RNA helicase DHX37 facilitates liver cancer progression by cooperating with PLRG1 to drive super enhancer-mediated transcription of cyclin D1

We provide evidence highlighting a close cooperative mechanistic interaction between DHX37 and PLRG1 that regulates CCND1 expression and promotes liver cancer progression, advancing our understanding of epigenetic and transcriptional dysregulations mediated by RNA helicases and super-enhancers in HCC, possibly facilitating cancer diagnosis and treatment. Huh 7 cells were transfected with siRNA targeted indicated genes using Lipofectamine RNAiMAX or were transfected with Flag-DHX37 targeted indicated genes lentivirus. Chromatin immunoprecipitation followed by sequencing (ChIP-seq) was performed using indicated antibodies to study the H3K27ac status and binding sites of transcription factor in Huh 7 cell. Cleavage Under Targets and Tagmentation (CUT&Tag) was performed to explore whether super-enhancers are directly regulated by DHX37 or PLRG1. Whole-transcriptome sequencing (RNA-Seq) was perfemed to identify the downstream target genes regulated by DHX37 through silenced DHX37 by siRNA in Huh 7 cells.

本研究提供证据，揭示DHX37与PLRG1之间存在紧密的协同机制性互作，该互作可调控CCND1的表达并促进肝癌进展，加深了我们对RNA解旋酶（RNA helicases）和超级增强子（super-enhancers）介导的肝细胞癌（hepatocellular carcinoma, HCC）中表观遗传与转录失调的理解，或可为癌症的诊断与治疗提供新思路。本研究采用Lipofectamine RNAiMAX试剂，将靶向指定基因的小干扰RNA（small interfering RNA, siRNA）转染至Huh7细胞；同时转染携带Flag标签DHX37且靶向指定基因的慢病毒。使用指定抗体开展染色质免疫共沉淀测序（Chromatin immunoprecipitation followed by sequencing, ChIP-seq），以分析Huh7细胞中组蛋白H3赖氨酸27乙酰化（H3K27ac）修饰状态及转录因子结合位点。通过靶向切割与标签化（Cleavage Under Targets and Tagmentation, CUT&Tag）技术，探究DHX37或PLRG1是否直接调控超级增强子。此外，通过siRNA沉默Huh7细胞中的DHX37，结合全转录组测序（RNA-Seq），鉴定DHX37所调控的下游靶基因。