Tanshinones for prevention of bladder cancer progression

描述（由申请人提供）：本探索性提案旨在评估新型生物活性成分丹参酮I（T1）预防膀胱癌进展的疗效，并为了解T1作用机制提供必要的初步证据。膀胱癌是美国第五大最常见的恶性肿瘤。由于膀胱癌发生的病因学因素尚不清楚，而且膀胱癌患者在治疗后面临着转移和不受控制的局部复发的威胁，因此迫切需要进一步努力确定有效的干预或化学预防策略来防止膀胱癌进展。因此，寻找有效和安全的策略来预防或延缓膀胱癌的进展和转移仍然是膀胱癌研究的重中之重。在努力确定的生物活性成分，我们发现，丹参酮从中国草药丹参，特别是丹参酮I（T1），具有有效的活性，在抑制膀胱癌细胞的生长，部分通过诱导细胞凋亡在体外下调极光A的表达。T1在体外和体内均表现出抑制血管生成的活性。T1在体内、外的毒副作用均较T1小。基因功能分析表明，siRNA敲低Aurora A基因可显著抑制肿瘤细胞的生长并诱导其凋亡，T1诱导凋亡和抑制肿瘤细胞生长的活性在很大程度上被Aurora A基因功能的丧失所消除。这些有希望的初步结果支持的假设，T1可以作为一个有效的和安全的化学预防剂对膀胱癌的进展，诱导膀胱癌细胞凋亡和抑制血管生成，极光A可能是一个功能性的目标T1行动。由于一定水平的T1及其代谢物通过尿路排泄并与膀胱粘膜直接接触，T1通过血液循环和尿液暴露发挥其抗膀胱癌活性，在体内系统中的膀胱癌干预活性可能比体外评价的活性更强，原位膀胱肿瘤模型的应用是T1对膀胱癌进展进行相关评价的前提。为了检验假设，具体目标1是确定T1对原位膀胱肿瘤模型中高分化/低转移性和低分化/高转移性人膀胱肿瘤进展的影响;具体目标2是确定与T1体内疗效相关的细胞和分子生物标志物;具体目标3是进一步确定Aurora A的下调是否在功能上负责诱导膀胱癌细胞凋亡和抑制血管生成的T1活性。该提案将定义一种高效安全的膀胱癌进展化学预防剂，其结果可能导致未来的临床研究，以开发T1作为膀胱癌的化学预防和/或治疗剂。从这项研究中得出的结果也将为RO1的应用提供支持证据。

DESCRIPTION (provided by applicant): This exploratory proposal is to evaluate the efficacy of a novel bioactive component tanshinone I (T1) on preventing bladder cancer progression and to generate essential preliminary evidence to understand the mechanisms of T1 actions. Bladder cancer is the fifth most commonly diagnosed malignancy in the United States. With the unknown etiological factors for bladder carcinogenesis and the fact that bladder cancer patients are facing both threat of metastases and uncontrolled local recurrence after treatment, additional efforts to define effective intervention or chemoprevention strategies against bladder cancer progression are urgently needed. Therefore, the searching for efficacious and safe strategies to prevent or delay the progression and metastasis of bladder cancer remains the top priority in bladder cancer research. In an effort to identify the bioactive components, we found that tanshinones from a Chinese herb Danshen, especially tanshinone I (T1), had potent activities in inhibiting the growth of bladder cancer cells in part via induction of apoptosis in vitro associated with downregulation of Aurora A expression. T1 also showed potent activities in inhibiting angiogenesis in both in vitro and in vivo. Furthermore, T1 showed much less toxicity and side effect in vitro and in vivo. Gene function assays showed that knockdown of Aurora A by siRNA significantly reduced the growth and induced apoptosis of cancer cells, and the T1 activities in inducing apoptosis and inhibiting cell growth were largely eliminated by the loss of Aurora A function. These promising preliminary results support the hypotheses that T1 may serve as an efficacious and safe chemopreventive agent against bladder cancer progression by both inducing bladder cancer cell apoptosis and inhibiting angiogenesis, and that Aurora A may be a functional target for T1 action. Since certain levels of T1 and its metabolites are excreted through the urinary tract and are in direct contact with mucosa of the bladder, T1 may have more potent activity in bladder cancer intervention in the in vivo system than that evaluated in vitro by exerting its anti-bladder cancer activities via both blood circulation and urinary exposure, and application of orthotopic bladder tumor model is a prerequisite for relevant evaluation of T1 on bladder cancer progression. To test the hypothesis, specific aim 1 is to determine the effect of T1 on progression of both well-differentiated/low metastatic and poorly differentiated/highly metastatic human bladder tumors in orthotopic bladder tumor models; Specific aim 2 is determine the cellular and molecular biomarkers that are associated with the efficacy of T1 in vivo; Specific aim 3 is to proposed to further determine if downregulation of Aurora A is functionally responsible for the T1 activities in inducing apoptosis of bladder cancer cells and inhibiting angiogenesis. This proposal will define a highly efficacious and safe chemopreventive agent against bladder cancer progression, and the results may result in future clinical investigations to develop T1 as a chemopreventive and/or therapeutic agent for bladder cancer. The results derived from this research will also provide supporting evidence for the RO1 application.