Bilateral Peters' anomaly, aniridia and Wilms tumour (WAGR syndrome) in monozygotic twins

AIM

This study reports the bilateral association of Peters' anomaly and congenital aniridia in monozygotic twins subsequently diagnosed with Wilms tumour (WAGR syndrome).

METHODS

Two monozygotic female twins were referred at age 2 months with bilateral corneal opacity. A diagnosis of Peters' anomaly associated to aniridia was made in both eyes of both twins. Physical examination and ultrasonography were carried out at 12 months of age to explore the possibility of WAGR-related anomalies, specifically Wilms tumour. DNA were isolated and subjected to whole exome sequencing.

RESULTS

Peters' anomaly associated to aniridia in both eyes as well as bilateral Wilms tumour in both children were diagnosed. Exome analyses showed a large heterozygous deletion encompassing 6 648 473 bp in chromosome 11p13, using Integrative Genomics Viewer and AnnotSV software.

CONCLUSION

WAGR syndrome is a rare contiguous gene deletion syndrome with a greater risk of developing Wilms tumour associated with Peters' anomaly and congenital aniridia. However, co-occurrence of both anomalies was rarely reported in twins, and never in both eyes of monozygotic twins. Here, we report the bilateral association of Peters' anomaly and congenital aniridia in monozygotic twins with WAGR syndrome.

Robot-assisted radical nephrectomy for Wilms' tumor in children

INTRODUCTION

Surgical removal of the tumor is a key step in the management of nephroblastoma. Less invasive surgical approaches such as robot-assisted radical nephrectomy (RARN) has gained momentum over the past few years. This video presents a comprehensive step-by-step video for two cases: one uncomplicated left RARN and one more challenging right RARN.

MATERIALS & METHODS

Following the UMBRELLA/SIOP protocol, both patients received neoadjuvant chemotherapy. Under general anesthesia, in a lateral decubitus position, four robotic and one assistant port are placed. After mobilization of the colon, the ureter and gonadal vessels are subsequently identified. The renal hilum is dissected, and the renal artery and vein are divided. The kidney is dissected with sparing of the adrenal gland. The ureter and gonadal vessels are divided, and the specimen is removed through a Pfannenstiel incision. Lymph node sampling is performed.

RESULTS

Patients were 4 and 5 years old. The total surgical time was 95 and 200 min, with an estimated blood loss of 5 and 10 cc. The hospital stay was limited to 3 and 4 days. Both pathological reports confirmed the diagnosis of nephroblastoma, with tumour-free resection margins. No complications were observed 2 months postoperatively.

CONCLUSION

RARN is feasible in children.

Outcomes of patients with Wilms' tumour stage III due to positive resection margins only: An analysis of patients treated on the SIOP-WT-2001 protocol in the UK-CCLG and GPOH studies

Stage III Wilms' tumour (WT) represents a heterogeneous group which includes different criteria, but all stage III patients are treated according to the same study regiment. The aim of the study was to retrospectively analyse outcomes in patients with stage III due to positive resection margins (RM) only, sub-grouped in RM with viable (RM-v) and nonviable (RM-nv) tumour. Patients were treated pre- and postoperatively according to the SIOP-WT-2001 protocol in the UK-CCLG and GPOH WT trials and studies (2001-2020). There were 197 patients, including 134 with localised, abdominal stage III and 63 with overall stage IV, but abdominal stage III. Stage III due to RM-v had 126 patients, and due to RM-nv 71 patients. The overall 5-year local-relapse-free survival (RFS), event-free (EFS) and overall survival (OS) estimates for all patients with abdominal stage III RM were 95.7% (±SE1.5%), 85.1 (±SE2.6%) and 90.3% (±SE2.2%), respectively. Patients with stage III RM-nv had significantly better RFS and EFS than patients with RM-v (P = .027 and P = .003, respectively). A multivariate analysis showed that RM-v remained a significant factor for EFS when adjusted for age, presence of metastasis at diagnosis, histological risk group and overall stage in Cox regression analysis (P = .006). Patients with stage III due to RM-nv only exhibited no local recurrence and have a significantly better RFS and EFS than patients with RM-v. The results suggest that exclusion of RM-nv as a stage III criterion in the UMBRELLA staging system and consequent treatment reduction is warranted.

Correlations between histological characterizations and methylation statuses of tumour suppressor genes in Wilms' tumours

Wilms' tumour is a solid tumour that frequently occurs in children. Genetic changes in WT1 and epigenetic aberrations that affect imprinted control region 1 in WT2 loci are implicated in its aetiology. Moreover, tumour suppressor genes are frequently silenced by methylation in this tumour. In the present study, we analysed the methylation statuses of promoter regions of 24 tumour suppressor genes using a methylation-specific multiplex ligation-dependent probe amplification (MS-MLPA)-based approach in 6 Wilms' tumours. Methylation of RASSF1 was specific to all 6 Wilms' tumours and was not observed in normal tissues. Moreover, methylated HIC1 was identified in stromal-type Wilms' tumours and methylated BRCA1 was identified in epithelial-type Wilms' tumours. Unmethylated CASP8, RARB, MLH1_167, APC and CDKN2A were found only in blastemal predominant-type Wilms' tumour. Our results indicated that methylation of RASSF1 may be a vital event in the tumorigenesis of Wilms' tumour, which informs its clinical and therapeutic management. In addition, mixed-type Wilms' tumours may be classified according to epithelial, stromal and blastemal components via MS-MLPA-based approach.

A 5-year multidisciplinary care outcomes in children with wilms' tumour managed at a tertiary centre: A retrospective observational study

BACKGROUND

Over the last two decades, there has been significant improvement in the outcomes of children with Wilms' tumour (WT) in high income countries (HICs) with approximately 85% survival rate globally. This is partly attributable to a multi-disciplinary team approach to care and the evolution of more robust treatment measures. A previous review in our centre prior to multi-disciplinary team shows a survival rate of 31.48%, However, the survival rates from low- and middle-income countries are still low when compared to HICs due to delays in access to care at all levels, poor to non-existent health insurance coverage, limited workforce resources, weak health-care systems and infrastructure. The aim of this study is to determine the impact of a multi-disciplinary team approach on the treatment outcomes of children with WT.

METHODOLOGY

This is a 5-year retrospective review of all patients managed with WT at the Lagos University Teaching Hospital, Lagos, Nigeria. Information was extracted from the patients' case notes, operation notes and ward admission records. The data were analysed with SPSS 25, and P < 0.05 was considered to be statistically significant.

RESULTS

Forty patients were included in the study; male to female ratio was 1.6:1. The disease occurred in the right kidney in 23 patients (57.5%) and on the left in 17 patients (42.5%). The average duration of symptoms before presentation was 3.6 months (range 1-7 months), majority of patients presented with abdominal masses and were assessed as per unit protocol with abdominal Computerized tomography scan, chest X-ray and abdominal ultrasound scan to assign the patient International Society of Paediatric oncology regimen. The predominant stage at surgery was Stage III 26 (65%), while Stage IV was 9 (22.5%). Morbidity after chemotherapy was 10 (25%). Twenty-five patients (63%) completed chemotherapy while 15 patients (37%) started chemotherapy but defaulted midway. The 5-year survival rate was 75%. Increasing age and male sex were associated with reduced odds of mortality; however, this was not statistically significant. Increased duration of treatment, being treated with chemotherapy alone, as well as advanced tumour stage and histology were associated with increased odds of mortality, however, this was not statistically significant.

CONCLUSION

The development of an institutional WT treatment pathway involving a multidisciplinary team has resulted in improved outcomes. There is need for increased community awareness to improve the time to presentation.

Recent Advances in Pathology: the 2021 Annual Review Issue of The Journal of Pathology

The 2021 Annual Review Issue of The Journal of Pathology contains 14 invited reviews on current research areas of particular importance in pathology. The subjects included here reflect the broad range of interests covered by the journal, including both basic and applied research fields but always with the aim of improving our understanding of human disease. This year, our reviews encompass the huge impact of the COVID-19 pandemic, the development and application of biomarkers for immune checkpoint inhibitors, recent advances in multiplexing antigen/nucleic acid detection in situ, the use of genomics to aid drug discovery, organoid methodologies in research, the microbiome in cancer, the role of macrophage-stroma interactions in fibrosis, and TGF-β as a driver of fibrosis in multiple pathologies. Other reviews revisit the p53 field and its lack of clinical impact to date, dissect the genetics of mitochondrial diseases, summarise the cells of origin and genetics of sarcomagenesis, provide new data on the role of TRIM28 in tumour predisposition, review our current understanding of cancer stem cell niches, and the function and regulation of p63. The reviews are authored by experts in their field from academia and industry, and provide comprehensive updates of the chosen areas, in which there has been considerable recent progress. © 2021 The Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.

Dataset for the reporting of nephrectomy specimens for Wilms' tumour treated with preoperative chemotherapy: recommendations from the International Society of Paediatric Oncology Renal Tumour Study Group

Datasets for histopathological reporting of many cancer types are developed by the International Collaboration on Cancer Reporting (ICCR), and are used in order to ensure standardised and uniformly accepted reporting as one of the essential requirements for comparison across patient populations in evaluating and validating pathological prognostic and predictive factors. Wilms' tumours are rare, and international reporting guidelines have not yet been published by the ICCR. The assessment of Wilms' tumours differs according to the treatment approach. The Children's Oncology Group, whose approach is followed mainly in North America, advocates primary surgery, and the International Society of Paediatric Oncology Renal Tumour Study Group (SIOP-RTSG), whose approach is followed in most countries around the world, uses preoperative chemotherapy as a first step, resulting in different subclassifications, staging criteria, and histopathological prognostic factors. This dataset is developed for the countries and institutions following the SIOP-RTSG approach, and it contains core (required) and non-core (recommended) elements, based on the results of the previous SIOP-RTSG studies, which are incorporated in the latest SIOP-RTSG UMBRELLA 2016 Study protocol. The core elements include clinical information, additional specimen submitted, macroscopic tumour site and appearance, tumour focality, tumour dimensions, macroscopic extent of invasion, block identification key, histological tumour type, histological tumour grade and risk group assessment, microscopic extent of invasion, lymphovascular invasion, resection margin status, regional lymph node status, histologically confirmed distant metastases, and pathological staging (SIOP staging system). The dataset should improve communication for patient care and prognostic determination of the old and new histopathological features.

Nephroblastoma in a Sprague Dawley rat unrelated to titanium dioxide nanoparticle exposure in utero

Nephroblastoma is an embryonal tumour that has rarely been reported in laboratory rats. In this case report, a large nephroblastoma with peritoneal seeding was found during necropsy in an 11-month-old, female, Sprague Dawley rat. The rat had a history of indirect exposure to nano-TiO2 (titanium dioxide nanoparticles) during maternal gestation. A firm mass in the upper right abdominal quadrant was palpated. Four weeks later, the animal quickly declined. Nephroblastoma was confirmed by histopathology. Only one rat developed nephroblastoma among the ten littermates. Nephroblastomas in Sprague Dawley rats are typically spontaneous tumours with non-malignant mesenchymal elements. The capability to induce a nephroblastoma with nano-TiO2 is less likely in this case.

TRIM28 variants and Wilms' tumour predisposition

TRIM28 was recently identified as a Wilms' tumour (WT) predisposition gene, with germline pathogenic variants identified in around 1% of isolated and 8% of familial WT cases. TRIM28 variants are associated with epithelial WT, but the presence of other tumour components or anaplasia does not exclude the presence of a germline or somatic TRIM28 variant. In children with WT, TRIM28 acts as a classical tumour suppressor gene, with both alleles generally disrupted in the tumour. Therefore, loss of TRIM28 (KAP1/TIF1beta) protein expression in tumour tissue by immunohistochemistry is an effective strategy to identify patients carrying pathogenic TRIM28 variants. TRIM28 is a ubiquitously expressed corepressor that binds transcription factors in a context‐, species‐, and cell‐type‐specific manner to control the expression of genes and transposable elements during embryogenesis and cellular differentiation. In this review, we describe the inheritance patterns, histopathological and clinical features of TRIM28‐associated WT, as well as potential underlying mechanisms of tumourigenesis during embryonic kidney development. Recognizing germline TRIM28 variants in patients with WT can enable counselling, genetic testing, and potential early detection of WT in other children in the family. A further exploration of TRIM28‐associated WT will help to unravel the diverse and complex mechanisms underlying WT development. © 2021 The Authors. The Journal of Pathology published by John Wiley & Sons, Ltd. on behalf of The Pathological Society of Great Britain and Ireland.

Expansion of the renal capsular stroma, ureteric bud branching defects and cryptorchidism in mice with Wilms tumor 1 gene deletion in the stromal compartment of the developing kidney

Development of the mammalian kidney is orchestrated by reciprocal interactions of stromal and nephrogenic mesenchymal cells with the ureteric bud epithelium. Previous work showed that the transcription factor Wilms tumor 1 (WT1) acts in the nephrogenic lineage to maintain precursor cells, to drive the epithelial transition of aggregating precursors into a renal vesicle and to specify and maintain the podocyte fate. However, WT1 is expressed not only in the nephrogenic lineage but also transiently in stromal progenitors in the renal cortex. Here we report that specific deletion of Wt1 in the stromal lineage using the Foxd1^cre driver line results at birth in cryptorchidism and hypoplastic kidneys that harbour fewer and enlarged ureteric bud tips and display an expansion of capsular stroma into the cortical region. In vivo and ex vivo analysis at earlier stages revealed that stromal loss of Wt1 reduces stromal proliferation, and delays and alters branching morphogenesis, resulting in a variant architecture of the collecting duct tree with an increase of single at the expense of bifurcated ureteric bud tips. Molecular analysis identified a transient reduction of Aldh1a2 expression and of retinoic acid signalling activity in stromal progenitors, and of Ret in ureteric bud tips. Administration of retinoic acid partly rescued the branching defects of mutant kidneys in culture. We propose that WT1 maintains retinoic acid signalling in the cortical stroma, which, in turn, assures proper levels and dynamics of Ret expression in the ureteric bud tips, and thus normal ramification of the ureteric tree. © 2020 The Authors. The Journal of Pathology published by John Wiley & Sons, Ltd. on behalf of The Pathological Society of Great Britain and Ireland.

Relationship of tumour-associated macrophages with poor prognosis in Wilms' tumour

BACKGROUND

Wilms' tumour (WT) is the most common childhood renal tumour. Tumour-associated macrophages (TAMs) are a critical component of tumour microenvironments and contain two main subtypes, classically (M1) or alternatively (M2) activated macrophages. Evidence has revealed TAMs in predicting poor prognosis in some malignant tumours. However, the role of TAMs in WT is still unclear, and the relationship of different types of TAMs with prognosis has not been elucidated.

OBJECTIVE

The aim of the study was to explore the presence of two types of TAMs in WT and analyse the relationship of TAMs with prognosis.

STUDY DESIGN

Overall, 61 paediatric patients with WT underwent nephrectomy before any chemotherapy from April 2006 to March 2014. The tumour tissues were analysed by Western blot, immunohistochemistry, and immunofluorescence to explore the distribution of M1 and M2 macrophages in different stages. Kaplan-Meier analysis with regard to the relationship between the presence of TAMs and follow-up information was performed.

RESULTS

In the 61 patients (44 males and 17 females), there was a median age of 19 months (IQR 13-35.5); 47 patients are still alive, 11 died, 3 were lost to follow-up. According to the National Wilms Tumor Study (NWTS)-5 guidelines, the distribution of tumour stages was as follows: stage I, 27 patients; stage II, 18 patients; and stage III, 16 patients. The Western blot analysis showed that the density of M1 and M2 macrophages in tumour tissues were significantly greater than that in adjacent normal tissues. Immunohistochemistry showed the proportion of patients with positive M1-type macrophages across different stages: stage I, 66.7% (18/27); stage II, 44.4% (8/18); and stage III, 25% (4/16) (p = 0.027). The proportion of patients with positive M2-type macrophages across different stages: stage I, 25.9% (7/27); stage II, 55.6% (10/18); and stage III, 81.3% (13/16) (p = 0.002). Kaplan-Meier analysis suggested that patients with high densities of M2-type macrophages had shorter overall survival time than those with low densities (log-rank test, p = 0.011).

DISCUSSION

TAMs play a pivotal comments in the tumour microenvironment and tumorigenesis. With the progression of clinical stage, M2 macrophage densities increased greatly, and M1 macrophage density decreased. M2 macrophages represent a poor prognosis and can be utilized as a new indicator in pathological examination.

CONCLUSION

There is a high density of TAMs in WT, and M2-type macrophage density increases with tumour progression and implies a poor prognosis.

Volumetric assessment of unaffected parenchyma and Wilms' tumours: analysis of response to chemotherapy and surgery using a semi-automated segmentation algorithm in children with renal neoplasms

OBJECTIVE

To present our proof of concept with semi-automatic image recognition/segmentation technology for calculation of tumour/parenchyma volume.

METHODS

We reviewed Wilms' tumours (WTs) between 2000 and 2018, capturing computed tomography images at baseline, after neoadjuvant chemotherapy (NaC) and postoperatively. Images were uploaded into MATLAB-3-D volumetric image processing software. The program was trained by two clinicians who supervised the demarcation of tumour and parenchyma, followed by automatic recognition and delineation of tumour margins on serial imaging, and differentiation from uninvolved renal parenchyma. Volume was automatically calculated for both.

RESULTS

During the study period, 98 patients were identified. Of these, based on image quality and availability, 32 (38 affected moieties) were selected. Most patients (65%) were girls, diagnosed at age 50 ± 37 months of age. NaC was employed in 64% of patients. Surgical management included 27 radical and 11 partial nephrectomies. Automated volume assessment demonstrated objective response to NaC for unilateral and bilateral tumours (68 ± 20% and 53 ± 39%, respectively), as well as preservation on uninvolved parenchyma with partial nephrectomy (70 ± 46 cm³ at presentation to 57 ± 41 cm³ post-surgery).

CONCLUSION

Volumetric analysis is feasible and allows objective assessment of tumour and parenchyma volume in response to chemotherapy and surgery. Our data show changes after therapy that may be otherwise difficult to quantify. Use of such technology may improve surgical planning and quantification of response to treatment, as well as serving as a tool to predict renal reserve and long-term changes in renal function.

Clinical-morphological features of wilms’ tumour: analysis of literature data and a case from practice

Wilms’ tumour, or nephroblastoma, is a malignant tumour, originating from nephrogenic germ cells that copy histology of developing kidneys and often contain cells at different stages of their differentiation. The article analyses clinical-morphological features of Wilms’ tumour, which is typical for childhood and seldom occurs in adults. The authors suppose that one of the causes of Wilms’ tumour development can be maternal complications, which arise during pregnancy, leading to inhibition of glomerulogenesis and tubulogenesis in the offspring kidneys, an increase the number of foci of primitive (immature) tissue, from which this tumour, as it is known, can originate. The described саse from practice of Wilms’ tumour is of particular interest because of an untypical age category, when the above pathology was diagnosed, demonstrates necessity of a multidisciplinary approach to its identification and necessitates its inclusion into the differential diagnostic line for the detection of kidneys tumours in adults.

High-Risk Adult Wilms' Tumour in Pregnancy: A Case Report

Wilms' tumour is the most common renal neoplasm in children with an incidence of 10 cases per 1 million children and a median age at diagnosis of 3.5 years. In Western countries its occurrence in adults is 0.2 cases per million people in western countries and carries a poorer prognosis. The co-existence of Adult Wilms' tumour and pregnancy is extremely rare with less than 20 cases published in the English literature. We present a case of a Malawian woman who had progressive high-risk metastatic Adult Wilms' tumour in pregnancy after nephrectomy, radiotherapy and two lines of chemotherapy.

Evidence-based treatment of multicystic dysplastic kidney: a systematic review

OBJECTIVES

There is a lack of a standardised protocol for the investigation and non-operative management of paediatric multicystic dysplastic kidney (MCDK). Institutional protocols for non-operative management remain essentially ad hoc. The primary outcome of this systematic review is to establish the incidence of hypertension associated with an MCDK. The secondary outcome is to determine the malignancy risk associated with an MCDK. The tertiary outcome is to assess the rate of MCDK involution. Subsequent to these, an evidence-based algorithm for follow-up is described.

METHODOLOGY

A systematic review of all relevant studies published between 1968 and April 2017 was performed using the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. Studies were identified by specific inclusion and exclusion criteria, all of which included data relevant to the primary, secondary and tertiary outcomes. Hypertension was defined as systolic blood pressure greater than the 95th centile for gender, age and height centile. Subset analysis was performed for hypertension associated with an MCDK.

RESULTS

The primary outcome measure revealed a 3.2% (27/838) risk of developing hypertension associated with an MCDK. The secondary outcome measure noted a 0.07% malignancy risk (2/2820). The tertiary outcome measure established that 53.3% (1502/2820) had evidence of involution of the dysplastic kidney. A total of 44 cohort studies (2820 patients) were analysed.

CONCLUSION

Given the low risk of hypertension and malignancy, which is similar to the general population, the current conservative non-operative pathway is an appropriate management strategy. An algorithm to help support clinicians with ongoing management is proposed.

Review of phase I and II trials for Wilms' tumour - Can we optimise the search for novel agents?

Survival rates for patients with Wilms' tumour (WT) approximate 90% with refined use of currently available interventions. However, a subgroup of patients, with initial high-risk histopathology or relapsing disease, have a poor prognosis, and it is a challenge to identify and prioritise the development of new innovative approaches for these subgroups. We conducted a systematic literature search for published phase I and II clinical trials that registered patients with WTs and characterised the early phase trial activity, quantified response rates and highlighted avenues for further development. We identified 63 trials (48 phase I, three phase I/II, and 12 phase II trials) enrolling 214 patients with WTs, alongside other malignancies. The number of annually recruited WTs did not change significantly and was less than 20% of the potential candidates. The vast majority of the trials were conducted in North America, and 56 different interventions were investigated, including conventional chemotherapy and biologically targeted therapies. Overall, 33 WTs revealed some degree of tumour control. Of these, five patients demonstrated complete remission (2%), 15 patients partial response (7%) and 13 patients stable disease (6%). None of the included novel biologically targeted therapies emerged as promising interventions, and only conventional chemotherapy was able to induce a complete and partial response. We conclude that early phase trial recruitment of WTs is below expected levels, and the clinical outcome of the included patients is dismal. Improvement of the availability and recruitment to early phase trials for WTs, especially in Europe, is needed.

Biology and treatment of renal tumours in childhood

In Europe, almost 1000 children are diagnosed with a malignant renal tumour each year. The vast majority of cases are nephroblastoma, also known as Wilms' tumour (WT). Most children are treated according to Société Internationale d'Oncologie Pédiatrique Renal Tumour Study Group (SIOP-RTSG) protocols with pre-operative chemotherapy, surgery, and post-operative treatment dependent on stage and histology. Overall survival approaches 90%, but a subgroup of WT, with high-risk histology and/or relapsed disease, still have a much poorer prognosis. Outcome is similarly poor for the rare non-WT, particularly for malignant rhabdoid tumour of the kidney, metastatic clear cell sarcoma of the kidney (CCSK), and metastatic renal cell carcinoma (RCC). Improving outcome and long-term quality of life requires more accurate risk stratification through biological insights. Biomarkers are also needed to signpost potential targeted therapies for high-risk subgroups. Our understanding of Wilms' tumourigenesis is evolving and several signalling pathways, microRNA processing and epigenetics are now known to play pivotal roles. Most rhabdoid tumours display somatic and/or germline mutations in the SMARCB1 gene, whereas CCSK and paediatric RCC reveal a more varied genetic basis, including characteristic translocations. Conducting early-phase trials of targeted therapies is challenging due to the scarcity of patients with refractory or relapsed disease, the rapid progression of relapse and the genetic heterogeneity of the tumours with a low prevalence of individual somatic mutations. A further consideration in improving population survival rates is the geographical variation in outcomes across Europe. This review provides a comprehensive overview of the current biological knowledge of childhood renal tumours alongside the progress achieved through international collaboration. Ongoing collaboration is needed to ensure consistency of outcomes through standardised diagnostics and treatment and incorporation of biomarker research. Together, these objectives constitute the rationale for the forthcoming SIOP-RTSG 'UMBRELLA' study.

The WT1 gene--its role in tumourigenesis and prospects for immunotherapeutic advances

The Wilms Tumour 1 (WT1) gene is a complex gene which was originally linked to suppression of cancer in kidneys. Studies of WT1-knockout mice confirmed the important role of WT1 in the pathogenesis of Wilms' tumour, a tumour which accounts for 95% of all childhood renal tumours. In such cases, the WT1 gene acts as a tumour-suppressor gene. Subsequent research has shown that the WT1 gene in many other cases acts as an oncogene, most prominently in leukaemia and lung cancer (even though these cancer forms can emerge as a result of many other aetiological factors). Since WT1 acts as an oncogene in many different organs, it is of great importance to evaluate how and when the WT1 gene and protein act. This information can then be used to develop immunotherapy to stabilize and treat different malignant diseases. Both phase I and phase II studies have been carried out on candidate vaccines with varying but overall promising results. The immune response does not always correlate with the clinical response, however, and the efficacy of the treatment is often limited. Further development is, therefore, needed to understand how vaccines can be improved, so that they, can hopefully fulfil a clinical role in the future.

Angiogenin expression in human kidneys and Wilms' tumours: relationship with hypoxia and angiogenic factors

Angiogenin (ANG) is a potent angiogenic factor that is up-regulated by hypoxia. ANG expression is well documented in normal tissues and in common tumours, but its expression has not been reported in the normal human kidney or in Wilms' tumours (WT). We examined ANG expression in WTs, human fetal kidney (FK) and childhood kidney (NK) samples and studied its relationship with microvascular density (MVD) and with three other hypoxia-induced angiogenic factors: lactate dehydrogenase A (LDHA), vascular endothelial growth factor (VEGFA) and BHLHE40 (basic helix-loop-helix transcription factor E40). Total ANG protein levels were significantly lower in WTs when compared with those in 15 matched-paired NKs. ANG immunoreactivity was observed in the glomeruli, proximal tubules and vessels in the FKs and NKs, indicating that ANG plays a physiological role in the human kidney. ANG cellular localization and distribution in 27 WTs reflected the pattern observed in the FKs. ANG colocalized with LDHA in the perinecrotic areas of untreated WTs suggesting up-regulation by hypoxia. There was a significant correlation between CD31-MVD and ANG-MVD. ANG, CD31, VEGFA and BHLHE40 mRNA levels were significantly lower in 15 WTs compared with matched-paired NKs. Univariable and multivariable statistical analyses showed significant correlations between ANG and CD31, ANG and BHLHE40 mRNAs and a weaker relationship between ANG and VEGFA mRNAs. ANG expression in WTs recapitulates that seen during nephrogenesis, and correlation with CD31-MVDs and mRNAs is consistent with a contribution to angiogenesis in WTs. Our study contributes to the understanding of angiogenesis during development and in WTs.