Growth stimulating activity produced by human bladder cancer cells.

Growth promoting properties have been identified in the conditioned serum-free medium from cultures of the human transitional cell carcinoma cell line 647V. This activity appears to reside in a molecule of more than 5000 MW. The factor responsible for 647V growth is distinguished from epidermal growth factor, since it fails to inhibit the specific binding of epidermal growth factor by 647V cells, and 647V cells are not stimulated to grow by epidermal growth factor. It also does not appear to be an insulin-like growth factor-like molecule since it fails to competitively bind with human insulin-like growth factor-carrier protein.