Anti-inflammatory Activity of MTL-CEBPA, a Small Activating RNA Drug, in LPS-Stimulated Monocytes and Humanized Mice.

Excessive or inappropriate inflammatory responses can cause serious and even fatal diseases. The CCAAT/enhancer-binding protein alpha (CEBPA) gene encodes C/EBPα, a transcription factor that plays a fundamental role in controlling maturation of the myeloid lineage and is also expressed during the late phase of inflammatory responses when signs of inflammation are decreasing. MTL-CEBPA, a small activating RNA targeting for upregulation of C/EBPα, is currently being evaluated in a phase 1b trial for treatment of hepatocellular carcinoma. After dosing, subjects had reduced levels of pro-inflammatory cytokines, and we therefore hypothesized that MTL-CEBPA has anti-inflammatory potential. The current study was conducted to determine the effects of C/EBPα saRNA - CEBPA-51 - on inflammation in vitro and in vivo after endotoxin challenge. CEBPA-51 led to increased expression of the C/EBPα gene and inhibition of pro-inflammatory cytokines in THP-1 monocytes previously stimulated by E. coli-derived lipopolysaccharide (LPS). Treatment with MTL-CEBPA in an LPS-challenged humanized mouse model upregulated C/EBPα mRNA, increased neutrophils, and attenuated production of several key pro-inflammatory cytokines, including TNF-α, IL-6, IL-1ß, and IFN-γ. In addition, a Luminex analysis of mouse serum revealed that MTL-CEBPA reduced pro-inflammatory cytokines and increased the anti-inflammatory cytokine IL-10. Collectively, the data support further investigation of MTL-CEBPA in acute and chronic inflammatory diseases where this mechanism has pathogenic importance.

Targeting B-Raf inhibitor resistant melanoma with novel cell penetrating peptide disrupters of PDE8A - C-Raf.

BACKGROUND: Recent advances in the treatment of melanoma that involve immunotherapy and B-Raf inhibition have revolutionised cancer care for this disease. However, an un-met clinical need remains in B-Raf inhibitor resistant patients where first-generation B-Raf inhibitors provide only short-term disease control. In these cases, B-Raf inhibition leads to paradoxical activation of the C-Raf - MEK - ERK signalling pathway, followed by metastasis. PDE8A has been shown to directly interact with and modulate the cAMP microdomain in the vicinity of C-Raf. This interaction promotes C-Raf activation by attenuating the PKA-mediated inhibitory phosphorylation of the kinase. METHODS: We have used a novel cell-penetrating peptide agent (PPL-008) that inhibits the PDE8A - C-Raf complex in a human malignant MM415 melanoma cell line and MM415 melanoma xenograft mouse model to investigate ERK MAP kinase signalling. RESULTS: We have demonstrated that the PDE8A - C-Raf complex disruptor PPL-008 increased inhibitory C-Raf-S259 phosphorylation and significantly reduced phospho-ERK signalling. We have also discovered that the ability of PPL-008 to dampen ERK signalling can be used to counter B-Raf inhibitor-driven paradoxical activation of phospho-ERK in MM415 cells treated with PLX4032 (Vemurafenib). PPL-008 treatment also significantly retarded the growth of these cells. When applied to a MM415 melanoma xenograft mouse model, PPL-008C penetrated tumour tissue and significantly reduced phospho-ERK signalling in that domain. CONCLUSION: Our data suggests that the PDE8A-C-Raf complex is a promising therapeutic treatment for B-Raf inhibitor resistant melanoma.

Create a translational medicine knowledge repository--research downsizing, mergers and increased outsourcing have reduced the depth of in-house translational medicine expertise and institutional memory at many pharmaceutical and biotech companies: how will they avoid relearning old lessons?

Pharmaceutical industry consolidation and overall research downsizing threatens the ability of companies to benefit from their previous investments in translational research as key leaders with the most knowledge of the successful use of biomarkers and translational pharmacology models are laid off or accept their severance packages. Two recently published books may help to preserve this type of knowledge but much of this type of information is not in the public domain. Here we propose the creation of a translational medicine knowledge repository where companies can submit their translational research data and access similar data from other companies in a precompetitive environment. This searchable repository would become an invaluable resource for translational scientists and drug developers that could speed and reduce the cost of new drug development.

Translational strategies to implement personalized medicine: rheumatoid arthritis examples.

Advances in the molecular definition of disease, biomarker technologies and informatics have brought us to the threshold of a new way to individualize treatment for patients - personalized medicine. However, while the clinical translation of drug metabolism and cancer-related genomics data has resulted in accepted individualized treatment paradigms, this has not occurred as frequently or efficiently for patients with common chronic diseases such as rheumatoid arthritis. This gap between the rapidly increasing amount of disease-related genomic information and its clinical translation can be addressed through the creation and testing of personalized medicine treatment hypotheses using the same strategies that translational medicine scientists utilize to achieve proof-of-concept for drugs with novel targets. This is illustrated with three testable personalized medicine hypotheses for rheumatoid arthritis where known genetic markers in patients can potentially be used to select the most appropriate treatments and dose. Incentives resulting from changes in government and regulatory agency policies, investments in sample and data repositories, acceptance of new economic models by pharmaceutical companies and third party payers as well as more training, research support and academic opportunities for translational medicine scientists are all needed to speed up the implementation of personalized medicine for patients with rheumatoid arthritis and other common chronic diseases.

What's next in translational medicine?

Translational medicine is the integrated application of innovative pharmacology tools, biomarkers, clinical methods, clinical technologies and study designs to improve disease understanding, confidence in human drug targets and increase confidence in drug candidates, understand the therapeutic index in humans, enhance cost-effective decision making in exploratory development and increase phase II success. Translational research is one of the most important activities of translational medicine as it supports predictions about probable drug activities across species and is especially important when compounds with unprecedented drug targets are brought to humans for the first time. Translational research has the potential to deliver many practical benefits for patients and justify the extensive investments placed by the private and public sector in biomedical research. Translational research encompasses a complexity of scientific, financial, ethical, regulatory, legislative and practical hurdles that need to be addressed at several levels to make the process efficient. Several have resisted the idea of supporting translational research because of its high costs and the fear that it may re-direct funds from other biomedical disciplines. Resistance also comes from those more familiar with traditional clinical research methods. In this review, we argue that translational research should be seen as enabled by ongoing efforts in basic and clinical research and not competing with them. Translational research provides the knowledge necessary to draw important conclusions from clinical testing regarding disease and the viability of novel drug mechanisms. Advancing translational research requires education and new sources of funding. This could be achieved through public and congressional education by a joint coalition of patients' advocacy groups, academia, drug regulatory agencies and industry.

The ultimate model organism: progress in experimental medicine.

Experimental medicine is the use of innovative measurements, models and designs in studying human subjects for establishing proof of mechanism and concept of new drugs, for exploring the potential for market differentiation for successful drug candidates, and for efficiently terminating the development of unsuccessful ones. Humans are the ultimate 'model' because of the uncertain validity and efficacy of novel targets and drug candidates that emerge from genomics, combinatorial chemistry and high-throughput screening and the use of poorly predictive preclinical models. The in-depth investigation of the effects of drugs and the nature of disease progression is becoming ever more feasible because of advances in clinical biomarkers.

Prevention of organ allograft rejection by a specific Janus kinase 3 inhibitor.

Because of its requirement for signaling by multiple cytokines, Janus kinase 3 (JAK3) is an excellent target for clinical immunosuppression. We report the development of a specific, orally active inhibitor of JAK3, CP-690,550, that significantly prolonged survival in a murine model of heart transplantation and in cynomolgus monkeys receiving kidney transplants. CP-690,550 treatment was not associated with hypertension, hyperlipidemia, or lymphoproliferative disease. On the basis of these preclinical results, we believe JAK3 blockade by CP-690,550 has potential for therapeutically desirable immunosuppression in human organ transplantation and in other clinical settings.

Mapping of local renal blood flow with PET and H(2)(15)O.

UNLABELLED: We developed a noninvasive method for the mapping of regional renal blood flow in humans using PET and H(2)(15)O. METHODS: Fifteen subjects participated in the study, 5 with normal renal function and 10 with renal disease. The protocol used a whole-body PET scanner, intravenous bolus injection of 1,110-1,850 MBq H(2)(15)O and sequential imaging at 3 s per frame. (131)I-Iodohippuran was used to independently assess effective renal plasma flow in each subject. Hippuran clearance and renal blood flow (RBF) were measured twice, before and after treatment with probenecid, to verify that RBF is not affected. Flow analysis was based on the Kety model, according to the operational equation: C(t) = F integral C(a)(u)du - k integral C(u)du, where F is the RBF, k is the tissue-to-blood clearance rate, C is the PET concentration, and C(a) is the tracer concentration in the abdominal aorta. F and k were estimated by linear least squares on a pixel-by-pixel basis to produce quantitative maps (parametric images) of RBF. The flow maps were analyzed by regions of interest (largely excluding the medulla and collecting system) for each kidney on each slice and pooled to yield mean RBF. RESULTS: In the 5 healthy subjects, mean RBF was 3.4 +/- 0.4 mL/min/g. There was no difference in flow between kidneys (t = -0.59; n = 11; P > 0.95). Before treatment with probenecid, RBF was linearly related to hippuran clearance (r(2) = 0.92). Probenecid treatment significantly reduced hippuran clearance (P < 0.003), but RBF was unchanged (P > 0.17). Compared with healthy control subjects, RBF was significantly decreased in patients with renal disease (P < 0.002). Flow maps were of good quality in all subjects, exhibiting characteristic patterns, with higher values in regions composed largely of renal cortex. CONCLUSION: Parametric mapping of RBF with PET and H(2)(15)O provides a straightforward, noninvasive method for quantitative mapping of RBF, which may prove useful in research applications and in the management of patients whose therapy alters renal tubular transport.