Radioimmunoassay for phorbol esters using rabbit antisera against phorbol succinate

Journal Article · Tue Jan 01 04:00:00 EST 1985 · Cancer Res.; (United States)

OSTI ID:5853380

Tashjian, Jr, A H; Wolfson, G; Fearon, C W

The phorbol nucleus was succinylated and then conjugated to bovine albumin using dicyclohexylcarbodiimide. Rabbits given injections of the conjugate developed antibodies which rose in titer progressively with repeated immunization. By the ninth bleeding, the binding of one antiserum, diluted 1:15,000, was saturated with about 10 nM (/sup 3/H)phorbol-12,13-dibutyrate (( /sup 3/H)-PDBU) and had an average association constant, Ka, of 2.6 X 10(8) M-1. The serological specificity of the antisera was characterized by examining the inhibition of the (/sup 3/H)PDBU-anti-phorbol succinate immune system by 18 phorbol-related compounds. The specificities of antibodies from two rabbits tested in detail were qualitatively similar. The rank order of inhibitory activity for certain phorbol-related compounds was PDBU (concentration of inhibitor required to give 50% inhibition of PDBU binding (IC50) . 7.6 nM) . phorbol-13-acetate (IC50 . 8.2 nM) greater than phorbol-12,13-dibenzoate greater than 4-beta-phorbol (IC50 . 124 nM) greater than or equal to phorbol-12,13-diacetate greater than or equal to phorbol-12-myristate-13-acetate (IC50 . 184 nM) greater than phorbol-13,20-diacetate greater than phorbol-12-acetate (IC50 . 2300 nM). The following compounds showed no detectable serological activity: mezerein, 4-0-methylphorbol-12-myristate-13-acetate, ingenol, 4-alpha-phorbol, teleocidin B, and dihydroteleocidin B. These and other results indicated that the 4-beta-phorbol nucleus was required for serological activity, that esterification of the C-13 position with benzoate, acetate, or butyrate enhanced the immunoreactivity of 4-beta-phorbol, and that among the phorbol-related compounds examined there was no direct relationship between serological activity and biological potency as tumor promoters.

• Research Organization: Harvard School of Public Health, Boston, MA
• OSTI ID: 5853380
• Journal Information: Cancer Res.; (United States), Journal Name: Cancer Res.; (United States) Vol. 45:1; ISSN CNREA
• Country of Publication: United States
• Language: English

Related Subjects

550201 -- Biochemistry-- Tracer Techniques
560305* -- Chemicals Metabolism & Toxicology-- Vertebrates-- (-1987)
59 BASIC BIOLOGICAL SCIENCES
63 RADIATION, THERMAL, AND OTHER ENVIRON. POLLUTANT EFFECTS ON LIVING ORGS. AND BIOL. MAT.
ANIMALS
ANTIBODIES
CARBOXYLIC ACIDS
CARCINOGENS
CHEMICAL BONDS
DICARBOXYLIC ACIDS
ESTERS
IMMUNE REACTIONS
ISOTOPE APPLICATIONS
LABELLED COMPOUNDS
MAMMALS
ORGANIC ACIDS
ORGANIC COMPOUNDS
PHORBOL ESTERS
PROMOTERS
RABBITS
RADIOASSAY
RADIOIMMUNOASSAY
SUCCINIC ACID
TRACER TECHNIQUES
TRITIUM COMPOUNDS
TUMOR PROMOTERS
VERTEBRATES