Effect of light centrifugal force on the asporin gene expression in human periodontal ligament cells / 中华口腔医学杂志

<p><b>OBJECTIVE</b>To observe the expression of asporin, bone morphogenetic protein-2 (BMP-2) and alkaline phosphatase (ALP) in cultured human periodontal ligament cells in vitro under relative centrifugal force.</p><p><b>METHODS</b>Human periodontal ligament cell was cultured in vitro and applied 30 ×g centrifugal force for 0, 1, 2, 6, 10 hours. The expression of asporin, BMP-2 and ALP was observed with real time-PCR.</p><p><b>RESULTS</b>All the cells showed normal figuration. The expression of asporin, BMP-2, ALP in no force loading group did not have any statistical significance change (P > 0.05). In 1 hour force loading group, the expressions of asporin and BMP-2 were 0.50 ± 0.05 and 0.40 ± 0.13. In 2 hour force loading group, the expressions of asporin and BMP-2 were 0.42 ± 0.09 and 0.58 ± 0.19, which decreased significantly from no force loading group (P < 0.05). The expression of asporin and BMP-2 increased significantly in 6 hour force loading group than in 1 and 2 hour force loading groups (P < 0.05). Then the expression of asporin decreased to no force loading group level (P > 0.05) and the expression of BMP-2 decreased rapidly lower than no force loading group level (P < 0.05). During the 10 hour interval of stress loading, the expression of asporin and BMP-2 showed a positive correlation (r = 0.995, P < 0.05).</p><p><b>CONCLUSIONS</b>The expression of asporin in human periodontal ligament cell was stable. Short and light centrifugal force could up-regulate the expression of asporin rapidly, and suppress the abnormal BMP-2 expression back to baseline level.</p>

CD133(+) Colo205 colorectal cancer cells express high levels of ALDH1 in serum-free culture / 南方医科大学学报

<p><b>OBJECTIVE</b>To investigate the expression pattern of CD133 and ALDH1 in colorectal cancer cells line Colo205 cultured in serum-free medium (SFM) containing recombinant human epidermal growth factor (EGF) and basic fibroblast growth factor (bFGF).</p><p><b>METHODS</b>Colo205 cells were cultured in serum-free medium (SFM) containing human recombinant EGF and bFGF or in serum-supplemented medium (SSM). The expression of CD133 was analyzed in both groups, and CD133(+) and CD133(-) cells sorted from the SFM group using flow cytometry and observed microscopically for their growth status. The expression of CD133 and ALDH1 in CD133(+) cells and CD133(-) cells was detected by immunofluorescence assay. CD133(+) cells and CD133(-) cells were then injected subcutaneously into NOD/SCID mice and the expression of ALDH1 in the tumor tissues was detected by immunohistochemistry.</p><p><b>RESULTS</b>The cells in SFM group showed a significantly higher percentage of CD133(+) cells than those in SSM group (P<0.05). In SFM, CD133(+) cells were capable of forming tumor spheres while CD133(-) cells could not; CD133(+)cells strongly expressed CD133 and ALDH1 and CD133(-) cells did not. In mice, tumors generated by CD133(+) cells, but not by CD133(-) cells, positively expressed ALDH1.</p><p><b>CONCLUSIONS</b>CD133(+) Colo205 colorectal cancer cells in SFM containing human recombinant EGF and bFGF can form tumor spheres and strongly express ALDH1. ALDH1 may be one of the candidate markers of colorectal cancer stem cells.</p>

Application of genome-wide genechip for screening and identifying genes related to CD133(+)CD200(+) colorectal cancer stem cells / 南方医科大学学报

<p><b>OBJECTIVE</b>To screen and identity genes related to CD133(+)CD200(+) colorectal cancer stem cells.</p><p><b>METHODS</b>The two subpopulations of colorectal cancer cells, namely CD133(+)CD200(+) and CD133(-)CD200(-) cells, were sorted and verified by flow cytometry. The gene expression profiles of CD133(+)CD200(+)and CD133(-)CD200(-) colorectal cancer cells were examined using Affymetrix Human U133 Plus2.0 genome-wide genechip. The differentially expressed genes between the two cell subpopulations were analyzed to identify the genes responsible for the main effect in association with colorectal cancer stem cells. Real-time quantitative PCR was performed to confirm some of the differentially expressed genes identified by genechip.</p><p><b>RESULTS</b>The genechip result showed that 655 genes were differentially expressed in CD133(+)CD200(+) colorectal cancer stem cells by at least 3 folds, including 290 up-regulated and 365 down-regulated ones. Bioinformatics analysis and gene co-expression network building identified 3 genes (MDM2, PRKACG, and CACNA1G) with specific expression in CD133(+)CD200(+) colorectal cancer stem cells, and this result was confirmed by real-time quantitative PCR analysis.</p><p><b>CONCLUSION</b>A specific gene expression profile of colorectal cancer stem cells has been established through screening and identifying genes related to CD133(+)CD200(+)colorectal cancer stem cells by gene genechip technique, which provides a basis for further study of gene targeting therapy of colorectal cancer.</p>

Effects of gastrin on rat intestinal epithelial 1,25(OH)2D3-membrane associated rapid response steroid binding protein / 南方医科大学学报

<p><b>OBJECTIVE</b>To explore the effects of gastrin on the expression of 1,25(OH)2D3-membrane associated rapid response steroid (1,25D3-MARRS) binding protein in rat intestinal epithelium.</p><p><b>METHODS</b>SD rats received intraperitoneal injections of gastrin, omeprazole or physiological saline. The protein expression of 1,25D3-MARRS binding protein in SD rat intestinal was determined with Western blotting and immunohistochemistry, and its mRNA levels determined by RT-PCR. The serum calcium and phosphate levels in the rats were also detected.</p><p><b>RESULTS</b>Immunohistochemistry showed that 1,25D3-MARRS binding protein was expressed mainly in the nuclei, cytoplasm and membrane of the intestinal epithelial cells. Both the protein and mRNA expression levels of 1,25D3-MARRS binding protein were up-regulated after treatments with gastrin and omeprazole (P<0.05), but the serum calcium and phosphate concentrations showed no obvious increase.</p><p><b>CONCLUSION</b>1,25D3-MARRS binding protein, which is widely expressed with versatile functionalities, is regulated by gastrin and shows high potentials in the study of gastrointestinal diseases.</p>