Embryonic Stem Cell Preconditioned Microenvironment Suppresses Tumorigenic Properties in Breast Cancer

Stem Cell Res Ther. 2016 Jul 27;7(1):95. doi: 10.1186/s13287-016-0360-x.

Abstract

Background: Microenvironment is being increasingly recognized as a critical determinant in tumor progression and metastasis. However, the appropriate regulatory mechanism to maintain the normal balance between differentiation and self-renewal of the cancer cell in microenvironment is not well known.

Methods: 4T1 breast cancer cells were treated with embryonic stem (ES) cell conditioned medium which was collected from mouse ES cells. Inhibition of tumor cell growth was based on the reduction of cell proliferation and viability, and inhibition of aggressive properties of tumor cells were examined using the wound-healing and mammosphere assays. The expression of stem cell-associated genes was detected by quantitative RT-PCR.

Results: We used a real-time imaging system to investigate the effect of the mouse ES cell microenvironment on aggressive breast cancer cells in vitro and in vivo. Exposure of breast cancer cells in mouse ES cell conditioned medium resulted in inhibition of growth, migration, metastasis, and angiogenesis of cancer cells. For many tumors, aggressive properties were tightly related to Stat3 signaling activation. We specifically discovered that the ES cell microenvironment sufficiently suppressed Stat3 signaling pathway activation in aggressive tumor cells, leading to a reduction in tumorigenesis and invasiveness.

Conclusions: We identified important functions of Stat3 and their implications for antitumor effects of ES cell conditioned medium. Some factors secreted by ES cells could efficiently suppress Stat3 pathway activation in breast cancer cells, and were then involved in cancer cell growth, survival, invasion, and migration. This study may act as a platform to understand tumor cell plasticity and may offer new therapeutic strategies to inhibit breast cancer progression.

Keywords: Breast cancer cells; Embryonic stem cells; Imaging; Microenvironment; Stat3 signaling.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Biological Assay
  • Carcinogenesis / drug effects*
  • Carcinogenesis / genetics
  • Carcinogenesis / metabolism
  • Carcinogenesis / pathology
  • Cell Differentiation / drug effects
  • Cell Proliferation / drug effects
  • Cell Survival / drug effects
  • Culture Media, Conditioned / pharmacology*
  • Embryonic Stem Cells / cytology
  • Embryonic Stem Cells / metabolism*
  • Feeder Cells / cytology
  • Feeder Cells / metabolism
  • Female
  • Gene Expression
  • Mammary Neoplasms, Animal / drug therapy*
  • Mammary Neoplasms, Animal / genetics
  • Mammary Neoplasms, Animal / metabolism
  • Mammary Neoplasms, Animal / pathology
  • Mice
  • Mice, Inbred BALB C
  • Neoplasm Invasiveness
  • STAT3 Transcription Factor / antagonists & inhibitors
  • STAT3 Transcription Factor / genetics
  • STAT3 Transcription Factor / metabolism
  • Signal Transduction
  • Stem Cell Niche / genetics*
  • Tumor Cells, Cultured
  • Wound Healing / drug effects

Substances

  • Culture Media, Conditioned
  • STAT3 Transcription Factor
  • Stat3 protein, mouse