Activation Of Signaling Pathway Research Articles

A Review on Anaplastic Lymphoma Kinase (ALK) Rearrangements and Mutations: Implications for Gastric Carcinogenesis and Target Therapy.

Gastric adenocarcinoma is a complex disease with diverse genetic modifications, including Anaplastic Lymphoma Kinase (ALK) gene changes. The ALK gene is located on chromosome 2p23 and encodes a receptor tyrosine kinase that plays a crucial role in embryonic development and cellular differentiation. ALK alterations can result from gene fusion, mutation, amplification, or overexpression in gastric adenocarcinoma. Fusion occurs when the ALK gene fuses with another gene, resulting in a chimeric protein with constitutive kinase activity and promoting oncogenesis. ALK mutations are less common but can also result in the activation of ALK signaling pathways. Targeted therapies for ALK variations in gastric adenocarcinoma have been developed, including ALK inhibitors that have shown promising results in pre-clinical studies. Future studies are needed to elucidate the ALK role in gastric cancer and to identify predictive biomarkers to improve patient selection for targeted therapy. Overall, ALK alterations are a relevant biomarker for gastric adenocarcinoma treatment and targeted therapies for ALK may improve patients' overall survival.

AHR regulates liver enlargement and regeneration through the YAP signaling pathway

The aryl hydrocarbon receptor (AHR) is a transcription factor activated by ligands that participates in many important physiological processes. Although AHR activation is associated with hepatomegaly, the underlying mechanism remains unclear. This study evaluated the effects of AHR activation on liver enlargement and regeneration in various transgenic mice and animal models. Activation of AHR by the non-toxic ligand YH439 significantly induced liver/body weight ratio in wild-type mice (1.37-fold) and AHRfl/fl.ALB-CreERT2 mice (1.54-fold). However, these effects not present in AHRΔHep mice. Additionally, the activation of AHR promotes hepatocyte enlargement (1.43-fold or 1.41-fold) around the central vein (CV) and increases number of Ki67+ cells (42.5-fold or 48.8-fold) around the portal vein (PV) in wild-type mice and AHRfl/fl.ALB-CreERT2 mice. In the 70% partial hepatectomy (PHx) model, YH439 significantly induced hepatocyte enlargement (1.40-fold) and increased number of Ki67+ cells (3.97-fold) in AHRfl/fl.ALB-CreERT2 mice. However, these effects were not observed in AHRΔHep mice. Co-immunoprecipitation results suggested a potential protein-protein interaction between AHR and Yes-associated protein (YAP). Disruption of the association between YAP and transcription enhancer domain family member (TEAD) significantly inhibited AHR-induced liver enlargement and regeneration. Furthermore, AHR failed to induce liver enlargement and regeneration in YAPΔHep mice. Blocking the YAP signaling pathway effectively eliminated AHR-induced liver enlargement and regeneration. This study revealed the molecular mechanism of AHR regulation of liver size and regeneration through the activation of AHR-TEAD signaling pathway, thereby offering novel insights into the physiological role of AHR. These findings provide a theoretical foundation for the prevention and treatment of disorders associated with liver regeneration.

Cardioprotective effects of polydatin against myocardial injury in HFD/stz and high glucose-induced diabetes via a Caveolin 1-dependent mechanism

BackgroundDiabetic cardiomyopathy (DCM) is defined as cardiac dysfunction involving changes in structure, function, and metabolism in the absence of coronary artery disease, which eventually developed into heart failure. There is still a lack of effective drugs for the treatment of DCM, while the ameliorative effects of traditional herbs on DCM have been commonly reported. Polydatin (PD) is a glucoside derivative of traditional herbs of resveratrol, which has been shown to ameliorate the pathological development of DCM. However, the cardioprotective effect and mechanism of PD in the improvement of myocardial injury are still unclear. Aim of studyThis study aimed to investigate the cardio-protective role of PD on DCM and reveal the critical effect of Cav1 in PD’ regulation of DCM. Materials and methodsThe Cav1-/- and Cav1+/+ mice and H9C2 cells were used to induce DCM models and then given PD treatment (150 mg/kg) or not. The cardiac functions of all mice were checked via echocardiography, and myocardial histological changes were measured by H&E, periodic acid-schiff (PAS) and Masson staining. The markers expression of heart fibrosis and inflammation, and hypertrophic factors were detected using western blotting. The NF-κB signaling activation was performed by confocal, immunohistochemical, Electrophoretic mobility shift assay (EMSA) and western blotting. ResultsHere, we found that PD significantly improved the cardiac function and injury of diabetic Cav1+/+ mice, and enhanced the expression of Cav1 in the cardiac tissues of diabetic Cav1+/+ mice and HG-induced H9C2 cells. Further investigation showed that when Cav1 was knocked down, PD no longer plays the cardioprotective effect and inhibits the NF-κB signaling pathway activation in HFD/stz-treated diabetic mice and HG-induced H9C2 cells. ConclusionThese results demonstrated that PD inhibited the hyperglycemia-induced myocardial injury and inflammatory fibrosis of DCM models in vivo and in vitro, and targeting Cav1 may provide a novel understanding the mechanism of the treatment of PD in DCM.

Vangl2 regulates intercellular junctions by remodeling actin-based cytoskeleton through the Rock signaling pathway during spermatogenesis in Eriocheir sinensis

As a key planar cell polarity protein, Van Gogh-like 2 (Vangl2) is essential for mammalian spermatogenesis. As a decapod crustacean, Eriocheir sinensis exhibits distinct spermatogenic processes due to its unique seminiferous tubule morphology and hemolymph-testis barrier (HTB). To determine whether Vangl2 performs analogous functions in E. sinensis, we identified the Es-Vangl2. Es-Vangl2 exhibited high expression and wide distribution in the testes, indicating its crucial involvement in spermatogenesis. Following targeted knockdown of Es-Vangl2 in vivo, the structure of seminiferous tubules was disrupted, characterized by vacuolization of the germinal zone and obstruction of spermatozoon release. Concurrently, the integrity of the HTB was compromised, accompanied by reduced expression and aberrant localization of junction proteins. More importantly, the regulatory influence of Es-Vangl2 was manifested through modulating the organization of microfilaments, a process mediated by epidermal growth factor receptor pathway substrate 8 (Eps8). Further studies demonstrated that these phenotypes resulting from Es-Vangl2 knockdown were attributed to the inhibition of Rock signaling pathway activity, which was verified by the Es-Rock interference and Y27632 inhibition assays. In summary, the findings highlight the pivotal role of Es-Vangl2 in stabilizing HTB integrity by regulating Eps8-mediated actin remodeling through the Rock signaling pathway in the spermatogenesis of E. sinensis.

Silencing of KIAA1429, a N6-methyladenine methyltransferase, inhibits the progression of colon adenocarcinoma via blocking the hypoxia-inducible factor 1 signalling pathway.

KIAA1429 is an important 'writer' of the N6-methyladenine (m6A) modification, which is involved in tumour progression. This study was conducted to explore the mechanism of action of KIAA1429 in colon adenocarcinoma (COAD). KIAA1429-silenced COAD cell and xenograft tumour models were constructed, and the function of KIAA1429 was explored through a series of in vivo and in vitro assays. The downstream mechanisms of KIAA1429 were explored using transcriptome sequencing. Dimethyloxalylglycine (DMOG), an activator of HIF-1α, was used for feedback verification. The expression of KIAA1429 in COAD tumour tissues and cells was elevated, and KIAA1429 exhibited differential expression at different stages of the tumour. Silencing of KIAA1429 inhibited the proliferation, migration, and invasion of HT29 and HCT116 cells. The expression levels of NLRP3, GSDMD and Caspase-1 were decreased in KIAA1429-silenced HT29 cells, indicating the pyroptotic activity was inhibited. Additionally, KIAA1429 silencing inhibited the growth of tumour xenograft. Transcriptome sequencing and reverse transcription quantitative polymerase chain reaction revealed that after KIAA1429 silencing, the expression of AKR1C1, AKR1C2, AKR1C3 and RDH8 was elevated, and the expression of VIRMA, GINS1, VBP1 and ARF3 was decreased. In HT29 cells, KIAA1429 silencing blocked the HIF-1 signalling pathway, accompanied by the decrease in AKT1 and HIF-1α protein levels. The activation of HIF-1 signalling pathway, mediated by DMOG, reversed the antitumour role of KIAA1429 silencing. KIAA1429 silencing inhibits COAD development by blocking the HIF-1 signalling pathway.

Arsenic trioxide induces innate immune response and inflammatory response in chicken liver via cGAS-STING/NF-κB pathway

Arsenic is a toxic metal-like element widely used in the pesticide, preservative and semiconductor industries. However, accumulation of arsenic through the food chain can cause serious damage to animal and human health. However, the toxic mechanism of arsenic-induced hepatotoxicity in chickens is not clear, and the present study aimed to investigate the potential role of cGAS-STING and NF-κB pathways on inflammatory injury in chicken liver. In this study, 75 white-feathered broilers were divided into a control group, a low-dose arsenic group (4 mg/kg) and a high-dose arsenic group (8 mg/kg) to investigate the toxic effects of arsenic on chicken liver. In this study, we found that pathological changes such as inflammatory cell infiltration and vesicular degeneration occurred in the liver when exposed to ATO. Crucially, exposure to ATO triggered the cGAS-STING pathway and markedly raised the levels of mRNA and protein expression of cGAS, STING, TBK1, and IRF7. The type I interferon response was also triggered. Simultaneously, STING induced the activation of the conventional NF-κB signaling pathway and stimulated the expression of genes associated with inflammation, such as IL-6, TNF-α and IL-1β. In summary, the induction of inflammatory responses via cGAS-STING and NF-κB signaling pathways under high ATO exposure provides new ideas for further studies on the toxicological mechanisms of arsenic.

Effect of Sortilin1 on promoting angiogenesis and systemic metastasis in hepatocellular carcinoma via the Notch signaling pathway and CD133

Hepatocellular carcinoma (HCC) is known to be lethal disease. However, its prognosis remains poor, primarily because the precise oncogenic mechanisms underlying HCC progression remain elusive, thus hampering effective treatment. Here, we aimed to identify the potential oncogenes in HCC and elucidate the underlying mechanisms of their action. To identify potential candidate genes, an integrative analysis of eight publicly available genomic datasets was performed, and the functional implications of the identified genes were assessed in vitro and in vivo. Sortilin 1 (SORT1) was identified as a potential candidate oncogene in HCC, and its overexpression in HCC cells was confirmed by analyzing spatial transcriptomic and single-cell data. Silencing SORT1 in Huh-7 and Hep3B cells significantly reduced HCC progression in vitro and in vivo. Functional analyses of oncogenic pathways revealed that SORT1 expression regulated the Notch signaling pathway activation and CD133 expression. Furthermore, analysis of epigenetic regulation of the candidate gene and its clinical implications using The Cancer Genome Atlas Liver Hepatocellular Carcinoma (TCGA LIHC) and our HCC cohort (AJOU_HCC cohort) data demonstrated an inverse correlation between the methylation status of the SORT1 promoter region, specifically at the cg16988986 site, and SORT1 mRNA expression, indicating the epigenetic regulation of SORT1 in HCC. In addition, the distinct methylation status of cg16988986 was significantly associated with patient survival. In conclusion, SORT1 plays a pivotal role in HCC by activating the Notch signaling pathway and increasing CD133 expression. These findings suggest SORT1 as a promising therapeutic target for HCC.

Unlocking the Potential: Epstein-Barr Virus (EBV) in Gastric Cancer and Future Treatment Prospects, a Literature Review

Gastric cancer (GC) is a complex disease with various etiologies. While Helicobacter pylori infection is still one of the leading risk factors for GC, increasing evidence suggests a link between GC and other infective agents such as Epstein Bar Virus (EBV). EBV-associated gastric cancer (EBVaGC) is now recognized as a distinct subgroup of GC, and the complex interactions between the virus and gastric mucosa may influence its development. A recent integrative analysis of the genome and proteome of GC tissues by The Cancer Genome Atlas project has identified EBVaGC as a specific subtype characterized by PIK3CA and ARID1A mutations, extensive DNA hyper-methylation, and activation of immune signaling pathways. These molecular characteristics are markers of the unique molecular profile of this subset of GC and are potential targets for therapy. This review aims to provide an overview of the current knowledge on EBVaGC. It will focus on the epidemiology, clinic-pathological features, and genetic characteristics of EBVaGC. Additionally, it will discuss recent data indicating the potential use of EBV infection as a predictive biomarker of response to chemotherapy and immune checkpoint inhibitors. The review also delves into potential therapeutic approaches for EBVaGC, including targeted therapies and adoptive immunotherapy, highlighting the promising potential of EBV as a therapeutic target.

New Insights into the Exosome-Induced Migration of Uveal Melanoma Cells and the Pre-Metastatic Niche Formation in the Liver.

UM is an aggressive intraocular tumor characterized by high plasticity and a propensity to metastasize in the liver. However, the underlying mechanisms governing liver tropism remain poorly understood. Given the emerging significance of exosomes, we sought to investigate the contribution of UM-derived exosomes to specific steps of the metastatic process. Firstly, we isolated exosomes from UM cells sharing a common genetic background and different metastatic properties. A comparison of protein cargo reveals an overrepresentation of proteins related to cytoskeleton remodeling and actin filament-based movement in exosomes derived from the parental cells that may favor the detachment of cells from the primary site. Secondly, we assessed the role of macrophages in reprogramming the HHSCs by exosomes. The activation of HHSCs triggered a pro-inflammatory and pro-fibrotic environment through cytokine production, upregulation of extracellular matrix molecules, and the activation of signaling pathways. Finally, we found that activated HHSCs promote increased adhesion and migration of UM cells. Our findings shed light on the pivotal role of exosomes in pre-metastatic niche construction in the liver.

Antimigratory Effect of Lipophilic Cations Derived from Gallic and Gentisic Acid and Synergistic Effect with 5-Fluorouracil on Metastatic Colorectal Cancer Cells: A New Synthesis Route.

Colorectal cancer (CRC) is the third leading cause of cancer deaths in the world. Standard drugs currently used for the treatment of advanced CRC-such as 5-fluorouracil (5FU)-remain unsatisfactory in their results due to their high toxicity, high resistance, and adverse effects. In recent years, mitochondria have become an attractive target for cancer therapy due to higher transmembrane mitochondrial potential. We synthesized gallic acid derivatives linked to a ten-carbon aliphatic chain associated with triphenylphosphonium (TPP+C10), a lipophilic cationic molecule that induces the uncoupling of the electron transport chain (ETC). Other derivatives, such as gentisic acid (GA-TPP+C10), have the same effects on colorectal cancer cells. Although part of our group had previously reported preparing these structures by a convergent synthesis route, including their application via flow chemistry, there was no precedent for a new methodology for preparing these compounds. In this scenario, this study aims to develop a new linear synthesis strategy involving an essential step of Steglich esterification under mild conditions (open flask) and a high degree of reproducibility. Moreover, the study seeks to associate GA-TPP+C10 with 5FU to evaluate synergistic antineoplastic effects. In addition, we assess the antimigratory effect of GA-TPP+C10 and TPP+C10 using human and mouse metastatic CRC cell lines. The results show a new and efficient synthesis route of these compounds, having synergistic effects in combination with 5FU, increasing apoptosis and enhancing cytotoxic properties. Additionally, the results show a robust antimigratory effect of GATPP+C10 and TPP+C10, reducing the activation pathways linked to tumor progression and reducing the expression of VEGF and MMP-2 and MMP-9, common biomarkers of advanced CRC. Moreover, TPP+C10 and GA-TPP+C10 increase the activity of metabolic signaling pathways through AMPK activation. The data allow us to conclude that these compounds can be used for in vivo evaluations and are a promising alternative associated with conventional therapies for advanced colorectal cancer. Additionally, the reported intermediates of the new synthesis route could give rise to analog compounds with improved therapeutic activity.

Selenium elicited an enhanced anti-inflammatory effect in primary bovine endometrial stromal cells with high cortisol background

BackgroundAn elevated endogenous cortisol level due to the peripartum stress is one of the risk factors of postpartum bovine uterine infections. Selenium is a trace element that elicits anti-inflammation and antioxidation properties. This study aimed to reveal the modulatory effect of selenium on the inflammatory response of primary bovine endometrial stromal cells in the presence of high-level cortisol. The cells were subjected to lipopolysaccharide to establish cellular inflammation. The mRNA expression of toll-like receptor 4 (TLR4), proinflammatory factors, and selenoproteins was measured with qPCR. The activation of NF-κB and MAPK signalling pathways was detected with Western blot and immunofluorescence.ResultsThe pretreatment with sodium selenite (2 and 4 µΜ) resulted in a down-regulation of TLR4 and genes encoding proinflammatory factors, including interleukin (IL)-1β, IL-6, IL-8, tumour necrosis factor α, cyclooxygenase 2, and inducible nitric oxide synthase. Selenium inhibited the activation of NF-κB and the phosphorylation of mitogen-activated protein kinase kinase, extracellular signal-regulated kinase, p38MAPK and c-Jun N-terminal kinase/stress-activated protein kinase. The suppression of those genes and pathways by selenium was more significant in the presence of high cortisol level (30 ng/mL). Meanwhile the gene expression of glutathione peroxidase 1 and 4 was promoted by selenium, and was even higher in the presence of cortisol and selenium.ConclusionsThe anti-inflammatory action of selenium is probably mediated through NF-κB and MAPK, and is augmented by cortisol in primary bovine endometrial stromal cells.

Blocking Gremlin1 inhibits M1 macrophage polarization through Notch1/Hes1 signaling pathway in apical periodontitis.

Gremlin1 is a multifunctional protein whose expression is demonstrated to be involved in a series of physiology and pathological processes. The association between Gremlin1 and apcial periodontitis (AP) has been established. M1-polarized macrophages are crucial immune cells that exacerbate the progression of apical periodontal inflammatory response, but the function of Gremlin1 during macrophages activation in periapical lesions is still unclear. This study attempts to explore the regulatory effects of Gremlin1 on macrophage polarization on apical periodontitis microenviroment. Clinical specimens were used to determine the expression of Gremlin1 in periapical tissues by immunohistochemical (IHC) staining. Then, the disease models of periapical inflammation in rats were established, and adenovirus- associated virus (AAVs) was used to blockade Gremlin1 expression. Lentivirus carrying sh-Gremlin1 particles were used to transfect THP-1 induced M1-subtype macrophages. To assess the expression of associated molecules, Western blot, immunofluorescence staining were performed. Gremlin1 was significantly up-regulated in the periapical tissues of subjects with AP as identified by IHC staining, and positively correlated with levels of M1 macrophage-associated genes. Rats AP model with inhibition of Gremlin1 in periapical lesions exhibited limited infiltration of macrophages and decreased expression of M1 macrophage-related genes in periapical lesions. Furthermore, Gremlin1 blockade substantially decreased the Notch1/Hes1 signaling pathway activation level. The in vitro experiments confirmed the above results. Taken together, current study illustrated that the Gremlin1 suppression in periapical lesions inhibited M1 macrophage polarization through Notch1/Hes1 axis. Moreover, Gremlin1 may act as a potential candidate in the treatment of AP.

Intra-amniotic delivery of tropomodulin 3 rescues cell apoptosis induced by miR-200b-3p upregulation via non-canonical nuclear factor kappa B pathways in ethylene thiourea induced anorectal malformations fetal rat

Ethylene thiourea (ETU), a metabolite of the fungicide ethylene bisdithiocarbamate (EBDC), has received great concern because of its harmful effects. ETU-induced anorectal malformations (ARMs) in rat models have been reported and widely used in the study of ARMs embryogenesis. Dysplasia of the lumbosacral spinal cord (LSSC), pelvic floor muscles (PFMs), and hindgut (HG) during intrauterine life affects postoperative defecation in patients with ARMs. However, the underlying toxic effects of ETU and pathological mechanisms in the three defecation-related tissues of fetuses with ARMs have not been reported. Thus, this study aimed to elucidate the molecular mechanisms involved in ARMs, with a focus on the dysregulation of miR-200b-3p and its downstream target tropomodulin 3 (TMOD3). The mRNA and protein levels of miR-200b-3p and TMOD3 in LSSC, PFMs, and HG of fetal rats with ARMs were evaluated by reverse transcription quantitative polymerase chain reaction and Western blotting (WB) on embryonic day 17 (E17). Further, a dual-luciferase reporter assay confirmed their targeting relationship. Gene silencing and overexpression of miR-200b-3p and TMOD3 were performed to verify their functions in HEK-293 T cells. Fetal rats with ARMs also received intra-amniotic microinjection of Ad-TMOD3 on E15, and key molecules in nuclear factor kappa (NF-κB) signaling and apoptosis were evaluated by WB on E21. Abnormally high levels of miR-200b-3p inhibited TMOD3 expression by binding with its 3′-untranslated region, leading to the activation of the non-canonical NF-κB signaling pathway, which is critical in the maldevelopment of LSSC, PFMs, and HG in ARMs rats. Furthermore, miR-200b-3p triggered apoptosis by directly targeting TMOD3. Notably, intra-amniotic Ad-TMOD3 microinjection revealed that the upregulation of TMOD3 expression mitigates the effects of miR-200b-3p on the activation of non-canonical NF-κB signaling and apoptosis in fetal rat model of ARMs. A novel miR-200b-3p/TMOD3/non-canonical NF-κB signaling axis triggered the massive apoptosis in LSSC, PFMs, and HG of ARMs, which was restored by the intra-amniotic injection of Ad-TMOD3 during embryogenesis. Our results indicate the potential of TMOD3 as a treatment target to restore defecation.

ShRNA-interfered of Nrf2 reveals a critical role for Keap1-Nrf2 signaling pathway during effects of Zearalenone induced oxidative stress in IPEC-J2 cells.

This study aims to verify the protective effect of the Kelch-like ECH-associated protein1 (Keap1)-nuclear factor erythroid 2-related factor 2 (Nrf2) signaling pathways by studying the effect of plasmids containing Nrf2-small hairpin RNA (shRNA) interference down-regulation of Nrf2 on zearalenone (ZEA) -induced intestinal porcine epithelial cells (IPEC-J2) oxidative stress. We constructed an IPEC-J2 model that interferes with Nrf2 expression, set blank (Control), negative control group (Sh-control), positive control group (Sh-Nrf2), and added 10, 20, and 40 μmol/L ZEA experimental group (Sh-Nrf2+ZEA10, Sh-Nrf2+ZEA20, and Sh-Nrf2+ZEA40). The study results showed that, compared with the Sh-Nrf2 group, ZEA significantly increased the apoptosis rate of IPEC-J2 in a time- and dose-dependent manner. Compared with the Sh-Nrf2 group, the activities of T-SOD and GSH-PX and relative expressions of Keap1 at mRNA and protein level in the Sh-Nrf2+ZEA20 and Sh-Nrf2+ZEA40 groups were significantly reduced, the MDA level, and the fluorescence intensity around and within the nucleus of ROS and Nrf2, and the relative expressions of Nrf2, Nqo1, and Ho1 at mRNA and protein level significantly increased. These results further prove that interfering with the expression of Nrf2 in IPEC-J2 cells affected the activation of the Keap1-Nrf2 signaling pathway and reduced the ability of cells to resist ZEA-induced oxidative stress. Therefore, the Keap1-Nrf2 signaling pathway had an important protective effect in ZEA-induced intestinal oxidative stress.

The role of ESM1 in the lipids metabolic reprogramming and angiogenesis of lung adenocarcinoma cells

BackgroundLung adenocarcinoma (LUAD) is one of the respiratory diseases with high mortality and incidence. As an important angiogenic factor, (Endothelial cell-specific molecule 1) ESM1 plays an important role in the occurrence and development of LUAD. However, the role and molecular mechanism of ESM1 on LUAD metabolic reprogramming and angiogenesis remain unclear. MethodsWe used multiple databases to analyze the prognostic significance and potential function of ESM1 in patients with LUAD. The expression of ESM1 in LUAD cells was down-regulated/overexpressed by RNA interference, and the effects of ESM1 on the proliferation, migration, lipid metabolism and angiogenesis of LUAD cells in vitro and in vivo were analyzed using MTT, EdU, wound healing, oil red O, tubule formation, xenograft tumor model and chicken embryo allantoic model. ResultsESM1 is closely associated with poor prognosis in LUAD patients. ESM1 promotes LUAD proliferation, migration, fatty acid synthesis and angiogenesis. It also accelerates the proliferation, migration, lipid synthesis and tubule formation of endothelial cells in the tumor microenvironment in the form of secreted protein. Mechanically, ESM1 can promote the activation of AKT signaling pathway and up-regulate the expression of SCD1 and FASN. ConclusionOur results suggest that ESM1 promotes the proliferation, migration, lipid reprogramming, and angiogenesis of LUAD cells by activating the AKT signaling pathway, suggesting that ESM1 may be a potential therapeutic target and prognostic marker in LUAD patients.

Transcriptional regulation of DLGAP5 by AR suppresses p53 signaling and inhibits CD8+T cell infiltration in triple-negative breast cancer

Triple-negative breast cancer (TNBC) is a challenging subtype with unclear biological mechanisms. Recently, the transcription factor androgen receptor (AR) and its regulation of the DLGAP5 gene have gained attention in TNBC pathogenesis. In this study, we found a positive correlation between high AR expression and TNBC cell proliferation and growth. Furthermore, we confirmed DLGAP5 as a critical downstream regulator of AR with high expression in TNBC tissues. Knockdown of DLGAP5 significantly inhibited TNBC cell proliferation, migration, and invasion. AR was observed to directly bind to the DLGAP5 promoter, enhancing its transcriptional activity and suppressing the activation of the p53 signaling pathway. In vivo experiments further validated that downregulation of AR or DLGAP5 inhibited tumor growth and enhanced CD8+T cell infiltration. This study highlights the crucial roles of AR and DLGAP5 in TNBC growth and immune cell infiltration. Taken together, AR inhibits the p53 signaling pathway by promoting DLGAP5 expression, thereby impacting CD8+T cell infiltration in TNBC.

Characterization of two melanoma cell lines resistant to BRAF/MEK inhibitors (vemurafenib and cobimetinib)

BackgroundBRAF (v-raf murine sarcoma viral oncogene homolog B1)/MEK (mitogen-activated protein kinase kinase) inhibitors are used for melanoma treatment. Unfortunately, patients treated with this combined therapy develop resistance to treatment quite quickly, but the mechanisms underlying this phenomenon are not yet fully understood. Here, we report and characterize two melanoma cell lines (WM9 and Hs294T) resistant to BRAF (vemurafenib) and MEK (cobimetinib) inhibitors.MethodsCell viability was assessed via the XTT test. The level of selected proteins as well as activation of signaling pathways were evaluated using Western blotting. The expression of the chosen genes was assessed by RT-PCR. The distribution of cell cycle phases was analyzed by flow cytometry, and confocal microscopy was used to take photos of spheroids. The composition of cytokines secreted by cells was determined using a human cytokine array.ResultsThe resistant cells had increased survival and activation of ERK kinase in the presence of BRAF/MEK inhibitors. The IC50 values for these cells were over 1000 times higher than for controls. Resistant cells also exhibited elevated activation of AKT, p38, and JNK signaling pathways with increased expression of EGFR, ErbB2, MET, and PDGFRβ receptors as well as reduced expression of ErbB3 receptor. Furthermore, these cells demonstrated increased expression of genes encoding proteins involved in drug transport and metabolism. Resistant cells also exhibited features of epithelial-mesenchymal transition and cancer stem cells as well as reduced proliferation rate and elevated cytokine secretion.ConclusionsIn summary, this work describes BRAF/MEK-inhibitor-resistant melanoma cells, allowing for better understanding the underlying mechanisms of resistance. The results may thus contribute to the development of new, more effective therapeutic strategies.

Rabies Virus Regulates Inflammatory Response in BV-2 Cells through Activation of Myd88 and NF-κB Signaling Pathways via TLR7.

Rabies is a fatal neurological infectious disease caused by rabies virus (RABV), which invades the central nervous system (CNS). RABV with varying virulence regulates chemokine expression, and the mechanisms of signaling pathway activation remains to be elucidated. The relationship between Toll-like receptors (TLRs) and immune response induced by RABV has not been fully clarified. Here, we investigated the role of TLR7 in the immune response induced by RABV, and one-way analysis of variance (ANOVA) was employed to evaluate the data. We found that different RABV strains (SC16, HN10, CVS-11) significantly increased CCL2, CXCL10 and IL-6 production. Blocking assays indicated that the TLR7 inhibitor reduced the expression of CCL2, CXCL10 and IL-6 (p < 0.01). The activation of the Myd88 pathway in BV-2 cells stimulated by RABV was TLR7-dependent, whereas the inhibition of Myd88 activity reduced the expression of CCL2, CXCL10 and IL-6 (p < 0.01). Meanwhile, the RABV stimulation of BV-2 cells resulted in TRL7-mediated activation of NF-κB and induced the nuclear translocation of NF-κB p65. CCL2, CXCL10 and IL-6 release was attenuated by the specific NF-κB inhibitor used (p < 0.01). The findings above demonstrate that RABV-induced expression of CCL2, CXCL10 and IL-6 involves Myd88 and NF-κB pathways via the TLR7 signal.

Possible link between familial susceptibility to cancer and the level of oxidative stress in thyroid cancer patients

BackgroundHereditary cancer is estimated to account for up to 10% of the worldwide cancer burden; 5% of all thyroid cancers are thought to be genetic. Inheritance of a deleterious mutation in genes associated with a high lifetime risk of developing cancer. Cancer-predisposing genes can promote the initiation and progression of thyroid cancer by enhancing the activation of major signaling pathways through oxidative stress mechanisms.AimIdentification of the possible link between familial susceptibility to cancer and the level of oxidative stress in thyroid cancer patients.MethodsPatients with thyroid cancer (with and without genetic predisposition) were investigated. Study participants were treated in Limited Liability Company (LLC) “Oncology Scientific Research Center” (Tbilisi, Georgia). The study group was collected between 2020 and 2021. In patients’ blood, the thyroid hormones content (free Triiodothyronine (fFT3), free Thyroxine (fFT4), bound Triiodothyronine (FT3), bound Thyroxine (FT4), Thyroid-stimulating hormone (TSH)), and oxidative stress intensity (total activity of non-enzymatic antioxidant system (TAA) and the lipid peroxidation product, malondialdehyde (MDA), content) were investigated.ResultsThe difference in free and bound forms of T3 and T4 levels in the blood serum between patients with thyroid cancer (Group 2 and Group 3) and the control group (Group 1) was not statistically significant (F1,2=0.5, p1,2=0.8, F1,3=2.31, p1,3=0.16). In patients with thyroid cancer the TSH level significantly increased compared to the control group (Group 1) (TSH (mean ± Std error): Group 1– 1.21 ± 0.12, Group 2–2.45 ± 0.11 (F1,2=107, p1,2<0.001), Group 3–2.47 ± 0.17 (F1,3=150, p1,3<0.001)) and the MDA levels increased by 4–5 fold. In patients with thyroid cancer from families with cancer aggregation(Group 2), the level of TAA statistically significantly decreased (F1 − 2=200; p1 − 2<0.001), in patients without genetic predisposition to cancer(Group 3), the level of TAA did not change compared to the control (F1 − 3= 2.13; p1 − 3=0.15),ConclusionsOxidative stress plays a critical role in tumorigenesis, and antioxidant/oxidant imbalance may contribute to the malignant transformation of normal tissue. In patients with familial susceptibility to cancer mutations of several genes, which are involved in the regulation of oxidative metabolism, may contribute to the disruption of the redox balance, increase the level of oxidative stress, and contribute to the development of thyroid cancer.

Dietary sodium modulates mTORC1-dependent trained immunity in macrophages to accelerate CKD development

Chronic Kidney Disease (CKD) is a significant global health issue linked to dietary habits, especially high salt intake. However, the precise mechanisms driving this progression remain incompletely understood. This study reveals that a high-salt diet intensifies macrophage trained immunity, leading to a marked pro-inflammatory response upon repeated pathogenic exposures, as evidenced by increased renal damage and fibrosis. Under high-salt conditions, there was an induction of CD45+F4/80+ macrophage infiltration into the renal tissue, accompanied by heightened production of inflammatory cytokines. Distinct responses were observed between circulating and resident renal macrophages to a high-salt diet, with a notable upsurge in the migration of pro-inflammatory macrophages, driven by CCL2-CCR2 signaling and aberrant mTORC1 pathway activation. Treatment with rapamycin-liposome effectively reduced this inflammatory cascade by mitigating mTORC1 signaling. Transplantation of monocytes from CKD mice with a high-salt diet significantly exacerbates renal inflammatory damage in the host mice, showing increased migratory tendency and inflammatory activity. The cell co-culture experiment further confirmed that macrophages derived from CKD mice, particularly those under conditions of high salt exposure, significantly induced apoptosis and inflammatory responses in renal tubular cells. Taken together, recurrent exposure to LPS elicits the activation of trained immunity, consequently augmenting inflammatory response of monocytes/macrophages in the involved kidneys. The high-salt diet exacerbates this phenomenon, attributable at least in part to the overactivation of the mTORC1 pathway. This research emphasizes the importance of dietary modulation and targeted immunological interventions in slowing CKD progression, providing new insights into mTORC1-mediated pathophysiological mechanisms and potential management strategies for CKD.