scholarly journals Expression of leukocyte alkaline phosphatase gene in normal and leukemic cells: regulation of the transcript by granulocyte colony- stimulating factor

Blood ◽  
1990 ◽  
Vol 76 (12) ◽  
pp. 2565-2571 ◽  
Author(s):  
A Rambaldi ◽  
M Terao ◽  
S Bettoni ◽  
ML Tini ◽  
R Bassan ◽  
...  

The levels of leukocyte alkaline phosphatase (LAP) messenger RNA (mRNA) are evaluated in B and T lymphocytes, monocytes, and polymorphonuclear cells (PMNs), and this transcript is found to be present only in PMNs. Precursors of the myelomonocytic pathway, represented by leukemic cells isolated from several cases of chronic myelogenous leukemia (CML) in its stable and blastic phase and acute myelogenous leukemia (AML), are devoid of LAP transcript. These data support the notion that LAP is a marker of the granulocyte terminal differentiation. Despite the absence of LAP mRNA in both the myeloid and the lymphoid precursors, nuclear run-on experiments show constitutive transcription of the LAP gene in leukemic cells obtained from AML, CML, as well as acute lymphoblastic leukemia (ALL) and B-cell chronic lymphocytic leukemia (B-CLL). In CML and in chronic myelo-monocytic leukemia (CMML) PMNs, granulocyte colony- stimulating factor (G-CSF) specifically accumulates LAP mRNA without showing a substantial increase in the rate of transcription of the LAP gene. Once increased by G-CSF, LAP mRNA is very stable, showing a half- life of more than 4 hours in the presence of actinomycin-D. G-CSF is suggested to play a pivotal role in the modulation of LAP transcript in PMNs.

Blood ◽  
1990 ◽  
Vol 76 (12) ◽  
pp. 2565-2571 ◽  
Author(s):  
A Rambaldi ◽  
M Terao ◽  
S Bettoni ◽  
ML Tini ◽  
R Bassan ◽  
...  

Abstract The levels of leukocyte alkaline phosphatase (LAP) messenger RNA (mRNA) are evaluated in B and T lymphocytes, monocytes, and polymorphonuclear cells (PMNs), and this transcript is found to be present only in PMNs. Precursors of the myelomonocytic pathway, represented by leukemic cells isolated from several cases of chronic myelogenous leukemia (CML) in its stable and blastic phase and acute myelogenous leukemia (AML), are devoid of LAP transcript. These data support the notion that LAP is a marker of the granulocyte terminal differentiation. Despite the absence of LAP mRNA in both the myeloid and the lymphoid precursors, nuclear run-on experiments show constitutive transcription of the LAP gene in leukemic cells obtained from AML, CML, as well as acute lymphoblastic leukemia (ALL) and B-cell chronic lymphocytic leukemia (B-CLL). In CML and in chronic myelo-monocytic leukemia (CMML) PMNs, granulocyte colony- stimulating factor (G-CSF) specifically accumulates LAP mRNA without showing a substantial increase in the rate of transcription of the LAP gene. Once increased by G-CSF, LAP mRNA is very stable, showing a half- life of more than 4 hours in the presence of actinomycin-D. G-CSF is suggested to play a pivotal role in the modulation of LAP transcript in PMNs.


Blood ◽  
1994 ◽  
Vol 83 (7) ◽  
pp. 1909-1921 ◽  
Author(s):  
M Gianni ◽  
M Terao ◽  
S Zanotta ◽  
T Barbui ◽  
A Rambaldi ◽  
...  

Abstract In this report we show a strong synergistic interaction between granulocyte colony-stimulating factor (G-CSF) and all-trans retinoic acid (ATRA) on the expression of leukocyte alkaline phosphatase (LAP) in freshly isolated acute promyelocytic leukemia (APL) blasts as well as in NB40 and HL-60 cell lines. The strong synergism observed in these cell types was not evident in two acute leukemia cell lines (K562 and GF-D8), in normal granulocytes, and in monocytes. In freshly isolated leukocytes derived from chronic myelogenous leukemia (CML), in the stable phase of the disease, a weaker interaction between ATRA and G- CSF was documented. The cross-talk between the cytokine and the retinoid was studied in detail in NB4, an immortalized APL leukemia cell line, retaining the 15′17 chromosomal translocation involving the retinoic acid receptor type alpha. The treatment of NB4 cells with G- CSF alone or ATRA alone leads to no increase and to minor induction in LAP activity, respectively. If the cells are treated with the two compounds simultaneously, a dramatic elevation of LAP is observed after 4 days. The synergism between G-CSF and ATRA is evident at concentrations of the retinoid between 10(-7) and 10(-5) mol/L and at concentrations of the cytokine between 1 and 10 ng/mL. The simultaneous presence of the two compounds is necessary to obtain maximal increase of LAP activity and the effect is cell density-dependent. Synergism is specific for G-CSF, and it is not observed with other cytokines and functional inducers of the granulocyte. The augmentation of LAP activity is the consequence of an increased transcriptional rate of the liver/bone/kidney-type (L/B/K-type) alkaline phosphatase gene, as determined by Northern blotting and nuclear run-on analysis using specific cDNA probes. Only one of the two possible alternatively spliced forms of L/B/K-type alkaline phosphatase transcript is detected in NB4 cells after stimulation with G-CSF and ATRA. This mRNA form, which is the one observed in normal polymorphonuclear leukocytes, contains the most upstream leader exon. In NB4 cells, ATRA induces G- CSF, alpha, and beta retinoic acid receptor transcripts, whereas G-CSF has minor effects on the expression of these mRNAs.


Blood ◽  
1974 ◽  
Vol 43 (5) ◽  
pp. 749-756 ◽  
Author(s):  
David W. Golde ◽  
Belina Rothman ◽  
Martin J. Cline

Abstract There is considerable evidence supporting a role for colony-stimulating factor (CSF) as a humoral regulator of leukopoiesis. Data on CSF levels in the serum and urine of patients with leukemia and on the in vitro responsiveness of leukemic cells to CSF have suggested a basis for considering leukemia as a primary disorder of leukopoietic regulation. We examined the question of leukemic cell production of CSF. Conditioned medium from cultured leukemic cells was tested for colony-stimulating activity against normal human bone marrow using a two-layer agar colony assay technique. The cells from patients with acute myelogenous leukemia and a patient with chronic myelogenous leukemia in blast crisis did not elaborate CSF nor did acute lymphocytic leukemia cells. CSF production was documented with cells obtained from patients with chronic myelogenous leukemia in the chronic phase and two patients with acute myelomonocytic leukemia. In acute leukemia the cellular production of CSF correlated closely with morphologic and functional maturation along the monocyte-macrophage line. Evidence was obtained that the adherent cells within the leukemic population were primarily responsible for CSF production. We interpret these data to indicate that neoplastic hematopoietic cells may produce CSF in relation to their capacity for mononuclear leukocyte differentiation.


Blood ◽  
1994 ◽  
Vol 83 (7) ◽  
pp. 1909-1921 ◽  
Author(s):  
M Gianni ◽  
M Terao ◽  
S Zanotta ◽  
T Barbui ◽  
A Rambaldi ◽  
...  

In this report we show a strong synergistic interaction between granulocyte colony-stimulating factor (G-CSF) and all-trans retinoic acid (ATRA) on the expression of leukocyte alkaline phosphatase (LAP) in freshly isolated acute promyelocytic leukemia (APL) blasts as well as in NB40 and HL-60 cell lines. The strong synergism observed in these cell types was not evident in two acute leukemia cell lines (K562 and GF-D8), in normal granulocytes, and in monocytes. In freshly isolated leukocytes derived from chronic myelogenous leukemia (CML), in the stable phase of the disease, a weaker interaction between ATRA and G- CSF was documented. The cross-talk between the cytokine and the retinoid was studied in detail in NB4, an immortalized APL leukemia cell line, retaining the 15′17 chromosomal translocation involving the retinoic acid receptor type alpha. The treatment of NB4 cells with G- CSF alone or ATRA alone leads to no increase and to minor induction in LAP activity, respectively. If the cells are treated with the two compounds simultaneously, a dramatic elevation of LAP is observed after 4 days. The synergism between G-CSF and ATRA is evident at concentrations of the retinoid between 10(-7) and 10(-5) mol/L and at concentrations of the cytokine between 1 and 10 ng/mL. The simultaneous presence of the two compounds is necessary to obtain maximal increase of LAP activity and the effect is cell density-dependent. Synergism is specific for G-CSF, and it is not observed with other cytokines and functional inducers of the granulocyte. The augmentation of LAP activity is the consequence of an increased transcriptional rate of the liver/bone/kidney-type (L/B/K-type) alkaline phosphatase gene, as determined by Northern blotting and nuclear run-on analysis using specific cDNA probes. Only one of the two possible alternatively spliced forms of L/B/K-type alkaline phosphatase transcript is detected in NB4 cells after stimulation with G-CSF and ATRA. This mRNA form, which is the one observed in normal polymorphonuclear leukocytes, contains the most upstream leader exon. In NB4 cells, ATRA induces G- CSF, alpha, and beta retinoic acid receptor transcripts, whereas G-CSF has minor effects on the expression of these mRNAs.


Sign in / Sign up

Export Citation Format

Share Document