Establishment of a rhabdoid tumor cell line with a specific chromosomal abnormality, 46,XY,t(11;22)(p15.5;q11.23).

The malignant rhabdoid tumor is a rare, poorly understood tumor which occurs primarily in children. The kidney is a frequent primary site of origin, but the tumor has arisen in other mesodermally derived tissues as well. Controversy exists regarding the embryonic origin of the rhabdoid tumor and recent histopathologic studies suggest that it may be of neuroepithelial origin. Our immunohistochemical and electron micrographic studies support this theory. No consistent chromosome abnormalities have been reported in this tumor and no cell lines are available for study. We have established and characterized the first rhabdoid tumor cell line. It possesses a specific chromosomal abnormality, 46,XY,t(11;22)(p15.5;q11.23). The translocation may provide an important clue to the pathogenesis of the tumor as well as an opportunity for further study of the involved chromosome regions.     

Localization of a tumor suppressor gene in 11p15.5 using the G401 Wilms' tumor assay

Multiple studies have underscored the importance of loss of tumor suppressor genes in the development of human cancer. To identify these genes, we used somatic cell hybrids in a functional assay for tumor suppression in vivo. A tumor suppressor gene in 11p15.5 was detected by transferring single human chromosomes into the G401 Wilms' tumor cell line. In order to better map this gene, we created a series of radiation-reduced t(X;11) chromosomes and characterized them at 24 loci between H-RAS and beta-globin. Interestingly, three of the chromosomes were indistinguishable as determined by genomic and cytogenetic analyses. Each contains an interstitial deletion with one breakpoint in 11p14.1 and the other breakpoint between the D11S601 and D11S648 loci in 11p15.5. PFGE analysis localized the 11p15.5 breakpoints to a 175 kb MluI fragment that hybridized to D11S601 and D11S648 probes. Genomic fragments from this 175 kb region were hybridized to DNA from mouse hybrid lines containing the delta t(X;11) chromosomes. This analysis detected the identical 11p15.5 breakpoint which disrupts a 7.8 kb EcoRI fragment in all three of the delta t(X;11) chromosomes, suggesting they are subclones of the same parent colony. Upon transfer into G401 cells, one of the chromosomes suppressed tumor formation in nude mice, while the other two chromosomes lacked this ability. Thus, our mapping data indicate that the gene in 11p15.5 which suppresses tumor formation in G401 cells must lie telomeric to the D11S601 locus. Koi et al. (Science 260: 361-364, 1993) have used a similar functional assay to localize a growth suppressor gene for the RD cell line centromeric to the D11S724 locus. The combination of functional studies by our lab and theirs significantly narrows the location of the tumor suppressor gene in 11p15.5 to the approximately 500 kb region between D11S601 and D11S724.      

Narrowing the critical region for a rhabdoid tumor locus in 22q11

Rhabdoid tumor is a rare malignant neoplasm of childhood that may occur in various locations, including the central nervous system and the kidney. Previous cytogenetic studies of primary rhabdoid tumors have demonstrated monosomy or deletion of chromosome 22 and have implicated the presence of a rhabdoid tumor suppressor gene that maps to 22q. We have employed fluorescence in situ hybridization to narrow the region for this locus in four rhabdoid tumor cell lines with translocations or deletions involving chromosome segment 22q11. The completion of a cosmid and yeast artificial chromosome contig spanning the immunoglobulin lambda gene locus to BCR has allowed us to map a critical region for a rhabdoid tumor gene to a 500 kb span of chromosome segment 22q11. Genes Chromosom Cancer 16:94–105 (1996). © 1996 Wiley-Liss, Inc.     

Monosomy 22 in a malignant peripheral nerve sheath tumour of the kidney in childhood: a genetic link with other malignant paediatric renal neoplasms?

A recurrent malignant spindle cell neoplasm of the kidney, occurring in a 11-year-old girl and corresponding to a malignant peripheral nerve sheath tumour is reported. The neurogenic differentiation was substantiated by the presence of PGP 9.5 neurofilament and S-100 protein positivity and by the ultrastructural features. Cytogenetic analysis revealed monosomy of chromosome 22 in the tumour while the constitutional karyotype was normal. Primary malignant peripheral nerve sheath tumour of the kidney is extremely rare and should, on morphology, be differentiated from stromal predominant Wilms' tumour and clear cell sarcoma of the kidney. Involvement of chromosome 22 has been described in a number of malignant renal tumours of childhood, such as Wilms' tumour (deletion), clear cell sarcoma (translocation), and rhabdoid tumour (deletion and translocation), thus suggesting common molecular mechanisms in pediatric malignant renal tumours.     

Differential expression of a novel ankyrin containing E3 ubiquitin-protein ligase, Hace1, in sporadic Wilms' tumor versus normal kidney

We have analyzed the chromosome 6q21 breakpoint of a non-constitutional t(6;15)(q21;q21) rearrangement in sporadic Wilms' tumor. This identified a novel gene encoding a protein with six N-terminal ankyrin repeats linked to a C-terminal HECT ubiquitin-protein ligase domain. We therefore designated this gene HACE1 (HECT domain and Ankyrin repeat Containing E3 ubiquitin-protein ligase 1). HACE1 is widely expressed in human tissues, including mature and fetal kidney. We show that Hace1 protein possesses intrinsic ubiquitin ligase activity, utilizes UbcH7 as a candidate partner E2 enzyme and localizes predominantly to the endoplasmic reticulum. Although the HACE1 locus was not directly interrupted by the translocation in the index Wilms' case, its expression was markedly lower in tumor tissue compared with adjacent normal kidney. Moreover, HACE1 expression was virtually undetectable in the SK-NEP-1 Wilms' tumor cell line and in four of five additional primary Wilms' tumor cases compared with patient-matched normal kidney. We found no evidence of HACE1 mutations or deletions, but hypermethylation of two upstream CpG islands correlates with low HACE1 expression in tumor samples. Our findings implicate Hace1 as a novel ubiquitin-protein ligase and demonstrate that its expression is very low in primary Wilms' tumors.     

Molecular genetic evidence for common pathogenesis of childhood and adult Wilms' tumor

A case of Wilms' tumor in an adult is reported, showing, by restriction fragment length polymorphism analysis of somatic and tumor DNA, the loss of alleles from the short arm of chromosome 11. Loss of alleles in this region has previously been reported in childhood Wilms' tumor. The findings of this study indicate that adult Wilms' tumor and childhood Wilms' tumor may share a common pathogenic pathway. These results may also be useful in differentiating between Wilms' tumor and renal cell carcinoma or sarcoma in adults when the histologic findings are unclear.     

Malignant rhabdoid tumor of the kidney--a case report.

Malignant rhabdoid tumor is a distinct renal tumor in children. It had been regarded as a rhabdomyosarcomatoid variant of Wilms' tumor, but it is now thought as a separate entity. We report a case of malignant rhabdoid tumor of the kidney in a 26-month-old girl who presented with a left abdominal mass. Grossly, a large mass in the lower pole of the left kidney was well encapsulated and measured 4 x 4 x 3.5cm. On cross section, it was soft and yellowish white and showed multifocal necroses. The mass was mainly located in the medial medullary portion and compressed the renal pelvis laterally. Microscopically, the tumor masses were hypercellular and anaplastic without definite blastematous elements. In larger portion, the tumor cells had abundant eosinophilic cytoplasm and hyaline globules. In addition to the classic "rhabdoid" feature, alveolar, sclerosing, and lymphomatous patterns were seen. Ultrastructurally, tumor cells with abundant cytoplasm contained tangles of intermediate filament corresponding to vimentin in immunostaining.     

Human sarcomatous Wilms' tumor. Characterization with 5H10, a newly established monoclonal antibody

Immunophenotypic features of human sarcomatous Wilms' tumor (SWT) were studied using a newly established mouse monoclonal antibody (5H10, IgG1). 5H10 was produced against CR-SW2, one of several transplanted SWT lines in nude mice, and defines a 200-kDa cell surface protein. The antibody was found to react equally with all subtypes of SWT; clear cell sarcoma of the kidney, malignant rhabdoid tumor of the kidney, and unclassified sarcoma. Furthermore, it reacted equivalently with surgically resected tumors, transplanted tumors in nude mice, and cell lines in vitro. On the other hand, 5H10 was entirely negative for any of the components of nephroblastic Wilms' tumor (NBW). Considering these results, 5H10 appears to recognize the antigen expressed preferentially on SWT, and therefore the subtypes of SWT may be closely related to one another immunophenotypically. In normal human tissues, however, 5H10 only reacted with fetal kidneys, its reactivity being restricted to the lower limbs of S-bodies in both the metanephros and mesonephros. No reactivity was identified in any other tissues including adult kidney. These results indicate that 5H10 detects an oncofetal antigen expressed preferentially in both SWTs and fetal kidney and that the histogenesis of SWT should be considered in connection with nephrogenesis.     

Study of childhood renal tumours using antisera to fibronectin, laminin, and epithelial membrane antigen.

Using a peroxidase-antiperoxidase staining procedure, formalin fixed paraffin embedded sections of fetal and normal kidney; benign (mesoblastic nephroma); and malignant tumours (Wilms' tumour, clear cell renal carcinoma, rhabdoid renal tumour, and bone metastasising renal tumour of childhood (BMRTC] were examined for their reactivity with antisera to fibronectin, laminin, and epithelial membrane antigen. Mesoblastic nephroma contained fibronectin but no laminin. Most Wilms' tumours lacked both fibronectin and laminin; 50% of rhabdoid renal tumours were positive for fibronectin and laminin--rhabdoid tumours as recognised morphologically may, in fact, be two separate entities. BMRTC and clear cell renal carcinoma lacked both fibronectin and laminin. Epithelial membrane antigen was present in most of the tubular Wilms' tumour but absent in blastemal Wilms' tumours. The presence of epithelial membrane antigen in rhabdoid tumours was surprising, as histologically, this type of tumour shows no sign of epithelial differentiation. Epithelial membrane antigen antiserum stained clear cell renal carcinomas: epithelial membrane antigen is found in the distal and not the proximal tubules of fetal and normal kidneys. Thus an obvious interpretation is that clear cell renal carcinomas originate from distal rather than from proximal tubules, as has always been thought. On the basis of these results and data from other published findings some possible histogenetic origins of childhood renal tumours were proposed.     

The cytogenetics of Wilms' tumor

A close association has been demonstrated between the congenital deletion 11p13 and predisposition to Wilms' tumor. Recent cytogenetic studies on Wilms' tumor cells from normal children strongly suggests that somatic changes in the short arm of chromosome #11 play an important role in the development of this tumor. The application of improved cytogenetic techniques coupled with molecular biologic analysis may help resolve questions regarding the requirement of additional changes (to alterations of 11p13) in order to evoke complete transformation leading to malignancy.     

Mapping a tumor suppressor gene to chromosome 2p13 in metanephric adenoma by microsatellite allelotyping

Twelve metanephric adenomas (MA) were studied for allelic imbalance at chromosomal regions known to be involved in the genetics of papillary renal cell tumors (RCT) and Wilms' tumors as well as for loci on chromosome 2p13-21. DNA was isolated from paraffin slides, and allelic status was established by fluorescently-labeled microsatellite markers. No allelic changes were seen in the Wilms' tumor gene region at chromosome 11p13 and in the papillary RCT gene region at chromosome 17q21.32. We delineated a tumor suppressor gene region of approximately 8-centimorgan genetic distance between loci D2S2153 and D2S380 on chromosome 2p13. Allelic changes at this region occurred in 56% of informative cases. Our results provide molecular evidence that MA is a genetic entity, and it can be differentiated from both Wilms' tumor and papillary renal cell adenoma.     

Aniridia and Wilms' tumor in a child constitutionally mosaic for 11p-;12q+: a new chromosomal change also present in Wilms' tumor cells of the blastema type

A child with congenital aniridia was assessed closely, by repeated abdominal ultrasound examinations, beginning at birth. The Wilms' tumor subsequently discovered and removed was analyzed karyotypically and found to have some cells with a terminal deletion of chromosome 11; in other cells this deletion was associated with a duplication in the long arm of chromosome 12. These findings were identical to those observed in the patient's peripheral blood mononuclear cells. This case further substantiates the association between changes in chromosome 11 and Wilms' tumor and demonstrates how chromosomal abnormalities in early infancy may lead to the development of Wilms' tumor.     

Cytogenetic analysis of 39 pediatric central nervous system tumors.

Consistent cytogenetic abnormalities have been described in many pediatric solid tumors, including Ewing's sarcoma, Wilms' tumor, and neuroblastoma. Similar analysis of pediatric central nervous system (CNS) tumors has been hampered by technical problems. We report chromosome results from 39 pediatric CNS tumors. Abnormalities of chromosome 17 were noted in 3 of 11 primitive neuroectodermal tumors (including i(17q) in 2 tumors), confirming data observed by other investigators. Cells from 2 of 11 primitive neuroectodermal tumors (PNET) exhibited loss or structural abnormalities involving chromosome 11. Loss or distal deletion of chromosome 7q was noted in cells from two PNETs. Because other investigators have shown loss of heterozygosity on 17p in about one-third of PNET, we propose that chromosome regions 7q and 11 are areas worthy of further study in pediatric PNET. Numerical abnormalities were noted in 6 of 21 astrocytomas. Hyperdiploidy was demonstrated in 1 of 4 pilocytic astrocytomas and pseudopolyploidy was demonstrated in 4 of 13 anaplastic astrocytomas. Structural chromosome abnormalities (translocations, deletions) were noted in 4 of 13 anaplastic astrocytomas. Complex structural anomalies were observed in one craniopharyngioma. A rhabdoid tumor of the brain exhibited multiple complex structural rearrangements but did not exhibit the monosomy 22 observed in some rhabdoid tumors. Hypodiploidy and loss of chromosome 22 were noted in a clinically aggressive meningioma, corroborating observations by other investigators.     

A cytogenetic study of Wilms' tumor

Cytogenetic studies were attempted on a sample of 33 Wilms' tumors using short- and long-term tissue culture techniques; most were studied after 2-13 wk in vitro. Abnormal karyotypes were found in 11 tumors, 10 of which had been treated previously with radiotherapy and/or chemotherapy. Insufficient growth of 17 tumors prevented cytogenetic analysis, and in 5 only normal karyotypes were found. Of the 11 tumors with abnormalities, 9 had modes within the diploid range, 1 was hypertriploid, and 1 showed hypodiploid variation. Except for chromosome #5, all chromosomes were involved in structural and numeric changes. Three tumors showed variation in the short arm of chromosome #11, and abnormalities of chromosomes #1, #3, #7, #9, #10, and #14 occurred in more than one tumor. A predisposition to Wilms' tumor is associated with a constitutional deletion of 11p13. From the present study, it is apparent that a similar cytogenetic change may play a primary role in the development of Wilms' tumor in normal individuals.     

Increased expression of osteopontin gene in atypical teratoid/rhabdoid tumor of the central nervous system.

The atypical teratoid/rhabdoid tumor, primary to the central nervous system, is a highly malignant and aggressive neoplasm of infancy and childhood. Although having distinct biological features and clinical outcomes, it is frequently misdiagnosed as primitive neuroectodermal tumor/medulloblastoma. To further distinguish the underlying pathogenesis and to identify biological markers for clinical use, an atypical teratoid/rhabdoid tumor-derived cell line was established and its gene expression pattern analyzed in comparison to the human astrocyte SVG12 cell line and the human DAOY medulloblastoma cell line using a complementary DNA microarray method. The osteopontin gene was found specifically upregulated in atypical teratoid/rhabdoid tumor cells. This specificity was confirmed by immunohistochemistry in pathological sections of tissues from atypical teratoid/rhabdoid tumor patients. Even though the role of osteopontin in the cytopathogenesis of atypical teratoid/rhabdoid tumor still needs to be determined, our data support that overexpressed osteopontin is a potential diagnostic marker for atypical teratoid/rhabdoid tumor.     

Germline INI1 mutation in a patient with a central nervous system atypical teratoid tumor and renal rhabdoid tumor

We describe a four-month-old child who presented with an atypical teratoid/rhabdoid tumor of the brain and subsequently developed a renal rhabdoid tumor. Distinct histologic features, immunophenotypic profiles, and deletions of chromosome 22 were supportive of two primary tumors. An identical mutation in exon 7 of the INI1 rhabdoid tumor suppressor gene was identified in both tumors, as well as in normal kidney tissue. We propose that this germline INI1 mutation predisposed the child to the development of both malignancies. These findings lend support to the hypothesis that rhabdoid tumors in all sites have a common genetic etiology.     

Wilms' tumor, overgrowth, and fetal growth factors: a hypothesis

A hypothesis is advanced suggesting that the association between high birthweight, overgrowth features of certain congenital malformations, and Wilms' tumor may be due to the action of loci in addition to the putative Wilms' tumor locus on the short arm of chromosome #11. These genes include insulin, insulin-like growth factor II and the c-Ha-ras 1 oncogene. The possible role of environmental factors in the oncogenesis of Wilms' tumor is discussed.     

Chromosome mechanisms and INI1 inactivation in human and mouse rhabdoid tumors

The human rhabdoid tumorigenesis orchestrated by INI1 inactivation is associated with specific rearrangements of chromosome 22 that correlate with preferential anatomic tumor locations. A literature review revealed significant correlations between an apparently normal karyotype and kidney tumors, monosomy 22 and cerebral tumors, and chromosome 22 translocations and tumors at other anatomic sites. In the mouse rhabdoid tumor model, specifically in the four tumors that we tested for loss of heterozygosity, neither partial deletion nor monosomy of chromosome 10 could be detected. In contrast to the human data, the only chromosome mechanism involved in the 18 mouse tumors studied appears to be a mitotic recombination or a nondisjunction-duplication. Additionally, and despite mouse tumor incidence across a variety of sites, no rhabdoid tumor could be observed in the mouse kidney. These data suggest that the chromosome mechanisms for INI1 inactivation and the selective cell survival pressure differ in human and mouse.     

Translocation (1;22)(p36;q11.2) with concurrent del(22)(q11.2) resulted in homozygous deletion of <Emphasis Type="Italic">SNF5/INI1</Emphasis> in a newly established cell line derived from extrarenal rhabdoid tumor

Malignant rhabdoid tumor (MRT) is a highly malignant pediatric cancer, which arises in various sites such as the kidney, brain, and soft tissues. Cytogenetic studies have revealed alterations of 22q11 in MRT. Recently, deletions and mutations of the SNF5/INI1 locus in 22q11.2 have been reported in MRT, suggesting that SNF5/INI1 is a tumor suppressor gene for MRT. Here we report our molecular cytogenetic study for a newly established cell line from extrarenal MRT with t(1;22)(p36;q11.2). Consequently, the reciprocal translocation was associated with the interstitial deletion of a small segment including SNF5/INI1, and another, chromosome 22, showed terminal deletion, the breakpoint of which was located 70–80 kb centromeric to SNF5/INI1, resulting in homozygous deletion of SNF5/INI1 in this cell line.     

Rhabdoid tumor of the kidney with primitive neuroectodermal tumor of the central nervous system: Associated tumors with different histologic,cytogenetic, and molecular findings

Rhabdoid tumor of the kidney (RTK) is associated with tumors of the central nevous system (CNS) in approximately 15% of cases. We describe the clinical features, histologic and cytogenetic findings, and molecular analysis of renal and CNS tumors from the same patient. The histology of the renal tumor was consistent with rhabdoid tumor. The CNS tumor was a primitive neuroectodermal tumor (PNET). The karyotype of the RTK was normal male. The PNET of the brain demonstrated monosomy 22 as the only cytogenetic abnormality, similar to reported cases of malignant rhabdoid tumor of the brain, but dissimilar to nonrandom cytogenetic findings in other CNS PNETs. Molecular cytogenetic and DNA marker studies confirmed loss of chromosome 22 in this patient's brain tumor. DNA allelotyping showed retention of both parental chromosome 22 alleles in the RTK and loss of the maternal allele in the PNET. Evaluation of additional RTKs and brain tumors occurring in the same patient may provide insight into the origins and relationships of these enigmatic tumors.