Search for the genes regulated by Histone deaetylase inhibitor and the Rb gene

HDAC抑制剂，如FK228和曲古抑素A(TSA)，可诱导多种人类癌细胞的生长停滞和凋亡。用MTS法和流式细胞仪检测了FK228或TSA作用72 h后对15例非小细胞肺癌(NSCLC)和5例小细胞肺癌(SCLC)等20株人肺癌细胞的细胞毒作用。为了研究肺癌细胞对FK228、TSA以及顺铂、卡铂、VP-16、SN-38、紫杉醇、多西紫杉醇、长春瑞滨、吉西他滨、SM5887等9种化疗药物的敏感性基因，我们对20株肺癌细胞进行了基因芯片分析。应用于表达数据的聚类算法显示了HDAC抑制剂和9种化疗药物之间的不同亚群。此外，我们还将表达数据与细胞系的IC50数据进行了比较。我们发现感觉…之间存在显著的关联对HDAC抑制剂和包括CST3在内的几个基因的表达水平的影响更大，但未能通过实时荧光PCR方法证实它们之间的显著关联。视网膜母细胞瘤肿瘤抑制蛋白(RB)在大多数人类肿瘤中被失活，包括非小细胞肺癌和小细胞肺癌。Rb通过抑制细胞周期所必需基因的转录来抑制细胞增殖，Rb基因在体外被证明能抑制小细胞肺癌细胞的致瘤性。为了抑制转录，Rb通过直接与E2F结合并组装含有染色质修饰酶(包括组蛋白脱乙酰酶)的多蛋白复合体，在功能上拮抗E2F的活性。然而，HDAC参与转录抑制的程度以及RB介导的抑制所需的程度尚不清楚。因为HDAC抑制剂诱导了NSCLC和SCLC细胞的凋亡。我们研究了Rb基因在肺癌细胞中的重组是否阻断了HDAC诱导的细胞凋亡途径。联合指数法显示，HDAC抑制剂与腺病毒-Rb或腺病毒-LacZ联合处理后，表现出相加或轻度的协同作用，说明Rb的重建不能阻断HDAC抑制剂诱导的细胞凋亡。较少

HDAC inhibitors, such as FK228 and trichostatin A(TSA), induce growth arrest and apoptosis in a variety of human cancer cells. We evaluated cytotoxicity by MTS assay and FACS analysis after 72 h of exposure to FK228 or TSA in 20 human lung cancer cell lines including 15 non-small cell lung cancer(NSCLC) and 5 small cell lung cancr(SCLC) cell lines. We found both FK228 and TSA steeply inhibited cell growth and induced apoptosis in 20 cell lines with nanomolar concentrations.To investigate genes to sensitivity of lung cancers cells to FK228, TSA and 9 chemotherapeutic agents including CDDP, CBDCA, VP-16, SN-38 Paclitaxel, Docetaxel, Vinorelbine, Gemcitabine, SM5887, we performed cDNA microarray analysis of 20 lung cancer cells. A clustering algorithm applied to the expression data showed distinguished subgroups between HDAC inhibitors and 9 chemotherapeutic agents. In addition, we compared the expression data with IC50 data of cell lines. We found significant associations between sensiti … More vity to HDAC inhibitors and expression levels of several genes including CST3, but failed to confirm their significant association by real-time PCR method.The retinoblastoma tumor suppressor protein(RB) is targeted for inactivation in the majority of human tumors, including NSCLC and SCLC. RB inhibits proliferation by repressing the transcription of genes that are essential for cell cycle progression and restoration of the Rb gene to SCLC cells has been shown to suppress the tumorigenecity in vitro. To repress transcription, RB functionally antagonize E2F acitivity through binding E2Fs directly and assembling multiprotein complexes containing chromatin-modifying enzymes, including histone deacetylases(HDACs). However, the extent to which HDACs participate in transcriptional repression and are required for RB-mediated repression is unclear. Since the HDAC inhibitors induced apoptosis in NSCLC and SCLC cells. We examined whether reconstitution of the Rb gene to lung cancer cells blocks the HDAC-induced apoptotic pathway. Combined treatment of HDAC inhibitors with Adenovirus-Rb or Adenovirus-LacZ as a control similarly showed additive to mild synergistic effects by combination index method, indicating reconstitution of Rb did not block the HDAC inhibitor-induced apoptosis. Less