Adenosine-N6-diethylthioether-N1-pyridoximine 5'-phosphate. A novel marker for human cancer detection

The Schiff base conjugate of vitamin B6 with adenosine-N6-diethylthioether was originally reported as unknown compound B6X and considered to function as a storage form for vitamin B6 utilization by tumor cells. This novel compound is present in tumor cells in culture, the blood of normal and tumor-bearing animals, and the circulation of healthy individuals and patients with various ailments including malignancies. However, its level in the blood of cancer patients is significantly much greater -a desirable feature for cancer detection. Using HPLC pair-ion, reverse phase chromatography blood samples from patients with various malignancies and ailments were screened on a blind basis for the novel compound following its extraction at pH 4.2. The results show that the level of the vitamin B6 metabolite in the blood of cancer patients is up to 4x or higher than levels seen in the blood of normal volunteers, patients in remission or patients with other diseases. In addition, patients receiving treatment had lower levels than before treatment. Normal volunteers, cancer patients prior to treatment, cancer patients on therapy, cancer patients at remission and patients with other ailments had levels of 162.2; 601.7; 497.9; 216.5 and 179.3 (SEM range +/- 18.76-46.60), respectively. A comparison of the control, remission and other ailments groups with the cancer patient groups shows them to be significantly different (P < 0.00001) and strongly supports the use of the novel vitamin B6 conjugate metabolite for detection of human cancers.