γ-Glutamyl hydrolase modulation and folate influence chemosensitivity of cancer cells to 5-fluorouracil and methotrexate.

Background: γ-Glutamyl hydrolase (GGH) regulates intracellular folate and antifolates for optimal nucleotide biosynthesis and antifolate-induced cytotoxicity, respectively. The modulation of GGH may therefore affect chemosensitivity of cancer cells, and exogenous folate levels may further modify this effect.

Methods: We generated a novel model of GGH modulation in human HCT116 and MDA-MB-435 cancer cells and investigated the effect of GGH modulation on chemosensitivity to 5-fluorouracil (5FU) and methotrexate (MTX) at different folate concentrations in vitro and in vivo.

Can targeted therapy be successful without metronomic scheduling?

In medical oncology, targeted therapy has emerged over the last decade, as the most promising strategy to fight cancer. In addition, a more complete understanding of tumor heterogeneity and pharmacology of the more conventional anti-cancer agents has led to development of metronomic chemotherapy (MC) (i.e.

Farletuzumab, an anti-folate receptor α antibody, does not block binding of folate or anti-folates to receptor nor does it alter the potency of anti-folates in vitro.

Purpose: Folate is a cofactor in the synthesis of purines and pyrimidines; folate analogs are potent cytotoxic drugs. Folate receptor alpha (FRα), a protein-mediating cellular accumulation of folate (and anti-folates), has limited expression in normal tissues and is overexpressed by numerous carcinomas. Limited distribution and high affinity for folic acid have resulted in the development of antibodies or the use of folic acid coupled to toxins or radionuclides as therapeutic and imaging agents.