Synthesis of adult-type hemoglobin in human erythremia cell line

Abstract

KMOE -2/05 cells, derived from a patient with acute erythremia, became benzidine-positive after the addition of cytosine arabinoside (CA). Radioimmunoassays using antihuman hemoglobin antibodies revealed an elevated amount of hemoglobin in the CA-exposed cells over that in the control cells (without CA). Isoelectric focusing of the CA-exposed cell lysate formed benzidine-positive foci in the positions of human adult Hb (HbA) and human fetal Hb (HbF). To determine the types of globin synthesized in the CA-exposed cells, globin chains internally labeled with [3H] leucine were purified by carboxy-methyl (CM)-Sephadex column chromatography, immunoadsorption by Sepharose-coupled antihuman Hb antibodies and Sephadex G-100. The labeled globin chains were finally separated by CM-cellulose chromatography in urea. Two distinct peaks of radioactivity were shown in exactly the same fractions as carrier human globin alpha- and beta-chains. These observations indicate that these KMOE -2/05 cells synthesize HbA.

Expression of the human .gamma.-globin gene after retroviral transfer to transformed erythroid cells

“…The 7* RNA levels in KMOE cells were comparable to the levels observed in MEL cells {Table II). Low endogenous globin RNA levels [less than 0.01% of the total poly(A)+ RNA) are consistent with the original observation that only a few percent of KMOE cells became benzidine positive after induction (Kaku et al, 1984).…”

“…We also studied the expression of normal or HPFH 7-globin genes in K562 (Lozzio & Lozzio, 1975) and KMOE (Kaku et al, 1984) cells, in which endogenous 7-or both 7-and /3-globin genes, respectively, are active. Although expression of a hybrid 7//3-globin gene was reported after transfer to K562 cells (Lin et al, 1987;Donovan-Peluso et al, 1987), expression from a transferred 7-globin gene with its natural 5' and 3' flanking sequences has not been reported.…”

Developmental Programs of Human Erythroleukemia Cells: Globin Gene Expression and Methylation

“…OCI-M2 was established from a 57-year-old patient with preleukemia (refractory anemia with excess of blasts) following the evolution of this condition to acute erythroleukemia (M6). KMOE cells (16,25) were established from a 2-year-old a The average number of copies per cell of individual P-, -y-, and &-globin mRNAs of each erythroleukemic cell line was estimated by comparison with a bone marrow sample from a patient with (-thalassemia by Si nuclease mapping, followed by comparative densitometry of the protected fragments (6,19). The estimated numbers in this sample were approximately 3,500 copies of -y-globin mRNA and 750 copies of &-globin mRNA (6).…”