Folic acid targeting of protein conjugates into ascites tumour cells from ovarian cancer patients

Despite a wealth of in vitro data describing the use of folic acid for drug and DNA delivery into ovarian cancer cell lints. there have been no report s describing the targeting of such compounds to freshly isolated tumour cel ls. We have carried out a study to determine the usefulness of folic acid a s a targeting ligand for ovarian cancer by measuring the uptake of Folic ac id-BSA-FITC in tumour cells isolated from the ascitic fluid of ovarian canc er patients. In 7 out of 7 patients we have found folic acid mediated uptak e of the fluorescently labelled albumin, with the accumulation (average cel l fluorescence) and differential uptake (ratio between receptor mediated an d fluid phase uptake) varying between patients. Accumulation of folic acid- albumin-FITC occurs in ascites tumour cells expressing the epithelial cell marker EMA, with a significant proportion of EMA negative cells also accumu lating the conjugate. There is no correlation between cell cycle and uptake of folic acid-BSA-FITC. These results suggest that folic acid-targeting of therapeutics is a promising approach for the treatment of ovarian cancer.