Biology subjects

Aoi, T.

Publications and source records attributed to Aoi, T..

3 recordsLinked to original sources

bioRxiv2026

Tumor Microenvironment Modulates Lineage Plasticity in Lung Squamous Cell Carcinoma

Lung squamous cell carcinoma (LUSC) is the second most common type of lung cancer, yet therapeutic options remain limited. A deeper understanding of its biology and molecular pathogenesis is essential for developing new treatment strategies. Here, we investigated the mechanisms of phenotypic plasticity in LUSC by comparing organoid-derived orthotopic lung models (ODOLs) and subcutaneous xenograft models (ODXs). ODXs showed greater tumor growth, squamous differentiation, and extracellular matrix (ECM) organization compared to ODOLs. Transcriptomic analyses revealed upregulation of multiple HIF1 and SOX2 target genes together with enhanced hypoxia signaling in ODXs. CRISPR/Cas9-mediated HIF1-knockout ODXs showed reduced SOX2 expression, tumor growth, and ECM organization, whereas SOX2-knockout ODXs reduced tumor growth without affecting HIF1 and ECM organization. These results indicate that HIF1 regulates squamous lineage maintenance through SOX2 and ECM remodeling. Spatial transcriptomics revealed enrichment of basal cell-like and squamous-differentiated tumor states in ODXs, whereas ODOLs displayed less differentiated phenotypes. These findings identify the tumor microenvironment as a critical determinant of lineage plasticity in LUSC and provide mechanistic insight into how hypoxia shapes tumor differentiation.

Cancer Biology↗

bioRxiv2025

Genotype-first approach revealed unrecognized breed-specific genetic diseases in dogs

Numerous dogs are affected by genetic diseases because of their unique breeding situation. The identification of pathogenic variants in dogs not only has veterinary benefits but also leads to the development of new human disease models. However, fewer pathogenic variants have been identified in dogs than in humans, and standard genetic approaches, such as large-scale case/control studies and family analyses, often fail to identify novel causative variants in dogs. To address this, we applied a genotype-first approach by developing a multiplex polymerase chain reaction (PCR)-based targeted sequencing method for dogs, analyzing 203 genes--most of which are related to human disease--from 6,333 dogs collected from a veterinary hospital, and characterizing pathogenic variant carriers. In total, 120 pathogenic variants in 83 genes were identified. Frequent pathogenic variants were enriched in specific dog breeds. Dogs homozygous for a pathogenic CHEK2 variant, frequently identified in French Bulldogs (5.74%, homozygous), showed a five-fold increased risk of cancer (P = 3.45 x 10-2). A pathogenic NOD2 variant was detected in half of the Italian Greyhounds. However, their medical records did not document the typical clinical symptoms observed in humans with NOD2 deficiency. Some pathogenic variants were present in three or fewer dogs, and 11.0% of these dogs exhibited symptoms potentially associated with gene defects. These rare variants could become common within a short period due to the canine breeding system to induce breed-specific genetic diseases. These findings suggest that the genotype-first approach successfully identified unrecognized breed-specific genetic diseases. Further characterization of dogs with pathogenic variants enable to define clinical diagnosis, providing an important spontaneous model for human genetic diseases.

genomics↗

bioRxiv2020

Population-wide Screening for Germline Variants of Hereditary Cancer Genes in 12K Unselected Japanese Colorectal Cancers and 27K Controls

Background & AimsColorectal cancer (CRC) is one of the most common cancers in Western countries and Japan. Currently, a few % of CRCs can be attributed to recognizable hereditary germline variants of known CRC susceptibility genes, predominantly the DNA mismatch repair genes. To establish a universal screening strategy for hereditary CRCs, it is necessary to explore the prevalence of hereditary CRC and pathogenic variants of multiple cancer-predisposing genes in non-European populations. MethodsWe analyzed the coding regions of 27 cancer-predisposing genes, including mismatch repair genes, APC, and BRCA1/2, in 12,503 unselected Japanese CRC patients and 23,705 controls aged [≥] 60 years without any personal or family history of cancer by target sequencing and genome-wide SNP chip data. Their clinical significance was assessed using ClinVar and the guidelines by the American College of Medical Genetics and Genomics and the Association for Molecular Pathology (ACMG/AMP). ResultsWe identified 4,804 variants in the 27 genes and annotated them as 397 pathogenic variants, 941 benign variants, and 3,466 variants of uncertain significance, of which 43.6% were registered in neither ClinVar nor dbSNP. In total, 3.3% of the unselected CRC patients and 1.5% of the controls had a pathogenic variant of the 27 genes. The pathogenic variants of MSH2 (odds ratio (OR) =18.1), MLH1 (OR=8.6), MSH6 (OR=4.9), APC (OR=49.4), BRIP1 (OR=3.6), BRCA1 (OR=2.6), BRCA2 (OR=1.9), and TP53 (OR=1.7) were significantly associated with CRC development in the Japanese population (P-values < 0.01, FDR<0.05). Furthermore, we confirmed copy number variants (CNVs) of MSH2/EPCAM, MLH1, and APC by multiplex ligation-dependent probe amplification (MLPA) and quantitative PCR in this cohort (n = 23), including whole gene duplications of MSH2 and APC. These pathogenic variants were significantly associated with the diagnostic age and personal/family history of other types of cancer. In total, at least 3.5% of the Japanese CRC population had a pathogenic variant or CNV of the 27 cancer-predisposing genes. ConclusionsThis is the largest study of CRC heredity in the Asian population and would contribute to the development of guidelines for genetic testing and variant interpretation for heritable CRCs. Universal screening for CRC risk should be assessed in multiple genes, including BRCA1/2 and BRIP1. These data would facilitate risk assessment of cancer and optimize the screening strategy.

genetics↗