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The present study aimed to better understand the possibility of utilizing all-trans retinoic acids (ATRA) in acute myeloid leukemia (AML). We found that ATRA significantly suppressed global translation and protein synthesis in AML cells. The efficacy of ATRA in treating AML required its translational regulatory functions, as shown by the fact that the decrease in the universal eukaryotic initiation factor 4E (eIF4E) was essential to maintain the induction of cell growth arrest and differentiation by ATRA. By establishing a specific translational landscape, we suggested that transcripts with simple 5′UTR gained a translational advantage in AML cells during ATRA stress. Based on that, the genes translationally regulated by ATRA were mainly enriched in phosphatidylinositol-3-kinase/Akt (PI3K/AKT) signaling; we subsequently revealed that PI3K/AKT activation was required for ATRA to effectively induce AML cell differentiation. However, PI3K/AKT has been reported to promote the stemness of AML cells. As such, we further suggested that sequential treatment including ATRA and PI3K/AKT inhibitor induced robust apoptosis, extremely inhibited the clonality of AML cells, and suppressed the FMS-like tyrosine kinase 3-internal tandem duplication (FLT3-ITD)-driven transformation of CD34+ hematopoietic stem/progenitor cells. Future clinical studies are warranted to further support the clinical application of the sequential strategy for the effective treatment of AML. [ABSTRACT FROM AUTHOR]

Acute myeloid leukaemia (AML) is a biologically heterogeneous disease with an overall poor prognosis; thus, novel therapeutic approaches are needed. Our previous studies showed that 4‐amino‐2‐trifluoromethyl‐phenyl retinate (ATPR), a new derivative of all‐trans retinoic acid (ATRA), could induce AML cell differentiation and cycle arrest. The current study aimed to determine the potential pharmacological mechanisms of ATPR therapies against AML. Our findings showed that E2A was overexpressed in AML specimens and cell lines, and mediate AML development by inactivating the P53 pathway. The findings indicated that E2A expression and activity decreased with ATPR treatment. Furthermore, we determined that E2A inhibition could enhance the effect of ATPR‐induced AML cell differentiation and cycle arrest, whereas E2A overexpression could reverse this effect, suggesting that the E2A gene plays a crucial role in AML. We identified P53 and c‐Myc were downstream pathways and targets for silencing E2A cells using RNA sequencing, which are involved in the progression of AML. Taken together, these results confirmed that ATPR inhibited the expression of E2A/c‐Myc, which led to the activation of the P53 pathway, and induced cell differentiation and cycle arrest in AML. [ABSTRACT FROM AUTHOR]

4-Amino-2-Trifluoromethyl-Phenyl Retinate (ATPR), a novel all-trans retinoic acid (ATRA) derivative, has been demonstrated that it had a variety of anti-tumor effects by exerting regulation on cellular proliferation, apoptosis and differentiation. Here, we found that ATPR is critical for alleviating myelodysplastic syndrome (MDS) and acute myelogenous leukemia. USO1, vesicle transport factor, belongs to tether protein family and involved in endoplasmic reticulum to Golgi trafficking of protein which is important to tumorigenesis. How USO1 contribute to MDS remain elusive. USO1 is aberrantly activated in MDS and AML in vivo and vitro, aberration of which might be a dominant mechanism for MDS cell survival. During the ATPR-induced remission of MDS, in vitro , USO1 presents a time and concentration-dependent decrease. Silencing of USO1 promotes myeloid differentiation of MDS cells and inhibits MDS cellular proliferation while USO1 over-expression has the opposite effect, suggesting that reduction of USO1 enhances the sensitivity of SKM-1 cells to ATPR treatment. Mechanistically, USO1 exerts its oncogenic role by inactivating Raf/ERK signaling, while ATPR is access to revise it. Notably, the activity of Raf/ERK pathway is required for the development and maintenance of MDS cell proliferation. Collectively, our results demonstrate the USO1- Raf/ERK signaling axis in MDS and highlight the negative role of USO1 in ATPR-regulated remission of MDS. [ABSTRACT FROM AUTHOR]

[Display omitted] Oncogene FLT3 internal tandem duplication (FLT3 -ITD) mutation accounts for 30 % of acute myeloid leukaemia (AML) cases and induces transformation. Previously, we found that E2F transcription factor 1 (E2F1) was involved in AML cell differentiation. Here, we reported that E2F1 expression was aberrantly upregulated in AML patients, especially in AML patients carrying FLT3 -ITD. E2F1 knockdown inhibited cell proliferation and increased cell sensitivity to chemotherapy in cultured FLT3 -ITD-positive AML cells. E2F1-depleted FLT3 -ITD+ AML cells lost their malignancy as shown by the reduced leukaemia burden and prolonged survival in NOD-PrkdcscidIl2rgem1/Smoc mice receiving xenografts. Additionally, FLT3 -ITD-driven transformation of human CD34+ hematopoietic stem and progenitor cells was counteracted by E2F1 knockdown. Mechanistically, FLT3 -ITD enhanced the expression and nuclear accumulation of E2F1 in AML cells. Further study using chromatin immunoprecipitation-sequencing and metabolomics analyses revealed that ectopic FLT3- ITD promoted the recruitment of E2F1 on genes encoding key enzymatic regulators of purine metabolism and thus supported AML cell proliferation. Together, this study demonstrates that E2F1-activated purine metabolism is a critical downstream process of FLT3 -ITD in AML and a potential target for FLT3 -ITD+ AML patients. [ABSTRACT FROM AUTHOR]

Mantle cell lymphoma (MCL) is a lymphoproliferative disorder that lacks reliable therapeutic options. Therefore, new treatment approaches for targeting novel biological pathways are required. 4-amino-2-trifluoromethyl-phenyl retinate (ATPR) synthesized by our group previously has been proven to have higher solubility and superior differentiation effects compared to those of conventional all-trans retinoic acid in acute myeloid leukemia. ATPR induces differentiation and inhibits the proliferation of acute promyelocytic leukemia. However, whether ATPR induces differentiation of MCL cells to normal immune cells has not been investigated. In this study, the proliferation of JEKO-1 cells was completely repressed, and differentiation was activated after ATPR treatment. The neural transcription factor SOX11 was further found to be highly expressed in MCL, but was downregulated by ATPR. After silencing SOX11 in vitro and in vivo, the malignant proliferation and inhibited differentiation of JEKO-1 cells were reversed, whereas the overexpression of SOX11 exacerbated the malignant phenotype of JEKO-1 cells. We also have added additional MCL cell lines (MINO) to complete the key pilot experiments. In addition, the CyclinD1/Rb/E2F1 axis was involved in MCL and was regulated by ATPR. In conclusion, ATPR promoted JEKO-1 cell differentiation via SOX11/CyclinD1/Rb/E2F1. This study provides experimental foundation for developing differentiation therapy for MCL with ATPR. • ATPR has obvious proliferation inhibition and differentiation induction in MCL. • SOX11, downregulated by ATPR, is an attractive target for MCL therapy. • SOX11 promotes tumor growth of MCL cells in vivo. • CyclinD1/Rb/E2F1 participates in ATPR induced differentiation via repressing SOX11. [ABSTRACT FROM AUTHOR]