[Inhibitory effect of interference hTERT and TRF2 gene on the growth of breast cancer MCF-7 cells].
OBJECTIVE
To explore the effect of combined gene therapy with interference hTERT and TRF2 gene on the treatment of breast cancer.


METHODS
Recombinant adenovirus rAd-hTERT and rAd-TRF2 expressing siRNA-hTERT and siRNA-TRF2 was constructed, and the vectors were transfected into MCF-7 cells. Than the expressions of hTERT and TRF2 proteins were detected by Western blot, the inhibition of MCF-7 cell proliferation by MTT colorimetry, and the changes of MCF-7 cell cycle by flow cytometry and the colony forming ability of MCF-7 cells by clone form test.


RESULTS
At 48 h after transfection, the relative expression amounts of hTERT protein of the PBS control group, rAd-blank group, rAd-HK control group, rAd-hTERT group, rAd-TRF2 group and rAd-hTERT and rAd-TRF2 group were 1.00, 0.94 +/- 0.02, 0.95 +/- 0.04, 0.18 +/- 0.04, 0.95 +/- 0.01 and 0.18 +/- 0.04, respectively. The relative expression amounts of TRF2 protein were 1.00, 1.01 +/- 0.08, 0.96 +/- 0.02, 0.95 +/- 0.08, 0.22 +/- 0.01 and 0.26 +/- 0.02, respectively. After transfection of rAd-hTERT or rAd-TRF2 into MCF-7 cells separately, the inhibition rate of cell proliferation was only 54.6% and 48.4%, there was 8.9% +/- 1.2% or 9.2% +/- 2.3% of MCF-7 cells into M phase, 66.4% +/- 1.5% or 64.6% +/- 1.9% of MCF-7 cells was arrested at G(0)/G(1) phase, and the cell colony forming ability was decreased significantly (cell colony number from 100 in PBS control group down to 41.3 +/- 5.1 and 43.7 +/- 6.4). But after transfection by rAd-hTERT and rAd-TRF2 simultaneously, the inhibition rate of cell proliferation was about 82.1%, and M phase cells was significantly reduced to 4.4% +/- 1.2%. Large numbers of cells were arrested at G(0)/G(1) phase (81.4% +/- 1.3%), and the cell colony forming ability was more significantly decreased (cell colony number there were only 29.2 +/- 3.9).


CONCLUSIONS
More effective effect of tumor gene therapy can be achieved by combination of interference hTERT and TRF2 genes as compared with interference by either of the single gene alone.
Chen
Shao-kun
SK
Department of Medical Genetics, Luzhou Medical College, China.
Liu
Lan
L
Shui
Qin-lin
QL
Yu
Hong
H
Zeng
Yong-qiu
YQ
Zhao
Jiao
J
D000256:Adenoviridae / Q000235:genetics; D001943:Breast Neoplasms / Q000235:genetics / Q000378:metabolism / Q000473:pathology*; D002453:Cell Cycle; D045744:Cell Line, Tumor; D049109:Cell Proliferation; D005260:Female; D015972:Gene Expression Regulation, Neoplastic; D015316:Genetic Therapy; D005822:Genetic Vectors; D006801:Humans; D034622:RNA Interference; D034741:RNA, Small Interfering / Q000235:genetics; D019098:Telomerase / Q000235:genetics* / Q000378:metabolism; D035341:Telomeric Repeat Binding Protein 2 / Q000235:genetics* / Q000378:metabolism; D014162:Transfection; D014410:Tumor Stem Cell Assay
D034741:RNA, Small Interfering; D035341:Telomeric Repeat Binding Protein 2; C509186:TERT protein, human; D019098:Telomerase