“…22 The original tumor of SP-C1 cells was moderately differentiated squamous cell carcinoma of tongue, and was not invasive into muscle layer. Cells were maintained in Dulbecco's modified eagle medium (DMEM, Sigma, St Louis, MO, USA) supplemented with 10% fetal calf serum (FCS, Moregate BioTech, Bulimba, Australia), 100 g/ml streptomycin, and 100 units/ml penicillin (Invitrogen Corp., Carlsbad, CA, USA).…”