[HTML][HTML] Epigenetic inhibition of miR-663b by long non-coding RNA HOTAIR promotes pancreatic cancer cell proliferation via up-regulation of insulin-like growth factor …

H Cai, Y An, X Chen, D Sun, T Chen, Y Peng, F Zhu… - Oncotarget, 2016 - ncbi.nlm.nih.gov
H Cai, Y An, X Chen, D Sun, T Chen, Y Peng, F Zhu, Y Jiang, X He
Oncotarget, 2016ncbi.nlm.nih.gov
Pancreatic cancer is one of the most deadly cancers with a poor prognosis. Although
microRNAs are involving in the carcinogenesis and development of pancreatic cancer, little
information is known regarding the role of miR-663b in pancreatic cancer. In this study, the
expression of miR-663b in pancreatic cancer cells was down-regulated by hypermethylation
in its putative promoter region, and overexpression of miR-663b repressed cell proliferation,
invasion and migration, and induced apoptosis in pancreatic cancer cells. Bioinformatics …
Abstract
Pancreatic cancer is one of the most deadly cancers with a poor prognosis. Although microRNAs are involving in the carcinogenesis and development of pancreatic cancer, little information is known regarding the role of miR-663b in pancreatic cancer. In this study, the expression of miR-663b in pancreatic cancer cells was down-regulated by hypermethylation in its putative promoter region, and overexpression of miR-663b repressed cell proliferation, invasion and migration, and induced apoptosis in pancreatic cancer cells. Bioinformatics analysis, luciferase report assay and rescue experiments showed that insulin-like growth factor 2 (IGF2) was a direct target of miR-663b. Results from clinical samples showed that the expression level of miR-663b correlated with the pathological grading, and the expression of miR-663b was down-regulated and was inversely correlated with IGF2 expression level in pancreatic cancer tissues. More importantly, the long non-coding RNA, HOX transcript antisense RNA (HOTAIR), was up-regulated in both pancreatic cancer cells and tissues, and HOTAIR suppressed the expression of miR-663b in pancreatic cancer by histone modification on H3K4me3 and H3K27me3 on miR-663b promoter. Further in vivo studies demonstrated that the stable overexpression of miR-663b or knock-down of HOTAIR inhibited tumor growth and was associated with IGF2 expression. In summary, our studies demonstrated that miR-663b is epigenetically repressed by HOTAIR and exerts its tumor-suppressive function via targeting IGF2 in pancreatic cancer.
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