Carbonic anhydrase II is induced in HL-60 cells by 1,25-dihydroxyvitamin D3: a model for osteoclast gene regulation.

Carbonic anhydrase II (CA II) generates the H+ required for osteoclast-mediated bone resorption in humans. We have developed the human promyelocytic cell line HL-60 as a model system with which to study the osteoclast-specific expression of the CA II gene. Treatment of the cell line with 1,25-dihydroxyvitamin D3 resulted in a dramatic de novo induction of CA II at both the protein and mRNA levels. CA II mRNA was also induced to a lesser extent by 12-O-tetradecanoyl phorbol 13-acetate. Treatment with dimethyl sulfoxide did not increase CA II mRNA. These findings indicate that the HL-60 cell line will be a useful model system to study the osteoclast-specific expression of the CA II gene.