Project description:BackgroundThere are still no absolute parameters predicting progression of adenoma into cancer. The present study aimed to characterize functional differences on the multistep carcinogenetic process from the adenoma-carcinoma sequence.MethodsAll samples were collected and mRNA expression profiling was performed by using Agilent Microarray high-throughput gene-chip technology. Then, the characteristics of mRNA expression profiles of adenoma-carcinoma sequence were described with bioinformatics software, and we analyzed the relationship between gene expression profiles of adenoma-adenocarcinoma sequence and clinical prognosis of colorectal cancer.ResultsThe mRNA expressions of adenoma-carcinoma sequence were significantly different between high-grade intraepithelial neoplasia group and adenocarcinoma group. The biological process of gene ontology function enrichment analysis on differentially expressed genes between high-grade intraepithelial neoplasia group and adenocarcinoma group showed that genes enriched in the extracellular structure organization, skeletal system development, biological adhesion and itself regulated growth regulation, with the P value after FDR correction of less than 0.05. In addition, IPR-related protein mainly focused on the insulin-like growth factor binding proteins.ConclusionThe variable trends of gene expression profiles for adenoma-carcinoma sequence were mainly concentrated in high-grade intraepithelial neoplasia and adenocarcinoma. The differentially expressed genes are significantly correlated between high-grade intraepithelial neoplasia group and adenocarcinoma group. Bioinformatics analysis is an effective way to study the gene expression profiles in the adenoma-carcinoma sequence, and may provide an effective tool to involve colorectal cancer research strategy into colorectal adenoma or advanced adenoma.
Project description:BackgroundColorectal carcinoma (CRC) often arises from benign adenoma after a stepwise accumulation of genetic alterations. Here, we profiled the dynamic landscapes of transcription factors (TFs) in the mucosa-adenoma-carcinoma progression sequence.MethodsThe transcriptome data of co-occurrent adenoma, carcinoma, and normal mucosa samples were obtained from GSE117606. Identification of differentially expressed TFs (DE-TFs) and subsequent function annotation were conducted in R software. Expression patterns of DE-TFs were clustered by Short Time-series Expression Miner software. Thereafter, modular co-expression analysis, Kaplan-Meier survival analysis, mutation profiling, and gene set enrichment analysis were conducted to investigate TF dynamics in colorectal tumorigenesis. Finally, tissue microarrays, including 51 tumors, 32 adenomas, and 53 normal tissues, were employed to examine the expression of significant candidates by immunohistochemistry staining.ResultsCompared to normal tissues, 20 (in adenoma samples) and 29 (in tumor samples) DE-TFs were identified. During the disease course, 28 expression patterns for DE-TFs and four co-expression modules were clustered. Notably, six DE-TFs, DACH1, GTF2IRD1, MEIS2, NR3C2, SOX9, and SPIB, were identified as having a dynamic signature along the colorectal adenoma-carcinoma sequence. The dynamic signature was of significance in GO enrichment, prognosis, and co-expression analysis. Among the 6-TF signature, the roles of GTF2IRD1, SPIB and NR3C2 in CRC progression are unclear. Immunohistochemistry validation showed that GTF2IRD1 enhanced significantly throughout the mucosa-adenoma-carcinoma sequence, while SPIB and NR3C2 kept decreasing in stroma during the disease course.ConclusionsOur study provided a dynamic 6-TF signature throughout the course of colorectal mucosa-adenoma-carcinoma. These findings deepened the understanding of colorectal cancer pathogenesis.
Project description:Both 5-methylcytosine (5mC) and 5-hydroxymethylcytosine (5hmC) are important epigenetic modifications in neurodevelopment. However, there is little research examining the genome-wide patterns of 5mC and 5hmC in brain regions of animals under natural high-altitude conditions. We used oxidative reduced representation bisulfite sequencing (oxRRBS) to determine the 5mC and 5hmC sites in the brain, brainstem, cerebellum, and hypothalamus of yak and cattle. We reported the first map of genome-wide DNA methylation and hydroxymethylation in the brain, brainstem, cerebellum, and hypothalamus of yak (living at high altitudes) and cattle. Overall, we found striking differences in 5mC and 5hmC between the hypothalamus and other brain regions in both yak and cattle. Genome-wide profiling revealed that 5mC level decreased and 5hmC level increased in the hypothalamus than in other regions. Furthermore, we identified differentially methylated regions (DMRs) and differentially hydroxymethylated regions (DhMRs), most of which overlapped with each other. Interestingly, transcriptome results for these brain regions also showed distinctive gene levels in the hypothalamus. Finally, differentially expressed genes (DEGs) regulated by DMRs and DhMRs may play important roles in neuromodulation and myelination. Overall, our results suggested that mediation of 5mC and 5hmC on epigenetic regulation may broadly impact the development of hypothalamus and its biological functions.
Project description:Advanced adenoma (AA) holds a significantly increased risk for progression to colorectal cancer (CRC), and we developed a noninvasive DNA methylation prediction model to monitor the risk of AA progression to CRC. We analyzed the differential methylation markers between 53 normal mucosa and 138 CRC tissues, as well as those in cfDNA (cell-free DNA) between 59 AA and 68 early-stage CRC patients. We screened the overlapping markers between tissue DNA and cfDNA for model variables and optimized the selected variables. Then, we established a cfDNA methylation prediction model (SDMBP model) containing seven methylation markers that can effectively discriminate early-stage CRC and AA in the training and validation cohorts, and the AUC (area under the curve) reached 0.979 and 0.918, respectively. Our model also reached high precision (AUC=0.938) in detecting advanced CRC (stage III/IV) and presented better performance than serum CEA and CA199 in screening CRC. The cd-score of the SDMBP model could also robustly predict the TNM stage of CRC. Overall, our SDMBP model can monitor the malignant progression from AA to CRC, and may provide a noninvasive monitoring method for high-risk populations with AA.
Project description:BACKGROUND: potential epigenetic biomarkers for malignant transformation to carcinoma ex pleomorphic adenoma (Ca ex PSA) have been sought previously with and without specific comparison with the benign variant, pleomorphic salivary adenoma (PSA). Previous analysis has been limited by a non-quantitative approach. We sought to demonstrate quantitative promoter methylation across a panel of tumour suppressor genes (TSGs) in both Ca ex PSA and PSA. METHODS: quantitative methylation-specific real-time polymerase chain reaction (qMSP) analysis of p16(INK4A), CYGB, RASSF1, RAR?, human telomerase reverse transcriptase (hTERT), Wilms' tumour 1 (WT1) and TMEFF2 gene promoters was undertaken on bisulphite-converted DNA, previously extracted from archival fixed tissue specimens of 31 Ca ex PSA and an unrelated cohort of 28 PSA. All target regions examined had formerly been shown to be hypermethylated in salivary and/or mucosal head and neck malignancies. RESULTS: the qMSP demonstrated abnormal methylation of at least one target in 20 out of 31 (64.5%) Ca ex PSA and 2 out of 28 (7.1%) PSA samples (P<0.001). RASSF1 was the single gene promoter for which methylation is shown to be a statistically significant predictor of malignant disease (P<0.001) with a sensitivity of 51.6% and a specificity of 92.9%. RAR?, TMEFF2 and CYGB displayed no apparent methylation, while a combinatory epigenotype based on p16, hTERT, RASSF1 and WT1 was associated with a significantly higher chance of detecting malignancy in any positive sample (odds ratio: 24, 95% CI: 4.7-125, P<0.001). CONCLUSIONS: we demonstrate the successful application of qMSP to a large series of historical Ca ex PSA samples and report on a panel of TSGs with significant differences in their methylation profiles between benign and malignant variants of pleomorphic salivary adenoma. qMSP analysis could be developed as a useful clinical tool to differentiate between Ca ex PSA and its benign precursor.
Project description:BackgroundProgression of colorectal cancer (CRC) has been explained by genomic abnormalities along with the adenoma-carcinoma sequence theory (ACS). The aim of our study is to elucidate whether the promoter DNA methylation of the cancer-specific methylation gene, cysteine dioxygenase 1 (CDO1), contributes to the carcinogenic process in CRC.MethodsThe study group comprised 107 patients with CRC who underwent surgical resection and 90 adenomas treated with endoscopic resection in the Kitasato University Hospital in 2000. We analyzed the extent of methylation in each tissue using quantitative TaqMan methylation-specific PCR for CDO1.ResultsThe methylation level increased along with the ACS process (p < 0.0001), and statistically significant differences were found between normal-appearing mucosa (NAM) and low-grade adenoma (p < 0.0001), and between low-grade adenoma and high-grade adenoma (p = 0.01), but not between high-grade adenoma and cancer with no liver metastasis. Furthermore, primary CRC cancers with liver metastasis harbored significantly higher methylation of CDO1 than those without liver metastasis (p = 0.02). As a result, the area under the curve by CDO1 promoter methylation was 0.96, 0.80, and 0.67 to discriminate cancer from NAM, low-grade adenoma from NAM, and low-grade adenoma from high-grade adenoma, respectively.ConclusionsCDO1 methylation accumulates during the ACS process, and consistently contributes to CRC progression.
Project description:Background Lipid metabolism-related genes (LMRGs) have been reported to be correlated with the immune infiltration of colorectal cancer (CRC). This study aimed to investigate the immune infiltration characteristics along the colorectal adenoma-carcinoma sequence (ACS) based on LMRGs. Methods Gene expression data of colorectal adenoma and carcinoma samples were obtained from the public databases. The “limma” package was applied to determine the differentially expressed LMRGs. Unsupervised consensus clustering was used to cluster colorectal samples. The features of the tumor microenvironment were analyzed by the “ESTIMATE”, “GSVA”, and “TIDE” algorithms. Results The expression of 149 differentially expressed LMRGs was defined as the LMRG signature. Based on this signature, the adenoma and carcinoma samples were divided into three clusters. Unexpectedly, these sequential clusters showed a directional relationship and collectively constituted the progressive course of colorectal ACS. Interestingly, the LMRG signature revealed that adenoma progression was accompanied by a progressive loss of immune infiltration and a stepwise establishment of a cold microenvironment, but carcinoma progression was characterized by a progressive gain of immune infiltration and a gradual establishment of a hot microenvironment. Conclusions The LMRG signature reveals dynamic immune infiltration along the colorectal ACS, which substantially changes the understanding of the tumor microenvironment of CRC carcinogenesis and provides novel insight into the role of lipid metabolism in this process. Supplementary Information The online version contains supplementary material available at 10.1186/s12944-023-01866-4.
Project description:Aimp16 Methylation frequently occurs in carcinogenesis. While it has been hypothesized that the p16 methylation states are dynamically maintained in cancer cells, direct evidence supporting this hypothesis has not been available until now.MethodsA fusion cell model was established which reprogrammed the native DNA methylation pattern of the cells. The methylation status of the p16 alleles was then repeatedly quantitatively analyzed in the fusion monoclonal, parental cancer cell lines (p16-completely methylated-AGS and unmethylated-MGC803), and HCT116 non-fusion cell using DHPLC and bisulfite sequencing. Histone methylation was analyzed using chromatin immuno-precipitation (ChIP)-PCR. P16 expression status was determined using immuno-staining and RT-PCR.ResultsThe methylation status for the majority of the p16 alleles was stably maintained in the fusion monoclonal cells after up to 60 passages. Most importantly, focal de novo methylation, demethylation, and hydroxymethylation were consistently observed within about 27% of the p16 alleles in the fusion monoclones, but not the homozygously methylated or unmethylated parental cells. Furthermore, subclones of the monoclones consistently maintained the same p16 methylation pattern. A similar phenomenon was also observed using the p16 hemi-methylated HCT116 non-fusion cancer cell line. Interestingly, transcription was not observed in p16 alleles that were hydroxymethylated with an antisense-strand-specific pattern. Also, the levels of H3K9 and H3K4 trimethylation in the fusion cells were found to be slightly lower than the parental AGS and MGC803 cells, respectively.ConclusionThe present study provides the first direct evidence confirming that the methylation states of p16 CpG islands is not only homeostatically maintained, but also accompanied by a dynamic process of transient focal methylation, demethylation, and hydroxymethylation in cancer cells.
Project description:BackgroundBiomarker discovery in colorectal cancer has mostly focused on methylation patterns in normal and colorectal tumor tissue, but adenomas remain understudied. Therefore, we performed the first epigenome-wide study to profile methylation of all three tissue types combined and to identify discriminatory biomarkers.ResultsPublic methylation array data (Illumina EPIC and 450K) were collected from a total of 1 892 colorectal samples. Pairwise differential methylation analyses between tissue types were performed for both array types to "double evidence" differentially methylated probes (DE DMPs). Subsequently, the identified DMPs were filtered on methylation level and used to build a binary logistic regression prediction model. Focusing on the clinically most interesting group (adenoma vs carcinoma), we identified 13 DE DMPs that could effectively discriminate between them (AUC = 0.996). We validated this model in an in-house experimental methylation dataset of 13 adenomas and 9 carcinomas. It reached a sensitivity and specificity of 96% and 95%, respectively, with an overall accuracy of 96%. Our findings raise the possibility that the 13 DE DMPs identified in this study can be used as molecular biomarkers in the clinic.ConclusionsOur analyses show that methylation biomarkers have the potential to discriminate between normal, precursor and carcinoma tissues of the colorectum. More importantly, we highlight the power of the methylome as a source of markers for discriminating between colorectal adenomas and carcinomas, which currently remains an unmet clinical need.
Project description:Colorectal cancer (CRC) is a major public health burden and one of the leading causes of cancer-related deaths worldwide. Screening programs facilitate early diagnosis and can help to reduce poor outcomes. Serum metabolomics can extract vital molecular information that may increase the sensitivity and specificity of colonoscopy in combination with histopathological examination. The present study identifies serum metabolite patterns of treatment-naïve patients, diagnosed with either advanced adenoma (AA) or CRC in colonoscopy screenings, in the framework of the SAKKOPI (Salzburg Colon Cancer Prevention Initiative) program. We used a targeted flow injection analysis and liquid chromatography-tandem mass spectrometry metabolomics approach (FIA- and LC-MS/MS) to characterise the serum metabolomes of an initial screening cohort and two validation cohorts (in total 66 CRC, 76 AA and 93 controls). The lipidome was significantly perturbed, with a proportion of lipid species being downregulated in CRC patients, as compared to AA and controls. The predominant alterations observed were in the levels of lyso-lipids, glycerophosphocholines and acylcarnitines, but additionally, variations in the quantity of hydroxylated sphingolipids could be detected. Changed amino acid metabolism was restricted mainly to metabolites of the arginine/dimethylarginine/NO synthase pathway. The identified metabolic divergences observed in CRC set the foundation for mechanistic studies to characterise biochemical pathways that become deregulated during progression through the adenoma to carcinoma sequence and highlight the key importance of lipid metabolites. Biomarkers related to these pathways could improve the sensitivity and specificity of diagnosis, as well as the monitoring of therapies.