COVID-19-The Shift of Homeostasis into Oncopathology or Chronic Fibrosis in Terms of Female Reproductive System Involvement.

The COVID-19 pandemic caused by the SARS-CoV-2 coronavirus remains a global public health concern due to the systemic nature of the infection and its long-term consequences, many of which remain to be elucidated. SARS-CoV-2 targets endothelial cells and blood vessels, altering the tissue microenvironment, its secretion, immune-cell subpopulations, the extracellular matrix, and the molecular composition and mechanical properties. The female reproductive system has high regenerative potential, but can accumulate damage, including due to SARS-CoV-2. COVID-19 is profibrotic and can change the tissue microenvironment toward an oncogenic niche. This makes COVID-19 and its consequences one of the potential regulators of a homeostasis shift toward oncopathology and fibrosis in the tissues of the female reproductive system. We are looking at SARS-CoV-2-induced changes at all levels in the female reproductive system.

Aerial warfare: An inducible production of volatile bioactive metabolites in a novel species of Scytinostroma sp.

Antimicrobial volatile organic compounds (VOCs) may provide fungi an advantage over other competing microorganisms. As these defensive metabolites are often produced in response to microbial competitors, they are easily overlooked in axenic cultures. We used media supplemented with spent medium from Candida albicans to induce the expression of a broad-spectrum antimicrobial response in a previously uncharacterised white-rot fungus, Scytinostroma sp. Crude extractions of Scytinostroma sp. metabolites were found to be cytotoxic to fibroblast cells and antimicrobial to filamentous fungi, yeasts and Gram-positive bacteria. Volatile antimicrobial activity was observed for Scytinostroma sp. cultures and metabolite extracts using antimicrobial assays in bi-compartmentalised plates. Culture headspace analysis using solid-phase microextraction (SPME) coupled to gas chromatography-mass spectrometry (GC-MS) revealed a pronounced shift in Scytinostroma sp. VOCs when cultured on media supplemented with C. albicans spent medium. We observed a significant increase in the levels of 45 identified VOCs, including 7 metabolites with reported antimicrobial activity. Using preparative HPLC combined with GC-MS, we determined that isovelleral is likely to be the main broad-spectrum antimicrobial metabolite produced by Scytinostroma sp. Isovelleral is a sesquiterpene dialdehyde with both antibiotic and antifeedant properties, previously detected in fruit bodies of other Basidiomycetes.

Non-Tumor Cells within the Tumor Microenvironment-The "Eminence Grise" of the Glioblastoma Pathogenesis and Potential Targets for Therapy.

Glioblastoma (GBM) is the most common malignancy of the central nervous system in adults. GBM has high levels of therapy failure and its prognosis is usually dismal. The phenotypic heterogeneity of the tumor cells, dynamic complexity of non-tumor cell populations within the GBM tumor microenvironment (TME), and their bi-directional cross-talk contribute to the challenges of current therapeutic approaches. Herein, we discuss the etiology of GBM, and describe several major types of non-tumor cells within its TME, their impact on GBM pathogenesis, and molecular mechanisms of such an impact. We also discuss their value as potential therapeutic targets or prognostic biomarkers, with reference to the most recent works on this subject. We conclude that unless all "key player" populations of non-tumor cells within the TME are considered, no breakthrough in developing treatment for GBM can be achieved.

Improving Efficiency of Direct Pro-Neural Reprogramming: Much-Needed Aid for Neuroregeneration in Spinal Cord Injury.

Spinal cord injury (SCI) is a medical condition affecting ~2.5-4 million people worldwide. The conventional therapy for SCI fails to restore the lost spinal cord functions; thus, novel therapies are needed. Recent breakthroughs in stem cell biology and cell reprogramming revolutionized the field. Of them, the use of neural progenitor cells (NPCs) directly reprogrammed from non-neuronal somatic cells without transitioning through a pluripotent state is a particularly attractive strategy. This allows to "scale up" NPCs in vitro and, via their transplantation to the lesion area, partially compensate for the limited regenerative plasticity of the adult spinal cord in humans. As recently demonstrated in non-human primates, implanted NPCs contribute to the functional improvement of the spinal cord after injury, and works in other animal models of SCI also confirm their therapeutic value. However, direct reprogramming still remains a challenge in many aspects; one of them is low efficiency, which prevents it from finding its place in clinics yet. In this review, we describe new insights that recent works brought to the field, such as novel targets (mitochondria, nucleoli, G-quadruplexes, and others), tools, and approaches (mechanotransduction and electrical stimulation) for direct pro-neural reprogramming, including potential ones yet to be tested.

The growth hormone receptor interacts with transcriptional regulator HMGN1 upon GH-induced nuclear translocation.

Growth hormone (GH) actions are mediated through binding to its cell-surface receptor, the GH receptor (GHR), with consequent activation of downstream signalling. However, nuclear GHR localisation has also been observed and is associated with increased cancer cell proliferation. Here we investigated the functional implications of nuclear translocation of the GHR in the human endometrial cancer cell-line, RL95-2, and human mammary epithelial cell-line, MCF-10A. We found that following GH treatment, the GHR rapidly translocates to the nucleus, with maximal localisation at 5-10 min. Combined immunoprecipitation-mass spectrometry analysis of RL95-2 whole cell lysates identified 40 novel GHR binding partners, including the transcriptional regulator, HMGN1. Moreover, microarray analysis demonstrated that the gene targets of HMGN1 were differentially expressed following GH treatment, and co-immunoprecipitation showed that HMGN1 associates with the GHR in the nucleus. Therefore, our results suggest that GHR nuclear translocation might mediate GH actions via interaction with chromatin factors that then drive changes in specific downstream transcriptional programs.

Developmentally regulated ceramide synthase 6 increases mitochondrial Ca2+ loading capacity and promotes apoptosis.

Ceramides, which are membrane sphingolipids and key mediators of cell-stress responses, are generated by a family of (dihydro) ceramide synthases (Lass1-6/CerS1-6). Here, we report that brain development features significant increases in sphingomyelin, sphingosine, and most ceramide species. In contrast, C(16:0)-ceramide was gradually reduced and CerS6 was down-regulated in mitochondria, thereby implicating CerS6 as a primary ceramide synthase generating C(16:0)-ceramide. Investigations into the role of CerS6 in mitochondria revealed that ceramide synthase down-regulation is associated with dramatically decreased mitochondrial Ca(2+)-loading capacity, which could be rescued by addition of ceramide. Selective CerS6 complexing with the inner membrane component of the mitochondrial permeability transition pore was detected by immunoprecipitation. This suggests that CerS6-generated ceramide could prevent mitochondrial permeability transition pore opening, leading to increased Ca(2+) accumulation in the mitochondrial matrix. We examined the effect of high CerS6 expression on cell survival in primary oligodendrocyte (OL) precursor cells, which undergo apoptotic cell death during early postnatal brain development. Exposure of OLs to glutamate resulted in apoptosis that was prevented by inhibitors of de novo ceramide biosynthesis, myriocin and fumonisin B1. Knockdown of CerS6 with siRNA reduced glutamate-triggered OL apoptosis, whereas knockdown of CerS5 had no effect: the pro-apoptotic role of CerS6 was not stimulus-specific. Knockdown of CerS6 with siRNA improved cell survival in response to nerve growth factor-induced OL apoptosis. Also, blocking mitochondrial Ca(2+) uptake or decreasing Ca(2+)-dependent protease calpain activity with specific inhibitors prevented OL apoptosis. Finally, knocking down CerS6 decreased calpain activation. Thus, our data suggest a novel role for CerS6 in the regulation of both mitochondrial Ca(2+) homeostasis and calpain, which appears to be important in OL apoptosis during brain development.

The long winding road to the safer glucocorticoid receptor (GR) targeting therapies.

Glucocorticoids (Gcs) are widely used to treat inflammatory diseases and hematological malignancies, and despite the introduction of novel anti-inflammatory and anti-cancer biologics, the use of inexpensive and effective Gcs is expected to grow. Unfortunately, chronic treatment with Gcs results in multiple atrophic and metabolic side effects. Thus, the search for safer glucocorticoid receptor (GR)-targeted therapies that preserve therapeutic potential of Gcs but result in fewer adverse effects remains highly relevant. Development of selective GR agonists/modulators (SEGRAM) with reduced side effects, based on the concept of dissociation of GR transactivation and transrepression functions, resulted in limited success, and currently focus has shifted towards partial GR agonists. Additional approach is the identification and inhibition of genes associated with Gcs specific side effects. Others and we recently identified GR target genes REDD1 and FKBP51 as key mediators of Gcs-induced atrophy, and selected and validated candidate molecules for REDD1 blockage including PI3K/Akt/mTOR inhibitors. In this review, we summarized classic and contemporary approaches to safer GR-mediated therapies including unique concept of Gcs combination with REDD1 inhibitors. We discussed protective effects of REDD1 inhibitors against Gcs-induced atrophy in skin and bone and underlined the translational potential of this combination for further development of safer and effective Gcs-based therapies.

The Extracellular Matrix-Derived Biomarkers for Diagnosis, Prognosis, and Personalized Therapy of Malignant Tumors.

The tumor biomarkers already have proven clinical value and have become an integral part in cancer management and modern translational oncology. The tumor tissue microenvironment (TME), which includes extracellular matrix (ECM), signaling molecules, immune and stromal cells, and adjacent non-tumorous tissue, contributes to cancer pathogenesis. Thus, TME-derived biomarkers have many clinical applications. This review is predominately based on the most recent publications (manuscripts published in a last 5 years, or seminal publications published earlier) and fills a gap in the current literature on the cancer biomarkers derived from the TME, with particular attention given to the ECM and products of its processing and degradation, ECM-associated extracellular vesicles (EVs), biomechanical characteristics of ECM, and ECM-derived biomarkers predicting response to the immunotherapy. We discuss the clinical utility of the TME-incorporating three-dimensional in vitro and ex vivo cell culture models for personalized therapy. We conclude that ECM is a critical driver of malignancies and ECM-derived biomarkers should be included in diagnostics and prognostics panels of markers in the clinic.

Lynch Syndrome Germline Mutations in Breast Cancer: Next Generation Sequencing Case-Control Study of 1,263 Participants.

Genome instability-the increased tendency of acquiring mutations in the genome and ability of a cell to tolerate high mutation burden-is one of the drivers of cancer. Genome instability results from many causes including defects in DNA repair systems. Previously, it has been shown that germline pathogenic mutations in DNA Mismatch Repair (MMR) pathway cause cancer-predisposing Lynch Syndrome. We proposed that Lynch Syndrome-related germline mutations (LS-mutations) are associated with breast cancer (BC). In this study, we performed Targeted Next-Generation Sequencing of MMR pathway genes MLH1, MSH2, MSH6, EPCAM, and PMS2 in a cohort of 711 patients with hereditary BC, 60 patients with sporadic BC, and 492 healthy donors. Sixty-nine patients (9.7%) with hereditary BC harbored at least one germline mutation in the MMR pathway genes, of them 32 patients (4.5%) harbored mutations in MMR pathway genes which we define as pathogenic or likely pathogenic, and of them 26 patients (3.6%) did not have any pathogenic mutations in DDR pathway genes, compared to two mutations in MMR pathway genes (0.4%) detected in a group of 492 healthy donors [p = 0.00013, OR = 8.9 (CI 95% 2.2-78.4)]. Our study demonstrates that LS-mutations are present in patients with hereditary BC more frequently than in healthy donors, and that there is an association of hereditary BC and mutations c.1321G>A in MLH1, c.260C>G and c.2178G>C in MSH2, c.3217C>T in MSH6, c.1268C>G and c.86G>C in PMS2 genes. This finding provides a rationale for including pathogenic LS-mutations into genetic counseling tests for patients with hereditary BC.

A novel small molecule that kills a subset of MLL-rearranged leukemia cells by inducing mitochondrial dysfunction.

Survival rates for pediatric patients suffering from mixed lineage leukemia (MLL)-rearranged leukemia remain below 50% and more targeted, less toxic therapies are urgently needed. A screening method optimized to discover cytotoxic compounds selective for MLL-rearranged leukemia identified CCI-006 as a novel inhibitor of MLL-rearranged and CALM-AF10 translocated leukemias that share common leukemogenic pathways. CCI-006 inhibited mitochondrial respiration and induced mitochondrial membrane depolarization and apoptosis in a subset (7/11, 64%) of MLL-rearranged leukemia cell lines within a few hours of treatment. The unresponsive MLL-rearranged leukemia cells did not undergo mitochondrial membrane depolarization or apoptosis despite a similar attenuation of mitochondrial respiration by the compound. In comparison to the sensitive cells, the unresponsive MLL-rearranged leukemia cells were characterized by a more glycolytic metabolic phenotype, exemplified by a more pronounced sensitivity to glycolysis inhibitors and elevated HIF1α expression. Silencing of HIF1α expression sensitized an intrinsically unresponsive MLL-rearranged leukemia cell to CCI-006, indicating that this pathway plays a role in determining sensitivity to the compound. In addition, unresponsive MLL-rearranged leukemia cells expressed increased levels of MEIS1, an important leukemogenic MLL target gene that plays a role in regulating metabolic phenotype through HIF1α. MEIS1 expression was also variable in a pediatric MLL-rearranged ALL patient dataset, highlighting the existence of a previously undescribed metabolic variability in MLL-rearranged leukemia that may contribute to the heterogeneity of the disease. This study thus identified a novel small molecule that rapidly kills MLL-rearranged leukemia cells by targeting a metabolic vulnerability in a subset of low HIF1α/low MEIS1-expressing MLL-rearranged leukemia cells.