The involvement of annexin II in resistance to UVB-induced cell death and in the increased nucleotide excision repair capacity of UV-damaged DNA in human cells.

ABSTRACT

Annexin II, an HSP27-interacting protein, is involved in the protection of human cells against UVC. UVB is concerned with deleterious actions on human health. In this study, we attempted to confirm the anti-UVB effect of annexin II, and to elucidate the mechanisms underlying annexin II-involving UV resistance. The RSa cells were more sensitive to UVB lethality than the AP(r)-1 cells. Overproduction of annexin II in RSa cells resulted in increased resistance to UVB lethality, while annexin II siRNA-transfected AP(r)-1 cells were sensitized to UVB lethality. The excision capacity of the two major types (CPD and 6-4PP) of UVC- and UVB-damaged DNA in AP(r)-1 cells was greater than in RSa cells. The excision capacity of the RSa cells improved following upregulation of annexin II, while the capacity of the AP(r)-1 cells decreased after annexin II downregulation. Our results suggest that annexin II is involved in the UV resistance of human cells, via functioning in nucleotide excision repair.