Multiple forms of parathyroid hormone-like proteins in a human tumour.
The extensive chromatographic characterization of four parathyroid hormone (PTH)-like proteins in a human bronchial carcinoid tumour associated with humoral hypercalcaemia and severe osteitis fibrosa is described. PTH-like bioactivity was detected in acetic acid extracts of the tumour using an in-vitro osteo-sarcoma cell bioassay. The active tumour proteins were positively charged at physiological pH and had apparent Mr of approximately 29,000, 16,000, 4000-9000 and less than 4000. The proteins were immunologically distinct from PTH, but each stimulated PTH-sensitive adenylate cyclase in cultured osteoblastic cells. There was no evidence of PTH gene expression by the tumour. These proteins represent different molecular forms of PTH-related protein.
Docherty
H M
HM
Department of Medicine, University of Birmingham, Queen Elizabeth Hospital.
Heath
D A
DA
D001681:Biological Assay; D001984:Bronchial Neoplasms / Q000032:analysis* / Q000150:complications / Q000235:genetics; D002276:Carcinoid Tumor / Q000032:analysis* / Q000150:complications / Q000235:genetics / Q000556:secondary; D000242:Cyclic AMP / Q000096:biosynthesis; D015342:DNA Probes; D006801:Humans; D006934:Hypercalcemia / Q000150:complications; D008113:Liver Neoplasms / Q000032:analysis / Q000556:secondary; D009363:Neoplasm Proteins / Q000032:analysis* / Q000235:genetics; D009693:Nucleic Acid Hybridization; D010002:Osteitis Fibrosa Cystica / Q000150:complications; D010281:Parathyroid Hormone / Q000032:analysis*; D044162:Parathyroid Hormone-Related Protein; D012334:RNA, Neoplasm / Q000032:analysis / Q000235:genetics; D014357:Trypsin / Q000378:metabolism; D014407:Tumor Cells, Cultured
D015342:DNA Probes; D009363:Neoplasm Proteins; C470121:PTHLH protein, human; D010281:Parathyroid Hormone; D044162:Parathyroid Hormone-Related Protein; D012334:RNA, Neoplasm; D000242:Cyclic AMP; D014357:Trypsin