Prostaglandin E1 reduces the keratinocyte toxicity of sorafenib by maintaining signal transducer and activator of transcription 3 (STAT3) activity and enhancing the cAMP response element binding protein (CREB) activity.

Hand-foot skin reaction (HFSR) is a common side effect of multiple tyrosine kinase inhibitors (mTKIs). HFSR can necessitate dose reductions or interruption of therapy owing to its negative effect on the quality of life. Therefore, effective use of mTKIs requires measures to prevent HFSR. We evaluated the effect of prostaglandin E1 (PGE1) on HFSR, because PGE1 is already used to treat bed sores and skin ulcers and has established angiogenic and antiproliferative effects in keratinocytes. We found that the pathogenesis of sorafenib-induced HFSR is characterized by a decrease in levels of a phosphorylated signal transducer and activator of transcription 3 (STAT3). We investigated the effect of PGE1 on the sorafenib-mediated reduction in phosphorylated STAT3 levels in HaCaT human epidermal keratinocytes. In cells treated with sorafenib, phosphorylated STAT3 levels decreased in a concentration-dependent manner, and this effect was blocked in cells treated with sorafenib and PGE1. Furthermore, the expression of phosphorylated STAT3, the antiapoptotic proteins myeloid cell leukemia-1 (Mcl-1) and survivin decreased in cells pretreated with an inhibitor of cAMP response element binding protein (CREB). Cell viability increased in cells treated with sorafenib and PGE1 compared with that in cells treated with sorafenib alone, and these effects were not observed in STAT3 knockdown HaCaT cells. Collectively, these findings indicate that PGE1 blocks the inhibitory effects of sorafenib on cell growth by maintaining the activity of STAT3 and enhancing the CREB activity. Therefore, PGE1 might represent an effective treatment for the prevention of sorafenib-induced HFSR.

Effects of Ascorbyl-2-phosphate Magnesium on Human Keratinocyte Toxicity and Pathological Changes by Sorafenib.

Hand-foot skin reaction is recognized as one of the most common adverse events related to multiple tyrosine kinase inhibitors, but an effective prevention method has not been identified. The chief aim of this study was to find a mechanism-based preventive method for the skin toxicity induced by sorafenib using vitamin C derivatives. The effects of ascorbyl-2-phosphate magnesium (P-VC-Mg) on the molecular and pathological changes induced by sorafenib were investigated in human keratinocyte HaCaT cells. The cell growth inhibition and apoptotic effects of sorafenib were attenuated by P-VC-Mg. Moreover, P-VC-Mg inhibited the decrease of signal transducer and activator of transcription 3 (STAT3) phosphorylation and the expression of apoptosis suppressors treated by sorafenib. HaCaT cells transfected with the STAT3 dominant-negative form (STAT3DN) and STAT3 small interfering RNA (siRNA) combined with P-VC-Mg did not exhibit the attenuation of cell growth inhibition. Interestingly, after exposure to sorafenib in a three dimensional (3D) skin model assay, the basal layer was significantly thickened and the granular and spinous layers became thinner. In contrast, after exposure to sorafenib with P-VC-Mg, the thickness of the basal, granular, and spinous layers was similar to that of the control image. These findings suggest that P-VC-Mg attenuates sorafenib-induced apoptosis and pathological changes in human keratinocyte cells and in the 3D skin model mediated by the maintenance of STAT3 activity.

Partial Excision and Ablative Carbon Dioxide Fractional Laser Therapy for Multiple Apocrine Hidrocystomas on the Periorbital Regions and Cheeks.

A 51-year-old Japanese woman presented with translucent papules on the periorbital area and cheeks that had progressively enlarged over five years. She underwent a skin biopsy and was diagnosed with multiple apocrine hidrocystomas. Her lesions became more pronounced and obscured her vision when her body warmed up, such as during bathing. To alleviate her symptoms, we began treatment by partially resecting the tumors on the lower eyelids. After surgery, her vision was no longer obscured. Approximately 1.5 years later, she underwent ablative 10,600 nm carbon dioxide fractional laser therapy for the mildly enlarged apocrine hidrocystomas on her lower eyelids and cheeks. At roughly six months of follow-up, the symptoms had improved, and the cosmetic results were satisfactory, although minor scarring and hypopigmentation were still evident. These case findings underscore the effectiveness of ablative carbon dioxide fractional lasers in treating apocrine hidrocystomas.

The mandatory role of IL-10-producing and OX40 ligand-expressing mature Langerhans cells in local UVB-induced immunosuppression.

The mechanism underlying the local UVB-induced immunosuppression is a central issue to be clarified in photoimmunology. There have been reported a considerable number of cells and factors that participate in the sensitization phase-dependent suppression, including Langerhans cells (LCs), regulatory T cells, IL-10, and TNF-alpha. The recent important finding that LC-depleted mice rather exhibit enhanced contact hypersensitivity responses urged us to re-evaluate the role of LCs along with dermal dendritic cells (dDCs) in the mechanism of UVB-induced immunosuppression. We studied the surface expression of OX40 ligand (OX40L) and the intracellular expression of IL-10 in LCs and dDCs from UVB-irradiated (300 mJ/cm(2)) skin of BALB/c mice and those migrating to the regional lymph nodes from UVB-irradiated, hapten-painted mice. In epidermal and dermal cell suspensions prepared from the UVB-irradiated skin, LCs expressed OX40L as well as CD86 and produced IL-10 at a higher level than Langerin(-) dDCs. The UVB-induced immunosuppression was attenuated by the administration of IL-10-neutralizing or OX40L-blocking Abs. In mice whose UVB-irradiated, hapten-painted skin was dissected 1 d after hapten application, the contact hypersensitivity response was restored, because this treatment allowed dDCs but not LCs to migrate to the draining lymph nodes. Moreover, LC-depleted mice by using Langerin-diphtheria toxin receptor-knocked-in mice showed impaired UVB-induced immunosuppression. These results suggest that IL-10-producing and OX40L-expressing LCs in the UVB-exposed skin are mandatory for the induction of Ag-specific regulatory T cells.

Pathogenesis of cholinergic urticaria in relation to sweating.

Cholinergic urticaria (CU) has clinically characteristic features, and has been frequently described in the literature. However, despite its comparatively old history, the pathogenesis and classification remains to be clarified. CU patients are occasionally complicated by anhidrosis and/or hypohidrosis. This reduced-sweat type should be included in the classification because the therapeutic approaches are different from the ordinary CU. It is also well-known that autologous sweat is involved in the occurrence of CU. More than half of CU patients may have sweat hypersensitivity. We attempt to classify CU and address the underlying mechanisms of CU based on the published data and our findings. The first step for classification of CU seems to discriminate the presence or absence of hypersensitivity to autologous sweat. The second step is proposed to determine whether the patients can sweat normally or not. With these data, the patients could be categorized into three subtypes: (1) CU with sweat hypersensitivity; (2) CU with acquired anhidrosis and/or hypohidrosis; (3) idiopathic CU. The pathogenesis of each subtype is also discussed in this review.

Dysfunction of melanocytes in photoleukomelanoderma following photosensitivity caused by hydrochlorothiazide.

We report a 68-year-old Japanese man who developed photoleukomelanoderma following prolonged photosensitivity caused by hydrochlorothiazide. He showed complete recovery from the leukomelanoderma with the discontinuation of the responsive drug and with topical application of tacrolimus hydrate and corticosteroid. Histological and immunohistochemical examination revealed that there were no melanin-positive cells in the hypopigmented area, despite the presence of melanocytes. These results and the clinical course indicate that leukomelanoderma is postulated temporary dysfunction of melanocytes. We also conducted a review of previous case reports regarding drug-induced photoleukomelanoderma.

12-O-tetradecanoylphorbol-13-acetate inhibits melanoma growth by inactivation of STAT3 through protein kinase C-activated tyrosine phosphatase(s).

The growth of most melanoma cells in vitro is inhibited by the tumor-promoting phorbol ester 12-O-tetradecanoylphorbol-13-acetate (TPA). In this study, the involvement of the signal transducer and activator of transcription 3 (STAT3) in the TPA-induced growth inhibition of melanoma cells was examined. The in vitro growth and DNA synthesis of five melanoma cell lines, whose STAT3 was activated (phosphorylated), was inhibited by TPA, whereas that of WM35 and WM39 cells, whose STAT3 activity was at negligible levels, was considerably slow and not affected by TPA. Blockade of STAT3 activity by small interfering RNAs suppressed the growth of WM1205Lu cells containing constitutively activated STAT3. Treatment of WM1205Lu cells with TPA decreased both the phosphorylated STAT3 and the DNA-binding activity of STAT3. Pretreatment of WM1205Lu cells with either a protein-tyrosine phosphatase inhibitor or a protein kinase C (PKC) inhibitor prevented the inhibitory effects of TPA on the level of phosphorylated STAT3. The five melanoma cell lines containing phosphorylated STAT3 commonly expressed PKCalpha, PKCdelta, and PKCepsilon. Introduction of the dominant negative mutant of one of these PKC isoforms into WM1205Lu cells inhibited the TPA-induced dephosphorylation of STAT3. A Src inhibitor attenuated the STAT3 phosphorylation in WM1205Lu cells. These results indicate that constitutively activated STAT3 is positively regulated by c-Src and negatively regulated by a PKC-activated tyrosine phosphatase(s) in melanoma cells. Because TPA did not affect c-Src activity, we conclude that the growth inhibitory effect of TPA on melanoma cells is mediated through inactivation of STAT3 by a PKC-activated tyrosine phosphatase(s).

Ultraviolet light induces Stat3 activation in human keratinocytes and fibroblasts through reactive oxygen species and DNA damage.

Stat3 is activated by the outer stressors, such as ultraviolet (UV) exposure. In this study, we investigated the Stat3 response to UV irradiation in human epidermal keratinocytes and dermal fibroblasts. Results indicated that UVB and UVC differentially activate Stat3 in these cells. The UV-induced Stat3 activation was mediated by both reactive oxygen species (ROS) and DNA damage, and the dominancy of ROS and DNA damage to activate Stat3 depended on the wavelength of UV. By using fibroblasts from a patient with xeroderma pigmentosum A (XP-A) and those transfected with human XPA gene, we found that UVB activates Stat3 via both ROS and DNA damage, while UVC does so mainly via DNA damage. The present data suggest that Stat3 activation in UV-exposed human skin is one of the initial events where DNA damage and ROS are involved.

Generalized eruptive xanthoma with prominent deposition of naked chylomicrons: evidence for chylomicrons as the origin of urate-like crystals.

Eruptive xanthoma is defined by the combination of its clinical and histopathological features. While a nodular dermal infiltrate rich in foamy macrophages and associated with extracellular lipid deposition is typical of eruptive xanthoma, some microscopical variability can be seen. Herein, we report an unusual case of eruptive xanthoma exhibiting triglyceride deposition in a peculiar configuration. A biopsy from a papular lesion showed prominent deposition of crystalline material, surrounded by many foamy histiocytes, in the upper and middle dermis. Such material has been previously termed 'urate-like crystals'. An immunohistochemical analysis using antibodies to lipoprotein suggested that the substance is composed of chylomicrons. This observation suggests that naked chylomicrons may be deposited in the dermis of patients with severe hypertriglyceridemia.

Ectopic extramammary Paget's disease: case report and literature review.

Extramammary Paget's disease that occurs in non-apocrine-bearing regions is referred to as ectopic and has been rarely reported. A 62-year-old man presented with a slowly progressive, asymptomatic light-brown plaque on his back. Histopathological examination revealed the presence of large pale cells with prominent nuclei, which proliferated diffusely and focally in the epidermis. Immuno-histochemically the tumour cells were positive for CK7, GCDFP-15, CEA, and p63. Based on these findings, we diagnosed the tumour as ectopic extramammary Paget's disease. We reviewed the English and Japanese literature and found 29 previously reported cases of ectopic extramammary Paget's disease, including our case, with a predominance of occurrence in the Asian population. The germinative milk line is known to be a possible site where extramammary Paget's disease occurs. Like-wise, some germinative apocrine-differentiating cells might exist on the trunk preferentially in Asians. Attention should be paid to the development of ectopic as well as triple or quadruple EMPD in Asians.

Genetic prediction of the effectiveness of biologics for psoriasis treatment.

Anti-tumor necrosis factor (TNF)-α therapy is used for the treatment of psoriasis, with varying outcomes. However, the specific cause of inadequate response or treatment failure remains unknown. The aim of the present study was to identify useful clinical biomarkers for predicting therapeutic responses or to serve as new drug targets for refractory psoriasis cases. We performed a genome-wide association study (GWAS) of 65 psoriasis patients who were prospectively followed after beginning anti-TNF-α therapy using Human Omni Express-8 v1.2 Beadchips. Patients were enrolled at the dermatology departments of Kobe University Hospital and six collaborative hospitals. Associations between single nucleotide polymorphisms (SNP) and changes in the Psoriasis Area and Severity Index (PASI) after 12 weeks of treatment were evaluated. After genome data collection and quality control, a total of 731 442 SNPs were identified in 65 Asian psoriasis patients who were treated with adalimumab or infliximab. Here, we present 10 SNPs, such as those in JAG2 and ADRA2A, that were associated with treatment responses to anti-TNF-α agents (strongest effect, P < 7.11E-06). This is the first GWAS to examine SNP associated with treatment responses in psoriasis patients. In addition, we identified other SNP that exhibited potential associations with anti-TNF-α treatment response, which merit further study. Of these, rs11096957 on TLR10, which is associated with increased TNF-α production, was previously reported to be associated with treatment responses to TNF-α inhibitors.

Association of Single Nucleotide Polymorphisms in STAT3 with Hand-Foot Skin Reactions in Patients with Metastatic Renal Cell Carcinoma Treated with Multiple Tyrosine Kinase Inhibitors: A Retrospective Analysis in Japanese Patients.

BACKGROUND: Signal transducer and activator of transcription (STAT)3 is a reported mediator of molecular-targeted drug-induced keratinocyte toxicity. AIM: Our purpose was to assess the association of single nucleotide polymorphisms (SNPs) in STAT3 with hand-foot skin reactions (HFSR) in patients with metastatic renal cell carcinoma (mRCC) treated with multiple tyrosine kinase inhibitors (mTKIs). PATIENTS AND METHODS: Sixty-five Japanese patients with clear cell renal cell carcinoma who were treated with any mTKI at Kobe University Hospital were retrospectively genotyped to elucidate a potential association between STAT3 polymorphisms and HFSR development. RESULTS: The final analysis included 60 patients. HFSR was observed in 46 patients. The GG, GC, and CC genotypes at rs4796793 were found in 9, 27, and 24 patients, respectively. Three other STAT3 polymorphisms exhibited tight linkage disequilibrium with rs4796793. A significant association was found between the rs4796793 allele and HFSR [G vs. C; odds ratio [OR], 4.33; 95 % confidence interval [CI], 1.80-10.45; P = 0.001]. The GG genotype had the highest OR compared with GC + CC genotypes (OR, 10.75; 95 % CI, 2.38-48.07; P = 0.001). In a time-to-event Kaplan-Meier analysis, a statistically significant difference was observed between the GC + CC and the GG genotypes (P = 0.009). CONCLUSIONS: The rs4796793 genotype appears to be a novel factor for mTKI-induced HFSR in patients with mRCC. Prospective translational trials with larger numbers of patients are required to confirm our results. This research suggests a potential benefit of STAT3 polymorphism screening in patients treated with mTKIs.

Phosphatidylinositol 3-kinase/Akt-dependent and -independent protection against apoptosis in normal human melanocytes.

Normal human melanocytes require the synergistic action of several growth-promoting agents for their growth in serum-free medium. The ability of four representative growth promoting agents including insulin, 12-O-tetradecanoylphorbol-13-acetate (TPA), basic fibroblast growth factor (bFGF), and 3-isobutyl-1-methylxanthine (IBMX), (iTbI) to protect melanocytes against apoptosis was examined. Also, the involvement of phosphatidylinositol (PI) 3-kinase and Akt, one of the downstream targets of PI 3-kinase, in the survival signaling pathway was examined. The percentage of apoptotic cells was negligible when the cells were grown in the presence of iTbI. Deprivation of iTbI from the culture medium for 72 h caused approximately 30% of melanocytes to undergo apoptosis and this was suppressed to variable extents by the addition of one of the iTbI to the medium. Insulin and TPA protected against apoptosis almost completely, whereas bFGF and IBMX rescued melanocytes from apoptosis to a lesser extent. Wortmannin, an inhibitor of PI 3-kinase, potently inhibited the protective effect of insulin on melanocytes, whereas it did not block the ability of TPA, bFGF, or IBMX to rescue the cells from apoptosis. Furthermore, apoptosis of melanocytes induced by deprivation of iTbI was prevented almost completely by infection with an adenovirus vector encoding a constitutively active mutant of either PI 3-kinase or Akt. These results indicate that melanocytes can operate both PI 3-kinase/Akt-dependent and -independent mechanisms for protection against apoptosis and that activation of the PI 3-kinase/Akt pathway is sufficient for protection against apoptosis induced by deprivation of growth-promoting agents.

Inhibition of the epidermal growth factor receptor suppresses telomerase activity in HSC-1 human cutaneous squamous cell carcinoma cells.

Activation of telomerase, which stabilizes the telomere length of chromosomes, is crucial for the continued growth or progression of cancer cells. In a previous study, we showed that telomerase is frequently activated in skin tumors. Because epidermal growth factor plays an important role during the tumorigenesis of epithelial tissue, we have now examined the role of epidermal growth factor signaling in regulating telomerase activity using HSC-1 human cutaneous squamous cell carcinoma cells. Treatment of HSC-1 cells with AG 1478, an inhibitor of the epidermal growth factor receptor, or with a neutralizing antibody to the epidermal growth factor receptor, significantly suppressed their telomerase activity, in association with inhibiting their growth. The suppression of telomerase activity was obvious at day 3 and was maximal at day 5 after treatment with AG 1478. The suppression of telomerase activity correlated with the decreased expression of human telomerase catalytic subunit (hTERT) mRNA, the rate-limiting determinant of its enzyme activity. The expression of c-Myc and of Sp1 proteins, transcription factors for hTERT, were also suppressed by AG 1478 in HSC-1 cells, but the expression of Ets-2 protein, another transcription factor, was not affected. The expression of Mad-1, a competitor of c-Myc, was increased. Inhibition of ERK, Src, or Akt suppressed telomerase activity in HSC-1 cells, but to a lesser extent than did treatment with AG 1478. Serum starvation suppressed telomerase activity, but addition of epidermal growth factor or transforming growth factor alpha did not increase it, indicating the involvement of other epidermal growth factor receptor ligands in the activation of telomerase in HSC-1 cells. These data indicate that blockade of the epidermal growth factor receptor might be effective in inhibiting telomerase activity of squamous cell carcinomas, which would lead to the suppression of tumor growth.

Flavonoids differentially regulate IFN gamma-induced ICAM-1 expression in human keratinocytes: molecular mechanisms of action.

The effect of plant flavonoids on intercellular adhesion molecule-1 (ICAM-1) expression in human keratinocyte was investigated. ICAM-1 is known to mediate skin inflammation. Among the flavonoids tested, taxifolin was the most potent in inhibiting interferon gamma (IFN gamma)-induced ICAM-1 protein as well as mRNA expression in human keratinocytes. Much smaller dosages of taxifolin were required in primary keratinocytes compared to HaCaT (immortalized cell) to achieve similar levels of inhibition in the inducible ICAM-1 expression. Regulation of inducible ICAM-1 expression by taxifolin was at transcriptional level by inhibiting the activation of signal transducers and activators of transcription (STAT)1 and protein tyrosine phosphorylation of Janus kinase (JAK)1 suggesting that the JAK-STAT pathway may be the molecular site of action of taxifolin. Finally, taxifolin pre-treatment also potently inhibited IFN gamma-induced ICAM-1 expression in a reconstructed human skin equivalent suggesting therapeutic potential of taxifolin in skin pathological conditions related to increased cell adhesion and inflammation.