Colorectal cancer (CRC) has traditionally been thought to develop through stepwise mutation of the APC tumour suppressor and other driver genes, coupled with expansion of positively selected clones. However, recent publications show that many premalignant lesions comprise multiple clones expressing different mutant APC proteins1-4. Here, by mediating transformation on different mouse backgrounds containing mutations in Kras or other common CRC driver genes, we establish that the presence of diverse priming events in the normal mouse intestinal epithelium can change the transformation and clonal-selection landscape, permitting the fixation of strong driver mutations in Apc and Ctnnb1 that are otherwise lost due to negative selection. These findings, combined with our demonstration of mutational patterns consistent with similar priming events in human CRC, suggest that the order in which driver mutations occur in intestinal epithelium can determine whether clones are positively or negatively selected and can shape subsequent tumour development.

No Abstract

Cancer is generally thought to be caused by expansion of a single mutant cell1. However, analyses of early colorectal cancer lesions suggest that tumors may instead originate from multiple, genetically distinct cell populations2,3. Detecting polyclonal tumor initiation is challenging in patients, as it requires profiling early-stage lesions before clonal sweeps obscure diversity. To investigate this, we analyzed normal colorectal mucosa, benign and dysplastic premalignant polyps, and malignant adenocarcinomas (123 samples) from six individuals with familial adenomatous polyposis (FAP). Individuals with FAP have a germline heterozygous APC mutation, predisposing them to colorectal cancer and numerous premalignant polyps by early adulthood4. Whole-genome and/or whole-exome sequencing revealed that many premalignant polyps-40% with benign histology and 28% with dysplasia-were composed of multiple genetic lineages that diverged early, consistent with polyclonal origins. This conclusion was reinforced by whole-genome sequencing of single crypts from multiple polyps in additional patients which showed limited sharing of mutations among crypts within the same lesion. In some cases, multiple distinct APC mutations co-existed in different lineages of a single polyp, consistent with polyclonality. These findings reshape our understanding of early neoplastic events, demonstrating that tumor initiation can arise from the convergence of diverse mutant clones. They also suggest that cell-intrinsic growth advantages alone may not fully explain tumor initiation, highlighting the importance of microenvironmental and tissue-level factors in early cancer evolution.

Colorectal cancer (CRC) arises through interactions between driver mutations, such as in APC and KRAS, and the tumor microenvironment (TME), including inflammatory factors. While chronic inflammation is a known risk factor, the role of transient mild inflammation in tumorigenesis remains unclear. This study assessed the impact of mild inflammation on CRC development using genetically modified KRAS mutant (mut), APC mut, and APC; KRAS double mut mouse models. Mice received tamoxifen at six weeks and were evaluated with or without a 5-day administration of 1.5% dextran sulfate sodium (DSS). Mice were sacrificed at 20 weeks, and tumor number, size, location, histology, immunofluorescence, and RNA sequencing were analyzed. Tumors were absent in APC and KRAS mut mice not treated with DSS, while APC; KRAS mut mice developed small proximal colon tumors. DSS-treated KRAS mut mice remained tumor-free, but APC and APC; KRAS mut mice developed multiple tumors throughout the colon. In APC; KRAS mut mice, DSS significantly increased tumor number and size in the proximal colon. Although DSS did not alter immune infiltration in proximal tumors, regulatory T cells and M2 macrophages were elevated in APC; KRAS compared to APC mutants, suggesting immunosuppressive TME. These findings indicate that transient inflammation promotes CRC development in APC mutant mice.Supplementary InformationThe online version contains supplementary material available at 10.1038/s41598-025-25577-1.

Medulloblastoma (MB), a malignant cerebellar embryonal tumor, is predominantly sporadic, with rare familial cases linked to germline mutations in SUFU, PTCH1, TP53, and APC, primarily driving WNT and SHH molecular subtypes. Familial non-WNT/non-SHH MBs remain poorly understood, with limited genetic insights. This study presents two siblings (11-year-old male, 16-year-old female) with non-WNT/non-SHH MBs. Whole exome sequencing (WES) was performed on tumor samples (MB1-T, MB2-T), peripheral blood (MB2-PB, parents), and analyzed for somatic/germline variants. Screening criteria excluded intronic/synonymous single nucleotide variants (SNVs) and common alleles. MB2 harbored somatic chromosome 17q gain (prognostic marker) and two deleterious NF1 mutations (p.G2785V, p.N2788Y), absent in MB1. Germline analysis identified rare variants in KYAT3, SPATA31A6, and CBWD6, with potential roles in metabolic reprogramming (KYAT3) and genomic instability (SPATA31A6). No known MB predisposition syndromes or mutations were detected. This first report of familial non-WNT/non-SHH MBs highlights novel somatic (NF1) and germline (KYAT3, SPATA31A6) variants, suggesting unexplored oncogenic mechanisms. The findings underscore the need for further research to elucidate drivers of non-WNT/non-SHH MBs and develop targeted therapies. WES proves critical in uncovering genetic underpinnings of rare familial MBs.

Whole-genome sequencing of sporadic vestibular schwannoma (VS) specimens will reveal novel genetic mutations and molecular pathways involved in the pathogenesis of the disease. The optimal treatment for VS remains uncertain due to the inability to predict tumor behavior, growth, and symptom progression. While molecular changes and mutational burden may govern tumor behavior, genotype-phenotype correlations are not well established. The objective of this study was to describe the genomic landscape of sporadic VS utilizing next-generation sequencing, namely whole-genome sequencing (WGS), to identify novel genes and pathways involved in tumor behavior. Tumor and matched peripheral whole blood specimens were collected from 28 patients with pathologically confirmed VS who underwent surgical resection. Demographic and clinical characteristics were obtained. Specimens were stratified by pre-operative hearing status, macrocystic change, and growth behavior. Whole-genome sequencing was performed on 23 specimens. Quality control, somatic variant calling, differential expression, and functional enrichment analysis were completed. Whole-genome sequencing revealed 46 genes mutated in 4 or more tumor samples. Genes including ADGRV1, OTOGL, TRIOBP, APC, and MUC genes were identified to be of particular relevance. CAPN5 and NRP2 were downregulated in tumors with cystic change. The NF2 gene was affected in 16 of 23 samples, with 32 identified mutations. Next-generation sequencing of sporadic vestibular schwannoma specimens identified numerous novel mutated genes and differentially expressed proteins, which may be important drivers of tumor behavior and pathogenesis.

BackgroundMost mutant adenomatous polyposis coli (APC) gene produced truncated APC protein (Trunc-APC), which has been shown to function as an oncogene in colorectal cancer (CRC) pathogenesis; however, its role in modulating innate immune responses within tumor cells remains unexplored.MethodsWe utilized CRISPR-Cas9 to knockout mutant APC and performed transcriptome sequencing across multiple CRC cell lines to investigate the immunomodulatory function of Trunc-APC. Subcellular fractionation, proteinase K protection assays, and immunofluorescence were employed to determine Trunc-APC subcellular localization. Protein interaction studies, ubiquitination assays, and aggregation analyses were conducted to elucidate Trunc-APC binding to MAVS and its impact on MAVS ubiquitination and RIG-I association. The effects of Trunc-APC deletion, alone or in combination with 5-azacytidine and trichostatin A, were evaluated on type I interferon activation, apoptosis, and tumor growth both in vitro and in vivo.ResultsWe found that Trunc-APC partially localizes to the mitochondrial outer membrane and attenuates type I interferon signaling by binding to MAVS, suppressing its K63-linked polyubiquitination, and disrupting MAVS-RIG-I interactions. Deletion of Trunc-APC, particularly when combined with 5-azacytidine and trichostatin A, enhanced innate immune activation, promoted tumor cell apoptosis, and significantly inhibited CRC tumor growth both in vitro and in vivo.ConclusionsOur study reveals a previously unrecognized role of Trunc-APC in dampening tumor-intrinsic innate immunity and suggests that co-targeting Trunc-APC with epigenetic therapy may offer a promising strategy to enhance anti-tumor immune responses in CRC.Supplementary InformationThe online version contains supplementary material available at 10.1186/s12967-025-07286-5.

Background: Ampullary cancer is a rare biliary tract cancer arising from one of the three epithelial tissues in the region. Leveraging a large patient-level genomic database, this study aims to identify, explore, and describe the genetic landscape of ampullary carcinoma and its implications. Methods: A retrospective analysis of ampullary cancer samples was conducted using the AACR Project GENIE database. Analysis of recurrent somatic mutations at large and between patient populations, and co-occurrence and mutual exclusivity of mutations was conducted, with a p-value < 0.05. Results: The most frequent mutations were identified as TP53 (53.2%), KRAS (46.6%), and SMAD4 (16.6%). Mutational differences were noted between sexes, White vs. Non-white groups, and histopathological subtypes. Significant mutual exclusivity was found between KRAS and ERBB2. Co-occurrence was observed in the ARID1A mutation with KMT2D, ERBB2, and PIK3CA; CDKN2A with the SMAD4 and KRAS mutations; TP53 mutation with the CTNNB1 mutation; and KRAS co-occurred with an APC mutation. Reduced survival rates were seen in populations with the TP53 or KRAS mutation. Conclusions: This study provides a detailed descriptive genomic landscape of ampullary carcinoma, highlighting frequent mutations between patient groups and the mutational burden of the DNA damage response pathway in ampullary cancer, laying important groundwork for the development of therapeutic targets and more individualized treatment regimens.

Multiple polyposis syndromes include Familial adenomatous polyposis (FAP), Peutz-Jeghers syndrome (PJS), Juvenile polyposis syndrome (JPS), PTEN hamartoma tumor syndrome (PHTS), MUTYH-associated polyposis (MAP), NTHL1-associated polyposis (NAP), Polymerase proofreading-associated polyposis (PPAP), and MBD4-associated polyposis. Common to these syndromes is the presence of polyps in the large intestine and very high risk of developing colorectal cancer (CRC), which can reach up to 100% in the case of FAP. The development of FAP is associated with pathogenic variants of the APC gene. However, pathogenic variants are not always detected in patients with FAP, which poses a significant clinical challenge for both patients and their families, who may be at increased risk for developing the disease. A second strong predisposition to CRC is MAP, characterized by biallelic pathogenic variants in the MUTYH gene, with a phenotype similar to FAP. This mini review focuses on potential approaches to improve the diagnosis of patients in whom pathogenic variants in the APC and MUTYH genes are not detected by routine testing.

Metastatic colorectal cancer (mCRC), particularly microsatellite stable (MSS) cases, often exhibits limited responsiveness to immunotherapy, leaving chemotherapy as the primary treatment option. While chemotherapy effectively targets tumor cells, its impact on the broader mutational landscape, including passenger mutations in large genes such as Titin (TTN), remains poorly understood. Passenger mutations, traditionally deemed biologically inert, may reflect tumor mutational burden (TMB) and influence treatment outcomes. In our study involving whole exome sequencing of paired primary and metastatic tumor samples from 22 mCRC patients, recurrent driver mutations in APC, KRAS, and TP53 were consistently observed. However, passenger mutations in large genes, particularly TTN, were notably enriched in chemonaïve specimens and associated with higher TMB. Chemotherapy-treated samples exhibited a significant reduction in these mutations, suggesting selective depletion of hypermutated subclones. Our findings demonstrate that chemotherapy may selectively reduce passenger mutations in mCRC, potentially influencing the persistence of hypermutated subclones. This highlights the potential role of passenger mutation patterns and TMB as biomarkers for treatment response and raises the hypothesis that they could help guide immunotherapy considerations for patients with MSS mCRC.

Simple SummaryGlycogen synthase kinase 3 (GSK3) contains two isoforms, GSK3α and GSK3β, which are key negative regulators of the Wnt/β-catenin signaling pathway. This study focuses on investigating the role of GSK3 in intestinal function. We found that GSK3α and GSK3β exhibit functional redundancy in the intestine. However, complete loss of GSK3 resulted in lethality in mice, accompanied by disruption of the intestinal cellular niche, aberrant proliferation and mislocalization of stem cells and Paneth cells, as well as impaired intestinal absorption and motility. Despite that both GSK3 deficiency and APC mutation led to upregulated β-catenin expression, the intestinal phenotypes of GSK3-deficient mice were different from ApcMin/+ mice. Notably, deletion of β-catenin partially rescued the hyperproliferation and mislocalization of Paneth cells and contributed to the restoration of the intestinal niche and function. Our findings indicate the essential role of GSK3 in maintaining intestinal homeostasis and reveal the dual function of the GSK3/β-catenin axis in regulating intestinal stem cell development and absorptive function.WNT/β-catenin signaling is essential for intestinal stem cell development and self-renewal, while its dysregulation can drive tumorigenesis. GSK3, a key negative regulator of β-catenin, in intestinal homeostasis remains incompletely understood. In this study, we investigated the role of GSK3 in intestinal development, niche maintenance, and physiological function. Unlike ApcMin/+ mice that developed intestinal polyps, neither GSK3α nor GSK3β deficiency disrupted intestinal homeostasis. However, complete GSK3 deletion (DKO) resulted in perinatal lethality, characterized by disturbed crypt–villus architecture, Paneth cell redistribution, and villus elongation. GSK3 deficiency disrupted the intestinal niche, leading to expanded and mislocalized stem cells and Paneth cells, along with reduced tuft and enteroendocrine cells. These alterations impaired nutrient absorption and gut motility. Mechanistically, β-catenin-positive cells were significantly increased following GSK3 deletion. Genetic ablation of β-catenin under GSK3-deficient conditions reduced stem and Paneth cell populations while restoring tuft and enteroendocrine cells, thereby ameliorating niche abnormalities and improving absorptive and peristaltic functions. This study indicates the essential role of GSK3/β-catenin signaling in maintaining intestinal niche integrity and digestive physiology, highlighting potential therapeutic targets for intestinal and digestive disorders.

Background: Colorectal cancer (CRC) patients and survivors, irrespective of treatment received, have increased rates of hypertension and diseases of vascular remodeling compared to those without cancer. Prior literature demonstrates endothelial dysfunction and smooth muscle cell (SMC) plasticity in the localized CRC tumor microenvironment, but it is unknown if the cancer itself contributes to more global vascular changes in patients. Hypothesis: CRC independently leads to vascular remodeling. Methods: Age and sex-matched C57BL/6J mice were compared to spontaneous CRC mice with heterozygous loss-of-function of adenomatous polyposis coli (APC Min+/- ). A metastatic model using orthotopic liver injections of a syngeneic CRC cell line (MC38) was also compared to sham liver implantations. Endothelial and SMC functional testing were performed using ex vivo carotid arteries treated with phenylephrine, acetylcholine (Ach), and sodium nitroprusside (SNP). Stress-strain testing was performed on ex vivo thoracic aortic rings subjected to progressive tension. Assessment of collagen and elastin content in these vessels was also performed using Picrosirius Red and Verhoeff-Van Gieson, respectively. Results: APC Min+/- mice have reduced endothelial dependent dilation (EDD) after treatment with ACh (Peak EDD 94.15 ± 6.8 % vs. 79.35 ± 14.44 %, P&lt;0.05), and increased aortic intrinsic mechanical wall stiffness (Elastic Modulus 3172 ± 1215 kPa vs 6890 ± 2284 kPa, P&lt;0.05). Vessels from APC Min+/- mice had increased collagen content (0.31± 0.12 % vs 0.5 ± 0.08 %, P&lt;0.05) and lower elastin content (0.59 ± 0.06 % vs 0.5 vs 0.09 %, P &lt; 0.05). The metastatic CRC model conversely suggested a pattern of reduced endothelium independent dilation (EID) after vessels were treated with SNP (Peak EID 91.90 ± 9.8 vs 87.49 ± 4.8, P&gt;0.05) as well as increased aortic intrinsic mechanical wall stiffness (Elastic Modulus 3274 ± 975 kPa vs 5527 ± 2277 kPa, P&lt;0.05). Collagen content was increased (0.6% ± 0.11 vs 0.68% ± 0.11 P&lt; 0.05), and elastin content decreased (0.6% ± 0.05 vs 0.57% ± 0.07 p&gt;0.05). Conclusion: Spontaneous and metastatic models of CRC both demonstrated increased vascular stiffness and adverse remodeling. Murine models differed in vascular functional testing for EDD and EID, suggesting possible roles for both endothelial and SMCs in this remodeling process. Ongoing work is focused on defining secretome differences to further clarify signaling drivers of these observed changes.

Desmoid tumors, known as aggressive fibromatosis, are derived from connective tissues, and local invasion is usually observed. Despite intensive efforts have been performed to investigate the novel anticancer agents in desmoid tumors, effective clinical management for treating desmoid tumors has not been developed yet. Additionally, the molecular mechanisms involved in the tumorigenesis of desmoid tumors have not been elucidated. In this study, given the frequent mutations of Wnt components and loss of function mutations in Trp53 in desmoid tumors, we developed the mouse models harboring Apc mutation with/without Trp53 knockout, Apc1638N/+, and Apc1638N/+/Trp53-/-, respectively. We then established two primary cells derived from desmoid tumors in Apc1638N/+ and Apc1638N/+/Trp53-/-. Next, we have screened 3120 chemicals from a Food and Drug Administration-approved chemical library and identified halofuginone hydrobromide (HH), a collagen I-targeting compound, as exhibiting the most significant growth inhibition effects on Apc1638N/+ and Apc1638N/+/Trp53-/- desmoid tumor cells. Notably, HH also showed dramatic anticancer effects on colorectal cancer cells and mouse tumor organoids derived from intestinal tumors (Apc1638N/+). Taken together, targeting collagen I is an effective therapeutic strategy for treating desmoid tumors and colorectal cancer patients.

Identifying and characterizing a novel APC promoter 1B deletion in a Chinese family with familial adenomatous polyposis.

Protective role of epithelial deoxyhypusine synthase in colorectal carcinogenesis caused by deletion of the adenomatous polyposis coli gene.

The prevalence of TP53, APC, and PIK3CA gene mutations in colorectal cancer patients: A Systematic Review and Meta-analysis

Gastric adenocarcinoma and proximal polyposis of the stomach (GAPPS) is an autosomal dominant syndrome characterized by polyposis localized in the gastric body and fundus with a strong tendency for adenocarcinoma. The genetic mutations that accumulate during the progression from normal mucosa through polyp to carcinoma in GAPPS remain unclear. We investigated the evolutionary process from normal mucosa to polyp and carcinoma in GAPPS. Through comprehensive mutational and transcriptome analyses, we aimed to provide insights into the biology of this disease. Whole-exome sequencing and RNA sequencing were performed on carcinoma, polyp, and normal mucosa samples from multiple sites from seven patients with GAPPS (n = 54 samples). We comprehensively investigated genomic alterations (including copy number alterations and somatic mutations), clonal architecture, and transcriptome dynamics during carcinogenesis. Genomic evolutionary analysis showed that in GAPPS, somatic mutations of APC occur in carcinoma and polyp while mutations of KRAS additionally occur in carcinoma. We also found the co-occurrence of APC and KRAS mutations in carcinoma recurrently both across cases and within subclones of the same case. The co-occurrence of APC/KRAS mutations may contribute to the carcinogenesis of GAPPS. Our study provides detailed information on the genomic and transcriptomic landscape in GAPPS carcinogenesis, conferring valuable insights into its underlying mechanisms.

ABSTRACTObjectiveGlobally, millions of cancer cases are diagnosed annually and mortality rates continue to rise with breast (BC), colorectal (CRC) and prostate (PC) cancer among the most prevalent. Race and ethnic disparities in cancer outcomes have been well‐documented; however, the underlying factors contributing to these disparities are currently unknown.DesignThis study utilised the Genomic Data Commons (GDC) Portal, a publicly accessible repository, therefore ethical approval was not required. Cancer incidence data were collected by prevalent gene mutations associated with BC, CRC and PC within White, Black and Asian populations. Rolling one‐year survival rates were constructed for each genetic mutation.ResultsFor BC, Black and Asian individuals exhibited higher percentages of cases associated with TP53 mutations compared to Whites. CRC incidence showed Black individuals exhibited higher percentages of cases associated with APC, KRAS and PIK3CA mutations compared to Whites and Asians. PC incidence demonstrated that Black individuals had elevated percentages of cases associated with SPOP, ATM and SYNE1 mutations compared to Whites and Asians. Asian individuals displayed significantly lower survival percentages over 10 years compared to White and Black populations across genetic mutations associated with BC. White individuals exhibited significantly higher survival percentages over 10 years compared to Black individuals across genetic mutations associated with CRC.ConclusionSignificant disparities exist in cancer incidence and survival rates across White, Black and Asian populations. These findings demonstrate the importance of targeted approaches in cancer prevention, diagnosis and treatment to address disparities and the need for equitable healthcare. Further research is needed to identify mechanisms driving such disparities and to develop effective strategies to improve cancer outcomes across diverse ethnic populations.

Intracellular transport relies on motor proteins such as kinesins to deliver cargo along microtubules, yet how they recognize cargo remains unclear. Here, we present high-resolution cryo–electron microscopy structures of the heterotrimeric kinesin-2 complex (KIF3A/KIF3B/KAP3) bound to the cargo protein APC. Our findings reveal a previously uncharacterized KIF3 tail hook-like motif, termed the “HAC” domain, which mediates binding to both KAP3 adaptor and APC cargo. Within this domain, the KIF3A helical regions ensure cargo specificity, while a β-hairpin and KIF3B provide structural support. Biochemical and neuronal experiments confirm its functional importance. Notably, the HAC/KAP3 structure resembles hook-like architectures seen in kinesin-1 and dynein, suggesting a shared cargo recognition framework. These findings also shed light on kinesin-2 cargo specificity and offer a structural framework for understanding related neuronal transport mechanisms.

Disclosure: L. Martel-Duguech: None. A. Doreille: None. M. Latour: None. M. Thibodeau: None. N. Dumas: None. I. Bourdeau: None. Z. El Haffaf: None. A. Lacroix: None.Background: Hyperparathyroidism-Jaw Tumor Syndrome (HPT-JT) is secondary to germline inactivating mutations of the tumor suppressor CDC73 gene. Affected patients often present in addition to severe HPT, lesions in kidney, uterus and thyroid. Primary bilateral macronodular adrenal hyperplasia (PBMAH) can be secondary to mutations in ARMC5 and less frequently in KDM1A, MEN1, APC or FH genes. We now report a patient with HPT-JT and germline CDC73 mutation who later developed PBMAH co-secreting cortisol and aldosterone without ARMC5 or MEN1 gene mutations. Case Presentation: a 54-y.o female was referred in 2013 for bilateral adrenal nodules with weight gain, fatigue, myopathy, hypertension with sleep apnea. Previous history included recurrent kidney stones since age 19, three parathyroidectomies (26, 46, 53 yo) for severe HPT, nephrocalcinosis, near end-stage renal disease and hysterectomy at age 35 for metrorrhagia. Abdominal CT without contrast showed PBMAH (multiple nodules up to 25 mm, 3 to 33 HU), very atrophic kidneys with extensive nephrocalcinosis and renal cysts. Hormonal dynamic testing confirmed suppressed ACTH with aberrant regulation of excess cortisol (443 nmol/L post-dex) and aldosterone production by vasopressin, upright posture and 5-HT4R agonists. Initial genetic testing excluded MEN1 pathogenic variants. Left adrenalectomy was performed in 2015 and pathology confirmed PBMAH; recent CYP11B2 IHC showed heterogeneous high expression of aldosterone synthase in wide portions of outer cortex, but it was negative in several central nodules, while CYP11B1 IHC is pending. Late night salivary cortisol and ACTH levels normalized with mild dysregulated cortisol secretion and residual primary aldosteronism was treated with spironolactone. In 2017, breast ductal carcinoma in situ (DCIS) was resected and she underwent kidney transplantation followed by immunosuppression including prednisone. Recently, progressive increase in cortisol secretion and ACTH suppression may require additional therapy. No jaw tumor was found at recent imaging. Genetic testing: in 2024, expanded panel genetic testing for HPT and PBMAH identified a pathogenic CDC73 pathogenic variant (c.512del, p.Arg171Serfs*31) without mutations in ARMC5, MEN1, RET, CASR, CDKN1B, GCM2. Family testing is currently under way. Conclusion: This is the first case of a patient with HPT-JT with CDC73 gene mutation who developed cortisol- and aldosterone-secreting PBMAH. This finding suggests the possibility that CDC73 mutations may also predispose to development of PBMAH.Presentation: Sunday, July 13, 2025