Date of Graduation
8-2013
Document Type
Thesis (MS)
Program Affiliation
Biomedical Sciences
Degree Name
Masters of Science (MS)
Advisor/Committee Chair
Dr. Anil Sood
Committee Member
Dr. Menashe Bar-ELi
Committee Member
Dr. Peiying Yang
Committee Member
Dr. Gary Gallick
Committee Member
Dr. Eric Wagner
Abstract
Background: Altered metabolism is a well-established trait in many cancers, and is an emerging hallmark of cancer. Recent resurgence of cancer metabolism studies has identified dysregulated metabolic pathways that produce novel oncometabolites in various cancers. However, large scale studies of dysregualted high grade serous epithelial ovarian cancers (HGSOC) are unknown.
Materials and Methods: Following IRB approval, metabolic profiling of 101 HGSOC patients and 15 normal ovaries were obtained using GC/LC mass spectrometry from 2 U.S. academic centers to identify highly up-regulated metabolites. Samples from a cohort of 135 and 208 patients from a single institution were evaluated for gene expression and protein expression of NAT8L, respectively. Gene expression of NAT8L and clinical outcomes were further investigated from publicly available databases from the cancer genomics atlas (TCGA) using www.cbioportal.org, and two previously published melanoma gene expression profiles. Reverse Phase Protein Array (RPPA) and gene expression array were evaluated in HeyA8 ovarian cancer cell lines to investigate the protein and gene expression changes associated with NAT8L siRNA. In vitro and in vivo v experiments of NAT8L siRNA were investigated to evaluate its effects on cancer proliferation, apoptosis, cell cycle, and invasion/migration.
Results: A total of 313 metabolites were identified between these two groups, of which 172 were significantly altered (p
HeyA8 and A2780 cell lines showed that NAT8L siRNA significantly increased total apoptosis compared to control (NT) siRNA by 38.53% (p
Genomic analysis of HEYA8 cells transfected with NAT8L siRNA compared to NT siRNA showed 1961 significantly different gene expression data (p
Conclusion: HGSOC metabolic profiling revealed highly altered metabolism compared to the normal ovary. NAA is one of the most up-regulated metabolites in HGSOC. High levels of NAA are associated with worse overall survival in HGSOC. Furthermore, high expression of its biosynthetic gene (NAT8L) is associated with vii worse overall survival in HGSOC, invasive breast, lung squamous, colon, uterine, melanoma and renal cell cancers. Inhibiting NAA production decreases tumor growth, and tilts the cancer cell to a more catabolic steady state. Therefore, our data indicate that targeting cancer’s NAA production maybe an effective therapeutic approach.