A systematic survey of HOX and TALE expression profiling in human cancers

Abstract

HOX and TALE genes encode homeodomain (HD)-containing transcription factors that act in concert in different tissues to coordinate cell fates and morphogenesis throughout embryonic development. These two evolutionary conserved families contain several members that form different types of protein complexes on DNA. Mutations affecting the expression of HOX or TALE genes have been reported in a number of cancers, but whether and how the two gene families could be perturbed together has never been explored systematically. As a consequence, the putative collaborative role between HOX and TALE members for promoting or inhibiting oncogenesis remains to be established in most cancer contexts. Here, we address this issue by considering HOX and TALE expression profiling in normal and cancer adult tissues, using normalized RNA-sequencing expression data deriving from The Cancer Genome Atlas (TCGA) and Genotype-Tissue Expression (GTEx) research projects. Information was extracted from 28 cancer types originating from 21 different tissues, constituting a unique comparative analysis of HOX and TALE expression profiles between normal and cancer contexts in human. We present the general and specific rules that could be deduced from this large-scale comparative analysis. Overall this work provides a precious annotated support to better understand the role of specific HOX/TALE combinatorial codes in human cancers.