Killed Bacillus subtilis spores expressing streptavidin: a novel carrier of drugs to target cancer cells.

Carriers of drugs in cancer therapy are required to reduce side-effects of the drugs to normal cells. Here we constructed killed recombinant Bacillus subtilis spores (SA1) that expressed streptavidin as a chimeric fusion to the spore coat protein CotB and used the spores as bioparticle carrier. When bound with biotinylated cetuximab these spores could specifically target to the epidermal growth factor receptor on HT 29 colon cancer cells, thereby delivered paclitaxel to the cells with 4-fold higher efficiency, as indicated by fluorescent intensity of paclitaxel Oregon Green 488 bound to HT29 cells. Based on real-time monitoring of cell index, the IC50 of growth of HT29 cells by paclitaxel-SA1-cetuximab was estimated to be 2.9 nM approximately 5-fold lower than water-soluble paclitaxel (14.5 nM). Instability of DNA content was observed when cells were treated with 16 nM paclitaxel-SA1-cetuximab, resulting in a 2-fold enhancement in polyploidy cells. Thus, by targeting the release of paclitaxel to HT29 cells, spore-associated cetuximab augmented the inhibitory effect of paclitaxel on cell division and proliferation. The SA1 could be used as a "universal" drug carrier to target specific biomarkers on cancer cells by conjugating with suitable biotinylated antibodies.

Genetic evidence of functional ficolin-2 haplotype as susceptibility factor in cutaneous leishmaniasis.

BACKGROUND: Ficolin-2 coded by FCN2 gene is a soluble serum protein that plays an important role in innate immunity. In this study, we analyzed five functional polymorphisms of the FCN2 gene for their possible association with cutaneous leishmaniasis. METHODS: Initially we screened 40 Syrian Arabs for the entire FCN2 gene. We investigated the contribution of FCN2 functional variants in 226 patients with cutaneous leishmaniasis and 286 healthy controls from Syria. Polymorphisms in the promoter regions (-986G/A, -602G/A, -4A/G) of the FCN2 gene were assessed by TaqMan real time PCR, whereas polymorphisms in exon8 (+6359C/T and +6424G/T) were assessed by DNA sequencing. We also measured serum ficolin-2 levels in 70 control Syrian Arabs and correlated the serum concentrations to FCN2 genotypes and haplotypes respectively. RESULTS: Nine new FCN2 variants including two with non synonymous substitutions in exon6 and exon8 were observed. The homozygous genotypes +6424T/T were distributed more in controls and none in patients (P = 0.04). The AGACG haplotype were observed more in patients than in controls (OR = 2.0, 95%CI 1.2-3.4, P = 0.006). The serum ficolin-2 levels were significantly distributed among the reconstructed ficolin-2 haplotypes (P<0.008) and the haplotype AGACG was observed with higher ficolin-2 levels in 70 control individuals. CONCLUSION: Our results demonstrate a significant association of FCN2 AGACG haplotype with cutaneous leishmaniasis in a Syrian Arab population. These first results provide a basis for a future study that could confirm or disprove possible relationships between FCN2 gene polymorphisms with cutaneous leishmaniasis.