HPI/AMF inhibition halts the development of the aggressive phenotype of breast cancer stem cells

Biochim Biophys Acta Mol Cell Res. 2017 Oct;1864(10):1679-1690. doi: 10.1016/j.bbamcr.2017.06.015. Epub 2017 Jun 23.

Abstract

Cancer stem cells are responsible for tumor recurrence and metastasis. A new highly reproducible procedure for human breast cancer MCF-7 stem cells (BCSC) isolation and selection was developed by using a combination of hypoxia/hypoglycemia plus taxol and adriamycin for 24h. The BCSC enriched fraction (i) expressed (2-15 times) the typical stemness protein markers CD44+, ALDH1A3 and Oct 3/4; (ii) increased its clonogenicity index (20-times), invasiveness profile (>70%), migration capacity (100%) and ability to form mammospheres, compared to its non-metastatic MCF-7 counterpart. This isolation and selection protocol was successful to obtain stem cell enriched fractions from A549, SiHa and medulloblastoma cells. Since the secretion of HPI/AMF cytokine seems involved in metastasis, the effects of erytrose-4-phosphate (E4P) and 6-phosphogluconate (6PG), potent HPI inhibitors, on the acquisition of the breast stem cell-like phenotype were also evaluated. The presence of E4P during the BCSC selection deterred the development of the stemness phenotype, whereas both extracellular E4P (5-250nM) and 6PG (1μM) as well as siRNA HPI/AMF depressed the BCSC invasiveness ability (>90%), clonogenicity index (>90%) and contents (50-96%) of stemness (CD44, ALDH1A), pluripotency (p38 MAPK, Oct3/4, wnt/β-catenin) and EMT (SNAIL, MMP-1, vimentin) markers. The cytokine inhibitor repertaxin (10nM) or the anti-IL-8 or anti-TGF-β monoclonal antibodies (10μg/mL) did not significantly affect the BCSC metastatic phenotype. E4P also diminished (75%) the formation and growth of MCF-7 stem cell mammospheres. These results suggested that E4P by directly interacting with extracellular HPI/AMF may be an effective strategy to deter BCSC growth and progression.

Keywords: Breast cancer; Hexose-phosphate isomerase; Metastatic phenotype; Stem cells.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Breast Neoplasms / drug therapy
  • Breast Neoplasms / genetics*
  • Breast Neoplasms / pathology
  • Cell Hypoxia / drug effects
  • Cell Movement / drug effects
  • Cell Proliferation / drug effects
  • Cell Proliferation / genetics*
  • Doxorubicin / administration & dosage
  • Epithelial-Mesenchymal Transition / drug effects*
  • Epithelial-Mesenchymal Transition / genetics
  • Female
  • Gluconates / administration & dosage
  • Humans
  • Intracellular Signaling Peptides and Proteins / antagonists & inhibitors
  • Intracellular Signaling Peptides and Proteins / genetics*
  • MCF-7 Cells
  • Neoplasm Metastasis
  • Neoplastic Stem Cells / drug effects
  • Neoplastic Stem Cells / pathology
  • Paclitaxel / administration & dosage
  • RNA, Small Interfering / genetics
  • Sugar Phosphates / administration & dosage
  • Sulfonamides / administration & dosage

Substances

  • GPS2 protein, human
  • Gluconates
  • Intracellular Signaling Peptides and Proteins
  • RNA, Small Interfering
  • Sugar Phosphates
  • Sulfonamides
  • Doxorubicin
  • erythrulose 4-phosphate
  • Paclitaxel
  • reparixin
  • 6-phosphogluconic acid