B7-H1 as a Biomarker for Therapy Failure in Patients with Favorable Histology Wilms Tumor

Assessment of the Circulating PD-1 and PD-L1 Levels and P53 Expression as a Predictor of Relapse in Pediatric Patients with Wilms Tumor and Hypernephroma

Background/Objectives: Wilms tumor (WT) is the most common form of pediatric renal tumor, accounting for over 90% of cases followed by hypernephroma. Some pediatric patients with WT (10%) experience relapse or metastasis and have poor survival rates. PD-L1 assists cancer cells in escaping damage from the immune system. P53 mutations are found in relapsed WT tumor samples. We hypothesized that testing circulating PD-1 and PD-L1 and P53 expression levels could offer a simple method to predict patient relapse and explore novel treatments for pediatric WTs and hypernephroma. Methods: Flow cytometric detection of cPD-1, cPD-L1, and P53 expression in relapsed and in-remission WT and hypernephroma before and after one year of chemotherapy was performed. Results: Our data shows increased levels of cPD-L1 in relapsed pediatric patients with WT or hypernephroma before and after chemotherapy. There were also slight and significant increases in cPD-1 levels in relapsed groups before chemotherapy. Additionally, we observed significant decreases in P53 expression after one year of chemotherapy in relapsed pediatric patients. Conclusions: Our study found that circulating PD-L1 can be used as a predictor marker for WT and hypernephroma relapse. In conclusion, these circulating markers can assist in monitoring relapse in WT and hypernephroma patients without the need for several biopsies.

Metastatic adult Wilms' tumor managed by chemotherapy, immunotherapy and target therapy: a case report

Wilms' tumor is a rare type of tumor in adult. Herein, we reported a case of 37-year-old female with adult Wilms' tumor (AWT) admitted in our institution. After a multidisciplinary team discussion, she underwent receiving immunotherapy plus chemotherapy and VEGF-targeted therapy. The tumor got smaller obviously after eight cycles of treatment. Our present case suggested that immunotherapy and anti-angiogenesis combined with chemotherapy is promising new approach for treating AWT. Moreover, we review the literatures reporting AWT with the purpose to improve the understanding of AWT treatment.

Checkpoint Immunotherapy in Pediatric Oncology: Will We Say Checkmate Soon?

Immune checkpoint inhibitors (ICIs) are a relatively new class of immunotherapy which bolsters the host immune system by "turning off the brakes" of effector cells (e.g., CTLA-4, PD-1, PD-L1). Although their success in treating adult malignancy is well documented, their utility in pediatric cancer has not yet been shown to be as fruitful. We review ICIs, their use in pediatric malignancies, and active pediatric clinical trials, exemplifying some of adult efforts that could be related to pediatric future trials and complications of ICI therapy. Through our review, we propose the consideration of ICI as standard therapy in lymphoma and various solid tumor types, especially in relapsed or refractory (R/R) disease. However, further studies are needed to demonstrate ICI effectiveness in pediatric leukemia.

Biomarkers and Corresponding Biosensors for Childhood Cancer Diagnostics

Although tremendous progress has been made in treating childhood cancer, it is still one of the leading causes of death in children worldwide. Because cancer symptoms overlap with those of other diseases, it is difficult to predict a tumor early enough, which causes cancers in children to be more aggressive and progress more rapidly than in adults. Therefore, early and accurate detection methods are urgently needed to effectively treat children with cancer therapy. Identification and detection of cancer biomarkers serve as non-invasive tools for early cancer screening, prevention, and treatment. Biosensors have emerged as a potential technology for rapid, sensitive, and cost-effective biomarker detection and monitoring. In this review, we provide an overview of important biomarkers for several common childhood cancers. Accordingly, we have enumerated the developed biosensors for early detection of pediatric cancer or related biomarkers. This review offers a restructured platform for ongoing research in pediatric cancer diagnostics that can contribute to the development of rapid biosensing techniques for early-stage diagnosis, monitoring, and treatment of children with cancer and reduce the mortality rate.

The tumor microenvironment and immune targeting therapy in pediatric renal tumors

This review highlights the role of several immunomodulating elements contributing to the tumor microenvironment of various pediatric renal tumors including Wilms tumor. The roles of innate and adaptive immune cells in renal tumors are summarized as well as immunomodulatory cytokines and other proteins. The expression and the predictive role of checkpoint modulators like PD-L1 and immunomodulating proteins like glypican-3, B7-H3, COX-2 are highlighted with a translational view toward potential therapeutic innovations. We further discuss the current state of preclinical models in advancing this field of study. Finally, examples of clinical trials of immunomodulating strategies such as monoclonal antibodies and chimeric antigen receptor T (CAR-T) cells for relapsed/refractory/progressive pediatric renal tumors are described.

Clinical significance of tumoral PD-L1 expression in Wilms tumors

BACKGROUND

Although cure rate for Wilms tumor (WT) is high recent years, there is still small fraction of patients suffering from tumor relapse or metastases. It is urgent to identify more valuable biomarkers associated with disease progression. Previous studies have shown that PD-L1 was abnormally expressed in various type of cancers and acted as predictor for poor prognosis for those cancers. PD-1/PD-L1 inhibitors have achieved great success in various malignancies with correlation between PD-L1 expression and responses. We conducted this retrospective study to better understand the role of PD-L1 in WT development.

OBJECTIVE

The aim of this study was to evaluate the expression rate of tumoral PD-L1 in WT and investigate the association of PD-L1 with tumor invasion and metastasis.

STUDY DESIGN

Seventy-seven patients with WT, including 20 cases of primary WTs with corresponding resected invasive/lymph node metastatic tumors were enrolled in the research. Immunohistochemistry was used to examine tumoral PD-L1 expression. Kaplan-Meier analysis with regard to the relationship between the expression of tumoral PD-L1 and follow-up information was performed.

RESULTS

Positive expression rate of tumoral PD-L1 was 28.6% in primary WT tissues, while 35% in associated invasive/metastatic ones. The tumoral PD-L1 expression in primary WTs were correlated with late stage and unfavorable histology (P = 0.007; P = 0.002). The expression rate of tumoral PD-L1 was higher in the progression group than that without distant metastasis or relapse (P = 0.038). The expression rate of PD-L1 between primary WTs and matched invasive/metastatic tissues was concordant (P = 0.435). Tumoral PD-L1 expression was associated with disease-free survival (DFS) and overall survival (OS) (P = 0.02; P = 0.03). Tumor PD-L1 expression was associated with DFS and OS in univariable analyses but not in multivariable Cox regression, adjusting for histology and tumor stage.

DISCUSSION

We found that PD-L1 expression was associated with the late-stage of WT and unfavorable histology, which were tightly associated with disease relapse and progression, predicting poor prognosis. The subsequent survival analysis also showed that PD-L1 expression was linked to both shorter DFS and OS. After adjustment for WT stage and histology, PD-L1 expression was no longer an independent predictor of DFS/OS. The value of PD-L1 as predictor for prognosis and potential therapeutic target in WT still need to be validated in large cohort in future.

CONCLUSION

Although PD-L1 expression correlated with established prognostic factors in our dataset, its value as a prognostic marker and therapeutic target, if any, remains to be shown in future.

Identification of a ferroptosis-related lncRNA signature with prognosis for Wilms tumor

BACKGROUND

Wilms tumor (WT) is a widespread urologic tumor in children. Ferroptosis, on the other hand, is a novel form of cell death associated with tumor development. In this study, we aim to explore the predictability of ferroptosis-related biomarkers in estimating prognosis in WT patients.

METHODS

To determine a link between ferroptosis-related gene expression and WT prognosis, we first collected RNA sequencing data and clinical information, involving 124 WT and 6 healthy tissue samples, from the TARGET database. Next, we screened the collected information for ferroptosis-related long non-coding RNA using Cox regression analysis, and constructed a signature model, as well as a nomogram, related to prognosis. Finally, we explored a potential link between ferroptosis-related lncRNA and tumor immunity and screened for possible immune checkpoints.

RESULTS

We constructed a WT prognosis prediction signature containing 12 ferroptosis-related lncRNAs. The area under the curves values, from the ROC curves, predicting overall survival rates at the 1, 3-, and 5-year timepoints were 0.775, 0.867, and 0.891 respectively. Moreover, we generated a nomogram, using clinical features and risk scores, carrying a C-index value of 0.836, which suggested a high predictive value. We also demonstrated significant differences in tumor immunity between low- and high-risk WT patients, particularly in the presence of B cells, NK cells, Th1 cells, Treg cells, inflammation promoting, and type I and II IFN responses. In addition, we showed that immune checkpoints like SIRPA, ICOSLG, LAG3, PVRIG, NECTIN1, and SIRPB2 can serve as potential therapeutic targets for WT.

CONCLUSIONS

Based on our analyses, we generated a ferroptosis-related lncRNA signature that can both estimate prognosis of WT patients and may provide basis for future WT therapy.

Pediatric Tumors-Mediated Inhibitory Effect on NK Cells: The Case of Neuroblastoma and Wilms' Tumors

Simple Summary

Neuroblastoma (NB) and Wilms’ tumor (WT) are the most common childhood solid extracranial tumors. The current treatments consist of a combination of surgery and chemotherapy or radiotherapy in high-risk patients. Such treatments are responsible for significant adverse events requiring long-term monitoring. Thus, a main challenge in NB and WT treatment is the development of novel therapeutic strategies to eliminate or minimize the adverse effects. The characterization of the immune environment could allow for the identification of new therapeutic targets. Herein, we described the interaction between these tumors and innate immune cells, in particular natural killer cells and monocytes. The detection of the immunosuppressive activity of specific NB and WT tumor cells on natural killer cells and on monocytes could offer novel cellular and molecular targets for an effective immunotherapy of NB and WT.

Abstract

Natural killer (NK) cells play a key role in the control of cancer development, progression and metastatic dissemination. However, tumor cells develop an array of strategies capable of impairing the activation and function of the immune system, including NK cells. In this context, a major event is represented by the establishment of an immunosuppressive tumor microenvironment (TME) composed of stromal cells, myeloid-derived suppressor cells, tumor-associated macrophages, regulatory T cells and cancer cells themselves. The different immunoregulatory cells infiltrating the TME, through the release of several immunosuppressive molecules or by cell-to-cell interactions, cause an impairment of the recruitment of NK cells and other lymphocytes with effector functions. The different mechanisms by which stromal and tumor cells impair NK cell function have been particularly explored in adult solid tumors and, in less depth, investigated and discussed in a pediatric setting. In this review, we will compare pediatric and adult solid malignancies concerning the respective mechanisms of NK cell inhibition, highlighting novel key data in neuroblastoma and Wilms’ tumor, two of the most frequent pediatric extracranial solid tumors. Indeed, both tumors are characterized by the presence of stromal cells acting through the release of immunosuppressive molecules. In addition, specific tumor cell subsets inhibit NK cell cytotoxic function by cell-to-cell contact mechanisms likely controlled by the transcriptional coactivator TAZ. These findings could lead to a more performant diagnostic approach and to the development of novel immunotherapeutic strategies targeting the identified cellular and molecular targets.

A Survival-Related Competitive Endogenous RNA Network of Prognostic lncRNAs, miRNAs, and mRNAs in Wilms Tumor

Wilms tumor (WT) commonly occurs in infants and children. We evaluated clinical factors and the expression of multiple RNAs in WT samples in the TARGET database. Eight long non-coding RNAs (lncRNAs; AC079310.1, MYCNOS, LINC00271, AL445228.3, Z84485.1, AC091180.5, AP002518.2, and AC007879.3), two microRNAs (miRNAs; hsa-mir-152 andhsa-mir-181a), and nine messenger RNAs (mRNAs; TCTEX1D4, RNF133, VRK1, CCNE1, HEY1, C10orf71, SPRY1, SPAG11A, and MAGEB18) were screened from differentially expressed RNAs and used to construct predictive survival models. These models showed good prognostic ability and were highly correlated with tumor stage and histological classification. Additionally, survival-related ceRNA network was constructed using 35 RNAs (15 lncRNAs, eight miRNAs, and 12 mRNAs). KEGG pathway analysis suggested the "Wnt signaling pathway" and "Cellular senescence" as the main pathways. In conclusion, we established a multinomial predictive survival model and a survival-related ceRNA network, which provide new potential biomarkers that may improve the prognosis and treatment of WT patients.

Wilms' Tumor Primary Cells Display Potent Immunoregulatory Properties on NK Cells and Macrophages

The immune response plays a crucial defensive role in cancer growth and metastasis and is a promising target in different tumors. The role of the immune system in Wilm's Tumor (WT), a common pediatric renal malignancy, is still to be explored. The characterization of the immune environment in WT could allow the identification of new therapeutic strategies for targeting possible inhibitory mechanisms and/or lowering toxicity of the current treatments. In this study, we stabilized four WT primary cultures expressing either a blastematous (CD56+/CD133-) or an epithelial (CD56-/CD133+) phenotype and investigated their interactions with innate immune cells, namely NK cells and monocytes. We show that cytokine-activated NK cells efficiently kill WT cells. However, after co-culture with WT primary cells, NK cells displayed an impaired cytotoxic activity, decreased production of IFNγ and expression of CD107a, DNAM-1 and NKp30. Analysis of the effects of the interaction between WT cells and monocytes revealed their polarization towards alternatively activated macrophages (M2) that, in turn, further impaired NK cell functions. In conclusion, we show that both WT blastematous and epithelial components may contribute directly and indirectly to a tumor immunosuppressive microenvironment that is likely to play a role in tumor progression.

Competitive endogenous RNA (ceRNA) regulation network of lncRNAs, miRNAs, and mRNAs in Wilms tumour

Background

Competitive endogenous RNAs (ceRNAs) have revealed a new mechanism of interaction between RNAs. However, an understanding of the ceRNA regulatory network in Wilms tumour (WT) remains limited.

Methods

The expression profiles of mRNAs, miRNAs and lncRNAs in Wilms tumour samples and normal samples were obtained from the Therapeutically Applicable Research to Generate Effective Treatment (TARGET) database. The EdgeR package was employed to identify differentially expressed lncRNAs, miRNAs and mRNAs. Functional enrichment analyses via the ClusterProfile R package were performed, and the lncRNA–miRNA–mRNA interaction ceRNA network was established in Cytoscape. Subsequently, the correlation between the ceRNA network and overall survival was analysed.

Results

A total of 2037 lncRNAs, 154 miRNAs and 3609 mRNAs were identified as differentially expressed RNAs in Wilms tumour. Of those, 205 lncRNAs, 26 miRNAs and 143 mRNAs were included in the ceRNA regulatory network. The results of Gene Ontology (GO) analysis revealed that the differentially expressed genes (DEGs) were mainly enriched in terms related to response to mechanical stimuli, transcription factor complexes, and transcription factor activity (related to RNA polymerase II proximal promoter sequence-specific DNA binding). The results of the Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis showed that the DEGs were mainly enriched in pathways related to the cell cycle. The survival analysis results showed that 16 out of the 205 lncRNAs, 1 out of 26 miRNAs and 5 out of 143 mRNAs were associated with overall survival in Wilms tumour patients (P < 0.05).

Conclusions

CeRNA networks play an important role in Wilms tumour. This finding might provide effective, novel insights for further understanding the mechanisms underlying Wilms tumour.

Immune expression in children with Wilms tumor: a pilot study

BACKGROUND

Given improvements in multimodality therapy, survival among children with Wilms tumor (WT) exceeds 90%. However, 15% of children with favorable histology and 50% of children with anaplastic WT experience recurrence or progression. Of patients with advanced disease, only 50% survive to adulthood. In adult malignancies (including renal tumors), patient survival has improved with the advent of immunotherapy. However, little is known about the immune microenvironment of WT, making the potential role of immunotherapy unclear.

OBJECTIVE

The objective of the study is to perform an exploratory, descriptive analysis of the immune milieu in WT.

STUDY DESIGN

Between 2016 and 2017, all pediatric patients with WT, some of whom received neoadjuvant chemotherapy, underwent ex vivo wedge biopsy at the time of nephrectomy. The fresh tumor tissue and peripheral blood samples were analyzed for infiltrating immune infiltrate and effector cells using flow cytometry. Immunohistochemistry was performed for CD4, CD8, and PD-L1 expression. Matched blood samples were obtained for each patient, and circulating immune cells were analyzed by flow cytometry.

RESULTS

A total of six patients were enrolled. One patient with neuroblastoma was excluded. The remaining five patients included the following: two with unilateral WT (resected before chemotherapy), two with bilateral WT (resected after neoadjuvant chemotherapy), and one with Denys-Drash syndrome, end-stage renal disease, and history of WT in the contralateral kidney. Immune analysis showed that WT were infiltrated by immune cells regardless of chemotherapy status. CD8 and CD4 T cells were present in the tumor tissue and exhibited an activated phenotype. Elevated levels of natural killer (NK) cells were observed in the tumors (Figure). Immune checkpoint PD-L1 was also found expressed in one of the tumors stained.

DISCUSSION

In this pilot study, it was found that WTs were infiltrated by immune cells (CD45+) both before and after chemotherapy. Elevated levels of NK cells infiltrating the tumor specimens, which were quantitatively increased compared with levels of NK cells circulating in the blood, were noted. T cells, particularly CD4+ and CD8+ T cells, were present in tumor specimens. Tumor-infiltrating CD4 and CD8 T cells displayed an activated phenotype as defined by increased expression of human leukocyte antigen-DR isotype (HLA-DR), programmed cell death protein 1 (PD1), and CD57. Together, these findings suggest that WT microenvironment is immune engaged and may be susceptible to immunotherapy similar to other malignancies.

CONCLUSIONS

These pilot data suggest an immune-engaged tumor microenvironment is present within WT. This implies that WT may be susceptible to immunotherapy similar to adult renal tumors and other adult malignancies. Follow-up studies are currently underway.

Potential Five-MicroRNA Signature Model for the Prediction of Prognosis in Patients with Wilms Tumor

Background

Wilms tumor (WT) is the most common type of pediatric renal malignancy, and is associated with poor prognosis. The aim of the present study was to identify microRNA (miRNA) signatures which might predict prognosis and categorize WTs into high- and low-risk subgroups.

Material/Methods

The miRNA expression profiles of WT patients and normal samples were obtained from the Therapeutically Applicable Research to Generate Effective Treatment database. Differentially expressed miRNAs between WT patients and normal samples were identified using the EdgeR package. Subsequently, correlations between differentially expressed miRNAs and the prognosis of overall survival were analyzed. Enrichment analyses for the targeted mRNAs were conducted via the Database for Annotation, Visualization, and Integration Discovery.

Results

A total of 154 miRNAs were identified as differentially expressed in WT. Of those, 18 miRNAs were associated with overall survival (P<0.05). A prognostic signature of 5 differentially expressed miRNAs (i.e., has-mir-149, has-mir-7112, has-mir-940, has-mir-1248, and has-mir-490) was constructed to classify the patients into high- and low-risk subgroups. The targeted mRNAs of these prognostic miRNAs were primarily enriched in Gene Ontology terms (i.e., protein autophosphorylation, protein dephosphorylation, and stress-activated MAPK cascade) and the Kyoto Encyclopedia of Genes and Genomes signaling pathways (i.e., MAPK, AMPK, and PI3K-Akt).

Conclusions

The 5-miRNA signature model might be useful in determining the prognosis of WT patients. As a promising prediction tool, this prognosis signature might serve as a potential biomarker for WT patients.

Various checkpoint molecules, and tumor-infiltrating lymphocytes in common pediatric solid tumors: Possibilities for novel immunotherapy

Long-term survival rates for pediatric patients with cancer have significantly improved, but novel approaches are desired for those with refractory/relapsed solid tumors. Recently, programed cell death-1/programed cell death-ligand-1 blockade has emerged as an effective option for many intractable cancers. However, not all patients show objective response to such therapy. On the other hand, several other checkpoint pathways, including Herpes virus entry mediator (HVEM)/B- and T-lymphocyte attenuator (BTLA), galectin-9 (GAL9)/T-cell immunoglobulin and mucin domain-3 (TIM3), and major histocompatibility complex class II (MHC-II)/lymphocyte activation gene-3 (LAG3), also regulate immune responses in the tumor microenvironment and may be alternative targets for novel immune therapies. In this study, we examined 65 common pediatric solid tumors and characterized the expression of Herpes virus entry mediator, GAL9, and MHC-II on tumor cells and their corresponding receptors B- and T-lymphocyte attenuator, TIM3, and LAG3, respectively, on tumor-infiltrating lymphocytes (TILs) with immunohistochemistry. Whereas the expression of GAL9 and MHC-II was limited, 73% of rhabdomyosarcomas and 100% of osteosarcomas expressed moderate to high levels of Herpes virus entry mediator on the tumor. TILs were detected in all tumor samples except one osteosarcoma. Interestingly, 45% of rhabdomyosarcomas, and 45% of osteosarcomas expressed moderate to high levels of both Herpes virus entry mediator on the tumor cells and B- and T-lymphocyte attenuator on the TILs. Results showed that a subset of pediatric solid tumors expressed tumor-associated checkpoint molecules, and TILs expressed corresponding receptors for these checkpoint molecules. Thus, immunogenic environments may be created, and checkpoint blockade may induce favorable immune responses.

CD151 promotes proliferation and migration of SK-NEP-1 cells via the GSK-3β/P21/cyclinD signaling pathway

Wilms'tumor is the most common malignant tumor with a poor clinical prognosis because of metastasis or recurrence among children worldwide. CD151, a member of transmembrane 4 superfamily, has now been confirmed to be involved in tumor progression including the proliferation, migration, invasion and metastasis of tumor cells. GSK-3β/P21/cyclinD signaling pathway plays a critical role in the cell cycle progression, regulating cellular proliferation. In this study, CD151 protein and mRNA levels were examined by western blot and RT-PCR. The proliferation of SK-NEP-1 cells was examined by CCK8 assay and the migration of SK-NEP-1 cells was detected with wound healing assay. Furthermore, p-GSK3β protein, GSK3β protein, p21protein and CyclinD protein were examined by western blot to verify whether CD151 could regulate the Wilms'tumor progression via the GSK-3β/P21/cyclinD signaling pathway. The RT-PCR and western blot results showed that CD151 protein was upregulated in Wilms'tumor cells compared with the control. The results by CCK8 assay and wound healing assay demonstrated that CD151 overexpression promoted the proliferation and migration in SK-NEP-1 cells and CD151 interference showed the opposite effects. Western blot assay revealed that CD151 activated the GSK-3β/P21/cyclinD signaling pathway and upregulated the expression of p-GSK3β protein, p21protein and CyclinD protein. It was also verified that CD151 promotes proliferation and migration of SK-NEP-1 cells through the GSK-3β/P21/cyclinD signaling pathway in this study. The specific aim of the study is to investigate and verify the role of CD151 in Wilm's tumor. Therefore, in-depth study on the molecular mechanisms will provide new strategies and methods for the treatment of Wilm's tumor.

MicroRNA‑199b promotes cell proliferation and invasion in Wilms' tumour by directly targeting Runt‑related transcription factor 3

Emerging evidence has demonstrated that the deregulation of microRNAs (miRNAs) contributes to Wilms' tumour (WT) malignant progression. Therefore, identifying the essential miRNAs for WT onset and progression may be a promising therapeutic method for patients with this disease. Dysregulation of miRNA‑199b (miR‑199b) serves significant roles in various types of human cancer. However, its expression patterns, possible functions and associated mechanisms in WT are largely unknown. In the present study, the expression of miR‑199b in WT tissues was detected by reverse transcription‑quantitative polymerase chain reaction (RT‑qPCR) analysis. The biological functions of miR‑199b overexpression in WT cells were determined using Cell counting kit‑8 and Transwell invasion assays. The mechanisms underlying the action of miR‑199b in WT cells were also investigated using bioinformatics analysis, a luciferase reporter assay, RT‑qPCR and western blot analysis. It was revealed that miR‑199b expression was upregulated in WT tissues. In addition, the downregulation of miR‑199b attenuated the proliferation and invasion of WT cells. Runt‑related transcription factor 3 (RUNX3) was mechanistically predicted as a potential target of miR‑199b. Subsequent experiments demonstrated that RUNX3 was a direct target gene of miR‑199b in WT. In addition, the downregulation of RUNX3 in the WT tissues was inversely correlated with the miR‑199b expression level. The recovered RUNX3 expression counteracted the oncogenic roles of miR‑199b in WT cells. Therefore miR‑199b may serve as an oncogene in WT progression by directly targeting RUNX3, thereby suggesting that the miR‑199b/RUNX3 axis may be a promising therapeutic target for patients with WT.

Axl promotes the proliferation, invasion and migration of Wilms' tumor and can be used as a prognostic factor

PURPOSE

Overexpression of Axl has been reported in many tumors, where it promotes tumorigenesis and progression, as well as correlates with the prognosis of different malignancies. However, Axl expression and its function have rarely been reported in Wilms' tumor (WT). This study aimed to reveal the clinical significance of Axl expression in patients with WT and determine its mechanisms.

MATERIALS AND METHODS

We analyzed the expression of Axl and its correlations with various clinicopathological features in 72 WT tissues and 72 adjacent non-cancerous tissues by immunohistochemistry. Cox proportional hazards regression models were used to investigate the correlations between Axl expression and the prognosis of WT patients. Fresh frozen samples from 20 WT patients were examined using Western blotting (WB) and real-time quantitative polymerase chain reaction (RT-qPCR). In WT cell line, after Axl knockdown by sh-Axl and growth arrest-specific 6 (Gas6) stimulation, the cell proliferation, migration and invasion abilities were detected by methyl-thiazolyl-tetrazolium (MTT), clone-forming, wound-healing and transwell assays. Meanwhile, the tumor-forming ability was tested on nude mice xenograft models. Finally, the expression of several proteins in signal pathways was quantified by WB assays.

RESULTS

Compared with the adjacent non-cancerous tissues, the expression of Axl was significantly higher in WT tissues (P<0.05). High expression of Axl was associated with tumor recurrence or lung metastasis of WT patients and was a prognostic factor for WT patients (P<0.05). In vitro assays, the proliferation, migration and invasion of WT cells decreased with Axl knockdown and significantly increased with Axl activation by Gas6 (P<0.05). In vivo assays, the ability of tumorigenicity in WT cells reduced dramatically after Axl knockout (P<0.05). Moreover, PI3K-Akt pathway proteins decreased with Axl knockdown.

CONCLUSION

Our results suggest that Axl is highly expressed in WT and is a prognostic factor, which could promote the progression of WT in vitro and in vivo. It may also be a potential biomarker for WT.

Biomarkers for Wilms Tumor: A Systematic Review

PURPOSE

Wilms tumor is the most common childhood renal malignancy and the fourth most common childhood cancer. Many biomarkers have been studied but there has been no comprehensive summary. We systematically reviewed the literature on biomarkers in Wilms tumor to quantify the prognostic implications of the presence of individual tumor markers.

MATERIALS AND METHODS

We searched for English language studies from 1980 to 2015 performed in patients younger than 18 years with Wilms tumor and prognostic data. The protocol was conducted per PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines. Two reviewers abstracted data in duplicate using a standard evaluation form. We performed descriptive statistics, then calculated relative risks and 95% confidence intervals for markers appearing in multiple level II or III studies.

RESULTS

A total of 40 studies were included examining 32 biomarkers in 7,381 patients with Wilms tumor. Studies had a median of 61 patients, 24 biomarker positive patients per series and a median followup of 68.4 months. Median percentages of patients with stages 1, 2, 3, 4 and 5 tumors were 28.5%, 26.4%, 24.5%, 14.1% and 1.7%, respectively, and 10.2% had anaplasia. The strongest negative prognostic association was loss of heterozygosity at 11p15, with a risk of recurrence of 5.00, although loss of heterozygosity at 1p and gain of function at 1q were also strongly linked to increased recurrence (2.93 and 2.86, respectively).

CONCLUSIONS

Several tumor markers are associated with an increased risk of recurrence or a decreased risk of overall survival in patients with Wilms tumor. These data suggest targets for development of diagnostic tests and potential therapies.

Tumor-targeted and immune-targeted monoclonal antibodies: Going from passive to active immunotherapy

Monoclonal antibodies (mAbs) have inaugurated the concepts of tumor-targeted therapy and personalized medicine. A new family of mAbs is currently emerging in the clinic, which target immune cells rather than cancer cells. These immune-targeted therapies have recently demonstrated long-term tumor responses in adults with refractory/relapsing metastatic solid tumors. Pediatric cancers are different from their adult counterparts in terms of histological features and immune infiltrates. However, the same immune checkpoint targets can be expressed within the microenvironment of pediatric tumors. The benefits of immune checkpoint blockade in pediatric cancers are currently under evaluation in early phase clinical trials.

Astrocyte elevated gene-1 overexpression in histologically favorable Wilms tumor is related to poor prognosis

OBJECTIVE

Astrocyte elevated gene-1 (AEG-1) is associated with tumorigenesis and progression in various types of human cancers. However, the status of AEG-1 expression and its significance in Wilms tumor are still unclear. In this study, we investigated the expression of AEG-1 and evaluated its clinical and prognostic significance in favorable-histology Wilms tumor (FHWT).

MATERIALS AND METHODS

Immunohistochemistry was performed to examine AEG-1 protein expression in paraffin-embedded tissues from 38 FHWT patients. All patients underwent radical nephrectomy from January 2003 to June 2008 with subsequent therapy according to National Wilms Tumor Study Group protocols. Statistical analyses were performed to evaluate the association between AEG-1 expression and clinical parameters.

RESULTS

We found high AEG-1 expression in 17 of 38 (44.7%) patients. AEG-1 expression was significantly correlated with clinical stage (p = 0.019) and status of recurrence (p = 0.023). Importantly, patients with high AEG-1 expression had a shorter disease-free survival and overall survival compared with those with low AEG-1 expression (p = 0.011 and p = 0.013).

CONCLUSION

AEG-1 expression is associated with FHWT outcome in this study, and AEG-1 may represent a novel and valuable predictor for prognostic evaluation of FHWT patients.