BCL6: somatic mutations and expression in early-stage chronic lymphocytic leukemia.

BCL6 somatic mutations affect normal and tumoral post germinal center B-lymphocytes. Our objective was to analyse expression, mutations and polymorphisms in the BCL6 gene and to correlate those variables with the clinical outcome in early-stage chronic lymphocytic leukemia (CLL). CLL samples were used for characterisation of the mutational status of BCL6/ immunoglobulin variable heavy chain (IGHV) genes, and expression of BCL6 was determined by real time PCR and immunoblot. Out of 68 cases, 29% show somatic mutations on BCL6 which occur exclusively in IGHV mutated cases. They are single nucleotide substitutions located mainly in two short mutational hot spots. CLL cells express different levels of BCL6 regardless of the mutational status, the number of mutations and polymorphisms. CLL cases expressing high levels of BCL6 have significantly shorter treatment-free interval. In conclusion, in early-stage patients with CLL, we found no correlation between expression and the mutations or polymorphism in BCL6, but high levels of BCL6 can discriminate patients with a worse prognosis.

Phycocyanin liposomes for topical anti-inflammatory activity: in-vitro in-vivo studies.

OBJECTIVES: The aim of this work was to investigate the anti-inflammatory activity of C-phycocyanin (C-PC) on skin inflammation after topical administration and the influence of liposomal delivery on its pharmacokinetic properties. METHODS: Liposomes of different size and structure were prepared with different techniques using soy phosphatidylcholine and cholesterol. Vesicular dispersions were characterised by transmission electron microscopy, optical and fluorescence microscopy for vesicle formation and morphology, dynamic laser light scattering for size distribution, and Zetasizer for zeta-potential. C-PC skin penetration and permeation experiments were performed in vitro using vertical diffusion Franz cells and human skin treated with either free or liposomal drug dispersed in a Carbopol gel. KEY FINDINGS: The protein was mainly localised in the stratum corneum, while no permeation of C-PC through the whole skin thickness was detected. Two percent C-PC-encapsulating liposomes showed the best drug accumulation in the stratum corneum and the whole skin, higher than that of the corresponding free 2% C-PC gel. Moreover, skin deposition of liposomal C-PC was dose dependent since skin accumulation values increased as the C-PC concentration in liposomes increased. The topical anti-inflammatory activity of samples was evaluated in vivo as inhibition of croton oil-induced or arachidonic acid-induced ear oedema in rats. CONCLUSIONS: The results showed that C-PC can be successfully used as an anti-inflammatory drug and that liposomal encapsulation is effective in improving its anti-inflammatory activity.

Conversion of liposomal 4-androsten-3,17-dione by A. simplex immobilized cells in calcium pectate.

Arthrobacter simplex ATCC 6946 free and immobilized cells were assayed for their ability to convert 4-androsten-3,17-dione (AD) to 1,4-androstadien-3,17-dione (ADD) in aqueous and liposomal media. Bioconversions were carried out in a 100 ml flask containing 25 ml of AD liposomal or aqueous medium for 3h, and AD concentrations ranging from 0.3 to 1.0 mM were tested. AD/ADD ratios in samples were determined by HPLC. Biotransformation of substrate entrapped in multilamellar vesicles (MLV) was demonstrated to be better than the corresponding free form. In the former case, 2h were necessary to completely bioconvert 1 mM AD. By contrast, 3h were needed to reach 50% bioconversion in (4%) ethanol medium containing 0.63 mM AD. The liposomal medium allows us to perform steroid conversions at high concentrations of AD, reusing immobilized cells in suitable conditions which are non-toxic for microorganisms.