LINking microRNAs, kidney development, and Wilms tumors.

In this issue of Genes & Development, Urbach and colleagues (pp. 971-982) provide compelling data suggesting a role for LIN28 in the pathogenesis of a significant percentage of Wilms tumors. These data extend our insights in the genetics underlying Wilms tumor development and emphasize the importance of stemness and microRNA-mediated processes in the origins of these tumors.

Lin28 sustains early renal progenitors and induces Wilms tumor.

Wilms Tumor, the most common pediatric kidney cancer, evolves from the failure of terminal differentiation of the embryonic kidney. Here we show that overexpression of the heterochronic regulator Lin28 during kidney development in mice markedly expands nephrogenic progenitors by blocking their final wave of differentiation, ultimately resulting in a pathology highly reminiscent of Wilms tumor. Using lineage-specific promoters to target Lin28 to specific cell types, we observed Wilms tumor only when Lin28 is aberrantly expressed in multiple derivatives of the intermediate mesoderm, implicating the cell of origin as a multipotential renal progenitor. We show that withdrawal of Lin28 expression reverts tumorigenesis and markedly expands the numbers of glomerulus-like structures and that tumor formation is suppressed by enforced expression of Let-7 microRNA. Finally, we demonstrate overexpression of the LIN28B paralog in a significant percentage of human Wilms tumor. Our data thus implicate the Lin28/Let-7 pathway in kidney development and tumorigenesis.

Phenotype evolution and health issues of adults with Beckwith-Wiedemann syndrome.

BACKGROUND: Beckwith-Wiedemann syndrome (BWS) phenotype usually mitigates with age and data on adulthood are limited. Our study aims at reporting phenotype evolution and health issues in adulthood. METHODS: 34 patients (16 males), aged 18-58 years (mean 28.5) with BWS were enrolled. RESULTS: 26 patients were molecularly confirmed, 5 tested negative, and 3 were not tested. Final tall stature was present in 44%. Four patients developed Wilms' Tumor (2, 3, 5, and 10 years, respectively); one hepatoblastoma (22 years); one acute lymphoblastic leukemia (21 years); one adrenal adenoma and testicular Sertoli cell tumor (22 and 24 years, respectively); and three benign tumors (hepatic haemangioma, uterine myoma, and mammary fibroepithelioma). Surgery for BWS-related features was required in 85%. Despite surgical correction several patients presented morbidity and sequelae of BWS pediatric issues: pronunciation/swallow difficulties (n = 9) due to macroglossia, painful scoliosis (n = 4) consistent with lateralized overgrowth, recurrent urolithiasis (n = 4), azoospermia (n = 4) likely consequent to cryptorchidism, severe intellectual disability (n = 2) likely related to neonatal asphyxia and diabetes mellitus (n = 1) due to subtotal pancreatectomy for intractable hyperinsulinism. Four patients (two males) had healthy children (three physiologically conceived and one through assisted reproductive technology). CONCLUSIONS: Adult health conditions in BWS are mostly consequent to pediatric issues, underlying the preventive role of follow-up strategies in childhood. Malignancy rate observed in early adulthood in this small cohort matches that observed in the first decade of life, cumulatively raising tumor rate in BWS to 20% during the observation period. Further studies are warranted in this direction.

Fetal programming and Wilms tumor.

BACKGROUND: The "fetal programming" hypothesis has been evaluated in many adult diseases including cancer, but not for Wilms tumor. Wilms tumor has been related to high birthweight, but little is known about other growth metrics such as a baby's birth length, ponderal index, or placenta size, which can shed additional light on growth patterns. METHODS: Cases of Wilms tumor (N = 217) were taken from the Danish Cancer Registry, and controls (N = 4340) were randomly selected from the Population Register and matched to cases by sex and age. Linkage to the Medical Births Registry provided information on gestational factors and fetal growth measurements, while linkage to the Patient Register provided information on maternal and child health conditions. RESULTS: Despite having typically normal to higher birthweights, Wilms tumor cases had smaller placentas (≤540 g; odds ratio (OR) = 4.24; 95% confidence interval (CI), 1.84-9.78) and a lower placenta-to-birthweight ratio (OR = 1.81; 95% CI, 1.17-2.82, per 1 SD decrease). Small placentas were more common among Wilms cases without congenital anomalies (OR = 6.43; 95% CI, 1.95-21.21). Wilms tumor cases had a higher prevalence of high birthweight (>4000 g; OR = 1.57; 95% CI, 1.11-2.22), birth length 55 cm or longer (OR = 1.74; 95% CI, 1.09-2.78), and being large for gestational age (OR = 1.79; 95% CI, 1.08-2.96). CONCLUSIONS: Our study corroborates earlier studies showing associations with high birthweight and suggests associations between Wilms tumor and decreased placental size and low placenta-to-birthweight ratio.

Estimated glomerular filtration rate after nephrectomy for Wilms tumor.

BACKGROUND: The aim of this study was to assess long-term residual kidney function after unilateral nephrectomy for non-syndromic Wilms tumor (NSWT). METHODS: Of the patients who underwent one-sided NSWT at Tohoku University Hospital between 1977 and 2003, nine were followed up until age ≥18 years. For these nine patients, we retrospectively evaluated estimated glomerular filtration rate (eGFR) in childhood (3-10 years old), adolescence (11-17 years old) and adulthood (≥18 years). RESULTS: Mean age at the last follow up was 23.0 years. Tumor classification was as follows: stage I tumor, n = 6; stage II tumor, n = 3; mixed-type nephroblastoma, n = 8; and congenital mesoblastic nephroma, n = 1. Mean eGFR was 101.3 ± 21.2 mL/min/1.73 m2 in childhood, 106.0 ± 32.1 mL/min/1.73 m2 in adolescence and 100.5 ± 20.7 mL/min/1.73 m2 in adulthood. Therefore, no significant change in eGFR was observed over the three life stages evaluated. Further, none of the patients met the diagnostic criteria for chronic kidney disease by early adulthood. CONCLUSIONS: eGFR after unilateral nephrectomy in patients with NSWT remained ≥60 mL/min/1.73 m2 during the transition from childhood to early adulthood, with no development of chronic kidney disease or end-stage kidney failure.

[Effect of LINE1-ORF1p overexpression on the proliferation of nephroblastoma WT_CLS1 cells].

OBJECTIVE: To prepare the LINE1-ORF1p polyclonal antibody, and to study the effect of LINE1-ORF1p on the proliferation of nephroblastoma WT_CLS1 cells. METHODS: A genetic engineering method was used to achieve prokaryotic expression of LINE1-ORF1p, and rabbits were immunized with LINE1-ORF1p to prepare polyclonal antibody. Indirect ELISA was used to evaluate antibody titer, and Western blot and immunohistochemistry were used to evaluate the specific ability of antibody to recognize LINE1-ORF1p. The eukaryotic expression vector pEGFP-N1-LINE1-ORF1 was constructed and used to transfect WT_CLS1 cells. Western blot and qRT-PCR were used to measure the protein and mRNA expression of LINE1-ORF1, respectively, and cell proliferation assay and colony-forming assay were used to evaluate the effect of LINE1-ORF1p on the proliferation of WT_CLS1 cells and the formation of tumor cell clone. RESULTS: The LINE1-ORF1p antibody prepared had a titer of >1:16 000 and could specifically recognize LINE1-ORF1p in cells and tumor tissue. WT_CLS1 cells transfected with pEGFP-N1-LINE1-ORF1 had significant increases in the mRNA and protein expression of LINE1-ORF1 and significantly enhanced cell proliferation ability and colony formation ability (P<0.05). CONCLUSIONS: LINE1-ORF1p can promote the growth of nephroblastoma cells and the formation of tumor cell clone, and may be involved in the pathogenesis of nephroblastoma.

An 11-year experience of acquired von Willebrand syndrome in children diagnosed with Wilms tumour in a tertiary referral centre.

Wilms tumour (WT) is the commonest primary malignant renal tumour of childhood. Acquired von Willebrand syndrome (avWS) is a well-described paraneoplastic phenomenon, but it is uncommon and may not be detected until clinically significant bleeding is encountered during interventional procedures. Previous studies on small cohorts of patients have determined an incidence of between 4 and 8%. We have performed a retrospective study on cases of WT presenting over an 11.5-year period to a paediatric haematology/oncology unit in a tertiary referral centre to review the incidence of avWS, bleeding phenotype, management, and response to treatment of the primary pathology.

Prospective analysis of long-term renal function in survivors of childhood Wilms tumor.

BACKGROUND: Considering the improved outcome, a better understanding of the late effects in Wilms tumor survivors (WT-S) is needed. This study was aimed at evaluating renal function and determining the prevalence of clinical and subclinical renal dysfunction in a cohort of WT-S using a multimodal diagnostic approach. METHODS: Thirty-seven WT-S were included in this prospective cross-sectional single center study. To evaluate renal function, glomerular filtration rate (GFR) and urinary protein excretion were assessed. Additionally, kidney sonomorphology and blood pressure were analyzed. RESULTS: All examined WT-S (mean age 28.7 years, mean follow-up 24.8 years) had been treated with a combination of surgery and chemotherapy; 59.5% had received adjuvant radiotherapy. Impaired glomerular renal function was detected in a considerable proportion of WT-S, with age-adjusted cystatin-based GFR estimation below age norm in 55.9%. A lower cystatin-based estimated GFR (eGFR) correlated with longer follow-up time and higher irradiation dose. In 5 patients (13.5%) albuminuria was identified. Analysis of sonomorphology detected compensatory contralateral renal hypertrophy in 83.3% of WT-S. Chronic kidney disease (CKD) ≥ stage II was present in 55.9% of WT-S. Blood pressure measurements revealed arterial hypertension in 15 (40.5%) WT-S (newly diagnosed n=10). In 24.3% both CKD ≥ stage II and arterial hypertension were determined. CONCLUSION: Even though WT-S are believed to carry a low risk for end-stage renal disease, in this study, a remarkable number of WT-S presented with previously unidentified subclinical signs of renal function impairment and secondary morbidity. Therefore, it is important to continue regular follow-up, especially after transition into adulthood.

Extrarenal Wilms' Tumor of the Female Genital System: A Case Report and Literature Review.

Extrarenal Wilms' Tumors (ERWTs) are rare. There have been only 25 cases of ERWT arising from the female genital system reported in the literature. In this paper, we report a 60-year-old woman with a complaint of vaginal bleeding and a polypoid mass in the uterine cavity by sonography that was demonstrated as ERWT by pathology after resection. The pathological characteristics, histological origination, diagnosis, therapy and prognosis of ERWT in female reproductive system are discussed in this paper in the purpose of improving the diagnosis and therapy of this rare tumor.

Renal function in survivors of nonsyndromic Wilms tumor treated with unilateral radical nephrectomy.

BACKGROUND: Partial nephrectomy is considered by some for children with unilateral Wilms tumor (UWT) to avoid the theoretical complication of renal insufficiency. In the current study, the authors evaluated the prevalence of hypertension and impaired renal function in long-term survivors of nonsyndromic UWT who were treated without nephrotoxic chemotherapy or ionizing radiation. METHODS: Eligibility included age ≤15 years at the time of diagnosis of nonsyndromic UWT, treatment receipt before 2002, and maintenance of disease remission after unilateral nephrectomy without receipt of abdominal irradiation or nephrotoxic chemotherapy. Renal function was assessed by urinalysis and estimated glomerular filtration rate (eGFR). Patients receiving antihypertensive medication or those with blood pressure readings of >140/90 mm Hg were considered to be hypertensive. RESULTS: A total of 75 patients with a median age at diagnosis of 3.2 years (range, 0.2-12.1 years) met eligibility criteria. The median length of follow-up was 19.6 years (range, 10.0-32.8 years). All but 1 patient had stage I/II disease. Sixty-eight patients (90.7%) patients had WT with favorable histology and 7 patients had anaplastic histology. Sixteen patients (21.3%) had an eGFR <90 mL/minute/1.73m(2), 2 of whom also had proteinuria (12.5%). No patient had an eGFR <60 mL/minute/1.73m(2). Five patients (6.7%) had hypertension, 3 of whom were receiving antihypertensive medications. At the time of last follow-up, no patient had developed end-stage renal disease. CONCLUSIONS: Patients with UWT who were treated with unilateral radical nephrectomy without nephrotoxic chemotherapy or ionizing radiation appear to be at low risk of developing significant long-term renal dysfunction. For this patient population, the routine use of partial nephrectomy does not appear justified. However, monitoring and counseling are important for identifying the rare patient who develops subtle renal insufficiency and therefore might be at an increased risk of adverse cardiovascular sequelae.

Overall Survival and Renal Function of Patients With Synchronous Bilateral Wilms Tumor Undergoing Surgery at a Single Institution.

OBJECTIVES: Wilms tumor is the most common renal cancer in children. Approximately 5% of children with Wilms tumor present with disease in both kidneys. The treatment challenge is to achieve a high cure rate while maintaining long-term renal function. We retrospectively reviewed our institutional experience with nephron sparing surgery (NSS) in patients with synchronous bilateral Wilms tumor (BWT) operated on between 2001 and 2014. METHODS: Imaging studies, surgical approach, adjuvant therapy, and pathology reports were reviewed. Outcomes evaluated included surgical complications, tumor recurrence, patient survival, and renal function, as assessed by estimated glomerular filtration rate. RESULTS: A total of 42 patients with BWT were identified: 39 (92.9%) patients underwent bilateral NSS; only 3 patients (7.1%) underwent unilateral nephrectomy with contralateral NSS. Postoperative complications included prolonged urine leak (10), infection (6), intussusception (2), and transient renal insufficiency (1). Three patients required early (within 4 months) repeat of NSS for residual tumor. In the long-term, 7 (16.7%) patients had local tumor recurrence (managed with repeat NSS in 6 and completion nephrectomy in 1) and 3 had an episode of intestinal obstruction requiring surgical intervention. Overall survival was 85.7% (mean follow-up, 4.1 years). Of the 6 patients who died, 5 had diffuse anaplastic histology. All of the patients had an estimated glomerular filtration rate more than 60 mL/min/1.73 m at the last follow-up; no patient developed end-stage renal disease. CONCLUSIONS: In patients with synchronous, BWT, bilateral NSS is safe and almost always feasible, thereby preserving maximal renal parenchyma. With this approach, survival was excellent, as was maintenance of the renal function.

RECK Gene Polymorphism is Associated with Susceptibility and Prognosis of Wilms' Tumor in Chinese Children.

BACKGROUND: Wilms' tumor (WT) is the most common malignant renal tumor in children. Previous studies suggested the reversion-inducing, cysteine-rich protein with Kazal motifs (RECK) down-regulation might have a role in numerous human cancers. The current study was done to investigate the associations of RECK single-nucleotide polymorphisms (SNPs) with the WT susceptibility in Chinese children. MATERIAL AND METHODS: We analyzed 2 SNPs (rs10972727 and rs11788747) in a total of 97 WT children and 194 healthy matched controls (1:2 ratio) by real-time PCR and PCR-RFLP genotyping analysis. RESULTS: We found that the G allele of rs11788747 in the RECK gene was significantly associated with WT in Chinese children (OR=0.7, 95% CI: 0.45-0.99; P=0.042); as with another SNP rs10972727, however, no statistically significant difference was detected. Further analysis showed there was also a statistically significant difference in genotype frequencies between terminal tumor stage (P=0.026) and metastatic groups (P=0.002). CONCLUSIONS: The present data indicate that there is a significant association between mutant G of rs11788747 in RECK and WT risk. G carriers with advanced tumor stage or with metastasis might have an increased risk of WT.

Dependence of Wilms tumor cells on signaling through insulin-like growth factor 1 in an orthotopic xenograft model targetable by specific receptor inhibition.

We have previously demonstrated an increased DNA copy number and expression of IGF1R to be associated with poor outcome in Wilms tumors. We have now tested whether inhibiting this receptor may be a useful therapeutic strategy by using a panel of Wilms tumor cell lines. Both genetic and pharmacological targeting resulted in inhibition of downstream signaling through PI3 and MAP kinases, G(1) cell cycle arrest, and cell death, with drug efficacy dependent on the levels of phosphorylated IGF1R. These effects were further associated with specific gene expression signatures reflecting pathway inhibition, and conferred synergistic chemosensitisation to doxorubicin and topotecan. In the in vivo setting, s.c. xenografts of WiT49 cells resembled malignant rhabdoid tumors rather than Wilms tumors. Treatment with an IGF1R inhibitor (NVP-AEW541) showed no discernable antitumor activity and no downstream pathway inactivation. By contrast, Wilms tumor cells established orthotopically within the kidney were histologically accurate and exhibited significantly elevated insulin-like growth factor-mediated signaling, and growth was significantly reduced on treatment with NVP-AEW541 in parallel with signaling pathway ablation. As a result of the paracrine effects of enhanced IGF2 expression in Wilms tumor, this disease may be acutely dependent on signaling through the IGF1 receptor, and thus treatment strategies aimed at its inhibition may be useful in the clinic. Such efficacy may be missed if only standard ectopic models are considered as a result of an imperfect recapitulation of the specific tumor microenvironment.

Function and size of the residual kidney after treatment of Wilms tumor.

Long-term damage to the residual kidney is of concern in the survivors of Wilms tumor. Our objective was to evaluate the long-term glomerular function and size of the residual kidney in these patients. Twenty-nine survivors of Wilms tumor diagnosed between July 1999 and June 2004 were enrolled. The glomerular function was assessed by creatinine clearance, 99mTc DTPA radionuclide scintigraphy and 24-hour urinary protein. Renal size was evaluated by ultrasonography. Median age at diagnosis and at enrollment were 2.87 ± 1.8 (range: 0.5-7.5) and 7.9 ± 3.8 years (range: 2.5-18). Median duration of follow-up was 4.78 ± 2.6 years (range: 1-8.8). Evidence of renal dysfunction in the form of either function or size was identified in eight (27.6%) children. Six children had subnormal glomerular filtration rate and one had proteinuria. Subnormal size of the residual kidney was observed in one child. Age at diagnosis, stage, and duration elapsed after nephrectomy had no association with renal dysfunction (P >.05). Long-term follow up is crucial to identify clinical nephrotoxicity among survivors of Wilms tumor.

Evaluation of renal function after successful treatment for unilateral, non-syndromic Wilms tumor.

Impaired renal function may occur in experimental animals following surgical removal of most functioning renal tissue ("hyperfiltration injury"). Although end-stage renal disease is uncommon among long-term survivors of unilateral, non-syndromic Wilms tumor, concern has been expressed that there may be an increased risk of less serious, but progressive, renal function impairment among these individuals. The recent development of equations for estimating glomerular filtration rate (eGFR) has facilitated the study of renal function in Wilms tumor survivors. However, the estimating equations were developed to categorize individuals with chronic kidney disease and have significant limitations with regard to the accuracy of individual GFR estimates. These limitations must be considered when utilizing the estimating equations in cross-sectional or longitudinal evaluations of renal function in cohorts of patients who have been treated successfully for Wilms tumor or other childhood cancers.

Ovarian function in female survivors of childhood malignancies.

BACKGROUND: Chemotherapy-induced infertility is a common side effect observed in women of fertile age after treatment for malignant disease. OBJECTIVES: to study gonadal function and fertility in female survivors of childhood malignancies. PATIENTS AND METHODS: Study included 30 female cancer survivors and 30 age-matched healthy females as a control group. Data collected regarding; type of malignancy, age at diagnosis, duration on and off treatment, treatment received (radiation or chemotherapeutic regimens), sexual, menstrual, pregnancy, and fertility histories were also recorded. Laboratory investigations included; T4, thyroid stimulating hormone (TSH), leutinizing hormone (LH), follicular stimulating hormone (FSH), and anti-Mullerian hormone (AMH). Pelviabdominal ultrasound was done to estimate the mean ovarian volume. RESULTS: Among patients; 80% had normal menarche and 6 (20%) had delayed menarche (P > .05). There was higher LH and FSH levels and lower AMH levels in patients (P < .05) with no significant difference in thyroid function tests (P > .05). Lower mean ovarian volume was observed among female survivors (6.32 ± 2.31 cm(3)) (P = .041). There was a higher FSH and LH levels among female survivors of solid tumors compared to those with hematological tumors (P = .05 and .04 respectively). There was a significant positive correlation between FSH level and patients' age at start of malignancy (r = 0.65, P = .014), age of menarche (r = 0.74, P = .036), and duration of treatment (r = 0.54, P = .025).There was a significant negative correlation between age of menarche and AMH level (r = -0.61, P = .03). CONCLUSION: Female survivors of childhood malignancies had reduced ovarian reserve and reduced mean ovarian volume, especially those with older age, older age of menarche, and longer treatment duration.

Renal function and solitary kidney disease: Wilms tumour survivors versus patients with unilateral renal agenesis.

AIMS: To test the hypothesis that Wilms tumour survivors (WTs) experience increased disturbance in renal function, even after prompt treatment, compared to patients with unilateral renal agenesis (URA). METHODS: To assess the renal function of 30 WTs and 17 individuals with URA, the estimated glomerular filtration rate (eGFR) was calculated using the Schwartz and Filler formulas as well as the new Schwartz equation for chronic kidney disease. To measure kidney damage, serum levels and urine excretion of ß(2)-microglobulin (B2M), cystatin C (Cys C), neutrophil gelatinase-associated lipocalin (NGAL) were tested, N-acetyl-ß-glucosaminidase (NAG), and albumin urine excretion and urine sediment were examined. Blood pressure was measured. RESULTS: No differences were found between the groups in terms of eGFR, serum Cys C, B2M and NGAL concentrations. The urine excretion of Cys C, NGAL and NAG was similar in both groups. URA patients had higher B2M excretion than WTs. Arterial hypertension was present in 7/30 (23%) WTs and 1/17 (6%) patients with URA. CONCLUSIONS: WTs have similar eGFR to individuals with URA and are more likely to have arterial hypertension. The patients with URA have signs of tubular damage. This study demonstrates the need for nephrological monitoring of individuals with a single kidney.

Assessment of gonadal function in boys and adolescents at the diagnosis of neoplastic disease.

OBJECTIVE: We assessed the gonadal function in boys with a newly diagnosed neoplastic disease prior to chemotherapy. Eighty-four boys (48 prepubertal and 36 pubertal) were evaluated, including 50 with acute lymphoblastic leukemia (ALL) or non-Hodgkin lymphoma (NHL), 10 with Hodgkin lymphoma (HL), and 24 with solid tumors. The control group consisted of 24 healthy prepubertal and 24 pubertal boys. The levels of follicle-stimulating hormone (FSH), luteinizing hormone (LH), inhibin B, and testosterone were determined, and testicular volumes were measured. RESULTS: Patients in prepuberty and early puberty (Tanner stages 1-3) diagnosed with ALL/NHL or solid tumor presented normal serum reproductive hormone levels, whereas in ALL/NHL patients in Tanner stages 4-5, the mean values of inhibin B were significantly lower (45.18 +/- 33.85 vs. 153.57 +/- 71.44 ng/L, p = 0.0027). In patients with HL in Tanner stages 4-5, a statistically significant lower mean inhibin B level (100.44 +/- 67.45 versus 153.57 +/-71.44 ng/L, p = 0.0027), higher mean FSH level (6.3 +/- 3.6 versus 4.6 +/- 2.2 mIU/mL, p = 0.05), and higher mean LH level (5.9 +/- 4.0 versus 3.6 +/- 1.8 mIU/mL, p = 0.05) were observed. No statistically significant differences were noted in assessed hormones in patients with solid tumors, independently of Tanner stage. CONCLUSION: Our analysis indicates that adolescents with ALL/NHL and HL prior to treatment, exhibit reduced levels of inhibin B, which indirectly suggests the possibility of spermatogenesis dysfunction.