Methods CSCs were isolated using the sphere-forming assay in serum-free medium under non-adherent conditions and characterized for the expression of mesenchymal stem cell markers (CD90, CD105, CD73) by flow cytometry. The chemosensitity of MNNG and CSCs to doxorubicin (DOX), cisplatin (CIS) and methotrexate (MTX) was evaluated using the MTT colorimetric assay after an incubation period of 48h. ...

A line of chick embryo cells (CEC) was obtained from CEC treated with N-methyl-N'-nitro-N-nitrosoguanidine (MNNG). The cells, designated CHCC-OU2, were contact-inhibited, formed no colony in soft agar and did not produce tumors when inoculated into syngeneic chickens. The electron microscopic examination and reverse transcriptase assay showed no virus production from the cells. Subgroup A avian...

Male inbred F344 weanbing rats were fed semipunified diets containing 20 or 5% beef fat. At 7 weeks of age, all animals except controls were given 1,2-dimethylhydrazine [DMH (150 mg/kg body weight s.c.; one dose)], methyl azoxymethanol acetate [MAM acetate (35 mg/kg body weight i.p.; one dose)], or methylnitrosourea (2.5 mg/rat/ week intrarectally; two doses), and autopsied 35 weeks later. No m...

Methods The isolation of CSCs was performed using the sphere formation assay in serum-free medium in non-adherent conditions. The cells were characterized for the expression of mesenchymal stem cell markers (CD90/ CD105/CD73) by flow cytometry. MNNG/HOS and CSCs were irradiated with X-rays at different doses (020Gy). The sensitivity to ionizing radiation was evaluated using the MTT assay after ...

Cytotoxicity of methylating agents is caused mostly by methylation of the O6 position of guanine in DNA to form O6-methylguanine (O6-meG). O6-meG can direct misincorporation of thymine during replication, generating O6-meG:T mismatches. Recognition of these mispairs by the mismatch repair (MMR) system leads to cell cycle arrest and apoptosis. MMR also modulates sensitivity to other antitumor dr...

MiR-34a-5p has been implicated in the tumorigenesis and progression of several types of cancer. However, the role of miR-34a-5p in osteosarcoma (OS) remains largely unknown. This study was performed in two multi-chemosensitive (G-292 and MG63.2) and two resistant (SJSA-1 and MNNG/HOS) OS cell lines. MiR-34a-5p promotes OS multi-chemoresistance via its repression of the Delta-like ligand 1 (DLL1...

An adaptive response to alkylating agents based upon the conformational change of a methylphosphotriester (MPT) DNA repair protein to a transcriptional activator has been demonstrated in a number of bacterial species, but this mechanism appears largely absent from eukaryotes. Here, we demonstrate that the human pathogen Aspergillus fumigatus elicits an adaptive response to sub-lethal doses of t...

There is evidence that reactive oxygen species (ROS) are important mediators of tumor promotion and progression. The molecular mechanisms involved in ROS-mediated signaling, however, are unclear at present. Using ionizing radiation and N-methyl-N'-nitro-N-nitrosoguanidine (MNNG) as model physical and chemical carcinogens, we have malignantly progressed 308 cells, a papilloma-producing mouse ker...