Nuclear-Biased DUSP6 Expression is Associated with Cancer Spreading Including Brain Metastasis in Triple-Negative Breast Cancer

Int J Mol Sci. 2019 Jun 24;20(12):3080. doi: 10.3390/ijms20123080.

Abstract

DUSP6 is a dual-specificity phosphatase (DUSP) involved in breast cancer progression, recurrence, and metastasis. DUSP6 is predominantly cytoplasmic in HER2+ primary breast cancer cells, but the expression and subcellular localization of DUSPs, especially DUSP6, in HER2-positive circulating tumor cells (CTCs) is unknown. Here we used the DEPArray system to identify and isolate CTCs from metastatic triple negative breast cancer (TNBC) patients and performed single-cell NanoString analysis to quantify cancer pathway gene expression in HER2-positive and HER2-negative CTC populations. All TNBC patients contained HER2-positive CTCs. HER2-positive CTCs were associated with increased ERK1/ERK2 expression, which are direct DUSP6 targets. DUSP6 protein expression was predominantly nuclear in breast CTCs and the brain metastases but not pleura or lung metastases of TNBC patients. Therefore, nuclear DUSP6 may play a role in the association with cancer spreading in TNBC patients, including brain metastasis.

Keywords: DEPArray; HER2; brain metastasis; circulating tumor cells (CTCs); dual-specificity phosphatase; single cell analysis; triple-negative breast cancer (TNBC).

MeSH terms

  • ATP Binding Cassette Transporter, Subfamily B / genetics
  • Animals
  • Antineoplastic Agents / pharmacology
  • Antineoplastic Agents, Immunological / pharmacology
  • Biomarkers, Tumor*
  • Brain Neoplasms / secondary*
  • Cell Line, Tumor
  • Cell Nucleus / genetics
  • Disease Models, Animal
  • Dual Specificity Phosphatase 6 / antagonists & inhibitors
  • Dual Specificity Phosphatase 6 / genetics*
  • Dual Specificity Phosphatase 6 / metabolism
  • Female
  • Fluorescent Antibody Technique
  • Gene Expression Regulation, Neoplastic* / drug effects
  • Histones / metabolism
  • Humans
  • MAP Kinase Signaling System
  • Mice
  • Neoplasm Invasiveness
  • Neoplasm Staging
  • Neoplastic Cells, Circulating / metabolism
  • Neoplastic Cells, Circulating / pathology
  • Protein Binding
  • Protein Transport
  • Receptor, ErbB-2 / genetics
  • Receptor, ErbB-2 / metabolism
  • Single-Cell Analysis
  • Triple Negative Breast Neoplasms / genetics*
  • Triple Negative Breast Neoplasms / metabolism
  • Triple Negative Breast Neoplasms / pathology*
  • Triple Negative Breast Neoplasms / therapy
  • Xenograft Model Antitumor Assays
  • p300-CBP Transcription Factors / metabolism

Substances

  • ABCB5 protein, human
  • ATP Binding Cassette Transporter, Subfamily B
  • Antineoplastic Agents
  • Antineoplastic Agents, Immunological
  • Biomarkers, Tumor
  • Histones
  • p300-CBP Transcription Factors
  • p300-CBP-associated factor
  • Receptor, ErbB-2
  • DUSP6 protein, human
  • Dual Specificity Phosphatase 6