Radiation-Induced Human Keratinocyte Transformation

摘要

We have shown that immortalised human epidermal keratinocyte (RHEK-1) cells can be transformed malignantly by two exposures to X radiation. These transformed cells showed morphological alteration, colony formation in soft agar, and induced carcinoma when transplanted into nude mice. Primary human epidermal keratinocytes exposed to radiation in this manner failed to show any evidence of transformation. SSCP analysis and DNA sequencing demonstrated the absence of point mutations, deletions and rearrangements in the RAS genes and exons 2-11 of the TP53 gene. Chromosomal changes in radiation-induced RHEK-1 cells have been examined. On the basis of commonality in having additional material in chromosome 11 in the region between q14/q22 in all tumourigenic, irradiated cell lines, and deletions in the same region in nontumourigenic, irradiated cell lines, it is deduced that this region of chromosome 11 may have some important genes that may play an important role in tumourigenesis.