Expression of the sensitive to apoptosis gene, SAG, as a prognostic marker in nonsmall cell lung cancer

Abstract

Inhibition of programmed cell death (apoptosis) is associated with increased tumor aggressiveness. We hypothesized that a novel sensitive to apoptosis gene, SAG, may be expressed in tumors of patients with nonsmall cell lung cancer (NSCLC) and may affect their clinical outcome. Expression of SAG messenger RNA was evaluated by reverse transcription polymerase chain reaction in 80 nonsmall cell lung carcinomas and 65 adjacent histologic nonmalignant lung samples using a LightCycler. The data were analyzed in reference to clinicopathologic data and survival. The SAG/GAPDH mRNA level in 80 NSCLC was 2.337 +/- 1.972. Of 65 paired NSCLC and nonmalignant lung samples, SAG/GAPDH mRNA levels were 2.313 +/- 2.064 and 1.696 +/- 1.910, respectively. The SAG mRNA level was significantly higher in NSCLC compared with nonmalignant lung tissue (p = 0.0169). There was no relationship between SAG gene expression and age, gender, T- or N-status or clinical stages. The NSCLC patients with high SAG/GAPDH expression (>1.8) had significantly poorer survival than the patients with low SAG/GAPDH expression (<1.8, p = 0.0227). Thus we suggest that SAG gene expression in NSCLC may be a useful prognostic marker.