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Akt signaling and inhibition of thrombospondin 1 is necessary for keratinocyte migration
P1004
P1006
Erbb2 activation of PI3K/Akt signaling and inhibition of thrombospondin 1 is necessary for keratinocyte migration Justin Madson, MD, PhD, The University of Oklahoma Health Sciences Center, Oklahoma City, OK, United States; Kelsey Tinkum, Creighton University, Omaha, NE, United States; Laura Hansen, PhD, Creighton University, Omaha, NE, United States
Quantification of light depolarization as a potential tool for differentiation of benign and malignant skin lesions Gurbir Dhadwal, MD, Photomedicine Institute, Department of Dermatology and Skin Science, Vancouver Coastal Health Research Institute and University of British Columbia, Vancouver, Canada; David I. McLean, MD, Photomedicine Institute, Department of Dermatology and Skin Science, Vancouver Coastal Health Research Institute and University of British Columbia, Vancouver, Canada; Harvey Lui, MD, Photomedicine Institute, Department of Dermatology and Skin Science, VCHRI/UBC and Cancer Imaging Department, BC Cancer Research Centre, Vancouver, Canada; Lioudmila Tchvialeva, PhD, Photomedicine Institute, Department of Dermatology and Skin Science, Vancouver Coastal Health Research Institute and University of British Columbia, Vancouver, Canada; Tim Lee, PhD, Photomedicine Institute, Department of Dermatology and Skin Science, VCHRI/UBC, Department of Cancer Control Research, BCCRC, Computing Science, SFU, Vancouver, Canada
Skin cancer is an important human health concern, with more than 1 million cases of nonmelanoma skin cancer in the United States each year. In previous studies where we have shown that Erbb2 increases skin carcinogenesis in mice, additional analysis of the data has revealed genes important in cell migration. Because these processes are important in cancer progression and may be regulated by Erbb2, we hypothesized that Erbb2 is required for normal migration and adhesion of keratinocytes. This hypothesis was tested by abrogating Erbb2 activity using the pharmacologic Erbb2 inhibitor AG825 or Erbb2-targeted siRNA on keratinocytes in culture. Keratinocyte migration was decreased by 98% and 85% upon pharmacologic inhibition or siRNA knockdown of Erbb2, respectively, as measured by scratch assay and confirmed with Boyden chamber assay. Because Erbb2 is known to activate p38, MEK1, and PI3K/Akt pathways, keratinocyte migration was investigated after pharmacologic inhibition of each pathway with SB202190, PD98059, and LY294002, respectively. Only LY294002 significantly inhibited keratinocyte migration, and this was confirmed using another pharmacologic AKT inhibitor. Akt activity, as measured by its phosphorylated form via Western blot, decreased by 66% and 45% after pharmacologic or siRNA inhibition of Erbb2, respectively. Potential genes involved in adhesion and migration elucidated by previous research revealed that Thrombospondin1 (Thbs1) may be a downstream target of Erbb2. As shown in previous microarray results and confirmed by real-time polymerase chain reacion studies, inhibition of Erbb2 upregulates the expression of Thbs1, an inhibitor of cell migration. Inhibition of both Erbb2 and Thbs1 results in normal keratinocyte migration. These data show that Erbb2 is necessary for keratinocyte migration through PI3K/Akt signaling. Furthermore, inhibition of Thbs1 by Erbb2 is essential for normal keratinocyte migration. Commercial support: None identified.
Background: The fact that skin depolarizes light is commonly exploited in dermatology by polarization dermoscopy to filter out light from the surface which maintains its initial polarization. A simple estimate of the amount of light maintaining its original linear polarization state can be quantified by capturing two images of the skin with polarization filters oriented perpendicular to each other and expressed as the degree of linear polarization. Objective: To determine if there are significant differences in the degree of linear polarization between different skin lesions. Methods: A device was built which can illuminate an area of skin with polarized red or blue laser light and then capture two images polarized perpendicular to each other. A convenience sample of patients attending a general dermatology clinic was obtained over 1 year. Data for melanoma (15), basal cell cancer (13), squamaous cell cancer (8), seborrheic keratosis (66), acquired nevus (15), and atypical nevus (25) was analyzed to calculate the degree of linear polarization. All malignant lesions were biopsy proven. Means were compared using ANOVA and subgroup analysis was conducted with Tukey HSD test at a ¼ 0.05. Results: We found a significant difference in the mean degree of linear polarization between benign and malignant lesions using red laser light (0.55 6 0.01 [SEM] vs 0.61 6 0.02; P ¼.024). Furthermore, we also found a significant difference between the mean degree of linear polarization of benign and malignant lesions using blue laser light (0.55 6 0.02 vs 0.63 6 0.03; P ¼ .049). On subgroup analysis, we found that there was a significant difference between seborrheic keratosis and melanoma using blue laser light (0.51 6 0.02 vs 0.68 6 0.04) and between seborrheic keratosis and atypical nevi using red laser light (0.52 6 0.01 vs 0.60 6 0.03) and blue laser light (0.51 6 0.02 vs 0.63 6 0.03). Conclusions: The degree of linear polarization is a simple method to quantify the degree to which a lesion depolarizes light. We were able to find significant differences between benign and malignant skin lesions and on subgroup analysis find a significant difference between seborrheic keratosis and melanoma or atypical nevi. There is a potential that the degree of linear polarization could be used to aid in the noninvasive differentiation of skin lesions. Commercial support: None identified.
P1005 Correlation of skin barrier function and sebaceous lipids on the face of women from three populations in the United States Apostolos Pappas, Johnson and Johnson Consumer Companies, Skillman, NJ, United States; Jared Fantasia, Johnson and Johnson Consumer Companies, Skillman, NJ, United States; Theresa Chen, Johnson and Johnson Consumer Companies, Skillman, NJ, United States It has been reported that skin barrier functions such as transepidermal water loss (TEWL) and hydration are different among whites, Asians, and African Americans. The factors that account for these differences are unclear. Because sebum is an important part of skin barrier functions, we compared the lipid components of sebum from three ethnic backgrounds: white, African American, and East Asian individuals. Females 18 to 25 and 35 to 45 years old with no visible acne were evaluated for skin surface hydration and barrier function. Skin surface lipids were analyzed following sebum collection using sebutapes. Significant differences (P \.05) were documented in skin hydration between African American and white panelists in both age groups, with East Asian in the middle. African American and white panelists also significantly differ (P \.05) in TEWL, with the trend being the reverse of the hydration trend (ie, white [ East Asian [ African American). These data indicate a superior barrier function for African Americans. African American females produced more facial lipids than the other two ethnic group females, with African American [ East Asian [ white. When analyzing the three lipid classes (free fatty acids, triglycerides, and wax esters), the trend became significant (P \.05) in the wax ester fraction when comparing African Americans to whites directly. In addition, seven lipids were identified in the wax ester fraction that were significantly different in quantity (P \.05) between African Americans and whites. These data suggest that the differential lipid composition in ethnic groups may contribute to the observed differences in barrier functions. Commercial support: Sponsored in full by Johnson and Johnson Consumer Companies.
AB28
J AM ACAD DERMATOL
P1007 NT201 and botulinum toxin have equivalent potency Dirk Dressler, MD, PhD, Hannover Medical School, Hannover, Germany; Gerd J Mander, PhD, Merz Pharmaceuticals GmbH, Frankfurt, Germany; Klaus Fink, PhD, Merz Pharmaceuticals, Frankfurt, Germany Background: The biologic potency of botulinum toxin (BoNT) drugs is determined in a mouse LD50 bioassay as described in the European Pharmacopeia, where the mouse unit is defined as one LD50 unit. However, clinical experience suggests that the potency labelling of BoNT drugs may vary. We wanted to compare the potency of a BoNT/A drug containing complex proteins (Allergan; Irvine, CA) and a BoNT/A drug free from complex proteins (NT201; Merz, Germany). Methods: The biologic potencies of five commercially available unexpired batches of NT201 and botulinum toxin were analyzed using the LD50 bioassay for NT201 batch release in a blinded fashion. Relative potencies were subjected to a quantal response parallel line probit analysis. Potency quantification was performed using the NT201 reference standard qualified against the NIBSC standard. Mean values of repeat measurements were compared by a 2-tailed t test for independent data. Results: The biologic potencies of both NT201 and botulinum toxin batches were found within the range specified in the European Pharmacopeia. The potencies of the NT201 (103.1 6 6.5; n ¼ 5) and botulinum toxin batches (101.7 6 6.2; n ¼ 5) were not statistically different (P ¼ .734). Conclusion: The potency labeling of NT201 and botulinum toxin is identical, confirming previously published clinical experience. Clinical dosage schemes of botulinum toxin and NT201 can be exchanged using a 1:1 conversion ratio, thereby allowing easy exchange between both products. Commercial support: The complete study and all printing costs are paid by Merz Pharmaceuticals.
FEBRUARY 2011
P1006
Erbb2 activation of PI3K/Akt signaling and inhibition of thrombospondin 1 is necessary for keratinocyte migration Justin Madson, MD, PhD, The University of Oklahoma Health Sciences Center, Oklahoma City, OK, United States; Kelsey Tinkum, Creighton University, Omaha, NE, United States; Laura Hansen, PhD, Creighton University, Omaha, NE, United States
Quantification of light depolarization as a potential tool for differentiation of benign and malignant skin lesions Gurbir Dhadwal, MD, Photomedicine Institute, Department of Dermatology and Skin Science, Vancouver Coastal Health Research Institute and University of British Columbia, Vancouver, Canada; David I. McLean, MD, Photomedicine Institute, Department of Dermatology and Skin Science, Vancouver Coastal Health Research Institute and University of British Columbia, Vancouver, Canada; Harvey Lui, MD, Photomedicine Institute, Department of Dermatology and Skin Science, VCHRI/UBC and Cancer Imaging Department, BC Cancer Research Centre, Vancouver, Canada; Lioudmila Tchvialeva, PhD, Photomedicine Institute, Department of Dermatology and Skin Science, Vancouver Coastal Health Research Institute and University of British Columbia, Vancouver, Canada; Tim Lee, PhD, Photomedicine Institute, Department of Dermatology and Skin Science, VCHRI/UBC, Department of Cancer Control Research, BCCRC, Computing Science, SFU, Vancouver, Canada
Skin cancer is an important human health concern, with more than 1 million cases of nonmelanoma skin cancer in the United States each year. In previous studies where we have shown that Erbb2 increases skin carcinogenesis in mice, additional analysis of the data has revealed genes important in cell migration. Because these processes are important in cancer progression and may be regulated by Erbb2, we hypothesized that Erbb2 is required for normal migration and adhesion of keratinocytes. This hypothesis was tested by abrogating Erbb2 activity using the pharmacologic Erbb2 inhibitor AG825 or Erbb2-targeted siRNA on keratinocytes in culture. Keratinocyte migration was decreased by 98% and 85% upon pharmacologic inhibition or siRNA knockdown of Erbb2, respectively, as measured by scratch assay and confirmed with Boyden chamber assay. Because Erbb2 is known to activate p38, MEK1, and PI3K/Akt pathways, keratinocyte migration was investigated after pharmacologic inhibition of each pathway with SB202190, PD98059, and LY294002, respectively. Only LY294002 significantly inhibited keratinocyte migration, and this was confirmed using another pharmacologic AKT inhibitor. Akt activity, as measured by its phosphorylated form via Western blot, decreased by 66% and 45% after pharmacologic or siRNA inhibition of Erbb2, respectively. Potential genes involved in adhesion and migration elucidated by previous research revealed that Thrombospondin1 (Thbs1) may be a downstream target of Erbb2. As shown in previous microarray results and confirmed by real-time polymerase chain reacion studies, inhibition of Erbb2 upregulates the expression of Thbs1, an inhibitor of cell migration. Inhibition of both Erbb2 and Thbs1 results in normal keratinocyte migration. These data show that Erbb2 is necessary for keratinocyte migration through PI3K/Akt signaling. Furthermore, inhibition of Thbs1 by Erbb2 is essential for normal keratinocyte migration. Commercial support: None identified.
Background: The fact that skin depolarizes light is commonly exploited in dermatology by polarization dermoscopy to filter out light from the surface which maintains its initial polarization. A simple estimate of the amount of light maintaining its original linear polarization state can be quantified by capturing two images of the skin with polarization filters oriented perpendicular to each other and expressed as the degree of linear polarization. Objective: To determine if there are significant differences in the degree of linear polarization between different skin lesions. Methods: A device was built which can illuminate an area of skin with polarized red or blue laser light and then capture two images polarized perpendicular to each other. A convenience sample of patients attending a general dermatology clinic was obtained over 1 year. Data for melanoma (15), basal cell cancer (13), squamaous cell cancer (8), seborrheic keratosis (66), acquired nevus (15), and atypical nevus (25) was analyzed to calculate the degree of linear polarization. All malignant lesions were biopsy proven. Means were compared using ANOVA and subgroup analysis was conducted with Tukey HSD test at a ¼ 0.05. Results: We found a significant difference in the mean degree of linear polarization between benign and malignant lesions using red laser light (0.55 6 0.01 [SEM] vs 0.61 6 0.02; P ¼.024). Furthermore, we also found a significant difference between the mean degree of linear polarization of benign and malignant lesions using blue laser light (0.55 6 0.02 vs 0.63 6 0.03; P ¼ .049). On subgroup analysis, we found that there was a significant difference between seborrheic keratosis and melanoma using blue laser light (0.51 6 0.02 vs 0.68 6 0.04) and between seborrheic keratosis and atypical nevi using red laser light (0.52 6 0.01 vs 0.60 6 0.03) and blue laser light (0.51 6 0.02 vs 0.63 6 0.03). Conclusions: The degree of linear polarization is a simple method to quantify the degree to which a lesion depolarizes light. We were able to find significant differences between benign and malignant skin lesions and on subgroup analysis find a significant difference between seborrheic keratosis and melanoma or atypical nevi. There is a potential that the degree of linear polarization could be used to aid in the noninvasive differentiation of skin lesions. Commercial support: None identified.
P1005 Correlation of skin barrier function and sebaceous lipids on the face of women from three populations in the United States Apostolos Pappas, Johnson and Johnson Consumer Companies, Skillman, NJ, United States; Jared Fantasia, Johnson and Johnson Consumer Companies, Skillman, NJ, United States; Theresa Chen, Johnson and Johnson Consumer Companies, Skillman, NJ, United States It has been reported that skin barrier functions such as transepidermal water loss (TEWL) and hydration are different among whites, Asians, and African Americans. The factors that account for these differences are unclear. Because sebum is an important part of skin barrier functions, we compared the lipid components of sebum from three ethnic backgrounds: white, African American, and East Asian individuals. Females 18 to 25 and 35 to 45 years old with no visible acne were evaluated for skin surface hydration and barrier function. Skin surface lipids were analyzed following sebum collection using sebutapes. Significant differences (P \.05) were documented in skin hydration between African American and white panelists in both age groups, with East Asian in the middle. African American and white panelists also significantly differ (P \.05) in TEWL, with the trend being the reverse of the hydration trend (ie, white [ East Asian [ African American). These data indicate a superior barrier function for African Americans. African American females produced more facial lipids than the other two ethnic group females, with African American [ East Asian [ white. When analyzing the three lipid classes (free fatty acids, triglycerides, and wax esters), the trend became significant (P \.05) in the wax ester fraction when comparing African Americans to whites directly. In addition, seven lipids were identified in the wax ester fraction that were significantly different in quantity (P \.05) between African Americans and whites. These data suggest that the differential lipid composition in ethnic groups may contribute to the observed differences in barrier functions. Commercial support: Sponsored in full by Johnson and Johnson Consumer Companies.
AB28
J AM ACAD DERMATOL
P1007 NT201 and botulinum toxin have equivalent potency Dirk Dressler, MD, PhD, Hannover Medical School, Hannover, Germany; Gerd J Mander, PhD, Merz Pharmaceuticals GmbH, Frankfurt, Germany; Klaus Fink, PhD, Merz Pharmaceuticals, Frankfurt, Germany Background: The biologic potency of botulinum toxin (BoNT) drugs is determined in a mouse LD50 bioassay as described in the European Pharmacopeia, where the mouse unit is defined as one LD50 unit. However, clinical experience suggests that the potency labelling of BoNT drugs may vary. We wanted to compare the potency of a BoNT/A drug containing complex proteins (Allergan; Irvine, CA) and a BoNT/A drug free from complex proteins (NT201; Merz, Germany). Methods: The biologic potencies of five commercially available unexpired batches of NT201 and botulinum toxin were analyzed using the LD50 bioassay for NT201 batch release in a blinded fashion. Relative potencies were subjected to a quantal response parallel line probit analysis. Potency quantification was performed using the NT201 reference standard qualified against the NIBSC standard. Mean values of repeat measurements were compared by a 2-tailed t test for independent data. Results: The biologic potencies of both NT201 and botulinum toxin batches were found within the range specified in the European Pharmacopeia. The potencies of the NT201 (103.1 6 6.5; n ¼ 5) and botulinum toxin batches (101.7 6 6.2; n ¼ 5) were not statistically different (P ¼ .734). Conclusion: The potency labeling of NT201 and botulinum toxin is identical, confirming previously published clinical experience. Clinical dosage schemes of botulinum toxin and NT201 can be exchanged using a 1:1 conversion ratio, thereby allowing easy exchange between both products. Commercial support: The complete study and all printing costs are paid by Merz Pharmaceuticals.
FEBRUARY 2011