RESUMO
This study was purposed to investigate the colony formation of high-proliferative potential colony-forming units (CFU-HPP) from bone marrow-derived hematopoietic cells of psoriatic patients and p16 gene promotor methylation in CFU-HPP cells, and to explore the relationship between the colony formation and the methylation status of p16 gene promoter. Bone marrow-derived mononuclear cells from psoriatic patients and normal controls were separated by density gradient centrifugation, and were cultured in methycellulose semi-solid culture medium with SCF, GM-CSF, IL-3 and IL-6 for 14 days to measure the colonies of CFU-HPP. The CFU-HPP colony cells were collected and methylation status of p16 gene promoter of CFU-HPP cell DNA modified with sodium bisulfite was detected by the methylation-specific polymerase chain reaction (MSP). The results showed that in methycellulose semi-solid culture system, the number and the size of CFU-HPP colonies of bone marrow of psoriatic patients were all significantly less than that of normal controls, the positive frequency of p16 gene promoter methylation in CFU-HPP cells was lower than that in CFU-HPP colony cells of normal controls. It is concluded that the colony formation capability of CFU-HPP from bone marrow hematopoietic progenitor cells in psoriatic patients is lower than that in normal controls, and the lower positive frequency of P16 gene promoter methylation in CFU-HPP cells perhaps closely correlated with lower CFU-HPP colony-forming capability.