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PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
5
pubmed:dateCreated
1986-6-2
pubmed:abstractText
PTH receptor-stimulating proteins may be a common mediator of humoral hypercalcemia of malignancy (HHM). Such proteins exhibit adenylate cyclase-stimulating activity (ACSA) in PTH-sensitive assays, and ACSA has been used to follow their purification. Acid/urea tumor extracts from a murine squamous carcinoma model of HHM were previously shown to have very high ACSA, which was partially, but incompletely, inhibited by the PTH antagonist Nle8,18,Tyr34-bovine PTH-(3-34) amide. ACSA from murine tumor extracts has now been further purified using solvent fractionation and reverse phase HPLC. Approximately half of the ACSA is attributable to a family of three proteins (peaks IA, IB, and IC) with properties characteristic of the PTH receptor-stimulating protein extracted from rat Leydig cell and human HHM tumors. The ACSA in these three peaks of murine tumor extract elutes in the same region as human tumor ACSA on reverse phase HPLC, has a dose-response curve parallel to that of PTH, and is fully inhibited by the PTH-(3-34) antagonist in both the renal cortical and rat osteosarcoma (ROS) adenylate cyclase assays. The remaining half of the ACSA from murine tumor extracts elutes as a single peak (peak II) at a higher acetonitrile concentration on reverse phase HPLC. In the renal cortical assay, its dose-response curve differs from that of PTH, its ACSA is not affected by the PTH-(3-34) antagonist, and it potentiates PTH- or peak I-stimulated adenylate cyclase activity. In the PTH-sensitive intact cell ROS assay, peak II exhibits no ACSA. We conclude that the potent ACSA of murine tumor acid/urea extract results in large part from amplification of the PTH-specific ACSA (peak I) by peak II. Peak II is a distinct protein, not previously reported in tumor extracts, that may act as a postreceptor step in the adenylate cyclase system.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
AIM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
May
pubmed:issn
0013-7227
pubmed:author
pubmed:issnType
Print
pubmed:volume
118
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
1982-8
pubmed:dateRevised
2007-11-14
pubmed:meshHeading
pubmed-meshheading:3009144-Adenylate Cyclase, pubmed-meshheading:3009144-Animals, pubmed-meshheading:3009144-Biological Assay, pubmed-meshheading:3009144-Carcinoma, Squamous Cell, pubmed-meshheading:3009144-Chromatography, High Pressure Liquid, pubmed-meshheading:3009144-Disease Models, Animal, pubmed-meshheading:3009144-Dogs, pubmed-meshheading:3009144-Hypercalcemia, pubmed-meshheading:3009144-Kidney Cortex, pubmed-meshheading:3009144-Mice, pubmed-meshheading:3009144-Neoplasm Proteins, pubmed-meshheading:3009144-Osteosarcoma, pubmed-meshheading:3009144-Parathyroid Hormone, pubmed-meshheading:3009144-Peptide Fragments, pubmed-meshheading:3009144-Rats, pubmed-meshheading:3009144-Receptors, Cell Surface, pubmed-meshheading:3009144-Receptors, Parathyroid Hormone, pubmed-meshheading:3009144-Skin Neoplasms
pubmed:year
1986
pubmed:articleTitle
Two species of adenylate cyclase-stimulating activity in a murine squamous carcinoma model of humoral hypercalcemia of malignancy.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S., Research Support, U.S. Gov't, Non-P.H.S.