Mutations In Adenomatous Polyposis Coli Gene Research Articles

Adenomatous Polyposis Coli Gene Mutations, Risk Factors, and Long-term Outcomes Associated With Desmoid Tumors in Patients With Familial Adenomatous Polyposis After Colectomy in Japan

Goals: To clarify the characteristics of desmoid tumors in Japanese patients with familial adenomatous polyposis after colectomy. Background: Few comprehensive reports have been published on desmoid tumors in Asian patients with familial adenomatous polyposis. Study: This retrospective study included the data of 81 patients with familial adenomatous polyposis who underwent surgery between 1978 and 2021. The adenomatous polyposis coli gene mutation sites, risk factors, and long-term outcomes associated with desmoid tumors in Japanese patients with familial adenomatous polyposis after colectomy were analyzed. Results: No association was observed between the gene mutation sites and desmoid tumor development in 40 patients who underwent genetic analyses. The rate of desmoid tumor development was 30.3% in 66 patients. Multivariate analysis revealed that age below 32 years at colectomy (hazard ratio = 5.491, 95% confidence interval 1.820-16.50, P < 0.001) and familial adenomatous polyposis-related malignancies other than colorectal cancer (hazard ratio = 5.574, 95% confidence interval 2.075-14.98, P < 0.001) were independent risk factors for desmoid tumor development following colectomy. The 10-year disease-specific survival and overall survival rates for desmoid tumors were 92.9% and 76.9%, respectively. The median surveillance duration was 90 months. Conclusions: Adenomatous polyposis coli gene mutation sites alone were not considered a factor for delaying or avoiding colectomy to prevent desmoid tumors in Japanese patients with familial adenomatous polyposis. The timing of colectomy and careful surveillance should be considered for managing patients at a high risk of developing desmoid tumors. Desmoid tumors in patients with familial adenomatous polyposis did not significantly impact prognosis, and pharmacological treatments are important for disease control.

Determination of the frequency and distribution of APC, PIK3CA, and SMAD4 gene mutations in Ugandan patients with colorectal cancer

Uganda is a developing low-income country with a low incidence of colorectal cancer, which is steadily increasing. Ugandan colorectal cancer (CRC) patients are young and present with advanced-stage disease. In our population, there is a scarcity of genetic oncological studies, therefore, we investigated the mutational status of CRC tissues, focusing in particular on the adenomatous polyposis coli (APC), phosphatidylinositol-4,5-bisphosphate 3-kinase catalytic subunit alpha (PIK3CA), and SMAD4 genes. Our objective was to determine whether there were any differences between other populations and Ugandan patients. We performed next-generation sequencing on the extracted DNA from formalin-fixed paraffin-embedded adenocarcinoma samples from 127 patients (mean (SD) age: 54.9 (16.0) years; male:female sex ratio: 1.2:1). Most tumours were located in the rectum 56 (44.1%), 14 (11%) tumours were high grade, and 96 (75.6%) were moderate grade CRC. Stage III + IV CRC tumours were found in 109 (85.8%) patients. We identified 48 variants of APC, including 9 novel APC mutations that were all pathogenic or deleterious. For PIK3CA, we found 19 variants, of which 9 were deleterious or pathogenic. Four PIK3CA novel pathogenic or deleterious variants were included (c.1397C > G, c.2399_2400insA, c.2621G > C, c.2632C > G). Three SMAD4 variants were reported, including two pathogenic or deleterious variants (c.1268G > T, c.556dupC) and one tolerant (c.563A > C) variant. One novel SMAD4 deleterious mutation (c.1268G > T) was reported. In conclusion, we provide clinicopathological information and new genetic variation data pertinent to CRC in Uganda.

Diagnosis, treatment, and prognosis of adult pancreatoblastoma.

Pancreatoblastoma (PB) is one of the rare malignant tumors that typically occurs in children. Cases of PB in adults are highly unusual. This disease often presents with subtle symptoms and lacks characteristic clinical manifestations, leading to diagnostic challenges. This study integrates the relevant literature on adult PB, conducting data analysis on clinical features, laboratory and imaging results, pathological characteristics, and treatments according to inclusion and exclusion criteria. Kaplan-Meier univariate analysis and Log-rank tests are employed to analyze survival data from adult PB follow-up, exploring factors influencing prognosis. A total of 65 articles were included, encompassing 103 cases of adult PB. The average age of PB patients was 41.78 years (range 19-81 years), and the male-to-female ratio was 1.06:1. Patients frequently presented with abdominal pain as the initial symptom. Laboratory results lacked specificity and imaging findings often presented as large, well-defined masses. PB exhibited distinctive pathological features, including squamous corpuscles (n = 76, 89.41%) and acinar differentiation (n = 34, 40%), with frequent positive expression of Trypsin, Chymotrypsin, and AACT (Alpha-1-Antichymotrypsin). APC (Adenomatous Polyposis Coli) gene mutation was the most common molecular alteration in adult PB. During the follow-up period, 43.59% of patients died (range 3 days to 348 months). The primary factors affecting prognosis were the presence of metastasis (χ2 = 3.996, p = 0.046) and incomplete surgical resection (χ2 = 5.586, p = 0.018), with mean survival times of 48 months and 27 months, respectively. PB in adults is an invasive tumor. The key to distinguishing PB from other pancreatic tumors lies in recognizing its unique pathological feature, the squamous corpuscles. Timely and complete surgical resection is the preferred treatment following diagnosis. Patients with incomplete resection or the presence of lymph nodes or (and) distant metastases have a poor prognosis.

Potential Role of APC Mutations in the Prognosis and Targeted Therapy of Gastric Adenocarcinoma

Background: Adenomatous polyposis coli (APC) gene, an oncogene, has been implicated in stomach adenocarcinoma (STAD), which is a common type of gastric cancer (GC). Although the relationship between APC gene mutations and gastric adenocarcinoma has been comprehensively studied, the potential role of these mutations in the prognosis and targeted therapy remains known.Methods: We utilized The Cancer Genome Atlas (TCGA) database to obtain gene expression matrices, clinical information, and mutation data from patients with STAD. The mutation status of the APC gene was analyzed, and its correlation with tumor mutational burden (TMB), microsatellite instability (MSI), and clinical prognosis in STAD was investigated. Gene set enrichment analysis (GSEA) was conducted to explore the pathological role of APC gene mutations in STAD metabolic pathways. Drug sensitivity analysis was conducted to identify potential targeted antitumor drugs for patients with APC gene mutations in gastric adenocarcinoma.Results: The results revealed that 88% (46/52) of STAD samples had nonsynonymous mutations. The mutation group exhibited a significantly higher TMB than the wild‐type group (p < 0.001), and the percentage of high MSI (MSI‐H) was significantly higher in the mutation group than in the wild‐type group (p < 0.001). Patients with APC mutations had a worse prognosis than those with APC wild‐type (p = 0.009). The APC gene mutation group displayed significant enrichment in amino acids, RNA, and several pathways (|NES| > 1 and nominal p value < 0.01). Compared to the wild‐type group, the mutation group exhibited a higher infiltration proportion of natural killer (NK) cells resting and eosinophils, whereas a lower infiltration proportion of monocytes and resting mast cells (p value < 0.05). AZD5991 exhibited significant sensitivity in patients with STAD carrying APC mutations (p = 0.028).Conclusion: APC gene mutations play a crucial role in the prognosis, molecular characteristics, and potential therapeutic strategies for gastric adenocarcinoma.

T cell migration and effector function differences in familial adenomatous polyposis patients with APC gene mutations.

Familial adenomatous polyposis (FAP) is an inherited disease characterized by the development of large number of colorectal adenomas with high risk of evolving into colorectal tumors. Mutations of the Adenomatous polyposis coli (APC) gene is often at the origin of this disease, as well as of a high percentage of spontaneous colorectal tumors. APC is therefore considered a tumor suppressor gene. While the role of APC in intestinal epithelium homeostasis is well characterized, its importance in immune responses remains ill defined. Our recent work indicates that the APC protein is involved in various phases of both CD4 and CD8 T cells responses. This prompted us to investigate an array of immune cell features in FAP subjects carrying APC mutations. A group of 12 FAP subjects and age and sex-matched healthy controls were studied. We characterized the immune cell repertoire in peripheral blood and the capacity of immune cells to respond ex vivo to different stimuli either in whole blood or in purified T cells. A variety of experimental approaches were used, including, pultiparamater flow cytometry, NanosString gene expression profiling, Multiplex and regular ELISA, confocal microscopy and computer-based image analyis methods. We found that the percentage of several T and natural killer (NK) cell populations, the expression of several genes induced upon innate or adaptive immune stimulation and the production of several cytokines and chemokines was different. Moreover, the capacity of T cells to migrate in response to chemokine was consistently altered. Finally, immunological synapses between FAP cytotoxic T cells and tumor target cells were more poorly structured. Our findings of this pilot study suggest that mild but multiple immune cell dysfunctions, together with intestinal epithelial dysplasia in FAP subjects, may facilitate the long-term polyposis and colorectal tumor development. Although at an initial discovery phase due to the limited sample size of this rare disease cohort, our findings open new perspectives to consider immune cell abnormalities into polyposis pathology.

Programmed cell death ligand-1 (PD-L1) expression in desmoid tumors: a retrospective study.

Desmoid tumor is a rare benign but locally aggressive monoclonal and fibroblastic proliferation. It lacks metastatic potential but is associated with a high local recurrence after surgery. It is either characterized by the Beta-catenin gene (CTNNB1) or the adenomatous polyposis coli gene (APC) mutation. The most appropriate treatment approach is watchful waiting with periodic follow-ups for asymptomatic patients. However, symptomatic patients who are not good candidates for surgery due to high morbidity risk may benefit from medical therapy. The new drugs targeting programmed cell death protein 1 (PD-1) and programmed death-ligand 1 (PD-L1) display promising results in many cancer types. This study assessed the PD-L1 status of desmoid tumors in 18 patients.Biopsy and resection materials of 18 patients diagnosed with desmoid tumors between April 2016 and April 2021 were retrieved and assessed for PD-L1 expression. The prepared slides were immunohistochemically stained with PD-L1 antibody using Leica Bond® automated immunohistochemistry stainer.No positive PD-L1 staining of the desmoid tumor cells was detected in any specimens. Intratumoral lymphocytes were present in all specimens. However, five of them were positively stained for PD-L1.Based on the results of our study, anti-PD-1/PD-L1 therapy may not be a valuable option in desmoid tumor treatment due to the lack of expression of PD-L1 by desmoid tumor cells. Nevertheless, the presence of positively stained intratumoral lymphocytes may warrant further studies.

APC mutation correlated with poor response of immunotherapy in colon cancer

ObjectiveAPC (adenomatous polyposis coli) gene mutation is a central initialization in colon cancer tumorigenesis. However, the connection between APC gene mutation and immunotherapy efficacy for colon cancer remains unknown. This study aimed to explore the impact of APC mutation on immunotherapy efficacy for colon cancer.MethodsColon cancer data from The Cancer Genome Atlas (TCGA) and Memorial Sloan Kettering Cancer Center (MSKCC) were used for the combined analysis. Survival analysis was performed to evaluate the association between APC mutation and immunotherapy efficacy in colon cancer patients. The expressions of immune check point molecules, tumor mutation burden (TMB), CpG methylation level, tumor purity (TP), microsatellite instability (MSI) status and tumor-infiltrating lymphocyte (TIL) in the two APC status were compared to evaluate the associations between APC mutation and immunotherapy efficacy indicators. Gene set enrichment analysis (GSEA) was performed to identify signaling pathways related to APC mutation.ResultsAPC was the most frequently mutated gene in colon cancer. The survival analysis demonstrated that APC mutation was correlated with a worse immunotherapy outcome. APC mutation was associated with lower TMB, lower expression of immune check point molecules (PD-1/PD-L1/PD-L2), higher TP, lower MSI-High proportion and less CD8 + T cells and follicular helper T cells infiltration. GSEA indicated that APC mutation up-regulated mismatch repair pathway, which may play a negative role in evoking an antitumor immune response.ConclusionAPC mutation is associated with worse immunotherapy outcome and inhibition of antitumor immunity. It can be used as a negative biomarker to predict immunotherapy response.

To Identify Adenomatous Polyposis Coli Gene Mutation as a Predictive Marker of Endometrial Cancer Immunotherapy

The adenomatous polyposis coli (APC) gene is the chromatin-remodeling-related gene and a typical tumor suppressor. Patients with a high expression of programmed death-ligand 1 (PD-L1) or a high level of tumor mutational burden (TMB) may benefit from immunotherapy in endometrial cancer (EC). This study aimed to demonstrate the role of APC in the diagnosis and immunotherapy treatment of EC. We performed an integrative analysis of a commercial panel including 520 cancer-related genes on 99 tumors from an endometrial cancer cohort in China and DNA-seq data from The Cancer Genome Atlas (TCGA) to identify new gene mutations as endometrial cancer immunotherapy markers. We found that the significant mutant genes that correlated with the PD-L1 expression and TMB were related to the chromatin state and generated a discovery set having 12 mutated genes, including the APC gene, which was identified as a new marker for immunotherapy. Further analysis revealed that tumors with the APC mutation had high TMB, increased expression of PD-L1, and increased lymphocytic infiltration. Next, we verified that APC has an inactive mutation in EC, which may affect the immune response, including PD-L1 expression, microsatellite instability, and lymphocytic infiltrate. Furthermore, patients with the APC mutation had longer overall survival. Our study demonstrates that APC could play an important role in enhancing the response to endometrial cancer treatment, particularly immunotherapy.

Identification of APC Mutation as a Potential Predictor for Immunotherapy in Colorectal Cancer.

To date, anticancer immunotherapy has presented some clinical benefits to most of advanced mismatch repair deficient (dMMR)/microsatellite instability-high (MSI-H) colorectal cancer (CRC) patients. In addition to MSI status, we aimed to reveal the potential predictive value of adenomatous polyposis coli (APC) gene mutations in CRC patients. A total of 238 Chinese CRC patients was retrospectively identified and analyzed for clinical features and gene alternations in APC-mutant type (MT) and APC-wild-type (WT) groups. Clinical responses were then evaluated from the public TCGA database and MSKCC immunotherapy database. Although programmed cell death ligand 1 (PD-L1) level, MSI status, loss of heterogeneity at the human leukocyte antigen (HLA LOH), and tumor neoantigen burden (TNB) level were not statistically different between the APC-MT group and APC-WT group, tumor mutation burden (TMB) level was significantly higher in APC-MT patients (P < 0.05). Furthermore, comutation analysis for APC mutations revealed co-occurring genomic alterations of PCDHB7 and exclusive mutations of CTNNB1, BRAF, AFF3, and SNX25 (P < 0.05). Besides, overall survival from MSKCC-CRC cohort was longer in the APC-WT group than in the APC-MT group (HR 2.26 (95% CI 1.05–4.88), P < 0.05). Furthermore, most of patients in the APC-WT group were detected as high-grade immune subtypes (C2–C4) comparing with those in the APC-MT group. In addition, the percentages of NK T cells, Treg cells, and fibroblasts cells were higher in APC-WT patients than in APC-MT patients (P < 0.05). In summary, APC mutations might be associated with poor outcomes for immunotherapy in CRC patients regardless of MSI status. This study suggested APC gene mutations might be a potential predictor for immunotherapy in CRC.

Three Novel Mutations of APC Gene Found in A Chinese Family with Familial Adenomatous Polyposis

Objective: To identify the causative adenomatous polyposis coli (APC) gene defects associated with a pedigree of familial adenomatous polyposis (FAP). Methods: FAP was diagnosed based on clinical manifestations, family history, as well as endoscopic and pathological examinations. The blood samples of the FAP pedigree members, colonic polyp patients, and normal individuals were collected. Genomic DNA was then extracted from those samples. APC mutation analysis was conducted via direct polymerase chain reaction (PCR) sequencing. Results: Three synonymous mutations and a missense mutation were found: c.5034G&gt;A (p.Gly1678Gly), c.5465T&gt;A (p.Val1822Asp), c.5880G&gt;A (p.Pro1960Pro), and c.5274T&gt;G (p.Ser1758Ser). Among them, the homozygous mutation on APC gene c.5034G&gt;A has been reported, while the other three mutations have not been reported in the Chinese Han population. Individuals with c.5465T&gt;A (p.Val1822ASP) missense mutation eventually suffer from colon cancer and have poor prognosis. We found no mutation in patients with simple intestinal polyp and in normal individuals. In addition, there were homozygous and heterozygous mutations in different patients from the same family. Conclusion: Three new mutations of APC gene were firstly reported in Han population. The missense mutation of c.5465T&gt;A (p.Val1822Asp) may be the cause of carcinogenesis in this FAP pedigree with poor prognosis.

The clinical significance of adenomatous polyposis coli (APC) and catenin Beta 1 (CTNNB1) genetic aberrations in patients with melanoma

BackgroundMelanoma-intrinsic activated β-catenin pathway, the product of the catenin beta 1 (CTNNB1) gene, has been associated with low/absent tumor-infiltrating lymphocytes, accelerated tumor growth, metastases development, and resistance to anti-PD-L1/anti-CTLA-4 agents in mouse melanoma models. Little is known about the association between the adenomatous polyposis coli (APC) and CTNNB1 gene mutations in stage IV melanoma with immunotherapy response and overall survival (OS).MethodsWe examined the prognostic significance of somatic APC/CTNNB1 mutations in the Cancer Genome Atlas Project for Skin Cutaneous Melanoma (TCGA-SKCM) database. We assessed APC/CTNNB1 mutations as predictors of response to immunotherapies in a clinicopathologically annotated metastatic patient cohort from three US melanoma centers.ResultsIn the TCGA-SKCM patient cohort (n = 434) presence of a somatic APC/CTNNB1 mutation was associated with a worse outcome only in stage IV melanoma (n = 82, median OS of APC/CTNNB1 mutants vs. wild-type was 8.15 vs. 22.8 months; log-rank hazard ratio 4.20, p = 0.011). APC/CTNNB1 mutation did not significantly affect lymphocyte distribution and density. In the 3-melanoma institution cohort, tumor tissues underwent targeted panel sequencing using two standards of care assays. We identified 55 patients with stage IV melanoma and APC/CTNNB1 genetic aberrations (mut) and 169 patients without (wt). At a median follow-up of more than 25 months for both groups, mut compared with wt patients had slightly more frequent (44% vs. 39%) and earlier (66% vs. 45% within six months from original diagnosis of stage IV melanoma) development of brain metastases. Nevertheless, time-to-development of brain metastases was not significantly different between the two groups. Fortunately, mut patients had similar clinical benefits from PD-1 inhibitor-based treatments compared to wt patients (median OS 26.1 months vs. 29.9 months, respectively, log-rank p = 0.23). Less frequent mutations in the NF1, RAC1, and PTEN genes were seen in the mut compared with wt patients from the 3-melanoma institution cohort. Analysis of brain melanoma tumor tissues from a separate craniotomy patient cohort (n = 55) showed that melanoma-specific, activated β-catenin (i.e., nuclear localization) was infrequent (n = 3, 6%) and not prognostic in established brain metastases.ConclusionsAPC/CTNNB1 mutations are associated with a worse outcome in stage IV melanoma and early brain metastases independent of tumor-infiltrating lymphocyte density. However, PD1 inhibitor-based treatments provide comparable benefits to both mut and wt patients with stage IV melanoma.

Canonical Wnt Signaling Drives Myopia Development and Can Be Pharmacologically Modulated.

PurposeThe purpose of this study was to evaluate the role of the canonical Wnt signaling in the development of the myopia.MethodsPlasma from adult patients with myopia, myopic animal models including the adenomatous polyposis coli (APC) gene mutation mouse model, and the form deprivation (FD) induced mouse model of myopia were used. Niclosamide, a canonical Wnt pathway inhibitor, was orally administrated in animal models. Plasma levels of DKK-1 were determined by using enzyme-linked immunosorbent assay. Refraction, vitreous chamber depth (VCD), axial length (AL), and other parameters, were measured at the end of the FD treatment. Canonical Wnt signaling changes were evaluated by Western blot analysis and immunostaining analysis.ResultsPlasma level of Wnt inhibitor DKK-1 was markedly decreased in patients with myopia. Meanwhile, the canonical Wnt pathway was progressively activated during myopia development in mice. Moreover, inhibition of canonical Wnt signaling by niclosamide in mouse models markedly reduced lens thickness (LT), VCD, and AL elongation, resulting in myopia inhibition.ConclusionsDysregulation of canonical Wnt signaling is a characteristic of myopia and targeting Wnt signaling pathways has potential as a therapeutic strategy for myopia.

Mutational screening through comprehensive bioinformatics analysis to detect novel germline mutations in the APC gene in patients with familial adenomatous polyposis (FAP).

BackgroundFamilial adenomatous polyposis (FAP) as a colon cancer predisposition syndrome is an autosomal‐dominant inherited condition and is diagnosed by the progress of hundreds or thousands of adenomatous colonic polyps in the colon. This study aims at the nature and effect of Adenomatous Polyposis Coli (APC) gene mutations in FAP tumorigenesis.MethodsThe genetic screening of 59 FAP Iranian patients in 10 families was performed by polymerase chain reactions and the direct sequencing of the entire coding exons of the APC gene. To do linkage haplotype analysis and multiplex PCR‐based microsatellite examination, six short tandem repeat loci were selected in this gene. To evaluate and predict the potentially deleterious effects, comprehensive bioinformatics pathogenicity assays were used.ResultsA total of 12 germline heterozygous and homozygous nucleotide variations were identified. They included two missense mutations, four nonsense mutations, which would lead to the truncated and nonfunctional protein products, four synonymous or silent variations, and two nucleotide deletions of 1 to 5 bp or frameshift mutations. In addition, three novel heterozygous nonsense mutations were found in exons 10, 14, and 15 of the gene. There was also p.Arg653Met as a novel heterozygote mutation in exon 14 of the gene.ConclusionsBioinformatics analysis and three‐dimensional structural modeling predicted that these missense and nonsense mutations generally are associated with the deleted or truncated domains of APC and have functional importance and mainly affected the APC protein. These findings may provide evidence for the progress of potential biomarkers and help to understand the role of the APC gene in FAP.

Lipid profiling of mouse intestinal organoids for studying APC mutations.

Inactivating mutations including both germline and somatic mutations in the adenomatous polyposis coli (APC) gene drives most familial and sporadic colorectal cancers. Understanding the metabolic implications of this mutation will aid to establish its wider impact on cellular behaviour and potentially inform clinical decisions. However, to date, alterations in lipid metabolism induced by APC mutations remain unclear. Intestinal organoids have gained widespread popularity in studying colorectal cancer and chemotherapies, because their 3D structure more accurately mimics an in vivo environment. Here, we aimed to investigate intra-cellular lipid disturbances induced by APC gene mutations in intestinal organoids using a reversed-phase ultra-high-performance liquid chromatography mass spectrometry (RP-UHPLC-MS)-based lipid profiling method. Lipids of the organoids grown from either wild-type (WT) or mice with APC mutations (Lgr5–EGFP-IRES-CreERT2 Apcfl/fl) were extracted and analysed using RP-UHPLC-MS. Levels of phospholipids (e.g. PC(16:0/16:0), PC(18:1/20:0), PC(38:0), PC(18:1/22:1)), ceramides (e.g. Cer(d18:0/22:0), Cer(d42:0), Cer(d18:1/24:1)) and hexosylceramides (e.g. HexCer(d18:1/16:0), HexCer(d18:1/22:0)) were higher in Apcfl/fl organoids, whereas levels of sphingomyelins (e.g. SM(d18:1/14:0), SM(d18:1/16:0)) were lower compared with WT. These observations indicate that cellular metabolism of sphingomyelin was up-regulated, resulting in the cellular accumulation of ceramides and production of HexCer due to the absence of Apcfl/fl in the organoids. Our observations demonstrated lipid profiling of organoids and provided an enhanced insight into the effects of the APC mutations on lipid metabolism, making for a valuable addition to screening options of the organoid lipidome.

APC c.4621C>T variant causing Gardner's syndrome in a Han Chinese family may be inherited through maternal mosaicism.

Gardner's syndrome is a rare autosomal dominant hereditary disease that is characterized by multiple colorectal polyps combined with extra-colonic presentation (such as osteoma or desmoid tumors) of familial adenomatous polyposis syndrome. Gardner's syndrome is caused by the mutation of the adenomatous polyposis coli (APC) gene, which is located at 5q21. The aim of the current study was to investigate the APC gene mutations present in a Han Chinese family diagnosed with Gardner's syndrome. The 38-year-old proband presented with clinical symptoms, and was later diagnosed with Gardner's syndrome. Genomic DNA was extracted from the peripheral venous blood of 150 normal controls as well as the family members of the proband. Analysis of the respective APC gene sequences was performed using PCR amplification and Sanger sequencing. Pathogenesis associated with the APC mutation was investigated using reverse-transcription quantitative PCR and determined through bioinformatics approaches. Haplotype analysis was performed to identify the genetic source of the mutation(s). In the initial screening for APC variants, the APC c.4621C>T variant was detected in the proband and his son, but was not detected in the proband's affected mother. The mRNA expression changed significantly according to age and the presence of the mutation in the blood of the patients. Haplotype analysis suggested the presence of maternal mosaicism for this mutation. Haplotype analysis revealed that the APC c.4621C>T variant in a patient with Gardner's syndrome was most likely derived from his mother through mosaicism. These results indicate the necessity to verify the possibility of gonadal mosaicism when a proband diagnosed with Gardner's syndrome appears to exhibit a de novo mutation.

A perspective on medicinal chemistry approaches towards adenomatous polyposis coli and Wnt signal based colorectal cancer inhibitors.

Colorectal cancer (CRC) is one of the major causes of carcinogenic mortality in numbers only after lung and breast cancers. The mutations in adenomatous polyposis coli (APC) gene leads to formation of colorectal polyps in the colonic region and which develop as a malignant tumour upon coalition with patient related risk factors. The protein-protein interaction (PPI) of APC with Asef (A Rac specific guanine nucleotide exchange factor) overwhelms the patient's conditions by rapidly spreading in the entire colorectal region. Most mutations in APC gene occur in mutated cluster region (MCR), where it specifically binds with the cytosolic β-catenin to regulate the Wnt signalling pathway required for CRC cell adhesion, invasion, progression, differentiation and stemness in initial cell cycle phages. The current broad spectrum perspective is attempted to elaborate the sources of identification, development of selective APC inhibitors by targeting emopamil-binding protein (EBP) & dehydrocholesterol reductase-7 & 24 (DHCR-7 & 24); APC-Asef, β-catenin/APC, Wnt/β-catenin, β-catenin/TCF4 PPI inhibitors with other vital Wnt signal cellular proteins and APC/Pol-β interface of colorectal cancer. In this context, this perspective would serve as a platform for design of new medicinal agents by targeting cellular essential components which could accelerate anti-colorectal potential candidates.

Canonical Wnt Signaling Drives Myopia Development and Can Be Pharmacologically Modulated

Background: Myopia has emerged as a major health issue in the world, due to the sight-threatening pathologies associated with high myopia. Even though previous studies have implicated that myopia is determined by a complex interaction of environmental and genetic factors, the pathogenesis of this disease remains unclear. Methods: Here we utilized plasma from patients with myopia, myopic animal models including the adenomatous polyposis coli (APC) gene mutation mouse model, and the form deprivation induced mouse model of myopia. Findings: Using these systems, we demonstrated that the over-activation of canonical Wnt pathway is associated with myopia. Moreover, inhibition of canonical Wnt signaling in mouse models markedly reduced axial elongation, resulting in myopia regression. Interpretation: Together, these results suggest that dysregulation of canonical Wnt signaling is a characteristic of myopia and suggest that targeting Wnt signaling pathways has potential as a therapeutic strategy for myopia. Funding Statement: This study was supported by the Natural Science Foundation of Fujian (No. 2019J05007, ZL); National Basic Research Program of China (Project 973) (No.2011CB50460); National Key Program of China (No. 2018YFA0107304); and National Natural Science Foundation of China (No.81870627). Declaration of Interests: The authors declare no conflicts of interest. Ethics Approval Statement: Approval was received from the Human Ethics committee of Xiamen Eye Center Affiliated to Xiamen University, in accordance with the Declaration of Helsinki. Informed consents were obtained from all subjects after explanation of the nature and possible consequences of the study. Mice were used, treated, and cared for in accordance with the ARVO Statement for the Use of Animals in Ophthalmic and Vision Research and the Guidelines of the Animal Experimental Committee of Xiamen University.

Lower Rate of CTNNB1 Mutations and Higher Rate of APC Mutations in Desmoid Fibromatosis of the Breast: A Series of 134 Tumors.

Desmoid fibromatosis (DF) is a rare, locally aggressive, nonmetastasizing fibroblastic/myofibroblastic tumor with a tendency to recur and an unpredictable clinical course. A "wait-and-see" policy is the new standard of care. DF are characterized by activating alterations of the wnt/β-catenin pathway: CTNNB1 or adenomatous polyposis coli gene (APC) mutations (these mutations being mutually exclusive). Desmoid-type fibromatosis of the breast (DFB) is rare with an incidence of 0.2% of breast tumors. The diagnosis of DFB is difficult, as it must be distinguished from metaplastic carcinoma and other spindle cell lesions. Sequencing of 128 DFB identified a lower rate of CTNNB1 mutations using Sanger (65.6%) or Sanger+next-generation sequencing (77.7%) and a higher rate of APC mutations (11.8%) than in all-site DF. By excluding patients with familial adenomatous polyposis (n=2), the rate of APC mutations in DFB was high (10.7%). The distribution of CTNNB1 mutations in DFB was different from all-site DF, with a higher rate of T41A (68.9%), a lower rate of S45F (5.7%), and a similar rate of S45T (12.6%). By combining the 2 molecular techniques in a 2-step manner (Sanger, then next-generation sequencing), we increased the detection rate of CTNNB1 mutations and lowered the rate of wild-type tumors from 34.4% to 9.8%, therefore improving the diagnosis of DFB. The identification of the exon 3 CTNNB1 mutation in breast spindle cell lesions is a highly specific tool for the diagnosis of DFB, in addition to extensive immunohistochemical analysis. Our study also underlines the importance of APC in DFB tumorigenesis. These findings have significant implications for patient care and management.

The fluctuation of APC gene in WNT signaling with adenine deletion of adenomatous polyposis coli, is associated in colorectal cancer

Colorectal cancer is one of the most important malignancies in the classification of gastrointestinal cancers. One of the predisposing factors at molecular level for this cancer is via WNT signaling which is associated with the vast numbers of different genes. Thus, in this study, we aimed to investigate whether Adenomatous Polyposis Coli gene (APC) mutation of rs41115in two locations such as 132.002 and 131.989 acts as a trigger or cause of colorectal cancer. Relatively, 30 blood samples of colorectal cancer patients and 30 normal blood samples as control group after colonoscopy and also confirmation of pathology report at Rohani Hospital in Babol (Iran) were investigated. The primers were designed in order to be included the rs41115 to identify the particular polymorphisms of gene. The polymerase chain reaction (PCR direct sequencing method) was used. Conclusively, deletion of adenine in two specific locations such as 131.989 and 132.002 has been identified, but there was no relationship between rs41115 polymorphisms located in adenomatous polyposis coli gene and colorectal cancer.

A novel mouse model of sporadic colon cancer induced by combination of conditional Apc genes and chemical carcinogen in the absence of Cre recombinase.

Although valuable insights into colon cancer biology have been garnered from human colon cancer cell lines and primary colonic tissues, and animal studies using human colon cancer xenografts, immunocompetent mouse models of spontaneous or chemically induced colon cancer better phenocopy human disease. As most sporadic human colon tumors present adenomatous polyposis coli (APC) gene mutations, considerable effort has gone into developing mice that express mutant Apc alleles that mimic human colon cancer pathogenesis. A serious limitation of many of these Apc-mutant murine models, however, is that these mice develop numerous tumors in the small intestine but few, if any, in the colon. In this work, we examined three spontaneous mouse models of colon tumorigenesis based upon the widely used multiple intestinal neoplasia (Min) mouse: mice with either constitutive or conditional Apc mutations alone or in combination with caudal-related homeobox transcription factor CDX2P-Cre transgene - either with or without exposure to the potent colon carcinogen azoxymethane. Using the CDX2 promoter to drive Cre recombinase transgene expression effectively inactivated Apc in colonocytes, creating a model with earlier tumor onset and increased tumor incidence/burden, but without the Min mouse model's small intestine tumorigenesis and susceptibility to intestinal perforation/ulceration/hemorrhage. Most significantly, azoxymethane-treated mice with conditional Apc expression, but absent the Cre recombinase gene, demonstrated nearly 50% tumor incidence with two or more large colon tumors per mouse of human-like histology, but no small intestine tumors - unlike the azoxymethane-resistant C57BL/6J-background Min mouse model. As such this model provides a robust platform for chemoprevention studies.