Association between novel genetic variants of Notch signaling pathway genes and survival of hepatitis B virus-related hepatocellular carcinoma.

BACKGROUND: Although the Notch pathway plays an important role in formation and progression of hepatocellular carcinoma (HCC), few studies have reported the associations between functional genetic variants and the survival of hepatitis B virus (HBV)-related HCC. METHODS: In the present study, we performed multivariable Cox proportional hazard regression analysis to evaluate associations between 36,101 SNPs in 264 Notch pathway-related genes and overall survival (OS) of 866 patients with HBV-related HCC. RESULTS: It was found that three independent SNPs (NEURL1B rs4868192, CNTN1 rs444927 and FCER2 rs1990975) were significantly associated with the HBV-related HCC OS. The number of protective genotypes (NPGs) were significantly associated with better survival in a dose-response manner (ptrend <0.001). Compared with the model with sole clinical factors, the addition of protective genotypes to the predict models significantly increased the AUC, i.e., from 72.72% to 75.13% (p = 0.002) and from 72.04% to 74.76 (p = 0.004) for 3-year and 5-year OS, respectively. The expression quantitative trait loci (eQTL) analysis further revealed that the rs4868192 C allele was associated with lower mRNA expression levels of NEURL1B in the whole blood (p = 1.71 × 10-3), while the rs1990975 T allele was correlated with higher mRNA expression levels of FCER2 in the whole blood and normal liver tissues (p = 3.51 × 10-5 and 0.033, respectively). CONCLUSIONS: Three potentially functional SNPs of NEURL1B, CNTN1 and FCER2 may serve as potential prognostic biomarkers for HBV-related HCC.

Genetic variants in m5C modification genes are associated with survival of patients with HBV-related hepatocellular carcinoma.

Hepatocellular carcinoma (HCC) is one of the most common malignant tumors with a high mortality rate. The 5-methylcytosine (m5C), a type of RNA modification, plays crucial regulatory roles in HCC carcinogenesis, metastasis, and prognosis. However, a few studies have investigated the effect of genetic variants in m5C modification genes on survival of patients with hepatitis B virus (HBV)-related HCC. In the present study, we evaluated associations between 144 SNPs in 15 m5C modification genes and overall survival (OS) in 866 patients with the HBV-related HCC. Expression quantitative trait loci (eQTL) analysis and differential expression analysis were conducted to investigate biological mechanisms. As a result, we identified that two SNPs (NSUN7 rs2437325 A > G and TRDMT1 rs34434809 G > C) were significantly associated with HBV-related HCC OS with adjusted allelic hazards ratios of 1.25 (95% confidence interval = 1.05-1.48 and P = 0.011) and 1.19 (1.02-1.38 and P = 0.027), respectively, with a trend of combined risk genotypes (Ptrend < 0.001). Moreover, the results of eQTL analyses showed that both NSUN7 rs2437325 G and TRDMT1 rs34434809 C alleles were associated with a reduced mRNA expression level in 208 normal liver tissues (P = 0.007 and P < 0.001, respectively). Taken together, genetic variants in the m5C modification genes may be potential prognostic biomarkers of HBV-related HCC after hepatectomy, likely through mediating the mRNA expression of corresponding genes.

Functional genetic variants of the disulfidptosis-related INF2 gene predict survival of hepatitis B virus-related hepatocellular carcinoma.

Disulfidptosis is a novel form of programmed cell death involved in migration and invasion of cancer cells, but few studies investigated the roles of genetic variants in disulfidptosis-related genes in survival of patients with hepatitis B virus (HBV)-related hepatocellular carcinoma (HCC). We used Cox proportional hazards regression analyses, Kaplan-Meier curves and receiver operating characteristic curves to assess effects of genetic variants in 14 disulfidptosis-related genes on overall survival of 866 HBV-HCC patients. The Bayesian false discovery probability was used for multiple testing corrections. We also investigated biological mechanisms of the significant variants through expression quantitative trait loci analyses using the data from publicly available databases, luciferase reporter assays and differential expression analyses. As a result, we identified two independently functional single nucleotide polymorphisms (SNPs) (INF2 rs4072285 G > A and INF2 rs4444271 A > T) that predicted overall survival of HBV-HCC patients, with adjusted hazard ratios of 1.60 (95% CI = 1.22-2.11, P = 0.001) and 1.50 (95% CI = 1.80-1.90, P < 0.001), respectively, after multiple testing correction. Luciferase reporter assays indicated that both INF2 rs4072285 A and INF2 rs4444271 T alleles increased INF2 mRNA expression levels (P < 0.001) that were also higher in HCC tumor tissues than in adjacent normal tissues (P < 0.001); such elevated INF2 expression levels were associated with a poorer survival of HBV-HCC patients (P < 0.001) in the TCGA database. In summary, this study supported that INF2 rs4072285 and INF2 rs4444271 may be novel biomarkers for survival of HBV-HCC patients.

Potentially Functional Genetic Variants in the NRF2 Signaling Pathway Genes are Associated With HBV-related Hepatocellular Carcinoma Survival.

The nuclear factor E2-related factor 2 (NRF2) signaling pathway is one of the most important cell defense pathways. However, it is unclear whether genetic variants in NRF2 signaling pathway genes are associated with the survival of hepatitis B virus (HBV)-related hepatocellular carcinoma (HCC). In the present study, we utilized a new hypothesis-driven approach based on biological pathways to investigate the associations between 17919 single nucleotide polymorphisms (SNPs) in 137 NRF2 signaling pathway genes and the overall survival (OS) of 866 patients with HBV-related HCC. As a result, two independent SNPs with potential biological function were identified to be significantly associated with HBV-related HCC OS: [SLC2A9 rs28643326 T>C: hazard ratio (HR) = 0.74, 95% confidence interval (95% CI) = 0.62-0.89, P < 0.001 and SLC5A10 rs2472711 G>T: HR = 0.81, 95% CI = 0.71-0.93, P = 0.003, respectively]. The expression quantitative trait loci (eQTL) analysis further revealed that the rs28643326 C allele was significantly associated with increased levels of SLC2A9 mRNA expression (P < 0.001), and higher mRNA expression levels of SLC2A9 in adjacent normal liver tissues were associated with better survival. Although the association between the rs2472711 T allele and the mRNA expression of SLC5A10 was not statistically significant (P = 0.200), the fact that rs2472711 is located at the DNase I hypersensitivity site and is a marker for promoter and enhancer histones also suggests that it may have the function of regulating its corresponding gene expression. In conclusion, genetic variants of NRF2 signaling pathway genes may serve as potential prognostic biomarkers for HBV-related HCC and also provide a solid basis for further mechanistic exploration.

Fluorescence probe for selectively monitoring biothiols within cells and mouse depression diagnosis.

As a global mental disorder, depression is associated with oxidative stress in the brain. Cysteine, a reductive biothiols, regulates the oxidative situation in many biological events including the stress that occurs in the tissues. Exploring the pathology and physiology of depression is still a challenge and always in an urgent need. Thus, developing a new method that could track Cys level without the interferes from other competing substances is of great importance. Herein, we developed a fluorescence probe that could selectively sensing Cys over other biothiols. Besides, we have demonstrated its desirable performance in cellular applications and mouse brain. This work provides a new method for Cys imaging and understanding pathogenesis of depression. We hope the work described here could be used as a potential chemical approach for the diagnosis of Cys associated diseases in clinical applications.

Host MKRN1-Mediated Mycobacterial PPE Protein Ubiquitination Suppresses Innate Immune Response.

Mycobacterium tuberculosis (Mtb), as an important intracellular pathogen, can invade and survive in macrophages and is capable of escaping the clearance of immune system. Despite decades of research efforts, the precise mechanism of immune escape and the virulence factors encoded by Mtb involved remain to be explored. Mtb-specific genomic regions of deletion (RD)-encoded proteins and PE/PPE family proteins have been implicated in immune evasion. Here, we screened more than forty RD-encoded proteins which might be involved in facilitating bacterial survival in macrophages, and found that a Mtb PPE68/Rv3873 protein, encoded by Mtb-RD1, is essential for efficient Mtb intracellular survival in macrophages. In terms of mechanism, we found that the ubiquitin ligase (E3) Makorin Ring Finger Protein 1 (MKRN1) of macrophage interacted with PPE68 and promoted the attachment of lysine (K)-63-linked ubiquitin chains to the K166 site of PPE68. K63-ubiquitination of PPE68 further bound src homology 2 domain-containing protein tyrosine phosphatase 1 (SHP1) to suppress K63-linked polyubiquitin chains of tumor necrosis factor receptor-associated factor 6 (TRAF6), and then remarkably suppressed TRAF6-driven NF-κB and AP-1 signaling and TNF-α, IL-6 and NO production. We demonstrate that the K63-linked ubiquitination of PPE68 by MKRN1 contributed to the PPE68-mediated mycobacterial immune escape. Our finding identifies a previously unrecognized mechanism by which host MKRN1-mediated-ubiquitination of mycobacterial PPE protein suppresses innate immune responses. Disturbing the interaction between host MKRN1 ubiquitin system and mycobacterial PPE protein might be a potential therapeutic target for tuberculosis.

HMGB1-mediated autophagy confers resistance to gemcitabine in hormone-independent prostate cancer cells.

As a main treatment of prostate cancer, castration therapy has been widely applied in the clinic. However, the therapeutic strategy for hormone-independent prostate cancer (HIPC) was not satisfied. Gemcitabine is an important chemotherapeutic agent that has been approved for the treatment of numerous human solid tumors, including HIPC, whereas the gemcitabine resistance has become a serious problem in clinical chemotherapy. In the present study, the mechanisms of resistance to gemcitabine were investigated in HIPC cell lines. The results demonstrated that the autophagy markers were induced significantly in HIPC cells subsequent to gemcitabine treatment. Meanwhile, administration of gemcitabine to HIPC cells increased the expression of high mobility group box1 (HMGB1). Furthermore, the gemcitabine-induced autophagy response was attenuated in stable HIPC cells harboring HMGB1 shRNA. Notably, the HIPC cells stably transfected with HMGB1 shRNA or treated with autophagy inhibitors were more sensitive to gemcitabine compared with the control group. These data suggested that inhibition of HMGB1 increased the sensitivity to gemcitabine by decreasing autophagy response in HIPC cells. Overall, the present findings demonstrate a new mechanism for the resistance to gemcitabine in HIPC cell lines.

BAP31, a promising target for the immunotherapy of malignant melanomas.

PURPOSE: Malignant melanoma's (MM) incidence is rising faster than that of any other cancer in the US and the overall survival at 5 years is less than 10%. B cell associated protein 31 (BAP31) is overexpressed in most MMs and might be a promising target for immunotherapy of this disease. EXPERIMENTAL DESIGN: Firstly, we investigated the expression profiles of human BAP31 (hBAP31) and mouse BAP31 (mBAP31) in human and mouse normal tissues, respectively. The expression level of hBAP31 in human MMs and mBAP31 in B16 melanoma cells was also analyzed. Then we constructed novel mBAP31 DNA vaccines and tested there ability to stimulate mBAP31-specific immune responses and antitumor immunity in B16 melanoma-bearing mice. RESULTS: For the first time, we found that protein expression of hBAP31 were dramatically upregulated in human MMs when compared with human normal tissues. Predominant protein expression of mBAP31 was found in mouse B16 melanoma cells but not in mouse important organs. When mice were immunized with mBAP31 DNA vaccines, strong cellular response to mBAP31 was observed in the vaccinated mice. CTLs isolated from immunized mice could effectively kill mBAP31-positive target mouse B16 melanoma tumor cells in vitro and vaccination with mBAP31 DNA vaccines had potent anti-tumor activity in therapeutic model using B16 melanoma cells. CONCLUSIONS: These are the first data supporting a vaccine targeting BAP31 that is capable of inducing effective immunity against BAP31-expressing MMs and will be applicable to human MMs and hBAP31 DNA vaccine warrants investigation in human clinical trials.

[Delay in formalin fixation and HER2 testing in gastric cancer].

OBJECTIVE: To evaluated HER2 status using immunohistochemistry (IHC) assay and fluorescence in situ hybridization (FISH) at two different time points of tissue fixation after surgical resection of gastric cancer, emphasizing the importance of standard operation and quality control in HER2 testing. METHODS: Forty-one resection specimens of advanced gastric cancer were collected with tissue fixation periods of < 30 min or > 30 min after surgical resection. HER2 status was evaluated by immunohistochemistry (IHC) assay and fluorescence in situ hybridization (FISH). RESULTS: The frequency of HER2 expression by IHC in the samples with fixation time of < 30 min was higher than that in those of > 30 min (P < 0.05). However, no significant difference was observed by FISH (P > 0.05) between the two groups. Samples of < 30 min fixation time had high concordant results between IHC and FISH (100.0% for both positive and negative cases, Rho = 0.724, P < 0.05). In addition, HER2 expression by IHC was significantly correlated with Lauren classification, histologic differentiation, TNM stage and gender (P < 0.05). CONCLUSION: The time to tissue fixation after surgical resection of more than 30 min has deleterious effect on the detection of HER2 by IHC although FISH testing is not affected.

The identification of CD163 expressing phagocytic chondrocytes in joint cartilage and its novel scavenger role in cartilage degradation.

BACKGROUND: Cartilage degradation is a typical characteristic of arthritis. This study examined whether there was a subset of phagocytic chondrocytes that expressed the specific macrophage marker, CD163, and investigated their role in cartilage degradation. METHODS: Cartilage from the knee and temporomandibular joints of Sprague-Dawley rats was harvested. Cartilage degradation was experimentally-induced in rat temporomandibular joints, using published biomechanical dental methods. The expression levels of CD163 and inflammatory factors within cartilage, and the ability of CD163(+) chondrocytes to conduct phagocytosis were investigated. Cartilage from the knees of patients with osteoarthritis and normal cartilage from knee amputations was also investigated. RESULTS: In the experimentally-induced degrading cartilage from temporomandibular joints, phagocytes were capable of engulfing neighboring apoptotic and necrotic cells, and the levels of CD163, TNF-α and MMPs were all increased (P<0.05). However, the levels of ACP-1, NO and ROS, which relate to cellular digestion capability were unchanged (P>0.05). CD163(+) chondrocytes were found in the cartilage mid-zone of temporomandibular joints and knee from healthy, three-week old rats. Furthermore, an increased number of CD163(+) chondrocytes with enhanced phagocytic activity were present in Col-II(+) chondrocytes isolated from the degraded cartilage of temporomandibular joints in the eight-week experimental group compared with their age-matched controls. Increased number with enhanced phagocytic activity of CD163(+) chondrocytes were also found in isolated Col-II(+) chondrocytes stimulated with TNF-α (P<0.05). Mid-zone distribution of CD163(+) cells accompanied with increased expression of CD163 and TNF-α were further confirmed in the isolated Col-II(+) chondrocytes from the knee cartilage of human patients with osteoarthritis, in contrast to the controls (both P<0.05). CONCLUSIONS: An increased number of CD163(+) chondrocytes with enhanced phagocytic activity were discovered within degraded joint cartilage, indicating a role in eliminating degraded tissues. Targeting these cells provides a new strategy for the treatment of arthritis.

[Prokaryotic expression, purification and identification of NY-ESO-1/GST fusion protein in E.coli].

AIM: To construct an expression plasmid for NY-ESO-1 gene and identify the expression of recombinant protein NY-ESO-1/GST in E.coli. METHODS: NY-ESO-1 segment was amplified from the testis cDNA library by RT-PCR and cloned into the prokaryotic expression vector pGEX4T-1 downstream tagged by GST to construct the expression plasmid pGEX-4T1-NY-ESO-1. The recombinant vector was transformed to BL21 (DE3) and NY-ESO-1/GST fusion protein was induced expression by IPTG. The protein was purified by urea elution and identified by SDS-PAGE and Western blotting. RESULTS: The NY-ESO-1 segment was successfully amplified and its sequence was identical with that published in GenBank. The BL21 (DE3) pLysS containing the pGEX-4T1-NY-ESO-1 expressed a M(r); 44 000 fusion protein under the induction of IPTG. The purity of the protein was 90%. Western blotting proved that NY-ESO-1/GST had a specific reaction with anti-GST mAb. CONCLUSION: The prokaryotic expression vector of NY-ESO-1 has been constructed and the fusion protein NY-ESO-1/GST of high purity is successfully expressed.

Development of highly sensitive chemiluminescence enzyme immunoassay based on the anti-recombinant H(C) subunit of botulinum neurotoxin type A monoclonal antibodies.

Botulinum neurotoxins (BoNTs) are the most poisonous substances ever known. The early detection of these toxins could bear more time for appropriate medical intervention. The standard method for detecting BoNTs is the mouse bioassay, which is time consuming (up to 4 days) and requires a large number of laboratory animals. The immunologic detection methods could detect the toxins within a day, but most of these methods are less sensitive compared with the mouse bioassay due to the lack of high-affinity antibodies. Recently, the recombinant H(C) subunit of botulinum neurotoxin type A (rAH(C)) was expressed as an effective vaccine against botulism, indicating that the rAH(C) could be an effective immunogen that raises the monoclonal antibody (mAb) for detecting BoNT/A. After immunized BALB/c mice with rAH(C), 56 mAbs were generated. Two of these mAbs were selected to establish a highly sensitive sandwich chemiluminescence enzyme immunoassay (CLEIA), in which FMMU-BTA-49 and FMMU-BTA-22 were used as capture antibody and detection antibody, respectively. The calculated limit of detection (LOD) based on molecular weight of rAH(C) and BoNT/A reached 0.45 pg mL(-1). This CLEIA can be used in the detection of BoNT/A in matrices such as milk and beef extract. This method has 20-40 fold lower LOD than that of the mouse bioassay and takes only 3 h to complete the detection, indicating that it can be used as a valuable method to detect and quantify BoNT/A.

Enhancement of DNA vaccine efficacy by targeting the xenogeneic human chorionic gonadotropin, survivin and vascular endothelial growth factor receptor 2 combined tumor antigen to the major histocompatibility complex class II pathway.

BACKGROUND: A number of strategies have been used to improve the efficacy of the DNA vaccine for the treatment of tumors. These strategies, ranging from activating CD4+ T cell, manipulating antigen presentation and/or processing to anti-angiogenesis, focus on one certain aspect in the functioning of the vaccine. Therefore, their combination is necessary for rational DNA vaccines design by synergizing different regimens and overcoming the limitations of each strategy. METHODS: A DNA fragment (HSV) encoding the C terminal 37 amino acids of human chorionic gonadotropin ß chain (hCGß), 5 different HLA-restricted cytotoxic T lymphocyte epitopes from human survivin and the third and fourth extracellular domains of vascular endothelial growth factor receptor 2 (VEGFR2) was inserted into the sequence between the luminal and transmembrane domain of human lysosome-associated membrane protein-1 cDNA for the construction of a novel DNA vaccine. RESULTS: This novel vaccine, named p-L/HSV, has a potent antitumor effect on the LL/2 lung carcinoma model in syngeneic C57BL/6 mice. The immunologic mechanism involved in the antitumor effect referred to the activation of both cellular and humoral immune response. In addition, the tumor vasculature was abrogated as observed by immunohistochemistry in p-L/HSV immunized mice. Furthermore, the immunized mice received an additional boost with p-L/HSV 6 months later and showed a strong immune recall response. CONCLUSIONS: The present study indicates that the strategies of combining antitumor with antiangiogenesis and targeting the tumor antigen to the major histocompatibility complex class II pathway cooperate well. Such a study may shed new light on designing vaccine for cancer in the future.

miR-30c-1* promotes natural killer cell cytotoxicity against human hepatoma cells by targeting the transcription factor HMBOX1.

Natural killer (NK) cells play a critical role in antitumor immunity, and the activation of NK cells is regulated by a series of NK cell receptors. Here, we show that crosslinking CD226, an important NK cell receptor, with the anti-CD226 mAb LeoA1 on NKL cells, regulated the expression of several microRNA and transmembrane tumor necrosis factor-α. Among them, miR-30c-1(*) was noticed because overexpression of miR-30c-1(*) triggered upregulation of transmembrane tumor necrosis factor-α expression and enhanced NK cell cytotoxicity against hepatoma cell lines SMMC-7721 and HepG2. Furthermore, we proved that the inhibitory transcription factor HMBOX1, which depressed the activation of NK cells, was the direct target gene of miR-30c-1(*). In conclusion, our results revealed a novel regulatory mechanism: miR-30c-1(*) promoted NK cell cytotoxicity against hepatoma cells by targeting HMBOX1.

Highly sensitive microplate chemiluminescence enzyme immunoassay for the determination of staphylococcal enterotoxin B based on a pair of specific monoclonal antibodies and its application to various matrices.

A highly specific and sensitive microplate chemiluminescent enzyme immunoassay (CLEIA) was established and validated for the detection of staphylococcal enterotoxin B (SEB). A pair of monoclonal antibodies (mAbs) that recognizes different epitopes of SEB was selected from 20 SEB-specific mAbs, and the experimental conditions were examined and optimized for the development of the CLEIA. This method exhibited high performance with a dynamic range of 0.01-5 ng/mL, and the measured limit of detection (LOD) was 0.01 ng/mL. Intra- and interassay coefficient variations were all lower than 13% at three concentrations (0.2, 0.4, and 2 ng/mL). For specificity studies, when this method was applied to test staphylococcal enterotoxins A, C1, and D, no cross-reactivity was observed. It has been successfully applied to the analysis of SEB in a variety of environmental, biological and humoral matrices such as sewage, tap water, river water, roast beef, peanut butter, cured ham, 10% nonfat dry milk, milk, orange juice, and human urine and serum. The aim of this article is to show that the highly sensitive, specific, and simple microplate CLEIA, based on a pair of highly specific monoclonal antibodies, has potential applications for quantifying SEB in public health and military reconnaissance.