Loss of MTUS1 in gastric cancer promotes tumor growth and metastasis.

Though the overall incidence of gastric cancer was decreasing in the developed countries in the past decades, it is still a serious threat to human health throughout the world. The molecular mechanisms underlying development of gastric cancer remains unclear. Though accumulating evidences shed a light on the implications of mitochondrial tumor suppressor (MTUS1) in carcinogenesis, the functional role of MTUS1 in regulation of proliferation and metastasis of gastric cancer cell is still poorly understood. In this study, we showed that the level of MTUS1 expression is relatively low in gastric cancer cell lines compared to normal gastric epithelial cells. By using clinical samples, we found that MTUS1 expression is downregulated in tumor tissues compared to non-cancerous counterpart, and loss of MTUS1 was associated with high incidence of lymph node metastasis and poor patient outcome. Moreover, we demonstrate that MTUS1 has a significant impact on both the proliferative and metastatic potential of gastric cancer cell line, which were further supported by using mice tumor xenograft models. The present data suggested MTUS1 as a potential tumor suppressor in gastric cancer and might lead to a better understanding of gastric carcinogenesis.