This paper reviews the distinctive roles played by the transcriptional coactivators CREB-binding protein(CBP) and p300 in Wnt/β-catenin signaling and cell physiology in colorectal cancer(CRC). Specifically, we focus ...This paper reviews the distinctive roles played by the transcriptional coactivators CREB-binding protein(CBP) and p300 in Wnt/β-catenin signaling and cell physiology in colorectal cancer(CRC). Specifically, we focus on the effects of CBP- and p300-mediated Wnt activity on(1) neoplastic progression;(2) the activities of butyrate, a breakdown product of dietary fiber, on cell signaling and colonic cell physiology;(3) the development of resistance to histone deacetylase inhibitors(HDACis), including butyrate and synthetic HDACis, in colonic cells; and(4) the physiology and number of cancer stem cells. Mutations of the Wnt/β-catenin signaling pathway initiate the majority of CRC cases, and we have shown that hyperactivation of this pathway by butyrate and other HDACis promotes CRC cell apoptosis. This activity by butyrate may in part explain the preventive action of fiber against CRC. However, individuals with a high-fiber diet may still develop neoplasia; therefore, resistance to the chemopreventive action of butyrate likely contributes to CRC. CBP or p300 may modify the ability of butyrate to influence colonic cell physiology since the two transcriptional coactivators affect Wnt signaling, and likely, its hyperactivation by butyrate. Also, CBP and p300 likely affect colonic tumorigenesis, as well as stem cell pluripotency. Improvement of CRC prevention and therapy requires a better understanding of the alterations in Wnt signaling and gene expression that underlie neoplastic progression, stem cell fate, and the development of resistance to butyrate and clinically relevant HDACis. Detailed knowledge of how CBP- and p300 modulate colonic cell physiology may lead to new approaches for anti-CRC prevention and therapeutics, particularly with respect to combinatorial therapy of CBP/p300 inhibitors with HDACis.展开更多
CBP60s(Calmodulin-binding protein 60)是植物所特有的钙调素结合蛋白家族之一,在调节黄瓜生长发育及应对盐胁迫时发挥重要作用。本研究利用生物信息学方法对黄瓜全基因组中筛选鉴定到的17个CBP60基因家族成员,进行基因序列特征、染色...CBP60s(Calmodulin-binding protein 60)是植物所特有的钙调素结合蛋白家族之一,在调节黄瓜生长发育及应对盐胁迫时发挥重要作用。本研究利用生物信息学方法对黄瓜全基因组中筛选鉴定到的17个CBP60基因家族成员,进行基因序列特征、染色体定位、亚细胞定位、基因结构、系统进化、启动子顺式作用元件和表达模式分析,探讨其基因功能及表达模式。黄瓜CBP60基因分子量为17307.87~99117.13 Da,等电点在5.55~9.96之间;17个CsCBP60基因家族成员不均匀分布在黄瓜染色体chr1、chr2、chr4、chr5上,部分基因在chr1上形成基因簇,并发生6个串联重复事件;亚细胞定位预测发现CsCBP60基因定位于叶绿体、细胞核、线粒体;CsCBP60基因均具有CaM结合结构域;CsCBP60基因家族可分为3个亚家族(ClassA-C),黄瓜与甜瓜的CBP60基因之间发生了10对共线性事件,与甜瓜亲缘最近。CsCBP60家族成员含有光响应和脱落酸响应、生长素响应、E-box、W-box等胁迫响应元件。在75 mmol/L NaCl处理24 h后,CsCBP60基因均有不同程度的响应,其中CsCBP60-1/3/7/8/9/11/15响应强烈,且在根部高表达,推测其可能在盐胁迫下发挥重要作用。本研究为进一步开展CsCBP60s功能研究提供了参考,有助于揭示该家族成员应对盐胁迫时的作用机制。展开更多
目的探讨槲皮素抑制前列腺癌的作用机制。方法应用蛋白印迹技术检查槲皮素(quercetin)对雄激素受体(androgen receptor,AR)的辅调节因子c-Jun和cAMP应答元件结合蛋白的结合蛋白[cAMP response elem entb ind ing prote in(CREB)-b ind i...目的探讨槲皮素抑制前列腺癌的作用机制。方法应用蛋白印迹技术检查槲皮素(quercetin)对雄激素受体(androgen receptor,AR)的辅调节因子c-Jun和cAMP应答元件结合蛋白的结合蛋白[cAMP response elem entb ind ing prote in(CREB)-b ind ing prote in,CBP]蛋白表达的影响;利用细胞转染技术检测c-Jun和CBP对AR功能的影响;免疫沉淀技术检验c-Jun与AR的蛋白-蛋白相互作用。结果槲皮素能够明显诱导c-Jun的高表达,高表达的c-Jun能够抑制AR的功能。槲皮素对CBP的蛋白表达水平无明显影响,而增加CBP的表达并不能逆转槲皮素对AR功能的抑制作用。免疫沉淀结果表明,c-Jun与AR存在蛋白-蛋白相互作用。结论槲皮素抑制前列腺癌的机制可能是通过c-Jun与AR的蛋白相互作用,而不是通过c-Jun竞争结合AR的辅激活因子CBP来实现的。展开更多
基金Supported by National Institutes of Health(Bethesda,MD)National Cancer Institute,No.1R15CA149589-01
文摘This paper reviews the distinctive roles played by the transcriptional coactivators CREB-binding protein(CBP) and p300 in Wnt/β-catenin signaling and cell physiology in colorectal cancer(CRC). Specifically, we focus on the effects of CBP- and p300-mediated Wnt activity on(1) neoplastic progression;(2) the activities of butyrate, a breakdown product of dietary fiber, on cell signaling and colonic cell physiology;(3) the development of resistance to histone deacetylase inhibitors(HDACis), including butyrate and synthetic HDACis, in colonic cells; and(4) the physiology and number of cancer stem cells. Mutations of the Wnt/β-catenin signaling pathway initiate the majority of CRC cases, and we have shown that hyperactivation of this pathway by butyrate and other HDACis promotes CRC cell apoptosis. This activity by butyrate may in part explain the preventive action of fiber against CRC. However, individuals with a high-fiber diet may still develop neoplasia; therefore, resistance to the chemopreventive action of butyrate likely contributes to CRC. CBP or p300 may modify the ability of butyrate to influence colonic cell physiology since the two transcriptional coactivators affect Wnt signaling, and likely, its hyperactivation by butyrate. Also, CBP and p300 likely affect colonic tumorigenesis, as well as stem cell pluripotency. Improvement of CRC prevention and therapy requires a better understanding of the alterations in Wnt signaling and gene expression that underlie neoplastic progression, stem cell fate, and the development of resistance to butyrate and clinically relevant HDACis. Detailed knowledge of how CBP- and p300 modulate colonic cell physiology may lead to new approaches for anti-CRC prevention and therapeutics, particularly with respect to combinatorial therapy of CBP/p300 inhibitors with HDACis.
文摘目的探讨槲皮素抑制前列腺癌的作用机制。方法应用蛋白印迹技术检查槲皮素(quercetin)对雄激素受体(androgen receptor,AR)的辅调节因子c-Jun和cAMP应答元件结合蛋白的结合蛋白[cAMP response elem entb ind ing prote in(CREB)-b ind ing prote in,CBP]蛋白表达的影响;利用细胞转染技术检测c-Jun和CBP对AR功能的影响;免疫沉淀技术检验c-Jun与AR的蛋白-蛋白相互作用。结果槲皮素能够明显诱导c-Jun的高表达,高表达的c-Jun能够抑制AR的功能。槲皮素对CBP的蛋白表达水平无明显影响,而增加CBP的表达并不能逆转槲皮素对AR功能的抑制作用。免疫沉淀结果表明,c-Jun与AR存在蛋白-蛋白相互作用。结论槲皮素抑制前列腺癌的机制可能是通过c-Jun与AR的蛋白相互作用,而不是通过c-Jun竞争结合AR的辅激活因子CBP来实现的。
