Tumor Suppressive Function of NQO1 in Cutaneous Squamous Cell Carcinoma (SCC) Cells.

Cutaneous squamous cell carcinoma (SCC) is a common cancer that significantly decreases the quality of life. It is known that external stimulus such as ultraviolet (UV) radiation induces cutaneous SCC via provoking oxidative stress. NAD(P)H dehydrogenase 1 (NQO1) is a ubiquitous flavoenzyme that functions as a guardian against oxidative stress. However, the effect of NQO1 on cutaneous SCC is not clearly elucidated. In this study, we investigated the effect of NQO1 on cutaneous SCC cells using the recombinant adenoviruses that can upregulate and/or downregulate NQO1 expression. Overexpression of NQO1 resulted in significant decrease of cell proliferation and colony forming activity of SCC lines (SCC12 and SCC13 cells). By contrast, knockdown of NQO1 increased the cell proliferation and colony forming activity. Accordingly, the levels of proliferation-related regulators, such as Cyclin D1, Cyclin E, PCNA, SOX2, and p63, were decreased by the overexpression of NQO1, while those were increased by knockdown of NQO1. In addition, NQO1 affected the invasion and migration of SCC cells in a very similar way, with the regulation of epithelial-mesenchymal transition- (EMT-) related molecules, including E-cadherin, N-cadherin, Vimentin, Snail, and Slug. Finally, the overexpression of NQO1 decreased the level of phosphorylated AKT, JNK, and p38 MAPK, while the knockdown of NQO1 increased the level of phosphorylated signaling molecules. Based on these data, NQO1 has tumor suppressive function in cutaneous SCC cells.

Antitumor Effect of Albendazole on Cutaneous Squamous Cell Carcinoma (SCC) Cells.

Drug repurposing and/or repositioning is an alternative method to develop new treatment for certain diseases. Albendazole was originally developed as an anthelmintic medication, and it has been used to treat a variety of parasitic infestations. In this study, we investigated the antitumor effect of albendazole and putative action mechanism. Results showed that albendazole dramatically decreased the cell viability of SCC cell lines (SCC12 and SCC13 cells). Albendazole increased apoptosis-related signals, including cleaved caspase-3 and PARP-1 in a dose-dependent fashion. The mechanistic study showed that albendazole induced endoplasmic reticulum (ER) stress, evidenced by increase of CHOP, ATF-4, caspase-4, and caspase-12. Pretreatment with ER stress inhibitor 4-PBA attenuated albendazole-induced apoptosis of SCC cells. In addition, albendazole decreased the colony-forming ability of SCC cells, together with inhibition of Wnt/ß-catenin signaling. These results indicate that albendazole shows an antitumor effect via regulation of ER stress and cancer stemness, suggesting that albendazole could be repositioned for cutaneous SCC treatment.

Inhibition of Poly(I:C)-Induced Inflammation by Salvianolic Acid A in Skin Keratinocytes.

BACKGROUND: Skin keratinocytes participate actively in inducing immune responses when external pathogens are introduced, thereby contributing to elimination of pathogens. However, in condition where the excessive inflammation is occurred, chronic skin disease such as psoriasis can be provoked. OBJECTIVE: We tried to screen the putative therapeutics for inflammatory skin disease, and found that salvianolic acid A (SAA) has an inhibitory effect on keratinocyte inflammatory reaction. The aim of this study is to demonstrate the effects of SAA in poly(I:C)-induced inflammatory reaction in skin keratinocytes. METHODS: We pre-treated keratinocytes with SAA then stimulated with poly(I:C). Inflammatory reaction of keratinocytes was verified using real-time polymerase chain reaction, enzyme-linked immunosorbent assay and Western blot. RESULTS: When skin keratinocytes were pre-treated with SAA, it significantly inhibited poly (I:C)-induced expression of inflammatory cytokines including interleukin (IL)-1ß, IL-6, IL-8, tumor necrosis factor-α, and CCL20. SAA inhibited poly(I:C)-induced activation of nuclear factor-κB signaling. And SAA also inhibited inflammasome activation, evidenced by decrease of IL-1ß secretion. Finally, SAA markedly inhibited poly(I:C)-induced NLRP3 expression. CONCLUSION: These results demonstrate that SAA has an inhibitory effect on poly(I:C)-induced inflammatory reaction of keratinocytes, suggesting that SAA can be developed for the treatment of inflammatory skin diseases such as psoriasis.

Inhibition of Insulin-Like Growth Factor-1-Induced Sebum Production by Bilobetin in Cultured Human Sebocytes.

BACKGROUND: Sebocytes are the major cells of sebaceous gland. The essential role of sebocytes is the production of sebum, a specific lipid mixture, that covers the body surface and provides the barrier function. At puberty, sebum production increases under the effects of various stimuli including androgens and insulin-like growth factor-1 (IGF-1). Excessive sebum production changes the microenvironment surrounding hair follicle, often leading to the onset of acne. OBJECTIVE: We previously performed screening test using cultured human sebocytes, and found that bilobetin had a potential for inhibiting lipid production. The aim of this study is to demonstrate the effects of bilobetin on IGF-1-induced lipogenesis in sebocytes. METHODS: We pretreated simian virus 40 T (SV40T)-transformed sebocytes with bilobetin then stimulated with IGF-1. Effects of bilobetin on lipogenesis of sebocytes were examined by thin layer chromatography and Western blot. RESULTS: Bilobetin markedly inhibited IGF-1-induced lipid production in sebocytes, especially in terms of production of squalene and wax ester. Supporting these results, bilobetin showed significant inhibitory effect on squalene synthase promoter activity. In addition, bilobetin significantly down-regulated lipogenic transcription factors such as sterol response element binding protein (SREBP)-1 and SREBP-2. To delineate the possible action mechanism, we investigated the effect of bilobetin on intracellular signaling. As a result, bilobetin inhibited IGF-1-induced phosphorylation of AKT. CONCLUSION: Together, these results suggest that bilobetin has an inhibitory potential on sebum production in sebocytes, being applicable for acne treatment.

Inhibition of collagen synthesis by IWR-1 in normal and keloid-derived skin fibroblasts.

AIMS: Keloid is a benign tumor that is characterized by the hyperproliferation of dermal fibroblasts and excessive deposition of extracellular matrix (ECM) especially the collagen. Aberrant activation of Wnt/ß-catenin signaling is implicated in the pathogenesis of keloid. In this study, we investigated the effects of IWR-1, a small molecule inhibitor for Wnt/ß-catenin signaling via the inhibition of tankyrase, on production of collagen and matrix metalloproteinase (MMP) in dermal fibroblasts. MAIN METHODS: We cultured human normal skin- and keloid-derived fibroblasts, then treated with IWR-1. The effects of IWR-1 on collagen and MMP production were determined by Western blot, ELISA and zymography. KEY FINDINGS: IWR-1 significantly suppressed the proliferation and migration of both the normal and keloid fibroblasts. IWR-1 also inhibited the production and secretion of type I collagen from the fibroblasts. In addition, IWR-1 significantly increased the expression of MMPs, such as MMP-1, MMP-3 and MMP-13, along with the increase of gelatinase activity. These results suggest that inhibitory effect of IWR-1 on collagen production may be related with the increased MMP activity. SIGNIFICANCE: This study provides the possible action mechanism of IWR-1 on regulation of collagen expression, on which to base further investigation for preventing skin fibrotic diseases such as keloid.

[Concentrations of PCDD/Fs in the atmosphere of Chongqing City and its seasonal variation].

As a comprehensive monitoring survey on polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs) in Chongqing, 20 ambient air samples taken from 5 locations in four seasons were studied. The PCDD/F TEQ concentrations varied from 0.017 pg x m(-3) to 0.21 pg x m(-3). The average value was (0.094 +/- 0.054) pg x m(-3). The PCDD/F concentrations varied by locations and seasons, and the orders were: urban area > suburban area > background area, and Winter > Spring > Autumn > Summer. The concentrations of PCDD/Fs were 2.2-4.6 times higher in the winter than during the summer. The PCA results indicated that PCDD/F homologue pattern varied by seasons. The PCDD/F homologue pattern in particle dominated in winter and spring, and the pattern in gas dominated in summer and autumn. The mass concentration of PCDD/F congener was significantly positively correlated with that of SO2, NO2, PM10 and TSP, and insignificantly negatively correlated with that of O3, respectively. The results showed that spatial distribution and seasonal variation of atmospheric PCDD/Fs in Chongqing was consistent with that of these conventional indicators, and the PCDD/Fs pollution was closely related with the emission sources of SO2, NO2, PM10 and TSP.

[Atmospheric emission of PCDD/Fs from secondary aluminum metallurgy industry in the southwest area, China].

Five secondary aluminum metallurgy enterprises in the southwest area of China were measured for emissions of PCDD/Fs. The results indicated that the emission levels of PCDD/Fs (as TEQ) were 0.015-0.16 ng x m(-3), and the average was 0.093 ng x m(-3) from secondary aluminum metallurgy enterprises. Emission factors of PCDD/Fs (as TEQ) from the five secondary aluminum metallurgy enterprises varied between 0.041 and 4.68 microg x t(-1) aluminum, and the average was 2.01 microg x t(-1) aluminum; among them, PCDD/Fs emission factors from the crucible smelting furnace was the highest. Congener distribution of PCDD/F in stack gas from the five secondary aluminum metallurgies was very different from each other. Moreover, the R(PCDF/PCDD) was the lowest in the enterprise which was installed only with bag filters; the R(PCDF/PCDD) were 3.8-12.6 (the average, 7.7) in the others which were installed with water scrubbers. The results above indicated that the mechanism of PCDD/Fs formation was related to the types of exhaust gas treatment device. The results of this study can provide technical support for the formulation of PCDD/Fs emission standards and the best available techniques in the secondary aluminum metallurgy industry.

[Atmospheric emission of PCDD/Fs from modern dry processing cement kilns with preheating in the southwest area, China].

Six cement kilns were measured for emissions of PCDD/Fs in the Southwest Area, China. The results indicated that the emission levels of PCDD/Fs were 0.0029-0.0062 ng-m(-3) (Average, 0.0043 ng X m(-3)) from cement kilns which did not burn solid waste, and 0.028 ng X m(-3) from co-processing sewage sludge in cement kiln. The levels of PCDD/Fs emissions from cement manufacturing in the Southwest Area were significantly below the national emissions standard (0.1 ng x m(-3)). Emission factors of PCDD/Fs from the six cement kilns varied between 0.0089 and 0.084 microg x t(-1) cement, which were near or below the lowest emission factor reported by UNEP in 2005. Moreover, the emission factor of PCDD/Fs from co-processing sewage sludge in cement kiln was 7.6 times of the average factors from the other five cement kilns. Moreover,congener distribution of PCDD/F in stack gas from the two types of cement kilns was very different. The results showed that modern dry process cement kilns with preheating have lower emissions of PCDD/Fs. This suggested that the product of co-processing solid waste in cement kilns should be largely enhanced in China in future.

Induction of connective tissue growth factor expression by sphingosylphosphorylcholine in cultured human skin fibroblasts.

Sphingosylphosphorylcholine (SPC) is a bioactive sphingolipid metabolite that can enhance wound healing. In an effort to find downstream effectors of SPC, we performed microarray analysis and found that the expression of the gene for connective tissue growth factor (CTGF) was significantly affected in human skin fibroblasts cultured in vitro. Northern blot analysis showed that SPC markedly induced CTGF mRNA expression in a dose- and time-dependent manner. Consistent with this result, Western blot analysis also showed that SPC significantly induced the CTGF production. Pretreatment with cycloheximide did not prevent the CTGF induction by SPC, indicating that SPC stimulates CTGF mRNA expression without the increased synthesis of a regulatory protein. Inhibition by pretreatment with Y27632, but not by PD98059 (a mitogen-activated protein kinase 1/2 inhibitor) and LY294002 (a phosphatidylinositol 3-kinase inhibitor), indicated that rho-kinase pathway was involved in SPC-induced CTGF expression. Together, these results reveal the potential importance of CTGF induction as a downstream event in SPC-induced cellular responses.

Involvement of urokinase-type plasminogen activator in sphingosylphosphorylcholine-induced angiogenesis.

Sphingosylphosphorylcholine (SPC) has been shown to accelerate wound healing. As angiogenesis is fundamental to proper wound healing, we examined the effect of SPC on angiogenesis using a well-established rat aortic ring assay. SPC significantly stimulated the sprouting of endothelial cells from rat aortic ring. Recognizing its potential effect on angiogenesis, we further investigated the action of SPC using human umbilical vein endothelial cells (HUVECs) cultured in vitro. SPC significantly accelerated the closure of in vitro wound. In addition, SPC markedly enhanced the chemotactic migration and capillary-like tube formation. Subsequently, we examined whether SPC affected the production of urokinase-type plasminogen activator (uPA), an important regulator of angiogenesis, and found that SPC stimulated the expression of uPA at both the transcriptional and translational levels. Consistent with these results, SPC increased the activity of cell-surface-associated plasminogen activator. Pretreatment with antiuPA antibody significantly diminished both the chemotactic migration and capillary-like tube formation, indicating the potential importance of uPA in SPC-induced angiogenesis. Together, these results suggest that SPC may affect angiogenesis in the wound-healing process via regulation of uPA production.