The function of homeobox genes and lncRNAs in cancer.

Recently, the homeobox (HOX) gene family has been reported as a factor in tumorigenesis. In the human genome, the HOX gene family contains 4 clusters with 39 genes and multiple transcripts. Mutation or abnormal expression of genes is responsible for developmental disorders. In addition, changes in the levels and activation of certain HOX genes has been associated with the development of cancer. Long non-coding RNAs (lncRNAs) have also been identified to serve critical functions in cancer. Although a limited number of lncRNAs have been previously investigated, the list of functional lncRNA genes has recently grown. Two of the most important and well-studied lncRNAs and HOX transcript genes are HOX transcript antisense RNA (HOTAIR) and HOXA distal transcript antisense RNA (HOTTIP). The present study aimed to review not only the function of the HOTAIR and HOTTIP genes in certain forms of cancer, but also to review other HOX genes and protein functions in cancer, particularly HOX family genes associated with lncRNAs.