HOTTIP expression was remarkably increased in GC tissues and cell lines compared with that in the normal control. Clinicopathologic analysis revealed that high HOTTIP expression correlated with larger tumor size, deeper invasion depth, positive lymph node metastasis, advanced TNM stage, and shorter overall survival. Multivariate regression analysis identified HOTTIP overexpression as an independent unfavorable prognostic factor in GC patients. Moreover, HOTTIP downregulation by si-HOTTIP transfection impaired GC cell proliferation, promoted cell apoptosis, and reduced cell invasion and migration