記述言語：英語   掲載種別：研究論文（学術雑誌）  

The process of metastasis is complex1. In breast cancer, there are frequently long time intervals between cells leaving the primary tumour and growth of overt metastases2,3. Reasons for disease indolence and subsequent transition back to aggressive growth include interactions with myeloid and fibroblastic cells in the tumour microenvironment and ongoing immune surveillance4-6. However, the signals that cause actively growing cells to enter an indolent state, thereby enabling them to survive for extended periods of time, are not well understood. Here we reveal how the behaviour of indolent breast cancer cells in the lung is determined by their interactions with alveolar epithelial cells, in particular alveolar type 1 cells. This promotes the formation of fibronectin fibrils by indolent cells that drive integrin-dependent pro-survival signals. Combined in vivo RNA sequencing and drop-out screening identified secreted frizzled-related protein 2 (SFRP2) as a key mediator of this interaction. Sfrp2 is induced in breast cancer cells by signals from lung epithelial cells and promotes fibronectin fibril formation and survival, whereas blockade of Sfrp2 expression reduces the burden of indolent disease.

DOI： 10.1038/s41556-020-0474-3

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記述言語：英語   掲載種別：研究論文（学術雑誌）  

Cancer-associated fibroblasts (CAFs) are activated fibroblasts and are the major stromal component in various types of malignancies. CAFs often undergo metabolic reprogramming to create an appropriate microenvironment for cancer progression. However, it remains unclear whether the metastatic properties of cancer cells affect aerobic glycolysis in stromal cells. Here, we show that gastric cancer (GC) cells with high metastatic potential strongly promote the metabolic switch from oxidative phosphorylation to aerobic glycolysis in fibroblasts. Transcriptome analysis showed that the expression of glycolysis-related genes, such as LDHA and ENO2, significantly changed in fibroblasts when they were cocultured with cancer cells with high metastatic potential compared to fibroblasts incubated with cancer cells with low metastatic potential. Glucose uptake, lactate production and oxygen consumption in fibroblasts were changed by coculture with GC cells with high metastatic potential. Thus, metabolic reprogramming in CAFs may reflect the metastatic properties of GC cells.

DOI： 10.1371/journal.pone.0234613

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記述言語：英語   掲載種別：研究論文（学術雑誌）  

Cancer-associated fibroblasts (CAFs), one of the major components of a tumour microenvironment, comprise heterogeneous populations involved in tumour progression. However, it remains obscure how CAF heterogeneity is governed by cancer cells. Here, we show that cancer extracellular vesicles (EVs) induce a series of chemokines in activated fibroblasts and contribute to the formation of the heterogeneity. In a xenograft model of diffuse-type gastric cancer, we showed two distinct fibroblast subpopulations with alpha-smooth muscle actin (α-SMA) expression or chemokine expression. MicroRNAs (miRNAs) profiling of the EVs and the transfection experiment suggested that several miRNAs played a role in the induction of chemokines such as CXCL1 and CXCL8 in fibroblasts, but not for the myofibroblastic differentiation. Clinically, aberrant activation of CXCL1 and CXCL8 in CAFs correlated with poorer survival in gastric cancer patients. Thus, this link between chemokine expression in CAFs and tumour progression may provide novel targets for anticancer therapy.

DOI： 10.1038/s41388-019-0832-4

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記述言語：英語   掲載種別：研究論文（学術雑誌）  

BACKGROUND: Conventional treatments of chronic hepatitis B virus (HBV) infection rarely achieve a decline of serum hepatitis B surface antigen (HBsAg) levels and eradication of the virus. AIM: To elucidate the antiviral mechanisms of a human microRNA, miR-302c-3p, against HBV replication. METHODS: The antiviral effect of miR-302c-3p was evaluated in vitro and in vivo by transfecting the miR-302c-3p mimic into HBV-infected HepG2-hNTCP-C4 cells and HBV transgenic mice respectively. RESULTS: miR-302c-3p decreased not only HBV replication but also production of HBsAg. Pregenomic RNA and HBsAg mRNA concentrations decreased in the cells treated with miR-302c-3p. Interestingly, the amount of cccDNA was significantly reduced in the miR-302c-3p-treated cells, in association with disappearance of the HBV core protein. An RNA immunoprecipitation assay showed that miR-302c-3p decreased the binding of the HBV polymerase to the pregenomic RNA by hybridising with the ε-loop region. A number of host genes were downregulated in miR-302c-3p-treated cells, including BMPR2 and HNF4A. Knockdown of these two genes by corresponding siRNAs also suppressed HBV replication and HBsAg secretion. The antiviral effect of miR-302c-3p was also observed in HBV transgenic mice. CONCLUSION: miR-302c-3p had anti-HBV activity, in vitro and in vivo, via several mechanisms.

DOI： 10.1111/apt.15197

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記述言語：英語   出版者・発行元：日本癌学会  

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記述言語：英語   掲載種別：研究論文（学術雑誌）  

Background: Hepatitis B virus (HBV) infection is a leading cause of persistent liver diseases, cirrhosis and hepatocellular carcinoma (HCC) worldwide. Since deregulation of microRNA (miRNA) expression by HBV infection contributes to enhanced viral replication and pathogenesis, modulation of miRNA activity can be a novel therapeutic approach towards HBV eradication. As the effects of the vast majority of miRNAs on HBV replication have not been empirically investigated, here, we aim to identify novel therapeutic targets that have a strong antiviral effect on HBV. Methods: HepG2-hNTCP-C4 cells were infected with HBV, and then were individually transfected with the library mimics of 2048 miRNAs. To assess the amount of intracellular and extracellular DNA and HBsAg, qPCR and ELISA were performed respectively. Results: From miRNA library screening, we identified 39 miRNAs as candidate repressors of HBV replication. Among them, 9 miRNAs, including miR-204, strongly decreased both HBV DNA and HBsAg in culture supernatant of HepG2-hNTCP-C4 cells. Furthermore, we also showed that inhibition of Rab22a, one of the targets of miR-204, also suppressed intracellular and extracellular HBV DNA expression in HepG2.2.15.7 cells. Conclusions: Our findings contribute to the understanding of the roles of miRNAs underlying HBV replication and show the possibility of developing a novel strategy for miRNA-mediated HBV treatment.

DOI： 10.18632/oncotarget.25557

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記述言語：英語   掲載種別：研究論文（学術雑誌）  

AIM: Early hepatocellular carcinoma (HCC) recurrence after curative resection is a known poor prognostic factor. We aimed to identify microRNAs associated with recurrence after curative HCC resection. METHODS: To identify risk factors for early recurrence and metastasis, 694 patients who underwent primary curative HCC resection were analyzed. We evaluated microRNA expression in cancerous and non-cancerous tissues by microarray and quantitative PCR analyses using 16 HCC samples. We defined patients who had a recurrence within 1 year of resection as the early recurrence (ER) group, patients who had a recurrence within 1-5 years as the late recurrence (LR) group, and patients who did not recur during the 5-year observation period as the no recurrence (NR) group. We examined the relationship between microRNA expression and clinical features. RESULTS: Multivariate analysis revealed that α-fetoprotein >31 ng/mL, tumor size >4 cm, and intrahepatic metastasis (IM) were significant factors. Afterwards, microarray analyses revealed that microRNA (miR)-125b-5p and miR-148a-3p were significantly downregulated in recurrent cases. The ratio of miR-125b-5p expression in cancerous versus non-cancerous tissue (miR-125b ratio), but not miR-148a-3p, was significantly lower in the ER group. Early recurrence was associated with reduced overall survival compared with the LR and NR group. The miR-125b ratio was significantly lower in the ER group than in the LR and NR groups. Multivariate analysis showed that a low miR-125b ratio and IM were independently associated with ER and disease-free survival. CONCLUSIONS: Assessing tissue miR-125b-5p expression and IM is useful for stratifying patients at risk of early HCC recurrence after curative resection.

DOI： 10.1111/hepr.12990

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記述言語：英語   掲載種別：研究論文（学術雑誌）  

Hepatitis B virus (HBV) infection is a leading cause of hepatocellular carcinoma worldwide. However, the strategy of HBV to escape from the host immune system remains largely unknown. In this study, we examined extracellular vesicles (EVs) secreted from human hepatocytes infected with HBV. EVs includeing exosomes are nano-size vesicles with proteins, mRNAs, and microRNAs (miRNAs), which can be transmitted to different cells. We found that 104 EV associated miRNAs were increased in hepatocytes more than 2-fold by HBV infection. We then selected those that were potentially implicated in immune regulation. Among them, five HBV-induced miRNAs were found to potentially target multiple sequences in the 3'UTR of IL-21, a cytokine that induces anti-viral immunity. Moreover, expression of a reporter gene with the 3' UTR of human IL-21 mRNA was suppressed by the five miRNAs individually. Finally, IL-21 expression in cloned human T cells was down-regulated by the five miRNAs. Collectively, this study identified the novel 3' UTR sequences of human IL-21 mRNA and potential binding sites of HBV-induced EV-miRNAs.

DOI： 10.1038/s41598-017-07853-x

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記述言語：英語   掲載種別：研究論文（学術雑誌）  

BACKGROUND & AIMS: An extracellular vesicle (EV) is a nanovesicle that shuttles proteins, nucleic acids, and lipids, thereby influencing cell behavior. A recent crop of reports have shown that EVs are involved in infectious biology, influencing host immunity and playing a role in the viral life cycle. In the present work, we investigated the EV-mediated transmission of hepatitis B virus (HBV) infection. METHODS: We investigated the EV-mediated transmission of HBV infection by using a HBV infectious culture system that uses primary human hepatocytes derived from humanized chimeric mice (PXB-cells). Purified EVs were isolated by ultracentrifugation. To analyze the EVs and virions, we used stimulated emission depletion microscopy. RESULTS: Purified EVs from HBV-infected PXB-cells were shown to contain HBV DNA and to be capable of transmitting HBV DNA to naive PXB-cells. These HBV-DNA-transmitting EVs were shown to be generated through a ceramide-triggered EV production pathway. Furthermore, we showed that these HBV-DNA-transmitting EVs were resistant to antibody neutralization; stimulated emission depletion microscopy showed that EVs lacked hepatitis B surface antigen, the target of neutralizing antibodies. CONCLUSIONS: These findings suggest that EVs harbor a DNA cargo capable of transmitting viral DNA into hepatocytes during HBV infection, representing an additional antibody-neutralization-resistant route of HBV infection.

DOI： 10.1016/j.jcmgh.2016.10.003

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記述言語：英語   掲載種別：研究論文（学術雑誌）  

Intercellular communication plays an important role in cancer initiation and progression through secretory molecules, including growth factors and cytokines. Recent advances have revealed that small membrane vesicles, termed extracellular vesicles (EVs), served as a regulatory agent in the intercellular communication of cancer. EVs enable the transfer of functional molecules, including proteins, mRNA and microRNAs (miRNAs), into recipient cells. Cancer cells utilize EVs to dictate the unique phenotype of surrounding cells, thereby promoting cancer progression. Against such "education" by cancer cells, non-tumoral cells suppress cancer initiation and progression via EVs. Therefore, researchers consider EVs to be important cues to clarify the molecular mechanisms of cancer biology. Understanding the functions of EVs in cancer progression is an important aspect of cancer biology that has not been previously elucidated. In this review, we summarize experimental data that indicate the pivotal roles of EVs in cancer progression.

DOI： 10.1007/s00018-016-2346-3

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記述言語：英語   掲載種別：研究論文（学術雑誌）  

BACKGROUND: While hepatitis B and C viral infection have been suppressed, non-B non-C hepatocellular carcinoma (NBNC-HCC) is considered to be rising in incidence terms in some developed countries where prevalence of those viral infections among HCC patients had been very high (such as Japan, Korea, and Italy). To elucidate critical molecular changes in NBNC-HCC, we integrated three large datasets relating to comprehensive array-based analysis of genome-wide DNA methylation (N = 43 pairs) and mRNA/miRNA expression (N = 15, and 24 pairs, respectively) via statistical modeling. RESULTS: Hierarchical clustering of DNA methylation in miRNA coding regions clearly distinguished NBNC-HCC tissue samples from relevant background tissues, revealing a remarkable tumor-specific hypomethylation cluster. In addition, miRNA clusters were extremely hypomethylated in tumor samples (median methylation change for non-clustered miRNAs: -2.3%, clustered miRNAs: -24.6%). The proportion of CpGs hypomethylated in more than 90% of the samples was 55.9% of all CpGs within miRNA clusters, and the peak methylation level was drastically shifted from 84% to 39%. Following statistical adjustment, the difference in methylation levels within miRNA coding regions was positively associated with their expression change. Receiver operating characteristic (ROC) analysis revealed a great discriminatory ability in respect to cluster-miRNA methylation. Moreover, miRNA methylation change was negatively correlated with corresponding target gene expression amongst conserved and highly matched miRNA sites. CONCLUSIONS: We observed a drastic negative shift of methylation levels in miRNA cluster regions. Changes in methylation status of miRNAs were more indicative of target gene expression and pathological diagnosis than respective miRNA expression changes, suggesting the importance of genome-wide miRNA methylation for tumor development. Our study dynamically summarized global miRNA hypomethylation and its genome-wide scale consequence in NBNC-HCC.

DOI： 10.1186/s12943-016-0514-6

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記述言語：英語   掲載種別：研究論文（学術雑誌）  

BACKGROUND: Gastric cancer (GC) is one of the most common human cancers. Genes expressed only in cancer tissue, especially on the cell membrane, will be useful biomarkers for cancer diagnosis and therapeutics. METHODS: To identify novel genes encoding transmembrane protein specifically expressed in GC, we generated an Escherichia coli ampicillin secretion trap (CAST) library from diffuse-type GC cell line MKN-45. CAST is a survival-based signal sequence trap method that exploits the ability of mammalian signal sequences to confer ampicillin resistance to a mutant β-lactamase lacking the endogenous signal sequence. RESULTS: By sequencing 1,536 colonies, we identified 23 genes encoding the transmembrane protein present in GC. Among these genes, TSPAN8 (also known as CO-029 and TM4SF3) gene, which encodes transmembrane protein tetraspanin 8, was emphasized as a candidate. Immunohistochemical analysis of tetraspanin 8 in human GC tissues revealed that 72 (34 %) of 210 GC cases were positive for tetraspanin 8, and microvessel density was significantly higher in tetraspanin 8-positive GC than in tetraspanin 8-negative GC. Furthermore, univariate and multivariate analyses revealed that tetraspanin 8 expression is an independent prognostic classifier of patients with GC. TSPAN8 knockdown by siRNA reduced the invasion of GC cell line. The reduction of invasiveness was retrieved by the tetraspanin 8-containing exosome. CONCLUSION: These results suggest that tetraspanin 8 is involved in tumor progression and is an independent prognostic classifier in patients with GC.

DOI： 10.1007/s10120-015-0478-z

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記述言語：英語   掲載種別：研究論文（学術雑誌）  

BACKGROUND: Gastric cancer (GC) is the fifth commonest malignancy worldwide and still one of the leading causes of cancer-related death. The aim of this study was to identify a novel prognostic marker or therapeutic target for GC. METHODS: We analyzed candidate genes from our previous Escherichia coli ampicillin secretion trap (CAST) libraries in detail, and focused on the FKTN gene because it was overexpressed in both GC cell line CAST libraries, MKN-1 and MKN-45. RESULTS: Quantitative reverse transcriptase PCR analysis of FKTN revealed that FKTN messenger RNA was overexpressed in nine of 28 (32.1 %) GC tissue samples compared with nonneoplastic gastric mucosa. Immunostaining of fukutin showed that 297 of 695 cases (42.7 %) were positive for fukutin. Fukutin-positive GC cases were significantly associated with differentiated histological features, and advanced T grade and N grade. In addition, fukutin expression was observed more frequently in the intestinal phenotype (51 %) of GC than in other phenotypes (37 %) when defined by the expression patterns of mucin 5AC, mucin 6, mucin 2, and CD10. FKTN small interfering RNA treatment decreased GC cell proliferation. CONCLUSIONS: These results indicate that the expression of fukutin may be a key regulator for progression of GC with the intestinal mucin phenotype.

DOI： 10.1007/s10120-015-0511-2

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記述言語：日本語   掲載種別：研究論文（学術雑誌）  

Intercellular communication plays an important role in the regulation of various cellular events. In particular, cancer cells and the surrounding cells communicate with each other, and this intercellular communication triggers cancer initiation and progression through the secretion of molecules, including growth factors and cytokines. Recent advances in cancer biology have indicated that small membrane vesicles, termed exosomes, also serve as regulatory agents in intercellular communications. Exosomes contain functional cellular components, including proteins and microRNAs (miRNAs), and they transfer these components to recipient cells. This exosome-mediated intercellular communication leads to increased growth, invasion, and metastasis of cancer. Thus, researchers regard exosomes as important cues to understanding the molecular mechanisms of cancer biology. Indeed, several lines of evidence have demonstrated that exosomes can explain multiple aspects of cancer biology. In addition, increasing evidence suggests that exosomes and their specific molecules are also attractive for use as biomarkers and therapeutic targets in cancer. Recent reports showed the efficacy of a novel diagnosis by detecting component molecules of cancer-derived exosomes, including miRNAs and membrane proteins. Furthermore, clinical trials that test the application of exosomes for cancer therapy have already been reported. From these points of view, we will summarize experimental data that support the role of exosomes in cancer progression and the potential of exosomes for use in novel diagnostic and therapeutic approaches for cancer.

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記述言語：英語   掲載種別：研究論文（学術雑誌）  

OBJECTIVE: To elucidate the mechanism of radiation-induced cancers, we analyzed the expression profiles of microRNAs extracted from formalin-fixed paraffin-embedded (FFPE) gastric cancer (GC) tissue samples from atomic bomb survivors. METHODS: The expression levels of miR-21, miR-24, miR-34a, miR-106a, miR-143, and miR-145 were measured by quantitative reverse transcription polymerase chain reaction (qRT-PCR). RESULTS: The expression of microRNAs was measured by qRT-PCR in a Hiroshima University Hospital cohort comprising 32 patients in the high-dose-exposed group and 18 patients in the low-dose-exposed group who developed GC after the bombing. The GC cases showing high expression of miR-24, miR-143, and miR-145 were more frequently found in the high-dose-exposed group than in the low-dose-exposed group. We next performed qRT-PCR of miR-24, miR-143, and miR-145 in a cohort from the Hiroshima Red Cross Hospital and Atomic-Bomb Survivors Hospital comprising 122 patients in the high-dose-exposed group and 48 patients in the low-dose-exposed group who developed GC after the bombing. High expressions of miR-24 and miR-143 were more frequently found in the high-dose-exposed group than in the low-dose-exposed group. Multivariate analysis demonstrated that only high expression of miR-24 was an independent predictor for the exposure status. CONCLUSION: These results suggest that the measurement of miR-24 expression from FFPE samples is useful to identify radiation-associated GC.

DOI： 10.1159/000398809

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記述言語：英語   掲載種別：研究論文（学術雑誌）  

The hepatitis B virus (HBV) infection is the leading cause of persistent liver diseases, cirrhosis, and hepatocellular carcinoma (HCC). However, the precise mechanism underlying the development of HBV-related diseases is not fully understood. In addition, the therapeutic strategies for the diseases are less than optimum. microRNAs (miRNAs) are small noncoding RNAs that have been described as a "fine-tuner" in various cellular events. The dysregulation of miRNAs play a role in the development of the cancer as well as viral interference. Recent articles have demonstrated that several miRNAs are deregulated by HBV infection and contribute to viral replication and pathogenesis. Thus, it suggests that the precise mechanism between miRNA and HBV biology will be leading to the development of the novel diagnosis and therapy. This chapter aims to provide the basic principals of miRNAs in development of the HBV-related diseases. We also discuss about the possibility of miRNAs on the clinical application for diagnosis and therapy of HBV-related diseases.

DOI： 10.1007/978-3-319-22671-2_19

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記述言語：英語   掲載種別：研究論文（学術雑誌）  

OBJECTIVE: Colorectal cancer (CRC) develops through the deregulation of gene expression and the accumulation of epigenetic abnormalities, leading to tumor cell acquisition of malignant features. MicroRNAs (miRNAs) play a critical role in cancer development, where they can act as oncogenes or oncosuppressors. METHODS: miR-148a expression was measured by qRT-PCR in patients with colorectal adenoma (n = 21) and CRC (stage I-IV, n = 159) using formalin-fixed paraffin-embedded tissue samples. In situ hybridization (ISH) using an miR-148a-specific probe was also performed. To further confirm the direct effect of miR-148a on matrix metalloproteinase (MMP)7 expression in CRC, MTT and cell invasion assays using HT29 and WiDr cells were performed. RESULTS: miR-148a expression was found to be clearly downregulated in high-grade adenoma compared to low-grade adenoma on both qRT-PCR and ISH analysis. Downregulation of miR-148a expression was significantly correlated with advanced clinicopathological features and was an independent prognostic classifier in patients with stage III CRC. In CRC cells and tissues, miR-148a expression was inversely correlated with the expression of MMP7. CONCLUSION: We showed the collaborative participation of miR-148a and MMP7 in CRC cell invasion. These results also demonstrate that the downregulation of miR-148a expression promotes CRC progression, especially carcinogenesis and cancer cell invasion.

DOI： 10.1159/000438826

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記述言語：英語   掲載種別：研究論文（学術雑誌）  

CD24 is a heavily glycosylated cell surface protein that is expressed in putative stem cells and is overexpressed in various human malignancies, yet the significant roles of CD24 in gastric cancer development are still elusive. We investigated the involvement of CD24 in gastric cancer aggressiveness, which is attributed to its heterogeneity. Cultured gastric cancer cells showed diverse expression patterns in CD24, whereas other defined cell surface markers, such as CD44 and CD133, were homogenous. Purely sorted CD24-negative gastric cancer cells showed strong alteration into the CD24-positive cell type in an autochthonous manner, and reached to steady expression levels. Our clinicopathological study revealed that CD24 positivity was an independent prognostic factor in both intestinal and diffuse types of gastric cancer. CD24 expression was correlated with the advanced stages, invasiveness, and lymph node metastasis of gastric cancer. Silencing of CD24 in cultured cells significantly decreased cell migration and invasion. Hypoxic treatment upregulated CD24 expression, and simultaneously induced cell motility and invasion of gastric cancer cells. Hypoxic treatment-induced CD24 expression was significantly attenuated by knockdown of hypoxia-inducible transcription factors. These data suggest that CD24-negative cells are capable of gaining cell motility and invasiveness through the induction of CD24, which is mediated by hypoxia. CD24 would be an attractive marker to define not only the heterogeneity but also the aggressiveness of gastric cancer cells. The mechanisms by which hypoxia induces CD24 expression would also be a potential therapeutic target for gastric cancer.

DOI： 10.1111/cas.12522

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記述言語：英語   掲載種別：研究論文（学術雑誌）  

Gastric cancer (GC) is one of the most common malignancies worldwide. In particular, scirrhous type GC is highly metastatic and is characterized clinically by rapid disease progression and poor prognosis. MicroRNAs (miRNAs) play crucial roles in cancer development and progression. We previously demonstrated by microarray analysis that microRNA-145 (miR-145) is one of the more highly expressed miRNAs in scirrhous type GC vs. non-scirrhous types of GC. In the present study, we investigated the role of miR-145 in scirrhous type GC. The expression levels of miR-145 assessed by quantitative RT-PCR were higher in scirrhous type GC tissue samples than in non-scirrhous type GC and corresponding normal tissues. GC patients with high miR-145 expression were at a more advanced tumor stage (P=0.0156) and had more scirrhous type histology (P=0.0054) than those with low miR-145 expression. Furthermore, miR-145 expression was significantly associated with poor prognosis in GC patients (P=0.0438). miR-145 expression was localized in stromal fibroblasts of scirrhous type GC but not in cancer cells. miR-145 was induced by treatment by transforming growth factor-β, and it enhanced the expression of α-smooth muscle actin, a marker of myofibroblasts, in both normal gastric fibroblasts and cancer-associated fibroblasts. These data suggest that miR-145 may contribute to the progression of scirrhous type GC by regulating activation of peri-tumoral fibroblasts.

DOI： 10.3892/or.2014.3333

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記述言語：英語   掲載種別：研究論文（学術雑誌）  

OBJECTIVES: Although chemotherapy for castration-resistant prostate cancer (CRPC) has been applied clinically in recent years, the effects are not sufficient. It is urgently necessary to develop novel therapeutics for CRPC. We previously generated Escherichia coli ampicillin secretion trap libraries of 2 prostate cancer (PCa) cell lines and normal prostate. By comparing the E. coli ampicillin secretion trap libraries of CRPC cell lines with those of androgen-sensitive PCa cell lines and normal prostate, we focused on the protein-tyrosine-phosphatase of regenerating liver 1 (PRL1) gene and analyzed its expression and biological function. MATERIALS AND METHODS: The expression of PRL1 was examined by quantitative reverse transcription polymerase chain reaction and immunohistochemistry in clinical PCa samples. The effects of PRL1 on PCa cells were evaluated by cell growth, migration, and invasion assays. To investigate the effect of PRL1 on epidermal growth factor receptor (EGFR) signaling, PRL1 knockdown PC3 cells were examined by Western blot and immunohistochemical analyses. RESULTS: Quantitative reverse transcription polymerase chain reaction revealed that PRL1 was expressed much more highly in PCa than in nonneoplastic prostate samples. High expression of PRL1 detected by immunohistochemistry correlated with poor prognosis after prostatectomy and combined androgen blockade therapy. Functional analysis indicated that PRL1 stimulated cell growth, migration, and invasion in PCa cell lines. Expression EGFR and matrix metalloproteinase 9 was reduced by knockdown of PRL1 in the PC3 cell line. CONCLUSIONS: PRL1 regulates expression of EGFR and modulates downstream targets. PRL1 has potential as a therapeutic target in PCa including CRPC.

DOI： 10.1016/j.urolonc.2014.03.007

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記述言語：英語   掲載種別：研究論文（学術雑誌）  

Scirrhous type gastric cancer is highly aggressive and has a poorer prognosis than many other types of gastric carcinoma, due to its characteristic rapid cancer cell infiltration and proliferation, extensive stromal fibrosis, and frequent peritoneal dissemination. The aim of the present study was to identify novel prognostic markers or therapeutic targets for scirrhous type gastric cancer. We reviewed a list of genes with upregulated expression in scirrhous type gastric cancer and compared their expression with that in normal stomach from our previous Escherichia coli (E. coli) ampicillin secretion-trap (CAST) analysis. We focused on the ZDHHC14 gene, which encodes zinc finger, DHHC-type containing 14 protein. qRT-PCR analysis of ZDHHC14 in 41 gastric cancer cases revealed that compared to mRNA levels in normal non-neoplastic gastric mucosa, ZDHHC14 mRNA was overexpressed in 27% of gastric cancer tissue samples. The overexpression of ZDHHC14 was significantly associated with depth of tumor invasion, undifferentiated histology and scirrhous pattern. The invasiveness of ZDHHC14-knockdown HSC-44PE and 44As3 gastric cancer cells was decreased in comparison with that of the negative control siRNA-transfected cells, together with downregulation of MMP-17 mRNA. Integrins α5 and β1 were also downregulated in ZDHHC14-knockdown 44As3 cells. Forced expression of ZDHHC14 activated gastric cancer cell migration and invasion in vitro. These results indicate that ZDHHC14 is involved in tumor progression in patients with scirrhous type gastric cancer.

DOI： 10.3892/or.2014.3166

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記述言語：英語   掲載種別：研究論文（学術雑誌）  

Gastric cancer (GC) is one of the most common malignancies worldwide. In particular, scirrhous type GC is highly metastatic and is characterized clinically by rapid disease progression and poor prognosis. MicroRNAs (miRNAs) play crucial roles in cancer development and progression. In the present study, we identified several miRNAs that are expressed at higher levels in scirrhous type GC than in non-scirrhous type GC by miRNA microarray analysis. Among these, microRNA-143 (miR-143) expression was higher in scirrhous type GC than in non-scirrhous types of GC. In situ hybridization and quantitative RT-PCR analysis showed that miR-143 is expressed by stromal fibroblasts but not by cancer cells. In stromal cells, miR-143 enhanced collagen type III expression in normal gastric fibroblasts and cancer-associated fibroblasts through activation of transforming growth factor-β)/SMAD signaling. Furthermore, high miR-143 expression in GC was associated with worse cancer-specific mortality (P = 0.0141). Multivariate analysis revealed that miR-143 was an independent prognostic factor. Treatment of GC cell lines with 5-aza-2'-deoxycytidine restored the expression of miR-143, and precursor miR-143 caused the inhibition of cancer cell invasion. These data suggest that miR-143 regulates fibrosis of scirrhous type GC through induction of collagen expression in stromal fibroblasts and that miR-143 expression serves as a prognostic marker of GC.

DOI： 10.1111/cas.12329

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記述言語：英語   掲載種別：研究論文（学術雑誌）  

Gastric cancer (GC) develops through deregulation of gene expression and accumulation of epigenetic abnormalities, leading to tumor cell acquisition of malignant features. MicroRNAs (miRNAs) play a critical role in cancer development where they can act as oncogenes or oncosuppressors. To identify miRNAs that are associated with some clinicopathologic features of GC and/or participate in tumor progression, miRNA expression in 20 GC tissues and five corresponding non-neoplastic gastric mucosa was examined by miRNA microarray. Oligonucleotide array analysis was carried out for miRNA target prediction. The functions of candidate miRNAs and their target genes were also analyzed by quantitative RT-PCR, Western blotting, reporter gene assay, and cell invasion assay. Comparison of miRNA expression profiles revealed that downregulation of miR-148a was identified in most of the GC tissues. Downregulation of miR-148a was significantly correlated with an advanced clinical stage, lymph node metastasis, and poor clinical outcome. Custom oligonucleotide array analysis revealed that MMP7 expression was markedly downregulated in miR-148a-overexpressing GC cells; MMP7 was found to be a direct and functional target of miR-148a, participating in cell invasion. These results suggest that miR-148a contributes to the maintenance of homeostasis in normal stomach tissue and plays an important role in GC invasion by regulating MMP7 expression.

DOI： 10.1111/cas.12330

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記述言語：英語   掲載種別：研究論文（学術雑誌）  

Esophageal squamous cell carcinoma (ESCC) is one of the most common malignancies worldwide. In the present study, to identify novel prognostic markers or therapeutic targets for ESCC, we reviewed a list of genes with upregulated expression in ESCC compared with normal esophagus, as identified by our serial analysis of gene expression (SAGE) analysis. We focused on the NRD1 gene, which encodes the nardilysin protein. Quantitative reverse transcription-polymerase chain reaction (qRT-PCR) in 34 ESCC tissue samples revealed that mRNA expression of NRD1 was upregulated in 56% of ESCC tissue samples. Immunohistochemical analysis of nardilysin in 109 ESCC tissue samples demonstrated that 43 (39%) ESCC cases were positive for nardilysin. Nardilysin-positive ESCC cases were more advanced in terms of T classification (P = 0.0007), N classification (P = 0.0164), and tumor stage (P < 0.0001) than nardilysin-negative ESCC cases. Furthermore, nardilysin expression was significantly associated with poorer prognosis (P = 0.0258). Univariate and multivariate analyses revealed that nardilysin expression is an independent prognostic classifier of patients with ESCC. The invasiveness of NRD1-knockdown TE1 and TE5 esophageal cancer cell lines was less than that of the negative control siRNA-transfected cell lines. Expression of MMP2 and MMP3 mRNA was significantly lower in NRD1-knockdown TE5 cells than in negative control siRNA-transfected cells. These results suggest that nardilysin is involved in tumor progression, and is an independent prognostic classifier in patients with ESCC.

DOI： 10.1111/cas.12316

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記述言語：英語   掲載種別：研究論文（学術雑誌）  

BACKGROUND: For several types of cancer, including gastric cancer (GC), tumor cells at the invasive front are considered to have a more aggressive behavior compared with those in the more central region. The aim of the present study was to analyze the expression of MMP-7, laminin γ2 and EGFR in a large number of GCs and to investigate how these expression patterns correlate with clinicopathologic parameters, infiltrative patterns, histology or mucin phenotype. METHODS: We immunohistochemically examined the expression of MMP-7, laminin γ2 and EGFR using a tissue microarray analysis of 790 GCs, and evaluated their clinicopathological significance. RESULTS: MMP-7, cytoplasmic laminin γ2, extracellular laminin γ2 and EGFR expression were observed in 25, 25, 8 and 21 % of the 790 GC cases, respectively. Expression of MMP-7, cytoplasmic laminin γ2 and EGFR was associated with advanced T grade, N grade and tumor stage. Extracellular laminin γ2 expression was not associated with any clinicopathologic parameters, infiltrative patterns, histology or mucin phenotype. Furthermore, we investigated the correlations of MMP-7, laminin γ2 and EGFR expression. MMP-7 expression was significantly more frequent in positive expression of cytoplasmic laminin γ2 than negative cases, and EGFR expression was significantly more frequent in positive expression of cytoplasmic laminin γ2 and MMP-7. CONCLUSIONS: Molecular expression of MMP-7, laminin γ2 or EGFR, and their combinations, may be associated with GC tumor aggressiveness. Assessment of expression of these molecules at the invasive front of primary tumors is clinically significant in predicting the malignant behavior of GC.

DOI： 10.1007/s10120-013-0302-6

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記述言語：英語   掲載種別：研究論文（学術雑誌）  

OBJECTIVE: Scirrhous-type gastric cancer (GC) is highly aggressive and has a poor prognosis due to rapid cancer cell infiltration accompanied by extensive stromal fibrosis. The aim of this study is to identify genes that encode transmembrane proteins frequently expressed in scirrhous-type GC. METHODS: We compared Escherichia coli ampicillin secretion trap (CAST) libraries from 2 human scirrhous-type GC tissues with a normal stomach CAST library. By sequencing 2,880 colonies from scirrhous CAST libraries, we identified a list of candidate genes. RESULTS: We focused on the TM9SF3 gene because it has the highest clone count, and immunohistochemical analysis demonstrated that 46 (50%) of 91 GC cases were positive for TM9SF3, which was observed frequently in scirrhous-type GC. TM9SF3 expression showed a significant correlation with the depth of invasion, tumor stage and undifferentiated GC. There was a strong correlation between TM9SF3 expression and poor patient outcome, which was validated in two separate cohorts by immunostaining and quantitative RT-PCR, respectively. Transient knockdown of the TM9SF3 gene by siRNA showed decreased tumor cell-invasive capacity. CONCLUSION: Our results indicate that TM9SF3 might be a potential diagnostic and therapeutic target for scirrhous-type GC.

DOI： 10.1159/000357821

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記述言語：英語   掲載種別：研究論文（学術雑誌）  

Renal cell carcinoma is the most frequently occurring neoplasm in the adult kidney, leading to poor prognosis. Therefore novel biomarkers are required for the prediction of early metastasis following nephrectomy. The aim of the present study was to investigate whether or not expression levels of miR-486, detected in RNA isolated from formalin-fixed paraffin-embedded tissue sections, can predict prognosis for patients with renal cell carcinoma (RCC). Expression levels of miR-486 were measured by quantitative reverse transcriptase-polymerase chain reaction in 150 RCC cases. Expression of miR-486 in RCC samples was ∼2.7-fold higher than in corresponding non-neoplastic kidney samples (P<0.0001). In stage III and IV RCC cases (n=46), a high miR-486 expression in tumors was associated with worse cancer-specific mortality, independent of clinical covariates, including TNM staging (P=0.0064). In addition, miR-486 expression tended to be associated with cancer-specific mortality in stage III and IV RCC patients who were not treated with interferon-α (Kaplan-Meier analysis, n=14, P=0.0574). These results suggest that miR-486 is a promising biomarker to identify poor prognosis in RCC patients. As expression of miR-486 was measured from formalin-fixed paraffin-embedded (FFPE) samples, this study demonstrated that measurement of miR-486 may be readily translated into clinical applications.

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記述言語：英語   掲載種別：研究論文（学術雑誌）  

Gastric cancer (GC) is one of the most common malignancies worldwide. The epidermal growth factor receptor (EGFR) molecule is very important in GC progression. To examine the correlation between EGFR and GC-related genes, we analyzed gene expression profiles of HT-29 cells treated with EGFR ligands and identified six genes upregulated by epidermal growth factor (EGF) and transforming growth factor (TGF)-α treatment. Among these, we focused on cadherin 17 (CDH17) encoding liver-intestine cadherin (LI-cadherin). Expression of LI-cadherin was induced by both EGF and TGF-α, as detected by quantitative RT-PCR and Western blot analysis. A luciferase assay showed that LI-cadherin promoter activity was enhanced by EGF or TGF-α in both HT-29 cells and MKN-74 GC cells. Immunohistochemical analysis of 152 GC cases showed that out of 58 LI-cadherin-positive cases, 24 (41%) cases were also positive for EGFR, whereas out of 94 LI-cadherin-negative cases, only 9 (10%) cases were positive for EGFR (P < 0.0001). Double-immunofluorescence staining revealed that EGFR and LI-cadherin were coexpressed. Significant correlation was found between LI-cadherin expression and advanced T grade and N grade. Both EGFR and LI-cadherin expression were more frequently found in GC cases with an intestinal mucin phenotype than in cases with a gastric mucin phenotype. These results indicate that, in addition to the known intestinal transcription factor caudal type homeobox 2, EGFR activation induces LI-cadherin expression and participates in intestinal differentiation of GC.

DOI： 10.1111/j.1349-7006.2012.02353.x

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記述言語：英語   掲載種別：研究論文（学術雑誌）  

Gastric cancer (GC) is one of the most common malignancies worldwide. Better knowledge of the changes in gene expression that occur during gastric carcinogenesis may lead to improvements in diagnosis, treatment and prevention. In this study, we screened for genes upregulated in GC by comparing gene expression profiles from microarray and serial analysis of gene expression and identified the HOXA10 gene. The aim of the present study was to investigate the significance of HOXA10 in GC. Immunohistochemical analysis demonstrated that 221 (30%) of 749 GC cases were positive for HOXA10, whereas HOXA10 was scarcely expressed in non-neoplastic gastric mucosa except in the case of intestinal metaplasia. Next, we analyzed the relationship between HOXA10 expression and clinicopathological characteristics. HOXA10 expression showed a significant inverse correlation with the depth of invasion and was observed more frequently in the differentiated type of GC than in the undifferentiated type of GC. HOXA10 expression was associated with GC with the intestinal mucin phenotype and correlated with CDX2 expression. Furthermore, the prognosis of patients with positive HOXA10 expression was significantly better than in the negative expression cases. 3-(4,5-dimethylthiazole-2-yl)-2,5-diphenyl tetrazolium bromide and wound healing assay revealed that knockdown of HOXA10 in GC cells by short interfering RNA transfection significantly increased viability and motility relative to the negative control, indicating that HOXA10 expression inhibits cell growth and motility. These results suggest that expression of HOXA10 may be a key regulator for GC with the intestinal mucin phenotype.

DOI： 10.1093/carcin/bgs121

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記述言語：英語   掲載種別：研究論文（学術雑誌）  

Gastric cancer (GC) is one of the most common malignancies worldwide. Recently, cancer stem cells (CSCs) in tumors were found to possess the ability to sustain tumor self-renewal, initiate tumor progression, and possibly also contribute to cancer metastasis. We immunohistochemically examined expression and distribution of representative CSC markers ALDH1, CD44, and CD133 in primary tumors and lymph node metastasis of GC. Among 190 GC primary tumors, 104 (55%) were positive for ALDH1, 117 (62%) were positive for CD44, and 18 (9%) were positive for CD133. Expression of these three CSC markers was significantly associated with advanced clinicopathologic factors. Patients with CD44- and CD133-positive GC had a poorer survival rate than patients with CD44- and CD133-negative GC (CD44: P < 0.001, CD133: P= 0.006). Univariate and multivariate Cox proportional hazards analysis revealed tumor node metastasis stage, CD44 expression, and CD133 expression to be independent predictors of survival in patients with GC. Comparison of CSC markers in primary and metastatic sites showed ALDH1 positivity to be significantly higher in diffuse-type lymph node metastasis than in the primary tumor (P < 0.001). These results indicate that these CSC markers are important in tumor invasion and metastasis and may be good markers indicating long-term survival in patients with GC.

DOI： 10.1111/j.1440-1827.2011.02760.x

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記述言語：英語   掲載種別：研究論文（学術雑誌）  

REG4, which encodes Reg IV protein, is a member of the calcium-dependent lectin superfamily and potent activator of the epidermal growth factor receptor/Akt/activator protein-1 signaling pathway. Several human cancers overexpress Reg IV, and Reg IV expression is associated with intestinal phenotype differentiation. However, regulation of REG4 transcription remains unclear. In the present study, we investigated whether CDX2 regulates Reg IV expression in gastric cancer (GC) cells. Expression of Reg IV and CDX2 was analyzed by Western blot and quantitative reverse transcription-polymerase chain reaction in 9 GC cell lines and 2 colon cancer cell lines. The function of the 5'-flanking region of the REG4 gene was characterized by luciferase assay. In 9 GC cell lines, endogenous Reg IV and CDX2 expression were well correlated. Using an estrogen receptor-regulated form of CDX2, rapid induction of Reg IV expression was observed in HT-29 cells. Reporter gene assays revealed an important role in transcription for consensus CDX2 DNA binding elements in the 5'-flanking region of the REG4 gene. Chromatin immunoprecipitation assays showed that CDX2 binds directly to the 5'-flanking region of REG4. These results indicate that CDX2 protein directly regulates Reg IV expression.

DOI： 10.1371/journal.pone.0047545

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記述言語：英語   掲載種別：研究論文（学術雑誌）  

Recent advances in the understanding of molecular stomach carcinogenesis are reviewed. As to molecular events in individual mucin phenotypes of gastric cancer, the CDX2-Reg IV-SOX9 pathway is associated with the intestinal mucin phenotype, while OLFM4 and CLDN18 are novel markers for the gastric phenotype. microRNAs play an important role in epigenetic deregulation in gastric cancer. Many microRNAs are up-regulated and down-regulated, and some of these are associated with histological differentiation and cancer progression. Reduced miR-200 may participate in the genesis of diffuse type gastric cancer by reducing E-cadherin expression. Genetic polymorphism is a crucial endogenous cause and a fundamental factor of cancer risk. PSCA polymorphism alters the susceptibility to diffuse type gastric cancer through modulation of cell proliferation activity. Cancer stem cells possess the capacity for self-renewal and cause the heterogeneous lineages of cancer cells. Cancer stem cells also show resistance to anti-tumor chemotherapy. Only a minor population of gastric cancer cells reveals the properties of cancer stem cells, and CD44 is one of the markers for gastric cancer stem cells. The origin of gastric cancer stem cells remains to be elucidated.

DOI： 10.1016/j.prp.2011.09.006

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記述言語：英語   掲載種別：研究論文（学術雑誌）  

Claudin-18 plays a key role in constructing tight junctions, and altered claudin-18 expression has been documented in various human malignancies; however, little is known about the biological significance of claudin-18 in colorectal cancer (CRC). The aim of this study is to investigate the significance of claudin-18 expression in CRC and its association with clinicopathological factors. We performed clinicopathological analysis of claudin-18 expression in a total of 569 CRCs by immunohistochemistry. Moreover, we investigated the association between claudin-18 and various markers including gastric/intestinal phenotype (MUC5AC, MUC6, MUC2 and CD10), CDX2, claudin-3, claudin-4, p53 and Ki-67. Claudin-18 expression was detected in 21 of the 569 CRCs (4%) and was seen exclusively on the cell membrane. Positive expression of claudin-18 showed a significant correlation with positive expression of MUC5AC (P < 0.0001) and negative expression of CDX2 (P= 0.0013). The prognosis of patients with positive claudin-18 expression was significantly poorer than in negative cases (P= 0.0106). Multivariate analysis revealed that T grade, M grade and claudin-18 expression were independent predictors of survival in patients with CRC. We revealed that claudin-18 expression correlates with poor survival in patients with CRC and is associated with the gastric phenotype.

DOI： 10.1111/j.1440-1827.2010.02587.x

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記述言語：英語   掲載種別：研究論文（学術雑誌）  

AIMS: The mucin phenotype is associated with clinicopathological findings and tumorigenesis in gastric cancer (GC). The aim was to search for a novel marker regulating the intestinal phenotype of GC. METHODS AND RESULTS: We performed microarray analyses, and GJB6 (encoding connexin 30) was identified as a gene associated with the intestinal phenotype. Immunostaining of connexin 30 in 169 GC cases revealed that 47 (28%) cases were positive for connexin 30, while connexin 30 was negative in nonneoplastic gastric tissue. Connexin 30-negative GC cases showed more advanced T grade, N grade, and tumor stage than connexin 30-positive GC cases. Six (13%) GC cases positive for connexin 30 were histologically of the differentiated type. In addition, the expression of gastric and intestinal phenotypes of GC was examined by immunostaining for MUC5AC, MUC6, MUC2, and CD10. Connexin 30 expression occurred more frequently in the intestinal phenotype (48%) than in other phenotypes (21%) of GC. CONCLUSION: These results indicate that the expression of connexin 30 is a novel differentiation marker mediating the biological behavior of intestinal phenotype GC.

DOI： 10.1159/000314966

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記述言語：英語   掲載種別：研究論文（学術雑誌）  

(6-4) photolyase repairs pyrimidine-pyrimidone (6-4) photoproducts generated in DNA upon UV light exposure. We studied the effects of blue light on the expression of this gene in Xenopus A6 cells. Exposure of the cells to blue light, but not red light, for 12h resulted in more than 20-fold increase of the (6-4) photolyase mRNA. By contrast, levels of the other two photolyase mRNAs, i.e., those for CPD photolyase and cryptochrome DASH, did not change significantly. Oxygen radicals presumably generated within the cells upon exposure to blue light were not the cause of the induction, since addition of neither hydrogen peroxide nor a photosensitizer, phenol red, in the culture medium increased the (6-4) photolyase mRNA level. These results support the possibility that the expression of (6-4) photolyase may be regulated by a mechanism involving an as yet ill-defined blue light photoreceptor in the peripheral tissues of Xenopus.

DOI： 10.1016/j.bbrc.2009.03.158

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記述言語：英語   出版者・発行元：日本癌学会  

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