Analysis of the inhibition of commitment of murine erythroleukemia (MEL) cells to terminal maturation by N6-methyladenosine.
Treatment of cultured murine erythroleukemia (MEL or Friend) cells with N6-methylated derivatives of adenosine inhibited erythroid cell differentiation induced by various agents. N6-Methyladenosine (N6mAdo) inhibited initiation of commitment to terminal maturation and prevented accumulation of hemoglobin in a concentration-dependent manner. Treatment with N6mAdo slowed cell growth without causing substantial inhibition in the rate of DNA synthesis and a marked decrease in viability and clonogenic potential of MEL cells. Furthermore, N6mAdo decreased the cytoplasmic accumulation of beta(major) globin mRNA and affected its structural integrity in MEL cells. Cells pre-exposed to N6mAdo failed to initiate commitment as early as control cells upon challenge with the inducer dimethyl sulfoxide. N6mAdo-induced inhibition of commitment was not reversed but rather was potentiated by the presence of adenine, L-homocysteine and/or L-methionine, agents involved in the active methylation cycle. To this respect, N6mAdo-induced inhibition of commitment was found to be different from that caused by cordycepin (3'-deoxyadenosine, an inhibitor of RNA methylation and mRNA polyadenylation). The latter inhibition was fully reversed by the addition of L-methionine. These findings indicate that N6-methyladenosine: (a) blocks a central process that is required for initiation of commitment; and (b) decreases accumulation of beta (major) globin mRNA, causes mRNA degradation and prevents hemoglobin synthesis. Due to the differential sensitivity of N6mAdo- and cordycepin-induced blockade of commitment to L-methionine, these agents inhibit commitment by acting via two different mechanisms impinging on the final pathway of MEL erythroid cell maturation.
Vizirianakis
I S
IS
Department of Pharmaceutical Sciences, School of Health Sciences, Aristotle University of Thessaloniki, Greece.
Wong
W
W
Tsiftsoglou
A S
AS
D000225:Adenine / Q000494:pharmacology; D000241:Adenosine / Q000031:analogs & derivatives* / Q000494:pharmacology; D000818:Animals; D002454:Cell Differentiation / Q000187:drug effects; D002455:Cell Division / Q000187:drug effects; D002470:Cell Survival / Q000187:drug effects; D003839:Deoxyadenosines / Q000494:pharmacology; D004121:Dimethyl Sulfoxide / Q000494:pharmacology; D006454:Hemoglobins / Q000378:metabolism; D006710:Homocysteine / Q000494:pharmacology; D004915:Leukemia, Erythroblastic, Acute; D008715:Methionine / Q000494:pharmacology; D051379:Mice; D012333:RNA, Messenger / Q000032:analysis; D013329:Structure-Activity Relationship; D014407:Tumor Cells, Cultured / Q000187:drug effects*
D003839:Deoxyadenosines; D006454:Hemoglobins; D012333:RNA, Messenger; D006710:Homocysteine; D008715:Methionine; C010223:N-methyladenosine; C058120:cordycepin; D000225:Adenine; D000241:Adenosine; D004121:Dimethyl Sulfoxide