ABSTRACT
BACKGROUND: Cytosine arabinoside-based chemotherapy coupled with anthracycline is currently the first-line treatment for acute myeloid leukaemia (AML), but diverse responses to the regimen constitute obstacles to successful treatment. Therefore, outcome prediction to chemotherapy at diagnosis is believed to be a critical consideration. METHODS: The mRNA expression of 12 genes closely involved in the actions of cytosine arabinoside and anthracycline was evaluated by real-time reverse transcriptase PCR (RT-PCR), in 54 diagnostic bone marrow specimens of M2-subtype AML. RESULTS: Low expression levels of ribonucleotide reductase M2 (RRM2) and high expression levels of topoisomerase 2 beta (TOP2B) were correlated with longer survival in a univariate analysis. Another interesting finding is that high ratios of TOP2B/RRM2 and TOP2B/TOP2 alpha (TOP2A) in a combined analysis were also shown to have a prognostic impact for longer survival with improved accuracy. Among the four markers, when adjusted for the influence of other clinical factors in multivariate analysis, the TOP2B/TOP2A ratio was significantly correlated with treatment outcomes; patients with high ratios trended toward longer disease-free survival (HR, 0.24; P=0.002) and overall survival (HR, 0.29; P=0.005). CONCLUSION: Genes with distinct expression profiles such as TOP2B/TOP2A expression ratio at diagnosis can be employed for outcome prediction after the treatment with standard regimens in AML patients with M2 subtype.
Subject(s)
Antigens, Neoplasm/genetics , DNA Topoisomerases, Type II/genetics , DNA-Binding Proteins/genetics , Leukemia, Myeloid, Acute/drug therapy , Anthracyclines/administration & dosage , Antigens, Neoplasm/metabolism , Antineoplastic Combined Chemotherapy Protocols/therapeutic use , Biomarkers, Tumor/analysis , Bone Marrow/metabolism , Cell Line, Tumor , Cytarabine/administration & dosage , DNA Topoisomerases, Type II/metabolism , DNA-Binding Proteins/metabolism , Disease-Free Survival , Drug Resistance, Neoplasm , Humans , Leukemia, Myeloid, Acute/diagnosis , Leukemia, Myeloid, Acute/genetics , Leukemia, Myeloid, Acute/mortality , Male , Middle Aged , Poly-ADP-Ribose Binding Proteins , Prognosis , Ribonucleoside Diphosphate Reductase/metabolism , Treatment OutcomeABSTRACT
Monoclonal antibodies were prepared against the high mobility group (HMG) protein 2b from chick liver chromatin and a monoclonal-antibody-based enzyme-linked immunosorbent assay (ELISA) was developed for chick HMG 2b. The sensitivity of the assay is about ten times that of the previously described radioimmunoassay and solid-phase enzyme immunoassay for HMG proteins. With the use of ELISA technique, the amount of HMG 2b (micrograms protein/mg DNA) in the livers of 1-day old and 70-day old chicks was found to be 2.56 +/- 0.4, and 1.20 +/- 0.2, respectively. The age-dependent change in the level of HMG proteins probably reflects changes in the functional state of chromatin during ageing.
Subject(s)
Chickens/metabolism , Enzyme-Linked Immunosorbent Assay , High Mobility Group Proteins/analysis , Liver/chemistry , Animals , Antibodies, Monoclonal/immunology , Chickens/growth & development , Chickens/immunology , Liver/growth & development , Male , Mice , Rabbits , Sensitivity and SpecificityABSTRACT
RNA synthesis in the nuclei of liver from newly hatched chicks was enhanced 1.25 fold at 10 min after intragastric administration of water. Differential inhibition of RNA synthesis by alpha-amanitin indicated that the enhancement mainly represented rRNA synthesis; the synthesis of mRNA and tRNA was scarcely affected. Enhanced RNA synthesis was accompanied by greater susceptibility of nuclei to digestion by micrococcal nuclease, indicating that the chromatin structure was modified. It was further shown that the "water effect" was mimicked by distention of the stomach by raising the pressure in the intragastric balloon. Since the prior administration of atropine abolished the "water effect", the enhancement of hepatic RNA synthesis may be mediated by hepatic nervous system.
