Several ATP-binding cassette (ABC) transporters can confer multidrug resistance to cancer cells by functioning as energy-dependent efflux pumps. The half-transporter ABCG2 and the widely studied P-glycoprotein (P-gp) are two ABC transporters that, when overexpressed, are capable of extruding a variety of structurally unrelated chemotherapy agents from cells. In this study, we demonstrate that h...

Purpose: Drugs that modify the production of cytokines may affect fracture healing. The immunosuppressive drug cyclosporin A is widely used to modify the immune response in transplantations and in treatment of rheumatoid disorders. We wanted to analyze the effect of cyclosporin A on fracture healing and on the development of trauma induced osteopenia. Methods: Experimental tibia fractures were ...

Cyclosporin A is an immunosuppressant drug that is used not only in solid transplant rejection, but also in moderate and severe forms of psoriasis, pyoderma, lupus or arthritis. Serious side effects of the drug such as skin cancer or gingival hyperplasia probably start with the latent proliferation process. Little is known about the influence of cyclosporin A on molecular signaling in epidermal...

Chemotherapy without radiation has not controlled most intraocular retinoblastoma, perhaps because of the common high expression of multidrug resistance P-glycoprotein that we found in retinoblastoma. Cyclosporin blocks P-glycoprotein-induced efflux of vincristine and teniposide in vitro, and possibly modulates responses to carboplatin. To avoid eye irradiation in bilateral retinoblastoma patie...

Aim: To evaluate the efficacy of oral cyclosporin A in the prevention and treatment of immune graft rejection in heavily vascularised, repeated keratoplasties with high risk for failure. Methods: 21 consecutive patients with 28 repeated corneal transplants and four quadrant vascularised recipient bed were treated with oral cyclosporin A for an average period of 12 months (range 1–41 months) and...

Cyslosporin A (CyA) treatment of psoriasis is warranted in severe cases where other, conventional antipsoriatic approaches have failed. Gingival hyperplasia is a rare side effect of cyclosporin A treatment in psoriasis patients. Previous studies in cyclosporin A-treated patients (mostly transplant recipients) have demonstrated correlation between cyclosporin A serum levels and oral hygiene stat...

BACKGROUND The multidrug resistance phenomenon results from the expression of P-glycoprotein (P-gp), a drug-efflux pump. Corticosteroids are substrates for P-gp, whose function can be inhibited by cyclosporin. This study evaluates the ability of cyclosporin to modulate dexamethasone uptake in multidrug resistant cells. METHODS The K 562 cell line, which does not express P-gp and a P-gp expres...

Raising cytosolic Ca2+ induces an increase in mitochondrial biogenesis in myotubes. This phenomenon mimics the adaptive responses of skeletal muscle to exercise. It has been hypothesized that increases in cytosolic Ca2+ during motor nerve activity stimulate mitochondrial biogenesis by activating calcineurin. Overexpression of constitutively active calcineurin increases expression of peroxisome ...

Cyclosporin A administration is associated with an increased incidence of hypertension. To evaluate the direct effects of the drug on the contractile responses of vascular tissue to adrenergic stimuli, rat caudal artery ring segments were studied before and after the addition of cyclosporin A or its ethanol vehicle in vitro. In a dose-related manner, cyclosporin A augmented the contractile resp...

Calcium (Ca(2+)) and calmodulin (CaM) are required for progression of mammalian cells from quiescence into S phase. In multiple cell types, cyclosporin A causes a G(1) cell cycle arrest, implicating the serine/threonine phosphatase calcineurin as one Ca(2+)/CaM-dependent enzyme required for G(1) transit. Here, we show, in diploid human fibroblasts, that cyclosporin A arrested cells in G(1) befo...