miR-148a inhibits self-renewal of thyroid cancer stem cells via repressing INO80 expression

Oncol Rep. 2016 Dec;36(6):3387-3396. doi: 10.3892/or.2016.5203. Epub 2016 Oct 25.


Anaplastic thyroid carcinoma (ATC) is aggressive and lethal with extrathyroidal invasion, distant metastasis, and resistance to conventional therapies. Cancer stem cells (CSCs) are proposed to be responsible for high recurrence rate in ATC. MicroRNAs (miRNAs) have recently been found as an important class of cellular regulators of ATC carcinogenesis. Identification of CSC-related miRNAs and targets is therefore a priority for the development of new therapeutic paradigms. Patient-derived ATC cells were cultured in conditional media on poly-hema-treated dish. ATC CSCs were isolated and enriched through as a series of steps including initial isolation of sphere-forming CSC population, subsequent amplification of this CSC population in a xenograft model treated with cisplatin, and purification of CSCs from xenograft tumors followed by final enrichment using sphere-forming assays. Expression of CSC markers was measured by flow cytometry, immunofluorescence staining, qPCR and western blot analyses. Expression of miRNAs in ATC-CSCs was profiled by microarray analysis. Proliferation and differentiation rates were determined based on the size of spheres formed in vitro and tumors formed in vivo. We successfully isolated and enriched an ATC-CSC population. We identified 17 miRNAs differentially expressed in primary ATC cells vs. ATC-CSCs, among which miRNA-148a was significantly downregulated in ATC-CSCs. Overexpression of miRNA148a in ATC-CSCs induced cell cycle arrest and loss of stem cell characteristics. In addition, we identified INO80 as a target gene of miR-148a. The expression of INO80 was upregulated in ATC-CSCs and downregulated upon miRNA-148 overexpression. Overexpression of miRNA-148a and knockdown of INO80 acted synergistically to decrease the expression of stem cell marker genes as well as to attenuate stem cell-specific properties including the ability to form tumors. This study identified novel contrasting roles for miR-148a and INO80 in the regulation of the stemness of ATC-CSCs and their capacity to initiate tumor formation. Our findings may open a new avenue for therapeutic development against ATC that targets INO80 in the CSCs through enhancing miRNA-148a levels.

MeSH terms

  • ATPases Associated with Diverse Cellular Activities
  • Aged
  • Animals
  • Antineoplastic Agents / pharmacology
  • Antineoplastic Agents / therapeutic use
  • Base Sequence
  • Binding Sites
  • Cell Self Renewal
  • Cisplatin / pharmacology
  • Cisplatin / therapeutic use
  • DNA Helicases / genetics*
  • DNA Helicases / metabolism
  • DNA-Binding Proteins
  • Female
  • Gene Expression
  • Gene Expression Regulation, Neoplastic
  • Humans
  • Mice, Inbred NOD
  • Mice, SCID
  • MicroRNAs / physiology*
  • Middle Aged
  • Neoplastic Stem Cells / physiology*
  • RNA Interference
  • Thyroid Carcinoma, Anaplastic / drug therapy
  • Thyroid Carcinoma, Anaplastic / genetics
  • Thyroid Carcinoma, Anaplastic / metabolism*
  • Thyroid Carcinoma, Anaplastic / pathology
  • Thyroid Gland / metabolism
  • Thyroid Gland / pathology
  • Thyroid Neoplasms / drug therapy
  • Thyroid Neoplasms / genetics
  • Thyroid Neoplasms / metabolism*
  • Thyroid Neoplasms / pathology
  • Tumor Cells, Cultured
  • Xenograft Model Antitumor Assays


  • Antineoplastic Agents
  • DNA-Binding Proteins
  • MIRN148 microRNA, human
  • MicroRNAs
  • ATPases Associated with Diverse Cellular Activities
  • DNA Helicases
  • INO80 protein, human
  • Cisplatin