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

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 APr-1 cells. Overproduction of annexin II in RSa cells resulted in increased resistance to UVB lethality, while annexin II siRNA-transfected APr-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 APr-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 APr-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.