Two novel approaches targeting cancer cell membrane for tumor therapy

Disruption of normal cell function by chemicals, UV radiation or viruses can cause various cancer. Drugs that have been developed for cancer therapy bind to various targets to correct disorder cell behavior, repair damaged DNA or promote cell apoptosis. However, there is rare study that focuses on cancer cell membrane as target. We propose two approaches for achieving our goal. One is to use phospholipase A₂ (PLA₂) to cleave phospholipid heads of the bilayer of cancer cells. Because PLA₂ has unique Ca²⁺ catalytic site and the pH of healthy tissue cells should be slightly alkaline at 7.2–7.5, it can be easily protected by CO₃²⁻ in the form of PLA₂–CaCO₃. While PLA₂–CaCO₃ accumulate in cancer cells in the acidic microenvironment of which the pH is below 7, it could be converted to active state (PLA₂-Ca²⁺) which can intensively damage the cancer cell membrane. The other one is to use both monoclonal antibodies and dimethylsulfoxide (DMSO). The internalization of targeted cancer cell antibodies could change the curvature of cell membrane from order state to disorder state, therefore strong detergent DMSO can destroy cancer cells at extreme low concentration. These two approaches present no harm for normal cells, therefore, drugs targeted cancer cell membrane might become a new and high effective clinical cancer therapy.     

Genetic approaches to cell biology and metabolism of spirochetes.

Genetic analysis and methodology have only comparatively recently been applied to the study of spirochetes. Although genetic transfer procedures for spirochetes are not widely available, there are several examples of progress in genetic analysis of spirochetes by other approaches. Some examples of these approaches are the following. 1) Genes for synthetic pathways in Treponema and Leptospira have been cloned by complementation of Escherichia coli serving as plasmid hosts. 2) The OspA protein of Borrelia burgdorferi has been overexpressed in E. coli without the signal peptide; the recombinant product has been suitable for circular dichroism as well as other biochemical analyses. 3) The heat shock proteins of B. burgdorferi are homologous to heat shock proteins of E. coli. 4) Enzyme activity profiles of B. burgdorferi and other spirochetes show strain heterogeneity and also indicate which biosynthetic and enzymatic activities are conserved within different spirochetes. 5) The gene organization of rRNA genes have revealed differences between spirochetes and other types of bacteria.     

Cell adhesion molecules in gene and cell therapy approaches for nervous system repair

The inability of the central nervous system (CNS) to efficiently repair damages results in severe functional impairment after trauma or neurodegenerative/demyelinating diseases. Regeneration failure is attributed to inhibitory molecules creating a nonpermissive environment for axonal regrowth, and dictates the necessity for the development of novel therapeutic strategies. An emerging approach for improving regeneration is the use of gene therapy to manipulate cell adhesion molecule expression in experimental animal models of degeneration. Alternatively, cell transplantation to replace lost neurons and the grafting of myelinating cells to repair demyelinating lesions are promising approaches for treating CNS injuries and demyelination. Schwann cells (SCs), oligodendrocyte progenitors, olfactory ensheathing cells and embryonic and neural stem cells have been shown to form myelin after transplantation into the demyelinated CNS. The repair capacity of the peripheral nervous system (PNS) is much higher, but there is still a limit to the amount of nerve loss that can be bridged after injury, and longer nerve gaps call for the use of conduits populated with living cells. In both cases, the interaction of grafted cells with the host environment is of paramount importance for the incorporation and functional integration of these cells and the manipulation of cell adhesion molecules is an attractive approach towards achieving this goal. In this review we summarize data from the recent literature regarding the manipulation of cell adhesion molecule expression towards CNS and PNS repair and discuss the prospects for future therapeutic applications.     

Quality approaches in cell therapy: patient and therapy-related aspects

Quality requirements for cell therapy programmes are those that involve regulation and licensing operating at a European and National level, for example, the EU Directive on Tissues and Cells, National Tissue Regulations and voluntary accreditation schemes usually associated with international organizations, for example, The Foundation for Accreditation of Cell Therapy–Joint Accreditation Committee of ISCT (Europe) and EBMT (FACT-JACIE) and the World Marrow Donor Association (WMDA). Important aspects of patient and therapy-related quality requirements are those for donors, including selection, evaluation and management. WMDA standards apply to unrelated donors, while, for example, in the UK the requirements of FACT-JACIE and the Competent Authority – the Human Tissue Authority, are essential. Donors must give appropriate consent and be properly evaluated to assess their fitness to donate and to exclude any condition that might harm the recipients of their cells. Testing must include markers of infectious disease , human leucocyte antigen typing and ABO group. A significant proportion of unrelated donor cell therapy products are collected from donors in other countries, including those outside the EU and organizations, such as the Alliance for Harmonization of Cell Therapy Accreditation aim to achieve an international consensus on the requirements for donors and the donation process, working with the European Union authorities and other bodies. Essential aspects of patient quality include definition of a minimum programme size, specifications for in- and out-patient facilities, access to appropriate supportive care, for example, intensive therapy units, provision of cytomegalovirus-appropriate blood products and access to doctors in radiation oncology, respiratory medicine and other key specialities. The Quality Management Programme is central to every aspect of a cell therapy programme today. Essential features include training programmes, audit, reporting and review of severe adverse events, accidents and complaints. The FACT-JACIE standards also define the requirements for therapy administration, including radiotherapy, clinical research and data management. The burden of inspection for cell therapy programmes is increasing but with the aim of improving quality and safety.     

Gene therapy approaches for cardiovascular diseases

Cardiovascular diseases are one of the main causes of mortality in Western countries. Gene therapy is emerging as a potential strategy for the treatment of cardiovascular diseases, such as peripheral arterial disease, ischemic heart disease, restenosis after angioplasty, vascular bypass graft occlusion and transplant-associated coronary artery disease. Since the initial experiments more than one decade ago, remarkable progress has been made in the field of gene transfer and human clinical trials are underway. In here we give an overview of available gene transfer strategies describing several delivery routes and currently used vectors in animal studies and clinical trials. Hereby we want to focus on new approaches including the potential combination of gene therapy with cell therapy and tissue engineering, gene silencing and recently developed techniques for targeting genes to the vascular wall and the myocardium.     

Genetic approaches for the identification of apoptotic components

Jun amino-terminal kinase (JNK) mediates a physiological stress signal that leads to cell death. However, the role of the JNK pathway in intrinsic cell death execution mechanisms is largely unknown. In a genetic screen for dominant suppressors of Reaper (Rpr)-induced cell death, we identified Drosophila chromosomal regions that contain genes which are homologous to apoptosis signal-regulating kinase (ASK1) and Drosophila tumor necrosis factor receptor-associated factor 1 (DTRAF1). We present evidence that the killer signal initiates the JNK pathway via proteasome-mediated degradation of Drosophila inhibitor of apoptosis protein 1 (DIAP1) to promote cell death.     

Novel approaches for therapy of chronic hepatitis C.

Currently available anti-HCV therapy is effective in only half of the patients and limited by side effects that often necessitate discontinuation. Therefore, new treatment strategies are being developed including (i) the optimization of current regimens, (ii) the use of additional agents working via novel mechanisms, and (iii) anti-fibrotic strategies. Many new antiviral compounds are now being studied in preclinical and clinical trials. This review will focus on drugs that have already entered the stage of phase 2 or phase 3 studies.     

Oncolytic parvoviruses. A new approaches for cancer therapy

Parvoviruses such as parvovirus H-1 (H-1PV) may selectively infect and lysis cancer cells. The parvoviruses also induce an immune system to eliminate the tumor cells through the formation of anti-cancer immunity. One of the possible mechanisms of antitumor activity is associated with the direct induction of apoptosis by parvoviral proteins NS1 and 11 kDa. Parvovirus-based vectors are promising for gene therapy of oncological diseases and genetic disorders in humans. Parvoviruses were successfully used for the experimental treatment on animal models of human glioma, neuroblastomas, lymphomas, pancreatic carcinoma, carcinomas and breast tumors. ParvOryx is the first oncolytic preparation constructed on the base of H-1PV; its phase I/IIa clinical trials in patients with glioblastoma multiforme are in process.     

New approaches for biocompatibility testing using cell culture

We are proposing two modified assays for biocompatibility testing which analyze the effects of cytotoxic substances leached from a biomaterial in cell culture. The biocompatibility of two vascular prostheses made of polytetrafluoroethylene was analyzed using the modified assays. One test, the "fluid medium assay" was modified by using small pieces of graft glued to a screening lid, thereby reducing the possibility of mechanical injury to cultured cells by free fragments of the tested biomaterial. Another test, the "cell inhibition assay" was modified in that the biomaterial to be tested was ground into small pieces while at very low temperature. The measure of cell toxicity used was the effect on DNA replication. Our results suggest that these modified assay methods can be used to evaluate the biocompatibility of biomaterials.     

药物基因组学——指导合理用药的基因组学

随着人类基因组研究的发展，人们认识到参与药物代谢的酶、转运蛋白、受体和其他药物靶蛋白基因的遗传多态性（主要是单核苷酸多态性）与许多药物在显效和毒性方面的个体差异有关。药物基因组学作为基于功能基因组学与分子药理学的一门科学，主要通过分析DNA的遗传变异和监测基因表达谱的改变来阐明药物反应差异的遗传学本质，这不仅能改善疾病的诊断、预测可能的药物反应，而且也推动了药物发现和发展的进程，最终将有助于指导临床合理用药。     

PMS treatment approaches and progesterone therapy

Two hundred thirty-nine patients met the diagnostic criteria for premenstrual syndrome (PMS) or possible PMS and were first treated with multiple nonhormonal approaches. After six weeks, 35% reported good improvement. Of 107 unimproved patients who subsequently received progesterone therapy, 53% reported good improvement at the six-month follow-up. This report suggests the range of treatment responses among women who seek treatment for premenstrual symptoms, but placebo-controlled study is essential. It appears useful to provide conservative treatment initially, with the addition of hormonal therapies only when symptoms are not reduced.     

Novel approaches to therapy for systemic lupus erythematosus: update 2005

This review covers the major advances in the therapeutic potentials related to systemic lupus erythematosus published in Medline between 2000 and February 2005. Controlled, open and Phase I–III trials were included. Anecdotal reports were excluded. Several trials have defined the role of cyclophosphamide, methotrexate, antimalarials, hormonal treatment and mycophenolate mofetil (Cellcept) in the management of systemic lupus erythematosus. The aims of novel biologics for systemic lupus erythematosus are to target the autoimmune disease at different points: B-cell depletion (rituximab [Rituxan®], anti-BLys antibodies [Lymphostat-B?]), inhibition of T–B interaction (rituximab), blockade of cytokines (anti-interleukin-10 antibodies), manipulation of idiotypes (intravenous immunoglobulin), tolerance induction to DNA and immunoglobulin-peptides and peptide therapy (abetimus sodium [Riquent^®]). Low-dose intravenous cyclophosphamide (Euro-Lupus protocol) is as effective as the conventional National Insitutes of Health protocol and is also associated with less toxicity. Stem cell transplantation for severe disease induces remission in most patients, however, the relapse rate in a third of patients and the associated morbity and mortality restricts its use to selected patients with life-threatening disease. Intravenous immunoglobulin, although utilized in open trials, is effective and safe for various manifestations of systemic lupus erythematosus. Major advances have been associated with mycophenolate mofetil and rituximab. Mycophenolate mofetil is effective for induction and maintenance therapy of lupus proliferative glomerulonephritis and is associated with fewer adverse events than monthly intravenous cyclophosphamide. Rituximab is a promising agent, and although its utilization is presently limited, it appears to be effective for lupus patients with severe disease.     

Emerging approaches for the therapy of autoimmune and chronic inflammatory disease

Progress in defining protein and gene signatures that characterize autoimmune-mediated inflammatory diseases has uncovered a large number of potential therapeutic targets. Preclinical data from rodent models can be generated rapidly, as can data from the genetic crosses of gene-deficient mice on autoimmune-susceptible backgrounds. But humans are not the same as mice, and however robust preclinical data might appear, therapeutic intervention in patients with autoimmune disease remains the definitive experiment. Several studies published in the past year have tested paradigms of autoimmune disease in clinical trials. Recent therapeutic approaches for targeting B-cell subsets and co-stimulatory pathways are described here in detail. It is our belief that the future of immunotherapy in the clinic will depend to some extent upon the availability of biomarkers for defining biological signatures of immune function in vivo.     

Gene therapy in peripheral nerve reconstruction approaches

Gene transfer to a transected peripheral nerve or avulsed nerve root is discussed to be helpful where neurosurgical peripheral nerve reconstruction alone will not result in full recovery of function. Axonal regeneration is supposed to be facilitated by this new therapeutic approach via delivery of specific regeneration promoting molecules as well as survival proteins for the injured sensory and motor neurons. Therefore gene therapy aims in long-term and site-specific delivery of those neurotrophic factors. This paper reviews methods and perspectives for gene therapy to promote functional recovery of severely injured and thereafter reconstructed peripheral nerves. Experimental in vivo and ex vivo gene therapy approaches are reported by different groups. In vivo gene therapy generally uses direct injection of cDNA vectors to injured peripheral nerves. Ex vivo gene therapy is based on the isolation of autologous cells followed by genetic modification of these cells in vitro and re-transplantation of the modified cells to the patient as part of tissue engineered nerve transplants. Vectors of different origin are published to be suitable for peripheral nerve gene therapy and this review discusses the different strategies with regard to their efficiency in gene transfer, their risks and their potential relevance for clinical application.     

Diagnostic approaches for viruses and prions in stem cell banks

Some stem cell lines may contain an endogenous virus or can be contaminated with exogenous viruses (even of animal origin) and may secrete viral particles or express viral antigens on their surface. Moreover, certain biotechnological products (e.g. bovine fetal serum, murine feeder cells) may contain prion particles. Viral and prion contamination of cell cultures and "feeder" cells, which is a common risk in all biotechnological products derived from the cell lines, is the most challenging and potentially serious outcome to address, due to the difficulty involved in virus and prion detection and the potential to cause serious disease in recipients of these cell products. Stem cell banks should introduce adequate quality assurance programs like the microbiological control program and can provide researchers with valuable support in the standardization and safety of procedures and protocols used for the viral and prion testing and in validation programs to assure the quality and safety of the cells.