PTBP1 promotes the progression of hepatocellular carcinoma by enhancing the oncogenic splicing switch of FGFR2.

Hepatocellular carcinoma (HCC) is the most common type of primary liver cancer accounting for 90% of cases. It is a highly invasive and deadly cancer with a gradual onset. Polypyrimidine tract-binding protein 1 (PTBP1) is an important RNA-binding protein involved in RNA metabolism and has been linked to oncogenic splicing events. While the oncogenic role of PTBP1 in HCC cells has been established, the exact mechanism of action remains unclear. This study aimed to investigate the functional connection between PTBP1 and dysregulated splicing events in HCC. Through immunoprecipitation-mass spectrometry analyses, we discovered that the proteins bound to PTBP1 were significantly enriched in the complex responsible for the alternative splicing of FGFR2 (fibroblast growth factor receptor 2). Further RNA immunoprecipitation and quantitative PCR assays confirmed that PTBP1 down-regulated the FGFR2-IIIb isoform levels and up-regulated the FGFR2-IIIc isoform levels in HCC cells, leading to a switch from FGFR2-IIIb to FGFR2-IIIc isoforms. Subsequent functional evaluations using CCK-8, transwell, and plate clone formation assays in HCC cell lines HepG2 and Huh7 demonstrated that FGFR2-IIIb exhibited tumor-suppressive effects, while FGFR2-IIIc displayed tumor-promoting effects. In conclusion, this study provides insights into the PTBP1-mediated alternative splicing mechanism in HCC progression, offering a new theoretical basis for the prevention and treatment of this malignancy. Mechanistically, the isoform switch from FGFR2-IIIb to FGFR2-IIIc promoted epithelial-mesenchymal transformation (EMT) of HCC cells and activated the FGFR cascades ERK and AKT pathways.

The application of CRISPR genome editing technologies in the pathogenesis studies, diagnosis, prevention and treatment of infectious diseases.

The CRISPR genome editing technology shows great application prospects in gene manipulation and infectious disease research, and is of great value for effective control and cure of infectious diseases. It has been utilized to generate specific disease models in cells, organoids and animals, which provide great convenience for research into the molecular mechanisms associated with infectious diseases. CRISPR screening technology enables high-throughput identification of risk factors. New molecular diagnostic tools based on CRISPR offer a more sensitive and faster method for detecting pathogens. The use of CRISPR tools to introduce resistance genes or to specifically destroy risk genes and virus genomes is intended to help prevent or treat infectious diseases. This review discusses the application of CRISPR genome editing technologies in the construction of disease models, screening of risk factors, pathogen diagnosis, and prevention and treatment of infectious diseases, thereby providing a reference for follow-up research in pathogenesis, diagnosis, prevention and treatment of infectious diseases.

Progresses on genetic susceptibility of COVID-19.

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection causes a broad clinical spectrum of coronavirus disease 2019 (COVID-19). Genetic factors might influence susceptibility to the SARS-CoV-2 infection or disease severity. Genome-wide association studies (GWASs) have identified multiple susceptible genes related to COVID-19 phenotypes, providing the scientific basis for the COVID-19 prevention and treatment. In this review, we summarize the recent progresses of COVID-19 susceptible genes, including the GWASs on multiple phenotypes of COVID-19, GWASs of COVID-19 in multiple ethnic populations, GWASs of COVID-19 based on multiple types of genetic variations, and the fine-mapping of the regions surrounding the susceptible genes.

PTBP1 Promotes Growth, Migration and Invasion of Cholangiocarcinoma Cells by Regulating mRNA Alternative Splicing / 中国生物化学与分子生物学报

Cholangiocarcinoma (CCA) is a highly invasive type of cancer with insidious onset and high mortality. Polypyrimidine tract-binding protein 1 (PTBP1) is highly over-expressed in various types of tumor tissues, which contributes to cancer progression. But the role of PTBP1 in CCA has not been explored yet. In this study, we aim to investigate the function of PTBP1 in CCA. Therefore, we used publicly available data from the cancer genome atlas (TCGA) to evaluate the dysregulation of PTBP1 in CCA. The results showed that the PTBP1 is significantly up-regulated in CCA tissues compared to the matched non-tumor tissues (P < 0. 05). We assessed the effects of PTBP1 on the growth of CCA cell lines RBE and HuH28 by performing CCK-8 and plate colony formation assays. The results showed that overexpression of PTBP1 significantly promoted the growth (P < 0. 01) of CCA cells, whereas knockdown of PTBP1 exhibited opposite effects. Transwell and Invasion assays revealed that overexpression of PTBP1 significantly promotes the migration and invasion of CCA cells (P < 0. 001), whereas knockdown of PTBP1 exhibited opposite effects (P < 0. 001). The RNA sequencing (RNA-seq) analysis in PTBP1-depleted cells showed that the up-regulated genes are significantly enriched in p53 signaling pathway, while the down-regulated genes are represented by cholesterol metabolism, Rho GTPase and TGF-β pathways. Then, the alternative splicing analysis revealed that inhibition of PTBP1 led to series of aberrant alternative splicing events, including several cancer-associated ones, such as splicing events within the TGF-β regulator TGIF1 and the p53 activity-correlated gene GNAS. These results indicate that PTBP1 promotes the progression of CCA likely by regulating the transcriptome alternative splicing to influence multiple cancer-associated signaling pathways.

Effect of MCUR1 on proliferation,cell cycle and apoptosis of K562 cells / 军事医学

Objective To investigate the effect of mitochondrial calcium uniporter(MCU)regulator 1(MCUR1)on proliferation,cell cycle and apoptosis of K562 cells and the possible molecular mechanism.Methods Recombinant plasmid vectors containing short hairpin RNAs(shRNAs)targeting MCUR1 were transfected into K562 cells,before the K562 cells stably expressing low MCUR1 were selected with G418.The expression of MCUR1 mRNA was detected by quantitative real-time polymerase chain reaction(qRT-PCR)assays.Western blotting(WB)assays were used to detect the expressions of MCUR1,P53,BAX and BCL2.The proliferation,cell cycle and apoptosis of K562 cells were detected by cell counting kit-8(CCK-8)assays and flow cytometry, respectively.Results The results of qRT-PCR and WB assays revealed that MCUR1 was stably down-regulated at mRNA and protein levels in the K562 cells transfected with shRNAs targeting MCUR1.Knockdown of MCUR1 significantly inhibited the cell proliferation, induced the cell apoptosis, but did not influence the cells cycle.Meanwhile, knockdown of MCUR1 increased the expression of P53 protein and the ratio of protein BAX/BCL2 in K562 cells.Conclusion MCUR1 promotes cell proliferation and inhibits cell apoptosis in K 562 cells.

Functional polymorphism in exon 5 and variant haplotype of the interleukin-1 receptor-associated kinase 1 gene are associated with susceptibility to and severity of sepsis in the Chinese population / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>The interleukin-1 (IL-1) receptor-associated kinase 1 (IRAK1) is believed to play an important role in the pathogenesis of sepsis. Recent studies have suggested that the IRAK1 functional genetic variant could affect the severity of sepsis in Caucasians. In this report, we have investigated whether polymorphisms at the IRAK1 gene are associated with the susceptibility to and severity of sepsis among the Chinese population.</p><p><b>METHODS</b>Haplotype-tagging single nucleotide polymorphisms (htSNPs) were selected from the HapMap database. They were genotyped in 255 patients with sepsis and 260 control subjects by PCR/restriction fragment length polymorphism (RFLP) analysis. The association between the selected htSNPs and the susceptibility to and severity of sepsis were estimated by Logistic regression with adjustments for age, sex, smoking, drinking, chronic disease status, Acute Physiology and Chronic Health Evaluation (APACHE) II score and primary diseases.</p><p><b>RESULTS</b>rs1059702 was selected to represent the six linked htSNPs for IRAK1. Genotype frequencies of the htSNPs were in Hardy-Weinberg equilibrium for females, as were allele frequencies for both sex groups. Associations were observed in females between the htSNPs C/C genotype and increased susceptibility to sepsis (odds ratio (OR), 5.46; 95% confidence interval (CI), 1.12 - 26.67; P = 0.018), and such associations were also observed between the IRAK1 variant haplotype (CC/C-allele) and increased susceptibility to sepsis (OR, 1.68; 95% CI, 1.05 - 2.70; P = 0.031) when compared with the T/T + T/C genotype and the wild-type haplotype (TC + TT/T-allele). In the multiple organ dysfunction syndrome (MODS) subgroup, the variant haplotype was also associated with increased severity of sepsis (OR, 2.37; 95% CI, 1.13 - 4.94; P = 0.02) when compared with the wild haplotype. This association was not significant in male patients.</p><p><b>CONCLUSIONS</b>The functional polymorphism in exon 5 and the variant haplotype of IRAK1 gene mediate susceptibility to and severity of sepsis. IRAK1 might be a genetic risk factor for the occurrence and development of sepsis in the Chinese population.</p>

TRAF6 polymorphisms not associated with the susceptibility to and severity of sepsis in a Chinese population / 世界急诊医学杂志（英文）

@#BACKGROUND: The tumor necrosis factor recepter associated factor (TRAF) 6 is an important intracellular adapter protein that plays a pivotal role in activating multiple inflammatory and immune related processes induced by cytokines. TRAF6 represents a strong candidate susceptibility factor for sepsis. We investigated whether polymorphisms at the TRAF6 gene are associated with the susceptibility to and severity of sepsis. METHODS: A hospital-based case-control study was conducted with 255 patients with sepsis and 260 controls who were recruited from Zhengzhou, China. Haplotype tagging single nucleotide polymorphisms (htSNPs) were selected from the HapMap database and genotyped using the SNPstream genotyping platform. The associations with the susceptibility and disease severity of sepsis were estimated by logistic regression, and adjusted for age, sex, smoking, drinking, chronic diseases status, APACHEII score and critical illness status. RESULTS: A total of 13 TRAF6 SNPs were tagged by 7 htSNPs. Five htSNPs (rs5030490, rs5030411, rs5030416, rs5030445 and rs3740961) were genotyped in the case control study. Genotype frequencies of the htSNPs were conformed to the Hardy-Weinberg equilibrium in both patients and controls. No significant association was found between the 5 htSNPs and the susceptibility to and severity of sepsis. Compared with the main haplotype -11120A/-10688T/-9423A/805G/12967G, no certain haplotype was associated with the significantly susceptibility to or severity of sepsis. CONCLUSION: TRAF6 gene polymorphisms might not play a major role in mediating the susceptibility to and severity of sepsis in the Chinese population. A larger population-based case-control study is warranted.

Association of the T1270533G polymorphism in GSTM1 gene coding region with susceptibility to nasopharyngeal carcinoma in a Chinese population / 南方医科大学学报

<p><b>OBJECTIVE</b>To explore the association of T1270533G polymorphism in the glutathione S-transferase M1 (GSTM1) gene with the susceptibility to nasopharyngeal carcinoma (NPC) and clinical phenotype of NPC in Chinese population. METHDOS: The genomic DNAs were obtained from 27 Chinese subjects, and the single nucleotide polymorphism (SNP) in all the exons and relevant intron-exon boundaries of GSTM1 were determined by PCR and direct sequencing. A case-control study was performed to analyze the SNP site T1270533G (the rare allele frequency is 22.2% in Chinese population) in the coding region by means of tetra-primer amplification refractory mutation system-polymerase chain reaction (ARMS-PCR) and sequencing.</p><p><b>RESULT</b>Sequence analysis identified 29 SNPs in GSTM1 gene, among which 13 SNPs presented high linkage disequilibrium with each other. No obvious relations were found between the variation in the coding region T1270533G and the clinical phenotype of NPC (RR=0.170, 95% CI =0.95-0.306 for TT homozygotes).</p><p><b>CONCLUSION</b>The missense mutation in the coding region T1270533G of GSTM1 gene that causes an amino acid change does not affect the detoxification function of GSTM1, and the T1270533G polymorphism does not have apparent relations to NPC susceptibility in Chinese subjects in Guangdong Province.</p>

Study on single nucleotide polymorphism of TLR4 in Chinese population / 中华医学遗传学杂志

<p><b>OBJECTIVE</b>To identify the single nucleotide polymorphisms(SNPs) in the regulatory and coding regions of human Toll-like receptor 4(TLR4) gene and to search for its new genetic makers.</p><p><b>METHODS</b>The 5' flank region, exons, parts of the introns, as well as 3' flank region of TLR4 gene were sequenced to identify and characterize the SNPs in Chinese population. SNP genotyping was performed by polymerase chain reaction-restriction fragment length polymorphism for 2 highly distributed SNPs.</p><p><b>RESULTS</b>Five novel SNPs were identified through a 4.98 kb sequencing of TLR4 gene. Among them, three were in 5'flank region, two in 3'UTR. In the sample of Han population from Chongqing, the minor allele frequencies of two highly distributed SNPs were 0.266 and 0.404 respectively.</p><p><b>CONCLUSION</b>Sampling analysis in Han population of Chongqing showed that the two highly distributed SNPs of TLR4 were common in Chinese population and could be used for genetic marker of TLR4 gene.</p>

An investigation of polymorphism in IL-1R1 gene in Chinese population and the functional prediction of a variation in the transmembrane region of IL-1R1 / 中华医学遗传学杂志

<p><b>OBJECTIVE</b>To identify the single nucleotide polymorphisms (SNPs) in the regulatory and coding regions of human interleukin-1 receptor type I (IL-1R1) gene and to assess their potential effect on the function of IL-1R1.</p><p><b>METHODS</b>The 5' flank region, exons, parts of the introns, as well as 3' flank region of IL-1R1 gene were sequenced to identify and characterize the SNPs in Chinese population. Effects of the SNP on the structure and function of IL-1R1 were analyzed by computational methods.</p><p><b>RESULTS</b>Sixteen SNPs were identified through a 9643 bp sequencing of IL-1R1 gene. Among them, four were in 5' flank region, four in intron region, one in coding region, and seven in 3' untranslated region. A novel SNP in Chinese population was involved in a structural change in IL-1R1, which may influence the signal transduction of IL-1R1.</p><p><b>CONCLUSION</b>The SNP in the IL-1R1 gene might influence its function as an important receptor of IL-1 family.</p>