Inhibition of DNA repair in ultraviolet-irradiated human cells by hydroxyurea

Id3 upregulates BrdU incorporation associated with a DNA damage response, not replication, in human pancreatic β-cells

“…In contrast, HU treated β-cells retained BrdU uptake in a large proportion of cells. 49 Our demonstration that Id3 expressing β-cells failed to enter the cell cycle was unexpected in the light of our finding that Id3 induces robust cell cycle entry of pancreatic ductal cells. 39 Ductal and β-cells are closely related developmentally; ducts give rise to neogenic β-cells during pancreas embryogenesis, 73 and we have shown that the process can be recapitulated in the adult human pancreas.…”

“…At low doses, HU selectively attenuates DNA replication by depleting the cellular deoxyribonucleotide pool while HU has a less marked effect on DNA repair. 49 We examined the effect of 10 …”

DNA Repair Synthesis and Ligation Affect the Processing of Excised Oligonucleotides Generated by Human Nucleotide Excision Repair

“…Inhibition of Gap Filling Enhances DNA Damage Checkpoint Signaling and Induces Cell Death-Inhibition of gap-filling synthesis has been reported to lead to enlargement of excision gaps in human cells (39) and to enhanced DNA damage checkpoint signaling by the ATR kinase (40,41), which likely occurs through the recruitment of the ATR kinase to RPA-coated ssDNA excision gaps (42)(43)(44)(45). To confirm these findings and validate our experimental conditions, we therefore monitored the phosphorylation status of a number of protein substrates of the ATR kinase in UV-irradiated quiescent cells in the absence or presence of HU/AraC to limit gap filling.…”

Squamous Cell Carcinoma Accompanying Chronic Myeloid Leukemia: Case Report and Review of the Literature

“…15 Hydroxyurea, has been shown to induce chromosomal damage and inhibition of DNA repair in ultraviolet (UV) irradiated human cells in vitro environment. 16,17 Therefore it is being thought that, hydroxyurea may interfere with cell replication in the basal layer of epidermis. 8 Thus, in patients recieving long term hydroxyurea therapy, the development of squamous and basal cell carcinomas does not seem to be occasional.…”

“…19 In addition to the impairment in DNA repair, Hydroxyurea is likely to interfere with DNA synthesis inducing chromosomal damage and as demonstrated by Francis et al, inhibits DNA repair in ultraviolet exposed human cells. 17 So, it disrupts the normal replication and repair mechanism of healthy cells causing secondary carinogenesis. Interaction of immunesuppression and malfunctioning of natural killer cells, which is a typical finding in chronic myelogenous leukemia can be added.…”