Aberrant rel/nfkb genes and activity in human cancer

CXXC5 drove inflammation and ovarian cancer proliferation via transcriptional activation of ZNF143 and EGR1

CXXC5, a zinc-finger protein, is known for its role in epigenetic regulation via binding to unmethylated CpG islands in gene promoters. As a transcription factor and epigenetic regulator, CXXC5 modulates various signaling processes and acts as a key coordinator. Altered expression or activity of CXXC5 has been linked to various pathological conditions, including tumorigenesis. Despite its known role in cancer, CXXC5's function and mechanism in ovarian cancer are unclear. We analyzed multiple public databases and found that CXXC5 is highly expressed in ovarian cancer, with high expression correlating with poor patient prognosis. We show that CXXC5 expression is regulated by oxygen concentration and is a direct target of HIF1A. CXXC5 is critical for maintaining the proliferative potential of ovarian cancer cells, with knockdown decreasing and overexpression increasing cell proliferation. Loss of CXXC5 led to inactivation of multiple inflammatory signaling pathways, while overexpression activated these pathways. Through in vitro and in vivo experiments, we confirmed ZNF143 and EGR1 as downstream transcription factors of CXXC5, mediating its proliferative potential in ovarian cancer. Our findings suggest that the CXXC5-ZNF143/EGR1 axis forms a network driving ovarian cell proliferation and tumorigenesis, and highlight CXXC5 as a potential therapeutic target for ovarian cancer treatment.

Critical and distinct roles of cell type-specific NF-κB2 in lung cancer

Different from the well-studied canonical NF-κB member RelA, the role of the noncanonical NF-κB member NF-κB2 in solid tumors, and lung cancer in particular, is poorly understood. Here we report that in contrast to the tumor-promoting role of RelA, NF-κB2 intrinsic to lung epithelial and tumor cells had no marked effect on lung tumorigenesis and progression. On the other hand, NF-κB2 limited dendritic cell number and activation in the lung but protected lung macrophages and drove them to promote lung cancer through controlling activation of noncanonical and canonical NF-κB, respectively. NF-κB2 was also required for B cell maintenance and T cell activation. The antitumor activity of lymphocyte NF-κB2 was dominated by the protumor function of myeloid NF-κB2; thus, NF-κB2 has an overall tumor-promoting activity. These studies reveal a cell type-dependent role for NF-κB2 in lung cancer and help understand the complexity of NF-κB action and lung cancer pathogenesis for better design of NF-κB-targeted therapy against this deadliest cancer.

Chronic Treatment with Nigella sativa Oil Exerts Antimanic Properties and Reduces Brain Inflammation in Rats

Nigella sativa (NS) is a native herb consumed habitually in several countries worldwide, possessing manifold therapeutic properties. Among them, anti-inflammatory features have been reported, presumably relating to mechanisms involved in the nuclear factor kappa-B pathway, among others. Given the observed association between neuroimmune factors and mental illness, the primary aim of the present study was to examine the effects of chronic NS use on manic-like behavior in rats, as well as analyze levels of brain inflammatory mediators following NS intake. Using male and female rats, baseline tests were performed; thereafter, rats were fed either regular food (control) or NS-containing food (treatment) for four weeks. Following intervention, behavioral tests were induced (an open field test, sucrose consumption test, three-chamber sociality test, and amphetamine-induced hyperactivity test). Subsequently, brain samples were extracted, and inflammatory mediators were evaluated, including interleukin-6, leukotriene B4, prostaglandin E2, tumor necrosis factor-α, and nuclear phosphorylated-p65. Our findings show NS to result in a marked antimanic-like effect, in tandem with a positive modulation of select inflammatory mediators among male and female rats. The findings reinforce the proposed therapeutic advantages relating to NS ingestion.

Effect of sodium stibogluconate in recruiting and awakening immune cells in the pleural fluid of pancreatic cancer: preparation for immunotherapy

Ascites and pleural effusion are recognized complications of pancreatic cancer. These diseases are accompanied by ascites and pleural effusion, and drug treatment is limited by high costs, long hospital stays, and failure rates. Immunotherapy may offer new option, but in most patients with late stages of cancer, immune cells may lose the ability to recognize tumor cells, how to activate their immune cells is a major problem, sodium glucosidate (SSG) is injected into ascites as a protein tyrosine phosphatase inhibitor to wake up immune cells and prepare for immunotherapy. We used single-cell RNA sequencing (scRNA-seq) to investigate whether and how SSG injected into ascites of pancreatic cancer elicits an immune response. Our study showed that the process of SSG fusion treatment of ascites and pleural effusion, the interaction between TandNK cells, MPs cells, monocytes and neutrophils was induced, and large numbers of genes were expressed, resulting in upregulation of immune response, which also approved that SSG is not only used as a protein tyrosine phosphatase inhibitor, but also it works as a protein tyrosine phosphatase inhibitor. It can also be used to regulate immune cell function, recruiting immune cells to the right place with the help of PD-1 or PD-L1 to fight cancer cells in ascites and pleural effusions in cancer patients.

Modulating the dynamics of NFκB and PI3K enhances the ensemble-level TNFR1 signaling mediated apoptotic response

Cell-to-cell variability during TNFα stimulated Tumor Necrosis Factor Receptor 1 (TNFR1) signaling can lead to single-cell level pro-survival and apoptotic responses. This variability stems from the heterogeneity in signal flow through intracellular signaling entities that regulate the balance between these two phenotypes. Using systematic Boolean dynamic modeling of a TNFR1 signaling network, we demonstrate that the signal flow path variability can be modulated to enable cells favour apoptosis. We developed a computationally efficient approach "Boolean Modeling based Prediction of Steady-state probability of Phenotype Reachability (BM-ProSPR)" to accurately predict the network's ability to settle into different phenotypes. Model analysis juxtaposed with the experimental observations revealed that NFκB and PI3K transient responses guide the XIAP behaviour to coordinate the crucial dynamic cross-talk between the pro-survival and apoptotic arms at the single-cell level. Model predicted the experimental observations that ~31% apoptosis increase can be achieved by arresting Comp1 - IKK* activity which regulates the NFκB and PI3K dynamics. Arresting Comp1 - IKK* activity causes signal flow path re-wiring towards apoptosis without significantly compromising NFκB levels, which govern adequate cell survival. Priming an ensemble of cancerous cells with inhibitors targeting the specific interaction involving Comp1 and IKK* prior to TNFα exposure could enable driving them towards apoptosis.

Co-occurrence of glioma and multiple sclerosis: Prevailing theories and emerging therapies

Though the concurrence of primary brain tumors and multiple sclerosis (MS) is exceedingly rare, instances have been noted in the literature as early as 1949. Given these observations, researchers have proposed various ideas as to how these malignancies may be linked to MS. Due to insufficient data, none have gained traction or been widely accepted amongst neurologists or neuro-oncologists. What is abundantly clear, however, is the mounting uncertainty faced by clinicians when caring for these individuals. Concerns persist about the potential for disease modifying therapies (DMTs) to initiate or promote tumor growth and progression, and to date, there are no approved treatments capable of mitigating both MS disease activity and tumor growth, let alone established guidelines that clinicians may refer to. Collectively, these gaps in the literature impose limitations to optimizing the care and management of this population. As such, our hope is to stimulate further discussion of this topic and prompt future investigations to explore novel treatment options and advance our understanding of these concurrent disease processes. To this end, the chief objective of this article is to evaluate proposed ideas of how the diseases may be linked, outline emerging therapies for both MS and brain tumors, and describe evidence-based approaches to diagnosing and treating this patient population.

MiR-196b-5p activates NF-κB signaling in non-small cell lung cancer by directly targeting NFKBIA

BACKGROUND

Our recent study found that QKI-5 regulated miRNA, miR-196b-5p, promotes non-small cell lung cancer (NSCLC) progression by directly targeting GATA6, TSPAN12 and FAS. However, the biological functions of miR-196b-5p in NSCLC progression and metastasis still remain elusive.

METHODS

Cell proliferation, migration, colony formation, cell cycle assays were used to investigate cellular phenotypic changes. Quantitative real-time PCR (qRT-PCR) and western blot analyses were used to measure expressions of relative gene and protein. Interaction between QKI-5 and miR-196b-5p was determined by RNA immunoprecipitation (RIP) assay. Luciferase reporter assay was used to determine direct binding between miR-196b-5p and NFKBIA 3'-UTR. ELISA assay was used to measure secreted IL6 proteins. Mice xenograft model was used to assess the functions of NFKBIA on in vivo tumor growth.

RESULTS

We demonstrated that the miR-196b-5p facilitates lung cancer cell proliferation, migration, colony formation, and cell cycle by directly targeting NFKBIA, a negative regulator of NFκB signaling. Knocking down NFKBIA increases IL6 mediated phosphorylation of signal transducer and activator of transcription 3 (STAT3) to promote lung cancer cell growth by activating NFκB signaling. The expression of NFKBIA was significantly downregulated in NSCLC tissue samples, and was negatively correlated with the expression miR-196b-5p. In addition, we found that downregulated QKI-5 expression was associated with the elevated miR-224 expression in NSCLC.

CONCLUSIONS

Our findings indicated that the miR-224/QKI-5/miR-196b-5p/NFKBIA signaling pathway might play important functions in the progression of NSCLC, and suggested that targeting this pathway might be an effective therapeutic strategy in treating NSCLC.

CLK2 and CLK4 are regulators of DNA damage-induced NF-κB targeted by novel small molecule inhibitors

Transcription factor NF-κB potently activates anti-apoptotic genes, and its inactivation significantly reduces tumor cell survival following genotoxic stresses. We identified two structurally distinct lead compounds that selectively inhibit NF-κB activation by DNA double-strand breaks, but not by other stimuli, such as TNFα. Our compounds do not directly inhibit previously identified regulators of this pathway, most critically including IκB kinase (IKK), but inhibit signal transmission in-between ATM, PARP1, and IKKγ. Deconvolution strategies, including derivatization and in vitro testing in multi-kinase panels, yielded shared targets, cdc-like kinase (CLK) 2 and 4, as essential regulators of DNA damage-induced IKK and NF-κB activity. Both leads sensitize to DNA damaging agents by increasing p53-induced apoptosis, thereby reducing cancer cell viability. We propose that our lead compounds and derivatives can be used in context of genotoxic therapy-induced or ongoing DNA damage to increase tumor cell apoptosis, which may be beneficial in cancer treatment.

The RELT Family of Proteins: An Increasing Awareness of Their Importance for Cancer, the Immune System, and Development

This review highlights Receptor Expressed in Lymphoid Tissues (RELT), a Tumor Necrosis Factor Superfamily member, and its two paralogs, RELL1 and RELL2. Collectively, these three proteins are referred to as RELTfms and have gained much interest in recent years due to their association with cancer and other human diseases. A thorough knowledge of their physiological functions, including the ligand for RELT, is lacking, yet emerging evidence implicates RELTfms in a variety of processes including cytokine signaling and pathways that either promote cell death or survival. T cells from mice lacking RELT exhibit increased responses against tumors and increased inflammatory cytokine production, and multiple lines of evidence indicate that RELT may promote an immunosuppressive environment for tumors. The relationship of individual RELTfms in different cancers is not universal however, as evidence indicates that individual RELTfms may be risk factors in certain cancers yet appear to be protective in other cancers. RELTfms are important for a variety of additional processes related to human health including microbial pathogenesis, inflammation, behavior, reproduction, and development. All three proteins have been strongly conserved in all vertebrates, and this review aims to provide a clearer understanding of the current knowledge regarding these interesting proteins.

NF-kB's contribution to B cell fate decisions

NF-κB signaling is essential to an effective innate and adaptive immune response. Many immune-specific functional and developmental outcomes depend in large on NF-κB. The formidable task of sorting out the mechanisms behind the regulation and outcome of NF-κB signaling remains an important area of immunology research. Here we briefly discuss the role of NF-κB in regulating cell fate decisions at various times in the path of B cell development, activation, and the generation of long-term humoral immunity.

The NF-κB multidimer system model: A knowledge base to explore diverse biological contexts

The nuclear factor κB (NF-κB) system is critical for various biological functions in numerous cell types, including the inflammatory response, cell proliferation, survival, differentiation, and pathogenic responses. Each cell type is characterized by a subset of 15 NF-κB dimers whose activity is regulated in a stimulus-responsive manner. Numerous studies have produced different mathematical models that account for cell type-specific NF-κB activities. However, whereas the concentrations or abundances of NF-κB subunits may differ between cell types, the biochemical interactions that constitute the NF-κB signaling system do not. Here, we synthesized a consensus mathematical model of the NF-κB multidimer system, which could account for the cell type-specific repertoires of NF-κB dimers and their cell type-specific activation and cross-talk. Our review demonstrates that these distinct cell type-specific properties of NF-κB signaling can be explained largely as emergent effects of the cell type-specific expression of NF-κB monomers. The consensus systems model represents a knowledge base that may be used to gain insights into the control and function of NF-κB in diverse physiological and pathological scenarios and that describes a path for generating similar regulatory knowledge bases for other pleiotropic signaling systems.

Inhibition of c-Rel expression in myeloid and lymphoid cells with distearoyl -phosphatidylserine (DSPS) liposomal nanoparticles encapsulating therapeutic siRNA

c-Rel, a member of the nuclear factor kappa B (NF-κB) family, is preferentially expressed by immune cells and is known to regulate inflammation, autoimmune diseases and cancer. However, there is a lack of therapeutic intervention to specifically inhibit c-Rel in immune cells. Recent success with Pfizer and Moderna mRNA lipid-encapsulated vaccines as well as FDA approved medicines based on siRNA prompted us to test a lipid nanoparticle-based strategy to silence c-Rel in immune cells. Specifically, we encapsulated c-Rel-targeting siRNA into distearoyl-phosphatidylserine (DSPS)-containing nanoparticles. DSPS is a saturated phospholipid that serves as the "eat-me" signal for professional phagocytes such as macrophages and neutrophils of the immune system. We demonstrated here that incorporation of DSPS in liposome nanoparticles (LNP) improved their uptake by immune cells. LNP containing high concentrations of DSPS were highly effective to transfect not only macrophages and neutrophils, but also lymphocytes, with limited toxicity to cells. However, LNP containing low concentrations of DSPS were more effective to transfect myeloid cells than lymphoid cells. Importantly, DSPS-LNP loaded with a c-Rel siRNA were highly effective to inhibit c-Rel expression in several professional phagocytes tested, which lasted for several days. Taken together, our results suggest that DSPS-LNP armed with c-Rel siRNA could be exploited to target immune cells to limit the development of inflammatory diseases or cancer caused by c-Rel upregulation. In addition, this newly developed DSPS-LNP system may be further tested to encapsulate and deliver other small molecule drugs to immune cells, especially macrophages, neutrophils, and lymphocytes for the treatment of diseases.

Indirect Mechanisms of Transcription Factor-Mediated Gene Regulation during Cell Fate Changes

Transcription factors (TFs) are the master regulators of cellular identity, capable of driving cell fate transitions including differentiations, reprogramming, and transdifferentiations. Pioneer TFs recognize partial motifs exposed on nucleosomal DNA, allowing for TF-mediated activation of repressed chromatin. Moreover, there is evidence suggesting that certain TFs can repress actively expressed genes either directly through interactions with accessible regulatory elements or indirectly through mechanisms that impact the expression, activity, or localization of other regulatory factors. Recent evidence suggests that during reprogramming, the reprogramming TFs initiate opening of chromatin regions rich in somatic TF motifs that are inaccessible in the initial and final cellular states. It is postulated that analogous to a sponge, these transiently accessible regions "soak up" somatic TFs, hence lowering the initial barriers to cell fate changes. This indirect TF-mediated gene regulation event, which is aptly named the "sponge effect," may play an essential role in the silencing of the somatic transcriptional network during different cellular conversions.

Long noncoding RNA HOTAIR regulates the stemness of breast cancer cells via activation of the NF-κB signaling pathway

Breast cancer is the most prevalent cancer among women, and it is characterized by a high rate of tumor development and heterogeneity. Breast cancer stem cells (CSCs) may well contribute to these pathological properties, but the mechanisms underlying their self-renewal and maintenance are still elusive. Here, we found that the long noncoding RNA HOTAIR is highly expressed in breast CSCs. HOTAIR is required for breast CSC self-renewal and tumor propagation. Mechanistically, we demonstrate that HOTAIR recruits the PRC2 protein complex to the promoter of IκBα to inhibit its expression, leading to activation of the NF-κB signaling pathway. The activated NF-κB signaling promotes downstream c-Myc and Cyclin D1 expression. Furthermore, our analysis of clinical samples from the GEPIA database indicated that the IκBα level, as well as the survival rate of patients, with high HOTAIR expression was significantly lower than that of patients with relatively low HOTAIR expression. Our data suggest that HOTAIR-mediated NF-κB signaling primes breast CSC self-renewal and tumor propagation. In sum, we have identified HOTAIR-based NF-κB signaling regulatory circuit that promotes tumorigenic activity in breast CSCs, further indicating that HOTAIR could be a promising target for clinical treatment of breast cancers.

Neuroprotective effects of a novel peptide from Lignosus rhinocerotis against 6‐hydroxydopamine‐induced apoptosis in PC12 cells by inhibiting NF‐κB activation

According to previous studies, oxidative stress is a leading cause of dopaminergic neuron death and may contribute to the pathogenesis of Parkinson's disease (PD). In the current study, we used chromatography of gel filtration to identify a novel peptide (Lignosus rhinocerotis peptide [LRP]) from the sclerotium of Lignosus rhinocerotis (Cooke) Ryvarden. Its neuroprotective effect was evaluated using an in vitro PD model constructed by 6-hydroxydopamine (6-OHDA)-stimulated to apoptosis in PC12 cells. The molecular weight of LRP is determined as 1532 Da and the secondary structure is irregular. The simple amino acid sequence of LRP is Thr-Leu-Ala-Pro-Thr-Phe-Leu-Ser-Ser-Leu-Gly-Pro-Cys-Leu-Leu. Notably, LRP has the ability to significantly boost the viability of PC12 cells after exposure to 6-OHDA, as well as enhance the cellular activity of antioxidative enzymes like superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GSH-Px). LRP also lowers the level of malondialdehyde (MDA), decreases the activation performance of Caspase-3, and reduces 6-OHDA-induced apoptosis via inhibition of nuclear factor-kappa B (NF-κB) activation. These data indicate that LRP may have the potential to act as a neuroprotective agent.

Aberrant transcription factors in the cancers of the pancreas

Transcription factors (TFs) are essential for proper activation of gene set during the process of organogenesis, differentiation, lineage specificity. Reactivation or dysregulation of TFs regulatory networks could lead to deformation of organs, diseases including various malignancies. Currently, understanding the mechanism of oncogenesis became necessity for the development of targeted therapeutic strategy for different cancer types. It is evident that many TFs go awry in cancers of the pancreas such as pancreatic ductal adenocarcinoma (PDAC) and pancreatic neuroendocrine neoplasms (PanNENs). These mutated or dysregulated TFs abnormally controls various signaling pathways in PDAC and PanNENs including RTK, PI3K-PTEN-AKT-mTOR, JNK, TGF-β/SMAD, WNT/β-catenin, SHH, NOTCH and VEGF which in turn regulate different hallmarks of cancer. Aberrant regulation of such pathways have been linked to the initiation, progression, metastasis, and resistance in pancreatic cancer. As of today, a number of TFs has been identified as crucial regulators of pancreatic cancer and a handful of them shown to have potential as therapeutic targets in pre-clinical and clinical settings. In this review, we have summarized the current knowledge on the role and therapeutic usefulness of TFs in PDAC and PanNENs.

Targeting p65 to inhibit Cas3 transcription by Onjisaponin B for radiation damage therapy in p65+/- mice

BACKGROUND

In response to radiation injury, p65 becomes activated. The formation of p65 is one target of Onjisaponin B (OB), but it has not been studied in radioprotection. In addition, there is a binding site for p65 in the promoter region of Cas3. This study evaluates the use of OB as an intervention to modulate p65/Cas3 following radiation exposure.

PURPOSE

This study aimed to confirm that OB regulated the transcription of Cas3 via p65 to overcome radiation-induced damage.

STUDY DESIGN AND METHODS

Cells and mice were exposed to X-rays at a dose of 6 Gy. Immunofluorescence was used to locate intracellular p65. For the protein and mRNA analyses, Western blotting and RT-qPCR-based assays were conducted accordingly. HE staining was used to observe pathological changes in tissues. DNA damage was detected by the comet assay and DNA ladder assay. Next, apoptosis was detected by flow cytometry and Hoechst staining.

RESULTS

Compared with the radiation group, the expression levels of p-p65 and c-Cas3 in the drug group were significantly down-regulated by OB 20 µg/ml. When the expression of p65 was suppressed in V79 and TC cells, OB did not significantly inhibit the activation of p65 or Cas3 in response to irradiation, nor did it significantly inhibit the phosphorylation of p65 and subsequent nuclear translocation. Overexpression of p65 in V79 and MTEC-1 cells resulted in OB significantly inhibiting the activation of p65 and Cas3, and the phosphorylation and translocation of p65 into the nucleus. At 3 d for V79 cells and 24 h for MTEC-1 cells after radiation, compared with the Cas3 over plasmid transfection group, the drug transfection group had no significant effect on reducing apoptosis. In p65+/- mice, expression of the p65 gene was knocked down, leading to increased tissue apoptosis and inflammation, and serious tissue pathological changes. The inhibition of p65 activation by OB after radiation exposure was not apparent in the thymus, although it was observed in the lung.

CONCLUSIONS

OB interfered with radiation injury by targeting and regulating p65/Cas3. Therefore, it has been concluded that p65 is an important target molecule for the treatment of radiation injury.

NF-κB: A novel therapeutic pathway for gastroesophageal reflux disease?

Although gastroesophageal reflux disease (GERD), a common chronic disease in clinical practice, has been widely studied, its potential adverse impact on patients is still a significant clinical concern. It is necessary to understand the pathogenesis of the disease and choose appropriate treatment according to its mechanism. The pathogenesis of GERD is diverse and complex. As the traditional treatment methods are expensive and ineffective in alleviating symptoms in some patients, new treatment options need to be explored. Our previous study suggested that the activation of nuclear factor-kappa beta (NF-κB) in esophageal mucosa may be related to the injury of epithelial barrier function caused by reflux. Based on the literature and our previous study results, it is speculated that inhibition of NF-κB activation may block the insult of GERD on the esophageal mucosal barrier. NF-κB may play an important role in the development of GERD. This article reviews the pathogenesis of GERD and the relationship between NF-κB and GERD, in order to provide new strategies for the treatment of GERD.

Human Papillomavirus 16 E6 and E7 Oncoproteins Alter the Abundance of Proteins Associated with DNA Damage Response, Immune Signaling and Epidermal Differentiation

The high-risk human papillomaviruses are oncogenic viruses associated with almost all cases of cervical carcinomas, and increasing numbers of anal, and oral cancers. Two oncogenic HPV proteins, E6 and E7, are capable of immortalizing keratinocytes and are required for HPV associated cell transformation. Currently, the influence of these oncoproteins on the global regulation of the host proteome is not well defined. Liquid chromatography coupled with quantitative tandem mass spectrometry using isobaric-tagged peptides was used to investigate the effects of the HPV16 oncoproteins E6 and E7 on protein levels in human neonatal keratinocytes (HEKn). Pathway and gene ontology enrichment analyses revealed that the cells expressing the HPV oncoproteins have elevated levels of proteins related to interferon response, inflammation and DNA damage response, while the proteins related to cell organization and epithelial development are downregulated. This study identifies dysregulated pathways and potential biomarkers associated with HPV oncoproteins in primary keratinocytes which may have therapeutic implications. Most notably, DNA damage response pathways, DNA replication, and interferon signaling pathways were affected in cells transduced with HPV16 E6 and E7 lentiviruses. Moreover, proteins associated with cell organization and differentiation were significantly downregulated in keratinocytes expressing HPV16 E6 + E7. High-risk HPV E6 and E7 oncoproteins are necessary for the HPV-associated transformation of keratinocytes. However their influence on the global dysregulation of keratinocyte proteome is not well documented. Here shotgun proteomics using TMT-labeling detected over 2500 significantly dysregulated proteins associated with E6 and E7 expression. Networks of proteins related to interferon response, inflammation and DNA damage repair pathways were altered.

CTSV (cathepsin V) promotes bladder cancer progression by increasing NF-κB activity

Chronic inflammation is positively associated with the development of urinary bladder cancer. However, its detailed regulatory mechanism remains elusive. The quantitative real-time polymerase chain reaction was used to measure mRNA levels of relative genes. The protein levels were monitored by western blotting. Cell proliferation and viability were evaluated by the cell counting Kit 8 (CCK8) and colony formation assays, respectively. The dual-luciferase reporter assay was performed to assay the transcriptional activity. In vivo experiments were implemented in nude mice as well. The TCGA database analysis suggested that the aberrant expression of cathepsin V (CTSV) was related to a poor outcome in bladder cancer patients. CTSV boosted the inflammation reaction, which facilitated the development of bladder cancer. The overexpression of CTSV increased the proliferation and viability of bladder cancer cells. On the contrary, the deletion of CTSV significantly inhibited the proliferation and viability of bladder cancer cells. The tumor repression resulting from CTSV deficiency in vitro was also verified in vivo. Moreover, multiple cancer-associated luciferase screening showed that the overexpression of CTSV triggered the inflammatory signaling pathway, which could be restored by introducing the NF-κB inhibitor. CTSV is upregulated and promotes proliferation through the NF-κB pathway in bladder cancer and may be a potential target in inflammation-associated bladder cancer.

Promoting antibody-dependent cellular phagocytosis for effective macrophage-based cancer immunotherapy

Macrophages are essential in eliciting antibody-dependent cellular phagocytosis (ADCP) of cancer cells. However, a satisfactory anticancer efficacy of ADCP is contingent on early antibody administration, and resistance develops along with cancer progression. Here, we investigate the mechanisms underlying ADCP and demonstrate an effective combinatorial strategy to potentiate its efficacy. We identified paclitaxel as a universal adjuvant that efficiently potentiated ADCP by a variety of anticancer antibodies in multiple cancers. Rather than eliciting cytotoxicity on cancer cells, paclitaxel polarized macrophages toward a state with enhanced phagocytic ability. Paclitaxel-treated macrophages down-regulated cell surface CSF1R whose expression was negatively correlated with patient survival in multiple malignancies. The suppression of CSF1R in macrophages enhanced ADCP of cancer cells, suggesting a role of CSF1R in regulating macrophage phagocytic ability. Together, these findings define a potent strategy for using conventional anticancer drugs to stimulate macrophage phagocytosis and promote the therapeutic efficacy of clinical anticancer antibodies.

FGD3 binds with HSF4 to suppress p65 expression and inhibit pancreatic cancer progression

Pancreatic cancer is regarded as the most lethal solid tumor worldwide. Deregulated and constitutively activated NF-κB signaling is one of the major characteristics of pancreatic cancer. The total expression level and subcellular localization of RelA/p65 have been shown to determine the activation of canonical NF-κB signaling in pancreatic cancer. FGD3, which is involved in regulating the actin cytoskeleton and cell shape, has been reported to inhibit cancer cell migration and predict a favorable prognosis in multiple types of cancer. However, the specific role of FGD3 in pancreatic cancer is still unknown. In this study, we conducted a systematic investigation of the cancer-related role of FGD3 in pancreatic cancer. We demonstrated that FGD3 was abnormally downregulated in pancreatic cancer tissues and that low expression of FGD3 was associated with unfavorable prognosis in patients with pancreatic cancer. Then, we showed that FGD3 inhibited pancreatic cancer cell proliferation, invasion and metastasis in vivo and in vitro. Moreover, we revealed that FGD3 silencing activated the NF-κB signaling pathway by promoting HSF4 nuclear translocation and increasing p65 expression in pancreatic cancer cells. Therefore, our results identified a novel and targetable FGD3/HSF4/p65 signaling axis in pancreatic cancer cells.

Receptor Activator of NF-κB (RANK) Confers Resistance to Chemotherapy in AML and Associates with Dismal Disease Course

Simple Summary

Acute myeloid leukemia (AML) is the most common form of acute leukemia in adults. Despite the emergence of new therapeutic agents in recent years, curation remains challenging, and new and better treatment options are needed. In the present study, we investigated the expression, prognostic significance, and functional role of the Receptor Activator of Nuclear Factor-κB (RANK) in AML. We found that RANK is expressed on leukemic cells in a substantial proportion of AML patients and is associated with a dismal disease course. We further demonstrated that signaling via RANK induces release of factors that favor AML cell survival and confers resistance to chemotherapeutics in AML treatment. Together, our findings identify RANK as novel prognostic marker and putative candidate for therapeutic intervention in AML to enhance response to treatment.

Abstract

Although treatment options of acute myeloid leukemia (AML) have improved over the recent years, prognosis remains poor. Better understanding of the molecular mechanisms influencing and predicting treatment efficacy may improve disease control and outcome. Here we studied the expression, prognostic relevance and functional role of the tumor necrosis factor receptor (TNFR) family member Receptor Activator of Nuclear Factor (NF)-κB (RANK) in AML. We conducted an experimental ex vivo study using leukemic cells of 54 AML patients. Substantial surface expression of RANK was detected on primary AML cells in 35% of the analyzed patients. We further found that RANK signaling induced the release of cytokines acting as growth and survival factors for the leukemic cells and mediated resistance of AML cells to treatment with doxorubicin and cytarabine, the most commonly used cytostatic compounds in AML treatment. In line, RANK expression correlated with a dismal disease course as revealed by reduced overall survival. Together, our results show that RANK plays a yet unrecognized role in AML pathophysiology and resistance to treatment, and identify RANK as “functional” prognostic marker in AML. Therapeutic modulation of RANK holds promise to improve treatment response in AML patients.

CD95L Inhibition Impacts Gemcitabine-Mediated Effects and Non-Apoptotic Signaling of TNF-α and TRAIL in Pancreatic Tumor Cells

Despite the potential apoptotic functions, the CD95/CD95L system can stimulate survival as well as pro-inflammatory signaling, particularly through the activation of NFκB. This holds true for the TNF/TNFR and the TRAIL/TRAILR systems. Thus, signaling pathways of these three death ligands converge, yet the specific impact of the CD95/CD95L system in this crosstalk has not been well studied. In this study, we show that gemcitabine stimulates the expression of pro-inflammatory cytokines, such as IL6 and IL8, under the influence of the CD95/CD95L system and the pharmacological inhibitor, sCD95Fc, substantially reduced the expression in two PDAC cell lines, PancTuI-luc and A818-4. The stem cell phenotype was reduced when induced upon gemcitabine as well by sCD95Fc. Moreover, TNF-α as well as TRAIL up-regulate the expression of CD95 and CD95L in both cell lines. Conversely, we detected a significant inhibitory effect of sCD95Fc on the expression of both IL8 and IL6 induced upon TNF-α and TRAIL stimulation. In vivo, CD95L inhibition reduced xeno-transplanted recurrent PDAC growth. Thus, our findings indicate that inhibition of CD95 signaling altered the chemotherapeutic effects of gemcitabine, not only by suppressing the pro-inflammatory responses that arose from the CD95L-positive tumor cells but also from the TNF-α and TRAIL signaling in a bi-lateral crosstalk manner.

Anti-Inflammatory Mechanisms of Novel Synthetic Ruthenium Compounds

Inflammation is the primary biological reaction to induce severe infection or injury in the immune system. Control of different inflammatory cytokines, such as nitric oxide (NO), interleukins (IL), tumor necrosis factor alpha-(TNF-α), noncytokine mediator, prostaglandin E2 (PGE2), mitogen activated protein kinases (MAPKs) and nuclear factor kappa B (NF-κB), facilitates anti-inflammatory effect of different substances. Coordination metal complexes have been applied as metallo-drugs. Several metal complexes have found to possess potent biological activities, especially anticancer, cardioprotective, chondroprotective and anti-parasitosis activities. Among the metallo drugs, ruthenium-based (Ru) complexes have paid much attention in clinical applications. Despite the kinetic nature of Ru complexes is similar to platinum in terms of cell division events, their toxic effect is lower than that of cisplatin. This paper reviews the anti-inflammatory effect of novel synthetic Ru complexes with potential molecular mechanisms that are actively involved.

Identification of Transcription Factor-Related Gene Signature and Risk Score Model for Colon Adenocarcinoma

The prognosis of colon adenocarcinoma (COAD) remains poor. However, the specific and sensitive biomarkers for diagnosis and prognosis of COAD are absent. Transcription factors (TFs) are involved in many biological processes in cells. As the molecule of the signal pathway of the terminal effectors, TFs play important roles in tumorigenesis and development. A growing body of research suggests that aberrant TFs contribute to the development of COAD, as well as to its clinicopathological features and prognosis. In consequence, a few studies have investigated the relationship between the TF-related risk model and the prognosis of COAD. Therefore, in this article, we hope to develop a prognostic risk model based on TFs to predict the prognosis of patients with COAD. The mRNA transcription data and corresponding clinical data were downloaded from TCGA and GEO. Then, 141 differentially expressed genes, validated by the GEPIA2 database, were identified by differential expression analysis between normal and tumor samples. Univariate, multivariate and Lasso Cox regression analysis were performed to identify seven prognostic genes (E2F3, ETS2, HLF, HSF4, KLF4, MEIS2, and TCF7L1). The Kaplan-Meier curve and the receiver operating characteristic curve (ROC, 1-year AUC: 0.723, 3-year AUC: 0.775, 5-year AUC: 0.786) showed that our model could be used to predict the prognosis of patients with COAD. Multivariate Cox analysis also reported that the risk model is an independent prognostic factor of COAD. The external cohort (GSE17536 and GSE39582) was used to validate our risk model, which indicated that our risk model may be a reliable predictive model for COAD patients. Finally, based on the model and the clinicopathological factors, we constructed a nomogram with a C-index of 0.802. In conclusion, we emphasize the clinical significance of TFs in COAD and construct a prognostic model of TFs, which could provide a novel and reliable model for the prognosis of COAD.

BRCC3 Promotes Tumorigenesis of Bladder Cancer by Activating the NF-κB Signaling Pathway Through Targeting TRAF2

NF-κB signaling is very important in cancers. However, the role of BRCC3-associated NF-κB signaling activation in bladder cancer remains to be characterized. Western blotting and IHC of tissue microarray were used to confirm the abnormal expression of BRCC3 in bladder cancer. Growth curve, colony formation, soft agar assay and Xenograft model were performed to identify the role of BRCC3 over-expression or knock-out in bladder cancer. Further, RNA-Seq and luciferase reporter assays were used to identify the down-stream signaling pathway. Finally, co-immunoprecipitation and fluorescence confocal assay were performed to verify the precise target of BRCC3. Here, we found that high expression of BRCC3 promoted tumorigenesis through targeting the TRAF2 protein. BRCC3 expression is up-regulated in bladder cancer patients which indicates a negative prognosis. By in vitro and in vivo assays, we found genetic BRCC3 ablation markedly blocks proliferation, viability and migration of bladder cancer cells. Mechanistically, RNA-Seq analysis shows that NF-κB signaling is down-regulated in BRCC3-deficient cells. BRCC3 binds to and synergizes with TRAF2 to activate NF-κB signaling. Our results indicate that high BRCC3 expression activates NF-κB signaling by targeting TRAF2 for activation, which in turn facilitates tumorigenesis in bladder cancer. This finding points to BRCC3 as a potential target in bladder cancer patients.

Epigenetic Silencing of miR-33b Promotes Peritoneal Metastases of Ovarian Cancer by Modulating the TAK1/FASN/CPT1A/NF-κB Axis

Peritoneal metastases are frequently found in high-grade serous carcinoma (HGSOC) patients and are commonly associated with a poor prognosis. The tumor microenvironment (TME) is a complex milieu that plays a critical role in epigenetic alterations driving tumor development and metastatic progression. However, the impact of epigenetic alterations on metastatic ovarian cancer cells in the harsh peritoneal microenvironment remains incompletely understood. Here, we identified that miR-33b is frequently silenced by promoter hypermethylation in HGSOC cells derived from metastatic omental tumor tissues. Enforced expression of miR-33b abrogates the oncogenic properties of ovarian cancer cells cocultured in omental conditioned medium (OCM), which mimics the ascites microenvironment, and in vivo tumor growth. Of note, restoration of miR-33b inhibited OCM-upregulated de novo lipogenesis and fatty acid β-oxidation in ovarian cancer cells, indicating that miR-33b may play a novel tumor suppressor role in the lipid-mediated oncogenic properties of metastatic ovarian cancer cells found in the omentum. Mechanistic studies demonstrated that miR-33b directly targets transforming growth factor beta-activated kinase 1 (TAK1), thereby suppressing the activities of fatty acid synthase (FASN) and carnitine palmitoyltransferase 1A (CPT1A) in modulating lipid metabolic activities and simultaneously inhibiting the phosphorylation of NF-κB signaling to govern the oncogenic behaviors of ovarian cancer cells. Thus, our data suggest that a lipid-rich microenvironment may cause epigenetic silencing of miR-33b, which negatively modulates ovarian cancer peritoneal metastases, at least in part, by suppressing TAK1/FASN/CPT1A/NF-κB signaling.

NF-κB-Dependent and -Independent (Moonlighting) IκBα Functions in Differentiation and Cancer

IκBα is considered to play an almost exclusive role as inhibitor of the NF-κB signaling pathway. However, previous results have demonstrated that SUMOylation imposes a distinct subcellular distribution, regulation, NF-κB-binding affinity and function to the IκBα protein. In this review we discuss the main alterations of IκBα found in cancer and whether they are (most likely) associated with NF-κB-dependent or NF-κB-independent (moonlighting) activities of the protein.

Entamoeba histolytica activation of caspase-1 degrades cullin that attenuates NF-κB dependent signaling from macrophages

While Entamoeba histolytica (Eh)-induced pro-inflammatory responses are critical in disease pathogenesis, the downstream signaling pathways that subsequently dampens inflammation and the immune response remains unclear. Eh in contact with macrophages suppresses NF-κB signaling while favoring NLRP3-dependent pro-inflammatory cytokine production by an unknown mechanism. Cullin-1 and cullin-5 (cullin-1/5) assembled into a multi-subunit RING E3 ubiquitin ligase complex are substrates for neddylation that regulates the ubiquitination pathway important in NF-κB activity and pro-inflammatory cytokine production. In this study, we showed that upon live Eh contact with human macrophages, cullin-1/4A/4B/5 but not cullin-2/3, were degraded within 10 minutes. Similar degradation of cullin-1/5 were observed from colonic epithelial cells and proximal colonic loops tissues of mice inoculated with live Eh. Degradation of cullin-1/5 was dependent on Eh-induced activation of caspase-1 via the NLRP3 inflammasome. Unlike cullin-4B, the degradation of cullin-4A was partially dependent on caspase-1 and was inhibited with a pan caspase inhibitor. Cullin-1/5 degradation was dependent on Eh cysteine proteinases EhCP-A1 and EhCP-A4, but not EhCP-A5, based on pharmacological inhibition of the cysteine proteinases and EhCP-A5 deficient parasites. siRNA silencing of cullin-1/5 decreased the phosphorylation of pIκ-Bα in response to Eh and LPS stimulation and downregulated NF-κB-dependent TNF-α mRNA expression and TNF-α and MCP-1 pro-inflammatory cytokine production. These results unravel a unique outside-in strategy employed by Eh to attenuate NF-κB-dependent pro-inflammatory responses via NLRP3 activation of caspase-1 that degraded cullin-1/5 from macrophages.

The protozoan parasite Entamoeba histolytica (Eh) is the etiologic agent for the disease amebiasis. It is a potent pathogen that deploys an arsenal of virulence factors to trigger and subvert host immune defenses. One of the hallmark features of the disease is amebic colitis and in extreme cases, it can lead to abscesses of the liver and brain. For unknown reasons, the parasite breaches colonic mucosal barriers and invade underlying tissues. The host immune system plays a decisive role in determining the outcome of the disease. At the molecular level, the interaction of Eh with macrophage is a turning point in shaping pro-inflammatory responses. Understanding host-pathogen intricacies at the molecular level is key in determining the complexity of the disease. In the context of amebiasis, the underlying molecular events that occur at the Eh-macrophage intercellular junction are partly unravelled. Here we sought to interrogate the mechanisms by which NF-κB signaling is aborted following Eh-macrophage contact and found two regulatory scaffold proteins, cullin-1 and -5 (cullin-1/5) of the multiple E3 ligase complex, are degraded leading to dampening of NF-κB signaling. During Eh-macrophage contact, cullin-1/4A/4B/5 were rapidly degraded whereas cullin-2/3 were not. The degradation of cullin-1/5 was highly dependent on Eh-induced caspase-1 activation via the NLRP3 inflammasome. In contrast, the degradation of cullin-4A but not cullin-4B, was partially dependent on caspase-1 and was inhibited with a cell-permeable pan caspase inhibitor. Intriguingly, we found that Eh virulence factor EhCP-A1 and EhCP-A4, but not EhCP-A5, played an important role in mediating the degradation of these proteins. Silencing cullin-1/5 decreased the phosphorylation of Iκ-Bα in response to Eh and LPS stimulation that markedly downregulated NF-κB-dependent TNF-α mRNA expression and TNF-α and MCP-1 pro-inflammatory cytokine production. This study unravelled a novel role for Eh-induced NLRP3 inflammasome activation of caspase-1 that intersected with the NF-κB pathway leading to the degradation of the novel substrates cullin-1/5 that regulates NF-κB-dependent pro-inflammatory cytokine production.

Biguanides drugs: Past success stories and promising future for drug discovery

Biguanides have attracted much attention a century ago and showed resurgent interest in recent years after a long period of dormancy. They constitute an important class of therapeutic agents suitable for the treatment of a wide spectrum of diseases. Therapeutic indications of biguanides include antidiabetic, antimalarial, antiviral, antiplaque, and bactericidal applications. This review presents an extensive overview of the biological activity of biguanides and different mechanisms of action of currently marketed biguanide-containing drugs, as well as their pharmacological properties when applicable. We highlight the recent developments in research on biguanide compounds, with a primary focus on studies on metformin in the field of oncology. We aim to provide a critical overview of all main bioactive biguanide compounds and discuss future perspectives for the design of new drugs based on the biguanide fragment.

A Novel Protein-Protein Interaction between RSK3 and IκBα and a New Binding Inhibitor That Suppresses Breast Cancer Tumorigenesis

Multiple cancer-related biological processes are mediated by protein-protein interactions (PPIs). Through interactions with a variety of factors, members of the ribosomal S6 kinase (RSK) family play roles in cell cycle progression and cell proliferation. In particular, RSK3 contributes to cancer viability, but the underlying mechanisms remain unknown. We performed a kinase library screen to find IκBα PPI binding partners and identified RSK3 as a novel IκBα binding partner using a cell-based distribution assay. In addition, we discovered a new PPI inhibitor using mammalian two-hybrid (MTH) analysis. We assessed the antitumor effects of the new inhibitor using cell proliferation and colony formation assays and monitored the rate of cell death by FACS apoptosis assay. IκBα is phosphorylated by the active form of the RSK3 kinase. A small-molecule inhibitor that targets the RSK3/IκBα complex exhibited antitumor activity in breast cancer cells and increased their rate of apoptosis. RSK3 phosphorylation and RSK3/IκBα complex formation might be functionally important in breast tumorigenesis. The RSK3/IκBα-specific binding inhibitor identified in this study represents a lead compound for the development of new anticancer drugs.

Targeting phosphoinositide 3-kinases and histone deacetylases in multiple myeloma

Background

Multiple myeloma (MM) is a type of hematological malignancy affecting the functions of plasma cells. The treatment of MM patients has changed dramatically with the use of new agents. However, unfortunately, it is still incurable. Therefore, a new approach for treating MM is still needed to improve patient outcomes.

Methods

Because the histone deacetylase (HDAC) and phosphoinositide 3-kinase (PI3K) pathway is a key signal in cancer cell biology, we investigated whether dual HDAC and PI3K inhibitors could suppress the myeloma cells.

Results

Gene expression of HDACs is high in myeloma cells. CUDC-907, a dual inhibitor of PI3K and HDAC, inhibits HDAC activity. Akt activity and expression of BCL-XL, MCL-1, and NF-κB p65 were reduced by CUDC-907 in a dose-dependent manner. The number of apoptotic and caspase 3/7-positive cells also increased in the myeloma cells. Combined treatment of myeloma cells with carfilzomib and CUDC-907 increased cytotoxicity compared to that observed with each drug alone.

Conclusions

Data from this study suggested that the administration of CUDC-907 might be a powerful strategy against myeloma cells, to enhance the cytotoxic effects of proteasome inhibitors.

Multi-organ proteomic landscape of COVID-19 autopsies

The molecular pathology of multi-organ injuries in COVID-19 patients remains unclear, preventing effective therapeutics development. Here, we report a proteomic analysis of 144 autopsy samples from seven organs in 19 COVID-19 patients. We quantified 11,394 proteins in these samples, in which 5,336 were perturbed in the COVID-19 patients compared to controls. Our data showed that cathepsin L1, rather than ACE2, was significantly upregulated in the lung from the COVID-19 patients. Systemic hyperinflammation and dysregulation of glucose and fatty acid metabolism were detected in multiple organs. We also observed dysregulation of key factors involved in hypoxia, angiogenesis, blood coagulation, and fibrosis in multiple organs from the COVID-19 patients. Evidence for testicular injuries includes reduced Leydig cells, suppressed cholesterol biosynthesis, and sperm mobility. In summary, this study depicts a multi-organ proteomic landscape of COVID-19 autopsies that furthers our understanding of the biological basis of COVID-19 pathology.

Inhibiting NF-κB Signaling Activation Reduces Retinal Neovascularization by Promoting a Polarization Shift in Macrophages

Purpose

Nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB) signaling is involved in regulating tumor angiogenesis and metastasis; however, the exact mechanism of action in retinal neovascularization (RNV) remains unclear. The purpose of this study was to determine the role and underlying mechanism of NF-κB in regulating RNV in retinal neovascularization mice.

Methods

Expression levels of NF-κB signaling were detected by immunofluorescence staining and western blotting in retinas of oxygen-induced retinopathy (OIR) mice. OIR mice were treated with either pyrrolidinedithiocarbamate (PDTC), a NF-κB signaling inhibitor, or PBS, and retinal flat-mounts were performed to quantify the area of RNV and the recruitment of retinal macrophages by immunofluorescence staining. Macrophage polarization detected by flow cytometric analysis and the expression of macrophage polarization-associated genes were evaluated by immunofluorescence staining, quantitative RT-PCR, and western blotting.

Results

Expression levels of phosphorylated IκBα (p-IκBα) and p-p65 increased in OIR mice. Inhibiting NF-κB signaling activation by PDTC significantly reduced RNV. After treatment with PDTC, a reduction in the quantity of macrophages was observed: M1 polarized macrophages decreased, and M2 polarized macrophages increased; the expression of M1 macrophage-associated cytokines decreased and M2 macrophage-associated cytokines increased in the retinas of OIR mice.

Conclusions

Blocking activation of NF-κB signaling reduces RNV by promoting polarization of M1 macrophages to M2 macrophages in OIR mice.

Transcription factors in colorectal cancer: molecular mechanism and therapeutic implications

Colorectal cancer (CRC) is a major cause of cancer mortality worldwide, however, the molecular mechanisms underlying the pathogenesis of CRC remain largely unclear. Recent studies have revealed crucial roles of transcription factors in CRC development. Transcription factors essential for the regulation of gene expression by interacting with transcription corepressor/enhancer complexes and they orchestrate downstream signal transduction. Deregulation of transcription factors is a frequent occurrence in CRC, and the accompanying drastic changes in gene expression profiles play fundamental roles in multistep process of tumorigenesis, from cellular transformation, disease progression to metastatic disease. Herein, we summarized current and emerging key transcription factors that participate in CRC tumorigenesis, and highlighted their oncogenic or tumor suppressive functions. Moreover, we presented critical transcription factors of CRC, emphasized the major molecular mechanisms underlying their effect on signal cascades associated with tumorigenesis, and summarized of their potential as molecular biomarkers for CRC prognosis therapeutic response, as well as drug targets for CRC treatment. A better understanding of transcription factors involved in the development of CRC will provide new insights into the pathological mechanisms and reveal novel prognostic biomarkers and therapeutic strategies for CRC.

Exploring the extensive crosstalk between the antagonistic cytokines- TGF-β and TNF-α in regulating cancer pathogenesis

A plethora of cytokines are produced in the tumor microenvironment (TME) those play a vital role in cancer prognosis. Though it is completely contextual, cytokines produced from an inflammatory micro-environment can either modulate cancer progression at early stages of tumor development or in later stages cytokine derived cues can in turn control tumor cell invasion and metastasis. Therefore, understanding the crosstalk between the key cytokines regulating cancer prognosis is critical for the development of an effective therapy. In this regard, the role of transforming growth factor-beta (TGF-β) in cancer is controversially discussed in general inhibition of TGF-β promotes de novo tumorigenesis whereas paradoxically, TGF-β can promote malignancy in already established tumors. Another important cytokine, TNF-α have intense crosstalk with TGF-β from the fact that in a non-cancer context, TGF-β promotes fibrosis whereas TNF-α has anti-fibrotic activity. We have recently reported that TGF-β-induced differentiation of epithelial cells to mesenchymal type is suppressed by TNF-α through regulation of cellular homeostatic machinery- autophagy. Moreover, there are also rare reports of synergy between these two cytokines as well. The crosstalk between TGF-β and TNF-α is not only limited to regulating cancer cell differentiation and proliferation but also includes involvement in cell death. In this review, we hence summarize the molecular mechanisms by which these two important cytokines, TGF-β and TNF-α control cancer prognosis.

p50 mono-ubiquitination and interaction with BARD1 regulates cell cycle progression and maintains genome stability

p50, the mature product of NFKB1, is constitutively produced from its precursor, p105. Here, we identify BARD1 as a p50-interacting factor. p50 directly associates with the BARD1 BRCT domains via a C-terminal phospho-serine motif. This interaction is induced by ATR and results in mono-ubiquitination of p50 by the BARD1/BRCA1 complex. During the cell cycle, p50 is mono-ubiquitinated in S phase and loss of this post-translational modification increases S phase progression and chromosomal breakage. Genome-wide studies reveal a substantial decrease in p50 chromatin enrichment in S phase and Cycln E is identified as a factor regulated by p50 during the G1 to S transition. Functionally, interaction with BARD1 promotes p50 protein stability and consistent with this, in human cancer specimens, low nuclear BARD1 protein strongly correlates with low nuclear p50. These data indicate that p50 mono-ubiquitination by BARD1/BRCA1 during the cell cycle regulates S phase progression to maintain genome integrity.

p50 is a constitutively produced NF-κB subunit that modulates the response to DNA damage. Here, the authors show that activation of ATR during S phase induces p50 interaction with BARD1 resulting in p50 mono-ubiquitination, facilitating cell cycle progression and promoting chromosome integrity.

SFMBT2-Mediated Infiltration of Preadipocytes and TAMs in Prostate Cancer

Infiltration of diverse cell types into tumor microenvironment plays a critical role in cancer progression including metastasis. We previously reported that SFMBT2 (Scm-like with four mbt domains 2) regulates the expression of matrix metalloproteinases (MMPs) and migration and invasion of cancer cells in prostate cancer. Here we investigated whether the down-regulation of SFMBT2 regulates the infiltration of preadipocytes and tumor-associated macrophages (TAMs) in prostate cancer. We found that the down-regulation of SFMBT2 promotes the infiltration of preadipocytes and TAMs through up-regulation of CXCL8, CCL2, CXCL10, and CCL20 expression in prostate cancer. Expression of CXCL8, CCL2, CXCL10, and CCL20 was also elevated in prostate cancer patients having a higher Gleason score (≥8), which had substantially lower SFMBT2 expression. We also found that the up-regulation of CXCL8, CCL2, CXCL10, and CCL20 expression is dependent on NF-κB activation in prostate cancer cells expressing a low level of SFMBT2. Moreover, increased IL-6 from infiltrated preadipocytes and TAMs promoted migration and invasion of prostate cancer cells expressing a low level of SFMBT2. Our study may suggest that SFMBT2 a critical regulator for the infiltration of preadipocytes and TAMs into the prostate tumor microenvironment. Thus, the regulation of SFMBT2 may provide a new therapeutic strategy to inhibit prostate cancer metastasis, and SFMBT2 could be used as a potential biomarker in prostate cancer metastasis.

TRIM22 activates NF-κB signaling in glioblastoma by accelerating the degradation of IκBα

NF-κB signaling plays a critical role in tumor growth and treatment resistance in GBM as in many other cancers. However, the molecular mechanisms underlying high, constitutive NF-κB activity in GBM remains to be elucidated. Here, we screened a panel of tripartite motif (TRIM) family proteins and identified TRIM22 as a potential activator of NF-κB using an NF-κB driven luciferase reporter construct in GBM cell lines. Knockout of TRIM22 using Cas9-sgRNAs led to reduced GBM cell proliferation, while TRIM22 overexpression enhanced proliferation of cell populations, in vitro and in an orthotopic xenograft model. However, two TRIM22 mutants, one with a critical RING-finger domain deletion and the other with amino acid changes at two active sites of RING E3 ligase (C15/18A), were both unable to promote GBM cell proliferation over controls, thus implicating E3 ligase activity in the growth-promoting properties of TRIM22. Co-immunoprecipitations demonstrated that TRIM22 bound a negative regulator of NF-κB, NF-κB inhibitor alpha (IκBα), and accelerated its degradation by inducing K48-linked ubiquitination. TRIM22 also formed a complex with the NF-κB upstream regulator IKKγ and promoted K63-linked ubiquitination, which led to the phosphorylation of both IKKα/β and IκBα. Expression of a non-phosphorylation mutant, srIκBα, inhibited the growth-promoting properties of TRIM22 in GBM cell lines. Finally, TRIM22 was increased in a cohort of primary GBM samples on a tissue microarray, and high expression of TRIM22 correlated with other clinical parameters associated with progressive gliomas, such as wild-type IDH1 status. In summary, our study revealed that TRIM22 activated NF-κB signaling through posttranslational modification of two critical regulators of NF-κB signaling in GBM cells.

A Nonsense N -Terminus NFKB2 Mutation Leading to Haploinsufficiency in a Patient with a Predominantly Antibody Deficiency

The noncanonical NF-κB pathway is implicated in diverse biological and immunological processes. Monoallelic C-terminus loss-of-function and gain-of-function mutations of NFKB2 have been recently identified as a cause of immunodeficiency manifesting with common variable immunodeficiency (CVID) or combined immunodeficiency (CID) phenotypes. Herein we report a family carrying a heterozygous nonsense mutation in NFKB2 (c.809G > A, p.W270*). This variant is associated with increased mRNA decay and no mutant NFKB2 protein expression, leading to NFKB2 haploinsufficiency. Our findings demonstrate that bona fide NFKB2 haploinsufficiency, likely caused by mutant mRNA decay and protein instability leading to the transcription and expression of only the wild-type allele, is associated with clinical immunodeficiency, although with incomplete clinical penetrance. Abnormal B cell development, hypogammaglobulinemia, poor antibody response, and abnormal noncanonical (but normal canonical) NF-κB pathway signaling are the immunologic hallmarks of this disease. This adds a third allelic variant to the pathophysiology of NFKB2-mediated immunodeficiency disorders.

Metastasis-Associated Protein 2 Represses NF-κB to Reduce Lung Tumor Growth and Inflammation

Although NF-κB is known to play a pivotal role in lung cancer, contributing to tumor growth, microenvironmental changes, and metastasis, the epigenetic regulation of NF-κB in tumor context is largely unknown. Here we report that the IKK2/NF-κB signaling pathway modulates metastasis-associated protein 2 (MTA2), a component of the nucleosome remodeling and deacetylase complex (NuRD). In triple transgenic mice, downregulation of IKK2 (Sftpc-cRaf-IKK2DN) in cRaf-induced tumors in alveolar epithelial type II cells restricted tumor formation, whereas activation of IKK2 (Sftpc-cRaf-IKK2CA) supported tumor growth; both effects were accompanied by altered expression of MTA2. Further studies employing genetic inhibition of MTA2 suggested that in primary tumor growth, independent of IKK2, MTA2/NuRD corepressor complex negatively regulates NF-κB signaling and tumor growth, whereas later dissociation of MTA2/NuRD complex from the promoter of NF-κB target genes and IKK2-dependent positive regulation of MTA2 leads to activation of NF-κB signaling, epithelial-mesenchymal transition, and lung tumor metastasis. These findings reveal a previously unrecognized biphasic role of MTA2 in IKK2/NF-κB-driven primary-to-metastatic lung tumor progression. Addressing the interaction between MTA2 and NF-κB would provide potential targets for intervention of tumor growth and metastasis. SIGNIFICANCE: These findings strongly suggest a prominent role of MTA2 in primary tumor growth, lung metastasis, and NF-κB signaling modulatory functions.

Loss of PTEN sensitizes head and neck squamous cell carcinoma to 5-AZA-2'-deoxycytidine

OBJECTIVE

Head and neck squamous cell carcinoma (HNSCC) is an aggressive cancer associated with poor survival. Phosphatase and tensin homolog (PTEN) is a tumor suppressor gene involved in the maintenance of stem cells. DNA methylation is a known epigenetic modification involved in tumor progression. In this study, we investigated the effect of the DNA demethylation agent 5-AZA-2'-deoxycytidine (5-AZA) over HNSCC and its population of cancer stem cells (CSCs) presenting dysfunctional PTEN.

STUDY DESIGN

The effects of 5-AZA on HNSCC were evaluated by using WSU-HN13 cells. CSC was assessed by sphere-forming assays, along with the endogenous levels of aldehyde dehydrogenase. The clonogenic potential of tumors was evaluated, along with the protein expression of mTOR signaling and the identification of nuclear factor-κB (NF-κB) and epithelial-mesenchymal transition (EMT)-associated genes, using real-time polymerase chain reaction (PCR).

RESULTS

We observed that loss of PTEN enhances tumor biologic behavior, including colony- and tumor sphere-forming abilities. We also found that 5-AZA has an inhibitory effect over the CSCs and molecular markers associated with the NF-κB and EMT pathways.

CONCLUSIONS

Our findings suggest that the stratification of treatment of HNSCC based on PTEN status may identify a subset of patients who can benefit from the coadministration of 5-AZA.

AEBP1 is a Novel Oncogene: Mechanisms of Action and Signaling Pathways

Adipocyte enhancer-binding protein 1 (AEBP1) is a transcriptional repressor involved in the regulation of critical biological processes including adipogenesis, mammary gland development, inflammation, macrophage cholesterol homeostasis, and atherogenesis. Several years ago, we first reported the ability of AEBP1 to exert a positive control over the canonical NF-κB pathway. Indeed, AEBP1 positively regulates NF-κB activity via its direct interaction with IκBα, a key NF-κB inhibitor. AEBP1 overexpression results in uncontrollable activation of NF-κB, which may have severe pathogenic outcomes. Recently, the regulatory relationship between AEBP1 and NF-κB pathway has been of great interest to many researchers primarily due to the implication of NF-κB signaling in critical cellular processes such as inflammation and cancer. Since constitutive activation of NF-κB is widely implicated in carcinogenesis, AEBP1 overexpression is associated with tumor development and progression. Recent studies sought to explore the effects of the overexpression of AEBP1, as a potential oncogene, in different types of cancer. In this review, we analyze the effects of AEBP1 overexpression in a variety of malignancies (e.g., breast cancer, glioblastoma, bladder cancer, gastric cancer, colorectal cancer, ovarian cancer, and skin cancer), with a specific focus on the AEBP1-mediated control over the canonical NF-κB pathway. We also underscore the ability of AEBP1 to regulate crucial cancer-related events like cell proliferation and apoptosis in light of other key pathways (e.g., PI3K-Akt, sonic hedgehog (Shh), p53, parthanatos (PARP-1), and PTEN). Identifying AEBP1 as a potential biomarker for cancer prognosis may lead to a novel therapeutic target for the prevention and/or treatment of various types of cancer.

C20orf27 Promotes Cell Growth and Proliferation of Colorectal Cancer via the TGFβR-TAK1-NFĸB Pathway

Background: Colorectal cancer (CRC) is a high incidence of malignant tumors that lacks highly effective and targeted drugs and thus it is in urgent need of finding new specific molecular targets. Methods and Results: In this study, by using WST-1 (Highly water-soluble tetrazolium salt-1) and colony formation assays, we found that C20orf27 (chromosome 20 open reading frame 27), a functionally unknown protein, enhanced the growth and proliferation of CRC cells. The nude mouse tumor formation experiments verified that C20orf27 promoted the growth of CRC. Signal pathway analysis identified the TGFβR-TAK1-NFĸB cascade as a mediator in C20orf27-induced CRC progression. Inhibition experiments using NFĸB inhibitors reversed this progression. Co-immunoprecipitation showed that C20orf27 promoted the activation of the TGFβR-TAK1-NFĸB pathway by interacting with PP1c (the catalytic subunit of type 1 phosphatase). Conclusions: Our results firstly characterized the functional role and molecular mechanism of C20orf27 in driving CRC growth and proliferation through the TGFβR-TAK1-NFĸB pathway, suggesting its potential as a novel CRC candidate therapeutic target and tumor marker.

Silencing CDC25A inhibits the proliferation of liver cancer cells by downregulating IL‑6 in vitro and in vivo

Cell division cycle 25A (CDC25A) is a core regulator of the cell cycle that has a dual‑specific phosphatase activity, which is closely associated with the occurrence and development of a tumor, and is overexpressed in liver cancer. However, the molecular mechanism of CDC25A in the development of liver cancer remains unclear. The purpose of the present study was to further investigate the effect of CDC25A on cell proliferation in vitro and in vivo and to investigate whether an interaction exists between CDC25A and interleukin (IL)‑6 in liver cancer. An Affymetrix human gene expression profiling chip screened differentially expressed genes in HepG2 cells with silenced CDC25A and the IL‑6 signaling pathway was revealed to be significantly inhibited (P<0.05). In the present study, the effects of CDC25A on cell proliferation and migration were analyzed using cell cycle, MTT and Transwell assays. Reverse transcription‑quantitative PCR, western blot and immunohistochemistry analyses confirmed that silencing the CDC25A gene downregulated the expression of IL‑6 in HepG2 cells and the mRNA and protein expression of IL‑1β, mitogen‑activated protein kinase kinase kinase 14 (NIK) and nuclear factor‑κB (NF‑κB), which are regulatory molecules upstream of IL‑6. In addition, silencing CDC25A by short hairpin RNA inhibited the development of liver cancer xenograft tumor types in nude mice, and decreased the expression of IL‑1β, NIK, NF‑κB and IL‑6 in xenograft tumor types. In conclusion, silencing CDC25A significantly inhibited the proliferation of liver cancer cells in vitro and in vivo, potentially via an interaction with IL‑6 through the downregulation of the IL‑1β/NIK/NF‑κB signaling axis.