Genomic defects in nonfamilial renal cell carcinoma. Possible specific chromosome change

Chromosomal abnormalities of clear cell renal cell carcinoma: frequent gain of chromosome 7

Gain of chromosome 7 is well known to be a characteristic abnormality of papillary renal cell carcinoma (RCC). The purpose of the present study was to perform cytogenetic analysis of G-band karyotype in 16 clear cell RCC obtained from nephrectomy. The age of patients ranged from 50 to 79 years and the tumor size in largest dimension ranged from 1.8 to 6.2 cm. As a result, the structural abnormality of chromosome 3 was most frequently observed (eight clones). Loss of chromosome 3 and gain of chromosome 7 followed (four clones). Among four clones showing gain of chromosome 7, two were associated with the abnormality of chromosome 3 and the remaining two were devoid of the abnormalities of chromosome 3. In addition, none of all four tumors showing gain of chromosome 7 demonstrated any foci of papillary growth pattern. The present study shows that gain of chromosome 7 is not exclusive to papillary RCC, but it can be found in clear cell RCC as well, and this finding may represent a diagnostic pitfall in distinguishing clear cell RCC from papillary RCC.

Losses of 1p and chromosome 14 in renal oncocytomas

We performed cytogenetic analyses of 8 renal oncocytomas to identify chromosomal regions involved in the tumorigenesis of oncocytomas. All cases showed chromosomal findings corresponding to established cytogenetic subsets of renal oncocytomas: 3 cases with normal karyotypes, 1 case with rearrangement of 11q, and 4 cases with losses of chromosome 14. In the latter cytogenetic subgroup, monosomy 14 was additionally accompanied by either monosomy 1 in 2 cases or loss of 1p in a third case, providing insights in the cytogenetic evolution of this subgroup.

Renal oncocytomas with 11q13 rearrangements: cytogenetic, molecular, and immunohistochemical analysis of cyclin D1

Two groups of renal oncocytomas have been cytogenetically defined by the loss of one or both of chromosomes Y and 1 or by structural rearrangement involving 11q12~q13. We report five renal oncocytomas with structural chromosomal rearrangements involving 11q13 with previously unreported partner chromosomes (namely, 1, 6, and 7). For two of the five cases, a t(6;11)(p21;q13) translocation was revealed; the others had t(1;11)(p13;q13), t(7;11)(q11.2;q13), and t(5;11)(q35; q13). Fluorescence in situ hybridization confirmed translocation of CCND1 at 11q13 to partner chromosomes 5, 6, and 7. Overexpression of cyclin D1, the protein product of CCND1, was detected in three of the five cases (60%) by means of immunohistochemical staining of formalin-fixed, paraffin-embedded tumor sections. In three cases for which fresh tissue was available, Southern blot analysis using the MDL-5 probe for the BCL1 breakpoint did not reveal rearrangement of BCL1. In addition, six consecutive renal oncocytomas diagnosed at our institution between 1999 and 2002 whose karyotypes did not show 11q13 translocations were all negative for cyclin D1 overexpression under immunohistochemical analysis. The findings of CCND1 rearrangement with FISH and correlation with cyclin D1 overexpression under immunohistochemical analysis suggest that cyclin D1 alterations play a role in the subset of renal oncocytomas with 11q translocations, although other genes may also be involved.

Cytogenetic analysis of 11 renal oncocytomas: further evidence of structural rearrangements of 11q13 as a characteristic chromosomal anomaly

We carried out cytogenetic analysis on 11 renal oncotytomas by using G-banding and DAPI-banding techniques. Four of our tumors exhibited structural rearrangements affecting chromosome 11 at band q13. Together with another case previously described by us, our tumors constitute the largest series of renal oncocytomas displaying translocations involving 11q13. A review of the literature disclosed only 6 similar oncocytomas, 1 tumor with a t(9;11)(p23;q12), 2 tumors with a nearly identical t(9;11)(p23;q13), and 3 tumors with a t(5;11)(q35;q13). Therefore, our findings provide further cytogenetic evidence that genes located on 11q12-13 may be involved in the tumorigenesis of renal oncocytomas.

Familial renal oncocytoma: clinicopathological study of 5 families

PURPOSE

We analyzed familial renal oncocytoma to provide a foundation for studies aimed at defining genes involved in the pathogenesis of renal oncocytoma.

MATERIALS AND METHODS

We describe 5 families with multiple members affected with renal oncocytoma. Tumors were analyzed pathologically, and affected and nonaffected members were screened clinically and genetically.

RESULTS

We identified 12 affected male and 3 affected female (ratio 4:1) individuals in the 5 families. In affected family members renal oncocytomas were often multiple and bilateral. No metastatic disease was observed. Most renal oncocytomas were detected incidentally in asymptomatic individuals or during screening of asymptomatic members of renal oncocytoma families. One identical twin pair was affected with bilateral multiple renal oncocytomas.

CONCLUSIONS

Renal oncocytoma may be inherited in some families.

Involvement of the chromosomal region 11q13 in renal oncocytoma: case report and literature review

Renal oncocytomas comprise a cytogenetically heterogeneous group of tumors consisting potentially of cytogenetic distinguishable subgroups. Review of the literature revealed loss of chromosome 1 and Y as a possible anomaly for at least one subset oncocytomas. The frequent finding of rearrangements involving chromosome 11 band q13 characterizes another subset of oncocytomas. We report the cytogenetic and pathological features of a renal oncocytoma diagnosed in a 72-year-old woman and found a t(9;11)(p23;q13) as a consistent abnormality. This supports the idea that translocations involving 11q13 define a further subset of oncocytoma.

Correlations of allelic imbalance of chromosome 14 with adverse prognostic parameters in 148 renal cell carcinomas

To investigate cumulative genetic alterations during development and progression of renal cell carcinoma (RCC), we examined DNAs that were isolated from 148 RCCs for allelic imbalance (AI) at four loci on chromosome arm 3p and at 26 loci on chromosome arm 14q by using polymorphic microsatellite markers and densitometric scanning. Because the analysis of solid tumor unbalanced rearrangements remains difficult due to the large proportion of cells that infiltrate from the stroma, we developed a method for the detection and quantification of AI between control and tumor samples by using polymerase chain reaction (PCR) amplification of microsatellite markers. This technique allows detection down to 20% of contaminating cells with good accuracy. We detected AI on 3p and 14q in 57 and 28% of RCC, respectively. A comparison of genetic changes with clinicopathological data showed that, in marked contrast to AI on 3p, AI on 14q was correlated significantly with the stage and grade of the tumors, with 56 and 58% of RCC in Stage IV and Grade 4, respectively, showing AI. Our results suggest that tumor suppressor genes on 3p, including the von Hippel-Lindau gene, may be involved in early steps of carcinogenesis in clear cell carcinoma and that AI on 14q may play an important role in the progression of clear cell and papillary chromophilic cell carcinomas. Loss of heterozygosity (LOH) on 14q may be a new prognostic factor in RCC. Despite the size of the series of tumors and the number of markers used, only rearrangements that involved the whole length of the long arm of chromosome 14 were observed in the present study. The localization of the putative tumor suppressor gene on 14q will require further investigation of RCC with structural rearrangements of 14q.

Comparative genomic hybridization for genetic analysis of renal oncocytomas

Renal oncocytomas are uncommon tumors of the kidney that are considered to be of low malignant potential. Neither conventional cytogenetic nor restriction fragment length polymorphism analyses have identified consistent genetic alterations in their genomic DNA. The purpose of the present study was to identify the genetic alterations associated with the development of renal oncocytomas. We studied 13 renal oncocytomas by using comparative genomic hybridization, and we identified loss of genetic material from chromosomes 1 and/or 14 in six of these tumors. These alterations may represent early genetic events in the development of these tumors.

A singular case of near-haploid stemline karyotype in a renal oncocytoma

Cytogenetic analysis of a human renal oncocytoma revealed a near-haploid chromosome number of 36 with the loss of chromosomes 1, 2, 3, 6, 8, 9, 15, 17, 21, and 22. Review of the literature disclosed that this cytogenetic configuration is extremely rare in solid human tumors and that no renal oncocytomas with near-haploid stemline karyotype have been described. These results are compared with the other published cases of oncocytoma.

Cytogenetic investigation of synchronous bilateral renal tumors

Cytogenetic investigations on synchronous bilateral renal tumors are scarce. We report our findings on 13 renal tumors from 5 patients and review the literature. In bilateral as well as in solitary tumors, cytogenetic findings in each tumor correlated with the histological patterns, i.e. combinations of trisomies for papillary renal cell carcinoma, loss of 3p-material for non-papillary renal cell carcinoma, and coincident loss of the Y chromosome and chromosome 1 in oncocytomas. Bilateral multifocal renal cell carcinomas were always of the papillary type and the karyotypes showed more or less the same numerical anomalies, with trisomies in different combinations in tumors within the same kidney as well as in both kidneys. Structural changes, in contrast, were different from tumor to tumor.

Loss of heterozygosity studies indicate that chromosome arm 1p harbors a tumor supressor gene for renal oncocytomas

We carried out a complete genome scan for loss of heterozygosity (LOH) in four renal oncocytomas by using highly polymorphic CA repeat microsatellite loci. Three of the four tumors exhibited LOH for chromosome arm 1p, and the oncocytomas of both female patients lost Xq. Therefore, these chromosome arms may harbor tumor suppressor genes involved in the etiology of this disease. Although the genomes of ontocytomas are relatively stable, two different microsatellite loci in one tumor were mutated by + or - 2 nt. Similar alterations in CA repeats that are probably due to spontaneous mutation have been observed in renal cell carcinomas.

Renal oncocytoma with a translocation t(9;11)(p23;q13)

We report a case of renal oncocytoma and confirm a tumor type specific translocation between chromosomes 9 and 11, that is t(9;11)(p23;q13q23). Each of the 45 cytogenetically analyzed metaphases of tumor cells showed a translocation of the long arm of chromosome 11 at q13 to chromosome 9 at 9p23 and to chromosome 20 at 20q13 that resulted in the following karyotype: 46,XX,der(11)ins(9;11)(p23;q13q23)ins(20;11)(q13;q23q25),del (22q13). Since genes encoding mitochondrial enzymes are clustered around the translocation site of chromosomes 11 and 20, they may have a role in the tumorigenesis of renal oncocytoma. In addition, if the development of oncocytomas shows different cytogenetic pathways the cytogenetic aberration of t(9;11)(p23;q12q13) can be of diagnostic help in differentiating a subset of oncocytoma from renal cell carcinoma.

Trisomy 7 in nonneoplastic cells

The somatic mutation theory of tumorigenesis states that mutations are necessary for tumor development. On the other hand, acquired, clonal chromosomal alterations are occasionally detected in otherwise normal, nonneoplastic cells--for example, loss of sex chromosomes occurs in bone marrow cells and lymphocytes in elderly individuals--and it is therefore evident that not all mutations are by themselves sufficient for neoplasia to occur. Thus, the finding of an acquired, clonal chromosomal abnormality does not constitute proof that a lesion is neoplastic. Trisomy 7 has, as the sole clonal chromosomal aberrations, been reported in a wide variety of epithelial tumor types but also in some mesenchymal and neurogenic neoplasms. It has been suggested to be a primary, i.e., tumor-initiating, abnormality in tumors of the bladder, brain, colon, kidney, lung, ovary, prostate, and thyroid. But data from cytogenetic studies of solid tumors, macroscopically normal tissue in the proximity of solid tumors, and nonneoplastic lesions now question the importance of a solitary +7 as a neoplasia-associated change. Most solid tumors in which trisomy 7 has been found as the sole change in one clone have also displayed other, cytogenetically unrelated, clones with complex karyotypic abnormalities. Such karyotypic differences among coexisting clones could indicate that the neoplasm is polyclonal, that the cytogenetically disparate clones have emerged during tumor progression from one original clone carrying submicroscopic genomic changes only, or that the clone with +7 does not represent the tumor parenchyma. The latter interpretation is supported by the finding of cells with trisomy 7 in macroscopically normal tissue outside tumors of the brain, kidney, and lung.(ABSTRACT TRUNCATED AT 250 WORDS)

Clonal chromosome changes in renal carcinoma do not correlate with clinical stages and histopathologic grades

We analyzed the correlations between chromosome abnormalities and clinical and histopathologic characteristics in 77 cases of renal cell carcinoma (RCC). Chromosome changes such as +5,+7,+8,+10,+18,+X,+Y, and -Y have been excluded from the analysis because they also occur in nonneoplastic kidney tissue and cytogenetic analysis indicates that these anomalies are not involved in tumor progression. The most frequent specific chromosome abnormalities in this sample were 3p rearrangements, trisomy 17, and hyperdiploidy and were not related to tumor stage or grade or to development of distant metastases.

Cytogenetic analysis of six renal oncocytomas and a chromophobe cell renal carcinoma. Evidence that -Y, -1 may be a characteristic anomaly in renal oncocytomas

Renal oncocytomas are benign tumors whose morphologic features may sometimes be confused with those of certain low-grade malignant neoplasms of the kidney, e.g., chromophobe cell and granular cell variants of renal carcinoma. The presence of a specific genetic abnormality might help differentiate these tumors. Because very few cytogenetic studies of renal oncocytomas have been published, we investigated a consecutive series of six such tumors. We also performed chromosome analysis on a chromophobe cell carcinoma because cytogenetic analyses of this tumor have not been previously reported. Tumor cell metaphases were analyzed after mechanical and enzyme disaggregation, in situ culture, and robotic harvesting. Clonal abnormalities were present in five of the six oncocytomas, and loss of chromosome 1 with loss of the Y chromosome occurred in two. Review of the literature disclosed four other renal oncocytomas with the 44,X,-Y,-1 karyotype. In the chromophobe cell carcinoma, we noted an abnormal clone with a del(11)(p12p15.1); similar anomalies were not observed in the renal oncocytomas. We conclude that renal oncocytomas have clonal chromosome abnormalities and that a subgroup of these tumors may be specifically associated with loss of chromosomes 1 and Y. Because this is a small series, further investigation may help establish whether cytogenetic studies can provide diagnostic and pathogenic information about renal oncocytomas.

Cytogenetic abnormalities in renal oncocytic neoplasms

We have performed cytogenetic studies on five renal oncocytic neoplasms (three grade 2 tumors and two grade 1 tumors) identified histologically by light microscopy. One grade 1 tumor failed to produce mitotic cells. The other four tumors exhibited both normal and abnormal cell lines. Numerical abnormalities were found in both the single grade 1 and two of the grade 2 tumors whereas structural abnormalities were limited to grade 2 tumors. Aneuploidy of chromosome 12 was observed in both grade 1 and 2 tumors. Grade 2 tumors showed more extensive numerical change than the grade 1 tumors. Abnormalities of chromosome 3 characteristic of renal cell carcinoma were not found in any tumor in this series. A combination of C-banding and HaeIII endonuclease banding was used to identify an ambiguous marker. In our four cases and in the cases previously reported, loss of a sex chromosome, abnormalities of chromosomes 1 and 22, and trisomy 12 are findings most often observed in renal oncocytoma.

Clonal aberrations of chromosomes X, Y, 7 and 10 in normal kidney tissue of patients with renal cell tumors

By means of G-banding techniques, chromosome aberrations were studied in short-term cultures of normal renal parenchymal cells from 45 patients with renal cell carcinoma. Clonal chromosomal aberrations were detected in 29 patients; loss of the Y chromosome as well as trisomy X, 5, 7, 9, 10, 12, and 18 was found. Chromosomes 7 and 10 were involved preferentially. Results of fluorescence in situ hybridization with chromosome 7- and 10-specific DNA probes on non-cultured normal kidney cells suggested that the aberrations developed in vivo.

Renal cell carcinoma

Renal cell carcinoma accounts for 3% of all adult cancers and has many unusual features in its presentation, diagnosis, and management. It develops in a significant number of patients with acquired renal cystic disease, a disorder found almost exclusively in chronic hemodialysis patients. Abnormalities of chromosome 3 are frequently found in sporadic and familial forms. Radical nephrectomy remains the only potentially curative therapy for this tumor.

On the significance of trisomy 7 and sex chromosome loss in renal cell carcinoma

Cytogenetic analysis of 30 renal cell carcinomas showed 3p aberrations in nine tumors, trisomy 7 in 17 tumors, and clonal loss of one sex chromosome in 14 tumors. The 3p aberrations and trisomy 7 were present in the same clone in two tumors and in separate clones in three tumors. Loss of one sex chromosome was present together with 3p aberrations in the same clone in one tumor and occurred in seemingly unrelated clones in two tumors. It occurred as the sole change in five tumors. Clones with trisomy 7 as the only change were present in six tumors. Trisomy 7 and loss of one sex chromosome were present in separate clones in four tumors and in the same clone in one tumor. Because +7 and -X/-Y were thus rarely present together with clonal structural abnormalities, in particular 3p changes, our findings make it highly unlikely that loss of one sex chromosome or trisomy 7 represents a primary change in renal cell carcinoma. We instead suggest that there is a tendency for normal kidney cells to lose an X or a Y chromosome and also to gain an extra copy of chromosome 7. This tendency is retained by renal carcinoma cells; therefore, trisomy 7 and sex chromosome loss should not be viewed as tumor-specific abnormalities in this context. Whether these simple numerical aberrations reflect in vivo mosaicism or are acquired in vitro remains unresolved.

Cytogenetic characterization of renal cell carcinoma in von Hippel-Lindau syndrome

We report the case of a 26-year-old man with von Hippel-Lindau syndrome (VHL) and two renal cell carcinomas (RCC), one of which was studied cytogenetically. Chromosomal analysis of the RCC showed a translocation that involved chromosomes 3 and 8 with subsequent loss of the derivative chromosome 8. The patient's peripheral lymphocytes showed a normal karyotype that indicated that there was not a constitutional chromosomal translocation. This is the third reported case of RCC in a patient with VHL in which loss of a portion of the short arm of chromosome 3 (3p) has occurred. Similar chromosomal changes that involve 3p have been reported in both familial and sporadic cases of RCC and have led to speculation that a tumor suppressor gene may be located in this region. Cytogenetic characterization of renal tumors could assume increasing significance in the diagnosis and classification of RCC and potentially may guide therapy. These studies may also lead to a better understanding of the biologic behavior of RCC and result in more informed patient evaluation and counseling.

Cytogenetic abnormalities in tumors of patients with von Hippel-Lindau disease

Von Hippel-Lindau (VHL) disease is an autosomal dominant disorder that causes the development of benign and malignant tumors in several organ systems. Tumors causing significant morbidity include retinal angioma, cerebellar hemangioblastoma (CH), renal cell carcinoma (RCC), and pheochromocytoma (Pheo). Cytogenetic studies of tumors in VHL patients are rare. Cytogenetic findings in tumors from 12 patients with VHL disease, including four RCCs, three CHs, and five Pheos are presented. Three of the four RCC cases were abnormal. Monosomy 3 or a deletion of 3p was present in all three abnormal cases. Complete or partial trisomy of chromosome 5 was present in two cases. A deletion of 14q, trisomy 7, and a missing Y were each observed in one case. These findings indicate that a deletion of 3p may be a primary cytogenetic change in RCCs associated with VHL disease in addition to playing a role in sporadic RCC. Duplications of 5q and deletions of 14q may be important secondary changes in the progression of the malignant phenotype. No visible cytogenetic abnormalities were observed in the three CHs, or in four of the Pheos. One of the five Pheos was found to exhibit mosaic trisomy 7; its significance is unclear at the present time.

Cytogenetics of bilateral renal cell carcinoma

We analyzed cytogenetically 6 tumors from 4 patients with bilateral renal cell carcinoma. Comparison among findings in these patients with bilateral disease and previously reported cases of unilateral tumor demonstrates that bilaterality is associated with a more frequent loss of a sex chromosome, and gain of chromosomes 7 and 3, whereas unilateral tumors often are associated with loss of chromosome 3 material. It is proposed that bilateral tumors are distinct genetically from unilateral tumors and that most bilateral tumors have a genetic propensity to either enhanced metastatic spread to other renal tissue or spontaneous degeneration.