SUMMARYCGN is a rapidly progressive glomerular disease. Monocytes/macrophages are frequently observed in glomeruli in cases of CGN and they are considered to play a crucial role in the pathogenesis of this disease. We described previously the glomerular expression of monocyte chemoattractant protein-1 (MCP-1), which is a potent chemoattractant for monocytes and a member of CC chemokine family, in an experimental model of CGN. In the present study we investigated the expression of mRNAs for other CC chemokines, namely, MCP-3, macrophage inflammatory protein-1a (MIP-1a), MIP-1b, RANTES and TCA3, all of which are chemotactic for monocytes, in the CGN model. First, we established a reverse transcriptase-polymerase chain reaction (RT-PCR) method by which mRNA for each of the CC chemokines could be amplified separately, and then we measured the levels of the expression of mRNAs for the chemokines in diseased glomeruli at several time points after induction of CGN. The mRNAs for all CC chemokines examined were expressed in glomeruli of rats with CGN. Moreover, induction of the gene expression of MIP-1a and MIP-1b seemed to occur earlier than that of the others. CC chemokines may contribute to the recruitment and activation of monocytes in CGN, and each individual CC chemokine may play an overlapping but distinct role in the pathogenesis of this disease.

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Five immortal cell lines derived from a Li-Fraumeni syndrome patient (MDAH 087) with a germline mutant p53 allele were characterized with respect to telomere length and genomic instability. The remaining wild-type p53 allele is lost in the cell lines. Telomerase activity was undetectable in all immortal cell lines. Five subclones of each cell line and five re-subclones of each of the subclones also showed undetectable telomerase activity. All five immortal cell lines exhibited variability in the mean length of terminal restriction fragments (TRFs). Subclones of each cell line, and re-subclones of the subclones also showed TRF variability, indicating that the variability is owing to clonal heterogeneity. Chromosome aberrations were observed at high frequencies in these cell lines including the subclones and re-subclones, and the principal types of aberrations were breaks, double minute chromosomes and dicentric chromosomes. In addition, minisatellite instability detected by DNA fingerprints was observed in the immortal cell lines. However, all of the cell lines were negative for microsatellite instability. As minisatellite sequences are considered recombinogenic in mammalian cells, these results suggest that recombination rates can be increased in these cell lines. Tumor-derived human cell lines, HT1080 cells and HeLa cells that also lack p53 function, exhibited little genomic instability involving chromosomal and minisatellite instabilities, indicating that chromosomal and minisatellite instabilities observed in the immortal cell lines lacking telomerase activity could not result from loss of p53 function.