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1.
Genes Dis ; 11(4): 101079, 2024 Jul.
Article in English | MEDLINE | ID: mdl-38560501

ABSTRACT

CYP3A5 is a cytochrome P450 (CYP) enzyme that metabolizes drugs and contributes to drug resistance in cancer. However, it remains unclear whether CYP3A5 directly influences cancer progression. In this report, we demonstrate that CYP3A5 regulates glucose metabolism in pancreatic ductal adenocarcinoma. Multi-omics analysis showed that CYP3A5 knockdown results in a decrease in various glucose-related metabolites through its effect on glucose transport. A mechanistic study revealed that CYP3A5 enriches the glucose transporter GLUT1 at the plasma membrane by restricting the translation of TXNIP, a negative regulator of GLUT1. Notably, CYP3A5-generated reactive oxygen species were proved to be responsible for attenuating the AKT-4EBP1-TXNIP signaling pathway. CYP3A5 contributes to cell migration by maintaining high glucose uptake in pancreatic cancer. Taken together, our results, for the first time, reveal a role of CYP3A5 in glucose metabolism in pancreatic ductal adenocarcinoma and identify a novel mechanism that is a potential therapeutic target.

2.
Nat Commun ; 14(1): 2581, 2023 05 04.
Article in English | MEDLINE | ID: mdl-37142594

ABSTRACT

Many signaling and other genes known as "hidden" drivers may not be genetically or epigenetically altered or differentially expressed at the mRNA or protein levels, but, rather, drive a phenotype such as tumorigenesis via post-translational modification or other mechanisms. However, conventional approaches based on genomics or differential expression are limited in exposing such hidden drivers. Here, we present a comprehensive algorithm and toolkit NetBID2 (data-driven network-based Bayesian inference of drivers, version 2), which reverse-engineers context-specific interactomes and integrates network activity inferred from large-scale multi-omics data, empowering the identification of hidden drivers that could not be detected by traditional analyses. NetBID2 has substantially re-engineered the previous prototype version by providing versatile data visualization and sophisticated statistical analyses, which strongly facilitate researchers for result interpretation through end-to-end multi-omics data analysis. We demonstrate the power of NetBID2 using three hidden driver examples. We deploy NetBID2 Viewer, Runner, and Cloud apps with 145 context-specific gene regulatory and signaling networks across normal tissues and paediatric and adult cancers to facilitate end-to-end analysis, real-time interactive visualization and cloud-based data sharing. NetBID2 is freely available at https://jyyulab.github.io/NetBID .


Subject(s)
Algorithms , Genomics , Humans , Bayes Theorem , Cell Transformation, Neoplastic/genetics , Research Design , Software
3.
Commun Biol ; 6(1): 249, 2023 03 08.
Article in English | MEDLINE | ID: mdl-36882565

ABSTRACT

Prognosis of children with high-risk hepatoblastoma (HB), the most common pediatric liver cancer, remains poor. In this study, we found ribonucleotide reductase (RNR) subunit M2 (RRM2) was one of the key genes supporting cell proliferation in high-risk HB. While standard chemotherapies could effectively suppress RRM2 in HB cells, they induced a significant upregulation of the other RNR M2 subunit, RRM2B. Computational analysis revealed distinct signaling networks RRM2 and RRM2B were involved in HB patient tumors, with RRM2 supporting cell proliferation and RRM2B participating heavily in stress response pathways. Indeed, RRM2B upregulation in chemotherapy-treated HB cells promoted cell survival and subsequent relapse, during which RRM2B was gradually replaced back by RRM2. Combining an RRM2 inhibitor with chemotherapy showed an effective delaying of HB tumor relapse in vivo. Overall, our study revealed the distinct roles of the two RNR M2 subunits and their dynamic switching during HB cell proliferation and stress response.


Subject(s)
Hepatoblastoma , Liver Neoplasms , Child , Humans , Cell Proliferation , Chronic Disease , Hepatoblastoma/drug therapy , Hepatoblastoma/genetics , Liver Neoplasms/drug therapy , Liver Neoplasms/genetics , Recurrence , Ribonucleoside Diphosphate Reductase/genetics
4.
bioRxiv ; 2023 Jan 24.
Article in English | MEDLINE | ID: mdl-36747774

ABSTRACT

Prognosis of children with high-risk hepatoblastoma (HB), the most common pediatric liver cancer, remains poor. In this study, we found ribonucleotide reductase (RNR) subunit M2 ( RRM2 ) was one of the key genes supporting cell proliferation in high-risk HB. While standard chemotherapies could effectively suppress RRM2 in HB cells, they induced a significant upregulation of the other RNR M2 subunit, RRM2B . Computational analysis revealed distinct signaling networks RRM2 and RRM2B were involved in HB patient tumors, with RRM2 supporting cell proliferation and RRM2B participating heavily in stress response pathways. Indeed, RRM2B upregulation in chemotherapy-treated HB cells promoted cell survival and subsequent relapse, during which RRM2B was gradually replaced back by RRM2. Combining an RRM2 inhibitor with chemotherapy showed an effective delaying of HB tumor relapse in vivo. Overall, our study revealed the distinct roles of the two RNR M2 subunits and their dynamic switching during HB cell proliferation and stress response.

5.
bioRxiv ; 2023 Jan 27.
Article in English | MEDLINE | ID: mdl-36747870

ABSTRACT

The sparse nature of single-cell omics data makes it challenging to dissect the wiring and rewiring of the transcriptional and signaling drivers that regulate cellular states. Many of the drivers, referred to as "hidden drivers", are difficult to identify via conventional expression analysis due to low expression and inconsistency between RNA and protein activity caused by post-translational and other modifications. To address this issue, we developed scMINER, a mutual information (MI)-based computational framework for unsupervised clustering analysis and cell-type specific inference of intracellular networks, hidden drivers and network rewiring from single-cell RNA-seq data. We designed scMINER to capture nonlinear cell-cell and gene-gene relationships and infer driver activities. Systematic benchmarking showed that scMINER outperforms popular single-cell clustering algorithms, especially in distinguishing similar cell types. With respect to network inference, scMINER does not rely on the binding motifs which are available for a limited set of transcription factors, therefore scMINER can provide quantitative activity assessment for more than 6,000 transcription and signaling drivers from a scRNA-seq experiment. As demonstrations, we used scMINER to expose hidden transcription and signaling drivers and dissect their regulon rewiring in immune cell heterogeneity, lineage differentiation, and tissue specification. Overall, activity-based scMINER is a widely applicable, highly accurate, reproducible and scalable method for inferring cellular transcriptional and signaling networks in each cell state from scRNA-seq data. The scMINER software is publicly accessible via: https://github.com/jyyulab/scMINER.

6.
Res Sq ; 2023 Jan 27.
Article in English | MEDLINE | ID: mdl-36747874

ABSTRACT

The sparse nature of single-cell omics data makes it challenging to dissect the wiring and rewiring of the transcriptional and signaling drivers that regulate cellular states. Many of the drivers, referred to as "hidden drivers", are difficult to identify via conventional expression analysis due to low expression and inconsistency between RNA and protein activity caused by post-translational and other modifications. To address this issue, we developed scMINER, a mutual information (MI)-based computational framework for unsupervised clustering analysis and cell-type specific inference of intracellular networks, hidden drivers and network rewiring from single-cell RNA-seq data. We designed scMINER to capture nonlinear cell-cell and gene-gene relationships and infer driver activities. Systematic benchmarking showed that scMINER outperforms popular single-cell clustering algorithms, especially in distinguishing similar cell types. With respect to network inference, scMINER does not rely on the binding motifs which are available for a limited set of transcription factors, therefore scMINER can provide quantitative activity assessment for more than 6,000 transcription and signaling drivers from a scRNA-seq experiment. As demonstrations, we used scMINER to expose hidden transcription and signaling drivers and dissect their regulon rewiring in immune cell heterogeneity, lineage differentiation, and tissue specification. Overall, activity-based scMINER is a widely applicable, highly accurate, reproducible and scalable method for inferring cellular transcriptional and signaling networks in each cell state from scRNA-seq data. The scMINER software is publicly accessible via: https://github.com/jyyulab/scMINER.

7.
Oncogene ; 42(15): 1196-1208, 2023 04.
Article in English | MEDLINE | ID: mdl-36828890

ABSTRACT

Intrahepatic cholangiocarcinoma (iCCA) is characterized by its highly desmoplastic stroma. Myofibroblasts (MFs) are present both within the tumor mass (intratumoral MFs, iMFs) and at the tumor border (peritumoral MFs, pMFs). Using a spheroid-based coculture system, we show that the initial iCCA-pMF contact is growth suppressive to the tumor cells. However, prolonged iCCA-pMF interaction elicits significant tumor cell invasion and dissemination. We find that vascular cell adhesion molecule-1 (Vcam1) level is elevated in tumor cells in contact with pMFs but low in disseminated tumor cells both in vitro and in vivo. A gene regulatory network analysis of mouse and patient iCCA tumors and Vcam1 knockout (Vcam1KO) demonstrate a heavy involvement of Vcam1 in epithelial-to-mesenchymal transition. While Vcam1KO has only a limited impact on tumor cell growth in their monoculture, Vcam1KO spheroids exhibit instant dissemination and a severe growth defect when cocultured with pMFs. When transplanted into the liver, Vcam1KO iCCA cells show a similar increase in dissemination but a significant defect in establishing primary and metastatic tumors. Incomplete blocking of Vcam1 in vivo reduces the size but increase the number of metastatic lesions. Overall, our study shows a spatiotemporal regulation of iCCA growth and dissemination by pMFs in a Vcam1-dependent manner.


Subject(s)
Bile Duct Neoplasms , Cholangiocarcinoma , Humans , Vascular Cell Adhesion Molecule-1/genetics , Vascular Cell Adhesion Molecule-1/metabolism , Myofibroblasts/metabolism , Cholangiocarcinoma/pathology , Bile Ducts, Intrahepatic/pathology , Bile Duct Neoplasms/genetics , Bile Duct Neoplasms/pathology
8.
Nat Cancer ; 4(2): 257-275, 2023 02.
Article in English | MEDLINE | ID: mdl-36585452

ABSTRACT

Inhibiting individual histone deacetylase (HDAC) is emerging as well-tolerated anticancer strategy compared with pan-HDAC inhibitors. Through preclinical studies, we demonstrated that the sensitivity to the leading HDAC6 inhibitor (HDAC6i) ricolinstat can be predicted by a computational network-based algorithm (HDAC6 score). Analysis of ~3,000 human breast cancers (BCs) showed that ~30% of them could benefice from HDAC6i therapy. Thus, we designed a phase 1b dose-escalation clinical trial to evaluate the activity of ricolinostat plus nab-paclitaxel in patients with metastatic BC (MBC) (NCT02632071). Study results showed that the two agents can be safely combined, that clinical activity is identified in patients with HR+/HER2- disease and that the HDAC6 score has potential as predictive biomarker. Analysis of other tumor types also identified multiple cohorts with predicted sensitivity to HDAC6i's. Mechanistically, we have linked the anticancer activity of HDAC6i's to their ability to induce c-Myc hyperacetylation (ac-K148) promoting its proteasome-mediated degradation in sensitive cancer cells.


Subject(s)
Breast Neoplasms , Humans , Female , Histone Deacetylase 6/metabolism , Breast Neoplasms/drug therapy , Histone Deacetylases/metabolism , Hydroxamic Acids/pharmacology , Hydroxamic Acids/therapeutic use
9.
Hepatology ; 76(5): 1275-1290, 2022 11.
Article in English | MEDLINE | ID: mdl-35179799

ABSTRACT

BACKGROUND AND AIMS: Hepatoblastoma (HB) is the most common pediatric liver cancer. Its predominant occurrence in very young children led us to investigate whether the neonatal liver provides a protumorigenic niche to HB development. APPROACH AND RESULTS: HB development was compared between orthotopic transplantation models established in postnatal day 5 (P5) and 60 (P60) mice (P5Tx and P60Tx models). Single-cell RNA-sequencing (sc-RNAseq) was performed using tumor and liver tissues from both models and the top candidate cell types and genes identified are investigated for their roles in HB cell growth, migration, and survival. CONCLUSIONS: We found that various HB cell lines including HepG2 cells were consistently and considerably more tumorigenic and metastatic in the P5Tx model than in the P60Tx models. Sc-RNAseq of the P5Tx and P60Tx HepG2 models revealed that the P5Tx tumor was more hypoxic and had a larger number of activated hepatic stellate cells (aHSCs) in the tumor-surrounding liver that express significantly higher levels of Cxcl1 than those from the P60Tx model. We found these differences were developmentally present in normal P5 and P60 liver. We showed that the Cxcl1/Cxcr2 axis mediated HB cell migration and was critical to HB cell survival under hypoxia. Treating HepG2 P60Tx model with recombinant CXCL1 protein induced intrahepatic and pulmonary metastasis and CXCR2 knockout (KO) in HepG2 cells abolished their metastatic potential in the P5Tx model. Lastly, we showed that in tumors from patients with metastatic HB, there was a similar larger population of aHSCs in the tumor-surrounding liver than in localized tumors, and tumor hypoxia was uniquely associated with prognosis of patients with HB among pediatric cancers. We demonstrated that the neonatal liver provides a prometastatic niche to HB development through the Cxcl1/Cxcr2 axis.


Subject(s)
Hepatoblastoma , Liver Neoplasms , Mice , Animals , Hepatoblastoma/metabolism , Chemokine CXCL1/metabolism , Receptors, Interleukin-8B/genetics , Liver Neoplasms/pathology , RNA
10.
Adv Sci (Weinh) ; 8(23): e2102686, 2021 12.
Article in English | MEDLINE | ID: mdl-34713618

ABSTRACT

Benzophenones are widely supplemented in personal care products, but little is known about its neurodevelopmental toxicity. The previous epidemiological study discovered a negative correlation between maternal exposure to a benzophenone metabolite 4-hydroxybenzophenone (4HBP) and child's neurodevelopment, yet the causal relationship and detailed mechanism remain to be defined. Here, it is reported that prenatal, but not postnatal, exposure to environmentally relevant level of 4HBP impairs hippocampus development and causes cognitive dysfunction in offspring mice. Transcriptomic analyses reveal that 4HBP induces the endoplasmic reticulum stress-induced apoptotic signaling and inflammatory response in hippocampal neural stem cells. Mechanistically, 4HBP exposure activates protein kinase R-like ER kinase (PERK) signaling, which induces CHOP, inhibits IκB translation, and transactivates p65, thereby promoting inflammation and apoptosis on multiple levels. Importantly, genetic or pharmacological inhibition of PERK pathway significantly attenuates 4HBP-induced NFκB signaling and neurodevelopmental abnormalities in mice and in a human brain organoid model. The study uncovers the neurodevelopmental toxicity of BP and cautions its exposure during pregnancy.

11.
Cell Rep ; 35(4): 109049, 2021 04 27.
Article in English | MEDLINE | ID: mdl-33910004

ABSTRACT

Transforming growth factor ß (TGF-ß) family ligands are key regulators of dendritic cell (DC) differentiation and activation. Epidermal Langerhans cells (LCs) require TGF-ß family signaling for their differentiation, and canonical TGF-ß1 signaling secures a non-activated LC state. LCs reportedly control skin inflammation and are replenished from peripheral blood monocytes, which also give rise to pro-inflammatory monocyte-derived DCs (moDCs). By studying mechanisms in inflammation, we previously screened LCs versus moDCs for differentially expressed microRNAs (miRNAs). This revealed that miR-424/503 is the most strongly inversely regulated (moDCs > LCs). We here demonstrate that miR-424/503 is induced during moDC differentiation and promotes moDC differentiation in human and mouse. Inversely, forced repression of miR-424 during moDC differentiation facilitates TGF-ß1-dependent LC differentiation. Mechanistically, miR-424/503 deficiency in monocyte/DC precursors leads to the induction of TGF-ß1 response genes critical for LC differentiation. Therefore, the miR-424/503 gene cluster plays a decisive role in anti-inflammatory LC versus pro-inflammatory moDC differentiation from monocytes.


Subject(s)
Anti-Inflammatory Agents/therapeutic use , Langerhans Cells/immunology , MicroRNAs/metabolism , Multigene Family/genetics , Transforming Growth Factor beta/metabolism , Animals , Anti-Inflammatory Agents/pharmacology , Cell Differentiation , Humans , Mice , Signal Transduction
12.
Leukemia ; 35(4): 984-1000, 2021 04.
Article in English | MEDLINE | ID: mdl-32733009

ABSTRACT

T-cell acute lymphoblastic leukemia (T-ALL) is a highly malignant pediatric leukemia, where few therapeutic options are available for patients which relapse. We find that therapeutic targeting of GLI transcription factors by GANT-61 is particularly effective against NOTCH1 unmutated T-ALL cells. Investigation of the functional role of GLI1 disclosed that it contributes to T-ALL cell proliferation, survival, and dissemination through the modulation of AKT and CXCR4 signaling pathways. Decreased CXCR4 signaling following GLI1 inactivation was found to be prevalently due to post-transcriptional mechanisms including altered serine 339 CXCR4 phosphorylation and cortactin levels. We also identify a novel cross-talk between GLI transcription factors and FOXC1. Indeed, GLI factors can activate the expression of FOXC1 which is able to stabilize GLI1/2 protein levels through attenuation of their ubiquitination. Further, we find that prolonged GLI1 deficiency has a double-edged role in T-ALL progression favoring disease dissemination through the activation of a putative AKT/FOXC1/GLI2 axis. These findings have clinical significance as T-ALL patients with extensive central nervous system dissemination show low GLI1 transcript levels. Further, T-ALL patients having a GLI2-based Hedgehog activation signature are associated with poor survival. Together, these findings support a rationale for targeting the FOXC1/AKT axis to prevent GLI-dependent oncogenic Hedgehog signaling.


Subject(s)
Forkhead Transcription Factors/metabolism , Precursor T-Cell Lymphoblastic Leukemia-Lymphoma/metabolism , Signal Transduction , Zinc Finger Protein GLI1/metabolism , Animals , Apoptosis , Biopsy , Cell Cycle Checkpoints , Computational Biology/methods , Disease Models, Animal , Disease Progression , Gene Expression Profiling , Gene Expression Regulation, Neoplastic , Gene Silencing , Hedgehog Proteins/metabolism , Humans , Immunohistochemistry , Mice , Mutation , Precursor T-Cell Lymphoblastic Leukemia-Lymphoma/diagnosis , Precursor T-Cell Lymphoblastic Leukemia-Lymphoma/etiology , Precursor T-Cell Lymphoblastic Leukemia-Lymphoma/mortality , Prognosis , Protein Binding , Proto-Oncogene Proteins c-akt/metabolism , Receptor, Notch1/genetics , Receptor, Notch1/metabolism , Receptors, CXCR4/metabolism , Transcription Factors
13.
Front Oncol ; 10: 968, 2020.
Article in English | MEDLINE | ID: mdl-32612958

ABSTRACT

Background: The PI3K/Akt/mTOR pathway in part impacts tumorigenesis through modulation of host immune activity. To assess the effects of Akt inhibition on the tumor micro-environment (TME), we analyzed tumor tissue from patients with operable hormone receptor positive, HER2 negative breast cancer (BC) treated on a presurgical trial with the Akt inhibitor MK-2206. Methods: Quantitative multiplex immunofluorescence (qmIF) was performed using CD3, CD8, CD4, FOXP3, CD68, and pancytokeratin on biopsy and surgical specimens of MK-2206 and untreated, control patients. nanoString was performed on surgical specimens to assess mRNA expression from MK-2206-treated vs. control patients. Results: Increased CD3+CD8+ density was observed in post vs. pre-treatment tissue in the MK-2206-treated vs. control patients (87 vs. 0.2%, p < 0.05). MK-2206 was associated with greater expression of interferon signaling genes (e.g., IFI6, p < 0.05) and lower expression of myeloid genes (CD163, p < 0.05) on differential expression and gene set enrichment analyses. Greater expression of pro-apoptotic genes (e.g., BAD) were associated with MK-2206 treatment (p < 0.05). Conclusion: Akt inhibition in operable BC was associated with a favorable immune profile in the TME, including increased CD3+CD8+ density and greater expression of interferon genes. Additional studies are warranted, as this may provide rationale for combining Akt inhibition with immunotherapy.

14.
Cell ; 181(2): 325-345.e28, 2020 04 16.
Article in English | MEDLINE | ID: mdl-32302571

ABSTRACT

The mechanisms underlying ribonucleoprotein (RNP) granule assembly, including the basis for establishing and maintaining RNP granules with distinct composition, are unknown. One prominent type of RNP granule is the stress granule (SG), a dynamic and reversible cytoplasmic assembly formed in eukaryotic cells in response to stress. Here, we show that SGs assemble through liquid-liquid phase separation (LLPS) arising from interactions distributed unevenly across a core protein-RNA interaction network. The central node of this network is G3BP1, which functions as a molecular switch that triggers RNA-dependent LLPS in response to a rise in intracellular free RNA concentrations. Moreover, we show that interplay between three distinct intrinsically disordered regions (IDRs) in G3BP1 regulates its intrinsic propensity for LLPS, and this is fine-tuned by phosphorylation within the IDRs. Further regulation of SG assembly arises through positive or negative cooperativity by extrinsic G3BP1-binding factors that strengthen or weaken, respectively, the core SG network.


Subject(s)
Cytoplasmic Granules/metabolism , DNA Helicases/metabolism , Poly-ADP-Ribose Binding Proteins/metabolism , RNA Helicases/metabolism , RNA Recognition Motif Proteins/metabolism , Ribonucleoproteins/metabolism , Cell Line, Tumor , Cytoplasm/metabolism , Cytoplasmic Structures/metabolism , HEK293 Cells , Humans , Phosphorylation , RNA/metabolism
15.
J Proteome Res ; 18(9): 3235-3244, 2019 09 06.
Article in English | MEDLINE | ID: mdl-31364357

ABSTRACT

Database searches of MS/MS spectra are the main approach to peptide/protein identification in proteomics. Since most database search engines only utilize a small portion of the original MS/MS signals for peptide detection, how to improve the quality of MS/MS signals is a primary concern for enhancement of the peptide/protein identification rate. A fundamental issue is that some noise MS signals, informative or uninformative, have to be filtered out prior to database searching. Herein, an integrative preprocessing algorithm was designed, termed pClean, which incorporates three modules to preprocess MS/MS spectra, such as the removal of isobaric-labeling related ions, the reduction in isotopic peaks, the deconvolution of ions with higher charges, and the clearance of uninformative MS/MS signals. In contrast to the currently available approaches to MS/MS data preprocessing, pClean enables treatment of MS/MS spectra with high mass accuracy and favors filtering for the labeling or nonlabeling of peptides. Data sets at various scales gained from mass spectrometers with high resolution were used to assess the quality of peptides identified after pClean treatment and to compare the pClean improvement with those of other software programs. On the basis of the analysis of peptides identified and the Mascot ion score, pClean was proven to be effective in the removal of mass spectral noise and the reduction of random matching. Compared with other software programs, pClean appeared to be beneficial in terms of preprocessing performances for the enhancement of confidence scores and the increase in peptides identified. pClean is available at https://github.com/AimeeD90/pClean_release .


Subject(s)
Databases, Protein , Proteomics/methods , Software , Tandem Mass Spectrometry/methods , Algorithms , Internet , Peptides/genetics , Peptides/isolation & purification , Proteins/genetics , Proteins/isolation & purification
16.
Genome Biol ; 19(1): 69, 2018 05 31.
Article in English | MEDLINE | ID: mdl-29855337

ABSTRACT

BACKGROUND: N 6 -methyladenosine (m6A) modification in mRNAs was recently shown to be dynamically regulated, indicating a pivotal role in multiple developmental processes. Most recently, it was shown that the Mettl3-Mettl14 writer complex of this mark is required for the temporal control of cortical neurogenesis. The m6A reader protein Ythdf2 promotes mRNA degradation by recognizing m6A and recruiting the mRNA decay machinery. RESULTS: We show that the conditional depletion of the m6A reader protein Ythdf2 in mice causes lethality at late embryonic developmental stages, with embryos characterized by compromised neural development. We demonstrate that neural stem/progenitor cell (NSPC) self-renewal and spatiotemporal generation of neurons and other cell types are severely impacted by the loss of Ythdf2 in embryonic neocortex. Combining in vivo and in vitro assays, we show that the proliferation and differentiation capabilities of NSPCs decrease significantly in Ythdf2 -/- embryos. The Ythdf2 -/- neurons are unable to produce normally functioning neurites, leading to failure in recovery upon reactive oxygen species stimulation. Consistently, expression of genes enriched in neural development pathways is significantly disturbed. Detailed analysis of the m6A-methylomes of Ythdf2 -/- NSPCs identifies that the JAK-STAT cascade inhibitory genes contribute to neuroprotection and neurite outgrowths show increased expression and m6A enrichment. In agreement with the function of Ythdf2, delayed degradation of neuron differentiation-related m6A-containing mRNAs is seen in Ythdf2 -/- NSPCs. CONCLUSIONS: We show that the m6A reader protein Ythdf2 modulates neural development by promoting m6A-dependent degradation of neural development-related mRNA targets.


Subject(s)
Adenine/analogs & derivatives , Brain/embryology , Neurogenesis , RNA Stability , RNA, Messenger/metabolism , RNA-Binding Proteins/physiology , Adenine/metabolism , Animals , Arsenites/toxicity , Brain/cytology , Brain/metabolism , Cell Proliferation , Cells, Cultured , Genes, Lethal , Methylation , Mice , Mice, Knockout , Mitosis , Neural Stem Cells/cytology , Neuronal Outgrowth , Neurons/cytology , RNA, Messenger/chemistry , RNA-Binding Proteins/genetics
17.
Sci Rep ; 7(1): 2784, 2017 06 01.
Article in English | MEDLINE | ID: mdl-28572667

ABSTRACT

A correction has been published and is appended to both the HTML and PDF versions of this paper. The error has not been fixed in the paper.

18.
Sci Rep ; 7(1): 25, 2017 12.
Article in English | MEDLINE | ID: mdl-28154415

ABSTRACT

Mouse model induced by azoxymethane (AOM) and dextran sodium sulfate (DSS) is generally accepted as an ideal object to study on the carcinogenesis mechanisms of human colorectal cancer (CRC). The genomic responses to the AOM/DSS treatment in mouse that possibly lead to elucidation of CRC pathological mechanism are still poorly understood. For the first time, we investigated the cancer genome landscape of AOM/DSS mouse model by exome sequencing, to testify its molecular faithfulness to human CRC. Of 14 neoplastic samples, 7575 somatic variants were identified, which resulted in 2507 mutant genes and exhibited a large diversity in both colorectal aberrant crypt foci (ACF) and tumors even those tissues that were gained from the similar morphology or same treatment period. Cross-species comparison of the somatic variants demonstrated the totally different patterns of variable sites, mutant genes and perturbed pathways between mouse and human CRC. We therefore come to a conclusion that the tumorigenesis at genomic level in AOM/DSS model may not be properly comparable with that in human CRC, and the molecular mechanism elicited from this animal model should be carefully evaluated.


Subject(s)
Azoxymethane , Colorectal Neoplasms/chemically induced , Colorectal Neoplasms/genetics , Dextran Sulfate , Genetic Variation , Neoplasms, Experimental/chemically induced , Neoplasms, Experimental/genetics , Aberrant Crypt Foci/genetics , Animals , Humans , Male , Mice, Inbred C57BL/genetics , Mutation , Exome Sequencing
19.
J Proteome Res ; 15(11): 4047-4059, 2016 11 04.
Article in English | MEDLINE | ID: mdl-27457664

ABSTRACT

A priority in solving the problem of drug resistance is to understand the molecular mechanism of how a drug induces the resistance response within cells. Because many cancer cells exhibit chromosome aneuploidy, we explored whether changes of aneuploidy status result in drug resistance. Two typical colorectal cancer cells, HCT116 and LoVo, were cultured with the chemotherapeutic drugs irinotecan (SN38) or oxaliplatin (QxPt), and the non- and drug-resistant cell lines were selected. Whole exome sequencing (WES) was employed to evaluate the aneuploidy status of these cells, and RNAseq and LC-MS/MS were implemented to examine gene expression at both mRNA and protein level. The data of gene expression was well-matched with the genomic conclusion that HCT116 was a near diploid cell, whereas LoVo was an aneuploid cell with the increased abundance of mRNA and protein for these genes located at chromosomes 5, 7, 12, and 15. By comparing the genomic, transcriptomic, and proteomic data, the LoVo cells with SN38 tolerance showed an increased genome copy in chromosome 14, and the expression levels of the genes on this chromosome were also significantly increased. Thus, we first observed that SN38 could impact the aneuploidy status in cancer cells, which was partially associated with the acquired drug resistance.


Subject(s)
Aneuploidy , Colorectal Neoplasms/pathology , Drug Resistance/genetics , Camptothecin/analogs & derivatives , Camptothecin/pharmacology , Cell Line, Tumor , Chromosomes, Human, Pair 14 , Colorectal Neoplasms/genetics , Gene Dosage , Gene Expression Profiling , HCT116 Cells , Humans , Irinotecan , Organoplatinum Compounds/pharmacology , Oxaliplatin
20.
J Proteomics ; 136: 13-24, 2016 Mar 16.
Article in English | MEDLINE | ID: mdl-26844761

ABSTRACT

UNLABELLED: Mammalian target of rapamycin complex 1 (mTORC1) plays important roles in regulating cell growth and proliferation, and the aberrant activation of mTORC1 has been observed in many human diseases. However, the proteins regulated by mTORC1 activation and their roles in mTORC1 downstream functions are still poorly understood. Using proteomic analysis, we found that proteins regulated by mTORC1 in MEFs could be categorized into eight functional groups including protein nuclear import and glycolysis. The positive regulation of Karyopherin subunit alpha-2 (KPNA2), an importer protein involved in protein nuclear import, by mTORC1 was verified in several other mouse and human cell lines. The regulation occurred at the transcriptional level, rather than at the level of S6K1- and 4E-BP1-dependent protein synthesis. KPNA2 knockdown partially blocked upregulation of glycolytic genes by mTORC1 activation, indicating that mTORC1 activation enhanced expression of glycolytic genes by increasing KPNA2 abundances. Furthermore, KPNA2 knockdown had no effects on the expression and subcellular localization of HIF1α, a transcription factor involved in regulating glycolytic genes downstream of mTORC1. In conclusion, our results proved that KPNA2 regulated the expression of glycolytic genes downstream of mTORC1 in a HIF1α-independent manner. SIGNIFICANCE: Identifying mTORC1-regulated proteins through proteomic method is a feasible way to study the downstream functions of mTORC1. In this study, we identified many mTORC1-regulated proteins using proteomic analysis by overlapping two different high vs low/no mTORC1 activity comparisons, TSC2(-/-) vs WT MEFs and TSC2(-/-) with/without rapamycin treatment. We found the abundances of many enzymes in glycolysis pathway and several proteins involved in protein nuclear import were positively regulated by mTORC1. More importantly, we first discovered that mTORC1 positively regulated the importer protein KPNA2, which participated in glycolysis regulation downstream of mTORC1 in a HIF1α-independent manner, indicating that mTORC1 regulates glycolysis through multiple ways.


Subject(s)
Gene Expression Regulation/physiology , Glycolysis/physiology , Hypoxia-Inducible Factor 1, alpha Subunit/metabolism , Multiprotein Complexes/metabolism , Nuclear Proteins/metabolism , TOR Serine-Threonine Kinases/metabolism , Animals , Cell Line, Transformed , Eukaryotic Initiation Factors/biosynthesis , Eukaryotic Initiation Factors/genetics , Humans , Hypoxia-Inducible Factor 1, alpha Subunit/genetics , Mechanistic Target of Rapamycin Complex 1 , Mice , Mice, Knockout , Multiprotein Complexes/genetics , Nuclear Proteins/genetics , Ribosomal Protein S6 Kinases, 90-kDa/biosynthesis , Ribosomal Protein S6 Kinases, 90-kDa/genetics , TOR Serine-Threonine Kinases/genetics , alpha Karyopherins
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