[Short hairpin RNA silencing of vascular endothelial growth factor, telomerase reverse transcriptase, and Bcl-xl expression in human laryngeal squamous carcinoma xenografted in nude mice].
OBJECTIVE
To investigate the biological impact of pEGFP-shVEGF-shTERT-shBcl-xl expression in human laryngeal squamous carcinomas xenografted in nude mice and the related antitumor mechanism.


METHODS
A recombinant plasmid vector containing 3 different short hairpin RNA (shRNA) segments including pEGFP-shVEGF-shTERT-shBcl-xl was constructed and directly injected into the grafted tumors of human laryngeal squamous carcinoma in nude mice. The mRNA and protein expressions were determined by real-time RT-PCR and Western blot respectively. Apoptosis was determined by TUNEL assay using a commercial kit. Intratumoral microvessel density (MVD) was assessed by immunhistochemistry.


RESULTS
On the 14th days after the final treatment, mRNA and protein expression of VEGF, TERT, and Bcl-xl were markedly suppressed. The tumor sizes were significantly smaller than those in the other two group, with an overall tumor inhibition ratio of 91.2%. MVD counts in the pEGFP-shVEGF-shTERT-shBcl-xl treated group were significantly lower than those of the other two groups, along with increased apoptotic cells.


CONCLUSIONS
The data showed that inhibition of VEGF, TERT, Bcl-xl expression by RNAi technique induces cellular apoptosis and suppresses the growth of laryngeal squamous carcinoma in vivo. VEGF, TERT and Bcl-xl may be involved in the development of laryngeal cancers. The findings suggest a synergistic tumor therapeutic effect through simultaneous inhibition of the three genes. Multi-target RNA interference may provide a powerful strategy against human laryngeal cancers.
Wang
Yan
Y
Department of Otolaryngology-Head and Neck Surgery, Renmin Hospital of Wuhan University, Wuhan 430060, China.
Chen
Shi-Ming
SM
Xiao
Bo-Kui
BK
Tao
Ze-Zhang
ZZ
D000818:Animals; D045744:Cell Line, Tumor; D015972:Gene Expression Regulation, Neoplastic / Q000187:drug effects*; D006801:Humans; D007822:Laryngeal Neoplasms / Q000235:genetics / Q000378:metabolism*; D051379:Mice; D008819:Mice, Nude; D035683:MicroRNAs / Q000494:pharmacology*; D034622:RNA Interference; D020133:Reverse Transcriptase Polymerase Chain Reaction; D014183:Transplantation, Heterologous / Q000379:methods; D042461:Vascular Endothelial Growth Factor A / Q000037:antagonists & inhibitors* / Q000235:genetics / Q000378:metabolism; D051020:bcl-X Protein / Q000037:antagonists & inhibitors* / Q000235:genetics
D035683:MicroRNAs; D042461:Vascular Endothelial Growth Factor A; D051020:bcl-X Protein