LncRNA H19-rich extracellular vesicles derived from gastric cancer stem cells facilitate tumorigenicity and metastasis via mediating intratumor communication network.

ABSTRACT

BACKGROUND: Extracellular vesicles (EVs) transport biologically active molecules, and represent a recently identified way of intercellular communication. Recent evidence has also reported that EVs shed by cancer stem cells (CSCs) make a significant contribution to carcinogenesis and metastasis. Here, this study aims to explore the possible molecular mechanism of CSCs-EVs in gastric cancer (GC) by mediating intratumor communication network. METHODS: CSCs and non-stem cancer cells (NSCCs) were sorted from GC cells, and EVs were isolated from CSCs. H19 was knocked down in CSCs, and CSCs-EVs or CSCs-EVs containing shRNA-H19 (CSCs-EVs-sh-H19) were co-cultured with NSCCs, followed by evaluation of the malignant behaviors and stemness of NSCCs. Mouse models of GC were established and injected with CSCs-EVs from sh-H19-treated NSCCs in vivo. RESULTS: CSCs had notable self-renewal and tumorigenic capacity compared with NSCCs. CSCs promoted the malignant behaviors of NSCCs and expression of stemness marker proteins through secretion of EVs. Inhibited secretion of CSCs-EVs curtailed the tumorigenicity and metastasis of NSCCs in vivo. H19 could be delivered by CSCs-EVs into NSCCs. H19 promoted the malignant behaviors of NSCCs and stemness marker protein expression in vitro along with tumorigenicity and liver metastasis in vivo, which was mechanistically associated with activation of the YAP/CDX2 signaling axis. CONCLUSION: Taken together, the present study points to the importance of a novel regulatory axis H19/YAP/CDX2 in carcinogenic and metastatic potential of CSCs-EVs in GC, which may be potential targets for anticancer therapy.