[Effects of RNA interference upon EGFR and its intracellular effective proteins in prostate cancer].
OBJECTIVE
To investigate the growth of prostate cancer in vitro or in vivo by inhibiting the expression of EGFR and its intracellular effective proteins with small RNA interference ( SiRNA).


METHODS
The hormone independence prostate cancer (HIPC) cell line PC-3 was transfected by EGFR SiRNA synthesized and cloned into a recombinant lentivirus vector. The growth rate of transfected PC-3 cell was measured by MTT. The expression of EGFR and the expression and phosphorylation of its intracellular proteins, such as Akt and MAPK, were detected by fluorescent Real-Time PCR and Western blot respectively. Meanwhile nude mice were transplanted with PC-3 cell to establish the tumor model and the tumor growth was observed.


RESULTS
The transfection efficiency was stable over 75% in PC-3 cell transfected with the recombinant lentivirus vector carrying EGFR SiRNA and the survival rate of PC-3 cell was only 40%-50%. Such depressant effects might be obtained by inhibiting the expression of EGFR mRNA and protein to only 10% as compared with their untreated levels (P < 0.01); meanwhile, the expression level and phosphorylation of Akt and MAPK also obviously decreased to 76.49% and 47.15% respectively (P < 0.05). Compared with the control group, the proliferation activity of tumors in nude mice was inhibited significantly by 34.83% (P < 0.05).


CONCLUSIONS
Lentivirus-mediated EGFR SiRNA can inhibit the growth of HIPC in vivo and in vitro by effectively suppressing the expression of EGFR and its intracellular proteins. The latter may be a potential candidate for future targeted therapy.
Long
Hui-min
HM
Department of Urology, the Affiliated Lihuili Hospital of Ningbo University, Ningbo 315040, China.
Chen
Wei-guo
WG
Yang
Xie-qiao
XQ
Li
Zhong-yi
ZY
Yan
Chun-yin
CY
D000818:Animals; D045744:Cell Line, Tumor; D066246:ErbB Receptors / Q000235:genetics / Q000378:metabolism*; D005822:Genetic Vectors; D047908:Intracellular Signaling Peptides and Proteins / Q000235:genetics / Q000378:metabolism; D008297:Male; D051379:Mice; D008819:Mice, Nude; D011471:Prostatic Neoplasms / Q000235:genetics* / Q000378:metabolism*; D034741:RNA, Small Interfering / Q000235:genetics*
D047908:Intracellular Signaling Peptides and Proteins; D034741:RNA, Small Interfering; D066246:ErbB Receptors