Original Articles
Fine Mapping of the Human Renal Oncocytoma-Associated Translocation (5;11)(q35;q13) Breakpoint

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Abstract

Recent cytogenetic analysis of a series of human renal oncocytomas revealed the presence of a recurring chromosomal translocation (5;11)(q35;q13) as sole anomaly in a subset of the tumors. The molecular characterization of this translocation was initiated using two primary t(5;11)-positive renal oncocytomas and a panel of somatic cell hybrids derived from one of these tumors, in conjunction with fluorescence in situ hybridization (FISH) and Southern blot analysis. The breakpoint in chromosome band 11q13 could be located within a genomic interval of at maximum 400 Kb immediately centromeric to the BCL1 locus.

Introduction

Oncocytomas are benign tumors that occur predominantly in the kidney, accounting for approximately 5% of all primary tumors at that site. Histologically, oncocytomas are characterized by the presence of epithelial cells with a strong granular eosinophilic cytoplasm. Ultrastructural examination revealed that these so-called oncocytic cells are densely packed with mitochondria, many of which show abnormal morphologic characteristics [1]. This phenotype, however, also can be found in some of the malignant neoplasms of the kidney such as the granular and chromophobic variants of renal cell carcinomas [2]. Although long-term follow-up studies have shown that oncocytomas do not metastasize, several reports indicate the invasive potential of these tumors 3, 4, 5. Preliminary cytogenetic studies performed on a limited series of renal oncocytomas have revealed a heterogeneous chromosomal constitution 3, 5, 6, 7Basically, two subgroups can be distinguished: (1) those with numerical anomalies, including -Y and -1 8, 9, 10; and (2) those with recurring structural anomalies, in particular t(5;11)(q35;q13) 11, 12or variants thereof 13, 14, 15. The t(5;11)(q35;q13) has been observed as sole cytogenetic anomaly in at least 3 independent cases and, as such, should be considered as a primary change. Deletion of 3p material that occurs in the majority of renal cell carcinomas 16, 17has not been observed in renal oncocytomas. The presence of mitochondrial DNA alterations has been reported by some investigators 18, 19. These latter observations, however, could not be substantiated by others [20].

In view of the steadily accumulating evidence that chromosomal changes play causal roles in cancer development 21, 22, 23, we assume that in this case, too, the chromosomal translocation points at a gene(s) that plays a crucial role in the pathogenesis of renal oncocytomas. Therefore, we initiated the fine mapping of the t(5;11)(q35;q13) breakpoint. Because band 11q13 is involved in a variety of malignant disorders, including mantle cell lymphomas, squamous cell carcinomas, breast cancer, multiple endocrine neoplasia type 1, and extragonadal germ cell tumors 24, 25, 26, 27, 28, 29, 30, and because 11q13 is relatively well mapped 24, 31, 32, we selected this region for detailed analysis. To this end, fluorescence in situ hybridization (FISH) with breakpoint region-specific probes was employed. In addition, a panel of oncocytoma-derived interspecies somatic cell hybrids was generated to facilitate our studies. The resulting mapping data are useful (1) to construct a detailed physical map of the breakpoint region; and (2) to provide a basis to isolate the breakpoint itself and the gene(s) involved in the development of renal oncocytomas.

Section snippets

Tumors and Somatic Cell Hybrids

Samples of the t(5;11)(q35;q13)–positive renal oncocytomas T88-1665 and T92-12439 were obtained from 2 different patients after radical nephrectomy at surgery. Following disaggregation of tumor cells with collagenase and subsequent short-term culturing, metaphase spreads were prepared using standard procedures. In addition, a panel of somatic cell hybrids was isolated after fusion of the thymidine kinase deficient (tk) Chinese hamster cell line A3 with T92-12439 cells. Fusion and hybrid

Characterization of t(5;11)(q35;q13) in Primary Tumors

Cytogenetic analysis of two primary renal oncocytomas (T88-1665 and T92-12439) revealed the presence of t(5;11) (q35;q13) as sole anomaly (Fig. 1). These primary tumors were used for a more detailed characterization of the translocation. Starting from the 11q13 region, FISH analyses were performed on metaphase spreads obtained from short-term cultured primary tumor cells. Double hybridizations with combinations of 11q13-specific cosmids (Table 1) and the alphoid probe (pCL11A) specific for the

Acknowledgements

The authors thank C. Collins, C. Larsson, Y. Nakamura, and J. Hoovers for generously providing probes. A. A. Sandberg is acknowledged referring tumor material to us. We thank S. van den Broek and the members of the Tumor Cytogenetics Group for continuous expert technical assistance. This work was supported by the Dutch Cancer Society (Koningin Wilhelmina Fund).

References (39)

  • RF Suijkerbuijk et al.

    Verification of isochromosome 12p and identification of other chromosome 12 aberrations in gonadal and extragonadal human germ cell tumors by bicolor fluorescence in situ hybridization

    Cancer Genet Cytogenet

    (1992)
  • C Collins et al.

    Construction and characterization of plasmid libraries enriched in sequences from single human chromosomes

    Genomics

    (1991)
  • RJ Sinke et al.

    Reverse mapping of the gene encoding the human fos-related antigen-1 (FRA-1) within chromosome band 11q13

    Genomics

    (1993)
  • ET Takahashi et al.

    A high-resolution cytogenetic map of human chromosome 5localization of 206 new cosmid markers by direct R-banding fluorescence in situ hybridization

    Genomics

    (1993)
  • B Tandler et al.

    Ultrastructure of oncocytoma of the parotid gland

    Lab Invest

    (1970)
  • KE Pshiramis et al.

    Chromosome anomalies suggestive of malignant transformation in bilateral renal oncocytoma

    J Urol

    (1986)
  • KE Pshiramis et al.

    Further evidence that renal oncocytoma has malignant potential

    J Urol

    (1988)
  • G Kovacs et al.

    Renal oncocytoma

    A cytogenetic and morphologic study. Cancer

    (1987)
  • E van den Berg et al.

    Cytogenetic analysis of epithelial renal cell tumorsRelationship with a new histopathological classification

    Int J Cancer

    (1993)
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