scholarly journals Retinoic acid and cyclic AMP synergistically induce the expression of liver/bone/kidney-type alkaline phosphatase gene in L929 fibroblastic cells

1993 ◽  
Vol 296 (1) ◽  
pp. 67-77 ◽  
Author(s):  
M Giannì ◽  
M Terao ◽  
S Sozzani ◽  
E Garattini

In L929 mouse fibroblastic cells, liver/bone/kidney type alkaline phosphatase (L/B/K-ALP) enzymic activity is induced by all-trans-retinoic acid at concentrations between 10(-6) and 10(-5) M. At lower concentrations, retinoic acid is incapable of inducing this enzymic activity per se, but increases cyclic AMP (cAMP)-mediated induction. This effect is observed after incubation of the retinoid with dibutyryl cAMP, 8-bromo cAMP or forskolin. The synergism is dependent on the order of addition of retinoic acid and the activator of the cAMP pathway. Contemporaneous addition of the two agents, or addition of cAMP prior to retinoic acid (but not addition of retinoic acid before cAMP), is necessary to produce this synergistic interaction. The synergism results in increased steady-state levels of L/B/K-ALP mRNA and it is the consequence of increased transcriptional activity of the gene. The expression of the mouse L/B/K-ALP gene is regulated by the presence of two leader exons, 1A and 1B, resulting in the synthesis of two alternatively spliced mRNAs that are different only in part of their 5′ untranslated region [Studer, Terao, Giannì and Garattini (1991) Biochem. Biophys. Res. Commun. 179, 1352-1360]. PCR amplification and nuclear run-on experiments performed using probes specific for each leader exon demonstrate that treatment of these cells with retinoic acid, forskolin or dibutyryl cAMP, and with the combination of the retinoid and one of the cAMP-elevating agents, leads to the accumulation of nascent and mature L/B/K-ALP mRNA containing exon 1B. The synergistic induction of the transcription of the L/B/K-ALP gene is well correlated with quantitative and qualitative changes of retinoic-acid-receptor mRNAs mediated by cAMP.

1990 ◽  
Vol 10 (1) ◽  
pp. 391-396
Author(s):  
L Hu ◽  
L J Gudas

Retinoic acid (RA) receptor alpha (RAR alpha) and RAR gamma steady-state mRNA levels remained relatively constant over time after the addition of RA to F9 teratocarcinoma stem cells. In contrast, the steady-state RAR beta mRNA level started to increase within 12 h after the addition of RA and reached a 20-fold-higher level by 48 h. This RA-associated RAR beta mRNA increase was not prevented by protein synthesis inhibitors but was prevented by the addition of cyclic AMP analogs. In the presence of RA, cyclic AMP analogs also greatly reduced the RAR alpha and RAR gamma mRNA levels, even though cyclic AMP analogs alone did not alter these mRNA levels. The addition of either RA or RA plus cyclic AMP analogs did not result in changes in the three RAR mRNA half-lives. These results suggest that agents which elevate the internal cyclic AMP concentration may also affect the cellular response to RA by altering the expression of the RARs.


Blood ◽  
2006 ◽  
Vol 107 (8) ◽  
pp. 3330-3338 ◽  
Author(s):  
Beatrice U. Mueller ◽  
Thomas Pabst ◽  
José Fos ◽  
Vibor Petkovic ◽  
Martin F. Fey ◽  
...  

Abstract Tightly regulated expression of the transcription factor PU.1 is crucial for normal hematopoiesis. PU.1 knockdown mice develop acute myeloid leukemia (AML), and PU.1 mutations have been observed in some populations of patients with AML. Here we found that conditional expression of promyelocytic leukemia-retinoic acid receptor α (PML-RARA), the protein encoded by the t(15;17) translocation found in acute promyelocytic leukemia (APL), suppressed PU.1 expression, while treatment of APL cell lines and primary cells with all-trans retinoic acid (ATRA) restored PU.1 expression and induced neutrophil differentiation. ATRA-induced activation was mediated by a region in the PU.1 promoter to which CEBPB and OCT-1 binding were induced. Finally, conditional expression of PU.1 in human APL cells was sufficient to trigger neutrophil differentiation, whereas reduction of PU.1 by small interfering RNA (siRNA) blocked ATRA-induced neutrophil differentiation. This is the first report to show that PU.1 is suppressed in acute promyelocytic leukemia, and that ATRA restores PU.1 expression in cells harboring t(15;17).


2001 ◽  
Vol 280 (3) ◽  
pp. G510-G517 ◽  
Author(s):  
Takeshi Nikawa ◽  
Madoka Ikemoto ◽  
Kaori Tokuoka ◽  
Shigetada Teshima ◽  
David H. Alpers ◽  
...  

We previously showed that vitamin A upregulated the expression of bone-type alkaline phosphatase (ALP) in fetal rat small intestine and rat intestinal IEC-6 cells. In this study, we examined interactions between retinoic acid (RA) and several growth factors/cytokines on the isozyme expression in IEC-6 cells. Epidermal growth factor and interleukins (ILs)-2, -4, -5, and -6 completely blocked the RA-mediated increase in ALP activity. In contrast, IL-1β markedly increased the activity, protein, and mRNA of the bone-type ALP only when RA was present. IL-1β and/or RA did not change the type 1 IL-1 receptor transcript level, whereas IL-1β enhanced the RA-induced expressions of retinoic acid receptor-β (RAR-β) and retinoid X receptor-β (RXR-β) mRNAs and RA-mediated RXR response element binding. The synergism of IL-1β and RA on ALP activity was completely blocked by protein kinase C (PKC) inhibitors. Our results suggest that IL-1β may modify the ALP isozyme expression in small intestinal epithelial cells by stimulating PKC-dependent, RAR-β- and/or RXR-β-mediated signaling pathways.


1991 ◽  
Vol 274 (3) ◽  
pp. 673-678 ◽  
Author(s):  
M Gianni ◽  
M Studer ◽  
G Carpani ◽  
M Terao ◽  
E Garattini

All-trans retinoic acid (RA) induces alkaline phosphatase (ALP) activity by 3-8-fold in murine F9 teratocarcinoma cells, in parallel with their differentiation towards primitive endoderm. The elevation of ALP activity is associated with increases in the amounts of liver/bone/kidney-type ALP protein and the respective transcript. These effects of RA are due to activation of ALP gene transcription rather than to an increase in the half-life of the mRNA. Induction of ALP mRNA does not require de novo protein synthesis, since it is not blocked by treatment with cycloheximide. Dibutyryl cyclic AMP, which is known to induce further differentiation of F9 cells from the primitive to the parietal endoderm, blocks the induction of ALP mRNA by RA.


Cancers ◽  
2020 ◽  
Vol 12 (5) ◽  
pp. 1313 ◽  
Author(s):  
Marta Sobas ◽  
Maria Carme Talarn-Forcadell ◽  
David Martínez-Cuadrón ◽  
Lourdes Escoda ◽  
María J. García-Pérez ◽  
...  

It has been suggested that 1–2% of acute promyelocytic leukemia (APL) patients present variant rearrangements of retinoic acid receptor alpha (RARα) fusion gene, with the promyelocytic leukaemia zinc finger (PLZF)/RARα being the most frequent. Resistance to all-trans-retinoic acid (ATRA) and arsenic trioxide (ATO) has been suggested in PLZF/RARα and other variant APLs. Herein, we analyze the incidence, characteristics, and outcomes of variant APLs reported to the multinational PETHEMA (Programa para el Tratamiento de Hemopatias Malignas) registry, and we perform a systematic review in order to shed light on strategies to improve management of these extremely rare diseases. Of 2895 patients with genetically confirmed APL in the PETHEMA registry, 11 had variant APL (0.4%) (9 PLZF-RARα and 2 NPM1-RARα), 9 were men, with median age of 44.6 years (3 months to 76 years), median leucocytes (WBC) 16.8 × 109/L, and frequent coagulopathy. Eight patients were treated with ATRA plus chemotherapy-based regimens, and 3 with chemotherapy-based. As compared to previous reports, complete remission and survival was slightly better in our cohort, with 73% complete remission (CR) and 73% survival despite a high relapse rate (43%). After analyzing our series and performing a comprehensive and critical review of the literature, strong recommendations on appropriate management of variant APL are not possible due to the low number and heterogeneity of patients reported so far.


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