Antitumor Macrophage Response to Bacillus pumilus Ribonuclease (Binase)

Mediators Inflamm. 2017:2017:4029641. doi: 10.1155/2017/4029641. Epub 2017 May 18.

Abstract

Extracellular bacterial ribonucleases such as binase from Bacillus pumilus possess cytotoxic activity against tumor cells with a potential for clinical application. Moreover, they may induce activation of tumor-derived macrophages either into the M1-phenotype with well-documented functions in the regulation of the antitumor immune response or into M2-macrophages that may stimulate tumor growth, metastasis, and angiogenesis. In this study, binase or endogenous RNase1 (but not RNA or short oligonucleotides) stimulated the expression of activated NF-κB p65 subunit in macrophages. Since no changes in MyD88 and TRIF adaptor protein expression were observed, toll-like receptors may not be involved in RNase-related NF-κB pathway activation. In addition, short exposure (0.5 hr) to binase induced the release of cytokines such as IL-6, МСР-1, or TNF-α (but not IL-4 and IL-10), indicative for the polarization into antitumor M1-macrophages. Thus, we revealed increased expression of activated NF-κB p65 subunit in macrophages upon stimulation by binase and RNase1, but not RNA or short oligonucleotides.

MeSH terms

  • A549 Cells
  • Animals
  • Bacillus pumilus / enzymology*
  • Bacterial Proteins / pharmacology*
  • Cell Line
  • Endoribonucleases / pharmacology*
  • Humans
  • Interleukin-10 / metabolism
  • Interleukin-6 / metabolism
  • Macrophages / drug effects*
  • Macrophages / metabolism
  • Mice
  • RAW 264.7 Cells
  • Ribonucleases / pharmacology*
  • Transcription Factor RelA / metabolism
  • Tumor Necrosis Factor-alpha / metabolism

Substances

  • Bacterial Proteins
  • Interleukin-6
  • Transcription Factor RelA
  • Tumor Necrosis Factor-alpha
  • Interleukin-10
  • Endoribonucleases
  • Ribonucleases
  • ribonuclease T(2)