SSRP1 Contributes to the Malignancy of Hepatocellular Carcinoma and Is Negatively Regulated by miR-497

Mol Ther. 2016 May;24(5):903-14. doi: 10.1038/mt.2016.9. Epub 2016 Jan 12.

Abstract

The aim of this study is to clarify the clinical implication and functional role of structure specific recognition protein 1 (SSRP1) in hepatocellular carcinoma (HCC) and explore the underlying mechanism of aberrant high expression of SSRP1 in cancers. In the present investigation, we validated that SSRP1 was upregulated in HCC samples. We also demonstrated that its upregulation was associated with several clinicopathologic features such as higher serum AFP level, larger tumor size, and higher T stage of HCC patients; and its high expression indicated shorter overall survival and faster recurrence. To investigate the role of SSRP1 in HCC progression, both loss- and gain-function models were established. We demonstrated that SSPR1 modulated both proliferation and metastasis of HCC cells in vitro and vivo. Furthermore, we demonstrated that SSRP1-modulated apoptosis process and its knockdown increased the sensitivity of HCC cells to doxorubicin, 5-Fluorouracil, and cisplatin. We also identified microRNA-497 (miR-497) as a posttranscriptional regulator of SSRP1. Ectopic expression of miR-497 inhibited 3'-untranslated-region-coupled luciferase activity and suppressed endogenous SSRP1 expression at both messenger RNA and protein levels. For the first time, we proved that SSRP1 upregulation contributed to HCC development and the tumor-suppressive miR-497 served as its negative regulator.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • 3' Untranslated Regions
  • Animals
  • Apoptosis
  • Carcinoma, Hepatocellular / genetics
  • Carcinoma, Hepatocellular / pathology*
  • Cell Line, Tumor
  • DNA-Binding Proteins / genetics*
  • Female
  • Gene Expression Regulation, Neoplastic
  • High Mobility Group Proteins / genetics*
  • Humans
  • Liver Neoplasms / genetics*
  • Male
  • Mice
  • MicroRNAs / genetics*
  • Neoplasm Staging
  • Neoplasm Transplantation
  • Transcriptional Elongation Factors / genetics*
  • Up-Regulation*

Substances

  • 3' Untranslated Regions
  • DNA-Binding Proteins
  • High Mobility Group Proteins
  • MIRN497 microRNA, human
  • MicroRNAs
  • SSRP1 protein, human
  • Transcriptional Elongation Factors