Activation of expression of p15, p73 and E-cadherin in leukemic cells by different concentrations of 5-aza-2'-deoxycytidine (Decitabine).
BACKGROUND
Inactivation of genes that suppress neoplasia by aberrant DNA methylation is a key event that occurs during the development of leukemia. The inhibitor of DNA methylation, 5-aza-2'-deoxycytidine (5AZA), which can re-activate these genes, is under clinical investigation for therapy of leukemia. The objective of this study was to determine the concentrations of 5AZA that will re-activate target silent genes in human leukemic cell lines.


METHODS
RT-PCR was used to evaluate the effect of concentrations of 1 to 100 ng/ml of 5AZA on the re-activation of p15 and p73 in KG1a myeloid leukemic cells and E-cadherin in HL-60 myeloid leukemic cells. The effect of 5AZA on inhibition of growth, DNA synthesis and colony formation in these cell lines was also investigated.


RESULTS
The extent of activation of the target genes was dependent on the concentration of 5AZA. For p15, pronounced activation was observed at 10 ng/ml or greater. For p73 and E-cadherin significant activation was observed at 100 ng/ml of 5AZA. Maximal inhibition of growth, DNA synthesis and colony formation occurred at 100 ng/ml.


CONCLUSIONS
The in vitro antineoplastic and gene re-activation activity of 5AZA is dependent on the concentration of this analog. These data may be helpful in the design of the optimal dose-schedule of 5AZA for the clinical therapy of leukemia.
Farinha
Nuno J
NJ
Service d'hematologie-oncologie, Hôpital Sainte-Justine, Montréal, Québec H3T 1C5, Canada.
Shaker
Sepideh
S
Lemaire
Maryse
M
Momparler
Louise
L
Bernstein
Mark
M
Momparler
Richard L
RL
D000964:Antimetabolites, Antineoplastic / Q000494:pharmacology*; D001374:Azacitidine / Q000031:analogs & derivatives* / Q000494:pharmacology*; D015820:Cadherins / Q000096:biosynthesis* / Q000235:genetics; D018797:Cell Cycle Proteins / Q000096:biosynthesis* / Q000235:genetics; D050762:Cyclin-Dependent Kinase Inhibitor p15; D004268:DNA-Binding Proteins / Q000096:biosynthesis* / Q000235:genetics; D000077209:Decitabine; D004305:Dose-Response Relationship, Drug; D015973:Gene Expression Regulation, Leukemic / Q000187:drug effects*; D016147:Genes, Tumor Suppressor; D018922:HL-60 Cells; D006801:Humans; D007951:Leukemia, Myeloid / Q000188:drug therapy* / Q000235:genetics / Q000378:metabolism; D009687:Nuclear Proteins / Q000096:biosynthesis* / Q000235:genetics; D000072160:Tumor Protein p73; D025521:Tumor Suppressor Proteins / Q000096:biosynthesis* / Q000235:genetics
D000964:Antimetabolites, Antineoplastic; C493966:CDKN2B protein, human; D015820:Cadherins; D018797:Cell Cycle Proteins; D050762:Cyclin-Dependent Kinase Inhibitor p15; D004268:DNA-Binding Proteins; D009687:Nuclear Proteins; C000606460:TP73 protein, human; D000072160:Tumor Protein p73; D025521:Tumor Suppressor Proteins; D000077209:Decitabine; D001374:Azacitidine