Objective: To isolate expressed sequence tags (ESTs) related to K562 cells erythroid differentiation.
Methods: Modified differential display reverse transcription polymerase chain reaction (DDRT-PCR) method was applied to identify differential ESTs in uninduced and induced K562 cells by HEMIN for 36 hours. Remarkable differential ESTs were firstly selected for cloning, sequencing and bioinformational analyzing. Several ESTs representing new sequence or providing functional clue were selected for Northern blot analysis.
Results: Sixty differentially expressed cDNA fragments related to K562 cells inducted into erythroid differentiation by HEMIN were obtained. Among them, 38 were upregulated and 22 downregulated. Among the 40 differential ESTs selected for cloning, sequencing and bioinformationally analyzing, 23 were found to match to known GenBank sequences and 10 represented cDNA sequences with only dbEST database matches and 7 ESTs have no any database matches. The results of 6 in 8 ESTs selected for Northern blot analysis were shown to be consistent with the differential expressions of DDRT-PCR.
Conclusions: The improved DDRT-PCR method had successfully overcome the problem of false positive. These ESTs provide some clue for studying the molecular mechanisms and regulation network of erythroid differentiation.