Proliferation enhancement by spontaneous multiplication of chromosome 7 in rheumatic synovial cells in vitro.
Mosaic trisomy of chromosome 7 is known to occur in a variety of non-neoplastic hyperproliferative disorders. In long-term cell cultures established from rheumatic synovium with mosaic trisomy 7, we observed a continuous increase in the proportion of cells with trisomy 7 to over 50% by the 10th in vitro passage. Simultaneous in situ hybridization with a repetitive chromosome-7-specific DNA probe and fluorescent Ki-67 labelling showed a strong correlation between trisomy 7 and an elevated proliferation index in cultured rheumatic synovial cells. Moreover, we observed a fraction of rapidly proliferating cells with up to eight copies of chromosome 7 as the sole cytogenetic change. Frequent somatic pairing of centromeres of two chromosomes 7 in interphase nuclei suggests either atypical non-disjunction with a persisting centromere or selective endoreduplication of chromosome 7.
Institut für Humangenetik, Universität des Saarlandes, Universitätskliniken Bau 68, Homburg/Saar, Germany.
A
A
Ermis
W
W
Henn
K
K
Remberger
C
C
Hopf
T
T
Hopf
K D
KD
Zang
D001172:Arthritis, Rheumatoid / Q000235:genetics* / Q000473:pathology; D002478:Cells, Cultured; D002897:Chromosomes, Human, Pair 7; D015342:DNA Probes; D006801:Humans; D017404:In Situ Hybridization, Fluorescence; D019394:Ki-67 Antigen; D009030:Mosaicism; D009363:Neoplasm Proteins / Q000032:analysis; D009687:Nuclear Proteins / Q000032:analysis; D013583:Synovial Membrane / Q000473:pathology*; D014314:Trisomy
D015342:DNA Probes; D019394:Ki-67 Antigen; D009363:Neoplasm Proteins; D009687:Nuclear Proteins