Biology subjects

li, Z.

Publications and source records attributed to li, Z..

5 recordsLinked to original sources

bioRxiv2024

RNA Splicing Junction Landscape Reveals Abundant Tumor-Specific Transcripts in Human Cancer

RNA splicing is a critical process governing gene expression and transcriptomic diversity. Despite its importance, a detailed examination of transcript variation at the splicing junction level remains scarce. Here, we perform a thorough analysis of RNA splicing junctions in 34,775 samples across multiple sample types. We identified 29,051 tumor-specific transcripts (TSTs) in pan-cancer, with a majority of these TSTs being unannotated. Our findings show that TSTs are positively correlated with tumor stemness and linked to unfavorable outcomes in cancer patients. Additionally, TSTs display mutual exclusivity with somatic mutations and are overrepresented in transposable element-derived transcripts possessing oncogenic functions. Importantly, TSTs can generate neoepitopes that bind to MHC class I molecules for immunotherapy. Moreover, TSTs can be detected in blood extracellular vesicles from cancer patients. Our results shed light on the intricacies of RNA splicing and offer promising avenues for cancer diagnosis and therapy. In briefThis study thoroughly analyzed RNA splicing junctions in 34,775 samples and identified 29,051 tumor-specific transcripts (TSTs), which may serve as novel cancer driver genes, neoantigens, and circulating biomarkers. Graphical abstract O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=153 SRC="FIGDIR/small/579246v1_ufig1.gif" ALT="Figure 1"> View larger version (35K): org.highwire.dtl.DTLVardef@7e1db2org.highwire.dtl.DTLVardef@1cfbe81org.highwire.dtl.DTLVardef@1e427e1org.highwire.dtl.DTLVardef@1f655f5_HPS_FORMAT_FIGEXP M_FIG C_FIG

cancer biology↗

bioRxiv2022

Screening candidate genes related to psoas muscle traits in Debao and Landrace pigs based on transcriptome analysis

To identify the important genes that affect the phenotypic differences between the Landrace and Debao pigs, especially the differences in metabolism and muscle growth. Differentially expressed genes of psoas major were detected by mRNA transcriptome sequencing in Landrace and Debao pigs. By extracting the total RNA of the psoas major muscle of the Landrace pig and the Debao pig, purifying the mRNA, constructing the cDNA library, conducting transcriptome sequencing, and then through the sequencing quality evaluation, we know that the sequencing quality of this study is relatively high. A total of 17,943 genes were detected in all samples, including 17,870 known genes and 73 new genes. Defined genes with |log2FC| greater than 2 and Q-value less than 0.001, and screened them as significantly differentially expressed genes. A total of 1661 differentially expressed genes were screened from the samples of Landrace pigs and Debao pigs, among which 1255 genes were differentially up-regulated and 406 genes were differentially down-regulated. Through differential gene analysis, it is concluded that these genes are mainly involved in metabolic regulation, muscle and fat development and other processes, especially some important functional genes such as MAPK14, FOS, SIRT1, KRAS, EGR1, CDNNB1, etc. To sum up, this study used transcriptome sequencing method, and then selected differentially expressed genes between Landrace pigs and Debao pigs through data analysis, and finally screened out important genes affecting phenotypic differences, which provided genetic support for breeding better breeds in the future.

genomics↗

bioRxiv2021

Near atomic structure of the inner ring of the Saccharomyces cerevisiae nuclear pore complex

Nuclear pore complexes (NPCs) mediate bidirectional nucleocytoplasmic transport of substances in eukaryotic cells. However, the accurate molecular arrangement of NPCs remains enigmatic owing to their huge size and highly dynamic nature. Here we determined the structure of the asymmetric unit of the inner ring (IR monomer) at 3.73 [A] resolution by single-particle cryo-electron microscopy, and created an atomic model of the intact IR consisting of 192 copies from 8 subunits. In each IR monomer, two approximately parallel rhomboidal structures of the inner and outer layers are sandwiched with the Z-shaped Nup188-Nup192 middle layer and Nup188, Nup192 and Nic96 link all subunits to constitute a relatively stable IR monomer, while the intact IR is assembled by loose and instable interactions between IR monomer. These structures reveal various interaction modes and extensive flexible connections in the assembly, providing a structural basis for the stability and malleability of IR. One-Sentence SummaryAccurate structure of inner ring reveals its assembly and function in dilation and constriction of nuclear pore complex.

biophysics↗

bioRxiv2019

LARP7 is a BRCA1 ubiquitinase substrate and regulates genome stability and tumorigenesis

Attenuated DNA repair leads to genomic instability and tumorigenesis. BRCA1/BARD1 are the best known tumor suppressors that promote homology recombination (HR) and arrest cell cycle at G2/M checkpoint. As E3 ubiquitin ligases, their ubiquitinase activity has been known to involve in the HR and tumor suppression, but the mechanism remains ambiguous. Here, we demonstrated upon genotoxic stress, BRCA1 together with BARD1 catalyzed the K48 ployubiquitination on LARP7, a 7SK RNA binding protein known to control RNAPII pausing, and thereby degraded it through 26S ubiquitin-proteasome pathway. Depleting LARP7 suppressed the expression of CDK1 complex, arrested cell at G2/M DNA damage checkpoint and reduced BRCA2 phosphorylation which thereby facilitated RAD51 recruitment to damaged DNA to enhance HR. Importantly, LARP7 depletion observed in breast patients lead to the chemoradiotherapy resistance both in vitro and in vivo. Together, this study unveils a mechanism by which BRCA1/BARD1 utilizes their E3 ligase activity to control HR and cell cycle, and highlights LARP7 as a potential target for cancer prevention and therapy.\n\nHighlightsO_LIDNA damage response downregulates LARP7 through BRCA1/BARD1\nC_LIO_LIBRCA1/BARD1 catalyzes the K48 polyubiquitination on LARP7\nC_LIO_LILARP7 promotes G2/M cell cycle transition and tumorigenesis via CDK1 complex\nC_LIO_LILARP7 disputes homology-directed repair that leads to tumor therapy resistance\nC_LI

molecular biology↗

bioRxiv2019

The Influence of Blood Collection Tubes in Biomarkers Screening by Mass Spectrometry

BackgroundMass spectrometry (MS) is one of the rapidly developing bio-analytical techniques in recent years and have found many biomarkers of variety of disease. Whereas pre-analytical process is one of most crucial procedure which would significantly influence the results of biomarkers screening. In the current study, we conducted a pilot analysis of serum to determine the effects of blood collection tubes in biomarkers screening.\n\nMethodsMagnetic bead separation and matrix-assisted laser desorption ionization time-of-flight mass spectrometry were used for qualitative analysis of healthy control and serum cancer patients. A total of 24 serum samples were analyzed in this study, of which were collected from patients or healthy control using non-additive tubes or coagulant activator tubes respectively. ClinProTools were used to compare the difference among the different groups.\n\nResultsThe results demonstrated that no matter for patients or normal people, the serum protein profile changed significantly when using coagulant tubes. We also found that the effect of coagulant on serum protein of patients was smaller than that of control group. There were significant differences among 27 peaks which were obtained in the control group and the control coagulant group. However, between patient group and patient coagulant group, only 1 differential peak were obtained. Coagulant changed the protein expression difference in the original serum, and the difference expanded, narrowed even reversed, most of which are small polypeptides (Mass<3000 Da), which significantly changed the results of biomarkers screening. The results showed that 19 potential biomarkers could be found with non-additive tubes and 16 potential biomarkers could be found with coagulate activator tubes, among which only 6 were the same.\n\nConclusionsThe choice of blood collection tube significantly influence the results of biomarkers screening by MS.

cancer biology↗