Presence of heparin binding growth factor in mouse bladder tumors and urine from mice with bladder cancer

Heparin affinity chromatography has been used to partially purify angiogenic factors from normal and neoplastic tissue. The same technique was used to partially purify angiogenic-like factors from two mouse bladder tumors and urine from mice with bladder cancer. Both MBT-2 and MB49 tumors contained heparin-binding 3T3 cell growth factor activity that was eluted by 1.2 to 1.4 M salt. The growth factor isolated from MBT-2 tumor was mitogenic for capillary endothelial cells. Analysis of the 1.2 M heparin eluate by high-pressure liquid chromatography showed that it consisted of two 3T3 cell growth factors with molecular weights of 16,000 and 26,000. The growth factor activity isolated from MB49 tumors had an affinity for Bio-rex 70 which was similar to other cationic heparin binding growth factors. Analysis of urine pooled from tumor-bearing mice by heparin-Sepharose chromatography demonstrated 3T3 cell growth factor activity in fractions eluted with 1 to 1.4 and 2.5 M dsalt, whereas no significant growth factor activity was detected in pooled urine from control mice. The growth factor activity found in mouse bladder tumors differed from epidermal growth factor, transforming growth factor-alpha, and platelet-derived growth factor in terms of affinity for heparin-Sepharose and molecular weight. The observation that urine from tumor-bearing mice contains increased concentrations of this growth factor compared to normal urine suggests that a similar relationship may exist for human urine.