The tumor immune microenvironment remodeling and response to HER2-targeted therapy in HER2-positive advanced gastric cancer.

Combination therapy with anti-HER2 agents and immunotherapy has demonstrated significant clinical benefits in gastric cancer (GC), but the underlying mechanism remains unclear. In this study, we used multiplex immunohistochemistry to assess the changes of the tumor microenvironment in 47 advanced GC patients receiving anti-HER2 therapy. Additionally, we performed single-cell transcriptional sequencing to investigate potential cell-to-cell communication and molecular mechanisms in four HER2-positive GC baseline samples. We observed that post-treated the infiltration of NK cells, CD8+ T cells, and B lymphocytes were significantly higher in patients who benefited from anti-HER2 treatment than baseline. Further spatial distribution analysis demonstrated that the interaction scores between NK cells and CD8+ T cells, B lymphocytes and M2 macrophages, B lymphocytes and Tregs were also significantly higher in benefited patients. Cell-cell communication analysis from scRNA sequencing showed that NK cells utilized CCL3/CCL4-CCR5 to recruit CD8+ T cell infiltration. B lymphocytes employed CD74-APP/COPA/MIF to interact with M2 macrophages, and utilized TNF-FAS/ICOS/TNFRSR1B to interact with Tregs. These cell-cell interactions contribute to inhibit the immune resistance of M2 macrophages and Tregs. Our research provides potential guidance for the use of anti-HER2 therapy in combination with immune therapy.

Neutrophil extracellular traps induced by the hypoxic microenvironment in gastric cancer augment tumour growth.

BACKGROUND: Inflammation-related predisposition to cancer plays an essential role in cancer progression and is associated with poor prognosis. A hypoxic microenvironment and neutrophil infiltration are commonly present in solid tumours, including gastric cancer (GC). Neutrophil extracellular traps (NETs) have also been demonstrated in the tumour immune microenvironment (TIME), but how NETs affect GC progression remains unknown. Here, we investigated the role of NET formation in the TIME and further explored the underlying mechanism of NETs in GC tumour growth. METHODS: Hypoxia-induced factor-1α (HIF-1α), citrulline histone 3 (citH3) and CD66b expression in tumour and adjacent nontumor tissue samples was evaluated by western blotting, immunofluorescence and immunohistochemical staining. The expression of neutrophil-attracting chemokines in GC cells and their hypoxic-CM was measured by qRT‒PCR and ELISA. Neutrophil migration under hypoxic conditions was evaluated by a Transwell assay. Pathway activation in neutrophils in a hypoxic microenvironment were analysed by western blotting. NET formation was measured in vitro by immunofluorescence staining. The protumour effect of NETs on GC cells was identified by Transwell, wound healing and cell proliferation assays. In vivo, an lipopolysaccharide (LPS)-induced NET model and subcutaneous tumour model were established in BALB/c nude mice to explore the mechanism of NETs in tumour growth. RESULTS: GC generates a hypoxic microenvironment that recruits neutrophils and induces NET formation. High mobility group box 1 (HMGB1) was translocated to the cytoplasm from the nucleus of GC cells in the hypoxic microenvironment and mediated the formation of NETs via the toll-like receptor 4 (TLR4)/p38 MAPK signalling pathway in neutrophils. HMGB1/TLR4/p38 MAPK pathway inhibition abrogated hypoxia-induced neutrophil activation and NET formation. NETs directly induced GC cell invasion and migration but not proliferation and accelerated the augmentation of GC growth by increasing angiogenesis. This rapid tumour growth was abolished by treatment with the NET inhibitor deoxyribonuclease I (DNase I) or a p38 MAPK signalling pathway inhibitor. CONCLUSIONS: Hypoxia triggers an inflammatory response and NET formation in the GC TIME to augment tumour growth. Targeting NETs with DNase I or HMGB1/TLR4/p38 MAPK pathway inhibitors is a potential therapeutic strategy to inhibit GC progression. Video Abstract.

SIRT1 enhances oxaliplatin resistance in colorectal cancer through microRNA-20b-3p/DEPDC1 axis.

Oxaliplatin (L-OHP) is a standard treatment drug for colorectal cancer (CRC), but acquired drug resistance limits the outcome of patients. We investigated the involvement of sirtuin 1 (SIRT1) in L-OHP resistance in the setting of CRC via microRNA-20b-3p/DEP domain containing 1 (miR-20b-3p/DEPDC1) axis. CRC tissues that were resistant or sensitive to L-OHP were harvested, in which SIRT1, miR-20b-3p, and DEPDC1 levels were tested. L-OHP-resistant-resistant CRC cells were transfected, subsequently, cellular proliferation, invasion, migration, and apoptosis were tested, and tumor resistance to L-OHP was observed. The binding of SIRT1 to miR-20b-3p promoter and the targeting relationship between miR-20b-3p and DEPDC1 were verified. An aberrant elevation in SIRT1 expression was seen in L-OHP-resistant CRC tissues and cells. Knockdown of SIRT1 sensitized CRC cells and xenografted CRC tumors to L-OHP. SIRT1 bound with miR-20b-3p promoter to regulate DEPDC1. Reducing miR-20b-3p or raising DEPDC1 levels weakened the effect of SIRT1 knockdown on L-OHP-resistant-CRC cells. SIRT1 enhances L-OHP resistance in CRC by mediating miR-20b-3p/DEPDC1 axis.

Predicting response to immunotherapy in gastric cancer via multi-dimensional analyses of the tumour immune microenvironment.

A single biomarker is not adequate to identify patients with gastric cancer (GC) who have the potential to benefit from anti-PD-1/PD-L1 therapy, presumably owing to the complexity of the tumour microenvironment. The predictive value of tumour-infiltrating immune cells (TIICs) has not been definitively established with regard to their density and spatial organisation. Here, multiplex immunohistochemistry is used to quantify in situ biomarkers at sub-cellular resolution in 80 patients with GC. To predict the response to immunotherapy, we establish a multi-dimensional TIIC signature by considering the density of CD4+FoxP3-PD-L1+, CD8+PD-1-LAG3-, and CD68+STING+ cells and the spatial organisation of CD8+PD-1+LAG3- T cells. The TIIC signature enables prediction of the response of patients with GC to anti-PD-1/PD-L1 immunotherapy and patient survival. Our findings demonstrate that a multi-dimensional TIIC signature may be relevant for the selection of patients who could benefit the most from anti-PD-1/PD-L1 immunotherapy.

The Association between Blood Indexes and Immune Cell Concentrations in the Primary Tumor Microenvironment Predicting Survival of Immunotherapy in Gastric Cancer.

The tumor microenvironment plays a vital role in tumor progression and treatment response. However, the association between immune cell concentrations in primary tumor and blood indexes remains unknown. Thus, we enrolled patients with gastric cancer (GC) in two cohorts. We used multiplexed immunohistochemistry to quantify in situ proteins covering rare cell types at sub-cellular resolution in 80 patients with GC in the first cohort. A high correlation between the LMR (lymphocyte-to-monocyte ratio)/NLR (neutrophil-to-lymphocyte ratio) and tumor immune microenvironment was found. The density of exhausted CD8 T cells including CD8+PD1−TIM3+, CD8+LAG3+PD1+, CD8+LAG3+PD1−, CD8+LAG3+PD1+TIM3− was negatively associated with LMR and positively associated with NLR (p < 0.05). Additionally, the higher density of macrophages in tumor core was associated with a higher platelet-to-lymphocyte ratio and systemic immune-inflammation index. Furthermore, we validated the prognostic value of LMR and NLR in an independent cohort of 357 gastric cancer patients receiving immunotherapy. Higher LMR at baseline was significantly associated with superior immune-related PFS (irPFS) and a trend of superior immune-related OS (irOS). Higher NLR was associated with inferior irOS. In conclusion, blood indexes were associated with immune cells infiltrating in primary tumors of GC. NLR and LMR are associated with the density of exhausted CD8+ T immune cells, which leads to prognostic values of immunotherapy.

Correlation between the accumulation of skin glycosylation end products and the development of type 2 diabetic peripheral neuropathy.

BACKGROUND: The accumulation of advanced glycation end products (AGEs) occurring in skin tissues can be measured by AGE Reader. Here, we assessed the correlation between AGEs values and the development of type 2 diabetic peripheral neuropathy (DPN). METHODS: The basic clinical information of 560 patients with T2DM was collected through an electronic system. AGEs and diabetic complication risk score was measured by AGE Reader, a non-invasive optical signal detector. All of the participants were classified into 4 groups based on Dyck criteria: grade 0 (non-DPN group), grade 1 (early stage group), grade 2 (middle stage group) and grade 3 (advanced group). Pearson correlation analysis and Spearman correlation analysis were used to evaluate the correlation between AGEs and other indexes. The sensitivity and specificity of glycosylated products were evaluated by ROC curve. RESULTS: With the increase of DPN severity, the accumulative AGEs showed an increasing trend. Significant differences (P = 0.000) of AGEs were found among grades 0, 1, 2, and 3 of DPN, and significant differences (P = 0.000) of AGEs were found between grades 1 and 3. There were significant differences in DPN risk score between grades 0, 1, 2, and 3, between grades 1, 2, and 3, and between grades 2 and 3 (P < 0.01 or P < 0.05). AGEs were positively correlated with age, blood uric acid, disease course, systolic blood pressure, the risk scores of the four major complications of diabetes, renal function indicators (serum creatinine, Cystatin C, homocysteine, the ratio of urinary albumin and creatinine, urinary microalbumin, α-microglobulin, urinary transferrin, urinary immunoglobulin), inflammatory indicators (white blood cell count, neutrophil count, neutrophil-to-lymphocyte ratio, C-reactive protein), and TCSS score. However, it was negatively correlated with BMI,fasting insulin, insulin 1-3 h postprandial, lymphocyte count, HOMA insulin resistance index and estimated glomerular filtration rate. The area under the AGEs cumulant and neuropathy risk score curve was 0.769 and 0.743, respectively. The confidence intervals were (71.2-82.6%) and (68.8-79.9%), respectively. The maximum Youden's index of AGEs cumulant was 0.440, and the corresponding AGEs cumulant value was 77.65. The corresponding sensitivity and specificity were 0.731 and 0.709, respectively. Furthermore, the maximum Youden's index of neuropathy risk score was 0.385, and the corresponding neuropathy risk score was 66.25. The corresponding sensitivity and the specificity were 0.676 and 0.709, respectively. CONCLUSION: The cumulative amount of skin AGEs can be used as the diagnostic index and the prediction and evaluation index of DPN severity. Moreover, the diabetic peripheral neuropathy risk score can predict the risk of DPN in patients with T2DM.

N6-methyladenosine-dependent modification of circGARS acts as a new player that promotes SLE progression through the NF-κB/A20 axis.

BACKGROUND: Certain circRNAs could be used as biomarkers to determine the risk of development and/or severity of systemic lupus erythematosus, and their new function in the regulation of gene expression has motivated us to investigate their role in SLE METHODS: Experimental methods including qRT-PCR, RNA immunoprecipitation (RIP), pulldown, dual luciferase reporter assay, RNA interference and cell transfection, RNA fluorescence in situ hybridization, western blotting, and mass spectrometry were used to assessed circGARS (hsa_circRNA_0009000) for immune functions and defined mechanisms by which circGARS promotes the progression in SLE. RESULTS: Our results demonstrated that the levels of circGARS was remarkably upregulated in SLE and correlated with clinicopathological features. CircGARS directly combined with microRNA-19a (miR-19a). Functionally, circGARS downregulated the expression of TNFAIP3 (A20, tumor necrosis factor alpha-induced protein 3) to mediate the activation of immune responses that were regulated by the nuclear factor-κB (NF-κB) pathway as a negative feedback mechanism. In addition, miR-19a regulated A20 (TNFAIP3) degradation by downregulating the expression of YTH N6-methyladenosine RNA-binding protein 2 (YTHDF2). CONCLUSIONS: The circGARS sponges miR-19a to regulate YTHDF2 expression to promote SLE progression through the A20/NF-κB axis and may act as an independent biomarker to help the treatment of SLE patients.

Increased Frequency of Circulating Classical Monocytes in Patients with Rosacea.

PURPOSE: Monocyte subsets, including classical, intermediate and non-classical monocytes, are involved in the pathogenesis of inflammatory or autoimmune diseases. The pathogenic role of monocytes in the peripheral blood mononuclear cells (PBMCs) of patients with rosacea remains unclear. This study aimed to assess frequencies of monocyte subsets in PBMCs from rosacea patients before and after clinical treatment. PATIENTS AND METHODS: We applied flow cytometry to examine frequencies of monocyte subsets in 116 patients with rosacea, while patients with 26 systemic lupus erythematosus (SLE), 28 acne and 42 normal healthy subjects without skin problems (HC) were recruited as controls. Expression of C-C chemokine receptor 2 (CCR2) on monocytes and plasma levels of CC-chemokine ligand 2 (CCL2), high mobility group box-1 (HMGB-1), interleukin-1 beta (IL-1ß) and tumor necrosis factor alpha (TNF-α) were measured in HC and rosacea patients before and after treatment. RESULTS: The frequency of classical monocytes, but not intermediate or non-classical monocytes, was higher in rosacea as compared with HC, which decreased after treatment. Frequencies of monocyte subsets showed no gender difference, while increased with age in patients but not in HC. Frequencies of classical monocytes in patients with erythematotelangiectatic rosacea (ETR) and ETR-papulopustular rosacea (PPR) overlap were significantly higher than HC or patients with only PPR or phymatous rosacea (PhR). There was a significant higher expression of CCR2 in classical monocytes, with higher plasma levels of CCL2, HMGB-1, IL-1ß and TNF-α in patients than in HC, which all significantly decreased after treatment. CONCLUSION: Our data indicated a possible association between abnormal classical monocytes frequencies and rosacea.

Association of CYP24A1 gene polymorphism with colorectal cancer in the Jiamusi population.

BACKGROUND: The population in Jiamusi has been reported to have the highest prevalence of colorectal cancer (CRC) in China. The genetic causal-effect for this occurrence among the residents remains unclear. Given the long cold seasons with people wearing more clothes and reduced UV exposure, we aimed to study the association between the vitamin D metabolism-related gene CYP24A1 polymorphism and CRC susceptibility. METHOD: A case-control study was conducted that included 168 patients with CRC and 710 age-matched healthy individuals as the control group. Plausible susceptible variations were sought and clinical phenotypic-genotype association analysis was performed. RESULTS: Overall, two CYP24A1 polymorphisms, rs6013905 AX (P = 0.02, OR = 1.89, 95%CI: 1.09-3.29) and rs2762939 GX (P = 0.02, OR = 1.52, 95%CI: 1.08-2.13) were significantly associated with CRC in the Jiamusi population. In the female group, three CYP24A1 polymorphisms, rs6013905 AX (P = 0.04, OR = 2.59, 95%CI: 1.03-6.49), rs2762939 GX (P = 0.01, OR = 2.35, 95%CI: 1.25-4.42), and rs6068816 GG (P = 0.05, OR = 1.89, 95%CI: 0.99-3.59) carriers were significantly associated with CRC. In clinical phenotypic-genotype analysis, rs6013905 GG (P = 0.05, OR = 4.00, 95%CI: 0.92-17.48) and rs2762939 GX (P = 0.03, OR = 4.87, 95%CI: 1.00-23.69) carriers were significantly associated with poorly differentiated CRC, while CYP24A1 rs6068816 AX was significantly associated with the tumor type (P = 0.02, OR = 2.08, 95%CI: 1.10-3.96) and location (P = 0.04, OR = 2.24, 95%CI: 1.05-4.77). CONCLUSION: CYP24A1 gene polymorphism may be a genetic risk factor attributable to the highest prevalence of CRC in Jiamusi people. Individuals with CYP24A1 gene polymorphism may have an increased barrier for vitamin D absorption, thus contributing to the risk of CRC development.

EIF2AK2 selectively regulates the gene transcription in immune response and histones associated with systemic lupus erythematosus.

PKR, also known as EIF2AK2, is an IFN-stimulated gene (ISG) and shows a higher expression in probands with systemic lupus erythematosus (SLE), which is likely responsible for the impaired translational and proliferative responses to mitogens in T cells from SLE patients. In this study, we overexpressed EIF2AK2 in HeLa cells to study EIF2AK2-regulated genes using RNA-seq technology, followed by bioinformatic analysis of target genes of EIF2AK2-regulated transcriptional factors (TFs). Overexpression of EIF2AK2 promotes HeLa cell apoptosis. EIF2AK2 selectively represses the transcription of histone protein genes associated with SLE, immune response genes and TF genes, which was validated by RT-qPCR experiments. Analysis of motifs overrepresented in the promoter regions of EIF2AK2-regulated genes revealed eighteen EIF2AK2-regulated TFs involved in establishing the EIF2AK2 network. Eight out of these predicted EIF2AK2-regulated TFs were further verified by RT-qPCR selectively in both HeLa and Jurkat cells, and most such as HEY2, TFEC, BATF2, GATA3 and ATF3 and FOXO6 are known to regulate immune response. Our results suggest that the dsRNA-dependent kinase EIF2AK2 selectively regulates the transcription of immune response and SLE-associated histone protein genes, and such a selectivity is likely to be operated by EIF2AK2-targeted TFs. The EIF2AK2-TFs axis potentially offers new therapeutic targets for counteracting immunological disease in the future.

Exploration of Potential Integrated Models of N6-Methyladenosine Immunity in Systemic Lupus Erythematosus by Bioinformatic Analyses.

Systemic lupus erythematosus (SLE) is a prototypical systemic autoimmune disease of unknown etiology. The epigenetic regulation of N6-methyladenosine (m6A) modification in immunity is emerging. However, few studies have focused on SLE and m6A immune regulation. In this study, we aimed to explore a potential integrated model of m6A immunity in SLE. The models were constructed based on RNA-seq data of SLE. A consensus clustering algorithm was applied to reveal the m6A-immune signature using principal component analysis (PCA). Univariate and multivariate Cox regression analyses and Kaplan-Meier analysis were used to evaluate diagnostic differences between groups. The effects of m6A immune-related characteristics were investigated, including risk evaluation of m6A immune phenotype-related characteristics, immune cell infiltration profiles, diagnostic value, and enrichment pathways. CIBERSORT, ESTIMATE, and single-sample gene set enrichment analysis (ssGSEA) were used to evaluate the relative immune cell infiltrations (ICIs) of the samples. Conventional bioinformatics methods were used to identify key m6A regulators, pathways, gene modules, and the coexpression network of SLE. In summary, our study revealed that IGFBP3 (as a key m6A regulator) and two pivotal immune genes (CD14 and IDO1) may aid in the diagnosis and treatment of SLE. The potential integrated models of m6A immunity that we developed could guide clinical management and may contribute to the development of personalized immunotherapy strategies.

Construction and Characterization of a Synergistic lncRNA-miRNA Network Reveals a Crucial and Prognostic Role of lncRNAs in Colon Cancer.

Non-coding RNAs such as long non-coding RNAs (lncRNAs) and microRNAs (miRNAs) have been found to be indispensable factors in carcinogenesis and cancer development. Numerous studies have explored the regulatory functions of these molecules and identified the synergistic interactions among lncRNAs or miRNAs, while those between lncRNAs and miRNAs remain to be investigated. In this study, we constructed and characterized an lncRNA-miRNA synergistic network following a four-step approach by integrating the regulatory pairs and expression profiles. The synergistic interactions with more shared regulatory mRNAs were found to have higher interactional intensity. Through the analysis of nodes in the network, we found that lncRNAs played roles that are more central and had similar synergistic interactions with their neighbors when compared with miRNAs. In addition, known colon adenocarcinoma (COAD)-related RNAs were found to be enriched in this synergistic network, with higher degrees, betweenness, and closeness. Finally, we proposed a risk score model to predict the clinical outcome for COAD patients based on two prognostic hub lncRNAs, MEG3 and ZEB1-AS1. Moreover, the hierarchical networks of these two lncRNAs could contribute to the understanding of the biological mechanism of tumorigenesis. For each lncRNA-miRNA interaction in the hub-related subnetwork and two hierarchical networks, we performed RNAup method to evaluate their binding energy. Our results identified two important lncRNAs with prognostic roles in colon cancer and dissected their regulatory mechanism involving synergistic interaction with miRNAs.

Fc receptor-like 1 intrinsically recruits c-Abl to enhance B cell activation and function.

B cell activation is regulated by the stimulatory or inhibitory co-receptors of B cell receptors (BCRs). Here, we investigated the signaling mechanism of Fc receptor-like 1 (FcRL1), a newly identified BCR co-receptor. FcRL1 was passively recruited into B cell immunological synapses upon BCR engagement in the absence of FcRL1 cross-linking, suggesting that FcRL1 may intrinsically regulate B cell activation and function. BCR cross-linking alone led to the phosphorylation of the intracellular Y281ENV motif of FcRL1 to provide a docking site for c-Abl, an SH2 domain-containing kinase. The FcRL1 and c-Abl signaling module, in turn, potently augmented B cell activation and proliferation. FcRL1-deficient mice exhibited markedly impaired formation of extrafollicular plasmablasts and germinal centers, along with decreased antibody production upon antigen stimulation. These findings reveal a critical BCR signal-enhancing function of FcRL1 through its intrinsic recruitment to B cell immunological synapses and subsequent recruitment of c-Abl upon BCR cross-linking.

Impact of Colon-Specific DNA Methylation-Regulated Gene Modules on Colorectal Cancer Patient Survival.

BACKGROUND Colorectal cancer (CRC) is the second most commonly diagnosed cancer in females and the third in males worldwide. Although existing evidence explained some critical functions of the single genetic abnormality in the pathogenesis of CRC, the function of interactors involved in the colon-specific regulatory network, especially DNA methylation regulated network is still poorly understood. MATERIAL AND METHODS In this work, matched gene expression and DNA methylation samples of CRC patients were retrieved. Differential gene expression and methylation analyses were performed. In addition, gene expression and DNA methylation were integrated into a colon-specific regulatory gene network, detecting the epigenetically regulated gene modules which drive CRC through an underlying epigenetic mechanism. Finally, the colon-specific DNA methylation-regulated gene modules were validated using an independent set of CRC patients. RESULTS Differential gene expression analysis demonstrated the upregulation of the cell cycle and DNA replication and downregulation of cGMP-PKG signaling pathway and calcium signaling pathway in CRC. Differentially methylated regions (DMRs) showed the different levels of methylation in promoters, CpG islands, and genes in CRC. In addition, gene expression and DNA methylation were integrated into a colon-specific regulatory gene network, detecting 8 epigenetically regulated gene modules which drive CRC through an underlying epigenetic mechanism. Interestingly, 2 of the colon-specific DNA methylation-regulated gene modules showed a significant predictive ability for the survival of an independent set of CRC patients. CONCLUSIONS The results of this study could open a new era and aid the development of novel therapeutic targets for the treatment of CRC patient.

Polymorphisms in the CHIT1 gene: Associations with colorectal cancer.

Colorectal cancer (CRC) is one of the most common solid tumors worldwide, often associated with inflammation. The microbes in the human intestine have a key role in inflammations and CRC. Chitotriose renders growth advantage to some bacteria, especially some pathogens, and thus has a role in inflammations. The enzyme chitotriosidase, encoded by the CHIT1 gene of the host, may degrade chitotriose with different efficiencies depending on the alleles. We sequenced the CHIT1 gene for 320 Chinese Han CRC patients and 404 normal controls, and focused on variations rs61745299 and rs35920428 within the CHIT1 gene for their possible roles in CRC. Statistical analyses were conducted using Chi-Square Tests as implemented in SPSS (version 19.0). Multiple sequence alignment was conducted using the Vector NTI, and protein expression levels were analyzed by western blotting. The two variations, rs61745299 and rs35920428 within the CDS region of CHIT1 gene, were associated with the risk of CRC (both with P values < 0.001). Western blotting analysis showed that the variations increased the expression levels of the CHIT1 and C-reaction protein genes in the cancer tissue. We conclude that the two variations of CHIT1, rs61745299 and rs35920428, increase expression of the gene and are associated with CRC in Chinese Han populations.

A review of cancer risk prediction models with genetic variants.

Cancer risk prediction models are important in identifying individuals at high risk of developing cancer, which could result in targeted screening and interventions to maximize the treatment benefit and minimize the burden of cancer. The cancer-associated genetic variants identified in genome-wide or candidate gene association studies have been shown to collectively enhance cancer risk prediction, improve our understanding of carcinogenesis, and possibly result in the development of targeted treatments for patients. In this article, we review the cancer risk prediction models that have been developed for popular cancers and assess their applicability, strengths, and weaknesses. We also discuss the factors to be considered for future development and improvement of models for cancer risk prediction.