Regulation of ABCB1 activity by microRNA-200c and microRNA-203a in breast cancer cells: the quest for microRNAs’ involvement in cancer drug resistance

Research output: Contribution to journalArticle

Abstract

Aim: ABCB1 is a major player in cancer drug resistance. The purpose of this study was to functionally assess the regulation of ABCB1 activity in a doxorubicin-resistant breast cancer cell line by miR-200c and miR-203.

Methods: Human breast carcinoma cell lines MCF-7 (Doxorubicin-sensitive and not expressing ABCB1) and KCR (Doxorubicin-resistant and expressing ABCB1) were used to evaluate the expression levels of miR-200c and miR-203 by Real-time quantitative PCR (RT-qPCR). The effects of transient ectopic expression of miRNA-200c and miR-203 on the expression of ABCB1 in KCR and MCF-7 cells was verified by RT-qPCR and Western Blot. The extrusion activity of the ABCB1 pump was analyzed by fluorescence microscopy and flow cytometry through fluorescence substrate retention assays (DiOC2) in the presence and absence of the ABCB1 inhibitor verapamil.

Results: RT-qPCR results indicated a 100,000-fold increase in ABCB1 mRNA expression levels in KCR cells compared to MCF-7 cells, and is inversely correlated with the expression of miR-203 and miR-200c. The insertion of miR-200c and miR-203 led to a higher retention of DiOC2 within KCR cells, and slightly reduced the protein levels of ABCB1 in KCR cells, although the high initial expression of ABCB1 masked the reduction in protein levels. The increased intracellular accumulation of the fluorescent due DiOC2 in the presence of the ABCB1 inhibitor verapamil correlated with the inhibition caused by miR-203 and miR-200c in transfected cells.

Conclusion: The present study demonstrates that miR-200c and miR-203 exert a negative modulating effect on the activity of ABCB1 associated with doxorubicin resistance.
Original languageEnglish
Pages (from-to)897-911
JournalCancer Drug Resistance
Volume2
DOIs
Publication statusPublished - 19 Sep 2019

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MicroRNAs
Drug Resistance
Doxorubicin
Breast Neoplasms
Real-Time Polymerase Chain Reaction
MCF-7 Cells
Verapamil
Neoplasms
Cell Line
P-Glycoprotein
Fluorescence Microscopy
Flow Cytometry
Fluorescence
Western Blotting
Messenger RNA
3,3'-diethyloxacarbocyanine
Proteins

Keywords

  • ABCB1
  • drug resistance
  • drug extrusion
  • breast cancer
  • miR2003
  • miR203

Cite this

@article{87b246bdd16e40528026ceb163254760,
title = "Regulation of ABCB1 activity by microRNA-200c and microRNA-203a in breast cancer cells: the quest for microRNAs’ involvement in cancer drug resistance",
abstract = "Aim: ABCB1 is a major player in cancer drug resistance. The purpose of this study was to functionally assess the regulation of ABCB1 activity in a doxorubicin-resistant breast cancer cell line by miR-200c and miR-203.Methods: Human breast carcinoma cell lines MCF-7 (Doxorubicin-sensitive and not expressing ABCB1) and KCR (Doxorubicin-resistant and expressing ABCB1) were used to evaluate the expression levels of miR-200c and miR-203 by Real-time quantitative PCR (RT-qPCR). The effects of transient ectopic expression of miRNA-200c and miR-203 on the expression of ABCB1 in KCR and MCF-7 cells was verified by RT-qPCR and Western Blot. The extrusion activity of the ABCB1 pump was analyzed by fluorescence microscopy and flow cytometry through fluorescence substrate retention assays (DiOC2) in the presence and absence of the ABCB1 inhibitor verapamil.Results: RT-qPCR results indicated a 100,000-fold increase in ABCB1 mRNA expression levels in KCR cells compared to MCF-7 cells, and is inversely correlated with the expression of miR-203 and miR-200c. The insertion of miR-200c and miR-203 led to a higher retention of DiOC2 within KCR cells, and slightly reduced the protein levels of ABCB1 in KCR cells, although the high initial expression of ABCB1 masked the reduction in protein levels. The increased intracellular accumulation of the fluorescent due DiOC2 in the presence of the ABCB1 inhibitor verapamil correlated with the inhibition caused by miR-203 and miR-200c in transfected cells.Conclusion: The present study demonstrates that miR-200c and miR-203 exert a negative modulating effect on the activity of ABCB1 associated with doxorubicin resistance.",
keywords = "ABCB1, drug resistance, drug extrusion, breast cancer, miR2003, miR203",
author = "Ana Armada and Gomes, {Bruno Costa} and Miguel Viveiros and Jos{\'e} Rueff and Rodrigues, {Ant{\'o}nio Sebasti{\~a}o}",
year = "2019",
month = "9",
day = "19",
doi = "10.20517/cdr.2019.24",
language = "English",
volume = "2",
pages = "897--911",
journal = "Cancer Drug Resistance",

}

TY - JOUR

T1 - Regulation of ABCB1 activity by microRNA-200c and microRNA-203a in breast cancer cells: the quest for microRNAs’ involvement in cancer drug resistance

AU - Armada, Ana

AU - Gomes, Bruno Costa

AU - Viveiros, Miguel

AU - Rueff, José

AU - Rodrigues, António Sebastião

PY - 2019/9/19

Y1 - 2019/9/19

N2 - Aim: ABCB1 is a major player in cancer drug resistance. The purpose of this study was to functionally assess the regulation of ABCB1 activity in a doxorubicin-resistant breast cancer cell line by miR-200c and miR-203.Methods: Human breast carcinoma cell lines MCF-7 (Doxorubicin-sensitive and not expressing ABCB1) and KCR (Doxorubicin-resistant and expressing ABCB1) were used to evaluate the expression levels of miR-200c and miR-203 by Real-time quantitative PCR (RT-qPCR). The effects of transient ectopic expression of miRNA-200c and miR-203 on the expression of ABCB1 in KCR and MCF-7 cells was verified by RT-qPCR and Western Blot. The extrusion activity of the ABCB1 pump was analyzed by fluorescence microscopy and flow cytometry through fluorescence substrate retention assays (DiOC2) in the presence and absence of the ABCB1 inhibitor verapamil.Results: RT-qPCR results indicated a 100,000-fold increase in ABCB1 mRNA expression levels in KCR cells compared to MCF-7 cells, and is inversely correlated with the expression of miR-203 and miR-200c. The insertion of miR-200c and miR-203 led to a higher retention of DiOC2 within KCR cells, and slightly reduced the protein levels of ABCB1 in KCR cells, although the high initial expression of ABCB1 masked the reduction in protein levels. The increased intracellular accumulation of the fluorescent due DiOC2 in the presence of the ABCB1 inhibitor verapamil correlated with the inhibition caused by miR-203 and miR-200c in transfected cells.Conclusion: The present study demonstrates that miR-200c and miR-203 exert a negative modulating effect on the activity of ABCB1 associated with doxorubicin resistance.

AB - Aim: ABCB1 is a major player in cancer drug resistance. The purpose of this study was to functionally assess the regulation of ABCB1 activity in a doxorubicin-resistant breast cancer cell line by miR-200c and miR-203.Methods: Human breast carcinoma cell lines MCF-7 (Doxorubicin-sensitive and not expressing ABCB1) and KCR (Doxorubicin-resistant and expressing ABCB1) were used to evaluate the expression levels of miR-200c and miR-203 by Real-time quantitative PCR (RT-qPCR). The effects of transient ectopic expression of miRNA-200c and miR-203 on the expression of ABCB1 in KCR and MCF-7 cells was verified by RT-qPCR and Western Blot. The extrusion activity of the ABCB1 pump was analyzed by fluorescence microscopy and flow cytometry through fluorescence substrate retention assays (DiOC2) in the presence and absence of the ABCB1 inhibitor verapamil.Results: RT-qPCR results indicated a 100,000-fold increase in ABCB1 mRNA expression levels in KCR cells compared to MCF-7 cells, and is inversely correlated with the expression of miR-203 and miR-200c. The insertion of miR-200c and miR-203 led to a higher retention of DiOC2 within KCR cells, and slightly reduced the protein levels of ABCB1 in KCR cells, although the high initial expression of ABCB1 masked the reduction in protein levels. The increased intracellular accumulation of the fluorescent due DiOC2 in the presence of the ABCB1 inhibitor verapamil correlated with the inhibition caused by miR-203 and miR-200c in transfected cells.Conclusion: The present study demonstrates that miR-200c and miR-203 exert a negative modulating effect on the activity of ABCB1 associated with doxorubicin resistance.

KW - ABCB1

KW - drug resistance

KW - drug extrusion

KW - breast cancer

KW - miR2003

KW - miR203

U2 - 10.20517/cdr.2019.24

DO - 10.20517/cdr.2019.24

M3 - Article

VL - 2

SP - 897

EP - 911

JO - Cancer Drug Resistance

JF - Cancer Drug Resistance

ER -