Transformation and chromosomal instability of human tracheal epithelial cells induced by formaldehyde / 第三军医大学学报

ABSTRACT

Objective To explore the mechanisms of chemical carcinogenesis and the relationship between malignant transformation and genomic/chromosomal instability of human bronchial epithelial cell line by formaldehyde.Methods BEAS-2B cell line was toxicated by formaldehyde and the LC_(50) of formaldehyde was tested by MTT assay.BEAS-2B cells were induced by formaldehyde at 20% LC_(50),and the transformation of BEAS-2B cells was identified and induced clones were selected.By G-banding technique,the metaphase modal chromosome number,karyotypes and nonrandom structural change of induced cell strains were analyzed.Results The growth rate of BEAS-2B cells induced by formaldehyde was significantly increased.The induced cells showed a trend of infinite proliferation and the anchorage independent growth was seen in 15~(th) generation cells.As compared with the relatively stable pseudodiploid karyotype of BEAS-2B cells,most of induced cells were triploid and/or tetraploid karyotypes and their chromosome 14 had lost two copies of chromosome replaced by the other two.They also had high frequency of unstable aberration(39%),including chromosome loss,endoduplication,translocation,breakage,two and/or three centromeres etc..Conclusion The formaldehyde could lead to progression of malignant transformation and result in genomic instability of human bronchial epithelial cells in vitro.