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1.
PLoS Pathog ; 20(2): e1012061, 2024 Feb.
Article in English | MEDLINE | ID: mdl-38416782

ABSTRACT

Alternative polyadenylation (APA) is a widespread mechanism of gene regulation that generates mRNA isoforms with alternative 3' untranslated regions (3' UTRs). Our previous study has revealed the global 3' UTR shortening of host mRNAs through APA upon viral infection. However, how the dynamic changes in the APA landscape occur upon viral infection remains largely unknown. Here we further found that, the reduced protein abundance of CPSF6, one of the core 3' processing factors, promotes the usage of proximal poly(A) sites (pPASs) of many immune related genes in macrophages and fibroblasts upon viral infection. Shortening of the 3' UTR of these transcripts may improve their mRNA stability and translation efficiency, leading to the promotion of type I IFN (IFN-I) signalling-based antiviral immune responses. In addition, dysregulated expression of CPSF6 is also observed in many immune related physiological and pathological conditions, especially in various infections and cancers. Thus, the global APA dynamics of immune genes regulated by CPSF6, can fine-tune the antiviral response as well as the responses to other cellular stresses to maintain the tissue homeostasis, which may represent a novel regulatory mechanism for antiviral immunity.


Subject(s)
Polyadenylation , Virus Diseases , mRNA Cleavage and Polyadenylation Factors , Humans , 3' Untranslated Regions/genetics , Down-Regulation , Immunity/genetics , mRNA Cleavage and Polyadenylation Factors/genetics , mRNA Cleavage and Polyadenylation Factors/metabolism , RNA, Messenger/genetics , RNA, Messenger/metabolism , Virus Diseases/genetics , Mice , Animals
2.
Urol Oncol ; 42(1): 23.e5-23.e13, 2024 01.
Article in English | MEDLINE | ID: mdl-38030468

ABSTRACT

PURPOSE: To determine the optimal cut-off value of Ki-67 for predicting the survival of patients with clear cell renal cell carcinoma (ccRCC) and tumor thrombus and to explore the correlation between Ki-67 expression and pathological features. PATIENTS AND METHODS: We retrospectively analyzed Ki-67 immunohistochemical staining of ccRCC and tumor thrombus resected from February 2006 to February 2022. The survival rate was evaluated using the Kaplan-Meier method. The optimal cut-off value of the Ki-67 expression for predicting survival was determined by the minimum P-value method. Clinicopathological data were compared based on Ki-67 status (low versus high expression). Univariate and multivariate Cox regression analysis was used to explore independent predictors. RESULTS: A total of 202 patients (median age, 58 years [IQR, 52-65 years], 147 men) with ccRCC and tumor thrombus were included in the study. The optimal cut-off value of Ki-67 for predicting survival was 30%. 159 (78.7%) and 43 (21.3%) patients were included in the low-expression and high-expression groups. Patients with Ki-67 high expression had significantly worse recurrence-free survival (P < 0.001) and cancer-specific survival (P < 0.001). Ki-67 high expression was associated with adverse pathological features, including tumor necrosis, ISUP nuclear grade, sarcomatoid differentiation, perirenal fat invasion, renal pelvis invasion, and inferior vena cava wall invasion (all P < 0.050). Ki-67 expression ≥ 30% (P = 0.016), tumor side (P = 0.003), diabetes (P = 0.040), blood loss (P = 0.016), inferior vena cava wall invasion (P = 0.016), and sarcomatoid differentiation (P = 0.014) were independent predictors of cancer-specific survival. CONCLUSION: The optimal cut-off level of Ki-67 in predicting the prognosis of ccRCC and tumor thrombus was 30%. The high expression of Ki-67 was associated with the aggressive pathological phenotype and poor prognosis.


Subject(s)
Carcinoma, Renal Cell , Carcinoma , Kidney Neoplasms , Thrombosis , Male , Humans , Middle Aged , Carcinoma, Renal Cell/pathology , Kidney Neoplasms/pathology , Ki-67 Antigen , Retrospective Studies , Vena Cava, Inferior/pathology , Thrombosis/surgery , Prognosis , Neoplastic Processes , Carcinoma/pathology , Cell Proliferation , Nephrectomy/methods
3.
J Magn Reson Imaging ; 59(1): 134-145, 2024 01.
Article in English | MEDLINE | ID: mdl-37134147

ABSTRACT

BACKGROUND: Venous tumor thrombus (VTT) consistency of renal cell carcinoma (RCC) is an important consideration in nephrectomy plus thrombectomy. However, evaluation of VTT consistency through preoperative MR imaging is lacking. PURPOSE: To evaluate VTT consistency of RCC through intravoxel incoherent motion-diffusion weighted imaging (IVIM-DWI) derived parameters (Dt , Dp , f, and ADC) and the apparent diffusion coefficient (ADC) value. STUDY TYPE: Retrospective. POPULATION: One hundred and nineteen patients (aged 55.8 ± 11.5 years, 85 male) with histologically-proven RCC and VTT who underwent radical resection. FIELD STRENGTH/SEQUENCES: 3.0-T; two-dimensional single-shot diffusion-weighted echo planar imaging sequence at 9 b-values (0-800 s/mm2 ). ASSESSMENT: IVIM parameters and ADC values of the primary tumor and the VTT were calculated. The VTT consistency (friable vs. solid) was determined through intraoperative findings of two urologists. The accuracy of VTT consistency classification based on the individual IVIM parameters of primary tumors and of VTT, and based on models combining parameters, was assessed. Type of operation, intra-operative blood loss, and operation length were recorded. STATISTICAL TESTS: Shapiro-Wilk test; Mann-Whitney U test; Student's t-test; Chi-square test; Receiver operating characteristic (ROC) analysis. Statistical significance level was P < 0.05. RESULTS: Of the enrolled 119 patients, 33 patients (27.7%) had friable VTT. Patients with friable VTT were significantly more likely to experience open surgery, have significantly more intraoperative blood loss, and significantly longer operative duration. The area under the ROC curve (AUC) values of Dt of the primary tumor and VTT in classifying VTT consistency were 0.758 (95% CI 0.671-0.832) and 0.712 (95% CI 0.622-0.792), respectively. The AUC value of the model combining Dp and Dt of VTT was 0.800 (95% CI 0.717-0.868). Furthermore, the AUC of the model combining Dp and Dt of VTT and Dt of the primary tumor was 0.886 (95% CI 0.814-0.937). CONCLUSION: IVIM-derived parameters had the potential to predict VTT consistency of RCC. EVIDENCE LEVEL: 3 Technical Efficacy: Stage 2.


Subject(s)
Carcinoma, Renal Cell , Kidney Neoplasms , Thrombosis , Humans , Male , Carcinoma, Renal Cell/diagnostic imaging , Carcinoma, Renal Cell/surgery , Retrospective Studies , Veins , Diffusion Magnetic Resonance Imaging/methods , Motion , Kidney Neoplasms/diagnostic imaging , Kidney Neoplasms/surgery , Thrombosis/diagnostic imaging
4.
Cell Rep ; 42(10): 113197, 2023 10 31.
Article in English | MEDLINE | ID: mdl-37777964

ABSTRACT

Cancer cells usually exhibit shortened 3' untranslated regions (UTRs) due to alternative polyadenylation (APA) to promote cell proliferation and migration. Upregulated CPSF6 leads to a systematic prolongation of 3' UTRs, but CPSF6 expression in tumors is typically higher than that in healthy tissues. This contradictory observation suggests that it is necessary to investigate the underlying mechanism by which CPSF6 regulates APA switching in cancer. Here, we find that CPSF6 can undergo liquid-liquid phase separation (LLPS), and elevated LLPS is associated with the preferential usage of the distal poly(A) sites. CLK2, a kinase upregulated in cancer cells, destructs CPSF6 LLPS by phosphorylating its arginine/serine-like domain. The reduction of CPSF6 LLPS can lead to a shortened 3' UTR of cell-cycle-related genes and accelerate cell proliferation. These results suggest that CPSF6 LLPS, rather than its expression level, may be responsible for APA regulation in cancer cells.


Subject(s)
Neoplasms , Polyadenylation , 3' Untranslated Regions/genetics , Cell Proliferation , Gene Expression Regulation , mRNA Cleavage and Polyadenylation Factors/genetics , Neoplasms/genetics , Humans , Cell Line, Tumor
5.
Curr Med Imaging ; 2023 Jul 18.
Article in English | MEDLINE | ID: mdl-37464833

ABSTRACT

OBJECTIVE: This article aims to explore the ADC value of ultrahigh b-value DWI and the diagnostic cutoff point in prostate cancer. METHODS: A total of 78 patients were included in this study. T2 weighted imaging (T2WI), conventional diffusion-weighted imaging (DWI) (1000 s/mm2), and DWI with ultrahigh b-values of 2000 s/mm2 and 3000 s/mm2 were performed in each patient. With reference biopsy as the gold standard, the apparent diffusion coefficient (ADC)s of each b-value DWI image were analyzed. According to different b-value receiver operating characteristic (ROC) curves, the ADC diagnostic cutoff point for prostate cancer was determined. RESULTS: A total of 154 lesions were identified as prostate cancer. The ADC values for conventional DWI and ultrahigh b-value DWI with 2000 s/mm2 and 3000 s/mm2 were 1.097×10-3 mm2/s (1.040-1.153), 0.809×10-3 mm2/s (0.766-0.851) and 0.622×10-3 mm2/s (0.591-0.652), respectively, in the peripheral zone and 1.085×10-3 mm2/s (1.022-1.147), 0.815×10-3 mm2/s (0.770-0.861) and 0.651×10-3 mm2/s (0.617-0.685) in the transition zone. The area under the curve (AUC)s of the ADC values from ultrahigh b-value DWI (2000 s/mm2 and 3000 s/mm2) were 0.824 and 0.852 in the peripheral zone and 0.905 for the ADC values from ultrahigh b-value DWI (3000 s/mm2) in the transition zone. In the peripheral zone, the ADC diagnostic cutoff values for prostate cancer were 0.75×10-3 mm2/s and 0.685×10-3 mm2/s in DWI at 2000 s/mm2 and 3000 s/mm2, respectively, and the diagnosis of transition zone cancer was 0.8×10-3 mm2/s and 0.634×10-3 mm2/s, respectively. CONCLUSION: The ADC values from ultrahigh b-value DWI demonstrated better consistency and diagnostic efficacy in the diagnosis of prostate cancer.

6.
J Mol Cell Biol ; 14(8)2022 12 26.
Article in English | MEDLINE | ID: mdl-36073763

ABSTRACT

In eukaryotic cells, both alternative splicing and alternative polyadenylation (APA) play essential roles in the gene regulation network. U1 small ribonucleoprotein particle (U1 snRNP) is a major component of spliceosome, and U1 snRNP complex can suppress proximal APA sites through crosstalking with 3' end processing factors. However, here we show that both knockdown and overexpression of SNRPA, SNRPC, SNRNP70, and SNRPD2, the U1 snRNP proteins, promote the usage of proximal APA sites at the transcriptome level. SNRNP70 can drive the phase transition of PABPN1 from droplet to aggregate, which may reduce the repressive effects of PABPN1 on the proximal APA sites. Additionally, SNRNP70 can also promote the proximal APA sites by recruiting CPSF6, suggesting that the function of CPSF6 on APA is related with other RNA-binding proteins and cell context-dependent. Consequently, these results reveal that, on the contrary to U1 snRNP complex, the free proteins of U1 snRNP complex can promote proximal APA sites through the interaction with 3' end processing machinery.


Subject(s)
Polyadenylation , Ribonucleoprotein, U1 Small Nuclear , Ribonucleoprotein, U1 Small Nuclear/genetics , Ribonucleoprotein, U1 Small Nuclear/metabolism , Alternative Splicing/genetics , RNA-Binding Proteins/genetics , RNA-Binding Proteins/metabolism , RNA Splicing
7.
EMBO Rep ; 23(11): e54686, 2022 11 07.
Article in English | MEDLINE | ID: mdl-36094741

ABSTRACT

N6-methyladenosine (m6 A) and alternative polyadenylation (APA) are important regulators of gene expression in eukaryotes. Recently, it was found that m6 A is closely related to APA. However, the molecular mechanism of this new APA regulation remains elusive. Here, we show that YTHDC1, a nuclear m6 A reader, can suppress proximal APA sites and produce longer 3' UTR transcripts by binding to their upstream m6 A sites. YTHDC1 can directly interact with the 3' end processing factor FIP1L1 and interfere with its ability to recruit CPSF4. Binding to the m6 A sites can promote liquid-liquid phase separation of YTHDC1 and FIP1L1, which may play an important role in their interaction and APA regulation. Collectively, YTHDC1 as an m6 A "reader" links m6 A modification with pre-mRNA 3' end processing, providing a new mechanism for APA regulation.


Subject(s)
Cell Nucleus , Polyadenylation , RNA, Messenger/genetics , RNA, Messenger/metabolism , Cell Nucleus/metabolism , Adenosine/metabolism , 3' Untranslated Regions
8.
J Proteomics ; 192: 346-357, 2019 02 10.
Article in English | MEDLINE | ID: mdl-30267875

ABSTRACT

The venom ducts of marine cone snails secrete highly complex mixtures of cysteine-rich active peptides, which are generally known as conotoxins or conopeptides and provide a potential fertile resource for pharmacological neuroscience research and the discovery of new drugs. Previous studies have devoted substantial effort to the identification of novel conopeptides, and the 109 cone snail species have yielded 7000 known conopeptides to date. Here, we used de novo deep transcriptome sequencing analyses combined with traditional Sanger sequencing and liquid chromatography-mass spectrometry/mass spectrometry (LC-MS/MS) to identify 30 distinct conopeptide precursors. Twenty of these were previously reported and the other 10 were novel conopeptide precursors. The study provides the first identification of the Con-ikot-ikot, NSF-bt05, O3 and I1 gene superfamilies in C. litteratus. A new putative superfamily was identified. In addition, the following cysteine frameworks were first identified in this study: CC-C-C-C-C-C-C-C-C-C-C-C-CC-C-C-C-C-C and C-C-C-C-C-CC-C. Several isomerases involved in post-translational modification of conopeptides were identified as well. The discovery of new conopeptides in C. litteratus will enhance our understanding of the conopeptide diversity in this particular clade of cone snails. We also found the existence of intraspecific variations in vermivorous species. Finally, the analysis strategy offers a relatively reliable workflow for screening for peptide drug candidates. SIGNIFICANCE: These novel conopeptides provide a potential resource for the development of new channel-targeting drugs. The intraspecific variation in C. litteratus enhance our understanding of the conopeptide diversity in this particular clade of cone snails. The identified three cysteine residues, which might participate in the formation of disulfide bonds, provide a clue to get the connectivity of cysteine frameworks. Finally, the analysis strategy offers a relatively reliable workflow for screening for peptide drug candidates.


Subject(s)
Conotoxins/metabolism , Conus Snail/metabolism , Peptides/metabolism , Animals , Chromatography, Liquid , Mass Spectrometry , Proteomics
9.
Genome Res ; 28(11): 1656-1663, 2018 11.
Article in English | MEDLINE | ID: mdl-30228199

ABSTRACT

3' UTRs play important roles in the gene regulation network via their influence on mRNA stability, translational efficiency, and subcellular localization. For a given gene, 3' UTRs of different lengths generated by alternative polyadenylation (APA) may result in functional differences in regulation. The mechanistic details of how length changes of 3' UTRs alter gene function remain unclear. By combining APA sequencing and polysome profiling, we observed that mRNA isoforms with shorter 3' UTRs were bound with more polysomes in six cell lines but not in NIH3T3 cells, suggesting that changing 3' UTRs to shorter isoforms may lead to a higher gene translational efficiency. By interfering with the expression of TNRC6A and analyzing AGO2-PAR-CLIP data, we revealed that the APA effect on translational efficiency was mainly regulated by miRNAs, and this regulation was cell cycle dependent. The discrepancy between NIH3T3 and other cell lines was due to contact inhibition of NIH3T3. Thus, the crosstalk between APA and miRNAs may be needed for the regulation of protein translational efficiency.


Subject(s)
MicroRNAs/genetics , Polyadenylation , Protein Biosynthesis , 3' Untranslated Regions , 3T3 Cells , Animals , Argonaute Proteins/genetics , Argonaute Proteins/metabolism , Autoantigens/genetics , Autoantigens/metabolism , Cell Cycle , Cells, Cultured , Humans , MCF-7 Cells , Mice , Polyribosomes/metabolism , RNA 3' Polyadenylation Signals , RNA, Messenger/genetics , RNA, Messenger/metabolism , RNA-Binding Proteins/genetics , RNA-Binding Proteins/metabolism , Species Specificity
10.
Sci Rep ; 8(1): 6824, 2018 05 01.
Article in English | MEDLINE | ID: mdl-29717174

ABSTRACT

Global shortening of 3'UTRs by alternative polyadenylation (APA) has been observed in cancer cells. However, the role of APA in cancer remains unknown. CCND1 is a proto-oncogene that regulates progression through the G1-S phase of the cell cycle; moreover, it has been observed to be switching to proximal APA sites in cancer cells. To investigate the biological function of the APA of CCND1, we edited the weak poly(A) signal (PAS) of the proximal APA site to a canonical PAS using the CRISPR/Cas9 method, which can force the cells to use a proximal APA site. Cell cycle profiling and proliferation assays revealed that the proximal APA sites of CCND1 accelerated the cell cycle and promoted cell proliferation, but UTR-APA and CR-APA act via different molecular mechanisms. These results indicate that PAS editing with CRISPR/Cas9 provides a good method by which to study the biological function of APA.


Subject(s)
Cell Cycle Checkpoints/physiology , Cyclin D1/metabolism , Polyadenylation/physiology , 3' Untranslated Regions/physiology , CRISPR-Cas Systems/physiology , Cell Proliferation/physiology , Cyclin D1/genetics , Genetic Loci , Genetic Vectors , HEK293 Cells , Humans , Mutation , Open Reading Frames/physiology , Poly A/metabolism , Protein Isoforms/metabolism , Proto-Oncogene Mas , RNA, Messenger/metabolism , Untranslated Regions/physiology
11.
J Immunol ; 199(9): 3106-3115, 2017 11 01.
Article in English | MEDLINE | ID: mdl-28954886

ABSTRACT

T cells are activated and differentiated into Th cells depending on the rapid and accurate changes in the cell transcriptome. In addition to changes in mRNA expression, the sequences of many transcripts are altered by alternative splicing and alternative polyadenylation (APA). We profiled the APA sites of human CD4+ T cell subsets with high-throughput sequencing and found that Th1 cells harbored more genes with shorter tandem 3' untranslated regions (UTRs) than did naive T cells. We observed that STAT5B, a key regulator of Th1 differentiation, possessed three major APA sites and preferred shorter 3' UTRs in Th1 cells. In addition, small nuclear ribonucleoprotein polypeptide A (SNRPA) was found to bind directly to STAT5B 3' UTR and facilitate its APA switching. We also found that p65 activation triggered by TCR signaling could promote SNRPA transcription and 3' UTR shortening of STAT5B. Thus we propose that the APA switching of STAT5B induced by TCR activation is mediated by SNRPA.


Subject(s)
3' Untranslated Regions/immunology , Cell Differentiation/immunology , Polyadenylation/immunology , Ribonucleoprotein, U1 Small Nuclear/immunology , STAT5 Transcription Factor/immunology , Th1 Cells/immunology , Humans , Receptors, Antigen, T-Cell/immunology , Signal Transduction/immunology
12.
Nat Commun ; 8: 14605, 2017 02 24.
Article in English | MEDLINE | ID: mdl-28233779

ABSTRACT

Alternative polyadenylation (APA) is an important regulatory mechanism of gene functions in many biological processes. However, the extent of 3' UTR variation and the function of APA during the innate antiviral immune response are unclear. Here, we show genome-wide poly(A) sites switch and average 3' UTR length shortens gradually in response to vesicular stomatitis virus (VSV) infection in macrophages. Genes with APA and mRNA abundance change are enriched in immune-related categories such as the Toll-like receptor, RIG-I-like receptor, JAK-STAT and apoptosis-related signalling pathways. The expression of 3' processing factors is down-regulated upon VSV infection. When the core 3' processing factors are knocked down, viral replication is affected. Thus, our study reports the annotation of genes with APA in antiviral immunity and highlights the roles of 3' processing factors on 3' UTR variation upon viral infection.


Subject(s)
Immunity, Innate/genetics , Polyadenylation/immunology , Receptors, Pattern Recognition/immunology , Signal Transduction/immunology , Virus Diseases/immunology , 3' Untranslated Regions/genetics , Animals , Down-Regulation , Female , Gene Expression Regulation/immunology , Humans , Leukocytes, Mononuclear , Macrophages , Mice , Mice, Inbred C57BL , Primary Cell Culture , Vesicular stomatitis Indiana virus/immunology
13.
PLoS One ; 10(12): e0145477, 2015.
Article in English | MEDLINE | ID: mdl-26710068

ABSTRACT

Gene transcribing with alternative polyadenylation (APA) sites leads to mRNA isoforms, which may encode different proteins or harbor different 3'UTRs. APA plays an important role in regulating gene expression network among various physiological processes, such as development, immune responses and cancer. Several methods of library construction for APA study have been developed to apply high-throughput sequencing. However, the requirement of high-input RNA and time-consuming nature of the current methods limited the studies of APA for the samples difficult to obtain. Here, we describe a new method based on our SAPAS in combining in vitro transcription (IVT) and magnetic beads purification. The new IVT-SAPAS provides a rapid and high-parallel procedure for APA library construction with low-input sample, which may be a new robust approach for studying APA.


Subject(s)
Polyadenylation , Sequence Analysis, RNA/methods , Transcription, Genetic , 3' Untranslated Regions/genetics , Binding Sites , Humans , MCF-7 Cells , Magnets , Microspheres , Time Factors
14.
Zhonghua Fu Chan Ke Za Zhi ; 50(3): 194-7, 2015 Mar.
Article in Chinese | MEDLINE | ID: mdl-26268409

ABSTRACT

OBJECTIVE: To investigate the association of PR gene exon 5 region H770H (rs1042839) single nucleotide polymorphism (SNP) with the genetic susceptibility to endometriosis (EM) in southern Han Chinese women. METHODS: Totally 431 EM patients and 499 non-EM women were collected and separated into EM group and control group, that all cases were confirmed by operation and pathology. A case-control study was performed in EM and control groups to evaluate the association of these SNP with the susceptibility to EM by using a fluorescent quantitative PCR-based high resolution melting (HRM) method. RESULTS: The C and T of PR H770H allele frequencies among the EM and control groups were 97.9% (844/862), 2.1% (18/862) and 99.4% (992/998), 0.6% (6/998), respectively. The CC, CT and TT of PR H770H genotype frequencies among the EM and control groups were 95.8% (413/431), 4.2% (18/431), 0 and 98.8% (493/499), 1.2% (6/499), 0, respectively. There were statistical significances in the PR H770H alleles and genotypes distributions between the two groups (χ(2)=7.386, P=0.007; χ(2)=8.135, P=0.004). Carrying allele C reduced the risk of EM (OR=0.986, 95%CI: 0.976-0.996), while carrying allele T enhanced the risk of EM (OR=3.319, 95% CI: 1.323-8.325); carrying genotype CC reduced the risk of EM 0.970 time (OR=0.970, 95% CI: 0.949-0.991), whereas carrying genotype CT enhanced the risk of EM 3.473 times (OR=3.473, 95%CI: 1.391-8.671). CONCLUSION: There is significant association between the polymorphism of PR H770H and genetic susceptibility to EM in southern Han Chinese women.


Subject(s)
Endometrial Neoplasms/genetics , Endometriosis/genetics , Genetic Predisposition to Disease/genetics , Polymorphism, Single Nucleotide/genetics , Promoter Regions, Genetic/genetics , Alleles , Asian People , Case-Control Studies , China , Female , Gene Frequency , Genotype , Humans , Polymerase Chain Reaction , Polymorphism, Genetic
15.
PLoS One ; 10(4): e0124324, 2015.
Article in English | MEDLINE | ID: mdl-25875641

ABSTRACT

Switching between different alternative polyadenylation (APA) sites plays an important role in the fine tuning of gene expression. New technologies for the execution of 3'-end enriched RNA-seq allow genome-wide detection of the genes that exhibit significant APA site switching between different samples. Here, we show that the independence test gives better results than the linear trend test in detecting APA site-switching events. Further examination suggests that the discrepancy between these two statistical methods arises from complex APA site-switching events that cannot be represented by a simple change of average 3'-UTR length. In theory, the linear trend test is only effective in detecting these simple changes. We classify the switching events into four switching patterns: two simple patterns (3'-UTR shortening and lengthening) and two complex patterns. By comparing the results of the two statistical methods, we show that complex patterns account for 1/4 of all observed switching events that happen between normal and cancerous human breast cell lines. Because simple and complex switching patterns may convey different biological meanings, they merit separate study. We therefore propose to combine both the independence test and the linear trend test in practice. First, the independence test should be used to detect APA site switching; second, the linear trend test should be invoked to identify simple switching events; and third, those complex switching events that pass independence testing but fail linear trend testing can be identified.


Subject(s)
Computational Biology/methods , Polyadenylation , 3' Untranslated Regions , Cell Line, Tumor , Databases, Factual , Humans , MCF-7 Cells , RNA, Messenger/genetics
16.
Mol Ecol ; 24(4): 771-84, 2015 Feb.
Article in English | MEDLINE | ID: mdl-25581109

ABSTRACT

Identifying the molecular markers for complex quantitative traits in natural populations promises to provide novel insight into genetic mechanisms of adaptation and to aid in forecasting population dynamics. In this study, we investigated single nucleotide polymorphisms (SNPs) using candidate gene approach from high- and low-fecundity populations of the brown planthopper (BPH) Nilaparvata lugens Stål (Hemiptera: Delphacidae) divergently selected for fecundity. We also tested whether the population fecundity can be predicted by a few SNPs. Seven genes (ACE, fizzy, HMGCR, LpR, Sxl, Vg and VgR) were inspected for SNPs in N. lugens, which is a serious insect pest of rice. By direct sequencing of the complementary DNA and promoter sequences of these candidate genes, 1033 SNPs were discovered within high- and low-fecundity BPH populations. A panel of 121 candidate SNPs were selected and genotyped in 215 individuals from 2 laboratory populations (HFP and LFP) and 3 field populations (GZP, SGP and ZSP). Prior to association tests, population structure and linkage disequilibrium (LD) among the 3 field populations were analysed. The association results showed that 7 SNPs were significantly associated with population fecundity in BPH. These significant SNPs were used for constructing general liner models with stepwise regression. The best predictive model was composed of 2 SNPs (ACE-862 and VgR-816 ) with very good fitting degree. We found that 29% of the phenotypic variation in fecundity could be accounted for by only two markers. Using two laboratory populations and a complete independent field population, the predictive accuracy was 84.35-92.39%. The predictive model provides an efficient molecular method to predict BPH fecundity of field populations and provides novel insights for insect population management.


Subject(s)
Fertility/genetics , Genetics, Population , Hemiptera/genetics , Animals , China , Female , Gene Frequency , Genes, Insect , Hemiptera/physiology , Linkage Disequilibrium , Models, Genetic , Molecular Sequence Data , Phenotype , Polymorphism, Single Nucleotide
17.
Nucleic Acids Res ; 43(Database issue): D59-67, 2015 Jan.
Article in English | MEDLINE | ID: mdl-25378337

ABSTRACT

Increasing amounts of genes have been shown to utilize alternative polyadenylation (APA) 3'-processing sites depending on the cell and tissue type and/or physiological and pathological conditions at the time of processing, and the construction of genome-wide database regarding APA is urgently needed for better understanding poly(A) site selection and APA-directed gene expression regulation for a given biology. Here we present a web-accessible database, named APASdb (http://mosas.sysu.edu.cn/utr), which can visualize the precise map and usage quantification of different APA isoforms for all genes. The datasets are deeply profiled by the sequencing alternative polyadenylation sites (SAPAS) method capable of high-throughput sequencing 3'-ends of polyadenylated transcripts. Thus, APASdb details all the heterogeneous cleavage sites downstream of poly(A) signals, and maintains near complete coverage for APA sites, much better than the previous databases using conventional methods. Furthermore, APASdb provides the quantification of a given APA variant among transcripts with different APA sites by computing their corresponding normalized-reads, making our database more useful. In addition, APASdb supports URL-based retrieval, browsing and display of exon-intron structure, poly(A) signals, poly(A) sites location and usage reads, and 3'-untranslated regions (3'-UTRs). Currently, APASdb involves APA in various biological processes and diseases in human, mouse and zebrafish.


Subject(s)
Databases, Nucleic Acid , Polyadenylation , Animals , Gene Expression , Humans , Internet , Mice , Poly A/analysis , RNA Cleavage , Zebrafish/genetics
18.
Nat Commun ; 5: 5896, 2014 Dec 19.
Article in English | MEDLINE | ID: mdl-25523484

ABSTRACT

Vertebrates diverged from other chordates ~500 Myr ago and experienced successful innovations and adaptations, but the genomic basis underlying vertebrate origins are not fully understood. Here we suggest, through comparison with multiple lancelet (amphioxus) genomes, that ancient vertebrates experienced high rates of protein evolution, genome rearrangement and domain shuffling and that these rates greatly slowed down after the divergence of jawed and jawless vertebrates. Compared with lancelets, modern vertebrates retain, at least relatively, less protein diversity, fewer nucleotide polymorphisms, domain combinations and conserved non-coding elements (CNE). Modern vertebrates also lost substantial transposable element (TE) diversity, whereas lancelets preserve high TE diversity that includes even the long-sought RAG transposon. Lancelets also exhibit rapid gene turnover, pervasive transcription, fastest exon shuffling in metazoans and substantial TE methylation not observed in other invertebrates. These new lancelet genome sequences provide new insights into the chordate ancestral state and the vertebrate evolution.


Subject(s)
Evolution, Molecular , Genome , Lancelets/genetics , Adaptation, Physiological , Animals , DNA Transposable Elements , Exons , Lancelets/classification , Lancelets/physiology , Vertebrates/classification , Vertebrates/genetics
19.
Hum Genet ; 133(10): 1299-309, 2014 Oct.
Article in English | MEDLINE | ID: mdl-25024040

ABSTRACT

Our recent genome-wide association study (GWAS) had discovered a new locus at 8p23 (rs2738048) associated with IgA nephropathy (IgAN) in Chinese Han patients, implicating the DEFA gene family within this locus as susceptibility genes. However, it is still unknown whether there are additional variations within these genes associated with the disease susceptibility. The aim of this study is to investigate the polymorphisms of DEFA genes in the susceptibility to IgAN and explore possible disease mechanisms. Sixteen tag single-nucleotide polymorphisms (tag SNPs) were selected for association study in 1,000 IgAN cases and 1,000 controls by using Sequenom MassArray system or TaqMan SNP genotyping assays. We found seven SNPs within DEFA genes that were significantly associated with IgAN, including rs2738048 discovered in our previous GWAS (p = 0.0007, OR = 0.77) and additional 6 SNPs (rs2615787, p = 0.0001, OR = 0.74; rs2738081, p = 0.0003, OR = 0.72; rs2738058, p = 0.0001, OR = 0.73; rs4288398, p = 0.0008, OR = 0.78; rs6984215, p = 0.002, OR = 0.63; rs12716641, p = 0.00002, OR = 0.71). Electrophoretic mobility shift assays and luciferase assays demonstrated that fragments containing rs2738048, rs2738081 and rs6984215 were transcription factor binding sites for CTF, SP1 and CdxA, respectively, and the allele status of rs2738048 and rs6984215 could significantly change the luciferase activity. These results suggest that polymorphisms within DEFA genes are involved in gene transcriptional regulation, and this may have some effect in mediating susceptibility to IgAN in southern Chinese.


Subject(s)
Asian People/genetics , Glomerulonephritis, IGA/genetics , Polymorphism, Single Nucleotide , alpha-Defensins/genetics , Adult , Case-Control Studies , Female , Gene Frequency , Genetic Predisposition to Disease , Genome-Wide Association Study , Glomerulonephritis, IGA/epidemiology , HEK293 Cells , Humans , Linkage Disequilibrium , Male , Multigene Family
20.
Int J Mol Med ; 33(6): 1423-30, 2014 Jun.
Article in English | MEDLINE | ID: mdl-24715051

ABSTRACT

Nasal polyps (NP) is highly associated with the disorder of immune cells. Alternative polyadenylation (APA) produces mRNA isoforms with different length of 3'­untranslated region (UTR) and regulates gene expression. It has been proven that this APA-mediated regulation of 3'UTR length is an immune-associated phenomenon. The aim of this study was to investigate the genome-wide alternative tandem 3'UTR length switching events in non-eosinophilic nasal polyp tissue. Thirteen patients diagnosed as having non-eosinophilic nasal polyps were included in this study. Nasal polyp tissue and control mucosa were collected during surgery. The 3' end library of cDNA was constructed. The recovered libraries were sequenced with second sequencing technology, and the sequencing data were analyzed by an in-house bioinformatics pipeline. Tandem 3'UTR length switching between samples was detected by a test of linear trend alternative to independence. We found a significant alteration in the tandem 3'UTR length in 1,920 genes in nasal polyp samples. Functional annotation results showed that several gene ontology (GO) terms were enriched in the list of genes with switched APA sites, including regulation of transcription, macromolecule catabolic localization and mRNA processing.The results suggested that APA-mediated alternative 3'UTR regulation plays an important role in the post-transcriptional regulation of gene expression in non-eosinophilic nasal polyps.


Subject(s)
High-Throughput Nucleotide Sequencing/methods , Nasal Polyps/genetics , Polyadenylation/genetics , 3' Untranslated Regions/genetics , Adult , Aged , Computational Biology/methods , DNA, Complementary/genetics , Female , Humans , Male , Middle Aged , Young Adult
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