TRAF4 Regulates Migration, Invasion, and Epithelial-Mesenchymal Transition via PI3K/AKT Signaling in Hepatocellular Carcinoma

Primary Glial Cell and Glioblastoma Morphology in Cocultures Depends on Scaffold Design and Hydrogel Composition

3D cell cultures better replicate the in vivo environment compared to 2D models. Glioblastoma multiforme, a malignant brain tumor, highly profits from its cellular environment. Here, the U87 glioblastoma cell line in the presence/absence of primary astrocytes is studied. Thiolated hyaluronic acid (HA-SH) hydrogel reinforced with microfiber scaffolds is compared to Matrigel. Hyaluronic acid is a major extracellular matrix (ECM) component in the brain. Poly(ɛ-caprolactone) (PCL) scaffolds are written by meltelectrowriting in a box and triangular shaped design with pore sizes of 200 µm. Scaffolds are composed of 10-layers of PCL microfibers. It is found that scaffold design has an impact on cellular morphology in the absence of hydrogel. Moreover, the used hydrogels have profound influences on cellular morphology resulting in spheroid formation in HA-SH for both the tumor-derived cell line and astrocytes, while cell viability is high. Although cocultures of U87 and astrocytes exhibit cell-cell interactions, polynucleated spheroid formation is still present for U87 cells in HA-SH. Locally restricted ECM production or inability to secrete ECM proteins may underlie the observed cell morphologies. Thus, the 3D reinforced PCL-HA-SH composite with glioma-like cells and astrocytes constitutes a reproducible system to further investigate the impact of hydrogel modifications on cellular behavior and development.

TRAF Family Member 4 Promotes Cardiac Hypertrophy Through the Activation of the AKT Pathway

Background Pathological cardiac hypertrophy is a major cause of heart failure morbidity. The complex mechanism of intermolecular interactions underlying the pathogenesis of cardiac hypertrophy has led to a lack of development and application of therapeutic methods. Methods and Results Our study provides the first evidence that TRAF4, a member of the tumor necrosis factor receptor-associated factor (TRAF) family, acts as a promoter of cardiac hypertrophy. Here, Western blotting assays demonstrated that TRAF4 is upregulated in cardiac hypertrophy. Additionally, TRAF4 deletion inhibits the development of cardiac hypertrophy in a mouse model after transverse aortic constriction surgery, whereas its overexpression promotes phenylephrine stimulation-induced cardiomyocyte hypertrophy in primary neonatal rat cardiomyocytes. Mechanistically, RNA-seq analysis revealed that TRAF4 promoted the activation of the protein kinase B pathway during cardiac hypertrophy. Moreover, we found that inhibition of protein kinase B phosphorylation rescued the aggravated cardiomyocyte hypertrophic phenotypes caused by TRAF4 overexpression in phenylephrine-treated neonatal rat cardiomyocytes, suggesting that TRAF4 may regulate cardiac hypertrophy in a protein kinase B-dependent manner. Conclusions Our results revealed the regulatory function of TRAF4 in cardiac hypertrophy, which may provide new insights into developing therapeutic and preventive targets for this disease.

SRC-3/TRAF4 facilitates ovarian cancer development by activating the PI3K/AKT signaling pathway

OBJECTIVE

Ovarian cancer is the seventh most common cancer in women, and it causes many deaths in women worldwide. Patients with ovarian cancer have a poor prognosis and low survival rate. This study aimed to explore the role of the SRC-3/TRAF4/PI3K/AKT pathway in ovarian cancer development.

METHODS

SRC-3 and TRAF4 expression in ovarian cancer cell lines were assessed using qRT-PCR and western-blotting. The expression of SRC-3 and TRAF4 in ovarian cancer cells was downregulated by transient transfection with sh-RNAs. An MTT assay was performed to evaluate cell proliferation. Cell migration and invasion were measured using a Transwell assay. Cell stemness was detected using a cell spheroidization assay and western blotting. The expression levels of stem cell factors and PI3K/AKT pathway proteins were determined by qRT-PCR and western blot analysis.

RESULTS

SRC-3 and TRAF4 were upregulated in ovarian cancer cell lines. TRAF4 is a downstream factor of SRC-3, and the protein level of TRAF4 was regulated by SRC-3. SRC-3 knockdown reduced TRAF4 expression. Silencing SRC-3 or TRAF4 inhibited cell proliferation, migration, and invasion, as well as the expression of stem cell factors. Furthermore, sh-TRAF4 as well as treatment with LY294002, the PI3K/Akt inhibitor, inhibited the phosphorylation of Akt and PI3K, thus repressing the activation of PI3K/AKT signaling pathway in ovarian cancer cell lines. However, TRAF4 overexpression reversed the effect of SRC-3 silencing on cell proliferation, migration, invasion, and stemness.

CONCLUSION

Our study demonstrated that SRC-3/TRAF4 promotes ovarian cancer cell growth, migration, invasion, and stemness by activating the PI3K/AKT pathway.

TRAF4 Inhibits the Apoptosis and Promotes the Proliferation of Breast Cancer Cells by Inhibiting the Ubiquitination of Spindle Assembly-Associated Protein Eg5

Tumor necrosis factor receptor associated factor 4 (TRAF4) is a RING domain E3 ubiquitin ligase that mediates the ubiquitination of various proteins and plays an important role in driving tumor progression. By studying the relationship between TRAF4 and Eg5, a member of the kinesin family that plays a critical role in spindle assembly, we demonstrated that TRAF4 regulated Eg5 ubiquitination and contributed to Eg5-mediated breast cancer proliferation and inhibited breast cancer apoptosis. TRAF4 and Eg5 were both highly expressed in breast cancer and their protein level was positively correlated. Relying on its Zinc fingers domain, TRAF4 interacted with Eg5 in the cytoplasm of breast cancer cells. TRAF4 was a mitosis-related protein, and by up-regulating the protein level of Eg5 TRAF4 participated in spindle assembly. Loss of TRAF4 resulted in monopolar spindles formation, but loss of function could be rescued by Eg5. Relying on its RING domain, TRAF4 up-regulated Eg5 protein levels by inhibition of Eg5 ubiquitination, thus stabilizing Eg5 protein level during mitosis. Furthermore, we found that Smurf2, a TRAF4-targeted ubiquitination substrate, mediated the regulation of Eg5 ubiquitination by TRAF4. TRAF4 inhibited the interaction between Smurf2 and Eg5, and down-regulated the protein level of Smurf2 by promoting its ubiquitination, thereby inhibited the Smurf2-catalyzed ubiquitination of Eg5 and up-regulated Eg5 protein levels. We also demonstrate that TRAF4 plays an important role in promoting cell proliferation and in inhibiting cell apoptosis induced by Eg5. In summary, our study suggests a new direction for investigating the role of TRAF4 in driving breast cancer progression.

Diagnosis and staging of HCV associated fibrosis, cirrhosis and hepatocellular carcinoma with target identification for miR-650, 552-3p, 676-3p, 512-5p and 147b

BACKGROUND: Chronic HCV infection progresses to fibrosis, cirrhosis and hepatocellular carcinoma (HCC). The latter represents the third most common cause for cancer mortality. Currently, there is no reliable non-invasive biomarker for diagnosis of HCV mediated disorders. OBJECTIVE: Profiling expression signature for circulatory miRNAs in the plasma of 167 Egyptian patients (40 healthy, 48 HCV fibrotic, 39 HCV cirrhotic and 40 HCV-HCC cases). METHODS: QRTPCR was used to quantify expression signature for circulatory miRNAs. RESULTS: MiR-676 and miR-650 were powerful in discriminating cirrhotic and late fibrosis from HCC. MiR-650 could distinguish mild (f0-f1) and advanced (f2-f3) fibrosis from HCC cases. MiR-650 and miR-147b could distinguish early fibrosis from healthy controls meanwhile miR-676 and miR-147b could effectively distinguish between mild chronic and (f1-f3) cases from healthy individuals. All studied miRNAs, except miR-512, can differentiate between (f0-f3) cases and healthy controls. Multivariate logistic regression revealed three potential miRNA panels for effective differentiation of HCC, cirrhotic and chronic liver cases. MiR-676-3p and miR-512-5p were significantly correlated in (f1-f3) fibrosis meanwhile miR-676 and miR-512 could differentiate between cirrhosis and (f0-f3) cases. Both miR-650 and miR-512-5p were positively correlated in the cirrhotic group and in (f0-f4) group. Putative targets for investigated miRNAs were also determined. CONCLUSIONS: Investigated miRNAs could assist in staging and diagnosis of HCV associated disorders.

Identification of Two Molecular Subtypes of Hepatocellular Carcinoma Based on Dysregulated Immune LncRNAs

Long non-coding RNAs (lncRNAs) as important regulators of gene expression also have critical functions in immune regulation. This study identified lncRNA modulators of immune-related pathways as biomarkers for hepatocellular carcinoma (HCC). The profile of lncRNA regulation in immune pathways in HCC was comprehensively mapped. To determine lncRNAs with immunomodulatory functions specific to HCC, the enrichment of lncRNAs in a collection of 17 immune functions was calculated applying gene set enrichment analysis (GSEA). Unsupervised clustering of samples were performed in the R package ConsensusClusterPlus to analyze subtype survival and immunological characteristics. The enrichment of 3,134 lncRNA–immune pathway pairs in both diseased and normal samples showed a total of 1,984 immunoregulatory functional lncRNAs specific to HCC only. In addition, 18 immune-related lncRNAs were disordered in HCC and were significantly associated with immune cell infiltration. Functional enrichment analysis indicated that the 18 dysregulated immune lncRNAs were enriched in cytokines, cytokine receptors, TGFb family members, TNF family members, and TNF family member receptor pathways. Two molecular subtypes of hepatocellular carcinoma were identified based on 18 dysregulated immune lncRNAs. Immunological profiling showed that subtype 1 samples with higher levels of cytokine response had a better survival, but subtype 2 samples with higher levels of tumor proliferation had poorer survival. This study identified 18 HCC-specific dysregulated immune lncRNAs and two HCC molecular subtypes with significant prognostic differences and immune characteristics. The current findings help understand the function of lncRNAs and promote the identification of immunotherapy targets.

Advance toward isolation, extraction, metabolism and health benefits of kaempferol, a major dietary flavonoid with future perspectives

As a major ubiquitous secondary metabolite, flavonoids are widely distributed in planta. Among flavonoids, kaempferol is a typical natural flavonol in diets and medicinal plants with myriad bioactivities, such as anti-inflammatory activity, anti-cancer activity, antioxidant activity, and anti-diabetic activity. However, the natural sources, absorption and metabolism as well as the bioactivities of kaempferol have not been reviewed comprehensively and systematically. This review highlights the latest research progress and the effect of kaempferol in the prevention and treatment of various chronic diseases, as well as its protective health effects, and provides a theoretical basis for future research to be used in nutraceuticals. Further, comparison of the different extraction and analytical methods are presented to highlight the most optimum for PG recovery and its detection in plasma and body fluids. Such review aims at improving the value-added applications of this unique dietary bioactive flavonoids at commercial scale and to provide a reference for its needed further development.

Long Non-coding RNA MAFG-AS1 Promotes Cell Proliferation, Migration, and EMT by miR-3196/STRN4 in Drug-Resistant Cells of Liver Cancer

Long non-coding RNAs (lncRNAs) have been shown to participate in the development and progression of several different types of cancer. Past studies indicated that lncRNA MAFG-antisense 1 (AS1) promotes colorectal cancer. However, the role of MAFG-AS1 in hepatocellular carcinoma (HCC) remains unclear. The aim of the present study is to examine the effect of lncRNA MAFG-AS1 on drug resistance HCC. The results indicated that MAFG-AS1 is upregulated in drug-resistant cells. Further, MAFG-AS1 promotes growth and migration of HCC by upregulating STRN4 through absorbing miR-3196. Thus, LncRNA MAFA-AS1 may become a novel target to treat HCC patients.

Longitudinal single-cell profiling reveals molecular heterogeneity and tumor-immune evolution in refractory mantle cell lymphoma

The mechanisms driving therapeutic resistance and poor outcomes of mantle cell lymphoma (MCL) are incompletely understood. We characterize the cellular and molecular heterogeneity within and across patients and delineate the dynamic evolution of tumor and immune cell compartments at single cell resolution in longitudinal specimens from ibrutinib-sensitive patients and non-responders. Temporal activation of multiple cancer hallmark pathways and acquisition of 17q are observed in a refractory MCL. Multi-platform validation is performed at genomic and cellular levels in PDX models and larger patient cohorts. We demonstrate that due to 17q gain, BIRC5/survivin expression is upregulated in resistant MCL tumor cells and targeting BIRC5 results in marked tumor inhibition in preclinical models. In addition, we discover notable differences in the tumor microenvironment including progressive dampening of CD8+ T cells and aberrant cell-to-cell communication networks in refractory MCLs. This study reveals diverse and dynamic tumor and immune programs underlying therapy resistance in MCL.

High expression of TRAF4 predicts poor prognosis in tamoxifen-treated breast cancer and promotes tamoxifen resistance

Tamoxifen is the main adjuvant endocrine therapeutic agent for patients with estrogen receptor positive breast cancer. However, the resistance to tamoxifen has become a serious clinical challenge and the underlying mechanisms are still poorly understood. TRAF4 is a member of tumor necrosis factor receptor-associated factor family and its role in tamoxifen resistance has not been found. In this study, we aimed to explore the roles of TRAF4 in tamoxifen-treated breast cancer and tamoxifen resistance. Through high-throughput sequencing and differential gene expression analyses, TRAF4 was identified as the research object in this study. The prognosis significance of TRAF4 was studied based on 155 tamoxifen-treated breast cancer patients obtained from Gene Expression Omnibus (GEO) database. We then investigated the TRAF4 expression level in tamoxifen-resistant and the tamoxifen-sensitive breast cancer cell lines with western blot and real-time quantitative PCR. The loss- and gain-of-function assay of TRAF4 in a tamoxifen-resistant cell line was evaluated using colony formation experiments and cell count kit-8 assay. We identified that TRAF4 was overexpressed in tamoxifen-resistant breast cancer cell line and TRAF4 overexpression was associated with worse overall survival (hazard ratio = 2.538, P = 0.017) and cancer-specific survival (hazard ratio = 2.713, P = 0.036) in tamoxifen-treated patients. Knockdown of TRAF4 reversed tamoxifen resistance, while overexpression of TRAF4 increased tamoxifen resistance, which confirmed the role of TRAF4 in tamoxifen resistance. Taken together, our study demonstrated that TRAF4 could be a novel prognostic biomarker for tamoxifen-treated breast cancer patients and a potential therapeutic target for tamoxifen resistance.

TRAF4/6 Is Needed for CD44 Cleavage and Migration via RAC1 Activation

The hyaluronan receptor CD44 can undergo proteolytic cleavage in two steps, leading to the release of its intracellular domain; this domain is translocated to the nucleus, where it affects the transcription of target genes. We report that CD44 cleavage in A549 lung cancer cells and other cells is promoted by transforming growth factor-beta (TGFβ) in a manner that is dependent on ubiquitin ligase tumor necrosis factor receptor-associated factor 4 or 6 (TRAF4 or TRAF6, respectively). Stem-like A549 cells grown in spheres displayed increased TRAF4-dependent expression of CD44 variant isoforms, CD44 cleavage, and hyaluronan synthesis. Mechanistically, TRAF4 activated the small GTPase RAC1. CD44-dependent migration of A549 cells was inhibited by siRNA-mediated knockdown of TRAF4, which was rescued by the transfection of a constitutively active RAC1 mutant. Our findings support the notion that TRAF4/6 mediates pro-tumorigenic effects of CD44, and suggests that inhibitors of CD44 signaling via TRAF4/6 and RAC1 may be beneficial in the treatment of tumor patients.

The role of circular RNAs in therapy resistance of patients with solid tumors

Circular RNAs (circRNAs) are a type of single-stranded RNA molecules forming a covalently closed, continuous structure, lacking 5'-3' polarity and polyadenylated tails. Recent advances in high-throughput sequencing technologies have revealed that these molecules are abundant, resistant to degradation and often expressed in a tissue- or developmental stage-specific manner. circRNAs are produced by back-splicing circularization of primary transcripts and exhibit a variety of functions, including regulation of transcription, translation and cellular localization. This review focuses on differentially expressed circRNAs conferring therapy resistance or sensitivity of solid tumors, such as carcinomas, sarcomas and lymphomas. Deregulated circRNAs can participate in the development of resistance to treatment by modulating regulatory pathways and cellular processes, including the mitogen-activated protein kinase pathway, epithelial-mesenchymal transition, apoptosis and autophagy.

Regulator combinations identify systemic sclerosis patients with more severe disease

Systemic sclerosis (SSc) is a heterogeneous autoimmune disorder that results in skin fibrosis, autoantibody production, and internal organ dysfunction. We previously identified 4 “intrinsic” subsets of SSc based upon skin gene expression that are found across organ systems. Gene expression regulators that underlie the SSc-intrinsic subsets, or are associated with clinical covariates, have not been systematically characterized. Here, we present a computational framework to calculate the activity scores of gene expression regulators and identify their associations with SSc clinical outcomes. We found that regulator activity scores can reproduce the intrinsic molecular subsets, with distinct sets of regulators identified for inflammatory, fibroproliferative, limited, and normal-like samples. Regulators most highly correlated with modified Rodnan skin score (MRSS) also varied by intrinsic subset. We identified subgroups of patients with fibroproliferative and inflammatory SSc with more severe pathophenotypes, such as higher MRSS and increased likelihood of interstitial lung disease (ILD). Using an independent cohort, we show that the group with more severe ILD was more likely to show forced vital capacity decline over a period of 36–54 months. Our results demonstrate an association among the activation of regulators, gene expression subsets, and clinical variables that can identify patients with SSc with more severe disease.

An association between the activation of regulators, gene expression subsets, and clinical variables identifies systemic sclerosis patients with more severe disease.

TRAF4 knockdown triggers synergistic lethality with simultaneous PARP1 inhibition in endometrial cancer

Endometrial cancer (EC) is one of the most common cancers among females worldwide. Advanced stage patients of EC have poor prognosis. Inevitable side effects and treatment tolerance of chemotherapy for EC remain to be addressed. Our results in this study showed that EC cells with higher tumor necrosis factor receptor-associated factor 4 (TRAF4) expression have lower sensitivity to poly ADP-ribose polymerase 1 (PARP1) inhibitors. Upon TRAF4 knockdown, the colony numbers of EC cells were markedly down-regulated, and the markers of DNA double-strand breakage were significantly up-regulated after the treatment of olaparib, a PARP1 inhibitor. TRAF4 knockdown reduced the phosphorylation of protein kinase B (Akt), promoted DNA double-strand breakage, and decreased levels of DNA repair related proteins, including phosphorylated-DNA-dependent protein kinase (p-DNA-PK) and RAD51 recombinase (RAD51). In addition, TRAF4's effect on the sensitivity of EC cells to olaparib was further found to be mainly mediated by Akt phosphorylation. Moreover, in vivo results showed that TRAF4 knockdown enhanced the sensitivity of EC to PARP1 inhibitors using a mouse xenograft model. Collectively, our data suggest that combined application of TRAF4 knockdown and PARP1 inhibition can be used as a promising strategy for synthetic lethality in EC treatment.

YY1-induced lncRNA ZFPM2-AS1 facilitates cell proliferation and invasion in small cell lung cancer via upregulating of TRAF4

Background

Newly identified lncRNA zinc finger protein, FOG family member 2 antisense RNA 1 (ZFPM2-AS1) is identified as an oncogenic gene. However, the role of ZFPM2-AS1 in small cell lung cancer (SCLC) is poorly comprehended.

Methods

The expression of genes in SCLC tissues and cells was measured by qRT-PCR. Colony formation, EdU, CCK-8, transwell and wound healing as well as in vivo assays revealed the function of ZFPM2-AS1 in SCLC. ChIP, luciferase reporter, RIP and RNA pull down assays demonstrated the binding relation among genes.

Results

ZFPM2-AS1 was significantly upregulated in SCLC tissues and cells. ZFPM2-AS1 deficiency attenuated SCLC cell proliferation, invasion and migration. In addition, ZFPM2-AS1 was transcriptionally activated by Yin Yang 1 (YY1) factor. Further, miR-3612 was confirmed as downstream miRNA of ZFPM2-AS1. Moreover, TNF receptor associated factor 4 (TRAF4) was the target gene of miR-3612 in SCLC. ZFPM2-AS1, miR-3612 and TRAF4 jointly constituted a competing endogenous RNA (ceRNA) network in SCLC. Finally, TRAF4 could countervail ZFPM2-AS1 downregulation-mediated function on SCLC cell proliferation and invasion in vitro and tumor growth in vivo.

Conclusion

Our study elucidated the oncogenic effect of ZFPM2-AS1 in SCLC progression, indicating it may be a therapeutic target for SCLC.

Bisdemethoxycurcumin Inhibits Hepatocellular Carcinoma Proliferation Through Akt Inactivation via CYLD-Mediated Deubiquitination

Background

Bisdemethoxycurcumin (BDMC), a stable bioactive ingredient in curcuminoids, is associated with various antitumor functions, such as proliferation inhibition, metastasis suppression and apoptosis induction, in many cancer types. However, the mechanism of BDMC in hepatocellular carcinoma (HCC) remains unclear.

Methods

We assessed the toxicity and the inhibitory effect of BDMC in the HepG2 cell line by using CCK-8 and colony formation assays. The regulatory effects of BDMC on Akt and MAPK signaling were investigated by Western blotting and immunoprecipitation.

Results

We found that the half-maximum inhibitory concentration (IC50) of BDMC after 48 hrs of treatment was 59.13 μM, and BDMC inhibited proliferation in a time- and dose-dependent manner in HepG2 cells. The inhibitory effect was caused by the inactivation of Akt signaling, but not Erk, Jnk or p38 signaling. In addition, the inactivation of Akt signaling was attributed to the inhibition of ubiquitination mediated by K63-Ub but not K48-Ub. Furthermore, we found that BDMC upregulated the expression of CYLD, leading to Akt deubiquitination and inactivation.

Conclusion

BDMC inhibited HCC cell proliferation, and that this effect was induced by Akt inactivation via CYLD-mediated deubiquitination.

Asparanin A from Asparagus officinalis L. Induces G0/G1 Cell Cycle Arrest and Apoptosis in Human Endometrial Carcinoma Ishikawa Cells via Mitochondrial and PI3K/AKT Signaling Pathways

Asparanin A (AA), a steroidal saponin from Asparagus officinalis L., has anticancer activity: however, its detailed molecular mechanisms in endometrial cancer (EC) have not been studied so far. We evaluated the anticancer activity and underlying mechanism of AA on EC cell line Ishikawa in vitro and in vivo. AA inhibited the Ishikawa cell proliferation and caused cell morphology alteration and cell cycle arrest in G0/G1 phase. Moreover, it could induce apoptosis through mitochondrial pathway, including the deregulation of Bak/Bcl-xl ratio which led to the generation of ROS, up-regulation of cytochrome c followed by decrease of Δψ_m, and activation of caspases, besides inhibition of the PI3K/AKT/mTOR pathway. In vivo data showed that administration of AA significantly inhibited the tumor tissue cell proliferation, reduced the tumor growth, and induced the apoptosis occurrence. AA can be a possible functional food ingredient to cure endometrial cancer followed by clinical trials.

Andrographolide Protects against HG-Induced Inflammation, Apoptosis, Migration, and Impairment of Angiogenesis via PI3K/AKT-eNOS Signalling in HUVECs

Andrographolide (Andr) is a major component isolated from the plant Andrographis paniculata. Inflammation, apoptosis, and impaired angiogenesis are implicated in the pathogenesis of high glucose (HG)-induced injury of vascular endotheliocytes. Our study is aimed at evaluating the effect of Andr on HG-induced HUVEC injury and the underlying mechanism. HUVECs were exposed to HG levels (33 mM) and treated with Andr (0, 12.5, 25, and 50 μM). Western blot analysis, real-time PCR, immunofluorescence staining, the scratch test, and the tube formation assay were performed to assess the effects of Andr. We discovered that Andr inhibited the inflammatory response (IL-1β, IL-6, and TNFα), decreased the apoptosis ratio and cell migration, and promoted tube formation in response to HG stimulation. Andr ameliorated the levels of phosphorylated PI3K (p-PI3K), phosphorylated AKT (p-AKT), and phosphorylated eNOS (p-eNOS). The expression of vascular endothelial growth factor (VEGF) protein, a vital factor in angiogenesis, was improved by Andr treatment under HG stimulation. LY294002 is a blocker of PI3K, MK-2206 2HCI (MK-2206) is a highly selective AKT inhibitor, and L-NAME is a suppressor of eNOS, all of which significantly reduce Andr-mediated protective effects in vitro. Hence, Andr may be involved in regulating HG-induced injury by activating PI3K/AKT-eNOS signalling in HUVECs.

Expression and Association of Tumor Necrosis Factor Receptor Associated Factor 4 (TRAF4) in Esophageal Squamous Cell Carcinoma

BACKGROUND At present, there is no effective targeted therapy for esophageal squamous cell carcinoma (ESCC), and it is urgent to find new targets for the treatment of ESCC. TRAF4 has been regarded as a cause of carcinogenesis due to overexpression in many cancer types and participation in multiple signaling pathways. However, there are few studies on TRAF4 in ESCC worldwide. Its expression in ESCC and whether it affects the prognosis of patients still remain unclear. MATERIAL AND METHODS We detected the expressions of TRAF4, ki-67, and p53 in 100 cases of ESCC and 80 cases of adjacent normal esophageal squamous epithelium tissues by immunohistochemical technique. We further explored the relationship between TRAF4 and ESCC and its prognosis through statistical analysis. RESULTS TRAF4 was highly expressed in ESCC tissues and was mainly expressed in the cytoplasm. Overexpression of TRAF4 in ESCC was also associated with high expression of ki-67 and p53 (P<0.05). We also found that patients with high expression of TRAF4 had significantly lower OS than in patients with low TRAF4 expression (P<0.05). Overexpression of TRAF4 was an independent risk factor affecting the prognosis of patients (P<0.05). CONCLUSIONS We found that TRAF4 was highly expressed in ESCC tissues and was mainly expressed in the cytoplasm of cancer cells. Overexpression of TRAF4 was an independent risk factor affecting the overall prognosis of patients. The results indicated that TRAF4 may become a new target for the treatment of ESCC in the future.

Circular RNA expression profiles of peripheral blood mononuclear cells in hepatocellular carcinoma patients by sequence analysis

Circular RNAs (circRNAs) are a large class of noncoding RNAs that have potential regulatory roles in disease pathogenesis and progression. Recently, circRNAs have been found to be expressed in hepatocellular carcinoma (HCC) tissues and involved in the development and metastasis of HCC. However, the significance of circRNAs in peripheral blood mononuclear cells (PBMCs) of HCC patients remains unclear. In this study, RNA sequencing analysis was performed to identify circRNAs from four HCC patients and three healthy controls to determine the expression pattern of circRNAs in the PBMCs and the circRNAs’ molecular regulatory networks in HCC pathogenesis. A total of 58 circRNAs were found to be significantly changed (≥2 or ≤0.5‐fold) in the PBMCs of HCC patients compared with those of the healthy cases. Six random representative circRNAs (three up‐ and three down‐regulated) were further validated by real‐time RT‐PCR in 72 samples of PBMCs from HCC patients and 30 control subjects. Chi‐square test indicated that one of the up‐regulated circRNA candidates—circ_0000798—was correlated with clinical variables. Highly expressed circ_0000798 was associated with poor overall survival of HCC patients. Receiver operating characteristic curve analysis further revealed that circ_0000798 was discriminating HCC patients from healthy controls. Finally, the predicted competing endogenous RNA network of circ_0000798 showed that it might act as a “sponge” of target microRNAs, that would subsequently regulate the expression of target genes in PBMCs. In summary, this is the first study to comprehensively identify dysregulated circRNAs in PBMCs of HCC patients, and its findings suggest that dysregulated circ_0000798 in PBMCs has potential as a convenient biomarker for diagnosing or prognosticating HCC.

Genetic Alterations of TRAF Proteins in Human Cancers

The tumor necrosis factor receptor (TNF-R)-associated factor (TRAF) family of cytoplasmic adaptor proteins regulate the signal transduction pathways of a variety of receptors, including the TNF-R superfamily, Toll-like receptors (TLRs), NOD-like receptors (NLRs), RIG-I-like receptors (RLRs), and cytokine receptors. TRAF-dependent signaling pathways participate in a diverse array of important cellular processes, including the survival, proliferation, differentiation, and activation of different cell types. Many of these TRAF-dependent signaling pathways have been implicated in cancer pathogenesis. Here we analyze the current evidence of genetic alterations of TRAF molecules available from The Cancer Genome Atlas (TCGA) and the Catalog of Somatic Mutations in Cancer (COSMIC) as well as the published literature, including copy number variations and mutation landscape of TRAFs in various human cancers. Such analyses reveal that both gain- and loss-of-function genetic alterations of different TRAF proteins are commonly present in a number of human cancers. These include pancreatic cancer, meningioma, breast cancer, prostate cancer, lung cancer, liver cancer, head and neck cancer, stomach cancer, colon cancer, bladder cancer, uterine cancer, melanoma, sarcoma, and B cell malignancies, among others. Furthermore, we summarize the key in vivo and in vitro evidence that demonstrates the causal roles of genetic alterations of TRAF proteins in tumorigenesis within different cell types and organs. Taken together, the information presented in this review provides a rationale for the development of therapeutic strategies to manipulate TRAF proteins or TRAF-dependent signaling pathways in different human cancers by precision medicine.

MiR-29a Inhibits Glioma Tumorigenesis through a Negative Feedback Loop of TRAF4/Akt Signaling

Background

MiR-29a is known as a repressor of human cancer. However, its relevance in glioma proliferation and invasion remains largely unknown. In this study, we aimed to investigate the function and mechanism of miR-29a in glioma tumorigenesis.

Methods

The expression of miR-29a was determined by using qRT-PCR. CCK-8, wound healing, and transwell invasion assays were carried out to analyze the effects of miR-29a in glioblastoma cells. qRT-PCR, luciferase reporter, and western blot experiments were done to validate the targeting of TRAF4/Akt pathway by miR-29a. The expression correlation between levels of TRAF4 and miR-29a was analyzed. Regulation of miR-29a expression by enhanced/reduced TRAF4/Akt expression was finally confirmed by qRT-PCR.

Results

MiR-29a was decreased in the glioma tissues, especially in those at higher grades. Following its mimic transfection, we validated that miR-29a inhibited cell proliferation, migration, and invasion. Consistently, miR-29a inhibition induced the opposite effects on cell proliferation, migration, and invasion. We confirmed TRAF4 as a direct target of miR-29a, which might mediate the Akt pathway activation. We showed a significantly negative expression correlation between TRAF4 and miR-29a in normal and glioma tissues. Finally we observed an upregulation of miR-29a in TRAF4/Akt activated cells.

Conclusion

MiR-29a is critical tumor suppressor for glioma tumorigenesis by forming a negative feedback loop of TRAF4/Akt signaling and represents a potent therapeutic candidate for treating gliomas.

Death receptor 6 promotes ovarian cancer cell migration through KIF11

The expression of death receptor 6 (DR6) is abnormal in some cancer types, but the function and underlying molecular mechanisms of DR6 in tumor progression are not yet clear. In the present study, our analysis of ovarian cancer RNA sequencing data from The Cancer Genome Atlas revealed that DR6 is upregulated in human ovarian cancer. We confirmed that the expression level of DR6 is upregulated in ovarian cancer tissues when compared with matched adjacent normal tissues. In addition, DR6 enhanced ovarian carcinoma cell migration ability, and decreased expression of DR6 inhibited the expression of matrix metalloprotease (MMP) 2 and MMP9, and increased the expression of E‐cadherin. Additionally, DR6 shRNA caused a significant decrease in phosphoinositide‐3‐kinase (PI3K), phospho (p) ‐AKT, p‐extracellular signal‐regulated kinase (ERK), and p‐mitogen‐activated protein kinase kinase expression in SKOV3 cells. These results suggested that DR6 can enhance ovarian carcinoma cell migration ability through the mitogen‐activated protein kinase/ERK and PI3K/AKT pathways. Notably, mass spectrometric analysis indicated that DR6 co‐purified with kinesin family member 11 (KIF11), and we verified the interaction between KIF11 and DR6 by co‐immunoprecipitation and glutathione S‐transferase pull‐down. Furthermore, we demonstrated that DR6 can bind tumor necrosis factor receptor‐associated factor 4 (TRAF4) with co‐immunoprecipitation. Overexpression of KIF11 or TRAF4 eliminated the suppression of carcinoma cell migration by DR6 knockdown. We also found that TRAF4 and KIF11 were upregulated in ovarian carcinomas and that their level of expression was positively correlated with that of DR6. The findings above suggest that DR6 may play a notable oncogenic role in ovarian malignancy by interacting with TRAF4 and KIF11, and that DR6 may be an effective therapeutic target in ovarian cancer.

The tumor suppressive miR-302c-3p inhibits migration and invasion of hepatocellular carcinoma cells by targeting TRAF4

MicroRNAs (miRNAs) have been recognized as key regulators of tumorigenesis and progression. Serum miR-302c-3p expression is prominently deregulated in HCV-related hepatocellular carcinoma (HCC). However, the expression of miR-302c-3p and its functional role in HBV-related HCC are rarely investigated. In this study, we found that the expression levels of miR-302c-3p were prominently down-regulated in HCC tissues compared to matched tumor-adjacent tissues. Moreover, miR-302c-3p under-expression was detected in HCC cell lines compared to a normal hepatic cell line LO2. Low miR-302c-3p expression was positively correlated with multiple tumor nodes, venous infiltration and advanced TNM tumor stage of HCC patients. Notably, our follow up data and TCGA data demonstrated that low miR-302c-3p expression predicted a poor survival of HCC patients. Functionally, miR-302c-3p overexpression inhibited migration and invasion of MHCC97H cells in vitro. Additionally, miR-302c-3p knockdown showed an opposite effect on these metastatic behaviors of HepG2 cells. MiR-302c-3p negatively regulated tumor necrosis factor receptor associated factor 4 (TRAF4) abundance by directly targeting 3'-UTR of TRAF4 mRNA. The expression of TRAF4 was up-regulated in HCC tissues. The level of TRAF4 mRNA was inversely correlated with miR-302c-3p expression in HCC specimens. Mechanistically, miR-302c-3p restrained AKT-mediated epithelial-mesenchymal transition (EMT) in HCC cells. Importantly, TRAF4 restoration reversed the inhibitory effect of miR-302c-3p on AKT-induced EMT and HCC cell metastasis. MK2206, an AKT inhibitor, inhibited miR-302c-3p knockdown-induced EMT in HepG2 cells. In summary, these results indicate that miR-302c-3p exhibits a tumor suppressive role in HCC by targeting TRAF4. Inhibition of miR-302c-3p/TRAF4 axis may serve as a therapeutic target for HCC.

FoxM1 drives ADAM17/EGFR activation loop to promote mesenchymal transition in glioblastoma

Mesenchymal transition (MES transition) is a hallmark of glioblastoma multiforme (GBM), however, the mechanism regulating the process remains to be elucidated. Here we report that FoxM1 drives ADAM17/EGFR activation loop to promote MES transition in GBM. Firstly, FoxM1 expression was positively associated with ADAM17 expression, and their expression was correlated with the mesenchymal features and overall patient survival of GBM. Overexpressing FoxM1 or ADAM17 increased the mesenchymal phenotype of glioma cells, which could be reversed by silencing FoxM1 or ADAM17. Importantly, FoxM1 bound to the ADAM17 promoter to transcriptionally upregulate its expression. Using gain- and loss-of-function studies, we showed that FoxM1/ADAM17 axis promoted the MES transition in glioma cells. Moreover, tissue microarray analysis and orthotopic xenograft model further confirmed that FoxM1/ADAM17 axis played key roles in malignancy of GBM. Mechanistically, FoxM1/ADAM17 axis activated the EGFR/AKT/GSK3β signaling pathway and ADAM17/EGFR/GSK3β axis could maintain FoxM1 stability in glioma cells. Taken together, our study demonstrated that FoxM1/ADAM17 feedback loop controlled the MES transition and regulated the progression of GBM, raising the possibility that deregulation of this loop might improve the durability of therapies in GBM.

Role of the overexpression of TRAF4 in predicting the prognosis of intrahepatic cholangiocarcinoma

The incidence of intrahepatic cholangiocarcinoma (ICC) is progressively increasing worldwide, and its prognosis remains poor. Accumulating evidence has demonstrated that tumor necrosis factor receptor-associated factor 4 (TRAF4), an adaptor protein, is involved in the carcinogenesis and progression of several tumor types. However, the function of TRAF4 in predicting prognosis, and mediating migration and invasion of ICC remains to be elucidated. In the present study, immunohistochemistry, western blotting and reverse transcription-quantitative polymerase chain reaction assays were used to determine that the expression of TRAF4 at the mRNA and protein levels in ICC tissues was significantly higher compared with that in non‑tumor tissues. The overexpression of TRAF4 was positively correlated with poor differentiation, regional lymphatic metastasis, and high tumor‑node-metastasis staging. Inhibiting the expression of TRAF4 using small interfering RNA decreased the migration and invasion of ICC cells in vitro. In addition, the AKT inhibitor perifosine eliminated the effect of TRAF4 on the invasion and migration of ICC cells in vitro. Clinically, the overexpression of TRAF4 was correlated with shorter overall survival rate and elevated recurrence rate in patients with ICC. Furthermore, patients with ICC with a high expression of TRAF4 and lymphatic metastasis were closely associated with a poorer prognosis compared with the other groups. Multivariate analysis indicated that the overexpression of TRAF4 was an independent prognostic indicator for patients with ICC. It was identified that a high level of TRAF4 facilitated the invasiveness of ICC cells via the activation of AKT signaling. The overexpression of TRAF4 may be a prognostic biomarker and candidate therapeutic target for patients with ICC.

LncRNA NR2F1-AS1 regulates hepatocellular carcinoma oxaliplatin resistance by targeting ABCC1 via miR-363

Emerging evidence has validated the vital role of long non‐coding RNA (lncRNA) in the chemoresistance of cancer treatment. In the present study, we investigate the function of lncRNA NR2F1‐AS1 on oxaliplatin (OXA) resistance of hepatocellular carcinoma (HCC) and discover the underlying molecular mechanism. Results revealed that lncRNA NR2F1‐AS1 was up‐regulated in oxaliplatin‐resistant HCC tissue and cells using microarray analysis and RT‐PCR. Meanwhile, ABCC1 protein was overexpressed in OXA‐resistant HCC cells (Huh7/OXA and HepG2/OXA). In vitro, NR2F1‐AS1 knockdown reduced the invasion, migration, drug‐resistant gene (MDR1, MRP5, LRP1) and IC50 value in Huh7/OXA and HepG2/OXA cells. In vivo, NR2F1‐AS1 knockdown decreased the tumour weight of HCC cells. Bioinformatics tools and luciferase reporter assay confirmed miR‐363 targeted the 3′‐UTR of NR2F1‐AS1 and ABCC1 mRNA, presenting that NR2F1‐AS1 promoted ABCC1 expression through endogenous sponging miR‐363. In summary, results conclude that NR2F1‐AS1 regulates HCC OXA resistance through targeting miR‐363‐ABCC1 pathway, providing a vital theoretic mechanism and therapeutic target for HCC chemoresistance.

PIWIL3/OIP5-AS1/miR-367-3p/CEBPA feedback loop regulates the biological behavior of glioma cells

Rationale: PIWI-interacting RNAs (piRNAs), a class of newly discovered small RNA molecules that function by binding to the Argonaute protein family (i.e., the PIWIL protein subfamily), and long noncoding RNAs (lncRNA) are implicated in several cancers. However, the detailed roles of ncRNAs in glioma remain unclear.

Methods: The expression of PIWIL3, piR-30188, OIP5-AS1, miR-367, CEBPA and TRAF4 were measured in glioma tissues and cells. The role of PIWIL3/OIP5-AS1/miR-367-3p/CEBPA feedback loop was evaluated in cell and animal models. The association of the above molecules was analyzed.

Results: Over-expression of PIWIL3, piR-30188 and miR-367-3p or knockdown of OIP5-AS1 resulted in inhibition of glioma cells progression. Binding sites between piR-30188 and OIP5-AS1 as well as between OIP5-AS1 and miR-367-3p were confirmed by RNA immunoprecipitation and luciferase assays. OIP5-AS1 knockdown or miR-367-3p over-expression contributed to a decrease in CEBPA (CCAAT/enhancer binding protein alpha) protein. Furthermore, CEBPA was detected as a target of miR-367-3p and played an oncogenic role in glioma. Treatment with CEBPA and miR-367-3p resulted in the modulation of downstream TRAF4 (TNF receptor-associated factor 4). PIWIL3 was also a target of CEBPA, forming a positive feedback loop in the growth regulation of glioma cells. Significantly, knockdown of OIP5-AS1 combined with over-expression of PIWIL3 and miR-367-3p resulted in tumor regression and extended survival in vivo.

Conclusion: These results identified a novel molecular pathway in glioma cells that may provide a potential innovative approach for tumor therapy.

Genetic Alterations of TRAF Proteins in Human Cancers

The tumor necrosis factor receptor (TNF-R)-associated factor (TRAF) family of cytoplasmic adaptor proteins regulate the signal transduction pathways of a variety of receptors, including the TNF-R superfamily, Toll-like receptors (TLRs), NOD-like receptors (NLRs), RIG-I-like receptors (RLRs), and cytokine receptors. TRAF-dependent signaling pathways participate in a diverse array of important cellular processes, including the survival, proliferation, differentiation, and activation of different cell types. Many of these TRAF-dependent signaling pathways have been implicated in cancer pathogenesis. Here we analyze the current evidence of genetic alterations of TRAF molecules available from The Cancer Genome Atlas (TCGA) and the Catalog of Somatic Mutations in Cancer (COSMIC) as well as the published literature, including copy number variations and mutation landscape of TRAFs in various human cancers. Such analyses reveal that both gain- and loss-of-function genetic alterations of different TRAF proteins are commonly present in a number of human cancers. These include pancreatic cancer, meningioma, breast cancer, prostate cancer, lung cancer, liver cancer, head and neck cancer, stomach cancer, colon cancer, bladder cancer, uterine cancer, melanoma, sarcoma, and B cell malignancies, among others. Furthermore, we summarize the key in vivo and in vitro evidence that demonstrates the causal roles of genetic alterations of TRAF proteins in tumorigenesis within different cell types and organs. Taken together, the information presented in this review provides a rationale for the development of therapeutic strategies to manipulate TRAF proteins or TRAF-dependent signaling pathways in different human cancers by precision medicine.

Ozone oil promotes wound healing by increasing the migration of fibroblasts via PI3K/Akt/mTOR signaling pathway

Skin injury affects millions of people via the uncontrolled inflammation and infection. Many cellular components including fibroblasts and signaling pathways such as transforming growth factor-β (TGF-β) were activated to facilitate the wound healing to repair injured tissues. C57BL/6 female mice were divided into control and ozone oil treated groups. Excisional wounds were made on the dorsal skin and the fibroblasts were isolated from granulation tissues. The skin injured mouse model revealed that ozone oil could significantly decrease the wound area and accelerate wound healing compared with control group. QPCR and Western blotting assays showed that ozone oil up-regulated collagen I, α-SMA, and TGF-β1 mRNA and protein levels in fibroblasts. Wound healing assay demonstrated that ozone oil could increase the migration of fibroblasts. Western blotting assay demonstrated that ozone oil increased the epithelial–mesenchymal transition (EMT) process in fibroblasts via up-regulating fibronectin, vimentin, N-cadherin, MMP-2, MMP-9, insulin-like growth factor binding protein (IGFBP)-3, IGFBP5, and IGFBP6, and decreasing epithelial protein E-cadherin and cellular senescence marker p16 expression. Mechanistically, Western blotting assay revealed that ozone oil increased the phosphorylation of PI3K, Akt, and mTOR to regulate the EMT process, while inhibition of PI3K reversed this effect of ozone oil. At last, the results from Cytometric Bead Array (CBA) demonstrated ozone oil significantly decreased the inflammation in fibroblasts. Our results demonstrated that ozone oil facilitated the wound healing via increasing fibroblast migration and EMT process via PI3K/Akt/mTOR signaling pathway in vivo and in vitro. The cellular and molecular mechanisms we found here may provide new therapeutic targets for the treatment of skin injury.

Caveolin-1 is required for TGF-β-induced transactivation of the EGF receptor pathway in hepatocytes through the activation of the metalloprotease TACE/ADAM17

Transforming growth factor-beta (TGF-β) plays a dual role in hepatocytes, inducing both pro- and anti-apoptotic responses, whose balance decides cell fate. Survival signals are mediated by the epidermal growth factor receptor (EGFR) pathway, which is activated by TGF-β in these cells. Caveolin-1 (Cav1) is a structural protein of caveolae linked to TGF-β receptors trafficking and signaling. Previous results have indicated that in hepatocytes, Cav1 is required for TGF-β-induced anti-apoptotic signals, but the molecular mechanism is not fully understood yet. In this work, we show that immortalized Cav1(-/-) hepatocytes were more sensitive to the pro-apoptotic effects induced by TGF-β, showing a higher activation of caspase-3, higher decrease in cell viability and prolonged increase through time of intracellular reactive oxygen species (ROS). These results were coincident with attenuation of TGF-β-induced survival signals in Cav1(-/-) hepatocytes, such as AKT and ERK1/2 phosphorylation and NFκ-B activation. Transactivation of the EGFR pathway by TGF-β was impaired in Cav1(-/-) hepatocytes, which correlated with lack of activation of TACE/ADAM17, the metalloprotease responsible for the shedding of EGFR ligands. Reconstitution of Cav1 in Cav1(-/-) hepatocytes rescued wild-type phenotype features, both in terms of EGFR transactivation and TACE/ADAM17 activation. TACE/ADAM17 was localized in detergent-resistant membrane (DRM) fractions in Cav1(+/+) cells, which was not the case in Cav1(-/-) cells. Disorganization of lipid rafts after treatment with cholesterol-binding agents caused loss of TACE/ADAM17 activation after TGF-β treatment. In conclusion, in hepatocytes, Cav1 is required for TGF-β-mediated activation of the metalloprotease TACE/ADAM17 that is responsible for shedding of EGFR ligands and activation of the EGFR pathway, which counteracts the TGF-β pro-apoptotic effects. Therefore, Cav1 contributes to the pro-tumorigenic effects of TGF-β in liver cancer cells.