THE PRODUCTION OF LACTOFERRIN-PRODUCING BACTEROIDES UNIFORMIS

Abstract To construct lactoferin-producing Bacteroides uniformis, the human lactoferrin gene(hLF) was inserted into pVAL-1, a E. coli-Bacteroides shuttle vector, to generate the recombinantplasmid pVLFK. Then, withE. coli HB101 (R751) as a donor either pVAL-1 or pVLFKwas transferred intoB. uniformis BU1001. The erythromycin resistant strains were selected andisolated as a plasmid containing strain. By PCR technique, the lactoferrin gene was detected inthe bacteria cell extract from each strain. The presence ofhLF has been shown as a 2.1 Kbamplicon inB. uniformis strain pVLFK. The expression of hLF was assessed by Northernhybridization and the gene product was detected by Western blot analysis with anti-humanlactoferrin monoclonal antibody. Although the transcription level ofhLF gene was extremelylow in the strain harboring pVLFK, the specific protein was detected by Western blot analysis.However the size of gene product in this strain was higher than that of standard human LF(SIGMA). The results revealed that a lactoferrin gene bearing plasmid could replicate and wasexpressed inB. uniformis strain pVLFK. The properties of this strain will be further study.Chiang Mai Med Bull 2001;40(4):187-194.

CENTELLA ASIATICA EXTRACT INDUCES CELL CYCLE ARREST IN CACO-2 HUMAN COLON CANCER CELLS

Centella asiatica  is traditionally a medicinal plant frequently employed in the practice of Thai folk medicine. This study examined the anti-tumor activity of the crude water extract of C. asiatica using human colon adenocarcinoma-derived Caco-2 cells. C. asiatica extract reduced the proliferation rate of Caco-2 cells significantly in a concentration- and time-dependent manner. The mechanism of cancer cell growth inhibition was shown to occur via cell cycle arrest. The extract induced S and G2-M arrest in Caco-2 cells accompanied apoptosis induction. The extract also increased the accumulation of cyclin B1 protein in the cells. These findings indicate that C. asiatica extract inhibited cell proliferation of Caco-2 cells through modification of the cell cycle events and this cell cycle arrest is associated, at least in part, with increased accumulation of cyclin B1 protein. Chiang Mai Med Bull 2005;44(1):21-28.

Genetic Structure in the Region Near the Sialidase Gens in Bacteroides fragilis

No Abstract Available.