CELL-TYPE-SPECIFIC MODULATION OF HOX GENE-EXPRESSION BY MEMBERS OF THE TGF-BETA SUPERFAMILY - A COMPARISON BETWEEN HUMAN OSTEOSARCOMA AND NEUROBLASTOMA CELL-LINES

Homeobox gene expression in osteoblast-like cells was investigated usi ng the polymerase chain reaction (PCR). A total of 13 homeobox genes w as detected in U-2 OS (human osteosarcoma) and MC3T3-E1 (mouse osteobl ast) cells by sequencing cloned PCR products, Using specific primers, a different pattern of Hox gene expression was shown for the neuroblas toma cell line SK-N-SH relative to U-2 OS and MC3T3-E1. Additionally, we showed that expression of HOXC6 in U-2 OS and SK-N-SH was different ially regulated by rhBMP-2, TGF-beta and activin-A. This suggests that specific Hox genes may be target genes for TGF-beta superfamily membe rs, and allows us to further understand the complex functions of these growth factors and how they relate to growth and development. (C) 199 7 Academic Press.