前列腺癌可在无激素状态下生长机制
来自俄亥俄州立大学综合癌症中心(Comprehensive Cancer Center),Dana-Farber癌症研究所的研究人员发现了晚期,非激素依赖性前列腺癌如何能够在没有激素的情况下继续生长的奥秘,这一研究成果公布在Cell杂志上。
文章的第一作者和共同通讯作者是俄亥俄州立大学分子与细胞生物化学助理教授王前奔博士,其早期毕业于首都医科大学,2002年获得马里兰大学医学院博士学位,曾获得过Travel Award青年科学家奖等奖项。
这项研究聚焦于雄激素受体,这种受体定位于前列腺和其它组织细胞的细胞核上,雄激素能结合这些受体,从而激活调控细胞生长的基因。
研究人员发现非雄激素依赖性前列腺癌症患者中,雄激素受体被重组,调控一组参与各种晚期细胞分裂的基因,导致细胞快速生长,并且研究还表明染色体的一种主要成分的修改导致了这种重组。
王前奔博士表示,“一些晚期前列腺癌的肿瘤生长并不需要雄激素,但是需要雄激素受体”,“我们的研究揭示了在非激素依赖性前列腺癌中雄激素受体的作用,以及这些受体如何在这种疾病中被激活,和调控哪些基因促进肿瘤生长的。”
前列腺癌是目前男性中最常见的癌症之一,据估计2009年美国新出现的病例高达192280例,其中27360例死亡。这项研究有利于进一步了解前列腺癌,并且有助于新治疗靶标的发现,从而为这种疾病的致命性阶段提出新的治疗方案。
王前奔博士与Dana-Farber癌症研究所的Myles Brown教授等人首先从激素依赖性和非激素依赖性前列腺癌细胞系,基因表达数据,以及人类肿瘤组织等方面入手,他们发现激素依赖性疾病中,雄激素受体调控细胞周期的早期阶段,但是在非激素依赖性前列腺癌中,这些受体被重组,选择性调控细胞分裂中的基因,而细胞分裂正是有丝分裂细胞周期的晚期活动。
这些基因中有一个名为“UBE2C”的基因受到了研究人员的**************,他们发现这一基因的表达增加与非激素依赖性阶段的生长密切相关,而且研究人员还发现这一基因相关的一个组蛋白上的表观遗传学变化能帮助雄激素受体结合并激活这一基因(非激素依赖性前列腺癌)。除此之外,非激素依赖性前列腺癌细胞的生长也需要UBE2C基因的过量表达。
王前奔博士说,“有趣的是UBE2C基因在乳腺癌,肺癌,卵巢癌,膀胱癌,甲状腺癌和食道癌中也会表达过量,这说明我们的发现也许具有更广泛的意义。”(生物谷Bioon.com)
生物谷推荐原始出处:
Cell, Volume 138, Issue 2, 245-256, 23 July 2009 doi:10.1016/j.cell.2009.04.056
Androgen Receptor Regulates a Distinct Transcription Program in Androgen-Independent Prostate Cancer
Qianben Wang1,2,14,,,Wei Li3,14,Yong Zhang4,Xin Yuan5,Kexin Xu1,Jindan Yu6,Zhong Chen2,Rameen Beroukhim1,7,Hongyun Wang5,Mathieu Lupien1,13,Tao Wu8,Meredith M. Regan4,Clifford A. Meyer4,Jason S. Carroll9,Arjun Kumar Manrai4,Olli A. J?nne10,Steven P. Balk5,Rohit Mehra6,Bo Han6,Arul M. Chinnaiyan6,Mark A. Rubin11,Lawrence True12,Michelangelo Fiorentino1,Christopher Fiore1,Massimo Loda1,Philip W. Kantoff1,X. Shirley Liu4,,andMyles Brown1,,
1 Department of Medical Oncology, Dana-Farber Cancer Institute and Harvard Medical School, Boston, MA 02115, USA
2 Department of Molecular and Cellular Biochemistry and the Comprehensive Cancer Center, Ohio State University College of Medicine, Columbus, OH 43210, USA
3 Division of Biostatistics, Dan L. Duncan Cancer Center and Department of Molecular and Cellular Biology, Baylor College of Medicine, Houston, TX 77030, USA
4 Department of Biostatistics and Computational Biology, Dana-Farber Cancer Institute and Harvard School of Public Health, Boston, MA 02115, USA
5 Cancer Biology Program, Hematology-Oncology Division, Department of Medicine, Beth Israel Deaconess Medical Center and Harvard Medical School, Boston, MA 02215, USA
6 Department of Pathology, University of Michigan Medical School, Ann Arbor, MI 48109, USA
7 Broad Institute of Harvard and MIT, Cambridge, MA 02139, USA
8 Department of System Biology, Harvard Medical School, Boston, MA 02115, USA
9 Cancer Research UK, Cambridge Research Institute, Robinson Way, Cambridge CB2 0RE, UK
10 Biomedicum Helsinki, Institute of Biomedicine (Physiology), University of Helsinki, Helsinki, FI-00014, Finland
11 Department of Pathology and Laboratory Medicine, Weill Cornell Medical College, New York, NY 10021, USA
12 Department of Pathology, University of Washington Medical Center, Seattle, WA 98195, USA
The evolution of prostate cancer from an androgen-dependent state to one that is androgen-independent marks its lethal progression. The androgen receptor (AR) is essential in both, though its function in androgen-independent cancers is poorly understood. We have defined the direct AR-dependent target genes in both androgen-dependent and -independent cancer cells by generating AR-dependent gene expression profiles and AR cistromes. In contrast to what is found in androgen-dependent cells, AR selectively upregulates M-phase cell-cycle genes in androgen-independent cells, including UBE2C, a gene that inactivates the M-phase checkpoint. We find that epigenetic marks at the UBE2C enhancer, notably histone H3K4 methylation and FoxA1 transcription factor binding, are present in androgen-independent cells and direct AR-enhancer binding and UBE2C activation. Thus, the role of AR in androgen-independent cancer cells is not to direct the androgen-dependent gene expression program without androgen, but rather to execute a distinct program resulting in androgen-independent growth.