title: Effects of the antisense v-myb' expression on K562 human leukemia cell proliferation and differentiation.
abstract: Recombinant plasmids containing v-myb' (803 bp fragment of the 3' end of v-myb) were constructed to induce sense or antisense v-myb' RNA expression with dexamethasone in human cells. These plasmids were used as a tool for the investigation of the role of c-myb gene in human leukemia cell proliferation and differentiation. They were transfected by electroporation into the K562 human leukemia cell line derived from a patient with chronic myelogenous leukemia in blastic crisis. After induction of transcription by dexamethasone, the plasmid with antisense v-myb' repressed the expression of p75c-myb from the endogenous c-myb gene of K562 cells. It also reduced the proliferation rate of K562 cells to 50% of the control level, and induced these K562 cells to express the myelomonocytic differentiation cell surface marker CD13 and increased NBT reducing activity. The plasmid with sense v-myb' did not have an effect on p75c-myb expression, the proliferation of K562 cells or the expression of myelomonocytic differentiation phenotypes. These observations suggest that antisense v-myb' RNA represses p75c-myb expression and that a decrease of p75c-myb suppresses K562 cell proliferation and induces its differentiation towards the myelomonocytic lineage.
authors.affiliation: First Department of Internal Medicine, Kagawa Medical School, Japan.
authors.forename: H
authors.initials: H
authors.lastname: Kamano
authors.forename: H
authors.initials: H
authors.lastname: Ohnishi
authors.forename: T
authors.initials: T
authors.lastname: Tanaka
authors.forename: K
authors.initials: K
authors.lastname: Ikeda
authors.forename: A
authors.initials: A
authors.lastname: Okabe
authors.forename: S
authors.initials: S
authors.lastname: Irino
mesh_terms: D015214:Antigens, Differentiation, Myelomonocytic / Q000378:metabolism; D001752:Blast Crisis / Q000235:genetics / Q000378:metabolism / Q000473:pathology; D018826:CD13 Antigens; D002454:Cell Differentiation; D002455:Cell Division; D015870:Gene Expression; D006801:Humans; D015464:Leukemia, Myelogenous, Chronic, BCR-ABL Positive / Q000235:genetics* / Q000378:metabolism / Q000473:pathology; D009857:Oncogenes; D010957:Plasmids; D011518:Proto-Oncogene Proteins / Q000235:genetics / Q000502:physiology; D020598:Proto-Oncogene Proteins c-myb; D011519:Proto-Oncogenes; D016372:RNA, Antisense / Q000378:metabolism*; D011995:Recombination, Genetic; D014407:Tumor Cells, Cultured / Q000378:metabolism / Q000473:pathology
chemical_list: D015214:Antigens, Differentiation, Myelomonocytic; D011518:Proto-Oncogene Proteins; D020598:Proto-Oncogene Proteins c-myb; D016372:RNA, Antisense; D018826:CD13 Antigens