Exos-siCD44) could efficiently targeted to silence its expression. When co-cultured on Exos-siCD44, breast cancer cells exhibited reduced cell proliferation and enhanced susceptibility to DOX and the same phenomenon was observed in mice. Conclusion：Drug-resistant breast cancer cells spread resistance capacity to sensitive ones by releasing exosomes to transfer proteins in intercellular.

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