ShRNA-mediated knock-down of CXCR7 increases TRAIL-sensitivity in MCF-7 breast cancer cells

Tumour Biol. 2015 Sep;36(9):7243-50. doi: 10.1007/s13277-015-3432-0. Epub 2015 Apr 20.

Abstract

This study aims to investigate the effects of CXCR7-shRNA on TRAIL-mediated apoptosis and suppression of invasive migration and the underlying mechanisms. (1) We constructed CXCR-7-shRNA lentiviral vectors and confirmed their silencing efficiency in MCF-7 cells by RT-PCR analysis. (2) The effects of CXCR7 and/or TRAIL on cell proliferation were examined by MTT assay. (3) Trans well invasion assay was used to examine the effects of CXCR7 silencing and/or TRAIL on MCF-7 cell invasive migration. (4) Expression of Caspase-3, and Caspase-8, and MMP-2 and MMP-9 proteins was examined by Western blot analysis. (1) Viral titers were 2.95 × 10(8) TU/ml, 3.01 × 10(8) TU/ml, 3.26 × 10(8) TU/ml, and 3.08 × 10(8) TU/ml, respectively. (2) CHXR7 shRNAs markedly decreased CXCR7 mRNA expression in MCF-7 cells, among which CXCR7-shRNA-1 showed significantly higher rate of inhibition (P < 0.05). (3) Combination of TRAIL and CXCR7-shRNA-1 resulted in marked suppression of cell proliferation in time-dependent manner (P < 0.05). (4) Cell invasion capacity was inhibited in each experimental group as compared to blank control group at 48 h post treatments (P < 0.05). Among them, combination of TRAIL and CXCR7-shRNA had the highest inhibitory effect (P < 0.05). (5) Western blot analysis indicated that TRAIL alone does not affect CXCR7 expression, but either TRAIL + CXCR7 shRNA or CXCR7 shRNA alone markedly suppressed CXCR7 protein expression. Furthermore, combination of TRAIL and CXCR-7-shRNA significantly increased Caspase-3 and Caspase-8 expression and decreased MMP-2 and MMP-9 expression (P < 0.05). Knock-down of CXCR-7 expression leads to augmented TRAIL-mediated suppression of MCF-7 cell proliferation and invasion.

Keywords: Breast cancer; CXCR7; RNAi; Recombinant lentiviral vector; TRAIL.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Apoptosis / genetics
  • Breast Neoplasms / genetics*
  • Breast Neoplasms / pathology
  • Cell Movement / genetics
  • Cell Proliferation / genetics*
  • Female
  • Gene Expression Regulation, Neoplastic
  • Genetic Vectors
  • Humans
  • MCF-7 Cells
  • Neoplasm Invasiveness / genetics
  • RNA, Small Interfering / genetics
  • Receptors, CXCR / biosynthesis
  • Receptors, CXCR / genetics*
  • TNF-Related Apoptosis-Inducing Ligand / biosynthesis
  • TNF-Related Apoptosis-Inducing Ligand / genetics*

Substances

  • ACKR3 protein, human
  • RNA, Small Interfering
  • Receptors, CXCR
  • TNF-Related Apoptosis-Inducing Ligand
  • TNFSF10 protein, human