子宮体癌におけるPARP(Poly ADP-ribose polymerase)阻害剤及び放射線照射の抗腫瘍効果に関する検討

学位の種別: 課程博士審査委員会委員 : (主査)東京大学教授 徳永 勝士, 東京大学准教授 甲賀 かをり, 東京大学講師 浦野 友彦, 東京大学講師 加藤 元博, 東京大学准教授 久米 春喜University of Tokyo(東京大学

Ultrasensitive detection of SARS-CoV-2 nucleocapsid protein using large gold nanoparticle-enhanced surface plasmon resonance

The COVID-19 pandemic has created urgent demand for rapid detection of the SARS-CoV-2 coronavirus. Herein, we report highly sensitive detection of SARS-CoV-2 nucleocapsid protein (N protein) using nanoparticle-enhanced surface plasmon resonance (SPR) techniques. A crucial plasmonic role in significantly enhancing the limit of detection (LOD) is revealed for exceptionally large gold nanoparticles (AuNPs) with diameters of hundreds of nm. SPR enhanced by these large nanoparticles lowered the LOD of SARS-CoV-2 N protein to 85 fM, resulting in the highest SPR detection sensitivity ever obtained for SARS-CoV-2 N protein

Genotype-Dependent Efficacy of a Dual PI3K/mTOR Inhibitor, NVP-BEZ235, and an mTOR Inhibitor, RAD001, in Endometrial Carcinomas

The PI3K (phosphatidylinositol-3-kinase)/mTOR (mammalian target of rapamycin) pathway is frequently activated in endometrial cancer through various PI3K/AKT-activating genetic alterations. We examined the antitumor effect of NVP-BEZ235—a dual PI3K/mTOR inhibitor—and RAD001—an mTOR inhibitor—in 13 endometrial cancer cell lines, all of which possess one or more alterations in PTEN, PIK3CA, and K-Ras. We also combined these compounds with a MAPK pathway inhibitor (PD98059 or UO126) in cell lines with K-Ras alterations (mutations or amplification). PTEN mutant cell lines without K-Ras alterations (n = 9) were more sensitive to both RAD001 and NVP-BEZ235 than were cell lines with K-Ras alterations (n = 4). Dose-dependent growth suppression was more drastically induced by NVP-BEZ235 than by RAD001 in the sensitive cell lines. G1 arrest was induced by NVP-BEZ235 in a dose-dependent manner. We observed in vivo antitumor activity of both RAD001 and NVP-BEZ235 in nude mice. The presence of a MEK inhibitor, PD98059 or UO126, sensitized the K-Ras mutant cells to NVP-BEZ235. Robust growth suppression by NVP-BEZ235 suggests that a dual PI3K/mTOR inhibitor is a promising therapeutic for endometrial carcinomas. Our data suggest that mutational statuses of PTEN and K-Ras might be useful predictors of sensitivity to NVP-BEZ235 in certain endometrial carcinomas

Advanced Mucinous Adenocarcinoma Arising from a Mature Cystic Teratoma: A Case Report and Literature Review

Purpose: To describe the postoperative progressive course of advanced-stage adenocarcinoma arising from a mature cystic teratoma (MCT) and review the literature regarding this disease. Methods: A 59-year-old woman visited our hospital with an abdominal mass. Laparotomy showed enlargement of the left ovary and dissemination throughout the abdominal and pelvic cavities. The diagnosis was FIGO stage IIIB adenocarcinoma arising from a MCT. We report this case in detail with a review of the literature. Results: A literature search yielded 9 cases of stage III adenocarcinoma with malignant transformation. Six of these 9 patients died within 12 months after diagnosis. Of the 8 patients who underwent postoperative chemotherapy, 3 survived for over 39 months. The review indicates that prognosis of adenocarcinoma is as poor as that for squamous cell carcinoma arising from a MCT. Conclusions: In general, as with this case, prognosis of advanced adenocarcinoma associated with a MCT is poor. However, we should be aware that not all patients are resistant to chemotherapy

Synergistic antitumor effects of combination PI3K/mTOR and MEK inhibition (SAR245409 and pimasertib) in mucinous ovarian carcinoma cells by fluorescence resonance energy transfer imaging

The aim of this study was to clarify the synergistic effects of dual inhibition of the PI3K/mTOR and MAPK pathways in ovarian mucinous carcinoma (OMC) cells, using fluorescence resonance energy transfer (FRET) imaging. We exposed 6 OMC cell lines to a PI3K/mTOR inhibitor (voxtalisib, SAR245409) and/or a MEK inhibitor (pimasertib), and evaluated synergistic effects using the Chou–Talalay method. Then, S6K (PI3K pathway) and ERK (MAPK pathway) kinase activities, and their individual proliferative or cytotoxic effects were calculated by time-lapse FRET imaging. In combination with SAR245409, pimasertib (30 nM) synergistically inhibited cell growth (combination indexes: 0.03–0.5) and induced apoptosis in all 6 OMC cell lines. FRET-imaging results demonstrated that ERK inhibition induced both anti-proliferation and apoptosis in a dose-dependent manner in both MCAS and OAW42 cells. However, S6K inhibition suppressed proliferation in a threshold manner in both cell lines, although apoptosis was only induced in OAW42 cells. These results demonstrated that combined PI3K/mTOR and MEK inhibition exhibited synergistic antitumor effects in OMC cells and that FRET imaging is useful for analyzing kinase activities in live cells and elucidating their cytostatic and cytotoxic effects

Adenocarcinoma arising from an ectopic pancreas in the duodenum : a case report

Background The malignant transformation of an ectopic pancreas in the duodenum is extremely rare. Herein, we report a case of an adenocarcinoma that arose from an ectopic pancreas. We also reviewed 14 cases of malignant transformations arising from an ectopic pancreas in the duodenum that were previously published. Case presentation An 81-year-old man with a 1-month history of vomiting was admitted to our institution. Esophagogastroduodenoscopy (EGD) and computed tomography (CT) scans revealed an obstruction at the first part of the duodenum. A distal gastrectomy was performed for diagnostic and therapeutic purposes. The histopathological examination of the resected specimen showed adenocarcinoma that arose from an ectopic pancreas (Heinrich type 1). The patient is alive without relapse at 18 months of follow-up. Conclusions Adenocarcinoma that arises from an ectopic pancreas should be considered when an obstruction is identified in the duodenum

Putative tumor suppression function of SIRT6 in endometrial cancer

AbstractSIRT6, a member of the sirtuin family, has been identified as a candidate tumor suppressor. To pursue the role of SIRT6 in endometrial cancer, we investigated the anti-tumorigenic function of SIRT6. The expression of SIRT6 negatively affected the proliferation of AN3CA and KLE endometrial cancer cells. Increased expression of SIRT6 resulted in the induction of apoptosis by repressing the expression of the anti-apoptotic protein survivin. Consistent with this result, a survivin inhibitor YM155 efficiently inhibited cellular proliferation and induced apoptosis. These results revealed that SIRT6 might function as a tumor suppressor of endometrial cancer cells

Cyclin D1 harboring the T286I mutation promotes oncogenic activation in endometrial cancer

金沢大学医薬保健研究域医学系Cyclin D1 is an important regulator of cell cycle progression. Phosphorylation of cyclin D1 at Thr286 by GSK3β triggers its nuclear export and cytoplasmic proteolysis via the 26S proteasome. Cyclin D1 overexpression is a common event in various types of human cancers; however, reports of mutations are extremely rare. We analyzed mutations of the cyclin D1 gene, CCND1, in 88 endometrial cancer tissue specimens and detected mutations in 2 cases (2.3%). Both were unreported mutations with substitution of threonine to isoleucine at codon 286 (T286I). These two tumors harbored coexisting mutations in K-ras, PIK3CA and/or PTEN and showed accumulation of cyclin D1 in the nucleus by immunohistochemistry. Furthermore, we analyzed the functions of mutant cyclin D1 (T286I) by luciferase assays, immunofluorescence, western blotting and clonogenic cell survival assays in HEK-293T cells. We found that exogenous mutant cyclin D1 (T286I) accumulated in the nuclei in HEK-293T cells, and that it inhibited the expression of pRb. Additionally, the number of colonies was increased by introduction of mutant cyclin D1 (T286I) compared to that of wild-type cyclin D1. In conclusion, we identified an unreported CCND1 mutation (T286I) in two endometrial cancers and revealed that the mutation was functional for inducing cell proliferation in human cells