MEIS homeobox genes in neuroblastoma.

The common pediatric tumor neuroblastoma originates from primitive neural crest-derived precursor cells of the peripheral nervous system. Neuroblastoma especially affects very young children, and can already be present at birth. Its early onset and cellular origin predict the involvement of developmental control genes in neuroblastoma etiology. These genes are indispensable for the tight regulation of normal embryonic development but as a consequence cause cancer and congenital diseases upon mutation or aberrant expression. To date however, the connotation of these genes in neuroblastoma pathogenesis is scant. This review recapitulates data on the MEIS homeobox control genes in cancer and focuses on neuroblastoma.

The role of the MEIS homeobox genes in neuroblastoma.

We recently found amplification of the TALE homeobox gene MEIS1 in the IMR32 neuroblastoma cell line. We now demonstrate high-level expression of the MEIS1 and MEIS2 genes, as well as efficient expression of most other TALE family member genes in a panel of neuroblastoma cell lines. Stable transfection of MEIS1-expressing cell lines with cDNA encoding a naturally occurring dominant-negative splice variant of MEIS1 (MEIS1E) yielded clones with impaired cell proliferation, gain of differentiated phenotype, and increased contact inhibition and cell death. This indicated a relevance of MEIS expression for neuroblastoma cell growth and proliferation. We therefore determined the gene expression profiles of several MEIS1E transfectants using serial analysis of gene expression (SAGE). A large number of genes showed differential expression as a result of MEIS1E expression. These include genes involved in developmental signalling pathways, chromatin binding, cell cycle control, proliferation, and apoptosis. The results presented provide important clues for the oncogenic function of MEIS1 in neuroblastoma.