Ontogeny of the proliferative shutoff in the prostate

本文建议的研究扩展和补充了父母赠款(NCI-RO1-55574)的目标。前列腺癌是美国和阿根廷男性最常见的癌症。这种癌症最初对雄激素(A)撤除的反应是通过细胞凋亡和细胞增殖减少。后来，癌细胞克服了这种抑制并复发。然而，除了依赖A的增殖和完全缺乏A反应外，还有一种前列腺癌表型，其增殖被雄激素抑制(A诱导的关闭)。雄激素通过涉及AS3基因的途径介导人前列腺癌细胞系的增殖停滞。AS3序列似乎是一个具有反式激活、蛋白质识别和DNA结合结构域的转录因子；它也有一个蛋白激酶基序。AS3内含子10的D13S171微卫星重复缺失与前列腺癌的不良预后相关。父母资助的研究目的是了解AS3抑制细胞增殖的分子机制。FIRCA建议的目的是进一步阐明AS3在大鼠前列腺发育和成年期细胞数量控制中的生理作用。具体目的#1：探讨AS3介导A诱导的大鼠前列腺原位关闭的假说。特定目的#2：研究出生后发育过程中增殖性关闭的个体发生。将综合运用对数相聚合酶链式反应、PAGE、原位杂交、免疫组织化学和形态计量学等技术。一旦评估了AS3的生理作用，就会产生和探索AS3通路在致癌过程中是否以及如何受到损害的假说。

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.