Reverse-phase high-performance liquid chromatography (HPLC) performed on urine from
cancer patients and normal controls revealed the presence of seven chromatographically distinct peaks of
transforming growth factor (TGF) activity, as measured by colony formation of normal rat kidney cells in soft
agar. Comparison of urines from normal donors and
cancer patients showed no differences in
EGF (
epidermal growth factor)-dependent beta-TGF-like activity but did reveal distinct patterns of
EGF-related,
EGF-independent alpha-TGF-like activity. All urine samples contained at least two chromatographically distinguishable forms of
EGF-dependent TGF activity, eluting from HPLC as broad peaks with 30 and 43%
acetonitrile. The remaining five TGFs eluted as sharp peaks with 32, 34, 35, 37, and 38%
acetonitrile, demonstrated
EGF-competing activity, and thus were functionally related to
EGF. Two of the five
EGF-related TGFs were consistently elevated only in the urine of
cancer patients and eluted with 32% (TGFA) and 37% (TGFD)
acetonitrile Two of the other
EGF-related TGFs, eluting with 34% (TGFB) and 35% (TGFC)
acetonitrile, were commonly found in both normals and
cancer patients. The fifth
EGF-related TGF,
TGFE, eluting with 38%
acetonitrile, was found only in normal donor specimens. TGFA corresponded to the unique Mr 30,000 TGF activity previously identified only in the urine of
cancer patients. These observations demonstrate that
cancer patients produce high levels of
EGF-related TGF activities which can be readily distinguished, using reverse-phase HPLC, from
EGF-related TGFs produced by normal individuals. Using a solid-phase competitive radioreceptor binding assay for
EGF, we demonstrated that quantitation of
EGF-competing activity is as sensitive and effective as the soft-
agar colony formation assay for distinguishing HPLC profiles of urinary TGF from
cancer patients versus that from normal individuals.