Endoplasmic reticulum stress stimulates the expression of cyclooxygenase-2 through activation of NF-kappaB and pp38 mitogen-activated protein kinase

EMT induction in normal breast epithelial cells by COX2-expressing fibroblasts

BACKGROUND

The tumor microenvironment (TME) plays a pivotal role in cancer progression, with cancer-associated fibroblasts (CAFs) significantly influencing tumor behavior. Especially, elevated COX2 expressing fibroblasts within the TME, notably in collagen-dense tumors like breast cancer, has been recently emphasized in the literature. However, the specific effect of COX2-expressing CAFs (COX2+ CAFs) on neighboring cells and their consequent role in cancer progression is not fully elucidated.

METHODS

We induced COX2+ fibroblasts by forcing the fibroblasts forming aggregates to undergo Nemosis as a proxy for COX2+ CAFs. This approach enabled us to simulate the paracrine interactions between COX2+ CAFs and normal breast epithelial cells via conditioned media from COX2+ fibroblasts. We developed an innovative in vitro platform that combines cell mechanics-based analysis and biomolecular assays to study the interactions between COX2+ fibroblasts and normal breast epithelial cells. By focusing on the mechanical characteristics of the cells and the epithelial-mesenchymal transition (EMT) marker expressions, we aimed to elucidate the paracrine mechanisms through which COX2+ CAFs influence the tumor microenvironment.

RESULTS

Our in vitro findings demonstrate that COX2+ fibroblasts, through conditioned media, induce significant alterations in the mechanical behavior of normal breast epithelial cells, as evidenced by monolayer expansion measurements using traction force microscopy (TFM). This transition was further corroborated by single-cell morphology and motility analyses, as well as increased expression of mesenchymal markers, including SNAI1 at the mRNA level and vimentin at the protein level. EP4 inhibition partially reversed these changes, preserving cell-cell interactions, limiting monolayer expansion, and reducing mesenchymal-like features, suggesting that PGE2-EP4 signaling plays a key role in mediating the paracrine effects of COX2+ fibroblasts. Together, our findings support a model in which PGE2-EP4 signaling contributes to EMT induction, potentially involving SNAI1 regulation, with implications for targeting stromal-epithelial interactions in breast cancer.

CONCLUSION

This study advances our understanding of the potential mechanisms by which COX2+ CAFs influence tumor progression within the breast tumor microenvironment (TME) through controlled in vitro investigations. By integrating cell mechanics-based analysis, biomolecular assays, and innovative in vitro cell-based modeling of COX2+ CAFs, we have delineated the contributory role of these cells in a controlled setting. These insights lay a groundwork for future studies that could explore the implications of these findings in vivo, potentially guiding targeted therapeutic strategies.

Narciclasine enhances cisplatin-induced apoptotic cell death by inducing unfolded protein response-mediated regulation of NOXA and MCL1

BACKGROUND

Platinum-based chemotherapy is commonly used to treat non-small cell lung cancer (NSCLC); however, innate and acquired resistance is clinically seen in many patients. Hence, a combinatorial approach with novel therapeutic agents to overcome chemoresistance is a promising option for improving patient outcomes. We investigated the combinational anticancer efficacy of cisplatin and narciclasine in three-dimensional NSCLC tumor spheroids.

METHODS

To assess the efficacy of cisplatin and narciclasine, cell viability assays, live/dead cell staining, cell death enzyme-linked immunosorbent assay (ELISA), western blot analysis for proteins related to apoptosis, and in vivo xenograft experiments were performed. The synergistic effects of cisplatin and narciclasine were elucidated through transcriptomic analysis and subsequent validation of candidate molecules by regulating their expression. To clarify the underlying molecular mechanisms, the activation of unfolded protein responses and kinetics of a candidate protein were assessed.

RESULTS

Narciclasine inhibited viability of NSCLC tumor spheroids and augmented the sensitivity of cisplatin-resistant tumor spheroids to cisplatin by inducing apoptosis. After conducting bioinformatic analysis using RNA sequencing data and functional validation experiments, we identified NOXA as a key gene responsible for the enhanced apoptosis observed with the combination of cisplatin and narciclasine. This treatment dramatically increased NOXA while downregulating anti-apoptotic MCL1 levels. Silencing NOXA reversed the enhanced apoptosis and restored MCL1 levels, while MCL1 overexpression protected tumor spheroids from combination treatment-induced apoptosis. Interestingly, narciclasine alone and in combination with cisplatin induced unfolded protein response and inhibited general protein synthesis. Furthermore, the combination treatment increased NOXA expression through the IRE1α-JNK/p38 axis and the activation of p53. Cisplatin alone and in combination with narciclasine destabilized MCL1 via NOXA-mediated proteasomal degradation.

CONCLUSIONS

We identified a natural product, narciclasine, that synergizes with cisplatin. The combination of cisplatin and narciclasine induced NOXA expression, downregulated MCL1, and ultimately induced apoptosis in NSCLC tumor spheroids. Our findings suggest that narciclasine is a potential natural product for combination with cisplatin for treatment of NSCLC.

Dihydroartemisinin suppresses COX-2-mediated apoptosis resistance in hepatocellular carcinoma under endoplasmic reticulum stress

Hepatocellular carcinoma (HCC) is the most common type of primary liver cancer, and its treatment still faces numerous challenges. Dihydroartemisinin (DHA), a derivative of artemisinin, has shown significant antitumor activity in preclinical research. Our study seeks to uncover the molecular mechanisms of DHA in HCC, potentially providing scientific evidence for its use as a supportive therapy in clinical settings. This study was conducted using various experimental approaches to systematically analyze the effects of DHA in HCC. Cell viability was evaluated by CCK-8 to determine the IC50 of DHA in HCC cells. Flow cytometry was used to measure the rates of apoptosis and reactive oxygen species (ROS) levels. Colony formation assays were performed to examine the inhibitory effects of DHA on HCC cell proliferation. The toxicity of DHA on HCC cells was evaluated through the lactate dehydrogenase release assay. Western blot was conducted to examine expression levels of proteins related to endoplasmic reticulum (ER) and apoptosis. Fluo-3 AM was utilized to label calcium ions (Ca2+), allowing for the detection of intracellular Ca2+ level changes. Additionally, ER tracker was employed to label the ER, with its morphological changes observed via immunofluorescence. DHA notably inhibited the vitality and proliferation of HCC cells and promoted cell apoptosis. Following DHA exposure, there were notable increases in ER stress markers, ROS, and Ca2+ levels. The morphology of the ER exhibited a loose and expanded state. The use of ER stress inhibitors attenuated these effects. Additionally, ER stress inducers facilitated the upregulation of COX-2, mediating apoptosis in HCC cells. Upon COX-2 knockdown, the apoptotic effect of DHA was markedly amplified. In HCC, DHA induces apoptosis in tumor cells by curbing the COX-2-mediated apoptotic resistance that arises during ER stress. This breakthrough reveals the molecular pathways through which DHA can aid in HCC treatment, offering valuable experimental data to support its clinical use as an adjuvant drug.

Macrophage ATF6 accelerates corticotomy-assisted orthodontic tooth movement through promoting Tnfα transcription

Corticotomy is a clinical procedure to accelerate orthodontic tooth movement characterized by the regional acceleratory phenomenon (RAP). Despite its therapeutic effects, the surgical risk and unclear mechanism hamper the clinical application. Numerous evidences support macrophages as the key immune cells during bone remodeling. Our study discovered that the monocyte-derived macrophages primarily exhibited a pro-inflammatory phenotype that dominated bone remodeling in corticotomy by CX3CR1CreERT2; R26GFP lineage tracing system. Fluorescence staining, flow cytometry analysis, and western blot determined the significantly enhanced expression of binding immunoglobulin protein (BiP) and emphasized the activation of sensor activating transcription factor 6 (ATF6) in macrophages. Then, we verified that macrophage specific ATF6 deletion (ATF6f/f; CX3CR1CreERT2 mice) decreased the proportion of pro-inflammatory macrophages and therefore blocked the acceleration effect of corticotomy. In contrast, macrophage ATF6 overexpression exaggerated the acceleration of orthodontic tooth movement. In vitro experiments also proved that higher proportion of pro-inflammatory macrophages was positively correlated with higher expression of ATF6. At the mechanism level, RNA-seq and CUT&Tag analysis demonstrated that ATF6 modulated the macrophage-orchestrated inflammation through interacting with Tnfα promotor and augmenting its transcription. Additionally, molecular docking simulation and dual-luciferase reporter system indicated the possible binding sites outside of the traditional endoplasmic reticulum-stress response element (ERSE). Taken together, ATF6 may aggravate orthodontic bone remodeling by promoting Tnfα transcription in macrophages, suggesting that ATF6 may represent a promising therapeutic target for non-invasive accelerated orthodontics.

Hepatitis B surface antigen: carcinogenesis mechanisms and clinical implications in hepatocellular carcinoma

Liver cancer is the third leading cause of death globally, with hepatitis B virus (HBV) infection being identified as the primary risk factor for its development. The occurrence of HBV-related hepatocellular carcinoma (HCC) is attributed to various mechanisms, such as chronic inflammation and liver cell regeneration induced by the cytotoxic immune response triggered by the virus, abnormal activation of oncogenes arising from HBV DNA insertion mutations, and epigenetic alterations mediated by viral oncoproteins. The envelope protein of the HBV virus, known as hepatitis B surface antigen (HBsAg), is a key indicator of increased risk for developing HCC in HBsAg-positive individuals. The HBsAg seroclearance status is found to be associated with recurrence in HCC patients undergoing hepatectomy. Additional evidence indicates that HBsAg is essential to the entire process of tumor development, from initiation to advancement, and acts as an oncoprotein involved in accelerating tumor progression. This review comprehensively analyzes the extensive effects and internal mechanisms of HBsAg during the various stages of the initiation and progression of HCC. Furthermore, it highlights the importance and potential applications of HBsAg in the realms of HCC early diagnosis and personalized therapeutic interventions. An in-depth understanding of the molecular mechanism of HBsAg in the occurrence and development of HCC is provided, which is expected to develop more precise and efficient strategies for the prevention and management of HCC in the future.

Relocating NSAIDs into the endoplasmic reticulum induces ER stress-mediated apoptosis in cancer cells

The endoplasmic reticulum (ER) is a vital subcellular organelle that orchestrates numerous essential biological processes, including protein synthesis and processing. Disruption of ER function can lead to ER stress, a condition closely associated with the progression and development of cancer. Consequently, inducing ER stress in cancer cells has emerged as an unconventional yet promising therapeutic approach. However, selectively targeting the ER within cancer cells remains a significant challenge. To address this, we have designed and synthesized a novel small-molecule library composed of non-steroidal anti-inflammatory drugs (NSAIDs), fluorescent probes, and ER-targeting moieties. Through screening the library in cancer cells, we identified a promising compound: an ibuprofen derivative conjugated with a dansyl group as a dual fluorescence tag and ER-targeting moiety. This ibuprofen derivative successfully localized into the ER of HCT-116 colon cancer cells within 3 h, induced ER stress by upregulating key stress markers such as CHOP, GRP94, IRE-1α, PERK, and Cas-12, while simultaneously inhibiting Cox-2. The resulting ER stress triggered autophagy by upregulating Beclin and LC3-II/LC3-I as autophagy markers, followed by apoptosis, culminating in significant cancer cell death, particularly when combined with bafilomycin A, 10-hydroxycamptothecin and obatoclax. This NSAID-based ER stress inducer provides a powerful tool for exploring the chemical biology of NSAIDs in the ER and holds great potential for advancing ER-targeted cancer therapies in combination with other anti-cancer drugs.

Molecular Mechanisms and Therapeutic Targets of Hepatitis B Virus Pre-S Mutant-Associated Hepatocellular Carcinoma Tumorigenesis

Background: Despite significant progress in diagnosis and therapeutics, hepatocellular carcinoma (HCC) is still among the most commonly occurring and life-taking human cancers globally, raising an urgent need for discovering effective therapeutic targets.Purpose: Chronic hepatitis B virus (HBV) infection is a major etiological factor associated with HCC development, progression, and prognosis. Pre-S mutants are naturally occurring mutated forms of HBV large surface proteins and predict a higher risk of HCC development and recurrence. Moreover, pre-S mutants function as important HBV oncoproteins which can promote HCC tumorigenesis through initiating a variety of oncogenic signaling pathways. Targeting pre-S mutant-induced oncogenic signaling pathways displays therapeutic potential in HCC.Research Design: This review summarizes the underlying molecular mechanisms of pre-S mutant-associated HCC tumorigenesis and highlights their potential in serving as therapeutic targets for HCC.

Exploring the dual role of endoplasmic reticulum stress in urological cancers: Implications for tumor progression and cell death interactions

The endoplasmic reticulum (ER) is crucial for maintaining calcium balance, lipid biosynthesis, and protein folding. Disruptions in ER homeostasis, often due to the accumulation of misfolded or unfolded proteins, lead to ER stress, which plays a significant role in various diseases, especially cancer. Urological cancers, which account for high male mortality worldwide, pose a persistent challenge due to their incurability and tendency to develop drug resistance. Among the numerous dysregulated biological mechanisms, ER stress is a key factor in the progression and treatment response of these cancers. This review highlights the dual role of aberrant ER stress activation in urologic cancers, affecting both tumor growth and therapeutic outcomes. While ER stress can support tumor growth through pro-survival autophagy, it primarily inhibits cancer progression via apoptosis and pro-death autophagy. Interestingly, ER stress can paradoxically aid cancer progression through mechanisms such as exosome-mediated immune evasion. Additionally, the review examines how pharmacological interventions, particularly with phytochemicals, can stimulate ER stress-mediated tumor suppression. Key regulators, including PERK, IRE1α, and ATF6, are discussed for their roles in upregulating CHOP levels and triggering apoptosis. In conclusion, a deeper understanding of ER stress in urological cancers not only clarifies the complex interactions between cellular stress and cancer progression but also provides new opportunities for innovative therapeutic strategies.

Evolution and diversity of the hepatitis B virus genome: Clinical implications

Hepatitis B virus (HBV) infection remains a significant global health burden. The genetic variation of HBV is complex. HBV can be divided into nine genotypes, which show significant differences in geographical distribution, clinical manifestations, transmission routes and treatment response. In recent years, substantial progress has been made through various research methods in understanding the development, pathogenesis, and antiviral treatment response of clinical disease associated with HBV genetic variants. This progress provides important theoretical support for a deeper understanding of the natural history of HBV infection, virus detection, drug treatment, vaccine development, mother-to-child transmission, and surveillance management. This review summarizes the mechanisms of HBV diversity, discusses methods used to detect viral diversity in current studies, and the impact of viral genome variation during infection on the development of clinical disease.

Regulation mechanism of endoplasmic reticulum stress on metabolic enzymes in liver diseases

The endoplasmic reticulum (ER) plays a pivotal role in protein folding and secretion, Ca2+ storage, and lipid synthesis in eukaryotic cells. When the burden of protein synthesis and folding required to be handled exceeds the processing capacity of the ER, the accumulation of misfolded/unfolded proteins triggers ER stress. In response to short-term ER stress, the unfolded protein response (UPR) is activated to allow cells to survive. When ER stress is severe and sustained, it typically provokes cell death through multiple approaches. It is well documented that ER stress and metabolic deregulation are functionally intertwined, both are considered contributing factors to the pathogenesis of liver diseases, including non-alcoholic fatty liver disease (NAFLD), alcoholic liver disease (ALD), ischemia/reperfusion (I/R) injury, viral hepatitis, liver fibrosis, and hepatocellular carcinoma (HCC). Hepatocytes are rich in smooth and rough ER, which harbor metabolic enzymes that are capable of sensing alterations in various nutritional status and external stimuli. Extensive research has focused on the molecular mechanism linking ER stress with metabolic enzymes. The purpose of this review is to summarize the current knowledge regarding the effects of ER stress on metabolic enzymes in various liver diseases and to provide potential therapeutic strategies for chronic liver diseases via targeting UPR.

Critical role of endoplasmic reticulum stress on bisphenol A-induced cytotoxicity in human keratinocyte HaCaT cells

Bisphenol A (BPA) is widely used in plastic and paper products, and its exposure can occur through skin contact or oral ingestion. The hazardous effects of BPA absorbed through the skin may be more severe; however, few studies have investigated the skin toxicity of BPA. This study investigated the effects of BPA on human epidermal keratinocyte cell lines, which is relevant for skin exposure. BPA treatment reduced cell viability in a time- and concentration-dependent manner and elevated oxidative and endoplasmic reticulum (ER) stress. N-acetylcysteine (NAC), an oxidative stress inhibitor, reduced BPA-induced reactive oxygen species (ROS) levels. However, only 10% of the decreased cell viability was restored at the highest NAC concentration. Treatment with tauroursodeoxycholic acid (TUDCA), which is an ER stress inhibitor, effectively countered the increase in ER stress-related proteins induced by BPA. Moreover, TUDCA treatment led to a reduction in oxidative stress, as demonstrated by the decrease in ROS levels, maintenance of mitochondrial membrane potential, and modulation of stress signaling proteins. Consequently, TUDCA significantly improved BPA-induced cytotoxicity in a concentration-dependent manner. Notably, combined treatment using TUDCA and NAC further reduced the BPA-induced ROS levels; however, no significant difference in cell viability was observed compared with that for TUDCA treatment alone. These findings indicated that the oxidative stress observed following BPA exposure was exacerbated by ER stress. Moreover, the principal factor driving BPA-induced cytotoxicity was indeed ER stress, which has potential implications for developing therapeutic strategies for diseases associated with similar stress responses.

Inhibition of NF-kB and COX-2 by andrographolide regulates the progression of cervical cancer by promoting PTEN expression and suppressing PI3K/AKT signalling pathway

In the face of recent advances in Cervical cancer (CC) treatment, therapeutic and surgical procedures for CC management are still inadequate. In the current study for the first time Andrographolide (Andro) has been explored for its multitarget therapeutic efficacy on NF-kB, COX-2, and PI3K/AKT expressions together in CC. The expression levels of NF-kB, COX-2, PI3K and PTEN in the CC patient samples, both at mRNA and protein levels have shown significant association with poor survival and increased tumor aggressiveness. The binding efficacy of Andro was investigated using molecular docking and molecular dynamic simulations, and the protein and ligand complex for NF-kB and COX-2 has shown high binding energy. Andro displayed cytotoxicity by impeding the in-vitro proliferation of CC cells. Andro significantly supressed the NF-kB, COX-2, and PI3K expression and enhanced the expression levels of PTEN at protein levels in-vitro. Andro induced apoptosis in a dose dependent manner and significantly inhibited the migration and invasion of CC cells. Andro exhibited similar activity in-vivo and suppressed the CC tumor growth in xenograft C57BL/6 mice model. The anti-tumor activity of Andro, both in-vitro and in-vivo has shown considerable downregulation of NF-kB and COX-2 and induced apoptosis through impeding the PI3K/AKT signalling pathway. These findings from the above study projects, administration of Andro as an effective alternate safe compound to curtail and impede cervical cancer progression.

Hepatitis B Surface Antigen Isoforms: Their Clinical Implications, Utilisation in Diagnosis, Prevention and New Antiviral Strategies

The hepatitis B surface antigen (HBsAg) is a multifunctional glycoprotein composed of large (LHB), middle (MHB), and small (SHB) subunits. HBsAg isoforms have numerous biological functions during HBV infection-from initial and specific viral attachment to the hepatocytes to initiating chronic infection with their immunomodulatory properties. The genetic variability of HBsAg isoforms may play a role in several HBV-related liver phases and clinical manifestations, from occult hepatitis and viral reactivation upon immunosuppression to fulminant hepatitis and hepatocellular carcinoma (HCC). Their immunogenic properties make them a major target for developing HBV vaccines, and in recent years they have been recognised as valuable targets for new therapeutic approaches. Initial research has already shown promising results in utilising HBsAg isoforms instead of quantitative HBsAg for correctly evaluating chronic infection phases and predicting functional cures. The ratio between surface components was shown to indicate specific outcomes of HBV and HDV infections. Thus, besides traditional HBsAg detection and quantitation, HBsAg isoform quantitation can become a useful non-invasive biomarker for assessing chronically infected patients. This review summarises the current knowledge of HBsAg isoforms, their potential usefulness and aspects deserving further research.

Altered Sox9 and FGF signaling gene expression in Aga2 OI mice negatively affects linear growth

Osteogenesis imperfecta (OI), or brittle bone disease, is a disorder characterized by bone fragility and increased fracture incidence. All forms of OI also feature short stature, implying an effect on endochondral ossification. Using the Aga2+/- mouse, which has a mutation in type I collagen, we show an affected growth plate primarily due to a shortened proliferative zone. We used single-cell RNA-Seq analysis of tibial and femoral growth plate tissues to understand transcriptional consequences on growth plate cell types. We show that perichondrial cells, which express abundant type I procollagen, and growth plate chondrocytes, which were found to express low amounts of type I procollagen, had ER stress and dysregulation of the same unfolded protein response pathway as previously demonstrated in osteoblasts. Aga2+/- proliferating chondrocytes showed increased FGF and MAPK signaling, findings consistent with accelerated differentiation. There was also increased Sox9 expression throughout the growth plate, which is expected to accelerate early chondrocyte differentiation but reduce late hypertrophic differentiation. These data reveal that mutant type I collagen expression in OI has an impact on the cartilage growth plate. These effects on endochondral ossification indicate that OI is a biologically complex phenotype going beyond its known impacts on bone to negatively affect linear growth.

The role of CcPTGS2a in immune response against Aeromonas hydrophila infection in common carp (Cyprinus carpio)

Prostaglandin-endoperoxide synthase 2 (PTGS2), a crucial enzyme in prostaglandin synthesis, catalyzes the conversion of arachidonic acid to prostaglandins and plays a significant role in the inflammatory response. This investigation aimed to determine the regulatory role of PTGS2a in the innate immune response to bacterial infection in fish. To achieve this objective, the CcPTGS2a gene was identified and characterized in common carp (Cyprinus carpio), and its function in immune defense was investigated. According to the sequence and structural analysis results, CcPTGS2a had an open reading frame of 1806 bp that encoded 602 amino acids. It was estimated that the protein's theoretical molecular weight was 69.0 kDa, and its isoelectric point was 8.10. The structure of CcPTGS2a was observed to be conserved, with an epidermal growth factor domain and a peroxidase domain present. Moreover, the amino acid sequence of CcPTGS2a exhibited significant homology with the amino acid sequences of several fish species. CcPTGS2a mRNA was detected in the healthy tissues of common carp, with higher expression in the head kidney, spleen, gills, and liver. Following the challenges with Aeromonas hydrophila and lipopolysaccharide, CcPTGS2a mRNA showed unique geographic and temporal expression patterns, with significant increases detected in the head kidney, gills, spleen, and liver. Additionally, the recombinant CcPTGS2a protein exhibited detectable bacterial binding to various bacteria. As determined by subcellular localization analysis, CcPTGS2a was predominantly localized in the nucleus and cytoplasm. Furthermore, it was discovered that the overexpression of CcPTGS2a stimulated the up-regulation of ferroptosis-related genes and inflammatory cytokine mRNA expression in fish and EPC (Epithelioma papulosum cyprinid) cells while concurrently reducing the bacterial load of A. hydrophila. In contrast, the interference of CcPTGS2a decreased the mRNA expression of ferroptosis-related genes and inflammatory cytokines in fish and EPC cells and increased the bacterial load of A. hydrophila. Notably, A. hydrophila stimulation resulted in the up-regulation of CcPTGS2a protein expression in EPC cells. These results suggested that CcPTGS2a was involved in the immune response to bacterial infections in common carp.

Increased plasma levels of monocyte chemoattractant protein-1 in patients with hepatitis B virus pre-S2 gene deletion mutation predict a higher risk of hepatocellular carcinoma recurrence after curative surgical resection

BACKGROUND

Despite resection surgery as a curative therapy for hepatocellular carcinoma (HCC), the high rate of postoperative HCC recurrence remains a big challenge for patient survival. Chronic hepatitis B virus (HBV) infection is the most important risk factor for HCC. Deletion mutation in the HBV pre-S2 gene leads to expression of an essential viral oncoprotein called pre-S2 mutant and represents an independent prognostic biomarker for HCC recurrence after curative surgical resection. Additionally, cytokines are multifunctional secreted proteins and implicated in all stages of HBV-related HCC tumorigenesis.

METHODS

This study aimed to identify the cytokines whose plasma levels were associated with pre-S2 gene deletion mutation and HCC recurrence and evaluate their potential to be combined with pre-S2 gene deletion mutation in predicting HCC recurrence.

RESULTS

Among a panel of 27 cytokines examined, plasma levels of monocyte chemoattractant protein-1 (MCP-1) were significantly upregulated in patients with pre-S2 gene deletion mutation or HCC recurrence. MCP-1 was validated as an independent prognostic biomarker for HCC recurrence. Moreover, patients with both the presence of pre-S2 gene deletion mutation and high levels of MCP-1 displayed a higher risk of HCC recurrence than patients with either one or none of these two biomarkers. The combination of pre-S2 gene deletion mutation and MCP-1 levels exhibited a better prognostic performance for HCC recurrence than each biomarker alone.

CONCLUSIONS

This study discovered that MCP-1 levels had a significance to be as a combination biomarker with pre-S2 gene deletion mutation providing an improved performance in predicting HCC recurrence after curative surgical resection.

Association of cyclooxygenase-2 expression with endoplasmic reticulum stress and autophagy in triple-negative breast cancer

Cyclooxygenase-2 plays a role in oncogenesis and its overexpression is associated with triple-negative breast cancer. However, the mechanisms whereby cyclooxygenase-2 contribute to breast cancer are complex and not well understood. Cyclooxygenase-2 overexpression causes hypoxia, oxidative stress, and endoplasmic reticulum stress. The aim of this study is to investigate the correlations among cyclooxygenase-2 expression, endoplasmic reticulum stress-associated molecules, and autophagy-associated molecules in triple-negative breast cancer. Surgical specimens from two cohorts of triple-negative breast cancer patients without neoadjuvant systemic therapy were analyzed: cohorts 1 and 2 consisted of 218 cases from 2004 to 2006 and 221 cases from 2007 to 2009, respectively. Specimens were evaluated by immunohistochemical examination of cyclooxygenase-2, endoplasmic reticulum stress markers, and autophagy markers expression using tissue microarrays. Cyclooxygenase-2 was overexpressed in 29.8% and 23.9% of cases in cohorts 1 and 2, respectively; and it was positively correlated with two out of three endoplasmic reticulum stress-associated molecules (XBP1, p = 0.025 and p = 0.003 in cohort 1 and cohort 2, respectively; PERK, p < 0.001 in both cohorts). Cyclooxygenase-2 was also positively correlated with two out of three autophagy markers (p62, p = 0.002 and p = 0.003 in cohort 1 and cohort 2, respectively; beclin1, p < 0.001 in both cohorts). Although cyclooxygenase-2 was not an independent prognostic factor for distant metastasis free survival and overall survival, its expression was associated with the expression of endoplasmic reticulum stress and autophagy molecules in triple-negative breast cancer.

The gp130/STAT3-endoplasmic reticulum stress axis regulates hepatocyte necroptosis in acute liver injury

AIM

To investigate the effect of the gp130/STAT3-endoplasmic reticulum (ER) stress axis on hepatocyte necroptosis during acute liver injury.

METHODS

ER stress and liver injury in LO2 cells were induced with thapsigargin, and in BALB/c mice with tunicamycin and carbon tetrachloride (CCl4). Glycoprotein 130 (gp130) expression, the degrees of ER stress, and hepatocyte necroptosis were assessed.

RESULTS

ER stress significantly upregulated gp130 expression in LO2 cells and mouse livers. The silencing of activating transcription factor 6 (ATF6), but not of ATF4, increased hepatocyte necroptosis and mitigated gp130 expression in LO2 cells and mice. Gp130 silencing reduced the phosphorylation of CCl4-induced signal transducer and activator of transcription 3 (STAT3), and aggravated ER stress, necroptosis, and liver injury in mice.

CONCLUSION

ATF6/gp130/STAT3 signaling attenuates necroptosis in hepatocytes through the negative regulation of ER stress during liver injury. Hepatocyte ATF6/gp130/STAT3 signaling may be used as a therapeutic target in acute liver injury.

Unraveling molecular characteristic of fluoride neurotoxicity on U87 glial-like cells: insights from transcriptomic and proteomic approach

The potential of fluoride (F) as a neurotoxicant in humans is still controversial in the literature. However, recent studies have raised the debate by showing different mechanism of F-induced neurotoxicity, as oxidative stress, energy metabolism and inflammation in the central nervous system (CNS). In the present study, we investigated the mechanistic action of two F concentration (0.095 and 0.22 μg/ml) on gene and protein profile network using a human glial cell in vitro model over 10 days of exposure. A total of 823 genes and 2,084 genes were modulated after exposure to 0.095 and 0.22 μg/ml F, respectively. Among them, 168 were found to be modulated by both concentrations. The number of changes in protein expression induced by F were 20 and 10, respectively. Gene ontology annotations showed that the main terms were related to cellular metabolism, protein modification and cell death regulation pathways, such as the MAP kinase (MAPK) cascade, in a concentration independent manner. Proteomics confirmed the changes in energy metabolism and also provided evidence of F-induced changes in cytoskeleton components of glial cells. Our results not only reveal that F has the potential to modulate gene and protein profiles in human U87 glial-like cells overexposed to F, but also identify a possible role of this ion in cytoskeleton disorganization.

In Vitro Anti-Inflammatory and Anticancer Evaluation of Mentha spicata L. and Matricaria chamomilla L. Essential Oils

Spearmint, Mentha spicata L., and the German chamomile, Matricaria chamomilla L., preparations are used against inflammatory conditions traditionally and in modern medicinal applications. This present study aimed to evaluate pharma-grade essential oils for their in vitro anti-inflammatory and anticancer effects using COX-1, COX-2, and 5-LOX enzyme assays, as well as their apoptosis potential through the caspase pathway. In addition, the (3-[4,5-dimethylthiazol-2-yl]-2,5 diphenyl tetrazolium bromide) (MTT) assay was applied to evaluate the in vitro cytotoxic effects using HEK293/A549, MCF7, and PC3 cell lines. Major components of M. spicata essential oil were confirmed both by gas chromatography (GC)-flame ionization detector (FID) and GC/mass spectrometry (MS) as 72.8% carvone, 12.6% limonene, 2.2% 1,8-cineole, 1.3% myrcene, and 1% trans-dihydrocarvone. The major components of M. chamomilla essential oil were also confirmed as 47.9% α-bisabolol oxide A, 16.8% α-bisabolol, 13.8%, (Z)-β-farnesene, 5.8% α-bisabolol oxide, and 4.7% α-bisabolene oxide A. The IC₅₀ values for M. chamomilla essential oil on A549, MCF7, PC3, and HEK293 cells were calculated as 208.54 ± 1.39, 315.44 ± 1.17, 197.52 ± 0.98, and 638.79 ± 1.15 μg/mL, respectively, whereas the IC₅₀ values for M. spicata essential oil on A549, MCF7, and PC3 cells were 672.13 ± 2.57, 708.27 ± 2.05, and 206.49 ± 1.48 μg/mL, respectively. For M. spicata essential oil, no cytotoxic effects on healthy HEK293 cells were observed at the tested concentrations. The essential oils increased the apoptotic activity, where all results were statistically significant. According to the anti-inflammatory evaluation, both M. chamomilla and M. spicata oils showed selective COX-2 inhibitions, where the SI values were calculated as 0.30 and 0.67, respectively. Overall, both M. spicata and M. chamomilla essential oils showed selective inhibition on the COX-2 enzyme and apoptosis against the selected cancer cell lines for the first time, to the best of our knowledge, with this specific dual mode of action. The initial results encourage further detailed in vivo experimental evaluations.

The Role of Single-Nucleotide Polymorphisms in Cholangiocarcinoma: A Systematic Review

Single-nucleotide polymorphisms (SNPs) play an essential role in various malignancies, but their role in cholangiocarcinoma (CCA) remains to be elucidated. Therefore, the purpose of this systematic review was to evaluate the association between SNPs and CCA, focusing on tumorigenesis and prognosis. A systematic literature search was carried out using PubMed, Embase, Web of Science and the Cochrane database for the association between SNPs and CCA, including literature published between January 2000 and April 2022. This systematic review compiles 43 SNPs in 32 genes associated with CCA risk, metastatic progression and overall prognosis based on 34 studies. Susceptibility to CCA was associated with SNPs in genes related to inflammation (PTGS2/COX2, IL6, IFNG/IFN-γ, TNF/TNF-α), DNA repair (ERCC1, MTHFR, MUTYH, XRCC1, OGG1), detoxification (NAT1, NAT2 and ABCC2), enzymes (SERPINA1, GSTO1, APOBEC3A, APOBEC3B), RNA (HOTAIR) and membrane-based proteins (EGFR, GAB1, KLRK1/NKG2D). Overall oncological prognosis was also related to SNPs in eight genes (GNB3, NFE2L2/NRF2, GALNT14, EGFR, XRCC1, EZH2, GNAS, CXCR1). Our findings indicate that multiple SNPs play different roles at various stages of CCA and might serve as biomarkers guiding treatment and allowing oncological risk assessment. Considering the differences in SNP detection methods, patient ethnicity and corresponding environmental factors, more large-scale multicentric investigations are needed to fully determine the potential of SNP analysis for CCA susceptibility prediction and prognostication.

Endoplasmic Reticulum Stress in Hepatitis B Virus and Hepatitis C Virus Infection

Endoplasmic reticulum (ER) stress, a type of cellular stress, always occurs when unfolded or misfolded proteins accumulating in the ER exceed the protein folding capacity. Because of the demand for rapid viral protein synthesis after viral infection, viral infections become a risk factor for ER stress. The hepatocyte is a cell with large and well-developed ER, and hepatitis virus infection is widespread in the population, indicating the interaction between hepatitis viruses and ER stress may have significance for managing liver diseases. In this paper, we review the process that is initiated by the hepatocyte through ER stress against HBV and HCV infection and explain how this information can be helpful in the treatment of HBV/HCV-related diseases.

HBV preS Mutations Promote Hepatocarcinogenesis by Inducing Endoplasmic Reticulum Stress and Upregulating Inflammatory Signaling

Simple Summary

Viral mutations at the preS region of hepatitis B virus (HBV) significantly increase the risk of developing hepatocellular carcinoma (HCC). Compared to HBV preS deletion, the oncogenic effect of preS combo mutation has rarely been investigated. With a cohort including 2114 subjects, we demonstrated that preS combo mutations G2950A/G2951A/A2962G/C2964A and C3116T/T31C significantly increased the risk of HCC in patients without antiviral treatment, whereas preS2 deletion significantly increased the risk of HCC in patients with antiviral treatment. The prevalence of C3116T/T31C (43.61%) was higher than preS2 deletion (7.16%). By using Sleeping Beauty mouse models and in vitro experiments, we found G2950A/G2951A/A2962G/C2964A, C3116T/T31C, and preS2 deletion promoted hepatocarcinogenesis by increasing levels of inflammatory cytokines, activating STAT3 pathway, enhancing endoplasmic reticulum stress, and altering gene expression profiles in inflammation- and metabolism-related pathways. These results suggest that preS combo mutations G2950A/G2951A/A2962G/C2964A and C3116T/T31C had similar oncogenic effects of preS2 deletion and should also be monitored.

Abstract

This study aimed to elucidate the effects and underlying mechanisms of hepatitis B virus (HBV) preS mutations on hepatocarcinogenesis. The effect of the preS mutations on hepatocellular carcinoma (HCC) occurrence was evaluated using a prospective cohort study with 2114 HBV-infected patients, of whom 612 received antiviral treatments. The oncogenic functions of HBV preS mutations were investigated using cancer cell lines and Sleeping Beauty (SB) mouse models. RNA-sequencing and microarray were applied to identify key molecules involved in the mutant-induced carcinogenesis. Combo mutations G2950A/G2951A/A2962G/C2964A and C3116T/T31C significantly increased HCC risk in patients without antiviral treatment, whereas the preS2 deletion significantly increased HCC risk in patients with antiviral treatment. In SB mice, the preS1/preS2/S mutants induced a higher rate of tumor and higher serum levels of inflammatory cytokines than did wild-type counterpart. The preS1/preS2/S mutants induced altered gene expression profiles in the inflammation- and metabolism-related pathways, activated pathways of endoplasmic reticulum (ER) stress, affected the response to hypoxia, and upregulated the protein level of STAT3. Inhibiting the STAT3 pathway attenuated the effects of the preS1/preS2/S mutants on cell proliferation. G2950A/G2951A/A2962G/C2964A, C3116T/T31C, and preS2 deletion promote hepatocarcinogenesis via inducing ER stress, metabolism alteration, and STAT3 pathways, which might be translated into HCC prophylaxis.

Association of Increased Programmed Death Ligand 1 Expression and Regulatory T Cells Infiltration with Higher Hepatocellular Carcinoma Recurrence in Patients with Hepatitis B Virus Pre-S2 Mutant after Curative Surgical Resection

Although surgical resection is available as a potentially curative therapy for hepatocellular carcinoma (HCC), high recurrence of HCC after surgery remains a serious obstacle for long-term patient survival. Therefore, the discovery of valuable prognostic biomarkers for HCC recurrence is urgently needed. Pre-S2 mutant is a mutant form of hepatitis B virus (HBV) large surface protein which is expressed from the HBV surface gene harboring deletion mutations spanning the pre-S2 gene segment. Pre-S2 mutant-positive HCC patients have been regarded as a high-risk population of HCC recurrence after resection surgery and display increased immune checkpoint programmed death ligand 1 (PD-L1) expression and pro-tumor regulatory T cells (Tregs) infiltration in tumor tissues. In this study, the association of higher levels of PD-L1 expression and Tregs infiltration in tumor tissues with post-operative HCC recurrence in pre-S2 mutant-positive HCC patients was evaluated. We found that patients with pre-S2 mutant in combination with higher levels of PD-L1 expression and Tregs infiltration in tumor tissues were independently associated with a higher risk of HCC recurrence (hazard ratio, 4.109; p value = 0.0011) and poorer recurrence-free survival (median, 8.2 versus 18.0 months; p value = 0.0004) than those of patients with either one or two of these three biomarkers. Furthermore, a combination of pre-S2 mutant, intra-tumoral PD-L1 expression, and tumor-infiltrating Tregs exhibited superior performance in identifying patients at a higher risk of HCC recurrence (area under the receiver operating characteristic curve, 0.8400). Collectively, this study suggests that higher levels of PD-L1 expression and Tregs infiltration in tumor tissues predicted a higher risk of HCC recurrence in pre-S2 mutant-positive HCC patients after curative surgical resection.

The Serum Hepatitis B Virus Large Surface Protein as High-Risk Recurrence Biomarker for Hepatoma after Curative Surgery

Chronic hepatitis B (CHB) virus infection is the most important cause of HCC and is also associated with tumor progression. The development of viral biomarkers for HCC prognosis is critical in evaluating relative risks to recurrence in the CHB HCC patients. We report that the large HBV surface protein (LHBS) expression increased in the tumors, implicating that it played a significant role in tumor development. To detect the LHBS in serum and evaluate its association with HCC progression, we developed a sandwich ELISA method for LHBS. The mouse monoclonal antibodies for the pre-S1, pre-S2, and HBS regions were in-house generated and constructed into a chemiluminescent sandwich ELISA system, which allowed sensitive and quantitative measurement of the protein. Using this ELISA assay, we estimated the expression of LHBS in CHB and HCC patients. We found that the serum LHBS level was correlated with the HBS but not the viral titer in serum, indicating that HBV surface proteins’ expression does not mainly depend on viral replication. Moreover, both serum LHBS and HBS levels were lower in the HCC patients than in the CHB. The liver LHBS signals, detected by immunohistochemical staining, showed significant correlations with the serum LHBS and HBS levels. In addition, the more elevated serum LHBS but not HBS level was significantly associated with cirrhosis and worse disease-free and overall survival rates, based on the multivariate analysis. Conclusion: LHBS plays a specific role in tumor progression and is an independent parameter associated with HCC recurrence. Serum LHBS represents a novel noninvasive biomarker for HCC patients with a worse prognosis after surgery.

HIV-1-Mediated Acceleration of Oncovirus-Related Non-AIDS-Defining Cancers

With the advent of combination antiretroviral therapy (cART), overall survival has been improved, and the incidence of acquired immunodeficiency syndrome (AIDS)-defining cancers has also been remarkably reduced. However, non-AIDS-defining cancers among human immunodeficiency virus-1 (HIV-1)-associated malignancies have increased significantly so that cancer is the leading cause of death in people living with HIV in certain highly developed countries, such as France. However, it is currently unknown how HIV-1 infection raises oncogenic virus-mediated cancer risks in the HIV-1 and oncogenic virus co-infected patients, and thus elucidation of the molecular mechanisms for how HIV-1 expedites the oncogenic viruses-triggered tumorigenesis in the co-infected hosts is imperative for developing therapeutics to cure or impede the carcinogenesis. Hence, this review is focused on HIV-1 and oncogenic virus co-infection-mediated molecular processes in the acceleration of non-AIDS-defining cancers.

Alcohol and Prostate Cancer: Time to Draw Conclusions

It has been a long-standing debate in the research and medical societies whether alcohol consumption is linked to the risk of prostate cancer (PCa). Many comprehensive studies from different geographical areas and nationalities have shown that moderate and heavy drinking is positively correlated with the development of PCa. Nevertheless, some observations could not confirm that such a correlation exists; some even suggest that wine consumption could prevent or slow prostate tumor growth. Here, we have rigorously analyzed the evidence both for and against the role of alcohol in PCa development. We found that many of the epidemiological studies did not consider other, potentially critical, factors, including diet (especially, low intake of fish, vegetables and linoleic acid, and excessive use of red meat), smoking, family history of PCa, low physical activity, history of high sexual activities especially with early age of first intercourse, and sexually transmitted infections. In addition, discrepancies between observations come from selectivity criteria for control groups, questionnaires about the type and dosage of alcohol, and misreported alcohol consumption. The lifetime history of alcohol consumption is critical given that a prostate tumor is typically slow-growing; however, many epidemiological observations that show no association monitored only current or relatively recent drinking status. Nevertheless, the overall conclusion is that high alcohol intake, especially binge drinking, is associated with increased risk for PCa, and this effect is not limited to any type of beverage. Alcohol consumption is also directly linked to PCa lethality as it may accelerate the growth of prostate tumors and significantly shorten the time for the progression to metastatic PCa. Thus, we recommend immediately quitting alcohol for patients diagnosed with PCa. We discuss the features of alcohol metabolism in the prostate tissue and the damaging effect of ethanol metabolites on intracellular organization and trafficking. In addition, we review the impact of alcohol consumption on prostate-specific antigen level and the risk for benign prostatic hyperplasia. Lastly, we highlight the known mechanisms of alcohol interference in prostate carcinogenesis and the possible side effects of alcohol during androgen deprivation therapy.

Transcriptome analysis reveals the molecular mechanism of Yiqi Rougan decoction in reducing CCl4-induced liver fibrosis in rats

Background

Liver fibrosis develops from various chronic liver diseases, and there is currently a lack of specific treatment strategies. Yiqi Rougan decoction (YQRG) is a traditional Chinese medicine that has shown durative effects in the treatment of liver fibrosis; however, the mechanism associated with YQRG-related improvements in liver fibrosis remains to be experimentally determined. This study evaluated the therapeutic effect of YQRG on carbon tetrachloride (CCl₄)-induced liver fibrosis in rats and its molecular mechanism.

Methods

We used low-, medium-, and high-dose YQRG to treat CCl₄-induced liver fibrosis in rats, followed by assessment of liver injury and fibrosis according to liver appearance, body weight, liver mass index, histopathologic examination, and serum testing. Additionally, we performed transcriptome analysis using RNA-sequencing (RNA-seq) technology, including cluster, Gene Ontology (GO), and pathway analyses, to identify differentially expressed genes (DEGs), and protein and gene expression were detected by immunofluorescence (IFC), western blot and real-time quantitative PCR.

Results

The results showed that YQRG effectively alleviated CCl₄-induced liver injury and fibrosis in rats, including observations of improved liver function, decreased activity of hepatic stellate cells (HSCs), and decreased extracellular matrix (ECM) deposition. Moreover, we identified downregulated and upregulated DEGs in the model group relative to the control and YQRG-treated groups, with GO analysis revealing their enrichment in biological processes, such as endoplasmic reticulum stress (ERS), apoptosis, and autophagy. Furthermore, pathway analysis showed that YQRG treatment downregulated the mitogen-activated protein kinase (MAPK) and phosphoinositide 3-kinase/Akt (PI3K/AKT) signalling pathways and upregulated other signalling pathways, including those related to peroxisome proliferator-activated receptors(PPAR) and AMP-activated protein kinase(AMPK), with these findings subsequently verified experimentally.

Conclusion

These findings showed that YQRG improved CCl₄-induced liver fibrosis through multiple mechanisms and pathways, offering critical insight into the YQRG-related therapeutic mechanism and promoting further research into its potential application.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13020-021-00552-w.

mTOR Signaling: The Interface Linking Cellular Metabolism and Hepatitis B Virus Replication

Mammalian target of rapamycin (mTOR) is a conserved Ser/Thr kinase that includes mTOR complex (mTORC) 1 and mTORC2. The mTOR pathway is activated in viral hepatitis, including hepatitis B virus (HBV) infection-induced hepatitis. Currently, chronic HBV infection remains one of the most serious public health issues worldwide. The unavailability of effective therapeutic strategies for HBV suggests that clarification of the pathogenesis of HBV infection is urgently required. Increasing evidence has shown that HBV infection can activate the mTOR pathway, indicating that HBV utilizes or hijacks the mTOR pathway to benefit its own replication. Therefore, the mTOR signaling pathway might be a crucial target for controlling HBV infection. Here, we summarize and discuss the latest findings from model biology research regarding the interaction between the mTOR signaling pathway and HBV replication.

The non-canonical mechanism of ER stress-mediated progression of prostate cancer

Background

The development of persistent endoplasmic reticulum (ER) stress is one of the cornerstones of prostate carcinogenesis; however, the mechanism is missing. Also, alcohol is a physiological ER stress inducer, and the link between alcoholism and progression of prostate cancer (PCa) is well documented but not well characterized. According to the canonical model, the mediator of ER stress, ATF6, is cleaved sequentially in the Golgi by S1P and S2P proteases; thereafter, the genes responsible for unfolded protein response (UPR) undergo transactivation.

Methods

Cell lines used were non-malignant prostate epithelial RWPE-1 cells, androgen-responsive LNCaP, and 22RV1 cells, as well as androgen-refractory PC-3 cells. We also utilized PCa tissue sections from patients with different Gleason scores and alcohol consumption backgrounds. Several sophisticated approaches were employed, including Structured illumination superresolution microscopy, Proximity ligation assay, Atomic force microscopy, and Nuclear magnetic resonance spectroscopy.

Results

Herein, we identified the trans-Golgi matrix dimeric protein GCC185 as a Golgi retention partner for both S1P and S2P, and in cells lacking GCC185, these enzymes lose intra-Golgi situation. Progression of prostate cancer (PCa) is associated with overproduction of S1P and S2P but monomerization of GCC185 and its downregulation. Utilizing different ER stress models, including ethanol administration, we found that PCa cells employ an elegant mechanism that auto-activates ER stress by fragmentation of Golgi, translocation of S1P and S2P from Golgi to ER, followed by intra-ER cleavage of ATF6, accelerated UPR, and cell proliferation. The segregation of S1P and S2P from Golgi and activation of ATF6 are positively correlated with androgen receptor signaling, different disease stages, and alcohol consumption. Finally, depletion of ATF6 significantly retarded the growth of xenograft prostate tumors and blocks production of pro-metastatic metabolites.

Conclusions

We found that progression of PCa associates with translocation of S1P and S2P proteases to the ER and subsequent ATF6 cleavage. This obviates the need for ATF6 transport to the Golgi and enhances UPR and cell proliferation. Thus, we provide the novel mechanistic model of ATF6 activation and ER stress implication in the progression of PCa, suggesting ATF6 is a novel promising target for prostate cancer therapy.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13046-021-02066-7.

Mitofusin 2 Deficiency Causes Pro-Inflammatory Effects in Human Primary Macrophages

Mitofusin 2 (MFN2) is a mitochondrial outer membrane GTPase, which modulates mitochondrial fusion and affects the interaction between endoplasmic reticulum and mitochondria. Here, we explored how MFN2 influences mitochondrial functions and inflammatory responses towards zymosan in primary human macrophages. A knockdown of MFN2 by small interfering RNA decreased mitochondrial respiration without attenuating mitochondrial membrane potential and reduced interactions between endoplasmic reticulum and mitochondria. A MFN2 deficiency potentiated zymosan-elicited inflammatory responses of human primary macrophages, such as expression and secretion of pro-inflammatory cytokines interleukin-1β, -6, -8 and tumor necrosis factor α, as well as induction of cyclooxygenase 2 and prostaglandin E₂ synthesis. MFN2 silencing also increased zymosan-induced nuclear factor kappa-light-chain-enhancer of activated B cells and mitogen-activated protein kinases inflammatory signal transduction, without affecting mitochondrial reactive oxygen species production. Mechanistic studies revealed that MFN2 deficiency enhanced the toll-like receptor 2-dependent branch of zymosan-triggered responses upstream of inhibitor of κB kinase. This was associated with elevated, cytosolic expression of interleukin-1 receptor-associated kinase 4 in MFN2-deficient cells. Our data suggest pro-inflammatory effects of MFN2 deficiency in human macrophages.

Unique Features of Hepatitis B Virus-Related Hepatocellular Carcinoma in Pathogenesis and Clinical Significance

Simple Summary

Hepatitis B virus (HBV) infection is the major risk factor for hepatocellular carcinoma (HCC). Understanding the unique features for HBV-induced HCC can shed new light on the unmet needs in its early diagnosis and effective therapy. During decades of chronic hepatitis B, hepatocytes undergoing repeated damage and regeneration accumulate genetic changes predisposing to HCC development. In addition to traditional mutations in viral and cellular oncogenes, HBV integration into the cell chromosomes is an alternative genetic change contributing to hepatocarcinogenesis. A striking male dominance in HBV-related HCC further highlights an interaction between androgen sex hormone and viral factors, which contributes to the gender difference via stimulating viral replication and activation of oncogenes preferentially in male patients. Meanwhile, a novel circulating tumor biomarker generated by HBV integration shows great potential for the early diagnosis of HCC. These unique HBV-induced hepatocarcinogenic mechanisms provide new insights for the future development of superior diagnosis and treatment strategies.

Abstract

Hepatitis B virus (HBV) infection is one of the important risk factors for hepatocellular carcinoma (HCC) worldwide, accounting for around 50% of cases. Chronic hepatitis B infection generates an inflammatory microenvironment, in which hepatocytes undergoing repeated cycles of damage and regeneration accumulate genetic mutations predisposing them to cancer. A striking male dominance in HBV-related HCC highlights the influence of sex hormones which interact with viral factors to influence carcinogenesis. HBV is also considered an oncogenic virus since its X and surface mutant proteins showed tumorigenic activity in mouse models. The other unique mechanism is the insertional mutagenesis by integration of HBV genome into hepatocyte chromosomes to activate oncogenes. HCC survival largely depends on tumor stages at diagnosis and effective treatment. However, early diagnosis by the conventional protein biomarkers achieves limited success. A new biomarker, the circulating virus–host chimera DNA from HBV integration sites in HCC, provides a liquid biopsy approach for monitoring the tumor load in the majority of HBV–HCC patients. To maximize the efficacy of new immunotherapies or molecular target therapies, it requires better classification of HCC based on the tumor microenvironment and specific carcinogenic pathways. An in-depth study may benefit both the diagnosis and treatment of HBV-related HCC.

Hepatitis B Virus Pre-S Gene Deletions and Pre-S Deleted Proteins: Clinical and Molecular Implications in Hepatocellular Carcinoma

Hepatocellular carcinoma (HCC) is one of the most frequent and fatal human cancers worldwide and its development and prognosis are intimately associated with chronic infection with hepatitis B virus (HBV). The identification of genetic mutations and molecular mechanisms that mediate HBV-induced tumorigenesis therefore holds promise for the development of potential biomarkers and targets for HCC prevention and therapy. The presence of HBV pre-S gene deletions in the blood and the expression of pre-S deleted proteins in the liver tissues of patients with chronic hepatitis B and HBV-related HCC have emerged as valuable biomarkers for higher incidence rates of HCC development and a higher risk of HCC recurrence after curative surgical resection, respectively. Moreover, pre-S deleted proteins are regarded as important oncoproteins that activate multiple signaling pathways to induce DNA damage and promote growth and proliferation in hepatocytes, leading to HCC development. The signaling molecules dysregulated by pre-S deleted proteins have also been validated as potential targets for the prevention of HCC development. In this review, we summarize the clinical and molecular implications of HBV pre-S gene deletions and pre-S deleted proteins in HCC development and recurrence and highlight their potential applications in HCC prevention and therapy.

Combined COX-2/PPARγ Expression as Independent Negative Prognosticator for Vulvar Cancer Patients

Vulvar cancer incidence numbers have been rising steadily over the past decades. Especially the number of young patients with vulvar cancer increased recently. Therefore, the need to identify new prognostic factors for vulvar carcinoma is more apparent. Cyclooxygenase-2 (COX-2) has long been an object of scientific interest in the context of carcinogenesis. This enzyme is involved in prostaglandin synthesis and the latter binds to nuclear receptors like PPARγ. Therefore, the aim of this study was to investigate COX-2- and PPARγ- expression in tissues of vulvar carcinomas and to analyze their relevance as prognostic factors. The cytoplasmatic expression of COX-2 as well as PPARγ is associated with a significantly reduced survival, whereas nuclear expression of PPARγ results in a better survival. Especially the combined expression of both COX-2 and PPARγ in the cytoplasm is an independent negative prognosticator for vulvar cancer patients.

Age-adjusted mortality from pancreatic cancer increased NINE-FOLD in japan from 1950 to 1995 - Was a low-protein quasi-vegan diet a key factor in their former low risk?

During the last half of the twentieth century, age-adjusted mortality from pancreatic cancer in Japan rose about nine-fold in both sexes. Well-characterized risk factors such as smoking, obesity/metabolic syndrome, and heavy alcohol use appear to explain only a modest part of this rise. It is proposed that a diet relatively low in protein, and particularly low in animal protein, was a key determinant of the low risk for pancreatic cancer in mid-century Japan. It is further proposed that pancreatic acinar cells, owing to their extraordinarily high rate of protein synthesis, are at high risk for ER stress; that such stress plays a fundamental role in the induction of most pancreatic cancers; and that low-protein diets help to offset such stress by modulating activities of the kinases GCN2 and mTORC1 while increasing autocrine and systemic production of fibroblast growth factor 21. This model appears to clarify the role of various risk factors and protective factors in pancreatic cancer induction. A vegan or quasi-vegan low-protein diet may have broader potential for decreasing risk for a range of common "Western" cancers.

Mechanisms of Hepatitis B Virus-Induced Hepatocarcinogenesis

Hepatitis B virus (HBV) is a major cause of hepatocellular carcinoma (HCC). There are approximately 250 million people in the world that are chronically infected by this virus, resulting in nearly 1 million deaths every year. Many of these patients die from severe liver diseases, including HCC. HBV may induce HCC through the induction of chronic liver inflammation, which can cause oxidative stress and DNA damage. However, many studies also indicated that HBV could induce HCC via the alteration of hepatocellular physiology that may involve genetic and epigenetic changes of the host DNA, the alteration of cellular signaling pathways, and the inhibition of DNA repair mechanisms. This alteration of cellular physiology can lead to the accumulation of DNA damages and the promotion of cell cycles and predispose hepatocytes to oncogenic transformation.

Increased Expression of Programmed Death Ligand 1 in Hepatocellular Carcinoma of Patients with Hepatitis B Virus Pre-S2 Mutant

Purpose

Chronic hepatitis B virus (HBV) infection is a major risk factor for hepatocellular carcinoma (HCC), a leading cause of cancer-related death worldwide. The HCC patients who harbor HBV pre-S2 mutant, an oncoprotein that plays key roles in HCC development, have been closely associated with a worse prognosis after curative surgical resection, suggesting an urgent need for alternative therapeutic options to improve their survival. In this study, we aimed to evaluate the expression profiles of programmed death 1 (PD-1) and programmed death ligand 1 (PD-L1), two of the most well-studied immune checkpoint molecules that promote tumor immune evasion, in tumor of the pre-S2 mutant-positive/high HCC patients.

Methods

We classified 40 HBV-related HCC patients into the pre-S2-positive/high and -negative/low groups by a next-generation sequencing-based approach. The fluorescent immunohistochemistry staining was performed to detect the expression of PD-1 and PD-L1 in HCC tissues of patients.

Results

We showed that patients with either deletion spanning pre-S2 gene segment or high percentage of pre-S2 plus pre-S1+pre-S2 deletion (the pre-S2 mutant-positive/high group) exhibited a significantly higher density of PD-L1-positive cells in HCC tissues than those without. Moreover, the percentage of pre-S2 plus pre-S1+pre-S2 deletion displayed a high positive correlation with the density of PD-L1-positive cells in HCC tissues.

Conclusion

The increased expression of PD-L1 in tumor tissues of the pre-S2 mutant-positive HCC patients suggest that pre-S2 mutant may play a potential role in dysregulation of tumor immune microenvironment in the progression of HBV-related HCC, implicating for the development of future therapeutic strategies.

The molecular mechanisms of celecoxib in tumor development

BACKGROUND

Clinical studies have shown that celecoxib can significantly inhibit the development of tumors, and basic experiments and in vitro experiments also provide a certain basis, but it is not clear how celecoxib inhibits tumor development in detail.

METHODS

A literature search of all major academic databases was conducted (PubMed, China National Knowledge Internet (CNKI), Wan-fang, China Science and Technology Journal Database (VIP), including the main research on the mechanisms of celecoxib on tumors.

RESULTS

Celecoxib can intervene in tumor development and reduce the formation of drug resistance through multiple molecular mechanisms.

CONCLUSION

Celecoxib mainly regulates the proliferation, migration, and invasion of tumor cells by inhibiting the cyclooxygenases-2/prostaglandin E2 signal axis and thereby inhibiting the phosphorylation of nuclear factor-κ-gene binding, Akt, signal transducer and activator of transcription and the expression of matrix metalloproteinase 2 and matrix metalloproteinase 9. Meanwhile, it was found that celecoxib could promote the apoptosis of tumor cells by enhancing mitochondrial oxidation, activating mitochondrial apoptosis process, promoting endoplasmic reticulum stress process, and autophagy. Celecoxib can also reduce the occurrence of drug resistance by increasing the sensitivity of cancer cells to chemotherapy drugs.

Activating Transcription Factor 6 Mediates Inflammatory Signals in Intestinal Epithelial Cells Upon Endoplasmic Reticulum Stress

BACKGROUND & AIMS

Excess and unresolved endoplasmic reticulum (ER) stress in intestinal epithelial cells (IECs) promotes intestinal inflammation. Activating transcription factor 6 (ATF6) is one of the signaling mediators of ER stress. We studied the pathways that regulate ATF6 and its role for inflammation in IECs.

METHODS

We performed an RNA interference screen, using 23,349 unique small interfering RNAs targeting 7783 genes and a luciferase reporter controlled by an ATF6-dependent ERSE (ER stress-response element) promoter, to identify proteins that activate or inhibit the ATF6 signaling pathway in HEK293 cells. To validate the screening results, intestinal epithelial cell lines (Caco-2 cells) were transfected with small interfering RNAs or with a plasmid overexpressing a constitutively active form of ATF6. Caco-2 cells with a CRISPR-mediated disruption of autophagy related 16 like 1 gene (ATG16L1) were used to study the effect of ATF6 on ER stress in autophagy-deficient cells. We also studied intestinal organoids derived from mice that overexpress constitutively active ATF6, from mice with deletion of the autophagy related 16 like 1 or X-Box binding protein 1 gene in IECs (Atg16l1^ΔIEC or Xbp1^ΔIEC, which both develop spontaneous ileitis), from patients with Crohn's disease (CD) and healthy individuals (controls). Cells and organoids were incubated with tunicamycin to induce ER stress and/or chemical inhibitors of newly identified activator proteins of ATF6 signaling, and analyzed by real-time polymerase chain reaction and immunoblots. Atg16l1^ΔIEC and control (Atg16l1^fl/fl) mice were given intraperitoneal injections of tunicamycin and were treated with chemical inhibitors of ATF6 activating proteins.

RESULTS

We identified and validated 15 suppressors and 7 activators of the ATF6 signaling pathway; activators included the regulatory subunit of casein kinase 2 (CSNK2B) and acyl-CoA synthetase long chain family member 1 (ACSL1). Knockdown or chemical inhibition of CSNK2B and ACSL1 in Caco-2 cells reduced activity of the ATF6-dependent ERSE reporter gene, diminished transcription of the ATF6 target genes HSP90B1 and HSPA5 and reduced NF-κB reporter gene activation on tunicamycin stimulation. Atg16l1^ΔIEC and or Xbp1^ΔIEC organoids showed increased expression of ATF6 and its target genes. Inhibitors of ACSL1 or CSNK2B prevented activation of ATF6 and reduced CXCL1 and tumor necrosis factor (TNF) expression in these organoids on induction of ER stress with tunicamycin. Injection of mice with inhibitors of ACSL1 or CSNK2B significantly reduced tunicamycin-mediated intestinal inflammation and IEC death and expression of CXCL1 and TNF in Atg16l1^ΔIEC mice. Purified ileal IECs from patients with CD had higher levels of ATF6, CSNK2B, and HSPA5 messenger RNAs than controls; early-passage organoids from patients with active CD show increased levels of activated ATF6 protein, incubation of these organoids with inhibitors of ACSL1 or CSNK2B reduced transcription of ATF6 target genes, including TNF.

CONCLUSIONS

Ileal IECs from patients with CD have higher levels of activated ATF6, which is regulated by CSNK2B and HSPA5. ATF6 increases expression of TNF and other inflammatory cytokines in response to ER stress in these cells and in organoids from Atg16l1^ΔIEC and Xbp1^ΔIEC mice. Strategies to inhibit the ATF6 signaling pathway might be developed for treatment of inflammatory bowel diseases.

Association of the Hepatitis B Virus Large Surface Protein with Viral Infectivity and Endoplasmic Reticulum Stress-mediated Liver Carcinogenesis

Hepatitis B is the most prevalent viral hepatitis worldwide, affecting approximately one-third of the world’s population. Among HBV factors, the surface protein is the most sensitive biomarker for viral infection, given that it is expressed at high levels in all viral infection phases. The large HBV surface protein (LHBs) contains the integral pre-S1 domain, which binds to the HBV receptor sodium taurocholate co transporting polypeptide on the hepatocyte to facilitate viral entry. The accumulation of viral LHBs and its prevalent pre-S mutants in chronic HBV carriers triggers a sustained endoplasmic reticulum (ER) overload response, leading to ER stress-mediated cell proliferation, metabolic switching and genomic instability, which are associated with pro-oncogenic effects. Ground glass hepatocytes identified in HBV-related hepatocellular carcinoma (HCC) patients harbor pre-S deletion variants that largely accumulate in the ER lumen due to mutation-induced protein misfolding and are associated with increased risks of cancer recurrence and metastasis. Moreover, in contrast to the major HBs, which is decreased in tumors to a greater extent than it is in peritumorous regions, LHBs is continuously expressed during tumorigenesis, indicating that LHBs serves as a promising biomarker for HCC in people with CHB. Continuing efforts to delineate the molecular mechanisms by which LHBs regulates pathological changes in CHB patients are important for establishing a correlation between LHBs biomarkers and HCC development.

Neonatal exposure to environment-relevant levels of tributyltin leads to uterine dysplasia in rats

Endocrine-disrupting chemicals (EDCs) are natural/synthetic compounds that mimic or inhibit the biological actions of endogenous hormones. Studies have revealed that environmental estrogen, such as bisphenol A (BPA), causes developmental defects in the uterus. Tributyltin (TBT) is a typical environmental androgen. In this study, we aimed to explore the effect and mechanism of TBT on uterine development. Neonatal female rats were exposed to TBT (10 and 100 ng/kg bw) from postnatal days 1 to 16. BPA (50 μg/kg bw) was used as a positive control. Neonatal exposure to environmental concentrations of TBT resulted in pathological changes in the uterus, including thickening of the uterine luminal epithelium, a low density of glands, endometrial inflammation and fibrosis. Further, TBT affected the Wnt signaling pathway, which might mediate developmental disorders of the endometrial epithelial cells and glands in the uterus. TBT exposure also activated the NF-κB signaling pathway, which triggered inflammation. Moreover, TBT exposure upregulated the TGF-β/Smads signaling pathway, possibly leading to endometrial fibrosis. In summary, our results demonstrate that neonatal exposure to an environment-relevant level of TBT leads to uterine dysplasia and provide potential molecular mechanisms. Our study is helpful for clarifying the effects of environmental androgens on the female reproduction system.

Insights Into the Role of Mitochondrial Ion Channels in Inflammatory Response

Mitochondria are the source of many pro-inflammatory signals that cause the activation of the immune system and generate inflammatory responses. They are also potential targets of pro-inflammatory mediators, thus triggering a severe inflammatory response cycle. As mitochondria are a central hub for immune system activation, their dysfunction leads to many inflammatory disorders. Thus, strategies aiming at regulating mitochondrial dysfunction can be utilized as a therapeutic tool to cure inflammatory disorders. Two key factors that determine the structural and functional integrity of mitochondria are mitochondrial ion channels and transporters. They are not only important for maintaining the ionic homeostasis of the cell, but also play a role in regulating reactive oxygen species generation, ATP production, calcium homeostasis and apoptosis, which are common pro-inflammatory signals. The significance of the mitochondrial ion channels in inflammatory response is still not clearly understood and will need further investigation. In this article, we review the different mechanisms by which mitochondria can generate the inflammatory response as well as highlight how mitochondrial ion channels modulate these mechanisms and impact the inflammatory processes.

Chronic Stress Contributes to Osteosarcopenic Adiposity via Inflammation and Immune Modulation: The Case for More Precise Nutritional Investigation

Chronic stress and low-grade chronic inflammation (LGCI) are key underlying factors formany diseases, including bone and body composition impairments. Objectives of this narrativereview were to examine the mechanisms by which chronic stress and LGCI may influenceosteosarcopenic adiposity (OSA) syndrome, originally named as ostoesarcopenic obesity (OSO).We also examined the crucial nutrients presumed to be affected by or cause of stress andinflammation and compared/contrasted them to those of our prehistoric ancestors. The evidenceshows that stress (particularly chronic) and its related inflammatory processes, contribute toosteoporosis, sarcopenia, and adiposity ultimately leading to OSA as a final and most derangedstate of body composition, commencing at the mesenchymal cell lineage disturbance. Thefoods/nutrients consumed by modern humans, as well as their altered lifestyle, also contribute tostress, LGCI and subsequently to OSA. The processes can also go in opposite direction when stressand inflammation impact nutritional status, particularly some micronutrients' levels. Whilenutritional management of body composition and LGCI have been studied, the nutrients (and theirquantities) most affected by stressors and those which may act toward the alleviation of stressfulstate, ultimately leading to better body composition outcomes, need to be elucidated.

Advanced Glycation End Products (AGEs): Biochemistry, Signaling, Analytical Methods, and Epigenetic Effects

The advanced glycation end products (AGEs) are organic molecules formed in any living organisms with a great variety of structural and functional properties. They are considered organic markers of the glycation process. Due to their great heterogeneity, there is no specific test for their operational measurement. In this review, we have updated the most common chromatographic, colorimetric, spectroscopic, mass spectrometric, and serological methods, typically used for the determination of AGEs in biological samples. We have described their signaling and signal transduction mechanisms and cell epigenetic effects. Although mass spectrometric analysis is not widespread in the detection of AGEs at the clinical level, this technique is highly promising for the early diagnosis and therapeutics of diseases caused by AGEs. Protocols are available for high-resolution mass spectrometry of glycated proteins although they are characterized by complex machine management. Simpler procedures are available although much less precise than mass spectrometry. Among them, immunochemical tests are very common since they are able to detect AGEs in a simple and immediate way. In these years, new methodologies have been developed using an in vivo novel and noninvasive spectroscopic methods. These methods are based on the measurement of autofluorescence of AGEs. Another method consists of detecting AGEs in the human skin to detect chronic exposure, without the inconvenience of invasive methods. The aim of this review is to compare the different approaches of measuring AGEs at a clinical perspective due to their strict association with oxidative stress and inflammation.

Mechanisms underlying reduced weight gain in intestinal fatty acid-binding protein (IFABP) null mice

Intestinal-fatty acid binding protein (IFABP; FABP2) is a 15-kDa intracellular protein abundantly present in the cytosol of the small intestinal (SI) enterocyte. High-fat (HF) feeding of IFABP-/- mice resulted in reduced weight gain and fat mass relative to wild-type (WT) mice. Here, we examined intestinal properties that may underlie the observed lean phenotype of high fat-fed IFABP-/- mice. No alterations in fecal lipid content were found, suggesting that the IFABP-/- mice are not malabsorbing dietary fat. However, the total excreted fecal mass, normalized to food intake, was increased for the IFABP-/- mice relative to WT mice. Moreover, intestinal transit time was more rapid in the IFABP-/- mice. IFABP-/- mice displayed a shortened average villus length, a thinner muscularis layer, reduced goblet cell density, and reduced Paneth cell abundance. The number of proliferating cells in the crypts of IFABP-/- mice did not differ from that of WT mice, suggesting that the blunt villi phenotype is not due to alterations in proliferation. IFABP-/- mice were observed to have altered expression of genes and proteins related to intestinal structure, while immunohistochemical analyses revealed increased staining for markers of inflammation. Taken together, these studies indicate that the ablation of IFABP, coupled with high-fat feeding, leads to changes in gut motility and morphology, which likely contribute to the relatively leaner phenotype occurring at the whole-body level. Thus, IFABP is likely involved in dietary lipid sensing and signaling, influencing intestinal motility, intestinal structure, and nutrient absorption, thereby impacting systemic energy metabolism.NEW & NOTEWORTHY Intestinal fatty acid binding protein (IFABP) is thought to be essential for the efficient uptake and trafficking of dietary fatty acids. In this study, we demonstrate that high-fat-fed IFABP-/- mice have an increased fecal output and are likely malabsorbing other nutrients in addition to lipid. Furthermore, we observe that the ablation of IFABP leads to marked alterations in intestinal morphology and secretory cell abundance.

Mitogen-Activated Protein Kinase (MAPK) and Obesity-Related Cancer

Obesity is a major public health concern worldwide. The increased risk of certain types of cancer is now an established deleterious consequence of obesity, although the molecular mechanisms of this are not completely understood. In this review, we aim to explore the links between MAPK signalling and obesity-related cancer. We focus mostly on p38 and JNK MAPK, as the role of ERK remains unclear. These links are seen through the implication of MAPK in obesity-related immune paralysis as well as through effects on the endoplasmic reticulum stress response and activation of aromatase. By way of example, we highlight areas of interest and possibilities for future research in endometrioid endometrial cancer and hepatocellular carcinoma associated with non-alcoholic fatty liver disease (NAFLD), non-alcoholic steatohepatitis (NASH) and MAPK.

Adolescent exposure to environmental level of PCBs (Aroclor 1254) induces non-alcoholic fatty liver disease in male mice

Polychlorinated biphenyls (PCBs) are persistent organic pollutants found in various environmental media, and there is growing evidence that PCBs may contribute to the pathogenesis of non-alcoholic fatty liver disease (NAFLD). The purposes of this study were to investigate whether environmental level of Aroclor 1254 (a commercial mixture of PCBs) exposure to adolescent male mice could induce the development of NAFLD and the mechanisms involved. Twenty-one-day-old male C57BL/6 mice were exposed to Aroclor 1254 (0.5-500 μg/kg body weight) by oral gavage once every third day for 60 days. The results showed that exposure to Aroclor 1254 increased body weight and decreased the liver-somatic index in a dose-dependent manner. Aroclor 1254 administration increased lipid accumulation in the liver and induced the mRNA expression of genes associated with lipogenesis, including acetyl-CoA carboxylase 1 (Acc1), acetyl-CoA carboxylase 2 (Acc2) and fatty acid synthase (Fasn). Moreover, Aroclor 1254 decreased peroxisome proliferator-activated receptor alpha (PPARα) signaling and lipid oxidation. In addition, we found that Aroclor 1254 administration induced oxidative stress in mouse liver and elevated the protein level of cyclooxygenase 2 (COX-2), an inflammatory molecule, possibly via the endoplasmic reticulum (ER) stress inositol-requiring enzyme 1α-X-box-binding protein-1 (IRE1α-XBP1) pathway, but not the nuclear factor-κB (NF-κB) pathway. In summary, adolescent exposure to environmental level of PCBs stimulated oxidative stress, ER stress and the inflammatory response and caused NAFLD in male mice. This work provides new insight into the idea that adolescent exposure to environmental level of PCBs might induce the development of NAFLD under the regulation of ER stress in males.

Effect of ER stress on sphingolipid levels and apoptotic pathways in retinal pigment epithelial cells

Background

We aimed to determine sphingolipid levels and examine apoptotic pathways in human retinal pigment epithelial cells (ARPE-19) undergoing endoplasmic reticulum (ER) stress.

Methods

Cells were treated with tunicamycin (TM) to induce ER stress and tauroursodeoxycholic acid (TUDCA), an ER stress inhibitor, was administered to decrease cytotoxicity. Cell viability was measured by MTT assay. Levels of C16–C24 sphingomyelins (SM) and C16–C24 ceramides (CERs) were determined by LC-MS/MS. Glucose-regulated protein 78-kd (GRP78) and nuclear factor kappa-b subunit 1 (NFκB1) gene expressions were evaluated by quantitative PCR analysis, while GRP 78, NF-κB p65, cleaved caspase-3 and caspase-12 protein levels were assesed by immunofluorescence. Ceramide-1-phosphate (C1P) levels were determined by immunoassay, while caspase −3 and −12 activity in cell lysates were measured via a fluorometric method.

Results

Induction of ER stress in TM treated groups were confirmed by significantly increased mRNA and protein levels of GRP78. TM significantly decreased cell viability compared to controls. Treatment with TUDCA along with TM significantly increased cell viability compared to the TM group. A significant increase was observed in C22–C24 CERs, C1P, caspase-3, caspase-12, NFκB1 mRNA and NF-κB p65 protein levels in cells treated with TM compared to controls. Administration of TUDCA lead to a partial decrease in GRP78 expression, NFκB1 mRNA, NF-κB p65 protein, C22–C24 CERs and C1P levels along with a decrease in caspase-3 and -12 activity.

Conclusions

The results of this study reveal the presence of increased long chain CERs, C1P and apoptotic markers in retinal cells undergoing ER stress.

COX-2 Signaling in the Tumor Microenvironment

Tumorigenesis is a multistep, complicated process, and many studies have been completed over the last few decades to elucidate this process. Increasingly, many studies have shifted focus toward the critical role of the tumor microenvironment (TME), which consists of cellular players, cell-cell communications, and extracellular matrix (ECM). In the TME, cyclooxygenase-2 (COX-2) has been found to be a key molecule mediating the microenvironment changes. COX-2 is an inducible form of the enzyme that converts arachidonic acid into the signal transduction molecules (thromboxanes and prostaglandins). COX-2 is frequently expressed in many types of cancers and has been closely linked to its occurrence, progression, and prognosis. For example, COX-2 has been shown to (1) regulate tumor cell growth, (2) promote tissue invasion and metastasis, (3) inhibit apoptosis, (4) suppress antitumor immunity, and (5) promote sustainable angiogenesis. In this chapter, we summarize recent advances of studies that have evaluated COX-2 signaling in TME.