Project description:Background: Liver cancer is the third deadliest type of cancer, posing a serious threat to human health. Hepatocellular carcinoma (HCC) is the most common type of primary liver cancer. C. sinensis, classified as a definite group I carcinogen by the IARC (International Agency for Research on Cancer), is an important risk factor for HCC. Although many studies have shown that C. sinensis infection affects the prognosis of HCC patients, the specific mechanisms are still unclear, especially the dynamics and regulatory roles of chromatin accessibility. Results: In this study, we integrated ATAC-seq, RNA-seq, and ChIP-seq data to elucidate changes in the epigenetics of HCC after the C. sinensis infection. Many different accessibility regions (DARs) were identified both in tumors and adjacent tissue after the C. sinensis infection. Meanwhile, top TFs whose motifs were enriched in DAR were found, such as HNF4a, FOXI1, etc. Although there were slight deviations, epigenetic changes were found to be consistent with gene expression levels. We also revealed that H3K9ac, H3K4me2, H3K4me3, H3K27ac, and H3K4me1 were associated with chromatin accessibility. Importantly, we also found potential evidence that C. sinensis infection would alter the spatial structure of the HCC genome. Finally, both molecular experimental results and clinical data certified that C. sinensis infection would promote the metastasis of HCC. Conclusions: C. sinensis infection will remodel the chromatin accessibility of HCC, leading to changes in gene expression levels. This study provides conclusive evidence that C. sinensis infection alters the epigenetics of HCC.
Project description:Background The Lycophyta species are the extant taxa most similar to early vascular plants that were once abundant on Earth. However, their distribution has greatly diminished. So far, the absence of chromosome level assembled lycophyte genomes, has hindered our understanding of evolution and environmental adaption of lycophytes. Findings We present the reference genome of the tetraploid aquatic quillwort, Isoetes sinensis, a lycophyte. This genome represents the first chromosome-level assembled genome of a tetraploid seed-free plant. Comparison of genomes between I. sinensis and the diploid I. taiwanensis revealed of genomic features and polyploid of lycophytes. Comparison of the I. sinensis genome with those of other species representing the evolutionary lineages of green plants revealed the inherited genetic tools for transcriptional regulation and most phytohormones in I. sinensis. The presence and absence of key genes related to development and stress responses provides insights into environmental adaption of lycophytes. Conclusions The high-quality reference genome and genomic analysis presented in this study are crucial for future genetic research and the conservation of not only I. sinensis but also other lycophytes.
