Endoplasmic reticulum stress: Multiple regulatory roles in hepatocellular carcinoma

Alterations of the microenvironment of hepatocellular carcinoma in different unfolded protein response activity states

BACKGROUND

The unfolded protein response (UPR) is an adaptive and cytoprotective sensing-signaling network. Numerous studies have indicated the crucial role of UPR in the anti-tumor drug resistance and the modification of tumor microenvironment (TME). The aim of this study is to analyze the alterations of microenvironment and key regulatory genes in hepatocellular carcinoma (HCC) with high UPR activity.

METHODS

We profiled differentially expressed genes (DEGs) by UPR activity, and the biological functions of DEGs and the alterations of signaling pathways were explored. The Immune/Stromal scores and relative abundance of infiltrating cells of HCC tissues with RNA sequencing data downloaded from The Cancer Genome Atlas (TCGA) were calculated by the xCell and ESTIMATE algorithm. The correlations between the prognostic UPR-related genes with the microenvironment scores and infiltrating cells were analyzed using R package "corrplot".

RESULTS

Our results demonstrated that UPR-related genes mainly involved in immune-related signaling pathways. Microenvironment analysis revealed that HCC tissues with higher UPR activity had lower Stromal scores and the relative abundance of various infiltrating cells including hematopoietic stem cells (HSC), lymphatic endothelial cells (LECs), microvascular endothelial cells, endothelial cells (ECs) and adipocytes decreased most significantly. Kaplan-Meier survival analysis indicated that the decline of Stromal scores and corresponding infiltrating stromal cells would result in worse prognosis. The expression levels of CLEC3B, RAMP3, GPR182 and DNASE1L3 were significantly positively correlated with Stromal scores and various infiltrating stromal cells, and down-regulation of these genes were also associated with worse prognosis of HCC.

CONCLUSIONS

HCC with high UPR activity had lower Stromal scores and worse prognosis. Down-regulated genes CLEC3B, RAMP3, GPR182 and DNASE1L3 may play an important regulatory role in the modification of microenvironment of HCC with high UPR activity.

Licorice attenuates cisplatin-induced hepatotoxicity by alleviating endoplasmic reticulum stress and apoptosis

Cisplatin (CP), a widely used antineoplastic drug, could induce hepatotoxicity and is also one of the most common reasons for drug-induced liver injury (DILI). Licorice (Chinese name GanCao, GC) is a commonly used herbal drug in traditional Chinese medicine (TCM) that has been shown to treat liver diseases and DILI. CP has been documented to induce apoptosis through the promotion of endoplasmic reticulum (ER) stress. However, the exact role of ER stress in the pathogenesis of CP-induced hepatotoxicity remains unclear. A rat DILI model was constructed through intraperitoneal injection of CP, and the anti-DILI effect of GC was detected by liver coefficients, liver function tests, pathological staining, and oxidative stress indices. Additionally, the ER stress and apoptosis indices were investigated by quantitative real-time PCR (qRT-PCR), Western blotting, and immunofluorescence (IF) on CP-induced toxicity in rat liver tissues and LO2 cells. In the model group, liver function indicators significantly elevated, liver lesions more pronounced, and the reactive oxygen species (ROS) level in the liver increased, the expression of ER stress markers, apoptosis factors, and indicators related to the protein kinase RNA-like ER kinase/activating transcription factor 4/C/EBP homologous protein (PERK/ATF4/CHOP) pathway significantly elevated. Treatment of the CP-induced toxicity in the rat model with GC significantly improved liver function, reduced liver lesions, decreased liver ROS. In addition, GC significantly inhibited the expression of ER stress markers, apoptosis factors, and indicators related to PERK/ATF4/CHOP pathway, demonstrating the anti-CP-induced hepatotoxicity effect of GC. In this study, we verified the protective effect of GC in CP-induced hepatotoxicity in rats and clarified its mechanisms related to ER stress and apoptosis.

SEL1L-mediated endoplasmic reticulum associated degradation inhibition suppresses proliferation and migration in Huh7 hepatocellular carcinoma cells

BACKGROUND

Proteins play a central role in regulating biological functions, and various pathways regulate their synthesis and secretion. Endoplasmic reticulum-associated protein degradation (ERAD) is crucial for monitoring protein synthesis and processing unfolded or misfolded proteins in actively growing tumor cells. However, the role of the multiple ERAD complexes in liver cancer remains unclear.

AIM

To elucidate the effects of SEL1L-mediated ERAD on Huh7 and explore the underlying mechanisms in vivo and in vitro.

METHODS

Huh7 cells were treated with ERAD inhibitor to identify ERAD's role. Cell counting kit-8, 5-ethynyl-2'-deoxyuridine and colony formation experiments were performed. Apoptosis level and migration ability were assessed using fluorescence activated cell sorting and Transwell assay, respectively. Huh7 SEL1L knockout cell line was established via clustered regularly interspaced short palindromic repeats, proliferation, apoptosis, and migration were assessed through previous experiments. The role of SEL1L in vivo and the downstream target of SEL1L were identified using Xenograft and mass spectrometry, respectively.

RESULTS

The ERAD inhibitor suppressed cell proliferation and migration and promoted apoptosis. SEL1L-HRD1 significantly influenced Huh7 cell growth. SEL1L knockout suppressed tumor cell proliferation and migration and enhanced apoptosis. Mass spectrometry revealed EXT2 is a primary substrate of ERAD. SEL1L knockout significantly increased the protein expression of EXT2. Furthermore, EXT2 knockdown partially restored the effect of SEL1L knockout.

CONCLUSION

ERAD inhibition suppressed the proliferation and migration of Huh7 and promoted its apoptosis. EXT2 plays an important role and ERAD might be a potential treatment for Huh7 hepatocellular carcinoma.

Rabdosia rubescens (Hemsl.) H. Hara: A potent anti-tumor herbal remedy - Botany, phytochemistry, and clinical applications and insights

ETHNOPHARMACOLOGICAL RELEVANCE

Traditional Chinese herbal medicine has unique advantages as anti-cancer drugs and adjuvant therapies. Rabdosia rubescens (Hemsl.) H. Hara (R. rubescens) is a traditional medicinal plant known for its anti-inflammatory, antioxidant, antibacterial, anti-angiogenic and antitumor properties. The antitumor activity of R. rubescens is widely recognized among the folk communities in Henan Province, China.

AIM OF THE STUDY

This study reviews the botany, ethnopharmacology, phytochemistry, anti-tumor active ingredients, mechanisms, and clinical applications of R. rubescens, aiming to provide a comprehensive understanding for its use as an anti-cancer drug and adjuvant therapy.

MATERIALS AND METHODS

We systematically searched the literature in PubMed, Web of Science, and CNKI using the following keywords: "Rabdosia rubescens", "Isodon rubescens", "traditional application", "anti-tumor", "phytochemistry", "anti-tumor active compounds", "oridonin" and "clinical application". The search covered publications from 1997 to 2024. Inclusion criteria included original studies or reviews focusing on the anti-tumor properties of R. rubescens or its active components. Exclusion criteria included studies related to non-R. rubescens applications.

RESULTS

R. rubescens is a perennial herbaceous plant in the family Lamiaceae, mainly found in central and southern China. Historically, it has been used to treat conditions such as sore throat, cough, and excess phlegm. The plant contains various compounds, including diterpenes, triterpenes, steroids, flavonoids, phenolic acids, essential oils, amino acids, alkaloids, and polysaccharides, with diterpenes, triterpenes, flavonoids, and phenolic acids being the most active. This review identifies 50 compounds with anti-tumor properties, comprising 34 diterpenes, 2 triterpenes, 7 flavonoids, and 7 phenolic acids. Notably, besides oridonin and ponicidin, the ent-kaurane diterpenoids (20S)-11β,14β,20-trihydroxy-7α,20-epoxy-ent-kaur-16-en15-one and (20S)-11β,14β-dihydroxy-20-ethoxy7α,20-epoxy-ent-kaur-16-en-15-one demonstrate significant anti-tumor activity, attributed to their carbonyl group at C-15, hydroxyl group at C-1, and OEt group at C-20. Mechanistically, R. rubescens combats tumors by blocking the tumor cell cycle, promoting apoptosis, inhibiting cell migration and angiogenesis, inducing ferroptosis, reversing drug resistance, and enhancing radiosensitivity in tumor cells. Clinically, R. rubescens is available in various forms, including tablets, drops, syrups, capsules, and lozenges, and is primarily used for tonsillitis, pharyngitis, and stomatitis. According to the 2020 edition of the Pharmacopoeia of China, R. rubescens tablets are recognized as an adjuvant therapy for cancer. Clinical studies indicate that R. rubescens syrup, tablets, and thermal therapy can enhance cancer patient survival rates and lower tumor recurrence rates.

CONCLUSIONS

Given its traditional and modern uses, active anti-tumor components, and mechanisms, R. rubescens is a promising resource in traditional Chinese medicine for anti-tumor therapy. To realize its full potential, future research should explore additional active anti-tumor compounds beyond oridonin and ponicidin. For these key components, studies should focus on structural modifications to identify new active molecules and essential anti-tumor structures. Clinically, it is important to investigate how R. rubescens interacts with other Chinese herbs in anti-tumor formulations to enhance treatment efficacy and guide appropriate clinical use. Furthermore, future studies should undergo ethical review and include larger-scale randomized controlled trials to validate the efficacy of R. rubescens in treating tumors, thereby promoting its role as an anti-tumor traditional Chinese medicine.

PPARα suppresses growth of hepatocellular carcinoma in a high-fat diet context by reducing neutrophil extracellular trap release

Background & Aims

The role of infiltrating neutrophils in hepatocellular carcinoma (HCC) is modulated by cellular metabolism, specifically lipid homeostasis. Throughout the progression of HCC, alterations in lipid metabolism are intricately linked with regulation of neutrophil function and the release of neutrophil extracellular traps (NETs). However, how much the protumor effect of a high-fat diet (HFD) depends on NETs and the potential interplay between NETs and other leukocytes in HCC remains uncertain.

Methods

In this study, the molecular mechanism of NET release and the potential beneficial effects of PPARα agonists on the HCC microenvironment were explored through proteomics, metabolomics, tissue microarray, immunofluorescence, flow cytometry, western blot, and dual-luciferase reporter gene assays (n = 6 per group).

Results

Our study demonstrated a notable inhibition of PPARα signaling in HCC. Furthermore, the disruption of PPARα-mediated lipid metabolism was responsible for the release of NETs. The presence of a HFD was observed to induce mitochondrial impairment in neutrophils, leading to the activation of cGAS-STING by oxidized mitochondrial DNA (Ox-mtDNA). Consequently, this activation triggered the release of NETs containing Ox-mtDNA through the enhancement of NLRP3-GSDMD-N in a NF-κB-dependent manner. Moreover, the release of NETs within HCC tissues effectively isolated cytotoxic leukocytes in the outer regions of HCC.

Conclusions

Our study not only provides insight into the relationship between lipid metabolism disorders and NETs' tumor-promoting function, but also provides an important strategic reference for multi-target or combined immunotherapy of HCC.

Impact and implications

We have identified PPARα and its agonists as therapeutic targets for controlling the neutrophil extracellular traps associated with high lipid metabolism. Results from preclinical models suggest that PPARα can limit mitochondrial oxidative stress, inhibit cGAS-STING-NF-κB signaling, and limit the release of neutrophil extracellular traps, thereby increasing the contact of anti-tumor leukocytes and hepatocellular cancer cells and limiting tumor growth.

Autophagy-based therapy for hepatocellular carcinoma: from standard treatments to combination therapy, oncolytic virotherapy, and targeted nanomedicines

Human hepatocellular carcinoma (HCC) has been identified as a significant cause of mortality worldwide. In recent years, extensive research has been conducted to understand the underlying mechanisms of autophagy in the pathogenesis of the disease, with the aim of developing novel therapeutic agents. Targeting autophagy with conventional therapies in invasive HCC has opened up new opportunities for treatment. However, the emergence of resistance and the immunosuppressive tumor environment highlight the need for combination therapy or specific targeting, as well as an efficient drug delivery system to ensure targeted tumor areas receive sufficient doses without affecting normal cells or tissues. In this review, we discuss the findings of several studies that have explored autophagy as a potential therapeutic approach in HCC. We also outline the potential and limitations of standard therapies for autophagy modulation in HCC treatment. Additionally, we discuss how different combination therapies, nano-targeted strategies, and oncolytic virotherapy could enhance autophagy-based HCC treatment in future research.

Connections Between Endoplasmic Reticulum Stress and Prognosis of Hepatocarcinoma

Endoplasmic reticulum (ER) stress is a state in which misfolded or unfolded proteins accumulate in the lumen of the ER as a result of some exogenous or endogenous factors. It plays a crucial role in the pathogenesis of malignancies, affecting cell survival, proliferation, and metastasis in cancer. ER stress genes could provide new ideas for potential therapeutic targets in cancer. In our study, we aimed to construct an ER stress-related genes (ERGs) model for hepatocellular carcinoma (HCC). ERGs with differential expression and significant survival were screened to construct a prognostic model. The effectiveness of the model was successfully validated by external datasets. High and low-risk groups were classified based on risk scores. Functional analysis showed risk groups involved in the unfolded protein response, DNA repair, and other differential pathways. When compared to patients with low risk, the prognosis for HCC patients in the high-risk group might be worsened by disruptions in these pathways. Importantly, we considered genomic druggability and predicted drugs. Sorafenib-induced autophagy in HCC cells through an ES stress mechanism. Sorafenib was more sensitive for high-risk patients. In brief, our model predicted the prognosis of HCC and provided novel treatment strategies for the study of other cancers.

CHAC1: a master regulator of oxidative stress and ferroptosis in human diseases and cancers

CHAC1, an essential regulator of oxidative stress and ferroptosis, is increasingly recognized for its significant roles in these cellular processes and its impact on various human diseases and cancers. This review aims to provide a comprehensive overview of CHAC1's molecular functions, regulatory mechanisms, and effects in different pathological contexts. Specifically, the study objectives are to elucidate the biochemical pathways involving CHAC1, explore its regulatory network, and discuss its implications in disease progression and potential therapeutic strategies. As a γ-glutamyl cyclotransferase, CHAC1 degrades glutathione, affecting calcium signaling and mitochondrial function. Its regulation involves transcription factors like ATF4 and ATF3, which control CHAC1 mRNA expression. CHAC1 is crucial for maintaining redox balance and regulating cell death pathways in cancer. Its elevated levels are associated with poor prognosis in many cancers, indicating its potential as a biomarker and therapeutic target. Additionally, CHAC1 influences non-cancerous diseases such as neurodegenerative and cardiovascular disorders. Therapeutically, targeting CHAC1 could increase cancer cell sensitivity to ferroptosis, aiding in overcoming resistance to standard treatments. This review compiles current knowledge and recent discoveries, emphasizing CHAC1's vital role in human diseases and its potential in diagnostic and therapeutic applications.

Construction of an endoplasmic reticulum stress and cuproptosis -related lncRNAs signature in chemosensitivity in hepatocellular carcinoma by comprehensive bioinformatics analysis

Endoplasmic reticulum stress (ERS) and cuproptosis have remarkable effects on hepatocellular carcinoma (HCC) leading to a poor prognosis. The current study aimed to explore credible signature for predicting the prognosis of HCC based on ERS and cuproptosis-related lncRNAs. In our study, clinical and transcriptomic profiles of HCC patients were obtained from the Cancer Genome Atlas (TCGA) database. An ERS and cuproptosis-related lncRNA prognostic signature, including NRAV, SNHG3, LINC00839 and AC004687.1, was determined by correlation tests, Cox regression analysis, least absolute shrinkage, and selection operator (LASSO) methods. Survival and predictive value were evaluated using Kaplan-Meier and receiver operating characteristic (ROC) curves, while calibration and nomograms curves were developed. Besides the enrichment analyses for ERS and cuproptosis-related lncRNAs, mutational status and immune status were assessed with TMB and ESTIMATE. Additionally, consensus cluster analysis was employed to compare cancer subtype differences, while drug sensitivity and immunologic efficacy were evaluated for further exploration. qRT-PCR and CCK-8 were utilized to verify the alteration of the prognostic lncRNAs expression and proliferation in vitro. High-risk groups exhibited poorer prognosis. The signature exhibited robust predictive value as an independent prognostic indicator and showed significant correlation with clinicopathological features. In the enriched analysis, biological membrane pathways were enriched. Low-risk patients had lower TMB and higher immune status. A cluster analysis revealed that cluster 2 had the best clinical immunological efficacy and most active immune function. In brief, our constructed signature with ERS and cuproptosis-related lncRNAs was associated survival outcomes of HCC, and can be used to predict the clinical classification and curative effect.

The preventive effects of natural plant compound carvacrol against combined UVA and UVB-induced endoplasmic reticulum stress in skin damage of rats

The skin is constantly exposed to a variety of environmental stressors, including ultraviolet (UV) radiation. Exposure of the skin to UV radiation causes a number of detrimental biological damages such as endoplasmic reticulum (ER) stress. The ER stress response is a cytoprotective mechanism that maintains homeostasis of the ER by increasing the capacity of the ER against the accumulation of unfolded proteins in the ER. Carvacrol (CRV) is a monoterpenoid phenol found in essential oils with antimicrobial and anti-inflammatory activities. We investigated for the first time in the literature the potential protective role of CRV against combined UVA and UVB-induced skin damage by targeting the ER stress pathway in a rat model. For this purpose, expressions of Grp78, Perk, Atf6, Ire-1, Chop, Xbp1, Casp12, elF2α, and Traf2 genes related to ER stress were analyzed by RT-PCR and protein expression levels of GRP78, ATF6, CHOP, and XBP1 were determined by ELISA assay in tissue sections taken from the back of the rats. As a result of analysis, it was seen that the expression levels of aforementioned ER stress genes increased significantly in the UVA + UVB irradiated group compared to the control group, while their expression levels decreased markedly by supplementation of CRV in UVA + UVB + CRV group. With regard to expressions of foregoing proteins, their levels escalated notably with UVA + UVB application and decreased markedly by CRV supplementation. In conclusion, present study revealed that CRV ameliorates UVA + UVB-induced ER stress via reducing the expression of mRNA as well as proteins involved in the unfolded protein response (UPR) pathway and inducing apoptosis as evidenced from high Caspase12 level.

Marine-derived antimicrobial peptide piscidin-1 triggers extrinsic and intrinsic apoptosis in oral squamous cell carcinoma through reactive oxygen species production and inhibits angiogenesis

Cancer of the head and neck encompasses a wide range of cancers, including oral and oropharyngeal cancers. Oral cancer is often diagnosed at advanced stages and has a dismal prognosis. Piscidin-1, a marine antimicrobial peptide (AMP) containing approximately 22 amino acids, also exhibits significant anticancer properties. We investigated the possible anti-oral cancer effects of piscidin-1 and clarified the mechanisms underlying these effects. We treated the oral squamous cell carcinoma cell lines OC2 and SCC4 with piscidin-1. Cell viability and the expression of different hallmark apoptotic molecules, including reactive oxygen species (ROS), were tested using the appropriate MTT assay, flow cytometry and western blotting assays, and human umbilical vein endothelial cell (HUVEC) wound healing, migration, and tube formation (angiogenesis) assays. Piscidin-1 increases cleaved caspase 3 levels to induce apoptosis. Piscidin-1 also increases ROS levels and intensifies oxidative stress in the endoplasmic reticulum and mitochondria, causing mitochondrial dysfunction. Additionally, it decreases the oxygen consumption rates and activity of mitochondrial complexes I-V. As expected, the antioxidants MitoTEMPOL and N-acetylcysteine reduce piscidin-1-induced ROS generation and intracellular calcium accumulation. Piscidin-1 also inhibits matrix metalloproteinase (MMP)-2/-9 expression in HUVECs, affecting migration and tube formation angiogenesis. We demonstrated that piscidin-1 can promote apoptosis via both intrinsic and extrinsic apoptotic pathways and findings indicate that piscidin-1 has anti-proliferative and anti-angiogenic properties in oral cancer treatment. Our study on piscidin-1 thus provides a basis for future translational anti-oral cancer drug research and a new theoretical approach for anti-oral cancer clinical research.

Construction and validation of a prognostic signature based on seven endoplasmic reticulum stress-related lncRNAs for patients with head and neck squamous cell carcinoma

Endoplasmic reticulum stress (ERS) occurs when misfolded or unfolded proteins accumulate in the endoplasmic reticulum (ER), and it is often observed in tumors, including head and neck squamous cell carcinoma (HNSCC). Relevant studies have demonstrated the prognostic significance of ERS-related long non-coding RNAs (lncRNAs) in various cancers. However, the relationship between ERS and lncRNAs in HNSCC has received limited attention in previous studies. In this study, we aimed to develop an ERS-related lncRNAs prognostic model using correlation analysis, Cox regression analysis, least absolute shrinkage, and selection operator (LASSO) regression analysis based on data from The Cancer Genome Atlas (TCGA) database. The survival and predictive ability of this model were evaluated using Kaplan-Meier analysis and time-dependent receiver operating characteristics (ROC), while nomograms and calibration curves were constructed. Then, functional enrichment analyses, tumor mutation burden (TMB), tumor infiltration of immune cells, single sample Gene Set Enrichment Analysis (ssGSEA), and drug sensitivity analysis were performed. Additionally, we conducted a consensus cluster analysis to compare differences between subtypes of tumors. Finally, we validated the expression of the ERS-related lncRNAs that constructed prognostic risk score model in HNSCC tissues through quantitative real-time PCR (qRT-PCR). We developed a prognostic signature based on seven ERS-related lncRNAs, which showed better predictive performance than other clinicopathological features. The high-risk poor prognosis group had a poorer prognosis in comparison to the low-risk good prognosis. The area under the ROC curve (AUC) predicted by this model for 3-year survival rates of HNSCC patients was 0.805. Enrichment analysis revealed that the differentially expressed genes were primarily enriched in pathways related to immune responses and signal transduction. Low-risk patients had lower TMB, more immune cell infiltrations, and enhanced anti-tumor immunity. Cluster analysis indicated that cluster 3 may have a better prognosis and immunotherapy effect. In addition, the result of qRT-PCR was consistent with our analysis. This prognostic model based on seven ERS-related lncRNAs is a promising tool for risk stratification, survival prediction, and immune cell infiltration status assessment.

α-Hederin induces human colorectal cancer cells apoptosis through disturbing protein homeostasis

Protein homeostasis and quality control are crucial for normal cellular activities, and a severe imbalance in protein homeostasis can lead to cell death. α-Hederin, a pentacyclic triterpenoid saponin isolated from Fructus Akebia, has a clear role in promoting colorectal cancer (CRC) cell apoptosis and has been recently used for CRC therapy. However, whether the pro-apoptotic activity of α-hederin in CRC cells involves disturbing protein homeostasis remains unknown. Here, we aimed to uncover the underlying molecular mechanism of α-hederin-induced apoptosis in CRC cells. Cell viability and proliferation were examined by 3-(4,5-dimethylthiazol-2-yl)-2,5 diphenyl tetrazolium bromide (MTT) and 5-ethynyl-2'-deoxyuridine (EdU) assays, respectively. Apoptosis was detected using flow cytometry and western blotting. Autophagic flux was examined by western blotting and AdPlus-mCherry-GFP-LC3B adenovirus infection assays, and western blotting and immunofluorescence staining were performed to detect the expression of proteins in related pathways. The results showed that α-hederin significantly inhibited the growth and promoted the apoptosis of human CRC cells. Furthermore, α-Hederin induced endoplasmic reticulum (ER) stress, but inhibited proteasomal degradation. Also, the autophagic flux was blocked by α-hederin although this drug promoted autophagosome formation, and the lysosomal degradation was inhibited. Expression of p-JNK and p-p38 were increased by α-hederin. So, our findings provide strong evidence that α-hederin disrupts protein homeostasis by blocking ER-associated degradation (ERAD) and autophagic flux, thereby contributing to apoptosis. PERK-eIF2α-ATF4-CHOP and IRE1-ASK1-JNK/p38 signal pathway may be involved in those regulation. Our results make it a promising alternative or adjunct therapeutic candidate for CRC.

Endoplasmic Reticulum Stress and Metabolism in Hepatocellular Carcinoma

Hepatocellular carcinoma (HCC) is the most common type of primary liver cancer, accounting for 85% to 90% of all liver cancer cases. It is a hepatocyte-derived primary tumor, causing 550,000 deaths per year, ranking it as one of the most common cancers worldwide. The liver is a highly metabolic organ with multiple functions, including digestion, detoxification, breakdown of fats, and production of bile and cholesterol, in addition to storage of vitamins, glycogen, and minerals, and synthesizing plasma proteins and clotting factors. Due to these fundamental and diverse functions, the malignant transformation of hepatic cells can have a severe impact on the liver's metabolism. Furthermore, tumorigenesis is often accompanied by activation of the endoplasmic reticulum (ER) stress pathways, which are known to be highly intertwined with several metabolic pathways. Because HCC is characterized by changes in the metabolome and by an aberrant activation of the ER stress pathways, the aim of this review was to summarize the current knowledge that links ER stress and metabolism in HCC, thereby focusing on potential therapeutic targets.

The Dynamic Role of Endoplasmic Reticulum Stress in Chronic Liver Disease

Chronic liver disease (CLD) is a major worldwide public health threat, with an estimated prevalence of 1.5 billion individuals with CLD in 2020. Chronic activation of endoplasmic reticulum (ER) stress-related pathways is recognized as substantially contributing to the pathologic progression of CLD. The ER is an intracellular organelle that folds proteins into their correct three-dimensional shapes. ER-associated enzymes and chaperone proteins highly regulate this process. Perturbations in protein folding lead to misfolded or unfolded protein accumulation in the ER lumen, resulting in ER stress and concomitant activation of the unfolded protein response (UPR). The adaptive UPR is a set of signal transduction pathways evolved in mammalian cells that attempts to reestablish ER protein homeostasis by reducing protein load and increasing ER-associated degradation. However, maladaptive UPR responses in CLD occur due to prolonged UPR activation, leading to concomitant inflammation and cell death. This review assesses the current understanding of the cellular and molecular mechanisms that regulate ER stress and the UPR in the progression of various liver diseases and the potential pharmacologic and biological interventions that target the UPR.

Identification of an endoplasmic reticulum stress-related prognostic risk model with excellent prognostic and clinical value in oral squamous cell carcinoma

BACKGROUND

Recently, endoplasmic reticulum stress related gene (ERS) markers have performed very well in predicting the prognosis of tumor patients.

METHODS

The differentially expressed genes in Oral squamous cell carcinoma (OSCC) were obtained from TCGA and GTEx database. Three prognosis-related and differentially expressed ERSs were screened out by Least Absolute Selection and Shrinkage Operator (Lasso) regression to construct a prognostic risk model. Receiver Operating Characteristic Curve (ROC), riskplots and survival curves were used to verify the model's accuracy in predicting prognosis. Multi-omics analysis of immune infiltration, gene mutation, and stem cell characteristics were performed to explore the possible mechanism of OSCC. Finally, we discussed the model's clinical application value from the perspective of drug sensitivity.

RESULTS

Three genes used in the model (IBSP, RDM1, RBP4) were identified as prognostic risk factors. Bioinformatics analysis, tissue and cell experiments have fully verified the abnormal expression of these three genes in OSCC. Multiple validation methods and internal and external datasets confirmed the model's excellent performance in predicting and discriminating prognosis. Cox regression analysis identified risk score as an independent predictor of prognosis. Multi-omics analysis found strong correlations between risk scores and immune cells, cell stemness index, and tumor mutational burden (TMB). It was also observed that the risk score was closely related to the half maximal inhibitory concentration of docetaxel, gefitinib and erlotinib. The excellent performance of the nomogram has been verified by various means.

CONCLUSION

A prognostic model with high clinical application value was constructed. Immune cells, cellular stemness, and TMB may be involved in the progression of OSCC.

Therapeutic potential of alkaloid extract from Codonopsis Radix in alleviating hepatic lipid accumulation: insights into mitochondrial energy metabolism and endoplasmic reticulum stress regulation in NAFLD mice

Alkaloids are a class of naturally occurring bioactive compounds that are widely distributed in various food sources and Traditional Chinese Medicine. This study aimed to investigate the therapeutic effects and underlying mechanisms of alkaloid extract from Codonopsis Radix (ACR) in ameliorating hepatic lipid accumulation in a mouse model of non-alcoholic fatty liver disease (NAFLD) induced by a high-fat diet (HFD). The results revealed that ACR treatment effectively mitigated the abnormal weight gain and hepatic injury associated with HFD. Furthermore, ACR ameliorated the dysregulated lipid metabolism in NAFLD mice, as evidenced by reductions in serum triglyceride, total cholesterol, and low-density lipoprotein levels, accompanied by a concomitant increase in the high-density lipoprotein level. ACR treatment also demonstrated a profound anti-oxidative effect, effectively alleviating HFD-induced oxidative stress and promoting ATP production. These effects were achieved through the up-regulation of the activities of mitochondrial electron transfer chain complexes I, II, IV, and V, in addition to the activation of the AMPK/PGC-1α pathway, suggesting that ACR exhibits therapeutic potential in alleviating the HFD-induced dysregulation of mitochondrial energy metabolism. Moreover, ACR administration mitigated HFD-induced endoplasmic reticulum (ER) stress and suppressed the overexpression of ubiquitin-specific protease 14 (USP14) in NAFLD mice. In summary, the present study provides compelling evidence supporting the hepatoprotective role of ACR in alleviating lipid deposition in NAFLD by improving energy metabolism and reducing oxidative stress and ER stress. These findings warrant further investigation and merit the development of ACR as a potential therapeutic agent for NAFLD.

A comprehensive signature based on endoplasmic reticulum stress-related genes in predicting prognosis and immunotherapy response in melanoma

Melanoma is considered as one of the most invasion types of skin cancer with high mortality rates. Although combination of immune checkpoint therapy with local surgical excision provide a novel promising therapeutic strategies, the overall prognosis of melanoma patients remains unsatisfactory. Endoplasmic reticulum (ER) stress, a process of protein misfolding and undue accumulation, has been proven to play an indispensable regulatory role in tumor progression and tumor immunity. However, whether the signature based ER genes has predictive value for the prognosis and immunotherapy of melanoma has not been systematically manifested. In this study, the LASSO regression and multivariate Cox regression were applied to construct a novel signature for predicting melanoma prognosis both in the training and testing set. Intriguingly, we found that patients endowed with high- and low-risk scores displayed differences in clinicopathologic classification, immune cell infiltration level, tumor microenvironment, and immune checkpoint treatment response. Subsequently, based on molecular biology experiments, we validated that silencing the expression of RAC1, an ERG composed of the risk signature, could restrain the proliferation and migration, promote apoptosis, as well as increase the expression of PD-1/PD-L1 and CTLA4 in melanoma cells. Taken together, the risk signature was regarded as promising predictors for melanoma prognosis and might provide prospective strategies to ameliorate patients' response to immunotherapy.

Pathogenesis of Hepatocellular Carcinoma: The Interplay of Apoptosis and Autophagy

The pathogenesis of hepatocellular carcinoma (HCC) is a multifactorial process that has not yet been fully investigated. Autophagy and apoptosis are two important cellular pathways that are critical for cell survival or death. The balance between apoptosis and autophagy regulates liver cell turnover and maintains intracellular homeostasis. However, the balance is often dysregulated in many cancers, including HCC. Autophagy and apoptosis pathways may be either independent or parallel or one may influence the other. Autophagy may either inhibit or promote apoptosis, thus regulating the fate of the liver cancer cells. In this review, a concise overview of the pathogenesis of HCC is presented, with emphasis on new developments, including the role of endoplasmic reticulum stress, the implication of microRNAs and the role of gut microbiota. The characteristics of HCC associated with a specific liver disease are also described and a brief description of autophagy and apoptosis is provided. The role of autophagy and apoptosis in the initiation, progress and metastatic potential is reviewed and the experimental evidence indicating an interplay between the two is extensively analyzed. The role of ferroptosis, a recently described specific pathway of regulated cell death, is presented. Finally, the potential therapeutic implications of autophagy and apoptosis in drug resistance are examined.

The application of nanoparticles in immunotherapy for hepatocellular carcinoma

Hepatocellular carcinoma (HCC) remains one of the leading causes of cancer-related deaths worldwide, however, current clinical diagnostic and treatment approaches remain relatively limited, creating an urgent need for the development of effective technologies. Immunotherapy has emerged as a powerful treatment strategy for advanced cancer. The number of clinically approved drugs for HCC immunotherapy has been increasing. However, it remains challenging to improve their transport and therapeutic efficiency, control their targeting and release, and mitigate their adverse effects. Nanotechnology has recently gained attention for improving the effectiveness of precision therapy for HCC. We summarize the key features of HCC associated with nanoparticle (NPs) targeting, release, and uptake, the roles and limitations of several major immunotherapies in HCC, the use of NPs in immunotherapy, the properties of NPs that influence their design and application, and current clinical trials of NPs in HCC, with the aim of informing the design of delivery platforms that have the potential to improve the safety and efficacy of HCC immunotherapy，and thus, ultimately improve the prognosis of HCC patients.

Baicalein facilitates gastric cancer cell apoptosis by triggering endoplasmic reticulum stress via repression of the PI3K/AKT pathway

OBJECTIVE

Gastric cancer (GC) remains a prevailing threat to life. Baicalein exhibits anti-cancer properties. This study estimated the mechanism of baicalein in GC cell apoptosis by mediating endoplasmic reticulum stress (ERS) through the PI3K/AKT pathway.

METHODS

After treatment with different concentrations of baicalein, GC cell (HGC-27 and AGS) viability was detected by MTT assay. AGS cells more sensitive to baicalein treatment were selected as study subjects. The IC50 of baicalein on AGS cells was determined. Colony formation, cell cycle, and apoptosis were detected using crystal violet staining and flow cytometry. Levels of ERS-related and BTG3/PI3K/AKT pathway-related proteins were determined by Western blot. Intracellular Ca²⁺ level was measured using Fluo-3 AM fluorescence working solution. GC mouse models were established by subcutaneously injecting AGS cells into the right rib and were intragastrically administrated with baicalein. Tumor volume and weight were recorded. Expression of Ki67 in tumor tissues and positive expression of apoptotic cells were detected by immunohistochemistry and TUNEL staining.

RESULTS

Baicalein inhibited cell proliferation and induced G0/G1 arrest and apoptosis by regulating the cell cycle, and triggered ERS in GC cells. Baicalein impeded the PI3K/AKT pathway by activating BTG3, thereby triggering ERS and inducing apoptosis. BTG3 inhibition reversed baicalein-induced apoptosis and ERS. Baicalein regulated GC cells in a concentration-dependent manner. Moreover, in xenograft mice, baicalein prevented tumor growth, decreased Ki67-positive cells, activated BTG3, and inhibited the PI3K/AKT pathway, thus activating ERS and increasing apoptotic cells.

CONCLUSION

Baicalein facilitates GC cell apoptosis by triggering ERS via repression of the PI3K/AKT pathway.

Non-Lethal Concentrations of CdCl2 Cause Marked Alternations in Cellular Stress Responses within Exposed Sertoli Cell Line

Cadmium is a component of ambient metal pollution, which is linked to diverse health issues globally, including male reproductive impairment. Assessments of the acute effects of cadmium on male reproduction systems, such as testes, tend to be based on frank adverse effects, with particular molecular pathways also involved. The relationship between cytotoxicity potential and cellular stress response has been suggested to be one of the many possible drivers of the acute effects of cadmium, but the link remains uncertain. In consequence, there is still much to be learned about the cellular stress response induced by a non-lethal concentration of cadmium in male reproductive cells. The present study used temporal assays to evaluate cellular stress response upon exposure to non-lethal concentrations of Cadmium chloride (CdCl₂) in the Sertoli cell line (TM4). The data showed alternations in the expression of genes intimated involved in various cellular stress responses, including endoplasmic reticulum (ER) stress, endoplasmic unfolded protein stress (UPRmt), endoplasmic dynamics, Nrf2-related antioxidative response, autophagy, and metallothionein (MT) expression. Furthermore, these cellular responses interacted and were tightly related to oxidative stress. Thus, the non-lethal concentration of cadmium perturbed the homeostasis of the Sertoli cell line by inducing pleiotropic cellular stresses.

Potential of Copper and Copper Compounds for Anticancer Applications

Inducing cancer cell death has always been a research hotspot in life sciences. With the continuous deepening and diversification of related research, the potential value of metal elements in inducing cell death has been explored. Taking iron as an example, ferroptosis, mainly characterized by increasing iron load and driving the production of large amounts of lipid peroxides and eventually leading to cell death, has recently attracted great interest in the cancer research community. After iron, copper, a trace element, has received extensive attention in cell death, especially in inducing tumor cell death. Copper and its complexes can induce autophagy or apoptosis in tumor cells through a variety of different mechanisms of action (activation of stress pathways, arrest of cell cycle, inhibition of angiogenesis, cuproptosis, and paraptosis), which are promising in cancer therapy and have become new hotspots in cancer treatment research. This article reviews the main mechanisms and potential applications of novel copper and copper compound-induced cell death, focusing on copper compounds and their anticancer applications.

Identification of an endoplasmic reticulum stress-related gene signature to predict prognosis and potential drugs of uterine corpus endometrial cancer

Uterine corpus endometrial cancer (UCEC) is the sixth most common female cancer worldwide, with an increasing incidence. Improving the prognosis of patients living with UCEC is a top priority. Endoplasmic reticulum (ER) stress has been reported to be involved in tumor malignant behaviors and therapy resistance, but its prognostic value in UCEC has been rarely investigated. The present study aimed to construct an ER stress-related gene signature for risk stratification and prognosis prediction in UCEC. The clinical and RNA sequencing data of 523 UCEC patients were extracted from TCGA database and were randomly assigned into a test group (n = 260) and training group (n = 263). An ER stress-related gene signature was established by LASSO and multivariate Cox regression in the training group and validated by Kaplan-Meier survival analysis, Receiver Operating Characteristic (ROC) curves and nomograms in the test group. Tumor immune microenvironment was analyzed by CIBERSORT algorithm and single-sample gene set enrichment analysis. R packages and the Connectivity Map database were used to screen the sensitive drugs. Four ERGs (ATP2C2, CIRBP, CRELD2 and DRD2) were selected to build the risk model. The high-risk group had significantly reduced overall survival (OS) (P < 0.05). The risk model had better prognostic accuracy than clinical factors. Tumor-infiltrating immune cells analysis depicted that CD8+ T cells and regulatory T cells were more abundant in the low-risk group, which may be related to better OS, while activated dendritic cells were active in the high-risk group and associated with unfavorable OS. Several kinds of drugs sensitive to the high-risk group were screened out. The present study constructed an ER stress-related gene signature, which has the potential to predict the prognosis of UCEC patients and have implications for UCEC treatment.

Oridonin ameliorates acetaminophen-induced acute liver injury through ATF4/PGC-1α pathway

Acetaminophen (APAP) overdose-induced acute liver injury (ALI) causes hepatocyte cell death, oxidative stress, and inflammation. Oridonin (Ori), a covalent NLRP3-inflammasome inhibitor, ameliorates APAP-induced ALI through an unclear molecular mechanism. This study found that Ori decreased hepatic cytochrome P450 2E1 level and increased glutathione content to prevent APAP metabolism, and then reduced the necrotic area, improved liver function, and inhibited APAP-induced proinflammatory cytokines and oxidative stress. Ori also decreased activating transcription factor 4 (ATF4) protein levels and increased peroxisome proliferator-activated receptor-γ coactivator-1α (PGC-1α) to reduce APAP-induced endoplasmic reticulum stress activation and mitochondrial dysfunction. Furthermore, western blot and luciferase assay found that ATF4 inhibited transcription in the PGC-1α promoter -507 to -495 region to reduce PGC-1α levels, while ATF4 knockdown neutralized the hepatoprotective effect of Ori. Molecular docking showed that Ori bound to ATF4's amino acid residue glutamate 302 through 6, 7, and 18 hydroxyl bands. Our findings demonstrated that Ori prevented metabolic activation of APAP and further inhibited the ATF4/PGC-1α pathway to alleviate APAP overdose-induced hepatic toxicity, which illuminated its potential therapeutic effects on ALI.

Spermidine inhibits high glucose-induced endoplasmic reticulum stress in HT22 cells by upregulation of growth differentiation factor 11

Hyperglycemia-induced neuronal endoplasmic reticulum (ER) stress is particularly important for the pathogenesis of diabetic encephalopathy. Spermidine (Spd) has neuroprotection in several nervous system diseases. Our current study to explore the potential protective role of Spd in hyperglycemia-induced neuronal ER stress and the underlying mechanisms. HT22 cells were treated with high glucose (HG) to establish an in-vitro model of hyperglycemia toxicity. The HT22 cells' activity was tested by cell counting kit-8 assay. RNA interference technology was used to silence the expression of growth differentiation factor 11 (GDF11) in HT22 cells. The GDF11 expression levels of mRNA were assessed using reverse transcription-PCR (RT-PCR). Western blotting analysis was applied to evaluate the expressions of GRP78 and cleaved caspase-12. Spd markedly abolished HG-exerted decline in cell viability as well as upregulations of GRP78 and cleaved caspase-12 in HT22 cells, indicating the protection of Spd against HG-induced neurotoxicity and ER stress. Furthermore, we showed that Spd upregulated the expression of GDF11 in HG-exposed HT22 cells. While, silenced GDF11 expression by RNA interference reversed the protective effects of Spd on HG-elicited neurotoxicity and ER stress in HT22 cells. These results indicated that Spd prevents HG-induced neurotoxicity and ER stress through upregulation of GDF11. Our findings identify Spd as a potential treatment for diabetic encephalopathy as well as ER stress-related neurologic diseases.

Comparative RNA-Sequencing Analysis Reveals High Complexity and Heterogeneity of Transcriptomic and Immune Profiles in Hepatocellular Carcinoma Tumors of Viral (HBV, HCV) and Non-Viral Etiology

Background and Objectives: Hepatocellular carcinoma (HCC), the most common type of primary liver cancer, is the leading cause of cancer-related mortality. It arises and progresses against fibrotic or cirrhotic backgrounds mainly due to infection with hepatitis viruses B (HBV) or C (HCV) or non-viral causes that lead to chronic inflammation and genomic changes. A better understanding of molecular and immune mechanisms in HCC subtypes is needed. Materials and Methods: To identify transcriptional changes in primary HCC tumors with or without hepatitis viral etiology, we analyzed the transcriptomes of 24 patients by next-generation sequencing. Results: We identified common and unique differentially expressed genes for each etiological tumor group and analyzed the expression of SLC, ATP binding cassette, cytochrome 450, cancer testis, and heat shock protein genes. Metascape functional enrichment analysis showed mainly upregulated cell-cycle pathways in HBV and HCV and upregulated cell response to stress in non-viral infection. GeneWalk analysis identified regulator, hub, and moonlighting genes and highlighted CCNB1, ACTN2, BRCA1, IGF1, CDK1, AURKA, AURKB, and TOP2A in the HCV group and HSF1, HSPA1A, HSP90AA1, HSPB1, HSPA5, PTK2, and AURKB in the group without viral infection as hub genes. Immune infiltrate analysis showed that T cell, cytotoxic, and natural killer cell markers were significantly more highly expressed in HCV than in non-viral tumors. Genes associated with monocyte activation had the highest expression levels in HBV, while high expression of genes involved in primary adaptive immune response and complement receptor activity characterized tumors without viral infection. Conclusions: Our comprehensive study underlines the high degree of complexity of immune profiles in the analyzed groups, which adds to the heterogeneous HCC genomic landscape. The biomarkers identified in each HCC group might serve as therapeutic targets.

Orphan Nuclear Receptor Nur77 Mediates the Lethal Endoplasmic Reticulum Stress and Therapeutic Efficacy of Cryptomeridiol in Hepatocellular Carcinoma

Hepatocellular carcinoma (HCC) commonly possesses chronical elevation of IRE1α-ASK1 signaling. Orphan nuclear receptor Nur77, a promising therapeutic target in various cancer types, is frequently silenced in HCC. In this study, we show that cryptomeridiol (Bkh126), a naturally occurring sesquiterpenoid derivative isolated from traditional Chinese medicine Magnolia officinalis, has therapeutic efficacy in HCC by aggravating the pre-activated UPR and activating the silenced Nur77. Mechanistically, Nur77 is induced to sense IRE1α-ASK1-JNK signaling and translocate to the mitochondria, which leads to the loss of mitochondrial membrane potential (Δψm). The Bkh126-induced aggravation of ER stress and mitochondrial dysfunction result in increased cytotoxic product of reactive oxygen species (ROS). The in vivo anti-HCC activity of Bkh126 is superior to that of sorafenib, currently used to treat advanced HCC. Our study shows that Bkh126 induces Nur77 to connect ER stress to mitochondria-mediated cell killing. The identification of Nur77 as a molecular target of Bhk126 provides a basis for improving the leads for the further development of anti-HCC drugs.

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.

Integrative Analysis Reveals the Potential Role and Prognostic Value of GOLM1 in Hepatocellular Carcinoma

Overexpression of Golgi membrane protein 1 (GOLM1) is closely associated with hepatocellular carcinoma (HCC) vascular invasion. How GOLM1 may be involved in angiogenesis in HCC remains unclear. We explored how GOLM1 promotes angiogenesis in HCC and potential prognostic value. Expression levels of GOLM1 in HCC patients and healthy controls were obtained from The Cancer Genome Atlas (TCGA). Differentially expressed genes (DEGs) between HCC patients and controls were compared. GOLM1 was knocked out in the HCC cell line, and RNA sequencing and DEG expression analysis were performed compared with control cells. Based on TCGA data and cell line RNA sequencing data, DEGs affected by a high expression of GOLM1 were identified. Subsequently, enrichment analysis was performed to explore the functions and pathways of the DEGs affected by a high expression of GOLM1. A relevant network analysis was built. Cox regression, genomic variance analysis scores, minimum absolute shrinkage and selection operator regression, and random forest regression models were applied to determine the best prognostic model and validated using the GSE54236 dataset from the Gene Expression Omnibus (GEO). We determined the effect of GOLM1 expression on immune cell infiltration in liver cancer. GOLM1 was overexpressed in HCC tissues compared with controls, and its level correlated with tumor purity and prognosis. 400 DEGs affected by highly expressed GOLM1 were identified in TCGA and cell line RNA sequencing data. Enrichment analysis revealed that these DEGs may be related to biological processes of oxidative stress and angiogenesis and involved in the VEGF signaling pathway and protein processing in endoplasmic reticulum. We predicted a comprehensive regulatory network in which GOLM1 activated VEGF signaling to promote HCC angiogenesis. GOLM1 may interact with E2F1 and IGF2BP3 to promote angiogenesis. GOLM1 overexpression was associated with greater immune cell infiltration. A random forest regression model was the best prognostic model. Our study reveals a potential molecular mechanism of GOLM1 in promoting HCC. We developed two prognostic models based on DEG associated with GOLM1 overexpression to help stratify HCC prognosis and improve individualized treatment.

Circular RNA hsa_circ_0062682 Binds to YBX1 and Promotes Oncogenesis in Hepatocellular Carcinoma

Circular RNAs (circRNAs) have been shown to play an important role in the pathogenesis of hepatocellular carcinoma (HCC). By implementing available transcriptomic analyses of HCC patients, we identified an upregulated circRNA hsa_circ_0062682. Stable perturbations of hsa_circ_0062682 in Huh-7 and SNU-449 cell lines influenced colony formation, migration, cell proliferation, sorafenib sensitivity, and additionally induced morphological changes in cell lines, indicating an important role of hsa_circ_0062682 in oncogenesis. Pathway enrichment analysis and gene set enrichment analysis of the transcriptome data from hsa_circ_0062682 knockdown explained the observed phenotypes and exposed transcription factors E2F1, Sp1, HIF-1α, and NFκB1 as potential downstream targets. Biotinylated oligonucleotide pulldown combined with proteomic analyses identified protein interaction partners of which YBX1, a known oncogene, was confirmed by RNA immunoprecipitation. Furthermore, we discovered a complex cell-type-specific phenotype in response to the oncogenic potential of hsa_circ_0062682. This finding is in line with different classes of HCC tumours, and more studies are needed to shed a light on the molecular complexity of liver cancer.

Prognosis and immune infiltration analysis of endoplasmic reticulum stress-related genes in bladder urothelial carcinoma

Background: Abnormal activation of endoplasmic reticulum (ER) stress sensors and their downstream signalling pathways is a key regulator of tumour growth, tumour metastasis and the response to chemotherapy, targeted therapy and immunotherapy. However, the study of ER stress on the immune microenvironment of bladder urothelial carcinoma (BLCA) is still insufficient.

Methods: Firstly, 23 ER stress genes were selected to analyse their expression differences and prognostic value in BLCA based on the existing BLCA genome atlas data. According to the expression level of ER stress-related genes in BLCA, two independent clusters were identified using consensus cluster analysis. Subsequently, the correlation between these two clusters in terms of the immune microenvironment and their prognostic value was analysed. Finally, we analysed the prognostic value of the key ER stress gene HSP90B1 in BLCA and its corresponding mechanism that affects the immune microenvironment.

Results: Consensus clustering showed a worse prognosis and higher expression of immunoassay site-related genes (HAVCR2, PDCD1, CTLA4, CD274, LAG3, TIGIT and PDCD1LG2) in cluster 1 compared with cluster 2. Additionally, both TIMER and CIBERSORT algorithms showed that the expression of immune infiltrating cells in cluster 1 was significantly higher than that in cluster 2. Subsequently, HSP90B1 was identified as a key ER stress gene in BLCA, and its high expression indicated poor prognosis and was closely related to PD1. We also analysed the correlation between HSP90B1 expression and immune-infiltrating cell related biomarkers, which showed positive results. Finally, we verified the prognostic value of HSP90B1 in BLCA using an immunohistochemical assay in a tissue microarray of 100 patients with BLCA, validating the potential of HSP90B1 as a prognostic biomarker in patients with BLCA.

Conclusion: Our work reveals that ER stress genes play a crucial role in the BLCA immunological milieu, and HSP90B1 is a potential prognostic biomarker and therapeutic target for cancer immunotherapy.

Endoplasmic Reticulum Stress-Related Signature Predicts Prognosis and Drug Response in Clear Cell Renal Cell Carcinoma

Clear cell renal cell carcinoma (ccRCC) is the most common type of kidney cancer. The maximum number of deaths associated with kidney cancer can be attributed to ccRCC. Disruption of cellular proteostasis results in endoplasmic reticulum (ER) stress, which is associated with various aspects of cancer. It is noteworthy that the role of ER stress in the progression of ccRCC remains unclear. We classified 526 ccRCC samples identified from the TCGA database into the C1 and C2 subtypes by consensus clustering of the 295 ER stress-related genes. The ccRCC samples belonging to subtype C2 were in their advanced tumor stage and grade. These samples were characterized by poor prognosis and malignancy immune microenvironment. The upregulation of the inhibitory immune checkpoint gene expression and unique drug sensitivity were also observed. The differentially expressed genes between the two clusters were explored. An 11-gene ER stress-related prognostic risk model was constructed following the LASSO regression and Cox regression analyses. In addition, a nomogram was constructed by integrating the clinical parameters and risk scores. The calibration curves, ROC curves, and DCA curves helped validate the accuracy of the prediction when both the TCGA dataset and the external E-MTAB-1980 dataset were considered. Moreover, we analyzed the differentially expressed genes common to the E-MTAB-1980 and TCGA datasets to screen out new therapeutic compounds. In summary, our study can potentially help in the comprehensive understanding of ER stress in ccRCC and serve as a reference for future studies on novel prognostic biomarkers and treatments.

Ca2+ Transportome and the Interorganelle Communication in Hepatocellular Carcinoma

Hepatocellular carcinoma (HCC) is a type of liver cancer with a poor prognosis for survival given the complications it bears on the patient. Though damages to the liver are acknowledged prodromic factors, the precise molecular aetiology remains ill-defined. However, many genes coding for proteins involved in calcium (Ca²⁺) homeostasis emerge as either mutated or deregulated. Ca²⁺ is a versatile signalling messenger that regulates functions that prime and drive oncogenesis, favouring metabolic reprogramming and gene expression. Ca²⁺ is present in cell compartments, between which it is trafficked through a network of transporters and exchangers, known as the Ca²⁺ transportome. The latter regulates and controls Ca²⁺ dynamics and tonicity. In HCC, the deregulation of the Ca²⁺ transportome contributes to tumorigenesis, the formation of metastasizing cells, and evasion of cell death. In this review, we reflect on these aspects by summarizing the current knowledge of the Ca²⁺ transportome and overviewing its composition in the plasma membrane, endoplasmic reticulum, and the mitochondria.

Circular RNA circ_0008934 promotes hepatocellular carcinoma growth and metastasis through modulating miR-1305/TMTC3 axis

Circular RNAs (circRNAs) play important roles in the progression of hepatocellular carcinoma (HCC). However, the exact function of circ_0008934 in HCC is unknown. Our study aimed to investigate the expression characteristics of circ_0008934 in HCC and its effects on the proliferation and metastasis of HCC, and to explore the potential mechanism. In this study, circ_0008934 expression was found to be significantly upregulated in HCC tissues and cell lines by qRT-PCR. High level of circ_0008934 is closely associated with higher serum AFP (P < 0.001), larger tumor diameter (P = 0.012), microvascular invasion (P = 0.008) and poorer prognosis (P = 0.007) of HCC patients. Functionally, knockdown of circ_0008934 inhibited HCC cell proliferation, invasion and migration in vitro and vivo. Mechanically, circ_0008934 was a sponge of miR-1305 to facilitate the TMTC3 expression, and the TMTC3 expression in HCC tissues was negatively associated with the survival of HCC patients. Furthermore, rescued assays revealed that the circ_0008934 facilitated HCC proliferation, invasion and migration by regulating miR-1305/ TMTC3 signaling pathways. Overall, these results demonstrate that downregulation of circ_0008934 repress HCC growth and metastasis by upregulating miR-1305 to inhibit TMTC3, suggesting circ_0008934/ miR-1305/ TMTC3 regulatory axis may be a possible novel therapeutic target for HCC.