Metastasis-related miRNAs are overexpressed in CTCs and corresponding plasma; miR-21 expression levels highly correlate in CTCs and plasma; and miR-21, miR-146a, and miR-210 are valuable plasma biomarkers for discriminating patients from healthy individuals.
MicroRNA-21 (miR-21) is considered an onco-microRNA given its abilities to suppress the actions of several tumor suppressor genes and to promote tumor cell growth, invasion and metastasis.
MiR-21 is one of the important microRNAs associated with tumor progression and metastasis, but the molecular mechanisms underlying EMT and CSC phenotype during miR-21 contributes to migration and invasion of breast cancer cells remain to be elucidated.
miR-21 was highly expressed in tumour cells of 44% of cases and in cancer stroma of 51% of cases. miR-21 of tumour cells was not related to clinicopathological factors, whereas stromal miR-21 was related to many factors including tumour stage, size, and nodal metastasis.
MiRNA-21 is recognized as the main active candidate and high expression in many solid tumors consequential cell proliferation, differentiation, apoptosis, and closely related to metastasis of disease.
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).
MicroRNA‑21 (miR‑21) has been revealed to play a crucial role in regulating the biological behavior, including proliferation, migration, invasion and metastasis in certain cancers.
A total of 132 miRNAs were found to be altered in response to SS treatment, including miR-10b, miR-17, miR-21 and miR-9, which have been previously implicated in tumor invasion and metastasis.
A vast number of miRNAs, including the well-studied miR-21, miR-155 and miR-34, has been shown to regulate PDAC growth, invasion and metastasis in vitro and in vivo by targeting members of key signaling pathways.
Acidic Microenvironment Up-Regulates Exosomal miR-21 and miR-10b in Early-Stage Hepatocellular Carcinoma to Promote Cancer Cell Proliferation and Metastasis.
Although the reasons for the high relapse are not fully understood, the presence of chemo- and radiotherapy-resistant cancer stem/stem-like cells, where many oncomirs like microRNA-21 (miR-21) are upregulated, could be one of the underlying causes. miR-21 regulates the processes of invasion and metastasis by downregulating multiple tumor/metastatic suppressor genes including PTEN (phosphatase and tensin homolog).
Among the several types of miRNAs, microRNA-21 (miR-21) is dysregulated in several types of cancer and plays a key role in carcinogenesis, recurrence, and metastasis.
Because miR-21 appears to be overexpressed in human melanoma, we examined the role of miR-21 in cancer development and metastasis in B16 mouse melanoma cells.
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.
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.
Combination of ASOs therapy against miRNA-21 and miRNA-221 significantly inhibited primary tumor growth and metastasis compared to single antagomir treatment, especially, in L3.6plGres-SP-induced pancreatic tumor growth in vivo.