The Bloom syndrome helicase BLM and topoisomerase-IIβ-binding protein 1 (TopBP1) are key regulators of genome stability. It was recently proposed that BLM phosphorylation on Ser338 mediates its interaction with TopBP1, to protect BLM from ubiquitylation and degradation (Wang et al., 2013). Here, we show that the BLM-TopBP1 interaction does not involve Ser338 but instead requires BLM phosphoryla...

The 1:1 Cu(II) complexes of bleomycin (BLM) A2, BLM B2, epi-BLM B2, iso-BLM B2, depyruvamide-BLM A2, deglyco-BLM B2 and the structurally related peptides (P-5m, P-3A and P-3) have been comprehensively investigated by ESR and electrochemical methods. ESR spectra for Cu(II) complexes of BLM A2, epi-BLM B2, depyruvamide-BLM A2 and P-3 revealed the axially symmetric g-anisotropies. In contrast, ESR...

A sensitive new method to assay bleomycin (BLM) metabolism was developed using an ion-paired, reverse-phase high-pressure liquid chromatography technique in conjunction with fluorescence detection that allowed levels of BLM less than 20 ng/ml to be detected. The metabolism of bleomycin B2 in homogenates from benign and malignant human tumors was studied, and all 14 tumors were capable of metabo...

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 thymol at different concentratio...

Metabolic inactivation of bleomycin (BLM) by cysteine proteinase-like enzymes is thought to be a major mechanism of BLM tumor resistance. We now report that the human colon carcinoma COLO-205 is highly resistant to BLM and that E-64, a cysteine proteinase inhibitor, sensitizes COLO-205 to BLM. Treatment of COLO-205-bearing nude mice with either E-64 (40 mg/kg) or BLM (10 mg/kg) alone did not in...

Introduction: Due to interesting therapeutic properties of 46Sc and antineoblastic antibiotic, bleomycin (BLM), 46Sc-bleomycin (46Sc-BLM) was developed as a possible therapeutic compound. Methods: In this work, Sc-46 chloride was obtained by thermal neutron flux (4 × 1013 n.cm-2.s-1) of natural metallic scandium sample followed ...

A Bloom's deficient mouse model (Blm(m3/m3)) has been shown to induce colorectal tumorigenesis when crossed with Apc+/Min mice. Here, we investigated whether the Blm(m3/m3) genotype could induce tumorigenesis in extracolonic tissues in tuberous sclerosis 1-deficient (Tsc1+/-) mice that are predisposed to renal cystadenomas and carcinomas. Genotyping of offspring from Tsc1+/- Blm+/m3 intercrosse...

BLM helicase, the protein mutated in Bloom syndrome, is involved in signal transduction cascades after DNA damage. BLM is phosphorylated on multiple residues by different kinases either after stress induction or during mitosis. Here, we have provided evidence that both Chk1 and Chk2 phosphorylated the NH(2)-terminal 660 amino acids of BLM. An internal region within the DExH motif of BLM negativ...

Three bleomycin (BLM)-resistant sublines were isolated from a human head and neck squamous cell carcinoma cell line (A-253); these sublines (C-10, D-10, and G-11) were 4-, 9-, and 21-fold resistant to BLM A2, respectively. These sublines were selectively resistant to other members of the BLM class, namely BLM B2, peplomycin, talisomycin S10b, and bleomycinic acid; none of the sublines displayed...