scholarly journals Epigenetic reprogramming of DCCs into dormancy suppresses metastasis via restored TGFβ–SMAD4 signaling.

2021 ◽  
Author(s):  
Deepak Kumar Singh ◽  
Eduardo Farias ◽  
Saul Carcamo ◽  
Dan Hasson ◽  
Dan Sun ◽  
...  

Disseminated cancer cells (DCCs) identified in secondary organs, sometimes before the primary tumor becomes detectable and treated, can remain dormant for years to decades before manifesting. Microenvironmental and epigenetic mechanisms may control the onset and escape from dormancy, and here we reveal how a combination of the DNA methylation inhibitor 5-azacytidine (AZA) and retinoic acid receptor ligands all-trans retinoic acid (atRA), orchestrate a novel program of stable dormancy. Treatment of HNSCC tumor cells with AZA+atRA induced a SMAD2/3/4 dependent regulation of downstream transcriptional program that restored the anti-proliferative function of TGFβ signaling. Significantly, AZA+atRA or AZA+AM80, an RARα specific agonist, strongly suppresses lung metastasis formation. The metastatic suppression occurs via the induction and maintenance of phenotypically homogenous dormant SMAD4+/NR2F1+ non-proliferative DCCs. These findings suggest that strategies that maintain or induce dormancy programs may be a viable alternative strategy to improve patient outcomes by preventing or significantly delaying metastasis development.

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.


1995 ◽  
Vol 308 (1) ◽  
pp. 353-359 ◽  
Author(s):  
M Berggren Söderlund ◽  
G Johannesson ◽  
G Fex

all-trans-Retinoic acid, one of the hormonally active derivatives of vitamin A, occurs physiologically in plasma at a concentration below 10 nmol/l. The methods currently used for its quantification are based on HPLC, need about 1 ml of serum, are relatively laborious and thus not well suited for mass analysis. The affinity and specificity of retinoic acid receptors for all-trans-retinoic acid encouraged us to express both the entire human retinoic acid receptor beta (RAR-beta) and two versions of its retinoic acid-binding domain in Escherichia coli in the hope that these recombinant proteins might be used as binders in a ligand-binding assay for all-trans-retinoic acid. The recombinant receptors, the whole receptor [RAR-beta-(V7-Q448)], corresponding to domains A-F, and the ligand-binding domain [RAR-beta-(E149-Q448)], corresponding to domains D-F, were expressed in the vector pET 3d/BL21 (DE3) as inclusion bodies, solubilized with guanidinium chloride, renatured and purified by ion-exchange chromatography. RAR-beta-(P193-Q448), corresponding to domains E-F, was expressed in the vector pET 3d/BL21(DE3)pLysS, and purified by reversed-phase chromatography. Under non-denaturing conditions, the expressed whole receptor [RAR-beta-(V7-Q448)] and the D-F construct (RAR-beta-(E149-Q448)] behaved chromatographically as monomeric proteins whereas the E-F construct [RAR-beta-(P193-Q448)] had a strong tendency to aggregate. RAR-beta-(V7-Q448) and RAR-beta-(E149-Q448) had similar Kd values for all-trans-retinoic acid (1.4 and 0.6 nmol/l respectively) whereas RAR-beta-(P193-Q448) bound all-trans-retinoic acid less avidly (Kd 9.6 nmol/l). 9-cis-Retinoic acid bound to RAR-beta-(E149-Q448) and RAR-beta-(V7-Q448) as avidly as all-trans-retinoic acid. Competition experiments showed weak or no binding of 4-oxo-all-trans-retinoic acid, 4-oxo-13-cis-retinoic acid, 13-cis-retinoic acid, acitretin and retinol by RAR-beta-(E149-Q448).


2001 ◽  
Vol 19 (20) ◽  
pp. 4023-4028 ◽  
Author(s):  
Giorgina Specchia ◽  
Francesco Lo Coco ◽  
Marco Vignetti ◽  
Giuseppe Avvisati ◽  
Paola Fazi ◽  
...  

PURPOSE: Recent reports of extramedullary disease (EMD) at recurrence in acute promyelocytic leukemia (APL) have raised increasing concern about a possible role of retinoic acid (RA) therapy. PATIENTS AND METHODS: We analyzed the risk of developing EMD localization at relapse in APL patients enrolled onto two consecutive studies of the Gruppo Italiano Malattie Ematologiche dell’Adulto. The studies investigated chemotherapy alone (LAP0389) versus RA plus chemotherapy (AIDA). RESULTS: When all relapse types were taken into account, 94 (51%) of 184 patients and 131 (18%) of 740 patients who attained hematologic remission underwent relapse in the LAP0389 and AIDA studies, respectively (P < .0001). EMD localization was documented in five (5%) of 94 and 16 (12%) of 131 patients (P = .08). Hematologic and/or molecular relapse was diagnosed concomitantly in all but two patients with EMD in the AIDA study. For patients in the LAP0389 and AIDA series, the probability of EMD localization of any type at relapse was 3% and 4.5%, respectively (P = .79), while the probability of CNS involvement was 0.6% and 2% (P = .28). No significant differences were found with regard to mean WBC count and promyelocytic leukemia/retinoic acid receptor-alpha junction type in comparisons of patients with EMD and hematologic relapse. CONCLUSION: APL patients receiving all-trans retinoic acid in addition to chemotherapy have no increased risk of developing EMD at relapse as compared with those treated with chemotherapy alone.


Sign in / Sign up

Export Citation Format

Share Document