siRNA-mediated silencing of Nanog reduces stemness properties and increases the sensitivity of HepG2 cells to cisplatin

Gene. 2022 May 5:821:146333. doi: 10.1016/j.gene.2022.146333. Epub 2022 Feb 16.

Abstract

Liver cancer is one of the most lethal cancers having worldwide prevalence. Despite significant progress in cancer therapy, liver cancer-induced mortality is very high. Nanog, as an essential transcription factor modulating cellular multipotency, causes tumor progression, drug resistance, and preserves stemness properties in various tumors such as liver cancer. Thus, this research was conducted to evaluate the impact of combination therapy of Nanog siRNA/cisplatin on the sensitivity of liver cancer cells to this drug. HepG2 cells were transfected with Nanog siRNA and treated with cisplatin, individually and in combination. Then, it was observed that in transfected HepG2 cells, Nanog expression was significantly reduced at mRNA level and also these cells were sensitized to cisplatin. In addition, to assess the impact of Nanog siRNA and cisplatin individually and in combination on cells' viability, migration capacity, apoptosis, and cell cycle progression, the MTT, wound healing, colony formation assay, Annexin V/PI staining, and flow cytometry assays were applied on HepG2 cells, respectively. Also, the quantitive Real-Time PCR was used to check the expression of stemness-associated genes (CD44, CD133, and Sox2), and apoptosis-related genes (caspase-3, 8, 9, BAX and Bcl2) after combination therapy. It is indicated that the combination of Nanog siRNA and cisplatin significantly reduced proliferation, migration, and colony formation ability, as well as increased apoptosis rate, and cell cycle arrest. Also, it is found that the combination of Nanog siRNA and cisplatin down-regulated the expression of stemness-associated genes and up-regulated apoptosis-related genes in HepG2 cells. Hence, it can be suggested that Nanog inhibition in combination with cisplatin is a potential therapeutic strategy for developing new therapeutic approaches for liver cancer.

Keywords: Cisplatin; Combination therapy; Liver cancer; Nanog siRNA.

MeSH terms

  • AC133 Antigen / genetics
  • Biomarkers, Tumor / genetics*
  • Cell Movement / drug effects
  • Cell Proliferation / drug effects
  • Cell Survival / drug effects
  • Cisplatin / pharmacology*
  • Down-Regulation
  • Drug Resistance, Neoplasm / drug effects*
  • Drug Synergism
  • Gene Expression Regulation, Neoplastic / drug effects
  • Gene Silencing
  • Hep G2 Cells
  • Humans
  • Hyaluronan Receptors / genetics
  • Liver Neoplasms / drug therapy
  • Liver Neoplasms / genetics*
  • Nanog Homeobox Protein / antagonists & inhibitors
  • Nanog Homeobox Protein / genetics*
  • Neoplastic Stem Cells / chemistry
  • Neoplastic Stem Cells / drug effects
  • RNA, Small Interfering / pharmacology*
  • SOXB1 Transcription Factors / genetics

Substances

  • AC133 Antigen
  • Biomarkers, Tumor
  • CD44 protein, human
  • Hyaluronan Receptors
  • NANOG protein, human
  • Nanog Homeobox Protein
  • PROM1 protein, human
  • RNA, Small Interfering
  • SOX2 protein, human
  • SOXB1 Transcription Factors
  • Cisplatin