Multicolor spectral karyotype analysis of a transplantable human ileal carcinoid

In this report we present the results of a combined cytogenetic and multico lor spectral karyotype (SKY) analysis of a transplantable human ileal carci noid (GOT1). By using SKY it was possible to identify the origin and organi zation of all clonal marker chromosomes and to identify cryptic translocati ons not detectable by conventional chromosome banding. The stemline karyoty pe of low passage GOT1 cells was interpreted as 43,XX, der(1)del(1)(?), inv (2)(p25q13), del(3)(p21), del(5)(q13q31), del(6)(q13), -9, -13, -15, del(16 ) (q22). Analysis of the GOT1 cells after about 2.5 years of propagation in nude mice allowed us to follow the in vivo progression of this tumor. Rela tively few additional rearrangements had occurred during this period, indic ating that the GOT1 cells are genetically stable. Most of the abnormalities detected result in loss of whole or parts of chromosomes, suggesting that loss of multiple chromosomal regions, presumably containing tumor suppresso r genes, might be important genetic events in ileal carcinoids.