攝護腺癌為國人男性十大癌症死因之第五位。究其致病機制，異常活化或過量表現的雄性素受器 (androgen receptor; AR) 為攝護腺細胞癌化的重要原因。我們過去的研究發現，S6K1 (p70 ribosomal S6 kinase 1)為一protein serine/threonine kinase，在攝護腺癌細胞中有過量的表現，並且AR 的蛋白質穩定性會受到S6K1的調控，但兩者之間的調控機制並未釐清。本實驗主要探討S6K1是否會調控CIP2A (Cancerous Inhibitor of Protein Phosphatase 2A) 及AR的表現量，進而影響細胞生長能力之調控關係。在比對正常攝護腺細胞PZ-HPV-7與攝護腺癌細胞22Rv1及LNCaP；此三株細胞內，S6K1、CIP2A與AR之蛋白表現量和磷酸化程度均呈現正相關性。為了更進一步確認S6K1與CIP2A及AR表現量，並攝護腺細胞生長的能力之間的關係，在LNCaP細胞中大量表現S6K1野生型(wild-type; WT)能使CIP2A的蛋白表現量上升，並使AR的蛋白表現與磷酸化程度升高；相反的，在LNCaP細胞中大量表現S6K1顯性抑制突變組 (dominant-negative mutant; K100R)，以及在22Rv1與LNCaP細胞內以shRNA基因刪減 (knockdown) S6K1表現時，可發現CIP2A蛋白表現量下降，而AR的表現量與磷酸化程度也降低，且細胞生長能力受到抑制。當使用S6K1抑制劑PF-4708671對LNCaP細胞處理後，在濃度10 μM時，S6K1的活性與磷酸化程度受到抑制，且CIP2A和AR的表現量以及AR磷酸化程度皆下降。此外，在LNCaP與22Rv1細胞內刪減CIP2A表現，發現AR的蛋白表現量及磷酸化程度降低，並且其細胞生長能力下降。另外，以Dihydrotestosterone (DHT) 刺激LNCaP細胞導致AR活性 (以PSA表現量為證據) 和表現量明顯增加，同時S6K1及CIP2A的表現量也明顯上升，然而，投以AR抑制劑 Bicalutamide會削減DHT所促進之AR、S6K1及CIP2A之表現增加。藉由shRNA刪減AR表現量亦導致S6K1及CIP2A之表現量下降。由上述實驗結果可知，在攝護腺癌細胞內， S6K1、CIP2A與AR之間存在有交互調控其表現量之分子機制。

Prostate cancer (PCa) is one of the most troublesome diseases in Taiwanese males. Abnormally activation of androgens receptor (AR) cause the malignant transformation of PCa cells. Therefore, it is necessary to understand the relationship between the expression of AR and cells growth properties in PCa cells. Previous studies by our laboratory showed that the protein stability of AR is regulated by p70 ribosomal S6 kinase 1(S6K1), a serine/threonine kinase, but the mechanism between the two is not clarified. In this study, we explore the role of S6K1 in regulating the expression and activity of Cancerous Inhibitor of Protein Phosphatase 2A (CIP2A) and AR and the growth properties in PCa cells. We found that the correlation between S6K1, CIP2A and AR expression and phosphorylation in the normal progenitor cells (PZ-HPV-7) and the PCa cells (22Rv1 and LNCaP). Overexpression of the wild-type S6K1 in PZ-HPV-7 cells promotes their growth properties. Furthermore, overexpression of S6K1 in LNCaP cells promoted CIP2A and AR expression and AR phosphorylation. Conversely, knockdown of S6K1 expression in 22Rv1 or LNCaP cells cause reduced CIP2A expression and AR expression and phosphorylation as well as decreased cell growth. Treatment of 10 μM PF-4708671, a S6K1 inhibitor, in LNCaP cells cause the decreased phosphorylation or expression of S6K1, RPS6, CIP2A, PSA, and AR. In addition, knockdown of CIP2A expression in 22Rv1 or LNCaP cells led to reduced AR expression and phosphorylation. Interestingly, DHT can promote S6K1 and CIP2A expression in addition to AR activation, and DHT-promoted effects can be abolished by treatment of bicalutamide, an AR inhibitor. Knockdown of AR expression also caused decreased expression or phosphorylation of S6K1, RPS6, and CIP2A. In summary, our data supported the notion that among S6K1, CIP2A and AR existed the reciprocal regulation in their protein expression, which may cause the aberrant cell proliferation in PCa cells.

中文摘要---------I
Abstract--------II
縮寫對照表-------III
目錄------------IV
第一章、背景及重要性簡介--------------1
第二章、研究目的---------------------5
第三章、實驗設計---------------------7
第四章、實驗材料與方法----------------9
第五章、結果-----------------------15
第六章、討論-----------------------19
第七章、結論-----------------------21
第八章、未來研究--------------------23
第九章、圖表-----------------------25
第十章、參考文獻-------------------33
第十一章、附表---------------------35

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