A Novel Pot-Economy Approach to the Synthesis of Triantennary GalNAc-Oligonucleotide.

N-Acetylgalactosamine (GalNAc) is an efficient and multifunctional delivery tool in the development and synthesis of chemically modified oligonucleotide therapeutics (conjugates). Such therapeutics demonstrate improved potency in vivo due to the selective and efficient delivery to hepatocytes in the liver via receptor-mediated endocytosis, which is what drives the high interest in this molecule. The ways to synthesize such structures are relatively new and have not been optimized in terms of the yields and stages both in lab and large-scale synthesis.

Phenotypic assessment of antiviral activity for spiro-annulated oxepanes and azepenes.

Evolutionary potential of viruses can result in outbreaks of well-known viruses and emergence of novel ones. Pharmacological methods of intervening the reproduction of various less popular, but not less important viruses are not available, as well as the spectrum of antiviral activity for most known compounds. In the framework of chemical biology paradigm, characterization of antiviral activity spectrum of new compounds allows to extend the antiviral chemical space and provides new important structure-activity relationships for data-driven drug discovery.

A Complex of Marine Geophysical Methods for Studying Gas Emission Process on the Arctic Shelf.

The Russian sector of the arctic shelf is the longest in the world. Quite a lot of places of massive discharge of bubble methane from the seabed into the water column and further into the atmosphere were found there. This natural phenomenon requires an extensive complex of geological, biological, geophysical, and chemical studies.

Inhibition of autophagic flux differently modulates cannabidiol-induced death in 2D and 3D glioblastoma cell cultures.

Radiotherapy combined with chemotherapy is the major treatment modality for human glioblastoma multiforme (GBM). GBMs eventually relapse after treatment and the average survival of GBM patients is less than two years. There is some evidence that cannabidiol (CBD) can induce cell death and increases the radiosensitivity of GBM by enhancing apoptosis.

Correction: Inhibition of ATM kinase upregulates levels of cell death induced by cannabidiol and γ-irradiation in human glioblastoma cells.

[This corrects the article DOI: 10.18632/oncotarget.26582.

Inhibition of ATM kinase upregulates levels of cell death induced by cannabidiol and γ-irradiation in human glioblastoma cells.

Despite advances in glioblastoma (GBM) therapy, prognosis of the disease remains poor with a low survival rate. Cannabidiol (CBD) can induce cell death and enhance radiosensitivity of GBM but not normal astrocytes. Inhibition of ATM kinase is an alternative mechanism for radiosensitization of cancer cells.

Regulation of human glioblastoma cell death by combined treatment of cannabidiol, γ-radiation and small molecule inhibitors of cell signaling pathways.

Glioblastoma (GBM) is the most common primary malignant brain tumor in adults. The challenging problem in cancer treatment is to find a way to upregulate radiosensitivity of GBM while protecting neurons and neural stem/progenitor cells in the brain. The goal of the present study was upregulation of the cytotoxic effect of γ-irradiation in GBM by non-psychotropic and non-toxic cannabinoid, cannabidiol (CBD).

Fragment-Based Discovery of 5-Arylisatin-Based Inhibitors of Matrix Metalloproteinases 2 and 13.

Matrix metalloproteinases (MMPs) are well-established targets for several pathologies. In particular, MMP-2 and MMP-13 play a prominent role in cancer progression. In this study, a structure-based screening campaign was applied to prioritize metalloproteinase-oriented fragments.

2,3,5,6-Tetramethylpyrazine (TMP) down-regulated arsenic-induced heme oxygenase-1 and ARS2 expression by inhibiting Nrf2, NF-κB, AP-1 and MAPK pathways in human proximal tubular cells.

Our recent study demonstrated that sodium arsenite at a clinically relevant dose induced nephrotoxicity in human renal proximal tubular epithelial cell line HK-2, which could be inhibited by natural product 2,3,5,6-tetramethylpyrazine (TMP) with antioxidant activity. The present study demonstrated that arsenic exposure resulted in protein and enzymatic induction of heme oxygenase-1 (HO-1) in dose- and time-dependent manners in HK-2 cells. Blocking HO-1 enzymatic activity by zinc protoporphyrin (ZnPP) augmented arsenic-induced apoptosis, ROS production and mitochondrial dysfunction, suggesting a critical role for HO-1 as a renal protectant in this procession.

Regulation of viability, differentiation and death of human melanoma cells carrying neural stem cell biomarkers: a possibility for neural trans-differentiation.

During embryonic development, melanoblasts, the precursors of melanocytes, emerge from a subpopulation of the neural crest stem cells and migrate to colonize skin. Melanomas arise during melanoblast differentiation into melanocytes and from young proliferating melanocytes through somatic mutagenesis and epigenetic regulations. In the present study, we used several human melanoma cell lines from the sequential phases of melanoma development (radial growth phase, vertical growth phase and metastatic phase) to compare: (i) the frequency and efficiency of the induction of cell death via apoptosis and necroptosis; (ii) the presence of neural and cancer stem cell biomarkers as well as death receptors, DR5 and FAS, in both adherent and spheroid cultures of melanoma cells; (iii) anti-apoptotic effects of the endogenous production of cytokines and (iv) the ability of melanoma cells to perform neural trans-differentiation.

Radiation-induced glioblastoma signaling cascade regulates viability, apoptosis and differentiation of neural stem cells (NSC).

Ionizing radiation alone or in combination with chemotherapy is the main treatment modality for brain tumors including glioblastoma. Adult neurons and astrocytes demonstrate substantial radioresistance; in contrast, human neural stem cells (NSC) are highly sensitive to radiation via induction of apoptosis. Irradiation of tumor cells has the potential risk of affecting the viability and function of NSC.

Tetramethylpyrazine (TMP) protects against sodium arsenite-induced nephrotoxicity by suppressing ROS production, mitochondrial dysfunction, pro-inflammatory signaling pathways and programed cell death.

Although kidney is a target organ of arsenic cytotoxicity, the underlying mechanisms of arsenic-induced nephrotoxicity remain poorly understood. As tetramethylpyrazine (TMP) has recently been found to be a renal protectant in multiple kidney injuries, we hypothesize that TMP could suppress arsenic nephrotoxicity. In this study, human renal proximal tubular epithelial cell line HK-2 was used to elucidate the precise mechanisms of arsenic nephrotoxicity as well as the protective mechanism of TMP in these cells.

A role for TRAIL/TRAIL-R2 in radiation-induced apoptosis and radiation-induced bystander response of human neural stem cells.

Adult neurons, which are terminally differentiated cells, demonstrate substantial radioresistance. In contrast, human neural stem cells (NSC), which have a significant proliferative capacity, are highly sensitive to ionizing radiation. Cranial irradiation that is widely used for treatment of brain tumors may induce death of NSC and further cause substantial cognitive deficits such as impairing learning and memory.

Induction of apoptotic death and retardation of neuronal differentiation of human neural stem cells by sodium arsenite treatment.

Chronic arsenic toxicity is a global health problem that affects more than 100 million people worldwide. Long-term health effects of inorganic sodium arsenite in drinking water may result in skin, lung and liver cancers and in severe neurological abnormalities. We investigated in the present study whether sodium arsenite affects signaling pathways that control cell survival, proliferation and neuronal differentiation of human neural stem cells (NSC).

Sodium arsenite exposure inhibits AKT and Stat3 activation, suppresses self-renewal and induces apoptotic death of embryonic stem cells.

Sodium arsenite exposure at concentration >5 μM may induce embryotoxic and teratogenic effects in animal models. Long-term health effects of sodium arsenite from contaminated drinking water may result in different forms of cancer and neurological abnormalities. As cancer development processes seem to be originated in stem cells, we have chosen to examine the effects of sodium arsenite on signaling pathways and the corresponding transcription factors that regulate cell viability and self-renewal in mouse embryonic stem cells (ESC) and mouse neural stem/precursor cells.

Regulation of apoptosis in human melanoma and neuroblastoma cells by statins, sodium arsenite and TRAIL: a role of combined treatment versus monotherapy.

Treatment of melanoma cells by sodium arsenite or statins (simvastatin and lovastatin) dramatically modified activities of the main cell signaling pathways resulting in the induction of heme oxygenase-1 (HO-1) and in a downregulation of cyclooxygenase-2 (COX-2) protein levels. Through heme degradation and the production of carbon monoxide and biliverdin, HO-1 plays a protective role in different scenario of oxidative stress followed by mitochondrial apoptosis. Both sodium arsenite and statins could be efficient inducers of apoptosis in some melanoma cell lines, but often exhibited only modest proapoptotic activity in others, due to numerous protective mechanisms.

Radiation response and regulation of apoptosis induced by a combination of TRAIL and CHX in cells lacking mitochondrial DNA: a role for NF-κB-STAT3-directed gene expression.

Mitochondrial DNA depleted (ρ(0)) human skin fibroblasts (HSF) with suppressed oxidative phosphorylation were characterized by significant changes in the expression of 2100 nuclear genes, encoding numerous protein classes, in NF-κB and STAT3 signaling pathways, and by decreased activity of mitochondrial death pathway, compared to the parental ρ(+) HSF. In contrast, the extrinsic TRAIL/TRAIL-Receptor mediated death pathway remained highly active, and exogenous TRAIL in a combination with cycloheximide (CHX) induced higher levels of apoptosis in ρ(0) cells compared to ρ(+) HSF. Global gene expression analysis using microarray and qRT-PCR demonstrated that mRNA expression levels of many growth factors and their adaptor proteins (FGF13, HGF, IGFBP4, IGFBP6, and IGFL2), cytokines (IL6, ΙL17Β, ΙL18, ΙL19, and ΙL28Β) and cytokine receptors (IL1R1, IL21R, and IL31RA) were substantially decreased after mitochondrial DNA depletion.

Suppression of the proinflammatory response of metastatic melanoma cells increases TRAIL-induced apoptosis.

Melanoma is the most lethal form of human skin cancer. However, only limited chemotherapy is currently available for the metastatic stage of the disease. Since chemotherapy, radiation and sodium arsenite treatment operate mainly through induction of the intrinsic mitochondrial pathway, a strongly decreased mitochondrial function in metastatic melanoma cells, could be responsible for low efficacy of the conventional therapy of melanoma.

Radiation induced non-targeted response: mechanism and potential clinical implications.

Generations of students in radiation biology have been taught that heritable biological effects require direct damage to DNA. Radiation-induced non-targeted/bystander effects represent a paradigm shift in our understanding of the radiobiological effects of ionizing radiation in that extranuclear and extracellular effects may also contribute to the biological consequences of exposure to low doses of radiation. Although radiation induced bystander effects have been well documented in a variety of biological systems, including 3D human tissue samples and whole organisms, the mechanism is not known.

Regulation of early signaling and gene expression in the alpha-particle and bystander response of IMR-90 human fibroblasts.

Background: The existence of a radiation bystander effect, in which non-irradiated cells respond to signals from irradiated cells, is well established. To understand early signaling and gene regulation in bystander cells, we used a bio-informatics approach, measuring global gene expression at 30 minutes and signaling pathways between 30 minutes and 4 hours after exposure to alpha-particles in IMR-90 fibroblasts.

Methods: We used whole human genome microarrays and real time quantitative PCR to measure and validate gene expression.

Disruption of IGF-1R signaling increases TRAIL-induced apoptosis: a new potential therapy for the treatment of melanoma.

Resistance of cancer cells to apoptosis is dependent on a balance of multiple genetic and epigenetic mechanisms, which up-regulate efficacy of the surviving growth factor-receptor signaling pathways and suppress death-receptor signaling pathways. The Insulin-like Growth Factor-1 Receptor (IGF-1R) signaling pathway is highly active in metastatic melanoma cells by mediating downstream activation of PI3K-AKT and MAPK pathways and controlling general cell survival and proliferation. In the present study, we used human melanoma lines with established genotypes that represented different phases of cancer development: radial-growth-phase WM35, vertical-growth-phase WM793, metastatic LU1205 and WM9 [1].