食品タンパク質酵素分解物中のピログルタミルペプチドの構造、吸収および機能

京都大学新制・課程博士博士(農学)甲第24678号農博第2561号新制||農||1100(附属図書館)学位論文||R5||N5459(農学部図書室)京都大学大学院農学研究科応用生物科学専攻(主査)教授 佐藤 健司, 教授 菅原 達也, 教授 舟場 正幸学位規則第4条第1項該当Doctor of Agricultural ScienceKyoto UniversityDGA

Photobiologic and Photoimmunologic Characteristics of XPA Gene-Deficient Mice

Xeroderma pigmentosum group A (XPA) gene-deficient mice cannot repair UV-induced DNA damage and easily develop skin cancers by UV irradiation. Just like human XP patients, homozygous (–/–) mice developed stronger longer-lasting acute inflammation than did wild-type mice after a single irradiation with UVB. Moreover, the model mice showed more severe UV-induced damage of keratinocytes and Langerhans cells than did the control mice. UVB-induced local and systemic immunosuppression was greatly enhanced in the (–/–) mice. Treatment with indomethacin, an inhibitor of prostaglandin (PG) synthesis, inhibited UV-induced inflammation and abrogated immunosuppression. In XPA-deficient mice, the amount of PGE2 and the expression level of COX-2 mRNA greatly increased after UVB irradiation compared with wild-type mice. These results suggest that the excess DNA photoproducts remaining in XPA-deficient cells after UV radiation induce COX-2 expression and subsequently produce a high amount of PGE2, which causes the enhancement of inflammation and immunosuppression. In XPA-deficient mice, the natural killer cell activity significantly decreased after repeated exposures to UVB. Our experimental data indicate that cancer development in XP patients involves not only mutagenesis due to the defect in DNA repair, but also the enhanced UV-immunosuppression and intensified impairment of natural killer function

Identification of a novel intronic enhancer responsible for the transcriptional regulation of musashi1 in neural stem/progenitor cells

<p>Abstract</p> <p>Background</p> <p>The specific genetic regulation of neural primordial cell determination is of great interest in stem cell biology. The Musashi1 (Msi1) protein, which belongs to an evolutionarily conserved family of RNA-binding proteins, is a marker for neural stem/progenitor cells (NS/PCs) in the embryonic and post-natal central nervous system (CNS). Msi1 regulates the translation of its downstream targets, including <it>m-Numb </it>and <it>p21 </it>mRNAs. <it>In vitro </it>experiments using knockout mice have shown that Msi1 and its isoform Musashi2 (Msi2) keep NS/PCs in an undifferentiated and proliferative state. Msi1 is expressed not only in NS/PCs, but also in other somatic stem cells and in tumours. Based on previous findings, Msi1 is likely to be a key regulator for maintaining the characteristics of self-renewing stem cells. However, the mechanisms regulating <it>Msi1 </it>expression are not yet clear.</p> <p>Results</p> <p>To identify the DNA region affecting <it>Msi1 </it>transcription, we inserted the fusion gene <it>ffLuc</it>, comprised of the fluorescent <it>Venus </it>protein and firefly <it>Luciferase</it>, at the translation initiation site of the mouse <it>Msi1 </it>gene locus contained in a 184-kb bacterial artificial chromosome (BAC). Fluorescence and Luciferase activity, reflecting the <it>Msi1 </it>transcriptional activity, were observed in a stable BAC-carrying embryonic stem cell line when it was induced toward neural lineage differentiation by retinoic acid treatment. When neuronal differentiation was induced in embryoid body (EB)-derived neurosphere cells, reporter signals were detected in Msi1-positive NSCs and GFAP-positive astrocytes, but not in MAP2-positive neurons. By introducing deletions into the BAC reporter gene and conducting further reporter experiments using a minimized enhancer region, we identified a region, "D5E2," that is responsible for <it>Msi1 </it>transcription in NS/PCs.</p> <p>Conclusions</p> <p>A regulatory element for <it>Msi1 </it>transcription in NS/PCs is located in the sixth intron of the <it>Msi1 </it>gene. The 595-bp D5E2 intronic enhancer can transactivate <it>Msi1 </it>gene expression with cell-type specificity markedly similar to the endogenous Msi1 expression patterns.</p

Japanese Lung Cancer Society Guidelines for Stage IV NSCLC With EGFR Mutations

Patients with NSCLC in East Asia, including Japan, frequently contain EGFR mutations. In 2018, we published the latest full clinical practice guidelines on the basis of those provided by the Japanese Lung Cancer Society Guidelines Committee. The purpose of this study was to update those recommendations, especially for the treatment of metastatic or recurrent EGFR-mutated NSCLC. We conducted a literature search of systematic reviews of randomized controlled and nonrandomized trials published between 2018 and 2019 that multiple physicians had reviewed independently. On the basis of those studies and the advice from the Japanese Society of Lung Cancer Expert Panel, we developed updated guidelines according to the Grading of Recommendations, Assessment, Development, and Evaluation system. We also evaluated the benefits of overall and progression-free survival, end points, toxicities, and patients’ reported outcomes. For patients with NSCLC harboring EGFR-activating mutations, the use of EGFR tyrosine kinase inhibitors (EGFR TKIs), especially osimertinib, had the best recommendation as to first-line treatment. We also recommended the combination of EGFR TKI with other agents (platinum-based chemotherapy or antiangiogenic agents); however, it can lead to toxicity. In the presence of EGFR uncommon mutations, except for an exon 20 insertion, we also recommended the EGFR TKI treatment. However, we could not provide recommendations for the treatment of EGFR mutations with immune checkpoint inhibitors, including monotherapy, and its combination with cytotoxic chemotherapy, because of the limited evidence present in the literature. The 2020 Japanese Lung Cancer Society Guidelines can help community-based physicians to determine the most appropriate treatments and adequately provide medical care to their patients

SOX9 is a novel cancer stem cell marker surrogated by osteopontin in human hepatocellular carcinoma

The current lack of cancer stem cell (CSC) markers that are easily evaluated by blood samples prevents the establishment of new therapeutic strategies in hepatocellular carcinoma (HCC). Herein, we examined whether sex determining region Y-box 9 (SOX9) represents a new CSC marker, and whether osteopontin (OPN) can be used as a surrogate marker of SOX9 in HCC. In HCC cell lines transfected with a SOX9 promoter-driven enhanced green fluorescence protein gene, FACS-isolated SOX9+ cells were capable of self-renewal and differentiation into SOX9-cells, and displayed high proliferation capacity in vitro. Xenotransplantation experiments revealed that SOX9+ cells reproduced, differentiated into SOX9-cells, and generated tumors at a high frequency in vivo. Moreover, SOX9+ cells were found to be involved in epithelial-mesenchymal transition (EMT) and activation of TGFb/Smad signaling. Gain/loss of function experiments showed that SOX9 regulates Wnt/beta-catenin signaling, including cyclin D1 and OPN. Immunohistochemistry of 166 HCC surgical specimens and serum OPN measurements showed that compared to SOX9-patients, SOX9+ patients had significantly poorer recurrence-free survival, stronger venous invasion, and higher serum OPN levels. In conclusion, SOX9 is a novel HCCCSC marker regulating the Wnt/beta-catenin pathway and its downstream target, OPN. OPN is a useful surrogate marker of SOX9 in HCC

Trastuzumab タンザイ リョウホウ ガ チョコウ シタ セツジョ フノウ シンコウ イガン ノ 1レイ

Trastuzumab, a humanized monoclonal antibody directed against human epidermal growth factor receptor２ （HER２）, has been shown to be active against metastatic gastric cancer that overexpress HER２. A ７８-year-old man presented with an edema in the lower legs. He was diagnosed as having advanced gastric cancers with multiple liver metastases in our hospital. Immunohistochemistry of the tumor cells revealed HER２ overexpression with an intensity of ３＋. The patient was treated with DS-T chemotherapy （Docetaxel＋S‐１＋Trastuzumab） because of the presence of renal dysfunction. Due to the adverse effect appeared with his skin, DS-T chemotherapy has been canceled and trastuzumab chemotherapy was continued. After １１ months of trastuzumab monotherapy, metastatic liver tumors were diminished. There is very few report of a positive response to trastuzumab in a patient with HER２‐overexpressing metastatic gastric cancer