Store-operated Ca2+ channels in prostate cancer epithelial cells: function, regulation, and role in carcinogenesis

Cell Calcium. 2003 May-Jun;33(5-6):357-73. doi: 10.1016/s0143-4160(03)00049-6.

Abstract

Ca2+ homeostasis mechanisms, in which the Ca2+ entry pathways play a key role, are critically involved in both normal function and cancerous transformation of prostate epithelial cells. Here, using the lymph node carcinoma of the prostate (LNCaP) cell line as a major experimental model, we characterize prostate-specific store-operated Ca2+ channels (SOCs)--a primary Ca2+ entry pathway for non-excitable cells--for the first time. We show that prostate-specific SOCs share major store-dependent, kinetic, permeation, inwardly rectifying, and pharmacological (including dual, potentiation/inhibition concentration-dependent sensitivity to 2-APB) properties with "classical" Ca2+ release-activated Ca2+ channels (CRAC), but have a higher single channel conductance (3.2 and 12pS in Ca2+- and Na+-permeable modes, respectively). They are subject to feedback inhibition via Ca2+-dependent PKC, CaMK-II and CaM regulatory pathways and are functionally dependent on caveolae integrity. Caveolae also provide a scaffold for spatial co-localization of SOCs with volume-regulated anion channels (VRAC) and their Ca2+-mediated interaction. The TRPC1 and TRPV6 members of the transient receptor potential (TRP) channel family are the most likely molecular candidates for the formation of prostate-specific endogenous SOCs. Differentiation of LNCaP cells to an androgen-insensitive, apoptotic-resistant neuroendocrine phenotype downregulates SOC current. We conclude that prostate-specific SOCs are important determinants in the transition to androgen-independent prostate cancer.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Biomarkers
  • Calcium / metabolism*
  • Calcium Channels / genetics
  • Calcium Channels / metabolism*
  • Electrophysiology
  • Endoplasmic Reticulum / metabolism
  • Epithelial Cells / metabolism*
  • Epithelial Cells / pathology
  • Humans
  • Kinetics
  • Male
  • Oligonucleotides, Antisense / pharmacology
  • Prostatic Neoplasms / metabolism*
  • Prostatic Neoplasms / pathology
  • RNA, Messenger / drug effects
  • TRPC Cation Channels
  • TRPV Cation Channels
  • Tumor Cells, Cultured

Substances

  • Biomarkers
  • Calcium Channels
  • Oligonucleotides, Antisense
  • RNA, Messenger
  • TRPC Cation Channels
  • TRPV Cation Channels
  • TRPV6 channel
  • transient receptor potential cation channel, subfamily C, member 1
  • Calcium