CBX3 regulates efficient RNA processing genome-wide
GENOME RESEARCH
Authors: Smallwood, Andrea; Hon, Gary C.; Jin, Fulai; Henry, Ryan E.; Espinosa, Joaquin M.; Ren, Bing
Abstract
CBX5, CBX1, and CBX3 (HP1 alpha, beta, and gamma, respectively) play an evolutionarily conserved role in the formation and maintenance of heterochromatin. In addition, CBX5, CBX1, and CBX3 may also participate in transcriptional regulation of genes. Recently, CBX3 binding to the bodies of a subset of genes has been observed in human and murine cells. However, the generality of this phenomenon and the role CBX3 may play in this context are unknown. Genome-wide localization analysis reveals CBX3 binding at genic regions, which strongly correlates with gene activity across multiple cell types. Depletion of CBX3 resulted in down-regulation of a subset of target genes. Loss of CBX3 binding leads to a more dramatic accumulation of unspliced nascent transcripts. In addition, we observed defective recruitment of splicing factors, including SNRNP70, to CBX3 target genes. Collectively, our data suggest a role for CBX3 in aiding in efficient cotranscriptional RNA processing.
Identification of miR-758-3p as Potential Modulator of CBX5 Expression in Gastric Cancer
TECHNOLOGY IN CANCER RESEARCH & TREATMENT
Authors: Guo, Jinxing; Zhang, Zichao; Pan, Lijie; Zhou, Yuanhang
Abstract
Gastric cancer is one of the most frequently diagnosed cancer types in China and also the leading causes of cancer-related death. Previous study showed chromobox 5 expression was elevated in gastric cancer, but little is known regarding the precise molecular mechanisms by which chromobox 5 expression was modulated. In this study, we revealed that chromobox 5 could promote gastric cancer cell proliferation, migration, and invasion in vitro. We screened and identified microRNA-758-3p, whose expression was downregulated in gastric cancer tissues and cell lines, which was a potential upstream molecule of chromobox 5. Upregulation of microRNA-758-3p could markedly downregulate the expression of chromobox 5. Additionally, expression of microRNA-758-3p and chromobox 5 was inversely correlated in gastric cancer tissues. Moreover, microRNA-758-3p overexpression suppressed gastric cancer cell proliferation, migration, and invasion, but these effects can be partially reversed by chromobox 5 overexpression. Collectively, our results indicate that microRNA-758-3p serves as a tumor suppressor and plays a crucial role in inhibiting the proliferation, migration, and invasion of gastric cancer via targeting chromobox 5 and implicate its potential application in cancer therapy.