Ribosomal protein small subunit 15A (RPS15A) inhibits the apoptosis of breast cancer MDA-MB-231 cells via upregulating phosphorylated ERK1/2, Bad, and Chk1

J Cell Biochem. 2020 Jan;121(1):587-595. doi: 10.1002/jcb.29304. Epub 2019 Sep 18.

Abstract

Aim: To detect the expression and identify the role of Ribosomal protein S15A (RPS15A) in human breast cancer (BC).

Methods: Immunohistochemistry (IHC) was carried out for detecting the levels of RPS15A protein. Quantitative PCR was used to evaluate the mRNA level of RPS15A in one normal breast and three BC cell lines. Lentivirus-mediated shRNA targeting RPS15A was designed to investigate the impact of silencing RPS15A in MDA-MB-231 cell.

Results: Higher RPS15A expression was detected in tumor tissues than in para-cancer tissues, and higher RPS15A expression was related to larger tumor size and higher TNM stage. Also, RPS15A mRNA expression in all three BC cell lines was higher than that in normal breast cell (all P < .005). Further, RPS15A knockdown significantly suppressed MDA-MB-231 cell proliferation and induced apoptosis. Moreover, RPS15A knockdown increased the caspase-3/-7 activity, and suppressed the phosphorylated levels of ERK1/2, Bad, and Chk1 (all P < .01).

Conclusion: RPS15A inhibits apoptosis via upregulating phosphorylated ERK1/2, Bad, and Chk1 in MDA-MB-231 cell line.

Keywords: ERK1/2; apoptosis; breast cancer; caspase.

MeSH terms

  • Apoptosis
  • Biomarkers, Tumor / genetics
  • Biomarkers, Tumor / metabolism
  • Breast Neoplasms / genetics
  • Breast Neoplasms / metabolism
  • Breast Neoplasms / pathology*
  • Cell Proliferation
  • Checkpoint Kinase 1 / genetics
  • Checkpoint Kinase 1 / metabolism*
  • Female
  • Gene Expression Regulation, Neoplastic*
  • Humans
  • Middle Aged
  • Mitogen-Activated Protein Kinase 1 / genetics
  • Mitogen-Activated Protein Kinase 1 / metabolism*
  • Mitogen-Activated Protein Kinase 3 / genetics
  • Mitogen-Activated Protein Kinase 3 / metabolism*
  • Phosphorylation
  • Prognosis
  • Ribosomal Proteins / genetics
  • Ribosomal Proteins / metabolism*
  • Tumor Cells, Cultured
  • bcl-Associated Death Protein / genetics
  • bcl-Associated Death Protein / metabolism*

Substances

  • BAD protein, human
  • Biomarkers, Tumor
  • RPS15A protein, human
  • Ribosomal Proteins
  • bcl-Associated Death Protein
  • CHEK1 protein, human
  • Checkpoint Kinase 1
  • MAPK1 protein, human
  • MAPK3 protein, human
  • Mitogen-Activated Protein Kinase 1
  • Mitogen-Activated Protein Kinase 3