ALBERT

Description: Follicular Lymphoma (FL), one of the most frequent lymphoma entities in the western world, is characterized by a highly variable clinical course reaching from rapid progression with fatal outcome to cases with long term survival. In a recent study applying chromosomal comparative hybridization (CGH) to FL, in 70% of the cases genomic aberrations were detectable and a loss of genomic material on chromosomal bands 6q25-q27 was the strongest predictor for short overall survival. However, limitations of CGH as a screening method are a restricted genomic resolution to 3–10 Mbp and demanding non-automated evaluation procedures. Thus, high throughput analysis of genomic alterations for risk adapted patient stratification and monitoring within treatment trials should rely on efficient and automated diagnostic techniques. In this study, we used array CGH to a novel generation of DNA Chips containing 2800 genomic DNA probes. Target clones comprised i) contigs mapping to genomic regions of possible pathogenetic relevance in lymphoma (n=610 target clones mapping to e.g. 1p, 2p, 3q, 7q, 9p, 11q, 12q, 13q, 17p, 18q, X); ii) selected oncogenes and tumor suppressor genes (n=686) potentially relevant in hematologic neoplasms; and iii) a large genome-wide cluster of 1502 target DNA clones covering the genome at a distance of app. 2 Mbp (part of the golden path clone set). This chip represents a median genomic resolution of app. 1.5 Mbp. In total, DNAs from 70 FL samples were analyzed and results were compared to data from chromosomal CGH experiments and clinical data sets. The sensitivity of array CGH was considerably higher compared to chromosomal CGH (aberrations in 95% of cases vs 70% of cases). Most frequent aberrations were gain mapping to chromosome arms 2p (21%), 7p (24%), 7q (30%), 12p (17%), 12q (21%), 18p (21%) and 18q (34%) as well as losses mapping to chromosome arms 1p (19%), 6q (23%), 7p (20%), 11q (26%) and 17p (20%). In addition, several genomic aberrations were identified which have not been described before in FL. Currently, these aberrations are characterized in more detail and results will be correlated with the clinical data set. Moreover, three recurrent sites of genomic polymorphisms in human beings affecting chromosomes 5q, 14q and 15q were identified. In conclusion, these data underline the potential of array CGH for the sensitive detection of genomic imbalances in FL.

Description: This study tested the hypothesis that combination of antiangiogenic therapy and tumor immunotherapy of cancer is synergistic. To inhibit angiogenesis, mice were immunized with dendritic cells (DCs) transfected with mRNA that encode products that are preferentially expressed during neoangiogenesis: vascular endothelial growth factor receptor-2 (VEGFR-2) and Tie2 expressed in proliferating endothelial cells, and vascular endothelial growth factor (VEGF) expressed in the angiogenic stroma as well as the tumor cells used in this study. Immunization of mice against VEGF or VEGFR-2 stimulated cytotoxic T lymphocyte (CTL) responses and led to partial inhibition of angiogenesis. Antiangiogenic immunity was not associated with morbidity or mortality except for a transient impact on fertility seen in mice immunized against VEGFR-2, but not VEGF. Tumor growth was significantly inhibited in mice immunized against VEGF, VEGFR-2, and Tie2, either before tumor challenge or in the setting of pre-existing disease in murine B16/F10.9 melanoma and MBT-2 bladder tumor models. Coimmunization of mice against VEGFR-2 or Tie2 and total tumor RNA exhibited a synergistic antitumor effect. Synergism was also observed when mice were coimmunized with various combinations of defined tumor-expressed antigens, telomerase reverse transcriptase (TERT) or TRP-2, and VEGF or VEGFR-2. This study shows that coimmunizing mice against angiogenesis-associated and tumor-expressed antigens can deliver 2 compatible and synergistic cancer treatment modalities via a common treatment, namely immunization.

Description: Painful vaso-occlusive episodes in SCD are commonly associated with infection and other less definable stressors. Since epinephrine activates sickle red cell (SS RBC) adhesion in vitro, we studied the physiologic effect of adrenoceptor signaling activation by epinephrine on SS RBC adhesion to endothelium in vivo. We also investigated whether β-adrenoceptor blockade by propranolol would reduce adhesion and vaso-occlusion. Boluses of washed fluorescently labeled human SS RBCs, treated with epinephrine or vehicle in vitro, were infused into anesthetized athymic nude mice with window chambers implanted into their dorsal skin. Intravital microscopy of contralateral subdermal microvasculature was then performed to observe the dynamic interactions between flowing human SS RBCs and non-activated endothelium. Epinephrine induced human SS RBC adhesion, with frequent postcapillary obstruction. In contrast, neither sham-treated SS RBCs nor epinephrine-treated normal RBCs adhered appreciably to endothelium. Blood flow rates in venules of mice infused with epinephrine-treated SS RBCs was dramatically decreased, with fluxes of 19667±9048 and 6622±1494 circulating RBC/min/μm2 for sham-treated and epinephrine-treated cells, respectively (p=0.0074). SS RBC trapping in lung, spleen and kidney was assessed by fluorescence microscopy of frozen tissue sections collected 30 minutes post injection. Sham-treated SS RBCs were trapped to some degree in the lungs and spleen but only minimally in the kidney. However, epinephrine treatment markedly increased SS RBC trapping in all organs. To quantitate cell survival, sham-treated and epinephrine-treated SS RBCs labeled with different fluorescent dyes were co-infused into the same mouse. Blood samples were collected at intervals after infusion and analyzed by flow cytometry. Ten minutes after infusion, the percentage of circulating sham-treated SS RBCs was 3-fold higher than for epinephrine-treated cells, thus showing an inverse relationship between the percentage of circulating SS RBCs and the degree to which these cells were trapped in the organs studied. Finally, to determine whether propranolol can block epinephrine-induced SS RBC adhesion, SS RBCs were pretreated with propranolol, followed by treatment with epinephrine, then washed before infusion. Propranolol significantly inhibited the effect of epinephrine on SS RBC adhesion, resulting in markedly decreased obstruction of postcapillary vessels. Propranolol improved epinephrine-treated SS RBC circulation, with fluxes of 18809±7868, 3560±1443 and 16722±4985 circulating RBCs/min/μm2 for propranolol-treated, epinephrine-treated, and propranolol+epinephrine-treated cells, respectively (p