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G Belge

Publications and source records attributed to G Belge.

27 records · Page 2Linked to original sources

FISH analyses of a newly established thyroid tumor cell line showing a t(1;19)(p35 or p36.1;q13) reveal that the breakpoint lies between 19q13.3-13.4 and 19q13.4.

Translocations involving the long arm of human chromosome 19 are specific chromosomal alterations found in a subset of benign thyroid tumors. In the present communication we describe the establishment of an SV40-transformed cell line derived from a thyroid adenoma with a t(1;19)(p35 or p36.1;q13). Cytogenetic studies were carried out on this cell line, using a series of cosmids mapping along the long arm of chromosome 19. In situ hybridization with probes for RYR1, ATP1A3, BCKDHA, ERCC1, POLD1, and TRPT revealed that only TRPT mapped distal to the breakpoint of the translocation. The results indicated that the breakpoint is located between POLD1 and TRPT at the boundary between chromosome bands 19q13.3 and 19q13.4.

Chromosomes, Human, Pair 1↗

A characteristic sequence of trisomies starting with trisomy 7 in benign thyroid tumors.

The cytogenetic results from a series of 113 thyroid hyperplasias and adenomas are reported; 15 showed clonal karyotypic alterations. In addition to a group showing translocations involving 19q13, another subset of lesions characterized by polysomies can be found. Based on our own cases belonging to this subset and a review of the cases reported in the literature, we conclude that the characteristic feature of this group is a sequence that always starts with trisomy 7, but that sometimes even leads to chromosome numbers in the hypertriploid range. This subset of thyroid tumors may be an example of a more common genetic pathway in human solid tumors.

Adult↗

Cytogenetic biclonality corresponding to multiphasic differentiation in an atypical thyroid adenoma.

Cytogenetic aberrations have been described in about 30% of benign thyroid tumors, but their role for tumorigenesis or progression has not yet been elucidated. We describe the cytogenetic analyses in a thyroid adenoma with two different clonal cytogenetic stemlines: 45,XX,der(1)t(1;14)(p13;q11.2-q(13),t(5;12)(q11.2;q24),del(9)(q12),- 10,der(11)t(11;?;19)(p15;q13),der(14)t(14;15)(q11.2-q13;q23),del(15)(q23 ), der(15)t(9;15)(q12;p10),der(19)t(10;19)(q11.2;q13)/46,X,?inv(x),?inv(3) (p21q29),t(3;8)(q26;q12). Histologic examination revealed an atypical follicular thyroid adenoma containing microfollicular, follicular, trabecular-solid, and oncocytic components. There may be a direct relation between the different cytogenetic stemlines and the histologic diversity of the tumor. Thyroid tumors with complex karyotypes involving the 19q13 breakpoint may represent advanced stages of karyotypic evolution and therefore warrant an extensive clinical follow-up.

Adenoma↗

Aberrations of chromosome 19. Do they characterize a subtype of benign thyroid adenomas?

We describe the cytogenetic findings in two benign thyroid hyperplasias with aberrations of chromosome 19. In the first patient, two of four nodules showed identical translocations involving chromosome 19 and 22: 46,XX,der(19)t(19;?)(q13;?),der(22)t(22;?)(q12;?), the remaining nodules had an apparently normal karyotype. Two nodules from a second patient were karyotyped. One showed a karyotype 46,XX,t(1;19)(p35-36.1;q13) and the other had a normal karyotype. From these results as well as those reported previously, we can conclude that structural changes of chromosome 19 characterize a subgroup of thyroid adenomas, thyroid hyperplasias, or both.

Adenoma↗

Expression of SV40 T-antigen in lipoma cells with a chromosomal translocation T(3;12) is not sufficient for direct immortalization.

12q13-15 changes are the most frequent cytogenetic abnormalities in human tumor cells. To test their biological significance we used an assay based on lipoma cells with a limited in vitro lifetime and this type of chromosomal aberration. Lipoma cells with a reciprocal translocation t(3;12)(q28;q14) were transformed by transfection with a plasmid containing the SV40 "early region". The transformed cells showed an altered morphology with loss of contact inhibition, formation of foci, and T-antigen expression. They were immortalized after a growth crisis. The karyotypic patterns before and after the crisis show that the translocation together with expression of SV40 T-antigen is not sufficient for direct immortalization.

Adult↗

Cytogenetic investigations on a cell line derived from a carcinoma arising in a salivary gland pleomorphic adenoma.

This article discusses the results of cytogenetic investigations of a cell line derived from a malignant tumor arising in a benign salivary gland pleomorphic adenoma. Initial karyotypic studies became possible with cells of the second in vitro passage and revealed the existence of hypertetraploidy. Furthermore, a marked polysomy 7 and a translocation involving 12q13-15, a breakpoint also frequently seen in benign pleomorphic adenomas, were noteworthy. During long term culture, the number of chromosomes per cell decreased as well as the number of copies of chromosome 7. Cell tumorigenicity was proved by heterotransplantation to nude mice. The resulting tumors were karyotyped again. No significant changes of the chromosome number or of the degree of polysomy 7 were found compared to the cells before heterotransplantation. In contrast, the cells from the nude mice tumors showed a remarkable number of different isochromosomes probably indicating an unknown factor supporting the generation of isochromosomes. The consistent presence of the t(12;?)(q13-15;?) makes the cell line well suited for molecular studies of this breakpoint region.

Adenoma, Pleomorphic↗