MicroRNA-30a Inhibits Colorectal Cancer Metastasis Through Down-Regulation of Type I Insulin-Like Growth Factor Receptor

Downregulation of Long Noncoding RNA Myocardial Infarction Associated Transcript Suppresses Cell Proliferation, Migration, Invasion, and Glycolysis by Regulation of miR-488-3p/IGF1R Pathway in Colorectal Cancer

Background: Colorectal cancer (CRC) is a significant public problem and the third cause of cancer-induced death all over the world. Long noncoding RNA (lncRNA) has been reported as a vital mediator in human cancer. However, the precise role of lncRNA myocardial infarction associated transcript (MIAT) in CRC is unclear. Materials and Methods: The abundance of MIAT, miR-488-3p, and the type 1 insulin-like growth factor receptor (IGF1R) was measured by real-time quantitative polymerase chain reaction assay. Western blot assay was carried out to assess the protein level in CRC samples or control group. The cell activity, abilities of migration and invasion, and glycolysis were evaluated by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-2H-tetrazol-3-ium bromide (MTT), transwell, and testing glucose consumption and lactate product, correspondingly. The target association between miR-488-3p, MIAT, or IGF1R was predicted and established by bioinformatics tools, dual-luciferase reporter, and RNA pull-down assays, correspondingly. The effects of MIAT silencing in vivo were analyzed by animal experiments. Results: LncRNA MIAT was upregulated in CRC sample and that was positively correlated with IGF1R expression. Loss-of-functional assay suggested that knockdown of MIAT impeded cell activity, migration, invasion, and glycolysis of CRC cells in vivo, along with xenograft growth in vivo. Moreover, silencing of IGF1R inhibited the progression of CRC. Therefore, overexpression of IGF1R could abolish silencing of MIAT-induced effects on CRC cells. Mechanistically, MIAT was a sponge for miR-488-3p, thereby regulating IGF1R expression in CRC. Conclusion: The present study confirmed that the "MIAT/miR-488-3p/IGF1R" pathway was involved in the development of CRC, which may be the target for developing therapeutic approaches for CRC.

Circ-MFN2 Positively Regulates the Proliferation, Metastasis, and Radioresistance of Colorectal Cancer by Regulating the miR-574-3p/IGF1R Signaling Axis

Numerous studies have shown that the expression of circular RNA (circRNA) is closely related to the malignant progression of cancer. However, the role of circ-MFN2 in colorectal cancer (CRC) is unclear. Our study aims to explore the role and mechanism of circ-MFN2 in CRC progression. The relative expression levels of circ-MFN2, microRNA (miR)-574-3p and insulin-like growth factor 1 receptor (IGF1R) were detected by quantitative real-time polymerase chain reaction (qRT-PCR). Cell viability was determined using 3-(4, 5-dimethyl-2 thiazolyl)-2, 5-diphenyl-2-H-tetrazolium bromide (MTT) assay. The colony number and radioresistance of cells were assessed using colony formation assay. Moreover, the migration and invasion of cells were measured using transwell assay. Tumor xenograft model was constructed to evaluate the effect of circ-MFN2 knockdown on CRC tumor growth. Furthermore, dual-luciferase reporter assay was used to verify the interaction between miR-574-3p and circ-MFN2 or IGF1R. In addition, the protein level of IGF1R was evaluated by western blot (WB) analysis. Circ-MFN2 expression was elevated in CRC tissues and cells. Knockdown of circ-MFN2 restrained the proliferation, migration, invasion, and radioresistance of CRC cells in vitro. Furthermore, silenced circ-MFN2 also reduced the tumor volume and weight of CRC in vivo. MiR-574-3p could be sponged by circ-MFN2, and its inhibitor reversed the suppression effect of circ-MFN2 silencing on CRC progression. Moreover, IGF1R was a target of miR-574-3p, and its overexpression reversed the inhibition effect of miR-574-3p mimic on CRC progression. In addition, circ-MFN2 could positively regulate IGF1R expression by sponging miR-574-3p. Our results revealed that circ-MFN2 promoted the proliferation, metastasis and radioresistance of CRC through regulating the miR-574-3p/IGF1R axis, suggesting that circ-MFN2 might be a novel therapeutic biomarker for CRC.

Significant changes in synovial fluid microRNAs after high tibial osteotomy in medial compartmental knee osteoarthritis: Identification of potential prognostic biomarkers

High tibial osteotomy (HTO) is a well-established treatment for medial compartmental knee osteoarthritis. Several microRNAs (miRNAs) are involved in osteoarthritis progression and are useful as osteoarthritis-related biomarkers. In this prospective study, we investigated differentially expressed microRNAs in the synovial fluid (SF) before and after HTO in patients with medial compartmental knee osteoarthritis to identify microRNAs that can be used as prognostic biomarkers. We used miRNA-PCR arrays to screen for miRNAs in SF samples obtained preoperatively and 6 months postoperatively from 6 patients with medial compartmental knee osteoarthritis who were treated with medial open wedge HTO. Differentially expressed miRNAs identified in the profiling stage were validated by real-time quantitative PCR in 22 other patients who had also been treated with HTO. All patients radiographically corresponded to Kellgren-Lawrence grade II or III with medial compartmental osteoarthritis. These patients were clinically assessed using a visual analogue scale and Western Ontario McMaster Universities scores. Mechanical axis changes were measured on standing anteroposterior radiographs of the lower limbs assessed preoperatively and at 6 months postoperatively. Among 84 miRNAs known to be involved in the inflammatory process, 14 were expressed in all SF specimens and 3 (miR-30a-5p, miR-29a-3p, and miR-30c-5p) were differentially expressed in the profiling stage. These 3 miRNAs, as well as 4 other miRNAs (miR-378a-5p, miR-140-3p, miR-23a-3p, miR-27b-3p), are related to osteoarthritis progression. These results were validated in the SF from 22 patients. Clinical and radiological outcomes improved after HTO in all patients, and only 2 miRNAs (miR-30c-5p and miR-23a-3p) were significantly differentially expressed between preoperative and postoperative 6-month SF samples (p = 0.006 and 0.007, respectively). Of these two miRNAs, miR-30c-5p correlated with postoperative pain relief. This study provides potential prognostic miRNAs after HTO and further investigations should be considered to determine clinical implications of these miRNAs.

Role of Regulatory Oncogenic or Tumor Suppressor miRNAs of PI3K/AKT Signaling Axis in the Pathogenesis of Colorectal Cancer

Colorectal cancer (CRC) is the leading cause of cancer death worldwide and its incidence is increasing. In most patients with CRC, the PI3K/AKT signaling axis is over-activated. Regulatory oncogenic or tumor suppressor microRNAs (miRNAs) for PI3K/AKT signaling regulate cell proliferation, migration, invasion, angiogenesis, as well as resistance to chemo-/radio-therapy in colorectal cancer tumor tissues. Thus, regulatory miRNAs of PI3K/AKT/mTOR signaling represent novel biomarkers for new patient diagnosis and obtaining clinically invaluable information from post-treatment CRC patients for improving therapeutic strategies. This review summarizes the current knowledge of miRNAs' regulatory roles of PI3K/AKT signaling in CRC pathogenesis.

Circulating miR-30a-5p as a prognostic biomarker of left ventricular dysfunction after acute myocardial infarction

Left ventricular (LV) dysfunction after acute myocardial infarction (AMI) is associated with an increased risk of heart failure (HF) development. Diverse microRNAs (miRNAs) have been shown to appear in the bloodstream following various cardiovascular events. The aim of this study was to identify prognostic miRNAs associated with LV dysfunction following AMI. Patients were divided into subgroups comprising patients who developed or not LV dysfunction within six months of the infarction. miRNA profiles were determined in plasma and serum samples of the patients on the first day of AMI. Levels of 14 plasma miRNAs and 16 serum miRNAs were significantly different in samples from AMI patients who later developed LV dysfunction compared to those who did not. Two miRNAs were up-regulated in both types of material. Validation in an independent group of patients, using droplet digital PCR (ddPCR) confirmed that miR-30a-5p was significantly elevated on admission in those patients who developed LV dysfunction and HF symptoms six months after AMI. A bioinformatics analysis indicated that miR-30a-5p may regulate genes involved in cardiovascular pathogenesis. This study demonstrates, for the first time, a prognostic value of circulating miR-30a-5p and its association with LV dysfunction and symptoms of HF after AMI.

Long noncoding RNA PVT1 enhances the viability and invasion of papillary thyroid carcinoma cells by functioning as ceRNA of microRNA-30a through mediating expression of insulin like growth factor 1 receptor

OBJECTIVE

Invasion and metastasis of papillary thyroid carcinoma (PTC) significantly affects prognosis and quality of life of patients. Herein, we explored the binding relationship of long noncoding RNA PVT1 as ceRNA to microRNA-30a (miR-30a), and their effect on the development of PTC through regulating insulin like growth factor 1 receptor (IGF1R).

METHODS

PTC and adjacent normal tissues were collected, where the qRT-PCR and western blot assay were employed to evaluate the expression levels of PVT1, miR-30a and IGF1R. The correlation between PVT1 expression and clinicopathological characteristics of PTC patients was observed. PTC cell lines with the most/least significant difference from normal thyroid cells were selected and treated with siRNA PVT1 or overexpression PVT1 plasmids, miR-30a mimics or miR-30a inhibitors. Nucleus and cytoplasm segmentation was used to identify subcellular fractionation of PVT1. The binding relationship of PVT1 to miR-30a and the targeting relationship of miR-30a to IGF1R were confirmed by using bioinformatic prediction program, dual-luciferase reporter gene assay and RNA-pull down. Cell viability, cell cycle and apoptosis, invasion and migration capacities were assessed by MTT, flow cytometry, Transwell assay and scratch test, respectively. Western blot assay was employed to examine protein expression of IGF1R, apoptosis-related factors (caspase-3, cleaved capase-3) and epithelial-mesenchymal transition (EMT)-related factors (E-cadherin, Vimentin).

RESULTS

In the PTC tissues and cells, PVT1 and IGF1R were highly expressed and miR-30a was poorly expressed. PVT1 exerted its effects on PTC mainly in the cytoplasm. The PVT1 expression was correlated with TNM staging, LNM and tumor infiltration of PTC. The competitive binding of PVT1 to miR-30a enhanced expression of IGF1R. In the in vitro experiments, BCPAP and TPC-1 cells were selected. When subjected to siRNA PVT1 or miR-30a mimics, BCPAP and TPC-1 cells exhibited inhibited proliferation, cell cycle progression, invasion, migration, EMT (increased E-cadherin and reduced Vimentin) and promoted apoptosis (reduced caspase-3 and increased cleaved capase-3), and moreover, the expression of IGF1R was reduced.

CONCLUSION

This study provides evidence that long noncoding RNA PVT1 enhances the expression of IGF1R through competitive binding to miR-30a, whereby PVT1 facilitates the development of PTC.