Mechanisms Causing Cryptorchidism and Fetal Transformation of Testicular Cells

描述（由申请人提供）：在美国，至少4%的足月男孩是隐睾。这是睾丸发育不良综合征（TDS）的一个组成部分。TDS起源于胎儿发育期间，但经常在数年后首次被发现为睾丸癌、精子发生缺陷和排泄管囊肿/腺瘤。睾丸癌是年轻男性中最常见的潜在恶性肿瘤，出生时患有隐睾的人患睾丸癌的可能性要高3-11倍。我们的长期目标是描述睾丸隐睾和睾丸细胞转化为癌前细胞的分子机制。隐睾症可以遗传，但在人类中，没有个体基因改变与bb50 %的病例有关。越来越多的人认为内分泌干扰物（EDAs）经常导致隐睾症和睾丸癌。由于非实验性隐睾的低患病率，了解EDAs如何在表观遗传学上阻断睾丸下降基因的表达一直受到阻碍。这个项目克服了这个障碍。我们建议研究AK Kodiak岛Aliulik半岛上的锡特卡黑尾鹿（SBTD）种群，记录显示76%的隐睾（91%的双侧，BCO）。这一人群与其他地区未受影响的人群在基因上没有什么不同。我们推测：(1)SBTD患者隐睾的高发病率是由于胎儿在子宫内暴露于雌激素性EDA，这会改变睾丸编程和下降的关键基因的表达；(2) SBTD的TDS综合征将模仿人类的TDS综合征，使结果可用于人类。具体目标是：目标1。SBTD的基因及基因表达。研究BCO和非隐睾（NCO）成人睾丸和地方残余样本的基因表达和蛋白质积累。最初关注insi和LGR8/Great基因；然后是AR + ERa。比较BCO鹿和NCO鹿的基因失调序列，检测基因突变。微卫星DNA分析将描述每种动物的遗传背景。目标2。SBTD中的雌激素分子和潜在的EDA载体。直接的化学分析可以检测和量化罪魁祸首雌激素EDA，如果有的话，影响基因表达。MCF-7细胞检测应检测雌激素性EDA的作用，因此，可以表征暴露于EDA后InsIS、Great、AR和/或ER基因的表观遗传失调。结果将阐明基因与EDAs之间的相互作用是导致隐睾的原因。

DESCRIPTION (provided by applicant): In USA, at least 4% of full term boys are cryptorchid. This is one component of a testicular dysgenesis syndrome (TDS). TDS originates during fetal development, but frequently is first detected years later as testicular cancer, defective spermatogenesis, and cysts/adenomas of the excurrent ducts. Testicular cancer, the most common potentially malignant tumor in young men, is 3-11X more likely in those born cryptorchid. Our long-term goal is to delineate molecular mechanisms underlying cryptorchidism and transformation of testicular cells into precancerous cells. Cryptorchidism can be inherited, but in humans no individual gene alteration is associated with >5% of cases. There is increasing acceptance that endocrine disrupter agents (EDAs) frequently are causative for cryptorchidism and predispose for testicular cancer. Understanding how EDAs act epigenetically to block expressions of genes for testicular descent has been hampered by low prevalence of non-experimental cryptorchidism. This project overcomes that obstacle. We propose study of a population of Sitka Black-Tailed Deer (SBTD) on the Aliulik Peninsula of Kodiak Island, AK, documented to have 76% cryptorchidism (91% bilateral, BCO). This population is not genetically different from unaffected populations in other locales. We hypothesize that: (1) this extraordinarily high incidence of cryptorchidism in SBTD is due to in utero exposure of fetuses to an estrogenic EDA which alters expression of genes crucial in testicular programming and descent; and (2) TDS syndrome in SBTD will mimic that in humans, making results translatable to humans. Specific Aims are: Aim 1. Genes and Gene Expression in SBTD. Study gene expression and protein accumulation in samples of testes and gubernacular remnants from BCO and non- cryptorchid (NCO) adults. Initial focus on genes for InsIS and LGR8/Great; then AR plus ERa. Compare sequences of genes dysregulated in BCO deer with those in NCO deer to detect genetic mutations. Microsatellite DNA analyses will characterize each animal's genetic background. Aim 2. Estrogenic molecules in SBTD and potential EDA vectors. Direct chemical analysis might detect and quantify culprit estrogenic EDA, if any, affecting gene expression. Assay with MCF-7 cells should detect action of estrogenic EDA and, hence, allow characterization of epigenetic dysregulation of InsIS, Great, AR, and/or ER genes after exposure to EDA. Results will clarify the interaction of genetics and EDAs as cause of cryptorchidism.