Caveolin-2 is regulated by BRD4 and contributes to cell growth in pancreatic cancer.

BACKGROUND: The bromodomain and extra-terminal domain (BET) family of proteins, especially BRD4 play an important role in epigenetic regulation, and are essential for cell survival and also are promising anticancer targets. This study aims to analyze the effect of BRD4 on the cell growth and progression of pancreatic cancer and novel mechanisms involved. METHODS: Expression of BRD4 in pancreatic cancer and paired adjacent noncancerous tissues from 76 patients was analyzed by western blotting, immunohistochemistry, and real time PCR. Its correlation with the clinicopathological characteristics and prognosis of pancreatic cancer patients was analyzed. The effects of BRD4 on the cell proliferation were detected by colony formation assay and sulforhodamine B assay. Migration and invasion were determined by Transwell assays, and the effect of BRD4 on subcutaneous tumor formation was verified in nude mice. Cell cycle analysis was detected by flow cytometry. The potential downstream targets of BRD4 and related molecular mechanisms were clarified by RNA sequencing, chromatin immunoprecipitation and dual luciferase reporter assay. RESULTS: BRD4 was overexpressed in pancreatic cancer. Biological results showed that BRD4 functioned as tumor promoter, facilitated cell proliferation, migration and invasion in vitro and in vivo. Further, caveolin-2 was selected as the downstream gene of BRD4 by RNA sequencing. Caveolin-2 overexpression can partially reverse the decreased cell growth ability caused by BRD4 knockdown, but did not affect cell migration and invasion. Chromatin immunoprecipitation assay and dual luciferase reporter assay revealed BRD4 could bind to the promoter region of caveolin-2 and upregulate caveolin-2 expression. Clinical data further indicated a positive correlation between BRD4 and caveolin-2 expression. BRD4 (high)/caveolin-2 (high) correlated with shorter overall survival of patients with pancreatic cancer. Multivariate analysis revealed that both BRD4 and caveolin-2 were independent factors. CONCLUSIONS: Our findings reveal the oncogenic effects of BRD4 in pancreatic cancer and elucidate a possible mechanism by which BRD4 and caveolin-2 act to enhance cell growth. Targeting the BRD4-caveolin-2 interaction by development of BET inhibitors will be a therapeutic strategy for pancreatic cancer.

A novel feedback loop between high MALAT-1 and low miR-200c-3p promotes cell migration and invasion in pancreatic ductal adenocarcinoma and is predictive of poor prognosis.

BACKGROUND: It was demonstrated that long non-coding RNAs occupied an important position in tumor pathogenesis and progression. We have previously found that the metastasis-associated lung adenocarcinoma transcript 1 (MALAT-1) promotes cell proliferation and metastases in pancreatic ductal adenocarcinoma (PDAC). The present study was aimed to discuss the underlying mechanisms. METHODS: Bioinformatics method was used to identify the miRNA target of MALAT-1. Expressions of relative genes were assessed by quantitative real-time PCR and western blotting, respectively. Sulforhodamine B assay and Transwell assay were employed to detect cell proliferation, migration and invasion, respectively. Moreover, RNA immunoprecipitation was performed to determine whether RNA-induced silencing complex contained MALAT-1 and its potential binding miRNA. Luciferase assays was used to confirm potential binding site. RESULTS: Bioinformatics search predicted that miR-200c-3p was a direct target of MALAT-1. Further, we found a reciprocal suppression between MALAT-1 and miR-200c-3p expression. In terms of mechanisms, high MALAT-1 and low miR-200c-3p may form a novel feedback loop. On the one hand, MALAT-1 functioned as a competing endogenous RNA to suppress miR-200c-3p expression, leading to upregulation of ZEB1 expression. On the other hand, miR-200c-3p inhibited the level of MALAT-1 expression was in a way similar to miRNA-mediated downregulation of target genes. Clinical data further indicated that MALAT-1 and ZEB1 expression was negatively correlated with miR-200c-3p transcript level of PDAC tissues. There was a positive correlation between MALAT-1 and ZEB1 level. MALAT-1 (high)/miR-200c-3p (low) correlated with shorter overall survival of PDAC patients. Multivariate analysis revealed that both MALAT-1 and miR-200c-3p levels were independent prognostic factors. CONCLUSION: Our findings firstly revealed a novel feedback loop between high MALAT-1 and low miR-200c-3p. Targeting the feedback loop between high MALAT-1 and low miR-200c-3p will be a therapeutic strategy for PDAC.

Vaccine-Derived Neutralizing Antibodies to the Human Cytomegalovirus gH/gL Pentamer Potently Block Primary Cytotrophoblast Infection.

UNLABELLED: Human cytomegalovirus (HCMV) elicits neutralizing antibodies (NAb) of various potencies and cell type specificities to prevent HCMV entry into fibroblasts (FB) and epithelial/endothelial cells (EpC/EnC). NAb targeting the major essential envelope glycoprotein complexes gB and gH/gL inhibit both FB and EpC/EnC entry. In contrast to FB infection, HCMV entry into EpC/EnC is additionally blocked by extremely potent NAb to conformational epitopes of the gH/gL/UL128/130/131A pentamer complex (PC). We recently developed a vaccine concept based on coexpression of all five PC subunits by a single modified vaccinia virus Ankara (MVA) vector, termed MVA-PC. Vaccination of mice and rhesus macaques with MVA-PC resulted in a high titer and sustained NAb that blocked EpC/EnC infection and lower-titer NAb that inhibited FB entry. However, antibody function responsible for the neutralizing activity induced by the MVA-PC vaccine is uncharacterized. Here, we demonstrate that MVA-PC elicits NAb with cell type-specific neutralization potency and antigen recognition pattern similar to human NAb targeting conformational and linear epitopes of the UL128/130/131A subunits or gH. In addition, we show that the vaccine-derived PC-specific NAb are significantly more potent than the anti-gH NAb to prevent HCMV spread in EpC and infection of human placental cytotrophoblasts, cell types thought to be of critical importance for HCMV transmission to the fetus. These findings further validate MVA-PC as a clinical vaccine candidate to elicit NAb that resembles those induced during HCMV infection and provide valuable insights into the potency of PC-specific NAb to interfere with HCMV cell-associated spread and infection of key placental cells. IMPORTANCE: As a consequence of the leading role of human cytomegalovirus (HCMV) in causing permanent birth defects, developing a vaccine against HCMV has been assigned a major public health priority. We have recently introduced a vaccine strategy based on a widely used, safe, and well-characterized poxvirus vector platform to elicit potent and durable neutralizing antibody (NAb) responses targeting the HCMV envelope pentamer complex (PC), which has been suggested as a critical component for a vaccine to prevent congenital HCMV infection. With this work, we confirm that the NAb elicited by the vaccine vector have properties that are similar to those of human NAb isolated from individuals chronically infected with HCMV. In addition, we show that PC-specific NAb have potent ability to prevent infection of key placental cells that HCMV utilizes to cross the fetal-maternal interface, suggesting that NAb targeting the PC may be essential to prevent HCMV vertical transmission.

The M2 phenotype of tumor-associated macrophages in the stroma confers a poor prognosis in pancreatic cancer.

Macrophages play a critical role in the initiation and progression of various solid tumors. However, their prognostic significance in pancreatic ductal adenocarcinoma (PDAC) is poorly understood. This study investigated the distribution patterns of macrophages in PDAC and possible association with the overall survival (OS). We found significant differences in macrophage density (identified by CD68 and CD163 immunopositivity; p < 0.001 for both) between primary cancer and paired adjacent normal tissues. Most macrophages in cancerous pancreatic tissues were located in the stroma rather than the islets (p = 0.032 and p < 0.001). We also demonstrated that a high total macrophage density (characterized by CD68 immunopositivity) correlated with an absence of jaundice before surgery (p = 0.03) and that a high density of M2 macrophages (characterized by CD163 immunopositivity) in the stroma strongly correlated with the tumors located in the tail and body of the pancreas (p = 0.04). In addition, OS was shorter in patients with high-density M2 macrophage infiltration than in those with low-density M2 macrophage infiltration (p = 0.012). Moreover, multivariate analysis revealed that dense M2 macrophage infiltration into the stroma was an independent prognostic factor for PDAC patients (p = 0.02).

Dendritic cell-based vaccination with lentiviral vectors encoding ubiquitinated hepatitis B core antigen enhances hepatitis B virus-specific immune responses in vivo.

The activity of hepatitis B virus (HBV)-specific cytotoxic T lymphocytes (CTLs) plays a predominant role in the clearance of HBV. Dendritic cells (DCs) are key antigen-presenting cells and play an important role in the initiation of immune responses. We previously verified that lentiviral vector encoding ubiquitinated hepatitis B core antigen (LV-Ub-HBcAg) effectively transduced DCs to induce maturation, and the mature DCs efficiently induced T cell polarization to Th1 and generated HBcAg-specific CTLs ex vivo. In this study, HBV-specific immune responses of LV-Ub-HBcAg in BALB/c mice (H-2Kd) were evaluated. It was shown that direct injection of LV-Ub-HBcAg increased the production of cytokines IL-2 and IFN-γ, elicited strong antibody responses, and remarkably generated a high percentage of IFN-γ+CD8+ T cells with HBV-specific CTL responses in BALB/c mice. In addition, direct injection of LV-Ub-HBcAg induced potent anti-HBV immune responses, similar to those elicited by in vitro-transduced DCs. In conclusion, the DC-based therapeutic vaccine LV-Ub-HBcAg elicited specific antibody immune responses and induced robust specific CTL activity in vivo.

Tapasin modification on the intracellular epitope HBcAg18-27 enhances HBV-specific CTL immune response and inhibits hepatitis B virus replication in vivo.

HBV-specific cytotoxic T-lymphocyte (CTL) activity has a very important role in hepatitis B virus clearance. Present studies suggest that Tapasin, a endoplasmic reticulum (ER) chaperone, stabilizes the peptide-receptive MHC I conformation, allowing peptide exchange and increasing more peptides to be translocated into the ER. We have previously testified that cytoplasmic transduction peptide (CTP)-HBcAg(18-27)-Tapasin fusion protein could enter cytoplasm of dendritic cells, and enhance T cells' response to generate specific CTLs efficiently in vitro. In the present study, we evaluated specific immune responses of CTP-HBcAg(18-27)-Tapasin fusion protein in HLA-A2 transgenic mice (H-2K(b)) and anti-viral ability in HBV transgenic mice, and explored the mechanisms probably involved in. The studies showed that CTP-HBcAg(18-27)-Tapasin not only increased production of cytokine IFN-γ and interleukin-2 (IL-2), compared with CTP-HBcAg(18-27), HBcAg(18-27)-Tapasin, and PBS, but also significantly induced the higher percentages of IFN-γ+CD8(+) T cells and specific CTL responses in HLA-A2 transgenic mice. Moreover, enhancement of specific CTL activity induced by the fusion protein reduced HBV DNA and hepatitis B surface antigen (HBsAg) levels and decreased the expression of HBsAg and hepatitis B core antigen (HBcAg) in liver tissue of HBV transgenic mice. In addition, CTP-HBcAg(18-27)-Tapasin could upregulate the expression of JAK2, Tyk2, STAT1, and STAT4 in T lymphocytes in HLA-A2 transgenic mice splenocytes. However, there was no significant difference on the expressions of JAK1, JAK3, and STAT6 between each group. In conclusion, CTP-HBcAg(18-27)-Tapasin fusion protein could enhance not only the percentages of CTLs but also induce robust specific CTL activity and inhibits hepatitis B virus replication in vivo, which was associated with activation of the JAK/STAT signaling pathway.

[The fusion protein of cytoplasmic transduction peptide (CTP)-HBcAg18-27-Tapasin enhances specific immune response to hepatitis B virus and inhibits viral replication in transgenic mice].

OBJECTIVE: To investigate the effect of protein transduction domain-hepatitis B virus core antigen (CTP-HBcAg18-27)-Tapasin fusion protein-induced specific cytotoxic T lymphocyte (CTL) response on hepatitis B virus (HBV) replication in HBV transgenic mice. METHODS: Twenty HBV-transgenic mice were randomly divided into two groups for a 3-week course of once weekly subcutaneous immunizations with either CTP-HBcAg18-27-Tapasin fusion protein or CTP-HBcAg18-27. Mice administered isotonic saline served as blank controls. Expressions of cytokines in splenocytes were analyzed by flow cytometry. Serum levels of hepatitis B surface antigen (HBsAg) and HBV DNA were determined by microparticle enzyme immunoassay and real-time fluorescent PCR assay, respectively. Expression of HBsAg in hepatic tissues was detected by immunohistochemistry. RESULTS: Immunization with 100 mug of CTP-HBcAg18-27-Tapasin fusion protein led to a significant increase in proportions of CTLs in spleen (2.70%+/-0.20% vs. 50 mug of CTP-HBcAg18-27-Tapasin: 1.66%+/-0.53%, 50 mug of CTP-HBcAg18-27: 1.26%+/-0.56%, and blank controls: 0.75%+/-0.71%; F = 741.45, P = 0.000) and up-regulation of inflammatory cells in hepatic tissue. In addition, both immunizations of CTP-HBcAg18-27-Tapasin led to significant decreases in serum HBsAg and HBV DNA levels compared to those in the CTP-HBcAg18-27 group. CONCLUSION: HBV-related modification of the expression of the molecular chaperone Tapasin may affect its interaction with intracellular antigen peptides, thereby leading to increases the number of specific CTLs in the spleen, decreases in serum HBsAg and HBV DNA levels, and down-regulation of HBsAg expression in hepatic tissue. These results obtained in HBV-transgenic mice suggest that the CTP-HBcAg18-27-Tapasin fusion protein has anti-HBV activity.

Predictive value of positive lymph node ratio in patients with locally advanced gastric remnant cancer.

BACKGROUND: Traditional lymph node stage (N stage) has limitations in advanced gastric remnant cancer (GRC) patients; therefore, establishing a new predictive stage is necessary. AIM: To explore the predictive value of positive lymph node ratio (LNR) according to clinicopathological characteristics and prognosis of locally advanced GRC. METHODS: Seventy-four patients who underwent radical gastrectomy and lymphadenectomy for locally advanced GRC were retrospectively reviewed. The relationship between LNR and clinicopathological characteristics was analyzed. The survival analysis was performed using Kaplan-Meier survival curves and Cox regression model. RESULTS: Number of metastatic LNs, tumor diameter, depth of tumor invasion, Borrmann type, serum tumor biomarkers, and tumor-node-metastasis (TNM) stage were correlated with LNR stage and N stage. Univariate analysis revealed that the factors affecting survival included tumor diameter, anemia, serum tumor biomarkers, vascular or neural invasion, combined resection, LNR stage, N stage, and TNM stage (all P < 0.05). The median survival time for those with LNR0, LNR1, LNR2 and LNR3 stage were 61, 31, 23 and 17 mo, respectively, and the differences were significant (P = 0.000). Anemia, tumor biomarkers and LNR stage were independent prognostic factors for survival in multivariable analysis (all P < 0.05). CONCLUSION: The new LNR stage is uniquely based on number of metastatic LNs, with significant prognostic value for locally advanced GRC, and could better differentiate overall survival, compared with N stage.

[Effects of moxibustion at Yongquan (KI 1) on cognition function and lower limb motor function in patients with post-stroke cognitive impairment of kidney essence deficiency].

OBJECTIVE: To observe the effects of moxibustion at Yongquan（KI 1） on the cognitive function and lower limb motor function in patients with post-stroke cognitive impairment of kidney essence deficiency. METHODS: Eighty-four patients with post-stroke cognitive impairment of kidney essence deficiency were randomly divided into an observation group（42 cases，1 case dropped off）and a control group（42 cases，1 case dropped off）.The control group was treated with medication，electroacupuncture，rehabilitation training and repetitive transcranial magnetic stimulation（rTMS）；on the basis of the treatment as the control group，moxibustion at bilateral Yongquan（KI 1）was adopted in the observation group.Both groups were treated once a day，5 days a week with 2-day interval，4 weeks were required. The Montreal cognitive assessment (MoCA) score, mini-mental state examination (MMSE) score, Fugl-Meyer assessment-lower extremity (FMA-LE) score, Berg balance scale (BBS) score, functional independence measure (FIM) score, modified fall efficacy scale (MFES) score and scale for the differentiation of syndromes of vascular dementia (SDSVD) score before and after treatment were observed in the two groups. RESULTS: After treatment，the MoCA, MMSE, FMA-LE, BBS, FIM and MFES scores were higher than those before treatment in both groups (P<0.05), and the scores in the observation group were higher than those in the control group (P<0.05). After treatment，the SDSVD scores were lower than those before treatment in both groups (P< 0.05), and the SDSVD score in the observation group was lower than that in the control group (P< 0.05). CONCLUSION: Moxibustion at Yongquan（KI 1） can improve the cognitive function and motor and balance function of lower limbs in patients with post-stroke cognitive impairment of kidney essence deficiency，reduce the risk of fall and improve the quality of life.

Low voltage-driven high-performance thermal switching in antiferroelectric PbZrO3 thin films.

Effective control of heat transfer is vital for energy saving and carbon emission reduction. In contrast to achievements in electrical conduction, active control of heat transfer is much more challenging. Ferroelectrics are promising candidates for thermal switching as a result of their tunable domain structures. However, switching ratios in ferroelectrics are low (<1.2). We report that high-quality antiferroelectric PbZrO3 epitaxial thin films exhibit high-contrast (>2.2), fast-speed (<150 nanoseconds), and long-lifetime (>107) thermal switching under a small voltage (<10 V). In situ reciprocal space mapping and atomistic modelings reveal that the field-driven antiferroelectric-ferroelectric phase transition induces a substantial change of primitive cell size, which modulates phonon-phonon scattering phase space drastically and results in high switching ratio. These results advance the concept of thermal transport control in ferroic materials.

A retrospective study of clinicopathological characteristics and prognostic factors of Krukenberg tumor with gastric origin.

Background: Krukenberg tumor (KT) of gastric origin has a poor prognosis. The present study of KTs are mainly case reports and clinical analysis with few samples. Therefore, it is urgent to explore the clinicopathologic characteristics of KTs through large sample studies. To improve the understanding of the clinical diagnosis and treatment of KT, this paper retrospectively analyzed 10 years of gastric cancer (GC) database data, including clinicopathological and prognostic features, aiming to provide a clinical reference for the diagnosis and treatment of the tumor. Methods: The clinicopathological characteristics, treatments, and survival data were collected and analyzed from 130 patients with KTs of GC. Clinicopathological data included clinical manifestations, laboratory findings, imaging reports, pathology and immunohistochemistry (IHC) reports. We collected treatment regimens information on whether they had undergone surgery and chemotherapy and performed survival follow-up. Univariate and multivariate analysis were used to investigate the risk factors of KTs with gastric origin. Results: The median age of the patients was 41 years. A total of 63.1% of patients had synchronous ovarian metastasis, 70.8% had bilateral ovarian metastasis, 68.5% had peritoneum metastasis, and 98.5% had pathologically poorly differentiated adenocarcinoma. The positive rate of human epidermal growth factor receptor 2 (HER-2) was 1.8%. The follow-up rate was 90.8%, and the median overall survival (mOS) of ovarian metastasis was 13.0 months. Univariate analysis showed statistically significant prognostic factors including menstrual status, size of the gastric lesions and ovarian metastases, number of lymph node metastasis, interval to ovarian metastasis, resection of gastric lesions, peritoneal metastasis, oophorectomy, chemotherapy after ovarian metastases, two-drug regimen chemotherapy, albumin, serum cancer antigen 125 (CA-125) levels, platelet count, D-dimer, fibrinogen, and high pretreatment platelet-to-lymphocyte ratio (PLR) and systemic immune-inflammation index (SII). Fibrinogen [hazard ration (HR) =0.483; 95% confidence interval (CI): 0.300-0.777; P=0.003], size of ovarian metastasis (HR =1.808; 95% CI: 1.178-2.776; P=0.007), chemotherapy after ovarian metastasis (HR =0.195; 95% CI: 0.101-0.379; P=0.000), peritoneal metastasis (HR =2.742; 95% CI: 1.606-4.682; P=0.000) and oophorectomy (HR =1.720; 95% CI: 1.066-2.778; P=0.026) were independent prognostic factors. Conclusions: GC patients with KTs have some unique clinical features. Hypercoagulable states, peritoneal metastasis, and untimely chemotherapy and oophorectomy might be a worse predictor for KTs derived from gastric origin.

Distinguishable Prognostic Signatures and Tumor Immunogenicity Between Pancreatic Head Cancer and Pancreatic Body/Tail Cancer.

Background: Pancreatic head cancer and pancreatic body/tail cancer are considered to have different clinical presentations and to have altered outcomes. Methods: Ninety cases of pancreatic adenocarcinoma (PDAC) from our institution were used as a discovery set and 166 cases of PDAC from the TCGA cohort were used as a validation set. According to the anatomical location, the cases of PDAC were divided into the pancreatic head cancer group and the pancreatic body/tail cancer group. Firstly, the different biological functions of the two groups were assessed by ssGSEA. Meanwhile, ESTIMATE and CIBERSORT were conducted to estimate immune infiltration. Then, a novel anatomical site-related risk score (SRS) model was constructed by LASSO and Cox regression. Survival and time-dependent ROC analysis was used to prove the predictive ability of our model in two cohorts. Subsequently, an integrated survival decision tree and a scoring nomogram were constructed to improve prognostic stratification and predictive accuracy for individual patients. In addition, gseaGO and gseaKEGG pathway analyses were performed on genes in the key module by the R package. Results: Overall survival and the objective response rate (ORR) of patients with pancreatic body/tail cancer were markedly superior to those with pancreatic head cancer. In addition, distinct immune characteristics and gene patterns were observed between the two groups. Then, we screened 5 biomarkers related to the prognosis of pancreatic cancer and constructed a more powerful novel SRS model to predict prognosis. Conclusions: Our research shed some light on the revelation of gene patterns, immune and mutational landscape characterizations, and their relationships in different PDAC locations.

Efficient purification of toluene gas by anoxic denitrification.

As a part of volatile organic compounds (VOCs), toluene does harm to human health. This paper reported the purification of toluene waste gas by liquid-phase absorption and anoxic denitrification. In this work, two same biofilm reactors were set to treat toluene waste gas, one of which was added into nitrate as an electron acceptor. Then, the purification properties of toluene waste gas treated by anoxic denitrification and biological methods were compared. The results indicate that with the increase of toluene mass concentration, the toluene removal rate of the denitrifying reactor decreased slightly. When the inlet concentration increased from 50 mg m-3 to 3440 mg m-3, the removal efficiency of the denitrifying reactor remained over 94.1% while the removal efficiency of the traditional bioreactor decreased to 82.9%. The highest removal capacity of the denitrifying reactor was 127.2 g m-3 h-1, which was 11.8% higher than that of the traditional bioreactor. Toluene was degraded by denitrification inside the biofilm microenvironment hypoxia; the denitrification rate increased along with the increase of inlet concentration within certain limits and reached a maximum of 2.4 mg NO3--N L-1 h-1. Nitrate can act as an electron acceptor, and denitrification can promote aerobic degradation and intensify the concentration gradient inside the biofilm to strengthen the toluene transfer process.

CHPF promotes gastric cancer tumorigenesis through the activation of E2F1.

Chondroitin polymerizing factor (CHPF) is an important glycosyltransferase involved in the biosynthesis of chondroitin sulfate. However, the relationship between CHPF and gastric cancer has not been fully investigated. CHPF expression in gastric cancer tissues was detected by immunohistochemistry and correlated with gastric cancer patient prognosis. Cultured gastric cancer cells and human gastric epithelial cell line GES1 were used to investigate the effects of shCHPF and shE2F1 on the development and progression of gastric cancer by MTT, western blotting, flow cytometry analysis of cell apoptosis, colony formation, transwell and gastric cancer xenograft mouse models, in vitro and in vivo. In gastric cancer tissues, CHPF was found to be significantly upregulated, and its expression correlated with tumor infiltration and advanced tumor stage and shorter patient survival in gastric cancer. CHPF may promote gastric cancer development by regulating cell proliferation, colony formation, cell apoptosis and cell migration, while knockdown induced the opposite effects. Moreover, the results from in vivo experiments demonstrated that tumor growth was suppressed by CHPF knockdown. Additionally, E2F1 was identified as a potential downstream target of CHPF in the regulation of gastric cancer, and its knockdown decreased the CHPF-induced promotion of gastric cancer. Mechanistic study revealed that CHPF may regulate E2F1 through affecting UBE2T-mediated E2F1 ubiquitination. This study showed, for the first time, that CHPF is a potential prognostic indicator and tumor promoter in gastric cancer whose function is likely carried out through the regulation of E2F1.

Coordinated silencing of the Sp1-mediated long noncoding RNA MEG3 by EZH2 and HDAC3 as a prognostic factor in pancreatic ductal adenocarcinoma.

Objective: Pancreatic ductal adenocarcinoma (PDAC) is a disease with high mortality. Many so-called "junk" noncoding RNAs need to be discovered in PDAC. The purpose of this study was therefore to investigate the function and regulatory mechanism of the long noncoding RNA MEG3 in PDAC. Methods: The Gene Expression Omnibus database (GEO database) was used to determine the differential expression of long noncoding RNAs in PDAC, and MEG3 was selected for subsequent verification. Tissue and cell samples were used to verify MEG3 expression, followed by functional detection in vitro and in vivo. Microarrays were used to characterize long noncoding RNA and mRNA expression profiles. Competing endogenous RNA analyses were used to detect differential MEG3 and relational miRNA expression in PDAC. Finally, promoter analyses were conducted to explain the downregulation of MEG3 PDAC. Results: We generated a catalogue of PDAC-associated long noncoding RNAs in the GEO database. The ectopic expression of MEG3 inhibited PDAC growth and metastasis in vitro and in vivo, which was statistically significant (P < 0.05). Microarray analysis showed that multiple microRNAs interacted with MEG3. We also showed that MEG3, as a competing endogenous RNA, directly sponged miR-374a-5p to regulate PTEN expression. The transcription factor, Sp1, recruited EZH2 and HDAC3 to the promoter and transcriptionally repressed MEG3 expression. Finally, clinical data showed that MEG3 and miR-374a-5p expressions were correlated with clinicopathological features. Statistically, Sp1, EZH2, HDAC3, and miR-374a-5p were negatively correlated with MEG3 (P < 0.05). Conclusions: Reduced MEG3 levels played a crucial role in the PDAC malignant phenotype, which provided insight into novel and effective molecular targets of MEG3 for pancreatic cancer treatment.

JQ1 effectively inhibits vasculogenic mimicry of pancreatic ductal adenocarcinoma cells via the ERK1/2-MMP-2/9 signaling pathway both in vitro and in vivo.

Vasculogenic mimicry (VM) is an alternative type of blood and nutrition supply that is associated with more aggressive tumor biology and increased cancer-related mortality. However, the clinical implications of VM remain unclear in patients with pancreatic ductal adenocarcinoma (PDAC). The aim of this study was to investigate the clinical significance of VM in PDAC patients and to seek a novel and more efficient treatment strategy by targeting this unique process. Here, cluster of differentiation 34 (CD34)/periodic acid-Schiff (PAS) double-staining of 76 PDAC clinical specimens revealed that VM expression was related to clinical stage (P=0.049) and lymph node metastasis (P=0.023). Notably, VM expression was correlated with a poor prognosis in patients with PDAC. Additionally, we discovered that there was a positive correlation between the expressions of VM and phosphorylated extracellular signal regulated kinase (p-ERK1/2) in 76 clinical samples (P<0.001). Moreover, our results further indicated that treatment with the ERK1/2 inhibitor SCH772984 effectively blocked VM formation by repressing the production of p-ERK1/2-MMP-2/9, which have been established as classical markers of VM. Further, JQ1, a bromodomain and extraterminal domain (BET) inhibitor, also exerted significant inhibitory efficiency against VM formation by decreasing the activation of ERK1/2-MMP-2/9. In conclusion, our work suggests that VM is a marker of poor prognosis in patients with PDAC and that JQ1 can inhibit VM formation via the ERK1/2-MMP-2/9 signaling pathway.

Synergistic effects of the combination of 5-Aza­CdR and suberoylanilide hydroxamic acid on the anticancer property of pancreatic cancer.

Despite increasing advances in the diagnosis and treatment for pancreatic cancer, the mortality rate remains high world-wide. There is an urgent need for new therapies to improve survival and quality of life for pancreatic cancer patient. Epigenetic therapeutic agents such as 5-Aza­CdR and suberoylanilide hydroxamic acid (SAHA) have shown therapeutic effects for human cancers. We evaluated the efficacy of 5-Aza­CdR or SAHA and their combination as potential therapies for pancreatic cancer in vitro. Treatment with 5-Aza­CdR or SAHA inhibited pancreatic cancer cell proliferation, migration and induced cell arrest. However, 5-Aza­CdR alone can not induce cell apoptosis. Combination of the two agents enhanced the proliferation and migration inhibition, and induced more cells to G2 arrest and increased the cell apoptosis proportion. Furthermore, combination treatment with SAHA and 5-Aza­CdR significantly increased expression of TP53 and P16. The possible mechanism might be that the two agents inhibited the PI3K/AKT/PTEN signaling pathway. In conclusion, these data demonstrate a potential role for epigenetic modifier drugs for the management of pancreatic cancer.

Association of a novel point mutation in MSH2 gene with familial multiple primary cancers.

BACKGROUND: Multiple primary cancers (MPC) have been identified as two or more cancers without any subordinate relationship that occur either simultaneously or metachronously in the same or different organs of an individual. Lynch syndrome is an autosomal dominant genetic disorder that increases the risk of many types of cancers. Lynch syndrome patients who suffer more than two cancers can also be considered as MPC; patients of this kind provide unique resources to learn how genetic mutation causes MPC in different tissues. METHODS: We performed a whole genome sequencing on blood cells and two tumor samples of a Lynch syndrome patient who was diagnosed with five primary cancers. The mutational landscape of the tumors, including somatic point mutations and copy number alternations, was characterized. We also compared Lynch syndrome with sporadic cancers and proposed a model to illustrate the mutational process by which Lynch syndrome progresses to MPC. RESULTS: We revealed a novel pathologic mutation on the MSH2 gene (G504 splicing) that associates with Lynch syndrome. Systematical comparison of the mutation landscape revealed that multiple cancers in the proband were evolutionarily independent. Integrative analysis showed that truncating mutations of DNA mismatch repair (MMR) genes were significantly enriched in the patient. A mutation progress model that included germline mutations of MMR genes, double hits of MMR system, mutations in tissue-specific driver genes, and rapid accumulation of additional passenger mutations was proposed to illustrate how MPC occurs in Lynch syndrome patients. CONCLUSION: Our findings demonstrate that both germline and somatic alterations are driving forces of carcinogenesis, which may resolve the carcinogenic theory of Lynch syndrome.

Elevated COX-2 Expression Promotes Angiogenesis Through EGFR/p38-MAPK/Sp1-Dependent Signalling in Pancreatic Cancer.

Cyclooxygenase-2 (COX-2) was stated to be overexpression in various human malignancies associating with angiogenesis, metastasis and chemoresistence. Pancreatic ductal adenocarcinoma (PDAC) is a lethal disease displaying many of these characteristics. A common abnormality of PDAC is overexpression of specificity protein-1 (Sp1), which was said to correlate with malignant phenotypes of human cancers. Using RNA-seq data from The Cancer Genome Atlas (TCGA), we found that Sp1 expression was positively correlated with that of COX-2 in PDAC, and that the inhibition or overexpression of Sp1 in PDAC cells leads to decreased or elevated COX-2 expression. Luciferase reporter gene and chromatin immunoprecipitation (ChIP) assays revealed that elevated transcription of COX-2 requires Sp1 binding to sequence positions around -245/-240 of COX-2 promoter. Activated epidermal growth factor receptor (EGFR) and downstream p38 mitogen-activated protein kinase (p38-MAPK) were also profoundly altered in PDAC. The inhibition of EGFR/p38-MAPK signaling resulted in reduced Sp1 activation, decreased COX-2 and vascular endothelial growth factor (VEGF) expression. Thus, Sp1 could transcriptionally activate COX-2 expression in a process relies on activated EGFR/p38-MAPK signaling. Finally, we found that the inhibition of COX-2 leads to decreased angiogenesis in a process dependent on VEGF, which link COX-2 to angiogenesis in PDAC.

Correlated high expression of FXR and Sp1 in cancer cells confers a poor prognosis for pancreatic cancer: A study based on TCGA and tissue microarray.

Bile acids (BAs) was critical in the initiation and progression of various tumors. However, their prognostic significance in pancreatic cancer was still illusive. In the present study, the expression and biological significance of FXR, a major receptor of BAs, in the lethal disease were evaluated in mRNA and protein levels. We found that FXR protein was elevated in the cancerous tissues, which was significantly higher than the adjacent tissues (p < 0.05). Meanwhile, our data showed that FXR was positively correlated with primary tumor location (p = 0.04) and poor survival (p = 0.002). Finally, COX regression model indicated that FXR protein was an independent prognostic factor (p = 0.01; HR = 2.15; 95% CI 1.27-3.63). Consistently, we also found a significant difference of FXR expression between the high and low groups in mRNA level (p < 0.001), and that high FXR expression confers a poor prognosis (p < 0.001). More importantly, the correlation assay showed that FXR was positively correlated Sp1 in both protein (r = 0.351, p = 0.008) and mRNA levels (r = 0.263, p < 0.01), with the simultaneously high expression indicated the worst prognosis on protein (p < 0.001) and mRNA levels (p < 0.001). Additionally, we also showed that FXR was elevated in the pancreatic cancer cells responsible for proliferation and migration. Overall, the data suggested co-high expression of the two factors was an independent prognostic factor (p < 0.001; HR = 3.27; 95% CI 1.86-5.76). Based on these data, we proposed a model to link FXR to Sp1, which included triggered FXR, p38/MAPK and/or PI3K/AKT signaling and phosphorylated Sp1, to illustrate the potential crosstalk between the two factors.