[Effect of siRNA-mediated beta-catenin gene on Wnt signal pathway in lung adenocarcinoma A549 cell].
OBJECTIVE
To study the effects of siRNA-mediated beta-catenin down-regulation on Wnt/beta-catenin signal transduction pathway in lung adenocarcinoma A549 cells.


METHODS
A549 cell was divided into three groups: PGCsil-CTNNB1-siRNA group (transfection with beta-catenin interference plasmids), negative control group (transfection with negative control plasmids) and non-transfection group (blank control). For each group, real-time PCR was employed to detect the expression of beta-catenin and cyclin D1 (a target gene of Wnt/beta-catenin pathway). A MTT cell proliferation assay was performed to study the proliferating capacity. Flow cytometry was used for cell cycle analysis. Clone formation and Millicell chamber experiment were performed to evaluate the clone formation and migration capacities of cells.


RESULTS
The expression of beta-catenin and cyclin D1 in PGCsil-CTNNB1-siRNA cell decreased at the mRNA level. It was lower than negative control (0.002+/-0.001 vs 0.023+/-0.002, P<0.01; 0.005+/-0.002 vs 0.040+/-0.020, P<0.05) and blank control groups (beta-catenin mRNA: 0.021+/-0.003, P<0.01; cyclin D1 mRNA: 0.042+/-0.004, P<0.05). Also the proliferating capacity at Days 5-7 was inhibited in comparison with negative control and blank control groups (P<0.05, P<0.01). The cell-doubling time (58.1 h) was markedly longer than those of negative control group (37.9 h, P<0.05) and blank control group (34.2 h, P<0.05). The number of cells in G0-G1 phrase increased in PGCsil-CTNNB1-siRNA group (86.4%+/-2.6%) in comparison with negative control (73.8%+/-0.9%, P<0.01) and blank control groups (75.8%+/-1.5%, P<0.01). In PGCsil-CTNNB1-siRNA group, the clone formation ratio (31.6%+/-7.7%) was lower than negative control (46.9%+/-7.3%, P<0.05) and blank control groups (44.2%+/-2.5%, P<0.05). And the number of cells (16.0+/-3.8) passing through the membrane of Millicell chamber was smaller than negative control (32.7+/-3.1, P<0.01) and blank control groups (33.0+/-2.7, P<0.01).


CONCLUSIONS
Knocking down beta-catenin not only inhibits the Wnt/beta-catenin signal transduction pathway in lung adenocarcinoma A549 cells but also decreases cell proliferation, clone formation and migration capacity. Thus it may become a novel target for lung cancer therapy.
Teng
Ying
Y
Department of Chemotherapy, Cancer Center, Qilu Hospital, Shangdong University, Jinan 250012, China.
Wang
Xiu-wen
XW
Wang
Ya-wei
YW
Wang
Jian
J
D000230:Adenocarcinoma / Q000235:genetics / Q000378:metabolism* / Q000473:pathology; D045744:Cell Line, Tumor; D049109:Cell Proliferation; D015536:Down-Regulation; D015972:Gene Expression Regulation, Neoplastic; D006801:Humans; D008175:Lung Neoplasms / Q000235:genetics / Q000378:metabolism* / Q000473:pathology; D034741:RNA, Small Interfering; D015398:Signal Transduction; D014162:Transfection; D051153:Wnt Proteins / Q000378:metabolism*; D051176:beta Catenin / Q000235:genetics / Q000378:metabolism*
C495270:CTNNB1 protein, human; D034741:RNA, Small Interfering; D051153:Wnt Proteins; D051176:beta Catenin