Bladder Cancer Cells Express Functional Receptors for Granulocyte-Colony Stimulating Factor

The effects of human recombinant granulocyte-colony stimulating factor (G-CSF) on the growth of cultured human bladder cancer cells and G-CSF receptor on these cells were investigated. Human bladder cancer cell lines, KU-1 or NBT-2, were incubated with and without G-CSF. At 48 hours, 3H-thymidine uptake of both cells was significantly higher with G-CSF (one ng./ml., 10 ng./ml.) than that of control without G-CSF (p less than 0.05). The binding of 125I-labeled KW-2228, a muteins of G-CSF, to KU-1 and NBT-2 was inhibited by unlabeled KW-2228 in a dose-dependent manner. These results demonstrated that G-CSF stimulates the clonal growth of human bladder cancer cells by binding to its specific receptors.