Highly-metastatic colorectal cancer cell released miR-181a-5p-rich extracellular vesicles promote liver metastasis by activating hepatic stellate cells and remodelling the tumour microenvironment.

Liver metastasis of colorectal cancer (CRLM) is the most common cause of CRC-related mortality, and is typically caused by interactions between CRC cells and the tumour microenvironment (TME) in the liver. However, the molecular mechanisms underlying the crosstalk between tumour-derived extracellular vesicle (EV) miRNAs and the TME in CRLM have yet to be fully elucidated. The present study demonstrated that highly metastatic CRC cells released more miR-181a-5p-rich EVs than cells which exhibit a low metastatic potential, in-turn promoting CRLM. Additionally, we verified that FUS mediated packaging of miR-181a-5p into CRC EVs, which in-turn persistently activated hepatic stellate cells (HSCs) by targeting SOCS3 and activating the IL6/STAT3 signalling pathway. Activated HSCs could secrete the chemokine CCL20 and further activate a CCL20/CCR6/ERK1/2/Elk-1/miR-181a-5p positive feedback loop, resulting in reprogramming of the TME and the formation of pre-metastatic niches in CRLM. Clinically, high levels of serum EV containing miR-181a-5p was positively correlated with liver metastasis in CRC patients. Taken together, highly metastatic CRC cells-derived EVs rich in miR-181a-5p could activate HSCs and remodel the TME, thereby facilitating liver metastasis in CRC patients. These results provide novel insight into the mechanism underlying liver metastasis in CRC.

Zhao S ，Mi Y ，Zheng B ，Wei P ，Gu Y ，Zhang Z ，Xu Y ，Cai S ，Li X ，Li D ... -  《Journal of Extracellular Vesicles》

Colorectal cancer cell-derived extracellular vesicles transfer miR-221-3p to promote endothelial cell angiogenesis via targeting suppressor of cytokine signaling 3.

Secreted microRNAs (miRNAs) can serve as promising diagnostic markers for colorectal cancer (CRC). Herein, we evaluated the potential clinical significance of a signature of four circulating serum-derived miRNAs in CRC. We also demonstrated that extracellular vesicles (EVs) containing miR-221-3p could facilitate endothelial cell angiogenesis. The expressions of four circulating serum-derived miRNAs (miR-19a-3p, miR-203-3p, miR-221-3p, and let-7f-5p) were measured by real-time quantitative PCR, and their associations with lymph node metastasis were determined in CRC patients. Receiver operating characteristic curve analysis was used to determine their diagnostic accuracy. EVs were isolated and characterized from the conditioned media of human CRC cells (HCT116 and Caco2). Cell proliferation, transwell migration, and tube formation assays were performed to investigate the pro-angiogenic effect of miR-221-3p transferred by CRC-EVs into the endothelial cells. In silico analysis was used to show the regulatory functions of miR-221-3p on SOCS3, validated by luciferase and Western blotting assays. The expression levels of serum-derived miR-19a-3p, miR-203-3p, miR-221-3p, and let-7f-5p were significantly higher in CRC than in healthy individuals. The expression of miR-19a-3p, miR-203-3p, and miR-221-3p were positively correlated with the lymph node metastasis status. Moreover, SOCS3 was identified as a direct target of miR-221-3p and the secreted miR-221-3p shuttled by CRC-EVs regulated STAT3/VEGFR-2 signaling axis by targeting SOCS3 in endothelial cells. CRC-EVs promoted endothelial cell proliferation, migration, and the formation of vessel-like structures. The proangiogenic effect of CRC-EVs on the cells was recapitulated by miR-221-3p overexpression, showing the importance of EVs-derived miR-221-3p in promoting endothelial cell angiogenesis. We introduced a signature of four-circulating miRNAs (miR-19a-3p, miR-203-3p, miR-221-3p, and let-7f-5p) as a novel diagnostic biomarker for CRC. Besides, we revealed that miR-221-3p induces endothelial cell angiogenesis in vitro by targeting SOCS3.

Dokhanchi M ，Pakravan K ，Zareian S ，Hussen BM ，Farid M ，Razmara E ，Mossahebi-Mohammadi M ，Cho WC ，Babashah S ... -  《-》

Exosomal miR-106a-5p from highly metastatic colorectal cancer cells drives liver metastasis by inducing macrophage M2 polarization in the tumor microenvironment.

The tumor microenvironment (TME) is a dynamic system orchestrated by intricate cell-to-cell crosstalk. Specifically, macrophages within the TME play a crucial role in driving tumor progression. Exosomes are key mediators of communication between tumor cells and the TME. However, the mechanisms underlying exosome-driven crosstalk between tumor cells and macrophages during colorectal cancer (CRC) progression remain incompletely elucidated. Single-cell RNA sequencing were analyzed using the Seurat package. Exosomes were isolated using ultracentrifugation and characterized by transmission electron microscopy, nanoparticle tracking analysis, and western blot. miRNAs differentially expressed in exosomes were analyzed using the limma package. CD206 expression in CRC tissues, exosomes tracing, and exosomal miR-106a-5p transport were observed through immunofluorescence. Macrophage polarization was assessed via qRT-PCR, ELISA, and flow cytometry. The interactions between miR-106a-5p, hnRNPA1, and SOCS6 were evaluated using miRNA pull-down, RIP, and dual-luciferase reporter assays. Transwell assays and liver metastasis model explored the role of exosomal miR-106a-5p-induced M2 macrophages in promoting CRC liver metastasis. The proportion of M2 macrophages is increased in CRC with liver metastasis compared to those without. Highly metastatic CRC cells release exosomes enriched with miR-106a-5p, which promote macrophages M2 polarization by suppressing SOCS6 and activating JAK2/STAT3 pathway. These M2 macrophages reciprocally enhance CRC liver metastasis. hnRNPA1 regulate the transport of miR-106a-5p into exosomes. Clinically, elevated miR-106a-5p in plasma exosomes correlated with liver metastasis and poor prognosis. CRC-derived exosomal miR-106a-5p plays a critical role in promoting liver metastasis and is a potential biomarker for the prevention and treatment of CRC liver metastasis.

Liang Y ，Li J ，Yuan Y ，Ju H ，Liao H ，Li M ，Liu Y ，Yao Y ，Yang L ，Li T ，Lei X ... -  《JOURNAL OF EXPERIMENTAL & CLINICAL CANCER RESEARCH》

Extracellular vesicles-derived OncomiRs mediate communication between cancer cells and cancer-associated hepatic stellate cells in hepatocellular carcinoma microenvironment.

Tumor microenvironment (TME) is a critical determinant for hepatocellular carcinoma (HCC). Hepatic stellate cells (HSCs) are main interstitial cells in TME and play a vital role in early intrahepatic invasion and metastasis of HCC. The potential mechanism on the interactions between HSCs and HCC cells remains unclear. In this study, the effects of extracellular vesicles (EVs)-derived OncomiRs that mediate communication between HCC cells and cancer-associated hepatic stellate cells (caHSCs) and remold TME were investigated. The results found that the HCC cells-released EVs contained more various OncomiRs, which could activate HSCs (LX2 cells) and transform them to caHSCs, the caHSCs in turn exerted promotion effects on HCC cells through HSCs-released EVs. To further simulate the effects of OncomiRs in EVs on construction of pro-metastatic TME, a group of OncomiRs, miR-21, miR-221 and miR-151 was transfected into HCC cells and LX2 cells. These microRNAs in the EVs from OncomiRs-enhanced cells were demonstrated to have oncogenic effects on HCC cells by upregulating the activities of protein kinase B (AKT)/extracellular signal-regulated kinase (ERK) signal pathways. Equivalent results were also found in HCC xenografted tumor models. The findings suggested that the OncomiR secretion and transference by cancer cells-released EVs can mediate the communication between HCC cells and HSCs. HCC cells and caHSCs, as well as their secreted EVs, jointly construct a pro-metastatic TME suitable for invasion and metastasis of cancer cells, all these TME components form a positive feedback loop to promote HCC progression and metastasis.

Li J ，Yan Y ，Ang L ，Li X ，Liu C ，Sun B ，Lin X ，Peng Z ，Zhang X ，Zhang Q ，Wu H ，Zhao M ，Su C ... -  《-》

CXCR4/TGF-β1 mediated hepatic stellate cells differentiation into carcinoma-associated fibroblasts and promoted liver metastasis of colon cancer.

Tan HX ，Gong WZ ，Zhou K ，Xiao ZG ，Hou FT ，Huang T ，Zhang L ，Dong HY ，Zhang WL ，Liu Y ，Huang ZC ... -  《-》