Evaluating the efficacy of GIPR agonists on non-alcoholic fatty liver disease: A Mediation Mendelian Randomization Study.

OBJECTIVE: Non-alcoholic fatty liver disease (NAFLD) is becoming the most common chronic liver disease worldwide while still lacks drugs for treatment or prevention. We aimed to investigate the causal role of glucose-dependent insulinotropic polypeptide receptor agonists (GIPRAs) on NAFLD and identify the mediated risk factors by which GIPRAs exert their therapeutic effects. METHODS: Genetic proxies of GIPRAs were identified as cis-SNPs of GIPR associated with both the gene expression level and HbA1c and analyses including colocalization and linkage disequilibrium (LD) were performed for validation. We then performed two-sample two-step mendelian randomization to determine the causal effect of GIPRAs on NAFLD. RESULTS: The MR analysis suggested genetic proxies of GIPRAs were causally associated with reduced risk of NAFLD (Odds ratio (OR): 0.46, 95 % confidence interval (95 % CI): 0.24-0.88, P = 0.02) and T2DM (OR: 0.10, 95 % CI: 0.07-0.13, P < 0.01). In addition, Mediation analysis showed evidence of indirect effect of GIPRAs on NAFLD via TRIG (0.88, [0.85-0.92], P < 0.01) and HDL-C (0.85, [0.80-0.90], P < 0.01). CONCLUSIONS: Our study provided strong evidence to support the causal role of GIPRAs on reducing the risk of NAFLD probably through improving lipid metabolism, especially TG and HDL-C, providing guidance for future clinical trials.

Integrated analysis of Mendelian Randomization and Bayesian colocalization reveals bidirectional causal association between inflammatory bowel disease and psoriasis.

BACKGROUND: Observational studies have suggested an association between inflammatory bowel disease [IBD] and psoriasis. However, the detailed genetic basis, causality, and direction of this association remain unclear. METHODS: Bidirectional two-sample Mendelian Randomization [MR] analysis was conducted using summary statistics from published genome-wide association studies. Bayesian Colocalization and multivariable MR [MVMR] analyses were performed to identify candidate variants and risk genes involved in the shared genetic basis between IBD, psoriasis, and their subtypes. RESULTS: Genetically predicted IBD and Crohn's disease [CD] were associated with an increased risk of psoriasis, psoriasis vulgaris [PsV], and psoriatic arthritis [PsA] (IBD on psoriasis: pooled odds ratio [OR] 1.09, 95% confidence interval [CI] 1.04-1.14, p = .0001; CD on psoriasis: pooled OR 1.10, 95% CI 1.06-1.15, p < .0001) and vice versa (psoriasis on IBD: pooled OR 1.11, 95%CI 1.02-1.21), whereas CD only exhibited a unidirectional association with psoriasis. Colocalization analysis revealed eight candidate genetic variants and risk genes (including LINC00824, CDKAL1, IL10, IL23R, DNAJC27, LPP, RUNX3, and RGS14) associated with a shared genetic basis. Among these, IL23R, DNAJC27, LPP, and RGS14 were further validated by MVMR analysis. CONCLUSION: Our findings indicated bidirectional causal associations between IBD and psoriasis (including PsV and PsA), which were attributed primarily to CD rather than Ulcerative colitis [UC]. Furthermore, we identified several candidate variants and risk genes involved in the shared genetic basis of IBD and psoriasis. Acquiring a better understanding of the shared genetic architecture underlying IBD and psoriasis would help improve clinical strategies.

Single-cell transcriptome analysis reveals heterogeneity and convergence of the tumor microenvironment in colorectal cancer.

Introduction: Colorectal cancer (CRC) ranks second for mortality and third for morbidity among the most commonly diagnosed cancers worldwide. We aimed to investigate the heterogeneity and convergence of tumor microenvironment (TME) in CRC. Methods: We analyzed the single-cell RNA sequencing data obtained from the Gene Expression Omnibus (GEO) database and identified 8 major cell types and 25 subgroups derived from tumor, para-tumor and peripheral blood. Results: In this study, we found that there were significant differences in metabolic patterns, immunophenotypes and transcription factor (TF) regulatory patterns among different subgroups of each major cell type. However, subgroups manifested similar lipid metabolic patterns, immunosuppressive functions and TFs module at the end of the differentiation trajectory in CD8+ T cells, myeloid cells and Fibroblasts. Meanwhile, TFs regulated lipid metabolism and immunosuppressive ligand-receptor pairs were detected by tracing the differentiation trajectory. Based on the cell subgroup fractions calculated by CIBERSORTx and bulk RNA-sequencing data from The Cancer Genome Atlas (TCGA), we constructed an immune risk model and clinical risk model of CRC which presented excellent prognostic value. Conclusion: This study identified that the differentiation was accompanied by remodeling of lipid metabolism and suppression of immune function, which suggest that lipid remodeling may be an important trigger of immunosuppression. More importantly, our work provides a new perspective for understanding the heterogeneity and convergence of the TME and will aid the development of prognosis and immunotherapies of CRC patients.

Primary tumor location (right versus left side of the colon) and resection affect the survival of patients with liver metastases from colonic neuroendocrine carcinoma: a population-based study.

BACKGROUND: Colonic neuroendocrine carcinomas (co-NECs) are heterogeneous and aggressive, especially with regard to metastasis. Whether co-NECs on the right and left sides of the colon have different characteristics from colon adenocarcinoma is unknown. METHODS: The co-NEC patients were selected from the 2010-2017 Surveillance, Epidemiology, and End Results Program (SEER) database. The right and left sides of the colon were separated by the splenic flexure. Coarsened exact matching (CEM) was performed to adjust for relevant factors before regression models were constructed. RESULTS: A total of 669 pathologically diagnosed co-NEC patients with sufficient baseline data were identified from the SEER database. A total of 80.72% of the patients had co-NEC that originated from the right side of the colon, and their mean overall survival (mOS) was similar to that of the patients with left-sided co-NECs (right versus left: 22.30 m versus 22.55 m). A total of 44.84% of the patients were diagnosed with liver metastasis (46.68% right side versus 37.98% left side). In patients with liver metastasis, those with right-sided co-NECs had better survival than those with left-sided co-NECs (mOS right versus left: 15.37 m versus 9.62 m; adjusted hazard ratio (HR) = 0.69, 95% confidence interval (CI): 0.49-0.98, p = 0.035). To further investigate the survival benefits of primary site resection, we separated the patients who had liver metastasis according to the primary site and performed CEM to balance the groups (no patients underwent liver metastasis resection or intervention). The results suggested that primary surgery could benefit patients with both left- and right-sided co-NECs (adjusted HR = 0.50, 95% CI: 0.33-0.77, p = 0.001 on the right side; HR = 0.38, 95% CI: 0.16-0.89, p = 0.026 on the left side). CONCLUSIONS: Co-NECs frequently originate on the right side and commonly develop liver metastasis. Right-sided co-NECs are associated with better survival than left-sided co-NECs after liver metastasis has occurred. Primary site resection is associated with prolonged survival in co-NEC patients with liver metastasis, regardless of the side from which the co-NEC has originated.

Ultra-mutated colorectal cancer patients with POLE driver mutations exhibit distinct clinical patterns.

POLE mutations, which lead to an ultramutated phenotype in colorectal cancer (CRC), have been reported as a promising marker in immunotherapy. We performed sequencing of CRC cases in Zhejiang University (ZJU) and extracted obtainable data from recently published results, including The Cancer Genome Atlas (TCGA), Japanese studies and clinical trials, to present clinical patterns of POLE driver-mutated CRC and reveal its heterogeneity. The rate of somatic POLE driver mutations has been reported as 2.60% (ZJU cohort), 1.50% (TCGA cohort), 1.00% (Japan cohort), and 1.00% (Lancet cohort). POLE driver mutations show a clearly increased mutation burden (mean TMB: 217.98 mut/Mb in ZJU; 203.13 mut/Mb in TCGA). Based on pooled data, more than 70.00% of patients with POLE driver mutations were diagnosed before they were 55 years old and at an early disease stage (Stage 0-II >70.00%), and more than 70.00% were male. Among Asian patients, 68.40% developed POLE driver mutations in the left-side colon, whereas 64.00% of non-Asian patients developed them in the right-side colon (p < 0.01). The top three amino acid changes due to POLE driver mutations are P286R, V411L, and S459F. Investigators and physicians should ascertain the heterogeneity and clinical patterns of POLE driver mutations to be better equipped to design clinical trials and analyze the data.

Tumor-Infiltrating Lymphocyte-Based Risk Score for Predicting Prognosis in Gastric Cancer.

Tumor-infiltrating lymphocytes (TILs) in gastric cancer are closely related to clinical prognosis; however, little is known regarding the immune microenvironment in this disease. Thus, RNA-sequencing data from gastric cancer patients were downloaded from the Gene Expression Omnibus (GEO). The proportion of immune cells was determined based on a deconvolution algorithm (CIBERSORT), and gene expression profiles were analyzed in the context of clinical outcomes to construct an immune risk score. Data were analyzed using least absolute shrinkage and selection operator (LASSO) and multivariable Cox regression, to identify prognostic markers of gastric cancer survival. The model included four immune cell types: neutrophils, plasma cells, activated CD4+ memory T cells, and T follicular helper cells. Patients were classified into two subgroups based on risk score, and a significant difference in overall survival (OS) was seen between the subgroups in both the training and testing cohorts, particularly in patients with tumor stages ≥T3. Multivariable analysis revealed that both T-stage and risk score were independent prognostic factors for gastric cancer survival [hazard ratio (HR) 1.505; 95% confidence interval (CI) 1.043-2.173, HR 1.686; 95% CI 1.367-2.080]. Risk scores and clinical factors were then integrated into a nomogram to build a model with both good discriminatory power and accuracy in predicting clinical outcomes. Further analysis using gene set enrichment analysis (GSEA) identified strong associations of immune risk with TGF-ß and tumor metastasis-related pathways, which could inform research on the molecular mechanisms of gastric cancer. Collectively, the data presented here suggest that an immune risk model can make an important contribution to predictions prognosis in gastric cancer patients.

N6-methyladenosine (m6A) RNA methylation signature as a predictor of stomach adenocarcinoma outcomes and its association with immune checkpoint molecules.

OBJECTIVE: Although N6-methyladenosine (m6A) RNA methylation is the most common mRNA modification process, few studies have examined the role of m6A in stomach adenocarcinomas (STADs). METHODS: In this retrospective study, we analyzed 293 STAD samples from The Cancer Genome Atlas with complete clinicopathological feature profiles. The m6A methylation risk signature was derived from LASSO-Cox regression analyses with 15 m6A regulators. Statistical analysis was performed and figures were prepared using R software (https://www.R-project.org/). RESULTS: The m6A signature was established as follows: risk score = FTO × 0.127 + YTHDF1 × 0.004 + KIAA1429 × 0.044 + YTHDC2 × 0.112 - RBM15 × 0.135 - ALKBH5 × 0.019 - YTHDF2 × 0.028, which was confirmed as an independent prognostic indicator to predict overall survival of patients with STAD. Risk scores and tumor grades were closely associated. Cell cycle, p53 signaling pathways, DNA mismatch repair, and RNA degradation were enriched in the low-risk subgroup. This subgroup showed significantly higher expression of immune checkpoint molecules including PD-1 (programmed death 1), PD-L1 (programmed death-ligand 1), and CTLA-4 (cytotoxic T-lymphocyte-associated antigen 4), suggesting that the signature may be a useful immunotherapy predictor. CONCLUSIONS: We established an m6A methylation signature as an independent prognostic tool to predict overall survival, which may also be useful as an immunotherapy predictor.

Rectal NETs and rectosigmoid junction NETs may need to be treated differently.

Neuroendocrine tumors (NETs) are heterogeneous, and the incidence of NETs is rapidly increasing. We observed different survival in patients with rectal NETs and rectosigmoid junction NETs, which are treated similarly. We included patients with rectal and rectosigmoid junction NETs from the SEER database. The 5-year survival was set as the end-point. 6675 patients with rectal NETs and 329 patients with rectosigmoid junction NETs, were eligible for the analysis. Initially, the survival analyses suggested that the 5-year survival significantly differed between the patients with rectal and rectosigmoid junction NETs (HR = 0.82, 95% CI 0.70-0.95; P = .01). Tumor differentiation, an invasion deeper than T2, and lymph node and distant metastases were still important risk factors affecting survival for both location. While, the males showed better survival (HR = 0.69, 95% CI 0.55-0.88; P < .01) and primary tumor surgery had no benefits (P = .56) for patients with rectosigmoid junction NETs. The factors that predict regional lymph node metastases varied by location. In rectal NETs, invasion deeper than T1 and a tumor larger than 1 cm could significantly increase the risk of regional lymph node metastases (all OR > 5, P < .01). In rectosigmoid junction NETs, the risk of regional lymph node metastases was considered significantly higher with invasion deeper than T1 (all OR > 5, P < .01) and a tumor larger than 2 cm (OR = 31.32, 95% CI 2.53-387.57; P < .01). We advocate a clear and consistent definition of the rectosigmoid junction for future studies, and more studies are needed to determine the reason underlying differences between rectum and rectosigmoid junction.

Epigenetic silencing of protocadherin 10 in colorectal cancer.

Colorectal cancer (CRC) is one of the most common types of malignant tumor in the world and occurs through a multi-step process resulting from the accumulation of genetic and epigenetic alterations of the genome. Although the molecular mechanisms of the pathogenesis of CRC remain unclear, the inactivation of tumor suppressor genes (TSGs) through promoter methylation serves an important role. Aberrant methylation is a well-defined marker of CRC. At present, the epigenetic silencing of protocadherin 10 (PCDH10) has been identified as an important TSG with key roles in colorectal carcinogenesis, invasion and metastasis as a frequent and early event. Advances in gene methylation detection in tumor tissues and body fluids have led to the development of non-invasive screening methods for CRC. The present study aimed to review the epigenetic alteration of PCDH10 in CRC development, and the potential of PCDH10 to be a non-invasive biomarker for CRC.

Up-regulated NRIP2 in colorectal cancer initiating cells modulates the Wnt pathway by targeting RORß.

BACKGROUND: Colorectal cancer remains one of the most common malignant tumors worldwide. Colorectal cancer initiating cells (CCICs) are a small subpopulation responsible for malignant behaviors of colorectal cancer. Aberrant activation of the Wnt pathways regulates the self-renewal of CCIC. However, the underlying mechanism(s) remain poorly understood. METHODS: Via retroviral library screening, we identified Nuclear Receptor-Interacting Protein 2 (NRIP2) as a novel interactor of the Wnt pathway from enriched colorectal cancer colosphere cells. The expression levels of NRIP2 and retinoic acid-related orphan receptor ß (RORß) were further examined by FISH, qRT-PCR, IHC and Western blot. NRIP2 overexpressed and knockdown colorectal cancer cells were produced to study the role of NRIP2 in Wnt pathway. We also verified the binding between NRIP2 and RORß and investigated the effect of RORß on CCICs both in vitro and in vivo. Genechip-scanning speculated downstream target HBP1. Western blot, ChIP and luciferase reporter were carried to investigate the interaction between NRIP2, RORß, and HBP1. RESULTS: NRIP2 was significantly up-regulated in CCICs from both cell lines and primary colorectal cancer tissues. Reinforced expression of NRIP2 increased Wnt activity, while silencing of NRIP2 attenuated Wnt activity. The transcription factor RORß was a key target through which NRIP2 regulated Wnt pathway activity. RORß was a transcriptional enhancer of inhibitor HBP1 of the Wnt pathway. NRIP2 prevented RORß to bind with downstream HBP1 promoter regions and reduced the transcription of HBP1. This, in turn, attenuated the HBP1-dependent inhibition of TCF4-mediated transcription. CONCLUSIONS: NRIP2 is a novel interactor of the Wnt pathway in colorectal cancer initiating cells. interactions between NRIP2, RORß, and HBP1 mediate a new mechanism for CCIC self-renewal via the Wnt activity.

Metabolic enzymes: key modulators of functionality in cancer stem-like cells.

Cancer Stem-like Cells (CSCs) are a subpopulation of cancer cells with self-renewal capacity and are important for the initiation, progression and recurrence of cancer diseases. The metabolic profile of CSCs is consistent with their stem-like properties. Studies have indicated that enzymes, the main regulators of cellular metabolism, dictate functionalities of CSCs in both catalysis-dependent and catalysis-independent manners. This paper reviews diverse studies of metabolic enzymes, and describes the effects of these enzymes on metabolic adaptation, gene transcription and signal transduction, in CSCs.

The virus-induced protein APOBEC3G inhibits anoikis by activation of Akt kinase in pancreatic cancer cells.

Pancreatic cancer is one of the more common cancers with a poor prognosis. Some varieties of cancer are related to virus infection. As a virus-induced protein, APOBEC3G (A3G) presents extensive anti-virus ability, but the role of A3G in pancreatic cancer was previously unknown. The expression of A3G in pancreatic cancer was examined using TaqMan real-time qPCR, immunohistochemical and immunofluorescent staining. Subsequently, the role of A3G in pancreatic cancer was evaluated in vivo using the tumor xenograft model. Anoikis was detected by colony formation assay and flow cytometry in vitro. The Akt kinase activity and target protein PTEN were examined by co-immunoprecipitation and immunoblot. The virus-induced protein A3G was significantly up-regulated in pancreatic cancer, and the up-regulation of A3G promoted xenograft tumor formation. A3G inactivated PTEN by binding to the C2 tensin-type and PDZ domains, thereby inducing anoikis resistance through Akt activation. Our results demonstrate that the up-regulation of A3G in pancreatic cancer cells induces anoikis resistance, and they provide novel insight into the mechanism by which A3G affects the malignant behavior of pancreatic cancer cells.

Up-regulation of microRNA-1290 impairs cytokinesis and affects the reprogramming of colon cancer cells.

Abnormal cytokinesis increases the possibility of nuclear fusion in tumor cells. However, the role of microRNAs (miRNAs) in abnormal cytokinesis is unclear. Here, we found that miR-1290 was significantly up-regulated in clinical colon cancer tissues. Up-regulation of miR-1290 postponed cytokinesis and led to the formation of multinucleated cells. KIF13B was a target of miR-1290 that was involved in aberrant cytokinesis. Furthermore, enforced expression of miR-1290 activated the Wnt pathway and increased the reprogramming-related transcript factors c-Myc and Nanog. Our results suggest that up-regulation of miR-1290 in colon cancer cells impaired cytokinesis and affected reprogramming.

Frequent epigenetic silencing of PCDH10 by methylation in human colorectal cancer.

PURPOSE: Aberrant DNA methylation is common in cancer cells. Epigenetic alterations resulting in the loss of tumor suppression gene functions are frequently involved in tumor development and progression. Recently, methylation of PCDH10 was reported to be associated with multiple hematologic malignancies as well as some solid tumors. Whether the down-regulation of PCDH10 happens in CRC remains unknown. METHODS: Methylation status of PCDH10 was evaluated by methylation-specific PCR analysis. The effects of PCDH10 re-expression were determined in growth, colony formation, cell cycle, and invasion assays. RESULTS: In this study, we found that 100 % (8 of 8) of colorectal cancer cell lines were silenced for PCDH10, but not normal colorectal epithelial cells. Demethylation treatment confirmed that the reduced expression is associated closely with promoter methylation. Hyper-methylation of PCDH10 was also detected in 85 % of primary colorectal tumors, but not in adjacent normal colorectal tissues. CONCLUSIONS: Our results suggest that PCDH10 is an important tumor suppression gene with key roles of suppressing cell proliferation, clonogenicity, and inhibiting cell invasion in the development of colorectal cancer. Thus, PCDH10 methylation may constitute a useful biomarker of colorectal cancer patients.

MicroRNAs up-regulated by CagA of Helicobacter pylori induce intestinal metaplasia of gastric epithelial cells.

CagA of Helicobacter pylori is a bacterium-derived oncogenic protein closely associated with the development of gastric cancers. MicroRNAs (miRNAs) are a class of widespread non-coding RNAs, many of which are involved in cell growth, cell differentiation and tumorigenesis. The relationship between CagA protein and miRNAs is unclear. Using mammalian miRNA profile microarrays, we found that miRNA-584 and miRNA-1290 expression was up-regulated in CagA-transformed cells, miRNA-1290 was up-regulated in an Erk1/2-dependent manner, and miRNA-584 was activated by NF-κB. miRNA-584 sustained Erk1/2 activities through inhibition of PPP2a activities, and miRNA-1290 activated NF-κB by knockdown of NKRF. Foxa1 was revealed to be an important target of miRNA-584 and miRNA-1290. Knockdown of Foxa1 promoted the epithelial-mesenchymal transition significantly. Overexpression of miRNA-584 and miRNA-1290 induced intestinal metaplasia of gastric epithelial cells in knock-in mice. These results indicate that miRNA-584 and miRNA-1290 interfere with cell differentiation and remodel the tissues. Thus, the miRNA pathway is a new pathogenic mechanism of CagA.

Biochemical metabolic changes assessed by 31P magnetic resonance spectroscopy after radiation-induced hepatic injury in rabbits.

AIM: To compare the features of biochemical metabolic changes detected by hepatic phosphorus-31 magnetic resonance spectroscopy ((31)P MRS) with the liver damage score (LDS) and pathologic changes in rabbits and to investigate the diagnostic value of (31)P MRS in acute hepatic radiation injury. METHODS: A total of 30 rabbits received different radiation doses (ranging 5-20 Gy) to establish acute hepatic injury models. Blood biochemical tests, (31)P MRS and pathological examinations were carried out 24 h after irradiation. The degree of injury was evaluated according to LDS and pathology. Ten healthy rabbits served as controls. The MR examination was performed on a 1.5 T imager using a (1)H/(31)P surface coil by the 2D chemical shift imaging technique. The relative quantities of phosphomonoesters (PME), phosphodiesters (PDE), inorganic phosphate (Pi) and adenosine triphosphate (ATP) were measured. The data were statistically analyzed. RESULTS: (1) Relative quantification of phosphorus metabolites: (a) ATP: there were significant differences (P < 0.05) (LDS-groups: control group vs mild group vs moderate group vs severe group, 1.83 +/- 0.33 vs 1.55 +/- 0.24 vs 1.27 +/- 0.09 vs 0.98 +/- 0.18; pathological groups: control group vs mild group vs moderate group vs severe group, 1.83 +/- 0.33 vs 1.58 +/- 0.25 vs 1.32 +/- 0.07 vs 1.02 +/- 0.18) of ATP relative quantification among control group, mild injured group, moderate injured group, and severe injured group according to both LDS grading and pathological grading, respectively, and it decreased progressively with the increased degree of injury (r = -0.723, P = 0.000). (b) PME and Pi; the relative quantification of PME and Pi decreased significantly in the severe injured group, and the difference between the control group and severe injured group was significant (P < 0.05) (PME: LDS-control group vs LDS-severe group, 0.86 +/- 0.23 vs 0.58 +/- 0.22, P = 0.031; pathological control group vs pathological severe group, 0.86 +/- 0.23 vs 0.60 +/- 0.21, P = 0.037; Pi: LDS-control group vs LDS-severe group, 0.74 +/- 0.18 vs 0.43 +/- 0.14, P = 0.013; pathological control group vs pathological severe group, 0.74 +/- 0.18 vs 0.43 +/- 0.14, P = 0.005) according to LDS grading and pathological grading, respectively. (c) PDE; there were no significant differences among groups according to LDS grading, and no significant differences between the control group and experimental groups according to pathological grading. (2) The ratio of relative quantification of phosphorus metabolites: significant differences (P < 0.05) (LDS-moderate group and LDS-severe group vs LDS-control group and LDS-mild group, 1.94 +/- 0.50 and 1.96 +/- 0.72 vs 1.43 +/- 0.31 and 1.40 +/- 0.38) were only found in PDE/ATP between the moderate injured group, the severe injured group and the control group, the mild injured group. No significant difference was found in other ratios of relative quantification of phosphorus metabolites. CONCLUSION: (31)P MRS is a useful method to evaluate early acute hepatic radiation injury. The relative quantification of hepatic ATP levels, which can reflect the pathological severity of acute hepatic radiation injury, is correlated with LDS.