An association of carcinogenesis and decrease of cellular NAD concentration.
It is postulated that a decrease in nicotinamide adenine dinucleotide (NAD) concentration has a primary association with carcinogenesis. The following observations are presented as evidence: (1) NAD and adenosine triphosphate (ATP) concentrations are lower in cancer cells; (2) chemical carcinogens and radiation can cause a lowering of NAD concentration in precancerous cells: (3) biosynthesis of NAD in Ehrlich ascites tumor cells is altered; and (4) NAD is involved in regulating deoxyribonucleic acid (DNA) synthesis. The lowering of NAD concentration would lead to the expression of oncogene and/or virogene according to the protovirus hypothesis, and the cellular characteristics of cancer cells can also be explained through the lowering of cellular NAD concentration. Experimental approaches are also proposed.
D000255:Adenosine Triphosphate / Q000032:analysis; D000818:Animals; D002472:Cell Transformation, Viral; D004247:DNA / Q000096:biosynthesis; D006801:Humans; D009243:NAD / Q000032:analysis* / Q000096:biosynthesis; D009369:Neoplasms / Q000032:analysis / Q000209:etiology / Q000378:metabolism*; D051381:Rats; D012190:Retroviridae / Q000472:pathogenicity
D009243:NAD; D000255:Adenosine Triphosphate; D004247:DNA