Epigenetic therapy in myelodysplastic syndromes

Vitamin C Supplementation in the Treatment of Autoimmune and Onco-Hematological Diseases: From Prophylaxis to Adjuvant Therapy

Vitamin C is a water-soluble vitamin introduced through the diet with anti-inflammatory, immunoregulatory, and antioxidant activities. Today, this vitamin is integrated into the treatment of many inflammatory pathologies. However, there is increasing evidence of possible use in treating autoimmune and neoplastic diseases. We reviewed the literature to delve deeper into the rationale for using vitamin C in treating this type of pathology. There is much evidence in the literature regarding the beneficial effects of vitamin C supplementation for treating autoimmune diseases such as Systemic Lupus Erythematosus (SLE) and Rheumatoid Arthritis (RA) and neoplasms, particularly hematological neoplastic diseases. Vitamin C integration regulates the cytokines microenvironment, modulates immune response to autoantigens and cancer cells, and regulates oxidative stress. Moreover, integration therapy has an enhanced effect on chemotherapies, ionizing radiation, and target therapy used in treating hematological neoplasm. In the future, integrative therapy will have an increasingly important role in preventing pathologies and as an adjuvant to standard treatments.

Anticancer Effect of Spices Used in Mediterranean Diet: Preventive and Therapeutic Potentials

Cancer is one of the leading causes of death worldwide, with almost 10 million cancer-related deaths worldwide in 2020, so any investigation to prevent or cure this disease is very important. Spices have been studied widely in several countries to treat different diseases. However, studies that summarize the potential anticancer effect of spices used in Mediterranean diet are very limited. This review highlighted chemo-therapeutic and chemo-preventive effect of ginger, pepper, rosemary, turmeric, black cumin and clove. Moreover, the mechanisms of action for each one of them were figured out such as anti-angiogenesis, antioxidant, altering signaling pathways, induction of cell apoptosis, and cell cycle arrest, for several types of cancer. The most widely used spice in Mediterranean diet is black pepper (Piper nigrum L). Ginger and black cumin have the highest anticancer activity by targeting multiple cancer hallmarks. Apoptosis induction is the most common pathway activated by different spices in Mediterranean diet to inhibit cancer. Studies discussed in this review may help researchers to design and test new anticancer diets enriched with selected spices that have high activities.

New insights into neuropeptides regulation of immune system and hemopoiesis: effects on hematologic malignancies

Several neurotransmitters and neuropeptides were reported to join to or to cooperate with different cells of the immune system, bone marrow, and peripheral cells and numerous data support that neuroactive molecules might control immune system activity and hemopoiesis operating on lymphoid organs, and the primary hematopoietic unit, the hematopoietic niche. Furthermore, many compounds seem to be able to take part to the leukemogenesis and lymphomagenesis process, and in the onset of multiple myeloma. In this review, we will assess the possibility that neurotransmitters and neuropeptides may have a role in the onset of haematological neoplasms, may affect the response to treatment or may represent a useful starting point for a new therapeutic approach. More in vivo investigations are needed to evaluate neuropeptide's role in haematological malignancies and the possible utilization as an antitumor therapeutic target. Comprehending the effect of the pharmacological administration of neuropeptide modulators on hematologic malignancies opens up new possibilities in curing clonal hematologic diseases to achieve more satisfactory outcomes.

Drug Repositioning for the Treatment of Hematologic Disease: Limits, Challenges and Future Perspectives

Drug repositioning is a strategy to identify new uses for approved or investigational drugs that are used off-label outside the scope of the original medical indication. In this review, we report the most relevant studies about drug repositioning in hematology, reporting the signalling pathways and molecular targets of these drugs, and describing the biological mechanisms which are responsible for their anticancer effects. Although the majority of studies on drug repositioning in hematology concern acute myeloid leukemia and multiple myeloma, numerous studies are present in the literature on the possibility of using these drugs also in other hematological diseases, such as acute lymphoblastic leukemia, chronic myeloid leukemia, and lymphomas. Numerous anti-infectious drugs and chemical entities used for the therapy of neurological or endocrine diseases, oral antidiabetics, statins and medications used to treat high blood pressure and heart failure, bisphosphonate and natural substance such as artemisin and curcumin, have found a place in the treatment of hematological diseases. Moreover, several molecules drastically reversed the resistance of the tumor cells to the chemotherapeutic drugs both in vitro and in vivo.

Epigenetic Effects of Benzene in Hematologic Neoplasms: The Altered Gene Expression

Simple Summary

Benzene is produced by diverse petroleum transformation processes and it is widely employed in industry despite its oncogenic effects. In fact, occupational exposure to benzene may cause hematopoietic malignancy. The leukemogenic action of benzene is particularly complex. Possible processes of onset of hematological malignancies have been recognized as a genotoxic action and the provocation of immunosuppression. However, benzene can induce modifications that do not involve alterations in the DNA sequence, the so-called epigenetics changes. Acquired epigenetic modification may also induce leukemogenesis, as benzene may alter nuclear receptors, and cause changes at the protein level, thereby modifying the function of regulatory proteins, including oncoproteins and tumor suppressor proteins.

Abstract

Benzene carcinogenic ability has been reported, and chronic exposure to benzene can be one of the risk elements for solid cancers and hematological neoplasms. Benzene is acknowledged as a myelotoxin, and it is able to augment the risk for the onset of acute myeloid leukemia, myelodysplastic syndromes, aplastic anemia, and lymphomas. Possible mechanisms of benzene initiation of hematological tumors have been identified, as a genotoxic effect, an action on oxidative stress and inflammation and the provocation of immunosuppression. However, it is becoming evident that genetic alterations and the other causes are insufficient to fully justify several phenomena that influence the onset of hematologic malignancies. Acquired epigenetic alterations may participate with benzene leukemogenesis, as benzene may affect nuclear receptors, and provoke post-translational alterations at the protein level, thereby touching the function of regulatory proteins, comprising oncoproteins and tumor suppressor proteins. DNA hypomethylation correlates with stimulation of oncogenes, while the hypermethylation of CpG islands in promoter regions of specific tumor suppressor genes inhibits their transcription and stimulates the onset of tumors. The discovery of the systems of epigenetic induction of benzene-caused hematological tumors has allowed the possibility to operate with pharmacological interventions able of stopping or overturning the negative effects of benzene.

SIRT2 and SIRT3 expression correlates with redox imbalance and advanced clinical stage in patients with multiple myeloma

OBJECTIVES

Sirtuins comprise seven family elements (SIRT1-7) involved in various cell signalling pathways comprising cancer inhibition and tumorigenesis. The present study aims to evaluate SIRT2 and SIRT3 gene expression and potential redox reactions in patients with multiple myeloma (MM) at onset and its correlation with disease status, extent and presence of organ damage secondary to myeloma.

DESIGN & METHODS

Total RNA was extracted from 17 MM patients and 10 controls to assess gene expression using real-time PCR. The NAD+/NADH ratio as well as the levels of glutathione peroxidase (GPx) and hydrogen peroxide (HP) in peripheral blood mononuclear cells (PBMCs) were determined using established biochemical assays.

RESULTS

SIRT2 and SIRT3 expression is reduced in MM patients compared to healthy controls. Correlational analysis demonstrated that SIRT2 reduction is associated with advanced clinical stage and with more advanced bone lesions than in the remaining patients. SIRT3 expression is correlated with lytic bone lesions. Biochemical analysis indicated an imbalance of oxidative stress biomarkers with low concentrations of the antioxidant enzyme GPx, low amounts of NAD + and higher concentrations of pro-oxidant enzyme HP in PBMCs of MM patients compared to controls. Moreover, MM patients with bone lesions had lower concentrations of NAD + and GPx in PBMCs than patients without signs of bone disease. In addition, MM patients had higher quantities of intracellular HP than controls.

CONCLUSIONS

Our results demonstrate that SIRT2 and SIRT3 are downregulated in MM and that lower concentrations correlate with an advanced stage of disease and redox imbalance. We conclude that SIRT2 and SIRT3 together with oxidative stress biomarkers, may be useful for improved risk stratification of MM patients.

Oncolytic Viruses and Hematological Malignancies: A New Class of Immunotherapy Drugs

The use of viruses for tumour treatment has been imagined more than one hundred years ago, when it was reported that viral diseases were occasionally leading to a decrease in neoplastic lesions. Oncolytic viruses (OVs) seem to have a specific tropism for tumour cells. Previously, it was hypothesised that OVs’ antineoplastic actions were mainly due to their ability to contaminate, proliferate and destroy tumour cells and the immediate destructive effect on cells was believed to be the single mechanism of action of OVs’ action. Instead, it has been established that oncolytic viruses operate via a multiplicity of systems, including mutation of tumour milieu and a composite change of the activity of immune effectors. Oncolytic viruses redesign the tumour environment towards an antitumour milieu. The aim of our work is to evaluate the findings present in the literature about the use of OVs in the cure of haematological neoplastic pathologies such as multiple myeloma, acute and chronic myeloid leukaemia, and lymphoproliferative diseases. Further experimentations are essential to recognize the most efficient virus or treatment combinations for specific haematological diseases, and the combinations able to induce the strongest immune response.

Anticancer Activity of Rosmarinus officinalis L.: Mechanisms of Action and Therapeutic Potentials

Alternative treatments for neoplastic diseases with new drugs are necessary because the clinical effectiveness of chemotherapy is often reduced by collateral effects. Several natural substances of plant origin have been demonstrated to be successful in the prevention and treatment of numerous tumors. Rosmarinus officinalis L. is a herb that is cultivated in diverse areas of the world. There is increasing attention being directed towards the pharmaceutical capacities of rosemary, utilized for its anti-inflammatory, anti-infective or anticancer action. The antitumor effect of rosemary has been related to diverse mechanisms, such as the antioxidant effect, antiangiogenic properties, epigenetic actions, regulation of the immune response and anti-inflammatory response, modification of specific metabolic pathways, and increased expression of onco-suppressor genes. In this review, we aim to report the results of preclinical studies dealing with the anticancer effects of rosemary, the molecular mechanisms related to these actions, and the interactions between rosemary and anticancer drugs. The prospect of utilizing rosemary as an agent in the treatment of different neoplastic diseases is discussed. However, although the use of rosemary in the therapy of neoplasms constitutes a fascinating field of study, large and controlled studies must be conducted to definitively clarify the real impact of this substance in clinical practice.

Interactions between the MicroRNAs and Microbiota in Cancer Development: Roles and Therapeutic Opportunities

The human microbiota is made up of the fungi, bacteria, protozoa and viruses cohabiting within the human body. An altered microbiota can provoke diseases such as cancer. The mechanisms by which a modified microbiota can intervene in the onset and progression of neoplastic diseases are manifold. For instance, these include the effects on the immune system and the onset of obesity. A different mechanism seems to be constituted by the continuous and bidirectional relationships existing between microbiota and miRNAs. MiRNAs emerged as a novel group of small endogenous non-coding RNAs from that control gene expression. Several works seem to confirm the presence of a close connection between microbiota and miRNAs. Although the main literature data concern the correlations between microbiota, miRNAs and colon cancer, several researches have revealed the presence of connections with other types of tumour, including the ovarian tumour, cervical carcinoma, hepatic carcinoma, neoplastic pathologies of the central nervous system and the possible implication of the microbiota-miRNAs system on the response to the treatment of neoplastic pathologies. In this review, we summarise the physiological and pathological functions of the microbiota on cancer onset by governing miRNA production. A better knowledge of the bidirectional relationships existing between microbiota and miRNAs could provide new markers for the diagnosis, staging and monitoring of cancer and seems to be a promising approach for antagomir-guided approaches as therapeutic agents.

Precision oncology in Latin America: current situation, challenges and perspectives

BACKGROUND

Anti-cancer cytotoxic treatments like platinum-derived compounds often show low therapeutic efficacy, high-risk side effects and resistance. Hence, targeted treatments designed to attack only tumour cells avoiding these harmful side effects are highly needed in clinical practice. Due to this, precision oncology has arisen as an approach to specifically target alterations present only in cancer cells, minimising side effects for patients. It involves the use of molecular biomarkers present in each kind of tumour for diagnosis, prognosis and treatment. Since these biomarkers are specific for each cancer type, physicians use them to stratify, diagnose or take the best therapeutic options for each patient depending on the features of the specific tumour.

AIM

This review aims to describe the current situation, limitations, advantages and perspectives about precision oncology in Latin America.

MAIN BODY

For many years, many biomarkers have been used in a clinical setting in developed countries. However, in Latin American countries, their broad application has not been affordable partially due to financial and technical limitations associated with precarious health systems and poor access of low-income populations to quality health care. Furthermore, the genetic mixture in Latin American populations could generate differences in treatment responses from one population to another (pharmacoethnicity) and this should be evaluated before establishing precision therapy in particular populations. Some research groups in the region have done a lot of work in this field and these data should be taken as a starting point to establish networks oriented to finding clinically useful cancer biomarkers in Latin American populations.

CONCLUSION

Latin America must create policies allowing excluded populations to gain access to health systems and next generation anti-cancer drugs, i.e. high-cost targeted therapies to improve survival. Also, cancer clinical research must be oriented to establish cancer biomarkers adapted to specific populations with different ethnicity, allowing the improvement of patient outcomes.

Decitabine shows synergistic effects with arsenic trioxide against myelodysplastic syndrome cells via endoplasmic reticulum stress-related apoptosis

Most of the International Prognostic Scoring System (IPSS) high-risk patients with myelodysplastic syndrome partly responded to hypomethylating therapy even with transient remission, while arsenic trioxide (ATO) had partial effect in patients with MDS. Therefore, we sought to investigate the effects and possible mechanisms of the combination of ATO and decitabine (DAC) in MDS cells. In our study, the MUTZ-1 and SKM-1 cells were treated with ATO, DAC or both. Cell viability, cell apoptosis, levels of reactive oxygen species (ROS) and expressions of the endoplasmicreticulum (ER) stress-associated genes and proteins were examined. Results showed the combination of ATO and DAC synergistically inhibited the proliferation and induced apoptosis of MDS cells. Through the RNA-sequence and GSEA gene function analysis, ER stress-related pathway played an important role in apoptosis of MDS cells induced by the combination of ATO and DAC. ER stress-related genes DNA damage inducible transcript 3, GRP78, and activating transcription factor-6 were significantly highly expressed in combination group than those in single agent groups; proteins were confirmed by western blot. The levels of ROS significantly increased in the combination group. Furthermore, the apoptosis of (ATO+DAC) group MDS cells could be partially reversed by antioxidant agent N-acetylcysteine, accompanied by decreased expression of intracellular ROS and ER stress-related genes. These results suggested that the combination of ATO and DAC synergistically induced the apoptosis of MDS cells by increased ROS-related ER stress in MDS cells.

Spotlight on decitabine for myelodysplastic syndromes in Chinese patients

Myelodysplastic syndromes (MDSs) are a group of heterogeneous clonal hematopoietic stem cell malignancies with advanced median age. The silencing of tumor suppressor genes caused by DNA hypermethylation plays a crucial role in the pathogenesis of MDS. Decitabine, the available hypomethylating agent, is successfully used for the treatment and improves the outcome of MDS, and has become one of the most frequently administered disease-modifying therapies. With an aging population and a growing number of people exposed to benzene, the incidence of MDS has been increasing rapidly. The blinded regimen choice and the lack of a unified strategy create challenges for the treatment of MDS. Here, we present a review of clinical progress and prospects of decitabine treatment of MDS in the People’s Republic of China. We also discuss the optimization of therapy issues to improve the cure rate and prolong survival in patients with MDS.

Prognostic impact of the number of methylated genes in myelodysplastic syndromes and acute myeloid leukemias treated with azacytidine

The prognostic impact of the aberrant hypermethylation in response to azacytidine (AZA) remains to be determined. Therefore, we have analyzed the influence of the methylation status prior to AZA treatment on the overall survival and clinical response of myeloid malignancies. DNA methylation status of 24 tumor suppressor genes was analyzed by methylation-specific multiplex ligation-dependent probe amplification in 63 patients with myelodysplastic syndromes and acute myeloid leukemia treated with azacytidine. Most patients (73 %) showed methylation of at least one gene, but only 12 % of patients displayed ≥3 methylated genes. The multivariate analysis demonstrated that the presence of a high number (≥2) of methylated genes (P = 0.022), a high WBC count (P = 0.033), or anemia (P = 0.029) were independent prognostic factors associated with shorter overall survival. The aberrant methylation status did not correlate with the response to AZA, although four of the five patients with ≥3 methylated genes did not respond. By contrast, favorable cytogenetics independently influenced the clinical response to AZA as 64.7 % of patients with good-risk cytogenetic abnormalities responded (P = 0.03). Aberrant methylation status influences the survival of patients treated with AZA, being shorter in those patients with a high number of methylated genes.

Strategies to modulate heritable epigenetic defects in cellular machinery: lessons from nature

Natural epigenetic processes precisely orchestrate the intricate gene network by expressing and suppressing genes at the right place and time, thereby playing an essential role in maintaining the cellular homeostasis. Environment-mediated alteration of this natural epigenomic pattern causes abnormal cell behavior and shifts the cell from the normal to a diseased state, leading to certain cancers and neurodegenerative disorders. Unlike heritable diseases that are caused by the irreversible mutations in DNA, epigenetic errors can be reversed. Inheritance of epigenetic memory is also a major concern in the clinical translation of the Nobel Prize-winning discovery of induced pluripotent stem cell technology. Consequently, there is an increasing interest in the development of novel epigenetic switch-based therapeutic strategies that could potentially restore the heritable changes in epigenetically inherited disorders. Here we give a comprehensive overview of epigenetic inheritance and suggest the prospects of therapeutic gene modulation using epigenetic-based drugs, in particular histone deacetylase inhibitors. This review suggests that there is a need to develop therapeutic strategies that effectively mimic the natural environment and include the ways to modulate the gene expression at both the genetic and epigenetic levels. The development of tailor-made small molecules that could epigenetically alter DNA in a sequence-specific manner is a promising approach for restoring defects in an altered epigenome and may offer a sustainable solution to some unresolved clinical issues.

Reduced rRNA expression and increased rDNA promoter methylation in CD34+ cells of patients with myelodysplastic syndromes

Myelodysplastic syndromes (MDS) are clonal disorders of hematopoietic stem cells characterized by ineffective hematopoiesis. The DNA-hypomethylating agents 5-azacytidine and 5-aza-2'-deoxycytidine are effective treatments for patients with MDS, increasing the time to progression to acute myelogenous leukemia and improving overall response rates. Although genome-wide increases in DNA methylation have been documented in BM cells from MDS patients, the methylation signatures of specific gene promoters have not been correlated with the clinical response to these therapies. Recently, attention has been drawn to the potential etiologic role of decreased expression of specific ribosomal proteins in MDS and in other BM failure states. Therefore, we investigated whether rRNA expression is dysregulated in MDS. We found significantly decreased rRNA expression and increased rDNA promoter methylation in CD34(+) hematopoietic progenitor cells from the majority of MDS patients compared with normal controls. Treatment of myeloid cell lines with 5-aza-2'-deoxycytidine resulted in a significant decrease in the methylation of the rDNA promoter and an increase in rRNA levels. These observations suggest that an increase in rDNA promoter methylation can result in decreased rRNA synthesis that may contribute to defective hematopoiesis and BM failure in some patients with MDS.

How to control an infectious bead string: nucleosome-based regulation and targeting of herpesvirus chromatin

Herpesvirus infections of humans can cause a broad variety of symptoms ranging from mild afflictions to life-threatening disease. During infection, the large double-stranded DNA genomes of all herpesviruses are transcribed, replicated and encapsidated in the host cell nucleus, where DNA is typically structured and manoeuvred through nucleosomes. Nucleosomes individually assemble DNA around core histone octamers to form 'beads-on-a-string' chromatin fibres. Herpesviruses have responded to the advantages and challenges of chromatin formation in biologically unique ways. Although herpesvirus DNA is devoid of histones within nucleocapsids, nuclear viral genomes most likely form irregularly arranged or unstable nucleosomes during productive infection, and regular nucleosomal arrays resembling host cell chromatin in latently infected cells. Besides variations in nucleosome density, herpesvirus chromatin 'bead strings' undergo dynamic changes in histone composition and modification during the different stages of productive replication, latent infection and reactivation from latency, raising the likely possibility that epigenetic processes may dictate, at least in part, the outcome of infection and ensuing pathogenesis. Here, we summarise and discuss several new and important aspects regarding the nucleosome-based mechanisms that regulate herpesvirus chromatin structure and function in infected cells. Special emphasis is given to processes of histone deposition, histone variant exchange and covalent histone modification in relation to the transcription from the viral genome during productive and latent infections by human cytomegalovirus and herpes simplex virus type 1. We also present an overview on emerging histone-directed antiviral strategies that may be developed into 'epigenetic therapies' to improve current prevention and treatment options targeting herpesvirus infection and disease.

Over-expression of mitochondrial ferritin affects the JAK2/STAT5 pathway in K562 cells and causes mitochondrial iron accumulation

BACKGROUND

Mitochondrial ferritin is a nuclear encoded iron-storage protein localized in mitochondria. It has anti-oxidant properties related to its ferroxidase activity, and it is able to sequester iron avidly into the organelle. The protein has a tissue-specific pattern of expression and is also highly expressed in sideroblasts of patients affected by hereditary sideroblastic anemia and by refractory anemia with ringed sideroblasts. The present study examined whether mitochondrial ferritin has a role in the pathogenesis of these diseases.

DESIGN AND METHODS

We analyzed the effect of mitochondrial ferritin over-expression on the JAK2/STAT5 pathway, on iron metabolism and on heme synthesis in erythroleukemic cell lines. Furthermore its effect on apoptosis was evaluated on human erythroid progenitors.

RESULTS

Data revealed that a high level of mitochondrial ferritin reduced reactive oxygen species and Stat5 phosphorylation while promoting mitochondrial iron loading and cytosolic iron starvation. The decline of Stat5 phosphorylation induced a decrease of the level of anti-apoptotic Bcl-xL transcript compared to that in control cells; however, transferrin receptor 1 transcript increased due to the activation of the iron responsive element/iron regulatory protein machinery. Also, high expression of mitochondrial ferritin increased apoptosis, limited heme synthesis and promoted the formation of Perls-positive granules, identified by electron microscopy as iron granules in mitochondria.

CONCLUSIONS

Our results provide evidence suggesting that Stat5-dependent transcriptional regulation is displaced by strong cytosolic iron starvation status induced by mitochondrial ferritin. The protein interferes with JAK2/STAT5 pathways and with the mechanism of mitochondrial iron accumulation.

Epigenetic approaches in the treatment of myelodysplastic syndromes: clinical utility of azacitidine

Myelodysplastic syndromes (MDS) are a varied group of diseases leading to significant morbidity and mortality. Therapy of MDS has been difficult, with supportive cares used to ameliorate symptoms, and hematopoietic stem cell transplantation the only curative option. Agents, such as the cytidine analog azacitidine, exert an effect on DNA methyltransferase leading to a reduction in DNA methylation, a process thought to be key to the pathogenesis of MDS. Recently, azacitidine has been shown to prolong survival and improve quality of life in patients with MDS, while maintaining a favorable adverse effect profile. This review highlights the scientific rationale for the use of azacitidine in addition to its application in current clinical practice for patients with MDS.

Epigenetic alterations as cancer diagnostic, prognostic, and predictive biomarkers

Alterations of DNA methylation and transcription of microRNAs (miRNAs) are very stable phenomena in tissues and body fluids and suitable for sensitive detection. These advantages enable us to translate some important discoveries on epigenetic oncology into biomarkers for control of cancer. A few promising epigenetic biomarkers are emerging. Clinical trials using methylated CpG islands of p16, Septin9, and MGMT as biomarkers are carried out for predication of cancer development, diagnosis, and chemosensitivity. Circulating miRNAs are promising biomarkers, too. Breakthroughs in the past decade imply that epigenetic biomarkers may be useful in reducing the burden of cancer.