Developing a JAK Inhibitor for Targeted Local Delivery: Ruxolitinib Cream

Named after the two-faced Roman god of doorways, Janus kinases (JAKs) represent a class of tyrosine kinases. The JAK signaling pathway is pivotal for the downstream signaling of inflammatory cytokines, including interleukins, interferons, and multiple growth factors. This article provides an overview of the JAK pathway and signaling, its significance in immune-mediated dermatologic diseases and the development of a targeted, localized option of a selective JAK inhibitor, ruxolitinib cream. In the early 1990s, various discovery and clinical development programs were initiated to explore pharmaceutical inhibition of the JAK-STAT pathway. Incyte Corporation launched a strategy to identify molecules suitable for both topical as well as oral delivery. Ruxolitinib was designed as a molecule with low nanomolar potency selective for JAK1 and 2 enzymes, but without significant inhibition of non-JAK kinases, as well as physicochemical properties for both topical and oral administration. An oil-in-water emulsified ruxolitinib cream formulation was developed for topical application and was studied in multiple immune-mediated dermatologic diseases including psoriasis, alopecia areata, atopic dermatitis and vitiligo. Ruxolitinib cream represents a novel, JAK1/2 selective therapy that can be delivered directly to the skin to treat a number of cytokine-driven, inflammatory dermatoses.

Download Full-text

SHCA PHOSPHOTYROSINE DERIVED SIGNALING IS REQUIRED FOR THE MAINTENANCE OF CARDIAC FUNCTION

Clinical & Investigative Medicine ◽

10.25011/cim.v31i4.4829 ◽

2008 ◽

Vol 31 (4) ◽

pp. 23

Author(s):

Rachel Vanderlaan ◽

Rod Hardy ◽

Golam Kabir ◽

Peter Back ◽

A J Pawson

Keyword(s):

Extracellular Matrix ◽

Cardiac Function ◽

Tyrosine Kinases ◽

Sh2 Domain ◽

Scaffolding Protein ◽

Restricted Domain ◽

Downstream Signaling ◽

Matrix Interactions ◽

Extracellular Matrix Interactions ◽

Ptb Domain

Background: ShcA, a scaffolding protein, generates signalspecificity by docking to activated tyrosine kinases through distinct phosphotyrosine recognition motifs, while mediating signal complexity through formation of diverse downstream phosphotyrosine complexes. Mammalian ShcA encodes 3 isoforms having a modular architecture of a PTB domain and SH2 domain, separated by a CH1 region containing tyrosine phosphorylation sites important in Ras-MAPK activation. Objective and Methods: ShcA has a necessary role in cardiovascular development^1,2. However, the role of ShcA in the adult myocardium is largely unknown, also unclear, is how ShcA uses its signaling modules to mediate downstream signaling. To this end, cre/loxP technology was employed to generate a conditional ShcA allele series. The myocardial specific ShcA KO (ShcA CKO) and myocardial restricted domain mutant KI mice were generated using cre expressed from the mlc2v locus^3 coupled with the ShcA floxed allele and in combination with the individual ShcA domain mutant KI alleles^2. Results: ShcACKO mice develop a dilated cardiomyopathy phenotype by 3 months of life, typified by depressed cardiac function and enlarged chamber dimensions. Isolated cardiomyocytes from ShcA CKO mice have preserved contractility indicating an uncoupling between global heart function and single myocyte contractile mechanics. Force-length experiments suggest that the loss of shcAmediates the uncoupling through deregulation of extracellular matrix interactions. Subsequent, analysis of the ShcA myocardial restricted domain mutant KImice suggests that ShcA requires PTB domain docking to upstream tyrosine kinases and subsequent phosphorylation of the CH1 tyrosines important for downstream signaling. Conclusion: ShcA is required for proper maintenance of cardiac function, possibly regulation of extracellular matrix interactions. References: 1. Lai KV, Pawson AJ. The ShcA phosphotyrosine docking protein sensitizescardiovascular signaling in the mouse embryo. Genes and Dev 2000;14:1132-45. 2. Hardy WR. et al. Combinatorial ShcA docking interactions supportdiversity in tissue morphogenesis. Science2007;317:251-6. 3.Minamisawa, s. et al. A post-transcriptional compensatory pathway inheterozygous ventricular myosin light chain 2-deficient mice results in lack ofgene dosage effect during normal cardiac growth or hypertrophy. J Biol Chem 1999;274:10066-70.

Download Full-text

Development of the Sensing Platform for Protein Tyrosine Kinase Activity

Biosensors ◽

10.3390/bios11070240 ◽

2021 ◽

Vol 11 (7) ◽

pp. 240

Author(s):

Lan-Yi Wei ◽

Wei Lin ◽

Bey-Fen Leo ◽

Lik-Voon Kiew ◽

Chia-Ching Chang ◽

...

Keyword(s):

Tyrosine Kinase ◽

Tyrosine Kinases ◽

Protein Tyrosine Kinase ◽

Kinase Activity ◽

Significant Inhibition ◽

Tyrosine Kinase Activity ◽

Protein Tyrosine ◽

Sensing Platform ◽

Relative Standard ◽

Protein Tyrosine Kinase Activity

A miniature tyrosinase-based electrochemical sensing platform for label-free detection of protein tyrosine kinase activity was developed in this study. The developed miniature sensing platform can detect the substrate peptides for tyrosine kinases, such as c-Src, Hck and Her2, in a low sample volume (1–2 μL). The developed sensing platform exhibited a high reproducibility for repetitive measurement with an RSD (relative standard deviation) of 6.6%. The developed sensing platform can detect the Hck and Her2 in a linear range of 1–200 U/mL with the detection limit of 1 U/mL. The sensing platform was also effective in assessing the specificity and efficacies of the inhibitors for protein tyrosine kinases. This is demonstrated by the detection of significant inhibition of Hck (~88.1%, but not Her2) by the Src inhibitor 1, an inhibitor for Src family kinases, as well as the significant inhibition of Her2 (~91%, but not Hck) by CP-724714 through the platform. These results suggest the potential of the developed miniature sensing platform as an effective tool for detecting different protein tyrosine kinase activity and for accessing the inhibitory effect of various inhibitors to these kinases.

Download Full-text

Receptor Tyrosine Kinases in Kidney Development

Journal of Signal Transduction ◽

10.1155/2011/869281 ◽

2011 ◽

Vol 2011 ◽

pp. 1-10 ◽

Cited By ~ 14

Author(s):

Renfang Song ◽

Samir S. El-Dahr ◽

Ihor V. Yosypiv

Keyword(s):

Tyrosine Kinases ◽

Molecular Mechanisms ◽

Kidney Development ◽

Receptor Tyrosine Kinases ◽

Adaptor Proteins ◽

Downstream Signaling ◽

Arterial Blood ◽

Intracellular Signal ◽

Human Birth

The kidney plays a fundamental role in the regulation of arterial blood pressure and fluid/electrolyte homeostasis. As congenital anomalies of the kidney and urinary tract (CAKUT) constitute one of the most common human birth defects, improved understanding of the cellular and molecular mechanisms that lead to CAKUT is critical. Accumulating evidence indicates that aberrant signaling via receptor tyrosine kinases (RTKs) is causally linked to CAKUT. Upon activation by their ligands, RTKs dimerize, undergo autophosphorylation on specific tyrosine residues, and interact with adaptor proteins to activate intracellular signal transduction pathways that regulate diverse cell behaviours such as cell proliferation, survival, and movement. Here, we review the current understanding of role of RTKs and their downstream signaling pathways in the pathogenesis of CAKUT.

Download Full-text

Vav Family Proteins Couple to Diverse Cell Surface Receptors

Molecular and Cellular Biology ◽

10.1128/mcb.20.17.6364-6373.2000 ◽

2000 ◽

Vol 20 (17) ◽

pp. 6364-6373 ◽

Cited By ~ 106

Author(s):

Sheri L. Moores ◽

Laura M. Selfors ◽

Jessica Fredericks ◽

Timo Breit ◽

Keiko Fujikawa ◽

...

Keyword(s):

Growth Factor ◽

Cell Surface ◽

Tyrosine Phosphorylation ◽

Tyrosine Kinases ◽

Protein Tyrosine Kinase ◽

Receptor Activation ◽

Cell Surface Receptors ◽

Nucleotide Exchange ◽

Surface Receptors ◽

Downstream Signaling

ABSTRACT Vav proteins are guanine nucleotide exchange factors for Rho family GTPases which activate pathways leading to actin cytoskeletal rearrangements and transcriptional alterations. Vav proteins contain several protein binding domains which can link cell surface receptors to downstream signaling proteins. Vav1 is expressed exclusively in hematopoietic cells and tyrosine phosphorylated in response to activation of multiple cell surface receptors. However, it is not known whether the recently identified isoforms Vav2 and Vav3, which are broadly expressed, can couple with similar classes of receptors, nor is it known whether all Vav isoforms possess identical functional activities. We expressed Vav1, Vav2, and Vav3 at equivalent levels to directly compare the responses of the Vav proteins to receptor activation. Although each Vav isoform was tyrosine phosphorylated upon activation of representative receptor tyrosine kinases, integrin, and lymphocyte antigen receptors, we found unique aspects of Vav protein coupling in each receptor pathway. Each Vav protein coprecipitated with activated epidermal growth factor and platelet-derived growth factor (PDGF) receptors, and multiple phosphorylated tyrosine residues on the PDGF receptor were able to mediate Vav2 tyrosine phosphorylation. Integrin-induced tyrosine phosphorylation of Vav proteins was not detected in nonhematopoietic cells unless the protein tyrosine kinase Syk was also expressed, suggesting that integrin activation of Vav proteins may be restricted to cell types that express particular tyrosine kinases. In addition, we found that Vav1, but not Vav2 or Vav3, can efficiently cooperate with T-cell receptor signaling to enhance NFAT-dependent transcription, while Vav1 and Vav3, but not Vav2, can enhance NFκB-dependent transcription. Thus, although each Vav isoform can respond to similar cell surface receptors, there are isoform-specific differences in their activation of downstream signaling pathways.

Download Full-text

Receptor Tyrosine Kinases and Their Signaling Pathways as Therapeutic Targets of Curcumin in Cancer

Frontiers in Pharmacology ◽

10.3389/fphar.2021.772510 ◽

2021 ◽

Vol 12 ◽

Author(s):

Sareshma Sudhesh Dev ◽

Syafiq Asnawi Zainal Abidin ◽

Reyhaneh Farghadani ◽

Iekhsan Othman ◽

Rakesh Naidu

Keyword(s):

Signaling Pathways ◽

Cancer Progression ◽

Tyrosine Kinases ◽

Receptor Tyrosine Kinases ◽

Surface Proteins ◽

Downstream Signaling ◽

Anti Cancer ◽

Rtk Inhibitors

Receptor tyrosine kinases (RTKs) are transmembrane cell-surface proteins that act as signal transducers. They regulate essential cellular processes like proliferation, apoptosis, differentiation and metabolism. RTK alteration occurs in a broad spectrum of cancers, emphasising its crucial role in cancer progression and as a suitable therapeutic target. The use of small molecule RTK inhibitors however, has been crippled by the emergence of resistance, highlighting the need for a pleiotropic anti-cancer agent that can replace or be used in combination with existing pharmacological agents to enhance treatment efficacy. Curcumin is an attractive therapeutic agent mainly due to its potent anti-cancer effects, extensive range of targets and minimal toxicity. Out of the numerous documented targets of curcumin, RTKs appear to be one of the main nodes of curcumin-mediated inhibition. Many studies have found that curcumin influences RTK activation and their downstream signaling pathways resulting in increased apoptosis, decreased proliferation and decreased migration in cancer both in vitro and in vivo. This review focused on how curcumin exhibits anti-cancer effects through inhibition of RTKs and downstream signaling pathways like the MAPK, PI3K/Akt, JAK/STAT, and NF-κB pathways. Combination studies of curcumin and RTK inhibitors were also analysed with emphasis on their common molecular targets.

Download Full-text

The Indole Phytoalexin Derivatives Induced a Significant Inhibition on Src Kinase Activity of Human Cancer Cells

Proceedings ◽

10.3390/proceedings2019022003 ◽

2019 ◽

Vol 22 (1) ◽

pp. 3

Author(s):

Filiz Bakar-Ates

Keyword(s):

Cancer Cells ◽

Tyrosine Kinases ◽

Kinase Activity ◽

Human Cancer ◽

Src Kinase ◽

Significant Inhibition ◽

Kinase Assay ◽

Src Tyrosine Kinase ◽

Indole Phytoalexins ◽

Mcf 7

The Src, a protein kinase, is a family of protein tyrosine kinases (SFKs), and this protein catalyses the phosphorylation of tyrosine. The studies have revealed its key roles in regulating signal transduction from cell surface receptors. The Src kinases act as cytoplasmic signalling machinery through regulating various cellular processes, such as cell growth, differentiation, migration, and survival. The pleiotropic functions of the Src family emphasise the importance of family members which have also been accepted as cellular oncogenes. Indole phytoalexins, which have been identified in various plants, have a structure with indole nucleus with the side chain or a heterocycle containing nitrogen and sulphur atoms. The antiproliferative effects of some phytoalexins have been demonstrated in various cancers. Among the members of phytoalexins, brassinin is known with a dithiocarbamate moiety and S-alkyl piece linked to indole core, and camalexin has an indole structure substituted at position 3 by the 1,3-thiazol-2-yl group. The inhibitory effects of these compounds on cancer cell proliferation have been reported. The aim of this study is to evaluate the effects of compounds on Src kinase activity. Human MCF-7 breast carcinoma and SW480 colorectal carcinoma cells were treated with compounds, and the effects of compounds on Src kinase activity were evaluated by Src-tyrosine kinase assay. The data were also compared with the growth inhibitory potential of compounds. The results have shown that both brassinin and camalexin have significantly inhibited the activity of Src kinase at 10 mM and higher concentrations in MCF-7 and SW480 cell lines (p < 0.05). In conclusion, this study is the first to evaluate the role of indole phytoalexins on the Src kinase activity of cancer cells. The data obtained have proven that the indole phytoalexin structure can show anticancer activity as Src mediated. It is thought that existing data will shed light on novel anticancer drug development studies.

Download Full-text

SRC Kinase in Glioblastoma: News from an Old Acquaintance

Cancers ◽

10.3390/cancers12061558 ◽

2020 ◽

Vol 12 (6) ◽

pp. 1558 ◽

Cited By ~ 1

Author(s):

Claudia Cirotti ◽

Claudia Contadini ◽

Daniela Barilà

Keyword(s):

Receptor Tyrosine Kinase ◽

Tyrosine Kinases ◽

Receptor Tyrosine Kinases ◽

Metabolic Reprogramming ◽

Constitutive Activity ◽

Therapeutic Approaches ◽

Resistance To Therapy ◽

Downstream Signaling ◽

Wide Range ◽

Therapy Effectiveness

Glioblastoma multiforme (GBM) is one of the most recalcitrant brain tumors characterized by a tumor microenvironment (TME) that strongly supports GBM growth, aggressiveness, invasiveness, and resistance to therapy. Importantly, a common feature of GBM is the aberrant activation of receptor tyrosine kinases (RTKs) and of their downstream signaling cascade, including the non-receptor tyrosine kinase SRC. SRC is a central downstream intermediate of many RTKs, which triggers the phosphorylation of many substrates, therefore, promoting the regulation of a wide range of different pathways involved in cell survival, adhesion, proliferation, motility, and angiogenesis. In addition to the aforementioned pathways, SRC constitutive activity promotes and sustains inflammation and metabolic reprogramming concurring with TME development, therefore, actively sustaining tumor growth. Here, we aim to provide an updated picture of the molecular pathways that link SRC to these events in GBM. In addition, SRC targeting strategies are discussed in order to highlight strengths and weaknesses of SRC inhibitors in GBM management, focusing our attention on their potentialities in combination with conventional therapeutic approaches (i.e., temozolomide) to ameliorate therapy effectiveness.

Download Full-text

ALKALs are in vivo ligands for ALK family receptor tyrosine kinases in the neural crest and derived cells

Proceedings of the National Academy of Sciences ◽

10.1073/pnas.1719137115 ◽

2018 ◽

Vol 115 (4) ◽

pp. E630-E638 ◽

Cited By ~ 26

Author(s):

Andrey Fadeev ◽

Patricia Mendoza-Garcia ◽

Uwe Irion ◽

Jikui Guan ◽

Kathrin Pfeifer ◽

...

Keyword(s):

Neural Crest ◽

Tyrosine Kinases ◽

Pigment Cells ◽

Loss Of Function ◽

Pediatric Tumor ◽

Downstream Signaling ◽

Receptor Complexes ◽

Anaplastic Lymphoma ◽

Biochemical Analyses

Mutations in anaplastic lymphoma kinase (ALK) are implicated in somatic and familial neuroblastoma, a pediatric tumor of neural crest-derived tissues. Recently, biochemical analyses have identified secreted small ALKAL proteins (FAM150, AUG) as potential ligands for human ALK and the related leukocyte tyrosine kinase (LTK). In the zebrafish Danio rerio, DrLtk, which is similar to human ALK in sequence and domain structure, controls the development of iridophores, neural crest-derived pigment cells. Hence, the zebrafish system allows studying Alk/Ltk and Alkals involvement in neural crest regulation in vivo. Using zebrafish pigment pattern formation, Drosophila eye patterning, and cell culture-based assays, we show that zebrafish Alkals potently activate zebrafish Ltk and human ALK driving downstream signaling events. Overexpression of the three DrAlkals cause ectopic iridophore development, whereas loss-of-function alleles lead to spatially distinct patterns of iridophore loss in zebrafish larvae and adults. alkal loss-of-function triple mutants completely lack iridophores and are larval lethal as is the case for ltk null mutants. Our results provide in vivo evidence of (i) activation of ALK/LTK family receptors by ALKALs and (ii) an involvement of these ligand–receptor complexes in neural crest development.

Download Full-text

The JAK Inhibitor INCB20 Induces Antiproliferative and Apoptotic Effects in Human Myeloma Cells In Vitro and In Vivo.

Blood ◽

10.1182/blood.v106.11.3357.3357 ◽

2005 ◽

Vol 106 (11) ◽

pp. 3357-3357

Author(s):

Renate Burger ◽

Steven Legouill ◽

Yu-Tzu Tai ◽

Reshma Shringarpure ◽

Klaus Podar ◽

...

Keyword(s):

Tyrosine Kinases ◽

Thymidine Uptake ◽

Dependent Manner ◽

Jak Inhibitor ◽

Synthetic Compound ◽

Akt Phosphorylation ◽

Ic50 Values ◽

Dose Dependent

Abstract In multiple myeloma (MM), IL-6 plays an important role for tumor cell growth, survival, and drug resistance. Janus kinases (JAKs) are protein tyrosine kinases and constitutively associated with the gp130 chain of the IL-6 receptor complex. Their activation is one of the first steps in cytokine receptor-mediated signaling and critical for virtually all subsequent downstream signaling cascades. INCB20 is a small-molecule synthetic compound which, in biochemical assays, potently inhibited all four JAKs with IC50 values between 0.3 nM and 1.2 nM (for comparison, IC50 of AG490, another JAK inhibitor, was >50 μM). Consistent with the central role of JAKs in gp130-mediated signaling, INCB20 inhibited IL-6 induced phosphorylation of SHP-2, STAT1, STAT3, ERK1/2, and AKT in MM1.S cells. In contrast, AKT phosphorylation induced by IGF-1 remained unchanged. Evaluation of the cellular efficacy of INCB20 was performed using the IL-6 dependent INA -6 cell line. Growth of INA-6 cells was inhibited in a dose-dependent manner with an IC50 of approx. 0.5 μM, as measured by [3H]-thymidine uptake and an MTS-based assay (for comparison, the cellular IC50 of AG490 was 15–20 μM). This correlated with an increase in the percentage of apoptotic cells, as evaluated by Apo2.7 staining after 48 hours. Importantly, INA-6 growth was inhibited in the presence of bone marrow stromal cells accompanied by a decrease in phospho-STAT3 levels. Furthermore, in a subcutaneous INA-6-SCID model, INCB20 inhibited tumor growth (and phosphorylated STAT3) in a dose-dependent manner. Our studies provide the conceptual basis for the use of JAK inhibitors as a therapeutic approach in MM.

Download Full-text

Phase I dose-escalation study of ZK 304709, an oral multi-target tumor growth inhibitor (MTGI), administered for 14 days of a 28-day cycle

Journal of Clinical Oncology ◽

10.1200/jco.2006.24.18_suppl.2076 ◽

2006 ◽

Vol 24 (18_suppl) ◽

pp. 2076-2076 ◽

Cited By ~ 7

Author(s):

S. Ahmed ◽

R. Molife ◽

H. Shaw ◽

W. Steward ◽

A. Thomas ◽

...

Keyword(s):

Cell Cycle ◽

Tyrosine Kinases ◽

Oral Delivery ◽

Growth Inhibitor ◽

Maximum Tolerated Dose ◽

Primary Objective ◽

Dose Escalation Study ◽

Cycle Arrest ◽

Disease Stabilization ◽

Dose Levels

2076 Background: ZK 304709 is a novel oral MTGI that induces cell cycle arrest and inhibits tumour angiogenesis by selectively inhibiting Cyclin Dependent Kinases (CDKs) 1, 2, 4, 7 and 9,VEGF-R 1, 2 and 3, and PDGF-Rβ tyrosine kinases. Methods: Adult patients (pts) (WHO PS ≤2) with a histologically or cytologically confirmed solid tumor, resistant or refractory to conventional therapy, were eligible. ZK304709 was administered orally, once daily, at a 15 mg starting dose, on days 1–14 of a 28-day cycle, then escalated by 33–100% depending on incidence of drug-related toxicity ≥ grade (gr) 2 (CTC v2.0). At least 3 pts were treated at each dose level. The primary objective was to identify the maximum tolerated dose (MTD) and dose-limiting toxicities (DLT). Secondary objectives were to determine the tolerability, pharmacokinetic (PK) profile, and preliminary efficacy. Results: Interim results were available for 24 pts (19 M/5 F; median age 56.5) at 5 dose levels (15–120 mg qd). Pts received a median of 2 cycles (range 0–10). Common drug related toxicities were nausea, vomiting, and fatigue. Two DLT were observed: dizziness and hypertension. However, the MTD has yet to be established. The PK profile for dose levels up to 90 mg demonstrated rapid absorption and a dose-dependent increase of exposure and Cmax. Disease stabilization for ≥4 cycles has been observed. Conclusions: ZK 304709 was rapidly absorbed and has been tolerated on this schedule at up to 120 mg qd. The MTD has not been reached and enrolment is ongoing. These preliminary data demonstrate that oral delivery on this schedule of an agent that inhibits both cell cycle and angiogenesis is feasible. [Table: see text]

Download Full-text