Long noncoding RNA XLOC_006786 inhibits the proliferation, invasion and metastasis of osteosarcoma cells through NOTCH3 signaling pathway by targeting miR-491-5p

Recent research has indicated that Long noncoding RNAs (LncRNAs) are crucial in many disorders, especially tumors. However, the exact role of LncRNA XLOC_006786 (LncRNA-SPIDR-2:1) in malignancies, especially in human osteosarcoma, is unclear. The results of RT‒qPCR, western blotting, CCK-8 assays, and Transwell assays showed that LncRNA XLOC_006786 inhibited osteosarcoma cell proliferation, invasion, and migration, indicating that it may be a tumor suppressor gene in osteosarcoma. We found that LncRNA XLOC_006786 negatively regulated NOTCH3, which is an oncogenic gene in osteosarcoma, as we previously reported. Bioinformatics analysis showed that miR-491-5p may be a direct target of LncRNA XLOC_006786, while NOTCH3 is a key target of miR-491-5p. Then, we verified that LncRNA XLOC_006786 could prevent lung metastatic osteosarcoma in vivo. Taken together, our research showed that LncRNA XLOC_006786 suppresses osteosarcoma proliferation, invasion, and metastasis through the NOTCH3 signaling pathway by targeting miR-491-5p.

The Tumor Suppressor Roles and Mechanisms of MiR-491 in Human Cancers

MicroRNAs (miRNAs) are short non-coding RNAs that bind to the 3' untranslated region (3'' UTR) of target mRNAs to control gene expression post-transcriptionally. Recent indications have highlighted their important roles in a variety of pathophysiological conditions as well as human malignancies. Dysregulated miRNAs act as tumor suppressor genes or oncogenes in a variety of cancers. MiR-491 has been shown to have a major effect on tumorigenesis in multiple malignancies through binding to specific genes and signaling cascades, thereby preventing cancer progression. This review provides an overview of miR-491 expression in regulatory mechanisms and biological procedures of tumor cells, as well as the prospective possible treatment effects of various types of human cancers.

LBX2-AS1 promotes ovarian cancer progression by facilitating E2F2 gene expression via miR-455-5p and miR-491-5p sponging

LBX2‐AS1 is a long non‐coding RNA that facilitates the development of gastrointestinal cancers and lung cancer, but its participation in ovarian cancer development remained uninvestigated. Clinical data retrieved from TCGA ovarian cancer database and the clinography of 60 ovarian cancer patients who received anti‐cancer treatment in our facility were analysed. The overall cell growth, colony formation, migration, invasion, apoptosis and tumour formation on nude mice of ovarian cancer cells were evaluated before and after lentiviral‐based LBX2‐AS1 knockdown. ENCORI platform was used to explore LBX2‐AS1‐interacting microRNAs and target genes of the candidate microRNAs. Luciferase reporter gene assay and RNA pulldown assay were used to verify the putative miRNA‐RNA interactions. Ovarian cancer tissue specimens showed significant higher LBX2‐AS1 expression levels that non‐cancerous counterparts. High expression level of LBX2‐AS1 was significantly associated with reduced overall survival of patients. LBX2‐AS1 knockdown significantly down‐regulated the cell growth, colony formation, migration, invasion and tumour formation capacity of ovarian cancer cells and increased their apoptosis in vitro. LBX2‐AS1 interacts with and thus inhibits the function of miR‐455‐5p and miR‐491‐5p, both of which restrained the expression of E2F2 gene in ovarian cancer cells via mRNA targeting. Transfection of miRNA inhibitors of these two miRNAs or forced expression of E2F2 counteracted the effect of LBX2‐AS1 knockdown on ovarian cancer cells. LBX2‐AS1 was a novel cancer‐promoting lncRNA in ovarian cancer. This lncRNA increased the cell growth, survival, migration, invasion and tumour formation of ovarian cancer cells by inhibiting miR‐455‐5p and miR‐491‐5p, thus liberating the expression of E2F2 cancer‐promoting gene.

Aspirin enhances the sensitivity of hepatocellular carcinoma side population cells to doxorubicin via miR-491/ABCG2

Objective: To explore whether aspirin (ASA) enhances the sensitivity of hepatocellular carcinoma (HCC) side population (SP) cells to doxorubicin (Doxo) via miR-491/ATP-binding cassette sub-family G member 2 (ABCG2).Methods: Non-SP and SP cells were isolated from MHCC-97L cell line using flow cytometry analysis and fluorescence-activated cell sorting. Colony formation assay was performed to determine the colony-formation ability of cells. Cell viability of SP cells was determined with the MTT assay. Luciferase reporter assay was applied in confirming the binding between miR-491 and ABCG2.Results: Although the Doxo treatment lowered the colony-formation ability of both non-SP and SP cells, the colony-formation ability of SP cells was 2-fold higher than that of non-SP cells (P<0.05). Doxo slightly inhibited the cell viability of SP cells in a concentration-dependent manner; the addition of ASA dramatically enhanced the inhibitory effect of Doxo on SP cell viability in a concentration-dependent manner (P<0.05). Compared with non-SP cells, the miR-491 expression was significantly decreased in SP cells, which was significantly reversed by ASA (P<0.05). miR-491 directly controlled the ABCG2 expression. In the presence of Doxo, miR-491 inhibitor reduced the inhibitory effect of ASA on the cell viability of SP cells, which was significantly reversed by knockdown of ABCG2 (P<0.05).Conclusion: ASA enhanced the sensitivity of SP cells to Doxo via regulating the miR-491/ABCG2 signaling pathway.

The effects of Curcumin on HCT-116 cells proliferation and apoptosis via the miR-491/PEG10 pathway

Paternally expressed gene-10 (PEG10) could participate in several carcinomas and might be regulated by miR-491. To now, miR-491 was found to play an important role in the sensitivity and mechanism of drug usage in the treatment of colorectal cancer, and drug resistance is a key factor to affect the disease healing. In this study, miR-491, PEG10, Wnt1, and β-catenin expression levels and their correlation with colorectal cancer were assessed in cancer tissues and adjacent parts. And the target relationship between PEG10 and miR-491 was verified. Meanwhile, the impaction of Curcumin on miR-491, PEG10, and Wnt/β-catenin signaling pathway were analyzed in HCT-116 cells. The effects of PEG10 and Curcumin on human HCT-116 cells proliferation and apoptosis were investigated by MTT and flow cytometry assay. Results showed that the expression of miR-491 in colon cancer tissues was decreased, but PEG10, Wnt1, and β-catenin were higher than that in adjacent tissues. The PEG10 gene 3' UTR could combine with miR-491 seed sequence and miR-491 overexpression could cause a decrease in PEG10, Wnt1, and β-catenin levels in human HCT-116 cells. Furthermore, PEG10 overexpression increased the expression levels of Wnt1 and β-catenin, thereby promoting cell proliferation and inhibiting apoptosis. In addition, Curcumin could up-regulate miR-491, inhibit PEG10, and Wnt/β-catenin signaling pathway. Consequently, Curcumin reduced HCT-116 cells proliferation and promoted cells apoptosis via the miR-491/PEG10 pathway. In conclusion, PEG10 was a target gene of miR-491, miR-491/PEG10 strengthen the sensitivity of Curcumin in HCT-116 cells proliferation and apoptosis, which might act as an ideal diagnostic biomarker treatment methods.

Ginsenoside Rh2 Targets EGFR by Up-Regulation of miR-491 to Enhance Anti-tumor Activity in Hepatitis B Virus-Related Hepatocellular Carcinoma

Hepatocellular carcinoma (HCC) is one of the most aggressive tumors in humans. The typical therapeutic strategies include a combination of chemotherapy, radiotherapy, and surgery, whereas the survival rate of patients is very poor. Ginsenoside Rh2 has been reported to have therapeutic effects on some tumors, but its effect on HCC has not been extensively evaluated. Here, we show that ginsenoside Rh2 can effectively inhibit the proliferation and cell survival of HCC cells in vitro and in a mouse model. Moreover, the inhibition of the tumor growth appears to result from combined effects on decreased tumor cell proliferation and cell viability. Further analyses suggest that ginsenoside Rh2 may have its anti-tumor effect through inhibition of epidermal growth factor receptor (EGFR) signaling pathway. Recombinant EGFR was given together with ginsenoside Rh2 to the tumor cells, which completely blocked the anti-tumor effect of ginsenoside Rh2. Our data also show that miR-491 is up-regulated in SMMC-7721 cells after Rh2 treatment. There is a negative correlation between EGFR and miR-491 levels in SMMC-7721 cells and miR-491 directly targeted EGFR at translational level. Our data not only reveal an anti-tumor effect of ginsenoside Rh2 but also demonstrate that this effect may function via activation and inhibition of EGFR signaling in HCC cells. The results suggest miR-491 can be a promising regulatory factor in EGFR signal transduction.

miR-491 regulates glioma cells proliferation by targeting TRIM28 in vitro

Background

MicroRNAs are significantly involved in tumorigenesis and progression of glioma. However, the critical part they play in glioma have not been fully elaborated. miR-491 and Tripartite motif containing 28 (TRIM28) are reported to aberrantly express in glioblastoma multiforme (GBM). Here, we detected miR-491 and TRIM28 expression and function in glioma cells.

Methods

We analyzed miR-491 expressions in 20 primary human GBM tissues and 6 control brain tissues by qRT-PCR assays and searched for The Cancer Genome Atlas (TCGA) database. Then we predicted possible mRNA target of miR-491 by TargetScan/MicroRNA and confirmed it via luciferase reporter assays. Knock-down of miR-491 and transfection of pLenti-TRIM28 were performed in U251 and U87 cells. Proliferation ability was examined by MTT and clone formation assays.

Results

miR-491 expression was obviously reduced in GBM cells and tissues. There was a positive correlation between the down-regulation of miR-491 and poor prognosis. Spearman’s correlation analysis demonstrated that miR-491 expression was negatively correlated with TRIM28 protein level. Possible mRNA binding sites of miR-491 predicted by TargetScan/MicroRNA were proved by luciferase assays. Clone formation and MTT assays indicated that up-regulation of miR-491 inhibited the proliferation of glioma cells.

Conclusions

miR-491 regulates glioma cells proliferation in vitro by targeting TRIM28.

Electronic supplementary material

The online version of this article (doi:10.1186/s12883-016-0769-y) contains supplementary material, which is available to authorized users.

MiR-99a and MiR-491 Regulate Cisplatin Resistance in Human Gastric Cancer Cells by Targeting CAPNS1

Cisplatin is the first-line agent utilized for the clinical treatment of a wide variety of solid tumors including gastric cancer. However, the intrinsic or acquired cisplatin resistance is often occurred in patients with gastric cancer and resulted in failure of cisplatin therapy. In order to investigate if miRNA involves in cisplatin resistance of human gastric cancer, we first screened and compared the expression of miRNAs between cisplatin resistant gastric cancer cell lines SGC-7901/DDP and BGC-823/DDP and their sensitive parental cells by miRNAs microarray and followed by analysis of 2D-GE/MS to identify their target proteins. We found both miR-99a and miR-491 were upregulated while their target gene calpain small subunit 1 (CAPNS1) was downregulated in resistant gastric cancer cells. Dual-luciferase- reporter assays with wild-type and mutated CAPNS1 3'-UTR confirmed their specificity of targeting. Inhibition of miR-99a and miR-491, or overexpress CAPNS1 can enhance cisplatin sensitivity of the resistant cells while transfection of two miRNAs' mimics or si-CAPNS1 in the sensitive cells can induce their resistance. Moreover, our results demonstrated CAPNS1 positively regulated calpain1 and calpain2, the catalytic subunits of CAPNS1, and cleaved caspase3 which further cleaved PARP1 and directly induced apoptosis. Therefore, miR-99a and miR-491 might be work as novel molecules regulate cisplatin resistance by directly targeting CAPNS1 associated pathway in human gastric cancer cells.

Impulsivity and comorbid traits: a multi-step approach for finding putative responsible microRNAs in the amygdala

Malfunction of synaptic plasticity in different brain regions, including the amygdala plays a role in impulse control deficits that are characteristics of several psychiatric disorders, such as ADHD, schizophrenia, depression and addiction. Previously, we discovered a locus for impulsivity (Impu1) containing the neuregulin 3 (Nrg3) gene, of which the level of expression determines levels of inhibitory control. MicroRNAs (miRNAs) are potent regulators of gene expression, and have recently emerged as important factors contributing to the development of psychiatric disorders. However, their role in impulsivity, as well as control of Nrg3 expression or malfunction of the amygdala, is not well established. Here, we used the GeneNetwork database of BXD mice to search for correlated traits with impulsivity using an overrepresentation analysis to filter for biologically meaningful traits. We determined that inhibitory control was significantly correlated with expression of miR-190b, -28a, -340, -219a, and -491 in the amygdala, and that the overrepresented correlated traits showed a specific pattern of coregulation with these miRNAs. A bioinformatics analysis identified that miR-190b, by targeting an Nrg3-related network, could affect synaptic plasticity in the amygdala, targeting bot impulsive and compulsive traits. Moreover, miR-28a, -340, -219a, and possibly -491 could act on synaptic function by determining the balance between neuronal outgrowth and differentiation. We propose that these miRNAs are attractive candidates of regulation of amygdala synaptic plasticity, possibly during development but also in maintaining the impulsive phenotype. These results can help us to better understand mechanisms of synaptic dysregulation in psychiatric disorders.