卵巣明細胞癌に対するプリチデプシンの前臨床活性

Background/Aim: To evaluate the antitumor effects of Plitidepsin against clear cell carcinoma (CCC) of the ovary. Materials and Methods: The expression of eEF1A2 in ovarian cancer was assessed by immunohistochemistry. Using ovarian CCC cell lines, the antitumor effect of Plitidepsin was assessed both in vitro and in vivo. By over-expressing or knocking down the eEF1A2 expression, we investigated the role of eEF1A2 in the sensitivity of CCC cells to Plitidepsin. Results: Immunoreactivity to eEF1A2 was observed in 76.2% of CCC, which was significantly higher than other histological subtypes of ovarian cancer. Plitidepsin exhibited significant antitumor activity toward chemonaive and chemoresistant CCC cells both in vitro and in vivo. Ectopic expression of eEF1A2 in CCC cells resulted in increased sensitivity to Plitidepsin. In contrast, eEF1A2 knockdown decreased sensitivity of CCC cells to plitidepsin. Conclusion: Plitidepsin, a novel anti-cancer agent that targets eEF1A2, may be a promising agent for treating ovarian CCC.Clear cell carcinoma (CCC) of the ovary is known to be less sensitive to platinum-based frontline chemotherapy, and advanced-stage CCC is known to be associated with a worse prognosis than the more common histological subtype of serous adenocarcinoma (SAC). The lack of an effective chemotherapy for recurrent CCC is another important clinical problem (1). Therefore, novel strategies for both first-line treatment for advanced-stage CCC and salvage treatment for recurrent disease are needed. Plitidepsin (Aplidin®) is a novel anti-cancer agent currently investigated in late phases of clinical development. In 2018, the Australian regulatory agency approved Plitidepsin in combination with dexamethasone for the treatment of multiple myeloma. Plitidepsin was originally isolated from the Mediterranean tunicate Aplidium albicans in 1988: currently it is chemically synthesized by Pharma Mar (Madrid, Spain) (2). According to previous preclinical studies, Plitidepsin is active against a wide range of malignancies: hematological malignancies such as multiple myeloma, lymphoma, and leukemia, and solid tumors including non-small-cell lung carcinoma, pacncreas, breast, melanoma, sarcoma, gastric, and bladder cancer (3). Importantly, most reports demonstrated in vitro activity of Plitidepsin in a low nanomolar range. Accumulating evidence have suggested that Plitidepsin induces cell cycle arrest and apoptosis in a dose-dependent manner by inducing oxidative stress, decreasing intracellular levels of glutathione, upregulating the JNK and p38 MAPK pathways. In addition to cytotoxic and cytostatic activities, Plitidepsin is known to inhibit tumor-angiogenesis through the inhibition of vascular endothelial growth factor (VEGF) secretion from cancer cells. In ovarian cancer, Plitidepsin exhibited anti-proliferative activity in vitro, and significantly inhibited the growth of a xenograft in athymic mice. However, since most ovarian cancer cell lines used in the previous preclinical studies of Plitidepsin were derived from ovarian SAC, the therapeutic potential of Plitidepsin against ovarian CCC is unknown. The translation factor eEF1A2 is a tissue-specific variant of the eukaryotic Elongation Factor 1. The expression of eEF1A2 is normally confined to muscles and neurons (4). However, eEF1A2 is frequently over-expressed in various human malignancies and has oncogenic properties. Anand et al. (5) were the first to show that eEF1A2, while not normally expressed in ovary, is expressed in 30% of ovarian tumors. When examined according to histological subtypes, eEF1A2 was highly expressed in clear cell ovarian tumors compared to other histological subtypes of ovarian cancer (6). A recent study demonstrated that approximately 75% of ovarian CCC showed over-expression of eEF1A2 at the protein level (7). Although detailed mechanisms of action have not been completely investigated, Plitidepsin has been suggested to exert its antitumor activity by directly interacting with eEF1A2. Thus, plitidepsin might be a potential drug candidate for the treatment of CCC showing over-expression of eEF1A2. In the current study, after investigating the expression rate of eEF1A2 in ovarian cancer specimens, we evaluated the in vitro and in vivo therapeutic efficacy of Plitidepsin as a single agent against both chemonaive and chemorefractory ovarian CCC cells

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/)

Expression of MUC17 is regulated by HIF1α-mediated hypoxic responses and requires a methylation-free hypoxia responsible element in pancreatic cancer.

MUC17 is a type 1 membrane-bound glycoprotein that is mainly expressed in the digestive tract. Recent studies have demonstrated that the aberrant overexpression of MUC17 is correlated with the malignant potential of pancreatic ductal adenocarcinomas (PDACs); however, the exact regulatory mechanism of MUC17 expression has yet to be identified. Here, we provide the first report of the MUC17 regulatory mechanism under hypoxia, an essential feature of the tumor microenvironment and a driving force of cancer progression. Our data revealed that MUC17 was significantly induced by hypoxic stimulation through a hypoxia-inducible factor 1α (HIF1α)-dependent pathway in some pancreatic cancer cells (e.g., AsPC1), whereas other pancreatic cancer cells (e.g., BxPC3) exhibited little response to hypoxia. Interestingly, these low-responsive cells have highly methylated CpG motifs within the hypoxia responsive element (HRE, 5\u27-RCGTG-3\u27), a binding site for HIF1α. Thus, we investigated the demethylation effects of CpG at HRE on the hypoxic induction of MUC17. Treatment of low-responsive cells with 5-aza-2\u27-deoxycytidine followed by additional hypoxic incubation resulted in the restoration of hypoxic MUC17 induction. Furthermore, DNA methylation of HRE in pancreatic tissues from patients with PDACs showed higher hypomethylation status as compared to those from non-cancerous tissues, and hypomethylation was also correlated with MUC17 mRNA expression. Taken together, these findings suggested that the HIF1α-mediated hypoxic signal pathway contributes to MUC17 expression, and DNA methylation of HRE could be a determinant of the hypoxic inducibility of MUC17 in pancreatic cancer cells

子宮内膜側に発症する (Subtypel) 子宮腺筋症は黄体ホルモン療法による多量性器出血の危険因子である

We aimed to retrospectively analyze the risk factors of a continuous dienogest (DNG) therapy for serious unpredictable bleeding in patients with symptomatic adenomyosis. This is a retrospective study based on data extracted from medical records of 84 women treated with 2 mg of DNG orally each day between 2008 and 2017. 47 subjects were excluded from the original analyses due to an inadequate subcategorization into subtype I and subtype II and a lack of hemoglobin levels. The influence of various independent variables on serious unpredictable bleeding was assessed. Of the 37 eligible patients who received the continuous DNG therapy, 14 patients experienced serious unpredictable bleeding. Univariate analysis revealed that the serious bleeding group had subtype I adenomyosis (P = 0.027). There was no correlation between age, parity, minimum hemoglobin level before treatment, previous endometrial curettage, and duration of DNG administration, or uterine or adenomyosis size and the serious bleeding. A DNG-related serious unpredictable bleeding is associated with the structural type of adenomyosis (subtype I) in patients with symptomatic adenomyosis.博士（医学）・甲第800号・令和3年9月29日© The Author(s) 2019 Open Access This article is licensed under a Creative Commons Attribution 4.0 International License, which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made. The images or other third party material in this article are included in the article’s Creative Commons license, unless indicated otherwise in a credit line to the material. If material is not included in the article’s Creative Commons license and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder. To view a copy of this license, visit http://creativecommons.org/licenses/by/4.0/

Potential application of measuring serum infliximab levels in rheumatoid arthritis management: A retrospective study based on KURAMA cohort data

Infliximab (IFX) therapy has considerably improved the treatment of rheumatoid arthritis (RA). However, some patients still do not respond adequately to IFX therapy, or the efficacy of the treatment diminishes over time. Although previous studies have reported a relationship between serum IFX levels and therapeutic efficacy, the potential applications of IFX therapeutic drug monitoring (TDM) in clinical practice remain unclear. The purpose of this study was to investigate the potential applications of IFX TDM by analyzing a Japanese cohort database. Data were collected retrospectively from the Kyoto University Rheumatoid Arthritis Management Alliance cohort between January 1, 2011, and December 31, 2018. Serum IFX levels were measured using a liquid chromatography-tandem mass spectrometer. Out of the 311 RA patients that used IFX, 41 were eligible for the analysis. Serum IFX levels were significantly higher in responders than in non-responders. An optimal cut-off value was determined to be 0.32 μg/mL based on a receiver operating characteristic curve. At the IFX measurement point, a better therapeutic response was observed in the high IFX group (n = 32) than in the low IFX group (n = 9). Conversely, at the maximum effect point, when DAS28-ESR was the lowest between IFX introduction and measurement points, there were no differences in responder proportions between the low and high IFX groups. IFX primary ineffectiveness could be avoided with appropriate dose escalation without blood concentration measurement in clinical practice. In conclusion, IFX TDM could facilitate the identification of secondary non-responders and in turn, proper IFX use

MOA-2020-BLG-135Lb: A New Neptune-class Planet for the Extended MOA-II Exoplanet Microlens Statistical Analysis

We report the light-curve analysis for the event MOA-2020-BLG-135, which leads to the discovery of a new Neptune-class planet, MOA-2020-BLG-135Lb. With a derived mass ratio of $q=1.52_{-0.31}^{+0.39} \times 10^{-4}$ and separation $s\approx1$, the planet lies exactly at the break and likely peak of the exoplanet mass-ratio function derived by the MOA collaboration (Suzuki et al. 2016). We estimate the properties of the lens system based on a Galactic model and considering two different Bayesian priors: one assuming that all stars have an equal planet-hosting probability and the other that planets are more likely to orbit more massive stars. With a uniform host mass prior, we predict that the lens system is likely to be a planet of mass $m_\mathrm{planet}=11.3_{-6.9}^{+19.2} M_\oplus$ and a host star of mass $M_\mathrm{host}=0.23_{-0.14}^{+0.39} M_\odot$, located at a distance $D_L=7.9_{-1.0}^{+1.0}\;\mathrm{kpc}$. With a prior that holds that planet occurrence scales in proportion to the host star mass, the estimated lens system properties are $m_\mathrm{planet}=25_{-15}^{+22} M_\oplus$, $M_\mathrm{host}=0.53_{-0.32}^{+0.42} M_\odot$, and $D_L=8.3_{-1.0}^{+0.9}\; \mathrm{kpc}$. This planet qualifies for inclusion in the extended MOA-II exoplanet microlens sample.Comment: 22 pages, 6 figures, 4 tables, submitted to the AAS Journal