Expression of cellular homologues of retroviral onc genes in human hematopoietic cells.

Abstract

Total cellular poly(A)-enriched RNA from.a variety of fresh human leukemic blood cells and hematopoietic cell lines was analyzed for homology with molecularly cloned DNA probes containing the one sequence of Abelson. murine leukemia virus (Ab-MuLV), Harvey murine sarcoma virus (Ha-MuSV), simian sarcoma virus (SSV), and avian myelocytomatosis virus strain MC29. Results with the fresh blood cells paralleled those obtained with the cell lines. With Ab-MuLV and Ha,-MuSV, multiple RNA bands were visualized in all cell types examined without significant variation in the relative intensities of the bands. When SSV was used as the probe, expression of related one sequences was absent in all of the hematopoietic cell types examined except for one neoplastic T-cell line (HUT 102), which produces the human T-cell leukemia (lymphoma) retrovirus HTLV. In this cell line, a single band (4.2 kilobases) was -observed. With MC29 as the probe, a single band of 2.7 kilobases was visualized in all cell types examined with only a 1-to 2-fold-variation in intensity-of hybridization. An exception was the promyelocytic cell line, HL60, which expressed approximately 10-fold more MC29-related one sequences. With induction of differentiation of HL60 with either dimethyl sulfoxide or retinoic acid, a marked diminution in the amount of the MC29-related, but not the Ab-MuLV-related, onc message was observed.

Elevated expression of the human ras oncogene family in premalignant and malignant tumours of the colorectum

“…As shown in Figure 2g,i, Ki-ras and Haras related transcripts of 5.8kb in size were again found to be elevated in premalignant and malignant tissues as compared to normal colorectal mucosa. We also detected the 5.8kb sized transcripts using pT24-C3 (Goldfarb et al, 1982) and two 6.0kb Ha-ras related transcripts in human haematopoietic cell lines (Westin et al, 1982b). More recently, using an N-ras probe 3 different sized transcripts of 5.8, 2.2 and 1.5kb have been found in normal human fibroblasts and established human cell lines and it has been claimed that the 2.2kb transcript is related to the N-ras oncogene (Hall et al, 1983).…”

Structure and expression of the oncogene c-myc in fresh tumor material from patients with hematopoietic malignancies.

“…When washing blots containing RNA, the stringency applied was sufficient to eliminate hybridization to any contaminating DNA (data not shown), which can be a severe problem in this type of experiment as noted previously (32). With these methods, the promyelocytic cell line HL60, which has been shown to have an elevated myc RNA level (39), exhibited a level of myc expression 40-to 60-fold greater than that of normal MNL. The signal obtained from normal MNL RNA was usually undetectable, except after lengthy exposure of dot blots with low background; therefore, HL60 RNA was included in all blots to be used as a standard for estimating the level of expression of other samples.…”

“…An amplification of c-myc DNA has been found in HL60, a human promyelocytic leukemia cell line, and in primary leukemic cells from the same patient (10,13). In HL60, the level of myc RNA was shown to be elevated compared to other cell lines, presumably as a consequence of this gene amplification (39), but there is disagreement as to whether an elevated level of myc RNA accompanies the myc rearrangements seen in Burkitt's lymphoma and murine plasmacytoma (5,15,17,22,31,34,39).…”

Oncogenes and human leukemias

“…Several surveys of mRNA expression in human leukemias have been reported [62,[72][73][74][75][76][77][78][79][80][81]. These studies involve leukemia cell lines as well as fresh leukemia cells.…”