Cross-sensitivity between interferon and uv in human cell strains: IFr, HEC-1, and CRL1200

Correlation between susceptibility to the anticellular effect of human interferon (HuIFN) and ultraviolet (uv) lethality was examined in a set of isogeneous human cell lines (RSa and IFr cells), a human endometrial cancer cell line (HEC-1 cells), and a Xeroderma pigmentosum-derived fibroblast cell line ( CRL1200 cells). IFr cells, previously established as a HuIFN-alpha-resistant subline by exposing HuIFN-alpha- and uv-sensitive RSa cells to HuIFN-alpha preparations, appeared more refractory to uv than did the parent RSa cells in the cell proliferation and colony-formation studies. The extent of recovery from uv-inhibited total cellular DNA synthesis and uv-induced DNA-repair synthesis was enhanced to a greater extent in IFr cells than in RSa cells. The preexposure of RSa cells to HuIFN-alpha enhanced uv-induced DNA-repair replication activities. HEC-1 cells, which are reportedly totally refractory to HuIFN actions, appeared most resistant to uv, in all the tests. The uv-sensitive CRL1200 cells appeared highly susceptible to HuIFN-beta, in both cell proliferation and DNA-synthesis inhibition tests. These results support and extend our previous finding (N. Suzuki, J. Nishimaki , and T. Kuwata (1982). Mutat . Res. 106, 357-376) that susceptibility to the anticellular effect of HuIFN closely relates with uv lethality.