Autophagy Activity in Pulmonary Metastatic Tumor Tissues from Colorectal Cancer: A Pilot Study

PURPOSE: Autophagy has been reported to be involved in treatment failure in tumor. We aimed to evaluate autophagy activity in tumor tissue and compare them between the recurrence and non-recurrence groups. MATERIALS AND METHODS: We analyzed expressions of autophagy-related proteins in tumor tissues which were obtained from pulmonary metastases of colorectal cancer patients by Western blot. We also analyzed autophagosomes by transmission electron microscopy. RESULTS: Tumor tissues from recurrence group showed increased levels of LC3B-II, decreased levels of p62/SQSTM1, and also a marked accumulation of autophagosomes compared with tissues from non-recurrence group. CONCLUSION: The present study suggests that autophagy may be associated with treatment failure of metastatic colorectal cancer.