Asbestos-associated chromosomal changes in human mesothelial cells.

Replicative cultures of human pleural mesothelial cells were established from noncancerous adult donors. The cells exhibited normal mesothelial cell characteristics including keratin, hyaluronic acid mucin, and long branched microvilli, and they retained the normal human karyotype until senescence. The mesothelial cells were 10 and 100 times more sensitive to the cytotoxic effects of asbestos fibers than normal human bronchial epithelial or fibroblastic cells, respectively. In addition, cultures of mesothelial cells that survived two cytotoxic exposures of amosite fibers were aneuploid with consistent specific chromosomal losses indicative of clonal origin. These aneuploid cells exhibit both altered growth control properties and a population doubling potential of greater than 50 divisions beyond the culture life span (30 doublings) of the control cells.