Epigenetic regulation of DNA repair gene program by Hippo/YAP1-TET1 axis mediates sorafenib resistance in HCC.

Hepatocellular carcinoma (HCC) is a malignancy that occurs worldwide and is generally associated with poor prognosis. The development of resistance to targeted therapies such as sorafenib is a major challenge in clinical cancer treatment. In the present study, Ten-eleven translocation protein 1 (TET1) was found to be highly expressed in sorafenib-resistant HCC cells and knockdown of TET1 can substantially improve the therapeutic effect of sorafenib on HCC, indicating the potential important roles of TET1 in sorafenib resistance in HCC. Mechanistic studies determined that TET1 and Yes-associated protein 1 (YAP1) synergistically regulate the promoter methylation and gene expression of DNA repair-related genes in sorafenib-resistant HCC cells. RNA sequencing indicated the activation of DNA damage repair signaling was extensively suppressed by the TET1 inhibitor Bobcat339. We also identified TET1 as a direct transcriptional target of YAP1 by promoter analysis and chromatin-immunoprecipitation assays in sorafenib-resistant HCC cells. Furthermore, we showed that Bobcat339 can overcome sorafenib resistance and synergized with sorafenib to induce tumor eradication in HCC cells and mouse models. Finally, immunostaining showed a positive correlation between TET1 and YAP1 in clinical samples. Our findings have identified a previously unrecognized molecular pathway underlying HCC sorafenib resistance, thus revealing a promising strategy for cancer therapy.

Molecular epidemiology of Acinetobacter baumannii during COVID-19 at a hospital in northern China.

BACKGROUND: The wide spread of carbapenem-resistance clones of Acinetobacter baumannii has made it a global public problem. Some studies have shown that the prevalence of Acinetobacter baumannii clones can change over time. However, few studies with respect to the change of epidemiological clones in Acinetobacter baumannii during Corona Virus Disease 2019 (COVID-19) were reported. This study aims to investigate the molecular epidemiology and resistance mechanisms of Acinetobacter baumannii during COVID-19. RESULTS: A total of 95 non-replicated Acinetobacter baumannii isolates were enrolled in this study, of which 60.0% (n = 57) were identified as carbapenem-resistant Acinetobacter baumannii (CRAB). The positive rate of the blaOXA-23 gene in CRAB isolates was 100%. A total of 28 Oxford sequence types (STs) were identified, of which the most prevalent STs were ST540 (n = 13, 13.7%), ST469 (n = 13, 13.7%), ST373 (n = 8, 8.4%), ST938 (n = 7, 7.4%) and ST208 (n = 6, 6.3%). Differently, the most widespread clone of Acinetobacter baumannii in China during COVID-19 was ST208 (22.1%). Further study of multidrug-resistant ST540 showed that all of them were carrying blaOXA-23, blaOXA-66, blaADC-25 and blaTEM-1D, simultaneously, and first detected Tn2009 in ST540. The blaOXA-23 gene was located on transposons Tn2006 or Tn2009. In addition, the ST540 strain also contains a drug-resistant plasmid with msr(E), armA, sul1 and mph(E) genes. CONCLUSION: The prevalent clones of Acinetobacter baumannii in our organization have changed during COVID-19, which was different from that of China. ST540 strains which carried multiple drug-resistant mobile elements was spreading, indicating that it is essential to strengthen the molecular epidemiology of Acinetobacter baumannii.

An NF-κB/OVOL2 circuit regulates glucose import and cell survival in non-small cell lung cancer.

BACKGROUND: Tumor cells tend to utilize glycolysis rather than aerobic respiration even under aerobic conditions. OVOL2, an inhibitory C2H2 zinc finger transcription factor, is a potential tumor suppressor in cancers. However, the association between OVOL2 and tumor energy metabolism is unknown. METHODS: Western blotting was used to determine the expression of OVOL2 in different non-small cell lung cancer (NSCLC) cell lines and mouse models. The metabolic parameters in NSCLC cells following overexpression or knockdown OVOL2 were examined. To define the mechanism by which OVOL2 regulates aerobic glycolysis, interacting protein of OVOl2 and downstream molecular events were identified by luciferase assay and co-immunoprecipitation. We documented the regulatory mechanism in mouse xenograft models. Finally, clinical relevance of OVOL2, NF-κB signaling and GLUT1 was measured by immunostaining. RESULTS: OVOL2 is downregulated in NSCLC and overexpression of OVOL2 inhibits the survival of cancer cells. Moreover, OVOL2 directly binds to P65 and inhibits the recruitment of P300 but facilitates the binding of HDAC1 to P65, which in turn negatively regulates NF-κB signaling to suppress GLUT1 translocation and glucose import. In contrast, OVOL2 expression is negatively regulated by NF-κB signaling in NSCLC cells via the ubiquitin-proteasome pathway. Re-expression of OVOL2 significantly compromise NF-κB signaling-induced GLUT1 translocation, aerobic glycolysis in NSCLC cells and mouse models. Immunostaining revealed inverse correlations between the OVOL2 and phosphorylated P65 levels and between the OVOL2 and membrane GLUT1 levels, and a strong correlation between the phosphorylated P65 and membrane GLUT1 levels. CONCLUSIONS: These results suggest a regulatory circuit linking NF-κB and OVOL2, which highlights the role of NF-κB signaling and OVOL2 in the modulation of glucose metabolism in NSCLC. Video Abstract.

The prognostic values of serum markers in hepatocellular carcinoma after invasive therapies based on real-world data.

BACKGROUND AND AIMS: Hepatocellular carcinoma (HCC) is one of the most common malignancy with poor prognosis, and the mortality rate remains high. More than 70% of HCC patients have recurrence within 5 years after treatment. The purpose of this study is to evaluate the prognostic values of serum markers with retrospective data. METHODS: We applied real-world data (RWD) to analyze the prognostic values of six serum markers for HCC patients after treatment, including α-fetoprotein (AFP), α-fetoprotein-L3 (AFP-L3), Golgi protein73 (GP73), alanine aminotransferase (ALT), albumin (ALB), and total bilirubin (TBil). A total of 268 cases were enrolled to analyze recurrence-free survival (RFS), and 104 cases were used to analyze overall survival (OS). RESULTS: Our results demonstrated that patients with higher AFP and AFP-L3 had shorter RFS (p = 0.016 and 0.004), while higher GP73, ALT, and TBil experienced longer RFS (p = 0.000, 0.020, and 0.019). Patients with high-level GP73, ALT, TBil, and low-level ALB had significantly higher mortality rate (p=0.035, 0.008, 0.010, and 0.005). Multivariate analysis revealed that GP73 (HR = 1.548, p = 0.001) and ALT (HR = 1.316, p = 0.046) were identified as independent prognostic factors for RFS, ALB (HR = 0.127, p = 0.007), and ALT (HR = 0.237, p = 0.01) were identified as independent prognostic factors for OS. Subgroups analysis showed that GP73 had better prognostic values than other serum markers in early-stage HCC (p = 0.023). CONCLUSIONS: Our study demonstrates that AFP, AFP-L3, and GP73 can be used as prognostic indicators for predicting the recurrence of HCC, while liver function tests have better survival prediction values. GP73 can act as a promising prognostic marker for early-stage HCC.

Nosocomial spread of OXA-232-producing Klebsiella pneumoniae ST15 in a teaching hospital, Shanghai, China.

BACKGROUND: The spread and outbreak of Enterobacteriaceae producing OXA-48-like carbapenemases have become more and more prevalent in China. RESULTS: A total of 62 non-duplicated OXA-232-producing K. pneumoniae (OXA232Kp) were isolated between 2015 and 2017. An outbreak of OXA232Kp was observed in burn ICU. The 62 OXA232Kp isolates were all belongs to ST15 and categorized into two PFGE types (A and B). Type A was dominated of the isolates, which contained 61 clinical isolates and divided into 10 subtypes (A1-A10). In addition, most of OXA232Kp strains exhibited low-level carbapenems resistance. All strains carried a 6141 bp ColKP3 plasmid harboring the blaOXA-232 gene which is highly homologous to other blaOXA-232-bearing plasmids involved in other studies in eastern China. CONCLUSIONS: In this study, clone transmission of OXA232Kp ST15was observed. Highly significant homology among the blaOXA-232-bearing plasmids indicated the important role of the 6.1 kb ColE-like plasmid on the prevalence of blaOXA-232 gene in China.

Tumor-originated exosomal lncUEGC1 as a circulating biomarker for early-stage gastric cancer.

Conventional tumor markers for non-invasive diagnosis of gastric cancer (GC) exhibit insufficient sensitivity and specificity to facilitate detection of early gastric cancer (EGC). We aimed to identify EGC-specific exosomal lncRNA biomarkers that are highly sensitive and stable for the non-invasive diagnosis of EGC. Hence, in the present study, exosomes from the plasma of five healthy individuals and ten stage I GC patients and from culture media of four human primary stomach epithelial cells and four gastric cancer cells (GCCs) were isolated. Exosomal RNA profiling was performed using RNA sequencing to identify EGC-specific exosomal lncRNAs. A total of 79 and 285 exosomal RNAs were expressed at significantly higher levels in stage I GC patients and GCCs, respectively, than that in normal controls. Through combinational analysis of the RNA sequencing results, we found two EGC-specific exosomal lncRNAs, lncUEGC1 and lncUEGC2, which were further confirmed to be remarkably up-regulated in exosomes derived from EGC patients and GCCs. Furthermore, stability testing demonstrates that almost all the plasma lncUEGC1 was encapsulated within exosomes and thus protected from RNase degradation. The diagnostic accuracy of exosomal lncUEGC1 was evaluated, and lncUEGC1 exhibited AUC values of 0.8760 and 0.8406 in discriminating EGC patients from healthy individuals and those with premalignant chronic atrophic gastritis, respectively, which was higher than the diagnostic accuracy of carcinoembryonic antigen. Consequently, exosomal lncUEGC1 may be promising in the development of highly sensitive, stable, and non-invasive biomarkers for EGC diagnosis.

Yes-associated protein/TEA domain family member and hepatocyte nuclear factor 4-alpha (HNF4α) repress reciprocally to regulate hepatocarcinogenesis in rats and mice.

Great progress has been achieved in the study of Hippo signaling in regulating tumorigenesis; however, the downstream molecular events that mediate this process have not been completely defined. Moreover, regulation of Hippo signaling during tumorigenesis in hepatocellular carcinoma (HCC) remains largely unknown. In the present study, we systematically investigated the relationship between Yes-associated protein/TEA domain family member (YAP-TEAD) and hepatocyte nuclear factor 4-alpha (HNF4α) in the hepatocarcinogenesis of HCC cells. Our results indicated that HNF4α expression was negatively regulated by YAP1 in HCC cells by a ubiquitin proteasome pathway. By contrast, HNF4α was found to directly associate with TEAD4 to compete with YAP1 for binding to TEAD4, thus inhibiting the transcriptional activity of YAP-TEAD and expression of their target genes. Moreover, overexpression of HNF4α was found to significantly compromise YAP-TEAD-induced HCC cell proliferation and stem cell expansion. Finally, we documented the regulatory mechanism between YAP-TEAD and HNF4α in rat and mouse tumor models, which confirmed our in vitro results. CONCLUSION: There is a double-negative feedback mechanism that controls TEAD-YAP and HNF4α expression in vitro and in vivo, thereby regulating cellular proliferation and differentiation. Given that YAP acts as a dominant oncogene in HCC and plays a crucial role in stem cell homeostasis and tissue regeneration, manipulating the interaction between YAP, TEADs, and HNF4α may provide a new approach for HCC treatment and regenerative medicine. (Hepatology 2017;65:1206-1221).

Pregnane X receptor mediates sorafenib resistance in advanced hepatocellular carcinoma.

BACKGROUND: Kinase inhibitor sorafenib is the most widely used drug for advanced HCC clinical treatment nowadays. However, sorafenib administration is only effective for a small portion of HCC patients, and the majority develop sorafenib-resistance during treatment. Thus, it is urgent to discover the endogenous mechanism and identify new pharmaceutical targets of sorafenib-resistance. METHODS: Pregnane X receptor (PXR) was detected by immunohistochemistry and quantitative PCR. GST-pull down and LC-MS/MS was used to detect the interaction of PXR and Sorafenib. To test the properties of HCC tumor growth and metastasis, in vivo tumor explant model, FACS, trans-well assay, cell-survival inhibitory assay and Western blot were performed. In terms of mechanistic study, additional assays such as ChIP and luciferase reporter gene assay were applied. RESULTS: In the present work, we found high PXR level in clinical specimens is related to the poor prognosis of Sorafenib treated patients. By the mechanistic studies, we show that sorafenib binds to PXR and activates PXR pathway, and by which HCC cells develop sorafenib-resistance via activating. Moreover, PXR overexpression helps HCC cells to persist to sorafenib treatment. CONCLUSION: This study reports the endogenous sorafenib-resistance mechanism in HCC cells, which offers an opportunity to design new therapeutic approaches for HCC treatment. GENERAL SIGNIFICANCE: PXR mediates sorafenib-resistance in HCC cells and targeting PXR can be a useful approach to facilitate HCC treatment.

Combination of PCT, sNFI and dCHC for the diagnosis of ascites infection in cirrhotic patients.

BACKGROUND: It is difficult to diagnose ascites infection early in cirrhotic patients. The present study was to create and evaluate a new bioscore combined with PCT, sNFI and dCHC in the diagnosis of ascites infection in cirrhotic patients. METHODS: Two hundred and fifty-nine consecutive patients were enrolled; of which 51 patients were culture-positive spontaneous bacterial peritonitis (culture-positive SBP) and 58 patients were culture-negative SBP. The efficacy of procalcitonin(PCT), c-reactive protein (CRP), white blood cell (WBC), mean fluorescence intensity of mature neutrophils(sNFI) and difference in hemoglobin concentration between newly formed and mature red blood cells(dCHC) for diagnosing ascites infection was examined. These parameters were used to create a scoring system. The scoring system was analyzed by logistic regression analysis to determine which parameters were statistically different between ascites infection and non-ascites infection patients. Receiver operating characteristic curve (ROC) was used to analyze the diagnostic ability of bioscore for ascites infection. RESULTS: In ROC analysis, the area under the curves (AUC) for PCT was 0.852 (95% CI 0.803-0.921, P < 0.001), dCHC 0.837 (95% CI 0.773-0.923, P < 0.001), CRP 0.669 (95% CI 0.610-0.732, P = 0.0624), sNFI 0.838 (95% CI 0.777-0.903, P < 0.001), and WBC 0.624 (95% CI 0.500-0.722, P = 0.0881). Multivariate analysis revealed PCT, dCHC and sNFI to be statistically significant. The combination of these three parameters in the bioscore had an AUC of 0.937 (95% CI 0.901-0.994, P < 0.001). A bioscore of ≥3.40 was considered to be statistically significant in making a positive diagnosis of ascites infection. In different groups of ascites infection, bioscore also shown a high diagnostic value of AUC was 0.947(95% CI 0.882-0.988, P < 0.001) and 0.929 (95% CI 0.869-0.974, P < 0.001) for culture-positive SBP and culture-negative SBP group respectively. CONCLUSION: The composite markers of combining PCT, dCHC and sNFI could be a valuable diagnostic score to early diagnose ascites infection in patients with cirrhosis.

OVOL2, an Inhibitor of WNT Signaling, Reduces Invasive Activities of Human and Mouse Cancer Cells and Is Down-regulated in Human Colorectal Tumors.

BACKGROUND & AIMS: Activation of WNT signaling promotes the invasive activities of several types of cancer cells, but it is not clear if it regulates the same processes in colorectal cancer (CRC) cells, or what mechanisms are involved. We studied the expression and function of OVOL2, a member of the Ovo family of conserved zinc-finger transcription factors regulated by the WNT signaling pathway, in intestinal tumors of mice and human beings. METHODS: We analyzed the expression of OVOL2 protein and messenger RNA in CRC cell lines and tissue arrays, as well as CRC samples from patients who underwent surgery at Xiamen University in China from 2009 to 2012; clinical information also was collected. CRC cell lines (SW620) were infected with lentivirus expressing OVOL2, analyzed in migration and invasion assays, and injected into nude mice to assess tumor growth and metastasis. Tandem affinity purification was used to purify the OVOL2-containing complex from CRC cells; the complex was analyzed by liquid chromatography, tandem mass spectrometry, and immunoprecipitation experiments. Gene promoter activities were measured in luciferase reporter assays. We analyzed mice with an intestine-specific disruption of Ovol2 (Ovol2(flox/+) transgenic mice), as well as Apc(min/+) mice; these mice were crossed and analyzed. RESULTS: Analysis of data from patients indicated that the levels of OVOL2 messenger RNA were significantly lower in colon carcinomas than adenomas, and decreased significantly as carcinomas progressed from grades 2 to 4. Immunohistochemical analysis of a tissue array of 275 CRC samples showed a negative association between tumor stage and OVOL2 level. Overexpression of OVOL2 in SW620 cells decreased their migration and invasion, reduced markers of the epithelial-to-mesenchymal transition, and suppressed their metastasis as xenograft tumors in nude mice; knockdown of OVOL2 caused LS174T cells to transition from epithelial to mesenchymal phenotypes. OVOL2 bound T-cell factor (TCF)4 and ß-catenin, facilitating recruitment of histone deacetylase 1 to the TCF4-ß-catenin complex; this inhibited expression of epithelial-to-mesenchymal transition-related genes regulated by WNT, such as SLUG, in CRC cell lines. OVOL2 was a downstream target of WNT signaling in LS174T and SW480 cells. The OVOL2 promoter was hypermethylated in late-stage CRC specimens from patients and in SW620 cells; hypermethylation resulted in OVOL2 down-regulation and an inability to inhibit WNT signaling. Disruption of Ovol2 in Apc(min/+) mice increased WNT activity in intestinal tissues and the formation of invasive intestinal tumors. CONCLUSIONS: OVOL2 is a colorectal tumor suppressor that blocks WNT signaling by facilitating the recruitment of histone deacetylase 1 to the TCF4-ß-catenin complex. Strategies to increase levels of OVOL2 might be developed to reduce colorectal tumor progression and metastasis.

Application Value of Mass Spectrometry in the Differentiation of Benign and Malignant Liver Tumors.

BACKGROUND Differentiation of malignant from benign liver tumors remains a challenging problem. In recent years, mass spectrometry (MS) technique has emerged as a promising strategy to diagnose a wide range of malignant tumors. The purpose of this study was to establish classification models to distinguish benign and malignant liver tumors and identify the liver cancer-specific peptides by mass spectrometry. MATERIAL AND METHODS In our study, serum samples from 43 patients with malignant liver tumors and 52 patients with benign liver tumors were treated with weak cation-exchange chromatography Magnetic Beads (MB-WCX) kits and analyzed by the Matrix-Assisted Laser Desorption Time of Flight Mass Spectrometry (MALDI-TOF-MS). Then we established genetic algorithm (GA), supervised neural networks (SNN), and quick classifier (QC) models to distinguish malignant from benign liver tumors. To confirm the clinical applicability of the established models, the blinded validation test was performed in 50 clinical serum samples. Discriminatory peaks associated with malignant liver tumors were subsequently identified by a qTOF Synapt G2-S system. RESULTS A total of 27 discriminant peaks (p<0.05) in mass spectra of serum samples were found by ClinPro Tools software. Recognition capabilities of the established models were 100% (GA), 89.38% (SNN), and 80.84% (QC); cross-validation rates were 81.67% (GA), 81.11% (SNN), and 86.11% (QC). The accuracy rates of the blinded validation test were 78% (GA), 84% (SNN), and 84% (QC). From the 27 discriminatory peptide peaks analyzed, 3 peaks of m/z 2860.34, 2881.54, and 3155.67 were identified as a fragment of fibrinogen alpha chain, fibrinogen beta chain, and inter-alpha-trypsin inhibitor heavy chain H4 (ITIH4), respectively. CONCLUSIONS Our results demonstrated that MS technique can be helpful in differentiation of benign and malignant liver tumors. Fibrinogen and ITIH4 might be used as biomarkers for the diagnosis of malignant liver tumors.

The Wnt-ß-catenin pathway represses let-7 microRNA expression through transactivation of Lin28 to augment breast cancer stem cell expansion.

Wnt signalling through ß-catenin and the lymphoid-enhancing factor 1/T-cell factor (LEF1/TCF) family of transcription factors maintains stem cell properties in both normal and malignant tissues; however, the underlying molecular pathway involved in this process has not been completely defined. Using a microRNA microarray screening assay, we identified let-7 miRNAs as downstream targets of the Wnt-ß-catenin pathway. Expression studies indicated that the Wnt-ß-catenin pathway suppresses mature let-7 miRNAs but not the primary transcripts, which suggests a post-transcriptional regulation of repression. Furthermore, we identified Lin28, a negative let-7 biogenesis regulator, as a novel direct downstream target of the Wnt-ß-catenin pathway. Loss of function of Lin28 impairs Wnt-ß-catenin-pathway-mediated let-7 inhibition and breast cancer stem cell expansion; enforced expression of let-7 blocks the Wnt-ß-catenin pathway-stimulated breast cancer stem cell phenotype. Finally, we demonstrated that the Wnt-ß-catenin pathway induces Lin28 upregulation and let-7 downregulation in both cancer samples and mouse tumour models. Moreover, the delivery of a modified lin28 siRNA or a let-7a agomir into the premalignant mammary tissues of MMTV-wnt-1 mice resulted in a complete rescue of the stem cell phenotype driven by the Wnt-ß-catenin pathway. These findings highlight a pivotal role for Lin28/let-7 in Wnt-ß-catenin-pathway-mediated cellular phenotypes. Thus, the Wnt-ß-catenin pathway, Lin28 and let-7 miRNAs, three of the most crucial stem cell regulators, connect in one signal cascade.

A double-negative feedback loop between Wnt-ß-catenin signaling and HNF4α regulates epithelial-mesenchymal transition in hepatocellular carcinoma.

Wnt-ß-catenin signaling participates in the epithelial-mesenchymal transition (EMT) in a variety of cancers; however, its involvement in hepatocellular carcinoma (HCC) and downstream molecular events is largely undefined. HNF4α is the most prominent and specific factor maintaining the differentiation of hepatic lineage cells and a potential EMT regulator in HCC cells. However, the molecular mechanisms by which HNF4α maintains the differentiated liver epithelium and inhibits EMT have not been completely defined. In this study, we systematically explored the relationship between Wnt-ß-catenin signaling and HNF4α in the EMT process of HCC cells. Our results indicated that HNF4α expression was negatively regulated during Wnt-ß-catenin signaling-induced EMT through Snail and Slug in HCC cells. In contrast, HNF4α was found to directly associate with TCF4 to compete with ß-catenin but facilitate transcription co-repressor activities, thus inhibiting expression of EMT-related Wnt-ß-catenin targets. Moreover, HNF4α may control the switch between the transcriptional and adhesion functions of ß-catenin. Overexpression of HNF4α was found to completely compromise the Wnt-ß-catenin-signaling-induced EMT phenotype. Finally, we determined the regulation pattern between Wnt-ß-catenin signaling and HNF4α in rat tumor models. Our studies have identified a double-negative feedback mechanism controlling Wnt-ß-catenin signaling and HNF4α expression in vitro and in vivo, which sheds new light on the regulation of EMT in HCC. The modulation of these molecular processes may be a method of inhibiting HCC invasion by blocking Wnt-ß-catenin signaling or restoring HNF4α expression to prevent EMT.

Initiator Integrated Poly(dimethysiloxane)-Based Microarray as a Tool for Revealing the Relationship between Nonspecific Interactions and Irreproducibility.

Nonspecific interactions (NSIs) and irreproducibility greatly reduce the accuracy of antigen-antibody screening, which is key to the discovery of monoclonal antibody drugs and biomarkers identification. We previously developed a solid supporting material, polymer-coated initiator integrated poly(dimethysiloxane) (iPDMS), which is able to provide near-zero background for microarray screening. Here, we applied two monoclonal antibodies (mAbs), namely, anti-FLAG and HM1, to screen an iPDMS-based peptide microarray with 2083 peptides from 62 proteins to evaluate NSIs and irreproducibility. In addition to recognizing their cognate epitopes, the two mAbs also cross-reacted with random sequences, especially when they were used at high concentrations. At 50 µg mL(-1), 295 peptides (14.2% of the peptide library) had positive reactions to anti-FLAG and only 39 peptides (1.9%) reacted positively to HM1. Virtually all cross-reactions disappeared when the [mAbs] reached 0.01 µg mL(-1). Reproducible experiments of 404 peptides at various [mAbs] showed that only specific interactions, molecular mimicry, and mimotope were reproducible between different experiments. These findings suggest that irreproducibility was at least partially caused by NSIs. We also demonstrated that repeating tests and mAb dilution could effectively avoid NSI-related irreproducibility in serological screening. This will not only largely simplify the data analysis, but will also make immunoassays more reliable for clinical research.

A systematic investigation based on microRNA-mediated gene regulatory network reveals that dysregulation of microRNA-19a/Cyclin D1 axis confers an oncogenic potential and a worse prognosis in human hepatocellular carcinoma.

MicroRNAs (miRNAs) contribute to a wide variety of human diseases by regulating gene expression, leading to imbalances in gene regulatory networks. To discover novel hepatocellular carcinoma (HCC)-related miRNA-target axes and to elucidate their functions, we here performed a systematic investigation combining biological data acquisition and integration, miRNA-target prediction, network construction, functional assay and clinical validation. As a result, a total of 117 HCC differentially expressed miRNAs were identified, and 728 high confident target genes of these miRNAs were collected. Then, the interaction network of target genes was constructed and 221 key nodes with topological importance in the network were identified according to their topological features including degree, node-betweenness, closeness and K-coreness. Among these key nodes, Cyclin D1 had the highest node-betweenness, implying its bottleneck role in the network. Luciferase reporter assay confirmed that miRNA-19a, which was one of HCC downregulated miRNAs, directly targeted Cyclin D1 in HCC cells. Moreover, miR-19a might play inhibitory roles in HCC malignancy via regulating Cyclin D1 expression. Further clinical evidence also highlighted the prognostic potential of miR-19a/Cyclin D1 axis in HCC. In conclusion, this systematic investigation provides a framework to identify featured miRNAs and their target genes which are potent effectors in the occurrence and development of HCC. More importantly, miR-19a/Cyclin D1 axis might have promising applications as a therapeutic target and a prognostic marker for patients with HCC.

Comprehensive analysis of microRNA-regulated protein interaction network reveals the tumor suppressive role of microRNA-149 in human hepatocellular carcinoma via targeting AKT-mTOR pathway.

BACKGROUND: Our previous study identified AKT1, AKT2 and AKT3 as unfavorable prognostic factors for patients with hepatocellular carcinoma (HCC). However, limited data are available on their exact mechanisms in HCC. Since microRNAs (miRNAs) are implicated in various human cancers including HCC, we aimed to screen miRNAs targeting AKTs and investigate their underlying mechanisms in HCC by integrating bioinformatics prediction, network analysis, functional assay and clinical validation. METHODS: Five online programs of miRNA target prediction and RNAhybrid which calculate the minimum free energy (MFE) of the duplex miRNA:mRNA were used to screen optimized miRNA-AKT interactions. Then, miRNA-regulated protein interaction network was constructed and 5 topological features ('Degree', 'Node-betweenness', 'Edge-betweenness', 'Closeness' and 'Modularity') were analyzed to link candidate miRNA-AKT interactions to oncogenesis and cancer hallmarks. Further systematic experiments were performed to validate the prediction results. RESULTS: Six optimized miRNA-AKT interactions (miR-149-AKT1, miR-302d-AKT1, miR-184-AKT2, miR-708-AKT2, miR-122-AKT3 and miR-124-AKT3) were obtained by combining the miRNA target prediction and MFE calculation. Then, 103 validated targets for the 6 candidate miRNAs were collected from miRTarBase. According to the enrichment analysis on GO items and KEGG pathways, these validated targets were significantly enriched in many known oncogenic pathways for HCC. In addition, miRNA-regulated protein interaction network were divided into 5 functional modules. Importantly, AKT1 and its interaction with mTOR respectively had the highest node-betweenness and edge-betweenness, implying their bottleneck roles in the network. Further experiments confirmed that miRNA-149 directly targeted AKT1 in HCC by a miRNA luciferase reporter approach. Then, re-expression of miR-149 significantly inhibited HCC cell proliferation and tumorigenicity by regulating AKT1/mTOR pathway. Notably, miR-149 down-regulation in clinical HCC tissues was correlated with tumor aggressiveness and poor prognosis of patients. CONCLUSION: This comprehensive analysis identified a list of miRNAs targeting AKTs and revealed their critical roles in HCC malignant progression. Especially, miR-149 may function as a tumor suppressive miRNA and play an important role in inhibiting the HCC tumorigenesis by modulating the AKT/mTOR pathway. Our clinical evidence also highlight the prognostic potential of miR-149 in HCC. The newly identified miR-149/AKT/mTOR axis might be a promising therapeutic target in the prevention and treatment of HCC.

Effect of concentration, temperature, and time on the stability of hepatitis C virus nucleic acid in serum.

To explore the influence of storage temperature and time on the stability of different concentrations of hepatitis C virus nucleic acid (HCV RNA) samples and to provide data reference for laboratory quality control. Serum samples of 10 patients with HCV RNA detection quantitation of 106-108 IU/mL were collected. The samples of each patient were diluted into three concentrations: high, medium, and low. Then the samples of each concentration were divided into 21, which were divided into three groups according to the storage conditions of -20°C, 4°C, and 25°C, with seven samples in each group. The samples were selected from each group for quantitative detection of HCV RNA on day 0, day 1, day 3, day 5, day 7, day 14, and day 30. The results of each concentration and storage temperature sample remained stable within 5 days. Based on the mixed-effect linear model, the main effects of temperature, time, and concentration were statistically significant (P < 0.01). There was an interaction effect between concentration and time (P = 0.0448), and there was also an interaction effect between temperature and time (P < 0.01). There was no interaction effect between concentration and temperature (P = 0.11) or between concentration, temperature, and time (P = 0.90). The results of serum samples with different concentrations of the HCV RNA remained stable within 5 days. The lower the initial concentration of HCV RNA serum sample, the worse the stability; the higher the storage temperature, the worse the stability. If conditions permit, the laboratory should store such samples at -20°C. IMPORTANCE: Previously, there were few reports about the influence of different concentrations of sample nucleic acid on the stability of samples at various temperatures and times in various literatures. Therefore, it is necessary to analyze the influence of concentration factors on the stability of samples and test results at different storage times and temperatures. This study took the concentration of hepatitis C virus nucleic acid as the research object to further understand the stability of hepatitis C virus nucleic acid test samples under various storage conditions, to provide data reference for the treatment of hepatitis C virus nucleic acid and RNA test samples before clinical laboratory test, and provide guidance and help for the improvement of laboratory quality control.

Replicon-Based Typing About IncG Plasmids and Molecular Characterization of Five IncG Plasmids Carrying Carbapenem Resistance Gene bla KPC-2.

Purpose: To investigate the genetic diversity of IncG plasmids, we have proposed a typing scheme based on replicon repA and performed comparative genomic analysis of five IncG plasmids from China. Methods: p30860-KPC, p116965-KPC, pA1705-KPC, pA1706-KPC and pNY5520-KPC total in five IncG plasmids from clinical isolates of Pseudomonas and Enterobacteriaceae, respectively, were fully sequenced and were compared with the previously collected reference plasmid p10265-KPC. Results: Based on phylogeny, IncG-type plasmids are divided into IncG-I to IncG-VIII, the five plasmids belong to IncG-VIII. A detailed sequence comparison was then presented that the IncG plasmid involved accessory region I (Tn5563a/b/c/d/e), accessory region II (ISpa19), and accessory region III (bla KPC-2-region). Expect for the pNY5520-KPC, the rest of the plasmids had the same backbone structure as the reference one. Within the plasmids, insertion sequences Tn5563d and Tn5563e were identified, a novel unknown insertion region was found in Tn5563b/c/d/e. In addition, Tn6376b and Tn6376c were newly designated in the study. Conclusion: The data presented here including a typing scheme and detailed genetic comparison which provide an insight into the diversification and evolution history of IncG plasmids.

Loss of OVOL2 in Triple-Negative Breast Cancer Promotes Fatty Acid Oxidation Fueling Stemness Characteristics.

Triple-negative breast cancer (TNBC), the most aggressive subtype of breast cancer, has a poor prognosis and lacks effective treatment strategies. Here, the study discovered that TNBC shows a decreased expression of epithelial transcription factor ovo-like 2 (OVOL2). The loss of OVOL2 promotes fatty acid oxidation (FAO), providing additional energy and NADPH to sustain stemness characteristics, including sphere-forming capacity and tumor initiation. Mechanistically, OVOL2 not only suppressed STAT3 phosphorylation by directly inhibiting JAK transcription but also recruited histone deacetylase 1 (HDAC1) to STAT3, thereby reducing the transcriptional activation of downstream genes carnitine palmitoyltransferase1 (CPT1A and CPT1B). PyVT-Ovol2 knockout mice develop a higher number of primary breast tumors with accelerated growth and increased lung-metastases. Furthermore, treatment with FAO inhibitors effectively reduces stemness characteristics of tumor cells, breast tumor initiation, and metastasis, especially in OVOL2-deficient breast tumors. The findings suggest that targeting JAK/STAT3 pathway and FAO is a promising therapeutic strategy for OVOL2-deficient TNBC.