Skip to Main Content
 

Global Search Box

 
 
 
 

Files

File List


Teegarden_MS Thesis_2.pdf (1.32 MB)

ETD Abstract Container

Abstract Header

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

Teegarden, Matthew D
http://rave.ohiolink.edu/etdc/view?acc_num=osu1408121763

Abstract Details

2014, Master of Science, Ohio State University, Food Science and Technology.
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.
Steven Schwartz, Ph.D. (Advisor)
Yael Vodovotz, Ph.D. (Committee Member)
Steven Clinton, M.D., Ph.D. (Committee Member)
89 p.
Food Science

Recommended Citations

Citations

  • Teegarden, M. D. (2014). Determination of Biologically Relevant Vitamin D Metabolites in a Mouse Model of Non-Melanoma Skin Cancer [Master's thesis, Ohio State University]. OhioLINK Electronic Theses and Dissertations Center. http://rave.ohiolink.edu/etdc/view?acc_num=osu1408121763

    APA Style (7th edition)

  • Teegarden, Matthew. Determination of Biologically Relevant Vitamin D Metabolites in a Mouse Model of Non-Melanoma Skin Cancer. 2014. Ohio State University, Master's thesis. OhioLINK Electronic Theses and Dissertations Center, http://rave.ohiolink.edu/etdc/view?acc_num=osu1408121763.

    MLA Style (8th edition)

  • Teegarden, Matthew. "Determination of Biologically Relevant Vitamin D Metabolites in a Mouse Model of Non-Melanoma Skin Cancer." Master's thesis, Ohio State University, 2014. http://rave.ohiolink.edu/etdc/view?acc_num=osu1408121763

    Chicago Manual of Style (17th edition)

osu1408121763
12,347
© 2014, all rights reserved.
This open access ETD is published by The Ohio State University and OhioLINK.