👤 O Yamato

Canine hepatocellular carcinoma (HCC) requires further molecular characterization to identify diagnostic and therapeutic targets, and to establish whether dogs with this condition can model the human disease. Accordingly, we aimed to identify differentially expressed genes (DEGs) in canine HCC and evaluate cross-species transcriptomic dysregulation in canine and human HCC. Liver tissue samples from three dogs with HCC and three healthy dogs were subjected to next-generation sequencing, followed by RT-qPCR validation. Identified DEGs were then targeted in bioinformatics analyses (pathway enrichment, protein-protein interaction network, and hub gene analyses) for molecular characterization and comparison with human HCC datasets. We identified 975 DEGs (upregulated: 604; and downregulated: 371). Extracellular matrix-receptor interaction, focal adhesion, cell adhesion molecule, PI3K/Akt signaling, and cytokine/chemokine-related pathways were enriched. C1R, APOC3, C1QA, APOA1, C1QB, ACTG1, C1QC, CRP, ANXA5, and ANXA2 were identified as hub genes. Canine and human HCCs share 118 DEGs, highlighting conserved alterations in metabolic pathways, PI3K-Akt signaling, focal adhesion, and PPAR signaling pathways. Based on human HCC data, SPP1, NQO1, RRM2, APOA1, APOC3, ALDOB, and IGF1 were identified as prognosticators indicating poor overall survival. This study presents the first cross-species transcriptomic analysis of canine HCC, revealing significant molecular resemblances to human HCC, indicating it may be a promising comparative model for studying tumor biology, drug responses, and novel therapeutic interventions. Show less

Recent advances in the genetic understanding of acute myeloid leukemia (AML) have improved clinical outcomes in pediatric patients. However, ∼40% of patients with pediatric AML relapse, resulting in a relatively low overall survival rate of ∼70%. The objective of this study was to reveal the comprehensive genetic background of pediatric AML. We performed transcriptome analysis (RNA sequencing [RNA-seq]) in 139 of the 369 patients with de novo pediatric AML who were enrolled in the Japanese Pediatric Leukemia/Lymphoma Study Group AML-05 trial and investigated correlations between genetic aberrations and clinical information. Using RNA-seq, we identified 54 in-frame gene fusions and 1 RUNX1 out-of-frame fusion in 53 of 139 patients. Moreover, we found at least 258 gene fusions in 369 patients (70%) through reverse transcription polymerase chain reaction and RNA-seq. Five gene rearrangements were newly identified, namely, NPM1-CCDC28A, TRIP12-NPM1, MLLT10-DNAJC1, TBL1XR1-RARB, and RUNX1-FNBP1. In addition, we found rare gene rearrangements, namely, MYB-GATA1, NPM1-MLF1, ETV6-NCOA2, ETV6-MECOM, ETV6-CTNNB1, RUNX1-PRDM16, RUNX1-CBFA2T2, and RUNX1-CBFA2T3. Among the remaining 111 patients, KMT2A-PTD, biallelic CEBPA, and NPM1 gene mutations were found in 11, 23, and 17 patients, respectively. These mutations were completely mutually exclusive with any gene fusions. RNA-seq unmasked the complexity of gene rearrangements and mutations in pediatric AML. We identified potentially disease-causing alterations in nearly all patients with AML, including novel gene fusions. Our results indicated that a subset of patients with pediatric AML represent a distinct entity that may be discriminated from their adult counterparts. Based on these results, risk stratification should be reconsidered. Show less

Elucidating the regulation of glucose-stimulated insulin secretion (GSIS) in pancreatic islet β cells is important for understanding and treating diabetes. MIN6 cells, a transformed β-cell line derived from a mouse insulinoma, retain GSIS and are a popular in vitro model for insulin secretion. However, in long-term culture, MIN6 cells' GSIS capacity is lost. We previously isolated a subclone, MIN6 clone 4, from the parental MIN6 cells, that shows well-regulated insulin secretion in response to glucose, glybenclamide, and KCl, even after prolonged culture. To investigate the molecular mechanisms responsible for preserving GSIS in this subclone, we compared four groups of MIN6 cells: Pr-LP (parental MIN6, low passage number), Pr-HP (parental MIN6, high passage number), C4-LP (MIN6 clone 4, low passage number), and C4-HP (MIN6 clone 4, high passage number). Based on their capacity for GSIS, we designated the Pr-LP, C4-LP, and C4-HP cells as "responder cells." In a DNA microarray analysis, we identified a group of genes with high expression in responder cells ("responder genes"), but extremely low expression in the Pr-HP cells. Another group of genes ("non-responder genes") was expressed at high levels in the Pr-HP cells, but at extremely low levels in the responder cells. Some of the responder genes were involved in secretory machinery or glucose metabolism, including Chrebp, Scgn, and Syt7. Among the non-responder genes were Car2, Maf, and Gcg, which are not normally expressed in islet β cells. Interestingly, we found a disproportionate number of known imprinted genes among the responder genes. Our findings suggest that the global expression profiling of GSIS-competent and GSIS-incompetent MIN6 cells will help delineate the gene regulatory networks for insulin secretion. Show less

Neuronal ceroid lipofuscinosis (NCL) is a neurodegenerative disease caused by a number of different genes. A mutational analysis of the feline CLN3 gene was performed in a cat with NCL that had vacuolated lymphocytes, which is a feature of human NCL caused by defects of the CLN3 gene. To determine the candidate gene(s) responsible for this case, NCL-specific ultrastructures of storage materials were analysed. A sequence analysis indicated that the CLN3 gene was not likely to be responsible for this case of feline NCL because no deleterious mutation was detected. An ultrastructural analysis did not reveal any candidate gene because of inconsistency with any pattern found in human NCL. These findings suggest that the diagnostic criteria for human NCL are not directly applicable to feline NCL. Show less

We analyzed mutation of the APC, AXIN1, and GSK3genes in 14 pituitary adenomas with abnormal nuclear accumulations of CTNNB1. These tumors did not harbor mutation of the CTNNB1 gene. The genes analyzed encode proteins associated with ubiquitin-mediated degradation of CTNNB1. Although the regions encoding functional domains of these protein products were analyzed, no significant genetic alterations were found. Furthermore, the antibody for the C-terminus of APC detected normal expression of the APC protein in these pituitary adenomas. Our present results imply that an unknown mechanism(s) accelerates the accumulation of CTNNB1 that plays an important role in the pathogenesis of human pituitary adenomas. However, the possibility that mutation of regions outside of our survey or epigenetic mechanism play an important role cannot be excluded. Show less