Hubbry Logo
CEBPACEBPAMain
Open search
CEBPA
Community hub
CEBPA
logo
8 pages, 0 posts
0 subscribers
Be the first to start a discussion here.
Be the first to start a discussion here.
Contribute something
CEBPA
CEBPA
CEBPA
View on Wikipedia
from Wikipedia
CEBPA
Identifiers
AliasesCEBPA, C/EBP-alpha, CEBP, CCAAT/enhancer binding protein alpha, CCAAT enhancer binding protein alpha
External IDsOMIM: 116897; MGI: 99480; HomoloGene: 3211; GeneCards: CEBPA; OMA:CEBPA - orthologs
Orthologs
SpeciesHumanMouse
Entrez

1050

12606

Ensembl

ENSG00000245848

ENSMUSG00000034957

UniProt

P49715

P53566

RefSeq (mRNA)

NM_004364
NM_001285829
NM_001287424
NM_001287435

NM_001287514
NM_001287515
NM_001287521
NM_001287523
NM_007678

RefSeq (protein)

NP_001272758
NP_001274353
NP_001274364
NP_004355

NP_001274443
NP_001274444
NP_001274450
NP_001274452
NP_031704

Location (UCSC)Chr 19: 33.3 – 33.3 MbChr 7: 34.82 – 34.82 Mb
PubMed search[3][4]
Wikidata
View/Edit HumanView/Edit Mouse

CCAAT/enhancer-binding protein alpha is a protein encoded by the CEBPA gene in humans.[5][6] CCAAT/enhancer-binding protein alpha is a transcription factor involved in the differentiation of certain blood cells.[7] For details on the CCAAT structural motif in gene enhancers and on CCAAT/Enhancer Binding Proteins see the specific page.

Function

[edit]

The protein encoded by this intronless gene is a bZIP transcription factor which can bind as a homodimer to certain promoters and gene enhancers. It can also form heterodimers with the related proteins CEBP-beta and CEBP-gamma, as well as distinct transcription factors such as c-Jun. The encoded protein is a key regulator of adipogenesis (the process of forming new fat cells) and the accumulation of lipids in those cells, as well as in the metabolism of glucose and lipids in the liver.[8] The protein has been shown to bind to the promoter and modulate the expression of the gene encoding leptin, a protein that plays an important role in body weight homeostasis. Also, the encoded protein can interact with CDK2 and CDK4, thereby inhibiting these kinases and causing cultured cells to stop dividing.[9] In addition, CEBPA is essential for myeloid lineage commitment and therefore required both for normal mature granulocyte formation and for the development of abnormal acute myeloid leukemia.[10]

Common mutations

[edit]

There are two major categories which CEBPA mutations can be categorized into. One category of mutations prevent CCAAT/enhancer-binding protein alpha DNA binding by altering its COOH-terminal basic leucine zipper domain. The other category of mutations disrupt the translation of the CCAAT/enhancer-binding protein alpha NH2 terminus. CEBPA mutations, which result in diminished CCAAT/enhancer-binding protein alpha activity, contribute to the transformation of myeloid antecedents.[11]

Interactions

[edit]

CEBPA has been shown to interact with Cyclin-dependent kinase 2[12] and Cyclin-dependent kinase 4.[12]

Clinical significance

[edit]

It has been shown that mutation of CEBPA has been linked to good outcome in both adult and pediatric acute myeloid leukemia patients.[13]

Significance in acute myeloid leukemia

[edit]

Acute myeloid leukemia is characterized by genetic abnormalities in hematopoietic progenitors. This includes excessive proliferation of blasts, and blocking the hematopoiesis of granulocytes. It has been shown that suppression of CEBPA expression and blocking of CCAAT/enhancer-binding protein alpha stops the differentiation of myeloid progenitors. For this reason, CCAAT/enhancer-binding protein alpha's role during granulocyte differentiation and CEBPA's role as a tumor suppressor gene is critically important in the prognosis of acute myeloid leukemia.[14]

Prognostic significance of CEBPA mutations

[edit]

CCAAT/enhancer-binding protein alpha, the transcription factor that is encoded by CEBPA, is very important in the differentiation of immature granulocytes. Mutation of the CEBPA gene has been shown to play a crucial role in leukemogenesis and prognosis in acute myeloid leukemia patients. In recent studies CEBPA mutations were found in between 7% and 15% of patients with acute myeloid leukemia. The three different types of mutations seen in these AML patients include germ-line N-terminal mutation, N-terminal frameshift mutation, and C-terminal mutation. These mutations are most frequently found in acute myeloid leukemia M1 or acute myeloid leukemia M2. Many reports link CEBPA mutations with a favorable outcome in acute myeloid leukemia. This is because these mutations are likely to induce differentiation arrest in these patients. Patients with CEBPA mutations have longer remission duration and survival time than those without the mutations.[11] Therefore, the presence of CEBPA mutations are directly associated with a more favorable course for the progression of the disease.[15]

Significance in solid tumors

[edit]

Recently it has been shown that epigenetic modification of the distal promoter region of CEBPA has resulted in downregulation of CEBPA expression in pancreatic cancer cells, lung cancer, and head and neck squamous cell carcinoma.[16][17]

Methylation of CEBPA as a prognostic biomarker in AML patients

[edit]

A recent study has found that higher levels of CEBPA methylation are directly proportionate with treatment response. The complete response rate increased proportionately with the level of CEBPA methylation. For this reason it has been proposed that methylation of CEBPA could be a very useful biomarker in acute myeloid leukemia prognosis.[18]

See also

[edit]

References

[edit]

Further reading

[edit]
[edit]
Revisions and contributorsEdit on WikipediaRead on Wikipedia

CEBPA

View on Grokipedia
from Grokipedia
CEBPA is a protein-coding gene located on chromosome 19q13.11 that encodes CCAAT/enhancer-binding protein alpha (C/EBPα), a basic leucine zipper (bZIP) transcription factor essential for regulating gene expression during cellular differentiation, particularly in myeloid progenitors, adipocytes, hepatocytes, and lung cells. The protein recognizes the CCAAT motif in promoter regions and functions by forming homodimers or heterodimers with other CEBP family members, such as CEBPB and CEBPG, to control processes like proliferation arrest, granulopoiesis, adipogenesis, and gluconeogenesis. CEBPA acts as a tumor suppressor by inhibiting uncontrolled cell growth and promoting terminal differentiation, with its expression modulated through differential translation starting from GUG or AUG codons, producing full-length and truncated isoforms. Mutations in CEBPA are strongly associated with (AML), occurring in approximately 10% of cases overall and up to 18% of cytogenetically normal AML subtypes. These mutations, often biallelic and involving both N-terminal and C-terminal regions, disrupt the protein's DNA-binding or dimerization capabilities, impairing myeloid differentiation and leading to leukemogenesis. In familial AML, heterozygous mutations in the combined with somatic C-terminal mutations follow a two-hit mechanism, conferring a high lifetime (>90%) of early-onset AML with favorable prognosis and specific features like normal and FAB M1/M2 subtypes. Beyond hematopoiesis, CEBPA influences metabolic regulation, including body weight and insulin sensitivity in adipose and liver tissues.

Molecular Biology

Gene Structure and Expression

The CEBPA is located on 19q13.1 in humans, spanning positions 33,299,934 to 33,302,564 (GRCh38.p14) on the reverse strand. It encompasses approximately 2.6 kb and is organized as an intronless gene with a single encoding the full coding sequence. This compact structure facilitates direct transcription of the coding region without splicing interruptions. Orthologs of CEBPA are conserved across mammals, including the Cebpa gene in mice on , reflecting evolutionary preservation of its regulatory roles. The promoter region upstream of the CEBPA coding sequence lacks a canonical but contains multiple binding sites, such as those for CREB, deltaCREB, E2F-2, E2F-3a, and STAT5A, enabling context-specific regulation. C/EBPα autoregulates its own promoter, contributing to feedback control of expression levels. CEBPA exhibits tissue-specific expression patterns, with high levels in the liver, and adipose tissues, and myeloid lineage cells, where it drives differentiation programs. It is also prominently expressed during embryonic development in organs such as the liver and adipose precursors, but remains at low basal levels in most other adult tissues like muscle and . Although the gene produces a single primary mRNA transcript, alternative translation initiation sites within this transcript generate distinct protein isoforms, such as the full-length p42 and truncated p30 forms.

Protein Structure and Isoforms

The CEBPA protein, also known as CCAAT/enhancer-binding protein alpha (C/EBPα), is a basic leucine zipper (bZIP) transcription factor consisting of 358 amino acids in its full-length form, with a calculated molecular weight of approximately 37.6 kDa, though it often migrates at around 42 kDa on SDS-PAGE due to post-translational modifications. The protein features an N-terminal transactivation domain (TAD) responsible for recruiting coactivators and initiating transcription, followed by a central bZIP domain that facilitates both DNA binding via its basic region and homodimerization or heterodimerization with other family members via the leucine zipper motif. This modular architecture allows C/EBPα to regulate gene expression by binding to specific DNA sequences, such as the CCAAT box, in a dimer-dependent manner. C/EBPα exists in two primary isoforms generated through alternative translation initiation from a single mRNA: the full-length p42 isoform, which initiates at the first AUG codon and encompasses both TAD1 (residues 1–127) and TAD2 (residues 175–206) along with the bZIP domain (residues 276–358), enabling robust transcriptional activation and differentiation programs; and the truncated p30 isoform, which starts at a downstream AUG codon (residue 152), lacking TAD1 but retaining TAD2 and the bZIP domain, thereby functioning primarily as a dominant-negative regulator by forming non-productive heterodimers with p42 that impair DNA binding and transactivation. The p42 isoform is the predominant activator in normal cellular contexts, while p30 levels can increase under stress or oncogenic conditions, shifting the balance toward proliferation. These isoforms arise without alternative splicing, relying instead on ribosomal scanning and uORF regulation for their relative expression ratios. Post-translational modifications further modulate C/EBPα activity, including phosphorylation at serine 21 (Ser21) within the TAD by mitogen-activated protein kinase (MAPK/ERK) pathways, which alters protein conformation, reduces DNA binding affinity, and promotes a shift from granulocytic to monocytic differentiation in myeloid cells. Sumoylation, primarily at lysine residues in the TAD and bZIP regions by SUMO1 or SUMO2/3, enhances transcriptional repression and stability but can inhibit activation depending on the isoform and cellular context, with p42 being more susceptible to sumoylation-mediated inhibition than p30. These modifications integrate extracellular signals to fine-tune C/EBPα function without altering isoform production. The bZIP domain of C/EBPα exhibits high evolutionary conservation across vertebrate species, sharing over 90% sequence identity with homologs in mammals, birds, and , which underscores its critical role in DNA recognition and dimerization preserved since early chordate divergence. This conservation extends to the leucine zipper heptad repeats and basic region residues essential for major groove interactions, highlighting the domain's ancient origin within the C/EBP family.

Biological Functions

Role in Differentiation and Development

CEBPA plays a pivotal role in promoting the terminal differentiation of myeloid progenitors into granulocytes, particularly neutrophils and monocytes, during . It acts as a key that drives the maturation of common myeloid progenitors into granulocyte-monocyte progenitors and subsequently into mature granulocytes by activating genes essential for neutrophil development, such as those involved in colony-stimulating factor signaling. In the absence of CEBPA, myeloid differentiation is severely impaired, as evidenced by studies showing that conditional disruption of CEBPA in adult mice leads to a profound block in granulocyte and monocyte production by preventing formation of granulocyte-monocyte progenitors. Knockout studies in mice have underscored CEBPA's indispensable function in hematopoiesis and other developmental processes. CEBPA-null mice exhibit a complete absence of mature , highlighting its necessity for granulocyte lineage commitment and maturation from fetal liver hematopoietic cells. These mice also display severe defects in liver development, including impaired and leading to neonatal lethality within hours of birth, as well as a lack of due to failed differentiation. Such phenotypes confirm CEBPA's broad regulatory influence beyond the hematopoietic system, extending to metabolic . In , CEBPA is crucial for the maturation of preadipocytes into adipocytes by inducing the expression of PPARγ and cooperating with C/EBPβ to activate downstream adipocyte-specific genes. This hierarchical regulation ensures the commitment and terminal differentiation of mesenchymal precursors into functional fat cells, with CEBPA acting downstream of early inducers like C/EBPβ to sustain lipid accumulation and insulin sensitivity. Embryonic roles of CEBPA further emphasize its developmental importance; it regulates fetal liver hematopoiesis by directing multipotential progenitors toward myeloid fates and restricting erythroid expansion, while in the , it promotes the differentiation of alveolar type II cells essential for production and respiratory maturation at birth. Recent findings indicate that CEBPA is also required for hematopoietic stem and generation during embryogenesis and for the development of Ly6Chigh monocytes, further emphasizing its role in early myeloid commitment. CEBPA's functions in differentiation are maintained through intricate feedback loops, including its auto-regulation via binding to its own promoter and enhancers to sustain expression during lineage commitment. Additionally, CEBPA engages in cross-talk with PU.1, where it modulates PU.1 activity to favor granulocytic over monocytic fates, and interacts with GFI-1 to reinforce myeloid priming in hematopoietic stem and progenitor cells. These regulatory circuits ensure stable lineage decisions and prevent aberrant proliferation in developing tissues.

Transcriptional Regulation Mechanisms

CEBPA functions as a transcription factor through its C-terminal basic leucine zipper (bZIP) domain, which enables DNA binding and dimerization. The bZIP domain recognizes the consensus DNA sequence 5'-T[TG]NNGNAA[TG]-3', a variant of the CAAT box, allowing CEBPA to bind target promoters either as homodimers or heterodimers with other C/EBP family members. This binding specificity facilitates precise regulation of gene expression in myeloid cells, where CEBPA predominantly operates during differentiation. The full-length p42 isoform of CEBPA serves as the primary activator, containing N-terminal domains that recruit co-activators such as CBP and p300. These co-activators promote , particularly at residues on histones H3 and H4, leading to and enhanced transcriptional initiation at target loci. In contrast, the truncated p30 isoform, initiated from an internal , lacks these full domains and acts as a dominant-negative regulator. By forming non-productive heterodimers with p42 or competing for the same DNA binding sites, p30 inhibits activation without supporting robust transcription, thereby fine-tuning or suppressing CEBPA-dependent gene expression in immature cells. In myeloid cells, CEBPA directly regulates key target genes essential for , including the receptor (CSF3R), (LTF), and c-fos (FOS). Binding to elements in the promoters of CSF3R and LTF drives their expression in cooperation with factors like PU.1 and RUNX1, promoting maturation. Similarly, CEBPA interacts with c-Fos via heterodimerization to modulate FOS expression, influencing lineage commitment toward granulocytes over monocytes. Beyond direct targets, CEBPA exerts indirect effects through lineage-specific networks, such as inducing secondary transcription factors that amplify myeloid differentiation programs. Upstream regulation of CEBPA expression integrates signals to control its availability during . In certain contexts, such as , CEBPε can induce CEBPA to promote granulocytic fate. Conversely, miR-124 inhibits CEBPA post-transcriptionally by binding its 3' , reducing protein levels and dampening differentiation in cells where miR-124 is often epigenetically silenced. These mechanisms ensure context-dependent activation of CEBPA's transcriptional output.

Genetic and Epigenetic Alterations

Somatic Mutations

Somatic mutations in the CEBPA gene, encoding the CCAAT/enhancer-binding protein alpha transcription factor, are acquired alterations that disrupt its function and contribute to leukemogenesis, particularly in acute myeloid leukemia (AML). These mutations are predominantly biallelic, involving both alleles of the gene, and occur in approximately 10% of all AML cases, with about 4% featuring biallelic changes. Recent classifications, such as the ELN 2022 guidelines and WHO 5th edition (as of 2022), recognize in-frame mutations in the basic leucine zipper (bZIP) domain—whether monoallelic or biallelic—as defining a favorable-risk subgroup in AML. They are most prevalent in cytogenetically normal AML (CN-AML), where frequencies range from 5% to 15%, and are rare in other leukemia subtypes such as acute lymphoblastic leukemia or chronic myeloid leukemia. The characteristic biallelic mutations consist of an N-terminal frameshift mutation, often insertions or deletions in the early coding region of exon 1, paired with a C-terminal in-frame mutation in the basic leucine zipper (bZIP) domain. N-terminal mutations, typically occurring in the transactivation domains (TAD1 and TAD2), lead to premature stop codons and production of a truncated 30-kDa isoform (p30) that acts as a dominant-negative protein by competing with the full-length 42-kDa isoform (p42) for binding partners without retaining transcriptional activity. C-terminal mutations, such as in-frame insertions or deletions, disrupt the alpha-helical structure of the bZIP domain, impairing DNA binding to target sites and homodimerization or heterodimerization with other proteins. Hotspots for these mutations are concentrated in codons 178-182 within the bZIP region for C-terminal changes and the initial 100-200 base pairs of the coding sequence for N-terminal frameshifts. Detection of these somatic mutations relies on targeted sequencing of 1 for N-terminal alterations and the bZIP-encoding region ( 3 and 4) for C-terminal changes, traditionally using , though next-generation sequencing panels have improved sensitivity in clinical settings. Biallelic status is confirmed by assessing both alleles, as monoallelic mutations are less common and often lack the same leukemogenic potential. These mutations collectively abolish CEBPA's role in myeloid differentiation, promoting a block in .

Promoter Methylation and Epigenetics

Hypermethylation of CpG islands within the CEBPA promoter region leads to transcriptional silencing of the gene, contributing to dysregulated myeloid differentiation in cancers such as (AML) and . In AML, this epigenetic modification occurs in approximately 12-51% of cases, with prevalence estimates around 20-30% among patients lacking CEBPA mutations, and it is associated with reduced CEBPA protein levels and adverse clinical outcomes, including poorer overall survival. Similarly, in non-small cell , promoter hypermethylation correlates with downregulated CEBPA expression, promoting tumor progression by impairing differentiation signals. The underlying mechanisms involve recruitment of DNA methyltransferases (DNMTs), such as DNMT1 and DNMT3A, to the CEBPA promoter, often mediated by oncogenic fusion proteins. In acute promyelocytic leukemia (APL), a subtype of AML characterized by the PML-RARA fusion, this fusion protein directly interacts with DNMTs to enforce hypermethylation at target loci, thereby suppressing gene expression and blocking granulocytic maturation. This process is compounded by histone modifications, where histone deacetylases (HDACs) are recruited to the promoter via corepressor complexes associated with PML-RARA, leading to chromatin condensation and further gene repression. In APL, CEBPA expression is downregulated, with hypermethylation observed in the upstream promoter region. Therapeutic strategies targeting this epigenetic silencing have shown promise in restoring CEBPA function. Hypomethylating agents like inhibit DNMT activity, reducing methylation at the CEBPA promoter and reactivating , which in turn promotes myeloid differentiation and in AML cells. Clinical studies demonstrate that such treatment can elevate CEBPA mRNA levels in responsive patients, highlighting its potential as a mechanism for overcoming epigenetic resistance. Beyond DNA methylation, other epigenetic regulators influence CEBPA expression post-transcriptionally. For instance, microRNAs such as miR-182 target the 3' untranslated region (3'UTR) of CEBPA mRNA, promoting its degradation or translational repression, which exacerbates silencing in hepatocellular carcinoma and AML contexts. This miRNA-mediated control adds a layer of complexity to CEBPA dysregulation, distinct from promoter modifications but synergistic in sustaining oncogenic states.

Protein Interactions

Key Binding Partners

CEBPA, a basic leucine zipper (bZIP) transcription factor, primarily exerts its effects through dimerization, forming both homodimers and heterodimers with other family members such as C/EBPβ, C/EBPγ, and C/EBPδ. These interactions occur via the conserved bZIP domain, which facilitates DNA binding to CCAAT/enhancer motifs and modulates target gene specificity during processes like granulocyte differentiation. For instance, CEBPA:AP-1 heterodimers are favored in monocytic differentiation, where AP-1 proteins influence dimer preference over CEBPA homodimers. Among co-activators, CEBPA physically associates with and p300, histone acetyltransferases that enhance transcriptional activation by acetylating at target promoters and also modifying CEBPA itself to regulate its activity. This interaction promotes granulopoietic , as demonstrated in myeloid cell models where CBP/p300 recruitment correlates with increased accessibility. Additionally, CEBPA interacts with CDK9, a component of the P-TEFb complex, which phosphorylates to facilitate transcriptional elongation of differentiation genes. CEBPA also engages repressors that limit its function in specific contexts. E2F1, through its dimerization partner DP, directly binds CEBPA via protein-protein interactions, repressing CEBPA transcriptional activity and contributing to control in progenitors; this was confirmed by co-immunoprecipitation and yeast two-hybrid assays showing CEBPA-E2F/DP complex formation independent of pocket proteins. In early hematopoietic progenitors, CEBPA forms inactive complexes with PU.1 (encoded by SPI1), where high PU.1 levels antagonize CEBPA DNA binding and differentiation potential, as evidenced by functional studies in myeloid cells. Beyond these, CEBPA interacts with RUNX1 to coordinate hematopoiesis, with co-immunoprecipitation revealing direct binding that recruits epigenetic modifiers like TET2 to myeloid enhancers. In TGF-β signaling, CEBPA associates with SMAD3, where SMAD3 binding represses CEBPA expression during epithelial-mesenchymal transition, supported by showing SMAD3 occupancy at the CEBPA locus post-TGF-β stimulation. These interactions have been validated through experimental approaches including co-immunoprecipitation, which captures endogenous complexes in cell lysates (e.g., for - and -E2F/DP), and yeast two-hybrid screening, which identifies binary interactions like those in the bZIP dimerization domain. Such methods confirm the direct physical nature of these partnerships, distinguishing them from indirect regulatory effects.

Functional Interaction Pathways

CEBPA plays a pivotal role in the hematopoietic regulatory network through its mutual antagonism with PU.1, which governs the switch between myeloid and lymphoid cell fates. In early hematopoietic progenitors, low PU.1 levels favor lymphoid differentiation, while higher levels promote myeloid commitment; CEBPA reinforces myeloid granulocytic fate by counteracting PU.1 activity. Specifically, PU.1 induces the expression of and Egr2, which repress CEBPA, whereas CEBPA activates Gfi1, inhibiting PU.1-dependent genes, thereby directing progenitors toward granulocytes over s. In the inflammatory response, CEBPA cooperates with to induce in macrophages, enhancing acute-phase responses during or stress. p50 directly binds the CEBPA promoter to upregulate its expression in response to inflammatory signals, allowing CEBPA to synergize with at promoters of genes like IL-6 and G-CSF, thereby amplifying and immune activation. Additionally, CEBPA interacts with in signaling pathways, where STAT3-mediated IL-6 induction stabilizes CEBPA binding to shared enhancers, promoting sustained transcription of pro-inflammatory mediators such as in activated macrophages. CEBPA contributes to cell cycle control by repressing target genes, facilitating G0 arrest essential for terminal differentiation in myeloid lineages. Through its N-terminal and basic region motifs, CEBPA directly inhibits E2F-dependent transcription of proliferation genes like cyclin E and α, coupling growth arrest with granulocytic maturation. studies of CEBPA mutants defective in E2F repression demonstrate impaired development and persistent proliferation, underscoring this mechanism's necessity for proper hematopoietic differentiation. In disease contexts, such as (AML), the AML1-ETO disrupts the CEBPA-RUNX1 axis, blocking granulocytic differentiation. AML1-ETO, arising from t(8;21) translocation, indirectly suppresses CEBPA expression by inhibiting its positive autoregulation on the CEBPA promoter, leading to reduced CEBPA protein levels and failure to activate RUNX1-dependent myeloid genes. This dysregulation maintains leukemic blasts in a proliferative state, as evidenced by restored differentiation upon CEBPA re-expression in AML1-ETO-positive cells. Systems biology models of CEBPA interactions reveal like feed-forward loops that stabilize hematopoietic fate decisions. In , CEBPA forms coherent feed-forward loops with RUNX1, where both factors co-bind and mutually reinforce targets such as G-CSF receptor, ensuring robust activation during differentiation.

Clinical Significance

Involvement in

CEBPA mutations play a central role in the pathogenesis of (AML), particularly through biallelic alterations that disrupt normal myeloid differentiation. These mutations, often involving both N-terminal and C-terminal regions of the gene, lead to the production of truncated or dominant-negative CEBPA proteins that fail to activate target genes essential for granulocytic maturation, resulting in the accumulation of immature myeloid blasts. This differentiation block is a key driver of leukemogenesis, as evidenced by functional studies showing that mutant CEBPA impairs the transcriptional regulation of genes like those involved in the GFI-1/PU.1 pathway, promoting self-renewal and proliferation of leukemic progenitors. CEBPA-mutated AML is recognized as a distinct diagnostic entity in the (WHO) classification, with updates in 2016 and 2022 specifying that biallelic , including at least one in the basic (bZIP) domain, define this subtype among cases with ≥20% blasts and normal . These are enriched in cytogenetically normal AML, comprising approximately 5-14% of adult cases and 5-15% of pediatric cases, with higher frequencies observed in younger patients and those lacking other recurrent abnormalities like . The subtype typically presents with FAB M1 or M2 morphology, monocytic features, and expression of and CD7 on blasts. Full leukemic transformation in CEBPA-mutated AML often requires cooperating genetic , such as in FLT3 (particularly internal tandem duplications, ITD) or , which enhance proliferative signaling and further impair differentiation. For instance, mutations occur in up to 28% of CEBPA double-mutant cases and contribute to dysregulated hematopoiesis, while FLT3-ITD co-occurrences, seen in about 16% of cases, provide additional oncogenic drive. These secondary hits collaborate with CEBPA alterations to initiate and maintain the leukemic state, as demonstrated in patient-derived samples where combined accelerate disease progression. Preclinical model systems have confirmed the oncogenic potential of CEBPA . Conditional knock-in models expressing patient-derived biallelic CEBPA develop a recapitulating human AML, including differentiation arrest at the stage, , and reduced latency to upon secondary hits like FLT3-ITD. These models highlight CEBPA as an initiating lesion and provide insights into the stepwise accumulation of required for full transformation.

Implications in Solid Tumors and Other Cancers

In solid tumors, CEBPA is frequently downregulated, often through promoter , which contributes to uncontrolled . In lung adenocarcinoma, a subtype of non-small cell , CEBPA expression is reduced in approximately 40-50% of cases, primarily due to epigenetic silencing via upstream promoter hypermethylation, leading to loss of its antiproliferative and differentiation-inducing effects. This downregulation promotes tumor growth by disrupting cell cycle arrest and pathways, as evidenced by studies showing that forced CEBPA re-expression in cell lines inhibits proliferation and induces type II pneumocyte-like differentiation. Somatic in CEBPA are rare in solid tumors but have been reported in hepatocellular carcinoma (HCC), where they may coexist with expression changes; however, altered CEBPA activity more commonly arises from other mechanisms like miRNA-mediated suppression or proteasomal degradation, exacerbating HCC progression. Beyond AML, CEBPA alterations occur in other hematologic malignancies, influencing disease biology. Monoallelic mutations in the CEBPA gene have been identified in (T-ALL), potentially disrupting and contributing to leukemogenesis, though they are less frequent than in myeloid disorders. In , CEBPA silencing, often through indirect epigenetic or posttranscriptional mechanisms such as lncRNA interference, correlates with disease progression and resistance to therapy, highlighting its role as a potential tumor suppressor in plasma cell neoplasms. Prognostically, biallelic CEBPA in AML are associated with favorable outcomes, with 5-year overall rates around 55% in intensively treated patients, reflecting lower rates compared to wild-type cases. In contrast, CEBPA promoter methylation serves as a marker of adverse across malignancies, predicting higher risk in AML by sustaining epigenetic silencing and impairing differentiation, as observed in cohorts where methylated cases showed inferior event-free . Diagnostically, CEBPA alterations are integral to AML risk stratification per the 2022 European LeukemiaNet (ELN) guidelines, where in-frame bZIP domain (mono- or biallelic) classify cases as favorable risk, guiding decisions on intensive therapy versus allogeneic transplantation. Next-generation sequencing (NGS) panels routinely detect these , enabling precise in clinical workflows for AML and emerging applications in solid tumors. Therapeutically, strategies targeting CEBPA dysfunction emphasize restoring its function to induce differentiation. All-trans retinoic acid (ATRA)-like agents promote myeloid maturation in CEBPA-altered AML by enhancing transcriptional activity, while (HDAC) inhibitors reverse promoter silencing, reactivating CEBPA expression and synergizing with to reduce proliferation in preclinical models. Ongoing trials post-2020, such as NCT06458257 evaluating allogeneic in high-relapse-risk CEBPA-mutant AML and NCT06529250 assessing intermediate-dose regimens, aim to optimize outcomes by addressing relapse vulnerability in these patients.

References

  1. https://www.ncbi.nlm.nih.gov/gene/1050
  2. https://medlineplus.gov/genetics/gene/cebpa/
  3. https://www.cancer.gov/publications/pdq/information-summaries/genetics/cebpa-hp-pdq
  4. https://www.ensembl.org/Homo_sapiens/Gene/Summary?g=ENSG00000245848
  5. https://omim.org/entry/116897
  6. https://www.ncbi.nlm.nih.gov/gene/12606
  7. https://www.genecards.org/cgi-bin/carddisp.pl?gene=CEBPA
  8. https://pmc.ncbi.nlm.nih.gov/articles/PMC4696001/
  9. https://ashpublications.org/blood/article/129/15/2083/36382/Expression-and-regulation-of-C-EBP-in-normal
  10. https://www.nature.com/articles/7310121
  11. https://www.science.org/doi/10.1126/sciadv.aaw4304
  12. https://pmc.ncbi.nlm.nih.gov/articles/PMC7115832/
  13. https://pmc.ncbi.nlm.nih.gov/articles/PMC2118199/
  14. https://pubmed.ncbi.nlm.nih.gov/22184527/
  15. https://atlasgeneticsoncology.org/gene/40050/cebpa-%28ccaat-enhancer-binding-protein-%28c-ebp%29-alpha%29
  16. https://www.nature.com/articles/ncomms10968
  17. https://www.science.org/doi/10.1126/science.7652557
  18. https://genesdev.cshlp.org/content/16/1/22.short
  19. https://pmc.ncbi.nlm.nih.gov/articles/PMC1895788/
  20. https://pmc.ncbi.nlm.nih.gov/articles/PMC1347037/
  21. https://royalsocietypublishing.org/doi/10.1098/rsob.240215
  22. https://www.pnas.org/doi/10.1073/pnas.2315659121
  23. https://www.sciencedirect.com/science/article/pii/S0006497120334844
  24. https://doi.org/10.1007/s12185-015-1764-6
  25. https://pmc.ncbi.nlm.nih.gov/articles/PMC10480322/
  26. https://pmc.ncbi.nlm.nih.gov/articles/PMC11966364/
  27. https://pmc.ncbi.nlm.nih.gov/articles/PMC7496298/
  28. https://doi.org/10.1038/85820
  29. https://doi.org/10.1038/s41375-019-0382-3
  30. https://doi.org/10.18632/oncotarget.23873
  31. https://doi.org/10.1038/sj.leu.2404124
  32. https://doi.org/10.1182/blood-2010-09-307280
  33. https://www.tandfonline.com/doi/full/10.1179/1607845413Y.0000000081
  34. https://pmc.ncbi.nlm.nih.gov/articles/PMC3069241/
  35. https://pubmed.ncbi.nlm.nih.gov/20927134/
  36. https://www.frontiersin.org/journals/genetics/articles/10.3389/fgene.2019.00133/full
  37. https://www.nejm.org/doi/full/10.1056/NEJMoa1005143
  38. https://haematologica.org/article/view/5943
  39. https://pubmed.ncbi.nlm.nih.gov/36864492/
  40. https://haematologica.org/article/view/7138/43085
  41. https://pmc.ncbi.nlm.nih.gov/articles/PMC3937760/
  42. https://www.nature.com/articles/s41467-017-00032-6
  43. https://www.sciencedirect.com/science/article/pii/S000649712032869X
  44. https://link.springer.com/article/10.1007/s12185-015-1764-6
  45. https://pubmed.ncbi.nlm.nih.gov/21543584/
  46. https://pubs.rsc.org/en/content/articlelanding/2020/cp/d0cp01796a
  47. https://pmc.ncbi.nlm.nih.gov/articles/PMC2863587/
  48. https://www.sciencedirect.com/science/article/pii/S0301472X1300920X
  49. https://pmc.ncbi.nlm.nih.gov/articles/PMC9569612/
  50. https://www.nature.com/articles/s41467-020-14556-x
  51. https://journals.plos.org/plosone/article?id=10.1371/journal.pone.0217580
  52. https://pmc.ncbi.nlm.nih.gov/articles/PMC2672404/
  53. https://www.sciencedirect.com/science/article/pii/S0753332223017365
  54. https://www.cell.com/cell/fulltext/S0092-8674(01)00516-5
  55. https://pubmed.ncbi.nlm.nih.gov/11283671/
  56. https://www.mdpi.com/1422-0067/14/1/1566
  57. https://www.frontiersin.org/journals/oncology/articles/10.3389/fonc.2022.806137/full
  58. https://pmc.ncbi.nlm.nih.gov/articles/PMC8844020/
  59. https://pmc.ncbi.nlm.nih.gov/articles/PMC11016528/
  60. https://link.springer.com/article/10.1007/s11899-023-00699-3
  61. https://www.sciencedirect.com/science/article/pii/S0006497121014099
  62. https://www.nature.com/articles/s41375-024-02140-x
  63. https://www.sciencedirect.com/science/article/pii/S1535610808000445
  64. https://pmc.ncbi.nlm.nih.gov/articles/PMC3380244/
  65. https://aacrjournals.org/cancerres/article/62/2/528/509251/Down-Regulation-and-Antiproliferative-Role-of-C
  66. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9724427/
  67. https://pubmed.ncbi.nlm.nih.gov/18182175/
  68. https://onkder.org/pdf.php?&id=1292
  69. https://ashpublications.org/blood/article/140/12/1345/485817/Diagnosis-and-management-of-AML-in-adults-2022
  70. https://clinicaltrials.gov/study/NCT06458257
  71. https://clinicaltrials.gov/study/NCT06529250
Add your contribution
Related Hubs
Contribute something
User Avatar
No comments yet.