BDH2 triggers ROS-induced cell death and autophagy by promoting Nrf2 ubiquitination in gastric cancer

Long non-coding RNA AC010457.1 promotes the growth and EMT of gastric cancer via the PI3K/AKT axis

Gastric cancer (GC) is a malignancy with a relatively high mortality rate. This study aimed to ascertain the prognostic significance of long non-coding RNA (lncRNA) AC010457.1 in GC and elucidate its role in disease progression. The Cancer Genome Atlas (TCGA) database was used to screen the prognosis-associated differentially expressed lncRNAs in GC patients. Kaplan-Meier curves, univariate and multivariate Cox regression analyses were applied to assess the prognostic significance of AC010457.1. In vitro and in vivo functional assays were performed to evaluate the effects of AC010457.1 on cellular proliferation and metastasis. Mechanistic investigations, including Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis, Western blotting (WB), Immunofluorescence (IF), and Immunohistochemistry (IHC), were used to explore the signaling pathways activated by AC010457.1. We demonstrated that AC010457.1 was abnormally upregulated in GC tissues, and that this aberrant upregulation was associated with a poor prognosis for GC patients. The functional experiments proved that the downregulated of AC010457.1 hindered GC cell proliferation, migration, and invasive potential. Furthermore, KEGG analysis revealed a significant association between AC010457.1 and the PI3K/AKT signaling pathway, which was further corroborated by WB analysis. Rescue experiments provided additional confirmation that AC010457.1 regulated PI3K/AKT promote GC proliferation, migration, and epithelial-mesenchymal transition (EMT). Collectively, our findings suggest that AC010457.1 overexpression serves as a distinct prognostic risk factor in GC and may represent a promising therapeutic target for the treatment of this malignancy.

ML385, an Nrf2 Inhibitor, Synergically Enhanced Celastrol Triggered Endoplasmic Reticulum Stress in Lung Cancer Cells

Lung cancer is one of the leading causes of death. Celastrol is a natural product that has shown anticancer activity but has not yet been applied in clinical settings due to its narrow therapeutic window. In this study, we discovered that celastrol stimulates an abnormal rise in the reactive oxygen species (ROS) level in lung cancer cells and that the ROS scavenger N-acetylcysteine (NAC) could counteract the cell death caused by celastrol. At the same time, celastrol upregulated the expression of cytoprotective transcription factor Nrf2 and its downstream proteins, which are effective in preventing the oxidative damage caused by ROS accumulation. Notably, we found that the overexpression of Nrf2 enhances the tolerance of lung cancer cells to celastrol and that lung cancer cells H460 with a Keap1 mutation are insensitive to celastrol. This indicates that the increase in Nrf2 contributes to the survival of lung cancer cells. Thus, we brought in an Nrf2 inhibitor ML385 to suppress the activation of Nrf2. We found that when ML385 and celastrol were added together the survival rates of lung cancer cells decreased more and the detected ROS level became much higher compared to treatment with celastrol alone. We also discovered that ML385 suppressed the expression of HO-1 and GCLC, which amplified celastrol-induced ATF4/CHOP-dependent endoplasmic reticulum stress (ER stress). Above all, our study found that ML385 enhanced celastrol-induced increases in ROS and ER stress, leading to lung cancer cell death. This research provides a potential strategy for the preclinical investigation of celastrol.

β-Elemene promotes ferroptosis and reverses radioresistance in gastric cancer by inhibiting the OTUB1-GPX4 interaction

Introduction

β-Elemene, derived from Curcuma zedoaria (Wenyujin), is clinically recognized for inducing apoptosis, inhibiting cell cycle progression, and reversing chemotherapy resistance in various cancers. However, its effects on radioresistant gastric cancer (GC) remain unclear.

Methods

In this study, radioresistant GC cell lines (MKN45/IR and AGS/IR) were established via multiple low-dose radiations. The impact of β-elemene on radiosensitivity was assessed using CCK-8 and clonogenic assays, with ferroptosis markers such as ROS, MDA, and Fe2+ levels measured. Additionally, the influence of β-elemene on GPX4 and its interaction with OTUB1 was examined through qRT-PCR, Western blot, immunofluorescence, co-immunoprecipitation, and in vivo studies.

Results

Our findings indicate that β-elemene reverses radioresistance in GC cells and significantly inhibits cell growth when combined with radiotherapy. β-Elemene treatment elevated ROS, MDA, and Fe2+ levels, enhancing ferroptosis, which was confirmed by Ferrostatin-1 and Deferoxamine inhibition studies. Mechanistic analysis revealed that β-elemene disrupts the OTUB1-GPX4 interaction, leading to increased GPX4 ubiquitination and degradation, thus promoting ferroptosis. In vivo studies further demonstrated that β-elemene combined with radiotherapy significantly suppressed tumor growth compared to radiotherapy alone.

Discussion

These results suggest that β-elemene effectively modulates radioresistance in GC by targeting the GPX4 pathway and inducing ferroptosis. This highlights its potential as a therapeutic adjunct in radiotherapy for resistant GC cases.

SCYL1-mediated regulation of the mTORC1 signaling pathway inhibits autophagy and promotes gastric cancer metastasis

BACKGROUND

The SCY1-like (SCYL) family has been reported to be closely related to cancer metastasis, but it has not been reported in gastric cancer (GC), and its specific mechanism is not clear.

METHODS

We utilized databases like Deepmap, TCGA, and GEO to identify SCYL1's role in GC. Clinical samples were analyzed for SCYL1 expression and its correlation with patient prognosis. In vitro and in vivo experiments were conducted to assess SCYL1's function in GC cell migration, invasion, and autophagy.

RESULTS

SCYL1 showed an increased expression in GC tissues, which correlated with a negative prognosis. In vitro experiments demonstrated that SCYL1 promotes GC cell migration and invasion and inhibits autophagy. GSEA indicated an inverse relationship between SCYL1 and autophagy, while a direct relationship was observed with the mTORC1 signaling pathway. Knockdown of SCYL1 enhanced autophagy, while activation of mTORC1 reversed this effect.

CONCLUSIONS

SCYL1 is a significant contributor to GC progression, promoting metastasis by activating the mTORC1 signaling pathway and inhibiting autophagy. These findings suggest SCYL1 as a potential therapeutic target for GC treatment.

Nrf2: A critical participant in regulation of apoptosis, ferroptosis, and autophagy in gastric cancer

Nuclear factor erythroid 2-related factor-2 (Nrf2) is a specific transcription factor that maintains redox homeostasis by regulating the expression of anti-oxidative stress-related genes. Hyperactivation of Nrf2 is involved in tumor progression and is associated with chemoresistance in a large number of solid tumors. Programmatic cell death (PCD), such as apoptosis, ferroptosis, and autophagy, plays a crucial role in tumor development and chemotherapy sensitivity. Accumulating evidence suggests that some anti-tumor compounds and genes can induce massive production of reactive oxygen species (ROS) via inhibiting Nrf2 expression, which exacerbates oxidative stress and promotes Gastric cancer (GC) cell death, thereby enhancing the sensitivity of GC cells to chemotherapy-induced PCD. In this review, we summarize the role of antitumor drugs in interfering in three different types of PCD (apoptosis, ferroptosis, and autophagy) in GC cells by modulating Nrf2 expression, as well as the molecular mechanisms through which targeting Nrf2 brings about PCD and chemosensitivity. It is reasonable to believe that Nrf2 serves as a potential therapeutic target, and targeting Nrf2 by drug or gene regulation could provide a new strategy for the treatment of GC.

Lipid profiling of RON and DEK-dependent signaling in breast cancer guides discovery of gene networks predictive of poor outcomes

Recurrent and metastatic breast cancer is frequently treatment resistant. A wealth of evidence suggests that reprogrammed lipid metabolism supports cancer recurrence. Overexpression of the RON and DEK oncoproteins in breast cancer is associated with poor outcome. Both proteins promote cancer metastasis in laboratory models, but their influence on lipid metabolite levels remain unknown. To measure RON- and DEK-dependent steady-state lipid metabolite levels, a nuclear magnetic resonance (NMR)-based approach was utilized. The observed differences identified a lipid metabolism-related gene expression signature that is prognostic of overall survival (OS), distant metastasis-free survival (DMFS), post-progression survival (PPS), and recurrence-free survival (RFS) in patients with breast cancer. RON loss led to decreased cholesterol and sphingomyelin levels, whereas DEK loss increased total fatty acid levels and decreased free glycerol levels. Lipid-related genes were then queried to define a signature that predicts poor outcomes for patients with breast cancer patients. Taken together, RON and DEK differentially regulate lipid metabolism in a manner that predicts and may promote breast cancer metastasis and recurrence.

Sodium Selenite Induces Autophagy and Apoptosis in Cervical Cancer Cells via Mitochondrial ROS-Activated AMPK/mTOR/FOXO3a Pathway

Selenium (Se) is an essential trace element known for its significant role in maintaining human health and mitigating disease progression. Selenium and its compounds exhibit high selective cytotoxicity against tumor cells. However, their anti-cervical cancer (CC) effects and underlying mechanisms have not been fully explored. This study found that sodium selenite (SS) inhibits the viability of HeLa and SiHa cells in a dose- and time-dependent manner. Intraperitoneal injection of 3 and 6 mg/kg SS for 14 days in female nude mice significantly inhibited the growth of HeLa cell xenografts without evident hepatotoxicity or nephrotoxicity. RNA sequencing results indicated that the AMP-activated protein kinase (AMPK), Forkhead box protein O (FOXO), and apoptosis signaling pathways are key regulatory pathways in SS's anti-CC effects, and SS's inhibition of HeLa cell proliferation may be related to autophagy and ROS-induced apoptosis. Further research has revealed that SS induces cell autophagy and apoptosis through the AMPK/mTOR/FOXO3a pathway, characterized by the upregulation of p-AMPK/AMPK, FOXO3a, LC3-II, cleaved-caspase3, and cleaved-PARP and the downregulation of p-mTOR/mTOR and p62. Additionally, SS impaired mitochondrial function, including decreased mitochondrial membrane potential, mitochondrial Ca2+ overload, and accumulation of mitochondrial reactive oxygen species (mtROS). Pretreatment with Mitoquinone mesylate (Mito Q) and compound C partially reversed SS-induced apoptosis, autophagy, and proliferation inhibition. Pretreatment with 3-methyladenine (3-MA) enhances SS-induced apoptosis and proliferation inhibition in HeLa cells but reverses these effects in SiHa cells. In summary, SS induces apoptosis, autophagy, and proliferation inhibition in HeLa and SiHa cells through the activation of the AMPK/mTOR/FOXO3a signaling pathway via mtROS. Autophagy activation may be a major risk factor for SS-induced apoptosis in SiHa cells but can protect HeLa cells from SS-induced apoptosis. These findings provide new evidence for understanding the molecular mechanisms underlying SS in potential new drug development for CC.

The role of reactive oxygen species in gastric cancer

Gastric cancer (GC) ranks fifth in cancer incidence and fourth in cancer-related mortality worldwide. Reactive oxygen species (ROS) are highly oxidative oxygen-derived products that have crucial roles in cell signaling regulation and maintaining internal balance. ROS are closely associated with the occurrence, development, and treatment of GC. This review summarizes recent findings on the sources of ROS and the bidirectional regulatory effects on GC and discusses various treatment modalities for GC that are related to ROS induction. In addition, the regulation of ROS by natural small molecule compounds with the highest potential for development and applications in anti-GC research is summarized. The aim of the review is to accelerate the clinical application of modulating ROS levels as a therapeutic strategy for GC.

RNA demethylase FTO participates in malignant progression of gastric cancer by regulating SP1-AURKB-ATM pathway

Gastric cancer (GC) is the 5th most prevalent cancer and the 4th primary cancer-associated mortality globally. As the first identified m6A demethylase for removing RNA methylation modification, fat mass and obesity-associated protein (FTO) plays instrumental roles in cancer development. Therefore, we study the biological functions and oncogenic mechanisms of FTO in GC tumorigenesis and progression. In our study, FTO expression is obviously upregulated in GC tissues and cells. The upregulation of FTO is associated with advanced nerve invasion, tumor size, and LNM, as well as the poor prognosis in GC patients, and promoted GC cell viability, colony formation, migration and invasion. Mechanistically, FTO targeted specificity protein 1 and Aurora Kinase B, resulting in the phosphorylation of ataxia telangiectasia mutated and P38 and dephosphorylation of P53. In conclusion, the m6A demethylase FTO promotes GC tumorigenesis and progression by regulating the SP1-AURKB-ATM pathway, which may highlight the potential of FTO as a diagnostic biomarker for GC patients' therapy response and prognosis.

Human gastric cancer progression and stabilization of ATG2B through RNF5 binding facilitated by autophagy-associated CircDHX8

The role of circDHX8 in the interplay between autophagy and gastric cancer (GC) progression remains unclear. In this study, we investigated the mechanism underlying the role of hsa_circ_003899 (circDHX8) in the malignancy of GC. Differential expression of circRNAs between GC and normal tissues was determined using circle-seq and microarray datasets (GSE83521). These circRNAs were validated using qPCR and Sanger sequencing. The function of circDHX8 was investigated through interference with circDHX8 expression experiments using in vitro and in vivo functional assays. Western blotting, immunofluorescence, and transmission electron microscopy were used to establish whether circDHX8 promoted autophagy in GC cells. To elucidate the mechanism underlying the circDHX8-mediated regulation of autophagy, we performed bioinformatics analysis, RNA pull-down, mass spectrometry (MS), RNA immunoprecipitation (RIP), and other western Blot related experiments. Hsa_circ_0003899 (circDHX8) was identified as upregulated and shown to enhance the malignant progression in GC cells by promoting cellular autophagy. Mechanistically, circDHX8 increased ATG2B protein levels by preventing ubiquitin-mediated degradation, thereby facilitating cell proliferation and invasion in GC. Additionally, circDHX8 directly interacts with the E3 ubiquitin-protein ligase RNF5, inhibiting the RNF5-mediated degradation of ATG2B. Concurrently, ATG2B, an acetylated protein, is subjected to SIRT1-mediated deacetylation, enhancing its binding to RNF5. Consequently, we established a novel mechanism for the role of circDHX8 in the malignant progression of GC.

Dysregulation of autophagy in gastric carcinoma: Pathways to tumor progression and resistance to therapy

The considerable death rates and lack of symptoms in early stages of gastric cancer (GC) make it a major health problem worldwide. One of the most prominent risk factors is infection with Helicobacter pylori. Many biological processes, including those linked with cell death, are disrupted in GC. The cellular "self-digestion" mechanism necessary for regular balance maintenance, autophagy, is at the center of this disturbance. Misregulation of autophagy, however, plays a role in the development of GC. In this review, we will examine how autophagy interacts with other cell death processes, such as apoptosis and ferroptosis, and how it affects the progression of GC. In addition to wonderful its role in the epithelial-mesenchymal transition, it is engaged in GC metastasis. The role of autophagy in GC in promoting drug resistance stands out. There is growing interest in modulating autophagy for GC treatment, with research focusing on natural compounds, small-molecule inhibitors, and nanoparticles. These approaches could lead to breakthroughs in GC therapy, offering new hope in the fight against this challenging disease.

mir-605-3p prevents liver premetastatic niche formation by inhibiting angiogenesis via decreasing exosomal nos3 release in gastric cancer

BACKGROUND

Cancer-induced pre-metastatic niches (PMNs) play a decisive role in promoting metastasis by facilitating angiogenesis in distant sites. Evidence accumulates suggesting that microRNAs (miRNAs) exert significant influence on angiogenesis during PMN formation, yet their specific roles and regulatory mechanisms in gastric cancer (GC) remain underexplored.

METHODS

miR-605-3p was identified through miRNA-seq and validated by qRT-PCR. Its correlation with the clinicopathological characteristics and prognosis was analyzed in GC. Functional assays were performed to examine angiogenesis both in vitro and in vivo. The related molecular mechanisms were elucidated using RNA-seq, immunofluorescence, transmission electron microscopy, nanoparticle tracking analysis, enzyme-linked immunosorbent assay, luciferase reporter assays and bioinformatics analysis.

RESULTS

miR-605-3p was screened as a candidate miRNA that may regulate angiogenesis in GC. Low expression of miR-605-3p is associated with shorter overall survival and disease-free survival in GC. miR-605-3p-mediated GC-secreted exosomes regulate angiogenesis by regulating exosomal nitric oxide synthase 3 (NOS3) derived from GC cells. Mechanistically, miR-605-3p reduced the secretion of exosomes by inhibiting vesicle-associated membrane protein 3 (VAMP3) expression and affects the transport of multivesicular bodies to the GC cell membrane. At the same time, miR-605-3p reduces NOS3 levels in exosomes by inhibiting the expression of intracellular NOS3. Upon uptake of GC cell-derived exosomal NOS3, human umbilical vein endothelial cells exhibited increased nitric oxide levels, which induced angiogenesis, established liver PMN and ultimately promoted the occurrence of liver metastasis. Furthermore, a high level of plasma exosomal NOS3 was clinically associated with metastasis in GC patients.

CONCLUSIONS

miR-605-3p may play a pivotal role in regulating VAMP3-mediated secretion of exosomal NOS3, thereby affecting the formation of GC PMN and thus inhibiting GC metastasis.

ECHDC2 inhibits the proliferation of gastric cancer cells by binding with NEDD4 to degrade MCCC2 and reduce aerobic glycolysis

BACKGROUND

The Enoyl-CoA hydratase/isomerase family plays a crucial role in the metabolism of tumors, being crucial for maintaining the energy balance and biosynthetic needs of cancer cells. However, the enzymes within this family that are pivotal in gastric cancer (GC) remain unclear.

METHODS

We employed bioinformatics techniques to identify key Enoyl-CoA hydratase/isomerase in GC. The expression of ECHDC2 and its clinical significance were validated through tissue microarray analysis. The role of ECHDC2 in GC was further assessed using colony formation assays, CCK8 assay, EDU assay, Glucose and lactic acid assay, and subcutaneous tumor experiments in nude mice. The mechanism of action of ECHDC2 was validated through Western blotting, Co-immunoprecipitation, and immunofluorescence experiments.

RESULTS

Our analysis of multiple datasets indicates that low expression of ECHDC2 in GC is significantly associated with poor prognosis. Overexpression of ECHDC2 notably inhibits aerobic glycolysis and proliferation of GC cells both in vivo and in vitro. Further experiments revealed that overexpression of ECHDC2 suppresses the P38 MAPK pathway by inhibiting the protein level of MCCC2, thereby restraining glycolysis and proliferation in GC cells. Ultimately, it was discovered that ECHDC2 promotes the ubiquitination and subsequent degradation of MCCC2 protein by binding with NEDD4.

CONCLUSIONS

These findings underscore the pivotal role of the ECHDC2 in regulating aerobic glycolysis and proliferation in GC cells, suggesting ECHDC2 as a potential therapeutic target in GC.

The ketone body β-Hydroxybutyrate as a fuel source of chondrosarcoma cells

Chondrosarcoma (CS) is a malignant bone tumor arising from cartilage-producing cells. The conventional subtype of CS typically develops within a dense cartilaginous matrix, creating an environment deficient in oxygen and nutrients, necessitating metabolic adaptation to ensure proliferation under stress conditions. Although ketone bodies (KBs) are oxidized by extrahepatic tissue cells such as the heart and brain, specific cancer cells, including CS cells, can undergo ketolysis. In this study, we found that KBs catabolism is activated in CS cells under nutrition-deprivation conditions. Interestingly, cytosolic β-hydroxybutyrate dehydrogenase 2 (BDH2), rather than mitochondrial BDH1, is expressed in these cells, indicating a specific metabolic adaptation for ketolysis in this bone tumor. The addition of the KB, β-Hydroxybutyrate (β-HB) in serum-starved CS cells re-induced the expression of BDH2, along with the key ketolytic enzyme 3-oxoacid CoA-transferase 1 (OXCT1) and monocarboxylate transporter-1 (MCT1). Additionally, internal β-HB production was quantified in supplied and starved cells, suggesting that CS cells are also capable of ketogenesis alongside ketolysis. These findings unveil a novel metabolic adaptation wherein nutrition-deprived CS cells utilize KBs for energy supply and proliferation.

A multilevel investigation to reveal the regulatory mechanism of lignin accumulation in juice sac granulation of pomelo

Granulation of juice sacs is a physiological disorder, which affects pomelo fruit quality. Here, the transcriptome and ubiquitinome of the granulated juice sacs were analyzed in Guanxi pomelo. We found that lignin accumulation in the granulated juice sacs was regulated at transcription and protein modification levels. In transcriptome data, we found that the genes in lignin biosynthesis pathway and antioxidant enzyme system of the granulated juice sacs were significantly upregulated. However, in ubiquitinome data, we found that ubiquitinated antioxidant enzymes increased in abundance but the enzyme activities decreased after the modification, which gave rise to reactive oxygen species (ROS) contents in granulated juice sacs. This finding suggests that ubiquitination level of the antioxidant enzymes is negatively correlated with the enzyme activities. Increased H2O2 is considered to be a signaling molecule to activate the key gene expressions in lignin biosynthesis pathway, which leads to the lignification in granulated juice sacs of pomelo. This regulatory mechanism in juice sac granulation of pomelo was further confirmed through the verification experiment using tissue culture by adding H2O2 or dimethylthiourea (DMTU). Our findings suggest that scavenging H2O2 and other ROS are important for reducing lignin accumulation, alleviating juice sac granulation and improving pomelo fruit quality.

Quercetin promotes ATG5-mediating autophagy-dependent ferroptosis in gastric cancer

Quercetin has been documented to possess a multitude of pharmacological effects, encompassing antioxidant, antiviral, antimicrobial, and anti-inflammatory properties. Nevertheless, the exact molecular mechanisms responsible for the anti-tumor properties of quercetin remain to be fully explicated. To this end, quercetin was administered to gastric cancer cells (in vitro) AGS and MKN45, as well as BALB/c mice (in vivo). The proliferation ability of cells was evaluated using cholecystokinin octapeptide (CCK-8) and colony formation assays. The evaluation of ferroptosis involved the measurement of iron, malondialdehyde (MDA), and lipid reactive oxygen species. Autophagy and apoptosis were evaluated using immunofluorescence staining, western blotting, and flow cytometry analysis. Our findings indicate that quercetin significantly inhibited cell viability and tumor volume compared to the control group. Additionally, quercetin was found to decrease glutathione (GSH), malondialdehyde, and reactive oxygen species (ROS) levels while suppressing beclin1 and LC3B levels in cancer cells. Remarkably, the utilization of siATG5 was found to reverse all the aforementioned effects of quercetin. Ultimately, the effects of quercetin on gastric cancer were validated. In summary, our findings provide evidence that quercetin facilitates autophagy-mediated ferroptosis in gastric cancer.

M6A demethylase ALKBH5 regulates FOXO1 mRNA stability and chemoresistance in triple-negative breast cancer

Resistance to chemotherapy is the main reason for treatment failure and poor prognosis in patients with triple-negative breast cancer (TNBC). Although the association of RNA N6-methyladenosine (m6A) modifications with therapy resistance is noticed, its role in the development of therapeutic resistance in TNBC is not well documented. This study aimed to investigate the potential mechanisms underlying reactive oxygen species (ROS) regulation in doxorubicin (DOX)-resistant TNBC. Here, we found that DOX-resistant TNBC cells displayed low ROS levels because of increased expression of superoxide dismutase (SOD2), thus maintaining cancer stem cells (CSCs) characteristics and DOX resistance. FOXO1 is a master regulator that reduces cellular ROS in DOX-resistant TNBC cells, and knockdown of FOXO1 significantly increased ROS levels by inhibiting SOD2 expression. Moreover, the m6A demethylase ALKBH5 promoted m6A demethylation of FOXO1 mRNA and increased FOXO1 mRNA stability in DOX-resistant TNBC cells. The analysis of clinical samples revealed that the increased expression levels of ALKBH5, FOXO1, and SOD2 were significantly positively correlated with chemoresistance and poor prognosis in patients with TNBC. To our knowledge, this is the first study to highlight that ALKBH5-mediated FOXO1 mRNA demethylation contributes to CSCs characteristics and DOX resistance in TNBC cells. Furthermore, pharmacological targeting of FOXO1 profoundly restored the response of DOX-resistant TNBC cells, both in vitro and in vivo. In conclusion, we demonstrated a critical function of ALKBH5-mediated m6A demethylation of FOXO1 mRNA in restoring redox balance, which in turn promoting CSCs characteristics and DOX resistance in TNBC, and suggested that targeting the ALKBH5/FOXO1 axis has therapeutic potential for patients with TNBC refractory to chemotherapy.

Dormant cancer cells and polyploid giant cancer cells: The roots of cancer recurrence and metastasis

Tumour cell dormancy is critical for metastasis and resistance to chemoradiotherapy. Polyploid giant cancer cells (PGCCs) with giant or multiple nuclei and high DNA content have the properties of cancer stem cell and single PGCCs can individually generate tumours in immunodeficient mice. PGCCs represent a dormant form of cancer cells that survive harsh tumour conditions and contribute to tumour recurrence. Hypoxic mimics, chemotherapeutics, radiation and cytotoxic traditional Chinese medicines can induce PGCCs formation through endoreduplication and/or cell fusion. After incubation, dormant PGCCs can recover from the treatment and produce daughter cells with strong proliferative, migratory and invasive abilities via asymmetric cell division. Additionally, PGCCs can resist hypoxia or chemical stress and have a distinct protein signature that involves chromatin remodelling and cell cycle regulation. Dormant PGCCs form the cellular basis for therapeutic resistance, metastatic cascade and disease recurrence. This review summarises regulatory mechanisms governing dormant cancer cells entry and exit of dormancy, which may be used by PGCCs, and potential therapeutic strategies for targeting PGCCs.

The role of TRPV4 in programmed cell deaths

Programmed cell death is a major life activity of both normal development and disease. Necroptosis is early recognized as a caspase-independent form of programmed cell death followed obviously inflammation. Apoptosis is a gradually recognized mode of cell death that is characterized by a special morphological changes and unique caspase-dependent biological process. Ferroptosis, pyroptosis and autophagy are recently identified non-apoptotic regulated cell death that each has its own characteristics. The transient receptor potential vanilloid 4 (TRPV4) is a kind of nonselective calcium-permeable cation channel, which is received more and more attention in biology studies. It is widely expressed in human tissues and mainly located on the membrane of cells. Several researchers have identified that the influx Ca2+ from TRPV4 acts as a key role in the loss of cells by apoptosis, ferroptosis, necroptosis, pyroptosis and autophagy via mediating endoplasmic reticulum (ER) stress, oxidative stress and inflammation. This effect is bad for the normal function of organs on the one hand, on the other hand, it is benefit for anticancer activities. In this review, we will summarize the current discovery on the role and impact of TRPV4 in these programmed cell death pathological mechanisms to provide a new prospect of gene therapeutic target of related diseases.

The role of ubiquitination and deubiquitination in PI3K/AKT/mTOR pathway: A potential target for cancer therapy

The PI3K/AKT/mTOR pathway controls key cellular processes, including proliferation and tumor progression, and abnormally high activation of this pathway is a hallmark in human cancers. The post-translational modification, such as Ubiquitination and deubiquitination, fine-tuning the protein level and the activity of members in this pathway play a pivotal role in maintaining normal physiological process. Emerging evidence show that the unbalanced ubiquitination/deubiquitination modification leads to human diseases via PI3K/AKT/mTOR pathway. Therefore, a comprehensive understanding of the ubiquitination/deubiquitination regulation of PI3K/AKT/mTOR pathway may be helpful to uncover the underlying mechanism and improve the potential treatment of cancer via targeting this pathway. Herein, we summarize the latest research progress of ubiquitination and deubiquitination of PI3K/AKT/mTOR pathway, systematically discuss the associated crosstalk between them, as well as focus the clinical transformation via targeting ubiquitination process.

Construction and validation of a immune-related prognostic gene DHRS1 in hepatocellular carcinoma based on bioinformatic analysis

A member of the short-chain dehydrogenase/reductase superfamily (DHRS1, SDR19C1) is a member of the short-chain dehydrogenase/reductase superfamily and a potential predictor of hepatocellular carcinoma (HCC). However, the role of DHRS1 in HCC immunity remains unclear. We systematically analyzed the association between DHRS1 and HCC immunity with transcriptional and clinical data from the Tumor Immune Estimation Resource, an integrated repository portal for tumor immune system interactions, and cBioPortal databases. Six DHRS1-associated immunomodulators strongly correlated with survival and were uncovered by exploiting univariate and multivariate Cox analyses. We created a risk score for each patient by adding the points from each immunomodulator and then classified them into high and low risk categories. Survival analysis were used to compare the overall survival between the 2 groups, and the receiver operating characteristic curve was applied to assess the accuracy of the risk score. Data from our center were adopted as the external validation set, the risk score was calculated using the risk coefficient of the 6 genes in the training cohort, and survival analysis were executed to verify the experimental group results. A nomogram was ultimately constructed with the R package. Our data revealed a correlation between the levels of immune cell infiltration and either the DHRS1 gene copy numbers or mRNA levels in HCC. Second, we generated a signature based on the 6 DHRS1-related immunomodulators (KDR, TNFRSF4, CD276, TNFSF4, SLAMF6, and SIGLEC9). We postulate that the generated risk scores would serve as an independent indicator of HCC prognosis, with an area under the receiver operating characteristic curve for the risk score of 0.743. We further established external validation sets to reconfirm the predictive validity of the risk score. Finally, a prognostic nomogram and calibration curve were created. The DHRS1 gene may exert an impact on HCC immunity. We posit that the nominated immune signature based on DHRS1-associated immunomodulators could constitute a promising prognostic biomarker in HCC.

B7-H3 confers stemness characteristics to gastric cancer cells by promoting glutathione metabolism through AKT/pAKT/Nrf2 pathway

BACKGROUND

Cancer stem-like cells (CSCs) are a small subset of cells in tumors that exhibit self-renewal and differentiation properties. CSCs play a vital role in tumor formation, progression, relapse, and therapeutic resistance. B7-H3, an immunoregulatory protein, has many protumor functions. However, little is known about the mechanism underlying the role of B7-H3 in regulating gastric cancer (GC) stemness. Our study aimed to explore the impacts of B7-H3 on GC stemness and its underlying mechanism.

METHODS

GC stemness influenced by B7-H3 was detected both in vitro and in vivo . The expression of stemness-related markers was examined by reverse transcription quantitative polymerase chain reaction, Western blotting, and flow cytometry. Sphere formation assay was used to detect the sphere-forming ability. The underlying regulatory mechanism of B7-H3 on the stemness of GC was investigated by mass spectrometry and subsequent validation experiments. The signaling pathway (Protein kinase B [Akt]/Nuclear factor erythroid 2-related factor 2 [Nrf2] pathway) of B7-H3 on the regulation of glutathione (GSH) metabolism was examined by Western blotting assay. Multi-color immunohistochemistry (mIHC) was used to detect the expression of B7-H3, cluster of differentiation 44 (CD44), and Nrf2 on human GC tissues. Student's t -test was used to compare the difference between two groups. Pearson correlation analysis was used to analyze the relationship between two molecules. The Kaplan-Meier method was used for survival analysis.

RESULTS

B7-H3 knockdown suppressed the stemness of GC cells both in vitro and in vivo . Mass spectrometric analysis showed the downregulation of GSH metabolism in short hairpin B7-H3 GC cells, which was further confirmed by the experimental results. Meanwhile, stemness characteristics in B7-H3 overexpressing cells were suppressed after the inhibition of GSH metabolism. Furthermore, Western blotting suggested that B7-H3-induced activation of GSH metabolism occurred through the AKT/Nrf2 pathway, and inhibition of AKT signaling pathway could suppress not only GSH metabolism but also GC stemness. mIHC showed that B7-H3 was highly expressed in GC tissues and was positively correlated with the expression of CD44 and Nrf2. Importantly, GC patients with high expression of B7-H3, CD44, and Nrf2 had worse prognosis ( P = 0.02).

CONCLUSIONS

B7-H3 has a regulatory effect on GC stemness and the regulatory effect is achieved through the AKT/Nrf2/GSH pathway. Inhibiting B7-H3 expression may be a new therapeutic strategy against GC.

CHSY3 promotes proliferation and migration in gastric cancer and is associated with immune infiltration

BACKGROUND

The glycosyltransferase CHSY3 is a CHSY family member, yet its importance in the context of gastric cancer development remains incompletely understood. The present study was thus developed to explore the mechanistic importance of CHSY3 as a regulator of gastric cancer.

METHODS

Expression of CHSY3 was verified by TCGA, GEO and HPA databases. Kaplan-Meier curve, ROC, univariate cox, multivariate cox, and nomogram models were used to verify the prognostic impact and predictive value of CHSY3. KEGG and GO methods were used to identify signaling pathways associated with CHSY3. TIDE and IPS scores were used to assess the immunotherapeutic value of CHSY3. WGCNA, Cytoscape constructs PPI networks and random forest models to identify key Hub genes. Finally, qRT-PCR and immunohistochemical staining were performed to verify CHSY3 expression in clinical specimens. The ability of CHSY3 to regulate tumor was further assessed by CCK-8 assay and cloning assay, EDU assay, migration assay, invasion assay, and xenograft tumor model analysis.

RESULTS

The expression of CHSY3 was discovered to be abnormally upregulated in GC tissues through TCGA, GEO, and HPA databases, and the expression of CHSY3 was associated with poor prognosis in GC patients. Correlation analysis and Cox regression analysis revealed higher CHSY3 expression in higher T staging, an independent prognostic factor for GC. Moreover, elevated expression of CHSY3 was found to reduce the benefit of immunotherapy as assessed by the TIDE score and IPS score. Then, utilizing WGCNA, the PPI network constructed by Cytoscape, and random forest model, the Hub genes of COL5A2, POSTN, COL1A1, and FN1 associated with immunity were screened. Finally, the expression of CHSY3 in GC tissues was verified by qRT-PCR and immunohistochemical staining. Moreover, the expression of CHSY3 was further demonstrated by in vivo and in vitro experiments to promote the proliferation, migration, and invasive ability of GC.

CONCLUSIONS

The results of this study suggest that CHSY3 is an important regulator of gastric cancer progression, highlighting its promise as a therapeutic target for gastric cancer.

Antitumor Activity of Berberine by Activating Autophagy and Apoptosis in CAL-62 and BHT-101 Anaplastic Thyroid Carcinoma Cell Lines

Introduction

Anaplastic thyroid carcinoma (ATC) is the most lethal thyroid carcinoma. Doxorubicin (DOX) is the only drug approved for anaplastic thyroid cancer treatment, but its clinical use is restricted due to irreversible tissue toxicity. Berberine (BER), an isoquinoline alkaloid extracted from Coptidis Rhizoma, has been proposed to have antitumor activity in many cancers. However, the underlying mechanisms by which BER regulates apoptosis and autophagy in ATC remain unclear. Thus, the present study aimed to assess the therapeutic effect of BER in human ATC cell lines CAL-62 and BHT-101 as well as the underlying mechanisms. In addition, we assessed the antitumor effects of a combination of BER and DOX in ATC cells.

Methods

The cell viability of CAL-62 and BTH-101 with treatment of BER for different hours was measured by CCK-8 assay, and cell apoptosis was assessed by clone formation assay and flow cytometric analysis. The protein levels of apoptosis protein, autophagy-related proteins and PI3K/AKT/mTORpathway were determined Using Western blot. Autophagy in cells was observed with GFP-LC3 plasmid using confocal fluorescent microscopy. Flow cytometry was used to detect intracellular ROS.

Results

The present results showed that BER significantly inhibited cell growth and induced apoptosis in ATC cells. BER treatment also significantly upregulated the expression of LC3B-II and increased the number of GFP-LC3 puncta in ATC cells. Inhibition of autophagy by 3-methyladenine (3-MA) suppressed BER-induced autophagic cell death. Moreover, BER induced the generation of reactive oxygen species (ROS). Mechanistically, we demonstrated that BER regulated the autophagy and apoptosis of human ATC cells through the PI3K/AKT/mTOR pathways. Furthermore, BER and DOX cooperated to promote apoptosis and autophagy in ATC cells.

Conclusion

Taken together, the present findings indicated that BER induces apoptosis and autophagic cell death by activating ROS and regulating the PI3K/AKT/mTOR signaling pathway.

Novel targets for gastric cancer: The tumor microenvironment (TME), N6-methyladenosine (m6A), pyroptosis, autophagy, ferroptosis and cuproptosis

Gastric cancer (GC) is a fatal illness, and its mortality rate is very high all over the world. At present, it is a serious health problem for any country. It is a multifactorial disease due to the rising drug resistance and the increasing global cancer burden, the treatment of GC still faces many obstacles and problems. In recent years, research on GC is being carried out continuously, and we hope to address the new targets of GC treatment through this review. At the same time, we also hope to discover new ways to fight GC and create more gospel for clinical patients. First, we discuss the descriptive tumor microenvironment (TME), N6-methyladenosine (m6A), pyroptosis, autophagy, ferroptosis, and cuproptosis. Finally, we expounded on the new or potential targets of GC treatment.

Kelch-like proteins in the gastrointestinal tumors

Gastrointestinal tumors have become a worldwide health problem with high morbidity and poor clinical outcomes. Chemotherapy and surgery, the main treatment methods, are still far from meeting the treatment needs of patients, and targeted therapy is in urgent need of development. Recently, emerging evidence suggests that kelch-like (KLHL) proteins play essential roles in maintaining proteostasis and are involved in the progression of various cancers, functioning as adaptors in the E3 ligase complex and promoting the specific degradation of substrates. Therefore, KLHL proteins should be taken into consideration for targeted therapy strategy discovery. This review summarizes the current knowledge of KLHL proteins in gastrointestinal tumors and discusses the potential of KLHL proteins as potential drug targets and prognostic biomarkers.

Smurf1 Facilitates Oxidative Stress and Fibrosis of Ligamentum Flavum by Promoting Nrf2 Ubiquitination and Degradation

Lumbar spinal stenosis (LSS), which can lead to irreversible neurologic damage and functional disability, is characterized by hypertrophy and fibrosis in the ligamentum flavum (LF). However, the underlying mechanism is still unclear. In the current study, the effect of Smurf1, a kind of E3 ubiquitin ligase, in promoting the fibrosis and oxidative stress of LF was investigated, and its underlying mechanism was explored. The expression of oxidative stress and fibrosis-related markers was assessed in the tissue of lumbar spinal stenosis (LSS) and lumbar disc herniation (LDH). Next, the expression of the top 10 E3 ubiquitin ligases, obtained from Gene Expression Omnibus (GEO) dataset GSE113212, was assessed in LDH and LSS, and confirmed that Smurf1 expression was markedly upregulated in the LSS group. Furthermore, Smurf1 overexpression promotes the fibrosis and oxidative stress of LF cells. Subsequently, NRF2, an important transcription factor for oxidative stress and fibrosis, was predicted to be a target of Smurf1. Mechanistically, Smurf1 directly interacts with Nrf2 and accelerates Nrf2 ubiquitination and degradation. In conclusion, the current study suggests that Smurf1 facilitated the fibrosis and oxidative stress of LF and induced the development of LSS by promoting Nrf2 ubiquitination and degradation.

Identification of a novel reactive oxygen species (ROS)-related genes model combined with RT-qPCR experiments for prognosis and immunotherapy in gastric cancer

Reactive oxygen species play a crucial role in the prognosis and tumor microenvironment (TME) of malignant tumors. An ROS-related signature was constructed in gastric cancer (GC) samples from TCGA database. ROS-related genes were obtained from the Molecular Signatures Database. Consensus clustering was used to establish distinct ROS-related subtypes related to different survival and immune cell infiltration patterns. Sequentially, prognostic genes were identified in the ROS-related subtypes, which were used to identify a stable ROS-related signature that predicted the prognosis of GC. Correlation analysis revealed the significance of immune cell iniltration, immunotherapy, and drug sensitivity in gastric cancers with different risks. The putative molecular mechanisms of the different gastric cancer risks were revealed by functional enrichment analysis. A robust nomogram was established to predict the outcome of each gastric cancer. Finally, we verified the expression of the genes involved in the model using RT-qPCR. In conclusion, the ROS-related signature in this study is a novel and stable biomarker associated with TME and immunotherapy responses.

Shikonin triggers GSDME-mediated pyroptosis in tumours by regulating autophagy via the ROS-MAPK14/p38α axis

BACKGROUND

Shikonin (SK), a botanical drug extracted from Lithospermum erythrorhizon, has been shown to inhibit tumour growth through apoptosis and necrosis. However, whether SK induces pyroptosis in cancer cells is still unknown.

PURPOSE

This study aims to investigated the mechanisms of SK-induced pyroptosis in tumour cells and mice.

METHODS

In vivo and in vitro methods were used in this study. Cell deaths were analysed by LDH and CCK-8 assay and western blotting. To investigated the signalling pathway of SK-induced pyroptosis, various genes expressions were supressed by shRNA or inhibitors. High-sensitivity mass spectrometry assay was used to identified potential factors that regulate GSDME-mediated pyroptosis. Finally, a mouse model was used to investigate the effect of SK administration on tumour growth in vivo.

RESULTS

The activation of BAX/caspase-3 signalling was essential for GSDME-mediated pyroptosis by SK. Mechanistically, the intracellular reactive oxygen species (ROS) generation induced by SK treatment initiated GSDME-dependant pyroptosis. SK stimulation induced protective autophagy in a ROS-dependant manner, and repressed autophagy significantly enhanced SK-induced pyroptosis. Moreover, MAPK14/p38α, a ROS sensor, modulated SK-induced autophagy and ultimately affected GSDME-dependant pyroptosis.

CONCLUSION

Here, for the first time we demonstrated that SK treatment induced GSDME-dependant pyroptosis in tumour cells. Our results demonstrated that SK initiates ROS signalling to drive pyroptosis in cancer cells.

Cell death affecting the progression of gastric cancer

Gastric cancer is a gastrointestinal tumor with high morbidity and mortality rates. Several factors influence its progression, cell death being an important element. In this review, we summarized the effects of necrosis, apoptosis, necroptosis, pyroptosis, ferroptosis, and eight less common cell death modalities on gastric cancer cells and the tumor microenvironment, detailed the molecular mechanisms of various cell death and their major regulatory pathways in gastric cancer, explored the prevalence and complexity of cell death in gastric cancer progression and highlighted the potentials of cell death-related therapies in gastric cancer.

Transcriptome Analysis and Single-Cell Sequencing Analysis Constructed the Ubiquitination-Related Signature in Glioma and Identified USP4 as a Novel Biomarker

Background

Glioma, the most frequent malignant tumor of the neurological system, has a poor prognosis and treatment problems. Glioma's tumor microenvironment is also little known.

Methods

We downloaded glioma data from the TCGA database. The patients in the TCGA database were split into two groups, one for training and the other for validation. The ubiquitination genes were then evaluated in glioma using COX and Lasso regression to create a ubiquitination-related signature. We assessed the signature's predictive usefulness and role in the immune microenvironment after it was generated. Finally, in vitro experiment were utilized to check the expression and function of the signature's key gene, USP4.

Results

This signature can be used to categorize glioma patients. Glioma patients can be separated into high-risk and low-risk groups in both the training and validation cohorts, with the high-risk group having a significantly worse prognosis (P<0.05). Following further investigation of the immune microenvironment, it was discovered that this risk grouping could serve as a guide for glioma immunotherapy. The activity, invasion and migration capacity, and colony formation ability of U87-MG and LN229 cell lines were drastically reduced after the important gene USP4 in signature was knocked down in cell tests. Overexpression of USP4 in the A172 cell line, on the other hand, greatly improved clonogenesis, activity, invasion and migration.

Conclusions

Our research established a foundation for understanding the role of ubiquitination genes in gliomas and identified USP4 as a possible glioma biomarker.

TRIM22 inhibits osteosarcoma progression through destabilizing NRF2 and thus activation of ROS/AMPK/mTOR/autophagy signaling

Osteosarcoma (OS) is a malignant bone tumor that mainly occurs in adolescents. It is accompanied by a high rate of lung metastasis, and high mortality. Recent studies have suggested the important roles of tripartite motif-containing (TRIM) family proteins in regulating various substrates and signaling pathways in different tumors. However, the detailed functional role of TRIM family proteins in the progression of OS is still unknown and requires further investigations. In this study, we found that tripartite motif-containing 22 (TRIM22) was downregulated in OS tissues and was hence associated with better prognosis. In vitro and in vivo functional analysis demonstrated that TRIM22 inhibits proliferation and metastasis of OS cells. Nuclear factor erythroid 2-related factor 2 (NRF2), a redox regulator, was identified as a novel target for TRIM22. TRIM22 interacts with and accelerates the degradation of NRF2 by inducing its ubiquitination dependent on its E3 ligase activity but independent of Kelch-like ECH-associated protein 1 (KEAP1). Further, a series of gain- and loss-of-function experiments showed that knockdown or overexpression of NRF2 reversed the functions of knockdown or overexpression of TRIM22 in OS. Mechanistically, TRIM22 inhibited OS progression through NRF2-mediated intracellular reactive oxygen species (ROS) imbalance. ROS production was significantly promoted and mitochondrial potential was remarkably inhibited when overexpressing TRIM22, thus activating AMPK/mTOR signaling. Moreover, TRIM22 was also found to inhibit Warburg effect in OS cells. Autophagy activation was found in OS cells which were overexpressed TRIM22, thus leading to autophagic cell death. Treatment with N-Acetylcysteine (NAC), a ROS scavenger or the autophagy inhibitor 3-Methyladenine (3-MA) abolished the decreased malignant phenotypes in TRIM22 overexpressing OS cells. In conclusion, our study indicated that TRIM22 inhibits OS progression by promoting proteasomal degradation of NRF2 independent of KEAP1, thereby activating ROS/AMPK/mTOR/Autophagy signaling that leads to autophagic cell death in OS. Therefore, our findings indicated that targeting TRIM22/NRF2 could be a promising therapeutic target for treating OS.

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TRIM22 inhibits proliferation and metastasis of OS cells.

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TRIM22 interacts with and accelerates NRF2 degradation by inducing its ubiquitination dependent on E3 ligase activity.

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TRIM22 inhibited OS progression through NRF2-mediated intracellular ROS imbalance.

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TRIM22 inhibits OS progression by promoting NRF2 degradation, thereby activating ROS/AMPK/mTOR/Autophagy signaling.

RAB27B inhibits proliferation and promotes apoptosis of leukemic cells via 3-Hydroxy butyrate dehydrogenase 2 (BDH2)

RAB27B is a member of Ras-like small GTPases that plays a role in endocytosis, exocytosis, and vesicle trafficking. We made an attempt to study the impacts of RAB27B on the proliferation and apoptosis of acute myeloid leukemia (AML) cells. The silencing of RAB27B was induced by siRNA for the detection of proliferation, cell cycle, and apoptosis, respectively by Cell Counting Kit-8 (CCK8), flow cytometry, and TUNEL. Related markers were also evaluated by Western blot analysis. The interaction between RAB27B and BDH2 was predicted by bioinformatics analysis and determined by immunoprecipitation. The gain of function of BDH2 was also detected by these functional assays. RAB27B exhibited high levels in AML cells, and RAB27B silencing led to reduced proliferation, increased cell cycle arrest and apoptosis levels. Then, the interaction between RAB27B and BDH2 was confirmed. Moreover, the effects of RAB27B inhibition on the proliferation, cell cycle arrest, and cell apoptosis were abolished after BDH2 overexpression. RAB27B inhibits proliferation and promotes apoptosis of leukemic cells by interacting with BDH2. Targeting RAB27B might be an effective method for the treatment of AML.

Mitochondrial oxidative stress mediated Fe-induced ferroptosis via the NRF2-ARE pathway

Ferroptosis is a regulated form of cell death induced by iron (Fe)-dependent lipid peroxidation. At present, the underlying molecular mechanisms remain elusive. Herein, we hypothesized that mitochondria and the NRF2 (transcription factor nuclear factor E2-related factor 2) are potential mediators of ferroptosis, considering their well-established involvement in the oxidative stress pathway. We found that a high iron diet increased hepatic iron content and promoted glutathione (GSH) depletion, lipid peroxidation and oxidative stress. Dietary iron overload also decreased mRNA and protein expression levels of glutathione peroxidase 4 (GPX4) and cystine-glutamate antiporter (SLC7A11), and increased mRNA and protein expression of acyl-CoA synthetase long-chain family member 4 (ACSL4), which are all markers of ferroptosis. Consistent with ferroptosis, iron overload promoted lipid peroxidation and the generation of mitochondrial reactive oxygen species (ROS), and decreased the mitochondrial membrane potential (MMP). Pre-treatment with deferoxamine mesylate (DFO, an iron chelator) alleviated ROS generation and lipid peroxidation, indicating a causative link between iron overload and lipid peroxidation. Suppression of mitochondrial oxidative stress attenuated ferroptosis. Experiments with HEK293T cells revealed that Fe-induced ferroptosis involved direct inhibition of NRF2 binding to antioxidant response elements (AREs) within the promoters of the gpx4 and slc7a11 genes, which in turn induced transcriptional silencing. In conclusion, our study provided a direct link between mitochondrial oxidative stress and ferroptosis via the NRF2-ARE pathway.

Agrimoniin sensitizes pancreatic cancer to apoptosis through ROS-mediated energy metabolism dysfunction

BACKGROUND

Pancreatic cancer is a fatal tumor, which is one of the most common malignant tumors at present. Patients with pancreatic cancer also respond poorly to chemotherapy or radiation therapy and may be accompanied by serious adverse reactions. Therefore, to find an effective way to inhibit the initiation and progression of pancreatic cancer is important to improve the survival and development of patients. Agrimoniin, a polyphenol compounds isolated from Agrimonia pilosa ledeb, has antiviral, antimicrobial, and anticancer activities in vivo and in vitro. However, its molecular mechanism in pancreatic cancer remains to be determined.

PURPOSE

We aimed to investigate the effect of agrimoniin in pancreatic cancer and its underlying mechanism in vivo and in vitro.

METHODS

The proliferation was detected by colony formation, cell proliferation and toxicity, and real-time cell analysis techniques. The apoptosis was detected by flow cytometry and Western blot. Flow cytometry was used to measure the level of reactive oxygen species (ROS) and apoptosis. The level of intracellular ROS or mitochondrial membrane potential was measured with a DCFH-DA or JC-1 probe. Cell metabolism assays were analyzed and evaluated by using Agilent Seahorse Bioscience XF96 Extracellular Flux Analyzer. The target proteins were analyzed by Western blot. Subcutaneous cancer models in nude mice were established to evaluate the anticancer effects in vivo.

RESULTS

Agrimoniin inhibited cell growth and promoted cell apoptosis by regulating cell metabolism in pancreatic cancer cells. Agrimoniin increased the ROS level in pancreatic cancer cells by suppressing Nrf2-dependent ROS scavenging system and disrupting normal mitochondrial membrane potential. We also found that agrimoniin significantly disrupted mitochondrial function and reduced the protein expression of mTOR/HIF-1α pathway and subsequently decreased oxygen consumption rate and extracellular acidification rate. Eventually, agrimoniin affected intracellular energy metabolism and induced apoptosis of pancreatic cancer cells.

CONCLUSIONS

These findings reveal the novel function of agrimoniin in promoting apoptosis of pancreatic cancer cells through mediating energy metabolism dysfunction. Altogether, the potential new targets and their synergies discovered in this research are of great significance for cancer treatment and drug development.

3-hydroxy butyrate dehydrogenase 2 deficiency aggravates systemic lupus erythematosus progression in a mouse model by promoting CD40 ligand demethylation

The implications of the CD40-CD40 ligand (CD40L) signaling pathway in systemic lupus erythematosus (SLE) were well documented, due to its important role among immune cells. Previous research found that 3-hydroxy butyrate dehydrogenase 2 (BDH2), a modulator of intracellular iron homeostasis and iron transportation promoted the pathogenic process of SLE by regulating the demethylation of cd70, cd11a, and cd40l genes among CD4 + T cells. The purpose of this study was to explore the role of BDH2 in oxidative damage-induced SLE. First, CD4 + T cells treated with H₂O₂ were injected into the tail vein of mice to establish a lupus model. CD40L knockdown significantly decreased CD40L expression on CD4 + T cells in the spleen of SLE mice. Compared with SLE model mice, the levels of serum anti-dsDNA antibody and urinary protein in the CD40L interference group were significantly decreased. CD40L knockdown alleviated the immune complex glomerulonephritis in syngeneic SLE mice. Moreover, the levels of IFN-γ and IL-2 were decreased. However, IL-4 and IL-10 levels were significantly upregulated in the serum of CD40L knockdown SLE mice, compared with SLE model mice. Accordingly, CD40L knockdown reduced Th1/Th2 percentage in SLE mice. Inhibiting the expression of BDH2 of CD4 + T cells promoted the demethylation of CD40L, while it inhibited cell proliferation, elevated oxidative stress through increased expression of CD40L, and thus, promoted the progress of SLE. Our results demonstrate that BDH2 aggravates the pathologic progression of SLE in mice, by increasing the demethylation level of CD40L among CD4 + T cells.

Polystyrene microplastics disrupt the blood-testis barrier integrity through ROS-Mediated imbalance of mTORC1 and mTORC2

It has been found that polystyrene microplastics (PS-MPs) exposure leads to decreased sperm quality and quantity, and we aim to explore the underlying mechanisms. Therefore, we gave 20 mg/kg body weight (bw) and 40 mg/kg bw 4 μm and 10 μm PS-MPs to male Balb/c mice by gavage. RNA sequencing of testes was performed. After PS-MPs exposure, blood-testis barrier (BTB) integrity was impaired. Since cytoskeleton was closely related to BTB integrity maintenance, and cytoskeleton disorganization could be induced by PS-MPs exposure in the testis, which resulted in the truncation of actin filaments and disruption of BTB integrity. Such processes were attributed to the differential expression of Arp3 and Eps8 (two of the most important actin-binding proteins). According to the transcriptome sequencing results, we examined the oxidative stress level in the testes and Sertoli cells. We found that PS-MPs exposure induced increased reactive oxygen species (ROS) level, which destroyed the balance between mTORC1 and mTORC2 (the mTORC1 activity was increased, while the mTORC2 activity was decreased). In conclusion, PS-MPs induced the imbalance of mTORC1 and mTORC2 via the ROS burst, and altered the expression profile of actin-binding proteins, resulting in F-actin disorganization and reduced expression of junctional proteins in the BTB. Eventually PS-MPs led to BTB integrity disruption and spermatogenesis dysfunction.

Protective Effects of Anwulignan against HCl/Ethanol-Induced Acute Gastric Ulcer in Mice

Gastric ulcer is one of the most common gastrointestinal diseases. Anwulignan (AN) is a major active component of Schisandra sphenanthera Rehd. This study was designed to evaluate the protective effect of AN against the acute gastric ulcer induced by HCl/ethanol in mice. The mice were given HCl/ethanol by gavage to establish an acute gastric ulcer model. Then, the serum and gastric tissue samples were taken for biochemical analyses. The results showed that the pretreatment with AN could significantly reduce the gastric ulcer index (GUI) and increase the ulcer inhibition rate, indicating that AN can protect against gastric ulcers. AN showed its antioxidant roles by decreasing the content of reactive oxygen species (ROS), malondialdehyde (MDA), and 8-hydroxydeoxyguanosine (8-OHdG) and increasing the activity of superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GSH-Px) and anti-inflammatory roles by decreasing the content of tumor necrosis factor-α (TNF-α), interleukin-6 (IL-6), interleukin-1β (IL-1β), and myeloperoxidase (MPO) and increasing the content of interleukin-2 (IL-2), interleukin-4 (IL-4), interleukin-10 (IL-10), prostaglandin E2 (PGE2), and nitric oxide (NO) in both serum and gastric tissue. Furthermore, AN also activated the NRF2/ARE signaling pathway and inhibited the MAPK/NF-κB signaling pathway. AN improves the acute gastric ulcer induced by HCl/ethanol in mice, which may be mainly through its antioxidant capacity and anti-inflammatory effect.

Role of RONS and eIFs in Cancer Progression

Various research works have piled up conflicting evidence questioning the effect of oxidative stress in cancer. Reactive oxygen and nitrogen species (RONS) are the reactive radicals and nonradical derivatives of oxygen and nitrogen. RONS can act as a double-edged weapon. On the one hand, RONS can promote cancer initiation through activating certain signal transduction pathways that direct proliferation, survival, and stress resistance. On the other hand, they can mitigate cancer progression via their resultant oxidative stress that causes many cancer cells to die, as some recent studies have proposed that high RONS levels can limit the survival of cancer cells during certain phases of cancer development. Similarly, eukaryotic translation initiation factors are key players in the process of cellular transformation and tumorigenesis. Dysregulation of such translation initiation factors in the form of overexpression, downregulation, or phosphorylation is associated with cancer cell's altering capability of survival, metastasis, and angiogenesis. Nonetheless, eIFs can affect tumor age-related features. Data shows that alternating the eukaryotic translation initiation apparatus can impact many downstream cellular signaling pathways that directly affect cancer development. Hence, researchers have been conducting various experiments towards a new trajectory to find novel therapeutic molecular targets to improve the efficacy of anticancer drugs as well as reduce their side effects, with a special focus on oxidative stress and initiation of translation to harness their effect in cancer development. An increasing body of scientific evidence recently links oxidative stress and translation initiation factors to cancer-related signaling pathways. Therefore, in this review, we present and summarize the recent findings in this field linking certain signaling pathways related to tumorigeneses such as MAPK and PI3K, with either RONS or eIFs.

Bdh2 Deficiency Promotes Endoderm-Biased Early Differentiation of Mouse Embryonic Stem Cells

3-hydroxybutyrate dehydrogenase-2 (Bdh2), a short-chain dehydrogenase, catalyzes a rate-limiting step in the biogenesis of the mammalian siderophore, playing a key role in iron homeostasis, energy metabolism and apoptosis. However, the function of Bdh2 in embryonic stem cells (ESCs) remains unknown. To gain insights into the role of Bdh2 on pluripotency and cell fate decisions of mouse ESCs, we generated Bdh2 homozygous knockout lines for both mouse advanced embryonic stem cell (ASC) and ESC using CRISPR/Cas9 genome editing technology. Bdh2 deficiency in both ASCs and ESCs had no effect on expression of core pluripotent transcription factors and alkaline phosphatase activity, suggesting dispensability of Bdh2 for self-renewal and pluripotency of ESCs. Interestingly, cells with Bdh2 deficiency exhibited potency of endoderm differentiation in vitro; with upregulated endoderm associated genes revealed by RNA-seq and RT-qPCR. We further demonstrate that Bdh2 loss inhibited expression of multiple methyltransferases (DNMTs) at both RNA and protein level, suggesting that Bdh2 may be essentially required to maintain DNA methylation in ASCs and ESCs. Overall, this study provides valuable data and resources for understanding how Bdh2 regulate earliest cell fate decision and DNA methylation in ASCs/ESCs.

Effects of Gentiopicroside on Oxidative Stress and Apoptosis in Gastric Cancer Cells

Gastric cancer (GC) cells were sorted into six groups: NC, different concentrations of gentiopi-croside, pcDNA-NC, pcDNA-Nrf2, pcDNA-NC + gentiopicroside, and pcDNA-Nrf2 + gentiopicroside. The detection and comparison of cell survival and apoptosis showed that the activity of GC cells decreased and the apoptosis rate increased after gentiopicroside treatment. Western blot detection was performed to determine the expression levels of proliferating cell nuclear antigen (PCNA), B-cell leukemia/lymphoma-2 (Bcl-2)-associated X protein (Bax), Bcl-2, Kelch-like epichlorohydrin-associated protein 1 (Keap1), nuclear factor erythroid 2-related factor 2 (Nrf2), and antioxidant response element (ARE). Kits were used to determine the malondialdehyde (MDA) content, superoxide dismutase (SOD) activity, and nicotinamide adenine dinucleotide phosphate (NADPH) oxidase activity. The MDA content, NADPH oxidase activity, and Keap1 and Bax expression levels increased, and the SOD activity and Bcl-2, PCNA, Nrf2, and ARE expression levels decreased. Nrf2 overexpression increased the cell activity, SOD activity, and Nrf2, ARE, PCNA, and Bcl-2 expression levels and reduced the apoptosis rate, MDA content, NADPH oxidase activity, and Bax and Keap1 expression levels. At the same time, Nrf2 overexpression reversed the effects of gentiopicroside on oxidative stress and apoptosis of GC cells. These results suggest that gentiopicroside probably promotes oxidative stress and apoptosis of GC cells by inhibiting the Keap1/Nrf2/ARE signaling pathway.

Nrf2 mediates the neuroprotective effect of isoflurane preconditioning in cortical neuron injury induced by oxygen-glucose deprivation

OBJECTIVE

To investigate how nuclear factor-E2-related factor 2 (Nrf2) involved in the protective effect of isoflurane (Iso) preconditioning in oxygen glucose deprivation (OGD)-induced cortical neuron injury.

METHODS

Primary mouse cortical neurons were divided into Control, ML385 (an Nrf2 inhibitor), Iso, Iso + ML385, OGD, ML385 + OGD, Iso + OGD, and Iso + ML385 + OGD groups. Lactate dehydrogenase activity (LDH) release and oxidative stress indexes were quantified. 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay was used to detect cell viability, Annexin V-FITC/propidium iodide (PI) staining to measure cell apoptosis, dichloro-dihydro-fluorescein diacetate (DCFH-DA) method to test reactive oxygen species (ROS), and quantitative reverse-transcription polymerase chain reaction (qRT-PCR) and Western blotting to evaluate genes and protein expression.

RESULTS

Iso preconditioning reduced LDH release and inhibited cell cytotoxicity in OGD-induced cortical neurons, which was abolished by ML385. Iso preconditioning increased the Nrf2 nuclear translocation in cortical neurons. Meanwhile, Iso decreased the OGD-induced apoptosis with the down-regulations of Bax and Caspase-3 and the up-regulation of Bcl-2, which was reversed by ML385. OGD enhanced the level of ROS and malondialdehyde (MDA) in cortical neurons, but reduced the activities of superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px), which were aggravated in ML385 + OGD group and mitigated in Iso + OGD group. No observable difference was found between OGD group and Iso + ML385 + OGD group regarding apoptosis-related proteins and oxidative stress-related indexes.

CONCLUSION

Iso preconditioning up-regulated Nrf2 level to play its protective role in OGD-induced mouse cortical neuron injury.

Activator-Mediated Pyruvate Kinase M2 Activation Contributes to Endotoxin Tolerance by Promoting Mitochondrial Biogenesis

Pyruvate kinase M2 (PKM2) is a key glycolysis enzyme, and its effect on macrophages has not been entirely elucidated. Here, we identified that the PKM2 small-molecule agonist TEPP-46 mediated PKM2 activation by inducing the formation of PKM2 tetramer and promoted macrophage endotoxin tolerance. Lipopolysaccharide (LPS)-tolerant mice had higher expression of the PKM2 tetramer, which was associated with a reduced in vivo immune response to LPS. Pretreatment of macrophages with TEPP-46 resulted in tolerance to LPS stimulation, as demonstrated by a significant reduction in the production of TNF-α and IL-6. We found that TEPP-46 induced mitochondrial biogenesis in macrophages. Inhibition of mitochondrial biogenesis by mtTFA knockdown effectively inhibited TEPP-46-mediated macrophage tolerance to endotoxins. We discovered that TEPP-46 promoted the expression of PGC-1α and that PGC-1α was the key regulator of mitochondrial biogenesis in macrophages induced by TEPP-46. PGC-1α was negatively regulated by the PI3K/Akt signaling pathway. Knockdown of PKM2 or PGC-1α uniformly inhibited TEPP-46-mediated endotoxin tolerance by inhibiting mitochondrial biogenesis. In addition, TEPP-46 protected mice from lethal endotoxemia and sepsis. Collectively, these findings reveal novel mechanisms for the metabolic control of inflammation and for the induction of endotoxin tolerance by promoting mitochondrial biogenesis. Targeting PKM2 appears to be a new therapeutic option for the treatment of sepsis and other inflammatory diseases.

Emerging role of NRF2 in ROS-mediated tumor chemoresistance

Chemoresistance is a central cause for the tumor management failure. Cancer cells disrupt the redox homeostasis through reactive oxygen species (ROS) regulatory mechanisms, leading to tumor progression and chemoresistance. The transcription factor nuclear factor erythroid 2-related factor 2 (NRF2) is a master regulator of neutralizing cellular ROS and restoring redox balance. Understanding the role of NRF2 in ROS-mediated chemoresistance can be helpful in the development of chemotherapy strategies with better efficiency. In this review, we sum up the roles of ROS in the development of chemoresistance to classical chemotherapy agents including cisplatin, 5-fluorouracil, gemcitabine, oxaliplatin, paclitaxel, and doxorubicin, and how to overcome ROS-mediated tumor chemoresistance by targeting NRF2. Finally, we propose that targeting NRF2 might be a promising strategy to resist ROS-driven chemoresistance and acquire better efficacy in cancer treatment.

NUCKS promotes cell proliferation and suppresses autophagy through the mTOR-Beclin1 pathway in gastric cancer

Background

Nuclear casein kinase and cyclin-dependent kinase substrate (NUCKS), a novel gene first reported in 2001, is a member of the high mobility group (HMG) family. Although very little is known regarding the biological roles of NUCKS, emerging clinical evidence suggests that the NUCKS protein can be used as a biomarker and therapeutic target in various human ailments, including several types of cancer.

Methods

We first assessed the potential correlation between NUCKS expression and gastric cancer prognosis. Then functional experiments were conducted to evaluate the effects of NUCKS in cell proliferation, cell cycle, apoptosis and autophagy. Finally, the roles of NUCKS on gastric cancer were examined in vivo.

Results

We found that NUCKS was overexpressed in gastric cancer patients with poor prognosis. Through manipulating NUCKS expression, it was observed to be positively associated with cell proliferation in vitro and in vivo. NUCKS knockdown could induce cell cycle arrest and apoptosis. Then further investigation indicated that NUCKS knockdown could also significantly induce a marked increase in autophagy though the mTOR-Beclin1 pathway, which could be was rescued by NUCKS restoration. Moreover, silencing Beclin1 in NUCKS knockdown cells or adding rapamycin in NUCKS-overexpressed cells also confirmed these results.

Conclusions

Our findings revealed that NUCKS functions as an oncogene and an inhibitor of autophagy in gastric cancer. Thus, the downregulation or inhibition of NUCKS may be a potential therapeutic strategy for gastric cancer.