Forkhead box m1 mRNA expression of lung of preterm and term rabbits.

Previous studies on forkhead box m1 (Foxm1) of mice demonstrated the correlation between this gene and lung maturation. However, no study has been conducted on human Foxm1 with regard to lung maturation. The aim of this study was to compare the mRNA expression of surfactant protein (SP)-A, -B, -C and Foxm1 gene of preterm rabbits to that of full-term ones and to determine the association between Foxm1 and lung maturation. New Zealand white rabbits were grouped according to gestational age. Cesarean sections were carried out after rabbits were divided into two groups of 30-31 days of gestation (term group, n=18) and 26-27 days of gestation (preterm group, n=18). mRNA expression levels of SP-A, -B, -C and Foxm1 were compared by using quantitative real-time reverse transcription-polymerase chain reaction (qRT-PCR). The relative ratios of SP-A, -B and -C mRNA expression levels of the preterm to term groups were 0.380, 0.563 and 0.448:1, respectively, on qRT-PCR. By contrast, Foxm1 expression was increased in the preterm group and its relative expression ratio to the term group was 2.166:1 for RT-PCR and qRT-PCR, which was double that of the Foxm1 gene in the term group. Moreover, a significant correlation between the expressions of these genes was found. Foxm1 is considered to be an important gene required for the lung maturation of preterm rabbits in correlation with SP genes.