Epigenetic silencing of peroxisome proliferator-activated receptor γ is a biomarker for colorectal cancer progression and adverse patients' outcome.
Epigenetic silencing of peroxisome proliferator-activated receptor γ is a biomarker for colorectal cancer progression and adverse patients' outcome.
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DOI：
10.1371/journal.pone.0014229
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发表时间：
2010-12-03
期刊：
影响因子：
3.7
通讯作者：
Colantuoni V
中科院分区：
文献类型：
--
作者：
Pancione M;Sabatino L;Fucci A;Carafa V;Nebbioso A;Forte N;Febbraro A;Parente D;Ambrosino C;Normanno N;Altucci L;Colantuoni V
过氧化物酶体增殖物激活受体γ (PPARG)表达与结直肠癌发病机制中发生的表观遗传变化之间的关系在很大程度上是未知的。我们研究了PPARG是否在结直肠癌（CRC）进展中受到表观遗传调控。western blot和免疫组化检测PPARG在结直肠癌组织和配对的正常粘膜中的表达，并与患者的临床病理参数和生存率相关。通过甲基化特异性pcr和亚硫酸盐测序分析PPARG启动子甲基化。PPARG表达和启动子甲基化在结直肠癌衍生细胞系中也进行了类似的检测。在基础条件下和表观遗传处理后进行染色质免疫沉淀，并对可能的调节因子进行敲除实验。通过免疫印迹和细胞增殖和侵袭性功能检测来监测基因表达。在30%的原发性crc中，启动子特定区域的甲基化与PPARG缺乏表达以及患者预后不良密切相关。值得注意的是，在pparg阴性的CRC细胞系中发现了相同的甲基化模式。用5 ' -aza-2 ' -脱氧胞苷进行表观遗传学处理可以恢复这种情况，并与曲古霉素A联合，显著地重新激活基因转录和受体活性。转录沉默是由于MeCP2、HDAC1和EZH2的募集，它们传递了抑制染色质特征，决定了细胞增殖和侵袭潜力的增加，这些特征可以通过实验恢复。我们的研究结果为CRC中PPARG的表观遗传沉默提供了一种新的机制见解，这可能与肿瘤进展的预后标志物有关。
The relationship between peroxisome proliferator-activated receptor γ (PPARG) expression and epigenetic changes occurring in colorectal-cancer pathogenesis is largely unknown. We investigated whether PPARG is epigenetically regulated in colorectal cancer (CRC) progression. PPARG expression was assessed in CRC tissues and paired normal mucosa by western blot and immunohistochemistry and related to patients' clinicopathological parameters and survival. PPARG promoter methylation was analyzed by methylation-specific-PCR and bisulphite sequencing. PPARG expression and promoter methylation were similarly examined also in CRC derived cell lines. Chromatin immunoprecipitation in basal conditions and after epigenetic treatment was performed along with knocking-down experiments of putative regulatory factors. Gene expression was monitored by immunoblotting and functional assays of cell proliferation and invasiveness. Methylation on a specific region of the promoter is strongly correlated with PPARG lack of expression in 30% of primary CRCs and with patients' poor prognosis. Remarkably, the same methylation pattern is found in PPARG-negative CRC cell lines. Epigenetic treatment with 5′-aza-2′-deoxycytidine can revert this condition and, in combination with trichostatin A, dramatically re-activates gene transcription and receptor activity. Transcriptional silencing is due to the recruitment of MeCP2, HDAC1 and EZH2 that impart repressive chromatin signatures determining an increased cell proliferative and invasive potential, features that can experimentally be reverted. Our findings provide a novel mechanistic insight into epigenetic silencing of PPARG in CRC that may be relevant as a prognostic marker of tumor progression.
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影响因子：
78.5
作者：
Issa, JP
通讯作者：
Issa, JP
影响因子：
30.8
作者：
Jones, PL;Veenstra, GJC;Wolffe, AP
通讯作者：
Wolffe, AP
影响因子：
4.8
作者：
Sabatino, L;Casamassimi, A;Colantuoni, V
通讯作者：
Colantuoni, V
影响因子：
50.3
作者：
Girnun, Geoffrey D.;Naseri, Elnaz;Spiegelman, Bruce M.
通讯作者：
Spiegelman, Bruce M.
DOI：
10.1016/j.bbadis.2010.01.012
发表时间：
2010-06-01
影响因子：
6.2
作者：
Capaccio, D.;Ciccodicola, A.;Colantuoni, V.
通讯作者：
Colantuoni, V.