Mutational profiling of acute myeloid leukemia with normal cytogenetics in Brazilian patients: the value of next-generation sequencing for genomic classification

High trophinin-associated protein expression predicts good survival in acute myeloid leukemia with normal cytogenetics

BACKGROUND

Nearly half of adult acute myeloid leukemia (AML) patients were classified into cytogenetic normal acute myeloid leukemia (CN-AML). The expression level of Trophinin associated protein (TROAP) was proven to be associated with the prognosis of several cancers, but it is still unclear in the prognosis of patients with CN-AML.

METHODS

We integrated CN-AML patients samples from 4 datasets to analyze the relationship between TROAP expression and the survival of CN-AML. In addition, we investigated 92 AML patients of The Cancer Genome Atlas (TCGA) database to analyze the relationship between TROAP expression and the survival of AML patients received chemotherapy. We investigated the relationship between the expression of TROAP and drug sensitivity in AML cell lines.

RESULTS

CN-AML patients with high TROAP expression were related to good event-free survival (EFS) and overall survival (OS). In AML patients received chemotherapy, high TROAP expression was associated with good survival prognosis. Additionally, the expression of TROAP gene in leukemia stem cells (LSC) + group was lower. Among multiple drugs, the lower the expression of TROAP, the lower the IC50.

CONCLUSION

TROAP could serve as an independent predictor of CN-AML patients and could act as a potential biomarker for the prognosis of CN-AML. TROAP expression levels were closely correlated with the drug sensitivity of multiple drugs.

Spectrum of gene mutations identified by targeted next-generation sequencing in Chinese leukemia patients

BACKGROUND

Despite targeted sequencing have identified several mutations for leukemia, there is still a limit of mutation screening for Chinese leukemia. Here, we used targeted next-generation sequencing for testing the mutation patterns of Chinese leukemia patients.

METHODS

We performed targeted sequencing of 504 tumor-related genes in 109 leukemia samples to identify single-nucleotide variants (SNVs) and insertions and deletions (INDELs). Pathogenic variants were assessed based on the American College of Medical Genetics and Genomics (ACMG) guidelines. The functional impact of pathogenic genes was explored through gene ontology (GO), pathway analysis, and protein-protein interaction network in silico.

RESULTS

We identified a total of 4,655 SNVs and 614 INDELs in 419 genes, in which PDE4DIP, NOTCH2, FANCA, BCR, and ROS1 emerged as the highly mutated genes. Of note, we were the first to demonstrate an association of PDE4DIP mutation and leukemia. Based on ACMG guidelines, 39 pathogenic and likely pathogenic mutations in 27 genes were found. GO annotation showed that the biological process including gland development, leukocyte differentiation, respiratory system development, myeloid leukocyte differentiation, mesenchymal to epithelial transition, and so on were involved.

CONCLUSION

Our study provided a map of gene mutations in Chinese patients with leukemia and gave insights into the molecular pathogenesis of leukemia.

[Research progress on uniparental disomy in cancer]

Uniparental disomy (UPD) refers to a chromosome defect that an individual's homologous chromosome or segments are inherited from one parent. UPD can cause either aberrant patterns of genomic imprinting or homozygosity of mutations, leading to various diseases, including cancer. The mechanisms of UPD formation are diverse but largely due to the incorrect chromosome separation during cell division. UPD does not alter the number of gene copies, thus is difficult to be detected by conventional cytogenetic techniques effectively. Assisted by the new techniques such as single nucleotide polymorphism arrays, more and more UPD-related cases have been reported recently. UPD events are non-randomly distributed across cancer types, which play important role in the occurrence, development and metastasis of cancer. Here we review the research progress on the formation mechanisms, detection methods, the involved chromosomal regions and genes, and clinical significance of UPD; and also discuss the directions for future studies in this field.

High NCALD expression predicts poor prognosis of cytogenetic normal acute myeloid leukemia

Background

Acute myeloid leukemia (AML) is a heterogeneous disease in terms of genetic basis, clinical, biological and prognostic, and is a malignant clonal disease of leukemia stem cells (LSCs). Nearly half of adult AML patients exhibit a cytogenetic normal acute myeloid leukemia (CN-AML). The expression level of NCALD gene was associated with the prognosis of ovarian cancer and non-small cell lung cancer (NSCLC). The expression level of NCALD gene is still unclear in the prognosis of patients with AML.

Method

We integrated 5 independent datasets totally 665 AML patients (497 CN-AML patients) to analyzed relation between NCALD gene expression and the clinical FAB classification, gene mutation, therapy, prognosis of CN-AML. We analyzed the NCALD gene expression with the prognosis and LSC of 165 AML patients from The Cancer Genome Atlas (TCGA) dataset and 78 AML patients from GEO dataset.

Results

High NCALD-expressing CN-AML patients were associated with poor event-free survival (EFS) and overall survival (OS) compared to low NCALD expression (EFS, P < 0.0001, OS, P < 0.0001). In AML patients of allogeneic hematopoietic stem cell transplantation (allo-HSCT), high NCALD expression was associated with poor survival prognosis in EFS and OS (EFS, P < 0.0051, OS, P = 0.028). Post-chemotherapy in AML patients, high NCALD expression led a worse prognosis in EFS and OS (EFS, P = 0.011; OS, P = 0.0056). In multivariate analysis, high NCALD expression was an independent prognostic factor that predicts shorter EFS and OS (EFS, P = 3.84E−05, OS, P = 8.53E−05) of CN-AML.

Conclusion

Our results indicate that high expression of NCALD gene is a poor prognostic factor for CN-AML. NCALD can be considered as independent predictors of CN-AML patients and can be used as a biomarker for the prognosis of CN-AML.

Electronic supplementary material

The online version of this article (10.1186/s12967-019-1904-5) contains supplementary material, which is available to authorized users.

JAK2-mutated acute myeloid leukemia: comparison of next-generation sequencing (NGS) and single nucleotide polymorphism array (SNPa) findings between two cases

JAK2 mutations are rare in de novo acute myeloid leukemia (AML), and JAK2-mutated acute myeloid leukemia (AML) patients usually have a previous history of myeloproliferative neoplasms (MPNs). Current advances in laboratory techniques, such as single nucleotide polymorphism array (SNPa) and next-generation sequencing (NGS), have facilitated new insight into the molecular basis of hematologic diseases. Herein, we present two cases of JAK2-mutated AML in which both SNPa and NGS methods added valuable information. Both cases had leukemogenic collaboration, namely, copy-neutral loss of heterozygosity (CN-LOH), detected on chromosome 9. One of the cases exhibited both JAK2 and IDH2 mutations, most likely having originated as an MPN with leukemic transformation, while the other case was classified as a de novo AML with JAK2, CEBPA, and FLT3 mutations.

Gene mutation patterns of Chinese acute myeloid leukemia patients by targeted next-generation sequencing and bioinformatic analysis

PURPOSES

The conventional risk stratification of acute myeloid leukemia (AML), based on cytogenetics, cannot meet the demand for accurate prognostic evaluations. In recent years, gene mutations are found to be potential markers for more accurate risk stratification, but reports on mutation screening of Chinese AML are limited. We aim to display the mutation patterns of Chinese AML patients, reveal the genotype-phenotype correlations and make a comparison with Caucasians patients.

METHODS

Genome DNA from 78 patients' bone marrow were extracted for targeted gene mutation panel by next-generation sequencing (NGS) technology. Statistics and bioinformatics were used to analyze the correlations between gene mutations and clinical features, as well as the comparison of our results with the Cancer Genome Atlas Research Network (TCGA) public AML dataset.

RESULTS

We found patients with mutations of FLT3 and TET2 had higher bone marrow blasts, peripheral blasts and white blood cell (WBC) count, mutations of SRSF2 were related with age, and mutations of FLT3-ITD, DNMT3A, IDH1, TET2 and SRSF2 were risk factors for overall survival. What's more, we discovered 15 novel mutations and difference of mutational incidence in 6 genes between Chinese and Caucasians AML. Bioinformatic analysis revealed some relationship between gene mutations and expressions as well as drug sensitivities.

CONCLUSIONS

We made an investigation on the mutation patterns of Chinese AML patients by NGS technique and revealed correlations between gene mutations and clinical features. Thus we recommend routine testing of suspected genes for better prognostic prediction and individualized treatment.