1. Department of Liver Surgery and Transplantation, Liver Cancer Institute, Zhongshan Hospital, Fudan University; Key Laboratory of Carcinogenesis and Cancer Invasion (Fudan University), Ministry of Education; Shanghai Key Laboratory of Organ Transplantation, Zhongshan Hospital, Fudan University, Shanghai, 200032, China.
2. Institute of Biomedical Sciences, Fudan University, Shanghai, 200032, China.
3. State Key Laboratory of Genetic Engineering, Fudan University, Shanghai, 200032, China.
4. Department of Clinical Laboratory, Shanghai Pudong New Area Gongli Hospital, Shanghai, 200135, China.
*These authors contributed equally to this work and share first authorship.
Hepatocellular carcinoma (HCC) is a major cause of cancer-related death worldwide. Although it has been known that hepatic stellate cells (HSCs) play critical roles in the development and progression of HCC, the molecular mechanism underlying crosstalk between HSCs and cancer cells still remains unclear. Here, we investigated the interactions between HSCs and cancer cells through an indirect co-culture system. The expressions of cellular and exosomal miR-148a-3p were evaluated by quantitative real-time PCR. Cell counting kit-8 was used for evaluating cell growth in vitro. Cell migration and invasion ability were evaluated by wound-healing and Transwell assays. Western blot, quantitative real-time PCR and Luciferase reporter assay were performed to determine the target gene of miR-148a-3p. A xenograft liver cancer model was established to study the function of exosomal miR-148a-3p in vivo.
We found that miR-148a-3p was downregulated in co-cultured HSCs and overexpression of miR-148a-3p in HSCs impaired the proliferation and invasiveness of HCC both in vitro and in vivo. Moreover, further study showed that the miR-148a-3p was also downexpressed in HSCs-derived exosomes, and increased HSCs-derived exosomal miR-148a-3p suppressed HCC tumorigenesis through ITGA5/PI3K/Akt pathway. In conclusion, our study demonstrated that exosome-depleted miR-148a-3p derived from activated HSCs accelerates HCC progression through ITGA5/PI3K/Akt axis.
Keywords: Exosome, MiR-148a-3p, Hepatic stellate cells, Hepatocellular carcinoma, Tumor microenvironment