Ontogeny of the proliferative shutoff in the prostate

本文提出的研究扩展和补充了父母补助金（NCI-RO1-55574）的目标。前列腺癌是美国和阿根廷男性中最常见的癌症。这种癌症最初通过细胞凋亡和细胞增殖减少对雄激素(A)的戒断作出反应。后来，癌细胞克服了这种抑制并复发。然而，除了A依赖性增殖和完全缺乏A反应外，还有一种前列腺癌表型，即雄激素抑制增殖（A诱导的关闭）。雄激素通过涉及AS3基因的途径介导人类前列腺癌细胞系的增殖关闭。AS3序列似乎是一个具有反式激活、蛋白质识别和DNA结合域的转录因子；它也有一个蛋白激酶基序。AS3内含子10中的D13S171微卫星重复序列缺失与前列腺癌的不良预后相关。本研究的目的是了解AS3抑制细胞增殖的分子机制。这项FIRCA提案的目的是进一步阐明AS3在大鼠发育和成年期前列腺细胞数量控制中的生理作用。具体目的1：探索AS3介导A-诱导的大鼠前列腺原位关闭的假设。具体目的2：研究出生后发育过程中增殖关闭的发生机制。将使用对数相PCR， PAGE，原位杂交，免疫组织化学和形态计量学等技术的组合。一旦AS3的生理作用被评估，关于AS3通路在癌变过程中是否以及如何被破坏的假设将被产生和探索。

The research proposed herein extends and complements the aims of the parent grant (NCI-RO1-55574). Prostate cancer is the most common cancer in American as well as in Argentinean men. This cancer initially responds to androgen (A)-withdrawal by undergoing apoptosis and decreased cell proliferation. Later on, cancer cells overcome this inhibition and relapse. However, in addition to A-dependent proliferation and total lack of A response, there is a prostate cancer phenotype whereby proliferation is inhibited by androgens (A-induced shutoff). Androgens mediate the proliferative shutoff in human prostate cancer cell lines by a, pathway involving the AS3 gene. The AS3 sequence seems to be a transcription factor with trans-activating, protein recognition, and DNA binding domains; it also has a protein kinase motif. Deletions involving the D13S171 microsatellite repeat in intron 10 of AS3 correlate with an unfavorable prognosis in prostate cancers. The research objective of the parent grant is to understand the molecular mechanisms underlying the inhibitory control of cell proliferation by AS3. The objective of this FIRCA proposal is to further elucidate the physiological role of AS3 in the control of cell number in the rat prostate during development and adulthood. Specific Aim #1: to explore the hypothesis that AS3 mediates the A- induced shutoff in the rat prostate in situ. Specific Aim #2: to investigate the ontogenesis of the proliferative shutoff during postnatal development. A combination of techniques such as log-phase PCR, PAGE, in situ hybridization, immunohistochemistry and morphometrics will be used. Once the physiological role of AS3 is assessed, hypotheses about whether and how the AS3 pathway is compromised during carcinogenesis will be generated and explored.