• Humans
• Colorectal Neoplasms/metabolism
• Colorectal Neoplasms/pathology
• Colorectal Neoplasms/genetics
• Galectins/metabolism
• Galectins/genetics
• Galactosyltransferases/metabolism
• Galactosyltransferases/genetics
• Epithelial-Mesenchymal Transition/drug effects
• Animals
• Cell Movement/drug effects
• Neoplasm Metastasis
• Disease Progression
• Cell Line, Tumor
• Signal Transduction
• Mice
• Receptors, Transforming Growth Factor beta/metabolism
• Mice, Nude
• Protein Binding
• Apoptosis/drug effects
• Transforming Growth Factor beta/metabolism
• Transforming Growth Factor beta/pharmacology
• Mice, Inbred BALB C

• AS-SUMMIT-109 Academia Sinica
• AS-GC-111-M03 Academia Sinica

• colorectal cancer
• microsatellite instability
• mismatch repair

• Humans
• Colorectal Neoplasms/genetics
• Colorectal Neoplasms/diagnosis
• Colorectal Neoplasms/pathology
• Microsatellite Instability
• Polymerase Chain Reaction
• Reagent Kits, Diagnostic
• Female
• Male
• Middle Aged

• Shaoguan Health Scientific Research Project (Y23055).
• 230329188031885 Shaoguan Social Development Science and Technology Collaborative Innovation System Construction Project

• HUWE1
• JAK2
• PPDPF
• Wnt/β-catenin pathway
• inflammation

• Humans
• Interleukin-6/adverse effects
• Interleukin-6/metabolism
• Phosphorylation
• beta Catenin/metabolism
• Wnt Signaling Pathway
• Janus Kinase 2/metabolism
• Colorectal Neoplasms/genetics
• Cell Proliferation
• Cell Line, Tumor
• Gene Expression Regulation, Neoplastic

• MOST | National Natural Science Foundation of China (NSFC)
• Science and Technology Commission of Shanghai Municipality (STCSM)

• APC gene
• adenoma
• colon
• mutation

• Female
• Humans
• Adult
• Colonic Polyps/genetics
• Adenomatous Polyposis Coli/genetics
• Adenomatous Polyposis Coli/pathology
• Colorectal Neoplasms/pathology
• Adenoma/genetics
• Colonic Neoplasms/genetics
• Codon

• Biomarker
• Cancer
• MicroRNA
• Therapeutic target
• miR-590-5p

• Carcinogenesis/genetics
• Cell Line, Tumor
• Cell Proliferation
• Gene Expression Regulation, Neoplastic
• Humans
• MicroRNAs/genetics

• Mismatch repair
• PD-L1
• Thyroid carcinoma

• B7-H1 Antigen/genetics
• Biomarkers, Tumor/genetics
• Biomarkers, Tumor/metabolism
• Humans
• Mismatch Repair Endonuclease PMS2/genetics
• Retrospective Studies
• Thyroid Neoplasms/genetics

• Colon cancer (CC)
• gene set enrichment analysis (GSEA)
• gene signature
• immune infiltration
• microsatellite status

Circulating tumor DNA (ctDNA) is a minimally invasive biomarker useful for monitoring minimum residual disease, recurrence, and treatment response in colorectal cancer (CRC). We analyzed circulating tumor DNA from patients with CRC to evaluate analytical and clinical performances using next-generation sequencing (NGS). It is clear that postoperative circulating tumor DNA detection provides valuable information to determine whether a patient might at high risk of disease recurrence or have a persistent tumor lesion. The NGS assay not only showed excellent analytical performance, but also shows a state-of-art diagnostic option in patient-oriented precision medicine.

The objective of this study was to characterize circulating tumor DNA (ctDNA) mutations in colorectal cancer (CRC) patients and evaluate their prognostic values during treatment. Forty-nine patients with CRC planned for operation were enrolled. A total of 115 plasma samples were collected pre-operation, post-operation, and post-chemotherapy. ctDNA analysis was performed using next-generation sequencing (NGS) including 14 genes. In 22 (44.9%) out of 49 patients, at least one mutation (40 total mutations) was detected in the initial plasma sample. The median sum of variant allele frequency was 0.74% (range: 0.10–29.57%). TP53 mutations were the most frequent (17 of 49 patients, 34.7%), followed by APC (18.4%), KRAS (12.2%), FBXW7 (8.2%), NRAS (2.0%), PIK3CA (2.0%), and SMAD4 (2.0%). After surgery, five (14.3%) out of 35 patients harbored ctDNA mutation. All five patients experienced relapse or metastasis during follow-up. It was noteworthy that all three patients with persistent ctDNA relapsed after R0 resection. After chemotherapy, ctDNA analysis was performed for 31 patients, all of which were ctDNA-negative. Analytical and clinical performances of NGS to utilize ctDNA in CRC were determined. Results revealed that postoperative ctDNA might serve as a marker for identifying risk of recurrence, thus contributing to patient-oriented treatment strategies.

• circulating tumor DNA
• colorectal cancer
• next-generation sequencing

Long-term oncologic differences in outcome between groups of patients with Lynch syndrome (LS) colorectal cancer (CRC) and sporadic CRC with microsatellite instability-high (MSI-H) are the focus of investigation in the current study.

Patients registered in the Korean Hereditary Tumor Registry and 2 tertiary referral hospitals treated for stage I–III CRC between 2005 and 2015 were retrospectively analyzed. Detection for both groups was performed using pedigree, microsatellite instability, and mismatch repair (MMR) gene testing. Multivariate analyses for overall survival (OS) and disease-free survival (DFS) were conducted.

Cases of LS (n = 77) and sporadic CRC with MSI-H (n = 96) were identified. LS CRC patients were younger in age and displayed tumor sidedness, typically involving left-sided colon and rectum, compared to patients with sporadic CRC with MSI-H. OS and DFS were lower for LS CRC relative to CRC with MSI-H (OS, 72.7% vs. 93.8%, P = 0.001; DFS, 71.4% vs. 88.5%, P = 0.001). In multivariate analyses, tumor sidedness, stage, and chemotherapy were independent factors for OS and DFS. LS CRC was a prognostic factor for poorer OS (hazard ratio, 2.740; 95% confidence interval, 1.003–7.487; P = 0.049), but not DFS.

Our findings indicate that LS CRC is associated with poorer outcomes compared to sporadic CRC with MSI-H, presenting distinct clinical features. In view of the current lack of knowledge on genetic and molecular mechanisms, appropriate management taking into consideration the difficulty of identification of CRC with hypermutable tumors harboring heterogeneity is essential.

• Colorectal neoplasms
• Lynch syndrome
• Microsatellite instability

• Immune checkpoint inhibitor
• Immunotherapy
• MSI-H
• Mismatch repair

Inflammatory bowel disease patients have a greatly increased risk of developing colitis-associated colon cancer (CAC); however, the basis for inflammation-induced genetic damage requisite for neoplasia is unclear. Using three models of CAC, we find that sustained inflammation triggers 8-oxoguanine DNA lesions. Strikingly, antioxidants or iNOS inhibitors reduce 8-oxoguanine and polyps in CAC models. Because the mismatch repair (MMR) system repairs 8-oxoguanine and is frequently defective in colorectal cancer (CRC), we test whether 8-oxoguanine mediates oncogenesis in a Lynch syndrome (MMR-deficient) model. We show that microbiota generates an accumulation of 8-oxoguanine lesions in MMR-deficient colons. Accordingly, we find that 8-oxoguanine is elevated in neoplastic tissue of Lynch syndrome patients compared to matched untransformed tissue or non-Lynch syndrome neoplastic tissue. While antioxidants reduce 8-oxoguanine, they do not reduce CRC in Lynch syndrome models. Hence, microbe-induced oxidative/nitrosative DNA damage play causative roles in inflammatory CRC models, but not in Lynch syndrome models.

It is unclear how microbial-induced inflammation promotes neoplastic transformation in colitis-associated cancer (CAC). Here, the authors use models of CAC to show that inflammation induces 8-oxoguanine lesions in DNA, and that antioxidants can reduce these DNA lesions as well as CAC.

• Colorectal Cancer
• FFPE
• Immunotherapies
• Mismatch repair
• Rapid detection

Microsatellite instability (MSI) is a clonal change in the number of repeated DNA nucleotide units in microsatellites. High-frequency MSI (MSI-H) colorectal cancers (CRCs) are known to have different clinicopathological features compared with microsatellite stable (MSS) CRCs. In addition, previous studies have shown that type2 diabetes mellitus (T2DM) is a risk factor for malignant tumors including CRCs. The aim of this study was to investigate the relationship between T2DM and MSI-H colorectal cancer.

The study design is a single center, cross-sectional study. Data from a series of 936 patients with CRCs were collected and MSI status was assessed.

In total, 29 (3.1%) and 907 (96.9%) tumors were classified as having MSI-H and low-frequency microsatellite instability or being MSS (MSS), respectively. Of the 936 patients, 275 (29.6%) were associated with T2DM. One (3.4%) of the 29 MSI-H patients and 274 (30.2%) of the 907 MSS patients had T2DM. Thus, the incidence of T2DM was significantly less frequent in MSI-H compared with MSS patients (Fisher’s exact test: p = 0.0007).

We conclude that MSS tumors are significantly more common than MSI-H tumors among individuals with T2DM.

• Aged
• Aged, 80 and over
• Colorectal Neoplasms/complications
• Colorectal Neoplasms/genetics
• Cross-Sectional Studies
• Diabetes Mellitus, Type 2/complications
• Diabetes Mellitus, Type 2/genetics
• Female
• Humans
• Male
• Microsatellite Instability
• Microsatellite Repeats/genetics
• Middle Aged
• Retrospective Studies

• BRAF
• MSI
• prognosis

• BRAF
• MSI
• chemotherapy
• colon cancer

The stability and integrity of the human genome are maintained by the DNA damage repair (DDR) system. Unrepaired DNA damage is a major source of potentially mutagenic lesions that drive carcinogenesis. In addition to gene mutation, DNA methylation occurs more frequently in DDR genes in human cancer. Thus, DNA methylation may play more important roles in DNA damage repair genes to drive carcinogenesis. Aberrant methylation patterns in DNA damage repair genes may serve as predictive, diagnostic, prognostic and chemosensitive markers of human cancer. MGMT methylation is a marker for poor prognosis in human glioma, while, MGMT methylation is a sensitive marker of glioma cells to alkylating agents. Aberrant epigenetic changes in DNA damage repair genes may serve as therapeutic targets. Treatment of MLH1-methylated colon cancer cell lines with the demethylating agent 5′-aza-2′-deoxycytidine induces the expression of MLH1 and sensitizes cancer cells to 5-fluorouracil. Synthetic lethality is a more exciting approach in patients with DDR defects. PARP inhibitors are the most effective anticancer reagents in BRCA-deficient cancer cells.

• DNA damage repair
• DNA methylation
• MGMT
• PARP inhibitor
• synthetic lethality

• DNA methyltransferase inhibitors
• colorectal cancer
• epigenetics
• methylation
• transcription
• tumor-suppressor gene

• Antibodies
• Antineoplastic combined chemotherapy
• Biomarkers
• Colorectal neoplasm
• Drug therapy
• Monoclonal/therapeutic use
• Tumor/genetics

• cancer
• cancer biology
• mutagenesis in vitro
• p53
• tumor suppressor gene

• adjuvant
• chemotherapy
• colorectal cancer
• microsatellite instability
• predictive biomarker

• braf vs kras
• cancer
• differential signalling
• targeted therapeutics
• rational drug combinations to overcome resistance

• Genes, ras/genetics
• Humans
• Mutation
• Neoplasms/drug therapy
• Neoplasms/genetics
• Proto-Oncogene Proteins B-raf/genetics
• Signal Transduction/genetics

• Adenomatous Polyposis Coli/blood
• Adenomatous Polyposis Coli/complications
• Adenomatous Polyposis Coli/diagnosis
• Adult
• Biomarkers, Tumor/blood
• Colorectal Neoplasms/diagnosis
• Colorectal Neoplasms/etiology
• Female
• Gastrins/blood
• Humans
• Male
• Middle Aged
• Protein Precursors/blood
• Radioimmunoassay
• Risk
• Risk Assessment

• KRAS
• age
• gender
• risk factor
• site

Research on hMLH1 and hMSH2 mutations tend to focus on Lynch syndrome (LS) and LS-like colorectal cancer (CRC). No studies to date have assessed the role of hMLH1 and hMSH2 genes in mass sporadic CRC (without preselection by MSI or early age of onset). We aimed to identify novel hMLH1 and hMSH2 DNA variants, to determine the mutation frequencies and sites in both sporadic and LS CRC and their relationships with clinicopathological characteristics of CRC in Northeast of China. 452 sporadic and 21 LS CRC patients were screened for germline and somatic mutations in hMLH1 and hMSH2 genes with PCR–SSCP sequencing. We identified 11 hMLH1 and seven hMSH2 DNA variants in our study cohort. Six of them were novel: four in hMLH1 gene (IVS8-16 A>T, c.644 GAT>GTT, c.1529 CAG>CGG and c.1831 ATT>TTT) and two in hMSH2 gene (−39 C>T, insertion AACAACA at c.1127 and deletion AAG at c.1129). In sporadic CRC, germline and somatic mutation frequencies of hMLH1/hMSH2 gene were 15.59% and 17.54%, respectively (p = 0.52). Germline mutations present in hMLH1 and hMSH2 genes were 5.28% and 10.78%, respectively (p<0.01). Somatic mutations in hMLH1 and hMSH2 genes were 6.73% and 11.70%, respectively (p = 0.02). In LS CRC, both germline and somatic mutation frequencies of hMLH1/hMSH2 gene were 28.57%. The most prevalent germline mutation site in hMSH2 gene was c.1168 CTT>TTT (3.90%), a polymorphism. Somatic mutation frequency of hMLH1/hMSH2 gene was significantly different in proximal, distal colon and rectal cancer (p = 0.03). Our findings elucidate the mutation spectrum and frequency of hMLH1 and hMSH2 genes in sporadic and LS CRC, and their relationships with clinicopathological characteristics of CRC.

• Adaptor Proteins, Signal Transducing/genetics
• Adenocarcinoma/genetics
• Adenocarcinoma/pathology
• Adult
• Base Sequence
• Case-Control Studies
• China
• Colorectal Neoplasms/genetics
• Colorectal Neoplasms/pathology
• DNA Mutational Analysis
• Exons
• Female
• Gene Frequency
• Genetic Association Studies
• Germ-Line Mutation
• Humans
• INDEL Mutation
• Male
• Middle Aged
• MutL Protein Homolog 1
• MutS Homolog 2 Protein/genetics
• Neoplasm Staging
• Nuclear Proteins/genetics
• Polymorphism, Single Nucleotide
• Tumor Burden

• Adenocarcinoma/epidemiology
• Adenocarcinoma/genetics
• Adenomatous Polyps/epidemiology
• Adenomatous Polyps/genetics
• Aged
• Colorectal Neoplasms/epidemiology
• Colorectal Neoplasms/genetics
• Cross-Sectional Studies
• DNA Mutational Analysis
• Genes, APC
• Humans
• Intestinal Polyps/epidemiology
• Intestinal Polyps/genetics
• Male
• Microsatellite Repeats/genetics
• Middle Aged
• Mutation
• Prevalence
• Proto-Oncogene Proteins/genetics
• Proto-Oncogene Proteins p21(ras)
• Smoking/adverse effects
• Smoking/epidemiology
• Smoking/genetics
• ras Proteins/genetics

Ultradeep sequencing of genomes permits the detection of very low-level genomic instability in non-neoplastic tissues of patients with the most common form of inherited colorectal cancer.

Early detection of cancer-associated genomic instability is crucial, particularly in tumour types in which this instability represents the essential underlying mechanism of tumourigenesis. Currently used methods require the presence of already established neoplastic cells because they only detect clonal mutations. In principle, parallel sequencing of single DNA filaments could reveal the early phases of tumour initiation by detecting low-frequency mutations, provided an adequate depth of coverage and an effective control of the experimental error. We applied ultradeep sequencing to estimate the genomic instability of individuals with hereditary non-polyposis colorectal cancer (HNPCC). To overcome the experimental error, we used an ultraconserved region (UCR) of the human genome as an internal control. By comparing the mutability outside and inside the UCR, we observed a tendency of the ultraconserved element to accumulate significantly fewer mutations than the flanking segments in both neoplastic and nonneoplastic HNPCC samples. No difference between the two regions was detectable in cells from healthy donors, indicating that all three HNPCC samples have mutation rates higher than the healthy genome. This is the first, to our knowledge, direct evidence of an intrinsic genomic instability of individuals with heterozygous mutations in mismatch repair genes, and constitutes the proof of principle for the development of a more sensitive molecular assay of genomic instability.

In hereditary non-polyposis colorectal cancer (HNPCC), a germline mutation in one allele of a gene responsible for repairing DNA damage predisposes the host to cancer, because subsequent somatic inactivation of the one wild-type allele leads to genomic instability that favours tumourigenesis. Nonneoplastic tissues of HNPCC individuals are believed to repair DNA normally, as they are heterozygous and thus are thought to be genomically stable. However, methods used to date are known to be incapable of detecting very low levels of genome instability. Here, we present a more sensitive procedure based on the resequencing of a HNPCC genomic region using next-generation sequencing technology. With this approach, we show that genomic instability is in fact detectable in nonneoplastic tissues of HNPCC patients compared with healthy donors. This constitutional instability may predispose them to acquiring the second somatic mutation event needed for cancer development.

• Colorectal Neoplasms, Hereditary Nonpolyposis/genetics
• Conserved Sequence/genetics
• Conserved Sequence/physiology
• DNA Repair/genetics
• DNA Repair/physiology
• DNA, Neoplasm/genetics
• Female
• Genes/genetics
• Genes, Neoplasm/genetics
• Genetic Predisposition to Disease/genetics
• Genomic Instability/genetics
• Genomic Instability/physiology
• Heterozygote
• Humans
• Male
• Middle Aged
• Mutation/genetics
• Mutation/physiology
• Polymorphism, Single Nucleotide/genetics
• Sensitivity and Specificity

Depending on the population studied, large genomic rearrangements (LGRs) of the mismatch repair (MMR) genes constitute various proportions of the germline mutations that predispose to hereditary non-polyposis colorectal cancer (HNPCC). It has been reported that loss of heterozygosity (LOH) at the LGR region occurs through a gene conversion mechanism in tumors from MLH1/MSH2 deletion carriers; however, the converted tracts were delineated only by extragenic microsatellite markers. We sought to determine the frequency of LGRs in Slovak HNPCC patients and to study LOH in tumors from LGR carriers at the LGR region, as well as at other heterozygous markers within the gene to more precisely define conversion tracts.

The main MMR genes responsible for HNPCC, MLH1, MSH2, MSH6, and PMS2, were analyzed by MLPA (multiplex ligation-dependent probe amplification) in a total of 37 unrelated HNPCC-suspected patients whose MLH1/MSH2 genes gave negative results in previous sequencing experiments. An LOH study was performed on six tumors from LGR carriers by combining MLPA to assess LOH at LGR regions and sequencing to examine LOH at 28 SNP markers from the MLH1 and MSH2 genes.

We found six rearrangements in the MSH2 gene (five deletions and dup5-6), and one aberration in the MLH1 gene (del5-6). The MSH2 deletions were of three types (del1, del1-3, del1-7). We detected LOH at the LGR region in the single MLH1 case, which was determined in a previous study to be LOH-negative in the intragenic D3S1611 marker. Three tumors displayed LOH of at least one SNP marker, including two cases that were LOH-negative at the LGR region.

LGRs accounted for 25% of germline MMR mutations identified in 28 Slovakian HNPCC families. A high frequency of LGRs among the MSH2 mutations provides a rationale for a MLPA screening of the Slovakian HNPCC families prior scanning by DNA sequencing. LOH at part of the informative loci confined to the MLH1 or MSH2 gene (heterozygous LGR region, SNP, or microsatellite) is a novel finding and can be regarded as a partial LOH. The conversion begins within the gene, and the details of conversion tracts are discussed for each case.

• 5' Untranslated Regions/genetics
• Base Sequence
• Cell Line, Tumor
• Colonic Neoplasms/genetics
• Colonic Neoplasms/pathology
• DNA Mutational Analysis
• Dinucleotide Repeats/genetics
• Down-Regulation
• ErbB Receptors/genetics
• Flow Cytometry
• Gene Frequency
• Genes, ras/genetics
• Genotype
• Humans
• Microsatellite Instability
• Mutagenesis, Insertional
• Mutation
• Poly A/genetics
• Polymerase Chain Reaction
• Polymorphism, Single-Stranded Conformational
• Proto-Oncogene Proteins B-raf/genetics
• Sequence Deletion
• Stomach Neoplasms/genetics
• Stomach Neoplasms/pathology
• Tumor Suppressor Protein p53/genetics

• R37 CA063585 NCI NIH HHS
• R01 CA098818 NCI NIH HHS
• R01CA098818 NCI NIH HHS
• R37 CA063585-16 NCI NIH HHS
• R01 CA098818-05 NCI NIH HHS
• R37 CA63585 NCI NIH HHS

• Adenomatous Polyps/complications
• Adenomatous Polyps/genetics
• Adenomatous Polyps/pathology
• Adult
• Aged
• Colorectal Neoplasms, Hereditary Nonpolyposis/complications
• Colorectal Neoplasms, Hereditary Nonpolyposis/genetics
• Colorectal Neoplasms, Hereditary Nonpolyposis/pathology
• DNA Mismatch Repair
• Female
• Humans
• Hyperplasia
• Immunohistochemistry
• Male
• Microsatellite Instability
• Middle Aged

• R01 CA092594 NCI NIH HHS
• CA92594 NCI NIH HHS