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Glioblastoma is the most common and highly malignant brain tumor in adults. New targeted therapeutic approaches are imperative. EGFRvIII has appealing therapeutic targets using monoclonal antibodies. Thus, endeavors toward developing new mAbs therapies for GBM capable of targeting the tumor EGFRvIII biomarker must prevail to improve the patient's prognosis. Here, we isolated and characterized an anti-EGFRvIII vNAR from a non-immune freshwater stingray mixed library, termed vNAR R426. The vNAR R426 and pEGFRvIII interaction was demonstrated by molecular docking and molecular dynamics, and the recognition of EGFRvIII in vitro was further confirmed by cell immunofluorescence staining. Moreover, the vNAR R426 was shown to be an effective cisplatin drug carrier in the U87-MG glioma cell line. The cisplatin-coupled vNAR demonstrated highly significant differences when compared to free CDDP at 72 h. Notably, the cisplatin-vNAR carrier achieved better efficacy in the U87-MG cell line. Thus, we described the vNAR R426 internalization by receptor-mediated endocytosis and the subsequent COPI-mediated nuclear translocation of EGFRvIII and highlighted the importance of this shuttle mechanism to enhance the targeted delivery of cisplatin within the glioma cell's nucleus and improved cytotoxic effect. In conclusion, vNAR R426 could be a potential therapeutic carrier for EGFRvIII-targeted glioblastoma and cancer therapies.

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OBJECTIVE: MicroRNAs play crucial roles in the pathogenesis of cancers. MiRNA-218-5p may act as either an oncogene or a tumor suppressor, but its role in the pathogenesis of Breast Cancer (BC) remains unclear. METHODS: Infiltrative breast ductal carcinoma as well as corresponding adjacent normal samples were collected from 30 patients. Mimics and inhibitors of miRNA-218-5p or corresponding negative controls were transfected into BC cells. miRNA-218-5p expression was detected by quantitative PCR. The effects of miRNA-218-5p on the malignant behaviors of BC were assessed. Dual-luciferase reporter assay was employed to evaluate the binding of miRNA-218-5p to LRIG1. RESULTS: BC tissues showed higher miRNA-218-5p expression as compared to the adjacent normal tissues. Ectopic miRNA-218-5p expression accelerated the cell cycle, cell growth and migration of BC, while repressed cell apoptosis. Interestingly, ectopic miRNA-218-5p expression down-regulated LRIG1 expression, and miRNA-218-5p could bind to LRIG1. Also, our study indicated that miRNA-218-5p up-regulated ErbB2 and EGFR expression by targeting LRIG1, suggesting that the LRIG1-mediated signaling pathway contributed to the pro-tumor effects of miRNA-218-5p on BC. CONCLUSION: MiRNA-218-5p up-regulates ErbB2 and EGFR expression by suppressing LRIG1 expression, thus promoting the malignant behaviors of BC. miRNA-218-5p may exert a pro-tumor effect on BC and serve as a therapeutic target for BC treatment.

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BACKGROUND: ABO blood group antigens (ABH antigens) are carbohydrate chains glycosylated on epithelial and red blood cells. Recent findings suggest reduced ABH expression in psoriasis and atopic dermatitis, a chronic inflammatory skin disease with retained scale. H antigen, a precursor for A and B antigens, is synthesized by fucosyltransferase 1 (FUT1). Desmosomes, critical for skin integrity, are known to require N-glycosylation for stability. We investigate the impact of H antigens, a specific type of glycosylation, on desmosomes in keratinocytes. METHOD: Primary human keratinocytes were transfected with FUT1 siRNA or recombinant adenovirus for FUT1 overexpression. Cell adhesion and desmosome characteristics and their underlying mechanisms were analyzed. RESULT: The knockdown of FUT1, responsible for H2 antigen expression in the skin, increased cell-cell adhesive strength and desmosome size in primary cultured keratinocytes without altering the overall desmosome structure. Desmosomal proteins, including desmogleins or plakophilin, were upregulated, suggesting enhanced desmosome assembly. Reduced H2 antigen expression via FUT1 knockdown led to increased keratinocyte differentiation, evidenced by elevated expression of differentiation markers. Epidermal growth factor receptor (EGFR) has been described to be associated with FUT1 and promotes cell migration and differentiation. The effects of FUT1 knockdown were recapitulated by an EGFR inhibitor concerning desmosomal proteins and cellular differentiation. Further investigation demonstrated that the FUT1 knockdown reduced EGFR signaling by lowering the levels of EGF ligands rather than directly regulating EGFR activity. Moreover, FUT1 overexpression reversed the effects observed in FUT1 knockdown, resulting in the downregulation of desmosomal proteins and differentiation markers while increasing both mRNA and protein levels of EGFR ligands. CONCLUSION: The expression level of FUT1 in the epidermis appears to influence cell-cell adhesion and keratinocyte differentiation status, at least partly through regulation of H2 antigen and EGFR ligand expression. These observations imply that the fucosylation of the H2 antigen by FUT1 could play a significant role in maintaining the molecular composition and regulation of desmosomes and suggest a possible involvement of the altered H2 antigen expression in skin diseases, such as psoriasis and atopic dermatitis.

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BACKGROUND: CD155 is a transmembrane protein that inhibits antitumor immune response and represents a predictor of worse prognosis in non-small-cell lung cancer (NSCLC). However, it remains unexplored its association with clinical characteristics and genomic status of Latin American patients. This study characterizes the CD155 expression and its clinical implications in this population. METHODS: Tissue biopsies from 86 patients with locally-advanced or metastatic NSCLC were assessed for CD155 protein expression, ALK rearrangements and EGFR mutations. Cutoff values for high CD155 expression (CD155high) were determined from receiver operating characteristic (ROC) curves according to 2-year survival. It was evaluated its association with clinicopathological features, median progression-free survival (mPFS) and overall survival (mOS). RESULTS: the cutoff score for CD155high was 155 in the entire cohort and in patients without oncogenic alterations, and it was 110 in patients with oncogenic alterations. Eighty-four patients (97.7%) were CD155 positive, of which fifty-six (65.0%) had CD155high. EGFR L858R mutation related to lower CD155 IHC score than exon 19 deletion. Individuals with CD155high showed a shorter mOS (13.0 vs. 30.8 months; HR: 1.96 [95% CI, 1.15-3.35]; p = 0.014). Patients without oncogenic alterations having a CD155high displayed shorter mPFS (1.6 vs. 6.4 months, HR: 2.09 [95% CI, 1.06-4.20]; p = 0.034) and mOS (2.9 vs. 23.1 months; HR: 1.27 [95% CI, 1.07- 4.42]; p = 0.032). Patients with oncogenic alterations having CD155high only showed a trend to shorter mOS (26.3 vs. 52.0 months; HR: 2.39 [95% CI, 0.98-5.83]; p = 0.058). CONCLUSION: CD155high is a predictor of worse outcomes in patients with advanced NSCLC, predominantly among those without oncogenic alterations. CD155 could be a potential biomarker and a molecular target in patients with poor responses to current therapies.

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The use of tyrosine kinase inhibitors (TKI) has been growing in veterinary oncology and in the past few years several TKI have been tested in dogs. However, different from human medicine, we lack strategies to select patients to be treated with each TKI. Therefore, this study aimed to screen different tumor subtypes regarding TKI target immunoexpression as a predictor strategy to personalize the canine cancer treatment. It included 18 prostatic carcinomas, 36 soft tissue sarcomas, 20 mammary gland tumors, 6 urothelial bladder carcinomas, and 7 tumors from the endocrine system. A total of 87 patients with paraffin blocks were used to perform immunohistochemistry (IHC) of human epidermal growth factor receptor 2 (HER-2), epidermal growth factor receptors 1 (EGFR1), vascular endothelial growth factor receptor 2 (VEGFR-2), platelet derived growth factor receptor beta (PDGFR-ß), c-KIT, and extracellular signal-regulated kinase 1/2 (ERK1/ERK2). The immunohistochemical screening revealed a heterogeneous protein expression among histological types with mesenchymal tumors showing the lowest expression level and carcinomas the highest expression. We have demonstrated by IHC screening that HER2, EGFR1, VEGFR-2, PDGFR-ß and ERK1/ERK2 are commonly overexpressed in dogs with different carcinomas, and KIT expression is considered relatively low in the analyzed samples.

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Brucella abortus (Ba) is a pathogen that survives inside macrophages. Despite being its preferential niche, Ba infects other cells, as shown by the multiple signs and symptoms humans present. This pathogen can evade our immune system. Ba displays a mechanism of down-modulating MHC-I on monocytes/macrophages in the presence of IFN-γ (when Th1 response is triggered) without altering the total expression of MHC-I. The retained MHC-I proteins are located within the Golgi Apparatus (GA). The RNA of Ba is one of the PAMPs that trigger this phenomenon. However, we acknowledged whether this event could be triggered in other cells relevant during Ba infection. Here, we demonstrate that Ba RNA reduced the surface expression of MHC-I induced by IFN-γ in the human bronchial epithelium (Calu-6), the human alveolar epithelium (A-549) and the endothelial microvasculature (HMEC) cell lines. In Calu-6 and HMEC cells, Ba RNA induces the retention of MHC-I in the GA. This phenomenon was not observed in A-549 cells. We then evaluated the effect of Ba RNA on the secretion of IL-8, IL-6 and MCP-1, key cytokines in Ba infection. Contrary to our expectations, HMEC, Calu-6 and A-549 cells treated with Ba RNA had higher IL-8 and IL-6 levels compared to untreated cells. In addition, we showed that Ba RNA down-modulates the MHC-I surface expression induced by IFN-γ on human monocytes/macrophages via the pathway of the Epidermal Growth Factor Receptor (EGFR). So, cells were stimulated with an EGFR ligand-blocking antibody (Cetuximab) and Ba RNA. Neutralization of the EGFR to some extent reversed the down-modulation of MHC-I mediated by Ba RNA in HMEC and A-549 cells. In conclusion, this is the first study exploring a central immune evasion strategy, such as the downregulation of MHC-I surface expression, beyond monocytes and could shed light on how it persists effectively within the host, enduring unseen and escaping CD8+ T cell surveillance.

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Cutaneous squamous cell carcinoma (cSCC) is a neoplasm type often diagnosed in dogs. However, studies focused on further investigating its molecular biology, mainly biomarkers to help implementing new therapies, remain scare in the literature. Thus, immunostaining and the gene expression of epidermal growth factor receptors (HER1 and HER2) in canine cSCC presenting different cell differentiation degrees were herein assessed. Thirty-two (32) canine cSCC were selected, classified based on to their cell differentiation degree and subjected to immunohistochemical study to assess HER1 and HER2 immunostaining intensity and distribution. In addition, HER1 and HER2 gene expression was investigated through real-time PCR. Membranous and cytoplasmic immunostaining were observed in both markers. HER2 prevailed in poorly differentiated cSCC; there was positive protein expression correlation between both markers. Mean HER1 gene expression was higher in moderately differentiated, whereas mean HER2 gene expression was higher in poorly differentiated cSCC. Moreover, there was gene expression correlation between markers, regardless of cell differentiation degree. Thus, HER2 protein immunostaining and gene expression were higher in poorly differentiated canine cSCC and it enabled understanding that increase observed in this epidermal growth factor receptor is proportional to this neoplasm's cell differentiation degree in canine species. Results in the current study helped better understanding canine cSCC's molecular biology; however, it is relevant studying other markers aiming to investigate signaling pathways.

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Although SARS-CoV-2 induces mucin hypersecretion in the respiratory tract, hyposalivation/xerostomia has been reported by COVID-19 patients. We evaluate the submandibular gland (SMGs) pathogenesis in SARS-CoV-2-infected K18-hACE2 mice, focusing on the impact of infection on the mucin production and structural integrity of acini, ductal system, myoepithelial cells (MECs) and telocytes. The spike protein, the nucleocapsid protein, hACE2, actin, EGF, TNF-α and IL-1ß were detected by immunofluorescence, and the Egfr and Muc5b expression was evaluated. In the infected animals, significant acinar hypertrophy was observed in contrast to ductal atrophy. Nucleocapsid proteins and/or viral particles were detected in the SMG cells, mainly in the nuclear membrane-derived vesicles, confirming the nuclear role in the viral formation. The acinar cells showed intense TNF-α and IL-1ß immunoexpression, and the EGF-EGFR signaling increased, together with Muc5b upregulation. This finding explains mucin hypersecretion and acinar hypertrophy, which compress the ducts. Dying MECs and actin reduction were also observed, indicating failure of contraction and acinar support, favoring acinar hypertrophy. Viral assembly was found in the dying telocytes, pointing to these intercommunicating cells as viral transmitters in SMGs. Therefore, EGF-EGFR-induced mucin hypersecretion was triggered by SARS-CoV-2 in acinar cells, likely mediated by cytokines. The damage to telocytes and MECs may have favored the acinar hypertrophy, leading to ductal obstruction, explaining xerostomia in COVID-19 patients. Thus, acinar cells, telocytes and MECs may be viral targets, which favor replication and cell-to-cell viral transmission in the SMG, corroborating the high viral load in saliva of infected individuals.

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Nox1 signaling is a causal key element in arterial hypertension. Recently, we identified protein disulfide isomerase A1 (PDI) as a novel regulatory protein that regulates Nox1 signaling in VSMCs. Spontaneously hypertensive rats (SHR) have increased levels of PDI in mesenteric resistance arteries compared with Wistar controls; however, its consequences remain unclear. Herein, we investigated the role of PDI in mediating Nox1 transcriptional upregulation and its effects on vascular dysfunction in hypertension. We demonstrate that PDI contributes to the development of hypertension via enhanced transcriptional upregulation of Nox1 in vascular smooth muscle cells (VSMCs). We show for the first time that PDI sulfenylation by hydrogen peroxide contributes to EGFR activation in hypertension via increased shedding of epidermal growth factor-like ligands. PDI also increases intracellular calcium levels, and contractile responses induced by ANG II. PDI silencing or pharmacological inhibition in VSMCs significantly decreases EGFR activation and Nox1 transcription. Overexpression of PDI in VSMCs enhances ANG II-induced EGFR activation and ATF1 translocation to the nucleus. Mechanistically, PDI increases ATF1-induced Nox1 transcription and enhances the contractile responses to ANG II. Herein we show that ATF1 binding to Nox1 transcription putative regulatory regions is augmented by PDI. Altogether, we provide evidence that HB-EGF in SHR resistance vessels promotes the nuclear translocation of ATF1, under the control of PDI, and thereby induces Nox1 gene expression and increases vascular reactivity. Thus, PDI acts as a thiol redox-dependent enhancer of vascular dysfunction in hypertension and could represent a novel therapeutic target for the treatment of this disease.

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Endothelial cells express multiple receptors mediating estrogen responses; including the G protein-coupled estrogen receptor (GPER). Past studies on nitric oxide (NO) production elicited by estrogens raised the question whether 17-ß-estradiol (E2) and natural phytoestrogens activate equivalent mechanisms. We hypothesized that E2 and phytoestrogens elicit NO production via coupling to distinct intracellular pathways signalling. To this aim, perfusion of E2 and phytoestrogens to the precontracted rat mesentery bed examined vasorelaxation, while fluorescence microscopy on primary endothelial cells cultures quantified single cell NO production determined following 4-amino-5-methylamino-2',7'-difluoroescein diacetate (DAF) incubation. Daidzein (DAI) and genistein (GEN) induced rapid vasodilatation associated to NO production. Multiple estrogen receptor activity was inferred based on the reduction of DAF-NO signals; G-36 (GPER antagonist) reduced 75 % of all estrogen responses, while fulvestrant (selective nuclear receptor antagonist) reduced significantly more the phytoestrogens responses than E2. The joint application of both antagonists abolished the E2 response but not the phytoestrogen-induced DAF-NO signals. Wortmannin or LY-294002 (PI3K inhibitors), reduced by 90% the E2-evoked signal while altering significantly less the DAI-induced response. In contrast, H-89 (PKA inhibitor), elicited a 23% reduction of the E2-induced signal while blocking 80% of the DAI-induced response. Desmethylxestospongin-B (IP3 receptor antagonist), decreased to equal extent the E2 or the DAI-induced signal. Epidermal growth factor (EGF) induced NO production, cell treatment with AG-1478, an EGF receptor kinase inhibitor reduced 90% DAI-induced response while only 53% the E2-induced signals; highlighting GPER induced EGF receptor trans-modulation. Receptor functional selectivity may explain distinct signalling pathways mediated by E2 and phytoestrogens.

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PURPOSE: We aimed to reveal the effects of rosmarinic acid (RA), which has come to the forefront with its antitumor and antioxidant properties in many studies recently in the ovarian adenocarcinoma cell line, on the epidermal growth factor receptor (EFGR) signaling pathway in the presence of doxorubicin (DOX). METHODS: Ovarian adenocarcinoma cell line (OVCAR3) and human skin keratinocyte cell line human skin keratinocyte cell line (HaCaT) were used as control. (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) test was applied to determine the effect of RA and DOX on the proliferation of OVCAR3 and HaCaT cells. Bcl2 expression and epidermal growth factor receptor (EGFR) and western blot analysis were performed to determine the expression levels of the markers. RESULTS: It was determined that RA (IC50 = 437.6 µM) and DOX (IC50 = 0.08 µM) have the ability to inhibit the proliferation of OVCAR3 cells and induce apoptosis in a 72-hour time and dose-dependent manner. Western blot showed that the expression level of Bcl-2 and EGFR in OVCAR3 cells was down-regulated by RA and DOX. CONCLUSIONS: Apoptosis in OVCAR3 cells can potentially be induced by RA via the EGFR pathway, and RA may be a potent agent for cancer therapy.

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In this research work, a series of 16 quinazoline derivatives bearing ibuprofen and an amino acid were designed as inhibitors of epidermal growth factor receptor tyrosine kinase domain (EGFR-TKD) and cyclooxygenase-2 (COX-2) with the intention of presenting dual action in their biological behavior. The designed compounds were synthesized and assessed for cytotoxicity on epithelial cancer cells lines (AGS, A-431, MCF-7, MDA-MB-231) and epithelial non-tumorigenic cell line (HaCaT). From this evaluation, derivative 6 was observed to exhibit higher cytotoxic potency (IC50) than gefitinib (reference drug) on three cancer cell lines (0.034 µM in A-431, 2.67 µM in MCF-7, and 3.64 µM in AGS) without showing activity on the non-tumorigenic cell line (>100 µM). Furthermore, assessment of EGFR-TKD inhibition by 6 showed a discreet difference compared to gefitinib. Additionally, 6 was used to conduct an in vivo anti-inflammatory assay using the 12-O-tetradecanoylphorbol-3-acetate (TPA) method, and it was shown to be 5 times more potent than ibuprofen. Molecular dynamics studies of EGFR-TKD revealed interactions between compound 6 and M793. On the other hand, one significant interaction was observed for COX-2, involving S531. The RMSD graph indicated that the ligand remained stable in 50 ns.

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Neuregulins (NRGs) are a family of signaling proteins that bind to receptor tyrosine kinases of the ErbB family (ErbB2 to ErbB4), which can homo- or heterodimerize depending on their structural features and cell type. Many studies have proposed that decreased NRG levels are a common characteristic of obesity. In liver and adipose tissue, the increase in NRG expression has protective effects against obesity. However, it is still unknown whether ErbBs expression is altered in this pathology. We hypothesized that high fat diet-induced obesity downregulates ErbB receptors expression in obese mice compared to normal weight mice. Males C57BL/6 mice (n=6-7 for each group) were fed for 12 weeks and divided into: (i) control diet (CD; 10%-kcal fat, 20%-kcal protein, 70%-kcal carbohydrates), and (ii) high fat diet (HFD; 60%-kcal fat, 20%-kcal protein, 20%-kcal carbohydrates). General parameters and ErbBs expression (qPCR, immunohistochemistry and Western blot) were evaluated. We observed a significant increase in final body weight (47%), adipose tissue to body weight ratio (244%) and HOMA-IR (69%), among other parameters, in obese mice. In HFD group significantly decreased ErbB2 (48%) and ErbB3 (66%) mRNA levels in liver (no change in ErbB4), and ErbB2 (43%), ErbB3 (76%) and ErbB4 (35%) in adipose tissue, compared to CD. Furthermore, ErbB2 and ErbB3 protein levels decreased significantly in HFD group compared to the CD in liver. Therefore, our results suggest that HFD-induced obesity significantly decreases ErbBs expression in liver and adipose tissue in this murine model, that may be associated with alterations in the NRG pathway in obese mice.

Las neuregulinas (NRGs) son una familia de proteínas de señalización que se unen a receptores tirosina quinasas de la familia ErbB (ErbB2 a ErbB4), que pueden homo- o heterodimerizar dependiendo de sus características estructurales y del tipo celular. Estudios han propuesto que la disminución de los niveles de NRG es una característica común de la obesidad. En el hígado y el tejido adiposo (TA), el aumento de la expresión de NRG tiene efectos protectores contra la obesidad. Sin embargo, aún se desconoce si la expresión de ErbBs está alterada en esta patología. Nuestra hipótesis es que la obesidad inducida por una dieta alta en grasas (DAG) disminuye la expresión de los ErbB en ratones obesos. Ratones machos C57BL/6 (n=6-7 para c/grupo) fueron alimentados durante 12 semanas y divididos en: (i) dieta control (DC; 10%-kcal grasa, 20%-kcal proteína, 70%-kcal carbohidratos), y (ii) DAG (60%-kcal grasa, 20%-kcal proteína, 20%-kcal carbohidratos). Se evaluaron los parámetros generales y la expresión de ErbBs (qPCR, inmunohistoquímica y Western blot). Observamos un aumento significativo del peso corporal final (47%), de la relación tejido adiposo/peso corporal (244%) y del HOMA-IR (69%), entre otros parámetros, en ratones obesos. En este grupo disminuyó significativamente los niveles de ARNm de ErbB2 (48%) y ErbB3 (66%) en el hígado (sin cambios en ErbB4), y de ErbB2 (43%), ErbB3 (76%) y ErbB4 (35%) en el TA. Además, los niveles de proteína ErbB2 y ErbB3 disminuyeron significativamente, en comparación con el grupo DC en el hígado. Nuestros resultados sugieren que la obesidad inducida por DAG disminuye significativamente la expresión de ErbBs en el hígado y el TA, que puede estar asociado con alteraciones en la vía NRG en ratones obesos.

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Recently, we reported that a recombinant Tepary bean (Phaseolus acutifolius) lectin (rTBL-1) induces apoptosis in colon cancer cell lines and that cytotoxicity was related to differential recognition of ß1-6 branched N-glycans. Sequencing analysis and resolution of the rTBL-1 3D structure suggest that glycan specificity could be strongly influenced by two arginine residues, R103 and R130, located in the carbohydrate binding pocket. The aim of this work was to determine the contribution of these residues towards cytotoxic activity. Two rTBL-1 mutants were produced in Pichia pastoris, biochemically characterized, and cytotoxic effects were evaluated on human colorectal cancer cells (HT-29). Substitution of either of the arginine residues with glutamines resulted in significant reductions in cytotoxic activity, with losses of 1.5 and 3 times for R103 and R130, respectively. Docking analysis showed that the mutations decreased lectin affinity binding to some Epidermal Growth Factor Receptor (EGFR)-related N-glycans. Together, these findings confirm that both of the selected arginine residues (R103 and R130) play a key role in the recognition of tumor cell glycoconjugates by rTBL-1.

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BACKGROUND: Epidermal growth factor receptor (EGFR) is frequently activated in head and neck squamous cell carcinoma (HNSCC) and serves as a valuable target for therapy. Despite the availability of the EGFR inhibitors Cetuximab, Afatinib, and Allitinib, there are limited predictive markers for their response. Understanding molecular aberrations in HNSCC could facilitate the identification of new strategies for patient clinical and biological classification, offering novel therapeutic avenues. METHODS: We assessed CCNA1, DCC, MGMT, CDKN2A/p16, and DAPK methylation status in HNSCC cell lines and their association with anti-EGFR treatment response. RESULTS: MGMT methylation status displayed high sensitivity and specificity in distinguishing sensitive and resistant HNSCC cell lines to Afatinib (AUC = 0.955) and Allitinib (AUC = 0.935). Moreover, DAPK methylation status predicted response to Allitinib with high accuracy (AUC = 0.852), indicating their putative predictive biomarker roles. CONCLUSION: These findings hold promise for the development of more personalized and effective treatment approaches for HNSCC patients.

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Cushing's disease (CD) is a life-threatening condition with a challenging diagnostic process and scarce treatment options. CD is caused by usually benign adrenocorticotrophic hormone (ACTH)-secreting pituitary neuroendocrine tumors (PitNETs), known as corticotropinomas. These tumors are predominantly of sporadic origin, and usually derive from the monoclonal expansion of a mutated cell. Somatic activating variants located within a hotspot of the USP8 gene are present in 11-62% of corticotropinomas, making USP8 the most frequent genetic driver of corticotroph neoplasia. In contrast, other somatic defects such as those affecting the glucocorticoid receptor gene (NR3C1), the BRAF oncogene, the deubiquitinase-encoding gene USP48, and TP53 are infrequent. Moreover, patients with familial tumor syndromes, such as multiple endocrine neoplasia, familial isolated pituitary adenoma, and DICER1 rarely develop corticotropinomas. One of the main molecular alterations in USP8-driven tumors is an overactivation of the epidermal growth factor receptor (EGFR) signaling pathway, which induces ACTH production. Hotspot USP8 variants lead to persistent EGFR overexpression, thereby perpetuating the hyper-synthesis of ACTH. More importantly, they condition a characteristic transcriptomic signature that might be useful for the clinical prognosis of patients with CD. Nevertheless, the clinical phenotype associated with USP8 variants is less well defined. Hereby we discuss the current knowledge on the molecular pathogenesis and clinical picture associated with USP8 hotspot variants. We focus on the potential significance of the USP8 mutational status for the design of tailored clinical strategies in CD.

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OBJECTIVES: Melanoma is one of the leading causes of cancer death. Kinesin Family member 22 (KIF22) is essential for the invasion of melanoma cells, but the role and mechanism of KIF22 in the proliferation and glycolysis in melanoma remains unknown. METHODS: KIF22 expression in melanoma tissues and the relationship between KIF22 high expression and overall survival rate in patients with melanoma were analyzed using the Tnmplot database. KIF22 expression in melanoma cells was examined by western blot. Then, KIF22 was silenced and CCK-8 assay, EDU staining and flow cytometry analysis were adopted for assessing cell proliferation and apoptosis. In addition, the glycolysis metabolism of melanoma cells was reflected by detecting Extracellular Acidification Rates (ECAR) and Oxygen Consumption Rates (OCR). The expression of proteins related to apoptosis, glycolysis and EGFR/STAT3 signaling was tested by western blot. Subsequently, melanoma cells were treated with EGF or Colivelin to further elucidate the regulatory effect of KIF22 on EGFR/STAT3 signaling. RESULTS: KIF22 expression was notably upregulated in melanoma tissues and cells, and KIF22 high expression was associated with a poor prognosis. Moreover, KIF22 insufficiency suppressed proliferation and accelerated apoptosis of melanoma cells. Additionally, glycolysis was reduced by KIF22 depletion, evidenced by the decreased ECAR and increased OCR, accompanied by the downregulated expression of HK2, PKM2 and LDHA. Importantly, the impacts of KIF22 depletion on the progression of melanoma were partially attenuated after EGF or Colivelin treatment. CONCLUSION: Collectively, KIF22 knockdown suppressed the proliferation and glycolysis and facilitated the apoptosis of melanoma cells by inactivating EGFR/STAT3 signaling.

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Sphingomyelinase D (SMase D), the main toxic component of Loxosceles venom, has a well-documented role on dermonecrotic lesion triggered by envenomation with these species; however, the intracellular mechanisms involved in this event are still poorly known. Through differential transcriptomics of human keratinocytes treated with L. laeta or L. intermedia SMases D, we identified 323 DEGs, common to both treatments, as well as upregulation of molecules involved in the IL-1 and ErbB signaling. Since these pathways are related to inflammation and wound healing, respectively, we investigated the relative expression of some molecules related to these pathways by RT-qPCR and observed different expression profiles over time. Although, after 24 h of treatment, both SMases D induced similar modulation of these pathways in keratinocytes, L. intermedia SMase D induced earlier modulation compared to L. laeta SMase D treatment. Positive expression correlations of the molecules involved in the IL-1 signaling were also observed after SMases D treatment, confirming their inflammatory action. In addition, we detected higher relative expression of the inhibitor of the ErbB signaling pathway, ERRFI1, and positive correlations between this molecule and pro-inflammatory mediators after SMases D treatment. Thus, herein, we describe the cell pathways related to the exacerbation of inflammation and to the failure of the wound healing, highlighting the contribution of the IL-1 signaling pathway and the ERRFI1 for the development of cutaneous loxoscelism.

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Medulloblastoma (MB) is a heterogeneous group of malignant pediatric brain tumors, divided into molecular groups with distinct biological features and prognoses. Currently available therapy often results in poor long-term quality of life for patients, which will be afflicted by neurological, neuropsychiatric, and emotional sequelae. Identifying novel therapeutic agents capable of targeting the tumors without jeopardizing patients' quality of life is imperative. Rosmarinic acid (RA) is a plant-derived compound whose action against a series of diseases including cancer has been investigated, with no side effects reported so far. Previous studies have not examined whether RA has effects in MB. Here, we show RA is cytotoxic against human Daoy (IC50 = 168 µM) and D283 (IC50 = 334 µM) MB cells. Exposure to RA for 48 h reduced histone deacetylase 1 (HDAC1) expression while increasing H3K9 hyperacetylation, reduced epidermal growth factor (EGFR) expression, and inhibited EGFR downstream targets extracellular-regulated kinase (ERK)1/2 and AKT in Daoy cells. These modifications were accompanied by increased expression of CDKN1A/p21, reduced expression of SOX2, and a decrease in proliferative rate. Treatment with RA also reduced cancer stem cell markers expression and neurosphere size. Taken together, our findings indicate that RA can reduce cell proliferation and stemness and induce cell cycle arrest in MB cells. Mechanisms mediating these effects may include targeting HDAC1, EGFR, and ERK signaling, and promoting p21 expression, possibly through an increase in H3K9ac and AKT deactivation. RA should be further investigated as a potential anticancer agent in experimental MB.

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INTRODUCTION: Zika virus (ZIKV) is a human teratogen that causes congenital Zika syndrome (CZS). AXL, TLR3, and STAT2 are proteins involved in the ZIKV's entry into cells (AXL) and host's immune response (TLR3 and STAT2). In this study, we evaluated the role of genetic polymorphisms in these three genes as risk factors to CZS, and highlighted which proteins that interact with them could be important for ZIKV infection and teratogenesis. MATERIALS AND METHODS: We evaluate eighty-eight children exposed to ZIKV during the pregnancy, 40 with CZS and 48 without congenital anomalies. The evaluated polymorphisms in AXL (rs1051008), TLR3 (rs3775291), and STAT2 (rs2066811) were genotyped using TaqMan® Genotyping Assays. A protein-protein interaction network was created in STRING database and analyzed in Cytoscape software. RESULTS: We did not find any statistical significant association among the polymorphisms and the occurrence of CZS. Through the analyses of the network composed by AXL, TLR3, STAT2 and their interactions targets, we found that EGFR and SRC could be important proteins for the ZIKV infection and its teratogenesis. CONCLUSION: In summary, our results demonstrated that the evaluated polymorphisms do not seem to represent risk factors for CZS; however, EGFR and SRC appear to be important proteins that should be investigated in future studies.