Variation of C-terminal domain governs RNA polymerase II genomic locations and alternative splicing in eukaryotic transcription.

The C-terminal domain of RPB1 (CTD) orchestrates transcription by recruiting regulators to RNA Pol II upon phosphorylation. With CTD driving condensate formation on gene loci, the molecular mechanism behind how CTD-mediated recruitment of transcriptional regulators influences condensates formation remains unclear. Our study unveils that phosphorylation reversibly dissolves phase separation induced by the unphosphorylated CTD.

Thr phosphorylation on RNA Pol II occurs at early transcription regulating 3'-end processing.

RNA polymerase II relies on a repetitive sequence domain (YSPTSPS) within its largest subunit to orchestrate transcription. While phosphorylation on serine-2/serine-5 of the carboxyl-terminal heptad repeats is well established, threonine-4's role remains enigmatic. Paradoxically, threonine-4 phosphorylation was only detected after transcription end sites despite functionally implicated in pausing, elongation, termination, and messenger RNA processing.

Targeting of REST with rationally-designed small molecule compounds exhibits synergetic therapeutic potential in human glioblastoma cells.

Background: Glioblastoma (GBM) is an aggressive brain cancer associated with poor prognosis, intrinsic heterogeneity, plasticity, and therapy resistance. In some GBMs, cell proliferation is fueled by a transcriptional regulator, repressor element-1 silencing transcription factor (REST).

Results: Using CRISPR/Cas9, we identified GBM cell lines dependent on REST activity.

Variation of C-terminal domain governs RNA polymerase II genomic locations and alternative splicing in eukaryotic transcription.

The C-terminal domain of RPB1 (CTD) orchestrates transcription by recruiting regulators to RNA Pol II upon phosphorylation. Recent insights highlight the pivotal role of CTD in driving condensate formation on gene loci. Yet, the molecular mechanism behind how CTD-mediated recruitment of transcriptional regulators influences condensates formation remains unclear.

Novel mitochondria-targeting compounds selectively kill human leukemia cells.

Acute myeloid leukemia (AML) is a heterogeneous group of aggressive hematological malignancies commonly associated with treatment resistance, high risk of relapse, and mitochondrial dysregulation. We identified six mitochondria-affecting compounds (PS compounds) that exhibit selective cytotoxicity against AML cells in vitro. Structure-activity relationship studies identified six analogs from two original scaffolds that had over an order of magnitude difference between LD50 in AML and healthy peripheral blood mononuclear cells.

A family of conserved bacterial virulence factors dampens interferon responses by blocking calcium signaling.

Interferons (IFNs) induce an antimicrobial state, protecting tissues from infection. Many viruses inhibit IFN signaling, but whether bacterial pathogens evade IFN responses remains unclear. Here, we demonstrate that the Shigella OspC family of type-III-secreted effectors blocks IFN signaling independently of its cell death inhibitory activity.

The heart arrhythmia-linked D130G calmodulin mutation causes premature inhibitory autophosphorylation of CaMKII.

The Ca/calmodulin (CaM)-dependent kinase II (CaMKII) is well known for transmitting Ca-signals, which leads to a multitude of physiological responses. Its functionality is believed to involve CaMKII holoenzyme dynamics where trans-autophosphorylation of the crucial phosphorylation site, T286 occurs. Phosphorylation of this site does not occur when stimulated exclusively with the arrhythmia associated D130G mutant form of CaM in vitro.

Mitochondrial metabolism as a target for acute myeloid leukemia treatment.

Acute myeloid leukemias (AML) are a group of aggressive hematologic malignancies resulting from acquired genetic mutations in hematopoietic stem cells that affect patients of all ages. Despite decades of research, standard chemotherapy still remains ineffective for some AML subtypes and is often inappropriate for older patients or those with comorbidities. Recently, a number of studies have identified unique mitochondrial alterations that lead to metabolic vulnerabilities in AML cells that may present viable treatment targets.

Calmodulin downregulation in conditional knockout HeLa cells inhibits cell migration.

The study of calmodulin (CaM) functions in living cells has been tackled up to date using cell-permeant CaM inhibitors or interference-RNA methods. CaM inhibitors may lack specificity and the siRNA interference approach is challenging, as all three CaM genes expressing an identical protein in mammals have to be blocked. Therefore, we recently introduced a novel genetic system using CRISPR/Cas9-mediated gene deletion and conditional CaM expression to study the function of CaM in HeLa cells.

An Automated Differential Nuclear Staining Assay for Accurate Determination of Mitocan Cytotoxicity.

The contribution of mitochondria to oncogenic transformation is a subject of wide interest and active study. As the field of cancer metabolism becomes more complex, the goal of targeting mitochondria using various compounds that inflict mitochondrial damage (so-called mitocans) is becoming quite popular. Unfortunately, many existing cytotoxicity assays, such as those based on tetrazolium salts or resazurin require functional mitochondrial enzymes for their performance.

The impact of calmodulin on the cell cycle analyzed in a novel human cellular genetic system.

Calmodulin (CaM) is the principle mediator of the Ca signal in all eukaryotic cells. A huge variety of basic cellular processes including cell cycle control, proliferation, secretion and motility, among many others are governed by CaM, which regulates activities of myriads of target proteins. Mammalian CaM is encoded by three genes localized on different chromosomes all producing an identical protein.

Utilizing Synergistic Potential of Mitochondria-Targeting Drugs for Leukemia Therapy.

Acute myeloid leukemia (AML) is an aggressive group of cancers with high mortality rates and significant relapse risks. Current treatments are insufficient, and new therapies are needed. Recent discoveries suggest that AML may be particularly sensitive to chemotherapeutics that target mitochondria.

A mechanism for increased sensitivity of acute myeloid leukemia to mitotoxic drugs.

Mitochondria play a central and multifunctional role in the progression of tumorigenesis. Although many recent studies have demonstrated correlations between mitochondrial function and genetic makeup or originating tissue, it remains unclear why some cancers are more susceptible to mitocans (anticancer drugs that target mitochondrial function to mediate part or all of their effect). Moreover, fundamental questions of efficacy and mechanism of action in various tumor types stubbornly remain.

ALG-2 participates in recovery of cells after plasma membrane damage by electroporation and digitonin treatment.

The calcium binding protein ALG-2 is upregulated in several types of cancerous tissues and cancer cell death may be a consequence of ALG-2 downregulation. Novel research suggests that ALG-2 is involved in membrane repair mechanisms, in line with several published studies linking ALG-2 to processes of membrane remodeling and transport, which may contribute to the fitness of cells or protect them from damage. To investigate the involvement of ALG-2 in cell recovery after membrane damage we disrupted the PDCD6 gene encoding the ALG-2 protein in DT-40 cells and exposed them to electroporation.

EGFR mutations and tumor metastases in patients with nonsmall cell lung cancer in the South of Russia.

Purpose: To assess the frequencies of somatic EGFR mutations in the tumor tissues of patients with non-small cell lung cancer (NSCLC) residing in the South of Russia (SR), and to define the relationship between genetic subtypes of NSCLC and the emergence of different types of metastases.

Methods: DNA was extracted from formalin-fixed parrafin embedded (FFPE) samples of 721 patients. A total of 29 somatic EGFR mutations were detected using commercial Therascreen EGFR RGQ PCR Kit.

A Proteomics Analysis Reveals 9 Up-Regulated Proteins Associated with Altered Cell Signaling in Colon Cancer Patients.

Colorectal cancer is the second most common cancer in women and third most common cancer in men. Cell signaling alterations in colon cancer, especially in aggressive metastatic tumors, require further investigations. The present study aims to compare the expression pattern of proteins associated with cell signaling in paired tumor and non-tumor samples of patients with colon cancer, as well as to define the cluster of proteins to differentiate patients with non-metastatic (Dukes' grade B) and metastatic (Dukes' grade C&D) colon cancer.

Circulating levels of proinflammatory mediators as potential biomarkers of post-traumatic knee osteoarthritis development.

Background: The identification of biomarkers of post-traumatic osteoarthritis (PTOA) progression is of clinical importance. The aims of this study were: (1) to assess the abilities of various soluble proinflammatory mediators in plasma to distinguish patients with knee PTOA from controls; (2) to determine the correlations between the mediators in plasma and those mediators in synovial fluid (SF); and (3) to explore the associations of the mediators with radiographic PTOA severity.

Materials And Methods: The concentrations of IL-1β, IL-6, IL-18, TNFα, and leptin were measured using ELISA.

OSCAR-collagen signaling in monocytes plays a proinflammatory role and may contribute to the pathogenesis of rheumatoid arthritis.

Osteoclast-associated receptor (OSCAR) is an activating receptor expressed by human myeloid cells. Collagen type I (ColI) and collagen type II (ColII) serve as ligands for OSCAR. OSCAR-collagen interaction stimulates RANK-dependent osteoclastogenesis.

Collagen induces maturation of human monocyte-derived dendritic cells by signaling through osteoclast-associated receptor.

Osteoclast-associated receptor (OSCAR) is widely expressed on human myeloid cells. Collagen types (Col)I, II, and III have been described as OSCAR ligands, and ColII peptides can induce costimulatory signaling in receptor activator for NF-κB-dependent osteoclastogenesis. In this study, we isolated collagen as an OSCAR-interacting protein from the membranes of murine osteoblasts.

Reevaluation of the proposed autocrine proliferative function of prolactin in breast cancer.

The pituitary hormone prolactin (PRL) has been implicated in tumourigenesis. Expression of PRL and its receptor (PRLR) was reported in human breast epithelium and breast cancer cells. It was suggested that PRL may act as an autocrine/paracrine growth factor.

Significance of calcium binding, tyrosine phosphorylation, and lysine trimethylation for the essential function of calmodulin in vertebrate cells analyzed in a novel gene replacement system.

Calmodulin (CaM) was shown to be essential for survival of lower eukaryotes by gene deletion experiments. So far, no CaM gene deletion was reported in higher eukaryotes. In vertebrates, CaM is expressed from several genes, which encode an identical protein, making it difficult to generate a model system to study the effect of CaM gene deletion.

Regulation of the ligand-dependent activation of the epidermal growth factor receptor by calmodulin.

Calmodulin (CaM) is the major component of calcium signaling pathways mediating the action of various effectors. Transient increases in the intracellular calcium level triggered by a variety of stimuli lead to the formation of Ca(2+)/CaM complexes, which interact with and activate target proteins. In the present study the role of Ca(2+)/CaM in the regulation of the ligand-dependent activation of the epidermal growth factor receptor (EGFR) has been examined in living cells.

Discovery of the improved antagonistic prolactin variants by library screening.

Prolactin (PRL), a potent growth stimulator of the mammary epithelium, has been suggested to be a factor contributing to the development and progression of breast and prostate cancer. Several PRL receptor (PRLR) antagonists have been identified in the past decades, but their in vivo growth inhibitory potency was restricted by low receptor affinity, rendering them pharmacologically unattractive for clinical treatment. Thus, higher receptor affinity is essential for the development of improved PRLR antagonistic variants with improved in vivo potency.

Prolactin and oestrogen synergistically regulate gene expression and proliferation of breast cancer cells.

The pituitary hormone prolactin (PRL) plays an important role in mammary gland development. It was also suggested to contribute to breast cancer progression. In vivo data strongly supported a crucial role of PRL in promoting tumour growth; however, PRL demonstrated only a weak, if any, pro-proliferative effect on cancer cells in vitro.