Myelodysplastic Syndromes: Diagnosis and Treatment

A Tox21 Approach to Altered Epigenetic Landscapes: Assessing Epigenetic Toxicity Pathways Leading to Altered Gene Expression and Oncogenic Transformation In Vitro

An emerging vision for toxicity testing in the 21st century foresees in vitro assays assuming the leading role in testing for chemical hazards, including testing for carcinogenicity. Toxicity will be determined by monitoring key steps in functionally validated molecular pathways, using tests designed to reveal chemically-induced perturbations that lead to adverse phenotypic endpoints in cultured human cells. Risk assessments would subsequently be derived from the causal in vitro endpoints and concentration vs. effect data extrapolated to human in vivo concentrations. Much direct experimental evidence now shows that disruption of epigenetic processes by chemicals is a carcinogenic mode of action that leads to altered gene functions playing causal roles in cancer initiation and progression. In assessing chemical safety, it would therefore be advantageous to consider an emerging class of carcinogens, the epigenotoxicants, with the ability to change chromatin and/or DNA marks by direct or indirect effects on the activities of enzymes (writers, erasers/editors, remodelers and readers) that convey the epigenetic information. Evidence is reviewed supporting a strategy for in vitro hazard identification of carcinogens that induce toxicity through disturbance of functional epigenetic pathways in human somatic cells, leading to inactivated tumour suppressor genes and carcinogenesis. In the context of human cell transformation models, these in vitro pathway measurements ensure high biological relevance to the apical endpoint of cancer. Four causal mechanisms participating in pathways to persistent epigenetic gene silencing were considered: covalent histone modification, nucleosome remodeling, non-coding RNA interaction and DNA methylation. Within these four interacting mechanisms, 25 epigenetic toxicity pathway components (SET1, MLL1, KDM5, G9A, SUV39H1, SETDB1, EZH2, JMJD3, CBX7, CBX8, BMI, SUZ12, HP1, MPP8, DNMT1, DNMT3A, DNMT3B, TET1, MeCP2, SETDB2, BAZ2A, UHRF1, CTCF, HOTAIR and ANRIL) were found to have experimental evidence showing that functional perturbations played “driver” roles in human cellular transformation. Measurement of epigenotoxicants presents challenges for short-term carcinogenicity testing, especially in the high-throughput modes emphasized in the Tox21 chemicals testing approach. There is need to develop and validate in vitro tests to detect both, locus-specific, and genome-wide, epigenetic alterations with causal links to oncogenic cellular phenotypes. Some recent examples of cell-based high throughput chemical screening assays are presented that have been applied or have shown potential for application to epigenetic endpoints.

Telomerase and telomere biology in hematological diseases: A new therapeutic target

Telomeres are structures confined at the ends of eukaryotic chromosomes. With each cell division, telomeric repeats are lost because DNA polymerases are incapable to fully duplicate the very ends of linear chromosomes. Loss of repeats causes cell senescence, and apoptosis. Telomerase neutralizes loss of telomeric sequences by adding telomere repeats at the 3' telomeric overhang. Telomere biology is frequently associated with human cancer and dysfunctional telomeres have been proved to participate to genetic instability. This review covers the information on telomerase expression and genetic alterations in the most relevant types of hematological diseases. Telomere erosion hampers the capability of hematopoietic stem cells to effectively replicate, clinically resulting in bone marrow failure. Furthermore, telomerase mutations are genetic risk factors for the occurrence of some hematologic cancers. New discoveries in telomere structure and telomerase functions have led to an increasing interest in targeting telomeres and telomerase in anti-cancer therapy.

The genetics of myelodysplastic syndrome: from clonal haematopoiesis to secondary leukaemia

Myelodysplastic syndrome (MDS) is a clonal disease that arises from the expansion of mutated haematopoietic stem cells. In a spectrum of myeloid disorders ranging from clonal haematopoiesis of indeterminate potential (CHIP) to secondary acute myeloid leukaemia (sAML), MDS is distinguished by the presence of peripheral blood cytopenias, dysplastic haematopoietic differentiation and the absence of features that define acute leukaemia. More than 50 recurrently mutated genes are involved in the pathogenesis of MDS, including genes that encode proteins involved in pre-mRNA splicing, epigenetic regulation and transcription. In this Review we discuss the molecular processes that lead to CHIP and further clonal evolution to MDS and sAML. We also highlight the ways in which these insights are shaping the clinical management of MDS, including classification schemata, prognostic scoring systems and therapeutic approaches.

Effect of Chinese medicine treatment based on pattern identification on cellular immunophenotype of myelodysplastic syndrome

OBJECTIVE

To observe the influence of treatment based on Chinese medicine pattern identification on cellular immunophenotype of the myelodysplastic syndrome (MDS).

METHODS

Sixty patients with MDS were randomly and equally assigned to the treatment group and the control group using a randomized digital table. Thirty patients in each group included 3 risk levels (low, moderate and high risks) with each level 10 patients according to the international prognostic scoring system. The control group was given conventional therapy which was also used in the treatment group. While the treatment group was given Zuogui Pill () and Yougui Pill () for low risk patients; Qingwen Baidu Decoction () and Bazhen Decoction () for moderate risk patients; Gexia Zhuyu Decoction () and Qinghao Biejia Decoction () combined with Shiquan Dabu Decoction () for high risk patients. After the treatment, the differences of overall response rate and immunophenotype (CD13, CD14, CD15, CD33 and CD34) of each group were analyzed.

RESULTS

The overall response rate of the treatment group was significantly higher than the control group in low risk and moderate risk patients (P=0.029), there was no statistical differences of overall response rate between the treatment group and the control group in high risk patients (P=0.089). The expressions of CD13, CD14, CD33 and CD34 in all three risk levels of the treatment group were obviously decreased after the treatment, while CD15 in all three risk levels of the treatment group was obviously increased after the treatment (P<0.05 or P<0.01). Meanwhile, the difference values of CD13 and CD33 in low risk level of the treatment group, CD33 and CD34 in moderate risk level of the treatment group as well as CD34 and CD15 in high risk level of the treatment group, were all greater than the control groups and they were statistically significant (P<0.05 or P<0.01).

CONCLUSIONS

It shows a better therapeutic effect if the MDS patients treated with Chinese medicine pattern identification in addition to conventional therapy. Since the treatment may inhibit the malignant clones and improve the dysmaturity of granulocyte differentiation, it is a feasible option in clinical practice.

Good riddance to the term "refractory anemia" in myelodysplastic syndromes

The term "refractory anemia" was used in 1937 by Cornelius Parker Rhoads to describe patients whose anemia did not improve after treatment with liver extract or iron salts, and this term has been used to denote patients with certain subtypes of myelodysplastic syndromes (MDS) since the 1976 and 1982 French-American-British (FAB) classifications of acute leukemias and MDS. In 2016, the World Health Organization (WHO) proposed elimination of "refractory anemia" in a more general proposal for reclassification of myeloid neoplasia. A scandal relating to Dr. Rhoads' possibly unethical medical experiments on anemic patients in Puerto Rico in 1931 and a racially offensive letter he wrote during that period prompted an international incident and Congressional-level inquiry. This dark history, as well as continued terminological problems with refractory anemia, suggest that this hoary term has indeed worn out its usefulness. This article reviews the history of "refractory anemia" and evolution in its use over the past 80 years. Rhoads' personal history, the potentially confusing nature of "refractory anemia", and the fact that it is possible none of the 100 patients Rhoads described in 1937 actually had MDS all support the new WHO reclassification proposal to eliminate this term.

Splicing factor gene mutations in the myelodysplastic syndromes: impact on disease phenotype and therapeutic applications

Splicing factor gene mutations are the most frequent mutations found in patients with the myeloid malignancy myelodysplastic syndrome (MDS), suggesting that spliceosomal dysfunction plays a major role in disease pathogenesis. The aberrantly spliced target genes and deregulated cellular pathways associated with the commonly mutated splicing factor genes in MDS (SF3B1, SRSF2 and U2AF1) are being identified, illuminating the molecular mechanisms underlying MDS. Emerging data from mouse modeling studies indicate that the presence of splicing factor gene mutations can lead to bone marrow hematopoietic stem/myeloid progenitor cell expansion, impaired hematopoiesis and dysplastic differentiation that are hallmarks of MDS. Importantly, recent evidence suggests that spliceosome inhibitors and splicing modulators may have therapeutic value in the treatment of splicing factor mutant myeloid malignancies.

Connect MDS/AML: design of the myelodysplastic syndromes and acute myeloid leukemia disease registry, a prospective observational cohort study

Background

Myelodysplastic syndromes (MDS) and acute myeloid leukemia (AML) are myeloid neoplasms in which outgrowth of neoplastic clones disrupts normal hematopoiesis. Some patients with unexplained persistent cytopenias may not meet minimal diagnostic criteria for MDS but an alternate diagnosis is not apparent; the term idiopathic cytopenia of undetermined significance (ICUS) has been used to describe this state. MDS and AML occur primarily in older patients who are often treated outside the clinical trial setting. Consequently, our understanding of the patterns of diagnostic evaluation, management, and outcomes of these patients is limited. Furthermore, there are few natural history studies of ICUS. To better understand how patients who have MDS, ICUS, or AML are managed in the routine clinical setting, the Connect MDS/AML Disease Registry, a multicenter, prospective, observational cohort study of patients newly diagnosed with these conditions has been initiated.

Methods/Design

The Connect MDS/AML Disease Registry will capture diagnosis, risk assessment, treatment, and outcomes data for approximately 1500 newly diagnosed patients from approximately 150 community and academic sites in the United States in 4 cohorts: (1) lower-risk MDS (International Prognostic Scoring System [IPSS] low and intermediate-1 risk), with and without del(5q); (2) higher-risk MDS (IPSS intermediate-2 and high risk); (3) ICUS; and (4) AML in patients aged ≥ 55 years (excluding acute promyelocytic leukemia). Diagnosis will be confirmed by central review. Baseline patient characteristics, diagnostic patterns, treatment patterns, clinical outcomes, health economics outcomes, and patient-reported health-related quality of life will be entered into an electronic data capture system at enrollment and quarterly for 8 years. A tissue substudy to explore the relationship between karyotypes, molecular markers, and clinical outcomes will be conducted, and is optional for patients.

Discussion

The Connect MDS/AML Disease Registry will be the first prospective, observational, non-interventional study in the United States to collect clinical information, patient-reported outcomes, and tissue samples from patients with MDS, ICUS, or AML receiving multiple therapies. Results from this registry may provide new insights into the relationship between diagnostic practices, treatment regimens, and outcomes in patients with these diseases and identify areas for future investigation.

Trial registration

Connect MDS/AML Disease Registry (NCT01688011). Registered 14 September 2012.

Electronic supplementary material

The online version of this article (doi:10.1186/s12885-016-2710-6) contains supplementary material, which is available to authorized users.

Deep Sequencing of Cell-Free Peripheral Blood DNA as a Reliable Method for Confirming the Diagnosis of Myelodysplastic Syndrome

BACKGROUND

Demonstrating the presence of myelodysplastic syndrome (MDS)-specific molecular abnormalities can aid in diagnosis and patient management. We explored the potential of using peripheral blood (PB) cell-free DNA (cf-DNA) and next-generation sequencing (NGS).

MATERIALS AND METHODS

We performed NGS on a panel of 14 target genes using total nucleic acid extracted from the plasma of 16 patients, all of whom had confirmed diagnoses for early MDS with blasts <5%. PB cellular DNA from the same patients was sequenced using conventional Sanger sequencing and NGS.

RESULTS

Deep sequencing of the cf-DNA identified one or more mutated gene(s), confirming the diagnosis of MDS in all cases. Five samples (31%) showed abnormalities in cf-DNA by NGS that were not detected by Sanger sequencing on cellular PB DNA. NGS of PB cell DNA showed the same findings as those of cf-DNA in four of five patients, but failed to show a mutation in the RUNX1 gene that was detected in one patient's cf-DNA. Mutant allele frequency was significantly higher in cf-DNA compared with cellular DNA (p = 0.008).

CONCLUSION

These data suggest that cf-DNA when analyzed using NGS is a reliable approach for detecting molecular abnormalities in MDS and should be used to determine if bone marrow aspiration and biopsy are necessary.

Low-dose decitabine plus all-trans retinoic acid in patients with myeloid neoplasms ineligible for intensive chemotherapy

In our previous in vitro trials, decitabine and all-trans retinoic acid (ATRA) demonstrated synergistic effects on growth inhibition, differentiation, and apoptosis in SHI-1 cells; in K562 cells, ATRA enhanced the effect of decitabine on p16 demethylation, and the combination of the two drugs was found to activate RAR-β expression (p16 and RAR-β are two tumor suppressor genes). On the rationale of our in vitro trials, we used low-dose decitabine and ATRA to treat 31 myeloid neoplasms deemed ineligible for intensive chemotherapy. The regimen consisted of decitabine at the dose of 15 mg/m(2) intravenously over 1 h daily for consecutive 5 days and ATRA at the dose of 20 mg/m(2) orally from day 1 to 28 except day 4 to 28 in the first cycle, and the regimen was repeated every 28 days. After 6 cycles, decitabine treatment was stopped, and ATRA treatment was continued for maintenance treatment. Treated with a median of 2 cycles (range 1-6), 7 patients (22.6 %) achieved complete remission (CR), 7 (22.6 %) marrow CR (mCR), and 4 (12.9 %) partial remission (PR). The overall remission (CR, mCR, and PR) rate was 58.1 %, and the best response (CR and mCR) rate was 45.2 %. The median overall survival (OS) was 11.0 months, the 1-year OS rate was 41.9 %, and the 2-year OS rate was 26.6 %. In univariate analyses, age, performance status, comorbidities, white blood cell counts and platelets at diagnosis, percentage of bone marrow blasts, karyotype, and treatment efficacy demonstrated no impacts on OS (P > 0.05, each). Main side effects were tolerable hematologic toxicities. In conclusion, low-dose decitabine plus ATRA is a promising treatment for patients with myeloid neoplasms judged ineligible for intensive chemotherapy.

Laboratory Test Utilization Management: General Principles and Applications in Hematopathology

As the cost of health care continues to rise and reimbursement rates decrease, there is a growing demand and need to cut overall costs, enhance quality of services, and maintain as a top priority the needs and safety of the patient. In this article, we provide an introduction to test utilization and outline a general approach to creating an efficient, cost-effective test utilization strategy. We also present and discuss 2 test utilization algorithms that are evidence-based and may be of clinical utility as we move toward the future of doing the necessary tests at the right time.

Protein Kinase D Enzymes as Regulators of EMT and Cancer Cell Invasion

The Protein Kinase D (PKD) isoforms PKD1, PKD2, and PKD3 are effectors of the novel Protein Kinase Cs (nPKCs) and diacylglycerol (DAG). PKDs impact diverse biological processes like protein transport, cell migration, proliferation, epithelial to mesenchymal transition (EMT) and apoptosis. PKDs however, have distinct effects on these functions. While PKD1 blocks EMT and cell migration, PKD2 and PKD3 tend to drive both processes. Given the importance of EMT and cell migration to the initiation and progression of various malignancies, abnormal expression of PKDs has been reported in multiple types of cancers, including breast, pancreatic and prostate cancer. In this review, we discuss how EMT and cell migration are regulated by PKD isoforms and the significance of this regulation in the context of cancer development.