Acute Myeloid Leukemia (AML) is the most common form of leukemia diagnosed in adults with the lowest survival rates. It is a heterogeneous disease and incidence rates increase yearly, with the overall survival of AML patients remaining low. Emerging treatment strategies are key in improving the recovery rates of those diagnosed with AML due to not all patients responding to currently used intense chemotherapeutics. For the best treatment of AML patients possible, new treatments must be developed and treatment biomarkers identified. Tetrandrine is a calcium channel blocker that is a potential treatment. It has demonstrated anti-proliferation, pro-autophagic and apoptotic, and multidrug resistance reversal effects on solid cancer varieties, thought to be potentiated by acquired genomic abnormalities, and it is hypothesised that it could be repurposed to act in a similar role in haematological cancers, namely AML. Although research into the effects of tetrandrine in AML is limited, the genomic abnormalities within subsets of the disease may reveal patients that would benefit from tetrandrine treatment. This review aims to explore the potential mechanisms of tetrandrine treatment in AML, drawing on information gained through tetrandrine treatment in solid cancer. The main focus will be interactions with genes, protein, and pathways commonly dysregulated in AML, namely Tumour Protein 53 (TP53), C-Myc (MYC), Kirsten Rate Sarcoma Virus (KRAS), Vascular Endothelial Growth Factor (VEGF), Fms-like tyrosine kinase 3 (FLT3) and Nuclear Receptor Subfamily 4A1 (NR4A1) as well as the NOD-, LRR- and pyrin domain-containing protein 3 (NLRP3)-inflammasome and calcium-calmodulin (CaM)-dependent protein kinase II (CaMKII).

Despite significant advancements in understanding the pathogenesis and treatment of hematological malignancies, including leukemia and multiple myeloma, the majority of patients continue to experience poor long-term outcomes. This is partly due to the difficulty of accurately recapitulating the malignant microenvironment in vitro, particularly the bone marrow niche. The complexity of the bone marrow microenvironment poses a challenge for the in vitro examination of hematological malignancies. Traditionally, 2D culture and animal models have been utilized, but these representations are limited and have been criticized for their lack of human physiological relevance. In an attempt to overcome this, 3D models have been developed that more accurately recapitulate the in vivo microenvironment. Herein, we present an overview of recent developments in 2D and 3D models used for studying the bone marrow niche in hematological malignancies, highlighting their advantages and limitations.

In solid tumours, high expression of the glycolytic enzyme, α-enolase (ENO1), predicts for poor patient overall survival (OS), and circulating autoantibodies to ENO1 correlate positively with diagnosis and negatively with advanced disease. Although ENO1 is one of the most highly expressed genes in acute myeloid leukaemia (AML), its potential role as a biomarker in AML or its precursor, myelodysplastic neoplasms (MDS), has not been investigated. A meta-analysis of nine AML online datasets (n = 1419 patients) revealed that high ENO1 expression predicts for poor OS (HR = 1.22, 95% CI: 1.10–1.34, p < 0.001). Additionally, when compared to AML in remission (n = 5), ENO1 protein detected by immunohistochemistry was significantly higher at diagnosis in bone marrow from both AML (n = 5, p < 0.01) and MDS patients (n = 12, p < 0.05), and did not correlate with percentage of blasts (r = 0.28, p = 0.21). AML patients (n = 34) had lower circulating levels of ENO1 autoantibodies detected by ELISA compared to 26 MDS and 18 controls (p = 0.003). However, there was no difference in OS between AML patients with high vs. low levels of anti-ENO1 autoantibodies (p = 0.77). BM immunostaining for ENO1 and patient monitoring of anti-ENO1 autoantibody levels may be useful biomarkers for MDS and AML.

Calcium/calmodulin-stimulated protein kinase II (CaMKII) is a family of broad substrate specificity serine (Ser)/threonine (Thr) protein kinases widely expressed in many tissues that is capable of mediating diverse functional responses depending on its cellular and molecular microenvironment. This review briefly summarises current knowledge on the structure and regulation of CaMKII and focuses on how the molecular environment, and interaction with binding partner proteins, can produce different populations of CaMKII in different cells, or in different subcellular locations within the same cell, and how these different populations of CaMKII can produce diverse functional responses to activation following an increase in intracellular calcium concentration. This review also explores the possibility that identifying and characterising the molecular interactions responsible for the molecular targeting of CaMKII in different cells in vivo, and identifying the sites on CaMKII and/or the binding proteins through which these interactions occur, could lead to the development of highly selective inhibitors of specific CaMKII-mediated functional responses in specific cells that would not affect CaMKII-mediated responses in other cells. This may result in the development of new pharmacological agents with therapeutic potential for many clinical conditions.

Acute myeloid leukaemia (AML) is a heterogeneous disease with one of the worst survival rates of all cancers. The bone marrow microenvironment is increasingly being recognised as an important mediator of AML chemoresistance and relapse, supporting leukaemia stem cell survival through interactions among stromal, haematopoietic progenitor and leukaemic cells. Traditional therapies targeting leukaemic cells have failed to improve long term survival rates, and as such, the bone marrow niche has become a promising new source of potential therapeutic targets, particularly for relapsed and refractory AML. This review briefly discusses the role of the bone marrow microenvironment in AML development and progression, and as a source of novel therapeutic targets for AML. The main focus of this review is on drugs that modulate/target this bone marrow microenvironment and have been examined in in vivo models or clinically.

The importance of Ca2+ signaling, and particularly Ca2+ channels, in key events of cancer cell function such as proliferation, metastasis, autophagy and angiogenesis, has recently begun to be appreciated. Of particular note are two-pore channels (TPCs), a group of recently identified Ca2+-channels, located within the endolysosomal system. TPC2 has recently emerged as an intracellular ion channel of significant pathophysiological relevance, specifically in cancer, and interest in its role as an anti-cancer drug target has begun to be explored. Herein, an overview of the cancer-related functions of TPC2 and a discussion of its potential as a target for therapeutic intervention, including a summary of clinical trials examining the TPC2 inhibitors, naringenin, tetrandrine, and verapamil for the treatment of various cancers is provided.

Brain and Acute Leukemia, Cytoplasmic (BAALC) is a protein that controls leukemia cell proliferation, differentiation, and survival and is overexpressed in several cancer types. The gene is located in the chromosomal region 8q22.3, an area commonly amplified in breast cancer and associated with poor prognosis. However, the expression and potential role of BAALC in breast cancer has not widely been examined. This study investigates BAALC expression in human breast cancers with the aim of determining if it plays a role in the pathogenesis of the disease. BAALC protein expression was examined by immunohistochemistry in breast cancer, and matched lymph node and normal breast tissue samples. The effect of gene expression on overall survival (OS), disease-free and distant metastasis free survival (DMFS) was assessed in silico using the Kaplan-Meier Plotter (n=3,935), the TCGA invasive breast carcinoma (n=960) and GOBO (n=821) data sets. Functional effects of BAALC expression on breast cancer proliferation, migration and invasion were determined in vitro . We demonstrate herein that BAALC expression is progressively increased in primary and breast cancer metastases when compared to normal breast tissue. Increased BAALC mRNA is associated with a reduction in DMFS and disease-free survival, but not OS, in breast cancer patients, even when corrected for tumor grade. We show that overexpression of BAALC in MCF-7 breast cancer cells increases the proliferation, anchorage-independent growth, invasion, and migration capacity of these cells. Conversely, siRNA knockdown of BAALC expression in Hs578T breast cancer cells decreases proliferation, invasion and migration. We identify that this BAALC associated migration and invasion is mediated by focal adhesion kinase (FAK)-dependent signaling and is accompanied by an increase in matrix metalloproteinase (MMP)-9 but not MMP-2 activity in vitro . Our data demonstrate a novel function for BAALC in the control of breast cancer metastasis, offering a potential target for the generation of anti-cancer drugs to prevent breast cancer metastasis.

Since their introduction several years ago, poly (ADP-ribose) polymerase (PARP) inhibitors (PARPi) have become the standard of care for breast and gynaecological cancers with BRCA gene mutations. Given that PARPi act by exploiting defective DNA repair mechanisms within tumour cells, they should be ideally suited to combatting haematological malignancies where these pathways are notoriously defective, even though BRCA mutations are rare. To date, despite promising results in vitro, few clinical trials in humans for haematological malignancies have been performed, and additional investigation is required. Paradoxically, secondary haematological malignancies have arisen in patients after treatment with PARPi, raising concerns about their potential use as therapies for any blood or bone marrow-related disorders. Here, we provide a comprehensive review of the biological, pre-clinical, and clinical evidence for and against treating individual haematological malignancies with approved and experimental PARPi. We conclude that the promise of effective treatment still exists, but remains limited by the lack of investigation into useful biomarkers unique to these malignancies.

Alzheimer's disease, the most common form of dementia, was first formally described in 1907 yet its etiology has remained elusive. Recent proposals that Aβ peptide may be part of the brain immune response have revived longstanding contention about the possibility of causal relationships between brain pathogens and Alzheimer's disease. Research has focused on infectious pathogens that may colonize the brain such as herpes simplex type I. Some researchers have proposed the respiratory bacteria Chlamydia pneumoniae may also be implicated in Alzheimer's disease, however this remains controversial. This review aims to provide a balanced overview of the current evidence and its limitations and future approaches that may resolve controversies. We discuss the evidence from in vitro, animal and human studies proposed to implicate Chlamydia pneumoniae in Alzheimer's disease and other neurological conditions, the potential mechanisms by which the bacterium may contribute to pathogenesis and limitations of previous studies that may explain the inconsistencies in the literature.

Reliance on glycolysis for energy production is considered a hallmark of cancer and the glycolytic enzyme a-enolase is overexpressed in a range of cancer types. However, recent studies have revealed that a-enolase is involved in a variety of unrelated physiological processes and can be found in multiple unexpected cellular locations. This review focuses on the unlikely role of a-enolase as an extracellular plasminogen-binding receptor localised to the plasma membrane. Conversion of plasminogen to plasmin on the surface of cancer cells enhances their ability to invade through stroma by activating collagenases and degrading fibrin as well as extracellular matrix proteins. Increased expression of a-enolase is associated with increased migration and invasion of cancer cells, and decreased metastasis-free survival in patients with several cancer types, including non-small cell lung, pancreatic, breast and colorectal cancers. Due to its overexpression in a range of cancer types and multi-functional roles in key areas of tumour metabolism and metastasis, a-enolase may be useful as a universal cancer prognostic biomarker or therapeutic target.

Multifunctional calcium/calmodulin-stimulated protein kinases control a broad range of cellular functions in a multitude of cell types. This family of kinases contain several structural similarities and all are regulated by phosphorylation, which either activates, inhibits or modulates their kinase activity. As these protein kinases are widely or ubiquitously expressed, and yet regulate a broad range of different cellular functions, additional levels of regulation exist that control these cell-specific functions. Of particular importance for this specificity of function for multifunctional kinases is the expression of specific binding proteins that mediate molecular targeting. These molecular targeting mechanisms allow pools of kinase in different cells, or parts of a cell, to respond differently to activation and produce different functional outcomes.

The importance of Ca2+ signalling in key events of cancer cell function and tumour progression, such as proliferation, migration, invasion and survival, has recently begun to be appreciated. Many cellular Ca2+-stimulated signalling cascades utilise the intermediate, calmodulin (CaM). The Ca2+/CaM complex binds and activates a variety of enzymes, including members of the multifunctional Ca2+/calmodulin-stimulated protein kinase (CaMK) family. These enzymes control a broad range of cancer-related functions in a multitude of tumour types. Herein, we explore the cancer-related functions of these kinases and discuss their potential as targets for therapeutic intervention.

Glioblastoma multiforme (GBM) is the most common and aggressive malignant primary brain tumour in humans and has a very poor prognosis. The existing treatments have had limited success in increasing overall survival. Thus, identifying and understanding the key molecule(s) responsible for the malignant phenotype of GBM will yield new potential therapeutic targets. The treatment of brain tumours faces unique challenges, including the presence of the blood brain barrier (BBB), which limits the concentration of drugs that can reach the site of the tumour. Nevertheless, several promising treatments have been shown to cross the BBB and have shown promising pre-clinical results. This review will outline the status of several of these promising targeted therapies.