Abstract
HOOK3, a member of the human hook microtubule-tethering protein family, has been implicated in the progression of cancer. However, the role of HOOK3 in the pathogenesis of gastric cancer (GC) remains incompletely understood. In this study, we investigated the expression of HOOK3 protein in GC tissues using immunohistochemistry (IHC). The findings of our study indicate that the expression levels of HOOK3 in GC tissues were relatively low. Furthermore, a significant negative association was seen between HOOK3 expression and the prognosis of patients with GC. The suppression of HOOK3 resulted in a notable increase in the proliferation, migration, invasion, and survival of GC cells. Conversely, the overexpression of HOOK3 had the opposite impact, reducing these cellular processes. Moreover, in vivo tests have shown evidence that the overexpression of HOOK3 significantly inhibited the formation of tumors and the spread of GC cells to the lungs. In a mechanistic manner, the analysis of RNA-seq data demonstrated that the knockdown of HOOK3 resulted in a notable increase in the expression of vascular endothelial growth factor A (VEGFA) in GC cells. Furthermore, the upregulation of VEGFA counteracted the impacts of HOOK3 upregulation on the proliferation, migration, invasion, and survival of GC cells. Furthermore, it was revealed that specificity protein 1 (SP1) exhibited the ability to bind to the promoter region of VEGFA. Moreover, the overexpression of SP1 successfully counteracted the inhibitory impact of HOOK3 overexpression on the expression of VEGFA in GC cells. In summary, the results of our study indicate that HOOK3 has a role in inhibiting the growth, migration, invasion, and survival of GC cells by modulating the SP1/VEGFA pathway. These findings contribute significant knowledge to our understanding of the underlying mechanisms involved in the development of GC.