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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 -
Gastroenterology Dec 2020Mutant KRAS promotes glutaminolysis, a process that uses steps from the tricarboxylic cycle to convert glutamine to α-ketoglutarate and other molecules via glutaminase... (Observational Study)
Observational Study
BACKGROUND & AIMS
Mutant KRAS promotes glutaminolysis, a process that uses steps from the tricarboxylic cycle to convert glutamine to α-ketoglutarate and other molecules via glutaminase and SLC25A22. This results in inhibition of demethylases and epigenetic alterations in cells that increase proliferation and stem cell features. We investigated whether mutant KRAS-mediated glutaminolysis affects the epigenomes and activities of colorectal cancer (CRC) cells.
METHODS
We created ApcKras mice with intestine-specific knockout of SLC25A22 (ApcKrasSLC25A22 mice). Intestine tissues were collected and analyzed by histology, immunohistochemistry, and DNA methylation assays; organoids were derived and studied for stem cell features, along with organoids derived from 2 human colorectal tumor specimens. Colon epithelial cells (1CT) and CRC cells (DLD1, DKS8, HKE3, and HCT116) that expressed mutant KRAS, with or without knockdown of SLC25A22 or other proteins, were deprived of glutamine or glucose and assayed for proliferation, colony formation, glucose or glutamine consumption, and apoptosis; gene expression patterns were analyzed by RNA sequencing, proteins by immunoblots, and metabolites by liquid chromatography-mass spectrometry, with [U-C]-glutamine as a tracer. Cells and organoids with knocked down, knocked out, or overexpressed proteins were analyzed for DNA methylation at CpG sites using arrays. We performed immunohistochemical analyses of colorectal tumor samples from 130 patients in Hong Kong (57 with KRAS mutations) and Kaplan-Meier analyses of survival. We analyzed gene expression levels of colorectal tumor samples in The Cancer Genome Atlas.
RESULTS
CRC cells that express activated KRAS required glutamine for survival, and rapidly incorporated it into the tricarboxylic cycle (glutaminolysis); this process required SLC25A22. Cells incubated with succinate and non-essential amino acids could proliferate under glutamine-free conditions. Mutant KRAS cells maintained a low ratio of α-ketoglutarate to succinate, resulting in reduced 5-hydroxymethylcytosine-a marker of DNA demethylation, and hypermethylation at CpG sites. Many of the hypermethylated genes were in the WNT signaling pathway and at the protocadherin gene cluster on chromosome 5q31. CRC cells without mutant KRAS, or with mutant KRAS and knockout of SLC25A22, expressed protocadherin genes (PCDHAC2, PCDHB7, PCDHB15, PCDHGA1, and PCDHGA6)-DNA was not methylated at these loci. Expression of the protocadherin genes reduced WNT signaling to β-catenin and expression of the stem cell marker LGR5. ApcKrasSLC25A22 mice developed fewer colon tumors than ApcKras mice (P < .01). Organoids from ApcKrasSLC25A22 mice had reduced expression of LGR5 and other markers of stemness compared with organoids derived from ApcKras mice. Knockdown of SLC25A22 in human colorectal tumor organoids reduced clonogenicity. Knockdown of lysine demethylases, or succinate supplementation, restored expression of LGR5 to SLC25A22-knockout CRC cells. Knockout of SLC25A22 in CRC cells that express mutant KRAS increased their sensitivity to 5-fluorouacil. Level of SLC25A22 correlated with levels of LGR5, nuclear β-catenin, and a stem cell-associated gene expression pattern in human colorectal tumors with mutations in KRAS and reduced survival times of patients.
CONCLUSIONS
In CRC cells that express activated KRAS, SLC25A22 promotes accumulation of succinate, resulting in increased DNA methylation, activation of WNT signaling to β-catenin, increased expression of LGR5, proliferation, stem cell features, and resistance to 5-fluorouacil. Strategies to disrupt this pathway might be developed for treatment of CRC.
Topics: Animals; Colon; Colorectal Neoplasms; DNA Demethylation; Drug Resistance, Neoplasm; Female; Fluorouracil; Follow-Up Studies; Gene Expression Regulation, Neoplastic; Gene Knockdown Techniques; Glutamine; Hong Kong; Humans; Intestinal Mucosa; Kaplan-Meier Estimate; Ketoglutaric Acids; Male; Mice, Knockout; Mitochondrial Membrane Transport Proteins; Neoplastic Stem Cells; Proto-Oncogene Proteins p21(ras); Wnt Signaling Pathway; Xenograft Model Antitumor Assays
PubMed: 32814111
DOI: 10.1053/j.gastro.2020.08.016 -
International Journal of Molecular... Oct 2022TRAF2- and NCK-interacting kinase (TNIK) has emerged as a promising therapeutic target for colorectal cancer because of its essential role in regulating the... (Review)
Review
TRAF2- and NCK-interacting kinase (TNIK) has emerged as a promising therapeutic target for colorectal cancer because of its essential role in regulating the Wnt/β-catenin signaling pathway. Colorectal cancers contain many mutations in the Wnt/β-catenin signaling pathway genes upstream of TNIK, such as the adenomatous polyposis coli () tumor suppressor gene. TNIK is a regulatory component of the transcriptional complex composed of β-catenin and T-cell factor 4 (TCF4). Inhibition of TNIK is expected to block the aberrant Wnt/β-catenin signaling caused by colorectal cancer mutations. Here we present structural insights into TNIK inhibitors targeting the ATP-binding site. We will discuss the effects of the binding of different chemical scaffolds of nanomolar inhibitors on the structure and function of TNIK.
Topics: Humans; beta Catenin; Wnt Proteins; Protein Serine-Threonine Kinases; Colorectal Neoplasms; Wnt Signaling Pathway
PubMed: 36361804
DOI: 10.3390/ijms232113010 -
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 -
Italian Journal of Pediatrics Aug 2020Hepatoblastoma (HB) is the most common malignant liver tumor in children. Abnormal activation of the Wnt/β-catenin signaling pathway plays an important role in the... (Review)
Review
Hepatoblastoma (HB) is the most common malignant liver tumor in children. Abnormal activation of the Wnt/β-catenin signaling pathway plays an important role in the formation and development of HB. Genes in HB show a global hypomethylation change, accompanied by hypermethylation of specific tumor suppressor genes (TSGs). This article reviews the hypermethylation changes in several TSGs, such as RASSF1A, SOCS1, APC, HHIP, and P16, and analyzes the pathways and mechanisms of TSGs regulating gene expression. The role of the methylation-regulating enzymes DNA methyltransferases (DNMTs) and ten-eleven translocation (TET) family members enzymes in the methylation changes of HB was analyzed, and it was speculated that the occurrence of HB is partly due to the obstruction of liver differentiation in the early stage of differentiation. The origin cells may be incompletely differentiated hepatocytes remaining in the liver of children after birth. Therefore, further studying the role of methylation regulating enzymes in methylation changes in HB is a promising future research direction.
Topics: DNA Methylation; Genes, Tumor Suppressor; Hepatoblastoma; Humans; Liver Neoplasms
PubMed: 32758256
DOI: 10.1186/s13052-020-00877-6 -
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 -
Clinics in Colon and Rectal Surgery Nov 2023Desmoid tumors (DT) represent the second high risk of tumor in familial adenomatous polyposis (FAP) patients. Although FAP-associated DTs (FAP-DT) are caused by germline... (Review)
Review
Desmoid tumors (DT) represent the second high risk of tumor in familial adenomatous polyposis (FAP) patients. Although FAP-associated DTs (FAP-DT) are caused by germline mutations in the adenomatous polyposis coli (APC) gene, extracolonic manifestations, sex, family history, genotype, and the ileal pouch anal anastomosis procedure are all linked to the development of DTs in FAP patients. Multidisciplinary management has replaced aggressive surgery as the preferred treatment of DTs. There is growing evidence to support the use of active surveillance strategy as first-line treatment for FAP-DT patients. Radiotherapy for intra-abdominal desmoids is now rarely used because of severe late toxicity. Pharmacotherapy, however, represents a promising future with the improvement of traditional cytotoxic drugs and the investigation of targeted drugs. Although nonsurgery treatment has been used widely nowadays, surgery remains the mainstay when symptomatic or life-threatening DTs are present. Further research will be needed for more optimal clinical practice.
PubMed: 37795470
DOI: 10.1055/s-0043-1767709