Proteome analysis associated with cadmium adaptation in U937 cells. Identification of calbindin-D28k as a secondary cadmium-responsive protein that confers resistance to cadmium-induced apoptosis

Hye Kyung Jeon, Hyung Seung Jin, Dong Hee Lee, Won Seok Choi, Chang Kiu Moon, Young J. Oh, Tae H. Lee

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11 Citations (Scopus)


Cadmium is a well known environmental toxicant and carcinogen. To identify proteins involved in cellular adaptive responses to cadmium, we established cadmium-adapted U937 cells that exhibit resistance to cadmium-induced apoptosis, and we performed comparative proteome analysis of these cells with parental cells that were either untreated or treated with cadmium. Newly identified proteins that were changed in expression level in both adapted cells and cadmium-treated parental cells included proteins implicated in cell proliferation and malignant transformation. Most interesting, a calcium-binding protein calbindin-D28k was increased only in the adapted cells but not in cadmium-exposed parental cells. The level of calbindin-D28k increased by the degree of cadmium adaptation and was stably maintained without selective pressure of cadmium. Cadmium-adapted U937 cells were resistant to the toxic effects of cytosolic calcium rise by cadmium treatment and by depletion of intracellular calcium stores, suggesting that enhanced calcium buffering by up-regulated calbindin-D28k may be responsible for acquiring resistance to cadmium-induced apoptosis. We demonstrated that overexpression of calbindin-D28k in MN9D neuronal cells resulted in reduced cadmium-induced apoptosis. Our study documents for the first time that cells respond to long term cadmium exposure by increasing calbindin-D28k expression, thereby attenuating cadmium-induced apoptosis.

Original languageEnglish
Pages (from-to)31575-31583
Number of pages9
JournalJournal of Biological Chemistry
Issue number30
Publication statusPublished - 2004 Jul 23


All Science Journal Classification (ASJC) codes

  • Biochemistry
  • Molecular Biology
  • Cell Biology

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