Related Experiment Videos
Nonrandom chromosome changes in methylnitrosourea (MNU) induced mouse T-cell lymphomas
M Kaelbling1, Y D Zhang, U B Dasgupta
1Department of Molecular Genetics, Albert Einstein College of Medicine, Bronx, New York 10461.
Abstract:
Since nonrandom chromosome changes in neoplastic cells have proven to be good indicators of the site of gene alterations related to transformation, the authors examined the chromosomes of T-cell lymphomas induced in RF/J strain mice with methylnitrosourea (MNU). All treated mice developed thymic lymphomas within 10 weeks of injection. Chromosomes of the thymus cells were examined at intervals before and during lymphoma development, as well as after they were passaged in syngeneic and in nude mice for periods up to 424 days. In preparations made directly from the thymus cells nonrandom numerical and structural alterations were found that involved the X, 3, 15, 4, 8, 12, 14 and 17. (Chromosomes showing alterations are listed in decreasing order of the frequency of their occurrence). In cells passaged in nude mice the chromosomes similarly altered were the 10, X, 3, 12, 6, 1, 4, 19, 15, 18 and 14. In tumor cells passaged in syngeneic mice most of the same chromosomes were involved but the order was 15, 14, X, 1, 5, 6, 3, 11 and 12. The X, 15, 14, 3 and 12 were aberrant in both direct preparations and in those from passaged cells, suggesting that these chromosomes carry genes which, when altered, are particularly important in the multistep process of neoplastic transformation. Most of these chromosomes, or their homologs in other species, have been found to be involved frequently in several different cancers of mice and men, as for example the region on the mouse 15 carrying the Myc and Pvt-1 genes.(ABSTRACT TRUNCATED AT 250 WORDS)
Insights
Researchers studied chromosome changes in mouse T-cell lymphomas induced by methylnitrosourea (MNU). Specific chromosomes (X, 15, 14, 3, 12) showed consistent alterations, indicating their crucial role in cancer development.
Area of Science:
- Oncology
- Genetics
- Cancer Research
Background:
- Nonrandom chromosome alterations in neoplastic cells are key indicators of gene changes related to cancer transformation.
- Methylnitrosourea (MNU) is a chemical mutagen known to induce various cancers, including T-cell lymphomas.
Purpose of the Study:
- To investigate chromosomal abnormalities in T-cell lymphomas induced by MNU in RF/J mice.
- To identify specific chromosomes consistently altered during lymphoma development and progression.
Main Methods:
- Induction of thymic lymphomas in mice using MNU.
- Karyotypic analysis of thymus cells at various stages of lymphoma development.
- Chromosomal examination of tumor cells passaged in syngeneic and nude mice.
Main Results:
- Nonrandom numerical and structural chromosomal alterations were observed in direct thymus cell preparations.
- Specific chromosomes (X, 3, 15, 4, 8, 12, 14, 17) were frequently involved in initial lymphoma development.
- Chromosomes X, 15, 14, 3, and 12 consistently showed alterations in both direct and passaged cells, suggesting their critical role.
Conclusions:
- The X, 15, 14, 3, and 12 chromosomes are likely to harbor genes critical for neoplastic transformation in T-cell lymphomas.
- These findings highlight conserved chromosomal regions involved in cancer across species, such as the mouse chromosome 15 region containing Myc and Pvt-1 genes.