The tumor suppressor role of microRNA-338-3p in renal cell carcinoma

The expression and significance of long non-coding RNA ITGB2-AS1 in renal clear cell carcinoma

OBJECTIVES

To explore the expression and significance of long non-coding RNA ITGB2-AS1 in kidney renal clear cell carcinoma (KIRC).

METHODS

The expression of ITGB2-AS1 in KIRC tissues of 45 KIRC patients in the first affiliated hospital of Henan University, Henan, China, from September 2018 to December 2020, KIRC cells were detected and the relationship of ITGB2-AS1 and overall survival of KIRC patients were analyzed. The expression of ITGB2-AS1 in KIRC cells Caki-1 and ACHN was interfered, and the changes of cell proliferation, invasion, migration, and apoptosis were detected. Dual luciferase reporter gene assay and RNA pull-down assay were carried out to verify the relationship between ITGB2-AS1 and miR-338-3p or miR-338-3p and epidermal growth factor receptor (EGFR). The expression of miR-338-3p and EGFR were detected after the interference of ITGB2-AS1.

RESULTS

The expression of ITGB2-AS1 was expressed highly in KIRC tissues and cells (p<0.05). The overall survival of KIRC patients with high ITGB2-AS1 was poorer than those with low ITGB2-AS1. In Caki-1 cell, downregulation of ITGB2-AS1 suppressed the cell proliferation, invasion and migration, promoted the cell apoptosis (p<0.05). In ACHN cell, upregulation of ITGB2-AS1 promoted the cell proliferation, invasion and migration and inhibited the apoptosis (p<0.05). The ITGB2-AS1 targeted and regulated the expression of miR-338-3p/EGFR.

CONCLUSION

The ITGB2-AS1 is expressed highly in KIRC and affects the survival of patients by regulating cell proliferation, invasion, and apoptosis.

SPRR3, a novel miR‑338‑3p target, regulates the malignant progression of clear cell renal cell carcinoma in vitro via the PI3K/Akt signaling pathway

Clear cell renal cell carcinoma (ccRCC) is the most common type of renal cell carcinoma and has a poor prognosis. However, its underlying mechanisms remain unclear. The present study aimed to evaluate the role of small proline-rich repeat protein 3 (SPRR3) in the proliferation, migration and invasion of ccRCC cells and to investigate its upstream and downstream regulatory mechanisms. Survival analysis was performed using the UALCAN website based on the The Cancer Genome Atlas database. Normal renal cell line HK-2 and ccRCC cell lines (786-O, CaKi-1 and UMRC-2) were used. Reverse transcription-quantitative PCR (RT-qPCR) was used to detect mRNA and microRNA (miRNA) levels. Western blotting was used to detect protein levels. Cell Counting Kit-8 and colony formation assays, a wound healing assay and a Transwell invasion assay were used to assess the proliferation, migration and invasion of ccRCC cells, respectively. Transfection of overexpression plasmids and small interfering RNAs were used to upregulate and knockdown SPRR3 expression, respectively. Transfection of miRNA-mimics was used to overexpress miR-338-3p. A luciferase reporter gene assay was used to verify the predicted binding relationship between SPRR3 mRNA and miR-338-3p. The results indicated the following: i) SPRR3 was a risk factor for the survival of patients with ccRCC, and was upregulated in ccRCC cell lines; ii) SPRR3 promoted the proliferation, migration and invasion of ccRCC cells; iii) SPRR3 regulated the tumor phenotypes of ccRCC cells via the PI3K/Akt pathway; iv) miR-338-3p directly targeted SPRR3 mRNA and negatively regulated SPRR3 expression; and v) miR-338-3p inhibited the PI3K/Akt pathway and the tumor phenotypes of ccRCC cells by downregulating SPRR3. In conclusion, SPRR3, as a novel target of miR-338-3p, regulated the proliferation, migration and invasion of ccRCC cells via the PI3K/Akt pathway; this finding not only enriches our understanding of the mechanism underlying ccRCC development, but also demonstrates a potential novel therapeutic target for this disease.

Clear Cell Renal Carcinoma: MicroRNAs With Efficacy in Preclinical In Vivo Models

In order to identify new targets and treatment modalities for clear cell renal carcinoma, we surveyed the literature with respect to microRNAs involved in this disease. In this review, we have focused on up- and down-regulated miRs which mediate efficacy in preclinical clear-cell renal carcinoma-related in vivo models. We have identified 10 up-regulated and 33 down-regulated micro-RNAs according to this criterion. As proof-of-concept, micro-RNAs interfering with VEGF (miR-205p) and mTOR (mir-99a) pathways, which are modulated by approved drugs for this disease, have been identified. miRs targeting hypoxia induced factor-2α (HIF-2α) (miR-145), E3 ubiquitinylases speckle-type POZ protein (SPOP) (miR 520/372/373) and casitas B-lineage lymphoma (CBL) (miR-200a-3p), interfere with druggable targets. Further identified miRs interfere with cell-cycle dependent kinases, such as CDK2 (miR-200c), CDK4, 6 (miR-1) and CDK4, 9 (206c). Transmembrane receptor Ral interacting protein of 76 kD (RLIP76), targeted by mir-137, has emerged as another important target for ccRCC. Additional miRs and their targets merrying further preclinical validation are discussed.

Long non-coding RNA NR2F1-AS1 promoted proliferation and migration yet suppressed apoptosis of thyroid cancer cells through regulating miRNA-338-3p/CCND1 axis

Thyroid cancer (TC) is a prevalent endocrine malignant cancer whose pathogenic mechanism remains unclear. The aim of the study was to investigate the roles of long non‐coding RNA (lncRNA) NR2F1‐AS1/miRNA‐338‐3P/CCND1 axis in TC progression. Differentially expressed lncRNAs and mRNAs in TC tissues were screened out and visualized by R program. Relative expression of NR2F1‐AS1, miRNA‐338‐3p and cyclin D1 (CCND1) was determined by quantitative real time polymerase chain reaction. In addition, Western blot analysis was adopted for evaluation of protein expression of CCND1. Targeted relationships between NR2F1‐AS1 and miRNA‐338‐3p, as well as miRNA‐338‐3p and CCND1 were predicted using bioinformatics analysis and validated by dual‐luciferase reporter gene assay. Besides, tumour xenograft assay was adopted for verification of the role of NR2F1‐AS1 in TC in vivo. NR2F1‐AS1 and CCND1 were overexpressed, whereas miRNA‐338‐3p was down‐regulated in TC tissues and cell lines. Down‐regulation of NR2F1‐AS1 and CCND1 suppressed proliferation and migration of TC cells yet greatly enhanced cell apoptotic rate. Silence of NR2F1‐AS1 significantly suppressed TC tumorigenesis in vivo. NR2F1‐AS1 sponged miRNA‐338‐3p to up‐regulate CCND1 expression to promote TC progression. Our study demonstrated that up‐regulation of NR2F1‐AS1 accelerated TC progression through regulating miRNA‐338‐3P/CCND1 axis.