[Efficiency of Escherichia coli and Bacillus subtilis Expression Systems for Production of Binase Mutants].

Bacillus pumilus ribonuclease (binase) exhibits cytotoxic and oncolytic properties, while causing genotoxic effects at high concentrations. Mutants that have reduced catalytic activity and preserve the antitumor properties of the native enzyme could exert lower toxic side effects. Mutant binase forms with the Lys26Ala and His101Glu single substitutions were obtained by site-directed mutagenesis.

Structural and Functional Differences between Homologous Bacterial Ribonucleases.

Small cationic guanyl-preferring ribonucleases (RNases) produced by the species share a similar protein tertiary structure with a high degree of amino acid sequence conservation. However, they form dimers that differ in conformation and stability. Here, we have addressed the issues (1) whether the homologous RNases also have distinctions in catalytic activity towards different RNA substrates and interactions with the inhibitor protein barstar, and (2) whether these differences correlate with structural features of the proteins.

The Cytotoxicity of RNase-Derived Peptides.

Bacterial ribonuclease binase exhibits a cytotoxic effect on tumor cells possessing certain oncogenes. The aim of this study was to identify the structural parts of the binase molecule that exert cytotoxicity. Out of five designed peptides, the peptides representing the binase regions 21-50 and 74-94 have the highest cytotoxic potential toward human cervical HeLa and breast BT-20 and MCF-7 cancer cells.

Antitumour Activity of the Ribonuclease Binase from in the RLS Tumour Model Is Associated with the Reorganisation of the miRNA Network and Reversion of Cancer-Related Cascades to Normal Functioning.

The important role of miRNA in cell proliferation and differentiation has raised interest in exogenous ribonucleases (RNases) as tools to control tumour-associated intracellular and extracellular miRNAs. In this work, we evaluated the effects of the RNase binase from on small non-coding regulatory RNAs in the context of mouse RLS lymphosarcoma inhibition. In vitro binase exhibited cytotoxicity towards RLS cells via apoptosis induction through caspase-3/caspase-7 activation and decreased the levels of miR-21a, let-7g, miR-31 and miR-155.

[Bacillus pumilus Ribonuclease Inhibits Migration of Human Duodenum Adenocarcinoma HuTu 80 Cells].

Migration of cancer cells from the primary tumor site to nearby tissues is the starting point of the metastatic process. The invasive properties of cells are especially important for carcinomas, since tumor cells need to overcome the basement membrane and go beyond its boundaries to the underlying tissues. Substances that reduce the invasive ability of malignant cells are promising as antimetastatic agents.