Extracellular vesicles from human umbilical cord mesenchymal stem cells treated with siRNA against ELFN1-AS1 suppress colon adenocarcinoma proliferation and migration

Recent evidence has shown that long noncoding RNAs (lncRNAs) play major roles in tumorigenesis and cancer progression. The cancer genome atlas program (TCGA) database was used to screen colon adenocarcinoma (COAD)-related differentially expressed lncRNAs, which revealed that lncRNA ELFN1-AS1 was highly expressed in COAD. This study aimed to explore the regulatory role of ELFN1-AS1 in COAD and construct a gene delivery system based on extracellular vesicles (EVs). We found that ELFN1-AS1 levels were obviously increased in COAD patients and COAD tumor cells. Knockdown of ELFN1-AS1 expression by siRNA inhibited COAD cell proliferation and migration. Moreover, silencing ELFN1-AS1 significantly reduced the activation of extracellular signal-regulated protein kinase (Erk), up-regulated the protein expression of E-cadherin and down-regulated vimentin. In addition, we treated human umbilical cord mesenchymal stem cells (hUCMSCs) with siRNA-ELFN1-AS1 and found that EVs from siRNA-ELFN1-AS1-treated hUCMSCs could inhibit COAD cell proliferation and migration in vitro. These findings suggested that ELFN1-AS1 could promote the progression of COAD and that hUCMSC-EVs might be an attractive vehicle for the clinical administration of lncRNA-specific siRNAs in patients with COAD.