Final results of a randomized multicenter phase II study of alvocidib, cytarabine, and mitoxantrone versus cytarabine and daunorubicin (7 + 3) in newly diagnosed high-risk acute myeloid leukemia (AML)

Antioxidants activities of phytochemicals perspective modulation of autophagy and apoptosis to treating cancer

The study of chemicals extracted from natural sources should be encouraged due to the significant number of cancer deaths each year and the financial burden imposed by this disease on society. The causes of almost all cancers involve a combination of lifestyle, environmental factors, and genetic and inherited factors. Modern medicine researchers are increasingly interested in traditional phytochemicals as they hold potential for new bioactive compounds with medical applications. Recent publications have provided evidence of the antitumor properties of phytochemicals, a key component of traditional Chinese medicine, thereby opening new avenues for their use in modern medicine. Various studies have demonstrated a strong correlation between apoptosis and autophagy, two critical mechanisms involved in cancer formation and regulation, indicating diverse forms of crosstalk between them. Phytochemicals have the ability to activate both pro-apoptotic and pro-autophagic pathways. Therefore, understanding how phytochemicals influence the relationship between apoptosis and autophagy is crucial for developing a new cancer treatment strategy that targets these molecular mechanisms. This review aims to explore natural phytochemicals that have demonstrated anticancer effects, focusing on their role in regulating the crosstalk between apoptosis and autophagy, which contributes to uncontrolled tumor cell growth. Additionally, the review highlights the limitations and challenges of current research methodologies while suggesting potential avenues for future research in this field.

Targeting apoptosis dysregulation in myeloid malignancies - The promise of a therapeutic revolution

In recent years, the therapeutic landscape of myeloid malignancies has been completely revolutionized by the introduction of several new drugs, targeting molecular alterations or pathways crucial for leukemia cells survival. Particularly, many agents targeting apoptosis have been investigated in both pre-clinical and clinical studies. For instance, venetoclax, a pro-apoptotic agent active on BCL-2 signaling, has been successfully used in the treatment of acute myeloid leukemia (AML). The impressive results achieved in this context have made the apoptotic pathway an attractive target also in other myeloid neoplasms, translating the experience of AML. Therefore, several drugs are now under investigation either as single or in combination strategies, due to their synergistic efficacy and capacity to overcome resistance. In this paper, we will review the mechanisms of apoptosis and the specific drugs currently used and under investigation for the treatment of myeloid neoplasia, identifying critical research necessities for the upcoming years.

Spatial transcriptomics reveals distinct and conserved tumor core and edge architectures that predict survival and targeted therapy response

The spatial organization of the tumor microenvironment has a profound impact on biology and therapy response. Here, we perform an integrative single-cell and spatial transcriptomic analysis on HPV-negative oral squamous cell carcinoma (OSCC) to comprehensively characterize malignant cells in tumor core (TC) and leading edge (LE) transcriptional architectures. We show that the TC and LE are characterized by unique transcriptional profiles, neighboring cellular compositions, and ligand-receptor interactions. We demonstrate that the gene expression profile associated with the LE is conserved across different cancers while the TC is tissue specific, highlighting common mechanisms underlying tumor progression and invasion. Additionally, we find our LE gene signature is associated with worse clinical outcomes while TC gene signature is associated with improved prognosis across multiple cancer types. Finally, using an in silico modeling approach, we describe spatially-regulated patterns of cell development in OSCC that are predictably associated with drug response. Our work provides pan-cancer insights into TC and LE biology and interactive spatial atlases ( http://www.pboselab.ca/spatial_OSCC/ ; http://www.pboselab.ca/dynamo_OSCC/ ) that can be foundational for developing novel targeted therapies.

Inhibition of multiple CDKs potentiates colon cancer chemotherapy via p73-mediated DR5 induction

Targeting cyclin-dependent kinases (CDKs) has recently emerged as a promising therapeutic approach against cancer. However, the anticancer mechanisms of different CDK inhibitors (CDKIs) are not well understood. Our recent study revealed that selective CDK4/6 inhibitors sensitize colorectal cancer (CRC) cells to therapy-induced apoptosis by inducing Death Receptor 5 (DR5) via the p53 family member p73. In this study, we investigated if this pathway is involved in anticancer effects of different CDKIs. We found that less-selective CDKIs, including flavopiridol, roscovitine, dinaciclib, and SNS-032, induced DR5 via p73-mediated transcriptional activation. The induction of DR5 by these CDKIs was mediated by dephosphorylation of p73 at Threonine 86 and p73 nuclear translocation. Knockdown of a common target of these CDKIs, including CDK1, 2, or 9, recapitulated p73-mediated DR5 induction. CDKIs strongly synergized with 5-fluorouracil (5-FU), the most commonly used CRC chemotherapy agent, in vitro and in vivo to promote growth suppression and apoptosis, which required DR5 and p73. Together, these findings indicate p73-mediated DR5 induction as a potential tumor suppressive mechanism and a critical target engaged by different CDKIs in potentiating therapy-induced apoptosis in CRC cells. These findings help better understand the anticancer mechanisms of CDKIs and may help facilitate their clinical development and applications in CRC.

Super enhancers: Pathogenic roles and potential therapeutic targets for acute myeloid leukemia (AML)

Acute myeloid leukemia (AML) is a malignant hematological tumor with disordered oncogenes/tumor suppressor genes and limited treatments. The potent anti-cancer effects of bromodomain and extra-terminal domain (BET) inhibitors, targeting the key component of super enhancers, in early clinical trials on AML patients, implies the critical role of super enhancers in AML. Here, we review the concept and characteristic of super enhancer, and then summarize the current researches about super enhancers in AML pathogenesis, diagnosis and classification, followed by illustrate the potential super enhancer-related targets and drugs, and propose the future directions of super enhancers in AML. This information provides integrated insight into the roles of super enhancers in this disease.

Treatment options for acute myeloid leukemia patients aged <60 years

Treatment of acute myeloid leukemia (AML) has changed over the last few years, after the discovery of new drugs selectively targeting AML blasts. Although 3/7 remains the standard of care for most AML patients, several new targeted agents (such as FLT3 inhibitors, CPX-351, gemtuzumab ozogamicin, BCL-2 inhibitor, and oral azacitidine), either as single agents or combined with standard chemotherapy, are approaching clinical practice, starting a new era in AML management. Moreover, emerging evidence has demonstrated that high-risk AML patients might benefit from both allogeneic stem cell transplant and maintenance therapy, providing new opportunities, as well as new challenges, for treating clinicians. In this review, we summarize available data on first-line therapy in young AML patients focusing on targeted therapies, integrating established practice with new evidence, in the effort to outline the contours of a new therapeutic paradigm, that of a “total therapy”, which goes beyond obtaining complete remission.

Phytochemical-loaded liposomes for anticancer therapy: an updated review

The major obstacles observed in current chemotherapy are severe adverse effects, narrow therapeutic indexes and multidrug resistance. Anticancer phytochemicals are extracted and purified from natural plants, providing alternative therapeutic approaches with recognized biomedical benefits. However, poor bioavailability, high dose requirements and non-specific targeting have made those molecules less effective. To tackle those issues, liposomal nanovesicles for phytochemical delivery are taken into consideration for improving the therapeutic effectiveness by increasing transportation across cell barriers and conferring attractive cancer-specific targeting capabilities. In the present review, the liposomal approaches of anticancer phytochemicals are discussed, and recent advances in these formulations applied to cancer phytotherapy are further reviewed by an informed approach.

Project 2025: Proposals for the Continued Success of Drug Development in Acute Myeloid Leukemia

The Food and Drug Administration Oncology Center of Excellence initiated Project 2025 to develop five-year goals in specific areas of oncology drug development. This meeting, in October 2020, brought together a panel of regulators and academic experts in acute myeloid leukemia (AML) to discuss opportunities to maximize the success that has recently occurred in AML drug development. The panel discussed challenges and opportunities in clinical trial design and novel endpoints, and outlined key considerations for drug development to facilitate continued growth in the field.

Interrogation of novel CDK2/9 inhibitor fadraciclib (CYC065) as a potential therapeutic approach for AML

Over the last 50 years, there has been a steady improvement in the treatment outcome of acute myeloid leukemia (AML). However, median survival in the elderly is still poor due to intolerance to intensive chemotherapy and higher numbers of patients with adverse cytogenetics. Fadraciclib (CYC065), a novel cyclin-dependent kinase (CDK) 2/9 inhibitor, has preclinical efficacy in AML. In AML cell lines, myeloid cell leukemia 1 (MCL-1) was downregulated following treatment with fadraciclib, resulting in a rapid induction of apoptosis. In addition, RNA polymerase II (RNAPII)-driven transcription was suppressed, rendering a global gene suppression. Rapid induction of apoptosis was observed in primary AML cells after treatment with fadraciclib for 6-8 h. Twenty-four hours continuous treatment further increased efficacy of fadraciclib. Although preliminary results showed that AML cell lines harboring KMT2A rearrangement (KMT2A-r) are more sensitive to fadraciclib, we found that the drug can induce apoptosis and decrease MCL-1 expression in primary AML cells, regardless of KMT2A status. Importantly, the diversity of genetic mutations observed in primary AML patient samples was associated with variable response to fadraciclib, confirming the need for patient stratification to enable a more effective and personalized treatment approach. Synergistic activity was demonstrated when fadraciclib was combined with the BCL-2 inhibitor venetoclax, or the conventional chemotherapy agents, cytarabine, or azacitidine, with the combination of fadraciclib and azacitidine having the most favorable therapeutic window. In summary, these results highlight the potential of fadraciclib as a novel therapeutic approach for AML.

An Overview of the Recent Development of Anticancer Agents Targeting the HIF-1 Transcription Factor

Hypoxia, a characteristic feature of solid tumors, is associated with the malignant phenotype and therapy resistance of cancers. Hypoxia-inducible factor 1 (HIF-1), which is responsible for the metazoan adaptive response to hypoxia, has been recognized as a rational target for cancer therapy due to its critical functions in hypoxic regions. In order to efficiently inhibit its activity, extensive efforts have been made to elucidate the molecular mechanism underlying the activation of HIF-1. Here, we provide an overview of relevant research, particularly on a series of HIF-1 activators identified so far and the development of anticancer drugs targeting them.

The important role of intensive induction chemotherapy in the treatment of acute myeloid leukemia

Introduction: Intensive induction chemotherapy followed by post-remission consolidation and/or allogeneic hematopoietic transplantation has been a standard-of-care therapy for acute myeloid leukemia (AML) for decades. In recent years, a plethora of new agents have been approved for AML treatment, dramatically changing the AML treatment landscape.Areas covered: This review provides an overview of the current role of intensive chemotherapy in the changing AML treatment landscape. PubMed-indexed publications (through 2020) and abstracts presented at major national and international conferences were reviewed for inclusion.Expert opinion: While intensive chemotherapy is standard-of-care therapy for younger patients with AML, older patients were historically viewed as universally ineligible for intensive chemotherapy; however, several studies suggest many older patients benefit from intensive chemotherapy with a curative intent, and a more holistic approach to determining eligibility for intensive treatment is recommended. Intensive strategies have also been expanded to include novel chemotherapy designs and chemotherapy in combination with targeted agents for patients with certain disease characteristics, which may permit more personalized treatment decisions. Intensive chemotherapy continues to play a pivotal role for the management of many AML patients and can offer the best chance of long-term remission, especially when followed by transplantation.

Targeting multiple signaling pathways: the new approach to acute myeloid leukemia therapy

Acute myeloid leukemia (AML) is the most common form of acute leukemia in adults and the second most common form of acute leukemia in children. Despite this, very little improvement in survival rates has been achieved over the past few decades. This is partially due to the heterogeneity of AML and the need for more targeted therapeutics than the traditional cytotoxic chemotherapies that have been a mainstay in therapy for the past 50 years. In the past 20 years, research has been diversifying the approach to treating AML by investigating molecular pathways uniquely relevant to AML cell proliferation and survival. Here we review the development of novel therapeutics in targeting apoptosis, receptor tyrosine kinase (RTK) signaling, hedgehog (HH) pathway, mitochondrial function, DNA repair, and c-Myc signaling. There has been an impressive effort into better understanding the diversity of AML cell characteristics and here we highlight important preclinical studies that have supported therapeutic development and continue to promote new ways to target AML cells. In addition, we describe clinical investigations that have led to FDA approval of new targeted AML therapies and ongoing clinical trials of novel therapies targeting AML survival pathways. We also describe the complexity of targeting leukemia stem cells (LSCs) as an approach to addressing relapse and remission in AML and targetable pathways that are unique to LSC survival. This comprehensive review details what we currently understand about the signaling pathways that support AML cell survival and the exceptional ways in which we disrupt them.

Phytochemical-Based Nanomedicine for Advanced Cancer Theranostics: Perspectives on Clinical Trials to Clinical Use

In the current chapter, a new strategic compilation of phytochemicals with potent antitumor properties has been addressed, most importantly focusing on cell cycle arrest and apoptotic signaling mechanism. A promising approach in tumor prevention is to eliminate cancer cells preferably via cell cycle arrest and programmed cell death with lesser harm to neighboring normal cells. Cancer cells have a survival advantage to escape apoptosis and relentlessly divide to proliferate, gearing up the cell cycle process. Recently, the use of phytochemical-derived conjugated chemotherapeutic agents has increased dramatically owing to its biocompatibility, low cytotoxicity, low resistance, and dynamic physiochemical properties discriminating normal cells in the treatment of various cancer types. For decades, biomedical investigations have targeted cell cycle and apoptotic cell death mechanism as an effective cancer-killing tool for systemically assessing the potential biological interactions of functional phytocompounds compared to its synthetic counterparts during their complete life cycles from entry, biodistribution, cellular/molecular interactions to excretion. Newly emerging nanotechnology application in anticancer drug formulations has revolutionized cancer therapy. Tissue-specific phyto-nanomedicine plays a vital role in advanced cancer diagnostics using liposome, micelle, and nanoparticles as a precise and effective delivery vehicle. This chapter specifically focuses on the therapeutic phytomolecules approved by the Food and Drug Administration (FDA, USA) along with phyto-chemopreventives currently on clinical trials (Phase-I/II/III/IV). Besides, detailed coverage is given to the FDA-approved nanotechnology-based formulations only in the areas of cancer theranostics via cell cycle arrest and apoptotic pathways including present challenges and future perspectives.

7-Imidazolyl-substituted 4'-methoxy and 3',4'-dimethoxy-containing polyfluoroflavones as promising antiviral agents

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Synthesis of the new 2-aryl-4-oxo-4H-polyfluorochromen-3-carboxylates as analogs of natural methoxy-containing flavones.

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The alternative flavone-5-hydroxyflavone and flavone-coumarin rearrangements of polyfluoroflavones in basic aqueous acetonitrile medium.

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New 7-(1H-imidazol-1-yl)-substituted polyfluorinated flavones and coumarins.

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Imidazolyl-functionalized flavones as high prospective antiviral agents.

A simple and convenient method for the synthesis of new methyl 2-(4-methoxyphenyl)- and 2-(3,4-dimethoxyphenyl)-4-oxo-4H-polyfluorochromen-3-carboxylates as analogs of natural methoxy-containing flavones is proposed. As a result of their directed modification under basic conditions, 7-imidazolyl-substituted derivatives were obtained. In aqueous-organic medium under basic conditions, 5,6,7,8-tetrafluoro-3-(methoxycarbonyl)flavones were transformed into 6,8-difluoro-5-hydroxy-7-(1H-imidazol-1-yl)-3-(methoxycarbonyl)flavones as a result of flavone-5-hydroxyflavone rearrangement, while 6,7,8-trifluorinated analogs underwent a flavone-coumarin rearrangement to give 6,8-difluoro-3-(hydroxyarylidene)-7-(1H-imidazol-1-yl)coumarins under the same conditions. Acid hydrolysis of methyl polyfluoroflavone-3-carboxylates allowed to obtain 2-aryl-4H-polyfluorochromen-4-ones. Evaluation of the antiviral activity of the synthesized compounds against influenza A (H1N1) and Coxsackie B3 viruses showed that 2-(3,4-dimethoxyphenyl)-5,6,8-trifluoro-7-(1H-imidazol-1-yl)-4H-chromene-4-one has the most promising properties.

Phase I Study of Alvocidib Followed by 7+3 (Cytarabine + Daunorubicin) in Newly Diagnosed Acute Myeloid Leukemia

PURPOSE

Alvocidib is a cyclin-dependent kinase 9 inhibitor leading to downregulation of the antiapoptotic BCL-2 family member, MCL-1. Alvocidib has shown clinical activity in a timed sequential regimen with cytarabine and mitoxantrone in relapsed/refractory and newly diagnosed acute myeloid leukemia (AML) but has not been studied in combination with traditional 7+3 induction therapy.

PATIENTS AND METHODS

A multiinstitutional phase I dose-escalation study of alvocidib on days 1-3 followed by 7+3 (cytarabine 100 mg/m²/day i.v. infusion days 5-12 and daunorubicin 60 mg/m² i.v. days 5-7) was performed in newly diagnosed AML ≤65 years. Core-binding factor AML was excluded.

RESULTS

There was no MTD on this study; the recommended phase II dose of alvocidib was 30 mg/m² i.v. over 30 minutes followed by 60 mg/m² i.v. infusion over 4 hours. There was one dose-limiting toxicity of cytokine release syndrome. The most common grade ≥3 nonhematologic toxicities were diarrhea (44%) and tumor lysis syndrome (34%). Overall, 69% (22/32) of patients achieved complete remission (CR). In an exploratory cohort, eight of nine (89%) patients in complete remission had no measurable residual disease, as determined by a centralized flow cytometric assay. Clinical activity was seen in patients with secondary AML, AML with myelodysplastic syndrome-related changes, and a genomic signature of secondary AML (50%, 50%, and 92% CR rates, respectively).

CONCLUSIONS

Alvocidib can be safely administered prior to 7+3 induction with encouraging clinical activity. These findings warrant further investigation of alvocidib combinations in newly diagnosed AML. This study was registered at clinicaltrials.gov identifier NCT03298984.

A distinct role for recombination repair factors in an early cellular response to transcription-replication conflicts

Transcription-replication (T-R) conflicts are profound threats to genome integrity. However, whilst much is known about the existence of T-R conflicts, our understanding of the genetic and temporal nature of how cells respond to them is poorly established. Here, we address this by characterizing the early cellular response to transient T-R conflicts (TRe). This response specifically requires the DNA recombination repair proteins BLM and BRCA2 as well as a non-canonical monoubiquitylation-independent function of FANCD2. A hallmark of the TRe response is the rapid co-localization of these three DNA repair factors at sites of T-R collisions. We find that the TRe response relies on basal activity of the ATR kinase, yet it does not lead to hyperactivation of this key checkpoint protein. Furthermore, specific abrogation of the TRe response leads to DNA damage in mitosis, and promotes chromosome instability and cell death. Collectively our findings identify a new role for these well-established tumor suppressor proteins at an early stage of the cellular response to conflicts between DNA transcription and replication.

Antiproliferative effects of L-asparaginase in acute myeloid leukemia

The antitumor enzyme L-asparaginase (L-Asp) has commonly been used for the treatment of acute lymphoblastic leukemia. However, the effects of L-Asp on acute myeloid leukemia (AML) and their underlying mechanisms have not been fully elucidated. In the present study, the effects of L-Asp on cell proliferation and apoptosis were investigated using the AML cell lines U937, HL-60 and KG-1a. The effects of combining L-Asp with mitoxantrone (MIT) and cytarabine (Ara-c) were also analyzed. The combination of MIT and Ara-C is known as MA therapy, and is a widely used therapeutic regimen for the treatment of elderly patients with refractory AML. When applied alone, L-Asp inhibited cell proliferation and induced apoptosis in each of the cell lines tested. Furthermore, the combined use of L-Asp with MA therapy further potentiated the inhibition of cell proliferation while increasing the induction of apoptosis. These findings provide evidence for the potential antitumor effect of L-Asp in AML, and indicate that improved efficacy maybe achieved by combining L-Asp with MIT and Ara-c. This combination may provide a promising new therapeutic strategy for the treatment of AML.

Transcriptional Silencing of MCL-1 Through Cyclin-Dependent Kinase Inhibition in Acute Myeloid Leukemia

Acute myeloid leukemia (AML) is the most common adult acute leukemia. Survival remains poor, despite decades of scientific advances. Cytotoxic induction chemotherapy regimens are standard-of-care for most patients. Many investigations have highlighted the genomic heterogeneity of AML, and several new targeted therapeutic options have recently been approved. Additional novel therapies are showing promising clinical results and may rapidly transform the therapeutic landscape of AML. Despite the emerging clinical success of B-cell lymphoma (BCL)-2 targeting in AML and a large body of preclinical data supporting myeloid leukemia cell (MCL)-1 as an attractive therapeutic target for AML, MCL-1 targeting remains relatively unexplored, although novel MCL-1 inhibitors are under clinical investigation. Inhibitors of cyclin-dependent kinases (CDKs) involved in the regulation of transcription, CDK9 in particular, are being investigated in AML as a strategy to target MCL-1 indirectly. In this article, we review the basis for CDK inhibition in oncology with a focus on relevant preclinical mechanism-of-action studies of CDK9 inhibitors in the context of their therapeutic potential specifically in AML.

Cyclin-dependent kinase (CDK) 9 and 4/6 inhibitors in acute myeloid leukemia (AML): a promising therapeutic approach

Introduction: Despite advancements over the last 2 years, outcomes for acute myeloid leukemia (AML) are poor; however, a greater comprehension of disease mechanisms has driven the investigation of new targeted treatments. Cyclin-dependent kinases (CDKs) regulate cell cycle progression, transcription and DNA repair, and are aberrantly expressed in AML. Targeting the CDK pathway is an emerging promising therapeutic strategy in AML.Areas covered: We describe the rationale for targeting CDK9 and CDK4/6, the ongoing preclinical and clinical trials and the potential of these inhibitors in AML. Our analysis included an extensive literature search via the Pubmed database and clinicaltrials.gov (March to August, 2019).Expert opinion: While CDK4/6 inhibitors are early in development for AML, CDK9 inhibition with alvocidib has encouraging clinical activity in newly diagnosed and relapsed/refractory AML. Preclinical data suggests that leukemic MCL-1 dependence may predict response to alvocidib. Moreover, MCL-1 plays a key role in resistance to BCL-2 inhibition with venetoclax. Investigational strategies of concomitant BCL-2 and CDK9 inhibition represent a promising therapeutic platform for AML. Furthermore, preclinical data suggests that CDK4/6 inhibition has selective activity in patients with KMT2A-rearrangements and FLT3 mutations. Incorporation of CDK9 and 4/6 inhibitors into the existing therapeutic armamentarium may improve outcomes in AML.

Direct and Indirect Targeting of HOXA9 Transcription Factor in Acute Myeloid Leukemia

HOXA9 (Homeobox A9) is a homeotic transcription factor known for more than two decades to be associated with leukemia. The expression of HOXA9 homeoprotein is associated with anterior-posterior patterning during embryonic development, and its expression is then abolished in most adult cells, with the exception of hematopoietic progenitor cells. The oncogenic function of HOXA9 was first assessed in human acute myeloid leukemia (AML), particularly in the mixed-phenotype associated lineage leukemia (MPAL) subtype. HOXA9 expression in AML is associated with aggressiveness and a poor prognosis. Since then, HOXA9 has been involved in other hematopoietic malignancies and an increasing number of solid tumors. Despite this, HOXA9 was for a long time not targeted to treat cancer, mainly since, as a transcription factor, it belongs to a class of protein long considered to be an "undruggable" target; however, things have now evolved. The aim of the present review is to focus on the different aspects of HOXA9 targeting that could be achieved through multiple ways: (1) indirectly, through the inhibition of its expression, a strategy acting principally at the epigenetic level; or (2) directly, through the inhibition of its transcription factor function by acting at either the protein/protein interaction or the protein/DNA interaction interfaces.

Heterogeneity in refractory acute myeloid leukemia

Successful clinical remission to therapy for acute myeloid leukemia (AML) is required for long-term survival to be achieved. Despite trends in improved survival due to better supportive care, up to 40% of patients will have refractory disease, which has a poorly understood biology and carries a dismal prognosis. The development of effective treatment strategies has been hindered by a general lack of knowledge about mechanisms of chemotherapy resistance. Here, through transcriptomic analysis of 154 cases of treatment-naive AML, three chemorefractory patient groups with distinct expression profiles are identified. A classifier, four key refractory gene signatures (RG4), trained based on the expression profile of the highest risk refractory patients, validated in an independent cohort (n = 131), was prognostic for overall survival (OS) and refined an established 17-gene stemness score. Refractory subpopulations have differential expression in pathways involved in cell cycle, transcription, translation, metabolism, and/or stem cell properties. Ex vivo drug sensitivity to 122 small-molecule inhibitors revealed effective group-specific targeting of pathways among these three refractory groups. Gene expression profiling by RNA sequencing had a suboptimal ability to correctly predict those individuals resistant to conventional cytotoxic induction therapy, but could risk-stratify for OS and identify subjects most likely to have superior responses to a specific alternative therapy. Such personalized therapy may be studied prospectively in clinical trials.

Emerging Therapies for Acute Myelogenus Leukemia Patients Targeting Apoptosis and Mitochondrial Metabolism

Acute Myelogenous Leukemia (AML) is a malignant disease of the hematopoietic cells, characterized by impaired differentiation and uncontrolled clonal expansion of myeloid progenitors/precursors, resulting in bone marrow failure and impaired normal hematopoiesis. AML comprises a heterogeneous group of malignancies, characterized by a combination of different somatic genetic abnormalities, some of which act as events driving leukemic development. Studies carried out in the last years have shown that AML cells invariably have abnormalities in one or more apoptotic pathways and have identified some components of the apoptotic pathway that can be targeted by specific drugs. Clinical results deriving from studies using B-cell lymphoma 2 (BCL-2) inhibitors in combination with standard AML agents, such as azacytidine, decitabine, low-dose cytarabine, provided promising results and strongly support the use of these agents in the treatment of AML patients, particularly of elderly patients. TNF-related apoptosis-inducing ligand (TRAIL) and its receptors are frequently deregulated in AML patients and their targeting may represent a promising strategy for development of new treatments. Altered mitochondrial metabolism is a common feature of AML cells, as supported through the discovery of mutations in the isocitrate dehydrogenase gene and in mitochondrial electron transport chain and of numerous abnormalities of oxidative metabolism existing in AML subgroups. Overall, these observations strongly support the view that the targeting of mitochondrial apoptotic or metabolic machinery is an appealing new therapeutic perspective in AML.

Nuclear Lipid Microdomains Regulate Daunorubicin Resistance in Hepatoma Cells

Daunorubicin is an anticancer drug, and cholesterol is involved in cancer progression, but their relationship has not been defined. In this study, we developed a novel experimental model that utilizes daunorubicin, cholesterol, and daunorubicin plus cholesterol in the same cells (H35) to search for the role of nuclear lipid microdomains, rich in cholesterol and sphingomyelin, in drug resistance. We find that the daunorubicin induces perturbation of nuclear lipid microdomains, localized in the inner nuclear membrane, where active chromatin is anchored. As changes of sphingomyelin species in nuclear lipid microdomains depend on neutral sphingomyelinase activity, we extended our studies to investigate whether the enzyme is modulated by daunorubicin. Indeed the drug stimulated the sphingomyelinase activity that induced reduction of saturated long chain fatty acid sphingomyelin species in nuclear lipid microdomains. Incubation of untreated-drug cells with high levels of cholesterol resulted in the inhibition of sphingomyelinase activity with increased saturated fatty acid sphingomyelin species. In daunodubicin-treated cells, incubation with cholesterol reversed the action of the drug by acting via neutral sphingomyelinase. In conclusion, we suggest that cholesterol and sphingomyelin-forming nuclear lipid microdomains are involved in the drug resistance.