The melanocortin receptor accessory protein 2 (MRAP2) plays an essential role in the regulation of metabolic homeostasis and deletion of which results in severe obesity syndrome in mice and human. Mam Show more
The melanocortin receptor accessory protein 2 (MRAP2) plays an essential role in the regulation of metabolic homeostasis and deletion of which results in severe obesity syndrome in mice and human. Mammalian MRAP2 is recognized as an endogenous physiological mediator through the potentiation of the MC4R signaling in vivo. Two isoforms of MRAP2 are identified in zebrafish genome, zMRAP2a and zMRAP2b. However, the mechanism of assembling dual topology and the regulatory roles of each complex on the melanocortin cascades remains unclear. In this study, we showed the bidirectional homo- and hetero-dimeric topologies of two zebrafish MRAP2 isoforms on the plasma membrane. Orientation fixed chimeric proteins could affect the trafficking and pharmacological properties of zMC4R signaling. Reciprocal replacement of zMRAP2a and zMRAP2b proteins elucidated the major participation of the carboxyl terminal as the functional domain for modulating zMC4R signaling. Our findings revealed the complex and dynamic conformational regulation of dual zebrafish MRAP2 proteins in vitro. Show less
Carbamoyl phosphate synthetase 1 (CPS1), which is the antigen for the hepatocyte paraffin 1 antibody, exhibits focal immunoreactivity in adenocarcinoma from the gastrointestinal tract, but its express Show more
Carbamoyl phosphate synthetase 1 (CPS1), which is the antigen for the hepatocyte paraffin 1 antibody, exhibits focal immunoreactivity in adenocarcinoma from the gastrointestinal tract, but its expression profiles and roles in gastric cancer (GC) remain largely unknown. The present study aimed to determine the expression pattern and prognostic value of CPS1 in Correa's cascade using tissues from 32 patients with chronic atrophic gastritis with intestinal metaplasia (IM), 62 patients with low- or high-grade intraepithelial neoplasia (IN) and 401 patients with GC. The expression of CPS1 was diffuse and strongly positive in 32 cases (100%) of IM of the glandular epithelium, and gradually downregulated in Correa's cascade, with a strongly positive ratio of 21 (70%) in low-grade IN and 4 (12.5%) in high-grade IN. The levels of CPS1 expression were significantly higher in diffuse-type GC, with 37 (26%) cases strongly positive for CPS1, compared with 14 (8%) in intestinal-type and 11 (13%) cases in mixed-type GC. In intestinal-type GC, CPS1 expression was completely lost in 107 (62%) of cases, which was associated with an advanced Tumor-Node-Metastasis stage (P=0.031) and depth of invasion (P=0.037). Kaplan-Meier analysis suggested that low CPS1 expression levels were independently associated with a short overall survival (OS) time in the three types of GC (P<0.001 in intestinal-type, P=0.003 in diffuse-type and P=0.018 in mixed-type GC). Furthermore, low levels of CPS1 mRNA and high methylation levels in the CPS1 promoter were associated with a short OS time in patients with GC. These results suggested that the expression of CPS1 was progressively downregulated in Correa's cascade, and that CPS1 may serve as a prognostic marker for patients with GC, regardless of tumor type. Show less
Emerging evidence suggests the involvement of caudal-related homoeobox transcription factor 2 (CDX2) in tumorigenesis of various cancers. Although CDX2 functions in cancer invasion and metastasis, few Show more
Emerging evidence suggests the involvement of caudal-related homoeobox transcription factor 2 (CDX2) in tumorigenesis of various cancers. Although CDX2 functions in cancer invasion and metastasis, fewer studies focus on the role of CDX2 during the induction of epithelial-mesenchymal transition (EMT) in colorectal cancer (CRC). Immunohistochemical analysis of CDX2 was performed. A series of in vitro and in vivo experiments were conducted to reveal the role of CDX2 in the invasion and metastasis of CRC. CDX2 was downregulated in CRC tissues and reduced CDX2 correlated with poor prognosis. Knockdown of CDX2 promoted colon cancer cell invasion in vitro and facilitated liver metastasis in vivo with inducing EMT phenotypes. Further investigation indicated that CDX2 retarded Akt and GSK-3β phosphorylation, and thereby diminished Snail expression, β-catenin stabilisation and nuclear translocation. The depletion of β-catenin neutralised the regulation of Slug and ZEB1 by CDX2 knockdown. Mechanistically, CDX2 antagonised PI3K/Akt activity in CRC by modulating PTEN expression. CDX2 directly bound to the promoter of PTEN and transactivated its expression. Our study first uncovered that CDX2 inhibits EMT and metastasis of CRC by regulation of Snail expression and β-catenin stabilisation via transactivation of PTEN expression. Show less
Yeast is one of the best-understood biological systems for genetic research. Over the last 40Â years, geneticists have striven to search for homologues of tumor suppressors in yeast to simplify cancer Show more
Yeast is one of the best-understood biological systems for genetic research. Over the last 40Â years, geneticists have striven to search for homologues of tumor suppressors in yeast to simplify cancer research. The star tumor suppressor p21, downstream target of p53, is one of the primary factors on the START point through negatively regulating CycD/E-CDK, the yeast counterpart Cln3-Cdk1. Not like yeast Whi5 that was identified as the analog of the retinoblastoma tumor suppressor protein (Rb) and hence promoted to uncover the mechanism of its cancer suppression, homologue of p21 had not been found in yeast. Our lab identified Cip1 in budding yeast as a novel negative regulator of G1-Cdk1 and proposed that Cip1 is an analog of human p21. Recently, we demonstrated a dual repressive function of Cip1 on START timing via the redundant Cln3 and Ccr4 pathways. This work in yeast may help clarify the complex regulation in human p53-p21 signaling cascade. In this review, we will discuss the yeast paralogs of star tumor suppressors in the control of G1/S transition and present the new findings in this field. Show less
Drug resistance is one of the major challenges for treatment of hepatocellular carcinoma (HCC) with sorafenib. Our present study found that sorafenib resistant (SR) HCC cells showed epithelial-mesench Show more
Drug resistance is one of the major challenges for treatment of hepatocellular carcinoma (HCC) with sorafenib. Our present study found that sorafenib resistant (SR) HCC cells showed epithelial-mesenchymal transition (EMT) characteristics with the downregulation of epithelial marker and upregulation of mesenchymal makers. The expression of Snail, a core factor of EMT, was increased in HCC/SR cells, while knockdown of Snail can restore sorafenib sensitivity and EMT potential of HCC/SR cells. Further, the upregulation of protein stability was responsible for the upregulation of Snail in HCC/SR cells. ATM and CSN2, which can stabilize Snail protein, were increased in HCC/SR cells. Knockdown of ATM and CSN2 can suppress the expression of Snail and increase sorafenib sensitivity of HCC/SR cells. It indicated that targeted inhibition of Snail might be helpful to overcome sorafenib resistance of HCC patients. Show less
Physiological modulation of melanocortin-4 receptor (MC4R) signaling by MRAP2 proteins plays an indispensable role in appetite control and energy homeostasis in the central nervous system. Great inter Show more
Physiological modulation of melanocortin-4 receptor (MC4R) signaling by MRAP2 proteins plays an indispensable role in appetite control and energy homeostasis in the central nervous system. Great interspecies differences of the interaction and regulation of melanocortin receptors by MRAP protein family have been reported in several diploid vertebrates but never been investigated in the tetrapod amphibian Xenopus laevis. Here, we performed phylogenetic and synteny-based analyses to explore the evolutionary aspects of dual copies of X. laevis MC4R (xlMC4R) and MRAP2 (xlMRAP2) proteins. Our data showed that xlMRAPs directly interacted with xlMC4Rs on the cell surface as a functional antiparallel dimeric topology and pharmacological studies suggested a homology specific regulatory pattern of the melanocortin system in X. laevis. Show less
An interaction between hypoxia and immunity has been confirmed in tumor tissue. However, there is no combined biomarker for diagnosis on this basis. Therefore, we developed a scoring formula based on Show more
An interaction between hypoxia and immunity has been confirmed in tumor tissue. However, there is no combined biomarker for diagnosis on this basis. Therefore, we developed a scoring formula based on markers of hypoxia and immunity. Firstly, the hypoxia-immune formula of lung adenocarcinoma (LUAD) was derived using LASSO-Cox regression in three cohorts from public database, and the corresponding score was calculated for each patient. The formula is as follows: combined hypoxia and immune index (CIHI) = LDHA expression × 0.2252 + GAPDH expression × 0.0727 + ANGPTL4 expression × 0.0724 + VEGFC expression × 0.1911 + DKK1 expression × 0.1355 + ADM expression × 0.0588 + BTK expression × -0.1659. Meanwhile, patients were divided into groups according to high and low CIHI, and expression profiles of hypoxia markers and immune markers were analyzed in different groups. CIHI was used to confirm that patients with high CIHI represented a state of hypoxia Show less
SCAP (SREBF chaperone) regulates SREBFs (sterol regulatory element binding transcription factors) processing and stability, and, thus, becomes an emerging drug target to treat dyslipidemia and fatty l Show more
SCAP (SREBF chaperone) regulates SREBFs (sterol regulatory element binding transcription factors) processing and stability, and, thus, becomes an emerging drug target to treat dyslipidemia and fatty liver disease. However, the current known SCAP inhibitors, such as oxysterols, induce endoplasmic reticulum (ER) stress and NR1H3/LXRα (nuclear receptor subfamily 1 group H member 3)-SREBF1/SREBP-1 c-mediated hepatic steatosis, which severely limited the clinical application of this inhibitor. In this study, we identified a small molecule, lycorine, which binds to SCAP, which suppressed the SREBF pathway without inducing ER stress or activating NR1H3. Mechanistically, lycorine promotes SCAP lysosomal degradation in a macroautophagy/autophagy-independent pathway, a mechanism completely distinct from current SCAP inhibitors. Furthermore, we determined that SQSTM1 captured SCAP after its exit from the ER. The interaction of SCAP and SQSTM1 requires the WD40 domain of SCAP and the TB domain of SQSTM1. Interestingly, lycorine triggers the lysosome translocation of SCAP independent of autophagy. We termed this novel protein degradation pathway as the SQSTM1-mediated autophagy-independent lysosomal degradation (SMAILD) pathway. Show less
EMT is an important biological process in the mechanism of tumor invasion and metastasis. However, there are still many unknowns about the specific mechanism of EMT in tumor. At present, a comprehensi Show more
EMT is an important biological process in the mechanism of tumor invasion and metastasis. However, there are still many unknowns about the specific mechanism of EMT in tumor. At present, a comprehensive analysis of EMT-related genes in colorectal cancer (CRC) is still lacking. All the data were downloaded from public databases including TCGA database (488 tumor samples and 52 normal samples) as the training set and the GEO database (GSE40967 including 566 tumor samples and 19 normal samples, GSE12945 including 62 tumor samples, GSE17536 including 177 tumor samples, GSE17537 including 55 tumor samples) as the validation sets. One hundred and sixty-six EMT-related genes (EMT-RDGs) were selected from the Molecular Signatures Database. Bioinformatics methods were used to analyze the correlation between EMT-RDGs and CRC prognosis, metastasis, drug efficacy, and immunity. We finally obtained nine prognostic-related EMT-RDGs (FGF8, NOG, PHLDB2, SIX2, SNAI1, TBX5, TIAM1, TWIST1, TCF15) through differential expression analysis, Unicox and Lasso regression analysis, and then constructed a risk prognosis model. There were significant differences in clinical characteristics, 22 immune cells, and immune functions between the high-risk and low-risk groups and the different states of the nine prognostic-related EMT-RDGs. The methylation level and mutation status of nine prognostic-related EMT-RDGs all affect their regulation of EMT. The Cox proportional hazards regression model was also constructed by the methylation sites of nine prognostic-related EMT-RDGs. In addition, the expression of FGF8, PHLDB2, SIX2, and SNAIL was higher and the expression level of NOG and TWIST1 was lower in the non-metastasis CRC group. Nine prognostic-related EMT-RDGs also affected the drug treatment response of CRC. Targeting these nine prognostic-related EMT-RDGs can regulate CRC metastasis and immune, which is beneficial for the prognosis of CRC patients, improve drug sensitivity in CRC patients. Show less
SARS-CoV-2 variants of interest and concern will continue to emerge for the duration of the COVID-19 pandemic. To map mutations in the receptor-binding domain (RBD) of the spike protein that affect bi Show more
SARS-CoV-2 variants of interest and concern will continue to emerge for the duration of the COVID-19 pandemic. To map mutations in the receptor-binding domain (RBD) of the spike protein that affect binding to angiotensin-converting enzyme 2 (ACE2), the receptor for SARS-CoV-2, we applied in vitro evolution to affinity-mature the RBD. Multiple rounds of random mutagenic libraries of the RBD were sorted against decreasing concentrations of ACE2, resulting in the selection of higher affinity RBD binders. We found that mutations present in more transmissible viruses (S477N, E484K and N501Y) were preferentially selected in our high-throughput screen. Evolved RBD mutants include prominently the amino acid substitutions found in the RBDs of B.1.620, B.1.1.7 (Alpha), B1.351 (Beta) and P.1 (Gamma) variants. Moreover, the incidence of RBD mutations in the population as presented in the GISAID database (April 2021) is positively correlated with increased binding affinity to ACE2. Further in vitro evolution increased binding by 1,000-fold and identified mutations that may be more infectious if they evolve in the circulating viral population, for example, Q498R is epistatic to N501Y. We show that our high-affinity variant RBD-62 can be used as a drug to inhibit infection with SARS-CoV-2 and variants Alpha, Beta and Gamma in vitro. In a model of SARS-CoV-2 challenge in hamster, RBD-62 significantly reduced clinical disease when administered before or after infection. A 2.9 Å cryo-electron microscopy structure of the high-affinity complex of RBD-62 and ACE2, including all rapidly spreading mutations, provides a structural basis for future drug and vaccine development and for in silico evaluation of known antibodies. Show less
Chordoma is a rare bone cancer with an unknown etiology. TBXT is the only chordoma susceptibility gene identified to date; germline single nucleotide variants and copy number variants in TBXT have bee Show more
Chordoma is a rare bone cancer with an unknown etiology. TBXT is the only chordoma susceptibility gene identified to date; germline single nucleotide variants and copy number variants in TBXT have been associated with chordoma susceptibility in familial and sporadic chordoma. However, the genetic susceptibility of chordoma remains largely unknown. In this study, we investigated rare germline genetic variants in genes involved in TBXT/chordoma-related signaling pathways and other biological processes in chordoma patients from North America and China. We identified variants that were very rare in general population and internal control datasets and showed evidence for pathogenicity in 265 genes in a whole exome sequencing (WES) dataset of 138 chordoma patients of European ancestry and in a whole genome sequencing (WGS) dataset of 80 Chinese patients with skull base chordoma. Rare and likely pathogenic variants were identified in 32 of 138 European ancestry patients (23%), including genes that are part of notochord development, PI3K/AKT/mTOR, Sonic Hedgehog, SWI/SNF complex and mesoderm development pathways. Rare pathogenic variants in COL2A1, EXT1, PDK1, LRP2, TBXT and TSC2, among others, were also observed in Chinese patients. We identified several rare loss-of-function and predicted deleterious missense variants in germline DNA from patients with chordoma, which may influence chordoma predisposition and reflect a complex susceptibility, warranting further investigation in large studies. Show less
Ocular surface changes may develop in patients with chronic renal failure (CRF) undergoing hemodialysis. In recent years, an association of CRF with dry eye syndrome has been emphasized. However, tear Show more
Ocular surface changes may develop in patients with chronic renal failure (CRF) undergoing hemodialysis. In recent years, an association of CRF with dry eye syndrome has been emphasized. However, tear proteomics of CRF patients has not been analyzed. Here, we performed systematic profiling of the tear film proteins in CRF patients through use of isobaric tags for relative and absolute quantitative (iTRAQ) MS/MS, aiming to identify associations between dry eye symptoms and expression of tear proteomic changes in patients with CRF undergoing hemodialysis. Twenty CRF patients and ten healthy subjects underwent a series of ophthalmic examinations. Tear samples from the participants were analyzed by iTRAQ approach. A total of 1139 tear proteins were screened, and 212 differentially expressed proteins were identified. The pattern changes included 77 whose expression levels were upregulated (fold increase >1.2) whereas 135 others that were downregulated (fold decrease <1/1.2). Bioinformatics analysis showed that these proteins were significantly enriched in lipid metabolism, inflammatory, and immune response pathways. Furthermore, APOA1, APOA4, APOB, APOE, S100A8, S100A9, S100A4, HSP90B and other molecules were significantly changed. Our study elucidated the characteristics of tear dynamics and protein markers in CRF patients undergoing hemodialysis. Significance: Despite the association of chronic renal failure (CRF) with dry eye disease, there are no reports describing potentially important differentially expressed tear proteins in CRF patients undergoing hemodialysis. It is still a challenge to obtain a comprehensive description of the pathogenesis of dry eye in CRF patients which hinders establishing a patient specific therapeutic scheme. Our study is the first iTRAQ proteomics analysis of the tears of patients with CRF, which reveals the changes in the protein expression profile in CRF patients afflicted with dry eye disease. The identity was verified of some relevant differentially expressed proteins, and they may be candidate diagnostic markers of dry eye disease in patients with CRF. These tear film protein constituents found in hemodialysis patients can be of important clinical significance in treating this condition. SIGNIFICANCE: Despite the association of chronic renal failure (CRF) with dry eye disease, there are no reports describing potentially important differentially expressed tear proteins in CRF patients undergoing hemodialysis. It is still a challenge to obtain a comprehensive description of the pathogenesis of dry eye in CRF patients which hinders establishing a patient specific therapeutic scheme. Our study is the first iTRAQ proteomics analysis of the tears of patients with CRF, which reveals the changes in the protein expression profile in CRF patients afflicted with dry eye disease. The identity was verified of some relevant differentially expressed proteins, and they may be candidate diagnostic markers of dry eye disease in patients with CRF. These tear film protein constituents found in hemodialysis patients can be of important clinical significance in treating this condition. Show less
miRNAs play critical roles in the regulation of many cardiovascular diseases. However, its role and potential mechanism in cardiac injury caused by obstructive sleep apnea (OSA) remain poorly elucidat Show more
miRNAs play critical roles in the regulation of many cardiovascular diseases. However, its role and potential mechanism in cardiac injury caused by obstructive sleep apnea (OSA) remain poorly elucidated. In the present study, we aimed to investigate the effects of miR-3574 on cardiomyocyte injury under intermittent hypoxia (IH). We confirmed that IH inhibited cell viability, induced cell apoptosis and suppressed miR-3574 expression in the H9c2. miR-3574 overexpression could ameliorate the effects of IH on the cell viability and cell apoptosis in the H9c2. Axin1 was a target gene of miR-3574, and miR-3574 overexpression reduced the expression of Axin1. miR-3574 could inhibit the IH-induced cardiomyocyte injury via downregulating Axin1. However, Axin1 could partially reverse these effects of miR-3574. Our study first reveals that miR-3574 could alleviate IH-induced cardiomyocyte injury by targeting Axin1, which may function as a novel and promising therapy target for OSA-associated cardiovascular diseases. H9c2 were exposed to IH condition. CCK-8 assay was applied to determine cell viability of H9c2. qRT-PCR was conducted to measure the expression level of mRNA and miRNA. Western blot assay was then performed to detect the protein levels. Finally, we used dual-luciferase reporter assay identify the potential target of miR-3574. Show less
LINGO-1 may be involved in the pathogenesis of cerebral ischemia. However, its biological function and underlying molecular mechanism in cerebral ischemia remain to be further defined. In our study, m Show more
LINGO-1 may be involved in the pathogenesis of cerebral ischemia. However, its biological function and underlying molecular mechanism in cerebral ischemia remain to be further defined. In our study, middle cerebral artery occlusion/reperfusion (MACO/R) mice model and HT22 cell oxygen-glucose deprivation/reperfusion (OGD/R) were established to simulate the pathological process of cerebral ischemia in vivo and in vitro and to detect the relevant mechanism. We found that LINGO-1 mRNA and protein were upregulated in mice and cell models. Down-regulation LINGO-1 improved the neurological symptoms and reduced pathological changes and the infarct size of the mice after MACO/R. In addition, LINGO-1 interference alleviated apoptosis and promoted cell proliferation in HT22 of OGD/R. Moreover, down-regulation of LINGO-1 proved to inhibit nuclear translocation of p-NF-ÎşB and reduce the expression level of p-JAK2 and p-STAT3. In conclusion, our data suggest that shLINGO-1 attenuated ischemic injury by negatively regulating NF-KB and JAK2/STAT3 pathways, highlighting a novel therapeutic target for ischemic stroke. Show less
Postoperative atrial fibrillation (POAF) is a common complication in coronary artery bypass grafting (CABG) procedures. This prospective study aimed to investigate predisposition of proteins and metab Show more
Postoperative atrial fibrillation (POAF) is a common complication in coronary artery bypass grafting (CABG) procedures. This prospective study aimed to investigate predisposition of proteins and metabolites correlated to POAF after CABG and related cellular pathways. Preoperative plasma samples from patients undergoing CABG procedures were prospectively collected. After CABG, the patients were grouped to POAF or sinus rhythm (N = 170; n = 90 in the discovery set and n = 80 in the validation set). The plasma samples were analyzed using proteomics, metabolomics, and bioinformatics to identify the differential proteins and differential metabolites. The correlation between differential proteins and POAF was also investigated by multivariable regression analysis and receiver operator characteristic analysis. In the POAF(+) group, 29 differential proteins and 61 differential metabolites were identified compared with the POAF(-) group. The analysis of integrated omics revealed that preoperative alteration of peroxisome proliferators-activated receptor α and glutathione metabolism pathways increased the susceptibility of POAF after CABG. There was a correlation between plasma levels of apolipoprotein-C3, phospholipid transfer protein, glutathione peroxidase 3, cholesteryl ester transfer protein, and POAF. The present study for first time at multi-omics levels explored the mechanism of POAF and validated the results in a new cohort of patients, suggesting preexisting differential proteins and differential metabolites in the plasma of patients prone to POAF after CABG. Dysregulation of peroxisome proliferators-activated receptor α and glutathione metabolism pathways related to metabolic remodeling and redox imbalance-associated electrical remodeling may play a key role in the pathogenesis of POAF. Lower plasma phospholipid transfer protein, apolipoprotein-C3, higher cholesteryl ester transfer protein and glutathione peroxidase 3 levels are linked with POAF. These proteins/metabolites may be developed as biomarkers to predict POAF. Show less
The prognosis‑associated genes of urinary bladder cancer have been systematically investigated in the Pathology Atlas project based on The Cancer Genome Atlas data. However, the biological functions o Show more
The prognosis‑associated genes of urinary bladder cancer have been systematically investigated in the Pathology Atlas project based on The Cancer Genome Atlas data. However, the biological functions of most genes in bladder cancer remain unknown. The present study investigated the biological function of 12 of the most significant survival‑associated genes (ABRACL, MITD1, ZNF524, EMP1, HSPB6, CXorf38, TRIM38, ZNF182, ZNF195, SPRN, PTPN6 and LIPT1) in urothelial cancer reported by the Pathology Atlas project, with respect to cell proliferation and migration. In vitro, proliferation and migration analyses of T24 cells were performed following the transfection of the 12 prognostic genes. The results were validated with a small interfering (si)RNA library. Immunohistochemistry (IHC) analysis of clinical samples was performed to determine the association between gene expression and tumor metastasis. Furthermore, RNA sequencing was used to investigate the downstream signals. Among the 12 prognostic genes, MIT‑domain containing protein 1 (MITD1) transfection was demonstrated to inhibit T24 cell migration to a certain degree. Experiments performed with a 7‑gene siRNA library demonstrated that MITD1 knockdown markedly upregulated cell migratory abilities. Mechanistically, the influence of MITD1 on cell signal transduction was assessed via RNA sequencing. Cell migration‑associated genes, including KISS1, SPANXB1, SPINT1, PIWIL2, SNAI1, APLN and CTHRC1 were dysregulated. IHC analysis demonstrated that MITD1 protein expression was notably lower in metastatic lymph nodes compared with the primary tumors. Taken together, the results of the present study suggest that the prognostic gene, MITD1 may serve as a migration inhibitor, and be developed as a potential therapeutic target for improving the prognosis of bladder cancer. Show less
Nasal-type natural killer/T-cell lymphoma (NKTCL) is an aggressive malignancy with poor survival outcomes that is relatively resistant to chemotherapy. N6-Methyladenosine (m6A) modification, the most Show more
Nasal-type natural killer/T-cell lymphoma (NKTCL) is an aggressive malignancy with poor survival outcomes that is relatively resistant to chemotherapy. N6-Methyladenosine (m6A) modification, the most prevalent modification of eukaryotic messenger RNA, is involved in the progression of various tumors. However, it is unclear whether it has a physiological role in NKTCL development. To address this question, we probed its function and molecular mechanisms in NKTCL. Initially, we demonstrated that Wilms' tumor 1-associated protein (WTAP), a major RNA N6-adenosine methyltransferase, was obviously upregulated in human NKTCL cell lines (YTS and SNK-6 cells), compared with normal NK cells. Functionally, depletion of WTAP noticeably repressed proliferation and facilitated apoptosis in YTS and SNK-6 cells. Moreover, intervention of WTAP evidently prohibited NKTCL cell chemotherapy resistance to cisplatin, as reflected by a lower inhibition of cell viability and decreased expression of drug resistance-associated protein expression MRP-1 and P-gp in YTS and SNK-6 cells. With regard to the mechanism, we revealed that WTAP enhanced dual-specificity phosphatases 6 (DUSP6) expression by increasing m6A levels of DUSP6 mRNA transcript, leading to oncogenic functions in NKTCL. Interestingly, WTAP contributed to the progression and chemotherapy sensitivity of NKTCL by stabilizing DUSP6 mRNA in an m6A-dependent manner. Taken together, these findings uncovered a critical function for WTAP-guided m6A methylation and identified DUSP6 as an important target of m6A modification in the regulation of chemotherapy resistance in NKTCL oncogenesis. This study highlights WTAP as a potential therapeutic target of NKTCL treatment. Show less
Triple-negative breast cancer (TNBC) is the most aggressive subtype of breast cancer. TNBC is enriched with breast cancer stem cells (BCSCs), which are responsible for cancer initiation, cancer progre Show more
Triple-negative breast cancer (TNBC) is the most aggressive subtype of breast cancer. TNBC is enriched with breast cancer stem cells (BCSCs), which are responsible for cancer initiation, cancer progression and worse prognosis. Our previous study found that HES1 was overexpressed and promoted invasion in TNBC. However, the role of HES1 in modulating BCSC stemness of TNBC remains unclear. Here, we found that HES1 upregulates Slug both in transcriptional level and in protein level. HES1 also has a positive correlation with Slug expression in 150 TNBC patient samples. TNBC patients with high HES1 and Slug levels show worse prognosis in both progression-free survival and overall survival analyses. Survival analyses indicate that the effects of HES1 on survival prognosis may depend on Slug. Furthermore, we reveal that HES1 is a novel transcriptional activator for Slug through acting directly on its promoter. Meanwhile, HES1 knockdown reduces BCSC self-renewal, BCSC population, and cancer cell proliferation in TNBC, whereas overexpression of Slug restores the oncogenic function of HES1, both Show less
Recent evidence supports an association between lipid metabolism dysfunction and the pathology of schizophrenia which has led to the search for peripheral blood-based biomarkers. The purpose of this s Show more
Recent evidence supports an association between lipid metabolism dysfunction and the pathology of schizophrenia which has led to the search for peripheral blood-based biomarkers. The purpose of this study was to investigate the proteins involved in lipid metabolism (especially apolipoprotein) and to explore their potential as biomarkers for schizophrenia. Using multiple reaction monitoring mass spectrometry (MRM-MS), we quantified 22 proteins in serum samples of 109 healthy controls (HCs) and 111 patients with schizophrenia (SCZ), who were divided into discovery and validation sets. We found serum apolipoprotein A4 (ApoA4) to be significantly decreased in SCZ patients compared to HCs (p=1.61E-05). Moreover, the serum ApoA4 level served as an effective diagnostic tool, achieving area under the receiver operating characteristic curves (AUROC) of 0.840 in the discovery set and 0.791 in the validation set. Additionally, apolipoprotein F (ApoF), angiotensinogen (AGT), and alpha1-antichymotrypsin (ACT) levels were significantly higher in patients with schizophrenia than in healthy controls. These proteins combined with ApoA4, provided higher diagnostic accuracy for schizophrenia in the discovery set (AUROC=0.901) and in the validation set (AUROC=0.879). Our results suggest that the serum level of ApoA4 is a novel potential biomarker for schizophrenia. The proteins identified in this study expand the pool of biomarker candidates for schizophrenia and may be linked to the underlying mechanism of the disease. Show less
Hepatocellular carcinoma (HCC) is highly malignant; nearly half of the new cases and deaths are in China. The poor prognosis of HCC is mainly due to late diagnosis; many new biomarkers have been devel Show more
Hepatocellular carcinoma (HCC) is highly malignant; nearly half of the new cases and deaths are in China. The poor prognosis of HCC is mainly due to late diagnosis; many new biomarkers have been developed for HCC diagnosis. However, few markers are quickly translated into clinical practice; early and differential diagnosis of HCC from cirrhosis and/or hepatitis is still a clinical challenge. Metabolomics and biochemical methods were used to reveal specific serum biomarkers of HCC. Most of the elevated metabolites in HCC and HBV patients were overlapped compared with controls. Urea was the specifically elevated serum biomarker of HCC patients. Moreover, urea combined with AFP and CEA can improve the sensitivity of HCC diagnosis. The plasma ammonia of HCC patients was significantly higher than healthy controls. Co-culture cell model revealed normal liver cells cooperated with cancer cells to metabolize ammonia into urea. The urea metabolism in cancer cells marginally depended on the expression of CPS1. However, the expression of CPS1 did not change with ammonium chloride, which might regulate the urea cycle through enzyme activity. The urea cycle could detoxify high concentrations of ammonia to promote cancer cell proliferation. Therefore, urea was a by-product of ammonia metabolism and could be a potential serum biomarker for HCC. The combined application of metabolomics and biochemical methods can discover new biomarkers for the early diagnosis of HCC and be quickly applied to clinical diagnosis. Show less
The urea cycle (UC) removes the excess nitrogen and ammonia generated by nitrogen-containing compound composites or protein breakdown in the human body. Research has shown that changes in UC enzymes a Show more
The urea cycle (UC) removes the excess nitrogen and ammonia generated by nitrogen-containing compound composites or protein breakdown in the human body. Research has shown that changes in UC enzymes are not only related to tumorigenesis and tumor development but also associated with poor survival in hepatocellular, breast, and colorectal cancers (CRC), etc. Cytoplasmic ornithine, the intermediate product of the urea cycle, is a specific substrate for ornithine decarboxylase (ODC, also known as ODC1) for the production of putrescine and is required for tumor growth. Polyamines (spermidine, spermine, and their precursor putrescine) play central roles in more than half of the steps of colorectal tumorigenesis. Given the close connection between polyamines and cancer, the regulation of polyamine metabolic pathways has attracted attention regarding the mechanisms of action of chemical drugs used to prevent CRC, as the drug most widely used for treating type 2 diabetes (T2D), metformin (Met) exhibits antitumor activity against a variety of cancer cells, with a vaguely defined mechanism. In addition, the influence of metformin on the UC and putrescine generation in colorectal cancer has remained unclear. In our study, we investigated the effect of metformin on the UC and putrescine generation of CRC in vivo and in vitro and elucidated the underlying mechanisms. In nude mice bearing HCT116 tumor xenografts, the administration of metformin inhibited tumor growth without affecting body weight. In addition, metformin treatment increased the expression of monophosphate (AMP)-activated protein kinase (AMPK) and p53 in both HCT116 xenografts and colorectal cancer cell lines and decreased the expression of the urea cycle enzymes, including carbamoyl phosphate synthase 1 (CPS1), arginase 1 (ARG1), ornithine trans-carbamylase (OTC), and ODC. The putrescine levels in both HCT116 xenografts and HCT116 cells decreased after metformin treatment. These results demonstrate that metformin inhibited CRC cell proliferation via activating AMPK/p53 and that there was an association between metformin, urea cycle inhibition and a reduction in putrescine generation. Show less
The disruption of gut microbes is associated with diabetic cardiomyopathy, but the mechanism by which gut microbes affect cardiac damage remains unclear. We explored gut microbes and branched-chain am Show more
The disruption of gut microbes is associated with diabetic cardiomyopathy, but the mechanism by which gut microbes affect cardiac damage remains unclear. We explored gut microbes and branched-chain amino acid (BCAA) metabolite catabolism in diabetic cardiomyopathy mice and investigated the cardioprotective effect of pyridostigmine. The experiments were conducted using a model of diabetic cardiomyopathy induced by a high-fat diet + streptozotocin in C57BL/6 mice. The results of high-throughput sequencing showed that diabetic cardiomyopathy mice exhibited decreased gut microbial diversity, altered abundance of the diabetes-related microbes, and increased abundance of the BCAA-producing microbes Clostridiales and Lachnospiraceae. In addition, diabetes downregulated tight junction proteins (ZO-1, occludin, and claudin-1) and increased intestinal permeability to impair the intestinal barrier. These impairments were accompanied by reduction in vagal activity that manifested as increased acetylcholinesterase levels, decreased acetylcholine levels, and heart rate variability, which eventually led to cardiac damage. Pyridostigmine enhanced vagal activity, restored gut microbiota homeostasis, decreased BCAA-producing microbe abundance, and improved the intestinal barrier to reduce circulating BCAA levels. Pyridostigmine also upregulated BCAT2 and PP2Cm and downregulated p-BCKDHA/BCKDHA and BCKDK to improve cardiac BCAA catabolism. Moreover, pyridostigmine alleviated abnormal mitochondrial structure; increased ATP production; decreased reactive oxygen species and mitochondria-related apoptosis; and attenuated cardiac dysfunction, hypertrophy, and fibrosis in diabetic cardiomyopathy mice. In conclusion, the gut microbiota, BCAA catabolism, and vagal activity were impaired in diabetic cardiomyopathy mice but were improved by pyridostigmine. These results provide novel insights for the development of a therapeutic strategy for diabetes-induced cardiac damage that targets gut microbes and BCAA catabolism. Show less
Previous genotyping-based assays have identified non-coding variants of several interleukins (ILs) being associated with genetic susceptibility to leprosy. However, understanding of the involvement of Show more
Previous genotyping-based assays have identified non-coding variants of several interleukins (ILs) being associated with genetic susceptibility to leprosy. However, understanding of the involvement of coding variants within all IL family genes in leprosy was still limited. To obtain the full mutation spectrum of all ILs in leprosy, we performed a targeted deep sequencing of coding regions of 58 ILs genes in 798 leprosy patients (age 56.2 ± 14.4; female 31.5%) and 990 healthy controls (age 38.1 ± 14.0; female 44.3%) from Yunnan, Southwest China. mRNA expression alterations of ILs in leprosy skin lesions or in response to M. leprae treatment were estimated by using publicly available expression datasets. Two coding variants in IL27 (rs17855750, p.S59A, p = 4.02 × 10 Show less
Glucose homeostasis is tightly controlled by balance between glucose production and uptake in liver tissue upon energy shortage condition. Altered glucose homeostasis contributes to the pathophysiolog Show more
Glucose homeostasis is tightly controlled by balance between glucose production and uptake in liver tissue upon energy shortage condition. Altered glucose homeostasis contributes to the pathophysiology of metabolic disorders including diabetes and obesity. Here, we aimed to analyse the change of proteomic profile upon prolonged fasting in mice with isobaric tag for relative and absolute quantification (iTRAQ) labelling followed by liquid chromatography-mass spectrometry (LC/MS) technology. Adult male mice were fed or fasted for 16Â hours and liver tissues were collected for iTRAQ labelling followed by LC/MS analysis. A total of 322 differentially expressed proteins were identified, including 189 upregulated and 133 downregulated proteins. Bioinformatics analyses, including Gene Ontology analysis (GO), Kyoto encyclopaedia of genes and genomes analysis (KEGG) and protein-protein interaction analysis (PPI) were conducted to understand biological process, cell component, and molecular function of the 322 differentially expressed proteins. Among 322 hepatic proteins differentially expressed between fasting and fed mice, we validated three upregulated proteins (Pqlc2, Ehhadh and Apoa4) and two downregulated proteins (Uba52 and Rpl37) by western-blotting analysis. In cultured HepG2 hepatocellular cells, we found that depletion of Pqlc2 by siRNA-mediated knockdown impaired the insulin-induced glucose uptake, inhibited GLUT2 mRNA level and suppressed the insulin-induced Akt phosphorylation. By contrast, knockdown of Pqlc2 did not affect the cAMP/dexamethasone-induced gluconeogenesis. In conclusion, our study provides important information on protein profile change during prolonged fasting with iTRAQ- and LC-MS/MS-based quantitative proteomics, and identifies Pqlc2 as a potential regulator of hepatic glucose metabolism and insulin signalling pathway in this process. Show less
MicroRNA-205 (miR-205) is believed to be related to the progress of tumors. HOXD9 has been proved to be expressed abnormally in several kinds of cancers. However, the role of miR-205 and HOXD9 in brea Show more
MicroRNA-205 (miR-205) is believed to be related to the progress of tumors. HOXD9 has been proved to be expressed abnormally in several kinds of cancers. However, the role of miR-205 and HOXD9 in breast cancer remains unclear. The biological role of miR-205 in breast cancer cell proliferation and chemoresistance was investigated. The expression of miR-205 in clinical tissues and breast cancer cell lines were analyzed using quantitative real-time PCR test (qRT-PCR). Overexpression and knockdown models of miR-205 were established to study cell proliferation and chemotherapy-resistant. Moreover, the potential relationships between miR-205 and HOXD9/Snail1 were measured using qRT-PCR, western blot, and chemotherapy-resistant study. miR-205 was lowly expressed in breast cancer tissues and cell lines. Overexpression of miR-205 could inhibit cell proliferation and chemotherapy-resistance. Moreover, we proved that miR-205 could target the HOXD9-Snail1 axis to suppress triple negative breast cancer cell proliferation and chemoresistance. The activation of Snail1 gene by HOXD9 was also proved in this study. The present study may provide a novel insight for the therapeutic strategies of breast cancer through targeting miR-205/HOXD9/Snail1. Show less
Loss of the cholesteryl ester transfer protein (CETP) function affects HDLc levels, but its effects on major HDL protein component ApoA1 are not well understood in patients with acute myocardial infar Show more
Loss of the cholesteryl ester transfer protein (CETP) function affects HDLc levels, but its effects on major HDL protein component ApoA1 are not well understood in patients with acute myocardial infarction (AMI). We investigated the effects of an East Asian loss-of-function variant (rs2303790; p.D442G) in CETP gene on HDLc and ApoA1 levels and its relationship with AMI. A total of 2327 AMI patients and 2615 age- and sex-matched controls from INTERHEART-China study were included. In controls, both levels of HDLc (1.24 vs. 1.04Â mmol/L, PÂ =Â 0.001) and ApoA1 (1.48 vs. 1.37Â mmol/L, PÂ =Â 0.042) were significantly higher in CETP variant G allele carriers compared to CETP wildtype D allele carriers. In AMI patients, levels of HDLc were significantly higher (1.14 vs. 1.01Â mmol/L, PÂ =Â 0.013) while levels of ApoA1 were not statistically difference (1.31 vs. 1.32Â mmol/L, PÂ =Â 0.468) in CETP variant group compared to CETP wildtype group. Moreover, CETP variant is associated with HDLc increase, but is not associated with AMI risk (PÂ =Â 0.564), even after adjusting for age, sex, history of hypertension and diabetes, waist to hip ratio, smoking, total cholesterol, LDL cholesterol, triglycerides, physical activity, depression, alcohol, vegetables and fruit consumption. Loss of CETP function is associated with increased HDLc and ApoA1 levels in healthy subjects, and in AMI patients, it is associated with HDLc levels but not ApoA1 levels. The lack of association of CETP variant with AMI may be related to the inability to increase ApoA1 levels and warranted further studies. Show less
Clear cell renal cell carcinoma (ccRCC) accounts for 80% of all renal cancers and has a poor prognosis. Chromobox (CBX) family protein expression has been reported in a variety of human malignancies, Show more
Clear cell renal cell carcinoma (ccRCC) accounts for 80% of all renal cancers and has a poor prognosis. Chromobox (CBX) family protein expression has been reported in a variety of human malignancies, but the roles of CBXs in ccRCC remain unclear. In this study, by using ONCOMINE, UALCAN, GEPIA, Kaplan-Meier Plotter, cBioPortal, and TIMER, we found the transcriptional levels of CBX3 and CBX4 in ccRCC tissues were significantly higher than those in normal kidney tissues, whereas the transcriptional levels of CBX1, CBX5, CBX6, and CBX7 were significantly reduced in ccRCC tissues. The promoters of CBX2, CBX3, CBX4, CBX5, CBX6, CBX7, and CBX8 were hypermethylated, whereas the CBX1 promoter was hypomethylated in ccRCC. The expression of CBX1, CBX3, CBX4, CBX5, CBX6, and CBX7 was significantly associated with clinicopathological parameters in ccRCC patients. ccRCC patients with high expression levels of CBX3, CBX4, and CBX8 and low expression levels of CBX1, CBX5, CBX6, and CBX7 showed a strong association with poor overall survival. Genetic alterations in CBXs were correlated with poor overall survival and disease-free survival in patients with ccRCC. Moreover, we found significant associations between the expression of CBXs and infiltration of immune cells (B cells, CD8+ T cells, CD4+ T cells, macrophages, neutrophils, and dendritic cells). Our results provide novel insights into the development of CBX-based biomarkers and therapeutic targets for ccRCC. Show less
The prevalence of metabolic syndrome (Mets) is closely related to an increased incidence of cardiovascular events. Angiopoietin-like protein 4 (ANGPTL4) is contributory to the regulation of lipid meta Show more
The prevalence of metabolic syndrome (Mets) is closely related to an increased incidence of cardiovascular events. Angiopoietin-like protein 4 (ANGPTL4) is contributory to the regulation of lipid metabolism, herein, may provide a target for gene-aimed therapy of Mets. This observational case control study was designed to elucidate the relationship between ANGPTL4 gene single nucleotide polymorphism (SNP) rs1044250 and the onset of Mets, and to explore the interaction between SNP rs1044250 and weight management on Mets. We have recruited 1018 Mets cases and 1029 controls in this study. The SNP rs1044250 was genotyped with blood samples, base-line information and Mets-related indicators were collected. A 5-year follow-up survey was carried out to track the lifestyle interventions and changes in Mets-related indicators. ANGPTL4 gene SNP rs1044250 is an independent risk factor for increased waist circumference (OR 1.618, 95% CI [1.119-2.340]; p = 0.011), elevated blood pressure (OR 1.323, 95% CI [1.002-1.747]; p = 0.048), and Mets (OR 1.875, 95% CI [1.363-2.580]; p < 0.001). The follow-up survey shows that rs1044250 CC genotype patients with weight gain have an increased number of Mets components (M [Q1, Q3]: CC 1 (0, 1), CT + TT 0 [- 1, 1]; p = 0.021); The interaction between SNP rs1044250 and weight management is a risk factor for increased systolic blood pressure (β = 0.075, p < 0.001) and increased diastolic blood pressure (β = 0.097, p < 0.001), the synergistic effect of weight management and SNP rs1044250 is negative (S < 1). ANGPTL4 gene SNP rs1044250 is an independent risk factor for increased waist circumference and elevated blood pressure, therefore, for Mets. However, patients with wild type SNP 1044250 are more likely to have Mets when the body weight is increased, mainly due to elevated blood pressure. Show less