Combination of IFN-gamma with STING agonist and PD-1 immune checkpoint blockade: a potential immunotherapy for gastric cancer.

Suppression of the cGAS-STING pathway is an immune escape mechanism in cancer cells. The critical role of this pathway in gastric cancer (GC) is not fully understood. Herein, we evaluated the effect of the interferon-gamma (IFN-gamma), STING agonist, PD-1 immune checkpoint blockade, and their combination on the cGAS-STING pathway in GC. Expression of cGAS and STING in tumor tissue samples and adjacent normal tissue (ANT) biopsies of fifty new GC patients was evaluated by quantitative real-time PCR (qRT-PCR). Moreover, cGAS and STING expression levels were examined in Peripheral Blood Mononuclear Cells (PBMC) samples of forty GC patients and twenty-five healthy subjects. The apoptosis rate of cancer cells was analyzed by Annexin V-FITC/PI. Cell proliferation was measured by the BrdU assay. Also, IFN-ß levels were evaluated in the supernatants of the treated groups. The cGAS expression was decreased in patients with distant metastasis. Co-cultures treated with IFN-gamma showed an elevated level of cGAS and STING expressions in PBMC and cancer cells. The rate of apoptosis increased in all the treatment groups. In addition, the rate of proliferation in PBMCs increased in different treated groups. The main role of PBMCs in cytotoxicity was determined by a comparative analysis of the viability of cells treated with all treatments, both with and without PBMCs. The production of IFN-ß was elevated in all treated groups. The current study suggests that a combination therapy using IFN-gamma, STING agonist, and anti-PD-1 antibody can provide a promising approach to the treatment of GC.

Therapeutic Effect of Levetiracetam Against Thioacetamide-Induced Hepatic Encephalopathy Through Inhibition of Oxidative Stress and Downregulation of NF-κB, NLRP3, iNOS/NO, Pro-Inflammatory Cytokines and Apoptosis.

Hepatic encephalopathy (HE) is a serious brain disorder which associated with neurological and psychiatric manifestations. Oxidative stress and neuroinflammation and apoptosis play main roles in the development of brain damage in HE. Levetiracetam is an antiseizure drug with established antioxidant and anti-inflammatory activities. In the present study we investigated the therapeutic effects of levetiracetam against brain injury in HE and its underlying mechanisms of action. Male C57BL/6 mice were subjected to the induction of HE by the injection of thioacetamide (200 mg/kg) for 2 days. Mice were treated with levetiracetam at two doses (50 or 100 mg/kg/day) for 3 days in the treatment groups. Animals were subjected to a behavioral test and the brain tissues were dissected for histopathological, biochemical, gene expression and immunofluorescence analysis. The results showed that levetiracetam alleviated body weight loss and improved locomotor activity of mice with HE. Levetiracetam treatment decreased the histopathological changes, lipid peroxidation and protein carbonylation while restored the antioxidants (GSH, SOD and CAT) in the brain. Levetiracetam decreased the expression and activity of NF-κB, NOD-like receptor pyrin domain-containing protein 3 (NLRP3) and pro-inflammatory cytokines (TNF-α, IL-1ß, IL-6, and IFN-γ) in the brain tissue. Administration of levetiracetam inhibited iNOS/NO pathway and myeloperoxidase (MPO) activity in the brain. Moreover, caspase-3 was decreased and the ratio of Bcl2/Bax was increased in the brain of mice treated with levetiracetam. These findings suggest that levetiracetam may be a promising therapeutic agent for brain injury in HE through inhibiting the oxidative, inflammatory and apoptotic pathways.

Levetiracetam attenuates experimental ulcerative colitis through promoting Nrf2/HO-1 antioxidant and inhibiting NF-κB, proinflammatory cytokines and iNOS/NO pathways.

Ulcerative colitis (UC) is a serious inflammatory disease of the colon. The pathogenic mechanisms of UC involve the activation of inflammatory and oxidative stress responses in the colon. Levetiracetam is an antiepileptic drug with anti-inflammatory and antioxidant effects. The aim of this study was to investigate the potential protective effect of levetiracetam against UC in a mouse model. UC was induced in mice by intrarectal administration of acetic acid and then mice were treated with levetiracetam (50 or 100 mg/kg/day, i.p.) for three days. The colonic tissue samples were dissected for biochemical, RT-PCR and immunofluorescence analysis. Results showed that levetiracetam treatment significantly decreased colonic mucosal injury as evidenced by the macroscopic and histopathological analysis. Levetiracetam induced Nrf2/HO-1 and antioxidants while reduced lipid peroxidation and myeloperoxidase activity in colon tissue. Levetiracetam treatment decreased NF-κB activity and the expression of proinflammatory mediators TNF-α, IL-6, IL-1ß, IFN-γ, MCP-1 and ICAM-1. The colonic levels of anti-inflammatory cytokines IL-10 and TGF-ß1 were increased by levetiracetam treatment. Furthermore, levetiracetam significantly diminished iNOS expression and NO production in colon tissue. These findings suggest that levetiracetam ameliorates the severity of UC in mice through the regulation of inflammatory and oxidative responses.

Synthesis and characterization of N-rich fluorescent bio-dots as a reporter in the design of dual-labeled FRET probe for TaqMan PCR: A feasibility study.

DNA-based analytical techniques have provided an advantageous sensing assay in the realm of biotechnology. Bio-inspired fluorescent nanodots are a novel type of biological staining agents with excellent optical properties widely used for cellular imaging and diagnostics. In the present research, we successfully synthesized bio-dots with excellent optical properties and high-quantum yield from DNA sodium salt through the hydrothermal method. We conjugated the bio-dots with 3' Eclipse Dark Quencher (Eclipse)-labeled single-strand oligodeoxyribonucleotide according to carbodiimide chemistry, to design a fluorescence resonance energy transfer (FRET) probe. The results confirmed the prosperous synthesis and surface functionalization of the bio-dot. Analysis of size, zeta potential, and FTIR spectroscopy verified successful bioconjugation of the bio-dots with probes. UV-visibility analysis and fluorescence intensity profile of the bio-dot and bio-dot@probes represented a concentration-dependent quenching of fluorescent signal of bio-dot by Eclipse after probe conjugation. The results demonstrated that TaqMan PCR was not feasible using the designed bio-dot@probes. Our results indicated that bio-dot can be used as an efficient fluorescent tag in the design of fluorescently labeled oligonucleotides with high biocompatibility and optical features.

Dexamethasone Reduces Cell Adhesion and Migration of T47D Breast Cancer Cell Line.

BACKGROUND: Aberrant expression of cell adhesion molecules and matrix metalloproteinase (MMPs) plays a pivotal role in tumor biological processes, including progression and metastasis of cancer cells. Targeting these processes and acquiring a detailed understanding of their underlying molecular mechanism are an essential step in cancer treatment. Dexamethasone (Dex) is a type of synthetic corticosteroid hormone used as adjuvant therapy in combination with current cancer treatments such as chemotherapy in order to alleviate its side effects like acute nausea and vomiting. Recent evidences suggest that Dex may have antitumor characteristics. OBJECTIVE: Dex affects the migration and adhesion of T47D breast cancer cells as well as cell adhesion molecules, e.g. cadherin and integrin, and MMPs by regulating the expression levels of associated genes. METHODS: In this study, we evaluated the cytotoxicity of Dex on the T47D breast cancer cell line through MTT assay. Cell adhesion assay and wound healing assay were performed to determine the impact of Dex on cell adhesion and cell migration, respectively. Moreover, real-time PCR was used to measure the levels of α and ß integrin, E-cadherin, N-cadherin, MMP-2, and MMP-9. RESULTS: Dex decreased the viability of T47D cells in a time and dose-dependent manner. Cell adhesion and migration of T47D cells were reduced upon Dex treatment. The expressions of α and ß integrin, E-cadherin, Ncadherin, MMP-2, and MMP-9 were altered in response to the Dex treatment. CONCLUSION: Our findings demonstrated that Dex may play a role in the prevention of metastasis in this cell line.

Recent advances in FRET-Based biosensors for biomedical applications.

Fluorescence resonance energy transfer (FRET)-based biosensors are effective analytical tools extensively used in fields of biomedicine, pharmacology, toxicology, and food sciences. Ratiometric imaging of substantial cellular processes, molecular components, and biological interactions is widely performed by these biosensors. A variety of FRET-based biosensors have provided comprehensive insights into underlying mechanisms of pathological conditions in live cells, tissues, and organisms. Moreover, integration of FRET-based biosensors with the current bioanalytical techniques allows for accurate, rapid, and sensitive diagnosis and proposes the advanced strategies for treatment. Precise analysis of ligand-receptor interactions by FRET-based biosensors has presented a basis for determination of novel therapeutic agents. Therefore, this study was designed to review the recent developments in FRET-based biosensors and their biomedical applications. In addition, characteristics, challenges, and outlooks of these biosensors were discussed.

Correlation Between Dexamethasone and miRNAs in the Regulation of Apoptosis, Drug-resistance, and Metastasis of Cancer Cell.

Dexamethasone (Dex) is a synthetic corticosteroid hormone derived from the steroid chemical group and is applicable in treating several pathological conditions like inflammation, autoimmune disease, and malignancies. Recent investigations on the mechanism of action of Dex and its possible interactions with other cellular regulatory networks may help explain the inconsistent effects of Dex in cancer treatment. Finetuning regulation of essential post-transcriptional regulators such as microRNA (miRNAs) has indispensable impacts on modulating fundamental cellular processes, including gene expression, cell proliferation, cell cycling, and apoptosis. Dex appears to act as a double-edged sword on cancer cell progression and metastasis through regulating miRNA networks. As a proof of concept, recent investigations have proved Dex to be effective in treatment of cancer either individually or in combination with other therapeutical compounds, while several evidences have point to the controversial effects of Dex in the promotion of cancer cell survival, drug-resistance, and metastasis. In addition, it has been proven that other non-coding RNAs (ncRNAs) can also be directly or indirectly affected by Dex. In this review, we aimed to investigate the controversial effect of Dex on the cancer-related miRNAs.

An update on advances in new developing DNA conjugation diagnostics and ultra-resolution imaging technologies: Possible applications in medical and biotechnological utilities.

DNA molecule engineering has become an attractive discipline in various research scopes. The profound influence of selective and sensitive sensing of DNA molecules in disease diagnosis and molecular imaging is established. In this perspective, we try to shed light on the state-of-the-art technology of DNA bioconjugation assays in DNA biosensor, DNA barcode, DNA nanostructures, and DNA ultra-resolution fluorescence imaging. Non-invasive, simple, and swift biotechniques benefit molecular diagnosis, evaluation of disease stages, and also play a central role in fundamental researches. We discuss the limitations of traditional procedures and the eminence impacts of the advanced methods with clinical applications in timely detection and management of diseases like cancer, genetic disorders, and recognition of microbial pathogens. The predictable and programmable DNA strands have paved the way for cellular and molecular imaging with the ability of single-molecule switching nanoscopy. Consequently, the DNA conjugation tool as an identification paradigm of biological agents in interaction with bio-spesific components is at the heart of biological processes.