Repurposing of neprilysin inhibitor 'sacubitrilat' as an anti-cancer drug by modulating epigenetic and apoptotic regulators.

Modifications in the epigenetic landscape have been considered a hallmark of cancer. Histone deacetylation is one of the crucial epigenetic modulations associated with the aggressive progression of various cancer subtypes. Herein, we have repurposed the neprilysin inhibitor sacubitrilat as a potent anticancer agent using in-silico protein-ligand interaction profiler (PLIP) analysis, molecular docking, and in vitro studies. The screening of PLIP profiles between vorinostat/panobinostat and HDACs/LTA4H followed by molecular docking resulted in five (Sacubitrilat, B65, BDS, BIR, and NPV) FDA-approved, experimental and investigational drugs. Sacubitrilat has demonstrated promising anticancer activity against colorectal cancer (SW-480) and triple-negative breast cancer (MDA-MB-231) cells, with IC50 values of 14.07 µg/mL and 23.02 µg/mL, respectively. FACS analysis revealed that sacubitrilat arrests the cell cycle at the G0/G1 phase and induces apoptotic-mediated cell death in SW-480 cells. In addition, sacubitrilat inhibited HDAC isoforms at the transcriptomic level by 0.7-0.9 fold and at the proteomic level by 0.5-0.6 fold as compared to the control. Sacubitrilat increased the protein expression of tumor-suppressor (p53) and pro-apoptotic makers (Bax and Bid) by 0.2-2.5 fold while decreasing the expression of anti-apoptotic Bcl2 and Nrf2 proteins by 0.2-0.5 fold with respect to control. The observed cleaved PARP product indicates that sacubitrilat induces apoptotic-mediated cell death. This study may pave the way to identify the anticancer potential of sacubitrilat and can be explored in human clinical trials.

New products of defense secretion in south east Asian whip scorpions (Arachnida: Uropygi: Thelyphonida).

Secretion products from the opisthosomal defense gland of south east Asian whip scorpions were identified for the first time by gas-chromatography and mass-spectrometry. Specimens of the genera Hypoctonus, Typopeltis and Ginosigma were tested. While some ingredients are present in large concentrations, others are possibly only side products and may be synthesized more incidentally. For this reason no important functional role is attributed to them. There are considerable individual differences concerning the concentrations of various ingredients. While the secretion products of most species of the genus Typopeltis--similar to Mastigoproctus--are characterized by acetic and octanoic acid in large concentrations, the secretion product of Hypoctonus siamensis provides octanoic acid only in a very low concentration but it is characterized by hexyl acetate.

Distinct primary structures of the major peptide toxins from the venom of the spider Macrothele gigas that bind to sites 3 and 4 in the sodium channel.

Six peptide toxins (Magi 1-6) were isolated from the Hexathelidae spider Macrothele gigas. The amino acid sequences of Magi 1, 2, 5 and 6 have low similarities to the amino acid sequences of known spider toxins. The primary structure of Magi 3 is similar to the structure of the palmitoylated peptide named PlTx-II from the North American spider Plectreurys tristis (Plectreuridae). Moreover, the amino acid sequence of Magi 4, which was revealed by cloning of its cDNA, displays similarities to the Na+ channel modifier delta-atracotoxin from the Australian spider Atrax robustus (Hexathelidae). Competitive binding assays using several 125I-labelled peptide toxins clearly demonstrated the specific binding affinity of Magi 1-5 to site 3 of the insect sodium channel and also that of Magi 5 to site 4 of the rat sodium channel. Only Magi 6 did not compete with the scorpion toxin LqhalphaIT in binding to site 3 despite high toxicity on lepidoptera larvae of 3.1 nmol/g. The K(i)s of other toxins were between 50 pM for Magi 4 and 1747 nM for Magi 1. In addition, only Magi 5 binds to both site 3 in insects (K(i)=267 nM) and site 4 in rat brain synaptosomes (K(i)=1.2 nM), whereas it showed no affinities for either mammal binding site 3 or insect binding site 4. Magi 5 is the first spider toxin with binding affinity to site 4 of a mammalian sodium channel.

Hair regeneration in a solfugid chemotactile sensillum during moulting (Arachnida: Solifugae).

The hair regeneration of a chemotactile sensillum was studied in the sunspiderGluvia during moulting. The sensilla in the old cuticle remain connected to the epidermis by dendrites which extend outwards during apolysis. The trichogen cells forming the new hairshaft in the exuvial space grow along the chemoreceptive dendrites, while the mechanoreceptive dendrites run separately. Morphogenetic aspects are discussed in comparison to results from other arthropods.