Gastric cancer is one of the most lethal
malignancies of
gastrointestinal cancer and its prognosis remains dismal because of the paucity of effective therapeutic targets. Here, we show that
cystatin 4 (CST4) is markedly upregulated in
gastric cancer cell lines and clinical tissues. Ectopic expression of CST4 in
gastric cancer cells promoted proliferation, migration, and invasion of
gastric cancer cells in vitro. Furthermore, CST4 overexpression significantly promoted the tumorigenicity of
gastric cancer cells in vivo, whereas silencing endogenous CST4 caused an opposite outcome. In addition, extracellular
leucine rich repeat and fibronectin type III domain containing 2 (ELFN2) was identified as a downstream target of CST4 in
gastric cancer cells and was positively correlated with ELFN2 expression in
gastric cancer tissues. Finally, we demonstrated that CST4 enhanced
gastric cancer aggressiveness by regulating ELFN2 signaling. Together, our results provide new evidence that CST4 overexpression promotes the progression of
gastric cancer and might represent a novel therapeutic target for its treatment.