The linc00501-HSP90B1-STAT3 positive feedback loop promotes malignant behavior in gastric cancer cells.

Long non-coding RNAs (lncRNAs) have been implicated in gastric cancer (GC) carcinogenesis and progression. However, the role of linc00501 in GC growth and metastasis remains unclear. In this study, we found that linc00501 was frequently upregulated in GC cells and tissues and was closely related to adverse GC clinicopathological features. Aberrant overexpression of linc00501 promoted GC cell proliferation, invasion, and metastasis both in vitro and in vivo. Mechanistically, linc00501 stabilized client protein STAT3 from deubiquitylation by directly interacting with cancer chaperone protein HSP90B1. Furthermore, the linc00501-STAT3 axis modulated GC cell proliferation and metastasis. In turn, STAT3 bound directly to the linc00501 promoter and positively activated linc00501 expression, thus forming a positive feedback loop, thereby accelerating tumor growth, invasiveness, and metastasis. In addition, linc00501 expression was positively correlated with STAT3 and p-STAT3 protein expression levels in gastric clinical samples. Our results reveal that linc00501 acts as an oncogenic lncRNA and that the linc00501-HSP90B1-STAT3 positive feedback loop contributes to GC development and progression, suggesting that linc00501 may be a novel potential biomarker and treatment target for GC.