Loss of PTEN/MMAC1 activity is a rare and late event in the pathogenesis of nephroblastomas

Somatic, Genetic and Epigenetic Changes in Nephrogenic Rests and Their Role in the Transformation to Wilms Tumors, a Systematic Review

OBJECTIVE

To review somatic genetic changes in nephrogenic rests (NR), which are considered to be precursor lesions of Wilms tumors (WT).

METHODS

This systematic review is written according to the PRISMA statement. PubMed and EMBASE were systematically searched for articles in the English language studying somatic genetic changes in NR between 1990 and 2022.

RESULTS

Twenty-three studies were included in this review, describing 221 NR of which 119 were pairs of NR and WT. Single gene studies showed mutations in WT1 and WTX, but not CTNNB1 to occur in both NR and WT. Studies investigating chromosomal changes showed loss of heterozygosity of 11p13 and 11p15 to occur in both NR and WT, but loss of 7p and 16q occurred in WT only. Methylome-based studies found differential methylation patterns between NR, WT, and normal kidney (NK).

CONCLUSIONS

Over a 30-year time frame, few studies have addressed genetic changes in NR, likely hampered by technical and practical limitations. A limited number of genes and chromosomal regions have been implicated in the early pathogenesis of WT, exemplified by their occurrence in NR, including WT1, WTX, and genes located at 11p15. Further studies of NR and corresponding WT are urgently needed.

MicroRNA-483-3p Promotes Proliferation, Migration, and Invasion and Induces Chemoresistance of Wilms' Tumor Cells

Wilms' tumor is the most common pediatric renal malignancy. MiRNAs are important regulators in multiple cancers including Wilms' tumor. In this study, we examined the role of miR-483-3p on proliferation, chemosensitivity, migration, and invasion of Wilms' tumor cells. The proliferation of Wilms' tumor cells was examined using WST-1 assay. The migration and invasion of Wilms' tumor cells were evaluated by transwell migration assay and matrigel invasion assay. The protein expression levels were detected by Western blot. The effect of miR-483-3p on doxorubicin-induced apoptosis in Wilms' tumor cells was evaluated by caspase-Glo3/7 assay. Forced expression of miR-483-3p promoted the proliferation, migration, and invasion in Wilms' tumor cells. Meanwhile, miR-483-3p decreased the sensitivity of Wilms' tumor cells after doxorubicin treatment. MiR-483-3p inhibited the doxorubicin-induced apoptosis in Wilms' tumor cells by the regulation of BAX and Bcl-2 expression. Furthermore, miR-483-3p regulated epithelial-mesenchymal transition by affecting the expression of E-cadherin, N-cadherin, snail, and vimentin in Wilms' tumor cells. Further studies showed that the expression levels of PTEN and p-AKT in Wilms' tumor cells were changed after aberrant expression of miR-483-3p by binding to 3'-UTR of PTEN. Our study suggests that miR-483-3p played important roles in proliferation and progression in Wilms' tumor cells and might serve as a potential prognostic biomarker and predict chemotherapy response in Wilms' tumor.

Expression of PTEN and Its Correlation with Proliferation Marker Ki-67 in Head and Neck Cancer

Introduction

PTEN is part of large family of tyrosine phosphatases and has been found inactivated in a wide variety of human cancers.

Aims

In the present study we have tried to determine the association of the expression patterns of this gene with carcinogenesis.

Methods

First, a systematic review was carried out to ascertain the importance of the PTEN gene and its role in carcinogenesis. In the second phase, a case-control study was designed using different expression analysis techniques. Expression of PTEN mRNA was analyzed using reverse transcriptase polymerase chain reaction (RT-PCR).

Results

Significantly downregulated expression of PTEN was observed in patients with head and neck cancer (HNC) compared to adjacent normal-tissue controls. These results were confirmed with quantitative polymerase chain reaction (qPCR). Significant downregulation of the gene was observed in HNC patients compared to adjacent normal-tissue controls. PTEN expression was correlated with different histopathological parameters of the study cohort by Spearman's correlation coefficient and a significant negative correlation was observed with pT stage (r = −0.271*; p<0.02) and grade (r = −0.228*; p<0.02) of HNC tissues. Furthermore, the expression variations of PTEN were correlated with the expression pattern of the proliferation marker Ki-67. Significantly (p<0.008) upregulated expression of Ki-67 was observed in HNC patients compared with adjacent normal-tissue controls This upregulation of Ki-67 was confirmed at the protein level by immunohistochemistry in HNC patients. When Spearman's correlation was carried out a significant negative correlation was observed between PTEN and Ki-67 (r = −0.230*; p<0.03).

Conclusions

Our data suggest that downregulation of PTEN and overexpression of Ki-67 may contribute to the initiation and progression of HNC.