Pit-1 inhibits BRCA1 and sensitizes human breast tumors to cisplatin and vitamin D treatment. Academic Article uri icon

Overview

abstract

  • The POU class 1 homeobox 1 (POU1F1, also known as Pit-1), pertaining to the Pit-Oct-Unc (POU) family of transcription factors, has been related to tumor growth and metastasis in breast. However, its role in response to breast cancer therapy is unknown. We found that Pit-1 down-regulated DNA-damage and repair genes, and specifically inhibited BRCA1 gene expression, sensitizing breast cancer cells to DNA-damage agents. Administration of 1α, 25-dihydroxy-3-epi-vitamin D3 (3-Epi, an endogenous low calcemic vitamin D metabolite) reduced Pit-1 expression, and synergized with cisplatin, thus, decreasing cell proliferation and apoptosis in vitro, and reducing tumor growth in vivo. In addition, fifteen primary cultures of human breast tumors showed significantly decreased proliferation when treated with 3-Epi+cisplatin, compared to cisplatin alone. This response positively correlated with Pit-1 levels. Our findings demonstrate that high levels of Pit-1 and reduced BRCA1 levels increase breast cancer cell susceptibility to 3-Epi+cisplatin therapy.

publication date

  • June 10, 2015

Research

keywords

  • Breast Neoplasms
  • Cisplatin
  • Genes, BRCA1
  • Transcription Factor Pit-1
  • Vitamin D

Identity

PubMed Central ID

  • PMC4546479

Scopus Document Identifier

  • 84979917760

PubMed ID

  • 25992773

Additional Document Info

volume

  • 6

issue

  • 16