[Study on reversion of malignant phenotype of glioma by siRNA targeting p75 neurotrophin receptor].
OBJECTIVE
To study the therapeutic efficacy of siRNA fragments silencing p75 neurotrophin receptor (p75(NTR)), which may be a key regulator of glioma cell apoptosis and invasion.


METHODS
The siRNA sequence fragments targeting p75(NTR) were designed and transferred into human glioma cell line U251. RT-PCR and immunocytochemistry method were used to explore the expression of p75(NTR) mRNA and protein. Cell adhesion assay was employed to detect cellular adhesion ability, and soft agar clone formation assay was adopted to identify oncogenicity, and a U251 glioma model was established in nude mice. The intracranial tumor volume was detected by MRI. The expression of p75(NTR), NGF and cyclin D2 were identified using immunohistochemistry. Cell apoptosis was detected by apoptosis kit in situ.


RESULTS
The siRNA fragments targeting p75(NTR) were capable of decreasing mRNA and protein expression of p75(NTR) in U251 glioma cell line. Both the cellular adhesion ability and oncogenicity were weakly relevant. The p75(NTR) expression level was negatively correlated with cyclin D2 and apoptosis, and positively correlated with NGF expression. The siRNA sequence fragments targeting p75(NTR) were effective in decreasing the gross volume of tumor; prolonged the survival time of mice, and the edge of tumor was much sharper than that of the control group.


CONCLUSIONS
The gene silencing technique by siRNA targeting p75(NTR) is capable of decreasing tumor invasion and cell proliferation as well as inducing cell apoptosis. It is expected to be a new choice for glioma gene therapy.
Department of Pathology, the Affiliated Hospital of the Medical College of Chinese People's Armed Police Force, Tianjin 300162, China.
Zhan-kao
ZK
Zhao
Zhong-min
ZM
Jiang
Xiao-zhi
XZ
Liu
Yan-ting
YT
Chen
Wen-juan
WJ
Jia
D000818:Animals; D017209:Apoptosis; D001932:Brain Neoplasms / Q000235:genetics / Q000378:metabolism / Q000473:pathology; D045744:Cell Line, Tumor; D002465:Cell Movement; D049109:Cell Proliferation; D056742:Cyclin D2 / Q000378:metabolism; D020868:Gene Silencing; D005910:Glioma / Q000235:genetics / Q000378:metabolism / Q000473:pathology; D006801:Humans; D008297:Male; D051379:Mice; D008819:Mice, Nude; D009361:Neoplasm Invasiveness; D009368:Neoplasm Transplantation; D020932:Nerve Growth Factor / Q000378:metabolism; D012333:RNA, Messenger / Q000378:metabolism; D034741:RNA, Small Interfering / Q000235:genetics*; D011897:Random Allocation; D020800:Receptor, Nerve Growth Factor / Q000235:genetics* / Q000378:metabolism
D056742:Cyclin D2; D012333:RNA, Messenger; D034741:RNA, Small Interfering; D020800:Receptor, Nerve Growth Factor; D020932:Nerve Growth Factor