Grape Proanthocyanidins Modulate MicroRNA Expression in Human pancreatic cancer cells

Mi(cro)RNAs are small non-coding RNAs of 18-25 nucleotides in length that modulate gene expression at the posttranscriptional level. Grape seed proanthocyanidins (GSPs), a biologically active component of grape seeds, have been shown to have positive effects on anti-cancer. In current study, to explore whether GSPs can regulate miRNA expression and possible molecular mechanisms involved in anti-cancer, we prepared the pancreatic cancer (PC) cells samples (SS3, SS12 and SS24) at 3, 12 and 24h after GSPs treatments respectively; and control samples (SC3, SC12 and SC24) were also collected accordingly. miRNA-seq transcriptome comparisons were performed, and 26, 85 and 85 differentially expressed (DE) miRNA were identified among SS3 vs. SC3, SS12 vs. SC12 and SS24 vs. SC24 respectively, indicating the GSPs treatments could modulate the expression of miRNAs globally. Subsequently, 74, 598 and 1204 target genes of these DE miRNAs were predicted in three comparisons, and GO and KEGG analysis revealed that multiple target genes were associated with proliferation and apoptosis of PC cells. Moreover, interaction network analyis of DE miRNAs and target genes associated with PC were also carried out, and fabulous co-expression relationships further suggested that GSPs treatment could probably repress the proliferation of PC cells by modulating the miRNAs expression Overall design: Transcriptome change of PANC-1 cells post Proanthocyanidins (20 µg/ml) exposure at 3, 12 and 24h were investigated. A biological replicate sequencing was carried out.

微小RNA（microRNAs，miRNAs）是一类长度为18~25个核苷酸的小型非编码RNA，可在转录后水平调控基因表达。葡萄籽原花青素（Grape seed proanthocyanidins, GSPs）是葡萄籽中的生物活性成分，已被证实具有抗肿瘤活性。
本研究为探究GSPs能否调控miRNA表达及其参与抗肿瘤的潜在分子机制，分别收集了经GSPs处理3、12、24小时的胰腺癌细胞（Pancreatic cancer, PC）样本（命名为SS3、SS12、SS24），并同步设置对应对照组样本（SC3、SC12、SC24）。
随后开展miRNA测序转录组比较分析，在SS3 vs. SC3、SS12 vs. SC12及SS24 vs. SC24三组对照中分别鉴定出26、85、85个差异表达（differentially expressed, DE）miRNA，提示GSPs处理可全局性调控miRNA的表达水平。
在上述三组比较中，分别预测得到74、598、1204个对应差异表达miRNA的靶基因。基因本体（Gene Ontology, GO）与京都基因与基因组百科全书（Kyoto Encyclopedia of Genes and Genomes, KEGG）富集分析显示，诸多靶基因与胰腺癌细胞的增殖及凋亡密切相关。
此外，本研究还针对差异表达miRNA与胰腺癌细胞相关靶基因开展了相互作用网络分析，其显著的共表达关联进一步表明，GSPs或可通过调控miRNA表达抑制胰腺癌细胞的增殖。
整体实验设计：本研究探究了经20 μg/ml原花青素处理后的PANC-1细胞在3、12、24小时后的转录组变化，并设置生物学重复进行测序。