Published papers

© Author(s) (or their employer(s)) 2020. Re-use permitted under CC BY-NC. No commercial re-use. See rights and permissions. Published by BMJ. Objectives: MicroRNAs (miRNAs) have recently been reported as useful diagnostic markers in cancer; however, relationships of miRNAs with adverse events during chemotherapy have yet to be fully described. In this study, we examined the relationship between serum miRNA and the risk of peripheral neuropathy (PN), a common and persistent adverse event induced by paclitaxel, in patients with breast cancer. Methods: A total of 84 serum samples from patients with breast cancer, who received paclitaxel as neoadjuvant or adjuvant chemotherapy, were obtained between January 2011 and September 2013 at National Cancer Center Hospital. Samples were divided, 2:1, into a training cohort and a test cohort, respectively; both cohorts included specimens from patients with severe PN (≥grade 2, PN group) and non-severe PN controls (non-PN group). The training cohort was used to identify miRNAs, and combinations thereof, that could predict PN, which then were validated in the test cohort. Results: Eighty-four patients received paclitaxel: 38 and 46 patients in the PN and non-PN groups, respectively. We identified 15 discriminatory miRNAs with |fold change|>0.5, and 14 combinations of three miRNAs showed the ability to discriminate, with sensitivity, specificity and accuracy of >50%. The most discriminatory miRNA, with the highest |fold change|, was miR-451a, which regulates the expression of the drug-transporter protein P-glycoprotein, potentially promoting paclitaxel resistance. Conclusion: MiR-451a could be a predictive marker for PN caused by paclitaxel-containing chemotherapy; however, further investigation of the underlying mechanism is required to determine the role of miR-451a.

© 2019 The Authors. Cancer Science published by John Wiley & Sons Australia, Ltd on behalf of Japanese Cancer Association. Uterine leiomyosarcoma (ULMS) is the major subtype of uterine sarcoma (US) and contributes to uterine cancer deaths. Although preoperative diagnosis of US remains challenging, frequent application of laparoscopic surgery for benign uterine leiomyomas (ULM) requires precise exclusion of US. MicroRNAs are stably present in the bloodstream, and the application of circulating miRNAs as disease biomarkers has been recognized. In the present study, we aimed to identify diagnostic biomarkers for distinguishing US from ULM by focusing on circulating miRNAs. All serum samples were collected preoperatively between 2009 and 2017, and all cases were histopathologically diagnosed. Whole miRNA profiles were obtained using a miRNA microarray. By analyzing expression levels of the miRNAs, candidate miRNAs were selected based on diagnostic performance in discriminating US from ULM, and a diagnostic model was then constructed. A total of 90 serum samples were analyzed, and clustering analyses revealed that the profiles of ULMS were distinct from those of controls. Based on leave-one-out cross-validation, seven miRNAs were selected as biomarker candidates. Based on model construction, the optimal model consisted of two miRNAs (miR-1246 and miR-191-5p), with an area under the receiver operating characteristic curve (AUC) for identifying ULMS of 0.97 (95% confidence interval [CI], 0.91-1.00). In contrast, serum lactate dehydrogenase had an AUC of only 0.64 (95% CI, 0.34-0.94). Seven serum miRNAs with high diagnostic performance for preoperative US screening were detected, and a promising diagnostic model for ULMS was generated.

© 2020, The Author(s). Lung cancer, the leading cause of cancer death worldwide, is most frequently detected through imaging tests. In this study, we investigated serum microRNAs (miRNAs) as a possible early screening tool for resectable lung cancer. First, we used serum samples from participants with and without lung cancer to comprehensively create 2588 miRNAs profiles; next, we established a diagnostic model based on the combined expression levels of two miRNAs (miR-1268b and miR-6075) in the discovery set (208 lung cancer patients and 208 non-cancer participants). The model displayed a sensitivity of 99% and specificity of 99% in the validation set (1358 patients and 1970 non-cancer participants) and exhibited high sensitivity regardless of histological type and pathological TNM stage of the cancer. Moreover, the diagnostic index markedly decreased after lung cancer resection. Thus, the model we developed has the potential to markedly improve screening for resectable lung cancer.

© 2019 The Authors Background & Aims: There is a long-standing debate regarding the biological significance of polyploidy in hepatocytes. Recent studies have provided increasing evidence that hepatocytes with different ploidy statuses behave differently in a context-dependent manner (eg, susceptibility to oncogenesis, regenerative ability after injury, and in vitro proliferative capacity). However, their overall transcriptomic differences in a physiological context is not known. Methods: By using microarray transcriptome analysis, we investigated the heterogeneity of hepatocyte populations with different ploidy statuses. Moreover, by using single-cell quantitative reverse-transcription polymerase chain reaction (scPCR) analysis, we investigated the intrapopulational transcriptome heterogeneity of 2c and 4c hepatocytes. Results: Microarray analysis showed that cell cycle–related genes were enriched in 8c hepatocytes, which is in line with the established notion that polyploidy is formed via cell division failure. Surprisingly, in contrast to the general consensus that 2c hepatocytes reside in the periportal region, in our bulk transcriptome and scPCR analyses, the 2c hepatocytes consistently showed pericentral hepatocyte-enriched characteristics. In addition, scPCR analysis identified a subpopulation within the 2c hepatocytes that co-express the liver progenitor cell markers Axin2, Prom1, and Lgr5, implying the potential biological relevance of this subpopulation. Conclusions: This study provides new insights into hepatocyte heterogeneity, namely 2c hepatocytes are preferentially localized to the pericentral region, and a subpopulation of 2c hepatocytes show liver progenitor cell–like features in terms of liver progenitor cell marker expression (Axin2, Prom1, and Lgr5).

© Gut and Liver. Gastric cancer remains one of the most common causes of cancer-related death worldwide, although the incidence is declining gradually. The primary risk factor for gastric cancer is Helicobacter pylori infection. The Kyoto global consensus report recommends eradication of H. pylori in all infected patients. However, because it is difficult to stratify the risk of carcinogenesis among patients with a history of H. pylori infection, annual endoscopic surveillance is performed for everyone after eradication. This review summarizes the current approaches used to screen for novel molecules that could assist in the diagnosis of gastric cancer and reduce mortality. Most well-studied molecules are tissue protein biomarkers expressed by the gastric epithelium and associated with metaplasia-dysplasia-carcinoma sequences. Other strategies focus on the origin of cancer stem cell-related markers, such as CD44, and immune reaction-related markers, such as matrix metallopeptidases. Noninvasive methods such as blood-based approaches are more attractive. Serum pepsinogen levels predict the severity of gastric mucosal atrophy before H. pylori eradication, whereas plasma ghrelin levels are associated with atrophy even after eradication. Cell-free DNAs and RNAs are attractive tools for the early detection of cancer. These ideas could lead to the development of more personalized strategies for cancer prevention based on cutting-edge technologies.

© 2020 by The Keio Journal of Medicine. Early detection of cancer is crucial for its ultimate control and the prevention of malignant progression. In Japan, a nationwide project was conducted between 2014 and 2019 to develop novel cancer detection tools using serum microRNAs (miRNAs). Using the National Cancer Center Biobank, we collected more than 10,000 serum samples from patients with malignant diseases, including rare cancers such as ovarian cancer, gliomas, and sarcomas. Subsequently, comprehensive miRNA microarray analyses were performed for all samples. This serum miRNA database provides insights regarding miRNA bio-marker candidates for each cancer type. Here, we summarize the major achievements of this national project. Notably, although circulating miRNAs packaged in extracellular vesicles are thought to be a cell-to-cell communication tool, the functional characteristics of the miRNAs listed in the project are still unknown. We hope that our findings will help elucidate the biological functions of circulating miR-NAs.

Sarcoma is a rare cancer with several subtypes; therefore, our understanding of the pathogenesis of sarcoma is limited, and designing effective treatments is difficult. Circulating microRNAs (miRNAs), including exosomal miRNAs, have attracted attention as biomarkers in cancer. However, the roles of miRNAs and exosomes in sarcoma remain unclear. The present analysis of tissue and serum miRNA expression in osteosarcoma, Ewing's sarcoma and dedifferentiated liposarcoma (DDLPS) identified miR-1246, -4532, -4454, -619-5p and -6126 as biomarkers for DDLPS. These miRNAs were highly expressed in human DDLPS cell lines and exosomes, suggesting that they are secreted from DDLPS tissues. The present results suggested that specific miRNAs may be used as biomarkers for early diagnosis or treatment targets in DDLPS.