|ognizant Communication Corporation|
VOLUME 12, NUMBER 11/12
Oncology Research, Volume 12, pp. 441-449
0965-0407/02 $20.00 + .00
Copyright © 2002 Cognizant Comm. Corp.
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Wilms' Tumor: A Paradigm for the New Genetics
Karim Malik,1 Pearlly Yan,2 Tim H.-M. Huang,2 and Keith W. Brown1
1Cancer and Leukaemia in Childhood Research Unit, University
of Bristol, Department of Pathology and Microbiology, School of Medical
Sciences, University Walk, Bristol BS8 1TD, UK
2Department of Pathology and Anatomical Sciences, Ellis Fischel Cancer Center, University of Missouri, 115 Business Loop I-70 West, Columbia, MO 65203
Carcinogenesis can be triggered by a diverse range of molecular lesions, a variety of which can be illustrated by Wilms' tumor (WT), a pediatric kidney cancer. Molecular defects observed in WTs include several independent targets and mechanisms best exemplified by changes on the short arm of chromosome 11. This article will review the molecular pathology of WT and emphasize the broader ramifications for cancer genetics. Consideration will be given to carcinogenic pathways, novel cellular molecules, and technologies that will assist in the rapid interpretation and assimilation of DNA sequence data arising from the sequencing of the human genome.
Key words: Wilms' tumor; Tumor suppressor genes; WT1; Epigenetics; Genomics
Address correspondence to Karim Malik, Cancer and Leukaemia in Childhood Research Unit, University of Bristol, Department of Pathology and Microbiology, School of Medical Sciences, University Walk, Bristol BS8 1TD, UK. Tel: +44 (0)117 9288603; Fax: +44 (0)117 9287896; E-mail: email@example.com
Novel mdm2 Splice Variants Identified in Pediatric Rhabdomyosarcoma Tumors and Cell Lines
Frank Bartel,1* Alan C. Taylor,1** Helge Taubert,2 and Linda C. Harris1
1Department of Molecular Pharmacology, St. Jude Children's
Research Hospital, Memphis, TN 38105
2Institute of Pathology, Faculty of Medicine, University of Halle-Wittenberg, Halle/Saale, Germany
Mdm2 is an oncogene that binds to and inactivates the tumor suppressor p53. However, the presence of oncogenic splice variants of mdm2 in human tumors that lack the p53 binding site has suggested a p53-independent transforming function for this protein. This report describes expression of 11 different mdm2 splice variants in pediatric rhabdomyosarcoma (RMS) cell lines and tumors at a frequency of 75% and 82%, respectively. Five of these isoforms have previously been described in other tumor histiotypes but six are novel and may be unique to RMS. There was no association between expression of splice variants and mdm2 gene amplification or p53 status. In addition, the frequency of splice variants was much higher than the incidence of mdm2 amplification or p53 mutations. These variants may be important to consider with respect to RMS tumor progression and therapeutic response.
Key words: mdm2; Isoforms; Rhabdomyosarcoma; Pediatric; p53
Address correspondence to Linda C. Harris, Department of Molecular Pharmacology, St. Jude Children's Research Hospital, Memphis, TN 38105. Tel: (901) 495-3833; Fax: (901) 521-1668; E-mail: firstname.lastname@example.org
*Present address: Institute of Pathology, Faculty of Medicine, University
of Halle-Wittenberg, Halle/Saale, Germany.
**No longer at St. Jude.
Mutation and Functional Analysis of IL-13 Receptors in Human Malignant Glioma Cells
Mariko Kawakami, Pamela Leland, Koji Kawakami, and Raj K. Puri
Laboratory of Molecular Tumor Biology, Division of Cellular and Gene Therapies, Center for Biologics Evaluation and Research, Food and Drug Administration, Bethesda, MD 20892
We have previously demonstrated that human brain tumor cells, in particular glioblastoma multiforme (GBM), express abundant receptors for interleukin-13 on the cell surface. These receptors are composed of IL-13 receptor (IL-13R)a1, IL-13Ra2, and IL-4Ra chains. The significance of overexpression of IL-13R on tumor cells is not known. Because expression of IL-13R on glioma cells is an unexpected phenomenon, we examined whether these receptors are polymorphic. Therefore, we analyzed cDNA for IL-13Ra1 and IL-13Ra2 chain genes by PCR-based single-strand conformation polymorphism and direct sequencing techniques for a possible polymorphism in 19 GBM, one normal human astrocyte, and two fibroblast cell lines. All analyzed samples except normal astrocytes overexpressed IL-13Ra2; however, none of these cell lines showed a mutation in cDNA for IL-13Ra2 chain. In contrast, all GBM samples, normal astrocytes, and fibroblasts expressed mRNA for IL-13Ra1 with apparent single nucleotide polymorphism in the transmembrane domain. To study the function of IL-13R on brain tumor cells, we investigated the regulation of adhesion molecules by IL-13 as assessed by flow cytometric analysis. A172 cell line expressed a low level of vascular cell adhesion molecule-1 (VCAM-1), while U251 and LA1-5g cell lines expressed intercellular adhesion molecule-1 (ICAM-1). On the other hand E-selectin was not expressed in any cell lines. Interestingly, IL-13 increased the expression level of VCAM-1 in A172 cell line in a dose- and time-dependent manner. However, IL-13 did not modulate any other adhesion molecules. These results suggest that IL-13R on GBM cells are not rearranged but appear to be functional.
Key words: Glioblastoma multiforme; Interleukin-13; Interleukin-13 receptors; PCR-SSCP; Adhesion molecules
Address correspondence to Raj K. Puri, M.D., Ph.D., Laboratory of Molecular Tumor Biology, Division of Cellular and Gene Therapies, Center for Biologics Evaluation and Research, Food and Drug Administration, NIH Building 29B, Room 2NN10, 29 Lincoln Drive MSC4555, Bethesda, MD 20892. Tel: (301) 827-0471; Fax (301) 827-0449; E-mail: email@example.com
Involvement of Claudin-1 in the b-Catenin/Tcf Signaling Pathway and its Frequent Upregulation in Human Colorectal Cancers
Nobutomo Miwa,1,2 Mikio Furuse,3 Shoichiro Tsukita,3 Norio Niikawa,2 Yusuke Nakamura,1 and Yoichi Furukawa1
1Laboratory of Molecular Medicine, Human Genome Center, Institute
of Medical Science, The University of Tokyo, Tokyo, Japan
2Department of Human Genetics, Nagasaki University School of Medicine, Nagasaki, Japan
3Department of Cell Biology, Faculty of Medicine, Kyoto University, Kyoto, Japan
Accumulation of b-catenin in cytoplasm and nuclei is frequently observed in a wide variety of tumors arising, for example, in the colon, liver, uterus, or brain. In association with Tcf/LEF transcription factors, b-catenin regulates expression of genes involved in the Wnt/wingless signaling pathway, but the precise mechanisms are unclear. Here we report evidence that the claudin-1 (CLDN1) gene is one of the genes regulated by b-catenin. Not only did expression of CLDN1 decrease significantly in response to reduction of intracellular b-catenin by adenovirus-mediated transfer of wild-type APC into the APC-deficient colon cancer cells, but also two putative Tcf4 binding elements in the 5´ flanking region of CLDN1 were confirmed to be responsible for activating its transcription. We documented increased expression of CLDN1 in all 16 primary colorectal cancers we examined, compared with adjacent noncancerous mucosae. Furthermore, immunohistochemical staining demonstrated that claudin-1 was weakly stained at apical boarder of lateral membrane of noncancerous epithelial cells and that it was strongly stained at all cell-cell boundaries and in the cytoplasms of cancer cells. Our results imply that claudin-1 is involved in the b-catenin-Tcf/LEF signaling pathway, and that increased expression of claudin-1 may have some role in colorectal tumorigenesis.
Key words: b-Catenin; Wnt/wingless signaling pathway; Claudin-1; Tight junction; Colon cancer
Address correspondence to Yoichi Furukawa, M.D., Ph.D., Laboratory of Molecular Medicine, Human Genome Center, Institute of Medical Science, The University of Tokyo, 4-6-1 Shirokanedai, Minato, Tokyo 108-8639, Japan. Tel: 81-3-5449-5373; Fax: 81-3-5449-5406; E-mail: firstname.lastname@example.org
Antitumor Activity of ER-51785, a New Peptidomimetic Inhibitor of Farnesyl Transferase: Synergistic Effect in Combination With Paclitaxel
Katsuji Nakamura,1 Atsumi Yamaguchi,1 Masayuki Namiki,1 Hiroshi Ishihara,1 Takeshi Nagasu,1 James J. Kowalczyk,2 Ana Maria Garcia,2 Michael D. Lewis,2 and Kentaro Yoshimatsu1
1Tsukuba Research Laboratories, Eisai Co. Ltd., 1-3 Tokodai
5-chome, Tsukuba-shi, Ibaraki 300-2635, Japan
2Eisai Research Institute, 4 Corporate Drive, Andover, MA 01810
Inhibitors of ras farnesylation have been extensively studied in the preclinical stage, and some of them are being developed in the clinic. Herein, we describe the antitumor activity of a new farnesyl transferase inhibitor, ER-51785. In vitro, ER-51785 selectively inhibited farnesyl transferase activity (IC50 = 77 nM) compared with geranylgeranyl transferase I activity (IC50 = 4200 nM). In cells, ER-51785 inhibited posttranslational processing of H-ras with IC50 = 28 nM, but not that of rap 1A at concentrations up to 50 mM. This compound also strongly inhibited colony formation of H-ras-transformed NIH 3T3 fibroblasts and EJ-1 bladder carcinoma cells. In vivo, ER-51785 showed potent tumor regression activity against EJ-1 xenografts but only modest activity against MIA PaCa-2 xenografts. Treatment of ER-51785 in combination with paclitaxel exhibited synergistic effects against colony formation and tumor growth of MIA PaCa-2 cells. The results presented herein support the idea that farnesyl transferase inhibitors alone and in combination with other chemotherapeutic agents have the potential to be developed as therapies for tumors expressing H-ras or K-ras oncogenes.
Key words: ER-51785; Farnesyl transferase; ras; Tumor regression; Xenograft
Address correspondence to Katsuji Nakamura, Tsukuba Research Laboratories, Eisai Co. Ltd., 1-3 Tokodai 5-chome, Tsukuba-shi, Ibaraki 300-2635, Japan. Tel: +81-298-47-5747; Fax: +81-298-47-2037; E-mail: email@example.com
Antisense of ATP Synthase Subunit e Inhibits the Growth of Human Hepatocellular Carcinoma Cells
Hao Ying, Yanlin Yu, and Yonghua Xu
Laboratory of Molecular and Cellular Oncology, Institute of Biochemistry and Cell Biology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, 320 Yue-yang Road, 200031, Shanghai, P. R. China
Differentially expressed genes between normal and hepatocellular carcinoma tissues were investigated using differential display. We identified a cDNA fragment that was overexpressed in cancer tissue. Homology analysis showed that the sequence was identical to human ATP synthase subunit e (hAS-e). Moreover, Northern blot analysis demonstrated that hAS-e was overexpressed in 10 of 11 (91%) specimens of hepatocellular carcinoma compared with corresponding normal tissues. We introduced antisense hAS-e into a human hepatocellular carcinoma BEL-7404 cell and found that downregulation of the hAS-e led to cell growth inhibition. It was also found that the antisense transfection could decrease the serum-stimulated activation of mitogen-activated protein kinase (MAP kinase). Together, the results suggest that antisense of hAS-e can inhibit cell proliferation through the MAP kinase pathway. Our data indicate that hAS-e may become a new target in gene therapy.
Key words: Differential display; Hepatocellular carcinoma; ATP synthase subunit e; Growth inhibition; Mitogen-activated protein kinase
Address correspondence to Yonghua Xu, Laboratory of Molecular and Cellular Oncology, Institute of Biochemistry and Cell Biology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, 320 Yue-yang Road, 200031, Shanghai, P. R. China. Tel/Fax: 86-21-64711349; E-mail: firstname.lastname@example.org
Molecular Characterization of the DICE1 (DDX26) Tumor Suppressor Gene in Lung Carcinoma Cells
Ilse Wieland,1 Albrecht Röpke,1 Markus Stumm,1 Christian Sell,2 Ulrich H. Weidle,3 and Peter F. Wieacker1
1Institute for Human Genetics, Otto-von-Guericke-University,
2Lankenau Institute for Medical Research, Wynnewood, PA
3Roche Diagnostics GmbH, Penzberg, Germany
We have determined the genomic structure of the candidate tumor suppressor gene DICE1 (DDX26). The DICE1 gene colocalizes with microsatellite marker D13S284 telomeric to the RB1 gene in chromosomal region 13q14.3. The DICE1 gene encodes 18 exons that are preceded by a GC-rich promoter region. CpG sites flanking a predicted TATA box were found to be hypermethylated in tumor cells that exhibited decreased DICE1 expression. This suggests tumor-specific transcriptional silencing of the DICE1 gene may occur. Aberrantly spliced products were detected in two of three DICE1-expressing cell lines. The predicted DICE1 amino acid sequence is evolutionarily conserved in mouse, fruit fly (D. melanogaster), and nematode (C. elegans). A DEAD box characteristic of ATP-dependent helicases is the predominant motif found in DICE1 and its mouse and fruit fly homologues. Motifs other than the DEAD box are reminiscent of members of the helicase superfamily II but there is considerable variation from the typical DEAD box helicases. Expression of DICE1 green fluorescent fusion protein showed a preferential localization of DICE1 in the nucleus. This suggests that DICE1 is involved in nuclear processes such as DNA repair, transcription, or RNA splicing.
Key words: Tumor suppressor gene; 13q14; Promoter hypermethylation; DEAD box; Nuclear localization
Address correspondence to Dr. I. Wieland, Institut füür Humangenetik, Otto-von-Guericke-Universitäät, Leipziger Str. 44, D-39120 Magdeburg, Germany. Tel: +49-391-67-15381; Fax: +49-391-67-15066; E-mail: email@example.com
Antitumor Effect of VNP20009, an Attenuated Salmonella, in Murine Tumor Models
Xiang Luo, Zujin Li, Stanley Lin, Trung Le, Martina Ittensohn, David Bermudes, Jacob D. Runyab, Shu-ying Shen, Jianping Chen, Ivan C. King, and Li-mou Zheng
Vion Pharmaceuticals, Inc., 4 Science Park, New Haven, CT 06511
VNP20009, a genetically modified strain of Salmonella typhimurium with deletions in the msbB and purI loci, exhibited antitumor activities when given systemically to tumor-bearing mice. VNP20009 inhibited the growth of subcutaneously implanted B16F10 murine melanoma, and the human tumor xenografts Lox, DLD-1, A549, WiDr, HTB177, and MDA-MB-231. A single intravenous injection of VNP20009, at doses ranging from 1 x 104 to 3 x 106 cfu/mouse, produced tumor growth inhibitions of 57-95%. Tumor volume doubling time, another indicator for tumor growth inhibition, also significantly increased in mice treated with VNP20009. Using mice with immune system deficiencies, we also demonstrated that the antitumor effects of VNP20009 did not depend on the presence of T and B cells. In addition, VNP20009, given intravenously, inhibited the growth of lung metastases in mice. Only live bacteria showed the antitumor effect.
Key words: VNP20009; Salmonella typhimurium; Murine tumor model; Antitumor effect
Address correspondence to Li-mou Zheng, Vion Pharmaceuticals, Inc.,
4 Science Park, New Haven, CT 06511. Tel: (203) 498-4210; Fax: (230) 781-8090;