miR-204-5p suppresses cell proliferation by inhibiting IGFBP5 in papillary thyroid carcinoma

https://doi.org/10.1016/j.bbrc.2015.01.037Get rights and content

Highlights

  • miR-204-5p expression is downregulated in PTC tissues and cell lines.

  • miR-204-5p suppresses proliferation and promotes apoptosis in PTC cells.

  • miR-204-5p suppresses IGFBP5 expression by direct binding to the 3′-UTR.

  • IGFBP5 overexpression reverses the effects of miR-204-5p.

Abstract

microRNAs (miRNAs) are frequently dysregulated in human malignancies. It was recently shown that miR-204-5p is downregulated in papillary thyroid carcinoma (PTC); however, the functional significance of this observation is not known. This study investigated the role of miR-204-5p in PTC. Overexpressing miR-204-5p suppressed PTC cell proliferation and induced cell cycle arrest and apoptosis. The results of a luciferase reporter assay showed that miR-204-5p can directly bind to the 3′ untranslated region (UTR) of insulin-like growth factor-binding protein 5 (IGFBP5) mRNA, and IGFBP5 overexpression partially reversed the growth-inhibitory effects of miR-204-5p. These results indicate that miR-204-5p acts as a tumor suppressor in PTC by regulating IGFBP5 expression and that miR-204-5p can potentially serve as an antitumorigenic agent in the treatment of PTC.

Introduction

Papillary thyroid carcinoma (PTC) is the most common histotype of thyroid malignancy, and its incidence has been steadily increasing over the past few decades [1], [2]. Although the majority of cases have excellent prognosis and therapeutic response, up to 30% of patients present with locoregional recurrence or distant metastases within 10 years [3], [4]. Thus, it is imperative to understand the molecular basis of PTC in order to develop effective diagnostic, prognostic, and therapeutic strategies for its treatment.

microRNAs (miRNAs) are 18–25-nt, non-coding, single-stranded RNAs that regulate gene expression at the post-transcriptional level by binding to the 3′-untranslated region (UTR) of target mRNAs [5], [6]. miRNAs regulate a variety of basic physiological processes, including the cell cycle, apoptosis, cell proliferation, migration, invasion, and differentiation [7], [8], [9], [10], and miRNA expression or function is dysregulated in various types of malignancies, including PTC [11]. For instance, overexpression of the tumor suppressor miR-146a decreased PTC cell survival and induced PTC cell apoptosis [12], while miR-199a-3p is downregulated in PTC and its overexpression in PTC cells inhibited migration and proliferation, thereby inducing cell death [1]. On the other hand, miR-222 and miR-146b levels are upregulated in recurrent PTC and serve as circulating biomarkers for this cancer [3]. A recent microarray analysis revealed that miR-204-5p was downregulated in PTC [13]; however, the functional significance of this observation is not known.

In the present study, we validated that miR-204-5p was obviously downregulated in PTC tissues and cell lines. miR-204-5p overexpression suppressed PTC cell growth and induced cell cycle arrest and apoptosis. Insulin-like growth factor-binding protein 5 (IGFBP5) was identified as a direct target of miR-204-5p regulation, and restoring IGFBP5 expression partially reversed the antitumorigenic effects of miR-204-5p.

Section snippets

Cell lines and tissues

Human PTC cell lines (TCP-1 and BCPAP) and HEK293T were cultured in Dulbecco's Modified Eagle's Medium (HyClone/Thermo Scientific, Beijing, China) supplemented with 10% fetal bovine serum at 37 °C in 5% CO2. Cells were passaged every 2–3 days. PTC and adjacent non-tumorous tissue samples were obtained with informed consent from 16 PTC patients who underwent curative resection at Shanghai Pudong Gongli Hospital. The study protocol was approved by the Ethics Committee of Shanghai Pudong Gongli

miR-204-5p expression is downregulated in PTC tissues and cell lines

miR-204-5p expression in 16 sets of PTC and adjacent normal tissue was assessed by qRT-PCR. miR-204-5p expression was downregulated in PTC relative to adjacent non-tumorous tissues (Fig. 1A). Similarly, miR-204-5p levels were reduced in the TPC-1 and BCPAP PTC cell lines as compared to normal tissue (Fig. 1B). These data indicate that miR-204-5p expression is attenuated in PTC.

miR-204-5p suppresses proliferation and promotes apoptosis in PTC cells

To investigate the biological function of miR-204-5p in PTC, TPC-1 and BCPAP cells were infected with a lentivirus

Discussion

miRNAs play critical roles in the initiation, promotion, and progression of human cancers by regulating target gene expression [15], [16]; as such, they can be functionally distinguished as tumor suppressors or oncogenes [17]. As a tumor suppressor, miR-204-5p is downregulated in minimal deviation adenocarcinoma [18], clear cell renal cell carcinoma [19], gastric cancer arising from Helicobacter pylori infection [20], and melanoma [21]. A recent study also found that miR-204-5p was frequently

Conflict of interest

The authors declare no conflict of interest.

Acknowledgments

This work was supported by Key Disciplines Group Construction Project of Pudong Health Bureau of Shanghai (PDWxq2014-9) and Shanghai Science and Technology Commission (15ZR1437100).

References (35)

  • O. Hobert

    Gene regulation by transcription factors and microRNAs

    Science

    (2008)
  • W.T. Liao et al.

    MicroRNA-30b functions as a tumour suppressor in human colorectal cancer by targeting KRAS, PIK3CD and BCL2

    J. Pathol.

    (2014)
  • S. Fernandez et al.

    miR-340 inhibits tumor cell proliferation and induces apoptosis by targeting multiple negative regulators of p27 in non-small cell lung cancer

    Oncogene

    (2014)
  • B.S. Li et al.

    MicroRNA-25 promotes gastric cancer migration, invasion and proliferation by directly targeting transducer of ERBB2, 1 and correlates with poor survival

    Oncogene

    (2014)
  • W. Tang et al.

    miR-27a regulates endothelial differentiation of breast cancer stem like cells

    Oncogene

    (2014)
  • T. Moriyama et al.

    MicroRNA-21 modulates biological functions of pancreatic cancer cells including their proliferation, invasion, and chemoresistance

    Mol. Cancer Ther.

    (2009)
  • X. Zhang et al.

    MicroRNA-146a targets PRKCE to modulate papillary thyroid tumor development

    Int. J. Cancer

    (2014)
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      A number of other studies have further established the tumor suppressive effect of miRNAs in PTC. Such miRNAs include miR-219-5p which targets estrogen receptor alpha [55] and EYA2 [56]; miR-31 which targets RNA-binding protein HuR [57]; miR-204-5p which targets IGFBP5 [58]; miR-126 which targets low-density lipoprotein receptorrelated protein 6 (LRP6) [59]; miR-29a [60] and miR-497 [61] both of which target Akt3; miR-375 with targets ERBB2 [62], miR-663 which targets TGFβ1 [63], miR-137 which targets CXCL12 [64]; miR-486-5p which targets fibrillin-1 [65]; miR-613 [66] and miR-577 [67] both of which target SphK2; miR-7 which targets CKS2 [68]; miR-195 which targets CCND1 and FGF2 [69]; miR-148a which targets STAT3 [70]; let-7b which targets HMGA2 [71]; miR-335 which targets ZEB2 [72]; miR-139 which targets fibronectin 1 [73]; miR-144 which targets WWTR1 [74]; miR-199a-5p which targets SNAI1 [48]; miR-622 which targets VEGF [75]; miR-361-5p which targets rho-associated coiled-coil kinase 1 (ROCK1) [76]; miR-4728 which targets MAPK [77]; miR-9 which targets BRAF [78]; miR-143-3p which targets MSI2 [79], miR-1266 which targets FGFR2 [80]; miR-188-5p which targets FGF5 [81], miR-384 which targets PRKACB [82], miR-873-5p which targets CXCL16 [83], miR-1256 which targets 5-hydroxytryptamine receptor 3A (HTR3A) [84], miR-326 which targets MAPK1 and ERBB4 [85], miR-381-3p which targets LRP6 [86] and miR-873 which is a target of circular RNA circFAT1(e2) [87]. Not just the papillary thyroid cancer, but the researchers have been interested in dysregulated miRNAs in anaplastic thyroid cancer (ATC) as well, for more than a decade now.

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    1

    These authors contributed equally to this work.

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