Exosome-derived miR-372-5p promotes stemness and metastatic ability of CRC cells by inducing macrophage polarization

Colorectal cancer (CRC) is the most common malignancy in the digestive system, and tumor metastasis is the main cause of death in clinical patients with CRC. It has been shown that exosomes promote phenotypic changes in macrophages and tumor metastasis in the CRC tumor microenvironment. In this study, we used miRNA-seq technology to screen out the highly expressed miR-372-5p among the miRNAs differentially expressed in plasma exosomes of clinical CRC patients. It was found that miR-372-5p highly expressed in HCT116 exosomes could be phagocytosed by macrophages and promote their polarization into M2 macrophages by regulating the PTEN/AKT pathway. Meanwhile, co-culture of CRC cells with conditioned medium (CM) of macrophages enhanced the EMT, stemness and metastasis of CRC cells. Mechanistically, CRC cells exosome-derived miR-372-5p induced polarized M2 macrophages to secrete chemokine C-X-C-Motif Ligand 12 (CXCL12), which activated the WNT/β-catenin pathway to promote the EMT, stemness and metastatic ability of CRC cells. In summary, this study elucidated the molecular mechanism of exosomal miR-372-5p promoting metastasis and stemness in CRC, which may provide new therapeutic targets for CRC metastasis and prognosis assessment.

The effect of miR-372-5p regulation on CDX1 and CDX2 in the gastric cancer cell line

OBJECTIVES

MicroRNA expression disruptions play an important function in the expansion of gastric cancer. Previous investigation has indicated that miR-372-5p doing as an oncogene in several malignancies. CDX1 and CDX2, as target genes of miR-372-5p, play the role of tumor suppressors and oncogenes in gastric cancer cells, respectively. The current investigation explored the effects of miR-372-5p regulation on CDX2 and CDX1 in AGS cell lines and studied their molecular mechanism.

METHODS

hsa-miR-372-5p miRCURY LNA miRNA Inhibitors and Mimic were transfected into AGS cell line. The cell viability and cell cycle calculation were defined by MTT assay and flow cytometry, respectively. The Expression levels of miR-372-5p, CDX1, CDX2 and transfection efficiency were measured using Real-time PCR. Statistical investigation p values <0.05 were considered to be meaningful.

RESULTS

miR-372-5p particularly was upregulated in control cells and also after transfection by mimic. While its expression was reduced by the inhibitor. Upregulation of miR-372-5p remarkably increased cell growth and led to accumulation in the G2/M phase, although the inhibitor decreased cell growth and accumulation in the S phase. Accordingly, upregulation of miR-372-5p increased CDX2 and decreased CDX1 expression. By inhibition of miR-372-5p, expression of CDX2 was decreased and expression of CDX1 was increased.

CONCLUSIONS

Up and down-regulation of miR-372-5P has a potential effect on the expression levels of its target genes, CDX1 and CDX22. Accordingly, the downregulation of miR-372-5p may be assumed as a possible therapeutic target in treating gastric cancer.

[MiR-372-5p regulates PI3K/AKT/CXCL12 signaling pathway by targeting PTEN to promote colorectal cancer cell metastasis]

OBJECTIVE

To investigate whether miR-372-5p regulates PI3K/AKT/CXCL12 signaling pathway by targeting PTEN to promote metastasis of colorectal cancer cells.

METHODS

We detected the differential expression of miR-372-5p using RT-qRCR in colorectal cancer and adjacent tissues, colorectal cancer cells and normal intestinal epithelial cells. Bioinformatic analysis and double luciferase assay were performed for verification of the targeting relationship between miR-372-5p and PTEN. Western blotting was used to assess the effects of transfection with miR-372-5p inhibitor and miR-372-5p mimics alone, co-transfection with miR-372-5p inhibitor and si-PTEN, and co-transfection with miR-372-5p mimics and PI3K inhibitor on the expressions of PTEN and CXCL12 and the activation of PI3K/AKT signal pathway; Transwell assay and scratch assay were used to examine the changes in the migration ability of the transfected cells, the cells co-transfected with miR-372-5p mimics and si-CXCL12, and the cells treated with conditioned medium from HCT116 cells transfected with miR-372-5p mimics.

RESULTS

The expression of miR-372-5p was significantly higher in colorectal cancer tissues than in adjacent tissues, and higher in HCT116 and SW620 cells than in NCM460 cells (P < 0.01). Double luciferase assay confirmed that PTEN was a potential target gene of miR-372-5p (P < 0.05). Transfection of HCT116 cells with miR-372-5p mimics obviously decreased PTEN protein expression, increase CXCL12 expression and the phosphorylation level of AKT, and lowered the cell migration ability, while transfection with miR-372-5p inhibitor produced the opposite effects (P < 0.05); si-PTEN obviously neutralized the effect of miR-372-5p inhibitor (P < 0.01). PI3K inhibitor significantly decreased CXCL12 expression and inhibited the cell migration (P < 0.05), and this effect was mitigated by miR-372-5p mimics (P < 0.01). Treatment with the conditioned medium from HCT116 cells transfected with miR-372-5p mimics significantly enhanced the migration ability of NCM460 cells, and this effect was suppressed by transfection with si-CXCL12 (P < 0.01).

CONCLUSION

MiR-372-5p activates PI3K/AKT signaling pathway by targeting PTEN and up-regulates CXCL12 expression to promoting metastasis of colorectal cancer cells.

Effects of FER1L4-miR-106a-5p/miR-372-5p-E2F1 regulatory axis on drug resistance in liver cancer chemotherapy

Liver cancer presents a challenge in today's healthcare system. This study aimed at investigating the effects of Fer-1 like family member 4 (FER1L4) on chemotherapy resistance and liver cancer development by using clinically collected liver cancer tissues and commercially purchased human liver cancer cisplatin-resistant cell line HUH-7/DDP. Bioinformatics analysis, dual luciferase reporter gene assay, and RNA pull-down were applied to predict and verify the possible binding relationships. The expressions of FER1L4, E2F transcription factor 1 (E2F1), microRNA-106a-5p (miR-106a-5p), or miR-372-5p were altered in the cells, followed by flow cytometry, Cell Counting Kit-8 (CCK-8), and Transwell assays to evaluate apoptotic, proliferative, and invasive abilities in vitro and nude mice xenografts to observe tumor growth in vivo. FER1L4 was highly expressed and miR-106-5p and miR-372-5p were poorly expressed in tumor cells and tissues. FER1L4 knockdown or the overexpression of miR-106-5p and miR-372-5p inhibited the cancerous cell proliferation and invasion while promoting apoptosis. FERIL4 silencing increased the miR-106-5p/miR-372-5p expression to inhibit the E2F1-activated nuclear factor κB (NF-κB) pathway. Besides, overexpressing FER1L4 led to an increased tumor growth in nude mice, which was reversed by the NF-κB inhibitor pyrollidine dithiocarbamate (PDTC). In conclusion, the results indicated that FER1L4 could inhibit the expression of miR-106a-5p/miR-372-5p, to activate E2F1-mediated NF-κB pathway, leading to drug resistance in liver cancer.

MEHP promotes the proliferation of oral cancer cells via down regulation of miR-27b-5p and miR-372-5p

Mono-2-ethyhexyl phthalate (MEHP), an environmental xenoestrogen, is widely used in the production of polyvinyl chloride materials and can be easily accumulated into human body. Emerging evidences showed that MEHP can regulate the progression of various cancers. Oral cancer cells could be directly exposed to MEHP during food and water digestion, while the roles of MEHP on the progression of oral cancer were rarely investigated. Our present study found that MEHP can trigger the proliferation of oral squamous cell carcinoma (OSCC) cells and increase the expression of proliferating cell nuclear antigen (PCNA). We checked the expression of various miRNAs which can target the 3'UTR of PCNA. Specifically, MEHP can decrease the expression of miR-27b-5p and miR-372-5p, which can directly bind with the 3'UTR of PCNA to inhibit its expression. Over expression of miR-27b-5p and miR-372-5p can abolish MEHP induced cell proliferation and expression of PCNA in OSCC cells. Further, MEHP can induce the expression of c-Myc, which can suppress the transcription of miR-27b-5p in OSCC cells. In vivo xenograft study on the basis of SCC-4 cells confirmed that MEHP can trigger the growth of OSCC and suppress the expression of miR-27b-5p and miR-372-5p. Collectively, our present study suggested that MEHP can promote the growth and progression of OSCC via down regulation of miR-27b-5p and miR-372-5p.