HOXC5 and HOXC8 expression are selectively turned on in human cervical cancer cells compared to normal keratinocytes

A growing number of data have sustained the involvement of homeobox genes expression deregulation in cancer. In this study, we have performed an exhaustive survey of the expression of the 39 class I HOX genes expressed in normal and malignant human cervix keratinocytes. Using RT-PCR, we observed that the vast majority (34/39) of HOX genes are expressed in normal keratinocytes. Only HOXA2, HOXA7, HOXC5, HOXC8 and HOXD12 were found to be silent. Interestingly, this pattern is conserved in the transformed keratinocytes (SiHa cells) except for the appearance of HOXC5 and HOXC8 mRNA. The HOXC5 and HOXC8 expression was also observed in two other transformed keratinocytes cell lines of independent origins, Eil-8 and 18-11S3, and confirmed by in situ hybridization. Our data add weight to the body of evidence attributing to a specific adult tissue a particular combination of expressed HOX genes and suggest that HOXC5 and/or HOXC8 could be involved in the process leading to the transformation of cervical keratinocytes.