98 research outputs found

    A comprehensive characterization and expression profiling of defensin family peptides in Arabidopsis thaliana with a focus on their abiotic stress-specific transcriptional modulation

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    In addition to defensins, plants possess an array of defensin-like peptides that share many of their characteristics, as well as a role in plant's innate immunity. Their involvement in the response to pathogens is well-known but the contribution in the plant response to abiotic stimuli is not fully understood. We have undertaken an in silico analysis to characterize all defensin family genes hitherto found in Arabidopsis, including genes encoding for defensin-like peptides, by detecting several peptides as candidates for further studies aiming to decipher specific responses to biotic and abiotic stresses, as well as to their crosstalk. We performed several analyses, including co- expression and cis-regulatory elements analyses, using transcriptomic data obtained from the ARS database, which integrates more than 20,000 Arabidopsis RNA-seq libraries. In silico analysis showed that jasmonates and ABA, together with transcription factors belonging to WRKY and AP2/EREBP families, modulate defensin and defensin-like gene expression. Indeed, the analysis performed in this study allowed to extract and organize omics data, which finally supported the inducible nature of defensins under both abiotic and biotic stresses. Moreover, in vivo expression analyses confirmed the heat and drought responsiveness of PDF1.4, , ATTI1, , PDF1.1, , DEFL 206, , defensin family genes selected for being upregulated by several abiotic conditions, at transcriptional level. Finally, the co-expression analysis provided information on other biological processes that may be correlated to the defensin induction, such as maintaining ROS homeostasis. Combining the comprehensive analysis of different transcriptional datasets with the integration of in vivo analyses emerged as a robust methodological approach to assess the proposed multi-stress responsive nature of defensin family genes

    Proteomic changes and molecular effects associated with Cr(III) and Cr(VI) treatments on germinating kiwifruit pollen

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    The present study is aimed at identifying molecular changes elicited by Cr(III) and Cr(VI) on germinating kiwifruit pollen. To address this question, comparative proteomic and DNA laddering analyses were performed. While no genotoxic effect was detected, a number of proteins whose accumulation levels were altered by treatments were identified. In particular, the upregulation of some proteins involved in the scavenging response, cell redox homeostasis and lipid synthesis could be interpreted as an oxidative stress response induced by Cr treatment. The strong reduction of two proteins involved in mitochondrial oxidative phosphorylation and a decline in ATP levels were also observed. The decrease of pollen energy availability could be one of the causes of the severe inhibition of the pollen germination observed upon exposure to both Cr(III) and Cr(VI). Finally, proteomic and biochemical data indicate proteasome impairment: the consequential accumulation of misfolded/damaged proteins could be an important molecular mechanism of Cr(III) toxicity in pollen

    The soluble proteome of tobacco Bright Yellow-2 cells undergoing H2O2-induced programmed cell death

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    Plant programmed cell death (PCD) is a genetically controlled process that plays an important role in development and stress responses. Reactive oxygen species (ROS) are key inducers of PCD. The addition of 50 mM H2O2 to tobacco Bright Yellow-2 (TBY-2) cell cultures induces PCD. A comparative proteomic analysis of TBY-2 cells treated with 50 mM H2O2 for 30 min and 3 h was performed. The results showed early down-regulation of several elements in the cellular redox hub and inhibition of the protein repair–degradation system. The expression patterns of proteins involved in the homeostatic response, in particular those associated with metabolism, were consistently altered. The changes in abundance of several cytoskeleton proteins confirmed the active role of the cytoskeleton in PCD signalling. Cells undergoing H2O2-induced PCD fail to cope with oxidative stress. The antioxidant defence system and the anti-PCD signalling cascades are inhibited. This promotes a genetically programmed cell suicide pathway. Fifteen differentially expressed proteins showed an expression pattern similar to that previously observed in TBY-2 cells undergoing heat shock-induced PCD. The possibility that these proteins are part of a core complex required for PCD induction is discussed

    Radiomics predicts response of individual HER2-amplified colorectal cancer liver metastases in patients treated with HER2-targeted therapy

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    The aim of our study was to develop and validate a machine learning algorithm to predict response of individual HER2-amplified colorectal cancer liver metastases (lmCRC) undergoing dual HER2-targeted therapy. Twenty-four radiomics features were extracted after 3D manual segmentation of 141 lmCRC on pretreatment portal CT scans of a cohort including 38 HER2-amplified patients; feature selection was then performed using genetic algorithms. lmCRC were classified as nonresponders (R−), if their largest diameter increased more than 10% at a CT scan performed after 3 months of treatment, responders (R+) otherwise. Sensitivity, specificity, negative (NPV) and positive (PPV) predictive values in correctly classifying individual lesion and overall patient response were assessed on a training dataset and then validated on a second dataset using a Gaussian naïve Bayesian classifier. Per-lesion sensitivity, specificity, NPV and PPV were 89%, 85%, 93%, 78% and 90%, 42%, 73%, 71% respectively in the testing and validation datasets. Per-patient sensitivity and specificity were 92% and 86%. Heterogeneous response was observed in 9 of 38 patients (24%). Five of nine patients were carriers of nonresponder lesions correctly classified as such by our radiomics signature, including four of seven harboring only one nonresponder lesion. The developed method has been proven effective in predicting behavior of individual metastases to targeted treatment in a cohort of HER2 amplified patients. The model accurately detects responder lesions and identifies nonresponder lesions in patients with heterogeneous response, potentially paving the way to multimodal treatment in selected patients. Further validation will be needed to confirm our findings

    Delta-Radiomics Predicts Response to First-Line Oxaliplatin-Based Chemotherapy in Colorectal Cancer Patients with Liver Metastases

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    SIMPLE SUMMARY: Oxaliplatin-based chemotherapy remains the mainstay of first-line therapy in patients with metastatic colorectal cancer (mCRC). Unfortunately, only approximately 60% of treated patients achieve response, and half of responders will experience an early onset of disease progression. Furthermore, some individuals will develop a mixed response due to the emergence of resistant tumor subclones. The ability to predicting which patients will acquire resistance could help them avoid the unnecessary toxicity of oxaliplatin therapies. Furthermore, sorting out lesions that do not respond, in the context of an overall good response, could trigger further investigation into their mutational landscape, providing mechanistic insight towards the planning of a more comprehensive treatment. In this study, we validated a delta-radiomics signature capable of predicting response to oxaliplatin-based first-line treatment of individual liver colorectal cancer metastases. Findings could pave the way to a more personalized treatment of patients with mCRC. ABSTRACT: The purpose of this paper is to develop and validate a delta-radiomics score to predict the response of individual colorectal cancer liver metastases (lmCRC) to first-line FOLFOX chemotherapy. Three hundred one lmCRC were manually segmented on both CT performed at baseline and after the first cycle of first-line FOLFOX, and 107 radiomics features were computed by subtracting textural features of CT at baseline from those at timepoint 1 (TP1). LmCRC were classified as nonresponders (R−) if they showed progression of disease (PD), according to RECIST1.1, before 8 months, and as responders (R+), otherwise. After feature selection, we developed a decision tree statistical model trained using all lmCRC coming from one hospital. The final output was a delta-radiomics signature subsequently validated on an external dataset. Sensitivity, specificity, positive (PPV), and negative (NPV) predictive values in correctly classifying individual lesions were assessed on both datasets. Per-lesion sensitivity, specificity, PPV, and NPV were 99%, 94%, 95%, 99%, 85%, 92%, 90%, and 87%, respectively, in the training and validation datasets. The delta-radiomics signature was able to reliably predict R− lmCRC, which were wrongly classified by lesion RECIST as R+ at TP1, (93%, averaging training and validation set, versus 67% of RECIST). The delta-radiomics signature developed in this study can reliably predict the response of individual lmCRC to oxaliplatin-based chemotherapy. Lesions forecasted as poor or nonresponders by the signature could be further investigated, potentially paving the way to lesion-specific therapies

    Delta-Radiomics Predicts Response to First-Line Oxaliplatin-Based Chemotherapy in Colorectal Cancer Patients with Liver Metastases

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    The purpose of this paper is to develop and validate a delta-radiomics score to predict the response of individual colorectal cancer liver metastases (lmCRC) to first-line FOLFOX chemotherapy. Three hundred one lmCRC were manually segmented on both CT performed at baseline and after the first cycle of first-line FOLFOX, and 107 radiomics features were computed by subtracting textural features of CT at baseline from those at timepoint 1 (TP1). LmCRC were classified as nonresponders (R−) if they showed progression of disease (PD), according to RECIST1.1, before 8 months, and as responders (R+), otherwise. After feature selection, we developed a decision tree statistical model trained using all lmCRC coming from one hospital. The final output was a delta-radiomics signature subsequently validated on an external dataset. Sensitivity, specificity, positive (PPV), and negative (NPV) predictive values in correctly classifying individual lesions were assessed on both datasets. Per-lesion sensitivity, specificity, PPV, and NPV were 99%, 94%, 95%, 99%, 85%, 92%, 90%, and 87%, respectively, in the training and validation datasets. The delta-radiomics signature was able to reliably predict R− lmCRC, which were wrongly classified by lesion RECIST as R+ at TP1, (93%, averaging training and validation set, versus 67% of RECIST). The delta-radiomics signature developed in this study can reliably predict the response of individual lmCRC to oxaliplatin-based chemotherapy. Lesions forecasted as poor or nonresponders by the signature could be further investigated, potentially paving the way to lesion-specific therapies

    Номінація частин руки в говірці села Невгоди Овруцького району Житомирської області

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    У статті розглянуто лексеми на позначення частин руки в сучасній середньополіській говірці, зокрема проаналізовано їхню семантику та мотивацію.В статье рассматриваются лексемы, обозначающие части руки, в современном среднеполесском говоре, а именно проанализирована их семантика и мотивация.The article deals with lexemes on designations of parts of the manuscript in the middle-polissya dialect. Their semantics and motivation are also analyzed

    High Circulating Methylated DNA Is a Negative Predictive and Prognostic Marker in Metastatic Colorectal Cancer Patients Treated With Regorafenib

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    Background: Regorafenib improves progression free survival (PFS) in a subset of metastatic colorectal cancer (mCRC) patients, although no biomarkers of efficacy are available. Circulating methylated DNA (cmDNA) assessed by a five-gene panel was previously associated with outcome in chemotherapy treated mCRC patients. We hypothesized that cmDNA could be used to identify cases most likely to benefit from regorafenib (i.e., patients with PFS longer than 4 months). Methods: Plasma samples from mCRC patients were collected prior to (baseline samples N = 60) and/or during regorafenib treatment (N = 62) for the assessment of cmDNA and total amount of cell free DNA (cfDNA). Results: In almost all patients, treatment with regorafenib increased the total cfDNA, but decreased cmDNA warranting the normalization of cmDNA to the total amount of circulating DNA (i.e., cmDNA/ml). We report that cmDNA/ml dynamics reflects clinical response with an increase in cmDNA/ml associated with higher risk of progression (HR for progression = 1.78 [95%CI: 1.01-3.13], p = 0.028). Taken individually, high baseline cmDNA/ml (above median) was associated with worst prognosis (HR for death = 3.471 [95%CI: 1.83-6.57], p < 0.0001) and also predicted shorter PFS (<16 weeks with PPV 86%). In addition, high cmDNA/ml values during regorafenib treatment predicted with higher accuracy shorter PFS (<16 weeks with a PPV of 96%), therefore associated with increased risk of progression (HR for progression = 2.985; [95%CI: 1.63-5.46; p < 0.0001). Conclusions: Our data highlight the predictive and prognostic value of cmDNA/ml in mCRC patients treated with regorafenib

    Sequential HER2 blockade as effective therapy in chemorefractory, HER2 gene-amplified, RAS wild-type, metastatic colorectal cancer: learning from a clinical case

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    Background Constitutive activation of HER2-dependent intracellular signalling by HER2 gene amplification or by HER2 mutations has been demonstrated as a mechanism of primary and secondary cancer resistance to cetuximab or panitumumab in preclinical and clinical models of metastatic colorectal cancer (mCRC). Both HER2 Amplification for Colorectal Cancer Enhanced Stratification (HERACLES) cohort A and My Pathway clinical trials provided clinical evidence that anti-HER2 therapies could be active in these patients. Patient and methods HER2 gene amplification and HER2 protein overexpression analysis were performed in tumour tissue by fluorescence in situ hybridisation and immunohistochemistry. HER2 positivity was defined according to HERACLES CRC-specific HER2 scoring criteria. DNA analysis for multiple assessment of gene mutations or amplifications was carried out with the next-generation sequencing (NGS) Ion AmpliSeq Colon and Lung Cancer Panel and by using a more extensive targeted high-multiplex PCR-based NGS panel (OncoMine Comprehensive Assay). Results We report the clinical case of a patient with HER2 gene amplified and RAS/BRAF wild-type mCRC who experienced a long lasting and relevant clinical efficacy from sequential anti-HER2 therapies (trastuzumab plus lapatinib, pertuzumab plus trastuzumab, trastuzumab emtansine, trastuzumab plus capecitabine) achieving a cumulative clinical benefit of 29 months, after failure of the first three lines of standard treatments, which included all the potentially active drugs in mCRC, and which accounted for only 14 months of disease control. HER gene amplification was confirmed by NGS on two different metastatic lesions during the evolution of the disease. Conclusion The clinical case highlights the role of HER2 gene amplification as a key genetic driver of cancer development and progression in mCRC and suggests that sequential HER2 blockade could be a potential therapeutic strategy
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