Induction of multiple sclerosis and response to tyrosine kinase inhibitors

FDA-Approved Kinase Inhibitors in Preclinical and Clinical Trials for Neurological Disorders

Cancers and neurological disorders are two major types of diseases. We previously developed a new concept termed "Aberrant Cell Cycle Diseases" (ACCD), revealing that these two diseases share a common mechanism of aberrant cell cycle re-entry. The aberrant cell cycle re-entry is manifested as kinase/oncogene activation and tumor suppressor inactivation, which are hallmarks of both tumor growth in cancers and neuronal death in neurological disorders. Therefore, some cancer therapies (e.g., kinase inhibition, tumor suppressor elevation) can be leveraged for neurological treatments. The United States Food and Drug Administration (US FDA) has so far approved 74 kinase inhibitors, with numerous other kinase inhibitors in clinical trials, mostly for the treatment of cancers. In contrast, there are dire unmet needs of FDA-approved drugs for neurological treatments, such as Alzheimer's disease (AD), intracerebral hemorrhage (ICH), ischemic stroke (IS), traumatic brain injury (TBI), and others. In this review, we list these 74 FDA-approved kinase-targeted drugs and identify those that have been reported in preclinical and/or clinical trials for neurological disorders, with a purpose of discussing the feasibility and applicability of leveraging these cancer drugs (FDA-approved kinase inhibitors) for neurological treatments.

Non-receptor tyrosine kinase signaling in autoimmunity and therapeutic implications

Autoimmune diseases are characterized by impaired immune tolerance towards self-antigens, leading to enhanced immunity to self by dysfunctional B cells and/or T cells. The activation of these cells is controlled by non-receptor tyrosine kinases (NRTKs), which are critical mediators of antigen receptor and cytokine receptor signaling pathways. NRTKs transduce, amplify and sustain activating signals that contribute to autoimmunity, and are counter-regulated by protein tyrosine phosphatases (PTPs). The function of and interaction between NRTKs and PTPs during the development of autoimmunity could be key points of therapeutic interference against autoimmune diseases. In this review, we summarize the current state of knowledge of the functions of NRTKs and PTPs involved in B cell receptor (BCR), T cell receptor (TCR), and cytokine receptor signaling pathways that contribute to autoimmunity, and discuss their targeting for therapeutic approaches against autoimmune diseases.

Expanding spectrum of anticancer drug, imatinib, in the disorders affecting brain and spinal cord

Imatinib is a tyrosine kinase inhibitor and is used as a first line drug in the treatment of Philadelphia-chromosome-positive chronic myeloid leukaemia and gastrointestinal stromal tumors. Being tyrosine kinase inhibitor, imatinib modulates the activities of Abelson gene (c-Abl), Abelson related gene (ARG), platelet-derived growth factor receptor (PDGFR), FMS-like tyrosine kinase 3 (FLT3), lymphocyte-specific protein (Lck), mitogen activated protein kinase (MAPK), amyloid precursor protein intracellular domain (AICD), α-synuclein and the stem-cell factor receptor (c-kit). Studies have shown the role of imatinib in modulating the pathophysiological state of a number of disorders affecting brain and spinal cord such as Alzheimer's disease, Parkinson's disease, stroke, multiple sclerosis and spinal cord injury. The present review discusses the role of imatinib in the above described disorders and the possible mechanisms involved in these diseases.

Predicting Effectiveness of Imatinib Mesylate in Tumors Expressing Platelet-Derived Growth Factors (PDGF-AA, PDGF-BB), Stem Cell Factor Ligands and Their Respective Receptors (PDGFR-α, PDGFR-β, and c-kit)

INTRODUCTION

This research aims to optimize and predict the effectiveness of imatinib mesylate (imatinib) in tumors expressing platelet-derived growth factors (PDGF-AA, BB), kit/stem cell factor (SCF) ligands and their respective receptors (PDGFR-α, PDGFR-β, and c-kit).

MATERIAL AND METHODS

Samples of normal primary human T cells were incubated with graded concentrations of 1-5 μM imatinib. The energy yield by imatinib doses in those samples was identified in H-thymidine proliferation assay as described before in earlier studies. Tumor models of human pancreatic adenocarcinoma L3.6pl (PDGFAA/PDGFR-α-positive and KIT-negative), human male gonad Leydig tumor cells MA10 (PDGF-AA/PDGFR-α- positive and KIT-positive), human small-cell lung cancer [H209 (KIT-positive), NCI-H526 (PDGFR β-positive and KIT-positive), and NCI-H82 (PDGFR β-positive and KIT-negative)], and human neuroblastoma SMS-KCNR (PDGF-BB/PDGFR-β-positive and KIT-positive) in athymic nude mice were used. The antitumor activity of different doses of imatinib in different regimens in those xenografts was predicted as described before in earlier studies.

RESULTS

The energy yield by drug doses was perfectly logarithmic correlated (r = 1) with the drug dose. An efficient dose-energy model with perfect fit (R = 1) estimating the energy yield by imatinib doses has been established to administer the personalized dose. Predictions for the antitumor activity of imatinib in those xenografts using the dose-energy model and the histologic grade of the control animals were 100 % identical to those actually induced.

CONCLUSION

The effect of imatinib is transient and reversible, reduces tyrosine phosphorylation of tumor-derived PDGFR-α, PDGFR-β, and c-kit without affecting their levels of expression. A resumption of tumor growth nearly identical to the growth prior to therapy should be expected whenever the treatment is stopped. Tumors of PDGF-AA/PDGFR-α exhibit significant resistance to imatinib which requires administering imatinib three times a day, whereas resistance of tumors of PDGF-BB/PDGFR-β or KIT-positive is relatively lower which requires administering imatinib two times a day only to produce an actual inhibition 100 % identical to that predicted for tumor growth.

Data to establish the optimal standard regimen and predicting the response to docetaxel therapy

This paper contains data to establish the optimal standard regimen and predicting the response to docetaxel therapy (Moawad, 2014) [1]. Docetaxel has been in use for over a decade without demonstrating data indicates a predictable response in the treatment of cancer. Data of puzzling response to docetaxel therapy was due to its cell cycle specific effect. Although several administered schedules were investigated, the relative therapeutic advantage of high versus low doses has not been identified yet. Also the antitumor target of docetaxel has not yet been identified to optimize therapy by predicting the response of patients prior to therapy to provide a protection against treatment failure. In the present paper, we demonstrate the data used to optimize docetaxel therapy and investigate the possibility of predicting for the first time the antitumor target of docetaxel.