INHIBITORY EFFECTS ON INVITRO-CELL GROWTH OF HUMAN UROTHELIAL TUMOR-CELL LINES UNDER THE COMBINED ADMINISTRATION OF HEMATOPOIETIC GROWTH-FACTORS AND CLINICALLY RELEVANT ANTINEOPLASTIC AGENTS

In five of eight human transitional carcinoma cell (TCC) lines a proliferative response has been reported during exposure to interleukin-3 (IL-3), granulocyte-macrophage colony stimulating factor (GM-CSF) and granulocyte colony stimulating factor (G-CSF). To elucidate possible growth-modulating effects of these factors combined with clinically relevant antineoplastic agents, cells of the human TCC lines EJ28 and T24 were exposed to methotrexate (MTX), vinblastine (VBL), doxorubicin (DXR) and cisplating (CDDP) with and without single or continuous exposure to IL-3, GM-CSF and G-CSF at concentrations of 1-100 ng/ml. Compared with cells exposed only to chemotherapy, significant inhibitory effects occurred as a result of continuous exposure to IL-3 or GM-CSF at the highest activities with CDDP and MTX in the T24 and EJ28 lines; continuous G-CSF administration (100 ng/ml) in combination with MTX led to significant growth inhibition in the EJ28 line. In contrast, no significant growth modulation was found on combined administration of DXR or VBL with any one of the three colony stimulating factors tested.