Jun-ichi Hamada

Hokkaido University, Sapporo-shi, Hokkaido, Japan

Are you Jun-ichi Hamada?

Claim your profile

Publications (61)192.8 Total impact

  • [Show abstract] [Hide abstract]
    ABSTRACT: By a proteomics-based approach, we identified an overexpression of fascin in colon adenocarcinoma cells (FPCKpP-3) which developed from non-tumorigenic human colonic adenoma cells (FPCK-1-1) and were converted to tumorigenic by foreign-body-induced chronic inflammation in nude mice. Fascin overexpression was also observed in the tumors arising from rat intestinal epithelial cells (IEC 6) converted tumorigenic in chronic inflammation induced in the same manner. Up-regulation of fascin expression in FPCK-1-1 cells by transfection with sense fascin cDNA converted the cells tumorigenic, whereas antisense fascin-cDNA-transfected FPCKpP-3 cells reduced fascin expression and lost their tumor-forming ability in vivo. The tumorigenic potential by fascin expression was consistent with their ability to survive and grow in the three-dimensional multicellular spheroids. We found that resistance to anoikis (apoptotic cell death consequential on insufficient cell-to-substrate interactions), which is represented by the three-dimensional growth of solid tumors in vivo, was regulated by fascin expression through caspase-dependent apoptotic signals. From these, we demonstrate that fascin is a potent suppressor to caspase-associated anoikis and accelerator of the conversion of colonic adenoma cells into adenocarcinoma cells by chronic inflammation. This article is protected by copyright. All rights reserved.
    Proteomics 02/2014; · 4.43 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: In this study, we examined the effects of hypoxia on the malignancy of human malignant pleural mesothelioma (MPM) cell lines, and found 1) hypoxia enhanced motility and invasiveness of human malignant pleural mesothelioma (MPM) cells; 2) this phenomenon resulted from increased expression of sialylated MUC1 through the activation of HIF-1 pathway; 3) two HIF-binding sites located in the promoter region of MUC1 were important for MUC1 transactivation under hypoxia. These findings are useful for better understanding molecular mechanisms of aggressive behavior of MPM cells and for targeting them in the clinical therapies for MPM patients.
    Cancer letters 07/2013; · 4.86 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: Sex-determining region Y-box 2 (SOX2) is well known as one of the "stemness" factors and is often expressed in cancers including breast cancer. In this study, we developed a reporter system using fluorescent protein driven by the promoter for SOX2 gene to detect and isolate living SOX2-positive cells. Using this system, we determined that SOX2 promoter activities were well correlated with SOX2 mRNA expression levels in 5 breast cancer cell lines, and that the cell population with positive SOX2 promoter activity (pSp-T(+)) isolated from one of the 5 cell lines, MCF-7 cells, showed a high SOX2 protein expression and high sphere-forming activity compared with very low promoter activity (pSp-T(low/-)). The pSp-T(+) population expressed higher mRNA levels of several stemness-related genes such as CD44, ABCB1, NANOG and TWIST1 than the pSp-T(low/-) population whereas the two populations expressed CD24 at similar levels. These results suggest that the cell population with SOX2 promoter activity contains cancer stem cell (CSC)-like cells which show expression profiles different from those of CSC-marker genes previously recognized in human breast cancers.
    Biochemical and Biophysical Research Communications 06/2013; · 2.41 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: Human malignant pleural mesothelioma (MPM) is highly aggressive, and its prognosis is very poor. For an early diagnosis of MPM and developing new therapeutic strategies against the malignancy, it is necessary to better understand biological characteristics of MPM. In this study, we established two cell lines from pleural effusions derived from patients with MPM. Both cell lines expressed tumor markers of mesothelioma such as mesothelin, podoplanin, WT1, calretinin and keratin 5/6 whereas they did not express either CEA or TTF-1 which are often used as markers of lung adenocarcinoma. The cell lines harboured wild-type TP53, produced hyaluronic acid, and were not infected with SV40. When these two cell lines were cultured under hypoxia (1% O(2)), they showed particular responses to the hypoxic condition, distinct from those to normoxic condition (21% O(2)). Namely, the ability to form a colony originating from a single cell (plating efficiency and cloning efficiency) was stimulated under hypoxia in both cell lines. On the other hand, when the assays of cell growth were started at a relatively high cell density, the growth of both cell lines, regardless of anchorage-dependent or -independent, decreased under hypoxia. The differences of their growth between under hypoxia and under normoxia, and those depending on the cell density, may provide useful hints for developing a new strategy for diagnosis or therapy of MPM.
    Biomedical Research 01/2013; 34(1):13-21. · 1.15 Impact Factor
  • Source
    03/2012; , ISBN: 978-953-51-0228-1
  • Yasuhiro Hida, Jun-Ichi Hamada
    [Show abstract] [Hide abstract]
    ABSTRACT: Lung cancer is a heterogeneous disease with several histologic subtypes. The two major pathologies, which account for approximately 70% of lung cancers, are adenocarcinoma (AD) and squamous cell carcinoma (SQ). Traditionally, these two subtypes have been categorized as non-small-cell lung cancer and treated similarly. However, they are different not only pathologically, but also functionally. For example, 18F-fluorodeoxyglucose positron emission tomography (FDG-PET), which assesses glucose metabolism in tumor tissues, shows that SQ has higher glucose metabolism than does AD. Matrix metalloproteinases (MMPs) and their inhibitors play pleiotropic roles in cancer development, carcinogenesis, apoptosis, angiogenesis, invasion and metastasis. Expression of MMPs and their associated molecules is different among the subtypes of lung cancer. Expression levels of MMP-2, MMP-7, reversion-inducing cysteine-rich protein with Kazal motifs (RECK), tissue inhibitors of metalloproteinase (TIMP)-1, and TIMP-2 are higher in AD than in SQ. In contrast, expression levels of MMP-1, MMP-8, MMP-9 and TIMP-3 are higher in SQ than in AD. Serum levels of a disintegrin and metalloproteinase (ADAM)-8 and ADAM-28 are higher in lung cancer patients than in healthy controls. High expression of ADAM-28 correlates with metastasis and recurrence, but there is no significant difference in ADAM-8 or ADAM-28 expression between AD and SQ. It is necessary to recognize the differential expression patterns of MMPs, their endogenous inhibitors and associated molecules for each subtype of lung cancer in order to develop clinical markers, therapeutic inhibitors and treatment strategies using MMP inhibitors.
    Anti-cancer agents in medicinal chemistry 01/2012;
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Phosphatase of regenerating liver (PRL) belongs to a class of the protein tyrosine phosphatase family, which is known so far to consist of 3 members, PRL-1, PRL-2, and PRL-3. The aim of this study was to uncover the role of PRL genes in development of oral malignancy. We analyzed expression levels of the 3 PRL genes in 50 human oral squamous cell carcinomas (OSCCs), 11 dysplasia and 12 normal mucosa tissues by a real-time RT-PCR method. PRL-3 but not PRL-1 or PRL-2 expressions were significantly higher in OSCC and dysplasia than in normal mucosa tissues. Additionally, PRL-3 expressions were significantly higher in OSCC tissues harboring dominant-negative p53 or recessive p53 mutation than in those harboring wild-type p53. These results suggest that PRL-3 plays a role in oral cancer development and can be useful as a marker of pre-malignant and malignant lesion of oral mucosa.
    Asian Pacific journal of cancer prevention: APJCP 01/2011; 12(4):947-51. · 1.27 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Patients with an oral squamous cell carcinoma (OSCC) often develop multiple malignant lesions. This report examined whether individual tumours developed in a patient show the same genetic alteration, such as p53 mutations. This case study describes three SCCs and three leukoplakias which developed simultaneously in a single 67-year-old Japanese man. A p53 mutation was detected in two of the three SCCs and one of the three leukoplakias. One SCC had a missense mutation at codon 285 (GAG>AAG, Glu>Lys) and the other a nonsense mutation at codon 336, and the leukoplakia had a missense mutation at codon 273 (CGT>CAT, Arg>His). This case showed that individual oral tumours may have different genetic changes even when they develop in a single patient. Therefore, this report provided strong evidence that in cases of multiple tumours it is necessary to design tailor-made therapies for each individual tumour rather than a single standardised therapy for all multiple tumours.
    Anticancer research 11/2010; 30(11):4773-8. · 1.71 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: Platelet-derived growth factor (PDGF) is a significant mediator in the proliferation of cancer-associated stromal fibroblasts (CAFs). The inhibition of CAF proliferation by blocking PDGF signaling could lead to a development of novel cancer therapy. We analyzed whether inhibiting proliferation of lung CAFs by imatinib mesylate, which has inhibitory activity on PDGF-receptor tyrosine kinase, could suppress the proliferative activity of lung cancer cells which coexisted in the tumor tissue. First, we established primary cultured fibroblasts from human lung cancer tissues. RT-PCR analysis showed that PDGF-receptors (PDGFRalpha and beta) were more highly expressed in the fibroblasts, whereas PDGFs (PDGF-A, and -B) were more in lung cancer cell lines. Western blotting showed that imatinib treatment inhibited phosphorylation of PDGFRbeta, Akt, and Erk1/2 in the fibroblasts. The treatment also significantly inhibited the proliferative activity of the fibroblasts. The inhibitory effects were exerted more definitely in co-administering imatinib and PDGF-BB, a dimer of the polypeptide chains of B, than in administering imatinib alone. The conditioned media of the fibroblasts significantly increased the proliferative activity of human lung cancer cell line A549 compared to control culture medium. The proliferation-stimulating effect on A549 cells decreased significantly in the conditioned media of the primary cultured fibroblasts that had been treated with imatinib. Our results suggest that imatinib has antitumor activity which is exerted by reducing the proliferation-stimulating effect of CAFs on lung cancer cells, as well as inhibiting the proliferation of CAFs, by way of blocking PDGF signaling.
    International Journal of Oncology 10/2010; 37(4):869-77. · 2.66 Impact Factor
  • American Journal of Hematology 07/2010; 85(7):535-7. · 4.00 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: HOX genes are known as master regulator genes which give cells positional information in embryogenesis. In this study, we compared the expression patterns of 39 HOX genes among human colorectal carcinomas from the right large intestine (cecum, ascending and transverse colon), those from the left large intestine (discending and sigmoid colon, and rectum) and hepatocellular carcinoma. The expression levels of each HOX gene were quantified by analysis based on the real-time RT-PCR. The expression patterns of HOX genes in colorectal and hepatocellular carcinoma tissues differed from those in their normal or non-cancerous tissues. Between the tumor tissues in the right-side large intestine and those in the left-side, different HOX genes were expressed in association with cancer. Further, the expression levels of HOXD8 in liver-metastatic tissues of colorectal carcinomas were as low as in non-cancerous liver tissues, and were significantly lower than those in the primary tissues. These results suggest that dysregulated expressions of HOX genes play an important role in carcinogenesis and malignant progression of colorectal and hepatocellular carcinomas.
    Oncology Reports 03/2010; 23(3):843-51. · 2.30 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: More than half of all human cancers are associated with mutations of the TP53 gene. In regard to the functional interaction with the remaining wild-type (WT) p53 allele, p53 mutations are classified into two types, recessive and dominant-negative (DN) mutations. The latter mutant protein has a DN activity over the remaining WT allele. We previously showed that the DN p53 mutant was useful as a predictor of poor outcome or a risk factor for metastatic recurrence in patients with some types of cancers, regardless of the presence or absence of loss of heterozygosity (LOH) of WT p53, suggesting that the DN p53 had 'gain-of-function (GOF)' activity besides the transdominance function. In this study, we investigated GOF activity of two DN p53 mutants which had a point mutation at codon 248 (R248Q and R248W), one of the hot spots, by transfecting them respectively into H1299 cells which originally expressed no p53 protein. Growth activity of the transfectants with the two mutants was not different from that of parent or Mock transfectants. Meanwhile, in vitro invasions of Matrigel and type I collagen gel by R248Q-transfectants were significantly higher than those by R248W-transfectants or the control cells. However, there were no differences in cell motile activities, expressions of extracellular matrix-degradative enzymes such as matrix metalloproteinases, urokinase-type plasminogen activator and heparanase, and their inhibitors, between R248Q- and R248W-transfectants. These findings indicate that the p53 mutants have a different quality in GOF activities even if the mutations occurred at the same codon. And detailed information of the status of p53, including transdominancy and GOF activity, is expected to be useful for diagnosis and therapeutic strategy fitting the individual patients.
    Biomedical Research 01/2010; 31(6):401-11. · 1.15 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: Melanoma has a high tendency to metastasize to lymph nodes, which is one of the clinicopathological factors to indicate poor prognosis. Recent investigations have shown the importance of lymphangiogenesis in lymph node metastasis in a variety of human tumors including melanoma. However, molecular mechanism of lymphatic metastasis is still poorly defined. We examined influence of interactions between normal lymphatic endothelial cells (LECs) and melanoma cells on cell migration. Medium conditioned with LEC (LEC-CM) contained chemotactic and chemokinetic activities for human melanoma cell lines. The chemotactic activity was fractionated in more than 100 kDa, and inactivated by heat-treatment. The chemotactic activity of LEC-CM was abolished by immunodepletion with anti-laminin-1 antibody. And immunoprecipitation and Western blot analyses revealed that LEC-CM contained laminin-421. When melanoma C8161 cells were treated with function-blocking antibodies to integrin alpha3 or alpha6, their chemotactic responses to LEC-CM were markedly reduced. Furthermore, the knock-down of tetraspanin CD151 weakened the chemotactic responses of C8161 and MeWo cells to LEC-CM. These data suggest that laminin-421 secreted by LEC possibly facilitates lymphatic metastasis through the induction of chemotaxis of melanoma cells.
    Pigment Cell & Melanoma Research 07/2009; 22(5):601-10. · 5.84 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: Using differential display analysis, we have identified a novel rat gene whose expression is increased during tumor progression in rat mammary carcinoma cell lines. This gene is an ortholog of the human chromosome 7 open reading frame 24 gene (C7orf24) and encodes a protein of 188 amino acids with no recognized protein domains. C7orf24 has been identified as γ-glutamyl cyclotransferase (GGCT), an important enzyme functioning in glutathione homeostasis. Our Northern and Western blot analyses revealed that the GGCT gene is expressed in various normal human and tumor tissues, as well as in cancer cell lines. Among the tumor tissues tested, lung tumor tissue expressed GGCT mRNA more strongly than normal lung tissue. The GGCT protein was found to be localized in the cytoplasmic region of cultured cells, where it forms a homodimer. Analysis of various deletion mutants of the GGCT protein revealed that the region containing amino acid residues 61-120 of the protein is required for its cytoplasmic localization. The comparison of the soft agar colony formation of HBL-100 cells stably expressing GGCT with that of control HBL-100 cells revealed that GGCT does not promote colony formation, suggesting that the role it plays in lung cancer cells is not related to tumorigenesis.
    Molecular Medicine Reports 01/2009; 2(3):385-91. · 1.17 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: We hypothesize that dysregulated expression levels of the developmental regulatory genes in the adult body result in tumor development and malignant progression. PAX genes discovered as human orthologous genes of Drosophila 'paired' encode transcription factors, which control the expression of target genes to go on along the program of development. In this study, we first quantified expression of 9 PAX genes in human nevus pigmentosus tissues, melanoma tissues and melanoma cell lines by the real-time reverse transcription-PCR method. As a result, we found that the expression levels of PAX4 and PAX9 were extremely low in melanoma tissues and cell lines compared to nevus pigmentosus tissues. We then established melanoma cells overexpressing PAX4 and examined roles of PAX4 in cell growth. PAX4-overexpression reduced in vitro cell growth of human melanoma C8161 and MeWo cells. BrdU-uptake assay and cell cycle analysis by flow cytometry indicated that the retardation of cell proliferation by PAX4-overexpression was due to decreased DNA synthesis and cell cycle arrest at the G0/G1 phase. Furthermore, treatment of C8161 and MeWo cells with 5-azacytidine, a DNA demethylating agent, induced the expression of PAX4, suggesting that DNA methylation repressed the PAX4 gene expression in human melanoma. These results suggest that PAX4 functions as a potent tumor suppressor.
    International Journal of Oncology 12/2008; 33(5):1065-71. · 2.66 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: The purpose of this research was to identify biomarkers for predicting cervical lymph node metastasis in oral squamous cell carcinoma (OSCC). We surveyed the expressions of 1289 cancer-related genes in 41 cases of OSCC by cDNA array analysis. We extracted genes upregulated or downregulated in their expression in association with lymph node metastasis. Of 1289 cancer-related genes, we identified 39 genes differentially expressed in OSCC with or without lymph node metastasis. Expression levels of 9 genes were lower, and those of 30 genes were higher, in node-positive cases. The genes expressed at higher levels in node-positive cases included angiogenesis-related molecules, cell adhesion molecules, and proteolytic enzymes. We suggest that these characteristic genes could provide, if verifiable, useful information for predicting the risk of lymph node metastasis in OSCC.
    Odontology 07/2008; 96(1):38-43. · 1.58 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: Human ESX1 is a 65-kilodalton (kDa) paired-like homeoprotein that is proteolytically processed into N-terminal 45-kDa and C-terminal 20-kDa fragments. The N-terminal ESX1 fragment, which contains the homeodomain, localizes to the nucleus and represses mRNA transcription from the K-ras gene. When we inoculated human colorectal carcinoma HCT116 constitutive expressing N-terminal region of ESX1 (N-ESX1) into nude mice, transfectant cells uniformly showed decreased tumor-forming activity compared with that of the parental cells. Furthermore, pretreatment of HCT116 carcinoma cells with a fusion protein consisting of N-ESX1 and the protein-transduction domain derived from the human immunodeficiency virus type-1 TAT protein gave rise to a dramatic reduction in the tumorigenicity of HCT116 cells in nude mice. Our results provide first in vivo evidence for the molecular targeting therapeutic application of the K-ras repressor ESX1, especially TAT-mediated transduction of N-ESX1, in the treatment of human cancers having oncogenic K-ras mutations.
    Biochemical and Biophysical Research Communications 06/2008; 370(1):189-94. · 2.41 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: Genetic alteration of p53 is a significant determining factor in the carcinogenesis. The loss of function, mutant p53 can possess a dominant negative effect on wild-type p53 and may also exert gain-of-function activity. It is, however, not clear how p53 functional status due to various types of mutation results in outcome of patients with oral cancer. A total of 60 oral SCC samples were subjected to yeast functional assay that screens human p53 function in yeast, and sequencing for determination of p53 mutations. The detected mutants were further investigated for their dominant negative activity using a yeast-based transdominance assay that tests dominant negative activity of a mutant p53 over wild-type p53 by coexpressing the mutant and wild-type p53 in a yeast transcriptional reporter system. p53 mutation was found in 42 out of 60 of which 10 (24%) exhibited dominant negative activity and 32 (76%) without dominant activity (recessive mutation). The remaining 18 (30%) were considered to have wild-type p53. The patients with dominant negative mutation had significantly shorter disease-free survival than patients with no mutation (log-rank test, p<0.001) and those with a recessive mutation (p<0.016). There were slight significant differences in disease-free survival were found between the patients with tumours harbouring a recessive p53 mutation and those with tumours harbouring a wild-type p53 (p<0.038). The presence and absence of a dominant negative p53 mutation may thus provide a predictor of early recurrence in oral SCC patients.
    Cancer letters 06/2008; 270(1):108-19. · 4.86 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: We examined expression patterns of matrix metalloproteinase (MMP), tissue inhibitor of metalloproteinase (TIMP), and reversion-inducing cysteine-rich protein with Kazal motifs (RECK) in colorectal cancer tissues to assess their prognostic significance. mRNA expressions of 17 MMPs, 4 TIMPs, and RECK were measured in 112 colorectal cancerous tissues, 20 normal mucosa tissues, and 11 metastatic liver lesions by real-time reverse-transcriptional-polymerase chain reaction. The protein level expressions were confirmed with immunohistochemistry. Cancers and normal mucosa displayed highly significant differences (P < 0.01) in expression of nine genes (MMP-1, -3, -7, -9, -10, -11, -12, -14, and RECK). Primary cancers and metastatic lesions showed highly significant differences (P < 0.01) in MMP-1, -10, -11, and TIMP-1. MMP-12 expression was higher in the primary tumors that were associated without hepatic metastasis than those with metastasis (P < 0.01). High expression of MMP-15 was related to longer disease-free survival (generalized Wilcoxon test, P < 0.0062; Cox hazard model, P < 0.028, hazard ratio, 0.099). MMP, TIMP, RECK expression patterns may provide an insight into extracellular matrix degrading (which is characteristic of colorectal cancers) and its role in metastasis.
    Journal of Surgical Research 06/2008; 146(1):32-42. · 2.02 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: Matrix metalloproteinase 1 (MMP-1) degrades extracellular matrix and thereby promotes tumor invasion and progression. In this study we examined the prognostic significance of tissue expression levels of MMP-1 mRNA in patients with invasive breast carcinoma. We assessed the prognostic value of MMP-1 mRNA expression in tumor tissue specimens from 85 breast carcinoma patients with a median follow-up time of 38 months (range, 2-48 months). MMP-1 mRNA levels were measured by real-time quantitative reverse transcriptase polymerase chain reaction (real time RT-PCR). The results were correlated with various clinicopathological parameters and clinical outcomes. mRNA expression levels of MMP-1 were higher in tumor tissue specimens than in adjacent normal breast tissue specimens from 15 patients (P < 0.023). MMP-1 mRNA levels showed no significant relationship with either tumor size or axillary node status but correlated inversely with estrogen receptor levels (P < 0.0043). High MMP-1 mRNA expression as determined by real-time RT-PCR correlated significantly with a high frequency of recurrence and fatal outcome (P < 0.025 and P < 0.020). Multivariate analysis using the Cox regression model indicated that high MMP-1 mRNA expression was an independent unfavorable prognostic factor (risk ratio, 6.37; P < 0.019). We have demonstrated for the first time the high mRNA expression of MMP-1 in patients whose carcinomas lack estrogen receptor expression. Our results suggest that MMP-1 is an important gene implicated in the progression of human breast cancer.
    Journal of Surgical Research 05/2008; 146(1):104-9. · 2.02 Impact Factor

Publication Stats

824 Citations
192.80 Total Impact Points


  • 2001–2013
    • Hokkaido University
      • • Department of Stem Cell Biology
      • • Institute for Genetic Medicine
      • • Graduate School of Medicine
      Sapporo-shi, Hokkaido, Japan
  • 2004
    • Hospital of the University of Pennsylvania
      Philadelphia, Pennsylvania, United States
  • 1997–2001
    • Hokkaido University Hospital
      Sapporo, Hokkaidō, Japan