As
serine and
cysteine proteinase inhibitors,
serpins, such as SERPINB5, cause ovarian, colorectal and pancreatic
adenocarcinomas. We identified SERPINB11 as a novel
estrogen-induced gene in chickens during oviduct development. The chicken is a unique animal model for research on human
ovarian cancer, because it spontaneously develops epithelial cell-derived
ovarian cancer as in women. Therefore, this study investigated the expression pattern, CpG methylation status, and
miRNA regulation of the SERPINB11 gene in normal and cancerous ovaries from chickens. Our results indicate that SERPINB11 is most abundant in the glandular epithelium of
endometrioid adenocarcinoma of cancerous, but not normal, ovaries of hens. In addition,
bisulfite sequencing revealed that about 30% of -110 CpG sites are methylated in
ovarian cancer cells, whereas -110 CpG sites are demethylated in normal ovarian cells. Next, we determined whether miR-1582 influences SERPINB11 expression via its
3'UTR and found that it does not directly target the
3'UTR of SERPINB11
mRNA. Therefore, it is unlikely that post-transcriptional regulation influences SERPINB11 expression in the chicken ovary. On the other hand, in human
ovarian cancer cells such as OVCAR-3, SKOV-3 and PA-1 cells, immunoreactive SERPINB11
protein was predominant in the cytoplasm and had a similar expression pattern to that in chicken
ovarian cancer cells. Collectively, these results suggest that SERPINB11 is a
biomarker for chicken ovarian
endometrioid carcinoma that could be used for diagnosis and monitoring effects of
therapies for the disease in women.