Genome-wide gene expression analysis in the placenta from fetus with trisomy 21.

BACKGROUND

We performed whole human genome expression analysis in placenta tissue (normal and T21) samples in order to investigate gene expression into the pathogenesis of trisomy 21 (T21) placenta. We profiled the whole human genome expression of placental samples from normal and T21 fetuses using the GeneChip Human Genome U133 plus 2.0 array. Based on these data, we predicted the functions of differentially expressed genes using bioinformatics tools.

RESULTS

A total of 110 genes had different expression patterns in the T21 placentas than they did in the normal placentas. Among them, 77 genes were up-regulated in the T21 placenta and 33 genes were down-regulated compared to their respective levels in normal placentas. Over half of the up-regulated genes (59.7%, n = 46) were located on HSA21. Up-regulated genes in the T21 placentas were significantly associated with T21 and its complications including mental retardation and neurobehavioral manifestations, whereas down-regulated genes were significantly associated with diseases, such as cystitis, metaplasia, pathologic neovascularization, airway obstruction, and diabetes mellitus. The interactive signaling network showed that 53 genes (40 up-regulated genes and 13 down-regulated genes) were an essential component of the dynamic complex of signaling (P < 1.39e-08).

CONCLUSIONS

Our findings provide a broad overview of whole human genome expression in the placentas of fetuses with T21 and a possibility that these genes regulate biological pathways that have been involved in T21 and T21 complications. Therefore, these results could contribute to future research efforts concerning gene involvement in the disease's pathogenesis.