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Objective: Although immune checkpoint blockade (ICB) therapy represents a bright spot in antitumor immunotherapy, its clinical benefits in colorectal cancer (CRC) are limited. Therefore, a new target for mediating CRC immunosuppression is urgently needed. Adenomatous polyposis coli (APC) mutations have been reported as early-stage characteristic events in CRC, but the role of truncated APC in the CRC immune microenvironment remains unclear and its clinical significance has yet to be explored., Design: Adenocarcinoma formation in the colon of the APC Min/+ mouse model, which displays features associated with the translation of truncated APC proteins, was induced by azoxymethane/dextran sodium sulfate. Multiplexed immunohistochemical consecutive staining on single slides and flow cytometry were used to explore the activation of immune cells and the expression of the immune checkpoint V-domain immunoglobulin suppressor of T-cell activation (VISTA) in the CRC tissues of APC WT and APC Min/+ mice. The construction of truncated APC vectors and an initial subserosal graft tumor mouse model was employed to mimic the tumor microenvironment (TME) during APC mutation. Methylated RNA immunoprecipitation-quantitative PCR assays were performed to investigate the N6-methyladenosine (m6A)-dependent transcriptional regulation of hypoxia-inducible factor-1 alpha (HIF1α) by methyltransferase-like protein 3 (METTL3). Mettl3 fl/fl vil1-cre +/- mice were used to demonstrate that targeting METTL3 is a mediator that mitigates the deleterious effects of the APC978∆-HIF1α axis on antitumor immunity. A chimeric VISTA humanized mouse model was used to evaluate the drug efficacy of the VISTA-targeted compound onvatilimab., Results: We showed that APC978∆, a truncated APC protein, mediated overexpression of METTL3, resulting in m6A methylation of HIF1α messenger RNA and high expression of HIF1α. Furthermore, HIF1α promotes the migration of myeloid-derived suppressor cells to the TME by binding to the promoters of MCP-1 and MIF. In addition, HIF1α enhances the expression of the immune checkpoint VISTA on CRC cells, weakening tumor immune monitoring., Conclusions: We elucidate that an underappreciated function of truncated APC in CRC is its ability to drive an immunosuppressive program that boosts tumor progression. Our work could provide a new perspective for the clinical application of immunotherapy in patients with CRC resistant to ICB therapy., Competing Interests: Competing interests: No, there are no competing interests., (© Author(s) (or their employer(s)) 2024. Re-use permitted under CC BY-NC. No commercial re-use. See rights and permissions. Published by BMJ.)

Objective: Sevoflurane (Sevo), a commonly used inhalant anesthetic clinically, is associated with a worsened cancer prognosis, and we investigated its effect on RNA methylase tRNA aspartic acid methyltransferase 1 (TRDMT1) expression and ovarian cancer (OC) cell malignant phenotypes., Methods: Human OC cells (OVCAR3/SKOV3) were pretreated with 3.6% Sevo and cultured under normal conditions for 48 h, with their viability assessed. After 2-h Sevo treatment or interference plasmid transfections to down-regulate TRDMT1/adenomatous polyposis coli (APC), changes in TRDMT1, APC and β-catenin expression, cell proliferative activity, cycle, apoptosis, migration, invasion, and 5-methylcytosine (m5C) methylation potential modification sites were evaluated. Additionally, APC mRNA m5C methylation level and stability, the binding of APC mRNA with TRDMT1, the binding intensity of APC and β-catenin, and β-catenin nuclear translocation were detected Lastly, Cyclin D1, cellular-myelocytomatosis viral oncogene (C-myc) and β-catenin protein levels, and ki67-positive rate were assessed., Results: Sevo treatment boosted cell cycle, proliferation, migration and invasion, suppressed apoptosis and APC expression, and up-regulated C-myc, β-catenin, TRDMT1 and Cyclin D1 levels. Silencing TRDMT1 or β-catenin partially averted Sevo-mediated promotion effects on cell malignant biological behaviors. Lowly-expressed APC annulled the effect of silencing TRDMT1 and promoted cell malignant behaviors. Sevo enhanced APC mRNA m5C modification and degradation and activated the APC/β-catenin pathway by increasing TRDMT1, thus encouraging OC growth in vivo., Conclusions: Sevo stimulated APC m5C modification and curbed its expression by up-regulating TRDMT1, which in turn activated the β-catenin pathway to stimulate OC cell cycle, invasion, proliferation, and migration and to suppress apoptosis., Competing Interests: Declarations. Ethics approval: All animal experiments were approved by the ethics committee of The Third Bethune Hospital of Jilin University. Considerable efforts were conducted to minimize the animal number and their pain. Consent for publication: Not applicable. Competing interests: The authors declare no competing interests., (© 2024. The Author(s).)

Background/aim: Desmoid tumors (DTs), or aggressive fibromatosis, are rare neoplasms arising from connective tissue, frequently exhibiting local invasiveness. The limited treatment options and high recurrence rates of DTs highlight the need for novel therapeutic strategies. This study investigated the efficacy of chlorhexidine dihydrochloride (CD) in inhibiting the growth of DTs and colorectal cancer (CRC)., Materials and Methods: A mouse model with Apc mutations, specifically Apc 1638N/+ , was generated to study DTs. DT cells (Apc 1638N+ ) (DTA) were collected from the mice for in vitro experiments. DTA were treated with CD, along with a CRC cell line (HCT-116), and tumor organoids derived from Apc 1638N/+ mice. The effects of CD were assessed through cell viability assay (WST assay), colony formation assay, and cell migration assay. We tested the induction of cell apoptosis through caspase 3/7 activity assays and immunoblot analysis of cleaved-caspase 3 and cleaved-PARP1. Additionally, CD was tested for its anti-tumor efficacy using an in vivo CRC xenograft model with the HCT-116 cell line., Results: CD significantly inhibited the viability, migration, and colony formation of DTA and CRC cells. It remarkably decreased the tumor growth in organoids derived from intestinal tumor cells in the Apc 1638N/+ mouse model. Furthermore, CD showed anti-tumor effects in an in vivo CRC xenograft model using the HCT-116 cell line., Conclusion: CD represents a promising therapeutic strategy for treating both DTs and CRC., (Copyright © 2024 International Institute of Anticancer Research (Dr. George J. Delinasios), All rights reserved.)

Background/aim: Desmoid tumors (DTs), also referred to as aggressive fibromatosis, originate from connective tissues and typically manifest with a propensity for local invasion. Despite extensive research efforts aimed at exploring novel anti-tumor agents for DTs, the development of effective clinical management strategies remains an ongoing challenge due to the limited success of current treatments, which frequently lead to inconsistent outcomes and a high recurrence rate of DTs. To overcome these limitations, we focused our research aim on a drug repositioning approach to identify existing medications that could be effective against DTs., Materials and Methods: Mouse models with Apc mutations, specifically Apc 1638N/+ and Apc 1638N/+ /Trp53 -/- , were generated to study DTs. Primary desmoid cells were isolated from these models for experimental analysis. Idarubicin hydrochloride (IDH), a topoisomerase II (TOPO II) inhibitor, was tested on these primary cells, colorectal cancer (CRC) cell lines, and tumor organoids derived from Apc 1638N/+ mice. Cell viability was determined with the WST reagent and colony formation assay was evaluated. The anti-tumor efficacy of IDH was tested in an in vivo CRC xenograft model using HCT-116 cells., Results: The TOPO II inhibitor IDH showed significant growth inhibition effects on Apc 1638N/+ and Apc 1638N/+ /Trp53 -/- cells. IDH also showed remarkable anti-tumor effects on CRC cell lines and tumor organoids derived from intestinal tumor cells of the Apc 1638N/+ mouse model. Furthermore, IDH exerted dramatic anti-tumor effects on an HCT-116 cell line xenograft mouse model., Conclusion: IDH could be a promising therapeutic agent for inhibiting DTs and CRC by targeting TOPO II., (Copyright © 2024 International Institute of Anticancer Research (Dr. George J. Delinasios), All rights reserved.)

The contribution of deubiquitylating enzymes (DUBs) to β-Catenin stabilization in intestinal stem cells and colorectal cancer (CRC) is poorly understood. Here, and by using an unbiassed screen, we discovered that the DUB USP10 stabilizes β-Catenin specifically in APC-truncated CRC in vitro and in vivo. Mechanistic studies, including in vitro binding together with computational modelling, revealed that USP10 binding to β-Catenin is mediated via the unstructured N-terminus of USP10 and is outcompeted by intact APC, favouring β-catenin degradation. However, in APC-truncated cancer cells USP10 binds to β-catenin, increasing its stability which is critical for maintaining an undifferentiated tumour identity. Elimination of USP10 reduces the expression of WNT and stem cell signatures and induces the expression of differentiation genes. Remarkably, silencing of USP10 in murine and patient-derived CRC organoids established that it is essential for NOTUM signalling and the APC super competitor-phenotype, reducing tumorigenic properties of APC-truncated CRC. These findings are clinically relevant as patient-derived organoids are highly dependent on USP10, and abundance of USP10 correlates with poorer prognosis of CRC patients. Our findings reveal, therefore, a role for USP10 in CRC cell identity, stemness, and tumorigenic growth by stabilising β-Catenin, leading to aberrant WNT signalling and degradation resistant tumours. Thus, USP10 emerges as a unique therapeutic target in APC truncated CRC., Competing Interests: Competing interests: MED is associated editor at Oncogene. Consent for publication: We have obtained consent to publish this paper from all the study participants., (© 2024. The Author(s).)

This study investigated the neurodevelopmental impact of pathogenic adenomatous polyposis coli (APC) gene variants in patients with familial adenomatous polyposis (FAP), a cancer predisposition syndrome. We hypothesized that certain pathogenic APC variants result in behavioral-cognitive challenges. We compared 66 FAP patients (cases) and 34 unaffected siblings (controls) to explore associations between APC variants and behavioral and cognitive challenges. Our findings indicate that FAP patients exhibited higher Social Responsiveness Scale (SRS) scores, suggesting a greater prevalence of autistic traits when compared to unaffected siblings (mean 53.8 vs. 47.4, Wilcoxon p = 0.018). The distribution of SRS scores in cases suggested a bimodal pattern, potentially linked to the location of the APC variant, with scores increasing from the 5' to 3' end of the gene (Pearson's r = 0.33, p = 0.022). While we observed a trend toward lower educational attainment in cases, this difference was not statistically significant. This study is the first to explore the connection between APC variant location and neurodevelopmental traits in FAP, expanding our understanding of the genotype-phenotype correlation. Our results emphasize the importance of clinical assessment for autistic traits in FAP patients, shedding light on the potential role of APC gene variants in these behavioral and cognitive challenges., (© 2024 The Author(s). American Journal of Medical Genetics Part B: Neuropsychiatric Genetics published by Wiley Periodicals LLC.)

Wnt signaling pathway activation is involved in the pathogenesis of a series of malignant tumors and is characterized by the nuclear accumulation of β-catenin protein. The occurrence of two or more Wnt pathway-associated tumors in a single individual is uncommon and generally attributed to inherited cancer syndrome, especially familial adenomatous polyposis (FAP). Herein, we presented a rare case of a child who suffered from the occurrence of Wnt-activated medulloblastoma and cribriform-morular thyroid carcinoma (CMTC) within a 9-year interval. She had no history of FAP and harbored an unexpected somatic mutation of the APC gene in the CMTC tumor. The potential agents involved in the pathogenesis of the two molecular-linked tumors other than FAP were discussed in this report., Competing Interests: Declaration of Conflicting InterestsThe authors declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article.

Translational initiation in protein synthesis is an important regulatory step in gene expression and its dysregulation may result in diseases such as cancer. Translational control by eIF4E/4E-BP has been well studied and contributes to mTOR signaling in various biological processes. Here, we report a novel translational control axis in the Wnt/β-catenin signaling pathway in colon tumorigenesis by eIF3a, a Yin-Yang factor in tumorigenesis and prognosis. We show that eIF3a expression is upregulated in human colon cancer tissues, pre-cancerous adenoma polyps, and associates with β-catenin level and APC mutation in human samples, and that eIF3a overexpression transforms intestinal epithelial cells. We also show that eIF3a expression is regulated by the Wnt/β-catenin signaling pathway with an active TCF/LEF binding site in its promoter and that eIF3a knockdown inhibits APC mutation-induced spontaneous colon tumorigenesis in APC min/+ mice. Together, we conclude that eIF3a upregulation in colon cancer is due to APC mutation and it participates in colon tumorigenesis by adding a translational control axis in the Wnt/β-catenin signaling pathway and that it can serve as a potential target for colon cancer intervention., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 The Authors. Published by Elsevier B.V. All rights reserved.)

Familial adenomatous polyposis and Lynch syndrome represent two different molecular pathways of colorectal carcinogenesis that are commonly considered mutually exclusive: chromosomal instability and microsatellite instability. Here, we report a rare case of familial adenomatous polyposis in an adult male with Lynch-like syndrome. A 46-year-old male patient was found to have hundreds of adenomatous polyps throughout the whole intestine, and irregular masses in rectum, sigmoid and transverse colon. Genetic test showed that the patient carried pathogenic germline APC (c.423-1G>A) variant and two variants of uncertain significance in MLH1 (p.R725H) and PTCH1 (p.S438N), combined with tumor characteristics of somatic AKT1/PIK3CA/KRAS co-mutations, microsatellite instability and high tumor mutation burden. The patient underwent laparoscopic total colectomy with abdominoperineal resection and end ileostomy, then received 4 cycles adjuvant chemotherapy of oxaliplatin with capecitabine. This patient was followed up to April 2024 and performed well without abnormalities in serum cancer biomarkers and radiological examinations.

Pathogenic constitutional APC variants underlie familial adenomatous polyposis, the most common hereditary gastrointestinal polyposis syndrome. To improve variant classification and resolve the interpretative challenges of variants of uncertain significance (VUSs), APC-specific variant classification criteria were developed by the ClinGen-InSiGHT Hereditary Colorectal Cancer/Polyposis Variant Curation Expert Panel (VCEP) based on the criteria of the American College of Medical Genetics and Genomics and the Association for Molecular Pathology (ACMG/AMP). A streamlined algorithm using the APC-specific criteria was developed and applied to assess all APC variants in ClinVar and the International Society for Gastrointestinal Hereditary Tumours (InSiGHT) international reference APC Leiden Open Variation Database (LOVD) variant database, which included a total of 10,228 unique APC variants. Among the ClinVar and LOVD variants with an initial classification of (likely) benign or (likely) pathogenic, 94% and 96% remained in their original categories, respectively. In contrast, 41% ClinVar and 61% LOVD VUSs were reclassified into clinically meaningful classes, the vast majority as (likely) benign. The total number of VUSs was reduced by 37%. In 24 out of 37 (65%) promising APC variants that remained VUS despite evidence for pathogenicity, a data-mining-driven work-up allowed their reclassification as (likely) pathogenic. These results demonstrated that the application of APC-specific criteria substantially reduced the number of VUSs in ClinVar and LOVD. The study also demonstrated the feasibility of a systematic approach to variant classification in large datasets, which might serve as a generalizable model for other gene- or disease-specific variant interpretation initiatives. It also allowed for the prioritization of VUSs that will benefit from in-depth evidence collection. This subset of APC variants was approved by the VCEP and made publicly available through ClinVar and LOVD for widespread clinical use., Competing Interests: Declaration of interests S.E.P. is a member of the scientific advisory panel of Baylor Genetics Laboratories., (Copyright © 2024 The Author(s). Published by Elsevier Inc. All rights reserved.)

Familial adenomatous polyposis (FAP) is a colorectal cancer (CRC) predisposition syndrome characterized by the presence of numerous colorectal adenomatous polyps, resulting from a single germline, heterozygous, likely pathogenic/pathogenic (LP/P) variant in the APC gene, an important tumor suppressor encoding gene. Classic FAP is considered in individuals with a germline LP/P variant in APC and have ≥100 colorectal adenomatous polyps beginning on average in adolescence, while attenuated FAP typically presents with fewer colorectal adenomatous polyps (10-<100 polyps) in adulthood. Both forms can feature extracolonic manifestations, such as desmoid tumors, thyroid cancer, and osteomas. Reported genotype-phenotype correlations in FAP provide valuable insights for healthcare providers, but variable expressivity persists even among individuals sharing a genotype. In this case study, we report two patients with the same pathogenic APC variant [c.4348C>T, p.Arg1450Ter] and different presentations and clinical findings. Case 1 describes a 21-year-old male with an extensive family history of cancer who was diagnosed with FAP at age 4. Case 2 describes a 22-year-old female with no family history who was diagnosed with FAP after she initially presented with a desmoid tumor. Despite genetic similarities, their clinical courses significantly differed, emphasizing the variable expressivity of FAP. These cases highlight the importance of individual management and surveillance, as genotype alone may not predict clinical outcomes. They also underscore the need for further research into factors that influence FAP expressivity., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Inc. All rights reserved.)

WNT3A is an intestinal ligand triggering the Wnt/β-catenin (Wnt) pathway, which can be enhanced by R-spondin 1 (RSPO1) through the RSPO1-LGR axis or antagonized by the adenomatous polyposis coli (APC) protein supporting β-catenin-degradation. Wnt interplays with several pathways including PI3K/mTOR (mTOR). In this study, we evaluated the influence of WNT3A-commercial and home-made culture media and RSPO1 protein on the Wnt and mTOR interplay in non-APC and APC-mutated intestinal patient-derived organoids (PDOs). Normal mucosa (NM) of sporadic CRC and FAP PDOs were cultured with: WNT3A-lacking/containing commercial (A/A+B) or home-made (BASAL/WNT3A-conditioned medium (CM)±RSPO1) media. In non-APC-mutated-PDOs (CRC-NM), WNT3A-CM, over commercial A+B, strongly activated Wnt-target-genes CCND1 and c-MYC . Most importantly, the addition of RSPO1 to home-made WNT3A-CM or A+B led to the downregulation of the mTOR-downstream-effector phospho-S6 ribosomal protein (p-S6R), highlighting the activation of the RSPO1-pS6R in both non-APC (CRC-NM) and APC-mutated (FAP-NM) PDOs, independently from LGR5 gene expression modulation. Our work demonstrates that home-made WNT3A-CM strongly impacts the crosstalk between Wnt and mTOR over commercial media, and proposes RSPO1 as a key regulator of the RSPO1-p-S6R axis in both non-APC and APC-mutated PDOs. Together, these findings represent an important methodological guide for scientists working in these fields to select the most appropriate intestinal PDO media.

Nonstop extension mutations, a.k.a. stop-lost or stop-loss mutations, convert a stop codon into a sense codon resulting in translation into the 3' untranslated region until the next in-frame stop codon, thereby extending the C-terminus of a protein. In cancer, only nonstop mutations in SMAD4 have been functionally characterized, while the impact of other nonstop mutations remain unknown. Here, we exploit our pan-cancer NonStopDB dataset and test all 2335 C-terminal extensions arising from somatic nonstop mutations in cancer for their impact on protein expression. In a high-throughput screen, 56.1% of the extensions effectively reduce protein abundance. Extensions of multiple tumor suppressor genes like PTEN, APC, B2M, CASP8, CDKN1B and MLH1 are effective and validated for their suppressive impact. Importantly, the effective extensions possess a higher hydrophobicity than the neutral extensions linking C-terminal hydrophobicity with protein destabilization. Analyzing the proteomes of eleven different species reveals conserved patterns of amino acid distribution in the C-terminal regions of all proteins compared to the proteomes like an enrichment of lysine and arginine and a depletion of glycine, leucine, valine and isoleucine across species and kingdoms. These evolutionary selection patterns are disrupted in the cancer-derived effective nonstop extensions., (© 2024. The Author(s).)

Background: Ulcerative colitis (UC) is a chronic inflammatory bowel disease (IBD) that is associated with increased risk of developing colitis-associated carcinoma (CAC). The genetic profile of CACs is fairly similar to the sporadic colorectal carcinomas (sCRCs), although showing certain differences in the timing and sequence of alterations that contribute to carcinogenesis. Also, both cancer types typically show a strong histological resemblance, which complicates the pathologists' diagnosis. Due to the different clinical consequences, it is of utmost importance to categorize the corresponding cancer type correctly., Methods: In this study, we determined the mutation profiles of 64 CACs and sCRCs in the hotspot regions of 50 cancer-associated genes and compared them to 29 controls to identify genetic gene variants that can facilitate the pathologists' diagnosis. Pearson Chi-Square or Fisher's exact tests were used for statistical analyses., Results: We found that sCRCs tend to mutate more frequently in APC and PIK3CA genes than CACs and that mainly males were affected. Our CAC cohort identified the KRAS G12D mutation as group-specific variant that was not detected in the sCRCs. When separating conventional from non-conventional CACs, it was discovered that the conventional type shows significantly more mutations for ATM., Conclusions: Taken together, our data highlights genetic differences between sCRC and CAC and enables the possibility to utilize specific gene alterations to support the pathologist's diagnosis., (© 2024. The Author(s).)

Background: Alternative polyadenylation (APA) affects most human genes and is recurrently dysregulated in all studied cancers. However, the mechanistic origins of this dysregulation are incompletely understood., Results: We describe an unbiased analysis of molecular regulators of poly(A) site selection across The Cancer Genome Atlas and identify that colorectal adenocarcinoma is an outlier relative to all other cancer subtypes. This distinction arises from the frequent presence of loss-of-function APC mutations in colorectal adenocarcinoma, which are strongly associated with long 3' UTR expression relative to tumors lacking APC mutations. APC knockout similarly dysregulates APA in human colon organoids. By mining previously published APC eCLIP data, we show that APC preferentially binds G- and C-rich motifs just upstream of proximal poly(A) sites. Lastly, we find that reduced APC expression is associated with APA dysregulation in tumor types lacking recurrent APC mutations., Conclusions: As APC has been previously identified as an RNA-binding protein that preferentially binds 3' UTRs during mouse neurogenesis, our results suggest that APC promotes proximal poly(A) site use and that APC loss and altered expression contribute to pervasive APA dysregulation in cancers., (© 2024. The Author(s).)

Loss-of-function mutations in the tumour suppressor APC are an initial step in intestinal tumorigenesis 1,2 . APC-mutant intestinal stem cells outcompete their wild-type neighbours through the secretion of Wnt antagonists, which accelerates the fixation and subsequent rapid clonal expansion of mutants 3-5 . Reports of polyclonal intestinal tumours in human patients and mouse models appear at odds with this process 6,7 . Here we combine multicolour lineage tracing with chemical mutagenesis in mice to show that a large proportion of intestinal tumours have a multiancestral origin. Polyclonal tumours retain a structure comprising subclones with distinct Apc mutations and transcriptional states, driven predominantly by differences in KRAS and MYC signalling. These pathway-level changes are accompanied by profound differences in cancer stem cell phenotypes. Of note, these findings are confirmed by introducing an oncogenic Kras mutation that results in predominantly monoclonal tumour formation. Further, polyclonal tumours have accelerated growth dynamics, suggesting a link between polyclonality and tumour progression. Together, these findings demonstrate the role of interclonal interactions in promoting tumorigenesis through non-cell autonomous pathways that are dependent on the differential activation of oncogenic pathways between clones., (© 2024. The Author(s).)

Escherichia coli strains producing the genotoxin colibactin, designated as CoPEC (colibactin-producing E. coli ), have emerged as an important player in the etiology of colorectal cancer (CRC). Here, we investigated the role of macroautophagy/autophagy in myeloid cells, an important component of the tumor microenvironment, in the tumorigenesis of a susceptible mouse model infected with CoPEC. For that, a preclinical mouse model of CRC, the Apc Min/+ mice, with Atg16l1 deficiency specifically in myeloid cells ( Apc Min/+ / Atg16l1[∆MC] ) and the corresponding control mice ( Apc Min/+ ), were infected with a clinical CoPEC strain 11G5 or its isogenic mutant 11G5 ∆clbQ that does not produce colibactin. We showed that myeloid cell-specific Atg16l1 deficiency led to an increase in the volume of colonic tumors in Apc Min/+ mice under infection with 11G5, but not with 11G5 ∆clbQ . This was accompanied by increased colonocyte proliferation, enhanced inflammasome activation and IL1B/IL-1β secretion, increased neutrophil number and decreased total T cell and cytotoxic CD8 + T cell numbers in the colonic mucosa and tumors. In bone marrow-derived macrophages (BMDMs), compared to uninfected and 11G5∆ clbQ -infected conditions, 11G5 infection increased inflammasome activation and IL1B secretion, and this was further enhanced by autophagy deficiency. These data indicate that ATG16L1 in myeloid cells was necessary to inhibit colonic tumor growth in CoPEC-infected Apc Min/+ mice via inhibiting colibactin-induced inflammasome activation and modulating immune cell response in the tumor microenvironment. Abbreviation : AOM, azoxymethane; APC, APC regulator of WNT signaling pathway; ATG, autophagy related; Atg16l1[∆MC] mice, mice deficient for Atg16l1 specifically in myeloid cells; CASP1, caspase 1; BMDM, bone marrow-derived macrophage; CFU, colony-forming unit; CoPEC, colibactin-producing Escherichia coli ; CRC, colorectal cancer; CXCL1/KC, C-X-C motif chemokine ligand 1; ELISA, enzyme-linked immunosorbent assay; IL, interleukin; MC, myeloid cell; MOI, multiplicity of infection; PBS, phosphate-buffered saline; pks , polyketide synthase; qRT-PCR, quantitative real-time reverse-transcription polymerase chain reaction; siRNA, small interfering RNA; TME, tumor microenvironment; TNF/TNF-α, tumor necrosis factor.

Gardner syndrome (GS) is a subtype of familial adenomatous polyposis (FAP) characterized by colorectal polyps, multiple osteomas, soft tissue tumors, and specific oral manifestations, such as jaw osteomas. GS is caused by mutations in the APC gene, resulting in a nonfunctional protein. This study reports a comprehensive clinical evaluation and genetic analysis of a Tunisian family affected by GS. Targeted exome sequencing and Sanger sequencing techniques were employed to identify and validate mutations in the APC gene. Clinical observations of the patient revealed multiple sebaceous cysts, frontal and maxillary osteomas, and several gastrointestinal polyps. Genetic analysis revealed a pathogenic variant (c.4652-4655del) in the APC gene, leading to a truncated protein. Additionally, genetic testing of the patient's child indicated that the child does not carry the APC pathogenic variant. In conclusion, our study highlights the importance of genetic testing in raising awareness of GS among clinicians to ensure early diagnosis and effective management, thereby reducing the risk of development and progression of colorectal cancer., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024. Published by Elsevier B.V.)

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&#95;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., (© 2024. The Author(s).)

Colorectal cancer (CRC) is a common cancer in younger adults. In patients undergoing liver resection with RAS-altered CRCs, there is evidence suggesting younger patients have worse outcomes than older patients. To explain this pattern, differences in associations between RAS status and other cancer-related biomarkers in tumors from younger versus older patients with CRC were evaluated in a cohort of 925 patients with CRC, 277 (30.0%) of whom were ≤50 years old, and 454 (49.1%) who had RAS-altered tumors. For 3 biomarkers, RNF43, APC, and microsatellite instability (MSI), the association with RAS status was significantly modified by age after adjustment for multiple testing. Specifically, younger patients with RAS-altered tumors were more likely to be MSI-high, RNF43 mutated, and APC wild type. These differences might contribute to the observed pattern of diminished survival in younger versus older patients with CRC with RAS-mutated tumors undergoing liver metastasis resection., (© The Author(s) 2024. Published by Oxford University Press.)

Purpose: Small bowel adenocarcinoma (SBA) is a rare malignancy of the gastrointestinal tract, and its unique location within the small intestine presents difficulties in obtaining tissue samples from the lesions. This limitation hinders the research and development of effective clinical treatment methods. Circulating tumor DNA (ctDNA) analysis holds promise as an alternative approach for investigating SBA and guiding treatment decisions, thereby improving the prognosis of SBA., Methods: Between January 2017 and August 2021, a total of 336 tissue or plasma samples were obtained and the corresponding mutation status in tissue or blood was evaluated with NGS., Results and Conclusions: The study found that in SBA tissues, the most commonly alternated genes were TP53, KRAS, and APC, and the most frequently affected pathways were RTK-RAS-MAPK, TP53, and WNT. Notably, the RTK-RAS-MAPK pathway was identified as a potential biomarker that could be targeted for treatment. Then, we validated the gene mutation profiling of ctDNA extracted from SBA patients exhibited the same characteristics as tissue samples for the first time. Subsequently, we applied ctDNA analysis on a terminal-stage patient who had shown no response to previous chemotherapy. After detecting alterations in the RTK-RAS-MAPK pathway in the ctDNA, the patient was treated with MEK + EGFR inhibitors and achieved a tumor shrinkage rate of 76.33%. Our study utilized the largest Chinese SBA cohort to uncover the molecular characteristics of this disease, which might facilitate clinical decision making for SBA patients., (© 2024. The Author(s), under exclusive licence to Federación de Sociedades Españolas de Oncología (FESEO).)

For over a century, fasting regimens have improved health, lifespan and tissue regeneration in diverse organisms, including humans 1-6 . However, how fasting and post-fast refeeding affect adult stem cells and tumour formation has yet to be explored in depth. Here we demonstrate that post-fast refeeding increases intestinal stem cell (ISC) proliferation and tumour formation; post-fast refeeding augments the regenerative capacity of Lgr5 + ISCs, and loss of the tumour suppressor gene Apc in post-fast-refed ISCs leads to a higher tumour incidence in the small intestine and colon than in the fasted or ad libitum-fed states, demonstrating that post-fast refeeding is a distinct state. Mechanistically, we discovered that robust mTORC1 induction in post-fast-refed ISCs increases protein synthesis via polyamine metabolism to drive these changes, as inhibition of mTORC1, polyamine metabolite production or protein synthesis abrogates the regenerative or tumorigenic effects of post-fast refeeding. Given our findings, fast-refeeding cycles must be carefully considered and tested when planning diet-based strategies for regeneration without increasing cancer risk, as post-fast refeeding leads to a burst in stem-cell-driven regeneration and tumorigenicity., (© 2024. The Author(s), under exclusive licence to Springer Nature Limited.)

Purpose: Several recurring pathogenic variants (PVs) in BRCA1/BRCA2 and additional cancer susceptibility genes are described in the ethnically diverse Israeli population. Since 2019, testing for these recurring PVs is reimbursed unselectively for all patients with breast cancer (BC) in Israel. The aim was to evaluate the yield of genotyping for these PVs in non-Ashkenazi Jewish (AJ) patients with BC diagnosed ≥age 50 years., Methods: Clinical and genotyping data of all patients with BC undergoing oncogenetic counseling at the Oncology Institute at Sheba Medical Center from June 2017 to December 2023 were reviewed., Results: Of 2706 patients with BC (mean age at diagnosis, 54 years; range, 20-92 years) counseled, 515 patients of non-AJ (all four grandparents) descent, diagnosed ≥age 50 years of age were genotyped, 55 with triple-negative BC (TNBC) and 460 with non-TNBC. One of the recurring PVs in BRCA1/BRCA2 were detected in 12.7% (7/55) of TNBC patients and 0.65% (3/460) of non-TNBC. One patient with non-TNBC had PMS2 PV. Low-penetrance variants were found in 2.5% of genotyped TNBC and in 3.7% of patients with non-TNBC, including CHEK2 c.499G>A (n = 3), APC c.3920T > A (n = 4), and heterozygous MUTYH c.1187G>A (n = 5). Following first-pass genotyping, 146 patients performed multigene panel testing, none carried a BRCA1/BRCA2 PV, and only 5/127 non-TNBC (3.9%) harbored PVs in CHEK2 (n = 2, c.846+1G>C and c.592+3A>T), ATM c.103C>T (n = 2), and NBN c.966C>G (n = 1)., Conclusions: The observed low rates of PV detection in non-AJ non-TNBC cases ≥age 50 years at diagnosis, mostly for clinically insignificant variants, questions the justification of unselected genotyping in this subset of patients., (© 2024 American Cancer Society.)

Background: There are known disparities in incidence and outcomes of colorectal cancer (CRC) by race and ethnicity. Some of these disparities may be mediated by molecular changes in tumors that occur at different rates across populations. Genetic ancestry is a measure complementary to race and ethnicity that can overcome missing data issues and better capture genetic similarity in admixed populations. We aimed to identify somatic mutations and tumor gene expression differences associated with both genetic ancestry and imputed race and ethnicity., Methods: Sequencing was performed with the Tempus xT NGS 648-gene panel and whole exome capture RNA-Seq for 8454 primarily late-stage CRC patients. Genetic ancestry proportions for five continental groups-Africa (AFR), American indigenous (AMR), East Asia (EAS), Europe (EUR), and South Asia (SAS)-were estimated using ancestry informative markers. To address data gaps, race and ethnicity categories were imputed, resulting in assignments for 952 Hispanic/Latino, 420 non-Hispanic (NH) Asian, 1061 NH Black, and 5763 NH White individuals. We assessed association of genetic ancestry proportions and imputed race and ethnicity categories with somatic mutations in relevant CRC genes and in 2608 expression profiles, as well as 1957 consensus molecular subtypes (CMS)., Results: Increased AFR ancestry was associated with higher odds of somatic mutations in APC, KRAS, and PIK3CA and lower odds of BRAF mutations. Additionally, increased EAS ancestry was associated with lower odds of mutations in KRAS, EUR with higher odds in BRAF, and the Hispanic/Latino category with lower odds in BRAF. Greater AFR ancestry and the NH Black category were associated with higher rates of CMS3, while a higher proportion of Hispanic/Latino patients exhibited indeterminate CMS classifications., Conclusions: Molecular differences in CRC tumor mutation frequencies and gene expression that may underlie observed differences by race and ethnicity were identified. The association of AFR ancestry with increased KRAS mutations aligns with higher CMS3 subtype rates in NH Black patients. The increase of indeterminate CMS in Hispanic/Latino patients suggests that subtype classification methods could benefit from enhanced patient diversity., (© 2024. The Author(s).)

Preclinical models that replicate patient tumours as closely as possible are crucial for translational cancer research. While in vitro cancer models have many advantages in assessing tumour response therapy, in vivo systems are essential to enable evaluation of the role of the tumour cell extrinsic factors, such as the tumour microenvironment and host immune system. The requirement for a functional immune system is particularly important given the current focus on immunotherapies. Therefore, we set out to generate an immunocompetent, transplantable model of colorectal cancer suitable for in vivo assessment of immune-based therapeutic approaches. Intestinal tumours from a genetically engineered mouse model, driven by expression of a Pik3ca mutation and loss of Apc, were transplanted into wild type C57BL/6 host mice and subsequently passaged to form a novel syngeneic transplant model of colorectal cancer. Our work confirms the potential to develop a panel of mouse syngeneic grafts, akin to human PDX panels, from different genetically engineered, or carcinogen-induced, mouse models. Such panels would allow the in vivo testing of new pharmaceutical and immunotherapeutic treatment approaches across a range of tumours with a variety of genetic driver mutations., Competing Interests: Wayne A. Phillips is a member of the editorial board of PLOS ONE. This does not alter our adherence to PLOS ONE policies on sharing data and materials. The authors have declared that no other competing interests exist., (Copyright: © 2024 de las Heras et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.)

A 35-year-old woman of Asian descent with epigastralgia was referred to our hospital. Esophagogastroduodenoscopy revealed gastric cancer in the upper body and carpeting fundic gland polyposis in the fornix and body. Computed tomography revealed no metastases. Total colonoscopy and capsule endoscopy revealed no polyposis, except in the stomach. The patient was diagnosed with advanced gastric cancer and underwent open total gastrectomy. We speculated that her gastric cancer was a hereditary tumor due to its early onset and accompanying fundic gland polyposis. Germline multi-gene panel testing identified a single-nucleotide variant, c.-191 T > G, in exon 1B of the adenomatous polyposis coli gene, which can cause gastric adenocarcinoma and proximal polyposis of the stomach. To our knowledge, this is the first manuscript to report the variant (c.-191 T > G) in promoter 1B of the adenomatous polyposis coli gene, which is related to a predisposition to gastric adenocarcinoma and proximal polyposis of the stomach., (© 2024. Japanese Society of Gastroenterology.)

Purpose: The advent of circulating tumor DNA (ctDNA) technology has provided a convenient and noninvasive means to continuously monitor cancer genomic data, facilitating personalized cancer treatment. This study aimed to evaluate the supplementary benefits of plasma ctDNA alongside traditional tissue-based next-generation sequencing (NGS) in identifying targetable mutations and tumor mutational burden (TMB) in colorectal cancers (CRC)., Methods: Our study involved 76 CRC patients, collecting both tissue and plasma samples for NGS. We assessed the concordance of gene mutational status between ctDNA and tissue, focusing on actionable genes such as KRAS, NRAS, PIK3CA, BRAF, and ERBB2. Logistic regression analysis was used to explore variables associated with discordance and positive mutation rates., Results: In total, 26 cancer-related genes were identified. The most common variants in tumor tissues and plasma samples were in APC (57.9% vs 19.7%), TP53 (55.3% vs 22.4%) and KRAS (47.4% vs 43.4%). Tissue and ctDNA showed an overall concordance of 73.53% in detecting actionable gene mutations. Notably, plasma ctDNA improved detection for certain genes and gene pools. Variables significantly associated with discordance included gender and peritoneal metastases. TMB analysis revealed a higher detection rate in tissues compared to plasma, but combining both increased detection., Conclusions: Our study highlights the importance of analyzing both tissue and plasma for detecting actionable mutations in CRC, with plasma ctDNA offering added value. Discordance is associated with gender and peritoneal metastases, and TMB analysis can benefit from a combination of tissue and plasma data. This approach provides valuable insights for personalized CRC treatment., (© 2024. The Author(s).)

APC is a tumor suppressor gene that exerts its effect through the regulation of the Wnt signaling pathway. Loss of function mutations of the gene are associated with familial adenomatous polyposis (FAP). Early diagnosis in FAP patients is essential to prevent the development of colorectal cancer. Extraintestinal manifestations often precede the formation of the polyposis; therefore, these manifestations may serve as a clinical indicator for the condition. The aim of this study was to assess genotype-phenotype associations between the location of APC mutations and various extraintestinal features, mainly focusing on osseous and dental anomalies. Analyses of our cases and the mutations available in the literature with these manifestations revealed that mutations in the N-terminal region (amino acids 1-~1000) of the protein are more frequently associated with only osseous anomalies, whereas dental manifestations are more prevalent in mutations in the middle region (amino acids 1000-~2100). In addition, supernumerary teeth were found to be the most common dental feature. Since dental abnormalities often precede intestinal polyposis, dentists have a crucial role in the early identification of patients at risk.

Young-onset colorectal cancer is an increasing concern worldwide due to the growing prevalence of Westernized lifestyles in childhood and adolescence. Environmental factors during early life, particularly early-life nutrition, significantly contribute to the increasing incidence. Recently, there have been reports of beneficial effects, including anti-inflammation and anti-cancer, of a unique fungus ( Antrodia camphorate , AC) native to Taiwan. The objective of this study is to investigate the impact of AC supplementation in early life on the development of young-onset intestinal tumorigenesis. APC 1638N mice were fed with a high-fat diet (HF) at 4-12 weeks of age, which is equivalent to human childhood/adolescence, before switching to a normal maintenance diet for an additional 12 weeks up to 24 weeks of age, which is equivalent to young to middle adulthood in humans. Our results showed that the body weight in the HF groups significantly increased after 8 weeks of feeding ( p < 0.05). Following a switch to a normal maintenance diet, the change in body weight persisted. AC supplementation significantly suppressed tumor incidence and multiplicity in females ( p < 0.05) and reduced IGF-1 and Wnt/β-catenin signaling ( p < 0.05). Moreover, it altered the gut microbiota, suppressed inflammatory responses, and created a microenvironment towards suppressing tumorigenesis later in life.

Background: Colorectal cancer is still the second leading cause of cancer-related deaths and thus biomarkers allowing prediction of the resistance of patients to therapy and estimating their prognosis are needed. We designed a panel of 558 genes with pharmacogenomics records related to 5-fluorouracil resistance, genes important for sensitivity to other frequently used drugs, major oncodrivers, and actionable genes. We performed a target enrichment sequencing of DNA from tumors and matched blood samples of patients, and compared the results with patient prognosis stratified by systemic adjuvant chemotherapy., Results: The median number of detected variants per tumor sample was 18.5 with 4 classified as having a high predicted functional effect and 14.5 moderate effect. APC, TP53, and KRAS were the most frequent mutated genes (64%, 59%, and 42% of mutated samples, respectively) followed by FAT4 (23%), FBXW7, and PIK3CA (16% for both). Patients with advanced stage III had more frequently APC, TP53, or KRAS mutations than those in stages I or II. KRAS mutation counts followed an increasing trend with grade (G1 < G2 < G3). The response to adjuvant therapy was worse in carriers of frameshift mutations in APC or 12D variant in KRAS, but none of these oncodrivers had prognostic value. Carriage of somatic mutations in any of the genes ABCA13, ANK2, COL7A1, NAV3, or UNC80 had prognostic relevance for worse overall survival (OS) of all patients. In contrast, mutations in FLG, GLI3, or UNC80 were prognostic in the same direction for patients untreated, and mutations in COL6A3, LRP1B, NAV3, RYR1, RYR3, TCHH, or TENM4 for patients treated with adjuvant therapy. The first association was externally validated. From all germline variants with high or moderate predicted functional effects (median 326 per patient), > 5% frequency and positive Manhattan plot based on 3-year RFS, rs72753407 in NFACS, rs34621071 in ERBB4, and rs2444274 in RIF1 were significantly associated with RFS, OS or both., Conclusions: The present study identified several putative somatic and germline genetic events with prognostic potential for colorectal cancer that should undergo functional characterization., (© 2024. The Author(s).)

Competing Interests: Competing interests: None declared.

Colorectal cancer (CRC) is the third most prevalent cancer worldwide. Current studies have demonstrated that tumor-derived extracellular vesicles (EVs) from different cancer cell types modulate the fibroblast microenvironment to contribute to cancer development and progression. Here, we isolated and characterized circulating large EVs (LEVs), small EVs (SEVs) and non-EV entities released in the plasma from wild-type (WT) mice and the APC Min/+ CRC mice model. Our results showed that human colon fibroblasts exposed from APC-EVs, but not from WT-EVs, exhibited the phenotypes of cancer-associated fibroblasts (CAFs) through EV-mediated NF-κB pathway activation. Cytokine array analysis on secreted proteins revealed elevated levels of inflammatory cytokine implicated in cancer growth and metastasis. Finally, non-activated cells co-cultured with supernatant from fibroblasts treated with APC-EVs showed increased mRNA expressions of CAFs markers, the ECM, inflammatory cytokines, as well as the expression of genes controlled by NF-κB. Altogether, our work suggests that EVs and non-EV components from APC Min/+ mice are endowed with pro-tumorigenic activities and promoted inflammation and a CAF-like state by triggering NF-κB signaling in fibroblasts to support CRC growth and progression. These findings provide insight into the interaction between plasma-derived EVs and human cells and can be used to design new CRC diagnosis and prognosis tools.

Background: Wnt/β-catenin signalling impairment accounts for 85% of colorectal cancers (CRCs), including sporadic and familial adenomatous polyposis (FAP) settings. An altered PI3K/mTOR pathway and gut microbiota also contribute to CRC carcinogenesis. We studied the interplay between the two pathways and the microbiota composition within each step of CRC carcinogenesis., Methods: Proteins and target genes of both pathways were analysed by RT-qPCR and IHC in tissues from healthy faecal immunochemical test positive (FIT+, n = 17), FAP (n = 17) and CRC (n = 15) subjects. CRC-related mutations were analysed through NGS and Sanger. Oral, faecal and mucosal microbiota was profiled by 16 S rRNA-sequencing., Results: We found simultaneous hyperactivation of Wnt/β-catenin and PI3K/mTOR pathways in FAP-lesions compared to CRCs. Wnt/β-catenin molecular markers positively correlated with Clostridium&#95;sensu&#95;stricto&#95;1 and negatively with Bacteroides in FAP faecal microbiota. Alistipes, Lachnospiraceae, and Ruminococcaceae were enriched in FAP stools and adenomas, the latter also showing an overabundance of Lachnoclostridium, which positively correlated with cMYC. In impaired-mTOR-mutated CRC tissues, p-S6R correlated with Fusobacterium and Dialister, the latter also confirmed in the faecal-ecosystem., Conclusions: Our study reveals an interplay between Wnt/β-catenin and PI3K/mTOR, whose derangement correlates with specific microbiota signatures in FAP and CRC patients, and identifies new potential biomarkers and targets to improve CRC prevention, early adenoma detection and treatment., (© 2024. The Author(s).)

According to conventional views, colon cancer originates from stem cells. However, inflammation, a key risk factor for colon cancer, has been shown to suppress intestinal stemness. Here, we used Paneth cells as a model to assess the capacity of differentiated lineages to trigger tumorigenesis in the context of inflammation in mice. Upon inflammation, Paneth cell-specific Apc mutations led to intestinal tumors reminiscent not only of those arising in patients with inflammatory bowel disease, but also of a larger fraction of human sporadic colon cancers. The latter is possibly because of the inflammatory consequences of western-style dietary habits, a major colon cancer risk factor. Machine learning methods designed to predict the cell-of-origin of cancer from patient-derived tumor samples confirmed that, in a substantial fraction of sporadic cases, the origins of colon cancer reside in secretory lineages and not in stem cells., (© 2024. The Author(s).)

Colorectal cancer (CRC) stands as a prevalent malignancy globally. A pivotal event in CRC pathogenesis involves the loss-of-function mutation in the APC gene, leading to the formation of benign polyps. Despite the well-established role of APC, the contribution of CUL4B to CRC initiation in the pre-tumorous stage remains poorly understood. In this investigation, we generated a murine model by crossing Apc Min/+ mice with Cul4b ΔIEC mice to achieve specific deletion of Cul4b in the gut epithelium against an Apc Min/+ background. By employing histological methods, RNA-sequencing (RNA-seq), and flow cytometry, we assessed alterations and characterized the immune microenvironment. Our results unveiled that CUL4B deficiency in gut epithelium expedited Apc Min/+ adenoma formation. Notably, CUL4B in adenomas restrained the accumulation of tumor-infiltrating myeloid-derived suppressor cells (MDSCs). In vivo inhibition of MDSCs significantly delayed the growth of CUL4B deleted Apc Min/+ adenomas. Furthermore, the addition of MDSCs to in vitro cultured Apc Min/+ ; Cul4b ΔIEC adenoma organoids mitigated their alterations. Mechanistically, CUL4B directly interacted with the promoter of Csf3, the gene encoding granulocyte-colony stimulating factor (G-CSF) by coordinating with PRC2. Inhibiting CUL4B epigenetically activated the expression of G-CSF, promoting the recruitment of MDSCs. These findings offer novel insights into the tumor suppressor-like roles of CUL4B in regulating Apc Min/+ adenomas, suggesting a potential therapeutic strategy for CRC initiation and progression in the context of activated Wnt signaling., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024. Published by Elsevier Inc.)

Triple-negative breast cancer (TNBC) patients are treated with traditional chemotherapy, such as the taxane class of drugs. One such drug, paclitaxel (PTX), can be effective in treating TNBC; however, many tumors will develop drug resistance, which can lead to recurrence. In order to improve patient outcomes and survival, there lies a critical need to understand the mechanism behind drug resistance. Our lab made the novel observation that decreased expression of the Adenomatous Polyposis Coli (APC) tumor suppressor using shRNA caused PTX resistance in the human TNBC cell line MDA-MB-157. In cells lacking APC, induction of apoptosis by PTX was decreased, which was measured through cleaved caspase 3 and annexin/PI staining. The current study demonstrates that CRISPR-mediated APC knockout in two other TNBC lines, MDA-MB-231 and SUM159, leads to PTX resistance. In addition, the cellular consequences and molecular mechanisms behind APC-mediated PTX response have been investigated through analysis of the BCL-2 family of proteins. We found a significant increase in the tumor-initiating cell population and increased expression of the pro-survival family member Bcl-2, which is widely known for its oncogenic behavior. ABT-199 (Venetoclax), is a BH3 mimetic that specifically targets Bcl-2. ABT-199 has been used as a single or combination therapy in multiple hematologic malignancies and has shown promise in multiple subtypes of breast cancer. To address the hypothesis that APC-induced Bcl-2 increase is responsible for PTX resistance, we combined treatment of PTX and ABT-199. This combination treatment of CRISPR-mediated APC knockout MDA-MB-231 cells resulted in alterations in apoptosis, suggesting that Bcl-2 inhibition restores PTX sensitivity in APC knockout breast cancer cells. Our studies are the first to show that Bcl-2 functional inhibition restores PTX sensitivity in APC mutant breast cancer cells. These studies are critical to advance better treatment regimens in patients with TNBC.

Telomere dynamics are linked to aging hallmarks, and age-associated telomere loss fuels the development of epithelial cancers. In Apc-mutant mice, the onset of DNA damage associated with telomere dysfunction has been shown to accelerate adenoma initiation via unknown mechanisms. Here, we observed that Apc-mutant mice engineered to experience telomere dysfunction show accelerated adenoma formation resulting from augmented cell competition and clonal expansion. Mechanistically, telomere dysfunction induces the repression of EZH2, resulting in the derepression of Wnt antagonists, which causes the differentiation of adjacent stem cells and a relative growth advantage to Apc-deficient telomere dysfunctional cells. Correspondingly, in this mouse model, GSK3β inhibition countered the actions of Wnt antagonists on intestinal stem cells, resulting in impaired adenoma formation of telomere dysfunctional Apc-mutant cells. Thus, telomere dysfunction contributes to cancer initiation through altered stem cell dynamics, identifying an interception strategy for human APC-mutant cancers with shortened telomeres., Competing Interests: Declaration of interests The authors declare no competing interests., (Copyright © 2024 Elsevier Inc. All rights reserved.)

Pulmonary large cell neuroendocrine carcinoma (LCNEC) is a highly aggressive neoplasm with biological heterogeneity. Mutations in multiple genes have been identified in LCNEC. However, associations between gene alterations, histopathological characteristics, and prognosis remain ambiguous. Here, we investigated the clinicopathologic, immunohistochemical, and genomic characteristics of 19 patients with LCNEC and 9 patients with atypical carcinoid (AC). We revealed high mutation frequencies of TP53 (89.5 %), RB1 (42.1 %), APC (31.6 %), and MCL1 (31.6 %) in LCNEC, while genetic alterations were rarely found in AC. APC alterations mainly occurred to the exon 16 and were only identified in LCNEC with wild-type RB1. The 19 LCNEC were further subgrouped into APC wild-type (LCNEC-APC MT , 6/19) and APC-mutated (LCNEC-APC WT , 13/19) subgroups. In comparison with LCNEC-APC WT , LCNEC-APC MT displayed lower TMB (median: 12.64 vs 4.20, P = 0.045), and relatively mild cytologic atypia. In addition, LCNEC-APC MT distinguished itself from AC and LCNEC-APC WT by obviously downregulated expression of neuroendocrine markers (CD56 and Syn, P < 0.01) and significantly altered expression of genes downstream of APC (β-catenin migrating into the cytoplasm and nucleus, P < 0.001; c-Myc upregulating, P = 0.005). The OS of LCNEC-APC MT was numerically intermediate between AC and LCNEC-APC WT . We first proposed that APC alterations were common in LCNEC with wild-type RB1 and that LCNEC-APC MT was associated with lower TMB and better OS in comparison with LCNEC-APC WT ., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024. Published by Elsevier B.V.)

Background: Visceral metastases are known to occur in advanced prostate cancer, usually when the tumour is resistant to androgen deprivation and, have worse outcomes regardless of therapies., Objective: To analyse genomic alterations in tumour samples according to their lymphatic, bone, and visceral metastatic stages and overall survival., Design, Setting, and Participants: We selected 200 patients with metastatic prostate cancer. Genomic profiling of 111 genes and molecular signatures (homologous recombination deficiency [HRD], microsatellite instability, and tumour burden mutation) was performed with the MyChoice test (Myriad Genetics, Inc, Salt Lake City, UT, USA)., Outcome Measurements and Statistical Analysis: The association between genomic profiles and visceral metastatic evolution was evaluated using logistic regression. Kaplan-Meier and Cox proportional hazard analyses were used for analyses of early death., Results and Limitations: A total of 173 (87%) genomic profiles were obtained. Eighty-four (49%) patients died during the follow-up period (median duration = 76 mo). TP53 was the most frequently mutated gene, followed by FANC genes, including BRCA2, and those of the Wnt-pathway (APC/CTNNB1). TP53 gene mutations were more frequent in patients of European (42%) than in those of African (16%) ancestry. An HRD score of >25 was predictive of FANC gene mutations. The mutational status of TP53 (p < 0.001) and APC (p = 0.002) genes were significantly associated with the risk of visceral metastases. The mutational status of CTNNB1 (p = 0.001), TP53 (p = 0.015), BRCA2 (p = 0.027), and FANC (p = 0.005) genes were significantly associated with an earlier age at death. The limitations are the retrospective study design based on a selection of genes and the low frequency of certain molecular events., Conclusions: Mutations in the TP53 gene and genes (APC/CTNNB1) related to the Wnt pathway are associated with metastatic visceral dissemination and early death. These genomic alterations could be considered as markers to identify prostate cancer patients at a high risk of life-threatening disease who might benefit from more intensified treatment or new targeted therapies., Patient Summary: In this report, we evaluated the relationships between genomic profiles (gene mutations and molecular signatures) of tumour samples from patients with metastatic prostate cancer and early death. We found that mutations of specific genes, notably TP53 and APC/CTNNB1 related to the Wnt pathway, are associated with visceral metastatic progression and an earlier age at death., (Copyright © 2023 European Association of Urology. Published by Elsevier B.V. All rights reserved.)

Objective: The incidence of early-onset colorectal cancer (EOCRC) is increasing globally; however, the molecular characteristics and prognosis of sporadic EOCRC are unclear. In this systematic review and meta-analysis, we aimed to investigate the incidence of gene mutations and their association with cancer survival in sporadic EOCRC, focusing on six common gene mutations ( TP53, BRAF, KRAS, NRAS, PTEN, and APC ). Methods: Ovid Embase and Ovid Medline electronic databases were searched for studies involving patients with sporadic EOCRC (i.e., diagnosed with colorectal cancer before the age of 50 years and with no evidence of hereditary syndromes predisposing to colorectal cancer). The included articles were evaluated using quality assessment tools. Meta-analysis was performed using random-effects and fixed-effects models. Cochran's Q statistic and the I2 index were used to assess heterogeneity. The incidence of the six common gene mutations listed above in sporadic EOCRC and their association with cancer survival were evaluated. Results: (1) Incidence of specific gene mutations in sporadic EOCRC . A total of 34 articles were included in this meta-analysis. The incidence of APC gene mutation was 36% (from 13 articles, 95%CI: 19%-55%, P =0.043); of KRAS gene mutation 30% (from 26 articles, 95%CI: 24%-35%, P =0.190); of BRAF gene mutation 7% (from 18 articles, 95%CI: 5%-11%, P =0.422); of NRAS gene mutation 4% (from five articles, 95%CI: 3%-5%, P =0.586); of PTEN gene mutation 6% (from six articles, 95%CI: 4%-10%, P =0.968); and of TP53 gene mutation 59% (from 13 articles, 95%CI: 49%-68%, P =0.164). (2) Association between gene mutations and survival in sporadic EOCRC . A total of six articles were included in this meta-analysis. Compared with wild-type BRAF, mutant BRAF was significantly associated with increased overall mortality risk in patients with EOCRC (pooled HR=2.85, 95%CI: 1.45-5.60, P =0.002). Subgroup analysis showed that the incidence of BRAF gene mutation was higher in Eastern than in Western countries, whereas the incidence of TP53, KRAS, NRAS , and APC gene mutations was lower. There was no significant difference in the incidence of PTEN gene mutation between different regions. Conclusion: Compared with colorectal cancer occurring in the general population, the incidence of APC and KRAS mutations is lower in EOCRC, whereas the incidence of TP53 mutation remains consistent. BRAF mutation is associated with increased overall mortality risk in patients with EOCRC.

DNA methylation is an epigenetic process that commonly occurs in genes' promoters and results in the transcriptional silencing of genes. DNA methylation is a frequent event in bladder cancer, participating in tumor initiation and progression. Bladder cancer is a major health issue in patients suffering from neurogenic lower urinary tract dysfunction (NLUTD), although the pathogenetic mechanisms of the disease remain unclear. In this population, bladder cancer is characterized by aggressive histopathology, advanced stage during diagnosis, and high mortality rates. To assess the DNA methylation profiles of five genes' promoters previously known to be associated with bladder cancer in bladder tissue of NLUTD patients, we conducted a prospective study recruiting NLUTD patients from the neuro-urology unit of a public teaching hospital. Cystoscopy combined with biopsy for bladder cancer screening was performed in all patients following written informed consent being obtained. Quantitative methylation-specific PCR was used to determine the methylation status of RASSF1, RARβ, DAPK, hTERT, and APC genes' promoters in bladder tissue samples. Twenty-four patients suffering from mixed NLUTD etiology for a median duration of 10 (IQR: 12) years were recruited in this study. DNA hypermethylation was detected in at least one gene of the panel in all tissue samples. RAR-β was hypermethylated in 91.7% samples, RASSF and DAPK were hypermethylated in 83.3% samples, APC 37.5% samples, and TERT in none of the tissue samples. In 45.8% of the samples, three genes of the panel were hypermethylated, in 29.2% four genes were hypermethylated, and in 16.7% and in 8.3% of the samples, two and one gene were hypermethylated, respectively. The number of hypermethylated genes of the panel was significantly associated with recurrent UTIs ( p = 0.0048). No other significant association was found between DNA hypermethylation or the number of hypermethylated genes and the clinical characteristics of the patients. Histopathological findings were normal in 8.3% of patients, while chronic inflammation was found in 83.3% of patients and squamous cell metaplasia in 16.7% of patients. In this study, we observed high rates of DNA hypermethylation of genes associated with bladder cancer in NLUTD patients, suggesting an epigenetic field effect and possible risk of bladder cancer development. Recurrent UTIs seem to be associated with increased DNA hypermethylation. Further research is needed to evaluate the impact of recurrent UTIs and chronic inflammation in DNA hypermethylation and bladder cancer etiopathogenesis in NLUTD patients.

The identification of targets that are expressed on the cell membrane is a main goal in cancer research. The Lymphocyte Antigen 6 Family Member G6D ( LY6G6D ) gene codes for a protein that is mainly present on the surface of colorectal cancer (CRC) cells. Therapeutic strategies against this protein like the development of T cell engagers (TCE) are currently in the early clinical stage. In the present work, we interrogated public genomic datasets including TCGA to evaluate the genomic and immunologic cell profile present in tumors with high expression of LY6G6D . We used data from TCGA, among others, and the Tumor Immune Estimation Resource (TIMER2.0) platform for immune cell estimations and Spearman correlation tests. LY6G6D expression was exclusively present in CRC, particularly in the microsatellite stable (MSS) subtype, and was associated with left-side tumors and the canonical genomic subgroup. Tumors with mutations of APC and p53 expressed elevated levels of LY6G6D. This protein was expressed in tumors with an inert immune microenvironment with an absence of immune cells and co-inhibitory molecules. In conclusion, we described clinical, genomic and immune-pathologic characteristics that can be used to optimize the clinical development of agents against this target. Future studies should be performed to confirm these findings and potentially explore the suggested clinical development options.

Familial adenomatous polyposis (FAP) is a heritable disease that increases the risk of colorectal cancer (CRC) development because of heterozygous mutations in APC. Little is known about the microenvironment of FAP. Here, single-cell RNA sequencing was performed on matched normal tissues, adenomas, and carcinomas from four patients with FAP. We analyzed the transcriptomes of 56,225 unsorted single cells, revealing the heterogeneity of each cell type, and compared gene expression among tissues. Then we compared the gene expression with that of sporadic CRC. Furthermore, we analyzed specimens of 26 FAP patients and 40 sporadic CRC patients by immunohistochemistry. Immunosuppressiveness of myeloid cells, fibroblasts, and regulatory T cells was upregulated even in the early stages of carcinogenesis. CD8 + T cells became exhausted only in carcinoma, although the cytotoxicity of CD8 + T cells was gradually increased according to the carcinogenic step. When compared with those in the sporadic CRC microenvironment, the composition and function of each cell type in the FAP-derived CRC microenvironment had differences. Our findings indicate that an immunosuppressive microenvironment is constructed from a precancerous stage in FAP., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier B.V. All rights reserved.)

Scope: Yogurt consumption is related to a decreased risk of colorectal cancer (CRC), but whether such association is causal remains unclear. Patients with familial adenomatous polyposis (FAP) are at increased risk of CRC development. Here, the study investigates the efficacy of yogurt for intestinal polyposis chemoprevention in Apc Min/+ mice, a preclinical model for human FAP., Methods and Results: A 10-week yogurt supplementation (15 g kg -1 ) in Apc Min/+ mice significantly reduces the intestinal polyp number (6.50 ± 0.97 versus 1.80 ± 0.49; p < 0.001) compared to controls. 16S rRNA gene-based microbiota analysis suggests that yogurt supplementation may greatly modulate the gut microbiome composition, especially in the relative abundance of Lactobacillus and Bifidobacterium. Importantly, the fecal concentration of d-lactate (d-Lac, 0.39 ± 0.04 µmol g -1 versus 8.14 ± 0.62 µmol g -1 ; p < 0.001) is boosted by yogurt, while oral administration with d-Lac (125 or 250 mg kg -1 ) reduces the polyp number by 71.43% or 77.14% (p < 0.001), respectively. The study also observes that d-Lac does not affect cell viability and anchorage-independence in CRC cells, but it greatly suppresses epidermal growth factor (EGF) or 12-O-tetradecanoylphorbol-13-acetate (TPA)-induced cell transformation in preneoplastic cells. Mechanistically, it demonstrates that d-Lac may attenuate epithelial cell transformation by targeting PI3K/AKT/β-catenin axis., Conclusion: Yogurt protects against intestinal polyposis in Apc Min/+ mice, and d-Lac may partially account for the chemopreventive effects above., (© 2024 Wiley‐VCH GmbH.)

In the Danish Polyposis Register, patients with over 100 cumulative colorectal adenomas of unknown genetic etiology, named in this study colorectal polyposis (CP), is registered and treated as familial adenomatous polyposis (FAP). In this study, we performed genetic analyses, including whole genome sequencing (WGS), of all Danish patients registered with CP and estimated the detection rate of pathogenic variants (PV). We identified 231 families in the Polyposis Register, 31 of which had CP. A polyposis-associated gene panel was performed and, if negative, patients were offered WGS and screening for mosaicism in blood and/or adenomas. Next-generation sequencing (NGS) was carried out for 27 of the families (four declined). PVs were detected in 11 families, and WGS revealed three additional structural variants in APC. Mosaicism of a PV in APC was detected in two families. As the variant detection rate of eligible families was 60%, 93% of families in the register now have a known genetic etiology., (© 2024. The Author(s).)

Microcystins (MCs), toxins generated by cyanobacteria, feature microcystin-LR (MC-LR) as one of the most prevalent and toxic variants in aquatic environments. MC-LR not only causes environmental problems but also presents a substantial risk to human health. This study aimed to investigate the impact of MC-LR on APC min/+ mice, considered as an ideal animal model for intestinal tumors. We administered 40 µg/kg MC-LR to mice by gavage for 8 weeks, followed by histopathological examination, microbial diversity and metabolomics analysis. The mice exposed to MC-LR exhibited a significant promotion in colorectal cancer progression and impaired intestinal barrier function in the APC min/+ mice compared with the control. Gut microbial dysbiosis was observed in the MC-LR-exposed mice, manifesting a notable alteration in the structure of the gut microbiota. This included the enrichment of Marvinbryantia , Gordonibacter and Family&#95;XIII&#95;AD3011&#95;group and reductions in Faecalibaculum and Lachnoclostridium . Metabolomics analysis revealed increased bile acid (BA) metabolites in the intestinal contents of the mice exposed to MC-LR, particularly taurocholic acid (TCA), alpha-muricholic acid (α-MCA), 3-dehydrocholic acid (3-DHCA), 7-ketodeoxycholic acid (7-KDCA) and 12-ketodeoxycholic acid (12-KDCA). Moreover, we found that Marvinbryantia and Family&#95;XIII&#95;AD3011&#95;group showed the strongest positive correlation with taurocholic acid (TCA) in the mice exposed to MC-LR. These findings provide new insights into the roles and mechanisms of MC-LR in susceptible populations, providing a basis for guiding values of MC-LR in drinking water.

Familial adenomatous polyposis (FAP) is an autosomal dominant syndrome caused by a germline mutation in the adenomatous polyposis coli (APC) gene, characterized by numerous colorectal adenomas. In addition, FAP patients may develop extraintestinal manifestations. Several cases of hepatocellular adenomas (HCA) detected accidentally in FAP patients have raised the so-far unsolved question of whether they represent a specific manifestation of FAP or a mere coincidence. To investigate the incidence of liver tumors in FAP patients, we analyzed our diagnostic database from 1991 to 2021. Among the 58 hepatic mass lesions identified, five HCAs occurring in three patients with FAP were identified, and comprehensive morphological, immunohistological, and molecular analysis employing targeted next-generation sequencing was conducted for characterization. The HCAs in this study showed no cytological or histological atypia. They displayed a diffuse, strong positivity for glutamine synthetase but no nuclear beta-catenin immunostaining. In two patients, the adenomas showed moderate immunoreactivity against serum amyloid A. Consistent with the diagnosis of FAP, molecular profiling revealed a pathogenic germline mutation of the APC gene in all analyzed adenomas as well as deleterious somatic second hits. All somatic mutations were localized between codons 1345 and 1577. No mutations were found in the catenin beta 1 gene. HCA in FAP patients can be a specific, although rare, neoplastic manifestation of this inborn disease and represents a distinct subgroup of HCAs. These benign tumors represent an important differential diagnosis for hepatic metastases in FAP patients and require adequate clinical and molecular (diagnostic) assessments for optimal patient guidance., (© 2023. The Author(s).)