キイ ナ ブンシ コウゾウ オ ユウシタ カゴウブツ ノ デンシ ブッセイ ニ カンスル リロンテキ ケンキュウ

熊本大

Surface Oxygen Vacancy Formation Energy Calculations in 34 Orientations of beta-Ga2O3 and theta-Al2O3

Computational exploration of previously unknown reactive sites is a powerful strategy for the emergence of new catalytic reactions. Exotic surfaces can be theoretically investigated, but there are very few, if any, computational models of high-index orientations that consider the reconstruction of the surface. A workflow to efficiently obtain a set of accessible terminations by removing those that are metastable against macroscopic facet formation and by comparing cleaved surfaces and surfaces suggested by a genetic algorithm (GA) for promising orientations is proposed and demonstrated using 34 orientations of beta-Ga2O3 and theta-Al2O3. Seven and six terminations considered to be experimentally accessible are found for beta-Ga2O3 and theta-Al2O3, respectively, where the highest surface energy was roughly twice that of the lowest. The lowest surface 0 vacancy formation - energies (E-Ovac) among accessible surfaces are 3.04 and 5.46 eV in the (101) and (20 (1) over bar) terminations for beta-Ga2O3 and theta-Al2O3, respectively, where the decreases in E-Ovac, from the most stable surface are 1.32 and 1.11 eV, respectively. The E-Ovac in accessible surfaces showed a good correlation with the descriptors of the local coordination environment, suggesting that exploiting surface O in an unfavorable environment in an accessible termination would enhance O-vacancy-related catalyst performance even in materials that do not show reactivity on the most stable surface

キイ ナ ブンシ コウゾウ オ ユウシタ カゴウブツ ノ デンシ ブッセイ ニ カンスル リロンテキ ケンキュウ

博士(理学)熊本大

Deregulation of the Histone Lysine-Specific Demethylase 1 Is Involved in Human Hepatocellular Carcinoma

Hepatocellular carcinoma (HCC) is the most common type of primary liver cancer and is a leading cause of cancer-related death worldwide. Given that the standard-of-care for advanced liver cancer is limited, there is an urgent need to develop a novel molecular targeted therapy to improve therapeutic outcomes for HCC. In order to tackle this issue, we conducted functional analysis of the histone lysine-specific demethylase (LSD1) to explore the possibility that this enzyme acts as a therapeutic target in HCC. According to immunohistochemical analysis, 232 of 303 (77%) HCC cases showed positive staining of LSD1 protein, and its expression was correlated with several clinicopathological characteristics, such as female gender, AFP (alpha-fetoprotein) levels, and HCV (hepatitis C virus) infectious. The survival curves for HCC using the Kaplan–Meier method and the log-rank test indicate that positive LSD1 protein expression was significantly associated with decreased rates of overall survival (OS) and disease-free survival (DFS); the multivariate analysis indicates that LSD1 expression was an independent prognostic factor for both OS and DFS in patients with HCC. In addition, knockout of LSD1 using the CRISPR/Cas9 system showed a significantly lower number of colony formation units (CFUs) and growth rate in both SNU-423 and SNU-475 HCC cell lines compared to the corresponding control cells. Moreover, LSD1 knockout decreased cells in S phase of SNU-423 and SNU-475 cells with increased levels of H3K4me1/2 and H3K9me1/2. Finally, we identified the signaling pathways regulated by LSD1 in HCC, including the retinoic acid (RA) pathway. Our findings imply that deregulation of LSD1 can be involved in HCC; further studies may explore the usefulness of LSD1 as a therapeutic target of HCC