RADCURE: An open-source head and neck cancer CT dataset for clinical radiation therapy insights.

PURPOSE: This manuscript presents RADCURE, one of the most extensive head and neck cancer (HNC) imaging datasets accessible to the public. Initially collected for clinical radiation therapy (RT) treatment planning, this dataset has been retrospectively reconstructed for use in imaging research. ACQUISITION AND VALIDATION METHODS: RADCURE encompasses data from 3346 patients, featuring computed tomography (CT) RT simulation images with corresponding target and organ-at-risk contours. These CT scans were collected using systems from three different manufacturers. Standard clinical imaging protocols were followed, and contours were manually generated and reviewed at weekly RT quality assurance rounds. RADCURE imaging and structure set data was extracted from our institution's radiation treatment planning and oncology information systems using a custom-built data mining and processing system. Furthermore, images were linked to our clinical anthology of outcomes data for each patient and includes demographic, clinical and treatment information based on the 7th edition TNM staging system (Tumor-Node-Metastasis Classification System of Malignant Tumors). The median patient age is 63, with the final dataset including 80% males. Half of the cohort is diagnosed with oropharyngeal cancer, while laryngeal, nasopharyngeal, and hypopharyngeal cancers account for 25%, 12%, and 5% of cases, respectively. The median duration of follow-up is five years, with 60% of the cohort surviving until the last follow-up point. DATA FORMAT AND USAGE NOTES: The dataset provides images and contours in DICOM CT and RT-STRUCT formats, respectively. We have standardized the nomenclature for individual contours-such as the gross primary tumor, gross nodal volumes, and 19 organs-at-risk-to enhance the RT-STRUCT files' utility. Accompanying demographic, clinical, and treatment data are supplied in a comma-separated values (CSV) file format. This comprehensive dataset is publicly accessible via The Cancer Imaging Archive. POTENTIAL APPLICATIONS: RADCURE's amalgamation of imaging, clinical, demographic, and treatment data renders it an invaluable resource for a broad spectrum of radiomics image analysis research endeavors. Researchers can utilize this dataset to advance routine clinical procedures using machine learning or artificial intelligence, to identify new non-invasive biomarkers, or to forge prognostic models.

LINC00668 promoted non-small lung cancer progression by miR-518c-3p/TRIP4 axis.

BACKGROUND: Non-small lung cancer ranks first in the cancer-related death of all malignant tumors. Exploring novel biological targets is of great significance for diagnosis and therapy of NSCLC. OBJECTIVE: In this study, we aimed to explore the effect of LINC00668 on the biological functions of NSCLC cells and the underlying mechanism. METHODS: RT-qPCR assays and western blot assays were utilized to estimate the relative gene expression at mRNA and protein levels, respectively. CCK8, colony formation, wound healing, transwell, and cell apoptosis assays were employed to assess cell function. IHC and FISH assays were used to determine the gene expression in NSCLC tissues. RIP and dual-luciferase assays were conducted to validate the combination between LINC00668 and miR-518c-3p. The correlation of expression between miR-518c-3p and LINC00668 or TRIP4 was determined by Pearson correlation analysis. RESULTS: LINC00668 was aberrantly upregulated in NSCLC tumor tissues and cell lines. Inhibition of LINC00668 significantly suppressed tumor proliferation, migration, invasion and promoted cell apoptosis. Mechanistically, LINC00668 could bind to miR-518c-3p, thus targeting the 3'UTR of TRIP4. TRIP4 overexpression rescued the weakened cell function mediated by LINC00668 silencing. CONCLUSIONS: LINC00668 acted as an oncogene in NSCLC progression through miR-518c-3p/TRIP4 axis. Our study disclosed a new mechanism of LINC00668 functioned in NSCLC and may give a deeper insight of the targeted therapy of NSCLC in the future.

Triamcinolone acetonide induces the autophagy of Ag85B-treated WI-38 cells via SIRT1/FOXO3 pathway.

BACKGROUND: Tracheobronchial stenosis due to tuberculosis (TSTB) seriously threatens the health of tuberculosis patients. The inflammation and autophagy of fibroblasts affect the development of TSTB. Triamcinolone acetonide (TA) can regulate the autophagy of fibroblasts. Nevertheless, the impact of TA on TSTB and underlying mechanism has remained unclear. OBJECTIVE: To study the impact of TA on TSTB and underlying mechanism. MATERIAL AND METHODS: In order to simulate the TSTB-like model in vitro, WI-38 cells were exposed to Ag85B protein. In addition, the cell counting kit (CCK)-8 assay was applied to assess the function of TA in Ag85B-treated WI-38 cells. Quantitative real-time polymerase chain reaction was applied to detect the mRNA level of sirtuin 1 (SIRT1) and forkhead box O3 (FOXO3a), and autophagy-related proteins were evaluated by Western blot analysis. Vascular endothelial growth factor (VEGF) level was investigated by immunohistochemical staining. Enzyme-linked immunosorbent serologic assay was applied to detect the secretion of inflammatory cytokines. Furthermore, hematoxylin and eosin staining was applied to observe tissue injuries. RESULTS: Ag85B affected WI-38 cell viability in a limited manner, while TA notably suppressed Ag85B-treated WI-38 cell viability. TA induced the apoptosis of Ag85B-treated WI-38 cells in a dose-dependent manner. In addition, Ag85B-treated WI-38 cells demonstrated the upregulation of interleukin (IL)-6, tumor necrosis factor-α (TNF-α), interferon gamma (IFN-γ), and fibrotic proteins (transforming growth factor-beta [TGF-ß] and vascular endothelial growth factor [VEGF]), which can be significantly destroyed by the TA. Meanwhile, TA reversed Ag85-induced inhibition of cell autophagy by mediation of p62, LC3, and Beclin1. Furthermore, silencing of SIRT1/FOXO3a pathway could reverse the effect of TA on the autophagy of Ag85B-treated cells. CONCLUSION: TA significantly induced the autophagy of fibroblasts in Ag85B-treated cells by mediation of SIRT1/FOXO3 pathway. This study established a new theoretical basis for exploring strategies against TSTB.

A risk score model based on TGF-ß pathway-related genes predicts survival, tumor microenvironment and immunotherapy for liver hepatocellular carcinoma.

BACKGROUND: Transforming growth factor-beta (TGF-ß) signal is an important pathway involved in all stages of liver hepatocellular carcinoma (LIHC) initiation and progression. Therefore, targeting TGF- ß pathway may be a potential therapeutic strategy for LIHC. Prediction of patients' tumor cells response requires effective biomarkers. METHODS: From 54 TGF-ß-related genes, this research determined the genes showing the greatest relation to LIHC prognosis, and developed a risk score model with 8 TGF-ß-related genes. The model divided LIHC patients from different datasets and platforms into low- and high-risk groups. Multivariate Cox regression analysis confirmed that the model was an independent prognostic factor for LIHC. The differences in genetic mutation, immune cell infiltration, biological pathway, response to immunotherapy or chemotherapy, and tumor microenvironment in LIHC samples showing different risks were analyzed. RESULTS: Compared with low-risk group, in the training set and test set, high-risk group showed shorter survival, lower stromal score and higher M0 macrophages scores, regulatory T cells (Tregs), helper follicular T cells. Moreover, high-risk samples showed higher sensitivity to cisplatin, imatinib, sorafenib and salubrinal and pyrimethamine. High-risk group demonstrated a significantly higher Tumor Immune Dysfunction and Exclusion (TIDE) score, but would significantly benefit less from taking immunotherapy and was less likely to respond to immune checkpoint inhibitors. CONCLUSIONS: In general, this work provided a risk scoring model based on 8 TGF-ß pathway-related genes, which might be a new potential tool for predicting LIHC.

A clinical laboratory-developed LSC17 stemness score assay for rapid risk assessment of patients with acute myeloid leukemia.

Leukemia stem cells (LSCs) are linked to relapse in acute myeloid leukemia (AML). The LSC17 gene expression score robustly captures LSC stemness properties in AML and can be used to predict survival outcomes and response to therapy, enabling risk-adapted, upfront treatment approaches. The LSC17 score was developed and validated in a research setting. To enable widespread use of the LSC17 score in clinical decision making, we established a laboratory-developed test (LDT) for the LSC17 score that can be deployed broadly in clinical molecular diagnostic laboratories. We extensively validated the LSC17 LDT in a College of American Pathologists/Clinical Laboratory Improvements Act (CAP/CLIA)-certified laboratory, determining specimen requirements, a synthetic control, and performance parameters for the assay. Importantly, we correlated values from the LSC17 LDT to clinical outcome in a reference cohort of patients with AML, establishing a median assay value that can be used for clinical risk stratification of individual patients with newly diagnosed AML. The assay was established in a second independent CAP/CLIA-certified laboratory, and its technical performance was validated using an independent cohort of patient samples, demonstrating that the LSC17 LDT can be readily implemented in other settings. This study enables the clinical use of the LSC17 score for upfront risk-adapted management of patients with AML.

Blue laser imaging combined with JNET (Japan NBI Expert Team) classification for pathological prediction of colorectal laterally spreading tumors.

BACKGROUND: Blue laser imaging (BLI) can provide useful information on colorectal laterally spreading tumors (LSTs) by visualizing the surface and vessel patterns in detail. The present research aimed to evaluate the diagnostic performance of BLI-combined JNET (Japan NBI Expert Team) classification for identifying LSTs. METHODS: This retrospective, multicenter study included 172 LSTs consisted of 6 hyperplastic polyps/sessile serrated polyps, 94 low-grade dysplasias (LGD), 60 high-grade dysplasias (HGD), 6 superficial submucosal invasive (m-SMs) carcinomas, and 4 deep submucosal invasive carcinomas. The relationship between the JNET classification and the histologic findings of these lesions were then analyzed. RESULTS: For all LSTs, non-experts and experts had a 79.7% and 90.7% accuracy for Type 2A (P = 0.004), a sensitivity of 94.7% and 96.8% (P = 0.718), and a specificity of 61.5% and 83.3% (P = 0.002) for prediction of LGD, respectively. The results also demonstrated 80.8% and 91.3% accuracy for Type 2B (P = 0.005), a sensitivity of 65.2% and 83.3% (P = 0.017), and a specificity of 90.6% and 96.2% (P = 0.097) for predicting HGD or m-SMs. For LST-granular (LST-G) lesions, Type 2A in experts had higher specificity (65.6% vs. 83.6%, P = 0.022) and accuracy (81.8% vs. 91.2%, P = 0.022). Type 2B in experts only had higher accuracy (82.5% vs. 92.0%, P = 0.019). However, no significant differences were noted for any comparisons between non-experts and experts for LST-non-granular (LST-NG) lesions. CONCLUSIONS: BLI combined with JNET classification was an effective method for the precise prediction of pathological diagnosis in patients with LSTs. Diagnostic performance of JNET classification by experts was better than that by non-experts for all examined LST or LST-G lesions when delineating between Type 2A and 2B, but there was no difference for the identification of LST-NG lesions by these two groups.

Circ_0000376 enhances the proliferation, metastasis, and chemoresistance of NSCLC cells via repressing miR-384.

BACKGROUND: Non-small cell lung cancer (NSCLC) is the most common cancer worldwide. Circular RNAs (circRNAs) are recently identified as important gene regulators with critical roles in cancer biology. In this study, we focus on the effect of circ_0000376 targeting miR-384 on malignant phenotypes of NSCLC cells. METHODS: Circ_0000376 and miR-384 expression in NSCLC tissue samples were measured using qRT-PCR. The association between pathological parameters and the circ_0000376 expression was analyzed as well. Human NSCLC cell lines A549 and NCI-H460 were used as cell models. CCK-8 and BrdU assay were used to assess the effect of circ_0000376 on NSCLC cell line proliferation and drug sensitivity. Transwell assay was conducted to detect the effect of circ_0000376 on migration and invasion. Further, luciferase reporter assay was employed to validate the targeting of miR-384 by circ_0000376. RESULTS: Circ_0000376 expression in NSCLC clinical samples was up-regulated and this was linked to unfavorable pathological parameters. Circ_0000376 markedly accelerated the proliferation and metastasis, and enhanced chemoresistance of NSCLC cells. Mechanically, circ_0000376 overexpression could bind with miR-384 and repress its expression. CONCLUSIONS: Circ_0000376 is a newly discovered oncogenic circRNA in NSCLC, and can be potentially regarded as a diagnostic biomarker and therapy target.

Exosome-mediated transfer of miR-1260b promotes cell invasion through Wnt/ß-catenin signaling pathway in lung adenocarcinoma.

Increasing evidence confirms that exosome-mediated transfer of microRNAs can influence cancer progression including tumor cell invasion, cell proliferation, and drug resistance via cell-cell communication. However, the potential role of exosomal-miR-1260b in lung adenocarcinoma (LAC) remains poorly understood. Thus, this study focused on investigating the function of exosomal-miR-1260b on cell invasion. Exosomal-miR-1260b was found to be higher in plasma of patients with LAC than that of healthy persons via quantitative real-time polymerase chain reaction assay. The sensitivity and specificity of exosomal-miR-1260b (cutoff point: 2.027) were 72% and 86%, and area under the curve of 0.845 (95% CI = 0.772-0.922). Elevated expression of miR-1260b in LAC tissues was positively correlated with exosomal-miR-1260b in plasma (r = .642, p < .05). Furthermore, ceramide biosynthesis regulated exosomal-miR-1260b secretion. Exosome-mediated transfer of miR-1260b promoted A549 cell invasion and was still functional inside A549 cells. Moreover, exosomal-miR-1260b regulated Wnt/ß-catenin signaling pathway by inhibiting sFRP1 and Smad4. This study identified a new regulation mechanism involving in cell invasion by exosome-mediated tumor-cell-to-tumor-cell communication. Targeting exosome-microRNAs may provide new insights into the diagnosis and treatment of LAC.

Next-Generation Sequencing Analysis of mRNA Profile in Cisplatin-Resistant Gastric Cancer Cell Line SGC7901.

BACKGROUND Cisplatin-resistant gastric cancer (GC) occurs in patients with GC treated with cisplatin-based chemotherapy, which results in disease progression and early recurrence during the treatment. MATERIAL AND METHODS To understand the initiation and developmental mechanism underlying cisplatin-resistant GC, we developed cisplatin-resistant SGC7901 cells (SGC7901/DDP) from the parental cells (SGC7901/S) by continuous exposure to increasing concentrations of cisplatin and subjected these 2 cell lines to RNA sequencing analysis. The data were verified by quantitative polymerase chain reaction and their functional role was evaluated by cell counting kit 8 assay and cell apoptosis and cell cycle flow cytometric analysis. Bioinformatics analysis was performed to classify the differentially-expressed genes (DEGs) involved in the development of cisplatin resistance. RESULTS In comparison with SGC7901/S cells, SGC7901/DDP cells showed a total of 3165 DEGs (2014 upregulated and 1151 downregulated, fold change ≥2, and adjusted P value <0.001). qRT-PCR confirmed the reliability of the RNA sequencing results. Depletion of the top 5 upregulated mRNAs reversed the resistant index, increased apoptotic SGC7901/DDP cells, and arrested the cells at G2/M phase. Gene ontology analysis revealed that the DEGs mainly regulate metabolic process, immune system, locomotion, cell adhesion, cell growth, cell death, cytoskeleton organization, cell binding, signal transducing activity, and antioxidant activity. Kyoto Encyclopedia of Genes and Genomes analysis showed that the DEGs were mainly involved in the PI3K-Akt signaling pathway, Rap1 signaling pathway, proteoglycans in cancer, regulation of actin cytoskeleton, and pathways in cancer. CONCLUSIONS The present study is the first to interrogate mRNAs profiles in human GC cells with cisplatin resistance using RNA sequencing, which may assist in discovering potential therapeutic targets for cisplatin-resistant GC patients.

Characterisation and functional analysis of an L-type lectin from the swimming crab Portunus trituberculatus.

L-type lectins are involved in glycoprotein secretion and are associated with immune responses. Herein, an L-type lectin was identified in swimming crab (Portunus trituberculatus). The 1347 bp PtLTL cDNA includes a 26 bp 5'-untranslated region (UTR), a 547 bp 3'-UTR with a poly(A) tail, and a 774 bp open reading frame encoding a 257 amino acid protein with a putative 21 residue signalling peptide. The protein includes an L-type lectin carbohydrate recognition domain containing four conserved cysteines. The 714 bp cDNA fragment encoding the mature peptide of PtLTL1 was recombined into pET-21a (+) with a C-terminally hexa-histidine tag fused in-frame and expressed in Escherichia coli Origami (DE3). Recombinant PtLTL1 caused agglutination of all three Gram-positive and Gram-negative bacterial strains tested. In addition, erythrocyte agglutination and LPS-binding activity were observed. PtLTL1 mRNA transcripts were most abundant in P. trituberculatus hepatopancreas and hemocytes, and expression was up-regulated in hemocytes challenged with Vibrio alginolyticus, suggesting PtLTL functions in the immune response against bacterial pathogens.

Synthesis and evaluation of new 5-aminolevulinic acid derivatives as prodrugs of protoporphyrin for photodynamic therapy.

Protoporphyrin IX (PpIX) is used as a photosensitizer in the photodynamic diagnosis (PDD) and photodynamic therapy (PDT) of cancer and is synthesized intracellularly from 5-aminolevulinic acid (5-ALA) precursors. Thirteen novel 5-ALA derivatives were designed and synthesized appropriately with tailored hydrophilicity and lipophilicity. The generation of PpIX was detected and their antitumor activity in vitro and in vivo was also investigated. It was shown that compounds 9b-c, 11b-c and 13a displayed a characteristic long wavelength absorption peak at 593 nm after 5 h incubation in mice fibrosarcoma S180 cells. After being exposed to 600 nm laser light irradiation, these compounds can inhibit cell proliferation in S180 cells in vitro. The growth of S180 cell tumors in Kunming mice was significantly inhibited by these compounds in vivo. Among these compounds, 13a has low dark toxicity and high phototoxicity, which makes it an effective and promising prodrug for PDT.

Attraction induced frictionless sliding of rare gas monolayer on metallic surfaces: an efficient strategy for superlubricity.

Friction on a nanoscale revealed rich load-dependent behavior, which departs strongly from the long-standing Amonton's law. Whilst electrostatic repulsion-induced friction collapse for rare gas sliding over metallic surfaces in a high-load regime was reported by Righi et al. (Phys. Rev. Lett., 2007, 99, 176101), the significant role of attraction on frictional properties has not been reported to date. In this study, the frictional motion of Xe/Cu(111), Xe/Pd(111) and Ar/Cu(111) was studied using van der Waals corrected density functional calculations. An attraction-induced zero friction, which is a signal of superlubricity, was found for the sliding systems. The superlubric state results from the disappearance of the potential corrugation along the favored sliding path as a consequence of the potential crossing in the attractive regime when the interfacial pressure approaches a critical-value. The finding of an attraction-driven friction drop, together with the repulsion-induced collapse in the high-load regime, which breaks down the classic Amonton's law, provides a distinct approach for the realization of inherent superlubricity in some adsorbate/substrate interfaces.

DKK1 maintained cancer stem-like properties of esophageal carcinoma cells via ALDH1A1/SOX2 axis.

Dickkopf-1 (DKK1) has been reported as a key regulator in the progression of esophageal carcinoma (EC). Aldehyde dehydrogenase 1A1 (ALDH1A1) possesses stem-like properties and predicts patient outcome in several cancers. However, whether DKK1 regulates cancer stem-like properties of EC cells through modulating ALDH1A1 activity remains unclear. In this study, we found that DKK1 knockdown significantly reduced cell proliferation, colony formation and CK18 expression. Additionally, knockdown of DKK1 also decreased the expression of ALDH1A1 involved in a c-Jun-dependent manner through a pathway consisting of p38/JNK/c-Jun pathway. Furthermore, the downregulation of ALDH1A1 gene expression in Eca109 resulted in decreased expression of cancer stem cell-associated markers SOX2, Bmi1 and vimentin. Therefore, our results demonstrated that DKK1 maintained cancer stem-like properties of EC cells via ALDH1A1/SOX2 axis. DKK1 may act as a therapeutic target for the treatment of EC.

The effects of dietary carbohydrate on the growth, antioxidant capacities, innate immune responses and pathogen resistance of juvenile Black carp Mylopharyngodon piceus.

The present study was focused on the growth, antioxidant capacities, innate immune responses and pathogen resistance in juvenile Black carp Mylopharyngodon piceus fed with graded levels of dietary carbohydrate (CHO) (0.6, 106.5, 194.3, 288.4, 379.1 and 473.8 g kg(-1)) for 9 weeks. Results showed that highest weight gain and special growth ratio was obtained at 288.4 g kg(-1) dietary CHO. And adequate dietary CHO content (288.4 g kg(-1)) could significantly increase the activities of superoxide dismutase (SOD), catalase (CAT) and glutathione peroxidase (Gpx), promote reduced glutathione (GSH) content and then increase the total antioxidant capacities (TAOC) in the liver of M. piceus. However, the malondialdehyde (MDA) levels in the fish liver could be significantly aggravated by excessive dietary CHO. Serum cortisol (COL) levels could be significantly increased in juvenile Black carp M. piceus fed with 379.1 g kg(-1) dietary CHO compared with CHO-deficient diets. Activities of alanine transaminase (GPT) and aspartate transaminase (GOT) were both decreased in the serum of juvenile Black carp M. piceus fed with 194.3 g kg(-1) dietary CHO compared with CHO-deficient diets (0.6 and 106.5 g kg(-1)) or CHO-excess diets (379.1 and 473.8 g kg(-1)). In addition, 288.4 g kg(-1) dietary CHO could significantly up-regulate the mRNA expression levels of hepcidin (HEPC), natural resistance-associated macrophage protein (NRAMP), tumor necrosis factor-α (TNF-α) and interferon (IFN), lysozyme (LYZ) and complement component 3 (C3) in the blood and liver samples of juvenile Black carp M. piceus compared with the CHO-deficient diets (0.6 and 106.5 g kg(-1)). Moreover, 288.4 g kg(-1) dietary CHO could also enhance the contents of C3 and plasma nitrogen monoxide (NO), and increase the activities of LYZ and total nitric oxide synthase (t-NOS) in the serum compared with the CHO-deficient or CHO-excess diets. Furthermore, the survival rates were also increased by adequate dietary CHO (194.3 and 288.4 g kg(-1)) fed to juvenile Black carp M. piceus after infection with Aeromonas hydrophila. In conclusion, these results suggest that adequate dietary CHO (288.4 g kg(-1)) could increase growth, reduce oxidative stress, enhance innate immune responses, improve the health states and then promote disease resistance in juvenile Black carp M. piceus.

Distinct GAB2 signaling pathways are essential for myeloid and lymphoid transformation and leukemogenesis by BCR-ABL1.

Tyrosine kinase inhibitors (TKIs) directed against BCR-ABL1, the product of the Philadelphia (Ph) chromosome, have revolutionized treatment of patients with chronic myeloid leukemia (CML). However, acquired resistance to TKIs is a significant clinical problem in CML, and TKI therapy is much less effective against Ph(+)B-cell acute lymphoblastic leukemia (B-ALL). BCR-ABL1, via phosphorylated Tyr177, recruits the adapter GRB2-associated binding protein 2 (GAB2) as part of a GRB2/GAB2 complex. We showed previously that GAB2 is essential for BCR-ABL1-evoked myeloid transformation in vitro. Using a genetic strategy and mouse models of CML and B-ALL, we show here that GAB2 is essential for myeloid and lymphoid leukemogenesis by BCR-ABL1. In the mouse model, recipients of BCR-ABL1-transducedGab2(-/-)bone marrow failed to develop CML-like myeloproliferative neoplasia. Leukemogenesis was restored by expression of GAB2 but not by GAB2 mutants lacking binding sites for its effectors phosphatidylinositol 3-kinase (PI3K) or SRC homology 2-containing phosphotyrosine phosphatase 2 (SHP2). GAB2 deficiency also attenuated BCR-ABL1-induced B-ALL, but only the SHP2 binding site was required. The SHP2 and PI3K binding sites were differentially required for signaling downstream of GAB2. Hence, GAB2 transmits critical transforming signals from Tyr177 to PI3K and SHP2 for CML pathogenesis, whereas only the GAB2-SHP2 pathway is essential for lymphoid leukemogenesis. Given that GAB2 is dispensable for normal hematopoiesis, GAB2 and its effectors PI3K and SHP2 represent promising targets for therapy in Ph(+)hematologic neoplasms.

Activating Mutations Affecting the Dbl Homology Domain of SOS2 Cause Noonan Syndrome.

The RASopathies constitute a family of autosomal-dominant disorders whose major features include facial dysmorphism, cardiac defects, reduced postnatal growth, variable cognitive deficits, ectodermal and skeletal anomalies, and susceptibility to certain malignancies. Noonan syndrome (NS), the commonest RASopathy, is genetically heterogeneous and caused by functional dysregulation of signal transducers and regulatory proteins with roles in the RAS/extracellular signal-regulated kinase (ERK) signal transduction pathway. Mutations in known disease genes account for approximately 80% of affected individuals. Here, we report that missense mutations altering Son of Sevenless, Drosophila, homolog 2 (SOS2), which encodes a RAS guanine nucleotide exchange factor, occur in a small percentage of subjects with NS. Four missense mutations were identified in five unrelated sporadic cases and families transmitting NS. Disease-causing mutations affected three conserved residues located in the Dbl homology (DH) domain, of which two are directly involved in the intramolecular binding network maintaining SOS2 in its autoinhibited conformation. All mutations were found to promote enhanced signaling from RAS to ERK. Similar to NS-causing SOS1 mutations, the phenotype associated with SOS2 defects is characterized by normal development and growth, as well as marked ectodermal involvement. Unlike SOS1 mutations, however, those in SOS2 are restricted to the DH domain.

Ethanol inhibition of porcine bioprosthetic heart valve cusp calcification is enhanced by reduction with sodium borohydride.

BACKGROUND AND AIM OF THE STUDY: Previous studies have shown that ethanol pretreatment of glutaraldehyde (GA)-fixed porcine aortic valve cusps (GPAV) significantly reduces bioprosthetic leaflet calcification. The anti-calcification mechanism is due to extraction of cholesterol and phospholipids, and a permanent alteration in collagen structure. It was noted in experimental implants that ethanol-pretreated GPAV occasionally show low levels of calcification. The study aim was to investigate whether this was due to unreacted aldehyde residues and other reducible compounds resulting from GA cross-linking. METHODS: GPAV were cross-linked in GA (0.6%) and stored at pH 7.4 in 0.2% GA. Cusps were pretreated with ethanol (80%, pH 7.4) for 24 h. Experimental groups included ethanol-pretreated cusps and GA-fixed controls that were pretreated with either sodium borohydride or sodium cyanoborohydride. Differential scanning calorimetry was used to measure shrink temperature as a measure of cross-linking. Subdermal implants of valve cusp tissue were carried out in 21-day-old Sprague-Dawley male rats. Implants were retrieved at 21 days and samples assessed for the extent of calcification using chemical analyses for Ca, and microscopy studies. RESULTS: Ethanol pretreatment significantly inhibited calcification compared with controls (13.3 +/- 5.6 versus 119.2 +/- 6.6 micrograms Ca/mg tissue; p < 0.001). However, sodium borohydride reduction under optimized conditions combined with ethanol pretreatment optimally reduced calcification (1.16 +/- 0.1 microgram Ca/mg; p < 0.05), whereas levels after sodium cyanoborohydride treatment (23.6 +/- 10.4 micrograms Ca/mg) were not significantly different to those after ethanol alone. Neither reducing agent was effective in inhibiting calcification without ethanol pretreatment. Furthermore, the reducing agents had no significant effect on shrink temperature. CONCLUSION: Inhibition of GPAV calcification with ethanol pretreatment can be enhanced through the optimized use of reducing agents. This indicates that reducible aldehyde-related moieties are likely responsible for breakthrough calcification, even after ethanol pretreatment.

Serotonin mechanisms in heart valve disease II: the 5-HT2 receptor and its signaling pathway in aortic valve interstitial cells.

Serotonin [5-hydroxytryptamine (5-HT)]-mediated cardiac valvular disease has been commonly observed in patients with carcinoid tumors. Previous research by others using reverse transcriptase-polymerase chain reaction demonstrated that aortic valve cells expressed predominantly 5-HT(2A/2B) receptors (5-HT(2A)R). Related investigations by our group using sheep aortic valve interstitial cell (SAVIC) cultures demonstrated that 5-HT both up-regulates transforming growth factor (TGF)-beta1 expression and activity, and also results in increased phospholipase C (PLC) activity. Thus, the present study investigated the hypothesis that the 5-HT signaling pathway in SAVICs involves 5-HT(2)Rs with associated G-protein signal transduction. The objectives were to functionally characterize in SAVIC cultures the native serotonin receptor subtypes using specific agonists and antagonists, and to delineate the serotonin-signaling pathway. 5-HT administration caused a marked stimulation of PLC activity. SAVIC studies of specific agents that target the 5-HT(2)R subtypes indicate that this response seemed to be mediated predominantly by 5-HT(2A)Rs. Furthermore, the sheep 5-HT(2A)R was identified by reverse transcriptase-polymerase chain reaction with sequence confirmation including comparisons to pig and human 5-HT(2A)R. Extracellular signal-regulated kinase (Erk 1/2) is a signaling molecule downstream from the 5-HT(2A)R. Both a protein kinase C inhibitor, GF109203X, and a Src inhibitor, PP1, attenuated 5-HT-stimulated Erk 1/2 activation. However, a 5-HT(2A)R antagonist, MDL 100907, inhibited 5-HT up-regulation of PLC and TGF-beta1, while having far less pronounced effects on Erk 1/2. In conclusion, these studies of the signal transduction activity of SAVICs in response to 5-HT have demonstrated that the 5-HT(2A)Rs are the most functionally active of the 5-HT(2)Rs in this cell type. Furthermore, 5-HT(2A)Rs are also involved in 5-HT up-regulation of active TGF-beta. 5-HT also mediated strong Erk 1/2 signaling via the MAP-kinase pathway, which was only in part because of 5-HT(2A)R activity. Thus, major 5-HT Erk 1/2 signaling beyond that controlled by 5-HT(2)Rs must involve other serotonin receptor types and/or secondary signaling events.