This Article Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Services Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via Google Scholar Google Scholar Articles by Shapiro, D. M. Articles by Zanar, E. Search for Related Content PubMed PubMed Citation Articles by Shapiro, D. M. Articles by Zanar, E.

Quantitative Biochemical Differences between Tumor and Host as a Basis for Cancer Chemotherapy

I. Vitamin B₆^*

Daniel M. Shapiro, Maurice E. Shils, L. S. Dietrich, A. Atti, E. Borries, A. Fine, R. Fugmann, P. Hayworth and E. Zanar

( Department of Surgery, College of Physicians and Surgeons, School of Public Health, and the Department of Biochemistry, College of Physicians and Surgeons, Columbia University, New York, N.Y.)

A mouse mammary carcinoma (755), previously demonstrated to be sensitive to desoxypyridoxine therapy, has a lower concentration of vitamin B₆ than the majority of the normal tissues of the host animal. A vitamin B₆-containing enzyme, glutamic-aspartic transaminase, is also present at a low concentration in the same tumor and is inhibited by desoxypyridoxine. This inhibition of transaminase in both tumor and normal tissues is inversely proportional to enzyme concentration. The vitamin B₆ level in the tumor is significantly decreased by testosterone therapy, although such treatment has no effect on tumor growth. Combination chemotherapy with testosterone and desoxypyridoxine results in inhibition of tumor growth with doses of the pyridoxine antagonist that are without carcinostatic effect when administered alone.

The data and pertinent literature are discussed as evidence for the hypothesis that the low concentrations of metabolites in neoplastic tissue furnish a basis for the selection of chemotherapeutic agents.

^* Supported by the Ruth Cutting Auchincloss Memorial Gift, Mary Madison McGuire Memorial Fund, and Merck, Inc., Rahway, New Jersey.

Dasian Foundation Fellow.

Received 4/23/53.