RAB6C, Member RAS Oncogene Family (RAB6C)

WTH3 promoter region was hypermethylated in multidrug-resistant MCF7 cells compared with the parental cell line. EMSA showed that different pools of nuclear proteins were attracted to the hypermethylated and nonmethylated WTH3 probes. RAB6C promoter region contains 2 atypical TATA boxes and 2 atypical CAATT boxes. They identified a GC-rich region that includes a CpG island and extends from position -485 relative to the translation initiation site into the 5-prime coding region. The promoter region contains several putative transcription factor-binding sites.The deduced 254-amino acid WTH3 protein shares significant homology with 2 isoforms of RAB6A, but it has a C-terminal extension compared with these proteins.Reexpression of WTH3 in multidrug-resistant cell lines increased their sensitivity to several anticancer drugs, including doxorubicin.