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. 2019 May 15:12:3661-3670.
doi: 10.2147/OTT.S200901. eCollection 2019.

Insulin-like growth factor II mRNA-binding protein 3 promotes cell proliferation, migration and invasion in human glioblastoma

Chao Wu  1 , Hongxin Ma  1 , Guijun Qi  1 , Fanyu Chen  1 , Jiancheng Chu  1
Affiliations

Insulin-like growth factor II mRNA-binding protein 3 promotes cell proliferation, migration and invasion in human glioblastoma

Chao Wu et al. Onco Targets Ther. .

Abstract

Background/Aims: Recently, the insulin-like growth factor mRNA-binding protein 3 (IMP3) has been reported to be involved in tumorigenesis. We aimed to study the expression and role of IMP3 in human glioblastoma. Methods: We analyzed the expression of IMP3 in 70 cases of glioma tissues, normal brain tissues and 5 kinds of cell lines using western blot. Immunohistochemistry (IHC) was used to evaluate the expression and distribution of IMP3 in glioma tissues. Colony formation, wound healing, migration and invasion assays and tumorigenesis in nude mice were used to explore the function of IMP3 in vitro and in vivo. The epithelial-mesenchymal transition (EMT)-related biomarkers were detected by western blot. Results: We found that the expression level of IMP3 was obviously higher in glioma tissues than that in normal brain tissues, and associated with glioma grade. In-vitro assays revealed that IMP3 overexpression significantly induced cell proliferation, migration, and invasion. Mechanically, IMP3 over-expression downregulated the expression of E-cadherin, but upregulated the expressions of N-cadherin, vimentin, snail, slug and MMP9. However, the inhibition of IMP3 impaired these oncogenic effects. In vivo assay also demonstrated that silencing of IMP3 inhibited tumor growth and improved survival of tumor-bearing xenograft nude mice. Conclusion: IMP3 can promote cell proliferation, migration and invasion by inducing EMT in glioblastoma. Thus, targeting IMP3 pathway may be a novel way to treat patients with glioblastoma.

Keywords: IMP3; glioblastoma; invasion; migration; proliferation.

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Conflict of interest statement

The authors declare that they have no conflicts of interest in this work.

Figures

Figure 1
Figure 1
IMP3 expression in glioma tissues and cells. (A) Representative IHC images showed IMP3 expression was decreased in normal brain tissues compared with primary glioma samples; original magnification: 400×. Western blot was performed to measure the expression of IMP3 protein in representative glioma tissues, and normal brain tissues (B), normal NHA cell, LN-18, U87, SHG-44, U251, and U373 cells (C). The expression levels of IMP3 proteins were normalized to GAPDH in each sample. Data are presented as mean ± SD of at least three independent experiments or 3 cases of representative samples. *P<0.01 vs N.T. or NHA;**P<0.01 vs low grade; “N.T.”=normal tissues; “C.T.”=cancer tissues.
Figure 2
Figure 2
Ectopic expression of IMP3 promotes tumourigenic properties. (A) IMP3 plasmids or vector control were transfected into U87 and U251 cell lines to overexpress IMP3, and then IMP3 expression was confirmed by western blot. (B) Cell proliferation was determined in U87 and U251 cells by MTT assay. (C) Colony formation assay was used to determine the proliferation capacity of U87 and U251 cells. (D and E) We used 10 nude mice (5 for each group) to investigate the role of IMP3 over-expression in the growth of U87 cells. Following post-inoculation 21 days, we measured the mean volume and weight of xenograft tumors. The data were represented by mean ± SD.*P<0.01, vs their respective controls.
Figure 3
Figure 3
Inhibition of IMP3 expression affects tumourigenic properties. (A) IMP3 siRNA or si-control were transfected into U87 and U251 cell lines to inhibit IMP3 expression, and then IMP3 expression was confirmed by western blot. (B) Cell proliferation was determined in U87 and U251 cells by MTT assay. (C) Colony formation assay was used to determine the proliferation capacity of U87 and U251 cells. Upper: images of colony formation assay (200× magnification); Lower: quantification data. (D and E) We used 10 nude mice (5 for each group) to investigate the role of si-IMP3 in the growth of U87 cells. Tumor volumes were measured with calipers every 3 days. Following post-inoculation 21 days, we measured the mean volume and weight of xenograft tumors. The data were represented by mean ± SD.*P<0.01, vs their respective controls.
Figure 4
Figure 4
IMP3 affects the survival of nude mice and EMT biomarkers in U87 cells. (A) The survival rates of nude mice containing U87 cells with IMP3 over-expression or IMP3 silencing were determined as follows: 100%×(number of survivors)/(number of challenged mice). (B) Western blot analysis was used to assess the levels of E-cadherin, N-cadherin, vimentin, snail, slug and MMP9 in U87 cells with over-expression of IMP3. (C) Western blot analysis was used to assess the levels of E-cadherin, N-cadherin, vimentin, snail, slug and MMP9 in U87 cells with IMP3 siRNAs. Data are presented as Mean ± SD of at least three independent experiments or 3 cases of representative samples. *P<0.01 vs their respective controls.
Figure 5
Figure 5
IMP3 expression promotes migration and invasion in vitro. Mitomycin C pretreated (10 µg/ml for 30 min) U87 (A) and U251 cells (B) were incubated with serum scarce media for 24 h, scratch was made and multiple images were collected in different time interval. Cell invasion assay was determined in U87 and U251 cells (C and D) by Transwell assay. All cells were transfected with IMP3 plasmids, IMP3 siRNAs, or their controls. The data were represented by mean ± SD. *P<0.01, vs their respective control.
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References

    1. Weathers SP, Han X, Liu DD, et al. A randomized phase II trial of standard dose bevacizumab versus low dose bevacizumab plus lomustine (CCNU) in adults with recurrent glioblastoma. J Neurooncol. 2016;129(3):487–494. doi:10.1007/s11060-016-2195-9 - DOI - PMC - PubMed
    1. Wick W, Roth P, Hartmann C, et al. Long-term analysis of the NOA-04 randomized phase III trial of sequential radiochemotherapy of anaplastic glioma with PCV or temozolomide. Neuro Oncol. 2016;18(11):1529–1537. doi:10.1093/neuonc/now133 - DOI - PMC - PubMed
    1. Salloum R, Hummel TR, Kumar SS, et al. A molecular biology and phase II study of imetelstat (GRN163L) in children with recurrent or refractory central nervous system malignancies: a pediatric brain tumor consortium study. J Neurooncol. 2016;129(3):443–451. doi:10.1007/s11060-016-2189-7 - DOI - PMC - PubMed
    1. Wick W, Gorlia T, Bady P, et al. Phase II study of radiotherapy and temsirolimus versus radiochemotherapy with temozolomide in patients with newly diagnosed glioblastoma without MGMT promoter hypermethylation (EORTC 26082). Clin Cancer Res. 2016;22(19):4797–4806. doi:10.1158/1078-0432.CCR-15-3153 - DOI - PubMed
    1. Jaspan T, Morgan PS, Warmuth-Metz M, et al. Implementation and expansion of the RANO criteria in a randomized phase II trial of pediatric patients with newly diagnosed high-grade gliomas. AJNR Am J Neuroradiol. 2016;37(9):1581–1587. doi:10.3174/ajnr.A4782 - DOI - PMC - PubMed