CTNNB1 Mutation Status Research Articles

Low-dose chemotherapy with methotrexate and vinblastine for Japanese patients with desmoid tumors: Relationship to CTNNB1 mutational status.

Background This study was conducted to determine the efficacy and safety of low-dose chemotherapy with meth otrexate (MTX) and vinblastine (VBL) for patients with desmoid tumors refractory to meloxicam treatment, focusing in particular on the relationship between the efficacy of this chemotherapy and catenin β-1 (CTNNB1) mutation status. Patients and methods Since March 2003, patients pathologically diagnosed with extraperitoneal desmoid tumors have been prospectively treated with meloxicam, a COX-2 inhibitor, at our institution. Patients with inoperable tumors who were resistant to meloxicam treatment underwent MTX and VBL therapy every other week. The responses of all patients were evaluated, and factors that were correlated with efficacy were analyzed, including CTNNB1 mutation status. Results Sixty-eight patients were prospectively treated with meloxicam. MTX + VBL therapy was administered in 15 patients. Six patients showed a partial response. Only one patient presented disease progression. A few patients showed grade 3–4 treatment-related toxicity with the administration of MTX and VBL every other week. Intriguingly, CTNNB1 status did not affect the efficacy of this treatment.

Low-dose chemotherapy with methotrexate and vinblastine for patients with desmoid tumors: relationship to CTNNB1 mutation status.

This study was conducted to determine the efficacy and safety of low-dose chemotherapy with methotrexate (MTX) and vinblastine (VBL) for patients with desmoid tumors refractory to meloxicam treatment, focusing in particular on the relationship between the efficacy of this chemotherapy and catenin β-1 (CTNNB1) mutation status. Since March 2003, patients pathologically diagnosed with extraperitoneal desmoid tumors have been prospectively treated with meloxicam, a COX-2 inhibitor, at our institution. Patients with inoperable tumors who were resistant to meloxicam treatment underwent MTX and VBL therapy every other week. The responses of all patients were evaluated, and factors that were correlated with efficacy were analyzed, including CTNNB1 mutation status. Sixty-eight patients were prospectively treated with meloxicam. MTX + VBL therapy was administered in 15 patients. Six patients showed a partial response. Only one patient presented disease progression. A few patients showed grade 3-4 treatment-related toxicity with the administration of MTX and VBL every other week. Intriguingly, CTNNB1 status did not affect the efficacy of this treatment. MTX and VBL treatment every other week is well tolerated and achieved a favorable response in patients resistant to meloxicam treatment, regardless of CTNNB1 mutation status.

Comprehensive genomic profiling of advanced stage endometrioid endometrial adenocarcinomas (EEAC) reveals differences associated with CTNNB1 mutation status and a high frequency of clinically relevant genomic alterations

Comprehensive genomic profiling of advanced stage endometrioid endometrial adenocarcinomas (EEAC) reveals differences associated with CTNNB1 mutation status and a high frequency of clinically relevant genomic alterations

Abstract LB-201: MYC and TP53 defects interact at medulloblastoma relapse to define rapidly progressive disease and can be targeted therapeutically

Abstract Disease recurrence following multi-modal therapy is the single most adverse event in medulloblastoma (MB). Currently >90% of relapsing patients die, accounting for ∼10% of childhood cancer deaths. MB is heterogeneous at diagnosis, comprising four molecular subgroups with distinct clinicopathological and molecular features and outcomes. The relevance of these features at relapse is unknown, making characterisation, modelling and targeted therapy of relapse biology essential to improve outcomes. However, relapsed MBs are not routinely biopsied in clinical practice. We undertook a first comprehensive investigation of the molecular, clinical and pathological features of 29 relapsed MBs and paired tumour samples taken at diagnosis, including the assessment of features with established significance at diagnosis (e.g. chromosome 17 and TP53 pathway status, MYC family (MYC, MYCN) gene amplification, polyploidy, CTNNB1 mutation and molecular subgroup status). Molecular subgroup was concordant at diagnosis and relapse, however evidence of alteration of all other features examined was found in relapsed tumours, with the majority of changes (30/44) representing acquired high-risk events. Most notably, MYC family gene amplifications and TP53 pathway defects commonly emerged in combination at relapse following conventional multimodal treatment (P=0.02, 7/22, 32%) and predicted rapid progression to death (P=0.016). These observations suggested aberrant activation of MYC family genes synergizes with TP53 inactivation in the genesis of biologically aggressive MB. To investigate any such relationship, we examined Trp53 status in our transgenic mouse model of spontaneously-arising MYCN-driven MB (GTML; Glt1-tTA/TRE-MYCN-Luc). Somatic Trp53 mutations were found in 83% of tumors (n=10/12). Direct modelling of this interaction in GTML/Trp53KI/KI mice dramatically enhanced MB formation with 100% penetrance (43/43, median survival 47 days) in GTML/Trp53KI/KI versus 6% (3/50) in GTML; P<0.0001), faithfully mimicked clinicopathological characteristics of TP53-MYC family gene-associated relapsed human tumors, and validated the essential role of TP53 in potentiating the growth of MYCN-driven MB. Finally, therapeutic inhibition of Aurora-A kinase using MLN8237 in these tumours, and in derived neurospheres in vitro, promoted degradation of MYCN, reduced tumor growth and prolonged survival. In summary, while subgroup status remains stable, MBs display altered molecular, pathological and clinical features at relapse, and the emergence of combined TP53-MYC family gene defects is common following conventional therapy. Their association with rapid demise, coupled with their biological validation as driving and therapeutically exploitable events in a novel mouse MB model, strongly support further investigation and routine biopsy of relapse disease to drive future individualised therapeutic strategies. Citation Format: Rebecca M. Hill, Sanne Kuijper, Janet Lindsey, Ed C. Schwalbe, Karen Barker, Jessica Boult, Daniel Williamson, Zai Ahmad, Albert Hallsworth, Sarra Ryan, Evon Poon, Simon Robinson, Ruth Ruddle, Florence Raynaud, Louise Howell, Colin Kwok, Abhijit Joshi, Sarah Nicholson, Stephen Crosier, Stephen Wharton, Tom Jacques, Keith Robson, Antony Michalski, Darren Hargrave, Barry Pizer, Simon Bailey, Fredrik J. Swartling, Kevin Petrie, William A. Weiss, Louis Chesler, Steve Clifford. MYC and TP53 defects interact at medulloblastoma relapse to define rapidly progressive disease and can be targeted therapeutically. [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr LB-201. doi:10.1158/1538-7445.AM2014-LB-201

PROGNOSTIC SIGNIFICANCE OF CLINICAL, HISTOPATHOLOGICAL, AND MOLECULAR CHARACTERISTICS OF MEDULLOBLASTOMAS IN THE PROSPECTIVE HIT2000 MULTICENTER CLINICAL TRIAL COHORT

BACKGROUND: This study aimed to prospectively evaluate clinical, histopathological and molecular variables for outcome prediction in medulloblastoma patients. METHODS: Patients from the HIT2000 cooperative clinical trial were prospectively enrolled based on the availability of sufficient tumor material and complete clinical information. This revealed a cohort of 184 patients (median age 7.6 years), which was randomly split at a 2:1 ratio into a training (n = 127), and a validation (n = 57) dataset. All samples were subjected to thorough histopathological investigation, CTNNB1 mutation analysis, quantitative PCR, MLPA and FISH analyses for cytogenetic variables, and methylome analysis. RESULTS: By univariable analysis, clinical factors (M-stage), histopathological variables (large cell component, endothelial proliferation, synaptophysin pattern), and molecular features (chromosome 6q status, MYC amplification, TOP2A copy-number, subgrouping) were found to be prognostic. Molecular consensus subgrouping (WNT, SHH, Group 3, Group 4) was validated as an independent feature to stratify patients into different risk groups. When comparing methods for the identification of WNT-driven medulloblastoma, this study identified CTNNB1 sequencing and methylation profiling to most reliably identify these patients. After removing patients with particularly favorable (CTNNB1 mutation, extensive nodularity) or unfavorable (MYC amplification) markers, a risk score for the remaining “intermediate molecular risk” population dependent on age, M-stage, pattern of synaptophysin expression, and MYCN copy-number status was identified and validated, with speckled synaptophysin expression indicating worse outcome. CONCLUSIONS: Methylation subgrouping and CTNNB1 mutation status represent robust tools for the risk-stratification of medulloblastoma. A simple clinico-pathological risk score for “intermediate molecular risk” patients was identified, which deserves further validation. SECONDARY CATEGORY: Pediatrics.

MTX and VBL treatment for patients with desmoid tumors resistant to meloxicam treatment: Relationship between efficacy and CTNNB1 mutation status.

e21525 Background: Treatment modalities for desmoid tumors have been changed because of the high recurrence rate even after wide resection. Since 2003, meloxicam, which is a selective COX-2 inhibit...

Genetic analysis of adamantinomatous craniopharyngioma (ACP)

From a cohort of 123 ACPs our aim was to gain further information on the molecular genetics and biology of this rare benign tumor entity. DNA was extracted from FFPE-tissue (partly by laser capture microdissection) and CTNNB1 mutational status was analysed by direct sequencing. Even though all ACPs show nuclear ß-catenin accumulation in some tumor cells indicating Wnt pathway activation, only 71% were found mutated at one of the 4 phosphorylation sites in CTNNB1 exon 3. 28 mutated cases were also screened for DDX3X mutations, which can be seen in ˜50% of CTNNB1-mutated medulloblastomas, but none were found. A significantly worse 6-year event-free survival was found in cases mutated at threonine41 compared to cases with other CTNNB1-mutations or cases lacking a mutation. 20 cases were further analysed by molecular inversion profiling, but no larger chromosomal aberrations were found. This method also detected APC-mutations in two cases as a possible alternative mechanism of Wnt activation.

CTNNB1 S45F mutation predicts poor efficacy of meloxicam treatment for desmoid tumors: a pilot study.

We hypothesized that patterns of CTNNB1 (β-catenin) mutations would affect the outcome of conservative therapy in patients with desmoid tumors. This study aimed to determine the significance of CTNNB1 (β-catenin) mutations in predicting the treatment outcome in patients with desmoid tumors treated with meloxicam, a cyclooxygenase-2 (COX-2) selective inhibitor. Between 2003 and 2012, consecutive thirty-three patients with extra-peritoneal sporadic desmoid tumors were prospectively treated with meloxicam as the initial systemic medical therapy. The efficacy of meloxicam was evaluated according to Response Evaluation Criteria in Solid Tumors (RECIST). DNA was isolated from frozen tissue or formalin-fixed materials. CTNNB1 mutation analysis was performed by direct sequencing. Positivity of nuclear β-catenin staining by immunohistochemistry was compared with the status of CTNNB1 mutations. The correlation between the efficacy of meloxicam treatment and status of CTNNB1 mutations was analyzed. Of the 33 patients with meloxicam treatment, one showed complete remission (CR), 7 partial remission (PR), 12 stable disease (SD), and 13 progressive disease (PD). The following 3 point mutations were identified in 21 of the 33 cases (64%): T41A (16 cases), S45F (4 cases) and S45P (one case). The nuclear expression of β-catenin correlated significantly with CTNNB1 mutation status (p = 0.035); all four cases with S45F mutation exhibited strong nuclear expression of β-catenin. S45F mutation was significantly associated with a poor response (all cases; PD) (p = 0.017), whereas the other mutations had no impact on efficacy. The CTNNB1 mutation status was of significant prognostic value for meloxicam treatment in patients with sporadic desmoid tumors.

BRAF V600E mutations are characteristic for papillary craniopharyngioma and may coexist with CTNNB1-mutated adamantinomatous craniopharyngioma

Craniopharyngiomas are epithelial, sellar tumours comprising two subtypes: adamantinomatous (aCP) and papillary (pCP). aCPs contain mutations in CTNNB1, encoding β-catenin: a component of the adherens junction and mediator of Wnt signalling. Reported frequency of CTNNB1 mutations varies widely (16–100 %) [6, 7]. Recently, it was reported that pCPs contain BRAF p.V600E mutations in 95 % of cases [2] and that CTNNB1 and BRAF mutations are mutually exclusive and specific to tumour subtype. We examined the relationship between mutation in CTNNB1 and BRAF and subcellular location of β-catenin in a series of 37 craniopharyngiomas. The region of BRAF exon 15 containing codon 600 was sequenced, as was exon 3 of CTNNB1. Immunohistochemistry (IHC) for β-catenin was used to examine its subcellular location and an antibody specific for the BRAF V600E mutation (clone VE1) was used to complement the sequencing findings in all aCP and pCPs. Methods are reported in Online Resource 1. We found BRAF V600E mutations in 81 % (17 of 21) pCPs by targeted Sanger sequencing and in 86 % (18 of 21) pCPs by IHC. Although there was agreement between methods in 95 % (20 out of 21) of cases, interpretation of anti-BRAF V600E staining was challenging due to occasional non-specific reactivity. aCP cases were selected for the study on the basis of their CTNNB1 mutation status [6 wild type and 10 mutant (9 T41I, 1 D32N)]. In all aCPs, translocation of β-catenin from membrane to cytosol/nucleus was observed, confirming the utility of β-catenin translocation as a diagnostic tool. Of 16 aCP cases, 14 (88 %) were BRAF wild type by sequencing and IHC. We observed BRAF V600E mutation in two aCP cases. This finding was validated by careful diagnostic review of morphology and comparison with IHC findings. Further validation was obtained by sequencing in forward and reverse directions from two DNA samples extracted on different occasions. In both these specimens, CTNNB1 mutation was also present (T41I) (Fig. 1). Fig. 1 BRAF V600E mutations in adamantinomatous craniopharyngioma. Two cases are shown (a–e and f–j). a, f Classical features of aCP (wet keratin, stellate reticulum, palisaded epithelium). b, g Translocation of β-catenin is shown in ... Sequencing of bulk tumour revealed no relationship between CTNNB1 mutation and cytosolic/nuclear accumulation of β-catenin. However, our study did not search for mutations at other loci, which could have led to an under-estimation of the proportion of specimens harbouring CTNNB1 mutations. In other studies on FFPE tissue that used Sanger dideoxy sequencing to search for CTNNB1 mutation, the rate was also not 100 % [3, 5, 7], suggesting that this method is not sufficiently sensitive to detect the presence of a mutation in all samples. In contrast, Brastianos et al. [2] found CTNNB1 mutations in 96 % of aCPs using mass spectrometric genotyping. We found BRAF V600E mutations in 81 % of pCPs. Difficulties interpreting BRAF V600E staining have been reported previously and suggest that in specimens with a significant amount of epithelium, sequencing may be more reliable for determining mutational status of BRAF [1, 8]. A mutation in BRAF was found in two aCP cases, both of which had a coexisting CTNNB1 mutation, demonstrating that although the majority of aCPs do not contain BRAF mutations, they are not exclusive to pCPs and can exist with mutations in CTNNB1. In the majority of cases, however, mutations segregate with tumour subtype: CTNNB1 in aCPs and BRAF in pCPs. While inhibition of the Wnt pathway has proved challenging and effective inhibitors are still largely in development, inhibitors of mutant BRAF have shown efficacy as chemotherapeutic agents in the treatment of melanoma [4]. The finding that BRAF V600E is mutated in the majority of pCPs offers the possibility for targeted BRAF-inhibitor therapy for patients with this tumour type.

β-Catenin Mutation Status and Outcomes in Sporadic Desmoid Tumors

Mutations in the gene-encoding β-catenin, CTNNB1, are highly prevalent in sporadic desmoid tumors and may predict the risk for recurrence. We sought to determine the prevalence of CTNNB1 mutations in a large cohort of sporadic desmoid tumors and to determine whether CTNNB1 mutation status correlates with disease outcome. Single-base extension genotyping of the CTNNB1 gene was performed on 145 sporadic, paraffin-embedded desmoid tumor specimens. Correlation of mutation status with outcome was performed on a subset of 115 patients who underwent macroscopically complete surgical resection. CTNNB1 mutations were detected in 106 of 145 (73%) tumor specimens and in 86 of 115 (75%) specimens from patients who underwent curative-intent surgical resection, including discrete mutations in the following codons of CTNNB1 exon 3: T41A (46%), S45F (25%), S45P (1.7%), and S45C (0.9%). Desmoid tumors of the superficial trunk were significantly less likely to harbor CTNNB1 mutations than tumors located elsewhere, but none of the other examined clinicopathologic factors were found to be associated with CTNNB1 mutation status. At a median follow-up of 31 months, 5-year recurrence-free survival was slightly, although not statistically significantly, worse for patients with β-catenin-mutated tumors than for those with wild-type tumors (58% vs. 74%, respectively). The specific CTNNB1 codon mutation did not correlate with the risk for recurrence. CTNNB1 mutations are indeed common in sporadic desmoid tumors. However, our study did not detect a statistically significant difference in recurrence risk according to either the CTNNB1 mutation status or the specific CTNNB1 mutation.

CTNNB1, AXIN1 and APC expression analysis of different medulloblastoma variants

OBJECTIVES:We investigated four components of the Wnt signaling pathway in medulloblastomas. Medulloblastoma is the most common type of malignant pediatric brain tumor, and the Wnt signaling pathway has been shown to be activated in this type of tumor.METHODS:Sixty-one medulloblastoma cases were analyzed for β-catenin gene (CTNNB1) mutations, β-catenin protein expression via immunostaining and Wnt signaling pathway-related gene expression. All data were correlated with histological subtypes and patient clinical information.RESULTS:CTNNB1 sequencing analysis revealed that 11 out of 61 medulloblastomas harbored missense mutations in residues 32, 33, 34 and 37, which are located in exon 3. These mutations alter the glycogen synthase kinase-3β phosphorylation sites, which participate in β-catenin degradation. No significant differences were observed between mutation status and histological medulloblastoma type, patient age and overall or progression-free survival times. Nuclear β-catenin accumulation, which was observed in 27.9% of the cases, was not associated with the histological type, CTNNB1 mutation status or tumor cell dissemination. The relative expression levels of genes that code for proteins involved in the Wnt signaling pathway (CTNNB1, APC, AXIN1 and WNT1) were also analyzed, but no significant correlations were found. In addition, large-cell variant medulloblastomas presented lower relative CTNNB1 expression as compared to the other tumor variants.CONCLUSIONS:A small subset of medulloblastomas carry CTNNB1 mutations with consequent nuclear accumulation of β-catenin. The Wnt signaling pathway plays a role in classic, desmoplastic and extensive nodularity medulloblastoma variants but not in large-cell medulloblastomas.

A nonrandom association of gastrointestinal stromal tumor (GIST) and desmoid tumor (deep fibromatosis): case series of 28 patients

Gastrointestinal stromal tumors (GISTs) and desmoid tumors (DTs) are two rare mesenchymal tumor. Anecdotal reports of individuals with both diseases led us to make the hypothesis that the association is a nonrandom event as the probability would be extremely low to observe such cases if they were independent events. We evaluated the existence of patients with GIST and DT in a large multicenter cohort at 10 institutions in the United States, Australia and Europe. Data on gender, age at diagnosis, KIT, PDGFRA, CTNNB1 mutation status and follow-up time after diagnosis were collected. We identified 28 patients diagnosed with both tumors. DT was diagnosed after GIST in 75% of patients and concomitantly in 21%. In only one case (4%), GIST was diagnosed after DT. KIT or PDGFRA mutations were detected in 12 of 14 GIST, 9 in KIT exon 11, 2 in KIT exon 9 and 1 in PDGFRA. A statistical analysis of these 28 cases suggests a nonrandom association between GIST and DT. Further studies may be able to elucidate the underlying biology responsible for this association.

Prevalence of the CTNNB1 mutation genotype in surgically resected fibromatosis of the breast

To investigate CTNNB1 mutation and β-catenin expression in resected breast fibromatosis and to identify potential molecular markers of fibromatosis of the breast. We selected 12 patients with fibromatosis of the breast who underwent surgical resection and were confirmed by histological examination. Ultrasonography findings for 10 patients were reviewed and only two cases were suspicious for fibromatosis on imaging. On core needle biopsy for pre-operative diagnoses, only three cases were histologically suspicious for fibromatosis. Mutations in exon 3 of CTNNB1 were detected by direct DNA sequencing in nine (75.0%) cases: all were c.121G>A (p.T41A), which was much more frequent in breast fibromatoses than in other soft tissue lesions. Nuclear β-catenin expression was observed in all cases and the level of expression was higher in cases with mutation. In eight of nine cases, the matched biopsy specimen showed the same CTNNB1 mutation status as the pre-operative specimen. In the majority of cases, clinical presentation and breast imaging are highly suspicious for carcinoma. Definitive pre-operative pathological diagnosis by core needle biopsy is difficult. CTNNB1 mutation and nuclear β-catenin expression are frequently detected in sporadic breast fibromatoses, suggesting their potential as a useful tool to distinguish breast fibromatoses from other neoplasms.

Reply to J.C. Lindsey et al

After the first report by Tabori et al and our article published in Journal of Clinical Oncology, the potential impact of TP53 mutation status in sporadic medulloblastoma has been controversially discussed in the field of neurooncology. The latest report by Lindsey et al, conducted in another completely independent cohort investigating TP53 and CTNNB1 mutation status in 50 patients with primary medulloblastoma supports our recently published data. In our study investigating 310 patients with primary medulloblastoma, TP53 mutations were detected in all major cytogenetic and transcriptomic subgroups of medulloblastoma but were clearly overrepresented among Wnt/Wingless (WNT) -driven tumors characterized by mutations in the CTNNB1 gene. This finding was confirmed by Lindsey et al in their cohort, given that three of five tumors harboring a TP53 mutation belonged to the WNT-subgroup. Inaddition,wefoundanoverrepresentationinMYCN-amplifiedmedulloblastoma that remains to be confirmed in independent cohorts. The results of a recent study by Gibson et al indicate that, in CTNNB1-mutated mice, the deletion of TP53 might be necessary for the accumulation of further mutations and therefore the development of medulloblastoma. Notably, these tumors anatomically resemble human WNT-subgroup medulloblastoma. Taken together, these data provide the first in vivo evidence of a cooperative role of concomitant mutations of CTNNB1 and TP53 in WNTmedulloblastoma tumorigenesis. Our cohort included two patients with Li-Fraumeni syndrome (LFS) as confirmed by the detection of TP53 germline mutation; one of the patients had not previously received a diagnosis of LFS. Interestingly, Lindsey et al also report one patient with a newly identified TP53 germline mutation (LFS) who died about one year after diagnosis. Accordingly, undiagnosed patients with hidden LFS might constitute a significant proportion of supposedly sporadic medulloblastoma with TP53 mutation. Concerning the patient outcome, the observations of Lindsey et al are in line with our results, showing that TP53 mutation is not associated with a poor patient outcome, in contrast with the report by Tabori et al. To evaluate the value of TP53 mutation status as a prognostic marker in medulloblastoma, it is essential to take into account that molecular characteristics of the tumor might determine the patient’s outcome (ie, WNT-driven tumors being associated with a favorable prognosis), that the clinical course of patients with LFS may differ from that of patients with medulloblastoma harboring a sporadic TP53 mutation, and that the impact of the TP53 mutation status on prognosis might depend on the different therapy regimen applied. Thus, it would be preferable to separately evaluate—ideally prospectively—the effect of TP53 mutation status on prognosis in the different trial arms within a randomized multicenter clinical trial. In conclusion, the study by Lindsey et al supports our findings that TP53 mutations occur in all molecular subgroups and are not per se an adverse prognostic marker across all subgroups of medulloblastoma. This supports the notion that medulloblastoma comprises distinct entities with specific genetic alterations that are decisive for the patient’s outcome.

Differential expression of glutamine synthetase and cytochrome P450 isoforms in human hepatoblastoma

Carcinogenesis is often linked to aberrant activation of Wnt/β-Catenin signalling, in many cases caused by activating CTNNB1 mutations (encoding β-Catenin). Recently, β-catenin was established as a decisive regulator of hepatic glutamine synthetase (GS) and cytochrome P450 (CYP) expression in mouse hepatocarcinogenesis. This study was aimed to analyse the connection of β-Catenin signalling and GS/CYP expression in human paediatric tumours. Samples from 23 paediatric tumours were analysed for activating mutations in CTNNB1. Protein expression of the model β-Catenin target GS and of various CYP isoforms was analysed and correlated with CTNNB1 mutational status and histological findings. Activating CTNNB1 mutations were frequent in hepatoblastoma (80%) and nephroblastoma (31%). In CTNNB1-mutated hepatoblastoma, expression of GS was only detected in tumour areas with epithelial, not with mesenchymal differentiation. Particularly high expression of glutamine synthetase was found in hepatoblastoma cells directly neighbouring a mesenchymal-type tumour area or stroma cells, associated with above-average cell proliferation. GS expression was not observed in CTNNB1-mutated nephroblastoma. Hepatoblastoma with activated β-Catenin expressed different CYPs relevant for the metabolism of cytostatic drugs, but with high interindividual variance and heterogeneity within a single tumour. GS and different CYPs are co-expressed in hepatoblastoma with activated β-Catenin. Moreover, other factors like histological subtype of tumour cells and cell–cell-interactions at the borders between different areas of the tumours affect expression of these β-Catenin target genes. Analysis of CYP expression in resected tumour tissue might be useful for the selection of appropriate cytostatics for post-operative chemotherapy.

New prognostic markers revealed by evaluation of genes correlated with clinical parameters in Wilms tumors

Current treatment protocols for Wilms tumor achieve 90% cure rates, but relapse risk and side effects from therapy remain challenging. Over the last decade, numerous markers have been proposed for classification and/or prediction of outcome. However, cohort sizes were quite variable and often small. We now provide a large-scale reassessment by real-time RT-PCR of 40 markers in 102 Wilms tumors followed by validation of potentially relevant markers in an independent set of 74 tumors. In the first data set, individual comparison with clinical data combined with adjustment for multiple testing and multivariate analysis revealed potentially relevant alteration of CA9, DKK1, EGR1, HEY2, MYC, MYCN, TERT, TOP2A, TRIM22, and VEGF expression in association with CTNNB1 mutation status, histological risk, response to chemotherapy, metastasis, relapse, or mortality. To further validate these data, potentially relevant genes for specific outcomes were reanalyzed in a second, independent tumor set. Here, univariate analysis confirmed the association of HEY2 with high-risk tumors and of TRIM22 with mortality. Even where significance levels could not be reached, the direction and extent of differential expression were generally reproducible. Multivariate analysis verified a weak correlation of TOP2A expression with metastasis and of TRIM22 with fatal outcome. Although we could corroborate only some of the previously reported associations of expression changes with clinical parameters, our results indicate that real-time RT-PCR analysis can facilitate further classification of Wilms tumor and prediction of outcome to adjust treatment accordingly. This article contains Supplementary Material available at http://www.interscience.wiley.com/jpages/1045-2257/suppmat.