Overexpression of DcR3 and its significance on tumor cell differentiation and proliferation in glioma

A TRIM21-based bioPROTAC highlights the therapeutic benefit of HuR degradation

Human antigen R (HuR) is a ubiquitously expressed RNA-binding protein, which functions as an RNA regulator. Overexpression of HuR correlates with high grade tumours and poor patient prognosis, implicating it as an attractive therapeutic target. However, an effective small molecule antagonist to HuR for clinical use remains elusive. Here, a single domain antibody (VHH) that binds HuR with low nanomolar affinity was identified and shown to inhibit HuR binding to RNA. This VHH was used to engineer a TRIM21-based biological PROTAC (bioPROTAC) that could degrade endogenous HuR. Significantly, HuR degradation reverses the tumour-promoting properties of cancer cells in vivo by altering the HuR-regulated proteome, highlighting the benefit of HuR degradation and paving the way for the development of HuR-degrading therapeutics. These observations have broader implications for degrading intractable therapeutic targets, with bioPROTACs presenting a unique opportunity to explore targeted-protein degradation through a modular approach.

Cell and Tissue Nanomechanics: From Early Development to Carcinogenesis

Cell and tissue nanomechanics, being inspired by progress in high-resolution physical mapping, has recently burst into biomedical research, discovering not only new characteristics of normal and diseased tissues, but also unveiling previously unknown mechanisms of pathological processes. Some parallels can be drawn between early development and carcinogenesis. Early embryogenesis, up to the blastocyst stage, requires a soft microenvironment and internal mechanical signals induced by the contractility of the cortical actomyosin cytoskeleton, stimulating quick cell divisions. During further development from the blastocyst implantation to placenta formation, decidua stiffness is increased ten-fold when compared to non-pregnant endometrium. Organogenesis is mediated by mechanosignaling inspired by intercellular junction formation with the involvement of mechanotransduction from the extracellular matrix (ECM). Carcinogenesis dramatically changes the mechanical properties of cells and their microenvironment, generally reproducing the structural properties and molecular organization of embryonic tissues, but with a higher stiffness of the ECM and higher cellular softness and fluidity. These changes are associated with the complete rearrangement of the entire tissue skeleton involving the ECM, cytoskeleton, and the nuclear scaffold, all integrated with each other in a joint network. The important changes occur in the cancer stem-cell niche responsible for tumor promotion and metastatic growth. We expect that the promising concept based on the natural selection of cancer cells fixing the most invasive phenotypes and genotypes by reciprocal regulation through ECM-mediated nanomechanical feedback loop can be exploited to create new therapeutic strategies for cancer treatment.

Vascular Normalization: A New Window Opened for Cancer Therapies

Preclinical and clinical antiangiogenic approaches, with multiple side effects such as resistance, have not been proved to be very successful in treating tumor blood vessels which are important targets for tumor therapy. Meanwhile, restoring aberrant tumor blood vessels, known as tumor vascular normalization, has been shown not only capable of reducing tumor invasion and metastasis but also of enhancing the effectiveness of chemotherapy, radiation therapy, and immunotherapy. In addition to the introduction of such methods of promoting tumor vascular normalization such as maintaining the balance between proangiogenic and antiangiogenic factors and targeting endothelial cell metabolism, microRNAs, and the extracellular matrix, the latest molecular mechanisms and the potential connections between them were primarily explored. In particular, the immunotherapy-induced normalization of blood vessels further promotes infiltration of immune effector cells, which in turn improves immunotherapy, thus forming an enhanced loop. Thus, immunotherapy in combination with antiangiogenic agents is recommended. Finally, we introduce the imaging technologies and serum markers, which can be used to determine the window for tumor vascular normalization.

A review of gliomas-related proteins. Characteristics of potential biomarkers

Brain tumors are one of the most commonly diagnosed cancers of the central nervous system. Of all diagnosed malignant tumors, 80% are gliomas. An unequivocal diagnosis of gliomas is not always simple, and there is a great need for research to find new treatment options and diagnostic approaches. This paper is focused on the glioma-related protein profiles as compared to healthy brain tissue, which is reflected in multiple correlations between biological aspects that influence proliferation, apoptosis evasion and the invasiveness of neoplastic cells. The work presents the possibilities of facilitating clinical practice with proteomic biomarkers, which offer a wider diagnostic spectrum and reduce the margin of mistake in histopathological or imaging diagnostic methods. In fact, many changes in the body's homeostasis can be overlooked due to the lack of symptoms or their non-specificity. Nevertheless, a single marker has limited reliability in distinguishing a particular tumor subtype, since the increased or decreased level of the protein of interest may differ between the stages or locations of the tumor. Moreover, the correlations between proposed proteins - presented in this paper - may help clinicians to choose the most optimal therapy, and estimate its effectiveness, or indicate new therapeutic targets affecting disrupted biochemical pathways.

TNFSF14: LIGHTing the Way for Effective Cancer Immunotherapy

Tumor necrosis factor superfamily member 14 (LIGHT) has been in pre-clinical development for over a decade and shows promise as a modality of enhancing treatment approaches in the field of cancer immunotherapy. To date, LIGHT has been used to combat cancer in multiple tumor models where it can be combined with other immunotherapy modalities to clear established solid tumors as well as treat metastatic events. When LIGHT molecules are delivered to or expressed within tumors they cause significant changes in the tumor microenvironment that are primarily driven through vascular normalization and generation of tertiary lymphoid structures. These changes can synergize with methods that induce or support anti-tumor immune responses, such as checkpoint inhibitors and/or tumor vaccines, to greatly improve immunotherapeutic strategies against cancer. While investigators have utilized multiple vectors to LIGHT-up tumor tissues, there are still improvements needed and components to be found within a human tumor microenvironment that may impede translational efforts. This review addresses the current state of this field.

Clinical significance and effect of MTDH/AEG-1 in bladder urothelial cancer: a study based on immunohistochemistry, RNA-seq, and in vitro verification

Background

Overexpression of metadherin/astrocyte elevated gene-1 (MTDH/AEG-1) has been implicated in various cancers. However, the clinical significance and the potential biological functions of MTDH/AEG-1 in bladder urothelial carcinoma (BUC) are not established.

Methods

In this study, the expression of MTDH/AEG-1in BUC was measured using the Cancer Genome Atlas (TCGA) database and immunohistochemistry, together with a meta-analysis, to investigate the expression and diagnostic value of MTDH/AEG-1. The possible association between MTDH/AEG-1 expression and the viability, proliferation, and apoptosis in BUC cell lines (T24, HT1376, and RT4) was also assessed in vitro by viability, MTS, colony formation, and caspase-3/7 assays, as well as Hoechst 33342 and propidium iodide (PI) double staining.

Results

MTDH/AEG-1 expression was significantly higher in BUC tissues than in normal bladder tissues, according to the TCGA and immunohistochemistry results, and these findings were verified by the meta-analysis. Functional knockdown of MTDH/AEG-1 suppressed BUC cell growth and induced apoptosis. Bioinformatics analyses indicated an involvement of MTDH/AEG-1 in several processes, including RNA binding, protein transport, intracellular transport, and the insulin signaling pathway.

Conclusion

We hypothesize that MTDH/AEG-1 could play essential roles in BUC, especially in cell growth and apoptosis, via the insulin signaling pathway.”

GFAP expression is influenced by astrocytoma grade and rs2070935 polymorphism

Glial fibrillary acidic protein (GFAP) is an intermediate filament that provides mechanical support to astrocytes. Rs2070935 is a single nucleotide polymorphism (SNP) located in the promoter region of the GFAP gene. The aim of this pilot study is to investigate GFAP expression at mRNA, protein levels and rs2070935 polymorphism in 50 different grade human astrocytoma samples. GFAP expression at mRNA level was measured using quantitative reverse transcription polymerase chain reaction (qRT-PCR) with SYBR Green dye, whereas the translational activity of the following gene was detected using western blot assay. Furthermore, genotypes of rs2070935 were identified using qPCR with TaqMan probes. As a result, GFAP mRNA and protein expression was found to be declining with increasing astrocytoma grade (p < 0.05). A tendency was observed between increased GFAP mRNA expression and shorter grade IV astrocytoma patient survival (p = 0.2117). The rs2070935 CC genotype was found to be associated with increased GFAP translational activity in grade II astrocytoma (p = 0.0238). Possible links between rs2070935 genotypes and alternative splicing of GFAP were also observed. The rs2070935 AA genotype was found to be associated with poor clinical outcome for grade IV astrocytoma patients (p = 0.0007), although the following data should be checked in a larger sample size of astrocytoma patients.

DcR3 induces epithelial-mesenchymal transition through activation of the TGF-β3/SMAD signaling pathway in CRC

Decoy receptor 3 (DcR3), a novel member of the tumor necrosis factor receptor (TNFR) family, was recently reported to be associated with tumorigenesis and metastasis. However, the role of DcR3 in human colorectal cancer (CRC) has not been fully elucidated. In this study, we found that DcR3 expression was significantly higher in human colorectal cancer tissues than in paired normal tissues, and that DcR3 expression was strongly correlated with tumor invasion, lymph node metastases and poor prognoses. Moreover, DcR3 overexpression significantly enhanced CRC cell proliferation and migration in vitro and tumorigenesis in vivo. Conversely, DcR3 knockdown significantly repressed CRC cell proliferation and migration in vitro, and DcR3 deficiency also attenuated CRC tumorigenesis and metastasis in vivo. Functionally, DcR3 was essential for TGF-β3/SMAD-mediated epithelial-mesenchymal transition (EMT) of CRC cells. Importantly, cooperation between DcR3 and TGF-β3/SMAD-EMT signaling-related protein expression was correlated with survival and survival time in CRC patients. In conclusion, our results demonstrate that DcR3 may be a prognostic biomarker for CRC and that this receptor facilitates CRC development and metastasis by participating in TGF-β3/SMAD-mediated EMT of CRC cells.

Anti-apoptosis Effect of Decoy Receptor 3 in Cholangiocarcinoma Cell Line TFK-1

Background:

Decoy receptor 3 (DcR3) is a protein with anti-apoptotic effect that belongs to the tumor necrosis factor receptor superfamily. DcR3 is highly expressed in a variety of malignant tumors including cholangiocarcinoma and its expression was found to be related to the clinical stage, the invasion, and the metastasis of the tumor. This in vitro study aimed to investigate the effect of downregulated expression of DcR3 on cell viability, cell apoptosis, and cell cycle in cholangiocarcinoma cell line TFK-1.

Methods:

Three different cell lines were cultured: human cholangiocarcinoma TFK-1, human biliary epithelial carcinoma HuCCT-1, and human cholangiocarcinoma RBE. The cholangiocarcinoma cell line with the highest expression of DcR3 was selected for further investigation. The expression of DcR3 was silenced/knocked down by transfection with DcR3-siRNA in the selected cell line. Various biological phenotype parameters such as cell viability, apoptosis, and cell cycle were observed.

Results:

The mRNA and protein levels of DcR3 were measured in the three cell lines, and TFK-1 was selected. After the treatment with DcR3-siRNA for 48 h, DcR3 mRNA and protein expression in the treatment group were 38.45% (P < 0.01) and 48.03% (P < 0.05) of that of the control, respectively. It was found that the cell viability decreased to 61.87% of the control group (P < 0.01) after the downregulation of DcR3 in cholangiocarcinoma cell line TFK-1 by transfection with DcR3-siRNA, while the percentage of apoptotic cells was 2.98 times as compared with the control group (P < 0.05). Compared with the control group the ratio of G₀/G₁ increased, and the ratio of G₂/M decreased in the treatment group. However, the differences were not statistically significant.

Conclusions:

The effect of DcR3 on the growth and apoptosis of cholangiocarcinoma has been demonstrated. DcR3 is not only a predictive marker for malignant tumor but it is also likely to be a potential target for cancer gene therapy. Further studies should focus on exploring the binding ligand of DcR3, the signaling pathway involved, and the molecular mechanism for the regulation of DcR3 expression in cholangiocarcinoma.

Decoy receptor 3: an endogenous immunomodulator in cancer growth and inflammatory reactions

Decoy receptor 3 (DcR3), also known as tumor necrosis factor receptor (TNFR) superfamily member 6b (TNFRSF6B), is a soluble decoy receptor which can neutralize the biological functions of three members of tumor necrosis factor superfamily (TNFSF): Fas ligand (FasL), LIGHT, and TL1A. In addition to ‘decoy’ function, recombinant DcR3.Fc is able to modulate the activation and differentiation of dendritic cells (DCs) and macrophages via ‘non-decoy’ action. DcR3-treated DCs skew T cell differentiation into Th2 phenotype, while DcR3-treated macrophages behave M2 phenotype. DcR3 is upregulated in various cancer cells and several inflammatory tissues, and is regarded as a potential biomarker to predict inflammatory disease progression and cancer metastasis. However, whether DcR3 is a pathogenic factor or a suppressor to attenuate inflammatory reactions, has not been discussed comprehensively yet. Because mouse genome does not have DcR3, it is not feasible to investigate its physiological functions by gene-knockout approach. However, DcR3-mediated effects in vitro are determined via overexpressing DcR3 or addition of recombinant DcR3.Fc fusion protein. Moreover, CD68-driven DcR3 transgenic mice are used to investigate DcR3-mediated systemic effects in vivo. Upregulation of DcR3 during inflammatory reactions exerts negative-feedback to suppress inflammation, while tumor cells hijack DcR3 to prevent apoptosis and promote tumor growth and invasion. Thus, ‘switch-on’ of DcR3 expression may be feasible for the treatment of inflammatory diseases and enhance tissue repairing, while ‘switch-off’ of DcR3 expression can enhance tumor apoptosis and suppress tumor growth in vivo.

Effect of DcR3-specific siRNA on cell growth suppression and apoptosis induction in glioma cells via affecting ERK and AKT

BACKGROUND

Previously, we found that the expression of decoy receptor 3 (DcR3) in gliomas was significantly upregulated compared to normal brain tissues. However, the effect of DcR3-specific small interfering RNA (siRNA) on cell biological function of glioma cells remains incompletely understood.

OBJECTIVE

The aim of this study was to explore the effect of DcR3 siRNA on cell growth and apoptosis of glioma cells and to investigate the potential downstream pathways affected by DcR3.

METHODS

DcR3-specific siRNA was transfected into three glioma cell lines (U251MG, LN-308, and U87MG) using combiMAGnetofection method. MTS tetrazolium assay and fluorimetric resorufin viability assay were used to assess the growth of glioma cells. Then, apoptosis was examined using the Hoechst 33342/propidium iodide double-staining assay and fluorescent caspase-3/7 assay. Meanwhile, Western blot was performed to explore the probable pathway by which DcR3-specific siRNA acts in glioma cells. Also, microarray dataset analysis was applied to analyze the potential function of DcR3 in glioma.

RESULTS

The DcR3-specific siRNA had a potent effect on cell growth and apoptosis of all three glioma cells tested, and the effects were time dependent. Among these three glioma cell lines, U251MG had the most significant effect with regard to growth inhibition and apoptosis induction. MTS assay showed that the proliferation rate at 72 and 96 hours after the transfection was 76.333%±5.131% (t=7.611, P=0.002) and 64.333%±5.859% (t=10.983, P<0.001), respectively. The viability rate of U251MG cells was 80.667%±2.309% (t=12.302, P<0.001) and 62.333%±2.082% (t=21.213, P<0.001) at 72 and 96 hours posttreatment, respectively. The caspase-3/7 activity of U251MG cells was 2.76 (t=-6.601, P=0.003) and 4.75 (t=-9.189, P=0.001) folds that of the mock control at 72 and 96 hours, respectively. The apoptosis rate was increased to 1.85 (t=-2.496, P=0.067) and 3.93 (t=-12.587, P<0.001) folds at 72 and 96 hours after transfection, respectively. Furthermore, the levels of phospho-ERK1/2 and phospho-AKT were significantly downregulated after DcR3 silencing.

CONCLUSION

The DcR3-specific siRNA could efficiently inhibit growth and induce apoptosis of cells via affecting ERK and AKT. Hence, DcR3-specific siRNA treatment could act as a supplementary targeted therapy strategy for gliomas.

Expression and clinicopathological implication of DcR3 in lung cancer tissues: a tissue microarray study with 365 cases

BACKGROUND

Decoy receptor 3 (DcR3) has been reported to be involved in different cancers. However, few related researches have been accomplished on the role of DcR3 in lung cancer.

OBJECTIVE

To explore the expression level and clinicopathological implication of DcR3 protein in lung cancer tissues.

MATERIALS AND METHODS

Immunohistochemistry was used to examine DcR3 protein expression in lung cancer (n=365) and normal lung tissues (n=26). The relationships between DcR3 expression and clinical parameters were further investigated. Furthermore, the diagnostic and clinicopathological value of DcR3 mRNA was analyzed based on The Cancer Genome Atlas database in lung cancer patients.

RESULTS

Compared to normal lung tissues, DcR3 expression was significantly higher in lung cancer (P=0.007) tissues, including small-cell lung cancer (P=0.001) and non-small-cell lung cancer (P=0.008). In addition, DcR3 expression was related to tumor-node-metastasis (TNM) stage (P<0.001), tumor diameter (P=0.007), distant metastasis (P<0.001), and lymph node metastasis (P<0.001) in lung cancers. When concerning non-small-cell lung cancer, consistent correlations between DcR3 expression and TNM stage (P<0.001), tumor diameter (P=0.019), distant metastasis (P<0.001), and lymph node metastasis (P<0.001) were found. Simultaneously, in small-cell lung cancer, TNM stage (P=0.004) and lymph node metastasis (P=0.005) were also associated with DcR3 expression. Additionally, receiver operator characteristic curve revealed that the area under curve (AUC) of DcR3 was 0.637 (95% confidence interval [CI] 0.531-0.742) for lung cancer. Furthermore, DcR3 was overexpressed in both adenocarcinoma and squamous cell carcinoma tissues than in noncancerous lung tissues (all P<0.0001) based on the data from The Cancer Genome Atlas. AUC of DcR3 was 0.726 (95% CI 0.644-0.788) for lung adenocarcinoma patients and 0.647 (95% CI 0.566-0.728) for squamous cell carcinoma patients. DcR3 expression was also related to the overall survival (P<0.001) and disease-free survival (P<0.001) of lung adenocarcinoma according to the data from The Cancer Genome Atlas.

CONCLUSION

Our study confirms that DcR3 might be involved in the tumorigenesis and deterioration of lung cancer. Therefore, the detection of DcR3 gains the potential to be applied in the clinic for screening and progression prediction of lung cancer.

Decoy Receptor 3 (DcR3) as a Biomarker of Tumor Deterioration in Female Reproductive Cancers: A Meta-Analysis

Background

DcR3 (decoy receptor 3) has been proposed be involved in development and prognosis of female reproductive cancers, including cervical cancer, ovarian cancer, and breast cancer. The purpose of this meta-analysis was to explore the evidence for the correlation between DcR3 and the clinicopathological characteristics, as well as the overall survival time, in female reproductive cancers.

Material/Methods

Relevant studies were searched for in PubMed, Wiley Online Library, Web of Science, Science Direct, Cochrane Central Register of Controlled Trials, Google Scholar, EMBASE, Ovid, LILACS, Chinese CNKI, Chong Qing VIP, Wan Fang, and China Biology Medicine disc up to 30 September 2015. Data on the relationship between DcR3 expression and TNM stage, differentiation, lymph node metastasis, age, and overall survival time were extracted. Pooled odds ratios (ORs) and 95% CIs (confidence intervals) were estimated by forest plot.

Results

Twelve studies with 1127 patients met the inclusion criteria for this meta-analysis. Overexpression of DcR3 was significantly related to the risk of female reproductive cancers (OR=10.69, 95% CI: 6.33–18.05), TNM stage (OR=5.51, 95% CI: 2.83–10.71), differentiation (OR=4.16, 95% CI: 2.28–7.60), lymph node metastasis (OR=5.89, 95% CI: 3.16–10.9), age (OR=0.85, 95% CI: 0.51–1.44), and overall survival time (OR=1.84, 95% CI: 0.58–5.83). Subgroup analyses showed that overexpression of DcR3 in cervical, ovarian, and breast cancer all had similar relationships with these clinicopathological parameters.

Conclusions

Our meta-analysis suggests that overexpression of DcR3 may play vital roles in the tumorigenesis and deterioration of female reproductive cancers. However, the relationship between DcR3 expression and prognosis needs further investigation.

Insights into the clinical value of cyclin-dependent kinase 5 in glioma: a retrospective study

Background

Previous studies suggested that expression of cyclin-dependent kinase 5 (CDK5) may promote the migration and invasion of human glioma cells. In this study, we aimed to evaluate the clinical value of CDK5 in different grades of glioma in relation to Ki-67 labeling index (LI).

Methods

We firstly assessed by immunohistochemistry the expression of CDK5 in 152 glioma tissues and 16 normal brain tissues and further explored the relationship between CDK5 expression and other clinical features.

Results

The positive ratio of CDK5 in gliomas (57.2 %) was higher than that in normal brain tissues (12.5 %, P = 0.001). Difference of CDK5 expression among four World Health Organization (WHO) grades was statistically significant (P = 0.001). The significant differences of CDK5 expression were also observed between WHO I glioma (34.8 %) and WHO III glioma (62.5 %), as well as WHO IV glioma (82.8 %; P = 0.026, P < 0.001, respectively). Furthermore, Spearman’s rank correlation confirmed that CDK5 was positively correlated with the pathological grade of glioma (r = 0.831, P < 0.001). The CDK5 expression was also positively correlated with Ki-67 LI (r = 0.347, P < 0.001).

Conclusions

The current result suggests that CDK5 may play an essential role in the tumorigenesis and aggressiveness of gliomas.

Aberrant expression of CDK5 infers poor outcomes for nasopharyngeal carcinoma patients

PURPOSE

Aberrant expression of CDK5 involved in epithelial-to-mesenchymal transition had been reported in various types of cancers, but its functions in nasopharyngeal carcinoma have not been fully clarified yet. The principal purpose of this research was to investigate the clinicopathological significance of CDK5 and its potential effect on NPC carcinogenesis.

METHODS

Pre-treated formalin-fixed paraffin-embedded biopsy samples of 393 patients between January 2011 and December 2013 were collected for tissue microarrays (TMAs). Immunohistochemistry was performed on sequential TMA sections stained with antibodies against CDK5, EGFR and P53.

RESULTS

The expression of CDK5 in NPC tissues was significantly higher than that in normal nasopharyngeal tissues. Among squamous carcinomas, the expression of CDK5 in undifferentiated tissues was noticeably increased compared with that in differentiated tissues. NPC patients in advanced T category showed a perceptibly higher level of CDK5 than those in early T category. The relative level of CDK5 in NPC sufferers with lymph node metastasis was obviously higher than that of patients without. Compared with patients in early TNM stages, the relative expression level of CDK5 of those in advanced TNM stages was notably up-regulated. Moreover, the CDK5 expression was positively correlated with EGFR and P53 expression. Nevertheless, no significant association was observed between CDK5 and gender, age or histological type.

CONCLUSION

Overexpression of CDK5 might be considered as a warning signal for NPC. Consequently, CDK5 could serve as a potential target for diagnosis and gene therapy for NPC patients.