Proteomic Characterization of Annexin l (ANX1) and Heat Shock Protein 27 (HSP27) as Biomarkers for Invasive Hepatocellular Carcinoma Cells

Dual-tracer positron emission tomography/computed tomography as an imaging probe of de novo lipogenesis in preclinical models of hepatocellular carcinoma

Background

De novo lipogenesis is upregulated in many cancers, and targeting it represents a metabolic approach to cancer treatment. However, the treatment response is unpredictable because lipogenic activity varies greatly among individual tumors, thereby necessitating the assessment of lipogenic activity before treatment. Here, we proposed an imaging probe, positron emission tomography/computed tomography (PET/CT) with dual tracers combining 11C-acetate and 18F-fluorodeoxyglucose (18F-FDG), to assess the lipogenic activity of hepatocellular carcinoma (HCC) and predict the response to lipogenesis-targeted therapy.

Methods

We investigated the association between 11C-acetate/18F-FDG uptake and de novo lipogenesis in three HCC cell lines (from well-differentiated to poorly differentiated: HepG2, Hep3B, and SkHep1) by examining the expression of lipogenic enzymes: acetyl-CoA synthetase 2 (ACSS2), fatty acid synthase (FASN), and ATP citrate lyase (ACLY). The glycolysis level was determined through glycolytic enzymes: pyruvate dehydrogenase expression (PDH). On the basis of the findings of dual-tracer PET/CT, we evaluated the treatment response to a lipase inhibitor (orlistat) in cell culture experiments and xenograft mice.

Results

Dual-tracer PET/CT revealed the lipogenic activity of various HCC cells, which was positively associated with 11C-acetate uptake and negatively associated with 18F-FDG uptake. This finding represents the negative association between 11C-acetate and 18F-FDG uptake. Because these two tracers revealed the lipogenic and glycolytic activity, respectively, which implies an antagonism between lipogenic metabolism and glucose metabolism in HCC. In addition, dual-tracer PET/CT not only revealed the lipogenic activity but also predicted the treatment response to lipogenesis-targeted therapy. For example, HepG2 xenografts with high 11C-acetate but low 18F-FDG uptake exhibited high lipogenic activity and responded well to orlistat treatment, whereas SkHep1 xenografts with low 11C-acetate but high 18F-FDG uptake exhibited lower lipogenic activity and poor response to orlistat.

Conclusion

The proposed non-invasive dual-tracer PET/CT imaging can reveal the lipogenesis and glycolysis status of HCC, thus providing an ideal imaging probe for predicting the therapeutic response of HCC to lipogenesis-targeted therapy.

The durum wheat annexin, TdAnn6, improves salt and osmotic stress tolerance in Arabidopsis via modulation of antioxidant machinery

TdAnn6 is a gene encoding an annexin protein in durum wheat (Triticum durum). The function of TdAnn6 in plant response to stress is not yet clearly understood. Here, we isolated TdAnn6 and characterized it in genetically modified Arabidopsis thaliana. Expressing TdAnn6 in Arabidopsis coincided with an improvement in stress tolerance at germination and seedling stages. In addition, TdAnn6-expressing seedling antioxidant activities were improved with lower level of malondialdehyde, and enhanced transcript levels of six stress-related genes during salt/osmotic stresses. Under greenhouse conditions, the TdAnn6 plants exhibited increased tolerance to salt or drought stress. To deepen our understanding of TdAnn6 function, we isolated a 1515-bp genomic fragment upstream of its coding sequence, designated as PrTdAnn6. The PrTdAnn6 promoter was fused to the β-glucuronidase reporter gene and transferred to Arabidopsis. By histochemical GUS staining, GUS activity was detected in the roots, leaves, and floral organs, but no activity was detected in the seeds. Furthermore, we noticed a high stimulation of promoter activity when A. thaliana seedlings were exposed to NaCl, mannitol, ABA, GA, and cold conditions. This cross-talk between tissue-specific expression and exogenous stress stimulation may provide additional layers of regulation for salt and osmotic stress responses in crops.

Heat Shock Proteins 27, 70, and 110: Expression and Prognostic Significance in Colorectal Cancer

Heat shock proteins (HSPs) are evolutionarily conserved chaperones occurring in virtually all living organisms playing a key role in the maintenance of cellular homeostasis. They are constitutively expressed to prevent and repair protein damage following various physiological and environmental stressors. HSPs are overexpressed in various types of cancers to provide cytoprotective function, and they have been described to influence prognosis and response to therapy. Moreover, they have been used as a tumor marker in blood serum biochemistry and they represent a potentially promising therapeutic target. To clarify prognostic significance of two canonical HSPs (27 and 70) and less known HSP110 (previously known as HSP105) in colorectal carcinoma (CRC), we retrospectively performed HSP immunohistochemistry on tissue microarrays from formalin-fixed paraffin-embedded tumor tissue from 297 patients with known follow-up. Survival analysis (univariate Kaplan-Meier analysis with the log-rank test and multivariate Cox regression) revealed significantly shorter overall survival (OS, mean 5.54 vs. 7.07, p = 0.033) and borderline insignificantly shorter cancer specific survival (CSS, mean 6.3 vs. 7.87 years, p = 0.066) in patients with HSP70+ tumors. In the case of HSP27+ tumors, there was an insignificantly shorter OS (mean 6.36 vs. 7.13 years, p = 0.2) and CSS (mean 7.17 vs. 7.95 years, p = 0.2). HSP110 showed no significant impact on survival. Using Pearson's chi-squared test, there was a significant association of HSP27 and HSP70 expression with advanced cancer stage. HSP27+ tumors were more frequently mismatch-repair proficient and vice versa (p = 0.014), and they occurred more often in female patients and vice versa (p = 0.015). There was an enrichment of left sided tumors with HSP110+ compared to the right sided (p = 0.022). In multivariate Cox regression adjusted on the UICC stage, grade and right/left side; both HSPs 27 and 70 were not independent survival predictors (p = 0.616 & p = 0.586). In multivariate analysis, only advanced UICC stage (p = 0) and right sided localization (p = 0.04) were independent predictors of worse CSS. In conclusion, from all three HSPs examined in our study, only HSP70 expression worsened CRC prognosis, although stage-dependent. The contribution of this article may be seen as a large survival analysis of HSPs 27 and 70 and the largest analysis of HSP110 described in CRC.

Xenograft Zebrafish Models for the Development of Novel Anti-Hepatocellular Carcinoma Molecules

Hepatocellular carcinoma (HCC) is the sixth most common type of tumor and the second leading cause of tumor-related death worldwide. Liver cirrhosis is the most important predisposing factor for HCC. Available therapeutic approaches are not very effective, especially for advanced HCC, which is the most common form of the disease at diagnosis. New therapeutic strategies are therefore urgently needed. The use of animal models represents a relevant tool for preclinical screening of new molecules/strategies against HCC. However, several issues, including animal husbandry, limit the use of current models (rodent/pig). One animal model that has attracted the attention of the scientific community in the last 15 years is the zebrafish. This freshwater fish has several attractive features, such as short reproductive time, limited space and cost requirements for husbandry, body transparency and the fact that embryos do not show immune response to transplanted cells. To date, two different types of zebrafish models for HCC have been developed: the transgenic zebrafish and the zebrafish xenograft models. Since transgenic zebrafish models for HCC have been described elsewhere, in this review, we focus on the description of zebrafish xenograft models that have been used in the last five years to test new molecules/strategies against HCC.

Methyl gallate, gallic acid-derived compound, inhibit cell proliferation through increasing ROS production and apoptosis in hepatocellular carcinoma cells

Hepatocellular carcinoma (HCC) is a global health problem. Currently, there is no effective therapeutic strategy for HCC. Methyl gallate (MG), from plant-derived phenolic gallic acid, has exhibited antitumor efficacy. However, the effect of MG on HCC is unclear. In vitro growth activity was detected by a sulforhodamine assay. A zebrafish xenotransplantation was applied to evaluate the inhibitory effect of MG. Reactive oxygen species (ROS) production, autophagy, and lysosome formation were detected by specific dyes. Finally, apoptosis was examined using annexin V-FITC/PI staining and western blot was performed to determine the molecular mechanism. It was demonstrated that MG treatment inhibited the proliferation of Hep3B, Mahlavu, and HepJ5 cells. Xenotransplantation also showed that MG inhibited the growth of Hep3B and HepJ5 cells. MG treatment increased cellular levels of superoxide and oxidative stress. Increases in autophagy and lysosome formation were found after MG treatment. The western blot analysis showed that MG activated cleavage of caspase-3 and poly (SDP ribose) polymerase (PARP), modulated levels of the Bcl2, Bax, and Bad ligands, and induced apoptosis. MG induced autophagy with notable activation of beclin-1, autophagy related 5+12 (ATG5+12), and conversion of light chain 3-I (LC3-I) to II. Our study showed that MG exposure inhibited HCC proliferation both in vitro and in vivo. And blocking autophagy enhanced MG-induced cytotoxicity in HCC cells. These findings suggested MG might serve as a powerful therapeutic supplement for human HCC patients.

Areca nut extract (ANE) inhibits the progression of hepatocellular carcinoma cells via activation of ROS production and activation of autophagy

Hepatocellular carcinoma (HCC) is a worldwide health problem. Currently, there is no effective therapeutic strategy for HCC patients. Chewing areca nut is closely associated with oral cancer and liver cirrhosis. The therapeutic effect of areca nut extract (ANE) on HCC is unknown. Our results revealed that ANE treatment caused a reduction in cell viability and an increase in cell apoptosis and suppressed tumor progression in xenograft models. ANE-treated didn't induce liver tumor in nude mice. For mechanism dissection, ANE treatment caused ROS-mediated autophagy and lysosome formation. Pretreatment with an ROS inhibitor, aminoguanidine hemisulfate (AGH), abolished ANE-induced ROS production. ANE treated cells caused an increase in light chain 3 (LC3)-I to -II conversion, anti-thymocyte globulin 5+12 (ATG5+12), and beclin levels, and apoptosis related-protein changes (an increases in BAX, cleaved poly(ADP-ribose) polymerase (c-PARP), and a decrease in the Bcl-2 level). In conclusion, our study demonstrated that the ANE may be a new potential compound for HCC therapy.

Cell Surface Proteins in Hepatocellular Carcinoma: From Bench to Bedside

Cell surface proteins act as the go-between in carrying the information from the extracellular environment to the intracellular signaling proteins. However, these proteins are often deregulated in neoplastic diseases, including hepatocellular carcinoma. This review discusses several recent studies that have investigated the role of cell surface proteins in the occurrence and progression of HCC, highlighting the possibility to use them as biomarkers of the disease and/or targets for vaccines and therapeutics.

Smoking as an Independent Risk Factor for Hepatocellular Carcinoma Due to the α7-Nachr Modulating the JAK2/STAT3 Signaling Axis

BACKGROUND

Hepatocellular carcinoma (HCC) is a worldwide health problem. Currently, there is no effective clinical therapeutic strategy for HCC. Smoking is associated with several malignant diseases including cancers.

EXPERIMENTAL APPROACH

However, the impact of smoking on HCC is still unresolved. Retrospectively reviewed HCC patients diagnosed between 1 January 2010 and 31 December 2015 at Taipei Medical University-Shuang Ho Hospital (Ministry of Health and Welfare). We found that smoking was associated with a poor prognosis, especially recurrence and patient survival after curative surgery using a clinicopathological analysis.

RESULTS

Our univariate and multivariate analyses showed that the α7-nicotinic acetylcholine receptor (α7-nAChR) was an oncogene and risk factor for post-resection recurrence. The α7-nAChR was overexpressed in HCC tissues compared to their non-tumor counterparts. Silencing the α7-nAChR reduced the viability of HCC cells, suppressed cellular proliferation, attenuated migration and invasion, and diminished the tumor's sphere-formation ability, with concurrent downregulation of expression levels of the TGR5, p-JAK2, p-STAT3 (Tyr705/Ser727), RhoA, ROCK1, MMP2, and MMP9 proteins. Furthermore, a positive correlation was found between α7-nAChR and JAK2 expressions (p = 0.01) in HCC specimens, as well as their membranous co-localization.

CONCLUSION

Together, we demonstrated that the α7-nAChR may be an independent prognosticator of the progression and prognosis of HCC patients. These findings suggest that the α7-nAChR drives the progression and recurrence of HCC through JAK2/STAT3 signaling and is a novel target for anti-HCC therapy.

HSP27 promotes epithelial-mesenchymal transition through activation of the β-catenin/MMP3 pathway in pancreatic ductal adenocarcinoma cells

Background

The precise role of heat shock protein 27 (HSP27), as a type of small molecular protein in HSPs, in pancreatic ductal adenocarcinoma (PDAC) remains to be elucidated. The aim of the present study was to investigate the expression and function of HSP27 in PDAC cells.

Methods

We first detected the expression of HSP27 in PDAC tissues. Combining with the clinical pathology characteristics of PDAC patients, the relationship between them was analyzed. Then, we knocked down HSP27 using short interfering RNA (siRNA) and observed its biological functions using scratch assay and matrigel invasion and migration assays in ASPC-1 and PANC-1 cells. In mechanism, we verified the β-catenin/MMP-3 pathway associated proteins in ASPC-1 and PANC-1 cells.

Results

We found that HSP27 was highly expression in PDAC tissues, and was positively correlated with tumor differentiation, TNM staging and poor prognosis of PDAC patients. In vitro, we down-regulated the expression of HSP27 in ASPC-1 and PANC-1 cells and found that the invasion and migration ability of PDAC cells were significantly depressed, meanwhile, the activation of the β-catenin/MMP-3 pathway was inhibited.

Conclusions

HSP27 may be used as a tumor biomarker for diagnosis of PDAC, and HSP27 can promote the invasion and migration of PDAC by activating the β-catenin/MMP3 Pathway. Therefore, inhibition of HSP27 has therapeutic potential for the treatment of PDAC.

Propyl gallate inhibits hepatocellular carcinoma cell growth through the induction of ROS and the activation of autophagy

The poor prognosis of hepatocellular carcinoma (HCC) has been attributed to a high frequency of tumor metastasis and recurrence even after successful surgical resection. With less than 30% of patients benefiting from curative treatment, alternative treatment regimens for patients with advanced HCC are needed. Propyl gallate (PG), a synthetic antioxidant used in preserving food and medicinal preparations, has been shown to induce cancer cell death, but the anticancer effects of PG in HCC are unclear. In the present study, we demonstrated that PG inhibited HCC cell proliferation in vitro and in zebrafish models in vivo in a dose- and time-dependent manner. PG also induced cell apoptosis and increased the number of necrotic cells in a time- and dose-dependent manner as determined using a high-content analysis system. We found that PG also increased the intracellular levels of superoxide and reactive oxidative stress as well as the formation of autophagosomes and lysosomes. Regarding the molecular mechanism, PG did not alter the levels of autophagy-related 5 (ATG5), ATG5/12 or Beclin-1 but increased the rate of the LC3-I to LC3-II conversion, suggesting autophagy induction. PG exposure increased the levels of the pro-apoptotic proteins cleaved caspase-3, cleaved PARP, Bax, and Bad and a decreased level of the anti-apoptotic protein Bcl-2. In conclusion, we demonstrate that PG inhibits HCC cell proliferation through enhanced ROS production and autophagy activation. Finally, PG-treated cells induced cell apoptosis and may be a new candidate for HCC therapy.

Silencing Heat Shock Protein 27 Inhibits the Progression and Metastasis of Colorectal Cancer (CRC) by Maintaining the Stability of Stromal Interaction Molecule 1 (STIM1) Proteins

The incidence of colorectal cancer (CRC) has significantly increased in recent decades, and this disease has become an important health issue worldwide. Currently, there is no useful prognostic or diagnostic biomarker for CRC. Heat shock protein 27 (HSP27) is a chaperone that interacts with many proteins. HSP27 has been shown to be overexpressed in many cancers, including colon cancer, and its overexpression is related to poor disease outcome. Although the importance of HSP27 as a biomarker cannot be underrated, its detailed mechanisms in colon cancer are still unclear. In vitro studies have indicated that silencing HSP27 reduces the proliferation, migration and invasion of colon cancer cells, and xenograft models have shown that silencing HSP27 decreases tumor progression. Tissue array results showed that colon cancer patients with high expression of HSP27 exhibited poor prognosis. In addition, we found a reduction of calcium influx through a decrease in STIM1 protein after HSP27 was abolished. The formation of puncta was decreased in HSP27 knockdown (HSP27KD) cells after thapsigargin (TG) treatment. Finally, we confirmed that the reduction of STIM1 after HSP27 silencing may be due to a loss of STIM1 stability instead of transcription. HSP27 may interact with STIM1 but not Orai1, as shown by immunoprecipitation assays. HSP27 and STIM1 were co-expressed in CRC specimens. Our study showed that HSP27 is a key mediator in the progression and metastasis of CRC by regulating the store-operated calcium entry. This novel pathway may provide a new direction for development of therapeutic strategies for CRC.

Identification and Comparison of Differentiation-Related Proteins in Hepatocellular Carcinoma Tissues by Proteomics

Histological differentiation is a major pathological criterion indicating the risk of tumor invasion and metastasis in patients with hepatocellular carcinoma. The degree of tumor differentiation is controlled by a complex interacting network of associated proteins. The principal aim of the present study is to identify the possible differentiation-related proteins which may be used for early diagnosis and more effective therapies. We compared poorly differentiated and well-differentiated hepatocellular carcinoma tissues by using 2-dimensional gel electrophoresis and matrix-assisted laser desorption ionization time-of-flight mass spectrometry. Among the 11 identified protein spots, 6 were found to be upregulated in poorly differentiated hepatocellular carcinoma tissues and 5 were correspondingly downregulated. Immunohistochemistry was performed on 106 hepatocellular carcinoma tissues to confirm the results of the proteomic analysis. By using bioinformatic tools GO and STRING, these proteins were found to be related to catalytic activity, binding, and antioxidant activity. In particular, our data suggest that overexpression of peroxiredoxin-2, annexin A2, and heat shock protein β-1 was correlated with tumor invasion, metastasis, and poor prognosis, and therefore, these proteins may serve as potential diagnostic and therapeutic biomarkers.

Mass spectrometry-assisted gel-based proteomics in cancer biomarker discovery: approaches and application

There is a critical need for the discovery of novel biomarkers for early detection and targeted therapy of cancer, a major cause of deaths worldwide. In this respect, proteomic technologies, such as mass spectrometry (MS), enable the identification of pathologically significant proteins in various types of samples. MS is capable of high-throughput profiling of complex biological samples including blood, tissues, urine, milk, and cells. MS-assisted proteomics has contributed to the development of cancer biomarkers that may form the foundation for new clinical tests. It can also aid in elucidating the molecular mechanisms underlying cancer. In this review, we discuss MS principles and instrumentation as well as approaches in MS-based proteomics, which have been employed in the development of potential biomarkers. Furthermore, the challenges in validation of MS biomarkers for their use in clinical practice are also reviewed.

IGFBP2 plays an important role in heat shock protein 27-mediated cancer progression and metastasis

Heat shock protein 27 (Hsp27) is a key chaperone that interacts with over 200 client proteins. The expression of Hsp27 might be correlated with poor outcome in many types of cancer. Previous study indicated that Hsp27 might be an important biomarker in hepatocellular carcinoma (HCC). However, the detailed mechanism is less well understood. The shRNA-mediated silencing of Hsp27 decreased the proliferation, migration and invasion of HCC cells. In a xenograft model, the silencing of Hsp27 reduced tumor progression. We revealed that the silencing of Hsp27 led to a reduction in insulin-like growth factor binding protein 2 (IGFBP2), which might mediate proliferation and metastasis through vimentin, snail and beta-catenin. The overexpression of IGFBP2 reversed the reductions in cell growth, migration and invasion. The tissue array results showed that HCC patients with high Hsp27 expression exhibited poor prognosis and increased metastasis. The Hsp27 expression was highly correlated with IGFPB2 in CRC specimen. ChIP and luciferase assays showed that Hsp27 does not directly bind the IGFBP2 promoter region to regulate the transcription of IGFBP2. In conclusion, our study demonstrated that Hsp27 is a key mediator of HCC progression and metastasis and that Hsp27 might regulate proliferation and metastasis through IGFBP2. This pathway might provide a new direction for the development of a novel therapeutic strategy for HCC.

Retrospective Proteomic Screening of 100 Breast Cancer Tissues

The present investigation has been conducted on one hundred tissue fragments of breast cancer, collected and immediately cryopreserved following the surgical resection. The specimens were selected from patients with invasive ductal carcinoma of the breast, the most frequent and potentially aggressive type of mammary cancer, with the objective to increase the knowledge of breast cancer molecular markers potentially useful for clinical applications. The proteomic screening; by 2D-IPG and mass spectrometry; allowed us to identify two main classes of protein clusters: proteins expressed ubiquitously at high levels in all patients; and proteins expressed sporadically among the same patients. Within the group of ubiquitous proteins, glycolytic enzymes and proteins with anti-apoptotic activity were predominant. Among the sporadic ones, proteins involved in cell motility, molecular chaperones and proteins involved in the detoxification appeared prevalent. The data of the present study indicates that the primary tumor growth is reasonably supported by concurrent events: the inhibition of apoptosis and stimulation of cellular proliferation, and the increased expression of glycolytic enzymes with multiple functions. The second phase of the evolution of the tumor can be prematurely scheduled by the occasional presence of proteins involved in cell motility and in the defenses of the oxidative stress. We suggest that this approach on large-scale 2D-IPG proteomics of breast cancer is currently a valid tool that offers the opportunity to evaluate on the same assay the presence and recurrence of individual proteins, their isoforms and short forms, to be proposed as prognostic indicators and susceptibility to metastasis in patients operated on for invasive ductal carcinoma of the breast.

Discs large homolog 5 decreases formation and function of invadopodia in human hepatocellular carcinoma via Girdin and Tks5

Invadopodium formation is a crucial early event of invasion and metastasis of hepatocellular carcinoma (HCC). However, the molecular mechanisms underlying regulation of invadopodia remain elusive. This study aimed to investigate the potential role of discs large homolog 5 (Dlg5) in invadopodium formation and function in HCC. We found that Dlg5 expression was significantly lower in human HCC tissues and cell lines than adjacent nontumor tissues and liver cells. Lower Dlg5 expression was associated with advanced stages of HCC, and poor overall and disease-free survival of HCC patients. Dlg5-silencing promoted epithelial-mesenchymal transition, invadopodium formation, gelatin degradation function, and invadopodium-associated invasion of HepG2 cells. In contrast, Dlg5 overexpression inhibited epithelial-mesenchymal transition, functional invadopodium formation, and invasion of SK-Hep1 cells. Both Girdin and Tks5, but not the Tks5 nonphosphorylatable mutant, were responsible for the enhanced invadopodium formation and invasion of Dlg5-silenced HepG2 cells. Furthermore, Dlg5 interacted with Girdin and interfered with the interaction of Girdin and Tks5. Dlg5 silencing promoted Girdin and Tks5 phosphorylation, which was abrogated by Girdin silencing and rescued by inducing shRNA-resistant Girdin expression. Moreover, Dlg5 overexpression significantly inhibited HCC intrahepatic and lung metastasis in vivo. Taken together, our data indicate that Dlg5 acts as a novel regulator of invadopodium-associated invasion via Girdin and by interfering with the interaction between Girdin and Tks5, which might be important for Tks5 phosphorylation in HCC cells. Conceivably, Dlg5 may act as a new biomarker for prognosis of HCC patients.

Transglutaminase 2 is upregulated in primary hepatocellular carcinoma with early recurrence as determined by proteomic profiles

The mechanism of early recurrence of hepato-cellular carcinoma (HCC) is not well understood. To examine whether early intrahepatic metastasis of HCC can be determined by the reliable molecular characteristics of the primary HCC, we focused on early-stage tumors of primary and solitary HCC cases. Proteomic differences were investigated between two groups, 11 early (recurrence within 12 months) and 10 late (no recurrence within 48 months) HCC cases, using two-dimensional fluorescence difference gel electrophoresis. Overall, 10 upregulated and 9 downregulated proteins were identified from a total of 1623 protein spots detected in early recurrent HCC. Cluster analysis using the 19 proteins successfully divided the 21 HCC samples exactly into the two above groups. A multifunctional protein, transglutaminase 2 (TGM2), was upregulated in the early recurrence group. Immunohistochemistry revealed the frequent observation of TGM2-positive HCC cells in the early group, with a tendency of TGM2-positive staining in HCC cells adjacent to fibrous stroma. To examine whether two major TGM2-associated pathways, epithelial-mesenchymal transition (EMT) and integrin signaling, were activated in the early recurrence group of HCC, downstream molecules of TGM2 were measured. The mRNA level of EMT-related genes was highly positively correlated with TGM2 mRNA. However, E-cadherin (CDH1) mRNA and protein were not downregulated in correlation with TGM2 expression. The phosphorylation of FAK and Akt and the downregulation of PTEN were not associated with the quantity of TGM2. Therefore, TGM2 might contribute to early HCC recurrence through signaling pathways not related to EMT and integrin signaling. The proteomics of strictly classified HCCs would be useful for characterizing pro-metastatic HCC and for developing a new therapeutic target for treatment of metastasis.

Bradykinin stimulates protein kinase D-mediated colonic myofibroblast migration via cyclooxygenase-2 and heat shock protein 27

BACKGROUND

Inflammatory bowel disease is characterized by episodic intestinal injury and repair. Myofibroblasts are gastrointestinal tract stromal cells that regulate the reparative process and are known targets of inflammatory mediators including bradykinin (BK). However, the mechanisms through which inflammation regulates myofibroblast-induced wound healing remain incompletely understood. Here, we demonstrate, for the first time, that BK stimulates myofibroblast migration through protein kinase D (PKD)-mediated activation of the cyclooxygenase-2 (COX-2) and heat shock protein 27 (Hsp27) pathways.

MATERIALS AND METHODS

CCD-18Co is a human colonic myofibroblast cell line used from passages 8 to 14. An in vitro scratch assay assessed the effect of BK (100 nM) on myofibroblast migration over 24 h in the presence or absence of several inhibitors (CID755673 [10 μM] and NS398 [10 μM]). Hsp27 small interfering RNA evaluated the effect of Hsp27 on colonic myofibroblast migration. Antibodies to pPKD, pHsp27, and COX-2 evaluated expression levels by Western blot.

RESULTS

BK stimulated myofibroblast migration over 24 h. BK also led to rapid and sustained phosphorylation of PKD at Ser-916, rapid phosphorylation of Hsp27 at Ser-82, and increased COX-2 expression over 4 h. BK-mediated COX-2 expression and Hsp27 phosphorylation were both inhibited by the PKD inhibitor CID755673. Similarly, BK-induced myofibroblast migration was significantly inhibited by CID755673 (P < 0.05), by the direct COX-2 inhibitor NS398 (P < 0.05), and by Hsp27 small interfering RNA (P < 0.05).

CONCLUSIONS

BK stimulates myofibroblast migration through PKD-mediated activation of COX-2 and Hsp27. PKD, COX-2, and Hsp27 all appear to regulate myofibroblast cell migration, a stromal population that may play an important role in mucosal healing in the setting of inflammation.

Relationship between TRAF6 and deterioration of HCC: an immunohistochemical and in vitro study

Objective

To explore the relationship between tumor necrosis factor receptor-associated factor 6 (TRAF6) and the clinicopathological features in HCC as well as its biological function.

Methods

Totally, 412 liver tissues were collected, including 171 hepatocellular carcinoma (HCC) and their corresponding non-tumor tissues, 37 cirrhosis and 33 normal liver tissues. The expression of TRAF6 was assessed by immunohistochemistry. Then, analysis of the correlations between TRAF6 expression and clinicopathological parameters in HCC was conducted. Furtherer, in vitro experiments on HepG2 and Hep3B cells were performed to validate the biological function of TRAF6 on HCC cells. TRAF6 siRNA was transfected into HepG2 and Hep3B cell lines and TRAF6 expression was evaluated with RT-qPCR and western blot. The assays of cell viability, proliferation, apoptosis and caspase-3/7 activity were carried out to investigate the effects of TRAF6 on HCC cells with RNA interference. Cell viability was assessed with Cell Titer-Blue kit. Cell proliferation was tested with MTS kit. Cell apoptosis was checked through morphologic detection with fluorescence microscope, as well as caspase-3/7 activity was measured with fluorogenic substrate detection.

Results

The positive expression rate of TRAF6 protein was 49.7 % in HCC, significantly higher than that of normal liver (12.1 %), cirrhosis (21.6 %) and adjacent non-cancerous tissues (36.3 %, all P < 0.05). Upregulated TRAF6 was detected in groups with metastasis (Z = −2.058, P = 0.04) and with low micro-vessel density (MVD) expression (Z = −2.813, P = 0.005). Spearman correlation analysis further showed that the expression of TRAF6 was positively correlated with distant metastasis (r = 0.158, P = 0.039) and negatively associated with MVD (r = −0.249, P = 0.004). Besides, knock-down of TRAF6 mRNA in HCC cell lines HepG2 and Hep3B both resulted in cell viability and proliferation inhibition, also cell apoptosis induction and caspase-3/7 activity activation.

Conclusions

TRAF6 may contribute to metastasis and deterioration of the HCC via influencing cell growth and apoptosis. Thus, TRAF6 might become a predictive and therapeutic biomarker for HCC.

Thrombomodulin Influences the Survival of Patients with Non-Metastatic Colorectal Cancer through Epithelial-To-Mesenchymal Transition (EMT)

Background

Treatment resistance and metastasis are the major causes of death among patients with colorectal cancer (CRC). Approximately 20% of surgically treated patients ultimately develop metastases during the follow-up period. Currently, the TNM system is the only available prognostic test. Therefore, the identification of new markers for CRC remains important. Thrombomodulin (TM), a glycoprotein, is involved in angiogenesis and has been linked to many malignant diseases. However, the function of TM in CRC remains unclear.

Methods

A total of 170 patients with CRC participated in this study. TM expression was analyzed via immunohistochemistry. Univariate (Kaplan-Meier) analysis was used to analyze patient outcomes, including overall survival (OS) and disease-free survival (DFS). TM expression was manipulated using shRNA or an overexpression system. Transwell migration assays, wound healing migration assays, and the xCELLigence biosensor system were used to detect cell proliferative and migratory capacities.

Results

TM expression in the tumor tissues significantly and positively correlated with the DFS and OS of non-metastatic patients with CRC (ps = 0.036 and 0.0218, respectively). Suppression of TM expression increased the proliferation and migration of DLD-1 cells. TM overexpression reduced the cells’ proliferative and migratory capacities. Cyclooxygenase (COX)-2 expression was up-regulated following TM silencing. Furthermore, the association between the migration of colon cancer cells and the levels of TM and epithelial-to-mesenchymal transition (EMT) markers (fibronectin, vimentin and ezrin) was confirmed in HT29 and DLD-1 cells.

Conclusions

Our study demonstrates that patients with non-metastatic CRC display low TM expression in their tumors and exhibit reduced DFS and OS. The enhanced expression of mesenchymal markers and COX-2 may be involved in the mechanisms that underlie recurrence in patients with cancer displaying low TM expression.

TNF-α stimulates colonic myofibroblast migration via COX-2 and Hsp27

BACKROUND

Crohn's disease (CD) is a chronic inflammatory enteropathy characterized by fibrotic strictures. Myofibroblasts (MFBs) are stromal cells of the gastrointestinal tract found in increased numbers in patients with CD and represent the key effector cells involved in pathologic fibrosis. MFB is a known target of tumor necrosis factor alpha (TNF-α), a proinflammatory cytokine strongly implicated in the pathophysiology of CD. However, the precise mechanisms through which TNF-α contributes to fibrosis remain incompletely understood. Here, we demonstrate for the first time that TNF-α increases MFB migration through the cyclooxygenase 2 (COX-2) and heat-shock protein 27 (Hsp27) pathways.

MATERIALS AND METHODS

The human colonic MFB cell line 18Co was grown to confluence on 35 × 10 mm cell culture dishes and used from passages 8-14. An in vitro scratch assay assessed the effect of TNF-α (10 ng/mL) on MFB migration over 24 h in the presence or absence of several inhibitors (NS398, SB203580, Hsp27 siRNA).

RESULTS

TNF-α significantly increased MFB migration over 24 h. TNF-α also led to the increased expression of COX-2 and stimulated rapid phosphorylation of Hsp27 at serine 82. TNF-α-induced COX-2 expression, Hsp27 phosphorylation, and MFB migration were all significantly inhibited by the P38 MAPK inhibitor SB203580 (P < 0.05). TNF-α-induced MFB migration was also significantly inhibited by NS398 (P < 0.05), a direct inhibitor of COX-2, and by siRNA targeting Hsp27 (P < 0.05).

CONCLUSIONS

TNF-α stimulates colonic MFB migration through P38 MAPK-mediated activation of COX-2 and Hsp27. Further elucidating these inflammatory signaling pathways may lead to novel therapeutic targets for the treatment of CD-related fibrosis and strictures.

Transcriptome profiling and pathway analysis of hepatotoxicity induced by tris (2-ethylhexyl) trimellitate (TOTM) in mice

Tris (2-ethylhexyl) trimellitate (TOTM) is commonly used as an alternative plasticizer for medical devices. But very little information was available on its biological effects. In this study, we investigated toxicity effects of TOTM on hepatic differential gene expression analyzed by using high-throughput sequencing analysis for over-represented functions and phenotypically anchored to complementary histopathologic, and biochemical data in the liver of mice. Among 1668 candidate genes, 694 genes were up-regulated and 974 genes were down-regulated after TOTM exposure. Using Gene Ontology analysis, TOTM affected three processes: the cell cycle, metabolic process and oxidative activity. Furthermore, 11 key genes involved in the above processes were validated by real time PCR. Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis revealed that these genes were involved in the cell cycle pathway, lipid metabolism and oxidative process. It revealed the transcriptome gene expression response to TOTM exposure in mouse, and these data could contribute to provide a clearer understanding of the molecular mechanisms of TOTM-induced hepatotoxicity in human.

Glucose-regulated protein 94 mediates metastasis by CCT8 and the JNK pathway in hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is one of the leading causes of cancer death worldwide. Cancer metastasis is a major obstacle in clinical cancer therapy. The mechanisms underlying the metastasis of HCC remain unclear. Glucose-regulated protein 94 (GRP94) is a key protein involved in mediating cancer progression, and it is highly expressed in HCC specimens. However, the role of GRP94 in cancer metastasis is unclear. A specific short hairpin RNA (shRNA) was employed to knock down GRP94 gene expression in HCC cell lines. Wound-healing migration, transwell migration, and invasion assays were performed to determine the migration and invasive ability of HCC cells. We demonstrated that silencing GRP94 inhibited HCC cell wound healing, migration, and invasion. Furthermore, our findings indicated that GRP94 knockdown might attenuate HCC cell metastasis by inhibiting CCT8/c-Jun/EMT signaling. Our study indicated that silencing GRP94 significantly reduced the migration and invasion abilities of HCC cells. Moreover, depleting GRP94 inhibited cell migration and invasion by downregulating CCT8/c-Jun signaling. Thus, our data suggest that the GRP94/CCT8/c-Jun/EMT signaling cascade might be a new therapeutic target for HCC.