Re-Sensitization of Resistant Ovarian Cancer SKOV3/CDDP Cells to Cisplatin by Curcumin Pre-Treatment.

A major challenging problem facing effective ovarian cancer therapy is cisplatin resistance. Re-sensitization of cisplatin-resistant ovarian cancer cells to cisplatin (CDDP) has become a critical issue. Curcumin (CUR), the most abundant dietary polyphenolic curcuminoids derived from turmeric (), has achieved previously significant anti-cancer effects against human ovarian adenocarcinoma SKOV-3/CDDP cisplatin-resistant cells by inhibition the gene expression of the antioxidant enzymes (, , , and ), transcription factor and signaling pathway (//).

Disruption of RNA Splicing Increases Vulnerability of Cells to DNA-PK Inhibitors.

DNA-dependent protein kinase (DNA-PK) is a key effector of non-homologous end joining (NHEJ)-mediated double-strand break (DSB) repair. Since its identification, a substantial body of evidence has demonstrated that DNA-PK is frequently overexpressed in cancer, plays a critical role in tumor development and progression, and is associated with poor prognosis in cancer patients. Recent studies have also uncovered novel functions of DNA-PK, shifting the paradigm of the role of DNA-PK in oncogenesis and renewing interest in targeting DNA-PK for cancer therapy.

The Nitro Group Reshapes the Effects of Pyrido[3,4-]quinazoline Derivatives on DYRK/CLK Activity and RNA Splicing in Glioblastoma Cells.

Serine-threonine protein kinases of the DYRK and CLK families regulate a variety of vital cellular functions. In particular, these enzymes phosphorylate proteins involved in pre-mRNA splicing. Targeting splicing with pharmacological DYRK/CLK inhibitors emerged as a promising anticancer strategy.

Key Proteins of Replication Stress Response and Cell Cycle Control as Cancer Therapy Targets.

Replication stress (RS) is a characteristic state of cancer cells as they tend to exchange precision of replication for fast proliferation and increased genomic instability. To overcome the consequences of improper replication control, malignant cells frequently inactivate parts of their DNA damage response (DDR) pathways (the ATM-CHK2-p53 pathway), while relying on other pathways which help to maintain replication fork stability (ATR-CHK1). This creates a dependency on the remaining DDR pathways, vulnerability to further destabilization of replication and synthetic lethality of DDR inhibitors with common oncogenic alterations such as mutations of , , , amplifications of , and others.

Genetically modified mice as a tool for the study of human diseases.

Modeling a human disease is an essential part of biomedical research. The recent advances in the field of molecular genetics made it possible to obtain genetically modified animals for the study of various diseases. Not only monogenic disorders but also chromosomal and multifactorial disorders can be mimicked in lab animals due to genetic modification.

Contact Inhibition of Proliferation Is Accompanied by Expression of the PHF10D Subunit of the Chromatin Remodeling Complex PBAF in Mouse and Human Cell Lines.

PHF10 is a subunit of the PBAF complex, which regulates the expression of many genes in developing and maturing organisms. PHF10 has four isoforms that differ in domain structure. The PHF10A isoform, containing a DPF domain at the C-terminus and 46 amino acids at the N-terminus, is necessary for the expression of proliferation genes; the functions of the other isoforms are less studied.

A novel chromatin-remodeling complex variant, dcPBAF, is involved in maintaining transcription in differentiated neurons.

The Polybromo-associated BAF (BRG1- or BRM-associated factors) (PBAF) chromatin-remodeling complex is essential for transcription in mammalian cells. In this study, we describe a novel variant of the PBAF complex from differentiated neuronal cells, called dcPBAF, that differs from the canonical PBAF existing in proliferating neuroblasts. We describe that in differentiated adult neurons, a specific subunit of PBAF, PHF10, is replaced by a PHF10 isoform that lacks N- and C-terminal domains (called PHF10D).

New Approach for Studying of Isoforms and High-Homology Proteins in Mammalian Cells.

In mammals, a large number of proteins are expressed as more than one isoform, resulting in the increased diversity of their proteome. Understanding the functions of isoforms is very important, since individual isoforms of the same protein can have oncogenic or pathogenic properties, or serve as disease markers. The high homology of isoforms with ubiquitous expression makes it difficult to study them.

Potentiation of Cisplatin Cytotoxicity in Resistant Ovarian Cancer SKOV3/Cisplatin Cells by Quercetin Pre-Treatment.

Previously, we demonstrated that the overexpression of antioxidant enzymes (, , , , and ), transcription factor , and the signaling pathway () contribute to the cisplatin resistance of SKOV-3/CDDP ovarian cells, and treatment with quercetin (QU) alone has been shown to inhibit the expression of these genes. The aim of this study was to expand the previous data by examining the efficiency of reversing cisplatin resistance and investigating the underlying mechanism of pre-treatment with QU followed by cisplatin in the same ovarian cancer cells. The pre-incubation of SKOV-3/CDDP cells with quercetin at an optimum dose prior to treatment with cisplatin exhibited a significant cytotoxic effect.

CDK8 and CDK19: positive regulators of signal-induced transcription and negative regulators of Mediator complex proteins.

We have conducted a detailed transcriptomic, proteomic and phosphoproteomic analysis of CDK8 and its paralog CDK19, alternative enzymatic components of the kinase module associated with transcriptional Mediator complex and implicated in development and diseases. This analysis was performed using genetic modifications of CDK8 and CDK19, selective CDK8/19 small molecule kinase inhibitors and a potent CDK8/19 PROTAC degrader. CDK8/19 inhibition in cells exposed to serum or to agonists of NFκB or protein kinase C (PKC) reduced the induction of signal-responsive genes, indicating a pleiotropic role of Mediator kinases in signal-induced transcriptional reprogramming.

Inhibition of Cyclin-Dependent Kinases 8/19 Restricts Bacterial and Virus-Induced Inflammatory Responses in Monocytes.

Hyperactivation of the immune system remains a dramatic, life-threatening complication of viral and bacterial infections, particularly during pneumonia. Therapeutic approaches to counteract local and systemic outbreaks of cytokine storm and to prevent tissue damage remain limited. Cyclin-dependent kinases 8 and 19 (CDK8/19) potentiate transcriptional responses to the altered microenvironment, but CDK8/19 potential in immunoregulation is not fully understood.

Genetically Engineered Mice Unveil In Vivo Roles of the Mediator Complex.

The Mediator complex is a multi-subunit protein complex which plays a significant role in the regulation of eukaryotic gene transcription. It provides a platform for the interaction of transcriptional factors and RNA polymerase II, thus coupling external and internal stimuli with transcriptional programs. Molecular mechanisms underlying Mediator functioning are intensively studied, although most often using simple models such as tumor cell lines and yeast.

Therapy-Induced Tumor Cell Senescence: Mechanisms and Circumvention.

Plasticity of tumor cells (multitude of molecular regulation pathways) allows them to evade cytocidal effects of chemo- and/or radiation therapy. Metabolic adaptation of the surviving cells is based on transcriptional reprogramming. Similarly to the process of natural cell aging, specific features of the survived tumor cells comprise the therapy-induced senescence phenotype.

Graphene Oxide Nanosurface Reduces Apoptotic Death of HCT116 Colon Carcinoma Cells Induced by Zirconium Trisulfide Nanoribbons.

Due to their chemical, mechanical, and optical properties, 2D ultrathin nanomaterials have significant potential in biomedicine. However, the cytotoxicity of such materials, including their mutual increase or decrease, is still not well understood. We studied the effects that graphene oxide (GO) nanolayers (with dimensions 0.

Synthetic Pathways and the Therapeutic Potential of Quercetin and Curcumin.

Polyphenols are considered popular ingredients in the pharmaceutical and medical fields due to their preventive and therapeutic properties. However, the potential effects and mechanisms of action of individual polyphenols remain largely unknown. Herein, we analyzed recent data on the synthetic pathways, features, and similarity of the properties of quercetin, as the most famous flavonoid, and curcumin, a representative of curcuminoids that despite their anti-oxidant activity, also have a pro-oxidant effect, depending on the concentration and the cellular environment.

Limitations of Tamoxifen Application for In Vivo Genome Editing Using Cre/ER System.

Inducible Cre-dependent systems are frequently used to produce both conditional knockouts and transgenic mice with regulated expression of the gene of interest. Induction can be achieved by doxycycline-dependent transcription of the wild type gene or OH-tamoxifen-dependent nuclear translocation of the chimeric Cre/ER protein. However, both of these activation strategies have some limitations.

Suppression of the Antioxidant System and PI3K/Akt/mTOR Signaling Pathway in Cisplatin-Resistant Cancer Cells by Quercetin.

We studied the effect of quercetin on ovarian adenocarcinoma SKOV-3 cell line and isogenic subline SKOV-3/CDDP resistant to the anticancer drug cisplatin. It was found that in resistant cells, quercetin in a concentration of 100 μM that causes a decrease in the cell viability suppressed the expression of genes encoding the key antioxidant enzymes (SOD2, CAT, GPX1, and HO-1), transcription factor Nrf2, and kinases of the PI3K/Akt/mTOR signaling pathway. In parental cells, quercetin, on the contrary, increased the expression of these genes.

Alternative RNA splicing modulates ribosomal composition and determines the spatial phenotype of glioblastoma cells.

Glioblastoma (GBM) is characterized by exceptionally high intratumoral heterogeneity. However, the molecular mechanisms underlying the origin of different GBM cell populations remain unclear. Here, we found that the compositions of ribosomes of GBM cells in the tumour core and edge differ due to alternative RNA splicing.

The Thioredoxin System of Mammalian Cells and Its Modulators.

Oxidative stress involves the increased production and accumulation of free radicals, peroxides, and other metabolites that are collectively termed reactive oxygen species (ROS), which are produced as by-products of aerobic respiration. ROS play a significant role in cell homeostasis through redox signaling and are capable of eliciting damage to macromolecules. Multiple antioxidant defense systems have evolved to prevent dangerous ROS accumulation in the body, with the glutathione and thioredoxin/thioredoxin reductase (Trx/TrxR) systems being the most important.

Suppression of PI3K/Akt/mTOR Signaling Pathway and Antioxidant System and Reversal of Cancer Cells Resistance to Cisplatin under the Effect of Curcumin.

The effect of curcumin on the resistance of SKOV-3 human ovarian adenocarcinoma cells to cisplatin was studied. It was found that curcumin induced "reversal" of cancer cells resistance, which was associated with suppression of the expression of genes encoding the key antioxidant enzymes (SOD1, SOD2, CAT, GPX1, and HO-1) and transcription factor Nrf2 and a decrease in the expression of genes encoding kinases of the PI3K/Akt/mTOR signaling pathway. The obtained results confirm the role of redox-dependent regulation in the "reversal" of cancer cells resistance to cisplatin.

Evaluation of New Antimicrobial Agents Based on (1-Indol-3-yl)methylium Salts: Activity, Toxicity, Suppression of Experimental Sepsis in Mice.

The antimicrobial activity and toxicity of three novel synthetic antibacterial agents containing (1-indol-3-yl)methylium fragment were studied in vitro and in vivo. All compounds in vitro revealed high activity (minimal inhibitory concentration (MIC) 0.13-1.

Novel O-acylated (E)-3-aryl-6,7-dihydrobenzisoxazol-4(5H)-one oximes targeting HSP90-HER2 axis in breast cancer cells.

Novel O-acylated (E)-3-aryl-6,7-dihydrobenzisoxazol-4(5H)-one oximes were designed as potential HSP90 inhibitors. A series of the compounds was synthesized by oximation of (E)-3-aryl-6,7-dihydrobenzisoxazol-4(5H)-ones followed by O-acylation with acylamidobenzoic acids. The obtained compounds showed an antiproliferative effect on three breast cancer cell lines (MCF7, MDA-MB-231 and HCC1954).

Conserved Structure and Evolution of DPF Domain of PHF10-The Specific Subunit of PBAF Chromatin Remodeling Complex.

Transcription activation factors and multisubunit coactivator complexes get recruited at specific chromatin sites via protein domains that recognize histone modifications. Single PHDs (plant homeodomains) interact with differentially modified H3 histone tails. Double PHD finger (DPF) domains possess a unique structure different from PHD and are found in six proteins: histone acetyltransferases MOZ and MORF; chromatin remodeling complex BAF (DPF1-3); and chromatin remodeling complex PBAF (PHF10).

Copper-Containing Nanoparticles and Organic Complexes: Metal Reduction Triggers Rapid Cell Death via Oxidative Burst.

Copper-containing agents are promising antitumor pharmaceuticals due to the ability of the metal ion to react with biomolecules. In the current study, we demonstrate that inorganic Cu in the form of oxide nanoparticles (NPs) or salts, as well as Cu ions in the context of organic complexes (oxidation states +1, +1.5 and +2), acquire significant cytotoxic potency (2-3 orders of magnitude determined by IC values) in combinations with N-acetylcysteine (NAC), cysteine, or ascorbate.

PHF10 subunit of PBAF complex mediates transcriptional activation by MYC.

The PBAF complex, a member of SWI/SNF family of chromatin remodelers, plays an essential role in transcriptional regulation. We revealed a disease progression associated elevation of PHF10 subunit of PBAF in clinical melanoma samples. In melanoma cell lines, PHF10 interacts with MYC and facilitates the recruitment of PBAF complex to target gene promoters, therefore, augmenting MYC transcriptional activation of genes involved in the cell cycle progression.