Integrated analysis reveals a novel 5-fluorouracil resistance-based prognostic signature with promising implications for predicting the efficacy of chemotherapy and immunotherapy in patients with colorectal cancer.

BACKGROUND: 5-Fluorouracil (5-FU) has been used as a standard first-line treatment for colorectal cancer (CRC) patients. Although 5-FU-based chemotherapy and immune checkpoint blockade (ICB) have achieved success in treating CRC, drug resistance and low response rates remain substantial limitations. Thus, it is necessary to construct a 5-FU resistance-related signature (5-FRSig) to predict patient prognosis and identify ideal patients for chemotherapy and immunotherapy. METHODS: Using bulk and single-cell RNA sequencing data, we established and validated a novel 5-FRSig model using stepwise regression and multiple CRC cohorts and evaluated its associations with the prognosis, clinical features, immune status, immunotherapy, neoadjuvant therapy, and drug sensitivity of CRC patients through various bioinformatics algorithms. Unsupervised consensus clustering was performed to categorize the 5-FU resistance-related molecular subtypes of CRC. The expression levels of 5-FRSig, immune checkpoints, and immunoregulators were determined using quantitative real-time polymerase chain reaction (RT‒qPCR). Potential small-molecule agents were identified via Connectivity Map (CMap) and molecular docking. RESULTS: The 5-FRSig and cluster were confirmed as independent prognostic factors in CRC, as patients in the low-risk group and Cluster 1 had a better prognosis. Notably, 5-FRSig was significantly associated with 5-FU sensitivity, chemotherapy response, immune cell infiltration, immunoreactivity phenotype, immunotherapy efficiency, and drug selection. We predicted 10 potential compounds that bind to the core targets of 5-FRSig with the highest affinity. CONCLUSION: We developed a valid 5-FRSig to predict the prognosis, chemotherapeutic response, and immune status of CRC patients, thus optimizing the therapeutic benefits of chemotherapy combined with immunotherapy, which can facilitate the development of personalized treatments and novel molecular targeted therapies for patients with CRC.

Taking advantage of the interaction between the sulfoxide and heme cofactor to develop indoleamine 2, 3-dioxygenase 1 inhibitors.

Taking advantage of key interactions between sulfoxide and heme cofactor, we used the sulfoxide as the anchor functional group to develop two series of indoleamine 2, 3-dioxygenase 1 (IDO1) inhibitors: 2-benzylsulfinylbenzoxazoles (series 1) and 2-phenylsulfinylbenzoxazoles (series 2). In vitro enzymatic screening shows that both series can inhibit the activity of IDO1 in low micromolar (series 1) or nanomolar (series 2) levels. They also show inhibitory selectivity between IDO1 and tryptophan 2, 3-dioxygenase 2. Interestingly, although series 1 is less potent IDO1 inhibitors of these two series, it exhibited stronger inhibitory activity toward kynurenine production in interferon-γ stimulated BxPC-3 cells. Enzyme kinetics and binding studies demonstrated that 2-sulfinylbenzoxazoles are non-competitive inhibitors of tryptophan, and they interact with the ferrous form of heme. These results demonstrated 2-sulfinylbenzoxazoles as type II IDO1 inhibitors. Furthermore, molecular docking studies supports the sulfoxide being of the key functional group that interacts with the heme cofactor. Compound 22 (series 1) can inhibit NO production in a concentration dependent manner in lipopolysaccharides (LPS) stimulated RAW264.7 cells, and can relieve pulmonary edema and lung injury in LPS induced mouse acute lung injury models.

ORF4 of the Temperate Archaeal Virus SNJ1 Governs the Lysis-Lysogeny Switch and Superinfection Immunity.

Recent environmental and metagenomic studies have considerably increased the repertoire of archaeal viruses and suggested that they play important roles in nutrient cycling in the biosphere. However, very little is known about how they regulate their life cycles and interact with their hosts. Here, we report that the life cycle of the temperate haloarchaeal virus SNJ1 is controlled by the product ORF4, a small protein belonging to the antitoxin MazE superfamily. We show that ORF4 controls the lysis-lysogeny switch of SNJ1 and mediates superinfection immunity by repression of genomic DNA replication of the superinfecting viruses. Bioinformatic analysis shows that ORF4 is highly conserved in two SNJ1-like proviruses, suggesting that the mechanisms for lysis-lysogeny switch and superinfection immunity are conserved in this group of viruses. As the lysis-lysogeny switch and superinfection immunity of archaeal viruses have been poorly studied, we suggest that SNJ1 could serve as a model system to study these processes.IMPORTANCE Archaeal viruses are important parts of the virosphere. Understanding how they regulate their life cycles and interact with host cells provide crucial insights into their biological functions and the evolutionary histories of viruses. However, mechanistic studies of the life cycle of archaeal viruses are scarce due to a lack of genetic tools and demanding cultivation conditions. Here, we discover that the temperate haloarchaeal virus SNJ1, which infects Natrinema sp. strain J7, employs a lysis-lysogeny switch and establishes superinfection immunity like bacteriophages. We show that its ORF4 is critical for both processes and acts as a repressor of the replication of SNJ1. These results establish ORF4 as a master regulator of SNJ1 life cycle and provides novel insights on the regulation of life cycles by temperate archaeal viruses and on their interactions with host cells.

Lp-PLA2 inhibition prevents Ang II-induced cardiac inflammation and fibrosis by blocking macrophage NLRP3 inflammasome activation.

Macrophage-mediated inflammation plays an important role in hypertensive cardiac remodeling, whereas effective pharmacological treatments targeting cardiac inflammation remain unclear. Lipoprotein-associated phospholipase A2 (Lp-PLA2) contributes to vascular inflammation-related diseases by mediating macrophage migration and activation. Darapladib, the most advanced Lp-PLA2 inhibitor, has been evaluated in phase III trials in atherosclerosis patients. However, the role of darapladib in inhibiting hypertensive cardiac fibrosis remains unknown. Using a murine angiotensin II (Ang II) infusion-induced hypertension model, we found that Pla2g7 (the gene of Lp-PLA2) was the only upregulated PLA2 gene detected in hypertensive cardiac tissue, and it was primarily localized in heart-infiltrating macrophages. As expected, darapladib significantly prevented Ang II-induced cardiac fibrosis, ventricular hypertrophy, and cardiac dysfunction, with potent abatement of macrophage infiltration and inflammatory response. RNA sequencing revealed that darapladib strongly downregulated the expression of genes and signaling pathways related to inflammation, extracellular matrix, and proliferation. Moreover, darapladib substantially reduced the Ang II infusion-induced expression of nucleotide-binding oligomerization domain-like receptor with pyrin domain 3 (NLRP3) and interleukin (IL)-1ß and markedly attenuated caspase-1 activation in cardiac tissues. Furthermore, darapladib ameliorated Ang II-stimulated macrophage migration and IL-1ß secretion in macrophages by blocking NLRP3 inflammasome activation. Darapladib also effectively blocked macrophage-mediated transformation of fibroblasts into myofibroblasts by inhibiting the activation of the NLRP3 inflammasome in macrophages. Overall, our study identifies a novel anti-inflammatory and anti-cardiac fibrosis role of darapladib in Lp-PLA2 inhibition, elucidating the protective effects of suppressing NLRP3 inflammasome activation. Lp-PLA2 inhibition by darapladib represents a novel therapeutic strategy for hypertensive cardiac damage treatment.

The SGK1 inhibitor EMD638683, prevents Angiotensin II-induced cardiac inflammation and fibrosis by blocking NLRP3 inflammasome activation.

Inflammation has emerged as a critical biological process contributing to hypertensive cardiac remodeling. Effective pharmacological treatments targeting the cardiac inflammatory response, however, are still lacking. Prior studies suggested that the serum- and glucocorticoid-inducible kinase (SGK1) plays a key role in inflammation and cardiac remodeling. Recently, a highly selective SGK1 inhibitor, EMD638683, was developed, though whether EMD638683 can prevent hypertension-induced cardiac fibrosis and the mechanisms by which this inhibitor may alter the disease process remain unknown. Using a murine Angiotension II (Ang II) infusion-induced hypertension model we found that EMD638683 treatment inhibited cardiac fibrosis and remodeling, with significant abatement of cardiac inflammation. EMD638683 was shown to suppress Ang II infusion-induced interleukin (IL)-1ß release, and substantially reduce nucleotide-binding oligomerization domain-like receptor with pyrin domain 3 (NLRP3) expression and caspase-1 activation in cardiac tissues. In vitro experiments revealed that EMD638683 ameliorated Ang II-stimulated IL-1ß secretion in macrophages by blocking NLRP3 inflammasome activation. By reducing IL-1ß production in macrophages, the transformation of fibroblasts to myofibroblasts was inhibited. The effects of EMD638683 on cardiac fibrosis were abolished by supplementation with exogenous IL-1ß. Administration of the NLRP3 inflammasome inhibitor MCC950 indicated that EMD638683 attenuated Ang II-induced cardiac inflammation and fibrosis by inhibiting the NLRP3 inflammasome/IL-1ß secretion axis. These findings indicate that the SGK1 inhibitor EMD638683 can negatively regulate NLRP3 inflammasome activation, and may represent a promising approach to the treatment of hypertensive cardiac damage.

Serum-glucocorticoid-regulated kinase 1 contributes to mechanical stretch-induced inflammatory responses in cardiac fibroblasts.

Excessive mechanical stretch induces production of proinflammatory mediators in cardiac fibroblasts, which could act as inflammatory supporter cells in heart failure. Accumulation evidence and our previous studies suggest that serum-glucocorticoid-regulated kinase 1 (SGK1) contributes to cardiac remodeling and fibrosis, development of heart failure. However, the role and mechanism of SGK1 in mechanical stretch-induced inflammation of cardiac fibroblasts remain unclear. Here, cardiac fibroblasts isolated from wild-type (WT) and SGK1 knockout (SGK1-/-) mice were stimulated by 18% cyclic stretch, under static condition as the control. The results showed that mechanical stretch increased SGK1 expression and activation in WT cardiac fibroblasts but not its isoform, SGK2 or SGK3 expression. Bio-Plex array revealed hyperstretch could enhance chemokines release in WT cardiac fibroblasts, but SGK1 knockout significantly attenuated chemokines production through blocking activation of nuclear factor-kappa B (NF-κB). Moreover, supernatants from WT cardiac fibroblasts subjected to hyperstretch promoted macrophage migration, enhanced expression of macrophage-derived profibrotic mediators, whereas supernatants from SGK1 deficiency suppressed these effects. Although SGK1 did not directly affect mechanical stretch-induced myofibroblast differentiation, SGK1 activation of cardiac fibroblasts facilitated myofibroblast differentiation through the upregulation of the profibrotic mediators secreted by macrophages. These results suggest that SGK1 may play a critical role in the inflammatory cascade of cardiac fibroblasts triggered by mechanical stretch; SGK1 could be used as a potential target for treatment of cardiac fibrosis and heart failure.

[Suppression effect of Mai Shu on formation of atherosclerotic plaque of apolipoprotein E knock-out mice].

The research aimed to investigate the suppression effect of Mai Shu which contains hawthorn, hippophae, medlar, phytosterols（ß-sitosterol, stigmasterol and campesterol）, ß-glucan and lycopeneon formation of atherosclerotic plaque in apolipoprotein E knock-out (ApoE-/-) mice. Liquid chromatography-ultravioletmass spectrometry（LC-UV-MC） methods were used to analyze the main chemical composition of Mai Shu. Atherosclerotic mice models were established by high-fat diet. The mice were administrated with Mai Shu (1, 2, 4 g·kg-1·d-1) or other contrast materials by intragastric route for 10 weeks continuously. At the end of administration, the blood of mice was collected for tests of the serum total cholesterol（TC）, total triglyceride（TG） and high density lipoprotein cholesterol（HDL-C） level. Atherosclerotic lesions in aorta and aortic root were assessed by calculating the relative area of lesions（oil red O stained）. Intravital fluorescence microscopic system was used to evaluate the leukocyte-endothelial adhesion in mesenteric artery of mice by detecting the rolling velocity of white blood cells（WBC）. Collagenous fibers and macrophages in lesions were detected by sirius red staining and immunological histological chemistry to evaluate the atherosclerotic plaque stability. Results showed that Mai Shu contains various flavonoids（9.5%）, phytosterols（23.8%） and polysaccharides（8.9%）. The serum lipid level of model animals was significantly higher than the control animals. Serum TC level was decreased by Mai Shu (4 g·kg-1, P < 0.001) compared to the untreated model. Serum TG level was reduced by Mai Shu (1, 2, 4 g·kg-1) compared to model（P < 0.01）. Area of atherosclerotic lesions in aorta and aortic root was decreased in Mai Shu group (aorta: 1 g·kg-1, P < 0.05; 2 g·kg-1, P < 0.01; 4 g·kg-1, P < 0.001; aortic root: 2, 4 g·kg-1, P < 0.01). Rolling velocity of white blood cells of Mai Shu (4 g·kg-1, P < 0.001) group was increased over the untreated model. Collagenous fibers in lesions were observationally increased by Mai Shu (1, 2 g·kg-1) and macrophages were decreased (2, 4 g·kg-1) compared to model. These results demonstrate that Mai Shu can obviously decrease the serum lipid levels and the risk of leukocyte-endothelial adhesion in ApoE-/- mice. The effect of Mai Shu may be associated with the decrease of macrophages in plaque.

Identification of immune-related genes and small-molecule drugs in hypertension-induced left ventricular hypertrophy based on machine learning algorithms and molecular docking.

Background: Left ventricular hypertrophy (LVH) is a common consequence of hypertension and can lead to heart failure. The immune response plays an important role in hypertensive LVH; however, there is no comprehensive method to investigate the mechanistic relationships between immune response and hypertensive LVH or to find novel therapeutic targets. This study aimed to screen hub immune-related genes involved in hypertensive LVH as well as to explore immune target-based therapeutic drugs. Materials and methods: RNA-sequencing data from a mouse model generated by angiotensin II infusion were subjected to weighted gene co-expression network analysis (WGCNA) to identify core expression modules. Machine learning algorithms were applied to screen immune-related LVH characteristic genes. Heart structures were evaluated by echocardiography and cardiac magnetic resonance imaging (CMRI). Validation of hub genes was conducted by RT-qPCR and western blot. Using the Connectivity Map database and molecular docking, potential small-molecule drugs were explored. Results: A total of 1215 differentially expressed genes were obtained, most of which were significantly enriched in immunoregulation and collagen synthesis. WGCNA and multiple machine learning strategies uncovered six hub immune-related genes (Ankrd1, Birc5, Nuf2, C1qtnf6, Fcgr3, and Cdca3) that may accurately predict hypertensive LVH diagnosis. Immune analysis revealed that fibroblasts and macrophages were closely correlated with hypertensive LVH, and hub gene expression was significantly associated with these immune cells. A regulatory network of transcription factor-mRNA and a ceRNA network of miRNA-lncRNA was established. Notably, six hub immune-related genes were significantly increased in the hypertensive LVH model, which were positively linked to left ventricle wall thickness. Finally, 12 small-molecule compounds with the potential to reverse the high expression of hub genes were ruled out as potential therapeutic agents for hypertensive LVH. Conclusion: This study identified and validated six hub immune-related genes that may play essential roles in hypertensive LVH, providing new insights into the potential pathogenesis of cardiac remodeling and novel targets for medical interventions.

Developing an m5C regulator-mediated RNA methylation modification signature to predict prognosis and immunotherapy efficacy in rectal cancer.

Background: Currently, a very small number of patients with colorectal cancer (CRC) respond to immune checkpoint inhibitor (ICI) treatment. Therefore, there is an urgent need to investigate effective biomarkers to determine the responsiveness to ICI treatment. Recently, aberrant 5-methylcytosine (m5C) RNA modification has emerged as a key player in the pathogenesis of cancer. Thus, we aimed to explore the predictive signature based on m5C regulator-related genes for characterizing the immune landscapes and predicting the prognosis and response to therapies. Methods: The Cancer Genome Atlas (TCGA) cohort was used as the training set, while GEO data sets, real-time quantitative PCR (RT-qPCR) analysis from paired frozen tissues, and immunohistochemistry (IHC) data from tissue microarray (TMA) were used for validation. We constructed a novel signature based on three m5C regulator-related genes in patients with rectal adenocarcinoma (READ) using a least absolute shrinkage and selection operator (LASSO)-Cox regression and unsupervised consensus clustering analyses. Additionally, we correlated the three-gene signature risk model with the tumor immune microenvironment, immunotherapy efficiency, and potential applicable drugs. Results: The m5C methylation-based signature was an independent prognostic factor, where low-risk patients showed a stronger immunoreactivity phenotype and a superior response to ICI therapy. Conversely, the high-risk patients had enriched pathways of cancer hallmarks and presented immune-suppressive state, which demonstrated that they are more insensitive to immunotherapy. Additionally, the signature markedly correlated with drug susceptibility. Conclusions: We developed a reliable m5C regulator-based risk model to predict the prognosis, clarify the molecular and tumor microenvironment status, and identify patients who would benefit from immunotherapy or chemotherapy. Our study could provide vital guidance to improve prognostic stratification and optimize personalized therapeutic strategies for patients with rectal cancer.

Targeting the KLF5-EphA2 axis can restrain cancer stemness and overcome chemoresistance in basal-like breast cancer.

Ephrin type-A receptor 2 (EphA2) is a member of the tyrosine receptor kinases, a family of membrane proteins recognized as potential anticancer targets. EphA2 highly expressed in a variety of human cancers, playing roles in proliferation, migration, and invasion. However, whether and how EphA2 regulates basal-like breast cancer (BLBC) cell stemness and chemoresistance has not been revealed. Here, KLF5 was proven to be a direct transcription factor for EphA2 in BLBC cells, and its expression was positively correlated in clinical samples from breast cancer patients. The inflammatory factor TNF-α could promote BLBC cell stemness partially by activating the KLF5-EphA2 axis. Moreover, phosphorylation of EphA2 at S897 (EphA2 pS897) induced by TNF-α and PTX/DDP contributes to chemoresistance of BLBC. Furthermore, the EphA2 inhibitor ALW-II-41-27 could effectively reduce EphA2 pS897 and tumor cell stemness in vitro and significantly enhance the sensitivity of xenografts to the chemotherapeutic drugs PTX and DDP in vivo. Clinically, tumor samples from breast patients with less response to neoadjuvant chemotherapy showed a high level of EphA2 pS897 expression. In conclusion, KLF5-EphA2 promotes stemness and drug resistance in BLBC and could be a potential target for the treatment of BLBC.

Computational identification and clinical validation of a novel risk signature based on coagulation-related lncRNAs for predicting prognosis, immunotherapy response, and chemosensitivity in colorectal cancer patients.

Background: Coagulation is critically involved in the tumor microenvironment, cancer progression, and prognosis assessment. Nevertheless, the roles of coagulation-related long noncoding RNAs (CRLs) in colorectal cancer (CRC) remain unclear. In this study, an integrated computational framework was constructed to develop a novel coagulation-related lncRNA signature (CRLncSig) to stratify the prognosis of CRC patients, predict response to immunotherapy and chemotherapy in CRC, and explore the potential molecular mechanism. Methods: CRC samples from The Cancer Genome Atlas (TCGA) were used as the training set, while the substantial bulk or single-cell RNA transcriptomics from Gene Expression Omnibus (GEO) datasets and real-time quantitative PCR (RT-qPCR) data from CRC cell lines and paired frozen tissues were used for validation. We performed unsupervised consensus clustering of CRLs to classify patients into distinct molecular subtypes. We then used stepwise regression to establish the CRLncSig risk model, which stratified patients into high- and low-risk groups. Subsequently, diversified bioinformatics algorithms were used to explore prognosis, biological pathway alteration, immune microenvironment, immunotherapy response, and drug sensitivity across patient subgroups. In addition, weighted gene coexpression network analysis was used to construct an lncRNA-miRNA-mRNA competitive endogenous network. Expression levels of CRLncSig, immune checkpoints, and immunosuppressors were determined using RT-qPCR. Results: We identified two coagulation subclusters and constructed a risk score model using CRLncSig in CRC, where the patients in cluster 2 and the low-risk group had a better prognosis. The cluster and CRLncSig were confirmed as the independent risk factors, and a CRLncSig-based nomogram exhibited a robust prognostic performance. Notably, the cluster and CRLncSig were identified as the indicators of immune cell infiltration, immunoreactivity phenotype, and immunotherapy efficiency. In addition, we identified a new endogenous network of competing CRLs with microRNA/mRNA, which will provide a foundation for future mechanistic studies of CRLs in the malignant progression of CRC. Moreover, CRLncSig strongly correlated with drug susceptibility. Conclusion: We developed a reliable CRLncSig to predict the prognosis, immune landscape, immunotherapy response, and drug sensitivity in patients with CRC, which might facilitate optimizing risk stratification, guiding the applications of immunotherapy, and individualized treatments for CRC.

Polymorphisms of SPRN (shadow of prion protein homology) in three breeds of sheep in China.

The key point, which is related to the susceptibility of prion diseases in animals, has been proved to be the prion protein gene (PRNP). However, animals, especially sheep and goats, with the same PRNP genotype are not equally susceptible to the diseases. The finding of SPRN (shadow of prion protein homology) provides a new aspect to understand the diseases as protein of SPRN (Shadoo) has similar neuroprotective function and conserved hydrophobic core with prion protein (PrP). Researchers have made some efforts to demonstrate the relationship between SPRN and PRNP. Stewart's work has shown that SPRN contained an alanine-rich sequence, which is homologous to a hydrophobic core with amyloidgenic characteristics in PrP. Here our work shows that the sheep of Inner Mongolia in China have several haplotypes with the similar results of Stewart and Daude's. However we find a new haplotype in a Sunite sheep, which is not reported by others.

Comprehensive Analysis of a Cancer-Immunity Cycle-Based Signature for Predicting Prognosis and Immunotherapy Response in Patients With Colorectal Cancer.

Immune checkpoint blockade (ICB) has been recognized as a promising immunotherapy for colorectal cancer (CRC); however, most patients have little or no clinical benefit. This study aimed to develop a novel cancer-immunity cycle-based signature to stratify prognosis of patients with CRC and predict efficacy of immunotherapy. CRC samples from The Cancer Genome Atlas (TCGA) were used as the training set, while the RNA data from Gene Expression Omnibus (GEO) data sets and real-time quantitative PCR (RT-qPCR) data from paired frozen tissues were used for validation. We built a least absolute shrinkage and selection operator (LASSO)-Cox regression model of the cancer-immunity cycle-related gene signature in CRC. Patients who scored low on the risk scale had a better prognosis than those who scored high. Notably, the signature was an independent prognostic factor in multivariate analyses, and to improve prognostic classification and forecast accuracy for individual patients, a scoring nomogram was created. The comprehensive results revealed that the low-risk patients exhibited a higher degree of immune infiltration, a higher immunoreactivity phenotype, stronger expression of immune checkpoint-associated genes, and a superior response to ICB therapy. Furthermore, the risk model was closely related to the response to multiple chemotherapeutic drugs. Overall, we developed a reliable cancer-immunity cycle-based risk model to predict the prognosis, the molecular and immune status, and the immune benefit from ICB therapy, which may contribute greatly to accurate stratification and precise immunotherapy for patients with CRC.

Comprehensive bioinformatics analysis identifies LAPTM5 as a potential blood biomarker for hypertensive patients with left ventricular hypertrophy.

Left ventricular hypertrophy (LVH) is a pivotal manifestation of hypertensive organ damage associated with an increased cardiovascular risk. However, early diagnostic biomarkers for assessing LVH in patients with hypertension (HT) remain indefinite. Here, multiple bioinformatics tools combined with an experimental verification strategy were used to identify blood biomarkers for hypertensive LVH. GSE74144 mRNA expression profiles were downloaded from the Gene Expression Omnibus (GEO) database to screen candidate biomarkers, which were used to perform weighted gene co-expression network analysis (WGCNA) and establish the least absolute shrinkage and selection operator (LASSO) regression model, combined with support vector machine-recursive feature elimination (SVM-RFE) algorithms. Finally, the potential blood biomarkers were verified in an animal model. A total of 142 hub genes in peripheral blood leukocytes were identified between HT with LVH and HT without LVH, which were mainly involved in the ATP metabolic process, oxidative phosphorylation, and mitochondrial structure and function. Notably, lysosomal associated transmembrane protein 5 (LAPTM5) was identified as the potential diagnostic marker of hypertensive LVH, which showed strong correlations with diverse marker sets of reactive oxygen species (ROS) and autophagy. RT-PCR validation of blood samples and cardiac magnetic resonance imaging (CMRI) showed that the expression of LAPTM5 was significantly higher in the HT with LVH model than in normal controls, LAPTM5 demonstrated a positive association with the left ventricle wall thickness as well as electrocardiogram (ECG) parameters widths of the QRS complex and QTc interval. In conclusion, LAPTM5 may be a potential biomarker for the diagnosis of LVH in patients with HT, and it can provide new insights for future studies on the occurrence and the molecular mechanisms of hypertensive LVH.

Prognostic Values and Underlying Regulatory Network of Cohesin Subunits in Esophageal Carcinoma.

Background: Cohesin is a highly conserved and ubiquitously expressed protein complex. While increasing evidence suggests that cohesin dysregulation is vital in the carcinogenesis of numerous malignancies, little is known about the prognostic values and potential mechanisms of cohesin subunits and direct regulators in esophageal carcinoma (ESCA). Methods: RNA-sequencing data from The Cancer Genome Atlas (TCGA) and Genome Tissue Expression (GTEx) were used. The subunits and regulators of cohesin affecting the prognosis of ESCA were screened by Kaplan-Meier survival analysis; univariate and multivariate Cox regression analyses were performed; and the receiver-operating characteristic (ROC) curve was determined. The ESCA hazard model and nomogram map were constructed by integrating the clinical data. We used functional analysis and protein-protein interaction (PPI) networks to explore underlying pathways. Finally, immunohistochemistry was performed to examine the expression levels of cohesin subunits in tissue microarray (TMA). Results: Transcriptome data from multiple ESCA patient datasets showed cohesin subunits SMC1A, SMC1B, SMC3, STAG1, STAG2, RAD21, and cohesin regulators including ESCO2, NIPBL, MAU2, WAPL, PDS5A and PDS5B were all upregulated in ESCA tissues compared to normal tissues. Survival analysis demonstrated that high STAG2 expression was significantly associated with poorer overall survival (OS) and progression-free survival (PFS) in esophageal adenocarcinoma (EAC). In contrast, high RAD21 expression was significantly correlated with better OS in esophageal squamous cell carcinoma (ESCC). Moreover, STAG2 and RAD21 were identified as independent prognostic factors and predictive biomarkers in EAC and ESCC, respectively. Functional enrichment analysis further revealed that STAG2 and RAD21 were mainly involved in the mitotic nuclear division, DNA repair, angiogenesis, epithelial-mesenchymal transition (EMT), and oncogenic signaling pathways. PPI analysis illustrated that STAG2 and RAD21 could cross-talk through cancer-associated modules and performed the core roles of the whole PPI network. Using TMA, STAG2 protein expression positively correlated with lymph node metastasis and advanced clinical stage of EAC patients, whereas there was a negative correlation between RAD21 protein expression and the malignant clinicopathological parameters in ESCC. Conclusion: These findings suggest that STAG2 and RAD21 can be used as predictive biomarkers for risk assessment and prognostic stratification in ESCA, which provide potential novel insights into molecular targets of ESCA.

Characterization of sialylation-related long noncoding RNAs to develop a novel signature for predicting prognosis, immune landscape, and chemotherapy response in colorectal cancer.

Aberrant sialylation plays a key biological role in tumorigenesis and metastasis, including tumor cell survival and invasion, immune evasion, angiogenesis, and resistance to therapy. It has been proposed as a possible cancer biomarker and a potential therapeutic target of tumors. Nevertheless, the prognostic significance and biological features of sialylation-related long noncoding RNAs (lncRNAs) in colorectal cancer (CRC) remain unclear. This study aimed to develop a novel sialylation-related lncRNA signature to accurately evaluate the prognosis of patients with CRC and explore the potential molecular mechanisms of the sialylation-related lncRNAs. Here, we identified sialylation-related lncRNAs using the Pearson correlation analysis on The Cancer Genome Atlas (TCGA) dataset. Univariate and stepwise multivariable Cox analysis were used to establish a signature based on seven sialylation-related lncRNAs in the TCGA dataset, and the risk model was validated in the Gene Expression Omnibus dataset. Kaplan-Meier curve analysis revealed that CRC patients in the low-risk subgroup had a better survival outcome than those in the high-risk subgroup in the training set, testing set, and overall set. Multivariate analysis demonstrated that the sialylation-related lncRNA signature was an independent prognostic factor for overall survival, progression-free survival, and disease-specific survival prediction. The sialylation lncRNA signature-based nomogram exhibited a robust prognostic performance. Furthermore, enrichment analysis showed that cancer hallmarks and oncogenic signaling were enriched in the high-risk group, while inflammatory responses and immune-related pathways were enriched in the low-risk group. The comprehensive analysis suggested that low-risk patients had higher activity of immune response pathways, greater immune cell infiltration, and higher expression of immune stimulators. In addition, we determined the sialylation level in normal colonic cells and CRC cell lines by flow cytometry combined with immunofluorescence, and verified the expression levels of seven lncRNAs using real-time quantitative polymerase chain reaction. Finally, combined drug sensitivity analysis using the Genomics of Drug Sensitivity in Cancer, Cancer Therapeutics Response Portal, and Profiling Relative Inhibition Simultaneously in Mixtures indicated that the sialylation-related lncRNA signature could serve as a potential predictor for chemosensitivity. Collectively, this is the first sialylation lncRNA-based signature for predicting the prognosis, immune landscape, and chemotherapeutic response in CRC, and may provide vital guidance to facilitate risk stratification and optimize individualized therapy for CRC patients.

Histone Deacetylase Inhibitors (HDACi) Promote KLF5 Ubiquitination and Degradation in Basal-like Breast Cancer.

Basal-like breast cancer (BLBC) accounts for approximately 15% of all breast cancer cases, and patients with BLBC have a low survival rate. Our previous study demonstrated that the KLF5 transcription factor promotes BLBC cell proliferation and tumor growth. In this study, we demonstrated that the histone deacetylase inhibitors (HDACi), suberoylanilide hydroxamic acid (SAHA), and trichostatin A (TSA), increased KLF5 acetylation at lysine 369 (K369), downregulated KLF5 protein expression levels, and decreased cell viability in BLBC cell lines. HDACi target KLF5 for proteasomal degradation by promoting KLF5 protein ubiquitination. K369 acetylation of KLF5 decreases the binding between KLF5 and its deubiquitinase, BAP1. These findings revealed a novel mechanism by which HDACi suppress BLBC, and a novel crosstalk between KLF5 protein acetylation and ubiquitination.

Spatially resolved metabolomics combined with multicellular tumor spheroids to discover cancer tissue relevant metabolic signatures.

Spatially resolved metabolomics offers unprecedented opportunities for elucidating metabolic mechanisms during cancer progression. It facilitated the discovery of aberrant cellular metabolism with clinical application potential. Here, we developed a novel strategy to discover cancer tissue relevant metabolic signatures by high spatially resolved metabolomics combined with a multicellular tumor spheroid (MCTS) in vitro model. Esophageal cancer MCTS were generated using KYSE-30 human esophageal cancer cells to fully mimic the 3D microenvironment under physiological conditions. Then, the spatial features and temporal variation of metabolites and metabolic pathways in MCTS were accurately mapped by using matrix-assisted laser desorption/ionization mass spectrometry imaging (MALDI-MSI) with a spatial resolution at ∼12 µm. Metabolites, such as glutamate, tyrosine, inosine and various types of lipids displayed heterogeneous distributions in different microregions inside the MCTS, revealing the metabolic heterogenicity of cancer cells under different proliferative states. Subsequently, through joint analysis of metabolomic data of clinical cancer tissue samples, cancer tissue relevant metabolic signatures in esophageal cancer MCTS were identified, including glutamine metabolism, fatty acid metabolism, de novo synthesis phosphatidylcholine (PC) and phosphatidylethanolamine (PE), etc. In addition, the abnormal expression of the involved metabolic enzymes, i.e., GLS, FASN, CHKA and cPLA2, was further confirmed and showed similar tendencies in esophageal cancer MCTS and cancer tissues. The MALDI-MSI combined with MCTS approach offers molecular insights into cancer metabolism with real-word relevance, which would potentially benefit the biomarker discovery and metabolic mechanism studies.

SEMA6B Overexpression Predicts Poor Prognosis and Correlates With the Tumor Immunosuppressive Microenvironment in Colorectal Cancer.

Background: Semaphorin 6b (SEMA6B) is a member of the semaphorin axon-guidance family and has been demonstrated to both induce and inhibit tumor progression. However, the role of SEMA6B in colorectal cancer (CRC) has remained unclear. This study sought to explore the promising prognostic biomarker for CRC and to understand the expression pattern, clinical significance, immune effects, and biological functions of SEMA6B. Methods: SEMA6B expression in CRC was evaluated via multiple gene and protein expression databases and we identified its prognostic value through The Cancer Genome Atlas (TCGA) and Gene Expression Omnibus (GEO) databases. Correlations between SEMA6B expression and components of the tumor immune microenvironment were analyzed by packages implemented in R, Tumor Immune Estimation Resource (TIMER), Gene Expression Profiling Interactive Analysis (GEPIA), and Tumor-Immune System Interactions database (TISIDB). RNA interference was performed to silence the expression of SEMA6B to explore its biological roles in the colon cancer cell lines HCT116 and LoVo. Results: The messenger RNA (mRNA) level of SEMA6B and the protein expression were higher in CRC tissues than adjacent normal tissues from multiple CRC datasets. High SEMA6B expression was significantly associated with dismal survival. Multivariate Cox regression analysis demonstrated that SEMA6B was an independent prognostic factor for progression-free survival (PFS). The nomogram showed a favorable predictive ability in PFS. Functional enrichment analysis and the Estimation of STromal and Immune cells in MAlignant Tumor tissues using Expression data (ESTIMATE) algorithm revealed that the gene cluster associated with the high SEMA6B group were prominently involved in immune responses and inflammatory activities. Notably, SEMA6B expression was positively correlated with infiltrating levels of CD4+ T cells, macrophages, myeloid-derived suppressor cells (MDSCs), regulatory T cells (Tregs), neutrophils, and dendritic cells. Moreover, SEMA6B expression displayed strong correlations with diverse marker sets of immunosuppressive cells in CRC. Integrative analysis revealed that immunosuppressive molecules and immune checkpoints were markedly upregulated in CRC samples with high SEMA6B expression. Furthermore, knockdown of SMEA6B in colon cancer cells significantly inhibited cell proliferation, migration, invasion and reduced the mRNA levels of immunosuppressive molecules. Conclusion: Our findings provide evidence that high SEMA6B expression correlated with adverse prognosis and the tumor immunosuppressive microenvironment in CRC patients. Therefore, SEMA6B may serve as a novel prognostic biomarker for CRC, which offers further insights into developing CRC-targeted immunotherapies.

A bioinformatics analysis on the potential role of ACE2 in cardiac impairment of patients with coronavirus disease 2019.

BACKGROUND: Coronavirus disease 2019 (COVID-19), caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), has been characterized as a pandemic around the world. Cardiac complications can occur in patients with COVID-19 and can be fatal in severe cases. Recently, it was reported that SARS-CoV-2 used the angiotensin-converting enzyme 2 (ACE2) as a cellular receptor to gain entry into the host cell. However, whether SARS-CoV-2 can directly infect heart tissues and the potential mechanism of cardiac injury in COVID-19 have not been determined. METHODS: To investigate the expression of ACE2 in heart tissues, we performed a bioinformatic analysis from public databases involving mRNA and protein expression. The correlation between ACE2 expression and virus-related genes was analyzed using the Gene Expression Profiling Interactive Analysis (GEPIA) database. Gene ontology (GO) and protein-protein interaction (PPI) analyses were performed to explore the roles of ACE2. RESULTS: ACE2 expression in the heart was significantly higher than that in the lung. Compared with the other coronavirus receptors, such as aminopeptidase N (ANPEP) or dipeptidyl peptidase 4 (DPP4), the mRNA and protein expression of ACE2 was increased in the heart. Moreover, the mRNA expression of ACE2 was substantially upregulated in patients with dilated cardiomyopathy. Importantly, the expression of ACE2 was positively correlated with genes that regulate viral reproduction and transmission. The GO and PPI analyses showed that the functions of proteins interacting with ACE2 were significantly enriched in the regulation of the viral process and inflammatory response. CONCLUSIONS: Our study provided bioinformatics evidence that the interaction between SARS-CoV-2 and ACE2 in the heart could contribute to COVID-19-mediated myocardial damage via the virus-induced cytopathic effect, triggering a cardiac inflammatory storm. Therefore, the close monitoring of cardiac function and early clinical intervention may be pivotal to preventing cardiac injury-related mortality in patients with COVID-19.