|ognizant Communication Corporation|
AN INTERNATIONAL JOURNAL
INCORPORATING ANTI-CANCER DRUG DESIGN
VOLUME 15, NUMBER 5
Oncology Research, Volume 15, pp. 239-247
0965-0407/05 $20.00 + .00
Copyright © 2005 Cognizant Comm. Corp.
Printed in the USA. All rights reserved.
Gene Therapeutic Exploration: Retrovirus-Mediated Soluble Vascular Endothelial Growth Factor Receptor-2 (sFLK-1) Inhibits the Tumorigenicity of S180, MCF-7, and B16 Cells In Vivo
Baijun Kou, Yulin Li, Yingai Shi, Jianxin Xia, Xinrui Wang, and Shan Wu
Laboratory of Pathobiology, Department of Pathology, College of Basic Medicine, Jilin University, Changchun, China
Inhibition of tumor angiogenesis is an anticancer strategy in which neovasculature is targeted because tumor progression relies on neovascularization. The soluble, truncated form of vascular endothelial growth factor receptor-2 (VEGFR-2), sFLK-1, is a well-known inhibitor of endothelial cells. This kind of soluble receptor retains its high-affinity binding to VEGF, but cannot work with the receptor tyrosine transphosphorylation and activation of downstream signal transduction to induce endothelial proliferation due to the lack of the tyrosine kinase domain. Therefore, we tried to use this sFLK-1 as an inhibitor for malignant tumor gene therapy. In this study we transferred a soluble VEGFR-2 (sFLK-1) from embryo mouse liver by RT-PCR to PA317 cells through retroviral vector (pLXSN) and obtained stable expression. NIH3T3 cells were used for measuring the virus titer. The virus titer in this experiment was 2 x 107 CFU/ml. After 7 days of preparing subcutaneous tumor models bearing S180, MCF-7, and B16 cells in mice, respectively, 2 x 107 PFU of recombinant retroviruses were injected locally into the tumors the treatment groups. After treatment, the tumor size and weight were significantly smaller than that of control (p < 0.05). After autopsy, the metastasic focus numbers in the treatment groups were also less than control groups. We also measured VEGFR-2 expression in tumor tissues by Western blot to check if sFLK-1 had been integrated into the cells of tumor tissues. Expression in the treatment groups was significantly greater than that of control groups (p < 0.001). Microvessel density (MVD) and proliferative cell nuclear antigen (PCNA) were investigated to determine whether the Re-sFLK-1 fragment had the ability to inhibit tumor angiogenesis and proliferation in mice bearing S180 and MCF-7 cells. The results showed that MVD and PCNA in the treatment groups were lower than in control groups. There were significant difference between treatment groups and control groups (p < 0.0001). The results indicated that retroviral-mediated sFLK-1 gene therapy in animal tumor models has significant therapeutic effect.
Key words: VEGF; Soluble receptor; Tumor growth; Angiogenesis; Retroviral vector; Gene therapy
Address correspondence to Dr. Baijun Kou, Warwick Medical School Research Wing, Clinical Sciences Building, Clifford Bridge Road, Walsgrave, Coventry, CV2 2DX, UK. Tel: +44-2476968687; Fax: +44-2476968653; E-mail: firstname.lastname@example.org
Bcl-2 as Prognostic Factor in Head and Neck Squamous Cell Carcinoma
Lorenzo Lo Muzio,1 Silvia Falaschini,1 Antonio Farina,2 Corrado Rubini,3 Furio Pezzetti,2 Giuseppina Campisi,4 Gaetano De Rosa,5 Mario Capogreco,6 and Francesco Carinci,7
1Department of Surgical Sciences, University
of Foggia, Foggia, Italy
2Institute of Histology, University of Bologna, Bologna, Italy
3Institute of Pathology, University of Ancona, Ancona, Italy
4Department of Dental Sciences, University of Palermo, Palermo, Italy
5Department of Biomorphological and Functional Sciences-Pathology Unit, University of Naples Federico II, Naples, Italy
6Department of Surgical Sciences, University of L'Aquila, L'Aquila, Italy
7Institute of Maxillofacial Surgery, University of Ferrara, Ferrara, Italy
A series of 66 cases of oral squamous cell carcinoma (OSCC) was retrospectively analyzed by immunohistochemistry for bcl-2 expression to verify its predictive value for clinical outcome in patients with OSCC. After grouping for bcl-2 expression, OSCCs were statistically analyzed for the variables age, gender, histological grading (G), TNM, staging, recurrence, and overall survival rate. Univariate and multivariate (Cox regression) analyses were performed. Thirty-six OSCC (54.5%) showed expression for bcl-2, whereas 30 (44.5%) were negative. No statistical association was found between bcl-2 expression and any variables considered at baseline. Overall disease-specific survival rate at 72 months was 51%, independently from the extent of the tumor. In terms of prognostic significance, the bcl-2-positive group showed more than 60% survival at 72 months whereas the bcl-2-negative group showed none. An independent association of bcl-2 expression was found with an improved overall survival rate (p = 0.048), although grading and staging were established to be the best baseline markers of prognosis. On the basis of these results, it is possible to suggest bcl-2 as an early marker of prognosis: lack of bcl-2 expression could constitute a hallmark of aggressive biological behavior in OSCC.
Key words: Head and neck; Cancer; Survival; bcl-2; Cox analysis
Address correspondence to Prof. Lorenzo Lo Muzio, Via Carelli 28, 71100 Foggia, Italy. Tel/Fax: (39) 881-685809; E-mail: email@example.com
Hypomethylation of the XIST Gene Promoter in Prostate Cancer
Thilo Laner,1 Wolfgang A. Schulz,1 Rainer Engers,2 Mirko Müller,1 and Andrea R. Florl1
1Urologische Klinik, Heinrich-Heine-Universität,
2Institut für Pathologie, Heinrich-Heine-Universität, Düsseldorf, Germany
In a process denoted "global hypomethylation" repetitive DNA sequences like LINE-1 retrotransposons become hypomethylated in human cancers, including a subset of prostate carcinomas. It is less well known to what extent single-copy sequences are affected by this phenomenon. Therefore, we have analyzed methylation and expression of the XIST gene by bisulfite sequencing and real-time RT-PCR. The promoter of this single-copy gene is strongly methylated in normal male cells, including leukocytes and normal prostate. In prostate cancer tissues and particularly in cell lines, partial hypomethylation was observed paralleling that of LINE-1 sequences. Weak XIST expression was found in normal prostate tissues, but none in leukocytes. Only slight increases in expression of this gene were found in cancer tissues and cell lines. Our data suggest that hypomethylation in prostate cancer is indeed "global," affecting repeat and unique sequences in parallel. Detection of partially hypomethylated XIST alleles in prostate cancer tissues might be useful for the identification of cases with pronounced hypomethylation, which tend to be more aggressive.
Key words: Prostate carcinoma; DNA methylation; X-chromosome inactivation; Tumor markers; Gene silencing; Retrotransposon
Address correspondence to Prof. Wolfgang A. Schulz, Ph.D., Department of Urology, Heinrich Heine University, Moorenstr. 5, 40225 Duesseldorf, Germany. Tel: 211-81-18966; Fax: 211-81-15846; E-mail: firstname.lastname@example.org
A Bisanthracycline (WP631) Represses uPAR Gene Expression and Cell Migration of RKO Colon Cancer Cells by Interfering With Transcription Factor Binding to a Chromatin-Accessible -148/-124 Promoter Region
Rajesh R. Nair,1 Heng Wang,1 Md. S. Jamaluddin,1 Izabella Fokt,2 Waldemar Priebe,2 and Douglas D. Boyd1
1Department of Cancer Biology, The
University of Texas MD Anderson Cancer Center, 1515 Holcombe Blvd., Houston,
TX 77030, USA
2Department of Bioimmunotherapy, The University of Texas MD Anderson Cancer Center, 1515 Holcombe Blvd. Houston, TX 77030, USA
The urokinase receptor (uPAR), transcriptionally activated in several cancers, contributes to tumor progression by promoting cell migration and proteolysis, and repressing expression of this gene could be of therapeutic utility. Indeed, targeting regulatory element(s) in the promoter may represent an efficient means for reducing expression because only two alleles have to be neutralized. We previously identified the -148/-124 promoter region, bound with Sp1 and Sp3, as regulatory for uPAR expression in vitro. The purpose of this study was twofold: to determine (a) the accessibility of this region in its natural chromatin setting and (b) the efficacy of WP631, a bisintercalator favoring GC-rich DNA sequences, in repressing endogenous uPAR expression in RKO colon cancer cells. In these cells, DNaseI hypersensitivity, genomic footprinting, and chromatin immunoprecipitation experiments revealed that the -148/-124 uPAR promoter region was accessible in chromatin and bound with Sp1, thus validating it as a therapeutic target. WP631 treatment competed for transcription factor binding to this regulatory region and reduced uPAR mRNA/protein. However, a chemically related compound (WP629), with low DNA binding affinity, failed to diminish uPAR protein amount. GAPDH mRNA level was only modestly affected by WP631, arguing against the possibility that this bisanthracycline universally represses expression of GC-rich promoter-driven genes. Further, uPAR function, as assessed by migration of cells across a vitronectin-coated filter, was attenuated with WP631. Thus, we have shown that the chromatinized -148/-124 regulatory region of the uPAR promoter is accessible to small molecules and that WP631, which disrupts the interaction of DNA binding proteins with this region, diminishes uPAR expression and function.
Key words: uPAR; Sp1; Transcription; Gene expression
Address correspondence to Douglas D. Boyd, Department of Cancer Biology, Box 173, MD Anderson Cancer Center, 1515 Holcombe Blvd., Houston, TX 77030, USA. Tel: 713-563-4918; E-mail: email@example.com
The Use of Complementary and Alternative Therapies by Patients With Cancer
Afaf Girgis,1,2 Jon Adams,3 and David Sibbritt3
1Centre for Health Research & Psycho-oncology
(CHeRP), The Cancer Council NSW & the University of Newcastle,
2School of Medical Practice and Population Health, Faculty of Health, University of Newcastle, Australia
3Centre for Clinical Epidemiology and Biostatistics, School of Medical Practice and Population Health, Faculty of Health, University of Newcastle, Australia
The aim of this research was to assess the prevalence and predictors of complementary and alternative therapy (CAT) use among cancer patients in Australia. A total of 1492 cancer patients attending nine major public cancer treatment centers in New South Wales, Australia, were asked to complete the Supportive Care Needs Survey. Of the 1354 consenting patients, 888 (65%) returned a completed survey. This article reports the secondary analyses of the survey data, specifically focusing on CAT use. For all cancers, 17.1% of patients were using at least one CAT. The two main demographic characteristics of CAT users were gender and age, where females were more likely to use CAT than males and that CAT use declined as age increased. Time since diagnosis was identified as the only significant clinical predictor of CAT use, where CAT use increased with time until 5 years since diagnosis. Our research shows that herbal treatments and naturopathy are the most popular CAT used by cancer patients (constituting over 30% of all CAT use recorded). The use of CAT among cancer patients is a significant issue in cancer care, especially considering the potential interactions between CAT and conventional medicines. Given that many cancer patients may not be aware of potential risks associated with these interactions it is important that oncologists and others involved in cancer patient care are informed about CAT and its use amongst their patients.
Key words: Complementary and alternative therapies; Cancer; Patients; Utilization
Address correspondence to Jon Adams, Ph.D., Senior Lecturer in Health Social Science, Centre for Clinical Epidemiology and Biostatistics, Level 3 David Maddison Building, Newcastle 2300, NSW, Australia. Tel: 61 2 492 36148; Fax: 61 2 492 36466; E-mail: firstname.lastname@example.org