Identification of a Tumor Microenvironment-relevant Gene set-based Prognostic Signature and Related Therapy Targets in Gastric Cancer.

Rationale: The prognosis of gastric cancer (GC) patients is poor, and there is limited therapeutic efficacy due to genetic heterogeneity and difficulty in early-stage screening. Here, we developed and validated an individualized gene set-based prognostic signature for gastric cancer (GPSGC) and further explored survival-related regulatory mechanisms as well as therapeutic targets in GC. Methods: By implementing machine learning, a prognostic model was established based on gastric cancer gene expression datasets from 1699 patients from five independent cohorts with reported full clinical annotations. Analysis of the tumor microenvironment, including stromal and immune subcomponents, cell types, panimmune gene sets, and immunomodulatory genes, was carried out in 834 GC patients from three independent cohorts to explore regulatory survival mechanisms and therapeutic targets related to the GPSGC. To prove the stability and reliability of the GPSGC model and therapeutic targets, multiplex fluorescent immunohistochemistry was conducted with tissue microarrays representing 186 GC patients. Based on multivariate Cox analysis, a nomogram that integrated the GPSGC and other clinical risk factors was constructed with two training cohorts and was verified by two validation cohorts. Results: Through machine learning, we obtained an optimal risk assessment model, the GPSGC, which showed higher accuracy in predicting survival than individual prognostic factors. The impact of the GPSGC score on poor survival of GC patients was probably correlated with the remodeling of stromal components in the tumor microenvironment. Specifically, TGFß and angiogenesis-related gene sets were significantly associated with the GPSGC risk score and poor outcome. Immunomodulatory gene analysis combined with experimental verification further revealed that TGFß1 and VEGFB may be developed as potential therapeutic targets of GC patients with poor prognosis according to the GPSGC. Furthermore, we developed a nomogram based on the GPSGC and other clinical variables to predict the 3-year and 5-year overall survival for GC patients, which showed improved prognostic accuracy than clinical characteristics only. Conclusion: As a tumor microenvironment-relevant gene set-based prognostic signature, the GPSGC model provides an effective approach to evaluate GC patient survival outcomes and may prolong overall survival by enabling the selection of individualized targeted therapy.

Preparation, characterization and in vitro-in vivo evaluation of bortezomib supermolecular aggregation nanovehicles.

BACKGROUNDS: Intolerable toxicity and unsatisfactory therapeutic effects are still big problems retarding the use of chemotherapy against cancer. Nano-drug delivery system promised a lot in increasing the patients' compliance and therapeutic efficacy. As a unique nano-carrier, supermolecular aggregation nanovehicle has attracted increasing interests due to the following advantages: announcing drug loading efficacy, pronouncing in vivo performance and simplified production process. METHODS: In this study, the supermolecular aggregation nanovehicle of bortezomib (BTZ) was prepared to treat breast cancer. RESULTS: Although many supermolecular nanovehicles are inclined to disintegrate due to the weak intermolecular interactions among the components, the BTZ supermolecules are satisfying stable. To shed light on the reasons behind this, the forces driving the formation of the nanovehicles were detailed investigated. In other words, the interactions among BTZ and other two components were studied to characterize the nanovehicles and ensure its stability. CONCLUSIONS: Due to the promising tumor targeting ability of the BTZ nanovehicles, the supermolecule displayed promising tumor curing effects and negligible systemic toxicity.

[Molecular Mechanism of Ventilator-associated Lung Injury Based on Keap1/Nfr2/ARE Signaling Pathway].

OBJECTIVE: To explore the molecular mechanism of ventilation induced lung injury (VILI) formation based on Keap1/Nfr2/ARE signaling pathway. METHODS: The VILI model was established by excessive mechanical ventilation in SD rats. HE staining was used to detect the pathological changes of lung tissue in the control group, normal tidal volume (VT) group and large VT group (VT 40 mL/kg). The wet weight of lung tissue was detected in each group. Dry weight (W/D) ratio change; BCA method was used to detect the changes of total protein in bronchoalveolar lavage fluid (BALF) of each group; ELISA was used to detect interleukin-1ß (IL-1ß) and leukocyte in BALF and serum of each group. The content of 8-OHdG in the lung tissue was detected by IL-8 and the content of malondialdehyde (MDA) in the lung tissue was detected by TBA method. The NLRP3, ASC and caspase-1 proteins in macrophages were detected by Western blot. The changes of Keap1 and Nrf2 proteins in lung tissues were detected by RT-PCR. The expressions of SOD mRNA and HO-1 mRNA in lung tissues of each group were detected by RT-PCR. RESULTS: Excessive mechanical ventilation could damage lung tissue, leading to alveolar rupture, inflammatory cell infiltration and erythrocytosis. Compared with the control group and normal VT group, the W/D value, 8-OHdG and MDA content in the large VT group, and total BALF, the contents of IL-1ß and IL-18 in protein, IL-1ß, IL-18 in serum increased significantly ( P<0.05). Compared with the control group and normal VT group, NLRP3, ASC, in macrophage of large VT group, the content of Keap1 protein in caspase-1 protein and lung tissue increased significantly ( P<0.05). The expression of Nrf2 protein, SOD mRNA and HO-1 mRNA in lung tissue decreased significantly. CONCLUSIONS: Large VT ventilation can cause acute inflammatory injury in lung tissue and lead to the occurrence of VILI. Inflammatory bodies of NLRP3 in alveolar macrophages are involved in this process, and the mechanism of NLRP3 inflammatory bodies is caused by hyperventilation in addition to mechanical injury. Decreased Keap1/Nrf2-ARE pathway inhibition and ROS clearance may also cause macrophage production of NLRP3 inflammatory bodies.

Inhibition of Bcl6b promotes gastric cancer by amplifying inflammation in mice.

BACKGROUND: Chronic gastritis has been demonstrated to be a key cause of gastric cancer (GC), and control of gastric inflammation is regarded as an effective treatment for the clinical prevention of gastric carcinogenesis. However, there remains an unmet need to identify the dominant regulators of gastric oncogenesis-associated inflammation in vivo. METHODS: The mouse model for the study of inflammation-associated GC was induced by Benzo[a]pyrene (BaP) intragastric administration in Bcl6b-/- and wildtype mice on a C57BL/6 background. 5-Aza-2'-deoxycytidine (5-Aza), the demethylation drug, was intraperitoneally injected to restore Bcl6b expression. Human GC tissue array was used to analyse patient survival based on BCL6B and CD3 protein expression. RESULTS: Bcl6b was gradually downregulated by its own promoter hypermethylation in parallel to an increasing inflammatory response during the progression of BaP-induced gastric carcinogenesis in mice. Moreover, knockout of Bcl6b dramatically worsened the severity of gastric cancer and aggravated the inflammatory response in the BaP-induced mice GC model. Re-activation of Bcl6b by 5-Aza impeded inflammatory amplification and BaP-induced GC development, prolonging survival time in wildtype mice, whereas no notable curative effect occurred in Bcl6b-/- mice with 5-Aza treatment. Finally, significant negative correlations were detected between the mRNA levels of BCL6B and inflammatory cytokines in human GC tissues; patients harbouring BCL6B-negetive and severe-inflammation GC tumours were found to exhibit the shortest survival time. CONCLUSIONS: Epigenetic inactivation of Bcl6b promotes gastric cancer through amplification of the gastric inflammatory response in vivo and offers a new approach for GC treatment and regenerative medicine.

[Hamilton-Thorne Integrated Visual Optical System â (IVOSâ ) versus IVOS â ¡ for human sperm analysis].

OBJECTIVE: To compare the computer-assisted sperm analysis (CASA) systems Hamilton-Thorne Integrated Visual Optical System Ⅰ (IVOSⅠ) and IVOS Ⅱ after verifying the performance of the latter so as to ensure the accuracy of the results of analysis. METHODS: Based on the criteria established in the 5th edition of the WHO Laboratory Manual for the Examination and Processing of Human Semen (WHO 5th Ed), we compared the main semen parameters obtained from IVOSⅠ with those generated by IVOS Ⅱ, and examined the consistency between the results of the two sperm analyzers. RESULTS: The linear relationship of the outlier test, bias estimation and scatter plot and the results of the outlier test of the two systems all met the requirements of comparison analysis and showed an obvious correlativity. The application scope of the results obtained from the apparatus indicated a reasonable value range, with r = 0.988 for sperm concentration, r = 0.975 for sperm progressive motility (PR), and r = 0.981 for total sperm motility. Evaluation of the acceptability of the predicted bias showed that the allowable total error (TEa) to be 6.67% with sperm concentration at 12 × 106 /ml and 2.34% with PR < 31%, their upper limit of the allowable error < 1/2. The results of IVOS Ⅱ conformed to the requirements of the WHO 5th Ed. CONCLUSIONS: The main parameters derived from IVOSⅠ and IVOS Ⅱ are comparable and consistent, indicating that both can be used for the examination of semen samples.

Long noncoding RNA MEG3 prevents vascular endothelial cell senescence by impairing miR-128-dependent Girdin downregulation.

Long noncoding RNAs (lncRNAs) are commonly associated with various biological functions, in which the function of lncRNA maternally expressed gene 3 (MEG3) has been identified in various cancers. Strikingly, an association between MEG3 with microRNAs (miRNAs), mRNAs, and proteins has been reported. This study investigates the role of MEG3 in vascular endothelial cell (VEC) senescence. Expression of Girdin and miR-128 was monitored in the blood vessel samples of young and old mice/healthy volunteers, along with the measurement of human umbilical vein endothelial cells (HUVECs). The relationship between MEG3/Girdin and miR-128 was determined and verified. Loss- and gain-of-function approaches were applied to analyze the regulatory effects of MEG3 on platelet phagocytosis and lipoprotein oxidation of HUVEC membrane. In addition, the effect of MEG3 on HUVEC senescence was evaluated by detection of the reactive oxygen species, telomerase activity, and telomere length. To further analyze the MEG3-mediated regulatory mechanism, miR-128 upregulation and inhibition were introduced into the HUVECs. Downregulated Girdin and upregulated miR-128 were found in the blood vessels of old individuals and old mice, as well as in senescent HUVECs. MEG3 downregulation was found to be capable of inhibiting Girdin but enhancing miR-128 expression. It was also indicated to inhibit platelet phagocytosis and reduce telomerase activity and telomere length, while enhancing lipoprotein oxidation and reactive oxygen species production, which ultimately contributed in preventing and protecting HUEVCs from senescence. These findings provide evidence supporting that MEG3 leads to miR-128 downregulation and Girdin upregulation, which promotes platelet phagocytosis, thus protecting VECs from senescence.

Chibby suppresses aerobic glycolysis and proliferation of nasopharyngeal carcinoma via the Wnt/ß-catenin-Lin28/let7-PDK1 cascade.

BACKGROUND: Great progress has been achieved in the study of the aerobic glycolysis or the so-called Warburg effect in a variety of cancers; however, the regulation of the Warburg effect in Nasopharyngeal carcinoma (NPC) has not been completely defined. METHODS: Gene expression pattern of NPC cells were used to test associations between Chibby and ß-catenin expression. Chibby siRNAs and over-expression vector were transfected into NPC cells to down-regulate or up-regulate Chibby expression. Loss- and gain-of function assays were performed to investigate the role of Chibby in NPC cells. Western blot, cell proliferation, Glucose uptake, Lactate release, ATP level, and O2 consumption assays were used to determine the mechanism of Chibby regulation of underlying targets. Finally, immunohistochemistry assay of fresh NPC and nasopharyngeal normal tissue sample were used to detect the expression of Chibby, ß-Catenin, and PDK1 by immunostaining. RESULTS: We observed that Chibby, a ß-catenin-associated antagonist, is down-regulated in nasopharyngeal carcinoma cell lines and inhibits Wnt/ß-Catenin signaling induced Warburg effect. Mechanism study revealed that Chibby regulates aerobic glycolysis in NPC cells through pyruvate dehydrogenase kinase 1(PDK1), an important enzyme involved in glucose metabolism. Moreover, Chibby suppresses aerobic glycolysis of NPC via Wnt/ß-Catenin-Lin28/let7-PDK1 cascade. Chibby and PDK1 are critical for Wnt/ß-Catenin signaling induced NPC cell proliferation both in vitro and in vivo. Finally, immunostaining assay of tissue samples provides an important clinical relevance among Chibby, Wnt/ß-Catenin signaling and PDK1. CONCLUSIONS: Our study reveals an association between Chibby expression and cancer aerobic glycolysis, which highlights the importance of Wnt/ß-catenin pathway in regulation of energy metabolism of NPC. These results indicate that Chibby and PDK1 are the potential target for NPC treatment.

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.

Aldose reductase interacts with AKT1 to augment hepatic AKT/mTOR signaling and promote hepatocarcinogenesis.

Marked up-regulation of aldose reductase (AR) is reportedly associated with the development of hepatocellular carcinoma (HCC). We investigated how aberrantly overexpressed AR might promote oncogenic transformation in liver cells and tissues. We found that overexpressed AR interacted with the kinase domain of AKT1 to increase AKT/mTOR signaling. In both cultured liver cancer cells and liver tissues in DEN-induced transgenic HCC model mice, we observed that AR overexpression-induced AKT/mTOR signaling tended to enhance lactate formation and hepatic inflammation to enhance hepatocarcinogenesis. Conversely, AR knockdown suppressed lactate formation and inflammation. Using cultured liver cancer cells, we also demonstrated that AKT1 was essential for AR-induced dysregulation of AKT/mTOR signaling, metabolic reprogramming, antioxidant defense, and inflammatory responses. These findings suggest that aberrantly overexpressed/over-activated hepatic AR promotes HCC development at least in part by interacting with oncogenic AKT1 to augment AKT/mTOR signaling. Inhibition of AR and/or AKT1 might serve as an effective strategy for the prevention and therapy of liver cancer.

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).

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.

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.

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.