Published papers

© 2018 Japanese Society of Gastroenterology. All rights reserved. When injected, indocyanine green (ICG) immediately combines with lipoproteins to fluoresce. Here, we studied whether ICG fluorescence is effective for endoscopic marking in gastric cancer surgery using a photodynamic eye (PDE) camera and fluorescent endoscope. An ICG solution was endoscopically injected into the submucosal layer of the gastric tumor 3 days before surgery. We observed the lesions using both a PDE camera and a fluorescent endoscope during laparotomy and laparoscopy, respectively; we also observed the fluorescent luminance and fluorescent size of the resected lesions. We could intraoperatively detect the size of the resected lesions in eight patients with early gastric cancer and six patients with advanced gastric cancer. We believe that the use of ICG fluorescence in endoscopic marking requires additional information, such as the volume of the ICG solution and the timing of the ICG injection.

Pineal parenchymal tumors (PPTs) are rare neoplasms which occupy less than 1% of primary CNS tumors. Because of their rare incidence, previous reports on PPTs are limited in number and the useful molecular markers for deciding histological grading and even selecting chemotherapy are undetermined. In this study, we conducted immunohistochemical analysis of 12 PPT specimens, especially for expression of O6-methylguanine DNA methyltransferase (MGMT) to assess whether temozolomide (TMZ) could serve as a possible alternative therapy for PPTs. We analyzed 12 PPTs, consisting of three pineocytomas, six PPTs of intermediate differentiation (PPTIDs), and three pineoblastomas. Immunohistochemical analysis was performed using antibodies against MGMT, synaptophysin, neurofilament protein (NF), p53, and neuronal nuclear antigen (NeuN). Immunohistochemically, 11 out of 12 cases were positive for MGMT. The mean MIB-1 labeling index was less than 1% in pineocytoma, 3.5% in PPTID, and 10.5% in pineoblastoma. All 12 cases were positive for synaptophysin and 11 cases, except one PPTID case, showed positive for NF. Nuclear staining of NeuN was negative in all cases although cytoplasmic staining of NeuN was observed in five cases. No case was positive for p53. Eleven out of 12 cases of PPTs demonstrated MGMT expression, suggesting chemoresistancy to TMZ treatment. This is the first report showing MGMT expression in PPTs. In addition, MIB-1 labeling index correlated with WHO grade, although the immunoreactivity of synaptophysin, NF, NeuN and p53 did not correlate with the histological grade.

Recent progress in molecule-targeting therapy may yield personalized therapeutic strategies for patients with metastatic brain tumors (MBT), the most frequently encountered intracranial tumors. For this purpose, we investigated the molecular expression profile of MBT to establish the pathological basis for personalized diagnosis. We studied 166 MBT specimens including 70 cases of lung cancer and 34 cases of breast cancer, and performed immunostaining for EGFR, COX-2, and O-6-methylguanine-DNA methyltransferase (MGMT), among others, which could be target molecules for therapeutic agents or enable prediction of drug efficacy. Loss of MGMT expression was observed in approximately 20-40 % of MBT derived from lung, breast, and gastrointestinal cancers, indicating the possibility of treatment of MBT patients with temozolomide. In addition, MBT expressed a variety of receptor tyrosine kinases, for example EGFR and HER2, and signal transduction molecules, for example phospho-mTOR and COX-2, irrespective of tumor origin, enabling individualized medication with molecule-targeting drugs. We also identified alteration of molecular expression profile in 4 MBT cases during recurrence. Our results not only reveal the molecular characteristics of MBT but also suggest the possibility of potent personalized medicine for MBT patients. © 2012 The Japan Society of Brain Tumor Pathology.

Glioblastoma multiforme (GBM) is one of the most aggressive human tumors with poor prognosis. Current standard treatment includes chemotherapy using DNA alkylating agent temozolomide (TMZ) concomitant with surgical resection and/or irradiation. However, GBM patients exhibit various levels of the elevated expression of DNA repair enzyme, due to MGMT causing resistance to TMZ. Determination of the MGMT-positive population of primary tumor is important to evaluate the therapeutic efficacy of TMZ. Here we generated TMZ-resistant GBM cells by introducing MGMT into TMZ-sensitive GBM cell line KMG4, and established a model to assess the TMZ-induced bystander effect on TMZ-resistant cells. By mixing TMZ-resistant and -sensitive cells, GBM tumors with MGMT positivity as 50%, 10%, and 1% were generated in vivo. We could not observe any bystander effect of TMZ-induced cell death in tumor with 50% MGMT positivity. Although the bystander effect was observed within 20 days in the case of tumor with 1% MGMT positivity, final tumor size at day 28 was the same as control without sensitive cells. This bystander effect was observed in vitro using conditioned medium of TMZ-damaged GBM cells, and PCR array analysis indicated that the conditioned medium stimulated stress and toxicity pathway and upregulated anti-oxidants genes expression such as catalase and SOD2 in TMZ-resistant cells. In addition, the reduction of the activity of anti-stress mechanism by using inhibitor of GSH synthesis potentiated TMZ-induced bystander effect. These results suggest that GSH inhibitor might be one of the candidates for combination therapy with TMZ for TMZ-resistant GBM patients. (C) 2012 Elsevier Ireland Ltd. All rights reserved.

Mesothelin is expressed in various types of malignant tumors, and we recently reported that the expression of mesothelin was related to unfavorable patient outcome in pancreatic ductal adenocarcinoma and gastric adenocarcinoma. In this study, we examined the clinicopathological significance of mesothelin expression in extrahepatic bile duct cancer (EHBDCA), especially in terms of its association with the staining pattern. Tissue samples from 61 EHBDCA (16 hilar cholangiocarcinoma, 17 upper bile duct adenocarcinoma, 20 middle bile duct adenocarcinoma and 8 distal bile duct adenocarcinoma) were immunohistochemically examined. The expression levels of mesothelin in tumor cells was classified into the localization of mesothelin in luminal membrane and/or cytoplasm, in addition to high and low according to the staining intensity and proportion as a conventional analysis. 'High-level expression' of mesothelin (47.5%) was statistically correlated with liver metastasis (P=0.013) and poorer patient outcome (P=0.022), while 'luminal' membrane positive' of mesothelin (52.5%) was more significantly correlated with liver metastasis (P=0.006), peritoneal metastasis (P=0.024) and unfavorable patient outcome (P=0.017). Moreover, we found that 'cytoplasmic expression' isolated from 'luminal membrane negative' of mesothelin represented the best patient prognosis throughout this study. We describe the expression pattern level of mesothelin, i.e., in luminal membrane or cytoplasm both high and low level, evidently indicate the patient prognosis of EH BDCA, suggesting the pivotal role of mesothelin in cancer promotion depending on its intracellular localization.

Introduction: Ductal adenocarcinoma of the prostate is a rare prostate cancer variant and associated with higher stage and greater risk of mortality. Optimal systemic therapy for metastatic ductal adenocarcinoma is not known. Case presentation: A 67-year-old man presented with ductal adenocarcinoma of the prostate accompanied by multiple lung metastases and advanced bone metastases. We performed channel transurethral resection of the prostate and confirmed the diagnosis of ductal adenocarcinoma of the prostate. DNA sequencing identified a TP53 somatic point mutation (p.Gly245Ser) as the pathogenic variant. Furthermore, a homozygous deletion was observed in mitogen-activated protein kinase kinase kinase 1. The patient received enzalutamide but deceased 5 months after presenting to our institution. Conclusion: To our knowledge, this is the first report of ductal adenocarcinoma of the prostate with a mitogen-activated protein kinase kinase kinase 1 homozygous deletion. Accumulation of whole-exome sequencing data is expected to inform future advances in therapy development.

Hereditary leiomyomatosis and renal cell carcinoma (HL (RCC)) entails cutaneous and uterine leiomyomatosis with aggressive type 2 papillary RCC-like histology. HLRCC is caused by pathogenic variants in the FH gene, which encodes fumarate hydratase (FH). Here, we describe an episode of young-onset RCC caused by a genomic FH deletion that was diagnosed via clinical sequencing. A 35-year-old woman was diagnosed with RCC and multiple metastases: histopathological analyses supported a diagnosis of FH-deficient RCC. Although the patient had neither skin tumors nor a family history of HLRCC, an aggressive clinical course at her age and pathological diagnosis of FH-deficient RCC suggested a germline FH variant. After counseling, the patient provided written informed consent for germline genetic testing. She was simultaneously subjected to paired tumor profiling tests targeting the exome to identify a therapeutic target. Although conventional germline sequencing did not detect FH variants, exome sequencing revealed a heterozygous germline FH deletion. As such, paired tumor profiling, not conventional sequencing, was required to identify this genetic deletion. RCC caused by a germline FH deletion has hitherto not been described in Japan, and the FH deletion detected in this patient was presumed to be of maternal European origin. Although the genotype-phenotype correlation in HLRCC-related tumors is unclear, the patient's family was advised to undergo genetic counseling to consider additional RCC screening.

Precision medicine, which includes comprehensive genome sequencing, is a potential therapeutic option for treating high-grade serous carcinoma (HGSC). However, HGSC is a heterogeneous tumor at the architectural, cellular, and molecular levels. Intratumoral molecular heterogeneity currently limits the precision of medical strategies based on the gene mutation status. This study was carried out to analyze the presence of 160 cancer-related genetic alterations in three tissue regions with different pathological features in a patient with HGSC. The patient exhibited histological heterogeneous features with different degrees of large atypical cells and desmoplastic reactions. TP53 mutation, ERBB2 and KRAS amplification, and WT1, CDH1, and KDM6A loss were detected as actionable gene alterations. Interestingly, the ERBB2 and KRAS amplification status gradually changed according to the region examined. The difference was consistent with the differences in pathological features. Our results demonstrate the need for sampling of the appropriate tissue region showing progression of pathological features for molecular analysis to solve issues related to tumor heterogeneity prior to developing precision oncology strategies.

INTRODUCTION: Deoxyribonucleic acid repair gene mutations are now being studied in a variety of solid tumors, with the hope of predicting prognosis, pathogenesis, and treatment outcomes. CASE PRESENTATION: We report the case of a Japanese patient with advanced castration-resistant prostate cancer who exhibited a prominent response to platinum therapy and had coexisting BRCA2 and PTEN mutations according to retrospective multigene panel analysis. CONCLUSION: Through a review of clinical outcomes and genetic/pathologic profiling, the presented case provides insights into future management strategies based on the tumor genetic status.

Ovarian mature cystic teratomas comprise tissues derived from all three germ layers. In rare cases, malignant tumors arise from ovarian mature cystic teratoma. A variety of tumors can arise from mature cystic teratoma, among which primary malignant melanoma (MM), for which no molecular analyses such as genomic sequencing have been reported to date, is exceedingly rare, thereby limiting possible therapeutic options using precision medicine. We used targeted gene sequencing to analyze the status of 160 cancer-related genes in a patient with MM arising from an ovarian mature cystic teratoma (MM-MCT). KRAS amplification and homozygous deletion in PTEN and RB1 were detected in tumor samples collected from the patient. No KRAS amplification has been previously reported in cutaneous MM, indicating that the carcinogenesis of MM-MCT differs from that of primary cutaneous melanomas. A better understanding of the underlying genetic mechanisms will help clarify the carcinogenesis of MM-MCT. In turn, this will enable treatment with novel targeting agents as well as the initial exploration of gene-based precision oncological therapies, which aim to improve treatment outcomes for patients with this disease.

Tumor angiogenesis is necessary for solid tumor progression and metastasis. Cyclooxygenase (COX)-2 is known to play an important role in cancer growth and invasion, and it activates the signaling pathways controlling cell proliferation, migration, apoptosis, and angiogenesis. COX-2 is reported to be expressed in many cancer cells. Several studies have reported successful treatment of cancer cells with COX-2 inhibitors (COX-2is). However, the effect of COX-2 inhibition on the tumor endothelium remains to be elucidated. Our study shows that COX-2 is expressed in the vasculature of surgically resected human tumors. To investigate the effects of COX-2 inhibition on the tumor endothelium in vitro, we isolated tumor endothelial cells (TECs) from human melanoma and oral carcinoma xenografts in mice, in which we confirmed that tumor growth was suppressed by inhibiting angiogenesis with the COX-2is NS398. COX-2 mRNA was upregulated in TECs compared to normal endothelial cells (NECs). Cell migration and proliferation were suppressed by NS398 in TECs but not in NECs. The effects of NS398 in vivo were consistent with the in vitro results. The number of CD133(+)/vascular endothelial growth factor receptor-2(+) cells in circulation was significantly suppressed by COX-2 inhibition. In addition, the number of progenitor marker-positive cells decreased in the tumor blood vessels after COX-2i treatment, which suggests that the homing of progenitor cells into the tumor was also blocked. We conclude that NS398 specifically targets both TECs and vascular progenitor cells without affecting NECs.

A clear cell variant of solid-pseudopapillary tumor (SPT) of the pancreas was initially reported in 2006 as a tumor that arose in the pancreatic body and tail in young adults; to date, only 4 cases of this entity have been reported. Here, we present the case of a 58-year-old man with clear cell variant of SPT with distinctive clinicopathologic features. The tumor was well demarcated, was 2.6 cm in size and mostly composed of multivacuolated clear cells with solid growth, and exhibited the characteristic immunohistochemical positivity of beta-catenin in the cytoplasm and nuclei of the neoplastic cells. In contrast to classical SPT with nuclear positivity, this case was negative for E-cadherin. Direct DNA sequencing of exon 3 of beta-catenin gene demonstrated a single amino acid substitution (serine to phenylalanine) in codon 37, which is the phosphorylation site by GSK beta and frequently found in classical SPT. Electron microscopy demonstrated enlarged mitochondria and endoplasmic reticulum. Despite the fact that previous cases of clear cell variant of SPT arose mainly in the pancreatic body and tail in female young adults (age, 26-32 years), this case suggested that it is possible for a clear cell variant of SPT to arise in the pancreatic head in a middle-aged man. Because the recognition of the clear cell variant of SPT is important for the appropriate diagnosis of primary pancreatic tumor, the present case with its distinctive characteristics may provide new information for a more profound understanding of the pancreatic SPT. (C) 2012 Elsevier Inc. All rights reserved.

Lymphoplasmacyte-rich meningioma (LPRM), the most rare variant of meningiomas, features extensive lymphoplasmacytic infiltrates. Although the jugular foramen (JF) is occasionally involved by several types of tumor, such as paragangliomas and schwannomas, meningioma in the JF is an infrequent disease. Here we present an extremely rare case of LPRM found in the JF. A 55-year-old woman complained of paresis in her right eyelid and palsy in the right side of her lip. Hoarseness and dysphagia also occurred in the following month. Radiologic examinations disclosed a mass lesion in the right JF, and the tumor was operatively removed. Microscopically, the tumor was composed of extensive lymphoplasmacytic infiltration with mild vascular proliferation and scattered sheets of epithelioid cells with plump cytoplasm. Although the obvious whorl formation or psammoma bodies were not observed, by immunochemistry the epithelioid cells were positive for epithelial membrane antigen and also progesterone receptor, indicating a meningothelial cell origin. Considering the histological and radiologic findings, we finally diagnosed the case as LPRM, making this the second reported case of LPRM in the JF.

Oncogenic stimuli such as H-Ras induce oncogene-induced senescence (OIS) in fibroblasts to protect against transformation. Here we found that a population of the human diploid fibroblasts can escape from OIS induced by H-RasV12. We designated these OIS-escaped cells as OISEC (OIS-escaped cells). OISEC lost the expression of p16 which plays an important role for cell cycle arrest for induction of senescence, but OISEC preserved the p16 expression machinery and exhibited senescence by the treatment with hydrogen peroxide (H(2)O(2)) as stress-induced premature senescence (SIPS). OISEC did not possess anchorage-independent growth potential, and functional disruption of p53 and Rb by SV40 early region encoding large T and small t antigens, induced the aneuploidy phenotype and colony-forming potential of OISEC together with the exhibition of in vivo tumor formation. Finally, we also found that the distinctive feature of OISEC is expression of transcription factors, Oct3/4, SOX2, and Nanog which is closely related to stem-like cell features. This study highlights the presence of a cell population which escaped from OIS, and this OISEC may transform into malignant cancer cells by the additional hits of several genes in vivo. (C) 2011 Elsevier Inc. All rights reserved.

Synovial sarcoma (SS) is an aggressive tumor that accounts for almost 10% of all soft tissue sarcomas. In this study, we found the expression of CD133 in human SS specimens, thus, we focused on the function of CD133 in SS. Separation of the CD133-positive and -negative subpopulations in SS cell lines clarified that the CD133-negative subpopulation exhibited enhanced growth and hyperphosphorylation of AKT. Treatment of Akt inhibitor suppressed the cell growth of CD133-negative subpopulation to the levels of CD133-positive cells. These results suggest that CD133 has negative effect on the growth of cells through AKT-dependent signalling pathway.

Objectives: Recent studies have shown that the high affinity of mesothelin-CA125 interaction might cause intracavitary tumor metastasis. We examined the clinicopathologic significance and prognostic implication of mesothelin and CA125 expression in pancreatic ductal adenocarcinoma. Methods: Tissue samples from 66 pancreatic ductal adenocarcinomas were immunohistochemically examined. Proportion and intensity of constituent tumor cells with mesothelin and CA125 expression were analyzed and classified as high-level expression, defined as expression by more than 50% of tumor cells and/or moderate to strong staining, or low-level expression otherwise. Results: A high level of mesothelin was correlated with a higher histological grade (P = 0.049) and the level of blood vessel permeation (P = 0.0006), whereas a high level of CA125 expression was correlated with a higher recurrence rate (P = 0.015). The expression of mesothelin was strongly correlated with that of CA125 (P = 0.0041). Co-expression of mesothelin and CA125 were associated with an unfavorable patient outcome (P = 0.0062). Conclusions: This is the first report showing that co-expression of mesothelin and CA125 were in pancreatic ductal adenocarcinoma, and such co-expression is associated with a poor prognosis. Our finding suggests that co-expression of these two factors plays a significant role in the acquisition of aggressive clinical behavior.