Human Homeobox Genes in Development and Cancer

The homeobox (HOX) genes encode highly conserved, homeodomain-containing transcriptional factors that play a central role in embryonic development and the maintenance of cellular identity crucial to the differentiation of adult stem cells. Implicitly, the pathophysiological relevance of these genes is life-long as evident in many developmental anomalies and adult disorders, particularly cancers. This review considers the normal pattern of HOX gene expression and the signalling pathways involved in its regulation, discusses the consequences of HOX gene dysregulation associated with dysmorphogenesis and carcinogenesis, and the plausibility of a common mechanism underlying both processes. Finally, it looks at the mechanisms that underlie potential interventions in cases where cancers are promoted by HOX gene dysregulation.