Treatment Strategies in Myelodysplastic Syndromes

Berries vs. Disease: Revenge of the Phytochemicals

Secondary metabolites and phytochemicals in plant-based diets are known to possess properties that inhibit the development of several diseases including a variety of cancers of the aerodigestive tract. Berries are currently of high interest to researchers due to their high dietary source of phytochemicals. Black raspberries (BRB), Rubus occidentalis, are of special interest due to their rich and diverse composition of phytochemicals. In this review, we present the most up-to-date preclinical and clinical data involving berries and their phytochemicals in the chemoprevention of a variety of cancers and diseases. BRBs possess a variety of health benefits including anti-proliferative properties, anti-inflammatory activity, activation of pro-cell-death pathways, modulation of the immune response, microbiome modulation, reduction in oxidative stress, and many more. However, little has been done in both preclinical and clinical settings on the effects of BRB administration in combination with other cancer therapies currently available for patients. With the high potential for BRBs as chemopreventive agents, there is a need to investigate their potential in combination with other treatments to improve therapeutic efficacy.

A Pilot Clinical Study to Investigate the Hypomethylating Properties of Freeze-dried Black Raspberries in Patients with Myelodysplastic Syndrome or Myeloproliferative Neoplasm

Myelodysplastic syndromes (MDS) and myelodysplastic/myeloproliferative neoplasms (MDS/MPN) are bone marrow disorders characterized by cytopenias and progression to acute myeloid leukemia. Hypomethylating agents (HMAs) are Food and Drug Administration-approved therapies for MDS and MDS/MPN patients. HMAs have improved patients' survival and quality of life when compared with other therapies. Although HMAs are effective in MDS and MDS/MPN patients, they are associated with significant toxicities that place a large burden on patients. Our goal is to develop a safer and more effective HMA from natural products. We previously reported that black raspberries (BRBs) have hypomethylating effects in the colon, blood, spleen, and bone marrow of mice. In addition, BRBs exert hypomethylating effects in patients with colorectal cancer and familial adenomatous polyposis. In the current study, we conducted a pilot clinical trial to evaluate the hypomethylating effects of BRBs in patients with low-risk MDS or MDS/MPN. Peripheral blood mononuclear cells (PBMCs) were isolated before and after three months of BRB intervention. CD45+ cells were isolated from PBMCs for methylation analysis using a reduced-representation bisulfite sequencing assay. Each patient served as their own matched control, with their measurements assessed before intervention providing a baseline for post-intervention results. Clinically, our data showed that BRBs were well-tolerated with no side effects. When methylation data was combined, BRBs significantly affected methylation levels of 477 promoter regions. Pathway analysis suggests that BRB-induced intragenic hypomethylation drives leukocyte differentiation. A randomized, placebo-controlled clinical trial of BRB use in low-risk MDS or MDS/MPN patients is warranted.

A phase II open-label study of the intravenous administration of homoharringtonine in the treatment of myelodysplastic syndrome

Homoharringtonine is an alkaloid inhibitor of protein synthesis with activity in myeloid malignancies. We report a phase II pilot study of homoharringtonine in myelodysplastic syndrome (MDS). Induction consisted of homoharringtonine at 2.5 mg/m(2) via continuous infusion for 7 days. Maintenance was given every 4 weeks. Nine patients were enrolled: five with refractory anaemia with excess blasts, two with refractory anaemia with excess blasts in transformation, one each with refractory anaemia and chronic myelomonocytic leukaemia respectively. Median age was 70 years (55-84) and 6 (66%) were male. Per International Prognostic Scoring System (IPSS) two patients were intermediate-1, five intermediate-2 and two high-risk. Median chemotherapy courses were one (1-3). One patient (11%) responded with complete haematological and cytogenetic remission after one course. Eight patients did not respond (four had stable disease, two progressed to acute leukaemia and two died during induction - from aspergillus pneumonia and intracerebral haemorrhage respectively). Grade 3/4 myelosuppression seen in 56% (5/9). Serious non-haematological toxicities included one case of grade 4 left bundle branch heart block and one grade 3 nephrotoxicity. Median time between courses was 42 days (35-72 days). In conclusion homoharringtonine might have clinical activity in some patients with MDS.

DNA methylation changes following 5-azacitidine treatment in patients with myelodysplastic syndrome

DNA methyltransferase inhibitor, 5-azacitidine (AC) is effective in myelodysplastic syndromes (MDS) and can induce re-expression in cancer. We analyzed the methylation of 25 tumor suppressor genes in AC-treated MDS. Hypermethylation of CDKN2B, FHIT, ESR1, and IGSF4 gene was detected in 9/44 patients. In concordance with the clinical response, a lack of or decreased methylation in 4 patients with hematologic improvements and persistent methylation in 4 others with no response was observed. The mRNA expression of CDKN2B, IGSF4, and ESR1 was significantly reduced in MDS. Our results suggest that methylation changes contribute to disease pathogenesis and may serve as marker to monitor the efficacy of treatments.

Myelodysplastic syndromes

Session 4 of the 2007 Workshop of the Society for Hematopathology/European Association for Haematopathology was devoted to myelodysplastic syndromes (MDSs). Submitted cases highlighted important issues and difficulties in relation to the diagnosis and classification of MDS. Much of the discussion focused on the correlation, or lack of it, between morphologic examination and other diagnostic techniques, cytogenetics in particular. The cases included examples of isolated del(5q) chromosomal abnormality, including the "classical" 5q- syndrome and other myeloid neoplasms. Other cytogenetic abnormalities in MDSs and the role of cytogenetics in diagnosing MDSs were addressed. Particularly challenging is the correct identification of fibrotic subtypes of MDSs and their separation from subsets of acute myeloid leukemia with myelofibrosis such as acute panmyelosis with myelofibrosis. The association and eventual relation of MDSs (hypoplastic in particular) with aplastic anemia, paroxysmal nocturnal hemoglobinuria, and other nonneoplastic disorders were illustrated. Novel cytogenetic and molecular genetic approaches are likely to revolutionize the classification of MDSs. However, it is unlikely that these new techniques will be capable, on their own, of adequately stratifying patients for treatment purposes. At least for the foreseeable future, the diagnosis of MDS requires integration of morphologic, immunophenotypic, and genetic features in the light of patient history and clinical manifestations.

Phosphoinositide-Phospholipase C β1 Mono-Allelic Deletion Is Associated With Myelodysplastic Syndromes Evolution Into Acute Myeloid Leukemia

Purpose

To evaluate the association between the presence of phosphoinositide-phospholipase C β1 (PI-PLCβ1) mono-allelic deletion with the clinical outcome of myelodysplastic syndromes (MDS) patients.

Methods

PI-PLCβ1, PI-PLCβ4, and PI-PLCγ1 cytogenetic investigations were performed on 80 newly diagnosed MDS patients (18 low risk, 26 intermediate 1, 18 intermediate 2, 18 high risk) comparing the results with the clinical outcome of the patients. Moreover, fluorescent in situ hybridization results were validated by real-time polymerase chain reaction (PCR). Finally, PI-PLCβ1 gene and protein expression were assessed by both real-time PCR and immunocytochemical experiments.

Results

Collectively, 35 (43.75%) of 80 of the MDS patients showed a specific mono-allelic deletion of PI-PLCβ1. Kaplan-Meier analysis revealed a significant association (P < .0001) between the PI-PLCβ1 mono-allelic deletion and a higher risk of evolution into acute myeloid leukemia (AML), since 23 of 35 MDS patients (65.7%) bearing the PI-PLCβ1 mono-allelic deletion evolved into AML. Even in multivariate analysis, the PI-PLCβ1 mono-allelic deletion retained a higher significance, with a P < .001, as a prognostic factor of evolution into AML (odds ratio [OR] 1.83; 95% CI, 2.26 to 17.24; P = .00045). Finally, PI-PLCβ1 deletion was related to an altered gene and protein expression.

Conclusion

PI-PLCβ1 mono-allelic deletion is associated with a worse clinical outcome in MDS patients, hinting at the identification of a new group at higher risk of AML evolution and representing a reliable prognostic tool. Moreover, targeting PI-PLCβ1 pathways might emerge as a new therapeutic strategy for MDS.

DNA demethylation protects from cleavable complex stabilization and DNA strand breakage induced by the topoisomerase type I inhibitor camptothecin

Methylation of cytosine in CpG sequences of the DNA in mammalian cells is an epigenetic feature regulated very exactly that bears importance for events like gene expression, DNA replication, transcription and genetic imprinting. Changes in the DNA methylation pattern, both hypermethylation and hypomethylation, have been observed in the carcinogenic process. These changes, in general, influence the DNA conformation in such a way that certain proteins are disturbed in their interactions with the molecule. In this paper, we investigated in cultured Chinese hamster ovary cells the influence of hypomethylation induced by the substitution of 5-aza-2'-deoxycytidine for cytidine in DNA on topoisomerase type I (topo I) function, measured as the capacity of the enzyme inhibitor camptothecin (CPT) to stabilize the topoisomerase-DNA complexes and to induce DNA strand breakage. Our results demonstrate that the degree of methylation in DNA correlates with the effectiveness of CPT to stabilize the topo I-DNA complexes and to induce DNA cleavage. A protective effect of hypomethylation, as a whole, has been observed.