Comparison of the conversion of 5-formyltetrahydrofolate and 5-methyltetrahydrofolate to 5,10-methylenetetrahydrofolates and tetrahydrofolates in human colon tumors.

Abstract

Four hr infusions i.v. of [6RS]5-formyltetrahydrofolate ([6RS]5-CHO-H4PteGlu; 500 mg/m2) and [6RS]5-methyltetrahydrofolate ([6RS]5-CH3-H4PteGlu; 500 mg/m2) were compared for their relative effects on expansion of pools of 5,10-methylenetetrahydrofolates (CH2-H4PteGlun) and tetrahydrofolates (H4PteGlun) in two human colon adenocarcinoma xenografts in mice. Expansion of these pools by 253-661% of control and increase in predominance of di-, tri-, and tetra-glutamate species were observed during [6RS]5-CHO-H4PteGlu infusion. In contrast, only modest pool size expansion (148-164% of control) and limited modulation of polyglutamate species were detected in four tumor lines during infusion with [6RS]5-CH3-H4PteGlu. The data suggest that [6RS]5-CH3-H4PteGlu is less effective than [6RS]5-CHO-H4PteGlu as a precursor for pools of CH2-H4PteGlun and H4PteGlun in colon tumors.

• Authors: J A Houghton, L G Williams, S S de Graaf, P J Cheshire, I W Wainer, P Jadaud, P J Houghton
• Journal: Cancer communications (Cancer Commun) Vol. 1 Issue 3 Pg. 167-74 ( 1989) ISSN: 0955-3541 [Print] United States
• PMID: 2639728 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't, Research Support, U.S. Gov't, P.H.S.)

Chemical References

• Formyltetrahydrofolates
• Pteroylpolyglutamic Acids
• Tetrahydrofolates
• 5,10-methylenetetrahydrofolic acid
• 5-methyltetrahydrofolate

Topics

• Adenocarcinoma (metabolism)
• Animals
• Biotransformation
• Cell Line
• Colonic Neoplasms (metabolism)
• Female
• Formyltetrahydrofolates (metabolism)
• Humans
• Kinetics
• Mice
• Mice, Inbred CBA
• Neoplasm Transplantation
• Pteroylpolyglutamic Acids (biosynthesis, isolation & purification)
• Tetrahydrofolates (biosynthesis, metabolism)
• Transplantation, Heterologous