Language：English   Publishing type：Research paper (scientific journal)   Publisher：PUBLIC LIBRARY SCIENCE  

Micro RNAs (miRNAs) regulate the expression of target genes posttranscriptionally by pairing incompletely with mRNA in a sequence-specific manner. About 30% of human genes are regulated by miRNAs, and a single miRNA is capable of reducing the production of hundreds of proteins by means of incomplete pairing upon miRNA-mRNA binding. Lately, evidence implicating miRNAs in the development of lung cancers has been emerging. In particular, miR-19a, which is highly expressed in malignant lung cancer cells, is considered the key miRNA for tumorigenesis. However, its direct targets remain underreported. In the present study, we focused on six potential miR-19a target genes selected by miRNA target prediction software. To evaluate these genes as direct miR-19a target genes, we performed luciferase, pull-down, and western blot assays. The luciferase activity of plasmids with each miR-19a-binding site was observed to decrease, while increased luciferase activity was observed in the presence of anti-miR-19a locked nucleic acid (LNA). The pull-down assay showed biotinylated miR-19a to bind to AGO2 protein and to four of six potential target mRNAs. Western blot analysis showed that the expression levels of the four genes changed depending on treatment with miR-19a mimic or anti-miR-19a-LNA. Finally, FOXP1, TP53INP1, TNFAIP3, and TUSC2 were identified as miR-19a targets. To examine the function of these four target genes in lung cancer cells, LK79 (which has high miR-19a expression) and A549 (which has low miR-19a expression) were used. The expression of the four target proteins was higher in A549 than in LK79 cells. The four miR-19a target cDNA expression vectors suppressed cell viability, colony formation, migration, and invasion of A549 and LK79 cells, but LK79 cells transfected with FOXP1 and TP53INP1 cDNAs showed no difference compared to the control cells in the invasion assay.

DOI： 10.1371/journal.pone.0137887

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：PUBLIC LIBRARY SCIENCE  

Synovial sarcoma is a relatively rare high-grade soft tissue sarcoma that often develops in the limbs of young people and induces the lung and the lymph node metastasis resulting in poor prognosis. In patients with synovial sarcoma, specific chromosomal translocation of t(X; 18) (p11.2; q11.2) is observed, and SS18-SSX fusion protein expressed by this translocation is reported to be associated with pathogenesis. However, role of the fusion protein in the pathogenesis of synovial sarcoma has not yet been completely clarified. In this study, we focused on the localization patterns of SS18-SSX fusion protein. We constructed expression plasmids coding for the full length SS18-SSX, the truncated SS18 moiety (tSS18) and the truncated SSX moiety (tSSX) of SS18-SSX, tagged with fluorescent proteins. These plasmids were transfected in synovial sarcoma SYO-1 cells and we observed the expression of these proteins using a fluorescence microscope. The SS18-SSX fusion protein showed a characteristic speckle pattern in the nucleus. However, when SS18-SSX was co-expressed with tSSX, localization of SS18-SSX changed from speckle patterns to the diffused pattern similar to the localization pattern of tSSX and SSX. Furthermore, cell proliferation and colony formation of synovial sarcoma SYO-1 and YaFuSS cells were suppressed by exogenous tSSX expression. Our results suggest that the characteristic speckle localization pattern of SS18-SSX is strongly involved in the tumorigenesis through the SSX moiety of the SS18-SSX fusion protein. These findings could be applied to further understand the pathogenic mechanisms, and towards the development of molecular targeting approach for synovial sarcoma.

DOI： 10.1371/journal.pone.0077564

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Language：Japanese   Publisher：岡山医学会  

DOI： 10.4044/joma.124.207

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Other Link： https://search.jamas.or.jp/index.php?module=Default&action=Link&pub_year=2012&ichushi_jid=J00175&link_issn=&doc_id=20121204300003&doc_link_id=10.4044%2Fjoma.124.207&url=https%3A%2F%2Fdoi.org%2F10.4044%2Fjoma.124.207&type=J-STAGE&icon=https%3A%2F%2Fjk04.jamas.or.jp%2Ficon%2F00007_3.gif

Language：English   Publishing type：Research paper (scientific journal)   Publisher：SPRINGER  

PURPOSE: We investigated the miRNA profile in peripheral nerve tumors and clarified the involvement of miRNA in the development and progression of MPNST in comparison with neurofibroma (NF). In addition, we attempted to seek associations between the miRNA and their potential targets in MPNST. METHODS: Global miRNA expression profiling was investigated for clinical samples of 6 MPNSTs and 6 NFs. As detected by profiling analysis, the expressions of miR-21 in clinical samples of 12 MPNSTs, 11 NFs, and 5 normal nerves, and 3 MPNST cell lines were compared using quantitative real-time reverse transcription PCR. MPNST cell line (YST-1) was transfected with miR-21 inhibitor to study its effects on cell proliferation, caspase activity, and the expression of miR-21 targets. RESULTS: Analysis of miRNA expression profiles in MPNST and NF revealed significantly altered expression levels of nine miRNAs, one of those, miR-21, and its putative target, programmed cell death protein 4 (PDCD4), were selected for further studies. miR-21 expression level in MPNST was significantly higher than that in NF (P < 0.05). In MPNST cells, transfection of miR-21 inhibitor significantly increased caspase activity (P < 0.01), significantly suppressed cell growth (P < 0.05), and upregulated protein level of PDCD4, indicating that miR-21 inhibitor could induce cell apoptosis of MPNST cells. CONCLUSIONS: These results suggest that miR-21 plays an important role in MPNST tumorigenesis and progression through its target, PDCD4. MiR-21 and PDCD4 may be candidate novel therapeutic targets against the development or progression of MPNSTs.

DOI： 10.1007/s00432-012-1223-1

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：PUBLIC LIBRARY SCIENCE  

The miR-17-92 cluster encodes 7 miRNAs inside a single polycistronic transcript, and is known as a group of oncogenic miRNAs that contribute to tumorigenesis in several cancers. However, their direct targets remain unclear, and it has been suggested that a single miRNA is capable of reducing the production of hundreds of proteins. The majority of reports on the identification of miRNA targets are based on computational approaches or the detection of altered mRNA levels, despite the fact that most miRNAs are thought to regulate their targets primarily by translational inhibition in higher organisms. In this study, we examined the target profiles of miR-19a, miR-20a and miR-92-1 in MCF-7 breast cancer cells by a quantitative proteomic strategy to identify their direct targets. A total of 123 proteins were significantly increased after the endogenous miR-19a, miR-20a and miR-92-1 were knocked down, and were identified as potential targets by two-dimensional electrophoresis and a mass spectrometric analysis. Among the upregulated proteins, four (PPP2R2A, ARHGAP1, IMPDH1 and NPEPL1) were shown to have miR-19a or miR-20a binding sites on their mRNAs. The luciferase activity of the plasmids with each binding site was observed to decrease, and an increased luciferase activity was observed in the presence of the specific anti-miRNA-LNA. A Western blot analysis showed the expression levels of IMPDH1 and NPEPL1 to increase after treatment with anti-miR-19a, while the expression levels of PPP2R2A and ARHGAP1 did not change. The expression levels of IMPDH1 and NPEPL1 did not significantly change by anti-miR-19a-LNA at the mRNA level. These results suggest that the IMPDH1 and NPEPL1 genes are direct targets of miR-19a in breast cancer, while the exogenous expression of these genes is not associated with the growth suppression of MCF-7 cells. Furthermore, our proteomic approaches were shown to be valuable for identifying direct miRNA targets.

DOI： 10.1371/journal.pone.0044095

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：AMER ASSOC CANCER RESEARCH  

Epidermal growth factor receptor (EGFR) tyrosine kinase inhibitors (TKI) have been strikingly effective in lung cancers harboring activating EGFR mutations. Unfortunately, the cancer cells eventually acquire resistance to EGFR-TKI. Approximately 50% of the acquired resistance involves a secondary T790M mutation. To overcome the resistance, we focused on EGFR suppression using microRNA-7 (miR-7), targeting multiple sites in the 30-untranslated region of EGFR mRNA. Two EGFR-TKI-sensitive cell lines (PC-9 and H3255) and two EGFR-TKI-resistant cell lines harboring T790M (RPC-9 and H1975) were used. We constructed miR-7-2 containing miR-7-expressing plasmid. After transfection of the miR-7-expressing plasmid, using cationic liposomes, a quantitative PCR and dual luciferase assay were conducted to examine the efficacy. The antiproliferative effect was evaluated using a cell count assay and xenograft model. Protein expression was examined by Western blotting. The miR-7 expression level of the transfectants was approximately 30-fold higher, and the luciferase activity was ablated by 92%. miR-7 significantly inhibited cell growth not only in PC-9 and H3255 but also in RPC-9 and H1975. Expression of insulin receptor substrate-1 (IRS-1), RAF-1, and EGFR was suppressed in the four cell lines. Injection of the miR-7-expressing plasmid revealed marked tumor regression in a mouse xenograft model using RPC-9 and H1975. EGFR, RAF-1, and IRS-1 were suppressed in the residual tumors. These findings indicate promising therapeutic applications of miR-7-expressing plasmids against EGFR oncogene-addicted lung cancers including T790M resistance by liposomal delivery. Mol Cancer Ther; 10(9); 1720-7. (C)2011 AACR.

DOI： 10.1158/1535-7163.MCT-11-0220

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：WILEY  

MicroRNAs (miRNAs) are small non-coding RNAs that post-transcriptionally repress the expression of target genes. Many miRNAs have been implicated in a number of diseases, including cancers. The miR-17-92 miRNA cluster is known as a body of oncogenic miRNAs, and has been shown to be overexpressed in several cancers, including lung cancer. Although the overexpression of miR-17-92 is clearly implicated in the development of lung cancer, only a few direct targets for the miR-17-92 cluster have been identified thus far. In this study, we examined miR-17-92 target profiles in SBC-3 small-cell lung cancer cells using a quantitative proteomic strategy to identify direct targets of the miR-17-92 cluster. By knocking down the expression of endogenous miR-19a, miR-20a and miR-92-1, which are contained in the cluster, 112 up-regulated proteins were detected and also identified as potential targets of these miRNAs. Among these candidate targets, we validated one direct target, RAB14. In conclusion, these findings suggest that proteomic approaches are valuable for identifying direct miRNA targets, and we were able to identify a novel direct target for the miR-92-1 using our proteomic strategy.

DOI： 10.1002/pmic.201000501

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：ELSEVIER IRELAND LTD  

It has been reported that the threonine-to-methionine substitution at amino acid position 790 (T790M) of the epidermal growth factor receptor (EGFR) gene is correlated with acquired resistance to gefitinib. We previously reported that there was some population that harbored the EGFR T790M mutation as a minor clone of tumor cells prior to drug treatment, may be causing resistance to gefitinib during treatment. This fact also suggests that the detection of the EGFR T790M mutation prior to treatment may predict the development of resistance. We also showed that pleural fluid is a useful specimen for detection of EGFR mutation using sensitive assays. In this study, we reported a female patient who was treated with gefitinib because an EGFR L858R mutation was found in her pleura[ fluid. Our patient showed partial response to gefitinib, but she had progressive disease only 4 months after the start of treatment. Furthermore, the EGFR T790M mutation was detected in the pleural fluid before gefitinib treatment by the mutant-enriched PCR assay. Our findings confirmed that the EGFR T790M mutation was occasionally present as a minor population in tumor cells before treatment and caused resistance after gefitinib administration. The detection of a small fraction of T790M-positive alleles may be useful to predict the clinical course of the gefitinib-treated non-small-cell lung cancer patients. (c) 2007 Elsevier Ireland Ltd. All rights reserved.

DOI： 10.1016/j.lungcan.2007.01.014

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：PROFESSOR D A SPANDIDOS  

The molecular pathogenesis of osteosarcoma is very complicated and associated with chaotic abnormalities on many chromosomal arms. We analyzed 12 cases of osteosarcomas with comparative genomic hybridization (CGH) to identify chromosomal imbalances, and detected highly frequent chromosomal alterations in chromosome 6q, 8p, 10p and 10q. To define the narrow rearranged region on chromosome 6 with higher resolution, loss of heterozygosity (LOH) analysis was performed with 21 microsatellite markers. Out of 31 cases, 23 cases (74%) showed allelic loss at least with one marker on chromosome 6q. We identified two distinct commonly deleted regions on chromosome 6 using markers D6S1565 located at 6q16 and 6q23MS1 at 6q23. The expression analysis of genes located at the deleted region was performed, and the decreased mRNA expression of the CCNC gene, one of the regulators of cell cycle, was detected. Growth of osteosarcoma cell line was significantly suppressed after the CCNC cDNA transfection. Fine mapping of the deleted region containing a possible tumor suppressor gene and the transfection assay suggest that the CCNC is a candidate tumor suppressor gene.

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：AMER ASSOC CANCER RESEARCH  

The threonine-to-methionine substitution at amino acid position 790 (T790M) of the epidermal growth factor receptor (EGFR) gene has been reported in progressing lesions after gefitinib treatment in non-small cell lung cancer (NSCLC) that causes sensitive tumors to become resistant to gefitinib. Alternatively, the EGFR T790M mutation might be present in small fractions of tumor cells before drug treatment, and the tumor cells harboring the T790M mutation might be enriched during the proliferation after drug treatment. We developed a mutant-enriched PCR assay to detect small fractions of cells with T790M mutation and used this technique to detect mutations in 280 NSCLCs, including gefitinib-treated 95 cases. Although the direct sequencing detected only I T790M mutant case, the mutant-enriched PCR (confirmed to enrich one mutant out of 1 X 10(3) wild-type alleles) detected 9 additional cases among 280 cases. As linkage to clinicopathologic factors, the T790M mutation showed no bias for sex, smoking status, or histology but was significantly more frequent in advanced tumors (9 of III cases) than in early-stage tumors (I of 169 cases; P = 0.0013). Among gefitinib-treated cases, gefitinib-sensitive mutations were found in 30 cases. The T790M mutation was present in 3 of 7 no-responders with the gefitinib-sensitive mutation and was not present in 19 responders (P = 0.014). Our results indicate that the T790M mutation is sometimes present in a minor population of tumor cells during the development of NSCLC and suggest that the detection of small fractions of T790M mutant alleles may be useful for predicting gefitinib resistance of NSCLCs with sensitive EGFR mutations.

DOI： 10.1158/0008-5472.CAN-06-1951

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：AMER ASSOC CANCER RESEARCH  

Purpose: Mutations in the epidermal growth factor receptor (EGFR) gene have been reported to be present in non-small cell lung cancer (NSCLC) and related to the responsiveness of tumors to EGFR tyrosine kinase inhibitors, suggesting its usefulness as a biomarker. Because clinical samples contain tumor and normal cells or genes, a highly sensitive assay for detecting mutation is critical for clinical applications.
Experimental Design: The mutant-enriched PCR is a rapid and sensitive assay with selective restriction enzyme digestion. We developed the mutant-enriched PCR assay targeting exons 19 and 21 of EGFR and applied the developed assay to detect mutations in 108 cases of surgically resected specimens of NSCLCs,18 samples of computed tomography (CT)-guided needle lung biopsies, and 20 samples of pleural fluid. In addition, results were then compared with those from direct sequencing and a nonenriched PCR assay.
Results: The mutant-enriched PCR that was proved to enrich one mutant of 2 x 103 normal genes detected mutations in 37 cases of 108 resected tumors, seven samples of CT-guided lung biopsies, and seven samples of pleural fluid. Among mutant cases, four resected tumors, two CT-guided lung biopsies, and two pleural fluid were identified as additional mutant cases by the mutant-enriched PCR, which were considered normal based on nonenriched assays.
Conclusions: Our results indicate that EGFR mutations are readily detectable by mutant-enriched PCR in various clinical samples. Thus, mutant-enriched PCR may provide a valuable method of potentially detecting a small fraction of mutant genes in heterogeneous specimens, indicating its possible use in clinical application for NSCLC.

DOI： 10.1158/1078-0432.CCR-05-0934

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：SPRINGER  

PURPOSE: Aims of the study are to narrow-down the hotspot region on 10q21 defined by previous genome-wide loss of heterozygosity (LOH) analysis in head and neck squamous cell carcinomas (HNSCC) and to define candidate tumor suppressor genes (TSG) concerned with 10q21. MATERIALS AND METHODS: LOH analysis was carried out with ten polymorphic microsatellite markers. Expression analysis was performed by semi-quantitative RT-PCR, and mutation analysis by PCR and direct sequencing. RESULTS: LOH analysis on 10q21 in 52 HNSCC indicated distinctive and frequent allelic loss at D10S589 (42%). Among flanking genes, we found the RHOBTB1 gene as a candidate TSG, since an intragenic marker demonstrated the highest LOH (44%). Expression analysis revealed down-regulation of RHOBTB1 mRNA in 37% of tumors. Interestingly, all the five tumors that showed decreased expression of RHOBTB1 were accompanied with LOH, supporting the haploinsufficiency and class 2 TSG characteristics of RHOBTB1. No pathogenic mutation of RHOBTB1 was found. Furthermore, another gene within the region, EGR2, was also taken under scope. LOH frequencies around the EGR2 gene were relatively low (23 and 33%). Albeit semi-quantitative expression analysis of EGR2 demonstrated downregulation in 45% of tumor samples, no relation was found between the expression levels and LOH status. CONCLUSION: Frequent allelic loss and decreased expression of RHOBTB1 suggested that this gene has a role in tumorigenesis of a subset of HNSCC.

DOI： 10.1007/s00432-005-0033-0

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：NATURE PUBLISHING GROUP  

Synovial sarcomas are soft-tissue tumors predominantly affecting children and young adults. They are molecular-genetically characterized by the SYT-SSX fusion gene generated from chromosomal translocation t(X; 18) (p11.2; q11.2). When we screened new gene products that interact with SYT or SSX proteins by yeast two-hybrid assay, we found that mSin3A, a component of the histone deacetylase complex, interacts with SYT but not with SSX. These results were confirmed by mammalian two-hybrid and pull-down assays. Analyses with sequential truncated proteins revealed a main mSin3A-interaction region on the SYT amino-terminal 93 amino acids, and another one on the region between 187th amino acid and break point. In luciferase assay, mSin3A repressed the transcriptional activity of reporter promoter mediated by SYT and hBRM/BRG1. Our results suggest that the histone deacetylase complex containing mSin3A may regulate the transcriptional activation mediated by SYT.

DOI： 10.1038/labinvest.3700174

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：PROFESSOR D A SPANDIDOS  

Certain tumor suppressor genes (TSG) residing on human chromosome 10q are implicated in astrocytic tumors. We thoroughly examined loss of heterozygosity (LOH) on chromosome 10q in astrocytic tumors to determine the extent of deletion and their relation to prognostic variables of patients. We analyzed 63 astrocytic tumors, including 9 diffuse astrocytomas, 36 anaplastic astrocytomas, and 18 glioblastomas. DNAs from tumors and leukocytes were analyzed for LOH at 18 microsatellite loci by polymerase chain reaction using fluorescence-labeled primers. Then correlation between LOH and clinicopathological variables was examined statistically. Twenty-four (66.7%) anaplastic astrocytomas and 15 (83.3%) glioblastomas had at least one LOH on chromosome 10q. However, diffuse astrocytomas exhibited no LOH. Nineteen tumors (10 anaplastic astrocytomas and 9 glioblastomas) were believed to have a total loss of one chromosome 10. Analyses on 20 tumors with interstitial LOH revealed that most of the high LOH regions matched the location of known TSGs, while some novel LOH regions were found preferentially in anaplastic astrocytoma. The median survivals of the total, partial, and no loss groups were 10.1, 14.8, and 46.8 months, respectively, indicating a significant difference in the survivals of these groups (P=0.0289). Thus, analyzing chromosome 10q loss is helpful for diagnosing malignancy in astrocytic tumors and for predicting patients' survival. Our data also suggested that there are novel TSGs for anaplastic astrocytoma at 10q24 and 10q26.

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：PROFESSOR D A SPANDIDOS  

CDH13 (H-cadherin) is a member of the cadherin superfamily, which plays an important role in cell recognition and adhesion. We examined the expression and methylation status of the CDH13 gene in diffuse large B cell lymphomas (B-DLCLs). We found decreased expression of the CDH13 gene in all of 6 hematopoietic cell lines by reverse transcription-polymerase chain reaction (RT-PCR). Promoter hypermethylation of the gene was detected in all 6 cell lines and in 13 of 19 (68%) B-DLCL samples by methylation-specific PCR. Interestingly, the methylation frequency of the CDH13 gene was comparable to those of the tumor suppressor genes p15 (68%) and p16 (74%) detected in B-DLCLs. Sequencing of bisulfite-treated DNA revealed hyper-methylation of the CpG islands of the CDH13 promoter in B-DLCLs and the cell lines. Treatment with 5-aza-2'-deoxycytidine restored CDH13 gene expression in a cell line in which promoter hyper-methylation and impaired expression of the CDH13 gene were observed. Loss of heterozygosity (LOH) around the CDH13 genes on chromosome 16q24 was detected in 6 of 15 (40%) informative cases with microsatellite marker D16S507 and in 6 of 15 (40%) cases with D16S422 in B-DLCLs. In all of 4 B-DLCL cases which showed both promoter methylation and LOH at the two marker loci, expression of the CDH13 gene was significantly low. These results suggest that silencing of the CDH13 gene by aberrant promoter methylation and allelic deletion is associated with tumorigenesis in a subset of B-DLCL.

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：ELSEVIER SCIENCE INC  

Objectives. To report our development of a new application of the inter-AN long polymerase chain reaction (PCR) for genomic scanning to screen for tumor-specific alterations in tumor DNA. Using this method, we detected a rearranged chromosomal region in renal cell carcinomas (RCCs). We then examined tumor-specific allelic loss in this region using microsatellite markers and determined whether a relationship was present between this allelic loss and the clinicopathologic features of the patients.
Methods. The inter-Alu long PCR genomic scan method was performed using RCC DNA samples and primers specific for a minor subset of the human repeat sequence Alu. We analyzed DNA samples from 42 pairs of matched normal and nonpapillary RCC tissues with seven microsatellite markers.
Results. The inter-Alu long PCR genomic scan method revealed an altered DNA region on chromosome 14q24-31, which is the location of several putative tumor suppressor genes. At least one of seven microsatellite markers on chromosome 14q24-31 showed loss of heterozygosity in 23 (54.8%) of 42 informative cases of RCC. The prevalent loss region was confined to a 2-Mb region around D14S67. We found a positive correlation between the presence of the loss of heterozygosity on 14q24-31 and tumor stage (P &lt; 0.05). We also found that cases with allelic loss at 14q24-31 had a poor prognosis (P = 0.045).
Conclusions. Our inter-Alu long PCR genomic scan method is a powerful method for the screening of DNA alterations, and our data suggest that the chromosome 14q24-31 region contains likely tumor suppressor genes associated with the progression of RCC. (C) 2004 Elsevier Inc.

DOI： 10.1016/j.urology.2004.03.015

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：LIPPINCOTT WILLIAMS & WILKINS  

Head and neck squamous cell carcinoma (HNSCC) is a frequent malignancy with a poor survival rate. Identifying the tumor suppressor gene (TSG) loci by genomic studies is an important step to uncover the molecular mechanisms involved in HNSCC pathogenesis. We therefore performed comprehensive analyses on loss of heterozygosity (LOH) using a genome-wide panel of 191 microsatellite markers in 22 HNSCC samples. We found 53 markers with significantly high LOH (&gt;30%) on 21 chromosomal arms; the highest values of those were observed on 3p, 9p, 13q, 15q, and 17p, corresponding to D3S2432 (67%), D9S921-D9S925 (67%) and GATA62F03 (86%), D13S1493 (60%), D15S211 (62%), and D17S1353 (88%), respectively. Fifteen hot spots of LOH were defined in 13 chromosomal arms: 2q22-23, 4p15.2, 4q24-25, 5q31, Sp23, 9p23-24, 9q31.3, 9q34.2, 10q21, 11q21-22.3, 14q11-13, 14q22.3, 17p13, 18q11, and 19q12 as loci reported previously in HNSCCs. Furthermore, we identified five novel hot spots of LOH on three chromosomal arms in HNSCC at 2q33 (D2S1384), 2q37 (D2S125), 8q12-13 (D8S1136), 8q24 (D8S1128), and 15q21 (D15S211). In conclusion, our comprehensive allelotype analyses have unveiled and confirmed a total of 20 possible TSG loci that could be involved in the development of HNSCC. These results provide useful clues for identification of putative TSGs involved in HNSCC by fine mapping of the suspected regions and subsequent analysis for functional genes.

DOI： 10.1097/01.LAB.0000047489.26246.E1

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：NATURE PUBLISHING GROUP  

Loss of heterozygosity (LOH) has been frequently detected at chromosome 7q31 region in human head and neck squamous cell carcinomas (HNSCC) and many other cancers, suggesting the existence of tumor suppressor genes (TSG). We analysed LOH at 7q31 region in 49 HNSCC by using six polymorphic microsatellite markers and found allelic deletion in 48% (22/46) of the informative cases. We detected two preferentially deleted regions, one is around D7S643 and the other around D7S486. When we redefined the map of 7q31 region according to the contiguous sequences, a recently identified gene, ING3, was found in the proximity of D7S643. ING3 protein harbors the PHD domain highly homologous among ING family proteins, in which we previously found mutations in a related gene, ING1. As only one missense mutation of the ING3 gene was found in HNSCC, we examined the expression level. Reverse-transcription-PCR analysis demonstrated decreased or no expression of ING3 mRNA in 50% of primary tumors as compared with that of matched normal samples. Especially, about 63% of tongue and larynx tumors showed the decrease and a tendency of higher mortality was observed in cases with decreased ING3 expression. All these findings suggest a possibility that the ING3 gene functions as a TSG in a subset of HNSCC.

DOI： 10.1038/sj.onc.1205540

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：KLUWER ACADEMIC PUBL  

We thoroughly examined loss of heterozygosity (LOH) around three candidate tumor suppressor genes on chromosome 10q to determine whether LOH of each tumor suppressor gene is associated with the previously defined clinical prognostic indices. We also examined whether LOH can help predict prognostic variables in astrocytomas.
We selected samples from 40 astrocytomas (grades 2-4), performed Ki-67 immunostaining, and counted positive cells. Using DNA from aliquots of tumor blocks and leukocytes, we investigated LOH around the PTEN, NEURL, and DMBT1 genes (10q23.3-26.1) with the silver staining procedure. We then statistically evaluated the relationship among histological features, regional LOH on chromosome 10q, and survival. The mean survival period for patients with LOH around PTEN was 7.2 months after surgery, while that for patients without LOH around PTEN was 21.4 months. Thus, LOH around PTEN was closely associated with a reduced overall survival (p = 0.0020) but LOH at NEURL or DMBT1 was not (p &gt; 0.05).
The combined features of an increase in histological grading and Ki-67-positive cells and the presence of LOH around PTEN significantly correlated with poor prognosis. These factors may be useful predictors of survival, and LOH analysis of tumor suppressor genes on chromosome 10q can contribute greatly to the treatment of patients with astrocytoma.

DOI： 10.1023/A:1016017711033

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：AMER SOC MICROBIOLOGY  

A rapid quantitative real-time PCR method was employed to quantify the copy number of E2 and E6 genes for analysis of the physical status of human papillomavirus type 16 (HPV-16) DNA. Significant differences with respect to both copy numbers were found when more than 40% of HPV- 161 DNA was integrated with disruption of the E2 gene in an experimental model. The physical status of HPV-16 DNA in 50 clinical samples was exclusively episomal in 21 cases (42%), concomitant in 14 cases (28%), and integrated in 15 cases (30%). The prevalence of integrated and/or concomitant forms of HPV-16 DNA increased with progression of cervical disease. Four of 11 cervical intraepithelial neoplasia involved integrated forms of HPV-16 DNA partially or exclusively. This rapid, sensitive technique is useful in the analysis of the physical status of HPV DNA.

DOI： 10.1128/JCM.40.3.863-867.2002

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：LIPPINCOTT WILLIAMS & WILKINS  

E2F is a family of transcription factors implicated in the regulation of gene expression required for progression through the G(1)-S transition. We have previously detected tumor-specific mutations at a trinucleotide repeat coding sequence of E2F-4 gene in a subset of human sporadic colorectal cancers. The purpose of this study was to investigate the potential functional consequences of these E2F-4 mutations. We transfected NIH3T3 fibroblasts with expression constructs containing wild-type as well as mutant E2F-4 cDNA, and the effect of the E2F-4 mutations on proliferation was examined. Alteration in transactivation of the E2F consensus promoter sequence was also examined by transient cotransfection of a E2F-4 with a DP-2 construct into cultured human cells. Transfected cell clones overexpressing mutant E2F-4 grew more rapidly and showed higher proliferative activity by increased immunohistochemical staining for proliferating cell nuclear antigen (PCNA). All three mutant forms of E2F-4 showed elevated transactivation of the E2F consensus promoter sequence. Thus, expression of mutant E2F-4s confers a growth advantage in vivo, and this effect may be related to the acquisition of a neoplastic phenotype.

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Authorship：Lead author   Language：English   Publishing type：Research paper (scientific journal)   Publisher：ACADEMIC PRESS INC ELSEVIER SCIENCE  

We have cloned a novel cDNA encoding a protein with eight WD repeat motifs and a domain similar to collagen. As the predicted size of the protein was 146 kDa, the gene was named WDC146. Here, we characterized the genomic structure, gene products, and the expression profiles. The human WDC146 gene had 22 exons spanning over 105 kb, and these exons were distributed in three islands intervened by two long introns of around 40 kb. A minimum promoter region was identified within a 0.5 kb 5'-upstream region of exon 1. WDC146 mRNA was most highly expressed in human testis on Northern blot analysis. In mouse tissues, the highest expression was also observed in testis. By in situ hybridization on rat tissues, WDC146 mRNA was detected preferentially in the pachytene stage of spermatocytes in testis, and weakly in white pulp/marginal band of spleen and in cortex of thymus. WDC146 protein was found to be localized in nucleus. These data implied that WDC146 protein may play important roles in the mechanisms of cytodifferentiation and/or DNA recombination. (C) 2001 Academic Press.

DOI： 10.1006/bbrc.2000.4163

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：AMER SOC MICROBIOLOGY  

Integration of human papillomavirus (HPV) DNA occurs early in cancer development and is an important event in malignant transformation of cervical cancer. Integration of HPVs preferentially disrupts or deletes the E2 open reading frame, which results in the loss of its expression, The preferential disruption of the E2 gene causes the absence of the E2 gene sequences in the PCR product following integration. Twenty-two carcinomas positive for HPV type 16 (HPV-16) DNA mere first tested far the disruption of the E2 gene by PCR. A specific fragment of the E2 gene was not amplified in 10 cases, suggesting integration of HPV DNA into the host genome. Next, multiplex PCR for the RPV E2 and E6 genes was carried out in the remaining 12 cases. Copy numbers of both genes should he equivalent in episomal forms, while the E2 gene copy number will be smaller than that for E6 following the preferential disruption of the E2 gene in concominant forms. Although relative ratios of HPV E2 to E6 PCR products (E2/E6 ratios) ranged from 1.40 to 2.34 in 10 of 12 cases, multiplex PCR products from 2 cases displayed extremely low ratios of 0.69 and 0.61, Southern blot hybridization with an HPV-16 probe revealed that only in these two cases was both episomal and integrated HPV DNA being carried simultaneously. Thus, multiplex PCR for the E2 and E6 genes of HPV-16 DNA following PCR for the E2 gene can distinguish the pure episomal form from a mixed form of episomal and integrated HPV DNA, Clinical application of this technique mill help researchers to understand the implication of the integration of HPV DNA for cervical carcinogenesis and cervical cancer progression.

Web of Science

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Language：Japanese   Publisher：生命科学系学会合同年次大会運営事務局  

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Language：English   Publisher：生命科学系学会合同年次大会運営事務局  

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Language：English   Publisher：日本癌学会  

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Language：English   Publisher：(公社)日本生化学会  

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Language：Japanese   Publisher：(公社)日本生化学会  

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Language：English   Publisher：日本癌学会  

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Language：English   Publisher：日本癌学会  

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Language：Japanese   Publisher：(公社)日本生化学会  

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Language：English   Publisher：日本癌学会  

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Language：English   Publishing type：Research paper, summary (international conference)   Publisher：AMER ASSOC CANCER RESEARCH  

DOI： 10.1158/1538-7445.AM2011-1158

Web of Science

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Language：English   Publisher：(公社)日本生化学会  

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Language：English   Publisher：(公社)日本生化学会  

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Language：English   Publisher：日本癌学会  

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Language：English   Publisher：日本癌学会  

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Language：English   Publisher：日本癌学会  

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Language：English   Publishing type：Research paper, summary (international conference)   Publisher：AMER ASSOC CANCER RESEARCH  

DOI： 10.1158/1538-7445.AM10-4041

Web of Science

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Language：English   Publishing type：Research paper, summary (international conference)   Publisher：AMER ASSOC CANCER RESEARCH  

DOI： 10.1158/1538-7445.AM10-LB-246

Web of Science

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Language：Japanese   Publisher：(NPO)日本肺癌学会  

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Language：English   Publisher：日本癌学会  

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Language：English   Publisher：日本癌学会  

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Language：Japanese   Publisher：(公社)日本整形外科学会  

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Language：English   Publisher：日本癌学会  

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Language：English   Publishing type：Research paper, summary (international conference)   Publisher：AMER ASSOC CANCER RESEARCH  

Web of Science

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Language：English   Publishing type：Research paper, summary (international conference)   Publisher：AMER ASSOC CANCER RESEARCH  

Web of Science

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Language：Japanese   Publisher：Japanese Proteomics Society (Japan Human Proteome Organisation)  

DOI： 10.14889/jhupo.2009.0.80.0

CiNii Article

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Language：English   Publisher：日本癌学会  

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Language：Japanese   Publisher：日本癌学会  

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Language：Japanese   Publisher：日本癌学会  

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Language：English   Publisher：日本癌学会  

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Language：English   Publisher：日本癌学会  

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Language：English   Publisher：日本癌学会  

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Language：Japanese   Publisher：(公社)日本整形外科学会  

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Language：Japanese   Publisher：日本癌学会  

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Language：Japanese   Publisher：日本癌学会  

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Language：Japanese   Publisher：(公社)日本整形外科学会  

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Language：Japanese   Publisher：日本癌学会  

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Language：Japanese   Publisher：日本脳腫瘍病理学会  

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Language：Japanese   Publisher：日本癌学会  

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Language：Japanese   Publisher：日本癌学会  

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Language：Japanese   Publisher：(一社)日本脳神経外科学会  

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Language：English   Publisher：(一社)日本解剖学会  

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