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Objective To assess the role of microRNA-9 in bone marrow mesenchymal stem cells differentiating into neurons and research the role of gene modification in spinal cord injury treatment.Methods Adherent culture was used to isolate and culture rat bone marrow mesenchymal stem cells (MSCs); microRNA-9-1 lentiviral vector was constructed.Acute spinal cord injury (SCI) models were established in 84 adult SD rats at T10/11 level according to the improved Allen's method; then,they were randomly divided into control group,MSCs group and miRNA group (n=28).One week after SCI,the rats of MSCs group were treated with MSCs implantation,and the rats of miRNA group were treated with MSCs-transfected microRNA-9-1 lentiviral vector; while rats of the control group only received the same amount of physical saline in the same region.The neurological functions were evaluated by using Basso-Beattie-Bresnahan (BBB) scale 1 and 3 days,and 1,2,4,6,8 and 12 weeks after SCI.The immunoreactivity of neuro filament 200 (NF-200) and glial fibrillary acidic protein (GFAP) was measured,and the percentage of positive response area was assayed and compared between groups.Results Four weeks after cell transplantation,statistical difference of BBB scale scores was noted between each two groups; the scores of miRNA group were significantly higher than those of the MSCs group and control group (P＜0.05).The immunohistochemistry staining indicated that the expression of NF-200 was significantly more intense and the expression of GFAP was significantly weaker in miRNA group than those of the other two groups (P＜0.05).Conclusion MicroRNA-9 may play an important role in bone marrow mesenchymal stem cells differentiating into neurons,and possess effects on repairing injured spinal cord and promoting functional recovery through promoting axonal regeneration and reducing the number of reactive glial cells in the spinal cord injury site.
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<p><b>OBJECTIVE</b>To study the serrated lesions of colon and to compare the malignant potential between traditional serrated adenomas (TSA) and conventional adenomas (CAD).</p><p><b>METHODS</b>A total of 5347 cases of colorectal polyps encountered in five regional hospitals during a five-year period were retrospectively reviewed. The serrated lesions were classified on the basis of histologic examination. One hundred and eighty-seven cases of CAD (including 160 cases of tubular adenoma and 27 cases of villous adenoma) and 36 cases of invasive adenocarcinoma were randomly selected as the controls. The degree of dysplasia and expressions of Ki-67, p53 and beta-catenin in TSA and CAD were compared.</p><p><b>RESULTS</b>Amongst the 5347 colorectal polyps studied, 258 cases (4.8%) of serrated lesions were found, which included 112 cases (43.4%, 112/258) of hyperplastic polyp, 78 cases (30.2%, 78/258) of TSA and 26 cases (10.1%, 26/258) of sessile serrated adenoma. Sixty-two cases of TSA were identified from 3 hospitals, in which moderate dysplasia was found in 13 cases. High-grade intraepithelial neoplasia and ICA were found in 6 cases (9.6%). Compared with the 187 cases of CAD, moderate dysplasia were found in 27 cases and high-grade intraepithelial neoplasia and invasive adenocarcinoma were found in 25 cases (13.3%, χ(2) = 19.373, P = 0.000). There was statistically significant difference between TSA and CAD in the degree of dysphasia. The expression of Ki-67, p53 and beta-catenin in TSA and CAD showed no significant difference (P > 0.05).</p><p><b>CONCLUSIONS</b>The incidence of serrated lesions is lower in northern Chinese population than that in Caucasians. TSA has obvious malignant potential; but the rate associated with high-grade intraepithelial neoplasia and invasive adenocarcinoma is lower than that in CAD.</p>