Rupinder K. Kanwar

Recent Advances on the Roles of NO in Cancer and Chronic Inflammatory Disorders

Nitric oxide (NO) is a short-life molecule produced by the enzyme known as the nitric oxide synthase (NOS), in a reaction that converts arginine and oxygen into citrulline and NO. There are three isoforms of the enzyme: neuronal NOS (nNOS, also called NOS1), inducible NOS (iNOS or NOS2), and endothelial NOS (eNOS or NOS3). It is now known that each of these isoforms may be expressed in a variety of tissues and cell types. This paper is a review of the current knowledge of various functions of NO in diseases. We discuss in more detail its role in Cancer, the role of NO in myocardial pathophysiology, in central nervous system (CNS) pathologies. Other diseases such as inflammation, asthma, in chronic liver diseases, inflammatory bowel disease (IBD), arthritis, are also discussed. This review also covers the role of NO in cardiovascular, central nervous, pancreas, lung, gut, kidney, myoskeletal and chronic liver diseases (CLD). The ubiquitous role that the simple gas nitric oxide plays in the body, from maintaining vascular homeostasis and fighting infections to acting as a neurotransmitter and its role in cancer, has spurred a lot of interest among researchers all over the world. Nitric oxide plays an important role in the physiologic modulation of coronary artery tone and myocardial function. Nitric oxide from iNOS appears to be a key mediator of such glial-induced neuronal death. The high sensitivity of neurons to NO is partly due to NO causing inhibition of respiration, rapid glutamate release from both astrocytes and neurons, and subsequent excitotoxic death of the neurons.

Chimeric aptamers in cancer cell-targeted drug delivery

Aptamers are single-stranded structured oligonucleotides (DNA or RNA) that can bind to a wide range of targets (“apatopes”) with high affinity and specificity. These nucleic acid ligands, generated from pools of random-sequence by an in vitro selection process referred to as systematic evolution of ligands by exponential enrichment (SELEX), have now been identified as excellent tools for chemical biology, therapeutic delivery, diagnosis, research, and monitoring therapy in real-time imaging. Today, aptamers represent an interesting class of modern pharmaceuticals which with their low immunogenic potential mimic extend many of the properties of monoclonal antibodies in diagnostics, research, and therapeutics. More recently, chimeric aptamer approach employing many different possible types of chimerization strategies has generated more stable and efficient chimeric aptamers with aptamer–aptamer, aptamer–nonaptamer biomacromolecules (siRNAs, proteins) and aptamer–nanoparticle chimeras. These chimeric aptamers when conjugated with various biomacromolecules like locked nucleic acid (LNA) to potentiate their stability, biodistribution, and targeting efficiency, have facilitated the accurate targeting in preclinical trials. We developed LNA-aptamer (anti-nucleolin and EpCAM) complexes which were loaded in iron-saturated bovine lactofeerin (Fe-blf)-coated dopamine modified surface of superparamagnetic iron oxide (Fe3O4) nanoparticles (SPIONs). This complex was used to deliver the specific aptamers in tumor cells in a co-culture model of normal and cancer cells. This review focuses on the chimeric aptamers, currently in development that are likely to find future practical applications in concert with other therapeutic molecules and modalities.

Targeting survivin in cancer: the cell-signalling perspective.

Survivin, a prominent anticancer target, is ubiquitously expressed in a plethora of cancers and the evolving complexity in functional regulation of survivin is yet to be deciphered. However, pertaining to the recent studies, therapeutic modulation of survivin is critically regulated by interaction with prominent cell-signalling pathways [HIF-1α, HSP90, PI3K/AKT, mTOR, ERK, tumour suppressor genes (p53, PTEN), oncogenes (Bcl-2, Ras)] and a wide range of growth factors (EGFR, VEGF, among others). In our article we discuss, in detail, an overview of the recent developments in the pharmacological modulation of survivin via cell-signalling paradigms and antisurvivin therapeutics, along with an outlook on therapeutic management of survivin in drug-resistant cancers.

Recent Advances in Anti-Survivin Treatments for Cancer

Apoptosis occurs via extrinsic or intrinsic signalling each triggered and regulated by many different molecular pathways. In recent years, the selective induction of apoptosis through survivin in tumour cells has been increasingly recognized as a promising approach for cancer therapy. Survivin has multiple functions including cytoprotection, inhibition of cell death, and cell-cycle regulation, especially at the mitotic process stage, all of which favour cancer survival. Many studies on clinical specimens have shown that survivin over expression is invariably up regulated in human cancers, associated with resistance to chemotherapy or radiation therapy, and linked to poor prognosis, suggesting that cancer cells survive with survivin. On the basis of these findings, survivin has been proposed as an attractive target for new anticancer interventions. Survivin inhibitors recently entered clinical trials. Recent studies suggest a possible role for survivin in regulating the function of normal adult cells. However, the expression and function of survivin in normal tissues are still not well characterized and understood. Still better understandings of survivins role in tumour versus normal cells are needed for designing the strategies to selectively disrupt survivin in cancers. In the present review, we summarise the importance of recent survivin-targeted cancer therapy for future clinical application.

Prevention of a chronic progressive form of experimental autoimmune encephalomyelitis by an antibody against mucosal addressin cell adhesion molecule-1, given early in the course of disease progression

A role for α4 and β7 integrins in mediating leucocyte entry into the central nervous system in the multiple sclerosis (MS)‐like disease experimental autoimmune encephalomyelitis (EAE) has been demonstrated. However, the individual contributions of their respective ligands mucosal addressin cell adhesion molecule‐1 (MAdCAM‐1), vascular cell adhesion molecule‐1 (VCAM‐1) and E‐cadherin expressed on the blood–brain barrier has not been determined. In the present paper, it is shown that an antibody directed against MAdCAM‐1, the preferential ligand for α4β7, effectively prevented the development of a progressive, non‐remitting, form of EAE, actively induced by injection of myelin oligodendrocyte glycoprotein peptide (MOG35–55) autoantigen. Combinational treatment with both anti‐MAdCAM‐1, VCAM‐1, and intercellular adhesion molecule‐1 (ICAM‐1) (ligand for integrin lymphocyte function‐associated antigen (LFA)‐1) mAbs led to more rapid remission than that obtained with anti‐MAdCAM‐1 antibody alone. However, neither MAdCAM‐1 monotherapy, nor combinational antibody blockade was preventative when administered late in the course of disease progression. In conclusion, MAdCAM‐1 plays a major contributory role in the progression of chronic EAE and is a potential therapeutic target for the treatment of MS. Critically, antivascular addressin therapy must be given early in the course of disease prior to the establishment of irreversible damage if it is to be effective, as a single treatment modality.

‘Iron-saturated’ lactoferrin is a potent natural adjuvant for augmenting cancer chemotherapy

Bovine lactoferrin (bLf), an iron‐containing natural defence protein found in bodily secretions, has been reported to inhibit carcinogenesis and the growth of tumours. Here, we investigated whether natural bLf and iron‐saturated forms of bLf differ in their ability to augment cancer chemotherapy. bLf was supplemented into the diet of C57BL/6 mice that were subsequently challenged subcutaneously with tumour cells, and treated by chemotherapy. Chemotherapy eradicated large (0.6 cm diameter) EL‐4 lymphomas in mice that had been fed iron‐saturated bLf (here designated Lf+) for 6 weeks prior to chemotherapy, but surprisingly not in mice that were fed lesser iron‐saturated forms of bLf, including apo‐bLf (4% iron saturated), natural bLf (∼15% iron saturated) and 50% iron‐saturated bLf. Lf+‐fed mice bearing either EL‐4, Lewis lung carcinoma or B16 melanoma tumours completely rejected their tumours within 3 weeks following a single injection of either paclitaxel, doxorubicin, epirubicin or flurouracil, whereas mice fed the control diet were resistant to chemotherapy. Lf+ had to be fed to mice for more than 2 weeks prior to chemotherapy to be wholly effective in eradicating tumours from all mice, suggesting that it acts as a competence factor. It significantly reduced tumour vascularity and blood flow, and increased antitumour cytotoxicity, tumour apoptosis and the infiltration of tumours by leukocytes. Lf+ bound to the intestinal epithelium and was preferentially taken up within Peyers patches. It increased the production of Th1 and Th2 cytokines within the intestine and tumour, including TNF, IFN‐γ, as well as nitric oxide that have been reported to sensitize tumours to chemotherapy. Importantly, it restored both red and white peripheral blood cell numbers depleted by chemotherapy, potentially fortifying the mice against cancer. In summary, bLf is a potent natural adjuvant and fortifying agent for augmenting cancer chemotherapy, but needs to be saturated with iron to be effective.

Ribosome Inactivating Proteins (RIPs) from Momordica charantia for Anti Viral Therapy

This review describes the nature and applications of ribosome inactivating proteins (RIPs) from Momordica charantia (bitter melon). RIPs from the plant kingdom have received much attention in biomedical research because they target conserved host protein synthesis machinery and show specificity towards human and animal cell targets. Recent studies aimed at unravelling the enzymatic activities of the M charantia RIPs provide a structural basis for their activities. It has been reported that RIPs are member of the single chain ribosome inactivating protein (SCRIP) family which act irreversibly on ribosome by removing adenine residue from eukaryotic ribosomal RNA. Various activities of RIPs include anti-tumor, broad anti-viral, ribonuclease and deoxyribonuclease. MAP30 (Momordica Anti-HIV Protein), alpha- and beta-momorcharins inhibit HIV replication in acutely and chronically infected cells and thus are considered potential therapeutic agent in HIV infection and AIDS. Further, MAP30 improved the efficacy of anti-HIV therapy when used in combination with other anti-viral drugs. MAP30 holds therapeutic promise over other RIPs because not only it is active against infection and replication of both HSV and HIV but is non toxic to normal cells. Here we review the nature, action, structure function relationship and applications of RIPs from Momordica charantia and evaluate their potential for anti-cancer and anti-viral therapy.

Nanoparticles in the treatment and diagnosis of neurological disorders: untamed dragon with fire power to heal

UNLABELLED The incidence of neurological diseases of unknown etiology is increasing, including well-studied diseases such as Alzhiemers, Parkinsons, and multiple sclerosis. The blood-brain barrier provides protection for the brain but also hinders the treatment and diagnosis of these neurological diseases, because the drugs must cross the blood-brain barrier to reach the lesions. Thus, attention has turned to developing novel and effective delivery systems that are capable of carrying drug and that provide good bioavailability in the brain. Nanoneurotechnology, particularly application of nanoparticles in drug delivery, has provided promising answers to some of these issues in recent years. Here we review the recent advances in the understanding of several common forms of neurological diseases and particularly the applications of nanoparticles to treat and diagnose them. In addition, we discuss the integration of bioinformatics and modern genomic approaches in the development of nanoparticles. FROM THE CLINICAL EDITOR In this review paper, applications of nanotechnology-based diagnostic methods and therapeutic modalities are discussed addressing a variety of neurological disorders, with special attention to blood-brain barrier delivery methods. These novel nanomedicine approaches are expected to revolutionize several aspects of clinical neurology.

Survivin Signaling in Clinical Oncology: A Multifaceted Dragon

Survivin is an inhibitor of apoptosis protein (IAP) family member preferentially expressed in a myriad of clinical cancers. The complex functional mechanism and regulatory roles of survivin in cell division and cell death has hindered current therapeutic regimes from decoding its diagnostic, prognostic, and therapeutic significance in the area of translational oncology. Pharmacological modulation of survivin was tagged with its evolving functional complexity associated with various cell‐signaling cascades including PI3K/AKT, mammalian target of rapamycin (mTOR), extracellular signal‐regulated kinases (ERK), mitogen‐activated protein kinases (MAPK), signal transducer and activator of transcription (STAT), hypoxia‐inducible factor‐1α (HIF‐1α), heat‐shock protein 90 (HSP90), p53, B‐cell lymphoma 2 (Bcl2), epidermal growth factor receptor (EGFR), vascular endothelial growth factor (VEGF) etc. The present review provides a multifaceted role of survivin and its mechanistic action in an array of clinical cancers. Furthermore, the utilization of novel nanotechnology‐based drug delivery systems for target‐specific hurling of tumors enabling contemporaneous detection, treatment, and therapeutic imaging in cancer therapy are discussed.

Molecular and Biotechnological Advances in Milk Proteins in Relation to Human Health

Milk and colostrum is a rich source of proteins/peptides which have crucial roles in both neonates and adults. Milk bioactive proteins and peptides are potential health-enhancing nutraceuticals for food. Many bioactive peptides/proteins may be used as nutraceuticals, for example, in the treatment of cancer, asthma, diarrhea, hypertension, thrombosis, dental diseases, as well as mineral malabsorption, and immunodeficiency. The following components of milk are of particular interest in the recent years: 1) Lactoferrin [Lf] has antibacterial, antifungal, antiviral, antiparasite and antitumor activities and accelerates immunomodulatory properties. Lf is a potent inhibitor for several enveloped and naked viruses, such as rotavirus, enterovirus and adenovirus. Lf is resistant to tryptic digestion and breast-fed infants excrete high levels of faecal Lf, so that its effect on viruses replicating in the gastrointestinal tract is of great interest. 2) Casein has been protective in experimental bacteremia by eliciting myelopoiesis. Casein hydrolyzates were also protective in diabetic animals, reduced the tumor growth and diminished colicky symptoms in infants. 3) A Proline rich polypeptide [PRP] revealed variety of immunotropic functions, including promotion of T-cell activation and inhibition of autoimmune disorders such as multiple sclerosis. 4) alpha-Lactalbumin [LA] demonstrates antiviral, antitumor and anti-stress properties. 5) Lactoperoxidase shows antibacterial properties. 6) Lysozyme is effective in treatment of periodentitis and prevention of tooth decay. Taken together, milk-derived proteins and peptides are bio-available and safe for the prevention and treatment of various disorders in humans and may play a complementary [natural agents] rather than a substitutional role to the toxic synthetic pharmacological drugs.