MiR-935 Promotes Clear Cell Renal Cell Carcinoma Migration and Invasion by Targeting IREB2

MiR-24-1-5p Hinders Malignant Phenotypes of Clear Cell Renal Cell Carcinoma by Targeting SHOX2

MiRNAs are essential epigenetic modulators that can regulate protein expression. According to the principle of base complementary pairing, miRNA is partially or completely complementary to the 3'-UTR region of its target gene, by which it inhibits the translation of the targeted gene. This study investigated the role of miR-24-1-5p in clear cell renal cell carcinoma (ccRCC). Data in TCGA-KIRC denoted that miR-24-1-5p was under-expressed in ccRCC. Bioinformatics analysis predicted that its target gene was SHOX2, which was significantly expressed in cancer tissues. Dual luciferase assay verified the targeting relationship between miR-24-1-5p and SHOX2. Cell function experiments demonstrated that overexpression of miR-24-1-5p significantly inhibited SHOX2 level and the malignant phenotypes of ccRCC cells. The above results illustrated that miR-24-1-5p/SHOX2 axis was critical for the oncogenesis and development of ccRCC, which might be helpful for us to understand the mechanism and novel therapeutic methods of ccRCC.

The Profile of MicroRNA Expression and Potential Role in the Regulation of Drug-Resistant Genes in Doxorubicin and Topotecan Resistant Ovarian Cancer Cell Lines

Epithelial ovarian cancer has the highest mortality among all gynecological malignancies. The main reasons for high mortality are late diagnosis and development of resistance to chemotherapy. Resistance to chemotherapeutic drugs can result from altered expression of drug-resistance genes regulated by miRNA. The main goal of our study was to detect differences in miRNA expression levels in two doxorubicin (DOX)- and two topotecan (TOP)-resistant variants of the A2780 drug-sensitive ovarian cancer cell line by miRNA microarray. The next aim was to recognize miRNAs as factors responsible for the regulation of drug-resistance genes. We observed altered expression of 28 miRNA that may be related to drug resistance. The upregulation of miR-125b-5p and miR-935 and downregulation of miR-218-5p was observed in both DOX-resistant cell lines. In both TOP-resistant cell lines, we noted the overexpression of miR-99a-5p, miR-100-5p, miR-125b-5p, and miR-125b-2-3p and decreased expression of miR-551b-3p, miR-551b-5p, and miR-383-5p. Analysis of the targets suggested that expression of important drug-resistant genes such as the collagen type I alpha 2 chain (COL1A2), protein Tyrosine Phosphatase Receptor Type K (PTPRK), receptor tyrosine kinase—EPHA7, Roundabout Guidance Receptor 2 (ROBO2), myristoylated alanine-rich C-kinase substrate (MARCK), and the ATP-binding cassette subfamily G member 2 (ABCG2) can be regulated by miRNA.

MicroRNA-155-5p Targets NR3C2 to Promote Malignant Progression of Clear Cell Renal Cell Carcinoma

BACKGROUND

The molecular heterogeneity of clear cell renal cell carcinoma (ccRCC) leads to a high mortality of the disease, which seriously threatens the life of patients. Therefore, this study explored the functional significance and mechanism of microRNA-155-5p and nuclear receptor subfamily 3 group C member 2 (NR3C2) in the regulation of ccRCC.

METHODS

Expression levels of microRNA-155-5p and NR3C2 mRNA in ccRCC cells were analyzed by qRT-PCR, and the protein expression of NR3C2 in human ccRCC cells was measured by Western blot. Biological functions were determined through a series of in vitro experiments. The interaction between microRNA-155-5p and NR3C2 was tested by luciferase reporter gene assay. In addition, the effect of overexpressed or silenced microRNA-155-5p on cell phenotypes was evaluated in ccRCC cells.

RESULTS

Experimental data suggested that overexpression or silencing of microRNA-155-5p in ccRCC could boost or suppress cancer cell proliferation and other malignant behaviors. Rescue experiments revealed that microRNA-155-5p facilitated the proliferation, migration, and invasion and suppressed the apoptosis of ccRCC by directly inhibiting the expression of NR3C2.

CONCLUSIONS

This is the first study to generate new insights into the role of microRNA-155-5p/NR3C2 interaction in promoting the process of ccRCC, and it is possible to bring a turning point for the treatment of ccRCC.

MiR-532-3p suppresses cell viability, migration and invasion of clear cell renal cell carcinoma through targeting TROAP

Clear cell renal cell carcinoma (ccRCC) is a subtype of renal cell cancer with the highest mortality, infiltration, and metastasis rate, threatening human health. Despite oncogenic role of TROAP in various cancers, its function in ccRCC remains to be unraveled. The differentially expressed mRNAs (DEmRNAs) and miRNAs (DEmiRNAs) were obtained by analyzing the related data sets of ccRCC in TCGA. The expression levels of mRNAs and miRNAs in the cell were detected by qRT-PCR, while the protein levels were characterized by western blot. The viability, migratory and invasive abilities of ccRCC cells were determined by MTT, wound healing and cell invasion assays. The combination of miRNA target site prediction and dual-luciferase reporter gene assay verified the binding relationship between miR-532-3p and TROAP. Research on ccRCC displayed that TROAP expression was upregulated, while miR-532-3p was down-regulated. Besides, upregulation of TROAP could accelerate viability, migratory and invasive potentials of ccRCC cells. On the contrary, miR-532-3p could downregulate TROAP level, but TROAP upregulation reversed the viability, migration, and invasion of ccRCC cells. MiR-532-3p could attenuate the viability, migration and invasion of ccRCC cells by targeting TROAP. This may generate novel insights into molecular therapeutic targets for ccRCC.

Discovery and validation of hsa_circ_0001953 as a potential biomarker for proliferative diabetic retinopathy in human blood

PURPOSE

This study aimed to determine whether circular RNAs (circRNAs) in whole blood could be served as novel non-invasive biomarkers for proliferative diabetic retinopathy (PDR).

METHODS

This retrospective cross-sectional study comprised 34 healthy participants, 34 PDR patients and 34 non-proliferative DR (NPDR) patients. High-throughput whole transcriptome sequencing was performed to explore the expression profile of circRNAs in the whole blood, and the candidate circRNAs were validated by quantitative real-time polymerase chain reaction (qRT-PCR). Receiver operating characteristic (ROC) analysis evaluated the ability of these candidate circRNAs in discriminating PDR patients from NPDR patients and healthy subjects. Finally, the networks of circRNA-miRNA-mRNA based on the candidate circRNAs were constructed.

RESULTS

Using sequencing and qRT-PCR, hsa_circ_0001953 was found to be elevated in PDR patients in contrast with the other two groups. Statistical analysis showed that the expression levels of hsa_circ_0001953 in PDR patients were positively related to the duration of diabetes and HbAc1. Receiver operating characteristic (ROC) curve analysis revealed that hsa_circ_0001953 was associated with a high diagnostic accuracy in discriminating PDR patients from NPDR patients and healthy controls, resulting in an area under the curve (AUC) of 0.87 and 0.92, respectively. The circRNA-miRNA-target gene networks for hsa_circ_0001953 showed that hsa_circ_0001953 could interact with dozens of miRNAs and some targeted mRNAs have been potentially involved in the pathogenesis of diabetes.

CONCLUSION

The present findings indicate that hsa_circ_0001953 in the whole blood may serve as a novel diagnostic biomarker and potential therapeutic target for PDR.

MicroRNA-935 Directly Targets FZD6 to Inhibit the Proliferation of Human Glioblastoma and Correlate to Glioma Malignancy and Prognosis

MicroRNAs (miRNAs) are involved in human glioblastoma (GB). MiR-935 has been reported to have both tumor-inhibiting and tumorigenesis effects, but its role in GB remains unclear. Because of the high mortality and morbidity associated with the malignancy of GB, a deeper understanding of the molecular crosstalk that occurs in GB is needed to identify new potential targets for treatment. At present, the mechanism of GB at the molecular level is not fully understood. With the aid of bioinformatic analysis, miR-935 was significantly downregulated in GB, and it presented a poorer outcome. In the glioma cell line and in the nude mice model, the miR-935 inhibited cell proliferation by modulating cell circles in vitro and in vivo. Then, the target genes of miR-935 were analyzed by using the online database, and the direct binding was tested with a luciferase analysis. FZD6 was found to be the direct target of miR-935. The effect of miR-935 was recovered by the overexpression of FZD6 in vitro. In addition, the negative correlation of miR-935 and the expression of FZD6 were confirmed in our clinical samples, and the expression of FZD6 has a strong correlation with tumor malignancy and prognosis. This study showed that miR-935 directly inhibited the expression of FZD6 and inhibited the cell proliferation, thereby suppressing the development of GB, suggesting that miR-935 is a cancer suppressor miRNA and may become a prognostic biomarker or a promising potential therapeutic target for human GBs.

Exosomes derived from chronic lymphocytic leukaemia cells transfer miR-146a to induce the transition of mesenchymal stromal cells into cancer-associated fibroblasts

Chronic lymphocytic leukaemia (CLL) is the most prevalent leukaemia and remains incurable. Mesenchymal stem cells (MSCs) can promote tumour progression by differentiating into cancer-associated fibroblasts (CAFs). However, the mechanisms by which tumour cells induce the transition of MSCs to CAFs are still largely undefined. Exosomes can regulate recipient cellular function by mediating intracellular communication. This study aimed to investigate whether CLL cells regulate the transition of bone marrow-derived MSCs (BM-MSCs) to CAFs via exosomal miR-146a delivery. The exosomes were isolated from CLL cell line MEC-1 (CLL-Exo) and then co-cultured with BM-MSCs. The expression of α-smooth muscle actin (α-SMA) and fibroblast-activated protein (FAP) were determined by immunofluorescence, quantitative real-time polymerase chain reaction and western blot. A luciferase reporter assay was performed to verify whether ubiquitin-specific peptidase 16 (USP16) was a target of miR-146a. CLL-Exo treatment up-regulated miR-146a and down-regulated expression of CAF markers (α-SMA and FAP) and USP16. The inducing effect of CLL-Exo on CAF marker expression was compromised when miR-146a expression was inhibited in CLL-Exo. USP16 was confirmed as a direct target of miR-146a and USP16 overexpression in BM-MSCs abrogated the CLL-Exo-mediated up-regulation of CAF markers. Collectively, CLL-Exo delivered miR-146a into BM-MSCs where miR-146a mediated transition of BM-MSCs into CAFs by targeting USP16.

miR-30d-5p suppresses proliferation and autophagy by targeting ATG5 in renal cell carcinoma

Previous reports have shown that miR-30d-5p functions as a tumor suppressor in prostate cancer and gallbladder carcinoma, but its role in renal cell carcinoma (RCC) remains elusive. This study was designed to explore the functional role of miR-30d-5p in proliferation and autophagy of RCC. Our results show that miR-30d-5p is significantly down-regulated in RCC tissues compared with normal tissues. miR-30d-5p overexpression suppressed cell proliferation, cell-cycle G1/S transition and autophagy, but promoted apoptosis in RCC cell lines (786-O and ACHN). Intriguingly, autophagy-related gene 5 (ATG5) was directly targeted by miR-30d-5p, as shown using luciferase reporter assay and biotin-avidin pull-down assay. Moreover, overexpression of ATG5 attenuated the inhibitory effect of miR-30d-5p on proliferation and autophagy in 786-O cells. These results suggest that miR-30d-5p suppresses proliferation and autophagy in RCC cells by targeting ATG5, and this pathway may be a suitable basis for the design of novel cancer therapeutics.

MicroRNA Signature in Renal Cell Carcinoma

Renal cell carcinoma (RCC) includes 2.2% of all diagnosed cancers and 1.8% of cancer-related mortalities. The available biomarkers or screening methods for RCC suffer from lack of sensitivity or high cost, necessitating identification of novel biomarkers that facilitate early diagnosis of this cancer especially in the susceptible individuals. MicroRNAs (miRNAs) have several advantageous properties that potentiate them as biomarkers for cancer detection. Expression profile of miRNAs has been assessed in biological samples from RCC patients. Circulatory or urinary levels of certain miRNAs have been proposed as markers for RCC diagnosis or follow-up. Moreover, expression profile of some miRNAs has been correlated with response to chemotherapy, immunotherapy or targeted therapeutic options such as sunitinib. In the current study, we summarize the results of studies that assessed the application of miRNAs as biomarkers, therapeutic targets or modulators of response to treatment modalities in RCC patients.

A novel circRNA, circNUP98, a potential biomarker, acted as an oncogene via the miR-567/ PRDX3 axis in renal cell carcinoma

In recent years, plenty of studies found that circular RNAs (circRNAs) were essential players in the initiation and progression of various cancers including the renal cell carcinoma (RCC). However, the knowledge about the circRNAs in carcinogenesis is still limited. Dysregulated expression of circNUP98 in RCC tissues was identified by the circular RNA microarray. RT‐PCR was performed to measure the expression of circNUP98 in 78 pairs of RCC tissues and adjacent normal tissues. Survival analysis was conducted to explore the association between the expression of circNUP98 and the prognosis of RCC. The function and underlying mechanisms of circSMC3 in RCC cells were investigated by RNAi, CCK‐8, Western blotting, bioinformatic analysis, ChIP assay, circRIP assay and dual luciferase reporter assay. CircNUP98 was up‐regulated in both RCC tissues and cell lines, and high expression of circNUP98 was correlated with poor prognosis of RCC patients. Silencing of circSMC3 inhibited the proliferation and promoted the apoptosis in a caspase‐dependent manner in RCC cells. Mechanistically, we revealed that silencing of circ NUP98 inhibited RCC progression by down‐regulating of PRDX3 via up‐regulation of miR‐567. Furthermore, STAT3 was identified as an inducer of circ NUP98 in RCC cells. CircNUP98 acts as an oncogene by a novel STAT3/circ NUP98/miR‐567/PRDX3 axis, which may provide a potential biomarker and therapeutic target for the treatment of RCC.