MiR-183 inhibits osteosarcoma cell growth and invasion by regulating LRP6-Wnt/β-catenin signaling pathway

https://doi.org/10.1016/j.bbrc.2018.01.170Get rights and content

Highlights

  • MiR-183 has a tumor-suppressive function in osteosarcoma.

  • LRP6 is a direct target of miR-183 in osteosarcoma.

  • MiR-183 interacted with LRP6 to suppress the Wnt/β-catenin pathway in osteosarcoma.

Abstract

Recent studies have demonstrated that microRNA-183 (miR-183) deregulates and plays major roles in many tumors. However, the role of miR-183 in osteosarcoma (OS) pathogenesis is still largely unknown. In this study, we first over-expressed and knocked down miR-183 in MG63 and U20S cells, respectively. Functional analyses showed that ectopic expression of miR-183 suppressed MG63 cell growth, migration, and invasion in vitro and in vivo, whereas knockdown of endogenous miR-183 in U20S cells significantly enhanced these abilities. Next, we characterized low density lipoprotein receptor-related protein 6 (LRP6) as a direct target of miR-183 that interacted with the 3′-untranslated region of LRP6. Furthermore, ectopic expression of LRP6 significantly abrogated the tumor-suppressive effect induced by miR-183. Finally, miR-183 regulated the tumor-suppressive functions in MG63 cells by suppressing the LRP6-Wnt/β-catenin signaling pathway. Therefore, our study demonstrates that miR-183 is a tumor suppressor microRNA that plays a major role in OS.

Introduction

Osteosarcoma (OS), which is characterized by production of osteoid or immature bone, derives from mesenchymal cells and mostly originates from bone and rarely from soft tissues [1]. This neoplasm has a highly malignant tendency, which mainly occurs in children and adolescents with an incidence rate of approximately 4.4 per million [2]. The overall 5-year survival rate of OS has improved to approximately 70% because of advances in surgical and synthetic therapeutic methods [3]. However, 30% of patients diagnosed with OS will not survive for more than 5 years, because of its highly malignant tendency to rapidly destroy surrounding tissues and metastasize [4].

MicroRNAs (miRNAs) are small, non-coding, 19–25 nucleotide RNAs that regulate gene expression by binding to the 3′-untranslated region (UTR) of their target mRNA molecules to repress transcription or induce mRNA degradation [5,6]. It has been demonstrated that miRNAs are involved in various cellular processes such as cell proliferation, apoptosis, metastasis, and invasion [7,8]. Growing evidence suggests that deregulation of miRNAs may contribute to many types of human cancers including OS [[9], [10], [11], [12]]. Extensive research has shown that microRNA-183 (miR-183) deregulates and plays major roles in many tumors including colorectal cancer, melanoma, prostate cancer, breast cancer, and OS [9,[13], [14], [15], [16]]. However, the role of miR-183 in OS pathogenesis is still largely unknown.

In the present study, we first showed that miR-183 had a tumor-suppressive function in OS by suppressing OS cell growth, migration, and invasion. Then, we characterized low density lipoprotein receptor-related protein 6 (LRP6) as a direct target of miR-183. MiR-183 interacted with the 3′-UTR of LRP6 to suppress the Wnt/β-catenin signaling pathway to mediate its tumor-suppressive effect on the proliferation and invasion of OS cells. These findings may be useful for the development of possible clinical approaches for OS treatment.

Section snippets

Cell lines and mice

OS cell lines SOSP-9607, MG63, U20S, Saos-2, and SV40, and immortalized human fetal osteoblastic cell line hFOB 1.19 were obtained from the American Type Culture Collection (Chicago, IL, USA) and grown in complete growth medium as recommended by the manufacturer. The cells were maintained in a humidified atmosphere with 5% CO2 at 37.1 °C. All cell lines were regularly authenticated by checking their morphology.

Female BALB/c mice (4–5 weeks old) and male BALB/c mice (5 weeks old) were obtained

MiR-183 expression patterns in OS cells

To examine the expression levels of miR-183 in OS cell lines SOSP-9607, MG63, U20S, and Saos-2, we employed qRT-PCR. The results showed that MG63 cells expressed the lowest level of miR-183 mRNA (p < 0.01) and U20S cells expressed the highest miR-183 level among the four OS cells compared with hFOB1.19 cells (p < 0.05) (Supplementary Fig. 1A). Next, MG63 cells were infected with miR-183 or control lentiviral vectors, and U20S cells were infected with miR183 inhibitor or control lentiviral

Discussion

OS is a tumor with rapid progression, a high metastatic potential, and poor clinical prognosis [21]. Because of the low survival rate of metastatic OS, it is urgent to develop novel and effective therapeutic strategies for OS. In the present study, we showed that miR-183 has a tumor-suppressive function in OS. To better understand the molecular mechanisms through which miR-183 suppressed the growth and metastasis of OS cells, we performed functional experiments. Our results demonstrated that

Conflicts of interest

The authors have no conflicts of interest to disclose.

Acknowledgments

None.

References (38)

  • J. Wan et al.

    Strategies and developments of immunotherapies in osteosarcoma

    Oncol Lett

    (2016)
  • R. Stupp et al.

    Radiotherapy plus concomitant and adjuvant temozolomide for glioblastoma

    N. Engl. J. Med.

    (2005)
  • E.C. Holland

    Gliomagenesis: genetic alterations and mouse models

    Nat. Rev. Genet.

    (2001)
  • F. Cui et al.

    MiR-125b inhibits tumor growth and promotes apoptosis of cervical cancer cells by targeting phosphoinositide 3-kinase catalytic subunit delta

    Cell. Physiol. Biochem.

    (2012)
  • H. Li et al.

    Stress response of glioblastoma cells mediated by miR-17-5p targeting PTEN and the passenger strand miR-17-3p targeting MDM2

    Oncotarget

    (2012)
  • H. Jin et al.

    Circular RNA hsa-circ-0016347 promotes proliferation, invasion and metastasis of osteosarcoma cells

    Oncotarget

    (2017)
  • C. Jiang et al.

    Triptolide inhibits the growth of osteosarcoma by regulating microRNA-181a via targeting PTEN gene in vivo and vitro

    Tumor Biol.

    (2017)
  • G. Palmini et al.

    What is new in the miRNA world regarding osteosarcoma and chondrosarcoma?

    Molecules

    (2017)
  • K. Motoyama et al.

    Over- and under-expressed microRNAs in human colorectal cancer

    Int. J. Oncol.

    (2009)
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