Background:The PI3K-AKT pathway is known to regulate cytokines in dust mite-induced pediatric asthma.However,the underlying molecular steps involved are not clear..Objective:In order to clarify further the molecular steps,this study investigated the expression of certain genes and the involvement of miRNAs in the PI3K-AKT pathway,which may affect the resultant cytokine-secretion.Methods:In-vivo and in-vitro ELISA and qRT-PCR,microarrays analyses were used in this study.Results:We found significant differences in plasma concentrations of some cytokines between the dust mite-induced asthma subjects and the healthy controls.The transcript levels of the SYK and PI3K genes were higher,while those of EGFR were lower in the former group.A down-expression of miRNA-27b-3p in the former group was found by microarray analysis.This was confirmed by qRT-PCR that found the miRNA-27b-3p transcripts that regulated the expression of SYK and EGFR was also significantly decreased(p < 0.01)in the same group.This correlated with the finding that the transcripts of SYK and its downstream PI3K were decreased in miRNA-27b-3p transfected HBE,but were increased in HBE transfected with the inhibitor.Conclusions:Our results indicated that the differential expression of the miRNAs in dust mite-induced pediatric asthma may regulate their target gene SYK and have an impact on the PI3K-AKT pathway associated with the production of cytokines,leading to an asthma attack.These findings should add new insight into the pathogenesis of pediatric asthma.