Title:Transcription Factor WT1 and Promoter CpG Hypomethylation Coactivate HOXA10 Expression in Ovarian Cancer
Volume: 20
Issue: 11
Author(s): Yi Jiang, Yongli Chu, Weiwei Tang, Yicong Wan, Lin Zhang and Wenjun Cheng
Affiliation:
Keywords:
HOXA10, WT1, hypomethylation, ovarian cancer, siRNA, 5-Aza-dC, Bisulfite DNA sequencing and Methylation-specific PCR.
Abstract: HOXA10 plays an important role in the body structure and development. Recently, patterns of deregulated HOX expression
have been identified in various cancers. Meanwhile, WT1 is closely associated with the HOXA10 gene, which is an inducible transcription
factor . We hypothesized that during the process of the ovarian cancer pathogenesis, the HOXA10 promoter CpG hypomethylation
coupled with decreased WT1 expression could co-regulate HOXA10 expression. After the treatment of 5-Aza-dC, ovarian cancer cell
lines(SKOV-3 and HEY) significantly increased HOXA10 expression. Transfection of HOXA10 siRNA with SKOV-3 and HEY ovarian
cancer cell lines significantly downregulated HOXA10 expression but upregulated WT1 expression, compared to the control siRNA
transfection. In ovarian cancer samples, the HOXA10 expression is significantly high. Nevertheless, the expression of HOXA10 is low in
normal ones(P<0.05). We tried to use the method of methylation-specific PCR(MSP) to find the CpG sites, which are located in the scope
of the WT1’s core-binding consensus(GCGG). In ovarian cancer samples, methylation prevalence was extremely high with the low expression
of HOXA10. However, in the normal ovarian samples, the methylation prevalence was lower with the high expression of
HOXA10(P<0. 05). In all samples of epithelial and normal ovarian samples collected, the WT1 expression with the promoter CpG hypomethylation
of HOXA10 both contribute to the regulation of HOXA10 expression. That is to say, HOXA10 promoter methylationpositive
combined with the WT1-positive result in the low expression of HOXA10. On the other hand, the HOXA10 expression was the
highest in methylation-negative and WT1-negative samples.
