Upregulation Of miR-149-3p Suppresses Spinal Chordoma Malignancy By Targeting Smad3

• Main Authors: Yao J, Wu X
• Format: Article
• Language: English
• Published: Dove Medical Press 2019-11-01
• Series: OncoTargets and Therapy
• Subjects: mir-149-3p; smad3; spinal chordoma; malignancy
• Online Access: https://www.dovepress.com/upregulation-of-mir-149-3p-suppresses-spinal-chordoma-malignancy-by-ta-peer-reviewed-article-OTT

Jie Yao,1 Xuejian Wu2 1Department of Spine, The Orthopedic Hospital of Zhengzhou, Zhengzhou, Henan 450099, People’s Republic of China; 2Department of Orthopaedics, First Affiliated Hospital of Zhengzhou University, Zhengzhou, Henan 450052, People’s Republic of ChinaCorrespondence: Xuejian WuDepartment of Orthopaedics, First Affiliated Hospital of Zhengzhou University, No.1 Jianshe East Road, Zhengzhou, Henan 450052, People’s Republic of ChinaTel [phone]Email [e-mail]: Dysregulation of miRNAs plays an important role in the malignancy of different tumors including chordoma. Expression of miR-149-3p was earlier reported to be downregulated in chordoma tissue. However, its biological role remains to be unrevealed in chordoma, especially in spinal chordoma.Methods: Expression of miR-149-3p and Smad3 was detected by RT-qPCR and Western blot. Chordoma malignancy was evaluated by cell proliferation, migration, invasion, and apoptosis using MTT assay, transwell assay, flow cytometry analyzing apoptosis rate, and Western blot-determined expression of Bcl-2, Bax, and cleaved caspase 3, respectively. The target binding between miR-149-3p and Smad3 was predicted by TargetScan Human website and confirmed by luciferase reporter assay and RNA immunoprecipitation. Xenograft tumors were generated, and expression of miR-149-3p and Smad3 was investigated in vivo.Results: miR-149-3p was downregulated in spinal chordoma tissues and cells, and its overexpression promoted chordoma cell apoptosis and inhibited proliferation, migration, and invasion in U-CH1 and MUG-Chor1 cells. Unexpectedly, Smad3 was a downstream target of miR-149-3p and negatively correlated with miR-149-3p expression in chordoma tissues. Besides, Smad3 was upregulated in chordoma tissues and its silencing had a similar effect as miR-149-3p overexpression in U-CH1 and MUG-Chor1 cells. Moreover, Smad3 upregulation could partially reverse the tumor-suppressive effect of miR-149-3p in chordoma cells. In vivo, the tumorigenesis of U-CH1 and MUG-Chor1 cells was impaired by upregulated miR-149-3p through decreasing Smad3 expression.Conclusion: miR-149-3p could serve as a tumor suppressor in spinal chordoma through targeting and downregulating Smad3.Keywords: miR-149-3p, Smad3, spinal chordoma, malignancy