Chromosome banding studies of several transplantable hepatomas

Abstract

The karyotypes of six aneuploid rapidly growing transplantable hepatomas widely deviated from the normal host cell have been examined by banding techniques. The tumors with long transplant history showed the most complex structural rearrangements (3683, 7288C, 3924A) yet were more homogenous compared to that of tumors with shorter transplant history such as 9611B and 9618A 2. Passage of a tumor through tissue culture increased very much the number of karyotypic variations even within the same stemline cells (7288Ctc). Chromosomes with normal banded patterns could be identified with great accuracy from the altered karyotypes of these hepatomas. Autosomes from the acrocentric group were preferentially involved in markers (#2, 6, 10). Most frequent chromosome rearrangements found in these fast growing hepatomas were derived by fusion and/or pericentric inversion of normal autosomes. The origin of most structurally rearranged chromosomes could be traced by their banding pattern. One identical marker, which was derived by pericentric inversion of #2 chromosome, was present in five hepatoma cell lines but no identical rearrangement common to all six tumors was evident. By the present banding techniques, however, common genetic changes, if any, occurring during the development of these neoplastic cells are undetectable by the relatively gross bands observed at the chromosomal level.