Analyzing the gene expression profile of anaplastic histology Wilms' tumor with real-time polymerase chain reaction arrays

Characterization of Alternative Splicing in High-Risk Wilms' Tumors

The significant heterogeneity of Wilms' tumors between different patients is thought to arise from genetic and epigenetic distortions that occur during various stages of fetal kidney development in a way that is poorly understood. To address this, we characterized the heterogeneity of alternative mRNA splicing in Wilms' tumors using a publicly available RNAseq dataset of high-risk Wilms' tumors and normal kidney samples. Through Pareto task inference and cell deconvolution, we found that the tumors and normal kidney samples are organized according to progressive stages of kidney development within a triangle-shaped region in latent space, whose vertices, or "archetypes", resemble the cap mesenchyme, the nephrogenic stroma, and epithelial tubular structures of the fetal kidney. We identified a set of genes that are alternatively spliced between tumors located in different regions of latent space and found that many of these genes are associated with the epithelial-to-mesenchymal transition (EMT) and muscle development. Using motif enrichment analysis, we identified putative splicing regulators, some of which are associated with kidney development. Our findings provide new insights into the etiology of Wilms' tumors and suggest that specific splicing mechanisms in early stages of development may contribute to tumor development in different patients.

HrpA anchors meningococci to the dynein motor and affects the balance between apoptosis and pyroptosis

BACKGROUND

In Neisseria meningitidis the HrpA/HrpB two-partner secretion system (TPS) was implicated in diverse functions including meningococcal competition, biofilm formation, adherence to epithelial cells, intracellular survival and vacuolar escape. These diverse functions could be attributed to distinct domains of secreted HrpA.

METHODS

A yeast two-hybrid screening, in vitro pull-down assay and immunofluorescence microscopy experiments were used to investigate the interaction between HrpA and the dynein light-chain, Tctex-type 1 (DYNLT1). In silico modeling was used to analyze HrpA structure. Western blot analysis was used to investigate apoptotic and pyroptotic markers.

RESULTS

The HrpA carboxy-terminal region acts as a manganese-dependent cell lysin, while the results of a yeast two-hybrid screening demonstrated that the HrpA middle region has the ability to bind the dynein light-chain, Tctex-type 1 (DYNLT1). This interaction was confirmed by in vitro pull-down assay and immunofluorescence microscopy experiments showing co-localization of N. meningitidis with DYNLT1 in infected epithelial cells. In silico modeling revealed that the HrpA-M interface interacting with the DYNLT1 has similarity with capsid proteins of neurotropic viruses that interact with the DYNLT1. Indeed, we found that HrpA plays a key role in infection of and meningococcal trafficking within neuronal cells, and is implicated in the modulation of the balance between apoptosis and pyroptosis.

CONCLUSIONS

Our findings revealed that N. meningitidis is able to effectively infect and survive in neuronal cells, and that this ability is dependent on HrpA, which establishes a direct protein-protein interaction with DYNLTI in these cells, suggesting that the HrpA interaction with dynein could be fundamental for N. meningitidis spreading inside the neurons. Moreover, we found that the balance between apoptotic and pyroptotic pathways is heavily affected by HrpA.

Genetic Polymorphisms of the TGFB1 Signal Peptide and Promoter Region: Role in Wilms Tumor Susceptibility?

The aim of the present study was to investigate the rs1800468 (G-800A), rs1800469 (C-509T), rs1800470 (C29T), and rs1800471 (G74C) TGFB1 genetic polymorphisms and their haplotype structures in patients with Wilms Tumor (WT) and neoplasia-free controls. The genomic DNA was extracted from 35 WT patients and 160 neoplasia-free children, and the TGFB1 polymorphisms were genotyped by polymerase chain reaction, followed by restriction fragment length polymorphism. The haplotype structures were inferred, and permutation and logistic regression tests were performed to check for differences in haplotype distribution between the control and WT individuals. Positive associations were found in the recessive model for rs1800469 T allele (OR: 8.417; 95% CI: 3.177 to 22.297; P < 0.001) and for the rs1800470 C allele (OR: 3.000; 95% CI: 1.296 to 6.944; P = 0.01). Haplotype analysis revealed a significant negative association between GCTG and WT (OR: 0.236, 95% CI: 0.105 to 0.534; P = 0.0002); by contrast, the GTTG haplotype was associated with increased risk for WT (OR: 12.0; 95% CI: 4.202 to 34.270; P < 0.001). Furthermore, rs1800469 was negatively correlated with tumor size and a trend toward a positive correlation for capsular invasion was observed in the dominant model (Tau-b: −0.43, P = 0.02 and tau-b: 0.5, P = 0.06, respectively). This is the first study with rs1800468, rs1800469, rs1800470, and rs1800471 TGFB1 polymorphisms in WT, and our results suggest that the TGFB1 promoter and signal peptide region polymorphisms may be associated with WT susceptibility and clinical presentation.

Targeting the HIF-1α-IGFBP2 axis therapeutically reduces IGF1-AKT signaling and blocks the growth and metastasis of relapsed anaplastic Wilms tumor

For patients with anaplastic Wilms tumor (WiT), metastasis and recurrence are common, and prognosis is generally poor. Novel therapies are needed to improve outcomes for patients with this high-risk WiT. A potential contributor to WiT development is constitutive activation of AKT by insulin-like growth factor 1 (IGF1) and its receptor (IGF1R) signaling pathway, but the complete underlying mechanism remains unclear. Here, we demonstrate that the hypoxia-inducible factor 1α (HIF-1α)-IGF binding protein 2 (IGFBP2) axis and the tumor-specific IGF1A are key players for constitutive activation of IGF1-AKT signaling leading to the tumor malignancy. HIF-1α and IGFBP2 are highly expressed in a majority of WiT patient samples. Deficiency of either HIF-1α or IGFBP2 or IGF1 in the tumor cells significantly impairs tumor growth and nearly abrogates metastasis in xenografted mice. Pharmacologic targeting of HIF-1α by echinomycin delivered via nanoliposomes can efficiently restrain growth and metastasis of patient-derived relapsed anaplastic WiT xenografts. Liposomal echinomycin is more potent and effective in inhibiting WiT growth than vincristine in an anaplastic WiT mouse model, and eliminates metastasis by suppressing HIF-1α targets and the HIF-1α-IGFBP2 axis, which governs IGF1-AKT signaling.

Inhibition of Wilms' Tumor Proliferation and Invasion by Blocking TGF-β Receptor I in the TGF-β/Smad Signaling Pathway

Wilms' tumor (WT) is a common embryonal tumor, and nephrogenic rests play a critical role in WT development. The transforming growth factor β (TGF-β) signaling pathway is fundamental to embryo development and cell growth and proliferation. Moreover, TGF-β contributes to WT development, but the mechanisms of disease pathogenicity are unknown. This study investigated whether the TGF-β signaling pathway was involved in WT and whether blocking TβRI receptor inhibited WT growth, proliferation, and invasion. A total of 60 WT patients with clinical data and surgical specimens were evaluated. Immunohistochemistry (IHC) was used to detect the expression of TGF-β1 and P-smad2/3. In vitro, the proliferation, migration, apoptosis, and epithelial-mesenchymal transition (EMT) protein expression were analyzed using the CCK8 assay, wound healing assay, transwell assay, flow cytometry, and western blot, respectively. In vivo, tumor morphology, tumor size, toxicity, and EMT protein expression were analyzed in tumor-bearing mice treated with a TβRI kinase inhibitor or PBS. High protein levels of TGF-β1 and P-samd2/3 were associated with clinical stage and metastasis or invasion. TβRI inhibition effectively suppressed WT proliferation and migration and promoted apoptosis in the human WT cell line G401, consequently decreasing EMT protein expression. In addition, the TβRI kinase inhibitor significantly impaired the subcutaneous growth of WT. It is worth noting that treatment with the TβRI kinase inhibitor did not cause liver and kidney injury. Our results indicate that the TGF-β/Smad signaling pathway plays a crucial role in WT progression. Blocking the TβRI receptor may be a novel strategy to treat and prevent WT.

The predictive value of transforming growth factor-β in Wilms tumor immunopathogenesis

Wilms tumor is the most common kidney malignancy in children, especially in children aged less than 6 years. Although therapeutic approach has reached successful rates, there is still room for improvement. Considering the tumor microenvironment, cytokines represent important elements of interaction and communication between tumor cells, stroma, and immune cells. In this regard, the transforming growth factor beta (TGF-β) family members play significant functions in physiological and pathological conditions, particularly in cancer. By regulating cell growth, death, and immortalization, TGF-β signaling pathways exert tumor suppressor effects in normal and early tumor cells. Thus, it is not surprising that a high number of human tumors arise due to alterations in genes coding for various TGF-β signaling components. Understanding the ambiguous role of TGF-β in human cancer is of paramount importance for the development of new therapeutic strategies to specifically block the metastatic signaling pathway of TGF-β without affecting its tumor suppressive effect. In this context, this review attempt to summarize the involvement of TGF-β in Wilms tumor.

Preliminary observations regarding the expression of collagen triple helix repeat-containing 1 is an independent prognostic factor for Wilms' tumor

PURPOSE

Overexpression of collagen triple helix-repeat containing 1 (CTHRC1) has been reported in many malignancies, where it plays an important role in tumorigenesis and progression. This study aimed to examine the clinical significance of CTHRC1 expression in patients with Wilms' tumor (WT).

METHODS

The expression of CTHRC1, and its correlations with various clinicopathological parameters, was analyzed using immunohistochemistry in 42 WT tissues and 42 adjacent non-cancerous tissues. Samples from 8 patients with WT were examined using Western blotting and quantitative real-time polymerase chain reaction (qRT-PCR). Kaplan-Meier analysis and Cox proportional hazards regression models were used to investigate the correlations between CTHRC1 expression and the prognosis of patients with WT.

RESULTS

Immunohistochemistry, Western blotting, and qRT-PCR revealed that the expression of CTHRC1 was significantly higher in WT tumors, compared to the expression in the adjacent non-cancerous tissues. Furthermore, high tumor expression of CTHRC1 was associated with tumor size, clinical stage, histopathological type, and vascular invasion/metastasis. Moreover, the proportions of expressing cells in the WT specimens was higher than the proportions in the matched adjacent non-cancerous tissues. Kaplan-Meier analysis revealed that patients with high CTHRC1 expression exhibited a shorter survival, compared to patients with low CTHRC1 expression. Univariate and multivariate analyses also revealed that CTHRC1 expression was an independent prognostic factor for overall survival.

CONCLUSIONS

Our preliminary results suggest that CTHRC1 is an independent prognostic factor, which may play an important role in tumorigenesis and progression, and may be a potential biomarker for WT.