[Inhibitory effect of knocking down microRNA-221 and microRNA-222 on glioma cell growth in vitro and in vivo].
OBJECTIVE
To study the inhibitory effect of knocking down microRNA(miR)-221 and miR-222 on human glioma cell growth and its possible mechanism.


METHODS
miRNA-221/222 antisense oligonucleotides (antisense miR221/222) were transfected into human glioma U251 cells by lipofectamine. Northern blot analysis was conducted to detect the mRNA expression of miR-221/222 in the control and transfected cell groups. The proliferation activity of cells was determined by MTT assay. Cell invasion ability was examined by transwell assay, and cell cycle kinetics and apoptosis were detected with flow cytometry. The expression of relevant proteins was analyzed by Western blotting. The therapeutic efficacy of antisense miR221/222 on the growth of xenograft tumors in nude mice were also observed.


RESULTS
In the antisense miR-221/222-transfected cells, the expression of miR-221/222 was significantly reduced; the cell invasion ability was suppressed, cell cycle was blocked at G(0)/G(1) phase, and apoptotic cells were increased. The growth of xenograft tumors treated with antisense miR-221/222 was also inhibited. In antisense miR-221/222 treated tumor cells, the expression of bcl-2 was down-regulated while connexin43, p27, PUMA, caspase-3, PTEN, TIMP3 and Bax up-regulated, and p53 expression not changed.


CONCLUSIONS
There is a significant inhibitory effect of antisense miR-221/222 on the growth of human glioma U251 cells. miR-221/222 may be considered as a candidate target for gene therapy of human gliomas.
Zhang
Chun-zhi
CZ
Department of Neurosurgery, Tianjin Medical University General Hospital and Laboratory of Neuro-Oncology, Tianjin Neurological Institute, Tianjin 300052, China.
Kang
Chun-sheng
CS
Pu
Pei-yu
PY
Wang
Guang-xiu
GX
Jia
Zhi-fan
ZF
Zhang
An-ling
AL
Han
Lei
L
Xu
Peng
P
D000818:Animals; D017209:Apoptosis; D001483:Base Sequence; D053148:Caspase 3 / Q000378:metabolism; D002453:Cell Cycle; D045744:Cell Line, Tumor; D049109:Cell Proliferation; D015536:Down-Regulation; D015972:Gene Expression Regulation, Neoplastic; D055785:Gene Knockdown Techniques; D015316:Genetic Therapy; D005910:Glioma / Q000378:metabolism / Q000473:pathology*; D006801:Humans; D019394:Ki-67 Antigen / Q000378:metabolism; D051379:Mice; D008807:Mice, Inbred BALB C; D008819:Mice, Nude; D035683:MicroRNAs / Q000096:biosynthesis* / Q000235:genetics; D008969:Molecular Sequence Data; D009368:Neoplasm Transplantation; D016376:Oligonucleotides, Antisense / Q000494:pharmacology; D051059:PTEN Phosphohydrolase / Q000378:metabolism; D019253:Proto-Oncogene Proteins c-bcl-2 / Q000378:metabolism; D012333:RNA, Messenger / Q000378:metabolism; D019717:Tissue Inhibitor of Metalloproteinase-3 / Q000378:metabolism; D014162:Transfection
D053148:Caspase 3; D019394:Ki-67 Antigen; D035683:MicroRNAs; D016376:Oligonucleotides, Antisense; D051059:PTEN Phosphohydrolase; D019253:Proto-Oncogene Proteins c-bcl-2; D012333:RNA, Messenger; D019717:Tissue Inhibitor of Metalloproteinase-3; C525709:MIR221, human; C525710:MIR222, human; C494929:PTEN protein, human