Survival Analysis of F98 Glioma Rat Cells Following Minibeam or Broad-Beam Synchrotron Radiation Therapy

Background: In the quest of a curative radiotherapy treatment for gliomas new delivery modes are being explored. At the Biomedical Beamline of the European Synchrotron Radiation Facility (ESRF), a new spatially-fractionated technique, called Minibeam Radiation Therapy (MBRT) is under development. The aim of this work is to compare the effectiveness of MBRT and broad-beam (BB) synchrotron radiation to treat F98 glioma rat cells. A dose escalation study was performed in order to delimit the range of doses where a therapeutic effect could be expected. These results will help in the design and optimization of the forthcoming in vivo studies at the ESRF. Methods: Two hundred thousand F98 cells were seeded per well in 24-well plates, and incubated for 48 hours before being irradiated with spatially fractionated and seamless synchrotron x-rays at several doses. The percentage of each cell population (alive, early apoptotic and dead cells, where either late apoptotic as necrotic cells are included) was assessed by flow cytometry 48 hours after irradiation, whereas the metabolic activity of surviving cells was analyzed on days 3, 4, and 9 post-irradiation by using QBlue test. Results

Opposite role of Bax and BCL-2 in the anti-tumoral responses of the immune system

BACKGROUND: The relative role of anti apoptotic (i.e. Bcl-2) or pro-apoptotic (e.g. Bax) proteins in tumor progression is still not completely understood. METHODS: The rat glioma cell line A15A5 was stably transfected with human Bcl-2 and Bax transgenes and the viability of theses cell lines was analyzed in vitro and in vivo. RESULTS: In vitro, the transfected cell lines (huBax A15A5 and huBcl-2 A15A5) exhibited different sensitivities toward apoptotic stimuli. huBax A15A5 cells were more sensitive and huBcl-2 A15A5 cells more resistant to apoptosis than mock-transfected A15A5 cells (pCMV A15A5). However, in vivo, in syngenic rat BDIX, these cell lines behaved differently, as no tumor growth was observed with huBax A15A5 cells while huBcl-2 A15A5 cells formed large tumors. The immune system appeared to be involved in the rejection of huBax A15A5 cells since i) huBax A15A5 cells were tumorogenic in nude mice, ii) an accumulation of CD8+ T-lymphocytes was observed at the site of injection of huBax A15A5 cells and iii) BDIX rats, which had received huBax A15A5 cells developed an immune protection against pCMV A15A5 and huBcl-2 A15A5 cells. CONCLUSIONS: We show that the expression of Bax and Bcl-2 controls the sensitivity of the cancer cells toward the immune system. This sensitization is most likely to be due to an increase in immune induced cell death and/or the amplification of an anti tumour immune respons

Biodistribution of gold nanoparticles in BBN-induced muscle-invasive bladder cancer in mice

Henry M Smilowitz,1 Lauren J Tarmu,1–3 Mary Melinda Sanders,4 John A Taylor III,5 Dharamainder Choudhary,6 Crystal Xue,7 Nathaniel A Dyment,8 Dan Sasso,1 Xiaomeng Deng,9 James F Hainfeld10 1Department of Cell Biology, University of Connecticut Health Center, Farmington, CT, 2Department of Human Behavior, College of Southern Nevada, North Las Vegas, 3Department of Anthropology, University of Nevada, Las Vegas, NV, 4Department of Anatomic Pathology, University of Connecticut Health Center, Farmington, CT, 5Department of Urology, University of Kansas Medical Center, Kansas City, KS, 6Department of Surgery, University of Connecticut Health Center, Farmington, CT, 7George Washington University School of Medicine, Washington, DC, 8Department of Orthopedic Surgery, University of Pennsylvania, Philadelphia, PA, 9David Geffen School of Medicine at UCLA, Los Angeles, CA, 10Nanoprobes, Inc, Yaphank, NY, USA Abstract: Bladder-sparing options are being developed for muscle-invasive bladder cancer in place of radical cystectomy, including the combination of chemotherapy and radiation therapy. We reasoned that improving the radiotherapy component of chemoradiation could improve the control of locally advanced disease. Previously, we showed that gold nanoparticles (AuNPs) are potent enhancers of radiation therapy. We hypothesized that if AuNPs were to preferentially localize to bladder tumors, they may be used to enhance the radiation component of muscle-invasive bladder tumor therapy. Mice were treated with the carcinogen N-butyl-N-(4-hydroxybutyl)nitrosamine (BBN) for 17, 20, and 22 weeks – long enough to induce muscle-invasive tumors. Mice were then anesthetized and injected intravenously with 1.9 nm AuNPs of which most were rapidly cleared from the blood and excreted after a 30–50 minute residence time in the bladder. We found AuNPs distributed throughout the bladder wall, but most of the AuNPs were associated with the stroma surrounding the tumor cells or extracellular keratin produced by the tumor cells. There were relatively few AuNPs in the tumor cells themselves. The AuNPs therefore localized to tumor-associated stroma and this tumor specificity might be useful for specific X-ray dose enhancement therapy of muscle-invasive bladder carcinomas. Keywords: N-butyl-N-(4-hydroxybutyl)nitrosamine, BBN, muscle-invasive bladder cancer, gold nanoparticles, mouse mode

Orthotopic transplantation of v-src-expressing glioma cell lines into immunocompetent mice: establishment of a new transplantable in vivo model for malignant glioma

OBJECT: The aim of this study was to develop and characterize a new orthotopic, syngeneic, transplantable mouse brain tumor model by using the cell lines Tu-9648 and Tu-2449, which were previously isolated from tumors that arose spontaneously in glial fibrillary acidic protein (GFAP)-v-src transgenic mice. METHODS: Striatal implantation of a 1-microl suspension of 5000 to 10,000 cells from either clone into syngeneic B6C3F1 mice resulted in tumors that were histologically identified as malignant gliomas. Prior subcutaneous inoculations with irradiated autologous cells inhibited the otherwise robust development of a microscopically infiltrating malignant glioma. Untreated mice with implanted tumor cells were killed 12 days later, when the resultant gliomas were several millimeters in diameter. Immunohistochemically, the gliomas displayed both the astroglial marker GFAP and the oncogenic form of signal transducer and activator of transcription-3 (Stat3). This form is called tyrosine-705 phosphorylated Stat3, and is found in many malignant entities, including human gliomas. Phosphorylated Stat3 was particularly prominent, not only in the nucleus but also in the plasma membrane of peripherally infiltrating glioma cells, reflecting persistent overactivation of the Janus kinase/Stat3 signal transduction pathway. The Tu-2449 cells exhibited three non-random structural chromosomal aberrations, including a deletion of the long arm of chromosome 2 and an apparently balanced translocation between chromosomes 1 and 3. The GFAP-v-src transgene was mapped to the pericentromeric region of chromosome 18. CONCLUSIONS: The high rate of engraftment, the similarity to the high-grade malignant glioma of origin, and the rapid, locally invasive growth of these tumors should make this murine model useful in testing novel therapies for human malignant gliomas