Transforming growth factors in urine from patients with primary brain tumors

Urine specimens obtained from 19 patients with primary brain tumors were examined for the activity of transforming growth factors (TGF's). Urine was assayed for TGF's by soft agar colony formation and iodine-125 (125I)-epidermal growth factor (EGF)-binding competition. Two nontransformed cell lines, clonal NRK49F and BALB/3T3 A31-1-1 cells, were used as indicator cells for the soft agar colony assay, while EGF receptor-rich A431 cells were used for 125I-EGF-binding competition assay. Urine samples were dialyzed against acetic acid, then lyophilized, prepared with gel-permeation chromatography, and assayed. All 19 patients and a control group of healthy individuals showed high levels of alpha-type TGF's with low molecular weight (4 to 8 kD) in all urine samples. In addition, alpha-type TGF's of high molecular weight (20 to 50 kD) were detected at high levels in urine from all 10 patients with high-grade astrocytoma; at intermediate levels in urine from one of two patients with low-grade astrocytoma and from two of four patients with meningioma; and at low levels in urine from one of two patients with low-grade astrocytoma, from two of four patients with meningioma, from one patient with oligodendroglioma, from two patients with neurinoma, and from all healthy control individuals. The high level of alpha-type TGF's with high molecular weight detected in urine from patients with high-grade astrocytoma could be useful as a tumor marker.