Myogenesis in Wilms Tumors Is Associated with Mutations of the <Emphasis Type="Italic">WT1</Emphasis> Gene and Activation of Bcl-2 and the Wnt Signaling Pathway

Wilms tumors with WT1 mutations [WT1(–)] have a stromal-predominant histology with varying extents of rhabdomyogenesis. These tumors also frequently have mutations in the beta-catenin gene (CTNNB1). We have investigated the molecular events that may explain the origins of rhabdomyogenesis in WT1(–) tumors. Of 35 Wilms tumors, we identified 12 with WT1 mutations, of which 9 carried CTNNB1 mutations. We compared WT1 wild-type tumors [WT1(+)] with WT1(–) tumors for histological features, localization of beta-catenin, Bcl-2 expression, and apoptosis using an in-situ end-labeling technique. WT1(+) tumors showed triphasic and blastemal- and epithelial predominant-histology. Expression of WT1, beta-catenin, and Bcl-2 recapitulated those of normal kidney epithelial development. Localization of beta-catenin was observed in the cytoplasm and cytoplasmic membrane of early glomerular epithelial structures. Bcl-2 is also expressed in condensing blastema and early glomerular epithelial structures which had little apoptosis. WT1(–) tumors, regardless of whether CTNNB1 mutations were detected or not, showed a stromal-rich phenotype with abundant expression of beta-catenin in the nucleus of the rhabdomyoblasts. Bcl-2 was expressed in rhabdomyoblasts, but not in blastemal cells undergoing apoptosis, suggesting that WT1 regulates Bcl-2 positively in the epithelial pathway, but negatively in the myogenic pathway. These data indicate that mutations in WT1 might alter the Wnt signaling pathway and Bcl-2 related-apoptosis. In WT1(–) tumors, the nuclear accumulation of beta-catenin and Bcl-2 expression are associated with rhabdomyogenesis, and dysregulation of Bcl-2 may be a mechanism by which the histogenesis (loss of blastemal component, muscle differentiation) may be explained.     

上海儿童医学中心WT-99方案诊治儿童肾母细胞瘤临床报告

目的：改善儿童肾母细胞瘤预后。方法：对1998年10月-2001年10月住院明确诊断为肾母细胞瘤及肾肉瘤的20例病人采用外科手术、内科化疗、选择性放疗,病理科、影像学科协作诊断综合治疗（即上海儿童医学中心WT-99方案）。按方案中条件根据分期及其他危险因素进行分组,并按分组给予不同药物组合和强度的化疗。Ⅰ期及Ⅱ期病理分型预后良好型的不放疗,估计手术不能完全切除时给予2个疗程术前化疗。结果：全组20例,年龄7个月至12岁。病理分类预后良好型14例,预后不良型3例;透明细胞肉瘤2例,横纹肌肉瘤样1例。临床结合病理分期为Ⅰ期5例,Ⅱ期5例,Ⅲ期6例,Ⅳ期3例,Ⅴ期1例。全组20例中获完全缓解18例（90％）,2例初治失败,缓解后复发1例。无病生存时间平均27个月17例（11-45个月）,占85％,目前均已停药。结论：所采用多专业联合诊断治疗工作模式及上海儿童医学中心WT-99诊治方案对儿童肾母细胞瘤有效。     

Hormonal Activity May Predict Aggressive Behavior in Neuroblastoma

Overproduction of catecholamines (dopamine [DA], norepinephrine [NE]) and their metabolites (homovanillic [HVA] and vanillylmandelic [VMA] acids) characterizes neuroblastoma (NB). In previous studies, increased urinary DA/NE, and DA/VMA ratios have been associated with poor prognosis, whereas low DA/NE ratios have been associated with longer disease-free survival. Higher urinary VMA, HVA, and NE levels have been found in association with low MYCN amplification, in contrast to cases with high MYCN amplification in which normal levels have been found. It is then believed that an “immature” catecholamine pattern indicates poor prognosis. We correlated urinary DA, NE, VMA, and HVA levels with age, clinical tumor stage, histological features (favorable [FH]/unfavorable [UH]) and MYCN status of 33 patients with NB. DA/VMA and DA/HVA ratios were also calculated. Wilcoxon rank sum and chi-squared tests were performed to determine statistical significance. Eighty-eight percent (15/17) of stage 3–4 cases had DA levels >2 times the upper limit of normal, but only 8% (1/12) of stage 1–2 cases had DA levels twice the upper limit of normal. In 61% (11/18) of stage 3–4 cases, the VMA level was >10 times the upper limit of normal, in contrast to stage 1–2 cases, in which only one patient (1/15) had a VMA level >10 times the upper limit of normal. Similar findings were obtained with urinary HVA and NE. Patients older than 12 months of age at diagnosis also had higher urinary levels of DA, VMA, HVA, and NE than those of patients younger than 12 months of age at diagnosis. Eighty-two percent (14/17) of stage 3–4 cases had DA/VMA ratios <0.78, with the other 18% (3/17) showing ratios between 1.4 and 8.82 (all stage 4 and >12 months of age). In contrast, all stage 1–2 cases (¹²) had ratios <1.4. All (12/12) non–MYCN-amplified cases had DA/VMA ratios <1.4 (0.06–0.84), while one MYCN-amplified case (1/3) had a ratio of 8.82; the other two MYCN-amplified cases had DA/VMA ratios of 0.09–0.11. Twenty-nine percent (2/7) of cases with UH had a DA/VMA ratio >1.4, but in all FH cases (14/14) the DA/VMA ratio was <1.4 (0.08–0.084). Similar to previous studies, we found that aggressive NB is associated with higher urinary levels of DA, VMA, HVA, and NE. We also confirmed the previous observation that there appears to be a subset of NB in which a possible blockade in DA metabolism is associated with poor prognostic features (>12 months, stage 4, UH, and MYCN amplification). A seemingly novel observation in our study is that all high DA/HVA and DA/VMA ratios were obtained in stage 4 tumors, suggesting an association between the inability to metabolize DA and the acquisition of metastatic potential. On the basis of our results, we would like to emphasize the importance of determining not only DA, HVA, and VMA urinary levels, to support the diagnosis of NB, but also DA/HVA and DA/VMA ratios as a rapid initial assessment of prognosis in these patients. Received August 27, 2001; accepted November 13, 2001.     

Decrease in LDL receptor-related protein expression and function correlates with advanced stages of Wilms tumors

BACKGROUND: The molecular processes responsible for the invasive phenotype of pediatric Wilms tumors (WT) are poorly understood. A candidate WT suppressor gene (WT1) has been found mutated in a number of these pediatric kidney tumors. However, the disruption of normal WT1 protein function cannot solely explain WT growth. The aim of the present study is to identify new molecular players that regulate the invasive character of WT. PROCEDURE: Fresh frozen samples from 45 renal tumors of Wilms were obtained from the National Wilms Tumor Study Group's Biological Samples Bank. Gelatin zymography, Western blotting, and immunodetection were used to compare tissue biopsies originating from the infiltrating (stage III), metastatic (stage IV), and anaplastic phenotype of Wilms tumors (WT). RESULTS: The expression of the low-density lipoprotein receptor-related protein (LRP) diminished in stage IV and anaplastic WT. Moreover, the expression of RAP, an LRP intracellular chaperone, was also decreased. The diminished expression of LRP and RAP correlated with increased levels of several known extracellular ligands that LRP usually recycles from the extracellular matrix (ECM) environment, including PAI-1, MMP-9, and TIMP-1. The proteolytic processing of MT1-MMP, a functional regulator of LRP, also correlated with the WT invasive phenotype. CONCLUSIONS: The low expression of LRP, whose function is regulated by MT1-MMP and whose activity in recycling ECM-associated proteolytic enzymes becomes drastically diminished in advanced stages of WT, may in part explain the acquired invasive potential of the developing WT pediatric cancer.     

Anaplastic histology Wilms’ tumors registered to the Japan Wilms’ Tumor Study Group are less aggressive than that in the National Wilms’ Tumor Study 5

Purpose

To evaluate the clinical features and treatment results of anaplastic histology (AH) Wilms’ tumor (WT) patients registered in the Japan Wilms’ Tumor Study (JWiTS) group to elucidate the clinical characteristics of AH in the Japanese population.

Patients and methods

Of 344 WT patients who were enrolled in JWiTS between 1995 and 2013, 17 had AH. Treatment using the JWiTS protocols was similar to the fifth National Wilms’ Tumor Study 5 (NWTS-5) protocols. Clinical characteristics and mutation status of TP53 gene were evaluated and compared with those in NWST-5 study.

Results

AH incidences in JWiTS were 4.9 %, lower than that in NWTS-5. Seven tumors had focal AH and 10 had diffuse AH. Clinical stages of AH patients were stage I in seven, stage II in three, stage III in five, stage IV in one and unknown in one. Four-year event-free survival and overall survival rates were 90.9 and 86.7 %, respectively. Two patients with diffuse AH and none with focal AH had TP53 mutation.

Conclusion

Japanese patients presented with higher incidence, earlier stages and may have better outcomes than American patients, indicating a possible biological heterogeneity of AH WT. Further analysis is necessary to elucidate the different characteristic of AH WT between Japanese and American populations.

     

Treatment of children with stage IV favorable histology Wilms tumor: A report from the National Wilms Tumor Study Group

The purpose of this study was to evaluate the effect of the sequential addition of doxorubicin and cyclophosphamide to the combination of vincristine and actinomycin D on the relapse-free survival of children with stage IV/favorable histology Wilms tumor. We reviewed the clinical courses of all randomized patients from National Wilms Tumor Study (NWTS)-2 and 3 with stage IV/favorable histology (FH) Wilms tumor. We determined the four-year relapse-free survival percentage for patients treated on NWTS-2 with the combination of vincristine (VCR) and actinomycin D (AMD) with (regimen D) or without (regimen C) doxorubicin (DOX), and for patients treated on NWTS-3 with the combination of VCR + AMD + DOX with (regimen J) or without (regimen DD-RT) cyclophosphamide (CTX). All children received whole lung radiation therapy. The four-year relapse-free survival percentage for children with stage IV/FH Wilms tumor treated with regimen C was 53.3%, compared to 57.7% for those treated with regimen D (P = 0.63). The four-year relapse-free survival percentage for children with stage IV/FH Wilms tumor treated with regimen DD-RT was 79.0%, compared to 80.9% for those treated on regimen J (P = 0.79). The four-year relapse-free survival for children with lung metastases only treated with regimen D on NWTS-2 was significantly lower than that of children treated with the related regimen DD-RT on NWTS-3 (P = 0.03). We conclude that the addition of doxorubicin to the combination of vincristine and actinomycin D and pulmonary irradiation did not clearly improve the four-year relapse-free survival percentage of children with stage IV/FH Wilms tumor, although the benefit may have been masked by the greater frequency of death due to toxicity in NWTS-2. There was no evidence that the addition of CTX to the three-drug treatment regimen improved the four-year relapse-free survival percentage of children with stage IV/FH Wilms tumor. The data with only two drugs derived from NWTS-2 suggest that there is a population of children with stage IV/FH Wilms tumor who can be successfully treated without an anthracycline. The goal of future research will be to identify this subgroup at the time of initial diagnosis. © 1996 Wiley-Liss, Inc.     

化疗对肾母细胞瘤细胞凋亡及坏死的影响

目的 了解化疗对肾母细胞瘤细胞凋亡和坏死的影响。方法 对４４例肾母细胞瘤进行随机分组，Ａ组２６例，给予ＶＡＣ术前化疗，其中８例尚加用了介入化疗，Ｂ组１８例，Ｉ期手术治疗。用ＴＵＮＥＬ技术和常规病理检查观察了全部标本的凋亡和坏死情况，并分组进行了比较。结果 术前化疗后Ａ组瘤体凋亡指数（ＡＩ）较Ｂ组明显增加；Ａ组中化疗时间超过两周的病例ＡＩ较不足两周病例也有明显上升；但死亡和获两年以上生存病例，介入和     

Flow cytometric analysis of DNA ploidy in 62 patients with Wilm's tumor

Flow cytometric analysis of DNA ploidy was done on nuclei extracted from paraffin-embedded tissue blocks from 62 patients with Wilms' tumor, the largest series reported to date. Thirty-eight tumors were aneuploid and 24 were diploid; there were no tetraploids. Sixty-seven percent of the diploids and 44.7% of the aneuploids survived; the difference was statistically significant (P <0.01). The 2 congenital mesoblastic nephromas were diploid; the only 2 adult patients were aneuploid. Aneuploids comprised 75% of those presenting in stage III/IV and 75% of the anaplastic tumors. Genetic heterogeneity, never before reported in Wilm's tumor, was found in 2 patients. Aneuploidy was an ominous prognostic factor, particularly when combined with tumor stage and histological grade. Offprint requests to: M. Rohatgi     

Management of Wilms tumors in Drash and Frasier syndromes

Background

Children with WT1 gene‐related disorders such as Denys–Drash syndrome (DDS) and Frasier syndrome (FS) are at increased risk of Wilms tumor and end‐stage renal disease. We investigated whether Wilms tumors in these patients displayed a specific phenotype or behavior and whether nephron‐sparing surgery was beneficial.

Procedure

We retrospectively studied all patients with DDS, FS, or other WT1 mutations treated at our institutions between 1980 and 2007.

Results

We identified 20 patients, of whom 18 had benign or malignant tumors. Wilms tumors occurred in 15 patients, being unilateral in 10 and bilateral in 5 (20 tumors). Median age at Wilms tumor diagnosis was 9 months. No patients had metastases. According to the International Society of Pediatric Oncology Working Classification, there were 19 intermediate‐risk tumors and one high‐risk tumor; no tumor was anaplastic. In patients with nephropathy who underwent unilateral nephrectomy for Wilms tumor or nephron‐sparing surgery for bilateral Wilms tumor, mean time to dialysis was 11 or 9 months, respectively. Other tumors included three gonadoblastomas (in two patients), one retroperitoneal soft‐tissue tumor, and one transitional cell papilloma of the bladder. Two patients, both with stage I Wilms tumor, died from end‐stage renal disease‐related complications. The median follow‐up time for the 18 survivors was 136 months (range, 17–224 months).

Conclusion

Most Wilms tumors in children with WT1‐related disorders were early‐stage and intermediate‐risk tumors, with a young age at diagnosis. In patients without end‐stage renal disease, nephron‐sparing surgery should be considered for delaying the onset of renal failure. Pediatr Blood Cancer 2009;52:55–59. © 2008 Wiley‐Liss, Inc.     

Wnt1信号通路蛋白分子在肾上腺及神经母细胞瘤组织中表达的研究

目的 观察新生儿肾上腺、>2岁小儿肾上腺和神经母细胞瘤组织中经典Wnt信号通路中Wnt1、β-catenin和CyclinD1的表达,探讨Wnt1信号通路调控异常与神经母细胞瘤的相关性.方法 应用免疫组化方法 检测新生儿肾上腺、>2岁小儿肾上腺及各期、各病理类型、化疗前后神经母细胞瘤组织中Wnt1信号通路中Wnt1、β-catenin和CycinD1的表达.结果术前未化疗的肿瘤Wnt1和β-catenin蛋白表达明显强于新生儿肾上腺组织,后者又明显强于>2岁小儿肾上腺(P=0.014),差别均具有高度的统计学意义;Ⅲ～Ⅳ期肿瘤的Wnt1和β-catenin蛋白表达较Ⅰ～Ⅱ期肿瘤高;Ⅲ～Ⅳ期肿瘤中术前未化疗的Wnt1和β-catenin蛋白表达明显高于术前化疗的肿瘤;组织预后不良型(UH)肿瘤Wnt1和β-catenin蛋白表达较组织预后良好型(FH)肿瘤高,差别具有高度的统计学意义.新生儿肾上腺及>2岁小儿肾上腺组织中CyclinD1染色均为阴性,而肿瘤组织中表达阳性,Ⅰ～Ⅱ期肿瘤与Ⅲ～Ⅳ期术前未化疗的肿瘤CyclinD1蛋白表达无差别;Ⅲ～Ⅳ期术前未化疗的肿瘤CyclinD1蛋白表达明显高于术前化疗的肿瘤,UH肿瘤的CyclinD1蛋白表达高于FH肿瘤.结论 Wnt1信号通路对肾上腺细胞分化成熟有一定的调控作用.Wnt1通路异常可能是参与神经母细胞瘤发生和侵袭的重要机制.     

Treatment and prognosis of 32 patients with bilateral Wilms' tumor

During the 29-year period 1955–1983, 32 children with bilateral Wilms' tumor were treated at the Hospital for Sick Children, Toronto (HSC) and the Royal Children's Hospital, Melbourne (RCH). Those whose tumors presented synchronously (n=22) had a good prognosis: 15 (68%) are alive and disease-free 12 to 204 months post-diagnosis with a median follow-up of 96 months. There were no deaths due to metastases. The asynchronous group (n=10) had a poor prognosis: only 3 are disease-free survivors, 2 long-term and 1 who has survived 17 months following diagnosis of the contralateral tumor. Five of the 7 deaths were due to metastases, possibly related to the immunosuppressive effect of the additional chemo/radiotherapy given for the separate treatment of both tumors. The poor prognosis could not be attributed to extent of disease or unfavourable histology as only 2 were stage IV at diagnosis of the second tumor and none had anaplastic histology. We recommend renal ultrasound and abdominal computerized axial tomography for an accurate diagnosis of synchronous Wilms' tumors, particularly in children at high risk for bilaterality, and for prolonged follow-up to detect asynchronous disease. Offprint requests to: R. M. Filler at the above address in Canada     

Opsoclonus-myoclonus-ataxia syndrome in neuroblastoma: histopathologic features-a report from the Children's Cancer Group

BACKGROUND: Opsoclonus-myoclonus-ataxia (OMA) is a paraneoplastic syndrome that occurs in about 2-3% of all cases of neuroblastoma. The histopathologic characteristics of neuroblastoma tumors associated with this syndrome were evaluated in a series of cases and controls. PROCEDURE: Pathology slides from a total of 54 neuroblastoma tumors were reviewed blindly. They included 13 tumors associated with opsoclonus-myoclonus and 41 age- and stage-matched controls. All tumors were classified into either the favorable (FH) or unfavorable histology (UH) group according to the International Neuroblastoma Pathology Classification (the Shimada system). Grade of lymphocytic infiltration was evaluated and presence or absence of lymphoid follicles was recorded in the individual tumor tissues. RESULTS: Twelve of 13 cases with opsoclonus-myoclonus were in the FH group. Twelve of 13 cases had diffuse (found in every section prepared from the multiple portions of the primary tumor) and extensive (occupying more than 50% of a single of multiple microscopic fields with x 100 magnification) lymphocytic infiltration with lymphoid follicles. Of the 41 control cases (27 FH and 14 UH tumors), 18 had focal areas of lymphocytic infiltration and six showed lymphoid follicles, but none had diffuse or extensive infiltration in their primary tumors. CONCLUSIONS: Diffuse and extensive lymphocytic infiltration with lymphoid follicles is a characteristic histologic feature of neuroblastic tumors with opsoclonus-myoclonus. This observation suggests an immune-mediated mechanism for this rare paraneoplastic syndrome.     

Profiling Loss of Heterozygosity Patterns in a Cohort of Favorable Histology Nephroblastoma Egyptian Patients: What is Consistent With the Rest of the World

According to the Fifth National Wilms Tumor Study (NWTS-5), tumor-specific loss of heterozygosity (LOH) for chromosomes 1p and 16q identifies a subset of patients with Wilms tumor (WT) who despite having favorable histology (FH) have a significantly increased risk of relapse and death. We aimed to find out 1p and 16q LOH frequencies in patients with FH-WT as well as its correlation to survival outcome and epidemiologic and clinical characteristics. Data of patients with FH-WT presenting to the National Cancer Institute, Egypt, were retrospectively analyzed. Paraffin blocks were tested for 1p and 16q LOH using polymorphic loci that span the minimal regions of LOH at this area. The study included 100 patients with a median age of 5 years. Thirty-nine patients (39%) showed LOH at 1p (n = 14), 16q (n = 13), or both (n = 12). LOH was most frequently encountered in patients above 10 years (5/5), advanced stages disease (80% of stage V and 50% of stages IV and III each). The 3-year overall survival (OS) and event-free survival (EFS) were significantly lower in patients with double LOH (75% and 50%, respectively), followed by 16q (92% and 54%), in comparison with 1p (93% each) and negative LOH (97% and 100%) cases, respectively (p = 0.001). Combined LOH (1p+16q), followed by 16q LOH alone, was predictive of poorer outcome and was associated with lower OS and EFS in patients with FH-WT. Our results showed a higher-risk disease that would suggest the need for an intensified upfront therapy in this group of patients.     

肾母细胞瘤诊治10年回顾

目的 对10年中收治的小儿肾母细胞瘤的发病特点和诊治进行回顾分析,讨论影响肾母细胞瘤治疗和预后的因素.方法 统计10年期间69例肾母细胞瘤患儿的临床资料,包括患儿性别,发病年龄,临床表现和分期,病理分型和治疗手段,并将患儿分别以临床分期和病理分型进行分层,用Kaplan-Meier进行单因素生存分析.结果平均发病年龄(3.25±2.78)岁,发现腹部包块为主要起病症状,其中Ⅰ期18例,Ⅱ期25例,Ⅲ20例,Ⅳ期6例.治疗手段为患肾切除,NWTSG的化疗方案和有限病例的放疗.随访时间4～123个月,平均生存时间(41±30.9)个月.生存率:总体生存率78.2%,其中Ⅰ期患儿100%,Ⅱ期患儿76%,Ⅲ期患儿70%,Ⅳ期患儿50%.Kaplan-Meier生存分析表明,Ⅰ期、Ⅱ期、Ⅲ期三组患儿的生存时间差别无统计学意义,但明显高于Ⅳ期组患儿(LogRank法,P=0.04).预后良好组织类型(FH)组生存率为86.9%,其中Ⅰ期为100%,Ⅱ期93.3%,Ⅲ期72.7%,Ⅳ期50%;预后不良组织类型(UH)组总体生存率为65.2%,Kaplan-Meier生存分析生存表明,二组的生存时间具有显著性差异(Log Rank法,P=0.004).结论 临床分期,病理类型和治疗手段是影响肾母细胞瘤患儿预后的重要因素.     

婴幼儿血管瘤组织中bcl-2和bax与细胞凋亡的研究

目的　研究凋亡调控基因bcl- 2和bax与婴幼儿血管瘤细胞增生、凋亡的关系,探讨其在血管瘤增生、消退中的作用机制。方法　采用免疫组化SP法检测血管瘤及血管畸形组织中增殖细胞核抗原(PCNA)及凋亡调控基因bcl -2和bax的表达;用末端脱氧核苷酸转移酶(TdT)介导的d UTP生物素缺口末端标记技术 (TUNEL)检测凋亡细胞。结果　bcl 2阳性表达率在增生期和消退期分别是82.14%和46.67%,两者之间差异存在显著性意义(P<0.01),消退期与血管畸形表达差异无显著性意义(P>0.05)。Bax在血管瘤增生期和消退期均为 100%表达,与血管畸形中的表达差异有显著性意义(P<0.01)。bcl 2和bax在血管畸形组织中均不表达。婴幼儿血管瘤增生期和消退期凋亡指数(apop tosisindex,AI)为30.52±10.25和80.22±6.82;增殖指数 (proliferativeindex,PI)分别为11.40±8.90和4.79±3.63,两者之间差异均存在显著性意义(P<0.01)。AI与bcl 2的表达呈负相关 (r=-0.318,P<0.05),AI与bax的表达无明显相关性 (r=-0.077,P>0.05),AI与bcl 2/bax比值呈负相关 (r=-0.307,P<0.05)。结论　在血管瘤增生消退中存在着逐渐活跃的凋亡现象,细胞凋亡是血管瘤的典型生物学特征,是血管瘤的自然消退的关键因素。bcl -2和bax参与了血管瘤中细胞凋亡的调节。     

Precipitants in 42 cases of erythema multiforme

A total of 42 children with erythema multiforme (aged 0.1 to 15.8 years, median 6.1 years) were treated between 1978 and 1997 at the Department of Paediatrics, University of Bern, Switzerland. Antecedent infections were noted in 30 cases: Mycoplasma pneumoniae infection (n = 14), acute upper respiratory tract disease (n = 10) and herpes simplex infection (n = 6). Four cases were associated with antecedent medication (n = 3) or immunization (n = 1). In 12 of the 30 patients in whom erythema multiforme followed an infectious disease, drugs described in the literature as inducers of erythema multiforme had been given for symptoms not suggestive of the condition. In the remaining eight children no precipitating agent could be detected. Conclusion In this survey infections were found as a definite or at least presumptive trigger of erythema multiforme in 71% of cases. Drugs (including immunization) implicated as triggers of erythema multiforme played a definite causative role in 10% and a presumptive role in a further 29% of patients. In 19% of patients an associated condition was not diagnosed. Received: 1 September 1998 / Accepted in revised form: 16 April 1999     

Clinicopathologic correlates of loss of heterozygosity in Wilms' tumor: A preliminary analysis

Wilms' tumor-specific loss of heterozygosity (LOH) for DNA markers located at chromosomes 11p13, 11p15, 16q, and 1p has been reported to occur in a minority of Wilms' tumors. We hypothesized that tumors classified by region of LOH would exhibit specific clinicopathologic patterns. We have therefore determined the constitutional and tumor genotypes for markers at 11p13, 11p15, 16q, and 1p in a large series of Wilms' tumor patients who were registered on a Pediatric Oncology Group study and on the National Wilms' Tumor Study, to determine whether tumor-specific LOH for any of these regions was associated with any specific phenotype. Of 286 cases, 27% had LOH at both 11p13 and p15 (BOTH), 3% at 11p13 only, 8% at 11p15 only, and 62% at neither. Significant associations were found between younger age at diagnosis and LOH for BOTH, but not for 11p15 only, and between the presence of intralobar nephrogenic rests and LOH for BOTH. The incidence of nephrogenic rests (all types combined) and of bilateral tumors was the same in tumors with or without LOH. There was a negative association between anaplastic histology and LOH for 11p. There was no association between LOH on 11p and outcome as assessed by relapse-free and overall survival. The associations between age at diagnosis and LOH are interpreted as suggesting the existence of a Wilms' tumor locus on 11p in addition to WT1 at 11p13 and the putative WT2 at 11p15. LOH for chromosome 16q was identified in 17% of 204 tumors and was associated with a significantly worse outcome. Outcome for patients with LOH for 1p was also worse but not significantly so. © 1996 Wiley-Liss, Inc.     

血管内皮生长因子、瘤内血管密度与神经母细胞瘤细胞增殖及转移的关系

目的观察血管内皮细胞生长因子(vascularendothelialgrowthfactor,VEGF)、血管内皮细胞相关抗原荆豆素(UEA)和增殖细胞核抗原(PCNA)在神经母细胞瘤(NB)中表达情况,探讨VEGF、瘤内微血管密度(MDV)与NB细胞增殖和转移的关系.方法应用免疫组化ABC法检测VEGF、UEA、PCNA在27例NB中的表达.应用RT-PCR方法测定患儿外周血、骨髓中微量瘤细胞(MRD).结果VEGF、UEA、PCNA表达均在进展期高于局灶期,预后不良型高于预后良好型,且均具有统计学意义.VEGF表达与MDV和PCNA指数(PCNALI)正相关(r分别为0.69和0.37,P<0.01).MDV与肿瘤转移强度正相关(r=0.73,P<0.01).结论VEGF可通过促进瘤内新生血管形成和细胞增殖在NB浸润转移中具有重要的作用.