Vanadium as Therapeutic Agent for Cancer

The antineoplastic activity of vanadium compounds has been studied for some time. In 1979, the metalocene compound, biscyclopentadienyldichloro-Vanadium(IV), (C5H5)VCI2, was found to have antitumor activity [161], The compound inhibited the growth of various cancer cell lines and the growth of solid tumors in vivo. Vanadium(V) peroxocomplexes with known insulin-mimetic activity were shown to have antitumor activity against murine leukemia cells at that time. Vanadocene compounds are now known to induce apoptosis in cell lines. The apoptotic signal 

Evidence is accumulating that vanadium interferes with the proper functioning of the cell cytoskeleton, which could also be involved in its antineoplastic effects. Taxol, a very successful chemotherapeutic drug, inhibits the function of microtubules in the cytoskeleton. In hepatomoa Morris 5123 cells, V(III) complexed with cysteine and derivatives inhibited the growth of these tumor cells and participated in the rearrangement of actin cytoskeleton architecture [166], 

Vanadium treatment in animals has been shown to interfere with the development of malignant tumors. In 1984, oral treatment with vanadyl sulfate was shown to decrease the induction of mammary carcinoma [167], New experiments have involved treatment to induce a mammary carcinoma in rats started on oral vanadate treatment that continued for 35 weeks. Vanadium treatment protected the rat from development of cancer as determined histologically. In addition, a significant reduction in incidence of total number of tumors and a delay in time to tumor appearance was observed. Vanadium-treated animals had lower tissue distribution of metallothio-nein, a prognostic marker for breast cancer. The mammary tissue in the vanadium-treated group showed increased apoptosis, which could be related to the anticarci-nogenic effect [168], 

Vanadium compounds have an inhibitory effect against induced rat hepatocar-cinogenesis by limiting cell proliferation and chromosomal aberrations in the pre-neoplastic stages of the development of this cancer [169], These antineoplastic effects of vanadium could be related to the induction of apoptosis and selective DNA damage in tumor cells [170], Vanadate has also proven effective against induction of colon carcinomas [171]. A vanadium(III) cysteine compound has been shown to 

---