Determination of Biologically Relevant Vitamin D Metabolites in a Mouse Model of Non-Melanoma Skin Cancer

Bibliographic Details
Main Author:	Teegarden, Matthew D.
Language:	English
Published:	The Ohio State University / OhioLINK 2014
Subjects:	Food Science
Online Access:	http://rave.ohiolink.edu/etdc/view?acc_num=osu1408121763

id	ndltd-OhioLink-oai-etd.ohiolink.edu-osu1408121763
record_format	oai_dc
spelling	ndltd-OhioLink-oai-etd.ohiolink.edu-osu14081217632021-08-03T06:26:57Z Determination of Biologically Relevant Vitamin D Metabolites in a Mouse Model of Non-Melanoma Skin Cancer Teegarden, Matthew D. Food Science Vitamin D is most notably associated with bone health, but a growing body of evidence suggests that it may also have a role in certain chronic diseases. An individual can produce sufficient levels of vitamin D via unprotected sun exposure, but this exposure is also a risk factor for non-melanoma skin cancer (NMSC). Despite this relationship, cell and animal studies suggest that vitamin D may have an important inhibitory role in the development of NMSC. The effects of consuming dietary vitamin D on this disease have not been investigated. Efforts to measure vitamin D status, 25-hydroxyvitamin D3 concentration, in biological microsamples by HPLC-MS/MS have been hampered by sensitivity thresholds and an interfering metabolite, C-3epi-25-hydroxyvitamn D3. Researchers commonly utilize chemical derivatization with 4-phenyl-3H-1,2,4-triazole-3,5(4H)-dione (PTAD) for signal enhancement, but the presence of C-3epi-25-hydroxyvitamn D3 remains a problem. The objectives of this research were to develop methodology for the analysis of PTAD-derivatized 25-hydroxyvitamin D3 and C-3epi-25-hydroxyvitamn D3 in skin and serum, and to apply this methodology to a study of dietary vitamin D in a mouse model of NMSC. Chromatographic separation of PTAD-derivatized 25-hydroxyvitamin D3 and C-3epi-25-hydroxyvitamn D3 was assessed using C18 columns of varying length and particle size. Multiple skin and serum extraction methods were evaluated, and those determined to be best fit for the purpose of this analysis were selected for use in subsequent sample processing. For skin, a 5:1 hexane/dichloromethane extraction was utilized, and a simple solid phase extraction method was selected for serum processing. Optimized chromatographic resolution was achieved with a Luna C18 (Phenomenex) 250 mm column (3 µm packing). Metabolite detection was optimized on a Qtrap 5500 mass spectrometer. This methodology will allow for more accurate assessment of vitamin D status in samples which require PTAD-derivatization for sensitive analysis. Using this optimized method, 25-hydroxyvitamin D3 and C-3epi-25-hydroxyvitamn D3 levels were evaluated in the skin and serum of Skh-1 hairless mice. Equal numbers of female (ntotal =75) and male (ntotal =75) mice were placed on diets with escalating doses of vitamin D3 (25, 150, 1000 IU) for 29 weeks. Within each dietary level, n=15 mice were exposed to UVB light, one minimal erythemal dose, three times weekly for the last 25 weeks of the study. Skin and serum of three mice from each gender/diet/UV group were assayed for 25-hydroxyvitamin D3 and C-3epi-25-hydroxyvitamn D3 (ntotal=36). The skin and serum levels of these metabolites rose in a dose-dependent manner. UV-exposed mice had lower serum levels of both metabolites. Male mice had greater levels of C-3epi-25-hydroxyvitamn D3 at the highest dose of vitamin D3. A strong correlation between skin and serum C-3epi-25-hydroxyvitamn D3 levels was observed, suggesting skin may be a source of circulating C-3epi-25-hydroxyvitamn D3. Furthermore, a role of C-3epi-25-hydroxyvitamn D3 in NMSC was postulated when levels of this metabolite were put into context with the cancer outcomes of this study. It is clear that dietary administration of vitamin D3 affects the development of NMSC, and this study will inform future work on the mechanisms by which these effects are modulated. 2014 English text The Ohio State University / OhioLINK http://rave.ohiolink.edu/etdc/view?acc_num=osu1408121763 http://rave.ohiolink.edu/etdc/view?acc_num=osu1408121763 unrestricted This thesis or dissertation is protected by copyright: all rights reserved. It may not be copied or redistributed beyond the terms of applicable copyright laws.
collection	NDLTD
language	English
sources	NDLTD
topic	Food Science
spellingShingle	Food Science Teegarden, Matthew D. Determination of Biologically Relevant Vitamin D Metabolites in a Mouse Model of Non-Melanoma Skin Cancer
author	Teegarden, Matthew D.
author_facet	Teegarden, Matthew D.
author_sort	Teegarden, Matthew D.
title	Determination of Biologically Relevant Vitamin D Metabolites in a Mouse Model of Non-Melanoma Skin Cancer
title_short	Determination of Biologically Relevant Vitamin D Metabolites in a Mouse Model of Non-Melanoma Skin Cancer
title_full	Determination of Biologically Relevant Vitamin D Metabolites in a Mouse Model of Non-Melanoma Skin Cancer
title_fullStr	Determination of Biologically Relevant Vitamin D Metabolites in a Mouse Model of Non-Melanoma Skin Cancer
title_full_unstemmed	Determination of Biologically Relevant Vitamin D Metabolites in a Mouse Model of Non-Melanoma Skin Cancer
title_sort	determination of biologically relevant vitamin d metabolites in a mouse model of non-melanoma skin cancer
publisher	The Ohio State University / OhioLINK
publishDate	2014
url	http://rave.ohiolink.edu/etdc/view?acc_num=osu1408121763
work_keys_str_mv	AT teegardenmatthewd determinationofbiologicallyrelevantvitamindmetabolitesinamousemodelofnonmelanomaskincancer
_version_	1719436966128254976

Determination of Biologically Relevant Vitamin D Metabolites in a Mouse Model of Non-Melanoma Skin Cancer

Similar Items