N-Glycoproteomics Study of Putative N-Glycoprotein Biomarkers of Drug Resistance in MCF-7/ADR Cells

Currently, chemotherapy is an important method for the treatment of various cancers. Nevertheless, it has many limitations, such as poor tumour selectivity and multi-drug resistance. It is necessary to improve this treatment method by incorporating a targeted drug delivery system aimed to reduce side effects and drug resistance. The present work aims to develop pH-sensitive nanocarriers containing magnetic mesoporous silica nanoparticles (MMSNs) coated with pH-responsive polymers for tumour-targeted drug delivery via the folate receptor. 2-Diethyl amino ethyl methacrylate (DEAEMA) was successfully grafted on MMSNs via surface initiated ARGET atom transfer radical polymerization (ATRP), with an average particle size of 180 nm. The end groups of poly (2-(diethylamino)ethyl methacrylate) (PDEAEMA) brushes were converted to amines, followed by a covalent bond with folic acid (FA) as a targeting agent. FA conjugated to the nanoparticle surface was confirmed by X-ray photoelectron spectroscopy (XPS). pH-Responsive behavior of PDEAEMA brushes was investigated by Dynamic Light Scattering (DLS). The nanoparticles average diameters ranged from ca. 350 nm in basic media to ca. 650 in acidic solution. Multifunctional pH-sensitive magnetic mesoporous nanoparticles were loaded with an anti-cancer drug (Doxorubicin) to investigate their capacity and long-circulation time. In a cumulative release pattern, doxorubicin (DOX) release from nano-systems was ca. 20% when the particle exposed to acidic media, compared to ca. 5% in basic media. The nano-systems have excellent biocompatibility and are minimally toxic when exposed to MCF-7, and -MCF-7 ADR cells.

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

Experimental Oncology ◽

10.31768/2312-8852.2017.39(1):25-29 ◽

2017 ◽

Vol 39 (1) ◽

pp. 25-29 ◽

Cited By ~ 4

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 ◽

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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.

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Preparation of pH and redox dual-sensitive core crosslinked micelles for overcoming drug resistance of DOX

Polymer Chemistry ◽

10.1039/c5py01783a ◽

2016 ◽

Vol 7 (9) ◽

pp. 1719-1729 ◽

Cited By ~ 43

Author(s):

Xiao-Qing Yi ◽

Quan Zhang ◽

Dan Zhao ◽

Jia-Qi Xu ◽

Zhen-Lin Zhong ◽

...

Keyword(s):

Drug Resistance ◽

Tumor Cells ◽

Crosslinked Micelles ◽

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When incubating the pH and redox dual-sensitive CCL/SS micelles with MCF-7/ADR cells, they could sufficiently overcome drug resistance to deliver DOX into MCF-7/ADR cells, leading to the apoptosis of tumor cells.

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

Journal of Clinical Oncology ◽

10.1200/jco.2017.35.15_suppl.e12028 ◽

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 ◽

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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.

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

Biomaterials ◽

10.1016/j.biomaterials.2014.07.049 ◽

2014 ◽

Vol 35 (35) ◽

pp. 9495-9507 ◽

Cited By ~ 47

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

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Doxorubicin induces drug resistance and expression of the novel CD44st via NF-κB in human breast cancer MCF-7 cells

Oncology Reports ◽

10.3892/or.2014.3131 ◽

2014 ◽

Vol 31 (6) ◽

pp. 2735-2742 ◽

Cited By ~ 32

Author(s):

XIN JIAN FANG ◽

HUA JIANG ◽

YA QUN ZHU ◽

LI YUAN ZHANG ◽

QIU HONG FAN ◽

...

Keyword(s):

Breast Cancer ◽

Drug Resistance ◽

Human Breast Cancer ◽

The Novel ◽

Human Breast ◽

Mcf 7

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Drug resistance associates with activation of Nrf2 in MCF-7/DOX cells, and wogonin reverses it by down-regulating Nrf2-mediated cellular defense response

Molecular Carcinogenesis ◽

10.1002/mc.21921 ◽

2012 ◽

Vol 52 (10) ◽

pp. 824-834 ◽

Cited By ~ 39

Author(s):

Yan Zhong ◽

Fengyi Zhang ◽

Zhongying Sun ◽

Wei Zhou ◽

Zhi-Yu Li ◽

...

Keyword(s):

Drug Resistance ◽

Defense Response ◽

Cellular Defense ◽

Mcf 7

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ELOVL2: a novel tumor suppressor attenuating tamoxifen resistance in breast cancer

10.21203/rs.3.rs-69357/v1 ◽

2020 ◽

Author(s):

Dawoon Jeong ◽

Juyeon Ham ◽

Hyeon Woo Kim ◽

Heejoo Kim ◽

Hwee Won Ji ◽

...

Keyword(s):

Breast Cancer ◽

Drug Resistance ◽

Cancer Patients ◽

Tumor Tissue ◽

Tamoxifen Resistance ◽

Colony Formation Assay ◽

Breast Cancer Patients ◽

Methylation Analysis ◽

Genome Wide ◽

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Abstract Background To comprehensively understand the molecular mechanism of tamoxifen resistance (TamR) acquisition by epigenetically regulated genes, it is essential to identify pivotal genes by genome-wide methylation analysis and verify their function in xenograft animal model and cancer patients. Methods The MCF-7/TamR breast cancer cell line was developed and a genome-wide methylation array was performed. The methylation and expression of ELOVL2 was validated in cultured cells, xenografted tumor tissue, and breast cancer patients by methylation-specific PCR, qRT-PCR, Western blot analysis, and immunohistochemistry. Deregulation of ELOVL2 and THEM4 was achieved using siRNA or generating stable transfectants. Tam sensitivity, cell growth, and apoptosis were monitored by colorimetric and colony formation assay and flow cytometric analysis. Pathway analysis was performed to generate networks for the differentially methylated genes in the MCF-7/TamR cells and for the differentially expressed genes in the ELOVL2-overexpressing cells. Results Genome-wide methylation analysis in the MCF-7/TamR cells identified elongation of very-long chain fatty acid protein 2 (ELOVL2) to be significantly hypermethylated and downregulated, which was further verified in the tumor tissues from TamR breast cancer patients (n = 28) compared with those from Tam-sensitive (TamS) patients (n = 33) (P < 0.001). Immunohistochemical analysis of tissues from cancer patients showed lower expression of ELOVL2 in the TamR than TamS tissues. Growth of the MCF-7/TamR cells overexpressing ELOVL2 was retarded in cell culture and also in xenograft tumor tissue. Strikingly, ELOVL2 attenuated resistance to Tam up to 70% judged by the colorimetric and colony formation assay and xenograft mouse model. ELOVL2 contributed to the recovery of Tam sensitivity by regulating a group of genes in the AKT and ERα signaling pathways, e.g., THEM4, which plays crucial roles in drug resistance. Conclusions ELOVL2 was hypermethylated and downregulated in TamR breast cancer patients compared with TamS patients. ELOVL2 is responsible for the recovery of Tam sensitivity. AKT- and ERα-hubbed networks are pivotal in ELOVL2 signaling, where THEM4 contributes to the relaying ELOVL2 signaling. This study implies that deregulation of a gene in fatty acid metabolism can lead to drug resistance, giving insight into the development of a new therapeutic strategy for drug-resistant breast cancer.

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The Establishment of Quantitatively Regulating Expression Cassette with sgRNA Targeting BIRC5 to Elucidate the Synergistic Pathway of Survivin with P-Glycoprotein in Cancer Multi-Drug Resistance

Frontiers in Cell and Developmental Biology ◽

10.3389/fcell.2021.797005 ◽

2022 ◽

Vol 9 ◽

Author(s):

Changping Deng ◽

Fabiao Hu ◽

Zhangting Zhao ◽

Yiwen Zhou ◽

Yuping Liu ◽

...

Keyword(s):

Drug Resistance ◽

Survivin Expression ◽

Regulatory System ◽

Multi Drug Resistance ◽

Specific Gene ◽

Expression Levels ◽

P Glycoprotein ◽

Biological Phenomena ◽

Reversal Index ◽

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Quantitative analysis and regulating gene expression in cancer cells is an innovative method to study key genes in tumors, which conduces to analyze the biological function of the specific gene. In this study, we found the expression levels of Survivin protein (BIRC5) and P-glycoprotein (MDR1) in MCF-7/doxorubicin (DOX) cells (drug-resistant cells) were significantly higher than MCF-7 cells (wild-type cells). In order to explore the specific functions of BIRC5 gene in multi-drug resistance (MDR), a CRISPR/Cas9-mediated knocking-in tetracycline (Tet)-off regulatory system cell line was established, which enabled us to regulate the expression levels of Survivin quantitatively (clone 8 named MCF-7/Survivin was selected for further studies). Subsequently, the determination results of doxycycline-induced DOX efflux in MCF-7/Survivin cells implied that Survivin expression level was opposite to DOX accumulation in the cells. For example, when Survivin expression was down-regulated, DOX accumulation inside the MCF-7/Survivin cells was up-regulated, inducing strong apoptosis of cells (reversal index 118.07) by weakening the release of intracellular drug from MCF-7/Survivin cells. Also, down-regulation of Survivin resulted in reduced phosphorylation of PI3K, Akt, and mTOR in MCF-7/Survivin cells and significantly decreased P-gp expression. Previous studies had shown that PI3K/Akt/mTOR could regulate P-gp expression. Therefore, we speculated that Survivin might affect the expression of P-gp through PI3K/Akt/mTOR pathway. In summary, this quantitative method is not only valuable for studying the gene itself, but also can better analyze the biological phenomena related to it.

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miR-520h Stimulates Drug Resistance to Paclitaxel by Targeting the OTUD3-PTEN Axis in Breast Cancer

BioMed Research International ◽

10.1155/2020/9512793 ◽

2020 ◽

Vol 2020 ◽

pp. 1-11 ◽

Cited By ~ 4

Author(s):

Wenwen Geng ◽

Haiyun Song ◽

Qianqian Zhao ◽

Ke Dong ◽

Qian Pu ◽

...

Keyword(s):

Breast Cancer ◽

Drug Resistance ◽

Molecular Mechanisms ◽

Target Genes ◽

Ectopic Expression ◽

Cancer Cell Line ◽

Luciferase Reporter ◽

Paclitaxel Resistance ◽

Exact Function ◽

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MicroRNAs (miRNAs) have been identified as negative posttranscriptional regulators of target genes and are involved directly in the pathological processes of tumors, including drug resistance. However, the exact function of miR-520h in breast cancer remains poorly understood. The aim of this study was to investigate the molecular mechanisms of miR-520h in paclitaxel resistance in the MCF-7 breast cancer cell line. Ectopic expression of miR-520h could promote the proliferation of breast cancer cells and inhibit paclitaxel-induced cell apoptosis. Inhibiting the expression of miR-520h could enhance the sensitivity to paclitaxel in paclitaxel-resistant MCF-7/Taxol cells. Furthermore, luciferase reporter assays showed that OTUD3 was a direct target of miR-520h. OTUD3 plays a necessary role in the paclitaxel resistance effect of miR-520h, and cotreatment with a miR-520h inhibitor and OTUD3 overexpression significantly enhanced MCF-7 cell sensitivity to paclitaxel. Moreover, miR-520h substantially inhibited the protein expression of PTEN via OTUD3 and subsequently affected downstream p-AKT pathway activity. In a clinical study, we also found that high miR-520h expression was associated with more aggressive pathological characteristic and poor prognosis. Therefore, our findings showed that miR-520h targeted the OTUD3-PTEN axis to drive paclitaxel resistance, and this miR might be an important potential target for breast cancer treatment.

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