Inhibition of the RLR signaling pathway by SARS-CoV-2 ORF7b is mediated by MAVS and abrogated by ORF7b-homologous interfering peptide.

Coronavirus disease 2019 (COVID-19) is caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection and characterized by dysregulated immune response. Studies have shown that the SARS-CoV-2 accessory protein ORF7b induces host cell apoptosis through the tumor necrosis factor alpha (TNF-α) pathway and blocks the production of interferon beta (IFN-ß). The underlying mechanism remains to be investigated. In this study, we found that ORF7b facilitated viral infection and production, and inhibited the RIG-I-like receptor (RLR) signaling pathway through selectively interacting with mitochondrial antiviral-signaling protein (MAVS). MAVS439-466 region and MAVS Lys461 were essential for the physical association between MAVS and ORF7b, and the inhibition of the RLR signaling pathway by ORF7b. MAVSK461/K63 ubiquitination was essential for the RLR signaling regulated by the MAVS-ORF7b complex. ORF7b interfered with the recruitment of tumor necrosis factor receptor-related factor 6 (TRAF6) and the activation of the RLR signaling pathway by MAVS. Furthermore, interfering peptides targeting the ORF7b complex reversed the ORF7b-suppressed MAVS-RLR signaling pathway. The most potent interfering peptide V disrupts the formation of ORF7b tetramers, reverses the levels of the ORF7b-inhibited physical association between MAVS and TRAF6, leading to the suppression of viral growth and infection. Overall, this study provides a mechanism for the suppression of innate immunity by SARS-CoV-2 infection and the mechanism-based approach via interfering peptides to potentially prevent SARS-CoV-2 infection.IMPORTANCEThe pandemic coronavirus disease 2019 (COVID-19) is caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection and continues to be a threat to public health. It is imperative to understand the biology of SARS-CoV-2 infection and find approaches to prevent SARS-CoV-2 infection and ameliorate COVID-19. Multiple SARS-CoV-2 proteins are known to function on the innate immune response, but the underlying mechanism remains unknown. This study shows that ORF7b inhibits the RIG-I-like receptor (RLR) signaling pathway through the physical association between ORF7b and mitochondrial antiviral-signaling protein (MAVS), impairing the K63-linked MAVS polyubiquitination and its recruitment of tumor necrosis factor receptor-related factor 6 (TRAF6) to MAVS. The most potent interfering peptide V targeting the ORF7b-MAVS complex may reverse the suppression of the MAVS-mediated RLR signaling pathway by ORF7b and prevent viral infection and production. This study may provide new insights into the pathogenic mechanism of SARS-CoV-2 and a strategy to develop new drugs to prevent SARS-CoV-2 infection.

Study on the mechanism underlying Trichosanthis peel injection-induced improvements in myocardial fibrosis markers in patients with chronic heart failure.

In this research, we aimed to observe the changes in myocardial fibrosis indices in patients with chronic heart failure before and after treatment and to evaluate the anti-chronic heart failure and ventricular remodelling effects of Trichosanthis peel (TP) injection. This study was a single-center, open, single-blind, randomized controlled study with an optimal efficacy design. Patients were consecutively and randomly divided into two groups, with 36 patients in the TP injection group and 36 patients in the conventional treatment group. ELISA was used to measure changes in myocardial fibrosis indices before and after discharge, including transforming growth factor ß (TGF-ß), serum hyaluronic acid (HA), type I procollagen (PCI), laminin (LN) and type III procollagen (PCIII). There was no significant difference between the two groups in clinical data or baseline level of myocardial fibrosis before treatment. After treatment, compared with the conventional treatment group, the myocardial fibrosis index was significantly decreased following TP injection. Our findings indicate that TP injection combined with conventional medicine can attenuate myocardial fibrosis by reducing angiotensin II, aldosterone, TGFß, HA, PCI, metallomatrix proteinase 2, connective tissue growth factor and LN and promote ventricular remodelling in patients with chronic heart failure.

Bacterial diversity in primary infected root canals of a Chinese cohort: analysis of 16 S rDNA sequencing.

PURPOSE: To characterize the bacterial community in the primarily infected root canals. METHODS: A total of 13 samples were collected from the primarily infected root canals. 16 S rDNA sequencing was performed to define bacterial community. Taxonomic annotation, bacterial hierarchical structures, community richness and diversity, and inter-subject variability of the bacterial community in the root canal samples were analyzed. Gender, age, and duration of the toothache-specific bacterial community associated with the patient groups were analyzed. RESULTS: A total of 359 Species were annotated and identified in the whole study cohort. The Alpha diversity analysis showed that the species diversity and detection rate of the 13 samples were high, which reflected the authenticity of sequencing results. The Beta diversity analysis was used to compare the degree of difference between different root canal samples. The 13 samples were divided into two groups according to the results, group A was samples I1-I12, and group B was samples I13. The bacterial species of group A samples were analyzed with the clinical characteristics of patients, and it was found that gender, and duration specific differences in bacterial species, and there was no significant difference in species types among different ages of patients. CONCLUSION: There were a wide diversity and inter-subject variability in the bacterial community in the primary infected root canals. While Porphyromonas gingivalis was the most abundant species, Fusobacterium nucleatum was the most variable species in the bacterial community of the root canal. The bacterial community at different taxonomic levels varied from sample to sample, despite consistent disease diagnoses. There was gender, duration-specific differences in the bacterial species in the primary infected root canals.

Fibromodulin overexpression drives oral squamous cell carcinoma via activating downstream EGFR signaling.

Accumulating evidence has shown that fibromodulin (FMOD) plays a pivotal role in tumorigenesis and metastasis. However, the biological function of FMOD in oral squamous cell carcinoma (OSCC) remains largely unclear to date. In this study, we confirmed that FMOD was overexpressed and showed a significant association with malignant progression and lymph node metastasis in OSCC. Depletion of FMOD inhibited OSCC proliferation and metastasis in vitro and in vivo. RNA sequencing, western blotting, and rescue assays verified that FMOD exerted oncogenic roles in OSCC via activation of EGFR signaling. In addition, FMOD was proved to be a putative target gene of miR-338-3p. Taken together, FMOD overexpression due to the reduced level of miR-338-3p promotes OSCC by activating EGFR signaling. Our findings provide direct evidence that targeting FMOD could be a promising therapeutic strategy for OSCC patients.

Inhibition of USP14 enhances anti-tumor effect in vemurafenib-resistant melanoma by regulation of Skp2.

BACKGROUND: The mutation of BRAF V600E often occurred in melanoma and results in tumorigenesis. BRAF mutation drives hyperactivation of the RAF-MAPK-ERK pathway. The acquired drug resistance upon prolonged use of BRAF inhibitors (such as vemurafenib) still remains the main obstacle. Previously, we have found that E3 ligase Skp2 over-expresses vemurafenib-resistant melanoma cells, and knockdown of Skp2 enhances the anti-tumor effect of vemurafenib. Interestingly, the literature has reported that the selective USP14/UCHL5 inhibitor b-AP15 displays great potential in melanoma therapy; however, the molecular mechanism still remains unknown. METHODS: In vitro, the effect of the combination regimen of vemurafenib (Vem, PLX4032) and b-AP15 on vem-sensitive and vem-resistant melanoma has been investigated by wound healing, colony formation, transwell invasion assay, flow cytometry, lysosome staining, and ROS detection. In vivo, the combination effect on vem-resistant melanoma has been evaluated with a nude mice xenograft tumor model. GST-pulldown and co-immunoprecipitation (co-IP) assays have been applied to investigate the interactions between USP14, UCHL5, and Skp2. Cycloheximide (CHX) assay and ubiquitination assays have been used to explore the effect of USP14 on Skp2 protein half-life and ubiquitination status. RESULTS: In the present study, we have revealed that repression of USP14 sensitizes vemurafenib resistance in melanoma through a previously unappreciated mechanism that USP14 but not UCHL5 stabilizes Skp2, blocking its ubiquitination. K119 on Skp2 is required for USP14-mediated deubiquitination and stabilization of Skp2. Furthermore, the mutated catalytic activity amino acid cysteine (C) 114 on USP14 abrogates stabilization of Skp2. Stabilization of Skp2 is required for USP14 to negatively regulate autophagy. The combination regimen of Skp2 inhibitor vemurafenib and USP14/UCHL5 inhibitor b-AP15 dramatically inhibits cell viability, migration, invasion, and colony formation in vemurafenib-sensitive and vemurafenib-resistant melanoma. Vemurafenib and b-AP15 hold cells in the S phase thus leading to apoptosis as well as the formation of the autophagic vacuole in vemurafenib-resistant SKMEL28 cells. The enhanced proliferation effect of USP14 and Skp2 is mainly due to a more effective reduction of cell apoptosis and autophagy. Further evaluation of various protein alterations has revealed that the increased expression of cleaved-PARP, LC3, and decreased Ki67 are more obvious in the combination of vemurafenib and b-AP15 treatment than those in single-drug treatment. Moreover, the co-treatment of vemurafenib and b-AP15 dramatically inhibits the growth of vemurafenib-resistant melanoma xenograft in vivo. Collectively, our findings have demonstrated that the combination of Skp2 inhibitor and USP14 inhibitor provides a new solution for the treatment of BRAF inhibitor resistance melanoma.

Combination of Paclitaxel and PXR Antagonist SPA70 Reverses Paclitaxel-Resistant Non-Small Cell Lung Cancer.

Paclitaxel (PTX) is one of the most efficient drugs for late-stage non-small cell lung cancer (NSCLC) patients. However, most patients gradually develop resistance to PTX with long-term treatments. The identification of new strategies to reverse PTX resistance in NSCLC is crucially important for the treatment. PTX is an agonist for the pregnane X receptor (PXR) which regulates PTX metabolism. Antagonizing PXR, therefore, may render the NSCLC more sensitive to the PTX treatment. In this study, we investigated the PXR antagonist SPA70 and its role in PTX treatment of NSCLC. In vitro, SPA70 and PTX synergistically inhibited cell growth, migration and invasion in both paclitaxel-sensitive and paclitaxel-resistant A549 and H460 lung cancer cells. Mechanistically, we found PTX and SPA70 cotreatment disassociated PXR from ABCB1 (MDR1, P-gp) promoter, thus inhibiting P-gp expression. Furthermore, the combination regimen synergistically enhanced the interaction between PXR and Tip60, which abrogated Tip60-mediated α-tubulin acetylation, leading to mitosis defect, S-phase arrest and necroptosis/apoptosis. Combination of PXT and SPA70 dramatically inhibited tumor growth in a paclitaxel-resistant A549/TR xenograft tumor model. Taken together, we showed that SPA70 reduced the paclitaxel resistance of NSCLC. The combination regimen of PTX and SPA70 could be potential novel candidates for the treatment of taxane-resistant lung cancer.

Nuclear Receptor PXR Confers Irradiation Resistance by Promoting DNA Damage Response Through Stabilization of ATF3.

Low response rate to radiotherapy remains a problem for liver and colorectal cancer patients due to inappropriate DNA damage response in tumors. Here, we report that pregnane X receptor (PXR) contributes to irradiation (IR) resistance by promoting activating transcription factor 3 (ATF3)-mediated ataxia-telangiectasia-mutated protein (ATM) activation. PXR stabilized ATF3 protein by blocking its ubiquitination. PXR-ATF3 interaction is required for regulating ATF3, as one mutant of lysine (K) 42R of ATF3 lost binding with PXR and abolished PXR-reduced ubiquitination of ATF3. On the other hand, threonine (T) 432A of PXR lost binding with ATF3 and further compromised ATM activation. Moreover, the PXR-ATF3 interaction increases ATF3 stabilization through disrupting ATF3-murine double minute 2 (MDM2) interaction and negatively regulating MDM2 protein expression. PXR enhanced MDM2 auto-ubiquitination and shortened its half-life, therefore compromising the MDM2-mediated degradation of ATF3 protein. Structurally, both ATF3 and PXR bind to the RING domain of MDM2, and on the other hand, MDM2 binds with PXR on the DNA-binding domain (DBD), which contains zinc finger sequence. Zinc finger sequence is well known for nuclear receptor peroxisome proliferator-activated receptor-γ (PPARγ) playing E3 ligase activity to degrade nuclear factor κB (NFκB)/p65. However, whether zinc-RING sequence grants E3 ligase activity to PXR remains elusive. Taken together, these results provide a novel mechanism that PXR contributes to IR resistance by promoting ATF3-mediated ATM activation through stabilization of ATF3. Our result suggests that targeting PXR may sensitize liver and colon cancer cells to IR therapy.

Insights into the critical role of the PXR in preventing carcinogenesis and chemotherapeutic drug resistance.

Pregnane x receptor (PXR) as a nuclear receptor is well-established in drug metabolism, however, it has pleiotropic functions in regulating inflammatory responses, glucose metabolism, and protects normal cells against carcinogenesis. Most studies focus on its transcriptional regulation, however, PXR can regulate gene expression at the translational level. Emerging evidences have shown that PXR has a broad protein-protein interaction network, by which is implicated in the cross signaling pathways. Furthermore, the interactions between PXR and some critical proteins (e.g., p53, Tip60, p300/CBP-associated factor) in DNA damage pathway highlight its potential roles in this field. A thorough understanding of how PXR maintains genome stability and prevents carcinogenesis will help clinical diagnosis and finally benefit patients. Meanwhile, due to the regulation of CYP450 enzymes CYP3A4 and multidrug resistance protein 1 (MDR1), PXR contributes to chemotherapeutic drug resistance. It is worthy of note that the co-factor of PXR such as RXRα, also has contributions to this process, which makes the PXR-mediated drug resistance more complicated. Although single nucleotide polymorphisms (SNPs) vary between individuals, the amino acid substitution on exon of PXR finally affects PXR transcriptional activity. In this review, we have summarized the updated mechanisms that PXR protects the human body against carcinogenesis, and major contributions of PXR with its co-factors have made on multidrug resistance. Furthermore, we have also reviewed the current promising antagonist and their clinic applications in reversing chemoresistance. We believe our review will bring insight into PXR-targeted cancer therapy, enlighten the future study direction, and provide substantial evidence for the clinic in future.

Low-density lipoprotein receptor and apolipoprotein A 5, myocardial infarction biomarkers in plasma-derived exosomes.

OBJECTIVES: Myocardial infarction (MI), a leading cause of death around the world, displays a complex pattern of inheritance. Previously, rare mutations in low-density lipoprotein receptor (LDLR) genes and apolipoprotein A V (APOA5) have been shown to contribute to MI risk in individual families. Exosomes provide a potential source of biomarkers for MI. This study is to determine the role of LDLR and APOA5 as biomarkers for early diagnosis of MI. METHODS: In this study, we detected the levels of LDLR, APOA5, and cardiac troponin T in plasma-derived exosomes in MI patients and age-matched healthy people by enzyme linked immunosorbent assay and observed the morphology and number of exosomes using transmission electron microscope and nanoparticle tracking analysis. Oxygen-glucose deprivation (OGD) method was used to induce MI in H9C2 cardiomyocytes to explore the effect of exosomes. RESULTS: We found that the levels of LDLR and APOA5 in plasma-derived exosomes in MI patients were significantly decreased. Furthermore, exosomes of MI patients were significantly larger in size and the concentration of exosomes was higher than that of age-matched non-MI people. In vitro experiments showed that OGD treatment induced apoptosis of myocardial cells and decreased the expression of LDLR and APOA5, while addition of exosomes isolated from healthy people rescued these phenotypes. CONCLUSION: Exosomal APOA5 and LDLR are intimately associated with MI, and thereby have the potential to function as diagnostic markers of MI.

Identifying Optimal Surgical Intervention-Based Chemotherapy for Gastric Cancer Patients With Liver Metastases.

BACKGROUND: This study aimed at evaluating the effects of surgical treatments-based chemotherapy in the treatment of gastric cancer with liver metastases (GCLM). It has not been established whether Liver-directed treatment (LDT) options such as hepatectomy and gastrectomy plus chemotherapy (HGCT), radiofrequency ablation and gastrectomy plus chemotherapy (RFAG), transarterial chemoembolization and gastrectomy plus chemotherapy (TACEG), gastrectomy plus chemotherapy (GCT) enhance the survival of GCLM patients. METHODS: We performed systematic literature searches in PubMed, EMBASE, and Cochrane library from inception to September 2021. We created a network plot to comprehensively analyze the direct and indirect evidence, based on a frequentist method. A contribution plot was used to determine inconsistencies, a forest plot was used to evaluate therapeutic effects, the publication bias was controlled by funnel plot, while the value of surface under the cumulative ranking curves (SUCRA) was calculated to estimate rank probability. RESULTS: A total of 23 retrospective studies were identified, involving 5472 GCLM patients. For OS and 1-, 2-, 3-year survival rate of all trials, meta-analysis of the direct comparisons showed significant better for HGCT treatments compared with GCT or PCT. In the comparison of the 5 treatments for 1-, 2-, 3-year survival rate, HGCT and RFAG were found to be more effective than GCT and PCT, respectively. By OS and 2-, 3-year survival rate analysis, RFAG was identified as the best option, followed by HGCT, TACEG, GCT and PCT. By 1-year survival rate analysis, HGCT and RFAG were identified as the most effective options. CONCLUSION: HGCT and RFAG has remarkable survival benefits for GCLM patients when compared to TACEG, GCT and PCT. HGCT was found to exhibit superior therapeutic effects for GCLM patients for 1-year survival rate while RFAG was found to be a prospective therapeutic alternative for OS and 2-, 3-year survival rate. SYSTEMATIC REVIEW REGISTRATION: identifier [10.37766/inplasy2020.12.0009].

Emerging Roles of SKP2 in Cancer Drug Resistance.

More than half of all cancer patients receive chemotherapy, however, some of them easily acquire drug resistance. Resistance to chemotherapy has become a massive obstacle to achieve high rates of pathological complete response during cancer therapy. S-phase kinase-associated protein 2 (Skp2), as an E3 ligase, was found to be highly correlated with drug resistance and poor prognosis. In this review, we summarize the mechanisms that Skp2 confers to drug resistance, including the Akt-Skp2 feedback loop, Skp2-p27 pathway, cell cycle and mitosis regulation, EMT (epithelial-mesenchymal transition) property, enhanced DNA damage response and repair, etc. We also addressed novel molecules that either inhibit Skp2 expression or target Skp2-centered interactions, which might have vast potential for application in clinics and benefit cancer patients in the future.

A nine-lncRNA signature predicts distant relapse-free survival of HER2-negative breast cancer patients receiving taxane and anthracycline-based neoadjuvant chemotherapy.

Multi-gene prognostic signatures of long non-coding RNAs (lncRNAs) provide new insights into mechanisms of HER2-negative breast cancer development and progression, and predict distant relapse-free survival (DRFS) of patients receiving taxane and anthracycline-based neoadjuvant chemotherapy. The aim of this study was to develop such a multi-lncRNAs signature. Optimal multiple candidate signature lncRNAs associated with DRFS were firstly identified by a univariate Cox proportional hazard regression survival analysis and a robust likelihood-based survival analysis of the GEO dataset GSE25055. A nine-lncRNA prognostic risk score model Risk Score = 0.0289 × EXPLOC100507388 - 0.0814 × EXPLINC00094 - 0.2422 × EXPSMG7-AS1 - 0.2433 × EXPPP14571 + 0.4690 × EXPASAP1-IT1 - 0.2483 × EXPLOC103344931 - 0.2464 × EXPFAM182A + 0.3349 × EXPHCG26 - 0.0216 × EXPLINC00963 was built according to the coefficients of multivariate survival analysis of the association between the candidate lncRNAs and survival. EXPlncRNA was the standardized log2-transformed expression level of the gene. According to this model, higher scores predicted lower survival probability. The area under Receiver operating characteristic (ROC) curve (AUC) was 0.777 to 0.823 from 1- to 7- year survival rate. The model and its individual lncRNAs differentiated survival probability between the higher scores (expression) and the lower scores (expression). The nine-lncRNA signature had the robust prognostic power compared with ER, PR, tumor size (T), lymph node invasion (N), TNM stage, pathologic response, chemosensitivity prediction and PAM50 signature. These results were consistent with those based on the GEO dataset GSE25065. The predictive nomograms integrating both the nine-lncRNA signature classifier and clinical-pathological risk factors were robust in predicting 1-, 3- and 5- year survival probabilities. These results supported that the nine-lncRNA signature was a robust and effective model in predicting DRFS of patients with HER2-negative breast cancer following taxane and anthracycline-based neoadjuvant chemotherapy.

Integrated Analysis Identifies a Nine-microRNA Signature Biomarker for Diagnosis and Prognosis in Colorectal Cancer.

BACKGROUND: Colorectal cancer (CRC) is the third most lethal and malignant type of cancer in the world. Abnormal expression of human microRNA-200a (hsa-miRNA-200a or miR-200a) has previously been characterized as a clinically noticeable biomarker in several cancers, but its role in CRC is still unclear. METHODS: Three CRC miRNA expression datasets were integratively analyzed by Least Absolute Shrinkage and Selector Operation (LASSO) and Support Vector Machine-Recursive Feature Elimination (SVM-RFE) algorithms. Nine candidate miRNAs were identified and validated for diagnostic and prognostic capability with the prediction model. The potential roles of the tumor suppressor miR-200a-3p in invasion, migration, and epithelial-mesenchymal transition of CRC cells were elaborated by in vitro studies. RESULTS: Nine miRNAs (miR-492, miR-200a, miR-338, miR-29c, miR-101, miR-148a, miR-92a, miR-424, and miR-210) were identified as potentially useful diagnostic biomarkers in the clinic. The overall accuracy rate of the nine miRNAs in the diagnostic model was 0.94, 0.89, and 0.978 in the testing, validation, and independent validation dataset, respectively. CRC patients in the GSE29622 cohort were separated by the prognostic model into the low-risk score group and the high-risk score group. The area under the receiver operating characteristic curve (AUC) was 0.872 and 0.783 for predicting the 1- to 10-year survival of CRC patients. The performance of the prognostic model was validated by an independent TCGA-Colon Adenocarcinoma (COAD) dataset with AUC values between 0.911 and 0.796 in predicting 1- to 10-year survival. Nomograms comprising risk scores, tumor stage, and TNM staging were generated for predicting 1-, 3-, and 5-year overall survival (OS) in the GSE29622 and TCGA-COAD datasets. Colony formation, invasion, and migration in DLD1 and SW480 cells were suppressed by overexpression of miR-200a-3p. Inhibition of miR-200a-3p function contributed to abnormal colony formation, migration, invasion, and epithelial-mesenchymal transition (EMT). miR-200a-3p binding sites were located within the 3'-untranslated region (3'-UTR) of the Forkhead box protein A1 (FOXA1) mRNA. CONCLUSION: We developed and validated a diagnostic and prognostic prediction model for CRC. miR-200a-3p was determined to be a potential diagnostic and prognostic biomarker for CRC.

Notch1 and PI3K/Akt signaling blockers DAPT and LY294002 coordinately inhibit metastasis of gastric cancer through mutual enhancement.

PURPOSE: Blockade of either Notch1 or PI3K/Akt pathway inhibits metastasis of gastric cancer. However, whether blockade of both pathways coordinately exerts such an effect remains unknown. In this study, we aimed to investigate the effects of combined treatment with Notch1 signaling blocker DAPT and PI3K/Akt signal blocker LY294002 on metastasis of gastric cancer. METHODS: Notch intracellular domain (NICD) and phosphorylated Akt (p-Akt) levels in gastric cancer tissues and their adjacent normal tissue samples and gastric cancer SGC7901 and AGS cells and normal GES-1 cells were determined using immunohistochemistry and Western blotting. The effects of combined DAPT and LY294002 on metastasis of gastric cancer were evaluated by examining migration and invasion potential of SGC7901 cells using wound healing and transwell assays, determining changes in the levels of epithelial-mesenchymal transition biomarkers and MMP-9, Notch1, HES1, and phosphorylation of Akt in gastric cancer SGC7901 cells and/or AGS cells in vitro using Western blotting, and metastasis of gastric cancer to lungs in BALB/c nude mice after treatment. RESULTS: NICD and p-Akt levels were significantly higher in gastric cancer tissues and SGC7901 and AGS cells than those in the normal control and GES-1 cells. Migration and invasion potential of SGC7901 cells, EMT biomarkers and MMP-9 in SGC7901 cells, and metastasis of gastric cancer to lungs in mice were coordinately inhibited by DAPT and LY294002. In addition, DAPT and LY294002 coordinately inhibited the levels of Notch1, HES1, and p-Akt in gastric cancer cells. CONCLUSION: DAPT and LY294002 coordinately inhibited metastasis of gastric cancer through mutual enhancement.

Survival and Clinicopathological Significance of SIRT1 Expression in Cancers: A Meta-Analysis.

Background: Silent information regulator 2 homolog 1 (SIRT1) is an evolutionarily conserved enzymes with nicotinamide adenine dinucleotide (NAD)+-dependent deacetylase activity. SIRT1 is involved in a large variety of cellular processes, such as genomic stability, energy metabolism, senescence, gene transcription, and oxidative stress. SIRT1 has long been recognized as both a tumor promoter and tumor suppressor. Its prognostic role in cancers remains controversial. Methods: A meta-analysis of 13,138 subjects in 63 articles from PubMed, EMBASE, and Cochrane Library was performed to evaluate survival and clinicopathological significance of SIRT1 expression in various cancers. Results: The pooled results of meta-analysis showed that elevated expression of SIRT1 implies a poor overall survival (OS) of cancer patients [Hazard Ratio (HR) = 1.566, 95% CI: 1.293-1.895, P < 0.0001], disease free survival (DFS) (HR = 1.631, 95% CI: 1.250-2.130, P = 0.0003), event free survival (EFS) (HR = 2.534, 95% CI: 1.602-4.009, P = 0.0001), and progress-free survival (PFS) (HR = 3.325 95% CI: 2.762-4.003, P < 0.0001). Elevated SIRT1 level was associated with tumor stage [Relative Risk (RR) = 1.299, 95% CI: 1.114-1.514, P = 0.0008], lymph node metastasis (RR = 1.172, 95% CI: 1.010-1.360, P = 0.0363), and distant metastasis (RR = 1.562, 95% CI: 1.022-2.387, P = 0.0392). Meta-regression and subgroup analysis revealed that ethnic background has influence on the role of SIRT1 expression in predicting survival and clinicopathological characteristics of cancers. Overexpression of SIRT1 predicted a worse OS and higher TNM stage and lymphatic metastasis in Asian population especially in China. Conclusion: Our data suggested that elevated expression of SIRT1 predicted a poor OS, DFS, EFS, PFS, but not for recurrence-free survival (RFS) and cancer-specific survival (CCS). SIRT1 overexpression was associated with higher tumor stage, lymph node metastasis, and distant metastasis. SIRT1-mediated molecular events and biological processes could be an underlying mechanism for metastasis and SIRT1 is a therapeutic target for inhibiting metastasis, leading to good prognosis.

An eight-lncRNA signature predicts survival of breast cancer patients: a comprehensive study based on weighted gene co-expression network analysis and competing endogenous RNA network.

PURPOSE: To identify a lncRNA signature to predict survival of breast cancer (BRCA) patients. METHODS: A total of 1222 BRCA case and control datasets were downloaded from the TCGA database. The weighted gene co-expression network analysis of differentially expressed mRNAs was performed to generate the modules associated with BRCA overall survival status and further construct a hub on competing endogenous RNA (ceRNA) network. LncRNA signatures for predicting survival of BRCA patients were generated using univariate survival analyses and a multivariate Cox hazard model analysis and validated and characterized for prognostic performance measured using receiver operating characteristic (ROC) curves. RESULTS: A prognostic score model of eight lncRNAs signature was identified as Prognostic score = (0.121 × EXPAC007731.1) + (0.108 × EXPAL513123.1) + (0.105 × EXPC10orf126) + (0.065 × EXPWT1-AS) + (- 0.126 × EXPADAMTS9-AS1) + (- 0.130 × EXPSRGAP3-AS2) + (0.116 × EXPTLR8-AS1) + (0.060 × EXPHOTAIR) with median score 1.088. Higher scores predicted higher risk. The lncRNAs signature was an independent prognostic factor associated with overall survival. The area under the ROC curves (AUC) of the signature was 0.979, 0.844, 0.99 and 0.997 by logistic regression, support vector machine, decision tree and random forest models, respectively, and the AUCs in predicting 1- to 10-year survival were between 0.656 and 0.748 in the test dataset from TCGA database. CONCLUSIONS: The eight-lncRNA signature could serve as an independent biomarker for prediction of overall survival of BRCA. The lncRNA-miRNA-mRNA ceRNA network is a good tool to identify lncRNAs that is correlated with overall survival of BRCA.

Association between RFC1 A80G polymorphism and the susceptibility to nonsyndromic cleft lip with or without cleft palate: a meta-analysis.

BACKGROUND: Reduced folate carrier 1 (RFC1) gene is a candidate for susceptibility to nonsyndromic cleft lip with or without cleft palate (NSCL/P). Association between RFC1 A80G polymorphism and NSCL/P have been studied. The published results are conflicting. METHODS: A meta-analysis of the association between RFC1 A80G polymorphism and NSCL/P was carried out using Stata13.0. A systematic literature search was performed through the PubMed, EMBASE, the Cochrane Library, Web of Science, ScienceDirect, EBSCOhost, China Biology Medicine databases, China National Knowledge Infrastructure and the Wanfang databases. All relevant studies up to 9 September 2019 were identified. RESULTS: Nine case-control studies including 4,229 total participants (1,334 NSCL/P children, 1,515 healthy children, 656 mothers of the NSCL/P children, and 724 mothers of healthy control children) were included in this study. The meta-analysis revealed that two genetic models of RFC1 A80G polymorphism in NSCL/P children increased risk of NSCL/P: the homozygote model (GG vs. AA, OR =2.346, 95% CI: 1.127-4.884) and the recessive model (GG vs. AG + AA, OR =1.503, 95% CI: 1.049-2.152). Further sensitivity analysis indicated that the frequency of G allele and GG genotype in NSCL/P children was significantly higher than those in the control. However, there was no significant statistical differences after Bonferroni correction. Subgroup analyses indicated the presence of the association of all the model with NSCL/P risk in the Indian children. RFC1 A80G polymorphism in the maternal population of NSCL/P children was not significantly associated with children NSCL/P. CONCLUSIONS: The RFC1 A80G polymorphism was a candidate for susceptibility to NSCL/P in the Indian pediatric population. More studies with larger samples are necessary to reach more conclusive outcomes.

Association between TIM-3 polymorphisms and cancer risk: a meta-analysis.

BACKGROUND: Single nucleotide polymorphisms (SNPs) of T-cell immunoglobulin- and mucin-domain-containing molecule 3 (TIM-3) were reported to individually associate with cancer risk. To further verify its correlation with human cancers, we evaluated the association of TIM-3 polymorphisms and the risk of cancer. METHODS: Data were collected from electronic databases. Two reviewers independently selected studies, extracted data and assessed quality of the studies. Data were meta-analyzed using the STATA 13.0 software. Crude odd ratio (OR) and 95% confidence interval was used to estimate the association between TIM-3 polymorphism and cancer susceptibility. RESULTS: All eligible case-control studies included a total of 4,852 participants (2,229 cases and 2,623 controls). The meta-analysis showed that TIM-3 SNPs (-1516G/T, -574G/T, +4259T/G, and haplotypes) were significantly associated with an increased risk of susceptibility toward all cancers. The subgroup analyses based on cancer types showed that TIM-3 -1516G/T SNP was only associated with an increased risk in developing cancers in the digestive system or in hospital-based populations. Moreover, the TIM-3 -574G/T SNP was associated with an increased cancer risk in the digestive system or other systems, while TIM-3 +4259T/G SNP was only associated with an increased cancer risk in hospital-based populations. Among the four haplotypes observed (GGT, TGT, GGG, and GTT), The GGG haplotype showed an increase in the odds of cancer by 2.614-fold (OR 2.614; 95% CI: 1.756-3.893) compared with the GGT haplotype. CONCLUSIONS: TIM-3 SNPs (-1516G/T, -574G/T, +4259T/G and the four haplotypes) were associated with an increased risk of developing human cancers.

Pregnane X receptor regulates the AhR/Cyp1A1 pathway and protects liver cells from benzo-[α]-pyrene-induced DNA damage.

Pregnane X receptor (PXR) plays an important role in protecting cells from mutagenic DNA damages induced by endogenous and exogenous toxicants. This protective function is often attributed to the PXR-regulated metabolic detoxification. Here we report a novel potential mechanism that PXR reduces benzo-[α]-pyrene(BaP)-induced DNA damage through inhibiting the transcriptional activity of aryl hydrocarbon receptor (AhR) which plays a pivotal role in the bioactivation of BaP. We have utilized three well-characterized cell lines, i.e. Hepa1c1c7, AhR +/+; Bpr lacks AhR obligatory partner ARNT; Tao, lacks AhR, to analyze pivotal role of AhR/ARNT complex in mediating the BaP-induced DNA damages using comet assay (single-cell gel electrophoresis). We found that PXR activation could significantly inhibit BaP-induced DNA damage in the HepG2 cells as well as mouse hepatocytes. Using PXR-null and wild type mouse hepatocytes we showed that PXR activation by pregnenolone 16α-carbonitrile (PCN) significantly inhibited BaP-induced DNA damage and this protective effect was abolished in PXR-null hepatocytes. Mechanistically, PXR activation inhibited expression of AhR-target genes for CYP1A1, CYP1B1 and CYP1A2 that are required for BaP biotransformation in cultured liver cells, or in the livers of C57BL/6J mice. Using an AhR-responsive reporter assay as well as chromatin immunoprecipitation assay we found that PXR activation transcriptionally represses AhR-regulated gene expression. Furthermore, we found that PXR directly bound AhR at its DNA-binding domain, and this association may play a role in preventing of the AhR from binding to its target genes as shown in the ChIP assay. Taken together, our study has revealed a novel mechanism by which PXR protects liver cells from BaP-induced DNA damage through inhibiting the BaP biotransformation.

The mobile monitoring of black carbon and its association with roadside data in the Chinese megacity of Shanghai.

High-level black carbon (BC) pollution is associated with traffic emissions in metropolitan areas with high vehicle density. Mobile monitoring was conducted to assess the in-vehicle BC exposure on three backbone ring roads (inner, middle, and outer ring roads) on October 14 and October 18, 2015 in Shanghai. Ambient BC monitoring was also simultaneously conducted in three fixed roadside stations from October 14 to October 20, 2015. Results of the mobile monitoring showed median BC personal exposure concentrations ranging from 5.0 µg m-3 on the inner ring road to 13.5 µg m-3 on the outer ring road. The ambient BC concentrations during the entire observation period showed an arithmetic mean and a standard deviation of 3.5 ± 2.9 µg m-3. The correlation analysis of urban roadside monitoring (Caoxi Road and South Zhongshan Road) and personal data showed a high and significant correlation. The results of this study highlight the critical level of BC pollution in Shanghai and facilitate the development of evidence-based public health interventions and control strategies to prevent the adverse health effects of BC pollution.