Clinical significance of Smac expression on non-small cell lung cancers
ABSTRACT ObjectiveThe aim of our study was to investigate the clinical significance of Smac (second mitochondria-derived activator of caspase)
expression on non-small cell lung cancer (NSCLC).
MethodsThe expression of Smac was evaluated on RNA and protein level in tumor tissues. The expression of Smac mRNA was examined by
RT-PCR in 59 samples of tumor tissues and matched normal lung tissues. The expression of Smac protein was examined by IHC
in 213 cancer tissues.
ResultsThe positive rate of Smac mRNA was found in 59.3% of cancer tissues, but only in 30.5% of matched normal tissues (P < 0.05). The positive rate of Smac protein was 76.5%. The expression of Smac in stage II disease was significantly higher
than that in stage I disease (P = 0.001). The survival of patients with Smac overexpression was significantly shorter than those who were negative.
ConclusionSmac might be involved in the progression of NSCLC, the biologic significance of Smac in primary lung cancer needs further
Key wordsSmac–non-small cell lung cancer (NSCLC)–RT-PCR–IHC