OBJECTIVES: Docetaxel has recently taken part in new chemotherapy regimens with promising activity especially in the first line therapy (induction chemotherapy) of head and neck cancer (SCCHN). Nevertheless a major problem concerning the response of SCCHN to chemotherapy is the high percentage of resting cells (G0-phase cells) being resistant to chemotherapy. To overcome this phenomenon we have investigated the capacity of several cytokines to switch on cells into division cycle and progress to the chemosensitive phases (S, M-phase). METHODS: Il-6, Serotonin, G-CSF and EGF were used to stimulate G0-phase squamous cell cancer cells (Detroit 562, A431, UM-SCC 10B) for reentry in the cell cycle to enhance the response to docetaxel. The proportion of G0-phase cells was detected through multicolor FACS analysis and Ki67 staining. RESULTS: Cell cycle reentering was most effective after combination treatment with Serotonin+EGF. The proportion of G0 phase cells was significantly reduced after stimulation with Serotonin+EGF (p
