SETBP1 mutations as a biomarker for myelodysplasia /myeloproliferative neoplasm overlap syndrome

Identification of a novel de novo mutation of SETBP1 and new findings of SETBP1 in tumorgenesis

BACKGROUND

In the past decade, SETBP1 has attracted a lot of interest on that the same gene with different type or level (germline or somatic) of variants could provoke different pathologic consequences such as Schinzel-Giedon syndrome, SETBP1 Haploinsufficiency Disorder (SETBP1-HD) and myeloid malignancies. Whole exome sequencing was conducted to detect the etiology of a pregnant woman with mental retardation. As a new oncogene and potential marker of myeloid malignancies, somatic SETBP1 variants in other cancers were rarely studied. We performed a pan-cancer analysis of SETBP1 gene in different cancers for the first time.

RESULTS

A novel heterozygous mutation of the SETBP1 gene (c.1724_1727del, p.D575Vfs*4) was found in the patient and the fetus and the mutation was predicted to result in a truncated protein. Reduced SETBP1 expression was associated with SETBP1-HD. The pan-cancer analysis of SETBP1 showed that SETBP1 overexpression should be given special attention in Bladder Urothelial Carcinoma (BLCA) and Stomach adenocarcinoma (STAD).

CONCLUSIONS

The de novo SETBP1 mutation was the genetic cause of SETBP1-HD in the family. BLCA and STAD might be related to SETBP1 overexpression.

The Role of SETBP1 in Gastric Cancer: Friend or Foe

Background

Gastric cancer (GC) remains a common disease with a poor prognosis worldwide. The SET binding protein 1 (SETBP1) has been implicated in the pathogenesis of several cancers and plays a dual role as an oncogene and a tumor suppressor gene. However, the role and underlying mechanism of SETBP1 in GC remain unclear.

Materials and Methods

We used next-generation RNA sequencing (RNA-seq) data from The Cancer Genome Atlas (TCGA) to explore the correlation between SETBP1 expression and tumor progression. We then quantified SETBP1 expression in GC cells with real-time quantitative polymerase chain reactions (RT-qPCR). The chi-square test and logistic regression were used to assess the correlation between SETBP1 expression and clinicopathological features. Kaplan-Meier survival analysis and Cox proportional hazards regression model were used to assess the relationship between SETBP1 expression and survival. Finally, gene set enrichment analyses (GSEA) were used to examine GC-related signaling pathways in low and high SETBP1 expressing samples.

Results

We found SETBP1 expression levels in GC tissues to be significantly lower than in adjacent non-tumor tissues in the TCGA database. In addition, SETBP1 expression differed significantly between groups classified by tumor differentiation. Furthermore, SETBP1 expression in diffuse-type GC was significantly higher than in intestinal-type GC. However, it did not differ significantly across pathological- or T-stage groups. RT-qPCR and comprehensive meta-analysis showed that SETBP1 expression is downregulated in GC cells and tissues. Interestingly, SETBP1 expression in poorly- or un-differentiated GC cells was higher than in well-differentiated GC cells. Moreover, the chi-square test and logistic regression analyses showed that SETBP1 expression correlates significantly with tumor differentiation. Kaplan–Meier curves indicated that patients with relatively high SETBP1 expression had a poor prognosis. Multivariate analyses indicated that SETBP1 expression might be an important predictor of poor overall survival in GC patients. GSEA indicated that 20 signaling pathways were significantly enriched in samples with high and low SETBP1 expression.

Conclusion

SETBP1 may play a dual role in GC progression.

Molecular Pathogenesis of BCR-ABL-Negative Atypical Chronic Myeloid Leukemia

Atypical chronic myeloid leukemia is a rare disease whose pathogenesis has long been debated. It currently belongs to the group of myelodysplastic/myeloproliferative disorders. In this review, an overview on the current knowledge about diagnosis, prognosis, and genetics is presented, with a major focus on the recent molecular findings. We describe here the molecular pathogenesis of the disease, focusing on the mechanisms of action of the main mutations as well as on gene expression profiling. We also present the treatment options focusing on emerging targeted therapies.

Up-front Treatment With Romiplostim in Children With Acquired Bone Marrow Failure: A Single Institutional Pediatric Case Series

BACKGROUND

Thrombopoietin receptor agonists are emerging as a therapeutic option for patients with aplastic anemia (AA) and myelodysplastic syndrome (MDS). We report our experience of treating children with AA/MDS with romiplostim, thrombopoietin receptor agonist.

OBSERVATIONS

Three children (AA, 2; MDS, 1) received romiplostim treatment at a median dose of 10 μg/kg/week (starting dose: 5 μg/kg/wk; 2.5 μg/kg/wk increment). Trilineage hematopoietic recovery occurred at a median of 13 weeks (range: 13 to 16 wk) without adverse events. Hematopoiesis continued to improve after therapy discontinuation (median follow-up: 2.8 y; range: 0.5 to 3.0).

CONCLUSION

Our experience supports the short-term safety and efficacy of romiplostim in children with AA/MDS.

Atypical CML- the role of morphology and precision genomics

Atypical chronic myeloid leukemia is an esoteric myeloid malignancy with features of both myeloproliferative and myelodysplastic syndromes. This disease is characterized primarily by morphologic-based criteria, and has clinical and molecular features overlapping with other myeloid malignancies. No one molecular abnormality is specific, and multiple mutations are often present in various combinations, due to the malignant multi-step clonal evolution of myeloid malignancies. In this review, we will address what we know about atypical chronic myeloid leukemia; evaluate how the molecular landscape in myeloid malignancies overlaps, and discuss what we can learn by incorporating individualized precision genomic strategies.

Clonal evolution revealed by next-generation sequencing in a long-term follow-up patient with hypereosinophilia

The natural history of primary hypereosinophilia remains poorly defined, given the underlying disease heterogeneity. Recently, targeted NGS helps to establish clonality in a subset of patients with hypereosinophilia. We first reported the clonal evolution in a long-term follow-up patient with hypereosinophilia. This case initially presented with chronic eosinophilic leukemia, not otherwise specified (CEL-NOS), successively transformed to myelodysplastic syndromes (MDS) and acute myeloid leukemia(s-AML). We identified three mutations at CEL-NOS phase, five and seven mutations at MDS and s-AML stages, respectively. Our data illustrate the clonal dynamic process associated with disease evolution from CEL-NOS to s-AML.

SRSF2 mutations in myelodysplasia/myeloproliferative neoplasms

Recurrent gene mutations have been described with varying frequencies in myelodysplasia (MDS) /myeloproliferative neoplasm (MPN) overlap syndromes (MMOS). Recent work has placed significant focus on understanding the role of gene lesions involving the spliceosomal machinery in leukemogeneis. SRSF2 is a gene encoding critical spliceosomal proteins. SRSF2 mutations appear to play an important role in pathogenesis of MMOS, particularly in chronic myelomonocytic leukemia. Inhibition of splicing may be a new therapeutic approach. E7107, a spliceosome inhibitor, has been shown to differentially inhibit splicing more in SRSF2-mutant cells leading to decreased leukemia burden in mice. H3B-8800 is a small molecule modulator of spliceosome complex and has been shown to lower leukemia burden in SRSF2-P95H mutant mice. This review focuses on the incidence of mutant SRSF2 across various MMOS as well as recent clinical development of spliceosome inhibitors.

Venetoclax and low-dose cytarabine induced complete remission in a patient with high-risk acute myeloid leukemia: a case report

Conventional combination therapies have not resulted in considerable progress in the treatment of acute myeloid leukemia (AML). Elderly patients with AML and poor risk factors have grave prognosis. Midostaurin has been recently approved for the treatment of FLT-3-mutated AML. Venetoclax, a BCL-2 inhibitor, has been approved for the treatment of relapsed and/or refractory chronic lymphoid leukemia. Clinical trials on applying venetoclax in combination with cytarabine and other agents to treat various hematological malignancies are currently underway. Here, we present a case of a male patient with poor performance status and who developed AML following allogeneic hematopoietic stem cell transplant for high-risk myelodysplasia. The patient with high risk AML achieved complete response to the combined treatment regimen of low-dose cytarabine and venetoclax. Furthermore, we reviewed current clinical trials on the use of venetoclax for hematological malignancies.