Search Results (320)

Oocytes and cumulus cells undergo meiotic resumption and proliferation via gonadotropins and growth factors during maturation, and various small G proteins are activated when COCs undergo physiological changes. This study investigated the influence of gonadotropins and growth factors on Ras and its GTPases during porcine COC maturation. Unmatured COCs were treated with FSH, LH, or EGF for 44 h. The mRNA expression levels of the Ras subfamily (H-Ras, K-Ras, N-Ras, and R-Ras), its GTPases (RASA1 and SOS1), and proliferation factors (ERK, CCNB1, and Cdc2) were analyzed using RT-PCR. In contrast to other Ras subfamilies, R-Ras expression is upregulated during COC maturation. We evaluated the effects of FSH, LH, and EGF at various concentrations that most effectively regulated the expression of R-Ras and GTPases. The results demonstrated that 0.5 µg/mL FSH, 10 IU/mL human chorionic gonadotropin (hCG), and 10 ng/mL EGF effectively enhanced R-Ras expression and cell proliferation. FSH supplementation during porcine COC maturation significantly upregulated R-Ras and ERK expression, independent of LH and EGF, and downregulated Cdc2 expression. These results indicated that FSH regulates R-Ras expression, thereby promoting cell proliferation during COC maturation. These results provide fundamental knowledge for understanding the role of Ras and its family members in the development of follicular environments in pigs. Full article

Hypertension and metabolic dysfunction-associated fatty liver disease (MAFLD) are both common chronic diseases globally. Nearly half of patients with hypertension are complicated by MAFLD. The mechanisms of the bidirectional promotion between the two remain unclear. The (pro) renin receptor ((P)RR) is one of the classic members of the renin–angiotensin system (RAS) and serves as the receptor for prorenin. Although the role of (P)RR in the induction and progression of hypertension has been extensively studied, its role and underlying mechanisms in MAFLD remain underreported. In this study, we aim to investigate the role of (P)RR in the pathogenesis of hypertension combined with MAFLD. In this study, SHRs were used for the model for hypertension combined with MAFLD. Liver lipid content analysis, liver H&E staining, the detection of (P)RR, ERK and downstream proteins related to fatty acid synthesis and transport, and RNA sequencing and data analysis were performed. In the in vitro experiments, we activated (P)RR using renin and established the lipid deposition model of HepG2 cells induced by renin for the first time. (P)RR was specifically blocked using handle region peptide (HRP), and Nile red fluorescence staining, (P)RR/ERK/PPARγ protein expression analysis, and immunofluorescence were performed to further verify the role of (P)RR in the pathogenesis of hypertension combined with MAFLD. Our results demonstrate that (P)RR plays a role in the development and progression of hypertension combined with MAFLD. The hepatic TG and FFA levels in the SHRs were increased, and the protein expression of the (P)RR/ERK/PPARγ pathway and downstream proteins related to fatty acid synthesis and transport were upregulated. HRP reversed the activation of these proteins and reduced intracellular lipid accumulation. In conclusion, our study first reveals that (P)RR is a potential therapeutic target for hypertension combined with MAFLD. And we found the (P)RR/ERK/PPARγ axis for the first time, which plays an important role in the progression of spontaneous hypertension combined with MAFLD. Full article

Recent diagnostic advances reveal that lymphatic disease in Noonan syndrome (NS) and other NS-like RASopathies often stems from central conducting lymphatic anomalies (CCLAs). The RAS/MAPK-ERK pathway plays a central role in lymphangiogenesis. Targeting this pathway with MEK-inhibitor trametinib has emerged as a promising therapeutic strategy for managing CCLAs in patients with NS-like RASopathies. This case series assessed the clinical outcomes of trametinib therapy in eight patients with NS-like RASopathies and CCLA, each offering unique insights into the therapeutic efficacy of MEK inhibition. In infants, a lower dose of 0.01 mg/kg/day and earlier discontinuation of trametinib therapy effectively alleviated the symptoms of congenital chylothorax and rescued the lymphatic phenotype, compared to similar published cases. Moreover, four patients aged >11 y showed a slower response and did not achieve complete symptomatic recovery. In conclusion, it is advised to consider trametinib therapy for patients with severe, therapy-refractory CCLA in patients with NS-like RASopathies. However, individual responses to trametinib therapy may vary, with some patients demonstrating more favorable outcomes than others. Further investigation into potential enhancers and suppressors of the lymphatic phenotype is necessary for more accurate treatment predictions. While these factors are likely genetic, we cannot rule out other intrinsic or physiological factors. Full article

Thyroid tumors are common in humans and cats, occurring most commonly as benign lesions, whereas thyroid carcinoma is barely detected in both species. Determining the mutational status of MAPK-related genes (BRAF, NRAS, HRAS, and KRAS) and the activation status of MAPK and mTOR pathways is crucial for establishing the diagnosis, treatment, and prognosis of human patients. So far, the role of such players in feline thyroid tumorigenesis remains underexplored. This study aims to elucidate the presence and implications of potential shared molecular mechanisms between human and feline thyroid tumors. Fifteen formalin-fixed paraffin-embedded feline thyroid epithelial tumors (four tumors with atypia and 11 with no atypia) were collected to perform mutational and immunohistochemical analyses. Sanger sequencing targeting human homologous hotspots revealed no mutations in BRAF (human codon 600) or RAS (human codon 61) regions. A KRAS missense mutation (p.Gln232His) was identified in two tumors with no atypia of follicular pattern (2/15, 13%). Regardless of the mutational status, pERK (Thr202/Ty204) was immuno-expressed in 10/11 (91%), pS6 (Ser235/236) in 100%, and pAKT (Ser473) in 8/11 (73%) of the tumors with no atypia. The expression patterns of pERK, pS6, and pAKT and their associations with clinical-pathological features seem to mirror the progression dynamics observed in human thyroid tumorigenesis. pAKT expression was associated with the presence of multiple tumor foci within the same thyroid lobe, suggesting its potential as a marker of aggressiveness in feline thyroid tumors. This study introduces cats as potential animal models for human thyroid tumorigenesis, with further research required to confirm such potential. Full article

Cardiovascular diseases are a leading cause of mortality, driving the search for alternative preventive strategies. This study investigates the antioxidant effects, among others, of a mixture of four bioactive peptides (BPs) derived from dry-cured pork ham on endothelial cells from healthy (C-HUVECs) and gestational diabetes (GD-HUVECs) pregnancies, as well as human plasma, using an integrative omics approach. Human umbilical vein endothelial cells (HUVECs) were treated with 300 μM purified BP, followed by transcriptomic and proteomic analyses. The results revealed significant alterations in mitochondrial gene expression and downregulation of genes associated with inflammation and oxidative stress in healthy HUVECs. Furthermore, BP treatment modulated key signalling pathways, including Ras and MAPK, leading to changes in the phosphorylation of ERK, AKT, and NF-κB, suggesting potential cardioprotective effects. The effects of BP were compared to those of the antioxidant hydroxytyrosol, highlighting their relative efficacy in vascular protection. The proteomic analysis of human plasma demonstrated BP-induced modulation of lipid metabolism, inflammation, and oxidative stress with notable changes in proteins such as APOA1 and MMP-8. These natural compounds demonstrate significant preventive potential in vascular health, highlighting their promise as effective tools for reducing cardiovascular risk before the progression of the pathology. These findings emphasize the importance of integrative omics in understanding the mechanisms behind BP’s effects and suggest promising applications for nutraceuticals aimed at cardiovascular protection. Full article

Background: Canine oral melanoma (COM) is an aggressive and often fatal neoplasm in dogs, with clinical and molecular similarities to human melanoma. Despite its relevance as a comparative oncology model, the molecular mechanisms underlying COM remain poorly understood. This study aimed to characterize gene expression profiles in COM to identify differentially expressed genes (DEGs), potential biomarkers, and therapeutic targets. Methods: In this pilot study, we performed RNA sequencing (RNA-seq) on tumor and healthy oral tissue samples from dogs. Two independent analytical pipelines—Bowtie2-DESeq2 and HISAT-StringTie-Ballgown—were used to ensure robustness in DEG detection. We also conducted pathway enrichment and isoform-level analyses to investigate biological processes and alternative splicing events. Results: Both approaches identified a core set of 929 common DEGs. Key oncogenic pathways, including MAPK/ERK and cell cycle regulation, were significantly affected, with notable upregulation of BRAF, NRAS, CDK4, and MITF (log2FC = 2.86, p < 0.001). The transcription factor SOX10 and the cytokine IL-33, both previously implicated in melanoma progression, were consistently overexpressed. Additionally, NF1, a known RAS pathway inhibitor, was also upregulated. Isoform analysis revealed novel transcript variants, suggesting a complex layer of post-transcriptional regulation in COM. Many DEGs remained uncharacterized, and chromosomal distribution analysis highlighted potential genomic influences. Conclusions: Our findings provide new insights into the molecular landscape of COM, reinforcing its utility as a model for human melanoma. The identification of conserved oncogenic pathways and novel transcript variants opens avenues for further functional studies and the development of targeted therapies in both veterinary and human oncology. Full article

The unique secondary messenger 2′3′-cGAMP, produced by cGAS in response to cytosolic dsDNA, plays a critical role in activating innate immunity by binding to and activating STING via cell-intrinsic, autocrine, or paracrine mechanisms. Recently, we identified Rab18 as a novel, STING-independent binder of 2′3′-cGAMP. Binding of 2′3′-cGAMP to Rab18 promotes Rab18 activation and induces cell migration. However, the downstream mechanisms by which 2′3′-cGAMP-induced Rab18 activation regulates cell migration remain largely unclear. Herein, using phospho-profiling analysis, we identify MAPK signaling as a key downstream effector of the 2′3′-cGAMP/Rab18 axis that promotes the expression of FosB2 and drives cell migration. Furthermore, we identify MMP3 as a major transcriptional target of FosB2, through which the 2′3′-cGAMP/Rab18/MAPK/FosB2 signaling pathway positively regulates cell migration. Together, our findings provide new mechanistic insights into how 2′3′-cGAMP signaling controls cell migration and suggest the potential of MAPK inhibitors to block 2′3′-cGAMP-induced migratory responses. Full article

Reciprocal signaling between acute myeloid leukemia (AML) cells and the surrounding bone-marrow microenvironment (BMME) promotes AML progression through several mechanisms. One of the most important mechanisms is the induction of Galectin-3 (Gal-3) expression by AML cells and bone marrow mesenchymal stromal cells (BM-MSCs). Emerging evidence indicates that Gal-3 upregulation in the BMME promotes AML cell adhesion and survival, leading to the development of chemotherapy resistance, relapse, and poor prognosis. Identifying the biological function and critical signaling pathways of Gal-3 may contribute to overcoming acquired drug resistance and preventing post-treatment relapse. Gal-3 is involved in several molecular signaling pathways, including PI3K/AKT/mTOR, Ras/Raf/MEK/ERK, JAK/STAT, JNK, Wnt/β-catenin, PLC/PKC and NF-κB, which are interconnected to promote AML cell survival and resistance to chemotherapy. This review focuses on the biological effects, molecular mechanisms of action and regulation of Gal-3 in the pathogenesis and progression of AML. The therapeutic potential of potent synthetic small-molecule Gal-3 inhibitors in high-risk patients with AML is also discussed based on preclinical and clinical evidence from several human diseases. Currently, the effect of these Gal-3 inhibitors in AML has not been investigated either in vitro or in vivo. The findings provide a rationale for targeting Gal-3 that may be a very promising therapeutic approach, especially for patients with relapsed/refractory AML, and may enhance the efficacy of conventional chemotherapeutic drugs and/or immune checkpoint inhibitors. Full article

Background/Objectives: Neurofibromatosis type 1 (NF1) is a prevalent inherited disorder, with approximately 50% of affected individuals developing plexiform neurofibromas (PNFs), which can progress to highly aggressive malignant peripheral nerve sheath tumors (MPNSTs). While selumetinib is FDA-approved for PNFs, its efficacy in MPNSTs is limited and associated with dose-limiting toxicities. NF1 deficiency drives tumorigenesis and alters immune dynamics via RAS hyperactivation. Given the substantial macrophage infiltration in NF1 lesions and its association with disease progression, we hypothesized that targeting tumor-promoting immune cells with the retinoid X receptor (RXR) agonist MSU-42011 could be an alternative therapeutic strategy, as it has shown promise in KRAS-driven cancers by decreasing pERK levels and reducing tumor-promoting immune cells. Methods: We examined the effects of MSU-42011 and selumetinib, alone and in combination, on NF1-deficient cells and in a syngeneic MPNST model. Results: In vivo, the combination of MSU-42011 and selumetinib significantly reduced tumor growth, pERK levels, and tumor-promoting macrophages and increased activated CD8⁺ T cells in syngeneic MPNST models. In NF1-deficient cells, MSU-42011 or selumetinib reduced pERK levels, with combination treatment achieving greater reductions. Conditioned media (CM) from NF1-deficient cells increased the protein and mRNA levels of several cytokines and chemokines in human THP1 cells and bone marrow-derived macrophages (BMDMs). MSU-42011 and selumetinib, alone or in combination, partially reversed this induction. Conclusions: These findings suggest RXR agonists may have therapeutic potential against NF1, and their combination with MEK inhibitors could represent a promising strategy for NF1-associated tumors. Further studies are needed to validate these results and assess their translational relevance. Full article

Changes in cell signaling pathways, which in normal conditions determine the maintenance of cell homeostasis and the correctness of its basic processes, may cause the transformation of a normal cell into a cancer cell. Alterations in cellular metabolism leading to oncogenesis are considered to be a hallmark of cancer cells. Therefore, a thorough understanding of cellular enzymes affecting metabolism and respiration, as well as intracellular pathways connected with them, seems crucial. These changes may be both prognostic and predictive factors, especially in terms of using molecularly targeted therapies. Aberrations in the pathways responsible for cell growth and angiogenesis are considered particularly important in the process of oncogenesis. Gliomas are the most common primary malignant tumors of the brain. The most important molecular disorders determining their particularly malignant nature are aberrations in the pathways responsible for cell growth and angiogenesis, such as the PI3K/Akt or RAS/MAPK/ERK signaling pathway, as well as excessive activity of enzymes, like hexokinases, which play a key role in glycolysis, autophagy, and apoptosis. The multitude of alterations detected in glioma cells, high heterogeneity, and the immunosuppressive environment within the tumor are the main features causing failures in the attempts to implement modern therapies. Full article

Colorectal cancer (CRC) is one of the most common cancers worldwide, with KRAS mutations occurring in approximately 40% of cases. These mutations drive tumorigenesis through the constitutive activation of key signaling pathways, such as RAS-RAF-MEK-ERK (MAPK) and PI3K-AKT-mTOR, contributing to therapeutic resistance and poor prognosis. Advances in molecular biology have led to significant breakthroughs, including the development of KRAS G12C inhibitors, such as sotorasib and adagrasib, which have shown promise in clinical trials. However, their efficacy is limited to a small subset of KRAS-mutant CRC, and resistance mechanisms often emerge through compensatory pathway activation. Combination strategies, including KRAS inhibitors with anti-EGFR agents, have been explored in trials like KRYSTAL-1 and CodeBreaK 300. Emerging research highlights the role of the tumor microenvironment in immune evasion and therapeutic resistance, offering opportunities for novel immunotherapy approaches, including KRAS neoantigen vaccines and adoptive T-cell therapy. Despite these advancements, challenges such as intratumoral heterogeneity, limited immune infiltration, and non-G12C KRAS mutations remain significant hurdles. This review provides a comprehensive overview of the molecular mechanisms, current advances and challenges, and future prospects in the management of KRAS-mutant CRC. Full article

In addition to the classically accepted pathophysiological features of Alzheimer’s disease (AD), increasing attention is paid to the role of the insulin-resistant state of the central nervous system. Glucagon-like peptide-1 receptor (GLP-1R) agonism demonstrated neuroprotective consequences by mitigating neuroinflammation and oxidative damage. The present review aims to offer a comprehensive overview of the neuroprotective properties of GLP-1R agonists (GLP-1RAs), with a particular focus on experimental animal models of AD. Ameliorated amyloid-β plaque and neurofibrillary tangle formation and deposition following exenatide, liraglutide, and lixisenatide treatment was confirmed in several models. The GLP-1RAs studied alleviated central insulin resistance, as evidenced by the decreased serine phosphorylation of insulin receptor substrate 1 (IRS-1) and restored downstream phosphoinositide 3-kinase/RAC serine/threonine–protein kinase (PI3K/Akt) signaling. Furthermore, the GLP-1RAs influenced multiple mitogen-activated protein kinases (extracellular signal-regulated kinase: ERK; c-Jun N-terminal kinase: JNK, p38) positively and suppressed glycogen synthase kinase 3 (GSK-3β) hyperactivation. A lower proportion of reactive microglia and astrocytes was associated with better neuronal preservation following their administration. Finally, restoration of cognitive functions, particularly spatial memory, was also observed for semaglutide and dulaglutide. GLP-1RAs, therefore, hold promising disease-modifying potential in the management of AD. Full article

Perfluorooctane sulfonate (PFOS), a persistent organic pollutant, has raised significant public health concerns because of its widespread environmental presence and potential toxicity. Epidemiological studies have linked PFOS exposure to respiratory diseases, but the underlying molecular mechanisms remain poorly understood. Male C57 BL/6J mice were divided into a control group receiving Milli-Q water, a low-dose PFOS group (0.2 mg/kg/day), and a high-dose PFOS group (1 mg/kg/day) administered via intranasal instillation for 28 days. Lung tissue transcriptome sequencing revealed significantly enriched differentially expressed genes in the Ras and Rap signaling pathways. Key genes including Rap1b, Kras, and BRaf as well as downstream genes, such as MAPK1 and MAP2K1, exhibited dose-dependent upregulation in the high-dose PFOS exposure group. Concurrently, the downstream effector proteins MEK, ERK, ICAM-1, and VEGFa were significantly elevated in bronchoalveolar lavage fluid (BALF). These alterations are mechanistically associated with increased oxidative stress, inflammatory cytokine release, and pulmonary tissue damage. The results indicated that PFOS-induced lung injury is likely predominantly mediated through the activation of the Rap1b- and Kras-dependent BRaf-MEK-ERK axis. These findings highlight the critical role of Ras/Rap signaling pathways in PFOS-associated respiratory toxicity and underscore the need to develop therapeutic interventions targeting these pathways to mitigate associated health risks. Full article

The Ras/PI3K/ERK signaling network is frequently mutated and overactivated in various human cancers. Focal adhesion kinase (FAK) is commonly overexpressed in several cancer types and has been implicated in treatment resistance mechanisms. A positive feedback loop between Ras, PI3K, the cytoskeleton, and FAK was previously shown to drive Ras signaling excitability. In this study, we investigated the effectiveness of targeting Ras signaling excitability by concurrently inhibiting FAK and PI3K in cervical and pancreatic cancer cells, which depend on activation Ras/PI3K signaling. We found that the combination of FAK and PI3K inhibitors synergistically suppressed the growth of cervical and pancreatic cancer cell lines through increased apoptosis and decreased mitosis. PI3K inhibitors alone caused only a transient suppression of downstream AKT activity and paradoxically increased FAK signaling in cancer cells. The addition of an FAK inhibitor effectively counteracted this PI3K-inhibitor-induced FAK activation. Furthermore, PI3K inhibitors were found to activate multiple receptor tyrosine kinases (RTKs), including insulin receptor, IGF-1R, EGFR, HER2, HER3, AXL, and EphA2. Taken together, our results suggest that FAK inhibition is necessary to counteract the compensatory RTK activation induced by PI3K inhibitors, thereby achieving more effective suppression of cancer cell growth. These findings highlight the therapeutic potential of combined FAK and PI3K inhibition in cancer treatment. Full article

Cancer, characterized by the uncontrolled proliferation of cells, is one of the leading causes of death globally, with approximately one in five people developing the disease in their lifetime. While many driver genes were identified decades ago, and most cancers can be classified based on morphology and progression, there is still a significant gap in knowledge about genetic aberrations and nuclear DNA damage. The study of two critical groups of genes—tumor suppressors, which inhibit proliferation and promote apoptosis, and oncogenes, which regulate proliferation and survival—can help to understand the genomic causes behind tumorigenesis, leading to more personalized approaches to diagnosis and treatment. Aberration of tumor suppressors, which undergo two-hit and loss-of-function mutations, and oncogenes, activated forms of proto-oncogenes that experience one-hit and gain-of-function mutations, are responsible for the dysregulation of key signaling pathways that regulate cell division, such as p53, Rb, Ras/Raf/ERK/MAPK, PI3K/AKT, and Wnt/β-catenin. Modern breakthroughs in genomics research, like next-generation sequencing, have provided efficient strategies for mapping unique genomic changes that contribute to tumor heterogeneity. Novel therapeutic approaches have enabled personalized medicine, helping address genetic variability in tumor suppressors and oncogenes. This comprehensive review examines the molecular mechanisms behind tumor-suppressor genes and oncogenes, the key signaling pathways they regulate, epigenetic modifications, tumor heterogeneity, and the drug resistance mechanisms that drive carcinogenesis. Moreover, the review explores the clinical application of sequencing techniques, multiomics, diagnostic procedures, pharmacogenomics, and personalized treatment and prevention options, discussing future directions for emerging technologies. Full article