Joachim Mark

Tumor etiology and chromosome pattern.

Fibrosarcomas induced in Chinese hamsters and rats by Rous sarcomla virus and 7,12-dimethylbenz(a)anthracene are associated with nonrandom chromosome variation. Although histologically indistinguishable, the tumors induced by the virus or chemical in each host species are characterized by completely different karyotypic patterns.

Chromosomal patterns in human meningiomas

Abstract The chromosomes of 12 human meningiomas have been studied. All of them had an abnormal stem line. The majority of the tumours had a hypodiploid stem line, and there was a peak at S = 45. Karyotype analyses demonstrated numerical and/or structural deviations in group G in about three quarters of the tumours. According to findings in the present and a previous study the preferential involvement of group G might be a phenomenon related to progression. Conversely to a previous study the present investigation showed markers in the stem lines of about half of the tumours. A statistical analysis of the chromosomal representation in the tumour stem lines indicated that the groups G and C were involved in the formation of markers, and that markers could be hidden in group C in cases without discernible structural deviations. Furthermore, in the meningiomas and in a group of malignant primary tumours (neurogenic tumours in children) the major deviations appeared to be restricted to the same chromosome groups. Thus, similar mechanisms for chromosomal variation seem to be operating in both benign and malignant human tumours.

Chromosomal characteristics of human pituitary adenomas

SummaryThe chromosomes in 7 human pituitary adenomas were studied in fixations directly from the tumours. A normal, diploid stemline was only found in two adenomas; the other 5 tumours had near-diploid and near-triploid stemlines, and one adenoma of the diploid group had a marker in its stemline. In ordinary chromosome groups the deviations engaged C and F chromosomes, particularly. This pattern was different from that found in meningomas and neurinomas. The common occurrence of chromosomal abnormalities in these three benign tumor types was in contrast to the usually normal, diploid stemline observed in other benign lesions in man (precancerous conditions excluded). Thus, the present study demonstrates that some benign human tumours may show chromosomal abnormalities without any obvious relation to a malignant transformation. Furthermore, these deviations seems to have different characteristics in different benign tumour types.

The chromosomal aberraation of double-minutes in three gliomas

SummaryThkek chromosomes of about 40 human malignant gliomas in adults have been studied. Three tumours had double-minutes (dms) in all or most of their cells whereas 5 additional gliomas showed the same aberration in sporadic cells. The humber of dms varied between 1 and more than a hundred. In most case the majority of the double-minutes were extremely smasll and they were morphologically similar to those seen in some murine sarcomas. Only a few of the dms seemed to be centric. The occurrence of dms could not be related to any particular deviations as regards ordinary chromosomes. Some observations suggested that the dms could be derived drom one or a few pulverized chromosomes. The period the dms could remain in the tumour cell population is probably limited. This problem is discussed together with a possible mechanism for their initial increase in number in the tumour cells.ZusammenfassungDie Chromosomen von etwa 40 malignen menschilchen Gliomen bei Erwachsenen wurden untersucht. Drei Geschwülste hatten „double-minutes” (dms) in allen oder in den meisten zellen, während 5 weitere gliome die gleiche Abweichung in einzelnen Zellen boten. Die Zahl derdms weckselte von 1 bis über 100. In den meisten Fällen waren die dms durchwegs äußerst klein und morphologisch ähnlich jenen bei einigen Mäusesarkomen. Nur einezelne dms erschienen Zeitrisch. Das Auftreten von dms war mit keiner speziellen Abweichung der gewöhnlichen Chromosomen in Zusammenhang zu bringen. inige Beobachtungen lassen vermuten, daß die dms aus einem oder wenigen pulversierten Chromosomen entstehen könnten. Die Lebensdauer der dms ist in einer tumorzellpopulation vermutlich begrenzt. Dieses Problem sowie ein möglicher Mechanismus ihrer initialen zahlenmmäßigen Zunahme in Tumorzellen werden diskutiert.

Two benign intracranial human tumours with an abnormal chromosomal picture

SummaryThe chromosomal findings in two benign, intracranial human tumours are described. A chromophobe pituitary adenoma had a stemline of 80, thus at the borderline between triploidy and tetraploidy. Structural aberrations were seen in 20% of the cells karyotyped. The other tumour, an angioblastic meningioma, had a hyperdiploid stemline with 47 chromosomes including a minute marker, and a closely related 48-chromosome sideline with 2 minute markers of different size. The results are discussed in relation to earlier findings in benign tumours, several benign animal neoplasms but only a few human tumours having so far been analyzed.ZusâmmenfassungDie Chromosomenbefunde bei zwei gutartigen intrakraniellen Geschwülsten beim Menschen werden beschrieben. Ein chromophobes Hypophysenadenom hatte eine Stammlinie von 80 und lag damit an der Grenze zwischen Tri-und Tetraploidie. Strukturabweichungen fanden sich in 20% der Zell-Karyotypen. Der andere Tumor, ein angioblastisches Meningiom, hatte eine hyperdiploide Stammlinie mit 47 Chromosomen einschließlich einem kleinen t-Marker und eine eng verwandte Seitenlinie von 48 Chromosomen mit zwei t-Markern verschiedener Größe. Die Befunde werden im Hinblick auf frühere Befunde bei gutartigen Geschwülsten diskutiert. Zwar wurden verschiedene benigne Tiergeschwülste, aber bisher nur sehr wenige menschliche Tumoren in dieser Hinsicht analysiert.

Two pseudodiploid human breast carcinomas studied with G-band technique.

Abstract The cytogenetical observations in 2 human breast carcinomas studied with G-band technique are reported. Both tumours had a pseudodiploid stemline. One of these had the constitution 46, XX, 2p−, +5, +8, 9p−, 16q−, 17p+, −20, −21; the details of the structural rearrangements could be completely clarified. The other stemline had the constitution 46, XX, 3q−, −6, +7, −8, 11q+, −15, 16q+, +2 different ring chromosomes; the details of the structural changes could be clarified to a considerable extent. A preferential pattern of chromosome variation in breast carcinoma is discussed on the basis of the present results and a review of the literature.

Origin of the marker chromosomes in an established hypotriploid glioma cell line studied with G-band technique

SummaryThe chromosomes of an established human glioma cell line were studied with G-band technique. The cell line had a hypotriploid mode, S=60−61, and there were 10 different marker types in the stemline karyotypes. The origin of most markers could be traced; C and D chromosomes were found to participate in the formation of at least eight markers. The findings in the present material, combined with the observations in a previously studied glioma cell line, indicated a preferential pattern of variation in chromosome groups C and D.ZusammenfassungDie Chromosomen einer humanen Gliomazellkultur wurden mit der G-Bandungstechnik untersucht. Die Kultur hatte eine hypotriploide Stammlinie (S=60−61) mit zehn verschiedenen Marker-Chromosomen im Stammliniekaryotypen. Der Ursprung der Mehrzahl der Marker-Chromosomen konnte festgestellt werden; die Chromosomen der Gruppe C und D hatten bei mindestens acht Markers an deren Bildung teilgenommen. Die vorliegende und eine frühere Untersuchung von Gliomakulturen deuten darauf hin, daß spezielle Chromosomen der Gruppen C und D an der Entwicklung des Stammliniekaryotypen dieser Tumoren beteiligt sind.

The fluorescence karyotypes of three human meningiomas with hyperdiploid-hypotriploid stemlines.

SummaryUsing the fluorescence technique, the chromosomes were studied in one hyperdiploid (S=50) and two hypotriploid (S=63–65 and S=67, respectively) human meningiomas. These stemline categories, rarely found in meningiomas, displayed the same pattern in group G as recently demonstrated in the hypodiploid-diploid tumours groups, namely a specific involvement of pair G 22. Different chromosomal mechanisms for the origin of triploid tumour stemlines were discussed. In meningiomas these mechanisms seemed to favour a progression towards a balanced triploid complement.

Rous sarcomas in mice: The chromosomal progression in primary tumours

Resume La progression chromosomique a ete etudiee dans 11 sarcomes de Rous primitifs de la souris, analyses a des stades successifs de leur developpement. Cinq sarcomes, qui avaient a lorigine une lignee diploide normale, ont constitue le materiel qui a permis letude des etapes vers la transplantation heteroploide. La nouvelle lignee pouvait souvent etre rattachee a une lignee collaterale heteroploide, et, dans certains cas, il etait possible de retrouver lorigine de cette lignee collaterale dans une petite fraction de cellules differant de la lignee principale. Les sarcomes qui avaient, des le premier examen, une lignee heteroploide, presentaient souvent des rearrangements chromosomiques supplementaires, mais sans quil y eut modification de la categorie de la lignee principale originelle. Ils conservaient donc la direction de la progression choisie par la tumeur. Alors que les etapes de la progression avaient un caractere general, la route suivie et la vitesse de la progression etaient propres a chaque tumeur. Il ny avait pas de correlation nette entre les changements de la vitesse de croissance et la progression chromosomique. Laspect histopathologique, en revanche, montrait une correlation avec les principales modifications de la progression. Le tableau chromosomique plein de dynamisme qui caracterise le sarcome de Rous est compare aux observations faites dans dautres tumeurs experimentales chez lanimal, et dans les cancers chez lhomme.

Chromosomal characteristics of secondary human brain tumours

Abstract The chromosomes in 20 secondary neoplasms in the CNS were studied in fixations taken directly from the tumours. Three quarters of the metastases had a triploid mode, and three quarters of these were in the hypotriploid zone. Near-diploid stemlines were next in frequency; a hypodiploid mode was most common, and 2 such tumours had as low stemline number as 34 and 36 , respectively. Tetraploid stemlines were not seen, but 1 metastasis had a pentaploid mode. In ordinary chromosome groups the deviations particularly involved groups C, D and G. Markers, and often a very high number, were ou nd in all but one stemline. A statistical analysis of the chromosomal representation demonstrated a correlation between the extent of the decrease of the acrocentrics and the frequency of markers. A study of the relative size of four different marker types indicated that these were formed by non-random mechanisms. In comparison with findings in neoplastic effusions the brain metastases showed more extreme numerical and structural features, possibly a property of neoplastic elements with a capacity to metastasize to the CNS.