[Expression of autophagy-related genes Beclin1 and MAPLC3 in non-small cell lung cancer]

Some studies have indicated that the down-regulation of autophagy-related genes might result in tumorigenesis. This study was to investigate the expression and significance of autophagy-related genes Beclin1 and microtubule-associated protein 1 light chain 3 (MAPLC3) in human non-small cell lung cancer (NSCLC).

The expression of Beclin1 and MAPLC3 in tumor tissues, adjacent non-cancerous tissues, and normal tissues from 72 specimens of NSCLC were detected by immunofluorescence staining, Western blot, and reverse transcription-polymerase chain reaction (RT-PCR).

The positive rates of Beclin1 and MAPLC3 were significantly lower in NSCLC tissues than in adjacent non-cancerous tissues and normal tissues (8.3% vs. 100% and 100% for Beclin1, chi2=199.40, P<0.01; 13.9% vs. 100% and 100%for MAPLC3, chi2=182.75, P<0.01). The mRNA levels of Beclin1 and MAPLC3 were significantly lower in NSCLC tissues than in adjacent non-cancerous tissues and normal tissues (1.30+/- 0.44 vs. 1.69+/-0.59 and 1.67+/-0.48 for Beclin1, F=6.6, P<0.01; 4.55+/-1.23 vs. 6.73+/-1.31 and 6.90+/-1.87 for MAPLC3, F=14.1, P<0.01). The protein levels of Beclin1 and MAPLC3 were significantly lower in NSCLC tissues than in adjacent non-cancerous tissues and normal tissues (3.49+/-0.72 vs. 5.31+/-1.16 and 6.33+/-1.58 for Beclin1, F=9.73, P<0.01; 2.43+/-0.35 vs. 3.12+/-0.73 and 3.41+/-0.90 for MAPLC3, F=3.22, P=0.04).

The expression of autophagy-related genes are down-regulated in NSCLC, which may relate to tumorigenesis and development of lung cancer.