RhEpo protects HNSCC cell lines against cisplatin-induced cell death. a Clonogenic assay demonstrating that in UMSCC-10B cells treated with 0.5 μM cisplatin, exposure to rhEpo at 1 and 10 U/ml resulted in a 1.7 ± 0.2 fold and 3.0 ± 0.2 fold increase in colony number, compared to control cells not exposed to rhEpo, respectively. In cell line UMSCC-22B treated with 1.0 μM cisplatin, rhEpo at 1 U/ml resulted in a 2.5 ± 0.1 fold increase in colony number compared to the control cells. b Micrographs of representative fields showing the cytoprotective effects of rhEpo on cell morphology after cisplatin treatment. Shrunken cytosol and fragmentation of cells into apoptotic bodies, depicted in the far left micrograph, was noticeably reduced upon exposure to rhEpo at 1 and 10 U/ml. Scale bar represents 50 μm.