Role of the Drug Transporter ABCC3 in Breast Cancer Chemoresistance

PLoS One. 2016 May 12;11(5):e0155013. doi: 10.1371/journal.pone.0155013. eCollection 2016.

Abstract

Increased expression of ABC-family of transporters is associated with chemotherapy failure. Although the drug transporters ABCG2, ABCB1 and ABCC1 have been majorly implicated in cancer drug resistance, recent studies have associated ABCC3 with multi drug resistance and poor clinical response. In this study, we have examined the expression of ABCC3 in breast cancers and studied its role in drug resistance and stemness of breast cancer cells in comparison with the more studied ABCC1. We observed that similar to ABCC1, the transcripts levels of ABCC3 was significantly high in breast cancers compared to adjacent normal tissue. Importantly, expression of both transporters was further increased in chemotherapy treated patient samples. Consistent with this, we observed that treatment of breast cancer cell lines with anti-cancer agents increased their mRNA levels of both ABCC1 and ABCC3. Further, similar to knockdown of ABCC1, knockdown of ABCC3 also significantly increased the retention of chemotherapeutic drugs in breast cancer cells and rendered them more chemo-sensitive. Interestingly, ABCC1 and ABCC3 knockdown cells also showed reduction in the expression of stemness genes, while ABCC3 knockdown additionally led to a reduction in the CD44high/CD24low breast cancer stem-like subpopulation. Consistent with this, their ability to form primary tumours was compromised. Importantly, down-modulation of ABCC3 rendered these cells increasingly susceptible to doxorubicin in xenograft mice models in vivo. Thus, our study highlights the importance of ABCC3 transporters in drug resistance to chemotherapy in the context of breast cancer. Further, these results suggest that combinatorial inhibition of these transporters together with standard chemotherapy can reduce therapy-induced resistance in breast cancer.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Antineoplastic Agents / pharmacology
  • Breast Neoplasms / genetics*
  • Breast Neoplasms / pathology
  • Cell Line, Tumor
  • Doxorubicin / pharmacology
  • Drug Resistance, Neoplasm / drug effects
  • Drug Resistance, Neoplasm / genetics*
  • Female
  • Gene Expression Regulation, Neoplastic / drug effects
  • Gene Knockdown Techniques
  • Humans
  • Mice, Inbred NOD
  • Mice, SCID
  • Multidrug Resistance-Associated Proteins / genetics*
  • Multidrug Resistance-Associated Proteins / metabolism
  • Neoplastic Stem Cells / drug effects
  • Neoplastic Stem Cells / metabolism
  • Neoplastic Stem Cells / pathology

Substances

  • Antineoplastic Agents
  • Multidrug Resistance-Associated Proteins
  • multidrug resistance-associated protein 3
  • Doxorubicin

Grants and funding

This work was partly supported by grants to AR from IISc and DBT-IISc partnership programme. Authors acknowledge support from UGC and DST-FIST to the Department of MRDG, IISc, SERB and CII for providing Prime Minister’s fellowship to SAB; AR is a Wellcome Trust DBT India Alliance Senior Fellow. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.