APRIL knockdown suppresses migration and invasion of human colon carcinoma cells

ObjectiveThe purpose of this study was to investigate the function of a proliferation-inducing ligand (APRIL) gene among the metastatic colorectal cancer (CRC) disease.MethodsCell adhesion, cell migration and invasion behavior were detected after knockdown of APRIL expression in the colon carcinoma cell line, SW480 by RNAi and the rescue experiments were performed with recombinant human APRIL (rhAPRIL) in vitro.ResultsThis original study indicated that knockdown of APRIL expression strongly inhibited colon carcinoma cell adhesion, cell migration and invasion in vitro. By contrast, reconstitution of APRIL expression with rhAPRIL in these APRILi cells, prominently restores CRC cell migration and invasion.ConclusionThese results strongly suggest that APRIL play an important role in the tumor development of the invasive or migratory behavior of CRC cells and may be a useful therapeutic target in the malignant colon carcinomas.     

Rapid determination of AKAP12 promoter methylation levels in peripheral blood using methylation-sensitive high resolution melting (MS-HRM) analysis: Application in colorectal cancer

BackgroundColorectal cancer is the third most common form of cancer and hypermethylation has been shown to increase the risk of developing this disease. DNA hypermethylation in the A kinase anchor protein 12 (AKAP12/Gravin) promoter region and the accompanied underexpression of it has been noted in a variety of human cancers.MethodsWe applied methylation-specific high resolution melting (MS-HRM) technology to detect quantitatively A kinase anchor protein 12 (AKAP12/Gravin) methylation in peripheral blood from 100 colorectal cancer patients and 50 healthy volunteers and in 3 colorectal cancer cell lines.ResultsIn this study 48 of the 100 colorectal cancer samples (48%) were found to be methylated at the AKAP12 promoter region. AKAP12 methylation was significantly higher in the colorectal cancer samples with differentiation (p = 0.03). We also compared the results generated by MS-HRM with a traditional methylation-specific PCR (MSP) assay. We found that intra-assay variability ranged from 6.14 to 9.90% and inter-assay variability ranged from 14.5 to 17.2%. The AKAP12 MS-HRM assay was able to reproducibly detect 1% methylated DNA, whereas the MSP method was unable to detect less than 5% methylation.ConclusionsWe demonstrate the utility of quantitative AKAP12 MS-HRM analysis of promoter methylation in peripheral blood samples. AKAP12 MS-HRM quantitative methods with excellent detection capabilities have many promising applications in the research and diagnosis of colorectal cancer.     

5-氮杂胞苷对骨髓瘤细胞增殖抑制作用及对XAF1基因表达的影响

目的 探讨5-氮杂胞苷处理对骨髓瘤细胞系RPMI 8226和XG-7细胞中XAF1基因表达的影响及体外抗骨髓瘤作用的机制.方法 采用逆转录PCR和Western blot方法检测骨髓瘤细胞系RPMI 8226和XG-7细胞中XAF1基因和蛋白的表达.采用甲基化特异性PCR(MSP)方法检测XAFI基因启动子CpG岛甲基化状态.采用0～5 μmoL/L 5-氮杂胞苷处理骨髓瘤细胞株.采用CCK-8比色法检测5-氮杂胞苷处理对骨髓瘤细胞增殖抑制作用.采用Annexin V/7-AAD染色流式细胞术检测细胞凋亡.结果 XG-7细胞不表达XAF1 mRNA及蛋白,RPMI 8226细胞表达XAF1 mRNA转录本1和2.XG-7和RPMI 8226细胞XAFl基因启动子CpG岛均存在过甲基化.XG-7和RPMI 8226细胞经2.5μmol/L 5-氮杂胞苷处理72 h后仅表达XAF1 mRNA转录本1并表达XAF1蛋白,并且XAF1基因启动子CpG岛甲基化程度降低.5-氮杂胞苷抗骨髓瘤作用呈时间和浓度依赖性.5-氮杂胞苷处理RPMI 8226和XG-7细胞48 h的IC50值分别为2.4 μmol/L和2.6 μmol/L.结论 骨髓瘤细胞中抑癌基因XAFI表达缺失或表达异常与XAF1基凶启动子CpG岛过甲基化有关.5-氮杂胞苷处理可以诱导XAF1 mRNA及蛋白表达.5-氮杂胞苷在临床上能达到的药物浓度下具有抗骨髓瘤作用,其作用机制是诱导骨髓瘤细胞凋亡.     

Knockdown of Forkhead box A1 suppresses the tumorigenesis and progression of human colon cancer cells through regulating the phosphatase and tensin homolog/Akt pathway

BackgroundThis study aimed to evaluate the role and the underlying mechanisms of Forkhead box A1 (encoded by FOXA1) in colon cancer.MethodsWe analyzed FOXA1 mRNA and protein expression in colon cancer tissues and cell lines. We also silenced FOXA1 expression in HCT116 and SW480 cells to evaluate the effects on cell proliferation, cell cycle, migration, and invasion by using MTT, colony formation, flow cytometry, and the Transwell assay, respectively.ResultsFOXA1 immunostaining was higher in colon cancer tissues than adjacent healthy tissues. FOXA1 mRNA and protein expression was significantly increased in human colon cancer cells compared with a normal colonic cell line. FOXA1 expression was also significantly higher in colorectal cancer tissues from TCGA data sets and was associated with worse prognosis in the R2 database. FOXA1 expression was negatively correlated with the extent of its methylation, and its knockdown reduced proliferation, migration, and invasion, and induced G2/M phase arrest in HCT116 and SW480 cells by suppressing the phosphatase and tensin homolog/Akt signaling pathway and inhibiting epithelial–mesenchymal transition.ConclusionFOXA1 may act as an oncogene in colon cancer tumorigenesis and development.     

A comprehensive association analysis between homocysteine metabolic pathway gene methylation and ischemic stroke in a Chinese hypertensive population

BackgroundIschemic stroke (IS) is a serious global health burden. In order to improve our understanding of the risk factors associated with IS, we investigated the combined effect of the methylation of five genes related to the metabolism of homocysteine on developing IS.MethodsQuantitative methylation‐specific PCR was used to measure the levels of promoter methylation in hypertensive and stroke patients. The cutoff value calculated by the maximum Youden index was used to classify the levels of gene methylation as hypomethylation and hypermethylation. Logistic regression was used to explore the relationship between gene methylation and IS.ResultsThe methylation levels of the genes encoding methylenetetrahydrofolate dehydrogenase 1 [MTHFD1], cystathionine β‐synthase [CBS], and dihydrofolate reductase [DHFR] in hypertensive patients were higher than those in stroke patients (all p < 0.01). MTHFD1 hypermethylation, CBS hypermethylation, and DHFR hypermethylation were protective factors for stroke after adjustment for confounding factors. Compared with individuals carrying none of the biomarkers, the ORs [95% CIs] for stroke of those with 1 and 2 elevated biomarkers were 4.068 [1.670–9.913] and 15.345 [6.198–37.994] after adjustment for confounding factors. The participants with a larger number of biomarkers had an increased risk of stroke (p for trend <0.001). For the combination biomarkers, the area under the curve of the receiver operating characteristic was 0.716.ConclusionA significant linear relationship between the number of elevated biomarkers and the risk of stroke has been observed, suggesting that elevations of these biomarkers could be used for potentially predicting the disease.     

Long noncoding RNA LINC01296 plays an oncogenic role in colorectal cancer by suppressing p15 expression

ObjectiveTo examine the role of the long noncoding RNA LINC01296 in colorectal carcinoma (CRC) and to explore the underlying mechanism.MethodsWe detected LINC01296 expression levels in a cohort of 51 paired CRC and normal tissues. We also assessed the effects of LINC01296 on cell proliferation and apoptosis in CRC cells in vitro, and measured its effect on tumor growth in an in vivo mouse model. We identified the potential downstream targets of LINC01296 and assessed its regulatory effects.ResultsExpression levels of LINC01296 were elevated in 37/51 CRC tissues compared with the corresponding normal tissues and were significantly associated with tumor stage, lymph node metastasis, and distant metastasis. Knockdown of LINC01296 using antisense oligonucleotides inhibited cell proliferation and promoted apoptosis of colon cancer cells in vitro and inhibited tumor growth in vivo. Knockdown of LINC01296 also significantly increased the gene expression of p15 in colon cancer cells. LINC01296-specific suppression of p15 was validated by the interaction between enhancer of zeste homolog 2 and LINC01296.ConclusionOverexpression of LINC01296 suppressed the expression of p15 leading to CRC carcinogenesis. These findings may provide the basis for novel future CRC-targeted therapies.     

Genome-wide DNA hypermethylation opposes healing in patients with chronic wounds by impairing epithelial-mesenchymal transition

An extreme chronic wound tissue microenvironment causes epigenetic gene silencing. An unbiased whole-genome methylome was studied in the wound-edge tissue of patients with chronic wounds. A total of 4,689 differentially methylated regions (DMRs) were identified in chronic wound-edge skin compared with unwounded human skin. Hypermethylation was more frequently observed (3,661 DMRs) in the chronic wound-edge tissue compared with hypomethylation (1,028 DMRs). Twenty-six hypermethylated DMRs were involved in epithelial-mesenchymal transition (EMT). Bisulfite sequencing validated hypermethylation of a predicted specific upstream regulator TP53. RNA-Seq analysis was performed to qualify findings from methylome analysis. Analysis of the downregulated genes identified the TP53 signaling pathway as being significantly silenced. Direct comparison of hypermethylation and downregulated genes identified 4 genes, ADAM17, NOTCH, TWIST1, and SMURF1, that functionally represent the EMT pathway. Single-cell RNA-Seq studies revealed that these effects on gene expression were limited to the keratinocyte cell compartment. Experimental murine studies established that tissue ischemia potently induces wound-edge gene methylation and that 5′-azacytidine, inhibitor of methylation, improved wound closure. To specifically address the significance of TP53 methylation, keratinocyte-specific editing of TP53 methylation at the wound edge was achieved by a tissue nanotransfection-based CRISPR/dCas9 approach. This work identified that reversal of methylation-dependent keratinocyte gene silencing represents a productive therapeutic strategy to improve wound closure.     

SELE gene as a characteristic prognostic biomarker of colorectal cancer

ObjectiveTo investigate the expression and clinical value of the E-selectin gene (SELE) in colorectal cancer (CRC).MethodsUsing gene expression profiles and clinicopathological data for patients with CRC from The Cancer Genome Atlas, and tumor and adjacent normal tissues from 31 patients with CRC from Xianyang Central Hospital, we studied the correlation between SELE gene expression and clinical parameters using Kaplan–Meier and Cox proportional hazards regression analyses.ResultsHigher expression of SELE was significantly associated with a poorer prognosis and shorter survival in patients with CRC. The median expression level of SELE was significantly higher in CRC tissues compared with healthy adjacent tissue. Cox regression analysis showed that the prognosis of CRC was significantly correlated with the expression of SELE. Immunohistochemical analysis also showed that positive expression of E-selectin increased significantly in line with increasing TNM stage.Conclusion: This study confirmed that SELE gene expression is an independent prognostic factor in patients with CRC.     

Hsa_hsa_circ_0081069 promotes the progression of colorectal cancer through sponging miR‐665 and regulating E2F3 expression

BackgroundCircular RNAs (circRNAs) have been implicated in the initiation and development of various cancers. This study explored the potential contribution of hsa_hsa_circ_0081069 in the progression of colorectal cancer (CRC).MethodsThe gene expression was analyzed by qRT‐PCR. Functional roles of hsa_circ_0081069 were examined by shRNA‐mediated silencing using CCK‐8 proliferation assay, Transwell migration and invasion assay, tube formation assay. The tumorigenesis and metastasis of CRC cells were assess in a xenograft mouse model.ResultsHsa_circ_0081069 was significantly upregulated in CRC tissues and cells. Hsa_circ_0081069 knockdown suppressed the proliferation, migration and invasion in CRC cells, as well as the angiogenesis. Silencing hsa_circ_0081069 also impaired the tumorigenesis of CRC cells in a xenograft mouse model. Furthermore, miR‐665 was identified as an interacting partner of hsa_circ_0081069, which was negatively regulated by hsa_circ_0081069. miR‐665 targeted the mRNA of E2F3 to suppress its expression. We further demonsatred that miR‐665/E2F3 axis mediated the functional role of hsa_circ_0081069 in regulating the malignant phenotype of CRC cells.ConclusionsCollectively, our study suggests that hsa_circ_0081069 could serve as a prognostic marker in progression of CRC. Targeting hsa_circ_0081069 and miR‐665/E2F3 axis could serve as potential therapeutic strategies for CRC treatment.     

KITENIN-targeting MicroRNA-124 Suppresses Colorectal Cancer Cell Motility and Tumorigenesis

MicroRNAs are increasingly implicated in the modulation of the progression of various cancers. We previously observed that KAI1 C-terminal interacting tetraspanin (KITENIN) is highly expressed in sporadic human colorectal cancer (CRC) tissues and hence the functional KITENIN complex acts to promote progression of CRC. However, it remains unknown that microRNAs target KITENIN and whether KITENIN-targeting microRNAs modulate CRC cell motility and colorectal tumorigenesis. Here, through bioinformatic analyses and functional studies, we showed that miR-124, miR-27a, and miR-30b negatively regulate KITENIN expression and suppress the migration and invasion of several CRC cell lines via modulation of KITENIN expression. Through in vitro and in vivo induction of mature microRNAs using a tetracycline-inducible system, miR-124 was found to effectively inhibit the invasion of CT-26 colon adenocarcinoma cells and tumor growth in a syngeneic mouse xenograft model. Constitutive overexpression of precursor miR-124 in CT-26 cells suppressed in vivo tumorigenicity and resulted in decreased expression of KITENIN as well as that of MYH9 and SOX9, which are targets of miR-124. Thus, our findings identify that KITENIN-targeting miR-124, miR-27a, and miR-30b function as endogenous inhibitors of CRC cell motility and demonstrate that miR-124 among KITENIN-targeting microRNAs plays a suppressor role in colorectal tumorigenesis.     

Hsa_circ_0005100 regulates tumorigenicity of colorectal carcinoma via miR‐145‐5p/ MACC1 axis

BackgroundCircular RNAs (circRNAs) are a kind of RNA molecules involved in the regulation of cancer progression, including colorectal carcinoma (CRC); nevertheless, their regulation mode is blurry. In the present work, we attempted to reveal the characteristics of hsa_hsa_circ_0005100 in CRC.MethodsDifferential expressions of hsa_circ_0005100, FMN2 mRNA, microRNA‐145‐5p (miR‐145‐5p), and MACC1 were indicated by qRT‐PCR and Western blot. The capacities of cell growth and motility were validated by the MTT assay, flow cytometry assay, EdU assay, colony formation assay, and transwell assay. Moreover, the targeted relationship of miR‐145‐5p and hsa_circ_0005100 or MACC1 was distinguished by dual‐luciferase reporter assay. The animal experiment was implemented to confirm the influence of hsa_circ_0005100 on tumorigenesis in vivo.ResultsHsa_circ_0005100 and MACC1 expression levels were increased, but miR‐145‐5p expression level was diminished in CRC. Hsa_circ_0005100 knockdown repressed cell proliferation, cell cycle, migration, and invasion, while expedited cell apoptosis in CRC cells. Furthermore, miR‐145‐5p was disclosed to block CRC via overturning MACC1. Hsa_circ_0005100 targeted miR‐145‐5p to modulate MACC1. Additionally, hsa_circ_0005100 knockdown also attenuated tumorigenesis in vivo.ConclusionHsa_circ_0005100 was a vital regulator in the development of CRC by miR‐145‐5p/MACC1 axis, which deepened the understanding of CRC pathogenesis from circRNA insights.     

Cancer Genes Hypermethylated in Human Embryonic Stem Cells

Developmental genes are silenced in embryonic stem cells by a bivalent histone-based chromatin mark. It has been proposed that this mark also confers a predisposition to aberrant DNA promoter hypermethylation of tumor suppressor genes (TSGs) in cancer. We report here that silencing of a significant proportion of these TSGs in human embryonic and adult stem cells is associated with promoter DNA hypermethylation. Our results indicate a role for DNA methylation in the control of gene expression in human stem cells and suggest that, for genes repressed by promoter hypermethylation in stem cells in vivo, the aberrant process in cancer could be understood as a defect in establishing an unmethylated promoter during differentiation, rather than as an anomalous process of de novo hypermethylation.     

5-氮杂胞苷对RASSF1去甲基化与胃癌细胞增殖和凋亡的关系

目的：探讨5-氮杂胞苷对RASSF1基因去甲基化与胃癌细胞增殖和凋亡的关系。方法将SGC7901胃癌细胞分为AZA组（5-氮杂胞苷处理）和CON组（未用5-氮杂胞苷处理）,比较两组细胞RASSF1基因启动子甲基化、基因表达、细胞周期和凋亡的差异。结果 CON组SGC7901胃癌细胞RASSF1基因启动子MSP处于甲基化状态,AZA组胃癌细胞未检测到甲基化,AZA组RASSF1基因mRNA和蛋白质表达水平高于CON组细胞。AZA组SGC7901胃癌细胞G0/G1期和凋亡率高于CON组细胞（P〈0.05）,S期、G2/M期和PI低于CON组细胞（P〈0.05）。结论5-氮杂胞苷可逆转胃癌细胞RASSF1基因启动子甲基化状态,使沉默的RASSF1基因重新获得表达而抑制胃癌细胞的增殖并促进其凋亡。     

Mir‐488 alleviates chemoresistance and glycolysis of colorectal cancer by targeting PFKFB3

BackgroundConsidering the boosting effect of glycolysis on tumor chemoresistance, this investigation aimed at exploring whether miR‐488/PFKFB3 axis might reduce drug resistance of colorectal cancer (CRC) by affecting glycolysis, proliferation, migration, and invasion of CRC cells.MethodTotally, 288 CRC patients were divided into metastasis/recurrence group (n = 107) and non‐metastasis/recurrence group (n = 181) according to their prognosis about 1 year after the chemotherapy, and their 3‐year overall survival was also tracked. Besides, miR‐488 expression was determined in peripheral blood of CRC patients and also in CRC cell lines (ie, W620, HT‐29, Lovo, and HCT116). The targeted relationship between miR‐488 and PFKFB3 was predicted by Targetscan software and confirmed by dual‐luciferase reporter gene assay. Moreover, glycolysis and drug tolerance of CRC cells lines were assessed.ResultsMiR‐488 expression was significantly decreased in metastatic/recurrent CRC patients than those without metastasis/recurrence (P < .05), and lowly expressed miR‐488 was suggestive of unfavorable 3‐year survival, large tumor size, poor differentiation, in‐depth infiltration, and advanced Duke stage of CRC patients (P < .05). Besides, CRC cell lines transfected by miR‐488 mimic demonstrated decreases in glucose uptake and lactate secretion, increases in oxaliplatin/5‐Fu‐sensistivity, as well as diminished capability of proliferating, invading, and migratory (P < .05), which were reversible by extra transfection of pcDNA3.1‐PFKFB3 (ie, miR‐488 mimic + pcDNA3.1‐PFKFB3 group). Finally, the mRNA level of PFKFB3 was down‐regulated by miR‐488 mimic in CRC cell lines after being targeted by it (P < .05).ConclusionThe miR‐488/PFKFB3 axis might clinically refine chemotherapeutic efficacy of CRC, given its modifying glycolysis and metastasis of CRC cells.