H. Kugoh et al., Cellular senescence of a human bladder carcinoma cell line (JTC-32) induced by a normal chromosome 11, CANC GENET, 116(2), 2000, pp. 158-163
Human chromosome 11 is expected to carry tumor suppressor genes for a varie
ty of human cancers, including bladder carcinoma. To examine the functional
role of a putative tumor suppressor gene(s) on this chromosome in the deve
lopment of bladder carcinoma, we performed microcell-mediated transfer of c
hromosome 11 into the bladder carcinoma cell line, JTC-32. Fifteen of 20 co
lonies formed by the transfer experiment showed a remarkable change in cell
morphology. They flattened and ceased growing, or senesced, prior to 10 po
pulation doublings. The presence of transferred chromosome 11-derived fragm
ents in the growth-arrested cells was confirmed by PCR-based polymorphism a
nalyses. The remaining 5 microcell hybrid clones exhibited a parental cell-
like morphology, and presumably escaped from senescence, which was accompan
ied by deletions and/or rearrangements of the transferred chromosome 11. On
the other hand, a transferred normal chromosome 7 neither changed the cell
morphology nor arrested the cell growth. These results support the hypothe
sis that chromosome 11 contains a gene or genes which restore the senescenc
e program lost during the immortalization process of JTC-32 cells. (C) Else
vier Science Inc., 1999. All rights reserved.