VITAMIN-B-6 AND CANCER - ADENOSINE-N6-DIETHYLTHIOETHER N1-PYRIDOXIMINE 5'-PO4, A CIRCULATING HUMAN TUMOR-MARKER

Studies in my laboratory on the metabolism and utilization of labeled vitamin B-6 by tumor-bearing animals and tumor cells in culture have s hown the production and presence in the circulation of a novel pyridox al 5'-phosphate conjugate metabolite (1-5). Using specific radiolabeli ng and analytical tests, its structure was tentatively identified (now confirmed) as adenosine-N6-diethylthioether-N1-pyridoximine 5'-phosph ate (4-6). The novel vitamin conjugate was isolated ft-om the plasma o f patients and control subjects following extraction with perchloric a cid and separation by pair-ion HPLC. This communication reports the ch romatographic separation of the novel compound and its plasma levels i n control subjects, cancer patients and patients with other ailments. The results show that the novel metabolite is a circulating human tumo r marker with levels of up to 4x or greater seen in cancer patients co mpared to controls and to subjects with other ailments. The results in dicate strongly that the novel circulating vitamin B6 conjugate compou nd can be successfully used for the detection of different malignancie s in humans by evaluating its level in circulation.