Suppressive effect of knockdown of miR-21 expression on U87 human glionto growth in vivo

Abstract

Objective To study the suppressive effect of knockdown of miR-21 on the U87 human giioma xenograft growth and the possible mechanism. Methods Nude mice bearing U87 human glioblastoma subcutaneously were treated with miRNA-21 anfisense oligonucleotides(AS-miR-21)intratumomlly every 3 d until the observation peded ended.The tumor volume of the mice treated withAS-miR-21 was measured regularly as compared with that in the control untreated mice and in the mice treated with scramble oligonucelotides(ODN).Finally,the tumors were removed from nude mice for the examination.In-sire hybridization and real-time PCR were conducted to detect the miRNA expression of miR-21.The biological charaetedsties of the tumors were evaluated by HE and immunohistochemieal staining, and the cell apoptosis was detected by TUNEL method. Resulls During the observation period,the tumor growth was delayed and the final tumor volume of AS-miR-21 heated group was smaller than that in the control and scramble ODN treatedg roup(F=6-056,P=0.007).The expression of miRNA precursor was knocked down in As-miRNA treated tunlors compared with that in untreated or scramble ODN treated tumors.Histopathological examination exhibited the appearance of degraded malignancy.The expressions of PCNA and MMP-9 were down-regulated while Septin-7 and P21 were up-regulated and apoptotic index was increased significantly (F=141.021,P=000) as well.Conclusion The suppressive effect of anti-miR-21 ODNs on the growth of U87 human glioma xenogratts is significant and miR-21 Call be taken as a candidate for gene therapy ofhuman glioma. Key words: miR-21; Antisense oligonucleotides; Glioma; Gene therapy