Abstract 1987: Exosome from CAF-ESCC aggravates tumor progression by its containing molecular miR-3656

Abstract

Abstract Background: Exosome plays an important role in cell communication and cell environment. But the mechanism of how exosome derived from cancer-associated fibroblast (CAF) influent esophageal squamous cell carcinoma (ESCC) progression is not clear. In this work, compared with normal fibroblast-derived exosomes (NDEs), we found that CAF derived exosomes (CDEs) can enhance the growth, migration, and invasion of ESCC cells obviously. Therefore, we would like to clarify the role of CDEs in ESCC progression. Methods and Results: Using microRNA array to analyze the different miRNAs in the CDEs and NDEs, we got a series of up-regulation miRNAs and two down-regulation miRNAs in CDEs. Among them, miR-3656 shows a significantly highest level. Then, we transfected miR-3656 mimics to the ESCC cells and found the mimics increased the growth, migration, and invasion of ESCC cells in cell proliferation assay. cell scratch tests and chamber invasion experiments. We established recombinant ESCC cells with miR-3656 high expression by the lentiviral system. The cells were injected into mice to form the xenograft tumor. The results showed the miR-3656 can enhance the tumor formation. After that, aided by TargetScan software, we found ACAP2, one of miR3656 targets, was significantly down-regulating in ESCC cells at the high level of miR-3656. When ACAP2 expression was knocked-down by siRNA, the proliferation and migration of ESCC cells was increased, which indicated ACAP2 a potential anti-tumor factor. Furthermore, we detected the different proteins between ESCC cells with high expression miR-3656 and normal ESCC cells through LC_MS; the results were analyzed by Integrate Pathway Analysis (IPA) system and many differential proteins were found to be involved of PI3K/AKT and Wnt pathways. Conclusions: In this study, we found the CDEs promote the progression of their sounding ESCC cells in vitro and in vivo. The main reason is that CDEs carry some tumor-promoting miRNAs that influent the target ESCC cells. Especially, miR-3656 expresses the highest level of miRNAs in CDEs. It not only decreases the expression of ACAP2 but also impacts the expression of proteins involved PI3K/AKT and Wnt pathways in ESCC cells. The results indicate the CDEs playing a very important role in ESCC progression. Citation Format: Xiaojia Chen, Yuan Jin, Bihui Zhang, Xiaocen LI, Baoqing Tian, Qiang Wang, An Hong. Exosome from CAF-ESCC aggravates tumor progression by its containing molecular miR-3656 [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 1987.