👤 Koichi Otani

Glioblastoma, isocitrate dehydrogenase wildtype (GBM, IDH-wt), is a highly aggressive brain tumor with a poor prognosis. Alterations in the fibroblast growth factor receptor (FGFR) gene family-such as FGFR::TACC fusions and FGFR1 mutations-have emerged as potential therapeutic targets; however, their clinical and genetic features in GBM, IDH-wt remain unclear. We analyzed 1076 GBM, IDH-wt cases using comprehensive genomic profiling data from the Center for Cancer Genomics and Advanced Therapeutics (C-CAT) database in Japan. FGFR alterations were detected in 8.0% of patients, including FGFR::TACC fusions (3.3%) and FGFR1 mutations (2.9%). The FGFR::TACC fusion-positive group was older at diagnosis and showed higher frequencies of TERT promoter mutation and MDM2 amplification, and lower frequencies of EGFR amplification and TP53 mutation, compared with the fusion-negative group. The FGFR1 mutation-positive group was enriched for ATRX, NF1, and PIK3CA mutations and had significantly fewer TERT promoter and PTEN mutations, compared with the mutation-negative group. No significant differences in overall survival were observed, although both groups tended to have longer median overall survival compared with their respective negative groups. This study represents the largest genomic cohort to date of FGFR alterations in GBM, IDH-wt. FGFR::TACC fusion-positive and FGFR1 mutation-positive GBMs exhibited distinct genetic profiles, highlighting the clinical relevance of molecular subclassification and providing insight for future therapeutic strategies. Show less

Environmental and genetic factors are suggested to exhibit factor-based association with HDL-cholesterol (HDL-C) levels. However, the population-based effects of environmental and genetic factors have not been compared clearly. We conducted a cross-sectional study using data from the Japan Multi-Institutional Collaborative Cohort (J-MICC) Study to evaluate the population-based impact of smoking, drinking, and genetic factors on low HDL-C. Data from 11,498 men and women aged 35-69 years were collected for a genome-wide association study (GWAS). Sixty-five HDL-C-related SNPs with genome-wide significance (P < 5 × 10 We found that smoking, drinking, daily activity, habitual exercise, egg intake, BMI, age, sex, and the SNPs CETP rs3764261, APOA5 rs662799, LIPC rs1800588, LPL rs328, ABCA1 rs2575876, LIPG rs3786247, and APOE rs429358 were associated with HDL-C levels. The gene-environmental interactions on smoking and drinking were not statistically significant. The PAF for low HDL-C was the highest in men (63.2%) and in rs3764261 (31.5%) of the genetic factors, and the PAFs of smoking and drinking were 23.1% and 41.8%, respectively. The present study showed that the population-based impact of genomic factor CETP rs3764261 for low HDL-C was higher than that of smoking and lower than that of drinking. Show less

Dietary protein deficiency and amino acid imbalance cause hepatic fat accumulation. We previously demonstrated that only arginine deficiency or total amino acid deficiency in a diet caused significant hepatic triglyceride (TG) accumulation in young Wistar rats. In this study, we explored the mechanisms of fatty liver formation in these models. We fed 6-week-old male Wistar rats a control diet (containing an amino acid mixture equivalent to 15% protein), a low-total-amino acid diet (equivalent to 5% protein; 5PAA), and a low-arginine diet (only the arginine content is as low as that of the 5PAA diet) for 2 weeks. Much greater hepatic TG accumulation was observed in the low-arginine group than in the low-total-amino acid group. The lipid consumption rate and fatty acid uptake in the liver did not significantly differ between the groups. In contrast, the low-total-amino acid diet potentiated insulin sensitivity and related signaling in the liver and enhanced de novo lipogenesis. The low-arginine diet also inhibited hepatic very-low-density lipoprotein secretion without affecting hepatic insulin signaling and lipogenesis. Although the arginine content of the low-arginine diet was as low as that of the low-total-amino acid diet, the two diets caused fatty liver via completely different mechanisms. Enhanced lipogenesis was the primary cause of a low-protein diet-induced fatty liver, whereas lower very-low-density lipoprotein secretion caused low-arginine diet-induced fatty liver. Show less

Genetic alterations in specific genes are critical events in carcinogenesis and hepatocellular carcinoma (HCC) progression. However, the genetic alterations responsible for HCC development, progression, and survival are unclear. We investigated the essential difference in genetic alterations between HCC and adjacent non-HCC tissues using next-generation sequencing technology. We found recurrent mutations in several genes such as telomerase reverse transcriptase (TERT; 65% of the total 104 HCCs), TP53 (38%), CTNNB1 (30%), AXIN1 (2%), PTEN (2%), and CDKN2A (2%). TERT promoter mutations were associated with older age (p = 0.005), presence of hepatitis C virus (HCV) infection (p = 0.003), and absence of hepatitis B virus (HBV) infection (p < 0.0001). In hepatitis B surface antigen (HBs Ag)-positive HCC without TERT promoter mutations, HBV integration into TERT locus was found in 47% patients and was mutually exclusive to TERT promoter mutations. Most (89%) HBV integrants were in the HBx region. TP53 mutations were associated with HBV infection (p = 0.0001) and absence of HCV infection (p = 0.002). CTNNB1 mutations were associated with absence of HBV infection (p = 0.010). Moreover, TERT promoter mutation was significantly associated with shorter disease-free survival (p = 0.005) and poor overall survival (p = 0.024). Gene alterations in TERT promoter, TP53, CTNNB1, and HBV integration were closely associated with HCC development, and mutations in TERT promoter are related to poor prognosis. These results are useful for understanding the underlying mechanism of hepatocarcinogenesis, diagnosis, and predicting outcomes of patients with HCC. Show less