[目的]探讨HPV18致癌基因E6选择性剪接在宫颈癌细胞中的潜在作用。[方法]HPV18感染或过表达HPV18致癌基因E6后,MTT法检测宫颈癌细胞C-33 A的增殖水平、逆转录PCR和琼脂糖凝胶电泳检测E6选择性剪接产物表达水平、免疫印迹检测E7蛋白表达...[目的]探讨HPV18致癌基因E6选择性剪接在宫颈癌细胞中的潜在作用。[方法]HPV18感染或过表达HPV18致癌基因E6后,MTT法检测宫颈癌细胞C-33 A的增殖水平、逆转录PCR和琼脂糖凝胶电泳检测E6选择性剪接产物表达水平、免疫印迹检测E7蛋白表达水平。高通量测序HPV18感染或不感染的C-33 A细胞后调控E6选择性剪接的关键分子。[结果]过表达E6并感染HPV18的C-33 A细胞的增殖水平(2.35±0.37 vs 1.27±0.28)显著上升,且高于未过表达E6(1.27±0.28 vs 0.68±0.11)(P<0.05)。HPV18感染和过表达SRSF3后,选择性剪接产物E6*Ⅰ水平上升(0.25±0.03 vs 0.65±0.13)、E7蛋白表达水平(0.20±0.04 vs 0.77±0.18)上升。敲低SRSF3和过表达miR-1208时,C-33 A细胞的增殖水平(1.30±0.18 vs 0.65±0.13,1.75±0.27 vs 0.75±0.13)显著下降(P<0.05)。与只过表达E6相比,E6与SRSF3共表达、E6过表达同时干扰miR-1208均能够显著促进C-33 A细胞的增殖水平(0.65±0.13 vs 1.65±0.40,0.59±0.11 vs 1.70±0.24)(P<0.05)。敲低SRSF3后,选择性剪接产物E6*Ⅰ水平下降(0.15±0.02 vs 0.57±0.15)、E7蛋白表达水平下降(0.20±0.04 vs 0.77±0.18)(P<0.05)。干扰miR-1208后,选择性剪接产物E6*Ⅰ水平上升(1.12±0.25 vs 2.56±0.33)、SRSF3(0.15±0.03 vs 0.75±0.15)和E7蛋白表达水平上升(0.65±0.11 vs 0.98±0.20);过表达miR-1208后,选择性剪接产物E6*Ⅰ水平下降(1.85±0.34 vs 1.15±0.20)、SRSF3(1.33±0.14 vs 0.20±0.05)和E7蛋白表达水平下降(0.88±0.13 vs 0.50±0.10)(P<0.05)。此外,miR-1208靶向SRSF3 mRNA的3′端非编码区。[结论]miR-1208靶向SRSF3 mRNA的3′端非编码区并减少SRSF3的蛋白表达水平。SRSF3能够促进HPV18致癌基因E6的选择性剪接和E7蛋白的表达。HPV18感染后操纵miR-1208/SRSF3/E6/E7调控轴促进宫颈癌细胞的增殖。展开更多
Alternative splicing of the pyruvate kinase M gene(PK-M)can generate the M2 isoform and promote aerobic glycolysis and tumor growth.However,the cancer-specific alternative splicing regulation of PK-M is not completely...Alternative splicing of the pyruvate kinase M gene(PK-M)can generate the M2 isoform and promote aerobic glycolysis and tumor growth.However,the cancer-specific alternative splicing regulation of PK-M is not completely understood.Here,we demonstrate that PK-M is regulated by reciprocal effects on the mutually exclusive exons 9 and 10,such that exon 9 is repressed and exon 10 is activated in cancer cells.Strikingly,exonic,rather than intronic,cis-elements are key determinants of PK-M splicing isoform ratios.Using a systematic sub-exonic duplication approach,we identify a potent exonic splicing enhancer in exon 10,which differs from its homologous counterpart in exon 9 by only two nucleotides.We identify SRSF3 as one of the cognate factors,and show that this serine/arginine-rich protein activates exon 10 and mediates changes in glucose metabolism.These findings provide mechanistic insights into the complex regulation of alternative splicing of a key regulator of the Warburg effect,and also have implications for other genes with a similar pattern of alternative splicing.展开更多
文摘[目的]探讨HPV18致癌基因E6选择性剪接在宫颈癌细胞中的潜在作用。[方法]HPV18感染或过表达HPV18致癌基因E6后,MTT法检测宫颈癌细胞C-33 A的增殖水平、逆转录PCR和琼脂糖凝胶电泳检测E6选择性剪接产物表达水平、免疫印迹检测E7蛋白表达水平。高通量测序HPV18感染或不感染的C-33 A细胞后调控E6选择性剪接的关键分子。[结果]过表达E6并感染HPV18的C-33 A细胞的增殖水平(2.35±0.37 vs 1.27±0.28)显著上升,且高于未过表达E6(1.27±0.28 vs 0.68±0.11)(P<0.05)。HPV18感染和过表达SRSF3后,选择性剪接产物E6*Ⅰ水平上升(0.25±0.03 vs 0.65±0.13)、E7蛋白表达水平(0.20±0.04 vs 0.77±0.18)上升。敲低SRSF3和过表达miR-1208时,C-33 A细胞的增殖水平(1.30±0.18 vs 0.65±0.13,1.75±0.27 vs 0.75±0.13)显著下降(P<0.05)。与只过表达E6相比,E6与SRSF3共表达、E6过表达同时干扰miR-1208均能够显著促进C-33 A细胞的增殖水平(0.65±0.13 vs 1.65±0.40,0.59±0.11 vs 1.70±0.24)(P<0.05)。敲低SRSF3后,选择性剪接产物E6*Ⅰ水平下降(0.15±0.02 vs 0.57±0.15)、E7蛋白表达水平下降(0.20±0.04 vs 0.77±0.18)(P<0.05)。干扰miR-1208后,选择性剪接产物E6*Ⅰ水平上升(1.12±0.25 vs 2.56±0.33)、SRSF3(0.15±0.03 vs 0.75±0.15)和E7蛋白表达水平上升(0.65±0.11 vs 0.98±0.20);过表达miR-1208后,选择性剪接产物E6*Ⅰ水平下降(1.85±0.34 vs 1.15±0.20)、SRSF3(1.33±0.14 vs 0.20±0.05)和E7蛋白表达水平下降(0.88±0.13 vs 0.50±0.10)(P<0.05)。此外,miR-1208靶向SRSF3 mRNA的3′端非编码区。[结论]miR-1208靶向SRSF3 mRNA的3′端非编码区并减少SRSF3的蛋白表达水平。SRSF3能够促进HPV18致癌基因E6的选择性剪接和E7蛋白的表达。HPV18感染后操纵miR-1208/SRSF3/E6/E7调控轴促进宫颈癌细胞的增殖。
基金supported by a fellowship from the Agency for Science,Technology and Research,Singapore.
文摘Alternative splicing of the pyruvate kinase M gene(PK-M)can generate the M2 isoform and promote aerobic glycolysis and tumor growth.However,the cancer-specific alternative splicing regulation of PK-M is not completely understood.Here,we demonstrate that PK-M is regulated by reciprocal effects on the mutually exclusive exons 9 and 10,such that exon 9 is repressed and exon 10 is activated in cancer cells.Strikingly,exonic,rather than intronic,cis-elements are key determinants of PK-M splicing isoform ratios.Using a systematic sub-exonic duplication approach,we identify a potent exonic splicing enhancer in exon 10,which differs from its homologous counterpart in exon 9 by only two nucleotides.We identify SRSF3 as one of the cognate factors,and show that this serine/arginine-rich protein activates exon 10 and mediates changes in glucose metabolism.These findings provide mechanistic insights into the complex regulation of alternative splicing of a key regulator of the Warburg effect,and also have implications for other genes with a similar pattern of alternative splicing.
