Cannabinoid Receptors Are Overexpressed in CLL but of Limited Potential for Therapeutic Exploitation.

The cannabinoid receptors 1 and 2 (CNR1&2) are overexpressed in a variety of malignant diseases and cannabinoids can have noteworthy impact on tumor cell viability and tumor growth. Patients diagnosed with chronic lymphocytic leukemia (CLL) present with very heterogeneous disease characteristics translating into highly differential risk properties. To meet the urgent need for refinement in risk stratification at diagnosis and the search for novel therapies we studied CNR expression and response to cannabinoid treatment in CLL. Expression levels of CNR1&2 were determined in 107 CLL patients by real-time PCR and analyzed with regard to prognostic markers and survival. Cell viability of primary CLL cells was determined in suspension and co-culture after incubation in increasing cannabinoid concentrations under normal and reduced serum conditions and in combination with fludarabine. Impact of cannabinoids on migration of CLL cells towards CXCL12 was determined in transwell plates. We found CNR1&2 to be overexpressed in CLL compared to healthy B-cells. Discriminating between high and low expressing subgroups, only high CNR1 expression was associated with two established high risk markers and conferred significantly shorter overall and treatment free survival. Viability of CLL primary cells was reduced in a dose dependent fashion upon incubation with cannabinoids, however, healthy cells were similarly affected. Under serum reduced conditions, no significant differences were observed within suspension and co-culture, respectively, however, the feeder layer contributed significantly to the survival of CLL cells compared to suspension culture conditions. No significant differences were observed when treating CLL cells with cannabinoids in combination with fludarabine. Interestingly, biologic activity of cannabinoids was independent of both CNR1&2 expression. Finally, we did not observe an inhibition of CXCL12-induced migration by cannabinoids. In contrast to other tumor entities, our data suggest a limited usability of cannabinoids for CLL therapy. Nonetheless, we could define CNR1 mRNA expression as novel prognostic marker.

Integrin beta-3 genetic variants and risk of venous thromboembolism in colorectal cancer patients.

BACKGROUND: Integrin ß3 is involved in tumor and endothelial cell biology as well as in platelet aggregation. Herein, we evaluated the predictive potential of three germline single nucleotide polymorphisms (SNPs) in the integrin ß3 gene (rs3809865, rs5918 and rs4642) to predict the risk of venous thromboembolism (VTE) in colorectal cancer (CRC) patients, which is one of the leading causes of death among cancer patients. METHODS: 112 patients diagnosed with CRC enrolled in the prospective Vienna Cancer and Thrombosis Study (CATS) were assessed with a median follow-up of 46 months. DNA was isolated from venous blood samples and SNPs were analyzed by the PCR-RFLP method. RESULTS: VTE occurred in 12% (n=13) of all patients. The SNPs rs5918 and rs4642 were not associated with VTE risk. For rs3809565, 23% (n=11) of patients had the A/A genotype, 4% (n=2) had the A/T genotype, but none (0%) had the T/T genotype. In the univariate analysis, patients with the A/A genotype had a significantly higher risk to develop VTE compared to the other polymorphisms (P=0.0005 after Fine and Gray). In the multivariable analysis, the predictive value remained significant. CONCLUSIONS: This study identified the rs3809865 A/A genotype as an independent risk factor for VTE in CRC patients. Our findings would help identify high risk patients and would be essential for tailored anticoagulant prophylaxis.

In vivo Tube Assay: An Optimised Protocol of the Directed in vivo Angiogenesis Assay by Implementing Immunohistochemistry.

BACKGROUND: Angiogenesis, the formation of new blood vessels, is an essential process under physiological and pathological conditions. METHOD: Here, we improved the directed in vivo angiogenesis assay (DIVAA®) test, which is based on the usage of small Matrigel-filled tubes that are implanted into mice subcutaneously for a period of up to 15 days. The subsequent ex vivo assessment of neoangiogenesis within the silicon tubes is then achieved by fluorometry. RESULTS: We showed that the immunohistochemical quantification of the ingrowth of endothelial cells, based on CD31, was superior to the fluorometric quantification advised in the manufacturer's instructions. We optimised the explantation procedure, ensuring the complete recovery of the ingrown vessels. Using this modified protocol, we investigated the effect of the length of stay of the implanted tubes as well as of the concentration of the growth factors VEGF and FGF on the assay. CONCLUSION: Our improved protocol offered an effective and reliable alternative to the original assay, which is expected to facilitate in vivo research on angiogenesis and, thus, might drive the development of novel therapeutic agents.

SAR-guided development and characterization of a potent antitumor compound toward B-cell neoplasms with no detectable cytotoxicity toward healthy cells.

Acute hematological diseases (leukemias and aggressive lymphomas) can be cured in approximately half of the patients, while the other patients die from their disease. Chronic leukemias and indolent lymphomas can be well controlled for years in most cases. However, the cure rate of these patients is low and the course of the disease is characterized by frequent recurrence. Therefore, novel agents for monotherapies or combination therapies still need to be explored. The presented study describes the identification of the chalcone derivative 15 on different types of human malignant cells of the lymphoid and myeloid lineage. Further experiments performed with compound 15 on peripheral blood mononuclear cells (PBMCs) of chronic lymphocytic leukemia (CLL) patients clearly stated a higher cytotoxicity in PBMC from CLL patients compared to healthy donors (HD). The newly identified chalcone derivative 15 showed a higher therapeutic potential than fludarabine, a drug already in use in lymphoma treatment.

Isolation independent methods of characterizing phage communities 1: strain typing using fingerprinting methods.

Since most of the phage genomes isolated from natural samples are previously unknown sequences, an isolation-independent approach is necessary to quantify the diversity of natural viral communities. Currently, two different methodological approaches are widely used to obtain genetic fingerprints of natural phage communities. While the separation of different viral genomes with pulsed field gel electrophoresis (PFGE) is based on the size of the genome, denaturing gradient gel electrophoresis (DGGE) uses minor differences in gene base composition to separate fragments of amplified DNA from natural viral communities. Finger printing techniques are a relatively fast and cheap tool to assess the diversity of environmental viruses. Together, PFGE and DGGE provide useful tools to study viral ecology in natural habitats.