miR-5195-3p Suppresses Cell Proliferation and Induces Apoptosis by Directly Targeting NEDD9 in Osteosarcoma

Circ_0007351 Exerts an Oncogenic Role In Colorectal Cancer Depending on the Modulation of the miR-5195-3p/GPRC5A Cascade

Circular RNAs (circRNAs) exert critical functions in colorectal cancer development. In this work, we wanted to elucidate the functional role and regulatory mechanism of circ_0007351 in colorectal cancer. For quantification of circ_0007351, microRNA (miR)-5195-3p and G Protein-coupled receptor class C group 5 member A (GPRC5A), a qRT-PCR, immunoblotting or immunohistochemistry assay was performed. Effects of circ_0007351/miR-5195-3p/GPRC5A cascade were evaluated by determining cell viability, proliferation, colony formation, motility, and invasion. Relationships among variables were assessed by dual-luciferase reporter assay. Animal studies were performed to evaluate circ_0007351's function in the growth of xenograft tumors. Circ_0007351 was markedly up-regulated in colorectal cancer tissues and cells. Down-regulation of circ_0007351 hindered cell growth, migration and invasiveness. Also, circ_0007351 depletion exerted a suppressive function in colorectal cell xenograft growth in vivo. Mechanistically, circ_0007351 sponged miR-5195-3p to sequester miR-5195-3p. Reduction of available miR-5195-3p neutralized the effects of circ_0007351 down-regulation on cell phenotypes. MiR-5195-3p directly targeted and inhibited GPRC5A. Circ_0007351 regulated GPRC5A expression by sponging miR-5195-3p. Moreover, the effects of circ_0007351 down-regulation on cell functional phenotypes were due to in part the reduction of GPRC5A expression. Our findings show that circ_0007351 down-regulation impedes proliferation, motility, and invasiveness in colorectal cancer cells at least in part via the regulation of the miR-5195-3p/GPRC5A cascade, highlighting that circ_0007351 inhibition may have a potential therapeutic value for colorectal cancer.

miR-4735-3p inhibits cell migration and invasion of gastric cancer by downregulating NEDD9

Gastric cancer (GC) comprises the 3rd cause of cancer-related death worldwide. Increased expression of neural precursor cell expressed, developmentally downregulated 9 (NEDD9) is commonly observed in GC, however, its underlying molecular mechanism in GC remains unknown. The potential interaction between miR-4735-3p and NEDD9 was predicted by TargetScan 7.1. Expression profiles of miR-4735-3p and NEDD9 were examined between GC tissues and normal tissues by reverse transcription-quantitative (RT-q) PCR. The relationship between miR-4735-3p and NEDD9 was validated by RT-qPCR, western blotting, dual luciferase reporter assay and RNA immunoprecipitation assay. Biological relationship between miR-4735-3p and NEDD9 was evidenced by the cell invasion and cell migration assays. NEDD9 level was negatively associated with miR-4735-3p level in GC tissues. miR-4735-3p suppressed NEDD9 levels in GC cells. NEDD9 was revealed to be a target gene of miR-4735-3p. miR-4735-3p overexpression suppressed cell migration and invasion of GC cells, which were antagonized by overexpression of NEDD9. Moreover, miR-4735-3p mimic decreased the levels of matrix metalloproteinases 2/9, increased the level of E-cadherin, which were reversed by overexpression of NEDD9. Collectively, the present study provided a potential mechanism for the tumor suppressor role of miR-4735-3p in GC by targeting NEDD9.

Hsa_circ_0001017 promotes cell proliferation, migration and invasion in osteosarcoma by sponging miR-145-5p

BACKGROUND

Circular RNAs (circRNAs) have displayed important roles in the development and progression of various cancers. However, the functions of the majority of circRNAs in osteosarcoma (OS) remain unknown.

METHODS

Circular RNA microarray analysis was performed in three OS cell lines (Saos-2, U2OS and MG63) and normal vascular endothelial cells. The co-differentially expressed circRNAs (CDECs) were identified in OS cell lines with the criterion of FDR (false discovery rate) < 0.05 and |fold change (FC)|> 2. Quantitative real-time PCR was used to validate the expression levels of selected CDECs. A series of functional assays, including MTT assay, flow cytometry and transwell assay were conducted in OS cells. The interaction between circRNA and miRNAs was confirmed by luciferase reporter assay and RNA immunoprecipitation assay.

RESULTS

A total of 241 CDECs, including 75 upregulated and 166 downregulated CDECs, were identified in three OS cell lines compared with normal vascular endothelial cells. PCR validation showed that hsa_circ_0000704, hsa_circ_0001017 and hsa_circ_0005035 were all highly expression in the three OS cell lines, compared with osteoblast cell lines (HECC, hFOB1.19 and HFF-1). Functionally, overexpression of circ_0001017 significantly promoted the cell proliferation, migration and invasion and decreased apoptosis in U2OS cells. Knockdown of circ_0001017 obtained the opposite results. Circ_0001017 may downregulate miR-145-5p through direct binding. Furthermore, the expression of miR-145-5p was negatively regulated by circ_0001017 in OS cells. In addition, further functional studies indicated that miR-145-5p inhibitor eliminated the effects caused by si-circ_0001017 in OS cells.

CONCLUSIONS

In conclusion, our study suggested that circ_0001017 may be a novel oncogenic factor during the progression and development of OS by targeting miR-145-5p.

MiR-5195-3p functions as a tumor suppressor in prostate cancer via targeting CCNL1

BACKGROUND

Accumulating evidence indicates that miR-5195-3p exerts tumor-suppressive roles in several tumors. However, the clinical significance and biological function of miR-5195-3p in prostate cancer (PCa) have not been reported yet.

METHODS

The expression levels of miR-5195-3p and Cyclin L1 (CCNL1) were determined using quantitative real-time PCR in clinical specimens and cell lines. The clinical significance of miR-5195-3p in patients with PCa was evaluated using Kaplan-Meier survival analysis and Cox regression models. Cell proliferation and cell cycle distribution were measured by CCK-8 assay and flow cytometry, respectively. The association between miR-5195-3p and CCNL1 was analyzed by luciferase reporter assay.

RESULTS

MiR-5195-3p expression levels were significantly downregulated in 69 paired PCa tissues compared with matched adjacent normal tissues. The decreased miR-5195-3p expression was associated with Gleason score and TNM stage, as well as worse survival prognosis. The in vitro experiments showed that miR-5195-3p overexpression suppressed the proliferation and cell cycle G1/S transition in PC-3 and DU145 cells. Elevated miR-5195-3p abundance obviously impaired tumor formation in vivo using PC-3 xenografts. Mechanistically, CCNL1 was a direct target of miR-5195-3p in PCa cells, which was inversely correlated with miR-5195-3p in PCa tissues. Importantly, CCNL1 knockdown imitated, while overexpression reversed, the effects of miR-5195-3p overexpression on PCa cell proliferation and cell cycle G1/S transition.

CONCLUSIONS

Our data suggest that miR-5195-3p functions as a tumor suppressor by targeting CCNL1 in PCa.

MicroRNA-5195-3p alleviates high glucose‑induced injury in human ARPE-19 cells by targeting GMFB

Hyperglycemia is generally considered to be an important cause of diabetic retinopathy (DR). The aim of the present study was to investigate the role of miR-5195-3p in high glucose (HG)-induced human retinal pigment epithelial ARPE-19 cell injury. Here, we first found that the expression level of miR-5195-3p was significantly downregulated in HG-stimulated ARPE-19 cells using reverse transcription quantitative PCR. Overexpression of miR-5195-3p attenuated the impaired cell viability, increased apoptosis and pro-inflammatory cytokines secretion in ARPE-19 cells under HG condition using CCK-8 assay, flow cytometry and ELISA assay, respectively. Luciferase reporter assay showed that miR-5195-3p could specifically bind to the 3’UTR of glia maturation factor-β (GMFB). GMFB overexpression reversed, while knockdown enhanced the protective effects of miR-5195-3p overexpression against HG-induced ARPE-19 cell injury. In summary, miR-5195-3p targeting GMFB might be a potential therapeutic target for DR.