Abstract 3487: Alcohol programs the pituitary to produce aggressive prolactin-producing tumors

Abstract

Abstract Chronic alcohol consumption is known to increase prolactin levels in blood and cell proliferation in pituitary prolactin-producing cells known as lactotropes, resulting in hyperprolactinemia in human and animals. We have recently shown that alcohol abuse during pregnancy result in fetal programming that alters lactotropic cell production of prolactin in the offspring during the adulthood. We determined whether fetal alcohol exposure increases the susceptibility to estrogen-induced pituitary prolactin-secreting tumors (prolactinomas). Pregnant Fischer 344 rats were fed between gestational days 7 and 21 with a liquid diet containing alcohol (AF), pair-fed with isocaloric liquid diet (PF), or fed ad libitum with rat chow (AD). At 90 days of age, female offspring rats were ovariectomized and received a subcutaneous estradiol implant. These rats were sacrificed at 3 moths after the estradiol implants. At the time of sacrifice, pituitaries of these animals were inspected for tumor and whole body were inspected for any tumor metastasis. Estradiol treatment increased pituitary weight about 5-folds in AD and PF treated groups and increased about 30-folds in the AF treated group. Most tumors in the AF group were hemorrhagic. About 30% AF rats had some tumors in the non-pituitary sites. AD and PF rats did not show any non-pituitary site tumor. Histopathological evaluation revealed that tumors in AF group were more densely packed cells as compare to the PF and AD groups who showed uniform cells with abundant cytoplasm. Pituitary tumor from AF animals showed strong nuclear p53, Ki67 and prolactin immunoreactivity. When AF rat pituitaries were grown in cultures, cells rapidly grew and formed colonies. Colony formation and rapid growth rate were not observed in cells of the pituitary from PF and AD rats. When pituitary tumor cells of AF-treated pituitary, but not AD- or PF-treated pituitaries were grown in ultra-low attachment plate, spheres developed. These spheres expressed genes and proteins related to multipotency (OCT4, NANOG, KLF4, SOX2, Nestin, CD34 and CD133). Differentiated cells from pituitary tumorspheres of AF animals successfully induce tumor in scid mice after three weeks from cells transplantation. In addition, pituitary tumor from AF animals showed strong immunoreactivity for N-cadherin and Snail, two epithelial-mesenchymal transitions (EMT) factors. Furthermore, RNA-seq of genes in tumor pituitaries of AF and AD rats revealed 8782 genes are significantly changed in AF compared to AD P<0.01. Many of these genes were involved in the cell migration, actin cytoskeletal regulation and cell-cell junction formations which are the most important phenotypes occur during EMT. These data provide evidence for the possible development of aggressive prolactinoma development in the pituitary after estrogen treatment in fetal alcohol exposed female rats. (This work is supported by a National Institute of Health grant R01 AA11591). Citation Format: Shaima Jabbar, Jinhee Park, William Belden, Dipak K. Sarkar. Alcohol programs the pituitary to produce aggressive prolactin-producing tumors. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr 3487.