The NF-κB subunit RelB regulates the migration and invasion abilities and the radio-sensitivity of prostate cancer cells

Fimepinostat Impairs NF-κB and PI3K/AKT Signaling and Enhances Gemcitabine Efficacy in H3.3K27M-Diffuse Intrinsic Pontine Glioma

Diffuse intrinsic pontine glioma (DIPG) is the most aggressive pediatric brain tumor, and the oncohistone H3.3K27M mutation is associated with significantly worse clinical outcomes. Despite extensive research efforts, effective approaches for treating DIPG are lacking. Through drug screening, we identified the combination of gemcitabine and fimepinostat as a potent therapeutic intervention for H3.3K27M DIPG. H3.3K27M facilitated gemcitabine-induced apoptosis in DIPG, and gemcitabine stabilized and activated p53, including increasing chromatin accessibility for p53 at apoptosis-related loci. Gemcitabine simultaneously induced a prosurvival program in DIPG through activation of RELB-mediated NF-κB signaling. Specifically, gemcitabine induced the transcription of long terminal repeat elements, activated cGAS-STING signaling, and stimulated noncanonical NF-κB signaling. A drug screen in gemcitabine-treated DIPG cells revealed that fimepinostat, a dual inhibitor of HDAC and PI3K, effectively suppressed the gemcitabine-induced NF-κB signaling in addition to blocking PI3K/AKT activation. Combination therapy comprising gemcitabine and fimepinostat elicited synergistic antitumor effects in vitro and in orthotopic H3.3K27M DIPG xenograft models. Collectively, p53 activation using gemcitabine and suppression of RELB-mediated NF-κB activation and PI3K/AKT signaling using fimepinostat is a potential therapeutic strategy for treating H3.3K27M DIPG.

SIGNIFICANCE

Gemcitabine activates p53 and induces apoptosis to elicit antitumor effects in H3.3K27M DIPG, which can be enhanced by blocking NF-κB and PI3K/AKT signaling with fimepinostat, providing a synergistic combination therapy for DIPG.

Enhanced Inhibition of Cancer Cell Migration by a Planar Catechin Analog

Cancer cell migration is related to malignancy and patient prognosis. We previously reported that intracellular reactive oxygen species (ROS) promoted cancer cellular migration and invasion and that an antioxidant enzyme could help to attenuate the malignancy. Catechin is known as an antioxidant, and we have developed a catechin analog, planar catechin, which showed an antioxidant activity significantly stronger than that of the parent (+)-catechin. In this study, we examined the effects of the planar catechin on the migration of gastric normal and cancer cells. A scratched assay showed that the planar catechin suppressed the cellular migration rates in both normal and cancer cells, while the prevention levels in cancer cells were remarkable compared to the normal cells. These results suggest that the planar catechin with the enhanced antioxidant activity effectively scavenged the ROS overexpressed in the cancer cells and inhibited cancer cellular activities, including migration.

The Role of the Toll-like Receptor 2 and the cGAS-STING Pathways in Breast Cancer: Friends or Foes?

Breast cancer stands as a primary malignancy among women, ranking second in global cancer-related deaths. Despite treatment advancements, many patients progress to metastatic stages, posing a significant therapeutic challenge. Current therapies primarily target cancer cells, overlooking their intricate interactions with the tumor microenvironment (TME) that fuel progression and treatment resistance. Dysregulated innate immunity in breast cancer triggers chronic inflammation, fostering cancer development and therapy resistance. Innate immune pattern recognition receptors (PRRs) have emerged as crucial regulators of the immune response as well as of several immune-mediated or cancer cell-intrinsic mechanisms that either inhibit or promote tumor progression. In particular, several studies showed that the Toll-like receptor 2 (TLR2) and the cyclic GMP-AMP synthase (cGAS)-stimulator of interferon genes (STING) pathways play a central role in breast cancer progression. In this review, we present a comprehensive overview of the role of TLR2 and STING in breast cancer, and we explore the potential to target these PRRs for drug development. This information will significantly impact the scientific discussion on the use of PRR agonists or inhibitors in cancer therapy, opening up new and promising avenues for breast cancer treatment.

Integration approach of transcriptomics and metabolomics reveals the toxicity of Anthracene and its chlorinated derivatives on human hepatic cells

Polycyclic aromatic hydrocarbons (PAHs) and Chlorinated PAHs (Cl-PAHs) are ubiquitous environmental contaminants. The toxicological information of anthracene (Ant) and its chlorinated derivatives is quite limited. In this study, an integrated metabolomic and transcriptomic analysis approach was adopted to assess the toxic effects triggered by Ant and its chlorinated derivatives, 2-chloroanthracene (2-ClAnt) and 9,10-dichloroanthracen (9,10-Cl2Ant), at human-relevant levels on human normal hepatocyte L02 cells. The cell viability test showed no significant effects on the viability of L02 cells exposed to Ant, 2-ClAnt and 9,10-Cl2Ant at doses of 5-500 nM for 24 h. However, based on transcriptomic analysis, Ant, 2-ClAnt and 9,10-Cl2Ant exposure at human-relevant levels obviously perturbed global gene expression in L02 cells and induced the differential expression of several genes related to cancer development. As the number of genes related to cancer development altered by 9,10-Cl2Ant is the largest, 9,10-Cl2Ant posed greater risks of tumor development than Ant and 2-ClAnt did. Metabolomics analysis demonstrated that Ant, 2-ClAnt and 9,10-Cl2Ant caused significant metabolic perturbation in L02 cells. Pathway enrichment analysis indicated that Ant, 2-ClAnt and 9,10-Cl2Ant mainly perturbed the lipid metabolism and nucleotide metabolism pathway. However, 9,10-Cl2Ant caused a wider perturbation to metabolic pathways than Ant and 2-ClAnt did. In addition, dysregulation of nucleotide metabolism perturbed by Ant, 2-ClAnt and 9,10-Cl2Ant may be associated with the genomic instability and further carcinogenesis.

The Molecular Basis and Clinical Consequences of Chronic Inflammation in Prostatic Diseases: Prostatitis, Benign Prostatic Hyperplasia, and Prostate Cancer

Chronic inflammation is now recognized as one of the major risk factors and molecular hallmarks of chronic prostatitis, benign prostatic hyperplasia (BPH), and prostate tumorigenesis. However, the molecular mechanisms by which chronic inflammation signaling contributes to the pathogenesis of these prostate diseases are poorly understood. Previous efforts to therapeutically target the upstream (e.g., TLRs and IL1-Rs) and downstream (e.g., NF-κB subunits and cytokines) inflammatory signaling molecules in people with these conditions have been clinically ambiguous and unsatisfactory, hence fostering the recent paradigm shift towards unraveling and understanding the functional roles and clinical significance of the novel and relatively underexplored inflammatory molecules and pathways that could become potential therapeutic targets in managing prostatic diseases. In this review article, we exclusively discuss the causal and molecular drivers of prostatitis, BPH, and prostate tumorigenesis, as well as the potential impacts of microbiome dysbiosis and chronic inflammation in promoting prostate pathologies. We specifically focus on the importance of some of the underexplored druggable inflammatory molecules, by discussing how their aberrant signaling could promote prostate cancer (PCa) stemness, neuroendocrine differentiation, castration resistance, metabolic reprogramming, and immunosuppression. The potential contribution of the IL1R-TLR-IRAK-NF-κBs signaling molecules and NLR/inflammasomes in prostate pathologies, as well as the prospective benefits of selectively targeting the midstream molecules in the various inflammatory cascades, are also discussed. Though this review concentrates more on PCa, we envision that the information could be applied to other prostate diseases. In conclusion, we have underlined the molecular mechanisms and signaling pathways that may need to be targeted and/or further investigated to better understand the association between chronic inflammation and prostate diseases.

cGAS-STING signalling in cancer: striking a balance with chromosomal instability

Chromosomal instability (CIN) is a hallmark of cancer that drives tumour evolution. It is now recognised that CIN in cancer leads to the constitutive production of misplaced DNA in the form of micronuclei and chromatin bridges. These structures are detected by the nucleic acid sensor cGAS, leading to the production of the second messenger 2'3'-cGAMP and activation of the critical hub of innate immune signalling STING. Activation of this immune pathway should instigate the influx and activation of immune cells, resulting in the eradication of cancer cells. That this does not universally occur in the context of CIN remains an unanswered paradox in cancer. Instead, CIN-high cancers are notably adept at immune evasion and are highly metastatic with typically poor outcomes. In this review, we discuss the diverse facets of the cGAS-STING signalling pathway, including emerging roles in homeostatic processes and their intersection with genome stability regulation, its role as a driver of chronic pro-tumour inflammation, and crosstalk with the tumour microenvironment, which may collectively underlie its apparent maintenance in cancers. A better understanding of the mechanisms whereby this immune surveillance pathway is commandeered by chromosomally unstable cancers is critical to the identification of new vulnerabilities for therapeutic exploitation.

RelB promotes the migration and invasion of prostate cancer DU145 cells via exosomal ICAM1 in vitro

RelB confers the aggressiveness to prostate cancer (PC) cells. Exosomes modulate the oncogenesis and progression of PC. We aimed to identify the downstream molecule in the exosomes, by which RelB increases the aggressiveness of DU145. Totally, 137 upregulated and 55 downregulated exosomal proteins were identified from RelB-knockdown DU145 cells by Liquid Chromatography-Mass Spectrometry. UALCAN, GeneMANIA and tissue microarray analysis revealed that intercellular adhesion molecule-1 (ICAM1) was positively related to and co-expressed with RelB in PC. Luciferase reporter assay revealed that RelB bound directly to the promoter of ICAM1. ICAM1 overexpression enhanced the migration and invasion abilities of DU145 cells. Exposure to exosomes derived from ICAM1 overexpressing cells (hICAM1-exo) strengthened the aggressiveness of RelB-knockdown cells, especially the migration and invasion capabilities. Mechanistically, the expression of ICAM1, Integrin β1, MMP9 and uPA were upregulated in RelB-knockdown cells upon hICAM1-exo treatment. Exosomal ICAM1 is the key molecule regulated by RelB, which increased the aggressiveness of DU145. The study suggests that cell-cell communication via exosomal ICAM1 is a novel mechanism by which RelB promotes PC progression.

Novel therapeutic regimens for urethane-induced early lung cancer in rats: Combined cisplatin nanoparticles with vitamin-D3

Lung cancer remains incurable; therefore, novel therapeutical approaches are of great demand. This study was designed to investigate the effectiveness of cisplatin nanoparticles combined with vitamin-D₃ on urethane-induced early lung cancer in rats and to clarify the underlying signaling mechanisms. Early lung cancer was induced in male Wistar rats by urethane. Rats were divided into six groups: I-control, II-cancer untreated, III-cancer + free cisplatin, IV-cancer + cisplatin nanoparticles, V-cancer + free cisplatin + vitamin-D₃ , VI-cancer + cisplatin nanoparticles + vitamin-D₃ . Inflammation, proliferation, and apoptosis were evaluated together with the levels of tumor marker CK-19 along with histological assessment. Treatment of lung cancer with either free or nanoparticles of cisplatin alone demonstrated significant suppression in the expression of inflammatory, anti-apoptotic and tumor markers compared to rats with lung cancer. Moreover, vitamin-D₃ supplementation with either cisplatin forms lead to a further decrease of all markers, markedly with cisplatin nanoparticles. The present study shows the synergistic effect of cisplatin-nanoparticles combined with vitamin-D₃ as a new therapy regimen against lung cancer. Further studies with larger sample sizes and longer duration are needed to confirm these results.

NF-κB signaling promotes castration-resistant prostate cancer initiation and progression

Prostate Cancer (PCa) is the second leading cause of cancer-related death in men. Adenocarcinoma of the prostate is primarily composed of Androgen Receptor-positive (AR⁺) luminal cells that require AR transcriptional activity for survival and proliferation. As a consequence, androgen deprivation and anti-androgens are used to treat PCa patients whose disease progresses following attempted surgical or radiation interventions. Unfortunately, patients with advanced PCa can develop incurable castration-resistant PCa (CRPCa) due to mutated, variant, or overexpressed AR. Conversely, low or no AR accumulation or activity can also underlie castration resistance. Whether CRPCa is due to aberrant AR activity or AR independence, NF-κB signaling is also implicated in the initiation and maintenance of CRPCa and, thus, the NF-κB pathway may be a promising alternative therapeutic target. In this review, we present evidence that NF-κB signaling promotes CRPCa initiation and progression, describe the dichotomic role of NF-κB in the regulation of AR expression and activity and outline studies that explore NF-κB inhibitors as PCa therapies.

The cGAS Paradox: Contrasting Roles for cGAS-STING Pathway in Chromosomal Instability

Chromosomal instability (CIN) is an intricate phenomenon that is often found in human cancer, characterized by persisting errors in chromosome segregation. This ongoing chromosome mis-segregation results in structural and numerical chromosomal abnormalities that have been widely described to promote tumor evolution. In addition to being a driver of tumor evolution, recent evidence demonstrates CIN to be the central node of the crosstalk between a tumor and its surrounding microenvironment, as mediated by the cGAS-STING pathway. The role that cGAS-STING signaling exerts on CIN tumors is both complex and paradoxical. On one hand, the cGAS-STING axis promotes the clearance of CIN tumors through recruitment of immune cells, thus suppressing tumor progression. On the other hand, the cGAS-STING pathway has been described to be the major regulator in the promotion of metastasis of CIN tumors. Here, we review this dual role of the cGAS-STING pathway in the context of chromosomal instability and discuss the potential therapeutic implications of cGAS-STING signaling for targeting CIN tumors.

Expression Of Intracellular Components of the NF-κB Alternative Pathway (NF-κB2, RelB, NIK and Bcl3) is Associated With Clinical Outcome of NSCLC Patients

A growing number of studies has shed light on the role of the NF-κΒ in non-small-cell lung cancer (NSCLC). To address the significance of major effectors of the NF-κΒ alternative pathway, we investigated the relationship between NF-κΒ2, RelB, NIK and Bcl3 expression (mRNA and protein) and the clinical outcome of NSCLC patients. NF-κΒ2, RelB, NIK and Bcl3 protein expression levels were assessed by immunohistochemistry in tissue samples from 151 NSCLC patients who had curative resection. mRNA levels were also evaluated in 69 patients using quantitative real-time PCR. Although all studied proteins were overexpressed in NSCLC (P < 0.001 for all), only RelB mRNA levels were strongly increased in cancerous specimens compared to tumor-adjacent non-neoplastic tissues (P = 0.009). Moreover, NF-κB2, RelB and Bcl3 expression was associated with overall survival (OS). In particular, cytoplasmic and mRNA expression of RelB was related to 5-year OS (P = 0.014 and P = 0.006, respectively). Multivariate analysis also showed that Bcl3 expression (nuclear and cytoplasmic) was associated with increased 5-year OS (P = 0.002 and P = 0.036, respectively). In addition, higher Bcl3 mRNA levels were associated with inferior OS in stages I & II and improved OS in stages III and IV after 5-year follow-up (P = 0.004 and P = 0.001, respectively). Furthermore, stage I patients with lower NF-κB2 mRNA levels had better 5-year survival in univariate and multivariate analysis (P = 0.031 and P = 0.028, respectively). Interestingly, RelB expression (cytoplasmic and mRNA) was inversely associated with relapse rates (P = 0.027 and P = 0.015, respectively), while low NIK cytoplasmic expression was associated with lower relapse rates (P = 0.019). Cytoplasmic NIK expression as well as NF-κB2/ Bcl3 detection was associated with lymph node infiltration (P = 0.039 and P = 0.014, respectively). The present study confirms the deregulation of the NF-κB alternative pathway in NSCLC and also demonstrates the importance of this pathway in prognosis, recurrence and infiltration of regional lymph nodes.

Inflammatory signaling in genomically instable cancers

Recent studies have shown that genomic instability in tumor cells leads to activation of inflammatory signaling through the cGAS/STING pathway. In this review, we describe multiple ways by which genomic instability leads to cGAS/STING-mediated inflammatory signaling, as well as the consequences for tumor development and the tumor microenvironment. Also, we elaborate on how tumor cells have apparently evolved to escape the immune surveillance mechanisms that are triggered by cGAS/STING signaling. Finally, we describe how cGAS/STING-mediated inflammatory signaling can be therapeutically targeted to improve therapy responses.

Downregulation of Pro-Inflammatory and Pro-Angiogenic Pathways in Prostate Cancer Cells by a Polyphenol-Rich Extract from Olive Mill Wastewater

Dietary phytochemicals are particularly attractive for chemoprevention and are able to modulate several signal transduction pathways linked with cancer. Olive oil, a major component of the Mediterranean diet, is an abundant source of phenolic compounds. Olive oil production is associated with the generation of a waste material, termed 'olive mill wastewater' (OMWW) that have been reported to contain water-soluble polyphenols. Prostate cancer (PCa) is considered as an ideal cancer type for chemopreventive approaches, due to its wide incidence but relatively long latency period and progression time. Here, we investigated activities associated with potential preventive properties of a polyphenol-rich olive mill wastewater extract, OMWW (A009), on three in vitro models of PCa. A009 was able to inhibit PCa cell proliferation, adhesion, migration, and invasion. Molecularly, we found that A009 targeted NF-κB and reduced pro-angiogenic growth factor, VEGF, CXCL8, and CXCL12 production. IL-6/STAT3 axis was also regulated by the extract. A009 shows promising properties, and purified hydroxytyrosol (HyT), the major polyphenol component of A009, was also active but not always as effective as A009. Finally, our results support the idea of repositioning a food waste-derived material for nutraceutical employment, with environmental and industrial cost management benefits.

RelB plays an oncogenic role and conveys chemo-resistance to DLD-1 colon cancer cells

Background

Nuclear transcription factor kappa B (NF-κB) subunits exhibit crucial roles in tumorigenesis and chemo-sensitivity. Recent studies suggest that RelB, the key subunit of the alternative NF-κB pathway, plays a critical role in the progression of diverse human malignancies. However, the significance of RelB in colorectal cancer (CRC) remains unclear. Here, we systematically explored the functions of the alternative NF-κB subunit RelB in colon cancer cells and its underlying mechanism.

Methods

Stably transfected RelB-shRNA DLD-1 cells were established using Lipofectamine 2000. NF-κB DNA-binding capability was quantified using an ELISA-based NF-κB activity assay. Cell growth was monitored by an x-Celligence system. Cell proliferation was analyzed by a CCK-8 and a Brdu proliferation assay. Response to 5-FU was assessed by an x-Celligence system. Cell apoptosis and cell cycle was detected using flow cytometry analyses. Cell migration and invasion abilities were detected by an x-Celligence system, Transwell inserts, and wound-healing assays. RelB expression and its clinical significance were analyzed using the CRC tissue microarray. The expression of NF-κB signaling subunits, AKT/mTOR signaling molecules, cell cycle related proteins, MMP2, MMP9, and Integrin β-1 were measured by Western blotting analyses.

Results

The RelB-silencing inhibited cell growth of DLD-1 cells. The RelB-silencing exerted the anti-proliferative by downregulation of AKT/mTOR signaling. The RelB-silencing caused G₀–G₁ cell cycle arrested likely due to decreasing the expression of Cyclin D1 and CDK4, concomitant with increased expression of p27^Kip1. The RelB-silencing enhanced cytotoxic effect of 5-FU and induced cell accumulation in S-phase. The RelB-silencing impaired the migration and invasion potential of DLD-1 cells, which was related to downregulation of MMP2, MMP9, and Integrin β-1. Importantly, the RelB expression was correlated with depth of tumor invasion, lymph node metastasis, metastasis stage, and pTNM stage. High-RelB expression was significantly correlated with poor overall survival in CRC patients.

Conclusion

Our studies here provided evidence that RelB plays an oncogenic role and conveys chemo-resistance to 5-FU. RelB can be considered as an independent indicator of prognosis in CRC.

Inflammation and NF-κB Signaling in Prostate Cancer: Mechanisms and Clinical Implications

Prostate cancer is a highly prevalent form of cancer that is usually slow-developing and benign. Due to its high prevalence, it is, however, still the second most common cause of death by cancer in men in the West. The higher prevalence of prostate cancer in the West might be due to elevated inflammation from metabolic syndrome or associated comorbidities. NF-κB activation and many other signals associated with inflammation are known to contribute to prostate cancer malignancy. Inflammatory signals have also been associated with the development of castration resistance and resistance against other androgen depletion strategies, which is a major therapeutic challenge. Here, we review the role of inflammation and its link with androgen signaling in prostate cancer. We further describe the role of NF-κB in prostate cancer cell survival and proliferation, major NF-κB signaling pathways in prostate cancer, and the crosstalk between NF-κB and androgen receptor signaling. Several NF-κB-induced risk factors in prostate cancer and their potential for therapeutic targeting in the clinic are described. A better understanding of the inflammatory mechanisms that control the development of prostate cancer and resistance to androgen-deprivation therapy will eventually lead to novel treatment options for patients.

The nuclear transcription factor RelB functions as an oncogene in human lung adenocarcinoma SPC-A1 cells

Background

Lung cancer is a leading public health issue worldwide. Although therapeutic approaches have improved drastically in the last decades, the prognosis of lung cancer patients remains suboptimal. The canonical nuclear transcription factor kappa B (NF-κB) signalling pathway is critical in the carcinogenesis of lung cancer. The non-canonical NF-κB signalling pathway (represented by RelB) has attracted increasing attention in the pathogenesis of haematological and epithelial malignancies. However, the function of RelB in non-small cell lung cancer (NSCLC) is still unclear. Recently, high expression of RelB has been detected in NSCLC tissues. We have also demonstrated that RelB expression is an independent prognostic factor in NSCLC patients.

Methods

The mRNA and protein expression of RelB in NSCLC tissues were detected by qRT-PCR and IHC assay. The cell growth of SPC-A1 cells was detected in real-time using the x-Celligence system and xenograft tumour assays. The proliferation capability of cells was detected using a CFSE assay. Cell apoptosis was measured using Annexin V/PI staining, cell cycle was analyzed by the cytometry. Cell migration abilities were detected using the x-Celligence system and wound healing assays. The relative amounts of the active and inactive gelatinases MMP-2 and MMP-9 were examined using gelatin zymography experiments. Apoptosis of RelB depletion SPC-A1 cells after ionizing radiation at 8 Gy. The expression of cellular proliferation signal pathway related-proteins were examined by Western blot analysis.

Results

The expression of RelB increases in NSCLC tissues. High RelB expression was significantly correlated with advanced-metastatic stage in patients with NSCLC. RelB-silencing inhibits cell growth in vitro and in vivo. We found that RelB affected cell proliferation by regulating AKT phosphorylation. RelB silencing attenuates the migration and invasion abilities of SPC-A1 cells and is likely related to the down regulation of MMP-9 activity and Integrin β-1 expression. In addition, RelB modulated radiation-induced survival of NSCLC cells predominantly by regulating Bcl-xL expression.

Conclusions

Given the involvement of RelB in cell proliferation, migration, invasion, and radio-resistance, RelB functions as an oncogene in NSCLC cells. Our data here shed light on unexplored aspects of RelB in NSCLC.

Activation of the non-canonical NF-κB/p52 pathway in vascular endothelial cells by RANKL elicits pro-calcific signalling in co-cultured smooth muscle cells

BACKGROUND

The intimal endothelium is known to condition the underlying medial smooth muscle cell (SMC) layer of the vessel wall, and is highly responsive to receptor-activator of nuclear factor-κB ligand (RANKL) and tumour necrosis factor-related apoptosis-inducing ligand (TRAIL), pro-calcific and anti-calcific agents, respectively. In this paper, we tested the hypothesis that RANKL-induced activation of endothelial NF-κB signalling is essential for pro-calcific activation of the underlying SMCs.

METHODS

For these studies, human aortic endothelial and smooth muscle cell mono-cultures (HAECs, HASMCs) were treated with RANKL (0-25 ng/ml ± 5 ng/ml TRAIL) for 72 h. Non-contact transwell HAEC:HASMC co-cultures were also employed in which the luminal HAECs were treated with RANKL (± 5 ng/ml TRAIL), followed by analysis of pro-calcific markers in the underlying subluminal HASMCs.

RESULTS

Treatment of either HAECs or HASMCs with RANKL activated the non-canonical NF-κB/p52 and canonical NF-κB/p65 pathways in both cell types. In RANKL ± TRAIL-treated HAECs, recombinant TRAIL, previously demonstrated by our group to strongly attenuate the pro-calcific signalling effects of RANKL, was shown to specifically block the RANKL-mediated activation of non-canonical NF-κB/p52, clearly pointing to the mechanistic relevance of this specific pathway to RANKL function within endothelial cells. In a final series of HAEC:HASMC transwell co-culture experiments, RANKL treatment of HAECs that had been genetically silenced (via siRNA) for the NF-κB2 gene (the molecular forerunner to NF-κB/p52 generation) exhibited strongly attenuated pro-calcific activation of underlying HASMCs relative to scrambled siRNA controls.

SUMMARY

These in vitro observations provide valuable mechanistic insights into how RANKL may potentially act upon endothelial cells through activation of the alternative NF-κB pathway to alter endothelial paracrine signalling and elicit pro-calcific responses within underlying vascular smooth muscle cells.

Chromosomal instability drives metastasis through a cytosolic DNA response

Chromosomal instability is a hallmark of cancer that results from ongoing errors in chromosome segregation during mitosis. Although chromosomal instability is a major driver of tumour evolution, its role in metastasis has not been established. Here we show that chromosomal instability promotes metastasis by sustaining a tumour cell-autonomous response to cytosolic DNA. Errors in chromosome segregation create a preponderance of micronuclei whose rupture spills genomic DNA into the cytosol. This leads to the activation of the cGAS-STING (cyclic GMP-AMP synthase-stimulator of interferon genes) cytosolic DNA-sensing pathway and downstream noncanonical NF-κB signalling. Genetic suppression of chromosomal instability markedly delays metastasis even in highly aneuploid tumour models, whereas continuous chromosome segregation errors promote cellular invasion and metastasis in a STING-dependent manner. By subverting lethal epithelial responses to cytosolic DNA, chromosomally unstable tumour cells co-opt chronic activation of innate immune pathways to spread to distant organs.

Regulation of mRNA gene expression of members of the NF-κB transcription factor gene family by angiotensin II and relaxin 2 in normal and cancer prostate cell lines

An increasing number of researchers are focusing on the influence of local peptide hormones such as angiotensin II (Ang II) and relaxin 2 (RLN2) in the regulation of inflammation and carcinogenesis. The interaction between the renin‑angiotensin system (RAS) and relaxin family peptide system (RFPS) is known to influence the proliferation, adhesion and migration of normal and cancer prostate cell lines. The aim of the present study was to evaluate changes in the expression of nuclear factor‑κB subunit 1 (NFKB1), nuclear factor‑κB subunit 2 (NFKB2), REL proto‑oncogene nuclear factor‑κB p65 subunit (REL), RELA proto‑oncogene nuclear factor‑κB subunit (RELA) and RELB proto‑oncogene nuclear factor‑κB subunit (RELB) mRNA caused by Ang II and RLN2. The members of NF‑kB family are involved in many processes associated with cancer development and metastasis. Reverse transcription‑quantitative polymerase chain reaction analysis identified that both peptide hormones have an influence on the relative expression of nuclear factor‑κB. Following treatment with either peptide, NFKB1 expression was downregulated in all prostate cancer cell lines (LNCaP, DU‑145 and PC3), but not in normal epithelial cells (PNT1A). Conversely, RELB mRNA was enhanced only in non‑cancerous prostate cells. RELA expression was strongly stimulated in the most aggressive cell line, whereas REL mRNA was unchanged. In many cases, the effect was strictly dependent on the cell line and/or the type of peptide: Ang II increased expression of both RELA and REL genes in the androgen‑dependent cell line while RLN2 enhanced NFKB2 and RELA mRNA in androgen‑independent cells (DU‑145). Further research is needed to understand the regulation of NF‑κB family members by key renin‑angiotensin system and RFPS peptides in prostate cancer cells; however, prostate carcinogenesis appears to be influenced by the balance between the cross‑regulation of nuclear factor‑κB (NF‑κB) and androgen receptor pathways by Ang II and relaxin 2.