[In vitro and in vivo inhibitory effect of Ad-ING4 gene on proliferation of human prostate cancer PC-3 cells].
OBJECTIVE
Adenovirus vector has been widely used in tumor gene therapy. ING4 is a member of growth inhibiting factors and a potent anti-tumor gene which could induce apoptosis of many tumor cells. This study was to investigate the inhibitory effects of adenovirus-mediated ING4 (Ad-ING4) gene on the proliferation of human prostate cancer PC-3 cells in vitro and in vivo, and to explore its mechanisms.


METHODS
Ad-ING4 was obtained by virus-amplification technique. After transfection of purified Ad-ING4 into PC-3 cells, the expression of ING4 was detected by reverse transcription-polymerase chain reaction(RT-PCR); the influence of Ad-ING4 transfection on cell proliferation was evaluated using MTT assay. Cell apoptosis was assessed using Hoechst33258 staining and flow cytometry. RT-PCR was performed to detect the mRNA levels of the transcription of apoptosis-related genes such as bcl-2, bax, p53, and caspase-3. Athymic nude mice bearing PC-3 tumors were intratumorally injected with Ad-ING4 (100 microL, 1x10(9) pfu/mL). Tumor growth was recorded. All nude mice were killed at the end of the experiment to observe the growth of xenografts. The expressions of Bcl-2, Bax, Caspase-3, and CD34 proteins in tumor tissues were detected by immunohistochemistry.


RESULTS
Human ING4 gene was successfully transcribed in PC-3 cells and induced apoptosis by up-regulating p53, bax, caspase-3 expression and down-regulating bcl-2 expression. Inhibition of cell proliferation was significant in PC-3 cells. Tumor growth was significantly inhibited in the Ad-ING4 group as compared with that in the Ad-GFP group and the PBS group (P<0.05). The weight inhibitory rate was 37.0% in the Ad-ING4 group. The expressions of Bax and Caspase-3 were up-regulated, and the expressions of Bcl-2 and CD34 were down-regulated in the Ad-GFP group.


CONCLUSIONS
Adenovirus-mediated ING4 gene exhibits anti-tumor ability in human prostate cancer PC-3 cells in vitro and in vivo, and induces apoptosis. This may be related to the up-regulations of p53, bax, Caspase-3 and down-regulation of bcl-2.
Yang
Hui-Cui
HC
Cell and Molecular Biology Institute, College of Medicine, Soochow University, Jiangsu, P. R. China.
Sheng
Wei-Hua
WH
Xie
Yu-Feng
YF
Miao
Jing-Cheng
JC
Wei
Wen-Xiang
WX
Yang
Ji-Cheng
JC
D000256:Adenoviridae / Q000235:genetics; D000818:Animals; D017209:Apoptosis; D053148:Caspase 3 / Q000235:genetics / Q000378:metabolism; D018797:Cell Cycle Proteins / Q000235:genetics* / Q000378:metabolism / Q000502:physiology; D045744:Cell Line, Tumor; D049109:Cell Proliferation; D005822:Genetic Vectors; D018398:Homeodomain Proteins / Q000235:genetics* / Q000378:metabolism / Q000502:physiology; D006801:Humans; D008297:Male; D051379:Mice; D008807:Mice, Inbred BALB C; D008819:Mice, Nude; D009368:Neoplasm Transplantation; D011471:Prostatic Neoplasms / Q000378:metabolism / Q000473:pathology*; D019253:Proto-Oncogene Proteins c-bcl-2 / Q000235:genetics / Q000378:metabolism; D012333:RNA, Messenger / Q000378:metabolism; D011897:Random Allocation; D014162:Transfection; D047368:Tumor Burden; D016159:Tumor Suppressor Protein p53 / Q000235:genetics / Q000378:metabolism; D025521:Tumor Suppressor Proteins / Q000235:genetics* / Q000378:metabolism / Q000502:physiology; D051028:bcl-2-Associated X Protein / Q000235:genetics / Q000378:metabolism
D018797:Cell Cycle Proteins; D018398:Homeodomain Proteins; C483230:ING4 protein, human; D019253:Proto-Oncogene Proteins c-bcl-2; D012333:RNA, Messenger; D016159:Tumor Suppressor Protein p53; D025521:Tumor Suppressor Proteins; D051028:bcl-2-Associated X Protein; D053148:Caspase 3