Parathyroid hormone-related proteins in cultured epithelial cells.
The distribution and molecular characteristics of parathyroid hormone-related protein (PTH-rP) in conditioned media and cell extracts of cultured human keratinocytes, and in media from a variety of both normal and transformed epithelial and non-epithelial cell cultures were studied. PTH-rP of Mr 20,000 was observed in keratinocyte-conditioned media, and a larger form, Mr 29,000, in the keratinocyte cell extract. PTH-like bioactivity was also detected in media from 12 out of 17 epithelial cell cultures, but was not present in media from 14 cell cultures of non-epithelial origin. The molecular size of the PTH-like protein present in the epithelial cell media was approximately 20,000, corresponding with the PTH-rP in keratinocyte-conditioned medium. These observations may explain why hypercalcaemia is most commonly associated with tumours of epithelial origin.
Docherty
H M
HM
Department of Medicine, University of Birmingham, Queen Elizabeth Hospital.
Dixon-Lewis
M J
MJ
Milton
P G
PG
Blight
A
A
Heath
D A
DA
D001681:Biological Assay; D002478:Cells, Cultured; D002850:Chromatography, Gel; D006801:Humans; D015603:Keratinocytes / Q000378:metabolism*; D009363:Neoplasm Proteins / Q000378:metabolism*; D010281:Parathyroid Hormone; D044162:Parathyroid Hormone-Related Protein
D009363:Neoplasm Proteins; C470121:PTHLH protein, human; D010281:Parathyroid Hormone; D044162:Parathyroid Hormone-Related Protein