[Expression of caspase-8 in non-small cell lung cancer and its role in invasion and metastasis of lung cancer A549 cells]
ABSTRACT 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.
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.
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).
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.