scholarly journals Bcl-2 Family Overexpression and Chemoresistance in Acute Myeloid Leukemia

2018 ◽  
Vol 19 (4) ◽  
pp. 299-309
Author(s):  
Alex José de Melo Silva

Abstract The family of Bcl-2 proteins is one of the most responsible for apoptosis pathway, that is a critical process to the maintenance of tissue homeostasis. Bcl-2 is an essential apoptotic regulator belonging to a family of functionally and structurally related proteins known as the Bcl-2 family. Some members of this family act as anti-apoptotic regulators, whereas others act in pro-apoptotic function. The relationship between the pro and anti-apoptotic proteins can regulate whether cells begin the apoptosis or remain its life cycle. Increasing of Bcl-2 expression has been found in some hematologic diseases, such as Acute Myeloid Leukemia (AML) and their effects on responsiveness to anticancer therapy have been recently described. Thus, this review aims to discuss apoptosis and the role of the Bcl-2 family of proteins in chemoresistance when overexpressed in patients committed with Acute Myeloid Leukemia submitted to chemotherapy treatment.

2020 ◽  
Vol 10 ◽  
Author(s):  
Cong Lu ◽  
Jiang Zhu ◽  
Xiangjun Chen ◽  
Yanjie Hu ◽  
Wei Xie ◽  
...  

The role of CXC chemokine receptors in tumors has been an increasingly researched focus in recent years. However, significant prognostic values of CXCR members in acute myeloid leukemia are yet to be explored profoundly. In this study, we firstly made an analysis of the relationship of CXCR family members and AML using samples from TCGA. Our results suggested that transcriptional expressions of CXCRs serve an important role in AML. CXCR transcript expressions, except CXCR1 expression, were significantly increased in AML. It displayed the expression pattern of CXCR members in different AML subtypes according to FAB classification. The correlations of CXCR transcript expression with different genotypes and karyotypes were also present. High CXCR2 expression was found to have a significantly worse prognosis compared with that of low CXCR2 expression, and CXCR2 was also found to be an independent prognostic factor. We also established a CXCR signature to identify high-risk subgroups of patients with AML. It was an independent prognostic factor and could become a powerful method to predict the survival rate of patients.


Blood ◽  
2011 ◽  
Vol 118 (21) ◽  
pp. 4191-4191
Author(s):  
Kathleen Wren Phelan ◽  
Sucha Nand ◽  
Laura C Michaelis

Abstract Abstract 4191 Background: Performance status is traditionally used to judge fitness in cancer patients. It is often a key factor in determining appropriateness for chemotherapy and entry into clinical trials. Most research on PS has been in solid tumor patients, but it is generally assumed to be valid in hematologic malignancies as well. However, PS assessment can be problematic, especially in patients who have become ill quickly or where there are conflicting parameters; e.g. patients whose function is limited but who are still actively working. We explored the role of PS in patients with AML to determine if alternative, more objectively determined parameters, could predict PS. We evaluated the relationship between PS and rates of complete remission (CR) and duration of overall survival (OS) as well as the relationship between objectively determined pretreatment parameters and these outcomes. Methods: Approval for retrospective data collection was obtained by the institutional IRB. A randomly selected cohort of 145 patients with newly diagnosed AML was identified using pharmacy records of treatment with induction agents cytarabine, daunorubicin or azacitidine. We excluded patients with acute promyelocytic leukemia. Pretreatment data was collected from the electronic medical record of each subject, including AML subtype, age, gender, PS, presence of infection at diagnosis, peripheral blood white blood cell count, peripheral blood blast percentage, hemoglobin, lactate dehydrogenase, aspartate transaminase, alanine transaminase, creatinine, albumin, left ventricular ejection fraction (LVEF), bone marrow cellularity, bone marrow blast percentage and cytogenetics. Achievement of complete remission was assessed and overall survival was calculated in months from diagnosis to either death or date of censorship. PS was obtained from physician notes and documented as a Zubrod score. In the absence of documentation, the authors reviewed medical records for presenting symptoms, mobility and functional status and made an assignment. Retrospective assignment of PS was reviewed and confirmed by at least two of the authors. Logistic regression was performed to examine the relationship between pretreatment characteristics and CR, and the effect of pretreatment characteristics and the assignment of PS, dichotomized as good (0–1) vs. poor (2–4). Linear regression analysis was used to investigate the relationship between pretreatment characteristics and OS. Results: A total of 120/145 (83%) were assigned a PS of 0, 1. Twenty patients were considered to have a PS of 2 and five patients had a PS of 3. There was a statistically significant relationship between a good PS assignment and a higher albumin level (OR 5.32, p=0.000, 95% CI 2.32, 12.22). There was no significant relationship between the remaining clinical parameters and PS assignment, including age at diagnosis. Ninety-three patients (64%) achieved a CR. There was no relationship between PS, assigned either contemporarily or retrospectively, with the achievement of CR. The median overall survival was 15 months (range 0 to 92 months). PS did not predict the duration of OS. As is well reported, CR was significantly more likely in younger (< 60 yrs) patients and patients with favorable cytogenetics. Median OS was also prolonged in these patients. No additional pretreatment characteristics were significantly related to CR or OS except LVEF. Patients with an LVEF greater than 50% were more likely to achieve a CR (P=0.0001) and had a longer OS. Conclusions: We found that, among pretreatment characteristics, a higher albumin level was associated with a good performance status. Age was not a predictor of PS. Contrary to expectations, in this population of treated AML patients, PS did not predict either CR or OS. In addition to the association of younger age and favorable cytogenetics with better outcomes, we found that a higher LVEF is also associated with higher CR rates, but this is likely explained by choice of chemotherapeutic agents. Our data calls into question the use of PS as a tool to guide therapy in routine clinical management of acute myeloid leukemia. Prospective studies should evaluate the utility of more objective and more reliably documented clinical parameters than PS for predicting patient outcome. Disclosures: No relevant conflicts of interest to declare.


Blood ◽  
2019 ◽  
Vol 134 (Supplement_1) ◽  
pp. 879-879
Author(s):  
Xiangguo Shi ◽  
Daisuke Nakada ◽  
Ayumi Kitano ◽  
Rebecca Murdaugh ◽  
Yu-Jung Tseng ◽  
...  

Acute myeloid leukemia (AML) is primarily a disease of older adults with poor treatment outcomes. Despite years of intensive research, the standard induction therapy for AML has remained largely unchanged for decades. Thus, the development of new and efficacious therapeutic targets for AML is urgently needed. Leukemia cells exhibit multiple metabolic aberrations that may be therapeutically targeted. Here, we show that nicotinamide adenine dinucleotide (NAD+) promotes leukemogenesis and causes chemotherapy treatment resistance through fueling energetic metabolism, and pinpoints nicotinamide nucleotide adenylyltransferase 1 (NMNAT1) is a novel therapeutic target for AML. To identify novel genes essential for AML, we performed a whole genome CRISPR dropout screen by using MOLM13 cell line and identified 1,951 essential genes (Fig. A). By searching druggable targets among these genes, we narrowed down to 345 genes, among which we found two genes, NMNAT1 (nicotinamide nucleotide adenylyltransferase 1) and NAMPT (nicotinamide phosphoribosyltransferase), both involved in key steps in NAD+ biosynthesis. We comprehensively analyzed dependency scores for all genes involved in the NAD+ biosynthetic pathways (de novo synthesis pathway, the Preiss-Handler pathway and the salvage pathway) across a broad panel of cancer cell lines from the Dependency Map database (https://depmap.org/portal/). The results showed that NMNAT1 and NAMPT are both strongly selective and uniquely required for hematological malignancies compared to other cancers (Fig. B). Since little success has been achieved for NAMPT inhibitors in clinical trials, our attention was drawn to NMNAT1, which encodes a nuclear localized enzyme catalyzing the final step in NAD+ biosynthesis. We confirmed that deletion of NMNAT1 in AML cells significantly reduced nuclear NAD+ level and cell viability over time while sparing normal hematopoietic progenitor cells, suggesting that NMNAT1 is targetable to AML. Overexpression of wild-type Nmnat1 but not the enzymatically inactive forms rescued NMNAT1-KO AML, indicating that the catalytic activity of NMNAT1 is required for AML. To study the role of NAD+ in AML, we first measured NAD+ levels in leukemic and normal cells, and found higher NAD+ levels in leukemia-initiating cells from a murine MLL-AF9-induced AML model compared to normal cells. Supplementation of NAD+ metabolites (NMN, NAM and NR) increased AML proliferation, enhanced glycolysis (lactate production) and oxidative phosphorylation (ATP production), resulting in chemotherapy resistance (Fig. C). Deletion of NMNAT1 sensitized AML cell to chemotherapy treatment. To study the role of NMNAT1 in leukemogenesis in vivo, we genetically deleted NMNAT1 in murine or human leukemia cells, transplanted them into recipient mice, and found that deletion of NMNAT1 reduced leukemic burden and extended leukemia-free survival (Fig. D). Finally, to reveal the molecular mechanisms underlying NMNAT1 KO-mediated cell death (increased levels of gamma-H2AX), RNA-seq and functional assay of NAD+ dependent enzymes were performed. We found that the reduction of nuclear NAD+ resulting from NMNAT1 deletion upregulated genes involved in DNA repair pathway, which may be linked to impaired PARPs and Sirtuins activity. Our findings reveal the important function of NAD+ in leukemogenesis and chemoresistance, and identify NMANT1 as a novel therapeutic target for AML. Figure Disclosures No relevant conflicts of interest to declare.


2019 ◽  
Vol XIV (1) ◽  
Author(s):  
A.M. Radzhabova ◽  
S.V. Voloshin ◽  
I.S. Martynkevich ◽  
A.A. Kuzyaeva ◽  
V.A. Shuvaev ◽  
...  

2021 ◽  
Vol 10 (1) ◽  
Author(s):  
Yiyi Yao ◽  
Fenglin Li ◽  
Jiansong Huang ◽  
Jie Jin ◽  
Huafeng Wang

AbstractDespite the advances in intensive chemotherapy regimens and targeted therapies, overall survival (OS) of acute myeloid leukemia (AML) remains unfavorable due to inevitable chemotherapy resistance and high relapse rate, which mainly caused by the persistence existence of leukemia stem cells (LSCs). Bone marrow microenvironment (BMM), the home of hematopoiesis, has been considered to play a crucial role in both hematopoiesis and leukemogenesis. When interrupted by the AML cells, a malignant BMM formed and thus provided a refuge for LSCs and protecting them from the cytotoxic effects of chemotherapy. In this review, we summarized the alterations in the bidirectional interplay between hematopoietic cells and BMM in the normal/AML hematopoietic environment, and pointed out the key role of these alterations in pathogenesis and chemotherapy resistance of AML. Finally, we focused on the current potential BMM-targeted strategies together with future prospects and challenges. Accordingly, while further research is necessary to elucidate the underlying mechanisms behind LSC–BMM interaction, targeting the interaction is perceived as a potential therapeutic strategy to eradicate LSCs and ultimately improve the outcome of AML.


2020 ◽  
Vol 15 (1) ◽  
pp. 1013-1023
Author(s):  
Lina Xing ◽  
Jinhai Ren ◽  
Xiaonan Guo ◽  
Shukai Qiao ◽  
Tian Tian

AbstractPrevious research has revealed the involvement of microRNA-212-5p (miR-212-5p) and cyclin T2 (CCNT2) in acute myeloid leukemia (AML). However, whether the miR-212-5p/CCNT2 axis is required for the function of decitabine in AML has not been well elucidated. Quantitative reverse transcription-polymerase chain reaction was used to examine enrichment of miR-212-5p. The relationship between CCNT2 and miR-212-5p was verified by the luciferase reporter assay. Cell apoptosis was evaluated by flow cytometry and western blot. CCK-8 assay was performed to determine cell viability. Decitabine significantly repressed cell viability, while promoted cell apoptosis. Meanwhile, the expression levels of cyclinD1, CDK4, and Bcl-2 were suppressed in cells with decitabine exposure, but Bax and caspase-3 expression levels were upregulated. Besides, miR-212-5p upregulation had the similar function with decitabine in AML cell proliferation and apoptosis. Subsequently, restoration of CCNT2 attenuated miR-212-5p overexpression-induced effects in Kasumi-1 and SKNO-1 cells. In addition, miR-212-5p depletion reversed decitabine-induced CCNT2 downregulation. The miR-212-5p/CCNT2 axis had an implication in the anti-leukemic effect of decitabine in AML.


BMC Cancer ◽  
2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Jun Li ◽  
Zheng Ge

Abstract Background Acute myeloid leukemia (AML) remains one of the most common hematological malignancies, posing a serious challenge to human health. HSPA8 is a chaperone protein that facilitates proper protein folding. It contributes to various activities of cell function and also is associated with various types of cancers. To date, the role of HSPA8 in AML is still undetermined. Methods In this study, public datasets available from the TCGA (Cancer Genome Atlas) and GEO (Gene Expression Omnibus) were mined to discover the association between the expression of HSPA8 and clinical phenotypes of CN-AML. A series of bioinformatics analysis methods, including functional annotation and miRNA-mRNA regulation network analysis, were employed to investigate the role of HSPA8 in CN-AML. Results HSPA8 was highly expressed in the AML patients compared to the healthy controls. The high HSPA8 expression had lower overall survival (OS) rate than those with low HSPA8 expression. High expression of HSPA8 was also an independent prognostic factor for overall survival (OS) of CN-AML patients by multivariate analysis. The differential expressed genes (DEGs) associated with HSPA8 high expression were identified, and they were enriched PI3k-Akt signaling, cAMP signaling, calcium signaling pathway. HSPA8 high expression was also positively associated with micro-RNAs (hsa-mir-1269a, hsa-mir-508-3p, hsa-mir-203a), the micro-RNAs targeted genes (VSTM4, RHOB, HOBX7) and key known oncogenes (KLF5, RAN, and IDH1), and negatively associated with tumor suppressors (KLF12, PRKG1, TRPS1, NOTCH1, RORA). Conclusions Our research revealed HSPA8 as a novel potential prognostic factor to predict the survival of CN-AML patients. Our data also revealed the possible carcinogenic mechanism and the complicated microRNA-mRNA network associated with the HSPA8 high expression in AML.


2016 ◽  
Vol 44 (9) ◽  
pp. S65 ◽  
Author(s):  
David Corrigan ◽  
Larry Luchsinger ◽  
Hans Snoeck

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