HNF-1β過剰発現を呈する卵巣明細胞癌においてGSK-3βは新たなシグナル伝達経路を介在する

Deubiquitinase USP28 is a target gene of the transcription factor HNF1 homeobox β (HNF-1β), which promotes the survival of ovarian clear cell carcinoma (OCCC) cell lines. However, the pharmacological inhibition of HNF-1β can cause several adverse effects as it is abundantly expressed in numerous organ systems, including the kidney, liver, pancreas and digestive tract. Therefore, small interfering RNA (siRNA) screening was performed in the current study to identify other potential downstream targets of the HNF-1β-mediated pathway. The results revealed that glycogen synthase kinase-3β (GSK-3β) may be a potential downstream target affecting cell viability. To further clarify the effects of GSK-3β, two human OCCC cell lines, TOV-21G (HNF-1β overexpressing line) and ES2 (HNF-1β negative) were transfected with siRNA targeting GSK-3β or control vectors. Loss-of-function studies using RNAi-mediated gene silencing indicated that HNF-1β facilitated GSK-3β expression, resulting in the loss of phosphorylated nuclear factor-κB (p-NFκB) and the reduction of TOV-21G cell proliferation. The cell proliferation assay also revealed that GSK-3β inhibitors rescued the effects of HNF-1β silencing on cell viability in a dose-dependent manner. Furthermore, the GSK-3β inhibitor, AR-A014418, effectively inhibited tumor cell proliferation in a xenograft mouse model. In conclusion and to the best of our knowledge, the current study was the first to determine that GSK-3β is a target gene of HNF-1β. In addition, the results of the present study revealed the novel HNF-1β-GSK-3β-p-NFκB pathway, occurring in response to DNA damage. Targeting this pathway may therefore represent a putative, novel, anticancer strategy in patients with OCCC.博士（医学）・甲第785号・令和3年3月15日Copyright: © Kawaharaet al. This is an open access article distributed under theterms of CreativeCommons Attribution License(https://creativecommons.org/licenses/by-nc-nd/4.0/)

A Model of Cancer Stem Cells Derived from Mouse Induced Pluripotent Stem Cells

Cancer stem cells (CSCs) are capable of continuous proliferation and self-renewal and are proposed to play significant roles in oncogenesis, tumor growth, metastasis and cancer recurrence. CSCs are considered derived from normal stem cells affected by the tumor microenvironment although the mechanism of development is not clear yet. In 2007, Yamanaka's group succeeded in generating Nanog mouse induced pluripotent stem (miPS) cells, in which green fluorescent protein (GFP) has been inserted into the 5′-untranslated region of the Nanog gene. Usually, iPS cells, just like embryonic stem cells, are considered to be induced into progenitor cells, which differentiate into various normal phenotypes depending on the normal niche. We hypothesized that CSCs could be derived from Nanog miPS cells in the conditioned culture medium of cancer cell lines, which is a mimic of carcinoma microenvironment. As a result, the Nanog miPS cells treated with the conditioned medium of mouse Lewis lung carcinoma acquired characteristics of CSCs, in that they formed spheroids expressing GFP in suspension culture, and had a high tumorigenicity in Balb/c nude mice exhibiting angiogenesis in vivo. In addition, these iPS-derived CSCs had a capacity of self-renewal and expressed the marker genes, Nanog, Rex1, Eras, Esg1 and Cripto, associated with stem cell properties and an undifferentiated state. Thus we concluded that a model of CSCs was originally developed from miPS cells and proposed the conditioned culture medium of cancer cell lines might perform as niche for producing CSCs. The model of CSCs and the procedure of their establishment will help study the genetic alterations and the secreted factors in the tumor microenvironment which convert miPS cells to CSCs. Furthermore, the identification of potentially bona fide markers of CSCs, which will help the development of novel anti-cancer therapies, might be possible though the CSC model

Cytokine Expression and Macrophage Localization in Xenograft and Allograft Tumor Models Stimulated with Lipopolysaccharide

T cell-deficient mice such as nude mice are often used to generate tumor xenograft for the development of anticancer agents. However, the functionality of the other immune cells including macrophages, dendritic cells (DCs), and myeloid-derived suppressor cells (MDSCs) in the xenograft are largely unknown. Macrophages and dendritic cells (DCs) acquire functionally distinct properties in response to various environmental stimuli; the interaction of these cells with MDSCs in tumor microenvironments regulates cancer progression. Nude mice are less likely to reject human cancer cells because of major histocompatibility complex (MHC) mismatches. The tumor microenvironment in a xenograft, comprising human and mouse cells, exhibits more complex bidirectional signaling and function than that of allograft. Here, we evaluated the differences of myeloid cells between them. Plasma interferon-γ and interleukin-18 concentrations in the xenograft tumor model after lipopolysaccharide (LPS) administration were significantly higher than those in the allograft tumor model. MHC class I, II, and CD80 expression levels were increased in CD11b+ and MDSC populations after LPS administration in the spleen of a xenograft tumor model but not in that of an allograft tumor model. Additionally, the number of CD80- and mannose receptor C type 1 (MRC1)-expressing cells was decreased upon LPS administration in the tumor of the xenograft tumor. These results suggest that functions of macrophages and DCs are sustained in the xenograft, whereas their functions in response to LPS were suppressed in the allograft. The findings will encourage the consideration of the effects of myeloid cells in the xenograft for drug development

Does Instruction of Oral Health Behavior for Workers Improve Work Performance?—Quasi-Randomized Trial

Oral disease can cause economic loss due to impaired work performance. Therefore, improvement of oral health status and prevention of oral disease is essential among workers. The purpose of this study was to investigate whether oral health-related behavioral modification intervention influences work performance or improves oral health behavior and oral health status among Japanese workers. We quasi-randomly separated participants into the intervention group or the control group at baseline. The intervention group received intensive oral health instruction at baseline and a self-assessment every three months. Both groups received oral examinations and answered the self-questionnaire at baseline and at one-year follow-up. At follow-up, the prevalence of subjects who use fluoride toothpastes and interdental brushes/dental floss were significantly higher in the intervention group than in the control group. Three variables (tooth brushing in workplace, using fluoride toothpaste, and experience of receiving tooth brushing instruction in a dental clinic) showed significant improvement only in the intervention group. On the other hand, work performance and oral status did not significantly change in either group. Our intensive oral health-related behavioral modification intervention improved oral health behavior, but neither work performance nor oral status, among Japanese workers

Association between Knowledge about Comprehensive Food Education and Increase in Dental Caries in Japanese University Students: A Prospective Cohort Study

In Japan, comprehensive food education (shokuiku) programs are carried out with the aim of improving dietary practices and thereby reducing the incidence of lifestyle-related diseases, including dental caries. The purpose of this prospective cohort study was to investigate the association between knowledge about shokuiku and the increase in dental caries among Japanese university students who had attended a shokuiku program while in junior/senior high school. A total of 562 students volunteered to undergo oral examinations over a three-year follow-up period, during which the number of cases of dental caries were recorded. Additional information was collected using a questionnaire survey regarding knowledge about shokuiku, dietary habits, and oral health behaviors. In logistic regression analysis, males who lacked knowledge about shokuiku had significantly higher odds for dental caries than those who did not (odds ratio (OR), 2.00; 95% confidence interval (CI), 1.12–3.58; p = 0.019). On the other hand, among females, those who frequently consumed sugar-sweetened soft drinks had significantly higher odds for dental caries than those who did not (OR, 1.89; 95% CI, 1.05–3.42; p = 0.035). These results suggest that having no knowledge about shokuiku is associated with a risk of increase in dental caries in Japanese male university students

Associations between dental knowledge, source of dental knowledge and oral health behavior in Japanese university students: A cross-sectional study

<div><p>The aim of this study was to investigate the associations between dental knowledge, the source of dental knowledge and oral health behavior in a group of students at a university in Japan. A total of 2,220 university students (1,276 males, 944 females) volunteered to undergo an oral examination and answer a questionnaire. The questionnaire assessed dental knowledge, the source of dental knowledge and oral health behavior (e.g., daily frequency of tooth brushing, use of dental floss and regular dental checkups). The odds ratio and 95% confidence interval for oral health behavior based on dental knowledge and source of dental knowledge were calculated using logistic regression models. Of the participants, 1,266 (57.0%) students obtained dental knowledge from dental clinics, followed by school (39.2%) and television (29.1%). Logistic regression analyses indicated that use of dental floss was significantly associated with source of dental knowledge from dental clinics (<i>P</i> = 0.006). Receiving regular dental checkups was significantly associated with source of dental knowledge; the positive source was dental clinic (<i>P</i> < 0.001) and the negative sources were school (<i>P</i> = 0.004) and television (<i>P</i> = 0.018). Dental clinic was the most common source of dental knowledge and associated with better oral health behavior among the Japanese university students in this study.</p></div

Differences in parameters between males and females.

<p>Differences in parameters between males and females.</p

Adjusted OR and 95% CIs for oral health behavior.

<p>Adjusted OR and 95% CIs for oral health behavior.</p