Aberrant expression and mechanism of miR-130b-3p/phosphatase and tensin homolog in nephroblastoma in children

Regulation of miRNAs Expression by Mutant p53 Gain of Function in Cancer

The p53 roles have been largely described; among them, cell proliferation and apoptosis control are some of the best studied and understood. Interestingly, the mutations on the six hotspot sites within the region that encodes the DNA-binding domain of p53 give rise to other very different variants. The particular behavior of these variants led to consider p53 mutants as separate oncogene entities; that is, they do not retain wild type functions but acquire new ones, namely Gain-of-function p53 mutants. Furthermore, recent studies have revealed how p53 mutants regulate gene expression and exert oncogenic effects by unbalancing specific microRNAs (miRNAs) levels that provoke epithelial-mesenchymal transition, chemoresistance, and cell survival, among others. In this review, we discuss recent evidence of the crosstalk between miRNAs and mutants of p53, as well as the consequent cellular processes dysregulated.

CircSLC7A6 promotes the progression of Wilms' tumor via microRNA-107/ ABL proto-oncogene 2 axis

The dysregulation of circular RNAs (circRNAs) has been proved to be involved in the carcinogenesis of various cancers. Nevertheless, the biological function of circSLC7A6 remains unclear in Wilms’ tumor (WT). In our study, we found that circSLC7A6 was upregulated in cancerous WT tissues and cells. Cell apoptosis was increased while cell viability, migration, and invasion were repressed by circSLC7A6 silencing. Besides, circSLC7A6 knockdown suppressed WT tumor growth in vivo. miR-107 was identified as a direct target of circSLC7A6, and circSLC7A6 could negatively regulate miR-107 expression. In addition, circSLC7A6 knockdown inhibited WT progression, while the effect was partially abolished by the downregulation of miR-107. Additionally, ABL proto-oncogene 2 axis (ABL2) was verified as a downstream gene of miR-107, and circSLC7A6 could upregulate ABL2 expression by serving as a ceRNA of miR-107. Moreover, functional assays revealed that ABL2 overexpression reversed the impact of circSLC7A6 depletion on cell proliferation, migration, invasion, and apoptosis of WT. In conclusion, the present study demonstrated that circSLC7A6 facilitated WT progression by upregulating ABL2 through inhibiting miR-107 expression. These results suggested that circSLC7A6 might serve as a potential therapeutic target for WT.

FOXO3a inhibits nephroblastoma cell proliferation, migration and invasion, and induces apoptosis through downregulating the Wnt/β‑catenin signaling pathway

Forkhead transcription factor O subfamily 3A (FOXO3a) is an important tumor suppressor gene that is expressed in renal tissue and has been reported to be downregulated in clear cell renal cell carcinoma (CCRCC). Notably, the overexpression of FOXO3a was previously discovered to inhibit the progression of CCRCC. However, the expression levels of FOXO3a in nephroblastoma cell lines remain unknown. The present study aimed to investigate the expression levels of FOXO3a in nephroblastoma cell lines and to determine the mechanism of action of the biological functions of FOXO3a. Western blotting and reverse transcription‑quantitative PCR were used to analyze the expression levels of FOXO3a in nephroblastoma cell lines. Subsequently, the effects of the overexpression of FOXO3a and the genetic knockdown of the Wnt/β‑catenin signaling protein Axin‑2 on the biological functions were determined through Cell Counting Kit‑8, cell colony formation assays, scratch and Transwell assay and flow cytometric analysis experiments. The expression levels of FOXO3a were discovered to be downregulated in nephroblastoma cell lines. The overexpression of FOXO3a inhibited the proliferation, invasion and migration of nephroblastoma cells, while inducing apoptosis. Furthermore, the overexpression of FOXO3a downregulated the expression levels of β‑catenin and Cyclin‑D1 proteins involved in the Wnt/β‑catenin signaling pathway. Cell proliferation and the migration and invasion ability of 17‑94 cells in shRNA‑Axin2‑2 group were promoted. Cell apoptosis was predominantly increased by overexpressed FOXO3a, which was reversed by shRNA‑Axin2‑1. The biological effects of overexpressing FOXO3a on nephroblastoma were reversed after activation of Wnt/β‑catenin. In conclusion, the findings of the present study suggested that FOXO3a may inhibit nephroblastoma cell proliferation, migration and invasion, while inducing apoptosis, by downregulating the Wnt/β‑catenin signaling pathway. These results may provide a novel method for the early diagnosis and precise treatment of nephroblastoma.