ABSTRACT
Objective To investigate the effect of cholesterol on the proliferation and differentiation of neural stem cells (NSCs) in ob/ob obese mice, and to explore the possible mechanism of central nervous systym dysfunction caused by obesity. Methods Selected 64-month-old ob/ob and wild type (WT) mice, and cell proliferation antigen (Ki67) and doublecortin (DCX) immunofluorescenct staining were used to detect ob/ob mice lateral ventricle subventricular zone (SVZ) neurogenesis level. Cultured SVZ NSCs isolated from 184-month-old ob/ob and WT mice, and BrdU incorporation experiment and β-III-tubulin (Tuj1) immunofluorescent staining were employed to detect the self-renewal and differentiation ability of NSCs. Matrix-assisted laser desorption/ionization time of flight mass spectrometry(MALDI- MS)was used to detect the lipid distribution in 4-month-old ob/ob and WT mice brain tissues, and measure the changes of cholesterol(ST) content and the expression genes related to cholesterol synthesis. Cultured 15 WT postnatal day 0(P0) mouse SVZ NSCs in vitro and electrotransfected with the small interfering RNA(siRNA) sequence of cholesterol synthesis rate-limiting enzyme 3-hydroxy-3-methyl-glutaryl coenzyme A reductase (Hmgcr) verified the knockdown efficiency, to detecte the effect of Hmgcr gene knockdown on NSCs by BrdU incorporation experiment and Tuj1 immunofluorescent staining. Results Compared with the WT mice, the number of Ki67
ABSTRACT
<p><b>OBJECTIVE</b>To investigate the expression of B cell specific MLV integration site-1 (Bmi-1) in colorectal cancer (CRC) and its correlation to the clinicopathological features and prognosis of CRC.</p><p><b>METHODS</b>Sixty CRC, 30 adenomas and 20 normal colorectal mucosal tissues were collected to detect the expression of Bmi-1 protein using immunohistochemistry, and the results were analyzed in comparison with the clinicopathological features and survival rate of patients.</p><p><b>RESULTS</b>The positivity rate of Bmi-1 expression in CRC tissue was 51.7%. In CRC, the rate of Bmi-1 overexpression was 25.0%, significantly higher than that in the adenomas and normal colorectal mucosal tissues (6.67% and 0%, respectively, P<0.05). The overexpression of Bmi-1 protein in CRC was obviously associated with distant metastasis and the TNM stage (P<0.05), but not with gender, age, tumor size, tumor site, histological type, differentiation degree and lymph node metastasis (P>0.05). But logistic regression analysis showed that Bmi-1 protein overexpression in CRC was associated only with distant metastasis (P<0.01,OR>1); Kaplan-Meier survival analysis showed that the survival rate of the patients with high Bmi-1 expression was significantly lower than that in patients with low expression (P<0.05).</p><p><b>CONCLUSION</b>The overexpression of Bmi-1 protein was significantly correlated to the tumorigenesis, metastasis and prognosis of CRC, and may serve as an indicator for evaluating the prognosis of CRC.</p>