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Cellular and Molecular Gastroenterology... 2021The Cancer Genome Atlas (TCGA) project has identified HER2 mutations or amplification in 7% of colon cancers. In addition to HER2 mutations, colon cancer patients also...
BACKGROUND AND AIMS
The Cancer Genome Atlas (TCGA) project has identified HER2 mutations or amplification in 7% of colon cancers. In addition to HER2 mutations, colon cancer patients also possess co-occurring mutations in genes such as APC. Here, we investigated the role of HER2 and APC mutations on the crypt-villus architecture of the intestinal epithelium, localization of secretory cells, and expression of intestinal stem cell markers.
METHODS
We generated a HER2 transgenic mouse (HER2 Tg) possessing an activating mutation commonly found in colorectal cancer patients, HER2, using transcription activator-like effector nucleases-based gene editing technology. We expressed the HER2 transgene in mouse small intestine and colon using Lgr5-Cre and Villin-Cre recombinases. In addition, we analyzed Lgr5-Cre; APC; HER2 Tg mice by morphologic and gene expression assays on intestinal sections and organoids derived from the epithelium.
RESULTS
HER2 expression resulted in hypertrophic crypt formation with expanded zones of proliferation. Proximal intestinal villi showed increased abundance of multiple differentiated lineages including extensive intermediate cell differentiation, as evidenced by MUC2/MMP7 co-immunofluorescence and transmission electron microscopy. HER2 expression in the context of APC loss resulted in further enhancement and expansion of the proliferative crypt compartment.
CONCLUSIONS
We established an epithelial intrinsic role for HER2 on enhanced cellular proliferation. Additionally, we determined that HER2 and APC mutations, when combined, promote enhanced proliferation of intestinal crypts.
Topics: Adenomatous Polyposis Coli Protein; Animals; Gene Editing; Hyperplasia; Intestinal Mucosa; Matrix Metalloproteinase 7; Mice; Mice, Transgenic; Mucin-2; Mutation; Receptor, ErbB-2
PubMed: 33930605
DOI: 10.1016/j.jcmgh.2021.04.012 -
Biomedicine & Pharmacotherapy =... Jan 2020The Apc mouse is an animal model for familial adenomatous polyposis, and aged Apc mice also spontaneously develop multiple tumors in their stomachs. However, gastric...
The Apc mouse is an animal model for familial adenomatous polyposis, and aged Apc mice also spontaneously develop multiple tumors in their stomachs. However, gastric premalignant lesions in Apc mice have not been well characterized. The stomachs of Apc mice were compared with those of their wild type littermates at 24 weeks with hematoxylin and eosin (H&E) staining and alcian blue staining. Ki67, CD68 and CA199 expression was analyzed by immunohistochemistry. The results revealed the presence of epithelial proliferation and inflammatory infiltration in the forestomachs, glandular atrophy and intestinal metaplasia in the gastric bodies, and dysplasia in the gastric antra. The effect of mutations in the Apc gene on chronic gastritis and gastric precancerous lesions was characterized in Apc mice. These results suggest that Apc mice represent a genetic model for mechanistic studies and drug discovery in gastric precancerous lesions.
Topics: Adenomatous Polyposis Coli; Animals; Dissection; Female; Gastric Mucosa; Ki-67 Antigen; Male; Mice, Inbred C57BL; Precancerous Conditions; Stomach
PubMed: 31810128
DOI: 10.1016/j.biopha.2019.109534 -
PloS One 2022Adenomatous polyposis coli (APC) is the most commonly mutated gene in colon cancer and can cause familial adenomatous polyposis (FAP). Hypermethylation of the APC...
Adenomatous polyposis coli (APC) is the most commonly mutated gene in colon cancer and can cause familial adenomatous polyposis (FAP). Hypermethylation of the APC promoter can also promote the development of breast cancer, indicating that APC is not limited to association with colorectal neoplasms. However, no pan-cancer analysis has been conducted. We studied the location and structure of APC and the expression and potential role of APC in a variety of tumors by using The Cancer Genome Atlas and Gene Expression Omnibus databases and online bioinformatics analysis tools. The APC is located at 5q22.2, and its protein structure is conserved among H. sapiens, M. musculus with C. elaphus hippelaphus. The APC identity similarity between homo sapiens and mus musculus reaches 90.1%. Moreover, APC is highly specifically expressed in brain tissues and bipolar cells but has low expression in most cancers. APC is mainly expressed on the cell membrane and is not detected in plasma by mass spectrometry. APC is low expressed in most tumor tissues, and there is a significant correlation between the expressed level of APC and the main pathological stages as well as the survival and prognosis of tumor patients. In most tumors, APC gene has mutation and methylation and an enhanced phosphorylation level of some phosphorylation sites, such as T1438 and S2260. The expressed level of APC is also involved in the level of CD8+ T-cell infiltration, Tregs infiltration, and cancer-associated fibroblast infiltration. We conducted a gene correlation study, but the findings seemed to contradict the previous analysis results of the low expression of the APC gene in most cancers. Our research provides a comparative wholesale understanding of the carcinogenic effects of APC in various cancers, which will help anti-cancer research.
Topics: Adenomatous Polyposis Coli; Adenomatous Polyposis Coli Protein; Animals; DNA Methylation; Genes, APC; Humans; Mice; Promoter Regions, Genetic
PubMed: 35303016
DOI: 10.1371/journal.pone.0265655 -
Pathology, Research and Practice Jun 2022Silencing of tumour-suppressor genes through promoter methylation is frequently observed in carcinogenesis. In this study, we determined the methylation status of...
Silencing of tumour-suppressor genes through promoter methylation is frequently observed in carcinogenesis. In this study, we determined the methylation status of RASSF1A, MGMT, APC, AXIN2 and DACT1 genes in 73 cases of non-small cell lung cancer. Methylation-sensitive high-resolution melting analysis (MS-HRM) was used to analyse the promoter methylation, which was further validated with Bisulfite pyrosequencing or Sanger sequencing. Promoter methylation of RASSF1A and APC was frequently found (56% and 49% of cases, respectively), while methylation of MGMT, AXIN2, DACT1 was observed in 30%, 19% and 16%, respectively. Concurrent gene methylation of at least two genes was observed in 55% of the examined cases, with a total of 89% of samples displaying methylation in one or more of the investigated genes. Further analysis of concurrent methylation revealed a positive correlation between AXIN2-DACT1 and an inverse correlation of APC-MGMT. Associations of methylated genes and clinicopathological features were emerged. In more detail, APC promoter methylation was correlated with smoking status (p= 0.020) and non-metastatic cases (p= 0.003). Moreover, MGMT methylation was preferentially found in TTF1-negative cases (p= 0.049). Interestingly, correlation occurred between AXIN2/DACT1 methylation and smoking status (p= 0.009) as well as tumour grade (p= 0.013), as none of these genes was methylated in the majority of smokers and one of the genes was methylated in high-grade tumours. We conclude that aberrant promoter methylation was observed in our cohort while concurrent methylation patterns were also determined. APC, MGMT and AXIN2/DACT1 methylation are potentially of clinical importance regarding prognosis and histological subtyping of NSCLC.
Topics: Adaptor Proteins, Signal Transducing; Axin Protein; Carcinoma, Non-Small-Cell Lung; DNA Methylation; DNA Modification Methylases; DNA Repair Enzymes; Humans; Lung Neoplasms; Nuclear Proteins; Promoter Regions, Genetic; Tumor Suppressor Proteins
PubMed: 35489124
DOI: 10.1016/j.prp.2022.153899 -
Proceedings of the National Academy of... Aug 2020Quantifying evolutionary dynamics of cancer initiation and progression can provide insights into more effective strategies of early detection and treatment. Here we...
Quantifying evolutionary dynamics of cancer initiation and progression can provide insights into more effective strategies of early detection and treatment. Here we develop a mathematical model of colorectal cancer initiation through inactivation of two tumor suppressor genes and activation of one oncogene, accounting for the well-known path to colorectal cancer through loss of tumor suppressors and and gain of the oncogene. In the model, we allow mutations to occur in any order, leading to a complex network of premalignant mutational genotypes on the way to colorectal cancer. We parameterize the model using experimentally measured parameter values, many of them only recently available, and compare its predictions to epidemiological data on colorectal cancer incidence. We find that the reported lifetime risk of colorectal cancer can be recovered using a mathematical model of colorectal cancer initiation together with experimentally measured mutation rates in colorectal tissues and proliferation rates of premalignant lesions. We demonstrate that the order of driver events in colorectal cancer is determined primarily by the fitness effects that they provide, rather than their mutation rates. Our results imply that there may not be significant immune suppression of untreated benign and malignant colorectal lesions.
Topics: Carcinogenesis; Colonic Neoplasms; Colorectal Neoplasms; Disease Progression; Genes, APC; Genes, p53; Genes, ras; Humans; Models, Theoretical; Mutation; Mutation Rate; Oncogenes; Proto-Oncogene Proteins p21(ras); Tumor Suppressor Protein p53
PubMed: 32788368
DOI: 10.1073/pnas.2003771117 -
Gastroenterology Nov 2023
PubMed: 37572759
DOI: 10.1053/j.gastro.2023.07.027 -
Cellular Signalling Sep 2023The Wnt/β-catenin signaling pathway is associated with the regulation of cancer stem cells, and it can be driven by epigenetic modifications. Here, we aim to identify...
The Wnt/β-catenin signaling pathway is associated with the regulation of cancer stem cells, and it can be driven by epigenetic modifications. Here, we aim to identify epigenetic modifications involved in the control of the Wnt/β-catenin signaling and investigate the role of this pathway in the accumulation of cancer stem cells (CSC) and chemoresistance of Head and Neck Squamous Cell Carcinoma (HNSCC). Quantitative-PCR, western blot, shRNA assay, viability assay, flow cytometry assay, spheres formation, xenograft model, and chromatin immunoprecipitation were employed to evaluate the Wnt/β-catenin pathway and EZH2 in wild-type and chemoresistant oral carcinoma cell lines, and in the populations of CSC and non-stem cells. We demonstrated that β-catenin and EZH2 were accumulated in cisplatin-resistant and CSC population. The upstream genes of the Wnt/β-catenin signaling (APC and GSK3β) were decreased, and the downstream gene MMP7 was increased in the chemoresistant cell lines. The inhibition of β-catenin and EZH2 combined effectively decreased the CSC population in vitro and reduced the tumor volume and CSC population in vivo. EZH2 inhibition increased APC and GSK3β, and the Wnt/β-catenin inhibition reduced MMP7 levels. In contrast, EZH2 overexpression decreased APC and GSK3β and increased MMP7. EZH2 and β-catenin inhibitors sensitized chemoresistant cells to cisplatin. EZH2 and H3K27me3 bounded the promoter of APC, leading to its repression. These results suggest that EZH2 regulates β-catenin by inhibiting the upstream gene APC contributing to the accumulation of cancer stem cells and chemoresistance. Moreover, the pharmacological inhibition of the Wnt/β-catenin combined with EZH2 can be an effective strategy for treating HNSCC.
Topics: Humans; Squamous Cell Carcinoma of Head and Neck; Cisplatin; beta Catenin; Glycogen Synthase Kinase 3 beta; Matrix Metalloproteinase 7; Cell Line, Tumor; Wnt Signaling Pathway; Head and Neck Neoplasms; Neoplastic Stem Cells; Gene Expression Regulation, Neoplastic; Enhancer of Zeste Homolog 2 Protein
PubMed: 37331417
DOI: 10.1016/j.cellsig.2023.110773 -
Scientific Reports Mar 2021Familial adenomatous polyposis (FAP) is an inherited syndrome caused by a heterozygous adenomatous polyposis coli (APC) germline mutation, associated with a profound...
Familial adenomatous polyposis (FAP) is an inherited syndrome caused by a heterozygous adenomatous polyposis coli (APC) germline mutation, associated with a profound lifetime risk for colorectal cancer. While it is well accepted that tumorigenic transformation is initiated following acquisition of a second mutation and loss of function of the APC gene, the role of heterozygous APC mutation in this process is yet to be discovered. This work aimed to explore whether a heterozygous APC mutation induces molecular defects underlying tumorigenic transformation and how different APC germline mutations predict disease severity. Three FAP-human embryonic stem cell lines (FAP1/2/3-hESC lines) carrying germline mutations at different locations of the APC gene, and two control hESC lines free of the APC mutation, were differentiated into colon organoids and analyzed by immunohistochemistry and RNA sequencing. In addition, data regarding the genotype and clinical phenotype of the embryo donor parents were collected from medical records. FAP-hESCs carrying a complete loss-of-function of a single APC allele (FAP3) generated complex and molecularly mature colon organoids, which were similar to controls. In contrast, FAP-hESCs carrying APC truncation mutations (FAP1 and FAP2) generated only few cyst-like structures and cell aggregates of various shape, occasionally with luminal parts, which aligned with their failure to upregulate critical differentiation genes early in the process, as shown by RNA sequencing. Abnormal disease phenotype was shown also in non-pathological colon of FAP patients by the randomly distribution of proliferating cells throughout the crypts, compared to their focused localization in the lower part of the crypt in healthy/non-FAP patients. Genotype/phenotype analysis revealed correlations between the colon organoid maturation potential and FAP severity in the carrier parents. In conclusion, this study suggest that a single truncated APC allele is sufficient to initiate early molecular tumorigenic activity. In addition, the results hint that patient-specific hESC-derived colon organoids can probably predict disease severity among FAP patients.
Topics: Adenomatous Polyposis Coli; Adenomatous Polyposis Coli Protein; Adult; Cell Line, Tumor; Cell Transformation, Neoplastic; Colorectal Neoplasms; Female; Genetic Predisposition to Disease; Genotype; Germ-Line Mutation; Heterozygote; Human Embryonic Stem Cells; Humans; Male; Middle Aged; Pedigree
PubMed: 33664379
DOI: 10.1038/s41598-021-84564-4 -
Journal of Visceral Surgery Apr 2020Nearly 5% of colorectal cancers are hereditary colorectal cancers, including adenomatous polyposis. The aim of this review was to highlight the current management of... (Review)
Review
Nearly 5% of colorectal cancers are hereditary colorectal cancers, including adenomatous polyposis. The aim of this review was to highlight the current management of adenomatous polyposis. The two main genetic conditions responsible for adenomatous polyposis are familial adenomatous polyposis (FAP) (caused by an autosomal dominant mutation of the APC gene) and MUTYH-associated polyposis (MAP) (caused by bi-allelic recessive mutations of the MUTYH (MutY human homolog) gene). FAP is characterized by the presence of >1000 polyps and a young age at diagnosis (mean age of 10). In the absence of screening, the risk of colorectal cancer at age 40 is 100%. It is recommended to start screening at the age of 10-12 years. For patients with FAP and MAP, it is also recommended to screen the upper gastrointestinal tract (stomach and duodenum). In FAP, prophylactic surgery aims to reduce the risk of death without impairment of patient quality of life. The best age for prophylactic surgery is not well-defined; in Europe, prophylactic surgery is usually performed at age 20 as the risk of cancer increases sharply during the third decade. There are three main surgical procedures employed: total colectomy with an ileorectal anastomosis, restorative coloproctectomy with a J pouch anastomosis and coloproctectomy with a stoma. Restorative coloproctectomy with J pouch anastomosis is the reference procedure; however, disease can vary in severity from one patient to another and this must be taken into account to decide which procedure should be performed. In conclusion, the management of adenomatous polyposis is complex but is well-defined by guidelines, particularly in France.
Topics: Adenomatous Polyposis Coli; Age Factors; Anastomosis, Surgical; Colectomy; DNA Glycosylases; Endoscopy, Gastrointestinal; Genes, APC; Genetic Markers; Humans; Laparoscopy; Mutation; Quality of Life
PubMed: 32113818
DOI: 10.1016/j.jviscsurg.2019.12.003 -
World Journal of Gastrointestinal... Dec 2019Adenomatous polyposis (AP) is classified according to cumulative adenoma number in classical AP (CAP) and attenuated AP (AAP). Genetic susceptibility is the major risk... (Review)
Review
Adenomatous polyposis (AP) is classified according to cumulative adenoma number in classical AP (CAP) and attenuated AP (AAP). Genetic susceptibility is the major risk factor in CAP due to mutations in the known high predisposition genes and . However, the contribution of genetic susceptibility to AAP is lower and less understood. New predisposition genes have been recently proposed, and some of them have been validated, but their scarcity hinders accurate risk estimations and prevalence calculations. AAP is a heterogeneous condition in terms of severity, clinical features and heritability. Therefore, clinicians do not have strong discriminating criteria for the recommendation of the genetic study of known predisposition genes, and the detection rate is low. Elucidation and knowledge of new AAP high predisposition genes are of great importance to offer accurate genetic counseling to the patient and family members. This review aims to update the genetic knowledge of AAP, and to expound the difficulties involved in the genetic analysis of a highly heterogeneous condition such as AAP.
PubMed: 31908716
DOI: 10.4251/wjgo.v11.i12.1101