Trisomy of chromosome 9q: specific chromosome change associated with tumorigenicity during the process of X-ray-induced neoplastic transformation in golden hamster embryo cells.
We have reported that trisomy of chromosome 7 is commonly observed in anchorage-independent clones isolated from X-irradiated golden hamster embryo cells. All 10 clones derived from different irradiated populations showed tumorigenicity when 1 x 10(7) cells were injected s.c. into nude mice (BALB/c, nu/nu). From karyotypic analysis, we found that 8 of 10 cells showed trisomy of chromosome 9. One cell line had a translocation between chromosomes 9q and 19q and trisomy of chromosome 7. The other cell line contained trisomy of chromosome 9 and a translocation between chromosomes 7q and 8q. Using Southern blot analysis, we observed no amplification of v-myc, v-Ha-ras, v-Ki-ras or N-ras-related oncogenes. Furthermore, we could not detect either an increase in expression of v-myc- and v-Ha-ras-related genes or the activation of any oncogene, by the NIH 3T3 transfection assay. Our results suggest that trisomy of chromosome 7 is insufficient for the expression of tumorigenicity and that increased dosage of chromosome 9q may play an important role in the malignant progression of X-ray-induced neoplastic transformation.
Suzuki
K
K
Division of Radiation Biology, Faculty of Pharmaceutical Sciences, Kanazawa University, Japan.
Yasuda
N
N
Suzuki
F
F
Nikaido
O
O
Watanabe
M
M
D000818:Animals; D015139:Blotting, Southern; D002471:Cell Transformation, Neoplastic / Q000235:genetics*; D002871:Chromosome Banding; D006224:Cricetinae; D015972:Gene Expression Regulation, Neoplastic; D008647:Mesocricetus; D051379:Mice; D008819:Mice, Nude; D009374:Neoplasms, Experimental / Q000235:genetics; D009381:Neoplasms, Radiation-Induced / Q000235:genetics; D009857:Oncogenes; D012334:RNA, Neoplasm / Q000235:genetics; D014314:Trisomy; D014965:X-Rays
D012334:RNA, Neoplasm