Effect of Dimethyl Sulfoxide on Cell Cycle Synchronization of in vitro Cultured Monkey (Maccaca fascicularis) Ear Skin Fibroblasts

Arrest of cells in the G0/G1 cell cycle phase is desired for somatic cell nuclear transfer procedures. This study determined the arresting effects of 0-2% Dimethyl Sulfoxide (DMSO) for 4-24 h on cell cycle stages of Maccaca fascicularis ear-derived fibroblasts. The effects of DMSO on apoptosis of these cells was also investigated. Cells were obtained from the ear of a 4 years old male monkey. Analysis of cell cycle distribution by fluorescence-activated cell sorting showed that 67.52, 14.37 and 18.11% of normally cycling cells were at G0/G1, S, G2/M phases, respectively. In the groups with 4 h DMSO treatments, cell cycle synchronization in G0/G1 phase for treatment with 1.5 and 2.0% DMSO (82.86 and 86.31%) was significantly higher than in other groups (0.5% for 78.84% and 1.0% for 78.65%) or the control group (67.52%). With 24 h treatments, the proportion of cells in G0/G1 was higher with 1% (90.45%), 1.5% (91.57%) and 2.0% DMSO (98.68%) than with 0.5% DMSO (78.22%) or the control group (70.33%). Under normal culture conditions, 4.63% of cells underwent apoptosis. Treatment with 1.5% DMSO, 2% DMSO for 4 h and 1% DMSO, 1.5% DMSO, 2% DMSO for 24 h resulted in apoptosis in 10.52, 12.75, 10.42, 12.75 and 17.07% of cells, respectively. In conclusion, the use of DMSO is suitable for cell cycle synchronization because it arrests cells at the G0/G1 phase but it also induces a high level of apoptosis, especially after 24 h for cultures treated with 2% DMSO.