[Expression of caspase-8    in non-small cell lung cancer and its  role in   invasion and metastasis of lung cancer A549 cells].
OBJECTIVE
To explore the expression of caspase-8 in non-small cell lung cancer (NSCLC) tissue, and its role in invasion and metastasis of lung cancer A549 cells.


METHODS
The expression of caspase-8 in the lung cancer tissues was detected by immunohistochemistry. RNA interference technology was used to silence the expression of caspase-8 in lung cancer A549 cells to explore the function of caspase-8 protein in invasion and metastasis of cancer cells by means of Western blot, Transwell and scratch migration assays.


RESULTS
The expression of  caspase-8 was found  in 38/52 cancer tissues,  22/30 adjacent tissues and 34/52 normal tissues. The tissues number of caspase-8  positive-expression  in different groups was  similar, but the intensity of caspase-8 expression in different groups was  statistically different(P<0.05).   In cancer tissues, the expression of caspase-8 indicated  more likely to have lymph node-metastasis  and worse clinical stage(P<0.05).   After RNA interference,  we successfully silenced the expression of caspase-8 in the lung cancer A549 cell,  and this was confirmed by Western blotting.   Transwell and cell scratch test  showed  that without the expression of caspase-8 A549 cells  had a lower   invasion and metastasis    abilities  compared to the control cells  (P<0.05).


CONCLUSIONS
Caspase-8 is not only an apoptosis protein, but  has non-apoptosis function,  such as promoting invasion and metastasis of  lung cancer A549 cell. In NSCLC,  it more likely locates in nucleus. And its expression in NSCLC may indicate a later  clinical  stage and a higher  probability of  lymph node metastasis.
Department of Thoracic Oncosurgery, Xi'an Jiaotong University, Xi'an, China.
Ning
N
Du
Xiang-fei
XF
Sun
Li-juan
LJ
Hu
Xin
X
Sun
Xiao-jun
XJ
Li
Yang
Y
Zhao
Hong
H
Ren
D000328:Adult; D000368:Aged; D002289:Carcinoma, Non-Small-Cell Lung / Q000201:enzymology* / Q000235:genetics / Q000473:pathology*; D053181:Caspase 8 / Q000235:genetics / Q000378:metabolism*; D045744:Cell Line, Tumor; D005260:Female; D015972:Gene Expression Regulation, Neoplastic; D006801:Humans; D008175:Lung Neoplasms / Q000201:enzymology* / Q000235:genetics / Q000473:pathology*; D008297:Male; D008875:Middle Aged; D009361:Neoplasm Invasiveness; D009362:Neoplasm Metastasis; D009367:Neoplasm Staging
D053181:Caspase 8