E2F是疾病治疗的潜在靶点

竞争性寡聚脱氧核糖核酸识别转录因子的DNA结合域,抑制了转录因子对基因的转录调控,转录因子E2F作为潜在的治疗靶点,可以用于抑制肾小球系膜细胞和血管内皮细胞的增生,在部分异常增生的疾病中显示了一定的应用前景。     

CircPRMT5 circular RNA promotes proliferation of colorectal cancer through sponging miR-377 to induce E2F3 expression

CircPRTM5 is associated with cell proliferation and migration in many kinds of malignancies. However, the functions and mechanisms of CircPRTM5 in CRC progression remain unclear. We explored the role and the mechanisms of CircPRTM5 in the development of CRC. Tissues of CRC patients and matched adjacent non-tumour tissues were collected to evaluate the expression of CircPRTM5. The expression of CircPRTM5 in CRC tissues was significantly higher than that in adjacent tissues. The biological functions of CircPRTM5 in CRC were determined by overexpression and down-regulation of CircPRTM5 in CRC cells in vitro and in vivo. The results indicate that knockdown of CircPRTM5 can significantly inhibit the proliferation of CRC cells. The potential mechanisms of CircPRTM5 in CRC development were identified by RT-qPCR, Western blotting analysis and luciferase reporter assay. CircPRTM5 competitively regulates the expression of E2F3 by capillary adsorption of miR-377. CircPRMT5 regulates CRC proliferation by regulating the expression of E2F3, which affects the expression of the cell cycle-associated proteins cyclinD1 and CDK2. CircPRTM5 exerts critical regulatory role in CRC progression by sponging miR-377 to induce E2F3 expression.     

BAP1 regulates cell cycle progression through E2F1 target genes and mediates transcriptional silencing via H2A monoubiquitination in uveal melanoma cells

Uveal melanoma (UM) is the most common form of primary intraocular malignancy in adult and has the tendency to metastasize. BAP1 mutations are frequently found in UM and are associated with a poor prognosis. The role of BAP1 in cell cycle regulation is currently a research highlight, but its underlying mechanism is not well understood. Here, we report that BAP1 knockdown can lead to G1 arrest and is accompanied by a decrease in the expression of S phase genes in OCM1 cells. Furthermore, in chromatin immunoprecipitation experiments, BAP1 could bind to E2F1 responsive promoters and the localization of BAP1 to E2F1-responsive promoters is host cell factor-1 dependent. Moreover, BAP1 knockdown leads to increased H2AK119ub1 levels on E2F responsive promoters. Together, these results provide new insight into the mechanisms of BAP1 in cell cycle regulation.     

靶向E2F1的shRNA抑制眼内视网膜母细胞瘤生长

视网膜母细胞瘤(retinoblastoma,RB)中由于Rb基因缺失或失活,转录调控因子E2F1始终处于活化状态,细胞不断增殖,E2F1活性增加是恶性肿瘤的普遍现象．根据人E2F1基因设计了3段shRNA,构建RNA干扰表达载体pSilencer-shE2F1,瞬时转染人视网膜母细胞瘤细胞株HXO-Rb-44和人肝癌细胞株SMMC-7721,通过荧光定量PCR检测E2F1表达水平的变化,PI (碘化丙锭)染色检测细胞周期各时相细胞数量以检测其对细胞周期的影响．根据筛选出的有效shRNA序列构建腺病毒载体并包装出腺病毒Ad-shE2F1,在裸鼠前房模型中,体外按50 moi的感染系数感染稳定表达绿色荧光蛋白(GFP)的人视网膜母细胞瘤细胞株48 h后,收集细胞,将2×10⁵细胞注射到裸鼠眼前房内,连续观察眼内肿瘤细胞生长情况并拍照记录．通过转染肿瘤细胞株检测E2F1转录水平,筛选到1个能明显抑制肿瘤细胞内E2F1表达的shRNA序列,并使细胞周期中S期细胞数减少．经Ad-shE2F1感染的RB肿瘤细胞与对照相比较,其在裸鼠眼前房内肿瘤生长减缓．结果说明,有效抑制hE2F1表达的shRNA具有抑制体内外人视网膜母细胞瘤生长的作用．