In the early stages of ovarian carcinogenesis, it is now thought that the fimbria acquires molecular and genetic alterations when exposed to inflammatory mediators and associated oxidative stress (reactive oxygen species-ROS) released during ovulatory events from the adjacent ovary. These changes lead to the ?p53 signature?- accumulation of mutant p53 protein (earliest genetic alteration in ovarian cancer), in the secretory cells of the fimbria ultimately leading to the development of serous tubal intraepithelial carcinoma (STIC), which spreads via shedding/exfoliation directly to the adjacent ovary and into the abdominal cavity. The p53 signatures and STIC lesions which evolve in an inflammatory, oxidative and DNA-toxic microenvironment are characterized by distinct features including loss of polarity, epithelial tufting, pleomorphic nuclei, abnormal p53 expression and a high-proliferative index. The discovery of these lesions and how they develop opens the door to the formulation of pharmacologic strategies that arrest and/or reverse the early transformative events in the fimbria, with immense potential to decrease ovarian cancer incidence and mortality through prevention. Previously, our work has focused primarily on the ovarian surface epithelium as the biologic target for ovarian cancer prevention using progestins and vitamin D. However, little is known regarding their biologic effects in the FTE. The objective of this study is to explore the impact of progestin and vitamin D on inflammation and oxidative stress in early carcinogenesis of ovarian cancer in in vitro and in vivo models of the disease. We hypothesize that inhibition of inflammatory and oxidative effects may comprise a biologic mechanism contributing to the cancer preventive effects of these agents. Furthermore, we will examine whether the combination of progestin and vitamin D is more effective than either agent alone. To test this hypothesis, we will utilize the following samples from the parent grant to evaluate inflammatory and oxidative stress pathways following administration of progestin and vitamin D: (1) cell cultures of primary FTE as well as transformed FTE harboring dominant negative mutant p53 obtained and established from pre- and postmenopausal women undergoing gynecologic surgery for benign indications, (2) paraffin sections of the fallopian tube and corresponding isolates (RNA, DNA, protein and plasma/serum) obtained from the mice (mogp-TAg and Dicer-PTEN) undergoing prevention trials with progestins and vitamin D.
In the early stages of ovarian carcinogenesis, it is now thought that the fimbria acquires molecular and genetic alterations when exposed to inflammatory mediators and associated oxidative stress (reactive oxygen species-ROS) released during ovulatory events from the adjacent ovary. These changes lead to the ?p53 signature?- accumulation of mutant p53 protein (earliest genetic alteration in ovarian cancer), in the secretory cells of the fimbria ultimately leading to the development of serous tubal intraepithelial carcinoma (STIC), which spreads via shedding/exfoliation directly to the adjacent ovary and into the abdominal cavity. The p53 signatures and STIC lesions which evolve in an inflammatory, oxidative and DNA-toxic microenvironment are characterized by distinct features including loss of polarity, epithelial tufting, pleomorphic nuclei, abnormal p53 expression and a high-proliferative index. The discovery of these lesions and how they develop opens the door to the formulation of pharmacologic strategies that arrest and/or reverse the early transformative events in the fimbria, with immense potential to decrease ovarian cancer incidence and mortality through prevention. Previously, our work has focused primarily on the ovarian surface epithelium as the biologic target for ovarian cancer prevention using progestins and vitamin D. However, little is known regarding their biologic effects in the FTE. The objective of this study is to explore the impact of progestin and vitamin D on inflammation and oxidative stress in early carcinogenesis of ovarian cancer in in vitro and in vivo models of the disease. We hypothesize that inhibition of inflammatory and oxidative effects may comprise a biologic mechanism contributing to the cancer preventive effects of these agents. Furthermore, we will examine whether the combination of progestin and vitamin D is more effective than either agent alone. To test this hypothesis, we will utilize the following samples from the parent grant to evaluate inflammatory and oxidative stress pathways following administration of progestin and vitamin D: (1) cell cultures of primary FTE as well as transformed FTE harboring dominant negative mutant p53 obtained and established from pre- and postmenopausal women undergoing gynecologic surgery for benign indications, (2) paraffin sections of the fallopian tube and corresponding isolates (RNA, DNA, protein and plasma/serum) obtained from the mice (mogp-TAg and Dicer-PTEN) undergoing prevention trials with progestins and vitamin D. Aim 1. Characterize the effects of progestin and vitamin D (calcitriol) on inflammation and oxidative stress pathways in an in vitro FTE model of ovarian cancer. Using primary FTE cells and FTE cells harboring molecular alterations typical of early transformative changes (signatures) in the fallopian tube, we will use immunofluorescence (IF) staining, western blot and ELISA assays to test whether progestins and vitamin D alter expression of mediators of inflammation and oxidative stress. We will test a variety of progestins alone and in combination with vitamin D to assess whether the effects are influenced by the type of progestin. Aim 2. Test whether the progestin-Depot medroxyprogesterone acetate (DMPA) and the vitamin D calcitriol analogue EB1089 inhibits inflammation and oxidative stress in the mogp-TAg and Dicer-PTEN mouse models of ovarian cancer. Female mice from Aim 3 of the parent grant will be used for cellular and molecular analyses. Detailed analysis of the tubes from these mice will help us to determine the extent to which vitamin D and progestin treatment inhibit inflammation and oxidative stress. Immunofluorescence (IF), immunohistochemistry (IHC), qPCR, western blotting and ELISA techniques will be used to examine the inhibitory effects of DMPA and EB1089 on inflammatory and oxidative stress markers.
