The silencing of replication protein A1 induced cell apoptosis via regulating Caspase 3

Life Sci. 2018 May 15:201:141-149. doi: 10.1016/j.lfs.2018.03.054. Epub 2018 Mar 28.

Abstract

Aims: Gastrointestinal cancers are a kind of deadly malignancy afflicting close to a million peoples worldwide. 5-Fluorouracil (5-Fu) is a main chemotherapeutic agent for cancer treatment. However, prolonged exposure of 5-Fu to cancer cells may cause chemoresistance and decrease the therapeutic potential of 5-Fu.

Main methods: Replication protein A (RPA) is a component of the origin recognition complex. In our study, we explored the role of RPA1 in hepatocellular carcinoma cell SMMC-7721, gastric cancer cell SGC-7901 and colorectal cancer HT-29 via lentiviral particles infection. Flow cytometry assay was used to examine the effect of RPA1 on cell proliferation, cell cycle and apoptosis. Western blot was employed to determine the role of RPA1 on Caspase 3 expression.

Key findings: Immunohistochemstry results showed that RPA1 was highly expressed in colorectal cancer tissues. Only 5-Fu or the knockdown of RPA1 suppressed cell clone formation, induced cell cycle arrest at the G1 phase and promoted cell apoptosis by regulating the protein level of Caspase 3. And the combination of the application of 5-Fu and RPA1 silencing significantly enhanced the above effects.

Significance: RPA1 serves as an oncogene during gastrointestinal cancers progression. These studies reveal a new target for gastrointestinal cancers therapy, and the combination of 5-Fu and silencing of RPA1 provides a new attractive therapeutic measure for gastrointestinal cancers.

Keywords: 5-Fluorouracil; Cell apoptosis; Colorectal cancer; Gastric cancer; Hepatocellular carcinoma; Replication protein A1.

MeSH terms

  • Apoptosis / genetics*
  • Caspase 3 / biosynthesis*
  • Caspase 3 / genetics
  • Cell Cycle / drug effects
  • Cell Cycle Checkpoints / drug effects
  • Cell Line, Tumor
  • Cell Proliferation / drug effects
  • Gastrointestinal Neoplasms / drug therapy
  • Gastrointestinal Neoplasms / pathology
  • Gene Silencing*
  • HT29 Cells
  • Humans
  • Replication Protein A / genetics*
  • Tumor Stem Cell Assay

Substances

  • RPA1 protein, human
  • Replication Protein A
  • CASP3 protein, human
  • Caspase 3