CEBPA Mutations In Patients Research Articles

CEBPA mutations in patients with de novo acute myeloid leukemia: data analysis in a Chinese population.

BackgroundThis study was aimed to explore the clinical characteristics and prognoses of acute myeloid leukemia (AML) patients with CEBPA mutations.Patients and methodsThree hundred and forty-five patients with de novo AML were retrospectively analyzed with regard to CEBPA mutations, clinical characteristics, therapeutic responses, and long-term outcomes.ResultsCEBPA mutations were detected in 59 patients (17.10%), with 47 cases harboring double mutations and 12 cases harboring single mutations. In those with a normal karyotype (NK), 44 cases (25.29%) were detected with CEBPA mutations. The following characteristics were observed in CEBPA-mutated patients: most (66.10%) of them were M1 or M2; they presented with higher peripheral white blood cell counts (23.71 [12.6, 60.02] ×109/L versus 7.34 [2.38, 26.63] ×109/L; u=4.944, P<0.001) and higher hemoglobin levels (89.64±23.05 g/L versus 75.65±23.65 g/L; t=4.156, P<0.001) than those observed in patients without the mutation; and the expression of CD7 and HLA-DR was higher, whereas that of CD34 and CD56 was lower in patients with the mutation than in those without the mutation. Compared with those without the mutation, patients with CEBPA mutations had a superior complete remission rate (75.0% versus 56.54%; χ2=6.185, P=0.013) and superior overall survival (P=0.034).ConclusionThe frequency of CEBPA mutations may be higher in Chinese patients with AML than has been reported in populations of western countries, and the presence of CEBPA mutations is an indication of favorable prognoses for these patients.

Favorable prognosis of biallelic CEBPA gene mutations in acute myeloid leukemia patients: a meta-analysis.

Increasing number of studies suggested that biallelic CEBPA (bi CEBPA) mutations were associated with favorable prognosis in patients with acute myeloid leukemia (AML), but the results remain inconclusive. We therefore present a meta-analysis to evaluate the prognostic value of bi CEBPA mutations in patients with AML. A comprehensive literature search was undertaken through August 2014 looking for eligible studies. Pooled hazard ratios (HRs) estimates and 95% confidence intervals (95% CIs) in overall survival (OS) and event-free survival (EFS) were used to calculate estimated effect. Ten studies covering a total of 6219 subjects were included in this analysis. Overall, bi CEBPA mutations were associated with favorable clinical outcome in patients with AML (HR for EFS: 0.41, 95% CI: 0.32-0.52; for OS: 0.37, 95% CI: 0.27-0.50), in cytogenetically normal (CN)-AML (HR for EFS: 0.38, 95% CI: 0.29-0.49; for OS: 0.32, 95% CI: 0.23-0.43). When took the cohort of monoallelic CEBPA (mo CEBPA) mutated and wild-type CEBPA (wt CEBPA) AML as a reference group, bi CEBPA mutated AML also shown beneficial outcomes (HR for OS: 0.52, 95% CI: 0.37-0.72). No significant difference was found between mo CEBPA mutation and wt CEBPA in patients with AML or CN-AML (P > 0.05). Bi CEBPA mutations in patients with AML are strongly associated with a favorable prognosis, which suggested that bi CEBPA mutations would potentially serve as a novel prognostic marker in AML.

A Comparison of Two Methods for Screening CEBPA Mutations in Patients with Acute Myeloid Leukemia

The goal of the study was to compare the performance of a fluorescence-based multiplex PCR fragment analysis to a direct sequencing method for detecting CEBPA mutations in patients with acute myeloid leukemia. Thirty-three samples were selected from a larger study of 107 cases of acute myeloid leukemia by screening for CEBPA mutations by sequence analysis. Of ten identified mutations, six (insertions and deletions) were detected by both sequencing and fragment methods. The fragment analysis method did not detect the remaining four base substitutions because the method cannot detect changes that result in identically sized products. The multiplex PCR fragment length analysis method therefore failed to detect substitution mutations accounting for 40% of total CEBPA mutations in our patient set. Our results indicate that fragment length analysis should not be used in isolation, and that direct sequencing is required to evaluate CEBPA gene mutational status in acute myeloid leukemia. A combination of the two assays may offer some advantages, chiefly in permitting more sensitive detection by fragment length analysis of insertions and deletions.

A Rapid and Sensitive Method for Large-Scale Screening of CEBPA Mutations in AML Patients with Normal Karyotype.

In 45% of patients with de novo acute myeloid leukemia (AML) no cytogenetic abnormalities can be detected (normal karyotype AML, NK-AML). Recently, several molecular markers with prognostic significance have been described which define distinct subgroups of NK-AML patients. Mutations in the CEBPA gene have shown to occur at about 8% of NK-AML in Western countries and confer a favorable prognosis. The C/EBPα protein, a member of the family of basic region leucine zipper (bZIP) transcriptional regulators, is important for normal granulocytic differentiation and is frequently disrupted in AML. We retrospectively analyzed bone-marrow samples of 442 patients with de novo NK-AML for the presence of CEBPA mutations and established a fast and sensitive screening method. A multiplex-PCR-gene scanning assay for combined detection of CEBPA and NPM mutation has recently been described in which, however, the primers did not cover the whole CEBPA gene. CEBPA mutations have been found to be distributed over the entire CEBPA gene and their functional and clinical consequences are not yet clear. Therefore, we designed a rapid CEBPA specific multiplex PCR-gene scanning assay covering the entire coding region of the CEBPA gene. Four primer pairs were designed, fluorescently labeled and included in 2 multiplex PCR reactions. The PCR products were electrophoresed on a genetic analyzer and the amplicon sizes were compared to wildtype CEBPA of U937 cell line by fragment length analysis. In order to evaluate our method, we analyzed 120 patient samples in parallel by both multiplex PCR and sequencing analysis. Using sequencing analysis as a gold standard, all of the CEBPA mutations could be detected by multiplex PCR and fragment length analysis. Thus, our multiplex PCR assay reached a sensitivity of 100%. The specificity was 89% due to the false positive detection of a 6 basepair duplication polymorphism in 2.5% of patients (Wouters BJ et al, Blood, 2007). 322 patient samples were subsequently screened for CEBPA mutations by the multiplex PCR assay. In case of alterations in the fragment length analysis, the relevant CEBPA region was sequenced to identify the exact type of mutation. Among 442 patients with NK-AML, 32 patients (7%) showed CEBPA mutations. Taken together, we identified 47 mutations in 32 patients, of which 17 patients had a single CEBPA mutation and 15 patients had more than one CEBPA mutation. We identified 30 out of frame insertion/deletion nonsense mutations resulting in an N-terminal stopcodon and 14 in frame insertion/deletion mutations as well as 3 out of frame insertion/deletion mutations in the C-terminal bZIP region. The only limitation of this method might be that single basepair substitutions, which do not affect the length of the amplicon, cannot be detected. Substitutions in the CEBPA gene are, however, rare events and often silent. In 120 sequenced AML patients we did not find any non-silent substitution. We established a fast and sensitive screening method suitable for large-scale detection of CEBPA mutation and applicable for inclusion in routine AML diagnostics. This is so far the largest reported analysis of CEBPA mutations in patients with NK-AML and might provide further insights into the functional and clinical relevance of the different types of CEBPA mutations and their correlation to other molecular markers in NK-AML.

Favorable prognostic significance of CEBPA mutations in patients with de novo acute myeloid leukemia: a study from the Acute Leukemia French Association (ALFA)

The transcription factor C/EBPalpha is crucial for differentiation of mature granulocytes. Recently, different CEBPA gene mutations likely to induce differentiation arrest have been described in nearly 10% of patients with acute myeloid leukemia (AML). In the present study, we retrospectively analyzed the prognostic significance of CEBPA mutations in 135 AML patients (French-American-British [FAB]-M3 excluded). All patients were prospectively enrolled between 1990 and 1996 in a multicenter trial of the ALFA (Acute Leukemia French Association) Group (median age 45 years, median follow-up 5.7 years). Mutations were assessed using direct sequencing of the CEBPA gene. Twenty-two mutations were found in 15 (11%) of 135 patients tested. Twelve patients had at least one mutation located in the N-terminal part of the protein leading to the lack of expression of the full-length C/EBPalpha protein. CEBPA mutations were present only in patients belonging to the intermediate cytogenetic risk subgroup and associated with the FAB-M1 subtype (P =.02). FLT3 internal tandem duplication (ITD) was found in 5 of 15 CEBPA-mutated as compared with 30 of 119 CEBPA-nonmutated cases tested (P =.54). Presence of CEBPA mutations was identified as an independent good prognosis factor for outcome even after adjustment on cytogenetics and FLT3 status (estimated 5-year overall survival 53% vs 25%, P =.04). FLT3-ITD appeared to act as a major bad prognosis factor in patients with CEBPA-mutated AML. We thus propose a risk classification that includes in the favorable subgroup all patients from the intermediate subgroup displaying CEBPA mutations when not associated with FLT3-ITD.