MicroRNA‑500a‑5p inhibits colorectal cancer cell invasion and epithelial‑mesenchymal transition

An in vitro approach to understand contribution of kidney cells to human urinary extracellular vesicles

Extracellular vesicles (EV) are membranous particles secreted by all cells and found in body fluids. Established EV contents include a variety of RNA species, proteins, lipids and metabolites that are considered to reflect the physiological status of their parental cells. However, to date, little is known about cell-type enriched EV cargo in complex EV mixtures, especially in urine. To test whether EV secretion from distinct human kidney cells in culture differ and can recapitulate findings in normal urine, we comprehensively analysed EV components, (particularly miRNAs, long RNAs and protein) from conditionally immortalised human kidney cell lines (podocyte, glomerular endothelial, mesangial and proximal tubular cells) and compared to EV secreted in human urine. EV from cell culture media derived from immortalised kidney cells were isolated by hydrostatic filtration dialysis (HFD) and characterised by electron microscopy (EM), nanoparticle tracking analysis (NTA) and Western blotting (WB). RNA was isolated from EV and subjected to miRNA and RNA sequencing and proteins were profiled by tandem mass tag proteomics. Representative sets of EV miRNAs, RNAs and proteins were detected in each cell type and compared to human urinary EV isolates (uEV), EV cargo database, kidney biopsy bulk RNA sequencing and proteomics, and single-cell transcriptomics. This revealed that a high proportion of the in vitro EV signatures were also found in in vivo datasets. Thus, highlighting the robustness of our in vitro model and showing that this approach enables the dissection of cell type specific EV cargo in biofluids and the potential identification of cell-type specific EV biomarkers of kidney disease.

MicroRNAs: Multifaceted Regulators of Colorectal Cancer Metastasis and Clinical Applications

Colorectal cancer (CRC) is the third-commonest malignant cancer, and its metastasis is the major reason for cancer-related death. The process of metastasis is highly coordinated and involves a complex cascade of multiple steps. In recent years, miRNAs, as highly conserved, endogenous, noncoding, single-stranded RNA, has been confirmed to be involved in the development of various cancers. Considering that miRNA is also involved in a series of biological behaviors, regulating CRC occurrence and development, we review and summarize the role of miRNAs and related signaling pathways in several CRC-metastasis stages, including invasion and migration, mobility, metabolism, epithelial-mesenchymal transition, tumor-microenvironment communication, angiogenesis, anoikis, premetastatic-niche formation, and cancer stemness. In addition, we review the application of miRNAs as diagnostic CRC markers and in clinical treatment resistance. This review can contribute to understanding of the mechanism of miRNAs in CRC progression and provide a theoretical basis for clinical CRC treatment.