Adipocyte-driven unfolded protein response is a shared transcriptomic signature of metastatic prostate carcinoma cells

Biochim Biophys Acta Mol Cell Res. 2021 Oct;1868(11):119101. doi: 10.1016/j.bbamcr.2021.119101. Epub 2021 Jul 16.

Abstract

A critical unknown in the field of skeletal metastases is how cancer cells find a way to thrive under harsh conditions, as exemplified by metastatic colonization of adipocyte-rich bone marrow by prostate carcinoma cells. To begin understanding molecular processes that enable tumor cells to survive and progress in difficult microenvironments such as bone, we performed unbiased examination of the transcriptome of two different prostate cancer cell lines in the absence or presence of bone marrow adipocytes. Our RNAseq analyses and subsequent quantitative PCR and protein-based assays reveal that upregulation of endoplasmic reticulum (ER) stress and unfolded protein response (UPR) genes is a shared signature between metastatic prostate carcinoma cell lines of different origin. Pathway analyses and pharmacological examinations highlight the ER chaperone BIP as an upstream coordinator of this transcriptomic signature. Additional patient-based data support our overall conclusion that ER stress and UPR induction are shared, important factors in the response and adaptation of metastatic tumor cells to their micro-environment. Our studies pave the way for additional mechanistic investigations and offer new clues towards effective therapeutic interventions in metastatic disease.

Keywords: BIP; Bone marrow adipocyte; Bone metastasis; ER stress; HSPA5; Prostate cancer; Unfolded protein response.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adipocytes / metabolism*
  • Animals
  • Cells, Cultured
  • Endoplasmic Reticulum Chaperone BiP
  • Endoplasmic Reticulum Stress / genetics
  • Humans
  • Male
  • Mice
  • Prostatic Neoplasms / genetics*
  • Prostatic Neoplasms / metabolism
  • Prostatic Neoplasms / pathology
  • RNA-Seq
  • Transcriptome
  • Unfolded Protein Response / genetics