Elevated expression of immunity-related GTPase family M in gastric cancer

Recent researches have suggested that autophagy may play critical roles in tumorigenesis. Immunity-related GTPase family M (IRGM) is a human protein highlighted for its contribution to autophagy upon inflammation and infections. Studies have shown that IRGM is involved in the development of several cancers. In the current study, we investigated expression of IRGM and gastric cancer. Levels of messenger RNA (mRNA) and protein were examined by real-time reverse transcription PCR (RT-PCR) and Western blot, respectively. Data showed that mRNA level of IRGM was significantly increased in peripheral blood mononuclear cells (PBMCs) of gastric cancer patients than in PBMCs from healthy controls (p > 0.05). Moreover, both mRNA and protein levels were significantly higher in cancer tissues compared to adjacent noncancerous stomach tissues (1.28-fold, p < 0.001; 1.19-fold, p < 0.01, respectively). However, the level of IRGM seemed not to be affected by Helicobacter pylori infection. In addition, we investigated the correlation between IRGM expression and cancer stages and identified that stage IV patients had upregulated mRNA level and protein level of IRGM in cancer tissues than those stage I patients. Our findings suggest that expression of IRGM is dysregulated in gastric cancer and that the molecule may affect progression of the disease.