MiRNA-1225 Inhibits Osteosarcoma Tumor Growth and Progression by Targeting YWHAZ

ABSTRACT:

Introduction

Osteosarcoma is the most common bone tumor and is characterized by the presence of malignant mesenchymal cells produced in the bone stroma. MiRNAs are known to function as post-transcriptional negative regulators of gene expression. Emerging evidence showed that miR-1225-5P functions as a tumor suppressor in several types of cancers. The detailed mechanisms of which miR-1225-5P suppresses tumor growth are not fully understood. The objective of the present study was to test the hypothesis that miR-1225-5P inhibits osteosarcoma cell growth in vitro and tumor growth in vivo by targeting YWHAZ expression.

Methods

Real-time PCR and Western blot were carried out to test the expression of miR-1225-5P and YWHAZ in osteosarcoma cell lines. Luciferase assay was used to demonstrate whether miR-1225-5P targets YWHAZ 3? UTR. To assess the function of miR-1225-5P in human osteosarcoma cell lines, gain-of-function and loss-of-function of miR-1225-5P were performed by transfecting miR-1225-5P mimic or miR-1225-5P inhibitor into osteosarcoma cell lines. Furthermore, cell cycle analysis was performed to elucidate the possible mechanisms of the action of miR-1225-5P and YWHAZ in human osteosarcoma cells. The potential therapeutic effect of miR-1225-5p was tested in human osteosarcoma xenograft mouse model, by intravenous injection of miR-1225-5P into nude mice. Tumor sizes were measured and lung metastasis was counted after the mice were sacrificed.

Results

The expression of miR-1225-5P was inversely correlated with the expression of YWHAZ in human osteosarcoma cell lines. Database search revealed that miR-1225-5P targeted YWHAZ 3? UTR. Transfection of miR-1225-5P mimic downregulated YWHAZ expression, which was demonstrated by real-time PCR, Western blot and luciferase assay. Over-expression of miR-1225-5P reduced human osteosarcoma cell growth, migration and invasion by downregulating YWHAZ expression. Cell growth, migration and invasion were increased by inhibiting miR-1225-5P in human osteosarcoma cells. The inhibition of cell growth, migration and invasion was rescued by over-expression of YWHAZ in osteosarcoma cells. Cell cycle analysis revealed that miR-1225-5P inhibited G1/G0 phase exit. In vivo xenograft model demonstrated that miR-1225-5P inhibited in vivo osteosarcoma tumor growth and lung metastasis.

Conclusion

Our findings suggested that miR-1225-5P inhibits osteosarcoma cell growth in vitro and tumor growth in vivo by targeting YWHAZ. This study suggested that miR-1225-5P can serve as a potential therapeutic method for treating osteosarcoma.

SUBMITTER: Gong Y 

PROVIDER: S-EPMC7797335 | biostudies-literature | 2021 Jan

REPOSITORIES: biostudies-literature