THE UPREGULATION OF PROTEINS LIGHT CHAIN 3 AND AUTOPHAGY-RELATED 5 AND THE OCCURRENCE OF INTESTINAL-TYPE GASTRIC CANCER

This study aims to investigate the expression levels and values of autophagy genes light chain 3 (LC3) and autophagy-related 5 (ATG5) in intestinal-type gastric cancer. Ninety samples of normal gastric mucosa, intraepithelial neoplasia, and gastric cancer tissue were used in this study. The messenger ribonucleic acid (mRNA) and protein expression levels of autophagy genes LC3 and ATG5 were detected using quantitative reverse transcription polymerase chain reaction, Western blot, and the immunohistochemistry method. The correlations of the autophagy genes and certain clinical pathological parameters were analyzed. The results showed that LC3 mRNA expression was 43.76 +/- 20.31 in the normal group, 111.29 +/- 18.65 in the intraepithelial neoplasia group, and 131.78 +/- 26.29 in the gastric cancer group, while ATG5 mRNA expression was 4.52 +/- 2.37 in the normal group, 7.09 +/- 1.88 in the intraepithelial neoplasia group, and 10.25 +/- 2.81 in the gastric cancer group. The differences between the groups were statistically significant (P < 0.05). The protein expression of LC3 in the normal group was 1.05 +/- 0.41, 1.53 +/- 0.36 in the intraepithelial neoplasia group, and 1.99 +/- 0.14 in the gastric cancer group. The protein expression of ATG5 was 0.78 +/- 0.24 in the normal group, 1.37 +/- 0.39 in the intraepithelial neoplasia group, and 2.04 +/- 0.63 in the gastric cancer group. The differences between the groups were statistically significant (P < 0.05). The positive rate of LC3 protein expression was 33.3% in the normal group and 60% in the intraepithelial neoplasia group, and the difference was statistically significant (chi(2) = 4.89; P = 0.04). In the gastric cancer group, the positive rate of LC3 protein expression was 83.3%, making it significantly higher than the intraepithelial neoplasia group, with a statistically significant difference (chi(2) = 4.02, P = 0.045). The positive rate of ATG5 protein expression was 23.3% in the normal group, 50.0% in the intraepithelial neoplasia group, and 76.7% in the gastric cancer group. The expression in the intraepithelial neoplasia group was much higher than in the normal group, with a statistically significant difference (chi(2) = 4.59, P = 0.03), and that of the gastric cancer group was much higher than that of the intraepithelial neoplasia group, with a statistically significant difference (chi(2) = 4.59, P = 0.03). LC3 protein expression was significantly correlated with depth of infiltration, and lymph node status. ATG5 protein expression was significantly correlated with age, depth of infiltration, and lymph node status. There was also a correlation between the LC3 and ATG5 proteins (correlation coefficient r = 0.72, P = 0.001). The enhanced autophagy activity of LC3 and ATG5 may participate in the occurrence and development of intestinal gastric cancer, and they may play a synergistic role in promoting the occurrence and development of intestinal gastric cancer. These findings provide clinical value for the diagnosis of intestinal gastric cancer.