Dataset Information

Downregulated exosomal microRNA-148b-3p in cancer associated fibroblasts enhance chemosensitivity of bladder cancer cells by downregulating the Wnt/β-catenin pathway and upregulating PTEN.

ABSTRACT:

Objective

Exosomes derived from cancer-associated fibroblasts (CAFs) are known as important drivers of tumor progression. Previously, microRNA (miR)-148b-3p has been found to be upregulated in bladder cancers as well as in body fluids (blood, urine) of bladder cancer patients. Here, we aimed to explore the role of CAF-derived exosome miR-148b-3p in bladder cancer progression and chemosensitivity.

Methods

Transwell, MTT, flow cytometry and colony formation assays were applied to assess the effects of CAF-derived exosomes on bladder cancer cell metastasis, epithelial-mesenchymal transition (EMT) and chemosensitivity. A dual luciferase reporter assay was employed to evaluate the targeting relationship between miR-148b-3p and PTEN. Gain- and loss- of function assays were conducted to explore the roles of miR-148b-3p and PTEN in the behavior of bladder cancer cells. The role of PTEN in the metastasis, EMT and chemosensitivity of bladder cancer cells was assessed both in vivo and in vitro.

Results

We found that CAF-derived exosomes promoted the metastasis, EMT and drug resistance of bladder cancer cells. We also found that CAF-derived exosomes could directly transport miR-148b-3p into bladder cancer cells. In a xenograft mouse model we found that CAF-derived exosomes increased miR-148b-3p expression levels and promoted tumor proliferation, metastasis and drug resistance. PTEN was validated as a target of miR-148b-3p. Concordantly, we found that PTEN overexpression inhibited EMT, metastasis and chemoresistance in bladder cancer cells, reversing the tumor promoting effects of miR-148b-3p via the Wnt/β-catenin pathway.

Conclusions

Our results suggest that miR-148b-3p downregulation in CAF-derived exosomes, thereby inhibiting the Wnt/β-catenin pathway and promoting PTEN expression, may offer potential opportunities for bladder cancer treatment.

SUBMITTER: Shan G

PROVIDER: S-EPMC7906940 | biostudies-literature |

REPOSITORIES: biostudies-literature

ACCESS DATA

Similar Datasets

Project description:BackgroundEmerging evidence has revealed that tumor-associated macrophages (TAMs) and exosomes play a crucial role in the microenvironment for tumor growth. However, the mechanisms through which exosomal miRNAs modulate TAMs and tumor development in breast cancer are not fully understood.MethodsWe constructed a macrophage model and an indirect coculture system consist of breast cancer cells and macrophages. Exosomes were isolated from BC cells culture supernatant and identified by transmission electron microscopy, Western blot and Nanosight LM10 system. The expression of miR-148b-3p in exosomes was determined by qRT-PCR and the effect of exosomal miR-148b-3p on macrophage polarization was measured using qRT-PCR and ELISA. The proliferation, migration and invasion of BC cells were estimated by EdU, wound healing assay and transwell assay. We employed bioinformatics, luciferase reporter assay and Western blot to identify the target gene of miR-148b-3p. Western blot was used to clarify the mechanism of exosomal miR-148b-3p mediated the crosstalk between BC cells and M2 macrophages.ResultsCancer-derived exosomes could induce M2 polarization of macrophages, which promoted the migration and invasion of breast cancer cells. We found that exosomal miR-148b-3p was overexpressed in breast cancer cell-derived exosomes and correlated with lymph node metastasis, late tumor stage and worse prognosis. Upregulated miR-148b-3p expression in exosomes modulated macrophage polarization by targeting TSC2, which promoted the proliferation and might affect migration and invasion of breast cancer cells. Interestingly, we found that exosomal miR-148b-3p could induce M2 macrophage polarization via the TSC2/mTORC1 signaling pathway in breast cancer.ConclusionOverall, our study elucidated that miR-148b-3p could be transported by exosomes from breast cancer cells to surrounding macrophages and induced M2 polarization by targeting TSC2, providing novel insights for breast cancer therapy.

Project description:BackgroundThis study evaluated the clinical relevance of a set of five serum-derived circulating microRNAs (miRNAs) in colorectal cancer (CRC). Additionally, we investigated the role of miR-20a-5p released by exosomes derived from cancer-associated fibroblasts (CAFs) in the context of CRC.MethodsThe expression levels of five circulating serum-derived miRNAs (miR-20a-5p, miR-122-5p, miR-139-3p, miR-143-5p, and miR-193a-5p) were quantified by real-time quantitative PCR (RT-qPCR), and their associations with clinicopathological characteristics in CRC patients were assessed. The diagnostic accuracy of these miRNAs was determined through Receiver Operating Characteristic (ROC) curve analysis. CAFs and normal fibroblasts (NFs) were isolated from tissue samples, and subsequently, exosomes derived from these cells were isolated and meticulously characterized using electron microscopy and Western blotting. The cellular internalization of fluorescent-labeled exosomes was visualized by confocal microscopy. Gain- and loss-of-function experiments were conducted to elucidate the oncogenic role of miR-20a-5p transferred by exosomes derived from CAFs in CRC progression. The underlying mechanisms were uncovered through luciferase reporter assay, Western blotting, enzyme-linked immunosorbent assays, as well as proliferation and migration assays.ResultsThe expression levels of serum-derived circulating miR-20a-5p and miR-122-5p were significantly higher in CRC and were positively correlated with advanced stages of tumorigenesis and lymph node metastasis (LNM). In contrast, circulating miR-139-3p, miR-143-5p, and miR-193a-5p were down-regulated in CRC and associated with early tumorigenesis. Except for miR-139-3p, they showed a negative correlation with LNM status. Among the candidate miRNAs, significantly elevated levels of miR-20a-5p were observed in both cellular and exosomal fractions of CAFs. Our findings indicated that miR-20a-5p induces the expression of EMT markers, partly by targeting PTEN. Exosomal miR-20a secreted by CAFs emerged as a key factor enhancing the proliferation and migration of CRC cells. The inhibition of miR-20a impaired the proliferative and migratory potential of CAF-derived exosomes in SW480 CRC cells, suggesting that the oncogenic effects of CAF-derived exosomes are mediated through the exosomal transfer of miR-20a. Furthermore, exosomes originating from CAFs induced increased nuclear translocation of the NF-kB p65 transcription factor in SW480 CRC cells, leading to increased interleukin-6 (IL-6) production.ConclusionsWe established a set of five circulating miRNAs as a non-invasive biomarker for CRC diagnosis. Additionally, our findings shed light on the intricate mechanisms underpinning the oncogenic impacts of CAF-derived exosomes and underscore the pivotal role of miR-20a-5p in CRC progression.