MicroRNA-29b Inhibits Angiogenesis by Targeting VEGFA through the MAPK/ERK and PI3K/Akt Signaling Pathways in Endometrial Carcinoma

Abstract

Objective: The purpose of this study is to explore the effects of microRNA-29b (miR-29b) regulating MAPK/ERK and PI3K/Akt signaling pathways on angiogenesis in endometrial carcinoma (EC) by targeting VEGFA. Methods: Between February 2013 and April 2015, 126 EC patients admitted to the Second Affiliated Hospital of Nanchang University were randomly selected, with 126 EC tissues and the corresponding adjacent normal tissues collected after surgery. The human EC cell lines RL-95-2 and HEC-1-B and human endometrial cells were assigned to the normal group (human endometrial cells), the blank group (untransfected RL-95-2 or HEC-1-B cells), the pMIR-control group (RL-95-2 or HEC-1-B cells transfected with an empty vector), the pMIR-miR-29b group (RL-95-2 or HEC-1-B cells transfected with the miR-29b plasmid), LNA-control group (RL-95-2 or HEC-1-B cells transfected with an oligonucleotide inhibitors control), the LNA-miR-29b inhibitors group (RL-95-2 or HEC-1-B cells transfected with miRCURY LNA^{^TM} miR-29b inhibitors), the LNA-miR-29b inhibitors + PD98059 group (RL-95-2 or HEC-1-B cells transfected with miRCURY LNA^{^TM} miR-29b inhibitors and PD98059, an inhibitor of the MAPK/ERK signaling pathway) and the LNA-miR-29b inhibitors + wortmannin group (RL-95-2 or HEC-1-B cells transfected with miRCURY LNA^{^TM} miR-29b inhibitors and wortmannin, an inhibitor of the PI3K/Akt signaling pathway). qRT-PCR and Western blotting were conducted to detect the miR-29b expression and the mRNA and protein expressions of VEGFA, ERK, Akt, mTOR and Bcl-2. Immunohistochemistry (IHC) was performed to determine the microvessel density (MVD) expression in the EC tissues, adjacent normal tissues and nude-mice. Results: Compared with the adjacent normal tissues, miR-29b expression was down-regulated, the mRNA and protein expressions of VEGFA, ERK, Akt, mTOR and Bcl-2 were up-regulated, and MVD expression was increased in the EC tissues. Compared with the normal group, miR-29b expression was down-regulated, while the mRNA and protein expressions of VEGFA, ERK, Akt, mTOR and Bcl-2 were up-regulated in the other groups. Compared with the blank, pMIR-control and LNA-control groups, miR-29b expression was increased, while mRNA and protein expressions of VEGFA, ERK, Akt, mTOR and Bcl-2 were decreased in the pMIR-miR-29b group. The LNA-miR-29b inhibitors group exhibited elevated miR-29b expression and decreased mRNA and protein expressions of VEGFA, ERK, Akt, mTOR and Bcl-2 (All P < 0.05). Additionally, miR-29b expression was reduced in the LNA-miR-29b inhibitors + PD98059 and LNA-miR-29b inhibitors + wortmannin groups. In comparison to the normal group, MVD expression was elevated in the other groups. Compared with the blank, pMIR-control, LNA-control, LNA-miR-29b inhibitors + PD98059 and LNA-miR-29b inhibitors + wortmannin groups, MVD expression was decreased in the pMIR-miR-29b group but increased in the LNA-miR-29b inhibitors group. Conclusion: Our results indicate that miR-29b negatively mo...

Activation of ERK and Mutual Regulation of Stat3 and SP1 Contribute to Inhibition of PDK1 Expression by Atractylenolide-1 in Human Lung Cancer Cells

“…Activation of ERK1/2 was involved in the anti-tumor resposnes in several other studies in different cancer types including lung [50, 51] although opposite reports have also been reported [52-54]. Thus, the possible dual roles of ERK signaling in terms of tumor suppressor or tumor promoter have been considered depending upon the reagents used, activity of ERK signaling, feedback loops, interaction with other kinase, and cell types studied [46].…”

The regulatory role of microRNAs in angiogenesis‐related diseases

“…Moreover, serum miR‐29c‐3p in AAA patients is also significantly increased compared with controls and are correlated with aneurysm diameter, which inhibits VEGFA in ECs,42 suggesting that it may inhibit angiogenesis in ECs. However, the levels of miR‐29a/b/c are obviously down‐regulated in various cancers, including endometrial carcinoma, hepatocellular carcinoma (HCC), gastric cancer and breast cancer 40, 43, 44, 45. MiR‐29b can repress angiogenesis in endometrial carcinoma by targeting VEGFA via the MAPK/ERK and PI3K/AKT signalling pathways 43.…”

“…However, the levels of miR‐29a/b/c are obviously down‐regulated in various cancers, including endometrial carcinoma, hepatocellular carcinoma (HCC), gastric cancer and breast cancer 40, 43, 44, 45. MiR‐29b can repress angiogenesis in endometrial carcinoma by targeting VEGFA via the MAPK/ERK and PI3K/AKT signalling pathways 43. Parallelly, miR‐29b is closely related to poor recurrence‐free survival of HCC patients, and miR‐29b overexpression can inhibit angiogenesis and tumourigenesis in vivo and weaken tube formation, and cell proliferation and migration in vitro via directly repressing MMP‐2 40.…”

MicroRNA-126 enhances the biological function of endothelial progenitor cells under oxidative stress via PI3K/Akt/GSK-3β and ERK1/2 signaling pathways

“…GSK3β is a downstream signaling molecule of Akt [41], and activation of Akt/GSK3β signaling inhibited oxidative stress and apoptosis in rats with cerebral hypoxic-ischemic injury [42]. Inhibition of MAPK/ERK and PI3K/Akt signaling was previously suggested to suppress angiogenesis in endometrial carcinoma [43]. Additionally, the Akt/GSK3β pathway is involved in the protection against AMI, and its activation stimulated tube formation and accelerated human aortic endothelial cell migration [44].…”