microRNA-345の過剰発現は、MUC1およびTJP2の発現を抑制することにより、膵管腺癌細胞株の浸潤能に影響を及ぼす

The majority of pancreatic carcinomas are pancreatic ductal adenocarcinomas (PDAC), and the presence of non-invasive pancreatic intraepithelial neoplasia or intraductal papillary mucinous neoplasm, as an associated lesion, is considered important. These microscopic hyperplastic or grossly papillomatous lesions exhibit varying degrees of morphological atypia and may develop into invasive carcinomas. In this study, we investigated whether mucin-1 (MUC1) is involved in the progression of pancreatic carcinoma and examined the mechanisms by which microRNAs regulate MUC1 expression in vitro. In PDAC cell lines, suppression of MUC1 expression reduced cell proliferation and invasion; PDAC cell lines transfected with an miR-345 precursor suppressed the expression of MUC1, and reduced cell proliferation and invasion. Tight junction protein 2 (TJP2), a putative target of miR-345, is regulated by MUC1. The suppression of TJP2 expression reduced cell proliferation by inducing apoptosis. These results suggest that MUC1 and TJP2, the putative target molecules of miR-345, are critical in maintaining the invasive potential of pancreatic carcinoma cells, and regulating their expression may prevent the progression of non-invasive pancreatic intraductal lesions to invasive carcinomas. This study provides new insights for the development of novel molecular targeted therapies for pancreatic carcinomas.博士（医学）・甲第866号・令和5年3月15

乳腺腺様嚢胞癌においてサイトケラチン5/6の腺腔形成細胞の染色性は類似病変との鑑別に有用である

Adenoid cystic carcinoma (AdCC) of the breast is an uncommon but distinct neoplasm composed of a dual cell population polarized around true glandular (luminal) spaces and pseudolumina. The aim of this study was to clarify whether various immunohistochemical markers (CK7, EMA, CD117, p63, calponin, CD10, S100, CK5/6, CK14, vimentin, and type IV collagen) can distinguish between the two cell types in classical AdCC (n = 14) and in collagenous spherulosis (n = 5). The sensitivity and specificity of these 11 markers to distinguish luminal from abluminal cells were evaluated using a curve created by plotting the true-positive rate (sensitivity) against the false-positive rate (1 - specificity) at threshold settings of 0, 10, 50, and 70 %. The most sensitive and specific markers for luminal cells in AdCC were CK7 and EMA; those for abluminal cells were type IV collagen, p63, and vimentin. CD10 and S100 did not act as abluminal markers in AdCC. CK5/6, one of the basal/myoepithelial markers, was expressed more frequently in luminal than in abluminal cells of AdCC. Thus, CK5/6 immunostaining resulted in a reverse expression pattern, analogous to what we recently documented in clear cells in mammary adenomyoepithelioma. In conclusion, compared with myoepithelial/abluminal cells of normal breast or collagenous spherulosis, the neoplastic abluminal cells of classical AdCC are characterized by enhanced vimentin and attenuated CD10 and S100. Furthermore, the luminal cells of AdCC show a unique aberrant staining pattern for CK5/6 that may aid in the differential diagnosis.博士（医学）・乙第1389号・平成28年11月24日© Springer-Verlag Berlin Heidelberg 2016The final publication is available at Springer via http://dx.doi.org/10.1007/s00428-016-1963-

内視鏡超音波ガイド下穿刺吸引の液状検体の残余を用いたK-ras 遺伝子検査は正診率を高める

Background: Endoscopic ultrasound-guided fine needle aspiration (EUS-FNA) technology is widely used for the diagnosis of pancreatic masses. However, in some cases, inadequate tissue volume or difficulty of morphological diagnosis are constraining factors for adequate cytopathological evaluation. K-ras mutation is the most frequently acquired genetic abnormality, occurring in approximately 90% of all patients with pancreatic ductal adenocarcinoma (PDAC). In the present study, the clinical utility of residual liquid-based cytology (LBC) specimens obtained using EUS-FNA for K-ras mutation analysis was evaluated. Methods: In this study, 81 patients with pancreatic lesions were examined. The cell block (CB) specimens separated from EUS-FNA samples were morphologically evaluated by hematoxylin-eosin (HE) staining. Final diagnoses were confirmed by CB specimens, surgical resection specimens, diagnostic imaging, and clinical follow-up. Genomic DNA of residual LBC specimens stored at 4°C for several months were extracted and assessed for K-ras mutations using a fluorescence resonance energy transfer-based preferential homoduplex formation assay. Results: K-ras mutation analysis using residual LBC samples was successful in all cases. The sensitivity, specificity, and accuracy of CB examination alone were 77.4%, 100%, and 81.3%, respectively, and those of the combination of CB examination and K-ras mutation analysis were 90.3%, 92.3%, and 90.7%, respectively. Furthermore, K-ras mutations were detected in 8 (57.1%) of 14 PDAC samples for which the CB results were inconclusive. Conclusion: These findings suggest that K-ras mutation analysis using residual LBC specimens improves the diagnostic accuracy of EUS-FNA.博士（医学）・乙第1492号・令和2年12月24日Copyright: © 2018 Sekita-Hatakeyama et al. This is an open access article distributed under the terms of the Creative Commons Attribution License(https://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited

Upshaw-Schulman症候群の糸球体障害には補体活性とADAMTS13欠損が関連している可能性がある

Introduction: Upshaw-Schulman syndrome (USS) is a congenital form of thrombotic thrombocytopenic purpura (TTP) associated with loss-of-function mutations in the ADAMTS13 gene, possibly leading to aberrant complement activation and vascular injury. However, USS is extremely rare, and there have been no systematic studies correlating histopathological severity with local ADAMTS13 expression and complement activation. Materials and methods: Here, we compared histopathological features, ADAMTS13 immunoreactivity, and immunoreactivity of complement proteins C4d and C5b-9 among renal biopsy tissues from five USS cases, ten acquired TTP cases, and eleven controls. Results: Pathological analysis revealed chronic glomerular sclerotic changes in the majority of USS cases (4 of 5), with minor glomerular pathology in the remaining case. In two of these four severe cases, more than half of the glomerular segmental sclerosis area was localized in the perihilar region. The average number of ADAMTS13-positive cells per glomerulus was significantly lower in USS cases than controls (p < 0.05). Conversely, C4d staining was significantly more prevalent in the glomerular capillary walls of USS cases than controls (p < 0.05), while C5b-9 staining did not differ significantly among groups. Conclusions: These findings suggest that the severity of glomerular injury in USS is associated with deficient ADAMTS13 expression and local complement activation, particularly in vascular regions with higher endothelial shear stress. We suggest that C4d immunostaining provides evidence for complement-mediated glomerular damage in USS.博士（医学）・甲第792号・令和3年3月15日Copyright © 2018 Elsevier Ltd. All rights reserved

Signet-ring Cell Carcinoma of the Stomach Metastasizing to Renal Cell Carcinoma: a Case Report and Review of the Literature

Metastasis of one neoplasm to another is also known as metastasis of “tumor to tumor”, “cancer to cancer”, “tumor in tumor”, and “one to another”. We describe the case of a 75-year-old woman with the metastasis of signet-ring cell carcinoma of the stomach to clear cell renal cell carcinoma. Six years earlier, the patient had undergone gastrectomy for early gastric cancer. She complained of lumbago, and a mass was found in her left kidney. Examination of a partial nephrectomy revealed clear cell renal cell carcinoma containing signet-ring cells. Morphological and immunohistochemical findings of the signet-ring cells found in kidney cancer and gastric cancer were identical. Subsequent examinations revealed the patient had multiple bone metastases. The diagnosis of carcinoma metastasizing to renal cell carcinoma can be challenging; therefore, additional clinical information and immunohistochemical panel studies are requisite

CNS WHO Grade 2 および Grade 3 髄膜腫における、MTAP免疫組織化学とFISH解析によるCDKN2Aコピー数および臨床病理学的特徴との相関性

CDKN2A homozygous deletion has occasionally been reported in atypical and anaplastic meningiomas and is considered as one of the genetic alterations commonly involved in their recurrence and malignant progression. Methylthioadenosine phosphorylase (MTAP) immunohistochemistry is a promising surrogate marker for CDKN2A homozygous deletion in different cancers but has not been examined in meningiomas. We performed CDKN2A FISH and MTAP immunohistochemistry on specimens from 30 patients with CNS WHO grade 2 (n = 27) and 3 (n = 3) meningiomas, including specimens from primary and recurrent tumors and then determined whether MTAP immunohistochemistry correlated with CDKN2A homozygous deletion and clinicopathological features. CDKN2A homozygous deletion was detected in 12% (3/26) of CNS WHO grade 2 and 67% (2/3) of CNS WHO grade 3 meningiomas; 3 cases exhibited temporal and/or spatial heterogeneity. MTAP loss was in excellent concordance with CDKN2A homozygous deletion (sensitivity; 100%, specificity; 100%). MTAP loss/CDKN2A homozygous deletion correlated with cellular proliferation (mitotic rate; p = 0.001, Ki-67 labeling index; p = 0.03) and poor prognosis (overall survival; p = 0.01, progression free survival; p < 0.001). Thus, MTAP immunostaining can be a surrogate marker for CDKN2A homozygous deletion in meningiomas, and MTAP loss/CDKN2A homozygous deletion may be an important prognostic factor for meningiomas.博士（医学）・甲第840号・令和4年3月15日© 2021 American Association of Neuropathologists, Inc. All rights reserved.This is a pre-copyedited, author-produced version of an article accepted for publication in Journal of neuropathology and experimental neurology following peer review. The version of record "Vol.81 issue 2 p.117-126 (2022 Jan 29)" is available online at: https://doi.org/10.1093/jnen/nlab127.発行元が定める登録猶予期間終了の後、本文を登録予定（2023.02

Pathogenesis of Combined High-Grade Squamous Intraepithelial Lesion and Adenocarcinoma in Situ of the Uterine Cervix: Human Papillomavirus Genotype and Methylation Status and Immunohistochemical Study

To determine the etiology of combined high-grade squamous intraepithelial lesion (HSIL) and adenocarcinoma in situ (AIS) of the uterine cervix, we examined human papillomavirus (HPV) subtypes, methylation status of the HPV-16 L1 gene, and immunohistochemical staining pattern of Krt7 in 8 cases of combined HSIL and AIS. Overall, 6 (75%) of 8 patients with combined HSIL and AIS were infected by the same subtype of HPV in both HSIL and AIS (cases 1&#8211;5, HPV-16; and case 6, HPV-18), whereas 2 (25%) patients showed infection with different subtypes of HPV (case 7, HPV-31 and -18; and case 8, HPV-52 and -16, in HSIL and AIS, respectively). The degrees of methylation at CpG islands within the HPV-16 L1 gene were almost equivalent between HSIL and AIS in cases 1&#8211;4, whereas a great difference in CpG methylation patterns between two was seen in only 1 case (case 5). In addition, both patients infected with different subtypes of HPV between HSIL and AIS were positive for Krt7 only within the AIS component. Based on these results, we propose two distinct developmental pathways of combined HSIL and AIS of the uterine cervix, the common pathway and the individual pathway