Structure-activity relationship study of mesyl and busyl phosphoramidate antisense oligonucleotides for unaided and PSMA-mediated uptake into prostate cancer cells.

Phosphorothioate (PS) group is a key component of a majority of FDA approved oligonucleotide drugs that increase stability to nucleases whilst maintaining interactions with many proteins, including RNase H in the case of antisense oligonucleotides (ASOs). At the same time, uniform PS modification increases nonspecific protein binding that can trigger toxicity and pro-inflammatory effects, so discovery and characterization of alternative phosphate mimics for RNA therapeutics is an actual task. Here we evaluated the effects of the introduction of several N-alkane sulfonyl phosphoramidate groups such as mesyl (methanesulfonyl) or busyl (1-butanesulfonyl) phosphoramidates into gapmer ASOs on the efficiency and pattern of RNase H cleavage, cellular uptake in vitro, and intracellular localization. Using Malat1 lncRNA as a target, we have identified patterns of mesyl or busyl modifications in the ASOs for optimal knockdown in vitro. Combination of the PSMA ligand-mediated delivery with optimized mesyl and busyl ASOs resulted in the efficient target depletion in the prostate cancer cells. Our study demonstrated that other N-alkanesulfonyl phosphoramidate groups apart from a known mesyl phosphoramidate can serve as an essential component of mixed backbone gapmer ASOs to reduce drawbacks of uniformly PS-modified gapmers, and deserve further investigation in RNA therapeutics.

Polymer/magnetite carriers functionalized by HER2-DARPin: Avoiding lysosomes during internalization and controlled toxicity of doxorubicin by focused ultrasound induced release.

Nanomedicine has revolutionized the available treatment options during the last decade, but poor selectivity of targeted drug delivery and release is still poses a challenge. In this study, doxorubicin (DOX) and magnetite nanoparticles were encapsulated by freezing-induced loading, coated with polymeric shell bearing two bi-layers of polyarginine/dextran sulphate and finally modified with HER2-specific DARPin proteins. We demonstrated that the enhanced cellular uptake of these nanocarriers predominantly occurs by SKOV-3 (HER2+) cells, in comparison to CHO (HER2-) cells, together with the controlled DOX release using low intensity focused ultrasound (LIFU). In addition, a good ability of DARPin+ capsules to accumulate in the tumor and the possibility of combination therapy with LIFU were demonstrated. A relatively high sensitivity of the obtained nanocarriers to LIFU and their preferential interactions with mitochondria in cancer cells make these carriers promising candidates for cancer treatment, including novel approaches to overcome drug resistance.

[Cholangiocellular cancer: the state of the problem and ways to improve the results of surgical treatment]. / Kholangiotselliuliarnyi rak: sostoianie problemy i puti uluchsheniia khirurgicheskogo lecheniia.

AIM: To improve the outcomes in patients with resectable biliary cancer. MATERIAL AND METHODS: There were 263 procedures for cholangiocellular carcinoma (CCC) for the period 1998­2017. Adjuvant chemotherapy was performed in 102 (38.8%) patients. Extensiveliver resections (78.9%) prevailed for intrahepatic cholangiocellular carcinoma (n=128), 6 (4.7%) patients required vascular resection. Seventy-seven pancreatoduodenectomies were performed for common bile duct cancer, portal vein resection was done in 8 (10.4%) patients. In case of Klatskin tumor (n=58) liver resection combined with bile duct resection (n=52) prevailed. Portal vein resection was done in 16 (27.6%) patients. RESULTS: Postoperative morbidity in patients with intrahepatic CCC was revealed in 68 (53.1%) cases, mortality ­ in 5 (3.9%) cases. Among patients with Klatskin tumor morbidity was revealed in 51 (87.9%) cases, mortality ­ in 6 (10.3%) cases. In patients with common bile duct cancer morbidity was revealed in 53 (68.8%) cases, mortality ­ in 4 (5.2%) cases. In whole cohort median overall survival was 30 months. R0-resection was associated with better long-term results (median 37 months) compared with R1­R2 resection (20 months; p=0.01). Lymph node involvement is associated with significantly worse prognosis (p=0.016), however 5-year survival is observed (25.6%). Adjuvant chemotherapy in R0-resection significantly improved long-term results: median was 46 months (vs. 30 in group without chemotherapy; p=0.02). In intrahepatic CCC patients multiple lesions or mechanical jaundice did not aggravate long-term results. CONCLUSION: R0-resection including lymphadenectomy, resection of adjacent organs and vessels is advisable for CCC. Isolated bile duct resection should be used as an exception. Adjuvant therapy improved long-term results. Multiple lymph node lesion or bile duct infiltration are not contraindications to surgery in intrahepatic CCC patients.

mRNA-Based Therapeutics - Advances and Perspectives.

In this review we discuss features of mRNA synthesis and modifications used to minimize immune response and prolong efficiency of the translation process in vivo. Considerable attention is given to the use of liposomes and nanoparticles containing lipids and polymers for the mRNA delivery. Finally we briefly discuss mRNAs which are currently in the clinical trials for cancer immunotherapy, vaccination against infectious diseases, and replacement therapy.

The bile steroid chenodeoxycholate is a potent antagonist at NMDA and GABA(A) receptors.

The bile steroids (BS) cholic acid and chenodeoxycholic acid are produced in hepatocytes and in the brain. Nothing is known about neuronal actions of BS. Deficiency in a 27-hydroxylase enzyme coincides with reduced production of chenodeoxycholic acid (CDCA) and a relative increase in cholic acid in an inherited lipid storage disease, cerebrotendinous xanthomatosis, characterized by neurological dysfunctions, which can be treated by dietary CDCA. We have examined the modulation of hypothalamic network activity by nine common BS. Cholate and CDCA significantly reduced the firing of hypothalamic neurons and synchronized network activity with CDCA being nearly 10 times more potent. The synthetic BS dehydrocholate synchronized the activity without affecting the firing rate. Gabazine, a GABA(A) receptor antagonist, occluded synchronization by BS. Whole-cell patch clamp recordings revealed a block of NMDA- and GABA(A)-receptors by BS. Potencies of nine common BS differed between NMDA and GABA(A) receptors, however in both cases they correlated with BS affinities for albumin but not with their lipophilicity, supporting a direct action at ligand gated ion channels. GABAergic synaptic currents displayed a faster decay under BS. Our data provide new insight into extrahepatic functions of BS revealing their neuroactive potential.

Integration of intraoperative 3D-ultrasound in a commercial navigation system.

STUDY AIMS: The purpose of this study was the integration of three-dimensional ultrasound data into a neuronavigation system, in order to allow a guided intraoperative resection control during neurosurgical interventions. MATERIAL AND METHODS: A system for iterative neuronavigation based on 3D-ultrasound (US) has been developed. The main components of the system are the ultrasound device Voluson 730 (GE Healthcare) with a 5 - 9 MHz probe, the navigation system VectorVision2 (BrainLAB AG) and a standard PC with Windows XP. The ultrasound data are transferred via DICOM from the ultrasound device to an external computer, where they are processed with a C++ program for representation in the neuronavigation coordinate system. The data transfer between the navigation system and the external computer is performed via the VVLink interface from BrainLAB. The feasibility test of the system was performed with an ultrasound phantom RMI 403GS (Gammex-RMI GmbH). RESULTS: The error of homologous points mapping from US datasets to a CT dataset in the neuronavigation system was determined to be 1.9 +/- 0.97 mm. The maximum time required to technically integrate the ultrasound data into the navigation system was 1.5 min. CONCLUSIONS: The developed system allows 3D-ultrasound based navigation to be carried out with a commercially available navigation system. The functionality of this system has been proven by technical tests. Recording and integration of the ultrasound data can be repeated at any time during surgery and can be used to update anatomical data and consequently for resection control. Another application is the intraoperative adaptation of preoperative datasets (MRI or CT) in order to compensate for "brain shift" during neurosurgical operations.

Long-lasting enhancement of corticostriatal transmission by taurine: role of dopamine and acetylcholine.

1. Taurine applied to mouse brain slices evokes a long-lasting enhancement (LLE) of corticostriatal synaptic transmission, LLE(TAU). 2. The occurrence of LLE(TAU) was significantly decreased in the presence of the specific antagonists at either D1 (SCH23390) or D2 (raclopride) dopamine (DA) receptors. 3. LLE(TAU) was prevented by scopolamine, a muscarinic antagonist, and significantly suppressed by the nicotinic antagonist mecamylamine. 4. Thus, dopaminergic and cholinergic mechanisms, in concert with the taurine transporter and glycine receptors, contribute critically to the induction of corticostriatal LLE(TAU).

[Radio-frequency ablation appliance in resection of the liver]. / Ispol'zovanie apparata radiochastotnoi ablatsii pri rezektsii pecheni.

Pilot experience with "Radionics Cool-Tip RF System" appliance for radio-frequency ablation (RFA) in hepatic resection in the patients with focal lesions of the liver is presented. Advantages of RFA as an alternative method for hemostasis are demonstrated. With this technique bisegmentectomy (II - III) was performed in 4 patients, right-sided hemihepatectomy - in 2 patients. RFA permitted to minimize intraoperative blood loss without increase of surgery time. There were no severe complications during surgery and in early postoperative period. The method permits to perform combined surgeries without a significant increase of surgical risk.

Activation of interneurons at the stratum oriens/alveus border suppresses excitatory transmission to apical dendrites in the CA1 area of the mouse hippocampus.

The consequences of activation or inactivation of interneurons at the CA1 stratum oriens/ alveus border for signal transmission at the apical dendritic region of pyramidal cells were investigated in slices from mice submerged in a perfusion chamber. A characteristic subpopulation of interneurons with a horizontal dendritic tree in this region, which sends a GABAergic projection to the apical dendrites of CA1 pyramidal cells is strongly excited by metabotropic glutamate receptor activation and receives GABAergic input from vasoactive intestinal polypeptide-containing interneurons. Pressure ejection of glutamate or the metabotropic agonist 1s,3r-aminocyclopentane dicarboxylic acid from micropipettes onto the stratum oriens/alveus border caused a long lasting (more than 90 min) decrease of field-excitatory postsynaptic potentials in the strata radiatum and lacunosum-moleculare. The GABAB antagonist CGP 35348 (100 microM in the perfusion fluid) partially and reversibly blocked this effect. Vasoactive intestinal polypeptide- (0.1 microM in the bath) excited neurons with response and firing properties characteristic for interneurons at the oriens/alveus border. Local pressure application of vasoactive intestinal polypeptide (10 microM) to the alveus region led, after a brief (2 min) and small (10%) increase, to a longer lasting (30-50 min) decrease (by 20-30%) in the slope of the field-excitatory postsynaptic potential in strata radiatum and lacunosum-moleculare. This action was completely blocked by bath application of CGP 35348. Local application of tetrodotoxin in the stratum oriens/alveus region markedly increased the slope of evoked dendritic excitatory postsynaptic potentials, and caused multiple firing of pyramidal cells. Thus, stratum oriens/alveus interneurons have a profound inhibitory effect on signal transmission in the apical dendritic area of CA1, which is, at least in part, mediated by GABAB receptors. It appears that the GABAB receptor-mediated effect in stratum lacunosum-moleculare is produced by vasoactive intestinal polypeptide-sensitive interneurons.