Genetic polymorphism of RAD51 influences susceptibility to colorectal cancer in Chinese population.

OBJECTIVE: The present study aimed to explore whether RAD51 polymorphism confers risk to colorectal cancer. PATIENTS AND METHODS: A total of 240 patients with colorectal cancer were selected. 390 healthy people who participated in normal physical examinations during the same period were selected as the control group. The polymorphism of RAD51 gene was detected by the polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) method. An updated meta-analysis was also conducted. RESULTS: Meta-analysis found no significant association between the RAD51 polymorphism and CRC risk (all p>0.05). PCR-RFLP method detected three kinds of genotypes (GG, GC, and CC) in both the colorectal cancer group and the control group. A significant association was only found in GC genotype (p<0.05). CONCLUSIONS: Our results demonstrated that RAD51 polymorphism has a crucial role in colorectal cancer risk and that GC genotype confers an increased risk of colorectal cancer in the Chinese population. The updated meta-analysis indicates that RAD51 polymorphism contributes no risk to colorectal cancer.

[Diverse functions of fibulin-5 in tumors].

Altered interactions between the extracellular matrix and cells play an important part in tumorigenesis and metastasis. As a member of matricellular glycoprotein, fibulin-5 is expressed in elastin-rich tissues and organizes the matrix structures by interacting with many extracellular proteins. Fibulin-5 expression is closely associated with normal embryonic development and organogenesis. Mice deficient for the fibulin-5 gene exhibit systemic elastic fiber defects with manifestation of loose skin, emphysematous lung and tortuous vessels. Additionally, fibulin-5 null mice exhibited increased angiogenesis after wound healing or PVA sponge implantation and matrigel implantation experiments show fibulin-5 inhibited vessel formation, suggesting fibulin-5 functions as an angiogenesis inhibitor. Fibulin-5 also plays critical roles in proliferation, migration and invasion of certain tumors, and the effect of fibulin-5 on tumorigenesis appears to be largely context-dependent. This effect might involve the inhibiting action of fibulin-5 on angiogenesis. This review focuses on recent advances in our understanding of the roles of fibulin-5 in tumorigenesis: both tumor promoting and suppressing activity of fibulin-5 are reviewed, and the emerging evidences of its promising potential as therapeutic options and/or targets in the treatment of cancer also highlighted.

Antigenic profile of Blomia tropicalis, Aleuroglyphus ovatus and Glycycometus malaysiensis

House dust mites and storage mites are well-known causes for allergenic diseases. The aim of this study was to investigate the immunogenic sites of Blomia tropicalis, Aleurogyphus ovatus and Glycycometus malaysiensis. The mites were maintained in a culture medium at 25ºC and 75% relative humidity. Mites were harvested either with heat escape or floatation method, purified, homogenized, quantified and used for the production of polyclonal antibody and immunostaining. For each species of mites, five male mice and five male rats were randomly selected and immunized intraperitoneally with respective crude mite extract at two-weekly intervals. Blomia tropicalis, A. ovatus or G. malaysiensis whole mites and paraffin-embedded mite sections were immunostained with the respective polyclonal antibody. The faecal pellets of mites were intensely stained for all the three species in the present study. The legs of sectioned A. ovatus were not immunogenic as compared with those of G. malaysiensis and B. tropicalis. The outer layer (cuticle) of whole mites and the eggs for these species were very immunogenic. Hence, the polyclonal antibodies obtained in this study may serve as potential tools in detecting the eggs and immature mites in environmental samples. Future studies should focus on the antigenic components of eggs since they were relatively abundant in dust and highly antigenic as seen in the present study.

Isolation and characterization of alginate-degrading bacteria for disposal of seaweed wastes.

AIMS: Isolation of novel alginate degrading bacteria for the disposal of seaweed waste in composting process. METHODS AND RESULTS: Decomposition of alginate polymers was checked by the 3,5-dinitrosalicylic acid (DNS) method for reducing sugar, and absorbance at 235 nm for unsaturated sugar. A bacterium A7 was isolated from wakame compost and confirmed to belong to the genus Gracilibacillus by partial 16S rDNA analysis. The optimum condition for the growth of A7 in a medium containing 5 g l(-1) of sodium alginate is as follows: pH, 8.5-9.5; NaCl, 0.5 mol l(-1); temperature, 30 degrees C and polypeptone as nutrient content, 2-5 g l(-1). In a laboratory-scale composting experiment, the alginate content in wakame compost decreased to 14.3% after 72 h of composting from an initial value of 36%, indicating the effectiveness of alginate decomposition of A7 in wakame composting. CONCLUSIONS: The bacterium A7 was found to be alginate lyase-producing in genus Gracilibacillus and effective in degrading alginate to oligosaccharides in wakame during composting process. SIGNIFICANCE AND IMPACT OF THE STUDY: Development of new methods for the disposal of marine wastes and production of functional products.