International Journal of Cell Cloning, Vol 5, 170-178, Copyright © 1987 by AlphaMed Press
Biphasic effect of vanadium salts on in vitro tumor colony growth
U Hanauske, AR Hanauske, MH Marshall, VA Muggia and DD Von Hoff
Vanadium is a trace element widely distributed in nature. It interferes
with a variety of enzyme systems and is also reported to increase DNA-
synthesis and in vitro clonal growth of human and mouse fibroblasts. The
purpose of the present study was to determine the effect of vanadium salts
on the in vitro growth of fresh human tumor specimens. Various
concentrations of ammonium metavanadate (AMV), vanadyl sulfate trihydrate
(VST) and ortho sodium vanadate (OSV) were tested in a human tumor cloning
assay (HTCA). Thirty-four evaluable specimens were tested at concentrations
of less than or equal to 10(-10) M of one or more vanadium salts. At this
concentration, colony formation was increased by greater than or equal to
150% as compared to control at one or more concentrations in 16 specimens
(47%). Twelve evaluable specimens were tested against various
concentrations greater than 10(-10) M. Colony formation was inhibited by
greater than or equal to 50% of the control at one or more concentrations
in all specimens. In further experiments we performed a head-to-head
comparison of OSV (10(-3)M) and our standard positive control for cell kill
(chromomycin A3, 100 micrograms/ml) in 34 specimens. OSV led to a
comparable or better cell kill in 28 tumors (82%). We conclude that
vanadium salts at low concentrations (less than or equal to 10(-10)M) can
stimulate in vitro colony formation from human tumors. At higher
concentrations (greater than 10(-10)M) tumor colony formation is inhibited.
OSV might be useful as a very inexpensive positive control in the HTCA. In
addition, the value of vanadium salts as antitumor agents should be further
investigated in vivo.
