Association between the CEBPA and c-MYC genes expression levels and acute myeloid leukemia pathogenesis and development

A significant correlation exists between CREBBP and CEBPA gene expression in de Novo adult acute myeloid leukemia

CREBBP, CEBPA, and DNMT3A are tumor suppressor genes whose dysfunction has been reported in hematologic malignancies. Acute myeloid leukemia (AML) is the most common type of acute leukemia in adults. We aim to assess the expression level of CREBBP, CEBPA, and DNMT3A genes in an Egyptian cohort with AML. We investigated the correlation between the selected genes' mRNA levels and their association with clinical characteristics and survival. Herein, 53 adult participants diagnosed with AML were enrolled in the study. Quantitative RT-PCR was used, and computational analysis was added to analyze the relationship between the three genes. CREBBP expression influenced TLC negatively (r = -0.328, p = 0.017). DNMT3A gene expression was found to be significantly associated with CD117 positive (p = 0.028). There was no significant difference between males and females in the relative CREBBP, CEBPA, and DNMT3A expression. Remarkably, AML-M3 cases were devoid of CREBBP expression. The correlation matrix of the three genes detected a significant correlation only between CREBBP and CEBPA expression (r = 0.518, p < 0.0001), though the computational correlation analysis of these two genes was not significant. Our finding may suggest a complementary role of CREBBP and CEBPA in AML pathogenesis; however, further investigation on larger samples is still warranted to study the relationship of these genes with AML survival. We are also reporting here an adult AML case with an additional chromosome 19 as the sole cytogenetic abnormality.

Shift of N-MYC Oncogene Expression in AML Patients Carrying the FLT3-ITD Mutation

Mutations in the FLT3 gene not only lead to abnormalities in its structure and function, but also affect the expression of other genes involved in leukemogenesis. This study evaluated the expression of genes that are more characteristic of neuroblastoma but less studied in leukemia. N-MYC oncogene expression was found to be more than 3-fold higher in primary AML patients carrying the FLT3-ITD mutation compared to carriers of other mutations as well as patients with normal karyotype (p = 0.03946). In contrast to the expression of several genes (C-MYC, SPT16, AURKA, AURKB) directly correlated to the allelic load of FLT3-ITD, the expression of the N-MYC oncogene is extremely weakly related or independent of it (p = 0.0405). Monitoring of N-MYC expression in some patients with high FLT3-ITD allelic load receiving therapy showed that a decrease in FLT3-ITD allelic load is not always accompanied by a decrease in N-MYC expression. On the contrary, N-MYC expression may remain elevated during the first three months after therapy, which is additional evidence of the emergence of resistance to therapy and progression of AML.

Melatonin finely tunes proliferation and senescence in hematopoietic stem cells

Human hematopoietic stem/progenitor cells (HSPCs) are pluripotent cells that gradually lose their self-renewal and regenerative potential, to give rise to mature cells of the hematopoietic system by differentiation. HSPC infusion is used to restore hematopoietic function in patients with a variety of onco-hematologic and immune-mediated disorders. The functionality of these cells is therefore of great importance to ensure the homeostasis of the hematopoietic system. Melatonin plays an important role as immunomodulatory and oncostatic hormone. In the present manuscript, we aimed at evaluating the activity of melatonin in modulating HSPC senescence, in the attempt to improve their hemopoietic regenerative potential. We exposed HSPCs to melatonin, in different conditions, and then analyzed the expression of genes regulating cell cycle and cell senescence. Moreover, we assessed cell senescence by β-galactosidase and telomerase activity. Our results showed the ability of melatonin to counteract HSPC senescence, thus paving the way for enhanced efficiency in their clinical application.

Gene Expression Profiling and Protein Analysis Reveal Suppression of the C-Myc Oncogene and Inhibition JAK/STAT and PI3K/AKT/mTOR Signaling by Thymoquinone in Acute Myeloid Leukemia Cells

Overexpression of c-Myc plays an essential role in leukemogenesis and drug resistance, making c-Myc an attractive target for cancer therapy. However, targeting c-Myc directly is impossible, and c-Myc upstream regulator pathways could be targeted instead. This study investigated the effects of thymoquinone (TQ), a bioactive constituent in Nigella sativa, on the activation of upstream regulators of c-Myc: the JAK/STAT and PI3K/AKT/mTOR pathways in HL60 leukemia cells. Next-generation sequencing (NGS) was performed for gene expression profiling after TQ treatment. The expression of c-Myc and genes involved in JAK/STAT and PI3K/AKT/mTOR were validated by quantitative reverse transcription PCR (RT-qPCR). In addition, Jess assay analysis was performed to determine TQ’s effects on JAK/STAT and PI3K/AKT signaling and c-Myc protein expression. The results showed 114 significant differentially expressed genes after TQ treatment (p < 0.002). DAVID analysis revealed that most of these genes’ effect was on apoptosis and proliferation. There was downregulation of c-Myc, PI3K, AKT, mTOR, JAK2, STAT3, STAT5a, and STAT5b. Protein analysis showed that TQ also inhibited JAK/STAT and PI3K/AKT signaling, resulting in inhibition of c-Myc protein expression. In conclusion, the findings suggest that TQ potentially inhibits proliferation and induces apoptosis in HL60 leukemia cells by downregulation of c-Myc expression through inhibition of the JAK/STAT and PI3K/AKT signaling pathways.

Identification of a prognostic signature based on copy number variations (CNVs) and CNV-modulated gene expression in acute myeloid leukemia

OBJECTIVES

Acute myeloid leukemia (AML) is caused by multiple genetic alterations in hematopoietic progenitors, and molecular genetic analyses have provided useful information for AML diagnosis and prognostication. This study aimed to integratively understand the prognostic value of specific copy number variation (CNV) patterns and CNV-modulated gene expression in AML.

METHODS

We conducted integrative CNV profiling and gene expression analysis using data from the Therapeutically Applicable Research To Generate Effective Treatments (TARGET) and The Cancer Genome Atlas (TCGA) AML cohorts. CNV-related genes associated with survival were identified using the TARGET AML cohort and validated using the TCGA AML cohort. Genes whose CNV-modulated expression was associated with survival were also identified using the TARGET AML cohort and validated using the TCGA AML cohort, and patient bone marrow samples were then used to further validate the effects of CNV-modulated gene expression on survival. CNV and mRNA survival analyses were conducted using proportional hazards regression models (Cox regression) and the "survminer" and "survival" packages of the R Project for Statistical Computing. Genes belonging to the Kyoto Encyclopedia of Genes and Genomes (KEGG) cancer panel were extracted from KEGG cancer-related pathways.

RESULTS

One hundred two CNV-related genes (located at 7q31-34, 16q24) associated with patient survival were identified using the TARGET cohort and validated with the TCGA AML cohort. Among these 102 validated genes, three miRNA genes (MIR29A, MIR183, and MIR335) were included in the KEGG cancer panel. Five genes (SEMA4D, CBFB, CHAF1B, SAE1, and DNMT1) whose expression was modulated by CNVs and significantly associated with clinical outcomes were identified, and the deletion of SEMA4D and CBFB was found to potentially exert protective effects against AML. The results of these five genes were also validated using patient marrow samples. Additionally, the distribution of CNVs affecting these five CNV-modulated genes was independent of the risk group (favorable-, intermediate-, and adverse-risk groups).

CONCLUSIONS

Overall, this study identified 102 CNV-related genes associated with patient survival and identified five genes whose expression was modulated by CNVs and associated with patient survival. Our findings are crucial for the development of new modes of prognosis evaluation and targeted therapy for AML.