Bloom syndrome (BS) is an autosomal recessive disorder characterized by a high incidence of cancer and genomic instability. BLM, the protein defective in BS, is a RecQ-like helicase, presumed to function in DNA replication, recombination, or repair. BLM localizes to promyelocytic leukemia protein (PML) nuclear bodies and is expressed during late S and G2. We show, in normal human cells, that th...

OBJECTIVE To prepare, characterize, and analyze the release behavior of bleomycin-loaded magnetite nanoparticles (BLM-MNPs) coated with polyacrylic acid (PAA) as a new drug delivery system that can be specifically distributed in the tumor site. METHODS BLM-MNPs coated with PAA were prepared using a solvothermal approach. The particles were characterized using scanning electron microscope (SEM...

Bloom's syndrome (BS) is a rare autosomal recessive disorder of humans characterized by severe pre- and postnatal growth deficiency, immunodeficiency, genomic instability, and a predisposition to a wide variety of neoplasms. The genomic instability is evidenced in BS somatic cells as a high incidence of gaps and breaks, chromatid exchanges, chromosome rearrangements, and locus-specific mutation...

bleomycin (blm)as an anti-cancer agent causes tissue toxicities through dna damaging and cell deaths. the aim of this study was to investigate the effects of thymol against genotoxicity and anti-proliferation induced by blm in normal human lymphocytes and ovarian cancer cells.peripheral blood samples were collected from human volunteers and were incubated with thymolat different concentrations ...

The chemotherapeutic agent bleomycin (BLM) is activated by reducing agents to break isolated DNA. Paradoxically, these same reducing agents protect cellular DNA from BLM damage. To resolve this paradox, we have examined the reaction of FeIIIBLM with DNA in the presence of ascorbate. As expected, ascorbate augments FeIIIBLM-induced DNA damage. However, when ascorbate is added to FeIIIBLM prior t...

Diverse functions, including DNA replication, recombination and repair, occur during S phase of the eukaryotic cell cycle. It has been proposed that p53 and BLM help regulate these functions. We show that p53 and BLM accumulated after hydroxyurea (HU) treatment, and physically associated and co-localized with each other and with RAD51 at sites of stalled DNA replication forks. HU-induced reloca...

The dicarboxylate, alpha-ketoglutarate (alphaKG), has been identified as the most likely physiological anion involved in renal proximal tubule basolateral membrane (BLM) dicarboxylate/organic anion exchange. In the present study, we characterized the uptake of alphaKG in BLM and brush-border membrane (BBM) vesicles isolated from rat kidney. In both membrane preparations, alphaKG uptake was Na+-...

RPA is a single-stranded DNA binding protein that physically associates with the BLM complex. RPA stimulates BLM helicase activity as well as the double Holliday junction dissolution activity of the BLM-topoisomerase IIIα complex. We investigated the effect of RPA on the ssDNA decatenase activity of topoisomerase IIIα. We found that RPA and other ssDNA binding proteins inhibit decatenation by t...

Telomerase-negative immortalized human cells maintain telomeres by alternative lengthening of telomeres (ALT) pathway(s), which may involve homologous recombination. We find that endogenous BLM protein co-localizes with telomeric foci in ALT human cells but not telomerase positive immortal cell lines or primary cells. BLM interacts in vivo with the telomeric protein TRF2 in ALT cells, as detect...