Final article is available at "wileyonlinelibrary.com" Takako Okamoto, Masaki Mandai, Noriomi Matsumura, Ken Yamaguchi, Hiroshi Kondoh, Yasuaki Amano, Tsukasa Baba, Junzo Hamanishi, Kaoru Abiko, Kenzo Kosaka, Susan K. Murphy, Seiichi Mori, Ikuo Konishi "Hepatocyte nuclear factor-1β (HNF-1β) promotes glucose uptake and glycolytic activity in ovarian clear cell carcinoma" Molecular Carcinogenesis 54:35–49 (2013) / 京都大学 / 0048 / 新制・論文博士 / 博士(医学) / 乙第12804号 / 論医博第2076号 / 新制||医||1001(附属図書館) / 80848 / 京都大学大学院医学研究科医学専攻 / (主査)教授 野田 亮, 教授 武藤 学, 教授 稲垣 暢也 / 学位規則第4条第2項該当 / Doctor of Medical Science / Kyoto University / DFAM

Ovarian cancer is a significant concern for women’s health as it is the most lethal of all gynaecological malignancies. One of the reasons for the high mortality of this disease is that traditionally used chemotherapeutic treatments tend to have poor initial or sustained efficacy against ovarian tumours. Resistance to such treatments may in part be mediated by autophagy, a cell survival process in which unnecessary or damaged components of the cytoplasm are engulfed within a double-membraned vesicle known as an autophagosome and ultimately degraded upon fusion of the autophagosome with a lysosome. Autophagy has been shown to be employed by cells to aid in their survival under stresses such as nutrient deprivation, hypoxia, chemotherapy treatment, and growth factor withdrawal. As these stresses are commonly encountered by ovarian cancer cells, it is possible that autophagy promotes ovarian cancer cell survival. This thesis aims to investigate which stimuli induce autophagy in ovarian cancer cells and whether or not this induction can promote cell survival. In addition, there is a particular focus on the comparison of autophagy utilization between subtypes of ovarian cancer, as the subtypes are in fact considered different diseases and may vary in their usage of autophagy. The first chapter of this thesis provides relevant background information on autophagy as well as ovarian cancer and its subtypes. In the second chapter, I describe studies in which tumours from a large cohort of patients with ovarian cancer are assessed for LC3A, a marker of autophagy, in addition to markers of other cellular processes including hypoxia. Here I found that LC3A was significantly associated with poor patient survival in patients with the clear cell subtype of ovarian cancer, but not other subtypes. I also found that LC3A expression was associated with markers of hypoxia in the clear cell patient tumours and that clear cell carcinoma cell lines preferentially induced autophagy in response to hypoxia in vitro as compared to cell lines of the high-grade serous subtype. These results indicate that clear cell ovarian tumours are uniquely dependent upon autophagy in response to hypoxia. In the third chapter, I investigated the autophagic response to treatment with the standard ovarian cancer chemotherapy drugs carboplatin and paclitaxel in a syngeneic mouse model of ovarian cancer. I found that these drugs did indeed induce autophagy and that the cancer cells utilized autophagy to promote resistance to these chemotherapeutics. In addition, when the tumour cells were grown in syngeneic mice, treatment with the autophagy inhibitor hydroxychloroquine resulted in a significant suppression of tumour growth. Together, my findings indicate that further investigation into the use of autophagy inhibitors in ovarian cancer patients is warranted and that different specific rational drug combinations for each subtype will likely yield optimal results. / Graduate

京都大学 / 0048 / 新制・課程博士 / 博士(医学) / 甲第19591号 / 医博第4098号 / 新制||医||1014(附属図書館) / 32627 / 京都大学大学院医学研究科医学専攻 / (主査)教授 野田 亮, 教授 武田 俊一, 教授 小川 修 / 学位規則第4条第1項該当 / Doctor of Medical Science / Kyoto University / DFAM

京都大学 / 0048 / 新制・課程博士 / 博士(医学) / 甲第21011号 / 医博第4357号 / 新制||医||1028(附属図書館) / 京都大学大学院医学研究科医学専攻 / (主査)教授 万代 昌紀, 教授 戸井 雅和, 教授 鈴木 実 / 学位規則第4条第1項該当 / Doctor of Medical Science / Kyoto University / DFAM

京都大学 / 0048 / 新制・課程博士 / 博士(医学) / 甲第21300号 / 医博第4389号 / 新制||医||1030(附属図書館) / 京都大学大学院医学研究科医学専攻 / (主査)教授 戸井 雅和, 教授 小川 修, 教授 武田 俊一 / 学位規則第4条第1項該当 / Doctor of Medical Science / Kyoto University / DFAM

京都大学 / 新制・課程博士 / 博士(医学) / 甲第23763号 / 医博第4809号 / 新制||医||1056(附属図書館) / 京都大学大学院医学研究科医学専攻 / (主査)教授 中島 貴子, 教授 戸井 雅和, 教授 伊藤 貴浩 / 学位規則第4条第1項該当 / Doctor of Medical Science / Kyoto University / DFAM

Le carcinome rénal à cellules claires (cRCC) est le principal type histologique de carcinome rénal et l'une des tumeurs les plus résistantes à la chimio et à la radiothérapie. L'absence de biomarqueurs pour la détection précoce et pour le suivi des patients est responsable d'un mauvais pronostic. Il est nécessaire d'identifier de nouveaux biomarqueurs et des cibles thérapeutiques pour améliorer la prise en charge des patients. Les microARNs, des petits ARN non codants de 22 nucléotides, qui ont été précédemment montrés comme favorisant l'initiation et la progression tumoral, semblent être de bons candidats. Nous avons focalisé notre étude sur (i) miR-21 qui est le principal oncomiR surexprimé dans le cRCC et (ii) le récepteur nucléaire PPARα (Peroxisome Proliferator Activated Receptor), l'une des cibles de miR-21.D'une part, sur une cohorte de 99 échantillons de cRCC primaires, nous avons montré que l'expression de miR-21 était plus élevée dans les tissus cancéreux que dans les tissus non tumoraux adjacents. In vitro, miR-21 est également surexprimé dans les lignées cellulaires de carcinomes rénaux comparées à la lignée cellulaire épithéliale HK-2 provenant de tubes proximaux humains. De plus, nous avons également montré que la surexpression de miR-21 augmente les propriétés de migration et d'invasion des cellules cancéreuses rénales ainsi que les voies de signalisation prolifératives et anti-apoptotiques, alors que des résultats opposés ont été observés en utilisant une stratégie d'inhibition anti-miR-21. Enfin, nous avons évalué le rôle du miR-21 dans la chimiorésistance du cRCC et montré, en outre, que l'inhibition de miR-21 augmentait significativement la chimiosensibilité au paclitaxel, au 5-fluorouracile, à l'oxaliplatine et au dovitinib, diminuait l'expression des transporteurs à efflux MRP1-6/ABCC1-6 et augmentait l'expression des transporteurs à influx SLC22A1/OCT1, SLC22A2/OCT2 et SLC31A1/CTR1. Ces résultats ont permis la publication d'un article dans Tumor Biology se trouvant en annexe.D'autre part, dans les tissus de patients atteints de cRCC, nous avons montré pour la première fois que la surexpression de miR-21 est en corrélation avec une perte d'expression de PPARα. In vitro, nous avons montré que miR-21 cible le 3'-UTR de PPARα et diminue son expression protéique et que la surexpression de miR-21 diminue l'activité transcriptionnelle de PPARα. En outre, la surexpression et l'activation de PPARα diminuent l'expression de miR-21. En effet, PPARα interagit avec les facteurs de transcription AP-1 et NF-κB et empêche ainsi leur liaison au promoteur de miR-21 diminuant ainsi sa transcription.En conclusion, nous avons montré que (i) miR-21 est un acteur clé de la progression du cancer du rein et joue un rôle important dans la résistance aux chimiothérapies et (ii) qu'il existe une boucle de régulation négative entre miR-21 et PPARα dans le cRCC. / Renal clear cell carcinoma (cRCC) is the major histological type of renal carcinoma and one of the most chemo- and radio-resistant tumors. The absence of biomarkers for early detection and for monitoring patients is responsible of a poor prognosis. It is necessary to identify new biomarkers and therapeutic targets to improve patient care. MicroRNAs, small noncoding RNAs of 22 nucleotides, which have been previously shown to promote malignant initiation and progression, appear to be good candidates.We focused our study on (i) miR-21 which is the main overexpressed oncomirs in cRCC and (ii) the nuclear receptor PPARα (Peroxisome Proliferator Activated Receptor), one of miR-21 targets.In one hand, by using a cohort of 99 primary cRCC samples, we showed that miR-21 expression in cancer tissues was higher than in adjacent non-tumor tissues. In vitro, miR-21 was also overexpressed in renal carcinoma cell lines compared to HK-2 human proximal tubule epithelial cell line. Moreover, we also showed that miR-21 overexpression increased migratory, invasive, proliferative, and anti-apoptotic signaling pathways whereas opposite results were observed using an anti-miR-21-based silencing strategy. Finally, we assessed the role of miR-21 in mediating cRCC chemoresistance and further showed that miR-21 silencing significantly increased chemosensitivity of paclitaxel, 5-fluorouracil, oxaliplatin and dovitinib, decreased expression of multi-drug resistance genes and increased SLC22A1/OCT1, SLC22A2/OCT2 and SLC31A1/CTR1 platinum influx transporter expression. These results led to the publication of an article in Tumor Biology in annex.In other hand, in cRCC tissue patients, we showed for the first time that miR-21 overexpression correlates with a loss of expression of PPARα. In vitro, we showed that miR-21 targets PPARα 3'-UTR and decreases its protein expression and miR-21 overexpression decreases the transcriptional activity of PPARα. Furthermore, PPARα overexpression and activation decrease miR-21 expression. In fact, PPARα interacts with AP-1 and NF-kappaB transcription factors and thus prevents their binding to the miR-21 promoter thus decreasing its transcription.In conclusion, we have shown that (i) miR-21 is a key actor of renal cancer progression and plays an important role in the resistance to chemotherapeutic drugs and (ii) there is a negative regulatory loop between miR-21 and PPARα in cRCC.