Inhibition of anthralin-caused skin tumor promotion and interleukin-1 alpha production by potent immunosuppressant FK506

Tacrolimus: 10 years of successful clinical application

Tacrolimus (FK506) is the first drug from the new class of drugs - calcineurin inhibitors. It has a great potential and can change the current approaches to treatment of different dermatoses. Topical forms of Tacrolimus are activated due to the effect on T-lymphocyte signal transduction, and they also inhibit gene transcription. As a result, the T-cell response to antigens is alleviated. Percutaneous absorption of Tacrolimus in affection foci is higher than in healthy skin. Due to this a smaller amount of the drug is absorbed by the skin as long as the skin is healed. Systemic absorption of Tacrolimus is low in the course of treatment. The maximum clinical experience has been gained in the field of applying Tacrolimus for treatment of atopic dermatitis. In a number of clinical studies, 0.03-0.3% Tacrolimus ointment efficiently reduced the severity of symptoms and course of atopic dermatitis in adults and children. Moreover, topical treatment with Tacrolimus did not involve any substantial toxic effects. The patients most often complained of local irritations in the area where the ointment was applied, which were transient by nature and did not demand the drug withdrawal. Today Tacrolimus is a valuable and safer alternative to glucocorticosteroids for treatment of atopic dermatitis. It can also be used for treating other dermatoses, which demands additional all-round examination.

Critical Review of Preclinical Approaches to Evaluate the Potential of Immunosuppressive Drugs to Influence Human Neoplasia

Many immunosuppressive drugs are associated with an increased risk of B-cell lymphoma, squamous cell carcinoma, and Kaposi sarcoma. Thirteen immunosuppressive drugs have been tested in 2-year carcinogenicity studies (abatacept; azathioprine; busulfan; cyclophosphamide; cyclosporine; dexamethasone; everolimus; leflunomide; methotrexate; mycophenolate mofetil; prednisone; sirolimus; and tacrolimus) and in additional models including neonatal and genetically modified mice; chemical, viral, ultraviolet, and ionizing radiation co-carcinogenesis, and in models with transplanted tumor cells. The purpose of this review is to outline the mechanisms by which immunosuppressive drugs can influence neoplasia, to summarize the available preclinical data on the 13 drugs, and to critically review the performance of the models. A combination of primary tumor and metastasis assays conducted with transplanted cells may provide the highest value for hazard identification and can be applied on a case-by-case basis. However, for both small molecules and therapeutic proteins, determining the relative risk to patients from preclinical data remains problematic. Classifying immunosuppressive drugs based on their mechanism of action and hazard identification from preclinical studies and a prospective pharmacovigilance program to monitor carcinogenic risk may be a feasible way to manage patient safety during the clinical development program and postmarketing.

A systematic review of the safety of topical therapies for atopic dermatitis

BACKGROUND

The safety of topical therapies for atopic dermatitis (AD), a common and morbid disease, has recently been the focus of increased scrutiny, adding confusion as how best to manage these patients.

OBJECTIVES

The objective of these systematic reviews was to determine the safety of topical therapies for AD.

METHODS

Databases searched included: OVID Medline, Medline In-Process and Other Non-Indexed Citations, Embase, and the Cochrane Central Register of Controlled Trials. In addition to the articles identified by this search, investigators were also referred to a list of links (most recently updated 25 September 2005) to recent Food and Drug Administration (FDA) studies, reports and meetings regarding the topical calcineurin inhibitors for further potential references. Only fully published papers available in English and data obtained from FDA sites were included. Furthermore, the criteria for inclusion and exclusion for each systematic review were further evaluated at a meeting of all of the content and evidence-based medicine experts participating in this process and alteration of the inclusion criteria was done at that time when it was felt necessary to avoid inclusion of lower-quality data in the review. Qualitative review of the abstracted data was performed and reviewed at a meeting of all of the content and evidence-based medicine experts.

RESULTS

While systemic exposure to these topical agents does occur, physiological changes appear to be uncommon and systemic complications rare and have only been found with use of topical corticosteroids.

CONCLUSIONS

Based on the data that are available the overall safety of AD therapies appears to be good with the only documented systemic side-effects of therapy those occasionally seen with use of topical corticosteroids.

Aktuelle Aspekte der Therapie mit topischen Calcineurininhibitoren

Since their approval, topical calcineurin inhibitors have proven to be effective medications in the treatment of atopic eczema. On March 10, 2005, the Food and Drug Administration (FDA) followed the advice of the Pediatric Advisory Council and issued a "black box warning" for the use of Protopic (Tacrolimus) und Elidel (Pimecrolimus). This FDA alert has caused worldwide uncertainty among parents and patients. Several dermatological societies have issued critical position statements. This report reviews the existing information underlying the warning and places it into the context of current knowledge.

Expression and Function of the Nuclear Factor of Activated T Cells in Colon Carcinoma Cells

Increasing evidence shows a crucial role of the Ca2+/ calcineurin-mediated activation of the nuclear factor of activated T cells (NFAT) in the regulation of a variety of processes in nonimmune cells. Here we provide evidence that NFATc1 and NFATc2 are expressed in human colon carcinoma cell lines. These proteins are translocated from the cytoplasm to the nucleus upon treatment with a combination of phorbol 12-myristate 13-acetate plus the calcium ionophore A23187. Subsequent to translocation to the nucleus, NFATc1 and NFATc2 were able to bind to a NFAT response element in the DNA, regulating transcriptional activation of genes containing a NFAT-responsive element such as cyclooxygenase-2 (COX-2). COX-2 expression and prostaglandin E2 (PGE2) production were induced upon pharmacological stimuli leading to NFAT activation and blunted by inhibition of calcineurin phosphatase with cyclosporin A or tacrolimus (FK506). Expression of NFAT wild type protein or the active catalytic subunit of calcineurin transactivates COX-2 promoter activity, whereas a dominant negative mutant of NFAT inhibited COX-2 induction in colon carcinoma cell lines. Furthermore, mutation or deletion of NFAT binding sites in the human COX-2 promoter greatly diminished its induction by phorbol 12-myristate 13-acetate/calcium ionophore A23187. These findings demonstrate the presence and activation of NFAT in human colon carcinoma cells, with important implications in the regulation of genes involved in the transformed phenotype as COX-2.

Tacrolimus: a review of its use for the management of dermatoses

The newly developed immunomodulator tacrolimus (FK506) is the first of a new class of agents that have enormous potential to change the way that dermatoses are treated and managed. Tacrolimus has been found to be active in a topical formulation with the latter exerting its effects by acting on the signal transduction pathways inside T cells and inhibiting gene transcription. The result is decreased responsiveness of T cells to antigens. Percutaneous absorption of tacrolimus is higher in diseased skin as opposed to healthy skin and, therefore, the drug will be taken in at progressively lower quantities as lesions heal. There is limited systemic absorption of tacrolimus over the course of therapy. The most extensive experience with tacrolimus has been in treating atopic dermatitis. In numerous trials, tacrolimus ointment 0.03-0.3% has shown to be effective in reducing the symptoms and severity of atopic dermatitis in adults and the paediatric population. Furthermore, there have been no significant toxic effects associated with topical therapy with tacrolimus. The most common complaint is that of local irritation after applying the ointment. This is generally transient and the patient is able to continue with therapy. The other dermatoses where tacrolimus has been used include contact dermatitis, psoriasis and pyoderma gangrenosum.