Isolation & characterization of tumour angiogenesis factor from solid tumours & body fluids from cancer patients

Tumour angiogenesis factor (TAF) was isolated from malignant solid tumours (10) and from pleural and peritoneal fluids (10) collected from cancer patients. Normal tissues and body fluids from individuals with no clinical history of cancer did not show any detectable levels of TAF. Also, no angiogenic activity was detectable in the benign tumour samples studied (2). The TAFs isolated were all ribonucleoproteins. Molecular weight determination by SDS-PAGE (9%) of the TAFs isolated by DEAE cellulose chromatography of tumour extracts showed them to be 18,000 dalton (D) ribonucleoproteins, while the TAFs isolated by immunoaffinity chromatography (using immobilized anti-TAF IgG) of solid tumour extracts and body fluids had a molecular weight of 38,000 D. The TAFs isolated by both the methods were found to be angiogenic by the chick chorioallantoic membrane and the mouse intradermal assays. Immunoaffinity chromatography could be used for the one-step purification of TAF from solid tumour extracts as well as from body fluids.