Umbilical artery tone in maternal obesity

Background: The increasing prevalence of obesity constitutes a major health problem in obstetrics with implications for feto-maternal growth and wellbeing. This study investigated and compared the contractile properties of umbilical arteries excised from obese women, with those excised from women with a normal body mass index (BMI). Methods: Sections of umbilical artery were obtained from umbilical cord samples immediately after delivery and mounted for isometric recording in organ tissue baths under physiological conditions. Cumulative additions of 5-Hydroxytryptamine (5-HT) and Prostaglandin F-2alpha (PgF2alpha) were added in the concentration range of 1 nmol/L to 10 micromol/L. Control vessels were exposed to Krebs physiological salt solution (PSS) only. The resultant effects of each drug addition were measured using the Powerlab hardware unit. Results: 5-HT exerted a significant effect on human umbilical artery tone at concentrations of 100 nmol/L, 1 micromol/L, and 10 micromol/L in normal (n = 5; P < 0.05) and obese ( n = 5; P < 0.05) women. The contractile effect was significantly greater in vessels from obese women {Mean Maximum Tension (MMT) = 4.2532 g} than in those from women of normal BMI (MMT = 2.97 g; P < 0.05). PgF2alpha exerted a significant contractile effect on vessels at 1 micromol/L and 10 micromol/L concentrations when compared with controls (n = 5; P < 0.05). There was a nonsignificant trend towards an enhanced tone response in vessels from obese women (MMT = 3.02 g; n = 5), in comparison to vessels from women of a normal BMI (MMT = 2.358 g; n = 5; P > 0.05). Conclusion: These findings support the hypothesis that endogenous regulation of umbilical artery tone is altered in association with maternal obesity. This may be linked to the cardiovascular effects of secretory products of adipose tissue, with implications for the feto-maternal circulation

Hypersialylation and multiple myeloma

There is growing recognition of the importance of sialylation as a critical post translational modification in cancer. In this article we review the role of increased cell surface sialylation (hypersialylation) in Multiple Myeloma as it relates to cellular trafficking and immune evasion. Knowledge of the specific effects of sialic acid on cell trafficking machinery and modulation of immune cell interactions will identify opportunities for therapeutic interventions. The available evidence indicates that hypersialylation facilitates disease progression and negatively impacts on response to treatment and overall survival. Further research is required to fully elucidate the mechanisms through which hypersialylation influences disease biology and therapy resistance with the ultimate goal of developing new treatment approaches to improve the outcomes of patients with Multiple Myeloma

Global Epigenetic Regulation of MicroRNAs in Multiple Myeloma

Epigenetic changes frequently occur during tumorigenesis and DNA hypermethylation may account for the inactivation of tumor suppressor genes in cancer cells. Studies in Multiple Myeloma (MM) have shown variable DNA methylation patterns with focal hypermethylation changes in clinically aggressive subtypes. We studied global methylation patterns in patients with relapsed/refractory MM and found that the majority of methylation peaks were located in the intronic and intragenic regions in MM samples. Therefore, we investigated the effect of methylation on miRNA regulation in MM. To date, the mechanism by which global miRNA suppression occurs in MM has not been fully described. In this study, we report hypermethylation of miRNAs in MM and perform confirmation in MM cell lines using bisulfite sequencing and methylation-specific PCR (MSP) in the presence or absence of the DNA demethylating agent 5-aza-2′-deoxycytidine. We further characterized the hypermethylation-dependent inhibition of miR-152, -10b-5p and -34c-3p which was shown to exert a putative tumor suppressive role in MM. These findings were corroborated by the demonstration that the same miRNAs were down-regulated in MM patients compared to healthy individuals, alongside enrichment of miR-152-, -10b-5p, and miR-34c-3p-predicted targets, as shown at the mRNA level in primary MM cells. Demethylation or gain of function studies of these specific miRNAs led to induction of apoptosis and inhibition of proliferation as well as down-regulation of putative oncogene targets of these miRNAs such as DNMT1, E2F3, BTRC and MYCBP. These findings provide the rationale for epigenetic therapeutic approaches in subgroups of MM

Inhibiting the oncogenic translation program is an effective therapeutic strategy in multiple myeloma

Published in final edited form as: Sci Transl Med. 2017 May 10; 9(389). https://doi.org/10.1126/scitranslmed.aal2668.Multiple myeloma (MM) is a frequently incurable hematological cancer in which overactivity of MYC plays a central role, notably through up-regulation of ribosome biogenesis and translation. To better understand the oncogenic program driven by MYC and investigate its potential as a therapeutic target, we screened a chemically diverse small-molecule library for anti-MM activity. The most potent hits identified were rocaglate scaffold inhibitors of translation initiation. Expression profiling of MM cells revealed reversion of the oncogenic MYC-driven transcriptional program by CMLD010509, the most promising rocaglate. Proteome-wide reversion correlated with selective depletion of short-lived proteins that are key to MM growth and survival, most notably MYC, MDM2, CCND1, MAF, and MCL-1. The efficacy of CMLD010509 in mouse models of MM confirmed the therapeutic relevance of these findings in vivo and supports the feasibility of targeting the oncogenic MYC-driven translation program in MM with rocaglates

The LIN28B/let-7 axis is a novel therapeutic pathway in Multiple Myeloma

MYC is a major oncogenic driver of Multiple Myeloma (MM) and yet almost no therapeutic agents exist that target MYC in MM. Here we report that the let-7 biogenesis inhibitor LIN28B correlates with MYC expression in MM and is associated with adverse outcome. We also demonstrate that the LIN28B/let-7 axis modulates the expression of MYC, itself a let-7 target. Further, perturbation of the axis regulates the proliferation of MM cells in vivo in a xenograft tumor model. RNA sequencing and gene set enrichment analyses of CRISPR-engineered cells further suggest that the LIN28/let-7 axis regulates MYC and cell cycle pathways in MM. We provide proof-of-principle for therapeutic regulation of MYC through let-7 with an LNA-GapmeR containing a let-7b mimic in vivo, demonstrating that high levels of let-7 expression repress tumor growth by regulating MYC expression. These findings reveal a novel mechanism of therapeutic targeting of MYC through the LIN28B/let-7 axis in MM that may impact other MYC dependent cancers as well

Multiple myeloma: The role of glycosylation in disease development and progression.

Multiple myeloma (MM) is a clonal plasma cell disorder that is characterized by skeletal destruction, renal failure, anaemia and hypercalcaemia. MM cells are intimately associated with the bone marrow microenvironment, with an array of adhesive interactions taking place between the bone marrow extracellular matrix (ECM) and the surface of MM cells. The considerable heterogeneity in the behaviour of MM is partially governed by differences in gene expression. As MM progresses further alterations in gene expression ensue, drug resistance increases and some cases develop bone marrow microenvironmental independence with spread to extra-medullary sites, possibly due to changes in adhesion properties. Despite recent advances in therapy MM remains an incurable disease. In particular, little progress has been made in patients with high-risk disease, in whom median survival remains less than 3 years (1). Knowledge of the events that underlie disease progression in MM is incomplete. Using chromosomal analysis and high throughput (HTP) genomic approaches important prognostic information can be obtained, stratifying patients into low and high-risk groups. These technologies, however do not give an account of the entire milieu within which the malignant plasma cells survive and proliferate. Considerable information may be overlooked using these approaches alone, particularly regarding the impact of PTMs on the ability of plasma cell surface proteins to interact with the surrounding microenvironment. The composition of the bone marrow microenvironment is also an important consideration if we are to acquire a deep understanding of what factors are at play, which may influence MM cell proliferation and survival within this supportive niche. PTMs are covalent, generally enzymatic, modifications that occur during or after the biosynthesis of proteins and serve to increase the functional diversity of proteins. These modifications include, but are not limited to, phosphorylation, ubiquitination, methylation, acetylation, glycosylation and proteolysis. This diverse array of protein modifications influences almost all aspects of normal and disease state cell biology. Several of these PTMs occur aberrantly in MM and have been implicated in the development of drug resistance (2-4). When considering MM cells within the bone marrow microenvironment it is important to consider PTMs that may functionally alter the properties of cell surface proteins, which act as an interface between the malignant cell and other bone marrow niche cells. One such PTM is glycosylation, which results in the alteration of sugar moieties on cell surface proteins, which can in turn alter their adhesive properties. Glycosylation is a stepwise process of covalent attachment of oligosaccharide chains to proteins, and alterations in this process have been associated with malignant transformation. Altered glycosylation is a universal feature of cancer cells and alterations in this process have been associated with a more aggressive phenotype in several solid and haematological malignancies. The glycosylation pattern of a cell can change rapidly depending on the cell-cell interaction, local microenvironment and immunological milieu. This process may significantly influence disease biology and risk of progression in MM plasma cells, where the cells are known to be dependent on bone marrow stromal cells and the bone marrow microenvironment for survival and proliferation signals. Many cytokines and adhesion molecules, critical for MM survival, are glycoproteins and depend on glycosylation for their normal function. The role of glycosylation in the interaction between the ECM and MM cells has not yet been defined. The study of the ECM in MM and other cancers has been slowed in the past by the lack of high throughput technologies that allow for rapid and detailed profiling of large insoluble ECM proteins. In MM adhesive interactions between MM cells and the ECM are known to confer drug resistance and may offer protection to MM cells from therapeutic agents. Therefore knowledge of the composition of the ECM is needed in order to further advance the identification of therapeutic targets to over come these mechanisms. The hypothesis of the work outlined in this thesis is that differential transcriptional regulation of glycosylation-associated genes, and consequent differences in glycosylation of plasma cell surface proteins, plays a role in the pathobiology of MM. The primary aim of this body of work is to explore the role of glycosylation in MM and to advance our understanding of the alterations that occur in this process in malignant plasma cells. A secondary aim of this work is to more clearly define the alterations that occur in the ECM of MM, as an important component of the bone marrow microenvironment, where glycosylated cell surface proteins are widely present The work presented in this thesis demonstrates that altered sialylation influences homing and survival of MM cells in the bone marrow niche invivo. Knockdown studies demonstrate that reduction in alpha 2,3 linked sialic acid on the surface of MM cells results in decreased tumour burden and prolonged survival in xenograft murine models. This study highlights the importance of altered glycosylation, particularly sialylation, in MM progression and metastasis. Further studies were undertaken to interrogate the bone marrow tumour microenvironment in MM, and a novel proteomics platform was applied, which facilitated the identification and annotation of ECM proteins in this disease. This work demonstrates that the tumour ECM is remodeled at an early stage in MM development in humans and this process continues as the disease progresses. The body of work presented serves to advance the current knowledge of the MM bone marrow microenvironment and the role of glycosylation in this disease.

Gene expression profiling as a prognostic tool in multiple myeloma

Multiple myeloma (MM) is an aggressive plasma cell malignancy with high degrees of variability in outcome, some patients experience long remissions, whilst others survive less than two years from diagnosis. Therapy refractoriness and relapse remain challenges in MM management, and there is a need for improved prognostication and targeted therapies to improve overall survival (OS). The past decade has seen a surge in gene expression profiling (GEP) studies which have elucidated the molecular landscape of MM and led to the identification of novel gene signatures that predict OS and outperform current clinical predictors. In this review, we discuss the limitations of current prognostic tools and the emerging role of GEP in diagnostics and in the development of personalised medicine approaches to combat drug resistance

Adoptive Immunotherapy and High-Risk Myeloma

Despite significant improvements in the treatment of multiple myeloma (MM), it remains mostly incurable, highlighting a need for new therapeutic approaches. Patients with high-risk disease characteristics have a particularly poor prognosis and limited response to current frontline therapies. The recent development of immunotherapeutic strategies, particularly T cell-based agents have changed the treatment landscape for patients with relapsed and refractory disease. Adoptive cellular therapies include chimeric antigen receptor (CAR) T cells, which have emerged as a highly promising therapy, particularly for patients with refractory disease. Other adoptive cellular approaches currently in trials include T cell receptor-based therapy (TCR), and the expansion of CAR technology to natural killer (NK) cells. In this review we explore the emerging therapeutic field of adoptive cellular therapy for MM, with a particular focus on the clinical impact of these therapies for patients with high-risk myeloma

Potential mechanisms of resistance to current anti-thrombotic strategies in Multiple Myeloma

Multiple Myeloma (MM) is a common haematological malignancy that is associated with a high rate of venous thromboembolism (VTE) with almost 10% of patients suffering thrombosis during their disease course. Recent studies have shown that, despite current thromboprophylaxis strategies, VTE rates in MM remain disappointingly high. The pathophysiology behind this consistently high rate of VTE is likely multifactorial. A number of factors such as anti-thrombin deficiency or raised coagulation Factor VIII levels may confer resistance to heparin in these patients, however, the optimal method of clinically evaluating this is unclear at present, though some groups have attempted its characterisation with thrombin generation testing (TGT). In addition to testing for heparin resistance, TGT in patients with MM has shown markedly varied abnormalities in both endogenous thrombin potential and serum thrombomodulin levels. Apart from these thrombin-mediated processes, other mechanisms potentially contributing to thromboprophylaxis failure include activated protein C resistance, endothelial toxicity secondary to chemotherapy agents, tissue factor abnormalities and the effect of immunoglobulins/“M-proteins” on both the endothelium and on fibrin fibre polymerisation. It thus appears clear that there are a multitude of factors contributing to the prothrombotic milieu seen in MM and further work is necessitated to elucidate which factors may directly affect and inhibit response to anticoagulation and which factors are contributing in a broader fashion to the hypercoagulability phenotype observed in these patients so that effective thromboprophylaxis strategies can be employed

Adoptive immunotherapy and high-risk myeloma

Despite significant improvements in the treatment of multiple myeloma (MM), it remains mostly incurable, highlighting a need for new therapeutic approaches. Patients with high-risk disease characteristics have a particularly poor prognosis and limited response to current frontline therapies. The recent development of immunotherapeutic strategies, particularly T cell-based agents have changed the treatment landscape for patients with relapsed and refractory disease. Adoptive cellular therapies include chimeric antigen receptor (CAR) T cells, which have emerged as a highly promising therapy, particularly for patients with refractory disease. Other adoptive cellular approaches currently in trials include T cell receptor-based therapy (TCR), and the expansion of CAR technology to natural killer (NK) cells. In this review we explore the emerging therapeutic field of adoptive cellular therapy for MM, with a particular focus on the clinical impact of these therapies for patients with high-risk myeloma. </p