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Nature Medicine Mar 2015Human colorectal tumors bear recurrent mutations in genes encoding proteins operative in the WNT, MAPK, TGF-β, TP53 and PI3K pathways. Although these pathways influence...
Human colorectal tumors bear recurrent mutations in genes encoding proteins operative in the WNT, MAPK, TGF-β, TP53 and PI3K pathways. Although these pathways influence intestinal stem cell niche signaling, the extent to which mutations in these pathways contribute to human colorectal carcinogenesis remains unclear. Here we use the CRISPR-Cas9 genome-editing system to introduce multiple such mutations into organoids derived from normal human intestinal epithelium. By modulating the culture conditions to mimic that of the intestinal niche, we selected isogenic organoids harboring mutations in the tumor suppressor genes APC, SMAD4 and TP53, and in the oncogenes KRAS and/or PIK3CA. Organoids engineered to express all five mutations grew independently of niche factors in vitro, and they formed tumors after implantation under the kidney subcapsule in mice. Although they formed micrometastases containing dormant tumor-initiating cells after injection into the spleen of mice, they failed to colonize in the liver. In contrast, engineered organoids derived from chromosome-instable human adenomas formed macrometastatic colonies. These results suggest that 'driver' pathway mutations enable stem cell maintenance in the hostile tumor microenvironment, but that additional molecular lesions are required for invasive behavior.
Topics: Adenocarcinoma; Adenoma; Animals; Class I Phosphatidylinositol 3-Kinases; Clustered Regularly Interspaced Short Palindromic Repeats; Colorectal Neoplasms; Gene Expression Regulation, Neoplastic; Genes, APC; Genes, p53; Genes, ras; Humans; In Vitro Techniques; Intestinal Mucosa; Mice; Mutation; Organoids; Phosphatidylinositol 3-Kinases; Smad4 Protein
PubMed: 25706875
DOI: 10.1038/nm.3802 -
Gastroenterology Jan 2022Genomic alterations that encourage stem cell activity and hinder proper maturation are central to the development of colorectal cancer (CRC). Key molecular mediators...
BACKGROUND AND AIMS
Genomic alterations that encourage stem cell activity and hinder proper maturation are central to the development of colorectal cancer (CRC). Key molecular mediators that promote these malignant properties require further elucidation to galvanize translational advances. We therefore aimed to characterize a key factor that blocks intestinal differentiation, define its transcriptional and epigenetic program, and provide preclinical evidence for therapeutic targeting in CRC.
METHODS
Intestinal tissue from transgenic mice and patients were analyzed by means of histopathology and immunostaining. Human CRC cells and neoplastic murine organoids were genetically manipulated for functional studies. Gene expression profiling was obtained through RNA sequencing. Histone modifications and transcription factor binding were determined with the use of chromatin immunoprecipitation sequencing.
RESULTS
We demonstrate that SRY-box transcription factor 9 (SOX9) promotes CRC by activating a stem cell-like program that hinders intestinal differentiation. Intestinal adenomas and colorectal adenocarcinomas from mouse models and patients demonstrate ectopic and elevated expression of SOX9. Functional experiments indicate a requirement for SOX9 in human CRC cell lines and engineered neoplastic organoids. Disrupting SOX9 activity impairs primary CRC tumor growth by inducing intestinal differentiation. By binding to genome wide enhancers, SOX9 directly activates genes associated with Paneth and stem cell activity, including prominin 1 (PROM1). SOX9 up-regulates PROM1 via a Wnt-responsive intronic enhancer. A pentaspan transmembrane protein, PROM1 uses its first intracellular domain to support stem cell signaling, at least in part through SOX9, reinforcing a PROM1-SOX9 positive feedback loop.
CONCLUSIONS
These studies establish SOX9 as a central regulator of an enhancer-driven stem cell-like program and carry important implications for developing therapeutics directed at overcoming differentiation defects in CRC.
Topics: AC133 Antigen; Animals; Cell Differentiation; Cell Proliferation; Colorectal Neoplasms; Enhancer Elements, Genetic; Gene Expression Regulation, Neoplastic; Genes, APC; HT29 Cells; Humans; Mice, Transgenic; Neoplastic Stem Cells; SOX9 Transcription Factor; Tumor Burden; Tumor Cells, Cultured; Wnt Signaling Pathway
PubMed: 34571027
DOI: 10.1053/j.gastro.2021.09.044 -
Frontiers in Oncology 2021The adenomatous polyposis coli () gene, known as tumor suppressor gene, has the two promoters 1A and 1B. Researches on have usually focused on its loss-of-function... (Review)
Review
The adenomatous polyposis coli () gene, known as tumor suppressor gene, has the two promoters 1A and 1B. Researches on have usually focused on its loss-of-function variants causing familial adenomatous polyposis. Hypermethylation, however, which is one of the key epigenetic alterations of the CpG sequence, is also associated with carcinogenesis in various cancers. Accumulating studies have successively explored the role of hypermethylation in gastrointestinal (GI) tumors, such as in esophageal, colorectal, gastric, pancreatic, and hepatic cancer. In sporadic colorectal cancer, the hypermethylation of CpG island in is even considered as one of the primary causative factors. In this review, we systematically summarized the distribution of gene methylation in various GI tumors, and attempted to provide an improved general understanding of DNA methylation in GI tumors. In addition, we included a robust overview of demethylating agents available for both basic and clinical researches. Finally, we elaborated our findings and perspectives on the overall situation of gene methylation in GI tumors, aiming to explore the potential research directions and clinical values.
PubMed: 33968756
DOI: 10.3389/fonc.2021.653222 -
Cancer Research Feb 2021The Wnt/β-catenin signaling pathway plays crucial roles in embryonic development and the development of multiple types of cancer, and its aberrant activation provides...
The Wnt/β-catenin signaling pathway plays crucial roles in embryonic development and the development of multiple types of cancer, and its aberrant activation provides cancer cells with escape mechanisms from immune checkpoint inhibitors. E7386, an orally active selective inhibitor of the interaction between β-catenin and CREB binding protein, which is part of the Wnt/β-catenin signaling pathway, disrupts the Wnt/β-catenin signaling pathway in HEK293 and adenomatous polyposis coli ()-mutated human gastric cancer ECC10 cells. It also inhibited tumor growth in an ECC10 xenograft model and suppressed polyp formation in the intestinal tract of mice, in which mutation of activates the Wnt/β-catenin signaling pathway. E7386 demonstrated antitumor activity against mouse mammary tumors developed in mouse mammary tumor virus (MMTV)-Wnt1 transgenic mice. Gene expression profiling using RNA sequencing data of MMTV-Wnt1 tumor tissue from mice treated with E7386 showed that E7386 downregulated genes in the hypoxia signaling pathway and immune responses related to the CCL2, and IHC analysis showed that E7386 induced infiltration of CD8 cells into tumor tissues. Furthermore, E7386 showed synergistic antitumor activity against MMTV-Wnt1 tumor in combination with anti-PD-1 antibody. In conclusion, E7386 demonstrates clear antitumor activity via modulation of the Wnt/β-catenin signaling pathway and alteration of the tumor and immune microenvironments, and its antitumor activity can be enhanced in combination with anti-PD-1 antibody. SIGNIFICANCE: These findings demonstrate that the novel anticancer agent, E7386, modulates Wnt/β-catenin signaling, altering the tumor immune microenvironment and exhibiting synergistic antitumor activity in combination with anti-PD-1 antibody.
Topics: Animals; Antineoplastic Agents; Cell Proliferation; Cells, Cultured; Disease Models, Animal; Female; Genes, APC; HEK293 Cells; Humans; Mice; Mice, Inbred C57BL; Mice, Nude; Mice, Transgenic; Neoplasms; Peptide Fragments; Protein Binding; Pyrazines; Sialoglycoproteins; Triazines; Wnt Signaling Pathway; Wnt1 Protein; beta Catenin
PubMed: 33408116
DOI: 10.1158/0008-5472.CAN-20-0782 -
European Journal of Cancer (Oxford,... Jul 2022The clinical development of immune checkpoint-targeted immunotherapies has been disappointing so far in paediatric solid tumours. However, as opposed to adults, very...
BACKGROUND
The clinical development of immune checkpoint-targeted immunotherapies has been disappointing so far in paediatric solid tumours. However, as opposed to adults, very little is known about the immune contexture of paediatric malignancies.
METHODS
We investigated by gene expression and immunohistochemistry (IHC) the immune microenvironment of five major paediatric cancers: Ewing sarcoma (ES), osteosarcoma (OS), rhabdomyosarcoma (RMS), medulloblastoma (MB) and neuroblastoma (NB; 20 cases each; n = 100 samples total), and correlated them with overall survival.
RESULTS
NB and RMS tumours had high immune cell gene expression values and high T-cell counts but were low for antigen processing cell (APC) genes. OS and ES tumours showed low levels of T-cells but the highest levels of APC genes. OS had the highest levels of macrophages (CSF1R, CD163 and CD68), whereas ES had the lowest. MB appeared as immune deserts. Tregs (FOXP3 staining) were higher in both RMS and OS. Most tumours scored negative for PD-L1 in tumour and immune cells, with only 11 of 100 samples positive for PD-L1 staining. PD-L1 and OX40 levels were generally low across all five indications. Interestingly, NB had comparable levels of CD8 by IHC and by gene expression to adult tumours. However, by gene expression, these tumours were low for T-cell cytotoxic molecules GZMB, GZMA and PRF1. Surprisingly, the lower the level of tumour infiltrative CD8 T-cells, the better the prognosis was in NB, RMS and ES. Gene expression analyses showed that MYCN-amplified NB have higher amounts of immune suppressive cells such as macrophages, myeloid-derived suppressor cells and Tregs, whereas the non-MYCN-amplified tumours were more infiltrated and had higher expression levels of Teff.
CONCLUSIONS
Our results describe the quality and quantity of immune cells across five major paediatric cancers and provide some key features differentiating these tumours from adult tumour types. These findings explain why anti-PD(L)1 might not have had single agent success in paediatric cancers. These results provides the rationale for the development of biologically stratified and personalised immunotherapy strategies in children with relapsing/refractory cancers.
Topics: B7-H1 Antigen; Bone Neoplasms; Child; Humans; Immunotherapy; Lymphocytes, Tumor-Infiltrating; Neuroblastoma; Osteosarcoma; Prognosis; Rhabdomyosarcoma; Sarcoma, Ewing; Tumor Microenvironment
PubMed: 35660252
DOI: 10.1016/j.ejca.2022.03.012 -
Arquivos Brasileiros de Cirurgia... 2018Colorectal cancer is a very frequent sort of neoplasm among the population, with a high mortality rate. It develops from an association of genetic and environmental... (Review)
Review
INTRODUCTION
Colorectal cancer is a very frequent sort of neoplasm among the population, with a high mortality rate. It develops from an association of genetic and environmental factors, and it is related to multiple cell signaling pathways. Cell cultures and animal models are used in research to reproduce the process of disease development in humans. Of the existing animal models, the most commonly used are animals with tumors induced by chemical agents and genetically modified animals.
OBJECTIVE
To present and synthesize the main animal models of colorectal carcinogenesis used in the research, comparing its advantages and disadvantages.
METHOD
This literature review was performed through the search for scientific articles over the last 18 years in PubMed and Science Direct databases, by using keywords such as "animal models", "colorectal carcinogenesis" and "tumor induction".
RESULTS
1,2-dimethylhydrazine and azoxymethane are carcinogenic agents with high specificity for the small and large intestine regions. Therefore, the two substances are widely used. Concerning the genetically modified animal models, there is a larger number of studies concerning mutations of the APC, p53 and K-ras genes. Animals with the APC gene mutation develop colorectal neoplasms, whereas animals with p53 and K-ras genes mutations are able to potentiate the effects of the APC gene mutation as well as the chemical inducers.
CONCLUSION
Each animal model has advantages and disadvantages, and some are individually efficient as to the induction of carcinogenesis, and in other cases the association of two forms of induction is the best way to obtain representative results of carcinogenesis in humans.
Topics: Animals; Animals, Genetically Modified; Colorectal Neoplasms; Disease Models, Animal
PubMed: 29972397
DOI: 10.1590/0102-672020180001e1369 -
Digestive Diseases and Sciences Jul 2023The most prevalent type of intestinal polyposis, colorectal adenomatous polyposis (CAP), is regarded as a precancerous lesion of colorectal cancer with obvious genetic... (Review)
Review
The most prevalent type of intestinal polyposis, colorectal adenomatous polyposis (CAP), is regarded as a precancerous lesion of colorectal cancer with obvious genetic characteristics. Early screening and intervention can significantly improve patients' survival and prognosis. The adenomatous polyposis coli (APC) mutation is believed to be the primary cause of CAP. There is, however, a subset of CAP with undetectable pathogenic mutations in APC, known as APC (-)/CAP. The genetic predisposition to APC (-)/CAP has largely been associated with germline mutations in some susceptible genes, including the human mutY homologue (MUTYH) gene and the Nth-like DNA glycosylase 1 (NTHL1) gene, and DNA mismatch repair (MMR) can cause autosomal recessive APC (-)/CAP. Furthermore, autosomal dominant APC (-)/CAP could occur as a result of DNA polymerase epsilon (POLE)/DNA polymerase delta 1 (POLD1), axis inhibition protein 2 (AXIN2), and dual oxidase 2 (DUOX2) mutations. The clinical phenotypes of these pathogenic mutations vary greatly depending on their genetic characteristics. Therefore, in this study, we present a comprehensive review of the association between autosomal recessive and dominant APC (-)/CAP genotypes and clinical phenotypes and conclude that APC (-)/CAP is a disease caused by multiple genes with different phenotypes and interaction exists in the pathogenic genes.
Topics: Humans; Adenomatous Polyposis Coli; Mutation; Genetic Association Studies; Genetic Predisposition to Disease; Genotype; Germ-Line Mutation; Phenotype; Genes, APC
PubMed: 36862359
DOI: 10.1007/s10620-023-07890-9 -
European Journal of Cell Biology 2022Adenomatous Polyposis Coli (APC) protein is mostly known as a tumor suppressor that regulates Wnt signaling, but is also an important cytoskeletal protein. Mutations in... (Review)
Review
Adenomatous Polyposis Coli (APC) protein is mostly known as a tumor suppressor that regulates Wnt signaling, but is also an important cytoskeletal protein. Mutations in the APC gene are linked to colorectal cancer and various neurological disorders and intellectual disabilities. Cytoskeletal functions of APC appear to have significant contributions to both types of these disorders. As a cytoskeletal protein, APC can regulate both actin and microtubule cytoskeletons, which together form the main machinery for cell migration. As APC is a multifunctional protein with numerous interaction partners, the complete picture of how APC regulates cell motility is still unavailable. However, some molecular mechanisms begin to emerge. Here, we review available information about roles of APC in cell migration and propose a model explaining how microtubules, using APC as an intermediate, can initiate leading edge protrusion in response to external signals by stimulating Arp2/3 complex-dependent nucleation of branched actin filament networks via a series of intermediate events.
Topics: Actins; Adenomatous Polyposis Coli Protein; Cell Movement; Genes, APC; Humans; Microtubules
PubMed: 35483122
DOI: 10.1016/j.ejcb.2022.151228 -
Anticancer Research Jul 2017Familial adenomatous polyposis (FAP) is a cancer syndrome caused by a germline mutation in the adenomatous polyposis coli (APC) gene. It is characterized by the presence... (Review)
Review
Familial adenomatous polyposis (FAP) is a cancer syndrome caused by a germline mutation in the adenomatous polyposis coli (APC) gene. It is characterized by the presence of hundreds of colonic polyps, which have a high tendency to undergo malignant transformation. Among associated lesions in FAP, desmoid tumors represent a common possible life-threatening condition that requires special attention. They are rare tumors occurring with a particularly high incidence in FAP, especially after surgery. In agreement with Knudson's 'two-hit' theory, the inactivation of the residual APC gene in FAP is a critical step in the development of both colorectal cancer and desmoids. Several lines of evidence show that germline mutations affect the functional domains of the APC gene that are responsible for interactions of the transcript with β-catenin, whereas somatic second mutations involve the downstream region of the gene. Hence, an understanding of the molecular pathways underlying desmoid progression in FAP could be important for research and a valid resource for the early prevention and tailored treatment of this disease. In this review, we provide an updated insight into desmoids in FAP syndrome, from molecular pathogenesis to the main issues in management, with special attention given to genetic and molecular features of these tumors.
Topics: Adenomatous Polyposis Coli; Animals; Fibromatosis, Aggressive; Genes, APC; Germ-Line Mutation; Humans; Incidence; Neoplasms
PubMed: 28668823
DOI: 10.21873/anticanres.11702 -
Nature Jun 2021A delicate equilibrium of WNT agonists and antagonists in the intestinal stem cell (ISC) niche is critical to maintaining the ISC compartment, as it accommodates the...
A delicate equilibrium of WNT agonists and antagonists in the intestinal stem cell (ISC) niche is critical to maintaining the ISC compartment, as it accommodates the rapid renewal of the gut lining. Disruption of this balance by mutations in the tumour suppressor gene APC, which are found in approximately 80% of all human colon cancers, leads to unrestrained activation of the WNT pathway. It has previously been established that Apc-mutant cells have a competitive advantage over wild-type ISCs. Consequently, Apc-mutant ISCs frequently outcompete all wild-type stem cells within a crypt, thereby reaching clonal fixation in the tissue and initiating cancer formation. However, whether the increased relative fitness of Apc-mutant ISCs involves only cell-intrinsic features or whether Apc mutants are actively involved in the elimination of their wild-type neighbours remains unresolved. Here we show that Apc-mutant ISCs function as bona fide supercompetitors by secreting WNT antagonists, thereby inducing differentiation of neighbouring wild-type ISCs. Lithium chloride prevented the expansion of Apc-mutant clones and the formation of adenomas by rendering wild-type ISCs insensitive to WNT antagonists through downstream activation of WNT by inhibition of GSK3β. Our work suggests that boosting the fitness of healthy cells to limit the expansion of pre-malignant clones may be a powerful strategy to limit the formation of cancers in high-risk individuals.
Topics: Adenoma; Adenomatous Polyposis Coli Protein; Animals; Cell Competition; Cell Differentiation; Female; Genes, APC; Glycogen Synthase Kinase 3 beta; Humans; Intestinal Neoplasms; Lithium Chloride; Male; Mice; Mutation; Organoids; Wnt Proteins
PubMed: 34079128
DOI: 10.1038/s41586-021-03558-4