Roadmap to personalized medicine

Abstract Standard clinical protocols and the concept “one drug fits all” that are currently used to treat illness in many cases are not effective, and strikingly so in the treatment of cancer, where 75% of therapeutic schemes are ineffective. The concept of personalized medicine is that the treatment of the disease is designed on the basis of the individual needs of each patient and the factors that influence their response to different drugs. Individualization of patient care has the potential to generate novel effective therapies, limit the adverse drug effects, create optimal treatments for individual patients, and decrease the cost associated with chronic illness and complications of drug usage. However, to achieve the goals of personalized medicine many challenges must be addressed. Here we discuss possible ways to increase the consistency of data generated by basic research and their suitability for application in medicine. New technologies employing systems biology and computer based approaches will facilitate overcoming many of the scientific challenges in the field. Changes in the education of researchers, health professionals, and the public are also required to successfully implement personalized medicine as a routine in the clinic. Finally, shift of the focus away from the development of blockbuster drugs in the biopharmaceutical industry, and modifications in the legal system to accommodate novel advancements need to be considered. The joint effort of all interested parties is needed to generate an efficient roadmap that will take us rapidly and safely to effective individual treatment, which will eliminate diseases and create better health care for all

Immunotherapy advances for mesothelioma treatment.

INTRODUCTION Mesothelioma is a rare type of cancer that is strongly tied to asbestos exposure. Despite application of different modalities such as chemotherapy, radiotherapy and surgery, patient prognosis remains very poor and therapies are ineffective. Much research currently focuses on the application of novel approaches such as immunotherapy towards this disease. Areas covered: The types, stages and aetiology of mesothelioma are detailed, followed by a discussion of the current treatment options such as radiotherapy, surgery, and chemotherapy. A description of innate and adaptive immunity and the principles and justification of immunotherapy is also included. Clinical trials for different immunotherapeutic modalities are described, and lastly the article closes with an expert commentary and five-year view, the former of which is summarised below. Expert commentary: Current efforts for novel mesothelioma therapies have been limited by attempting to apply treatments from other cancers, an approach which is not based on a solid understanding of mesothelioma biology. In our view, the influence of the hostile, hypoxic microenvironment and the gene expression and metabolic changes that resultantly occur should be characterised to improve therapies. Lastly, clinical trials should focus on overall survival rather than surrogate endpoints to avoid bias and inaccurate reflections of treatment effects

Promising investigational drug candidates in phase I and phase II clinical trials for mesothelioma

Introduction: Malignant mesothelioma is a rare and lethal malignancy primarily affecting the pleura and peritoneum. Mesothelioma incidence is expected to increase worldwide and current treatments remain ineffective, leading to poor prognosis. Within this article potential targets to improve the quality of life of the patients and assessment of further avenues for research are discussed. Areas covered: This review highlights emerging therapies currently under investigation for malignant mesothelioma with a specific focus on phase I and phase II clinical trials. Three main areas are discussed: immunotherapy (immune checkpoint blockade and cancer vaccines, among others), multitargeted therapy (such as targeting pro-angiogenic genes) and gene therapy (such as suicide gene therapy). For each, clinical trials are described to detail the current or past investigations at phase I and II. Expert opinion: The approach of applying existing treatments from other cancers does not show significant benefit, with the most promising outcome being an increase in survival of 2.7 months following combination of chemotherapy with bevacizumab. It is our opinion that the hypoxic microenvironment, the role of the stroma, and the metabolic status of mesothelioma should all be assessed and characterised to aid in the development of new treatments to improve patient outcomes

Oxidative stress and breast cancer biomarkers : the case of the cytochrome P450 2E1

Aim: The aim of the study is to investigate the impact of the cytochrome P450 2E1, which is the most efficient CYP450 family member in generating reactive oxygen species (ROS), on cellular energy metabolism of breast cancer cells and therefore the effects of CYP2E1 on breast carcinogenesis. Methods: The estrogen receptor positive MCF-7 and the triple negative MDAMB- 231 breast cancer cells were used as experimental system to estimate ROS generation in these cells overexpressing CYP2E1 and treated with the glycolytic inhibitors 3-bromopyruvate or 2-deoxyglucose in the presence or absence of the CYP2E1 inhibitor chlormethiazole. Adenosine triphosphate (ATP) assay was used to measure ATP production and lactate assay to quantify the efflux of lactic acid in breast cancer cells treated with the CYP2E1 inhibitor chlormethiazole, the mitochondrial membrane potential and cell viability assays were employed to assess the pathway of cellular energy production and cellular death respectively after treatment of MCF-7 and MDA-MB-231 with the CYP2E1 activator acetaminophen or the CYP2E1 inhibitor chlormethiazole. Results: T he r esults i ndicated i ncreased ROS generation i n b reast c ancer c ells overexpressing C YP2E1. ROS generation was differentially regulated in breast cancer cells upon treatment with the CYP2E1 inhibitor chlormethiazole. Chlormethiazole treated MCF-7 cells exhibited reduced lactate efflux implying that CYP2E1 directly or indirectly regulates the glycolytic rate in these cells. Furthermore the mitochondrial membrane potential of both MCF-7 and MDA-MB-231 cells was differentially affected by the CYP2E1 activator acetaminophen versus the CYP2E1 inhibitor chlormethiazole providing additional support for the involvement of CYP2E1 in energy metabolic pathways in breast cancer. Conclusion: Results presented in this study provide evidence to suggest that CYP2E1 regulates cellular energy metabolism of breast cancer cells in a manner dependent on cell type and potentially on the clinical staging of the disease therefore CYP2E1 is a possible breast cancer biomarker

The role of glucocorticoid receptor phosphorylation in Mcl-1 and NOXA gene expression

<p>Abstract</p> <p>Background</p> <p>The cyclin-dependent kinase (CDK) and mitogen-activated protein kinase (MAPK) mediated phosphorylation of glucocorticoid receptor (GR) exerts opposite effects on GR transcriptional activity and affects other posttranslational modifications within this protein. The major phosphorylation site of human GR targeted by MAPK family is the serine 226 and multiple kinase complexes phosphorylate receptor at the serine 211 residue. We hypothesize that GR posttranslational modifications are involved in the determination of the cellular fate in human lymphoblastic leukemia cells. We investigated whether UV signalling through alternative GR phosphorylation determined the cell type specificity of glucocorticoids (GCs) mediated apoptosis.</p> <p>Results</p> <p>We have identified putative Glucocorticoid Response Elements (GREs) within the promoter regulatory regions of the Bcl-2 family members NOXA and Mcl-1 indicating that they are direct GR transcriptional targets. These genes were differentially regulated in CEM-C7-14, CEM-C1-15 and A549 cells by glucocorticoids and JNK pathway. In addition, our results revealed that the S211 phosphorylation was dominant in CEM-C7-14, whereas the opposite was the case in CEM-C1-15 where prevalence of S226 GR phosphorylation was observed. Furthermore, multiple GR isoforms with cell line specific patterns were identified in CEM-C7-14 cells compared to CEM-C1-15 and A549 cell lines with the same antibodies.</p> <p>Conclusions</p> <p>GR phosphorylation status kinetics, and site specificity as well as isoform variability differ in CEM-C7-14, CEM-C1-15, and A549 cells. The positive or negative response to GCs induced apoptosis in these cell lines is a consequence of the variable equilibrium of NOXA and Mcl-1 gene expression potentially mediated by alternatively phosphorylated GR, as well as the balance of MAPK/CDK pathways controlling GR phosphorylation pattern. Our results provide molecular base and valuable knowledge for improving the GC based therapies of leukaemia.</p

Acute or chronic stress induce cell compartment-specific phosphorylation of glucocorticoid receptor and alter its transcriptional activity in Wistar rat brain

Chronic stress and impaired glucocorticoid receptor (GR) feedback are important factors for the compromised hypothalamic–pituitary–adrenal (HPA) axis activity. We investigated the effects of chronic 21 day isolation of Wistar rats on the extrinsic negative feedback part of HPA axis: hippocampus (HIPPO) and prefrontal cortex (PFC). In addition to serum corticosterone (CORT), we followed GR subcellular localization, GR phosphorylation at serine 232 and serine 246, expression of GR regulated genes: GR, CRF and brain-derived neurotropic factor (BDNF), and activity of c-Jun N-terminal kinase (JNK) and Cdk5 kinases that phosphorylate GR. These parameters were also determined in animals subjected to acute 30 min immobilization, which was taken as ‘normal’ adaptive response to stress. In isolated animals, we found decreased CORT, whereas in animals exposed to acute immobilization, CORT was markedly increased. Even though the GR was predominantly localized in the nucleus of HIPPO and PFC in acute, but not in chronic stress, the expression of GR, CRF, and BDNF genes was similarly regulated under both acute and chronic stresses. Thus, the transcriptional activity of GR under chronic isolation did not seem to be exclusively dependent on high serum CORT levels nor on the subcellular location of the GR protein. Rather, it resulted from the increased Cdk5 activation and phosphorylation of the nuclear GR at serine 232 and the decreased JNK activity reflected in decreased phosphorylation of the nuclear GR at serine 246. Our study suggests that this nuclear isoform of hippocampal and cortical GR may be related to hypocorticism i.e. HPA axis hypoactivity under chronic isolation stress

Protein disulfide isomerase A1 regulates breast cancer cell immunorecognition in a manner dependent on redox state

Oxidoreductase protein disulphide isomerases (PDI) are involved in the regulation of a variety of biological processes including the modulation of endoplasmic reticulum (ER) stress, unfolded protein response (UPR), ER‑mitochondria communication and the balance between pro‑survival and pro‑death pathways. In the current study the role of the PDIA1 family member in breast carcinogenesis was investigated by measuring ROS generation, mitochondrial membrane disruption, ATP production and HLA‑G protein levels on the surface of the cellular membrane in the presence or absence of PDIA1. The results showed that this enzyme exerted pro‑apoptotic effects in estrogen receptor (ERα)‑positive breast cancer MCF‑7 and pro‑survival in triple negative breast cancer (TNBC) MDA‑MB‑231 cells. ATP generation was upregulated in PDIA1‑silenced MCF‑7 cells and downregulated in PDIA1‑silenced MDA‑MB‑231 cells in a manner dependent on the cellular redox status. Furthermore, MCF‑7 and MDA‑MB‑231 cells in the presence of PDIA1 expressed higher surface levels of the non‑classical human leukocyte antigen (HLA‑G) under oxidative stress conditions. Evaluation of the METABRIC datasets showed that low PDIA1 and high HLA‑G mRNA expression levels correlated with longer survival in both ERα‑positive and ERα‑negative stage 2 breast cancer patients. In addition, analysis of the PDIA1 vs. the HLA‑G mRNA ratio in the subgroup of the living stage 2 breast cancer patients exhibiting low PDIA1 and high HLA‑G mRNA levels revealed that the longer the survival time of the ratio was high PDIA1 and low HLA‑G mRNA and occurred predominantly in ERα‑positive breast cancer patients whereas in the same subgroup of the ERα‑negative breast cancer mainly this ratio was low PDIA1 and high HLA‑G mRNA. Taken together these results provide evidence supporting the view that PDIA1 is linked to several hallmarks of breast cancer pathways including the process of antigen processing and presentation and tumor immunorecognition

The transcriptional cofactor PCAF as mediator of the interplay between p53 and HIF-1 alpha and its role in the regulation of cellular energy metabolism

Energy production is a very important function for the cells to maintain homeostasis, survive and proliferate. Cellular energy can be produced either through oxidative phosphorylation (OXPHOS) in the presence of oxygen or glycolysis in its absence. Cancer cells, even in the presence of oxygen prefer to produce energy through glycolysis and this confers them a survival advantage. Energy metabolism has recently attracted the interest of several laboratories as targeting the pathways for energy production in cancer cells could be an efficient anticancer treatment. For that purpose the role of various transcription factors in determining the pathway of energy production has been investigated extensively and there is evidence to suggest that oncogenic transcription factors promote glycolysis whereas tumour suppressors demote it. In line with this notion, the master regulator of cellular response to hypoxia, the Hypoxia Inducible Factor 1 (HIF-1) has been shown to induce the expression of a variety of genes encoding enzymes involved in glucose metabolism as well as OXPHOS favouring energy production through glucose metabolism in hypoxic cells. The tumour suppressor p53 on the other hand inhibits glycolysis and stimulates OXPHOS. One of the pathways through which p53 exerts these effects, is by inducing the inhibitor of glycolysis TIGAR and the cytochrome c oxidase assembly factor SCO2 gene expression under DNA damage conditions. However, the regulation of the expression of these genes in hypoxic conditions has been only partially elucidated. We hypothesised that under hypoxic conditions, TIGAR and SCO2 gene expression might be differentially regulated in cells bearing mutated p53 and in these cells the involvement of HIF-1 could be crucial. Indeed under hypoxia mimicking conditions, the TIGAR and SCO2 protein and mRNA levels were found to be modulated differentially in p53 wild type and mutant cell lines. The bioinformatics analysis revealed the presence of hypoxia responsive elements (HREs) within the regulatory region of the promoters of TIGAR and SCO2 genes. Firefly reporter assays and chromatin immunoprecipitation (ChIP) assays have indicated that HIF-1 plays a crucial role in the regulation of TIGAR gene expression. The direct involvement of HIF-1 in the regulation of SCO2 gene expression requires further investigation. We and others have recently reported that PCAF is a common cofactor for p53 and HIF-1α, regulating the protein stability and transcription target selectivity of both transcription factors thereby orchestrating the balance between life and death in cancer cells. We hypothesised that PCAF plays a similar role in the regulation of cellular energy metabolism by differentially targeting HIF-1α and p53 to the promoter of TIGAR and SCO2 genes. In this study we present evidence to support the notion that PCAF plays an import role in the regulation of TIGAR and SCO2 gene expression under hypoxic mimicking conditions. This conclusion was supported by assessing the functional consequences of PCAFwt and PCAFΔHAT overexpression on the intracellular lactate production, cellular oxygen consumption, NAD+/NADH ratio and ROS generation in cells under hypoxia mimicking conditions.EThOS - Electronic Theses Online ServiceGBUnited Kingdo

Errata Corrige: Stress-Induced Phosphorylation of C-Jun-N-Terminal Kinases and Nuclear Translocation of Hsp70 in the Wistar Rat Hippocampus (Vol 61, Pg 1, 2009)

In the paper entitled: Adžić, M., Đorđević, A., Krstić-Demonacos, M., & Radojčić, M. B. (2009). Stress-induced phosphorylation of c-Jun-N-terminal kinases and nuclear translocation of Hsp70 in the Wistar rat hippocampus. Archives of Biological Sciences, 61(1), 1-8. Fig. 1, on page 4, section b, should read "Nucleus" instead of "Cytoplasm