Calcium channel antagonist properties of the antineoplastic antiestrogen tamoxifen in the PC12 neurosecretory cell line

Journal Article · Thu Jan 01 00:00:00 EST 1987 · Cancer Res.; (United States)

OSTI ID:6860001

Greenberg, D A; Carpenter, C L; Messing, R O

In view of existing evidence that Ca2+ may be important for tumor cell growth and metastasis, we investigated the effects of three antineoplastic drugs on K+-stimulated /sup 45/Ca2+ uptake through voltage-dependent Ca2+ channels of the PC12 neurosecretory cell line. The agents chosen for study (vinblastine, doxorubicin, and tamoxifen) were those previously shown to inhibit Ca2+/calmodulin- or Ca2+/phospholipid-activated protein kinases. Neither vinblastine nor doxorubicin altered /sup 45/Ca2+ uptake at concentrations that inhibit these Ca2+-dependent enzymes. However, tamoxifen reduced uptake (50% inhibitory dose, 8.6 +/- 0.9 (SE) microM) and competed for Ca2+ channel antagonist binding sites labeled by (/sup 3/H)-(+)PN200-110 (ki = 2.2 +/- 0.3 microM). Ca2+ channel antagonist properties may contribute to the effects of antineoplastic agents such as tamoxifen.

• Research Organization: Univ. of California, San Francisco
• OSTI ID: 6860001
• Journal Information: Cancer Res.; (United States), Vol. 1
• Country of Publication: United States
• Language: English

Related Subjects

59 BASIC BIOLOGICAL SCIENCES
ANTINEOPLASTIC DRUGS
BIOLOGICAL EFFECTS
CALCIUM
UPTAKE
CALCIUM 45
CATIONS
CELL DIVISION
OXADIAZOLES
RATS
TAMOXIFEN
TRACER TECHNIQUES
TRITIUM COMPOUNDS
ALKALINE EARTH ISOTOPES
ALKALINE EARTH METALS
ANIMALS
AZOLES
BETA DECAY RADIOISOTOPES
BETA-MINUS DECAY RADIOISOTOPES
CALCIUM ISOTOPES
CHARGED PARTICLES
DAYS LIVING RADIOISOTOPES
DRUGS
ELEMENTS
EVEN-ODD NUCLEI
HETEROCYCLIC COMPOUNDS
INTERMEDIATE MASS NUCLEI
IONS
ISOTOPE APPLICATIONS
ISOTOPES
LABELLED COMPOUNDS
MAMMALS
METALS
NUCLEI
ORGANIC COMPOUNDS
ORGANIC NITROGEN COMPOUNDS
ORGANIC OXYGEN COMPOUNDS
RADIOISOTOPES
RODENTS
VERTEBRATES
550201* - Biochemistry- Tracer Techniques