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本帖最后由 ncRNA 于 2013-8-14 15:32 编辑
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1 Z8 A! F% k; S7 m! D* _% jCell子刊:解析促癌“垃圾DNA”
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6 l8 e, \8 r/ x- y% g% i0 G 来自德克萨斯大学健康科学中心癌症治疗与研究中心(CTRC)的研究人员,在乳腺癌形成的图画上又添加了一笔,在发表于8月12日《癌细胞》(Cancer cell)杂志上的一项新研究中,他们证实“远程雌激素反应元件”( distant estrogen response elements,DEREs)可以独立于癌基因起作用,促进肿瘤形成。( A: |/ `( h' y; w
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论文的主要作者Pei-Yin Hsu 博士说,DEREs似乎像集线器一样,同时远程控制了多个靶基因对雌激素刺激的反应。因此,它们是研究乳腺癌新疗法的主要目标,并且有可能用于诊断。- g' m, f, W: m2 M2 i. W
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论文的资深作者、癌症治疗与研究中心副主任Tim Hui-Ming Huang博士说,当DEREs加倍或是数量异常时,会促进肿瘤,尤其是雌激素受体阳性乳腺癌形成。降低DERE拷贝数可能有潜力治疗罹患这种侵袭性癌症的妇女。
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$ R" h3 X' X0 U$ ?" y% s9 ]# b两个位点的DEREs4 j; S1 {6 y& B. P
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研究人员分析了人类17号和23号染色体上的两个DERE簇,发现DEREs诱导了促生长因子,抑制了生长抑制基因。“值得注意的是,不止DERE与其他基因的互作,DERE-DERE之间的相互作用亦可能促进了肿瘤形成,”Hsu博士说。- u$ Y$ ~. k, x: K4 o( T( s, l
1 Z) A8 I6 Y6 t- V4 r+ [* z! R0 w研究小组还发现了一组DERE调控基因与他莫昔芬(tamoxifen)耐药之间的联系。他莫昔芬是一种广泛用于乳腺癌的激素治疗。Hsu博士说,通过测量DERE活性,或许能够评估一名妇女对于他莫昔芬的反应。 x/ L5 }& P# @; f! g6 N
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潜在的生物标志物
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5 d0 `- V) R0 \/ w9 C5 W此外,研究的两个DEREs有可能是判断一名妇女是否会形成雌激素受体阳性乳腺癌的好生物标记物。“也许我们可以预防某些这样的癌症,”Huang博士说。6 X; a3 v' h& c4 J
) M) z# i5 f* Y3 ZAmplification of Distant Estrogen Response Elements Deregulates Target Genes Associated with Tamoxifen Resistance in Breast Cancer
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A causal role of gene amplification in tumorigenesis is well known, whereas amplification of DNA regulatory elements as an oncogenic driver remains unclear. In this study, we integrated next-generation sequencing approaches to map distant estrogen response elements (DEREs) that remotely control the transcription of target genes through chromatin proximity. Two densely mapped DERE regions located on chromosomes 17q23 and 20q13 were frequently amplified in estrogen receptor-α-positive luminal breast cancer. These aberrantly amplified DEREs deregulated target gene expression potentially linked to cancer development and tamoxifen resistance. Progressive accumulation of DERE copies was observed in normal breast progenitor cells chronically exposed to estrogenic chemicals. These findings may extend to other DNA regulatory elements, the amplification of which can profoundly alter target transcriptome during tumorigenesis. |
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