A Data-Mining Approach for the Quantitative Assessment of Physicochemical Properties of Molecular Compounds in the Skin Flux.

This paper aimed to provide an insight into the mechanism of transdermal penetration of drug molecules with respect to their physicochemical properties, such as solubility (S), the presence of enantiomer (ET) and logarithm of octanol-water partition coefficient (log P), molecular weight (MW), and melting point (MP). Propionic acid derivatives were evaluated for their flux through full-thickness skin excised from hairless mice upon being delivered from silicone-based pressure-sensitive adhesive (PSA) matrices in the presence or absence of various enhancers. The skin fluxes of model compounds were calculated based on the data obtained using the method engaged with the diffusion cell system. The statistical design of experiments (DoE) based on the factorial approach was used to find variables that have a significant impact on the outcomes. For the prediction of skin flux, a quantitative equation was derived using the data-mining approach on the relationship between skin permeation of model compounds (~125 mg/ml) and involved physicochemical variables. The most influential variables for the skin flux of propionic acid derivatives were the melting point (0.97) followed by the presence of enantiomer (0.95), molecular mass (0.93), log P values (0.86), and aqueous solubility (0.80). It was concluded that the skin flux of molecular compounds can be predicted based on the relationship between their physicochemical properties and the interaction with cofactors including additives and enhancers in the vehicles.

A practical guide to the development of microneedle systems - In clinical trials or on the market.

Microneedle systems are a rapidly growing and promising technology for delivery of drugs, such as vaccines, small molecules, or biologics and for aesthetic skin treatment in local clinics; however, they remain relatively new from a regulatory perspective. There are strong demands for established procedures, test requirements for approval, and recent trends that industries/researchers related to microneedle systems can refer to. Some microneedle systems are commercially available, many are currently undergoing clinical trials, and some are pending approval for commercialization. This review focuses on microneedle systems that are either on the market or in clinical trials, their applicability and characteristics, and the critical evaluation and test methods necessary for their development and approval.

Enhancement of solubility and dissolution rate of baicalein, wogonin and oroxylin A extracted from Radix scutellariae.

Baicalein, wogonin, and oroxylin A are three major hydrophobic components in the extract of Radix scutellariae with wide spectrum of pharmacological applications. The purpose of this study was to enhance the solubility, dissolution rate and stability of baicalein, wogonin and oroxylin A by solid dispersion (SD) technique. SD of the extract with various polymers was prepared to select the best carrier. Solubility study, chemical stability study and dissolution study were performed to characterize the SD. The solubility of all three components, after forming solid dispersion with povidone K-30 (PVP K-30) was significantly increased in pH 6.8 medium at room temperature. Stability study conducted for 80days elucidated that the SD in powder state was fairly stable without the aid of Vitamin C (VC). VC was required as antioxidant to impart stability to baicalein in aqueous medium. The dissolution test of the SD of three components, admixed with VC at the weight ratio of 1:6 (Radix scutellariae extract: VC, w/w) exhibited faster dissolution rate with 100% release of all components. Pharmacokinetic study of baicalein solid dispersion revealed that AUC and Cmax significantly increased by solid dispersion preparation. Thus, the current developed method, being simple, economical and effective, can be useful for the production of soluble dosage forms of the extract of Radix scutellariae in commercial scale.

Development of DH-I-180-3 loaded lipid nanoparticle for photodynamic therapy.

Photodynamic therapy (PDT) is a promising noninvasive treatment modality for cancer. Photosensitizer and specific wave length of light are the key component of PDT. DH-I-180-3, a second generation photosensitizer, was incorporated into lipid nanoparticle for simultaneous fluorescent imaging and targeting therapy. Solid lipid nanoparticle (SLN) and nanostructured lipid carriers (NLC) based on poloxamer 188 as surfactant and lecithin as co-surfactant were prepared using solvent evaporation and hot homogenization technique. Stearic acid and Capmul(®) MCM C8 were utilized as solid lipid and liquid lipid, respectively. The particle size of SLN and NLCs was around 200 nm and decreased when a part of stearic acid was replaced with Capmul(®) MCM C8. Drug loading efficacy was significantly enhanced when the percentage amount of liquid lipid increased. All the polydispersity indices of the SLN/NLCs were below 0.3, and displayed a narrow particle size distribution. Zeta potentials of all the lipid nanoparticles were below -30 mV, maintaining sufficient repulsive force and achieving enhanced physical stability. No significant change in the particle size and polydispersity index was observed from lyophilized SLN/NLCs. When the photocytotoxic effects of the formulations were evaluated in MCF-7 cells, GI 50 of SLN was less than half of DH-I-180-3 solution, and NLCs containing either 5 or 15%w/w of Capmul(®) MCM C8 exerted higher cytotoxicity than SLN. The fluorescence microscope images displayed enhanced cellular accumulation of DH-I-180-3 loaded in SLN and NLCs, which was closely correlated with the photocytotoxicity results. It was concluded that the incorporation of DH-I-180-3 into the nanoparticles enhanced their targeting efficacy and improved photocytotoxicity.

Development of drug-in-adhesive patch formulations for transdermal delivery of fluoxetine: In vitro and in vivo evaluations.

The aim of this study was to develop drug-in adhesive (DIA) patch formulations for the transdermal delivery of fluoxetine (FX). The DIA patch formulations containing FX were prepared and optimized with various pressure sensitive adhesives, drug contents and enhancers. Among the various formulations, DuroTak 87-502B-based patch formulation containing 20% (w/w) FX with no enhancer was selected for in vivo pharmacokinetic study based on in vitro permeation studies using hairless mouse, rat and human cadaver skins. The Cmax of FX after the transdermal administration of the optimized patch formulation in rats was 52.38 ng/ml, and plasma concentration of FX was maintained for 36 h. Moreover, the predicted human Css (55.79 ng/ml) and Cmax (27.35 ng/ml) were in good agreement with the reported plasma levels (15-55 ng/ml) of oral FX in clinical applications. These results suggest that the optimized patch formulation could be further developed for clinical applications, providing the therapeutic plasma level of FX over an extended period. To the best of our knowledge, our results are the first reported in vitro and in vivo data on the preparation and optimization of FX-loaded DIA patch, showing its feasibility as an effective transdermal delivery system for FX.

Enhancement of solubility and dissolution of cilostazol by solid dispersion technique.

Cilostazol is practically insoluble in water and thus results in poor bioavailability. Only a few approaches have been reported for improving the bioavailability of cilostazol. Solid dispersion technique via solvent evaporation method was applied to improve the solubility and dissolution of cilostazol. Various polymers, mixture of polymer and surfactant, and mixture of polymers were screened as a carrier for the solid dispersion. Solubility of cilostazol was improved significantly when Eudragit(®) L100 was used as a carrier. However, addition of surfactant to Eudragit(®) L100 decreased the solubility slightly. Whereas, the mixture of Eudragit(®) L100 and Eudragit(®) S100 as a carrier system further increased the solubility. Based on the highest solubility obtained among the carriers screened, 1:1 ratio of Eudragit(®) L100 and Eudragit(®) S100 was selected as a carrier, and drug to carrier ratio was optimized to 1:5. Differential scanning calorimetry and X-ray diffraction studies showed that the characteristic peak of cilostazol disappeared in the solid dispersion, indicating that cilostazol existed in amorphous form in this formulation. Spray drying method was superior to vacuum drying method in terms of dissolution rate. Meanwhile, it was observed that the disintegration rate and the concentration of polymer had some effect on the crystallization of cilostazol in dissolution medium. Tablet formulation containing spray dried solid dispersion showed significant improvement in dissolution as compared to the commercial tablet.

Size-controlled biodegradable nanoparticles: preparation and size-dependent cellular uptake and tumor cell growth inhibition.

Biodegradable nanoparticles with diameters below 1000nm are of great interest in the contexts of targeted delivery and imaging. In this study, we prepared PLGA nanoparticles with well-defined sizes of ∼70nm (NP70), ∼100nm (NP100), ∼200nm (NP200), ∼400nm (NP400), ∼600nm (NP600) and ∼1000nm (NP1000) using facile fabrication methods based on a nanoprecipitation and solvent evaporation techniques. The nanoparticles showed a narrow size distribution with high yield. Then the size-controlled biodegradable nanoparticles were used to investigate how particle size at nanoscale affects interactions with tumor cells and macrophages. Interestingly, an opposite size-dependent interaction was observed in the two cells. As particle size gets smaller, cellular uptake increased in tumor cells and decreased in macrophages. We also found that paclitaxel (PTX)-loaded nanoparticles showed a size-dependent inhibition of tumor cell growth and the size-dependency was influenced by cellular uptake and PTX release. The size-controlled biodegradable nanoparticles described in this study would provide a useful means to further elucidate roles of particle size on various biomedical applications.

Prolyl isomerase Pin1 negatively regulates the stability of SUV39H1 to promote tumorigenesis in breast cancer.

Pin1, a conserved eukaryotic peptidyl-prolyl cis/trans isomerase, has profound effects on numerous key-signaling molecules, and its deregulation contributes to disease, particularly cancer. Although Pin1-mediated prolyl isomerization of protein servers as a regulatory switch in signaling pathways, the significance of proline isomerase activity in chromatin modifying complex remains unclear. Here, we identify Pin1 as a key negative regulator for suppressor of variegation 3-9 homologue 1 (SUV39H1) stability, a major methyltransferase responsible for histone H3 trimethylation on Lys9 (H3K9me3). Pin1 interacts with SUV39H1 in a phosphorylation-dependent manner and promotes ubiquitination-mediated degradation of SUV39H1. Consequently, Pin1 reduces SUV39H1 abundance and suppresses SUV39H1 ability to induce H3K9me3. In contrast, depletion of Pin1 in cancer cells leads to elevated SUV39H1 expression, which subsequently increases H3K9me3, inhibiting tumorigenecity of cancer cells. In a xenograft model with 4T1 metastatic mouse breast carcinoma cells, Pin1 overexpression increases tumor growth, whereas SUV39H1 overexpression abrogates it. In human breast cancer patients, immunohistochemical staining shows that Pin1 levels are negatively correlated with SUV39H1 as well as H3K9me3 levels. Thus, Pin1-mediated reduction of SUV39H1 stability contributes to convey oncogenic signals for aggressiveness of human breast cancer, suggesting that Pin1 may be a promising drug target for anticancer therapy.

Effect of pressure sensitive adhesive and vehicles on permeation of terbinafine across porcine hoof membrane.

The purpose of this study was to investigate characteristics of transungual drug delivery and the feasibility of developing a drug-in-adhesive formulation of terbinafine. The permeation of terbinafine from a PSA matrix across porcine hoof membrane was determined using a plate containing poloxamer gel. The permeation rate of terbinafine across hairless mouse skin was evaluated using a flow-through diffusion cell system. The permeation of terbinafine across the hoof membranes was the highest from the silicone adhesive matrix, followed by PIB, and most of the acrylic adhesives, SIS, and SBS. The rank order of permeation rate across mice skin was different from the rank order across porcine hooves. The amount of terbinafine permeated across the porcine hoof membranes poorly correlated with the amount of terbinafine remaining inside the hooves after 20 days, however, the ratio between rate of terbinafine partitioning into the hoof membrane and its rate of diffusion across the membrane was relatively constant within the same type of PSA. For influence of various vehicles in enhancing permeation of terbinafine across the hoof membrane, all vehicles except Labrasol(®) showed tendency to improve permeation rate. However, the enhancement ratio of a given vehicle differed from one adhesive to another with a moderate correlation between them. The infrared spectrum of the hoof treated with NMP, PPG 400 or PEG 200 indicated that the conformation of keratin changed from a non-helical to a helical structure.

SIRT1-mediated FoxO1 deacetylation is essential for multidrug resistance-associated protein 2 expression in tamoxifen-resistant breast cancer cells.

Our previous studies have shown that multidrug resistance protein 2 (MRP2) is overexpressed in tamoxifen-resistant MCF-7 breast cancer cells (TAMR-MCF-7 cells) and forkhead box-containing protein, O subfamily1 (FoxO1), functions as a key regulator of multidrug resistance 1 (MDR1) gene transcription. This study aimed to investigate the role of FoxO1 in regulating MRP2 gene expression in TAMR-MCF-7 cells. The proximal promoter region of the human MRP2 gene contains four putative FoxO binding sites, and MRP2 gene transcription was stimulated by FoxO1 overexpression in MCF-7 cells. Subcellular fractionation and immunoblot analyses revealed that basal MRP2 expression and nuclear levels of FoxO1 were enhanced in TAMR-MCF-7 cells compared to MCF-7 cells and the enhanced MRP2 gene transcription was suppressed by FoxO1 siRNA. Because nuclear localization of FoxO1 is regulated by SIRT1 deacetylase, we were further interested in whether SIRT1 is involved in MRP2 expression. Overexpression of SIRT1 with FoxO1 potentiated the gene transcriptional activity of MRP2, and the basal activity and expression of SIRT1 was increased in TAMR-MCF-7 cells. In addition, SIRT1 inhibition reduced both the nuclear FoxO1 levels and MRP2 expression and enhanced cytotoxic effects of paclitaxel and doxorubicin in TAMR-MCF-7 cells. These results suggest that FoxO1 activation via SIRT1-mediated deacetylation is closely related with up-regulation of MRP2 in TAMR-MCF-7 cells.

Enhanced systemic exposure of saquinavir via the concomitant use of curcumin-loaded solid dispersion in rats.

The present study aimed to evaluate the effect of curcumin-loaded solid dispersion on the pharmacokinetics of saquinavir in rats. Solid dispersion (SD) formulation was prepared with Solutol® HS15 to improve the solubility and bioavailability of curcumin. Subsequently, its inhibition effect on P-gp mediated cellular efflux was examined by using NCI/ADR-RES cells overexpressing P-gp. Compared to the untreated curcumin, SD formulation enhanced the cellular uptake of rhodamine-123, a P-gp substrate by approximately 3 folds in NCI/ADR-RES cells. The oral and intravenous pharmacokinetics of saquinavir were also determined in rats with/without curcumin in the different formulations. Compared to the control given saquinavir alone, curcumin-loaded solid dispersion significantly (p<0.05) increased the oral exposure of saquinavir in rats, while it did not affect the intravenous pharmacokinetics of saquinavir. The AUC and Cmax of oral saquinavir increased by 3.8- and 2.7-folds, respectively in the presence of curcumin-loaded solid dispersion. In contrast, the untreated curcumin did not affect the oral pharmacokinetics of saquinavir. These results suggest that SD formulation of curcumin should be effective to improve the in vivo effectiveness of curcumin as an absorption enhancer, leading to the improved oral exposure of saquinavir.

Inhibitory effects of a new 1H-pyrrolo[3,2-c]pyridine derivative, KIST101029, on activator protein-1 activity and neoplastic cell transformation induced by insulin-like growth factor-1.

Diarylureas and diarylamides derivatives are reported to have antitumor activity. Encouraged by the interesting antiproliferative activity of diarylurea and diarylamide derivatives, we synthesized a new series of diarylureas and diarylamides containing pyrrolo[3,2-c]pyridine scaffold. In this study, we demonstrate that a N-(3-(4-benzamido-1H-pyrrolo[3,2-c]pyridin-1-yl)phenyl)-4-morpholino-3-(trifluoromethyl)benzamide, KIST101029, inhibits neoplastic cell transformation induced by insulin-like growth factor 1 (IGF-1) in mouse epidermal JB6 Cl41 cells. The KIST101029 compound inhibited mitogen-activated protein kinase/extracellular signal-regulated kinase kinases (MEK), c-jun N-terminal kinases (JNK), and mechanistic target of rapamycin (mTOR) signaling pathways induced by IGF-1 in JB6 Cl41 cells, resulting in the inhibition of c-fos and c-jun transcriptional activity. In addition, the KIST101029 inhibited the associated activator protein-1 (AP-1) transactivation activity and cell transformation induced by IGF-1 in JB6 Cl41 cells. Consistent with these observations, in vivo chorioallantoic membrane assay also showed that the KIST101029 inhibited IGF-1-induced tumorigenicity of JB6 Cl41 cells. Importantly, KIST101029 suppressed the colony formation of A375 cells in soft agar. Taken together, these results indicate that a KIST101029 might exert chemopreventive effects through the inhibition of phosphorylation of MAPK and mTOR signaling pathway.

Pin1 is required for ultraviolet A-stimulated cyclooxygenase-2 induction in mouse epidermal cells.

Ultraviolet A (UVA) radiation (320-400 nm) is considered a major cause of human skin photoaging and skin cancer. Overexpression of cyclooxygenase-2 (COX-2) leads to prostanoid formation in skin tissue, disturbs the balance between proliferation and apoptosis, and subsequently promotes tumorigenesis. The peptidyl-prolyl isomerase Pin1 is known to be overexpressed in most cancer cell types and plays an important role in oncogenesis. Here, we studied whether exposure of JB6 Cl41 mouse epidermal cells to UVA affects COX-2 expression and the possible involvement of Pin1 activation. UVA increased COX-2 protein expression and prostaglandin E2 production in an energy-dependent manner. Pre-exposure of JB6 Cl41 cells to UVA potentiated epidermal growth factor-induced anchorage-independent growth; this effect was significantly suppressed by inhibition of COX-2. UVA-stimulated COX-2 expression was significantly decreased by inhibition of Pin1. The increased COX-2 gene transcription in response to UVA was preceded by activation of the transcription factors nuclear factor-κB (NF-κB), cAMP response element-binding protein (CREB), CCAAT/enhancer-binding proteins α and ß (C/EBPα and C/EBPß) and c-Jun/activator protein-1 (AP-1). Pin1 inhibitor treatment suppressed the activation of NF-κB, CREB, and C/EBP by UVA irradiation. Conversely, JB6 C141 cells overexpressing Pin1 showed increased basal COX-2 expression and NF-κB, CREB, C/EBP, and AP-1 activities. These results suggest that UVA-induced COX-2 expression is mediated by Pin1 activation and this is associated with malignant transformation of epidermal cells.

Application of Carbopol/PVP interpolymer complex to prepare mucoadhesive floating granule.

Novel mucoadhesive floating granule was prepared using Carbopol/PVP interpolymer complex to deliver hydrophilic drugs in a controlled manner. Acetaminophen was used as a model drug. Maximum floatability of the granules was obtained at the ratio of 1/1, where 95 % of the granules floated for 12 h. As the concentration of sodium bicarbonate increased, both the floating duration and the release rate of the drug increased. The granules without sodium bicarbonate floated only for 2 h and floating onset time was 15 min. The release rate of drug gradually increased as the drug content in the granule increased. As the drug content in the granules increased, duration of adhesion decreased. However, the decrease in adhesion duration was minimal up to 40 % of drug content. The release rate from the granules prepared by dry granulation method was faster than that by wet granulation. The granules prepared by dry granulation method led to formation of highly porous structure; whereas, that by wet granulation method showed non-porous structure. The optimum size of the granules to retard the release of the model drug was within the range of 3-4 mm. Based on both mucoadhesive and buoyant properties, the floating granules are expected to reside in the upper part of the stomach for sufficient period of time and release the drug in a sustained manner.

Enhancement of solubility and dissolution rate of cryptotanshinone, tanshinone I and tanshinone IIA extracted from Salvia miltiorrhiza.

Cryptotanshinone, tanshinone I and tanshinone IIA are three major components in the extract of Salvia miltiorrhiza with pharmacological significance. However, their effective utilization is limited due to poor water solubility and bioavailability. Solid dispersion (SD) of the extract of Salvia miltiorrhiza was prepared to enhance solubility and dissolution of the three major components. Various carriers were screened for SD preparation by conventional solvent method. Dissolution of the components from selected SD systems was compared with commercial tablets of the extract from Salvia miltiorrhiza. The solubility of three components viz., cryptotanshinone, tanshinone I and tanshinone IIA, after forming SD with either of povidone K-30 (PVP K-30) or poloxamer 407, exhibited enhanced solubility in pH 6.8 buffer. Dissolution test revealed that the amount of three components released was higher from SD tablets as compared to the commercial tablets. Pharmacokinetic profile was evaluated using cryptotanshinone as a representative compound. AUC of cryptotanshinone was significantly increased when administered as a solid dispersion.

Identification of cis-acting elements and signaling components of high affinity IgE receptor that regulate the expression of cyclooxygenase-2.

Allergic and inflammatory responses are functionally linked through a cascade of signaling events that connect the aggregation of the high affinity IgE receptor (FcεRI) on mast cells and the initiation of cyclooxygenase-2 (COX-2) expression. In this study, we identified the cis-acting elements in the cox-2 promoter that control the expression of COX-2 in RBL-2H3 mast cells. We also investigated how the inflammatory reaction is controlled by the allergic reaction by determining the signaling components employed by FcεRI in the transcriptional regulation of cox-2. Among cis-acting components present in the cox-2 promoter, the CREB binding site, as well as the AP-1 and proximal NF-IL6 binding sites to a lesser extent, were required for the transcriptional regulation of the cox-2 promoter. However, NF-κB and Ets-1 binding sites exerted negative effects on the cox-2 promoter activity. Among the signaling components of FcεRI, Fyn, PI 3-kinase, Akt, and p38 MAPK positively mediated the COX-2 expression. Conventional PKCs and atypical PKCs exerted opposite regulatory effects on the cox-2 promoter activity. Blockade of MEK/ERK pathway inhibited the cox-2 promoter activity and the COX-2 expression. These results reveal intricate functional interactions among different cis-acting elements in the transcriptional regulation of cox-2. Fyn-->PI 3-kinase-->Akt pathway directly stimulate. On the other hand, Lyn-->Syk pathway exerts auxiliary or compensatory influences on COX-2 expression via PKC and MEK/ERK.

Preparation and pharmacokinetic evaluation of curcumin solid dispersion using Solutol® HS15 as a carrier.

Solubility of curcumin at physiological pH was significantly increased by forming solid dispersion (SD) with Solutol® HS15. Since curcumin undergoes hydrolytic degradation, chemical stability study was conducted in pH 1.2, 6.8 and 7.4 buffer media. Solutol® HS15 exhibited superior stabilizing effect to Cremophor® RH40 and Kollidon® 30. The physical state of the dispersed curcumin in the polymer matrix was characterized by differential scanning calorimetry and X-ray diffraction studies. SD preparation transformed curcumin into amorphous form and facilitated micellar incorporation, thereby preventing hydrolysis in aqueous medium. In vitro drug release in pH 6.8 buffer revealed that SD (1:10) improved the dissolution of curcumin with approximately 90% release of the drug within 1h. Pharmacokinetic study of the solid dispersion formulation in rat showed that bioavailability of the drug was significantly improved as compared to pure curcumin. SD containing 1:10 ratio of drug and Solutol® HS15 resulted in approximately 5 fold higher AUC(0-12h). SD formulation was physically stable over the study period of 3 months.

Influence of formulation variables in transdermal drug delivery system containing zolmitriptan.

The effects of different formulation variables including pressure sensitive adhesive (PSA), thickness of the matrix, solvent system, inclusion of crystallization inhibitor, loading amount of drug and enhancers on the transdermal absorption of zolmitriptan were investigated. Acrylic adhesive with hydroxyl functional group provided good adhesion force and high flux of zolmitriptan. Pseudopolymorphs of zolmitriptan were found to possess different solid-state properties that affected the permeation rate. Polyoxyethylene alkyl ethers significantly increased the permeation of zolmitriptan through hairless mouse skin. However, these enhancers induced crystallization of zolmitriptan. Kollidon(®) 30 delayed the crystallization without altering the permeation profile of zolmitriptan. Stability studies suggested that terpenes did not induce crystallization of zolmitriptan in the patch and stable formulations could be produced by using cineole and limonene, or their combination.

5'-Nitro-indirubinoxime inhibits epidermal growth factor- and phorbol ester-induced AP-1 activity and cell transformation through inhibition of phosphorylation of Pin1.

5'-Nitro-indirubinoxime (5'-NIO), a derivative of indirubin, exhibits anti-cancer activity in a variety of human cancer cells. However, the underlying molecular mechanisms and molecular target(s) of the chemopreventive activities of 5'-NIO remain unknown. Here, we report that 5'-NIO inhibited the epidermal growth factor (EGF) or 12-O-tetradecanoylphorbol-13-acetate (TPA)-induced neoplastic cell transformation of JB6 Cl41 mouse skin epidermal cells without any cytotoxic effects. Western blot analysis revealed that 5'-NIO inhibited activities of Raf-1 (S338), MEK1/2, ERK1/2, JNK, and c-Jun induced by EGF or TPA, respectively, whereas it did not affect autophosphorylation of epidermal growth factor receptor (EGFR) induced by EGF or TPA. In addition, 5'-NIO exerted strong inhibitory effects on the EGF- or TPA-induced c-fos or c-jun transcriptional activity, and thereby inhibited the associated activator protein-1 (AP-1) transactivation activity induced by EGF or TPA. Importantly, 5'-NIO inhibited Pin1 phosphorylation at serine 16 induced by EGF or TPA, respectively, resulted in the inhibition of interaction between Pin1 and Raf-1. Immunoprecipitation/immunoblot analysis revealed that 5'-NIO bound with Pin1. Together, these findings suggest that 5'-NIO might act as an anticarcinogene in EGF- or TPA-induced carcinogenesis through the inhibition of interaction between Pin1 and Raf-1. © 2011 Wiley Periodicals, Inc.