title: Overexpression of microRNA-21 strengthens stem cell-like characteristics in a hepatocellular carcinoma cell line.
abstract: BACKGROUND
  Liver cancer stem cells (LCSCs) have been shown to express higher levels of microRNA-21 (miR-21). Here, we examine the possible contributions of miR-21 to the phenotype of LCSCs in culture and in xenograft tumors in nude mice.
  
  
  METHODS
  The hepatocellular carcinoma cell line MHCC-97H was stably transformed with a retroviral vector to establish cells overexpressing miR-21, while a cell line transformed with empty vector served as a negative control. RT-PCR and Western blotting were used to evaluate the effects of miR-21 overexpression on the expression of various LCSC markers, a Transwell assay was used to assess the effects on cell migration and invasion, and a spheroid formation assay was used to examine the effects on clonogenesis. The effects of miR-21 overexpression were also examined in tumors in nude mice.
  
  
  RESULTS
  An MHCC-97H cell line was constructed that stably overexpresses miR-21 at 7.78 ± 1.51-fold higher levels than the negative control cell line. Expression of the LCSC markers CD13, Ep-CAM, CD90, and OCT4 was significantly higher in the miR-21-overexpressing cell line than in the negative control at both mRNA and protein levels. The overexpressing cell line formed larger, tighter, and more numerous spheroids. Overexpression of miR-21 was associated with greater cell migration and invasion. Tumors of overexpressing cells in nude mice had a significantly larger mean volume after 34 days of growth (773.62 ± 163.46 mm3) than tumors of negative control cells (502.79 ± 33.94 mm3, p = 0.048), as well as greater mean weight (0.422 ± 0.019 vs. 0.346 ± 0.006 g, p = 0.003).
  
  
  CONCLUSIONS
  Overexpression of miR-21 strengthens the phenotype of LCSCs, facilitating invasion, migration, and tumorigenesis in hepatocellular carcinoma.
authors: Department of Hepatobiliary Surgery, Tumor Hospital of Guangxi Medical University, Nanning, 530021, Guangxi Zhuang Autonomous Region, China.|Department of General Surgery, The Second People's Hospital of Jing Men, Jingmen, 448000, Hubei Province, China.
authors: Jinghang
authors: J
authors: Jiang
authors: Department of General Surgery, The Second People's Hospital of Jing Men, Jingmen, 448000, Hubei Province, China.
authors: Peipei
authors: P
authors: Yang
authors: Department of Thyroid and Breast Surgery, The Central Hospital of Wuhan, Wuhan, 430041, Hubei Province, China.
authors: Zhe
authors: Z
authors: Guo
authors: Department of Immunology, School of Preclinical Medicine, Biological Targeting Diagnosis and Therapy Research Center, Guangxi Medical University, Nanning, 530021, Guangxi Zhuang Autonomous Region, China.
authors: Rirong
authors: R
authors: Yang
authors: Department of General Surgery, The First People's Hospital of Changde, Changde, 415000, Hunan Province, China.
authors: Haojie
authors: H
authors: Yang
authors: Department of Hepatobiliary Surgery, Tumor Hospital of Guangxi Medical University, Nanning, 530021, Guangxi Zhuang Autonomous Region, China.
authors: Fuquan
authors: F
authors: Yang
authors: Department of Hepatobiliary Surgery, Tumor Hospital of Guangxi Medical University, Nanning, 530021, Guangxi Zhuang Autonomous Region, China.
authors: Lequn
authors: L
authors: Li
authors: Department of Hepatobiliary Surgery, Tumor Hospital of Guangxi Medical University, Nanning, 530021, Guangxi Zhuang Autonomous Region, China. 474522490@qq.com.
authors: Bangde
authors: B
authors: Xiang
mesh_terms: D000818:Animals; D017209:Apoptosis; D015153:Blotting, Western; D006528:Carcinoma, Hepatocellular / Q000235:genetics / Q000378:metabolism / Q000473:pathology*; D002465:Cell Movement; D049109:Cell Proliferation; D006801:Humans; D008113:Liver Neoplasms / Q000235:genetics / Q000378:metabolism / Q000473:pathology*; D008297:Male; D051379:Mice; D008807:Mice, Inbred BALB C; D008819:Mice, Nude; D035683:MicroRNAs / Q000235:genetics*; D014411:Neoplastic Stem Cells / Q000378:metabolism / Q000473:pathology*; D012333:RNA, Messenger / Q000235:genetics; D060888:Real-Time Polymerase Chain Reaction; D020133:Reverse Transcriptase Polymerase Chain Reaction; D014407:Tumor Cells, Cultured; D023041:Xenograft Model Antitumor Assays
chemical_list: C524940:MIRN21 microRNA, human; D035683:MicroRNAs; D012333:RNA, Messenger
keywords: Cancer stem cell; Hepatocellular carcinoma; Liver cancer stem cells; Retroviral vector; microRNA-21