Cells from human bone giant cell tumors show a [Ca2+]o-sensing.
Giant cells from a human giant cell tumor of bone, showing several osteoclast features were tested for their capability of detecting the [Ca2+]o by a receptor like [Ca2+]o sensing. We found that cultured cells responded to elevation of [Ca2+]o, obtained adding 4 mM Ca2+ to the 2 mM Ca2+ containing buffer, by a transient increase of [Ca2+]i. Proliferative cells induced to differentiate by treatment with 10(-8) M 1,25 dihydroxyvitamin D3, were upregulated in their capability of responding to elevated [Ca2+]o. In fact, in this circumstance, the peak of [Ca2+]o-induced [Ca2+]i rise was increased compared to untreated cells. This suggests that 1,25 dihydroxyvitamin D3 induces a more efficient regulation of osteoclast activity.
Teti
A
A
Istituto di Anatomia Umana Normale, Università di Bari.
Argentino
L
L
Grano
M
M
Colucci
S
S
Zambonin Zallone
A
A
D001859:Bone Neoplasms / Q000378:metabolism*; D002118:Calcium / Q000378:metabolism* / Q000502:physiology; D005246:Feedback; D005870:Giant Cell Tumors / Q000378:metabolism*; D006801:Humans; D009994:Osmolar Concentration; D010010:Osteoclasts / Q000378:metabolism*; D015398:Signal Transduction; D014407:Tumor Cells, Cultured
D002118:Calcium