Position-Dependent Effects of AP Sites Within an Promoter G-Quadruplex Scaffold on Quadruplex Stability and Repair Activity of the APE1 Enzyme.

Apurinic/apyrimidinic (AP) sites are endogenous DNA lesions widespread in human cells. Having no nucleobases, they are noncoding and promutagenic. AP site repair is generally initiated through strand incision by AP endonuclease 1 (APE1).

Synthesis of furanotriterpenoids from betulin and evaluation of Tyrosyl-DNA phosphodiesterase 1 (Tdp1) inhibitory properties of new semi-synthetic triterpenoids.

For the first time, a synthetic route for preparing lupane and oleanane derivatives with a hydrogenated furan ring as a cycle A of triterpene scaffold is described. Most of the synthesized compounds, furanoterpenoids and their synthetic intermediates, were non-toxic against the tested cancer and non-cancerous cell lines, and evinced significant inhibitory activity with IC 1.0-9.

Suppression of planktonic and biofilm of Escherichia coli by the synergistic lantibiotics-polymyxins combinations.

Escherichia coli are generally resistant to the lantibiotic's action (nisin and warnerin), but we have shown increased sensitivity of E. coli to lantibiotics in the presence of subinhibitory concentrations of polymyxins. Synergistic lantibiotic-polymyxin combinations were found for polymyxins B and M.

Aberrant Repair of 8-Oxoguanine in Short DNA Bulges.

The presence of DNA damage can increase the likelihood of DNA replication errors and promote mutations. In particular, pauses of DNA polymerase at the site of damage can lead to polymerase slippage and the formation of 1-2-nucleotide bulges. Repair of such structures using an undamaged DNA template leads to small deletions.

The Molecular Mechanisms of Oleanane Aldehyde-β-enone Cytotoxicity against Doxorubicin-Resistant Cancer Cells.

Oleanane aldehyde-β-enone (), being the semi-synthetic derivative of the triterpenoid betulin, effectively inhibits the proliferation of HBL-100 and K562 cancer cells (IC 0.47-0.53 µM), as well as the proliferation of their resistant subclones with high P-gp expression HBL-100/Dox, K562/i-S9 and K562/i-S9_Dox (IC 0.