Using a mouse xenograft tumor model, we found that the overexpression of MEG3 suppressed tumor growth and metastasis while overexpression of miR‑21 had the opposite effects.
We demonstrated that Sphk2 gene silencing induced by nanoparticles in hepatocellular carcinoma (HCC) cells could reduce miRNA-21 sorting into exosomes, contributing to the inhibition of tumor cell migration and tumorigenic function of exosomes to normal liver cells.
Exosome biomarkers (such as HER2, CD47, Del-1, miR-1246 and miR-21) in breast cancer patients are significantly higher than those in healthy controls, exosomal GSTP1 and TRPC5 are related to chemotherapy resistance, exosome-carrying TRPC5, NANOG, NEUROD1, HTR7, KISS1R and HOXC are correlated to PFS, DFS or OS, and some exosomal proteins (HER2, KDR, CD49d, CXCR4 and CD44) as well as miRNAs (miR-340-5p, miR-17-5p, miR-130a-3p, miR-93-5p) are associated with tumor recurrence or distant organ metastasis.
The analysis of miR-21, miR-222 and miR-124-3p in serum exosomes of patients affected by gliomas can provide a minimally invasive and innovative tool to help the differential diagnosis of gliomas at their onset in the brain and predict glioma grading and non glial metastases before surgery.
We aimed to compare expression levels of miRNA-21, -103, -129, -150 in primary tumour tissues and its omental metastases from patients operated for advanced ovarian serous cancer.
Because of the established anti-apoptosis effect of miR-21, it is tempting to speculate that miR-21 might contribute to tumor metastasis by regulating anoikis. qRT-PCR analysis demonstrated that miR-21 expression in OE33/AR cells (subpopulation of human EA OE33 cells that acquired resistance to anoikis) was significantly increased.
MiR-21-5p was highly expressed in the tumor tissues of NSCLC patients, and its expression was significantly correlated with the clinical classification of NSCLC patients (χ<sup>2</sup>=7.154, <i>P</i>=0.007), tumor size (χ<sup>2</sup>=4.372, <i>P</i>=0.037), differentiation (χ<sup>2</sup>=13.713, <i>P</i>=0.001), lymph node metastasis (χ<sup>2</sup>=5.101, <i>P</i>=0.024), distant metastasis (χ<sup>2</sup>=12.599, <i>P</i>=0.000), and TNM stage (χ<sup>2</sup>=6.344, <i>P</i>=0.012), whereas it was positively correlated with the expression of SMAD7 protein (<i>r</i>=0.669, <i>P</i><0.05).
Finally, we investigated the regulatory mechanism of XIST acting as a competitive endogenous RNA (ceRNA) of miR-21-5p in OS progression and metastasis. lncRNA XIST was significantly downregulated in osteosarcoma tissues and osteosarcoma cells, and associated with recurrence and short overall survival in OS patients.
Cell models with bioinformatics approaches may help distinguish functional genes. miR‑652-5p, miR‑21‑5p, and their potential target genes may participate in ESCC development and metastasis.
Furthermore, Transwell assay results revealed that downregulation of HBx and treatment with miR‑21 inhibitors contributed to the inhibition of MHCC‑97H cell invasion and metastasis.
Therefore, we developed a combined therapy of microRNA-21 antisense oligonucleotides (ASO-miR-21) and gemcitabine (Gem) using a targeted co-delivery nanoparticle (NP) carrier and investigated the synergistic inhibitory effects on pancreatic cancer cells metastasis and growth.
Knocking down miR-21 inhibited the cell growth, invasion and migration abilities but promoted the cell apoptosis, while over-expressing miR-21 promoted cell growth and metastasis.
PIK3R1 targeting by miR-21 suppresses tumor cell migration and invasion by reducing PI3K/AKT signaling and reversing EMT, and predicts clinical outcome of breast cancer.