Proteomic profiling of eIF3a conditional knockout mice.

Eukaryotic translation initiation factor 3 subunit A (eIF3a) is the largest subunit of the eukaryotic translation initiation factor 3 (eIF3). eIF3a plays an integral role in protein biosynthesis, hence impacting the onset, development, and treatment of tumors. The proteins regulated by eIF3a are still being explored in vivo. In this study, a Cre-loxP system was used to generate eIF3a conditional knockout mice. Tandem mass tag (TMT) labeling with LC-MS/MS analysis was used to identify differentially expressed proteins (DEPs) in fat, lungs, skin, and spleen tissue of the eIF3a knockout mice and controls. Bioinformatics analysis was then used to explore the functions and molecular signaling pathways of these protein landscapes. It was observed that eIF3a is essential for life sustenance. Abnormal tissue pathology was found in the lungs, fat, skin, spleen, and thymus. In total, 588, 210, 324, and 944 DEPs were quantified in the lungs, fat, skin, and spleen, respectively, of the eIF3a knockout mice as compared to the control. The quantified differentially expressed proteins were tissue-specific, except for eight proteins shared by the four tissues. A broad range of functions for eIF3a, including cellular signaling pathway, immune response, metabolism, defense response, phagocytes, and DNA replication, has been revealed using bioinformatics analysis. Herein, several pathways related to oxidative stress in the Kyoto Encyclopedia of Genes and Genomes (KEGG) database, including nitrogen metabolism, peroxisome, cytochrome P450 drug metabolism, pyruvate metabolism, PPAR signaling pathway, phospholipase D signaling pathway, B-cell receptor signaling pathway, ferroptosis, and focal adhesion, have been identified. Collectively, this study shows that eIF3a is an essential gene for sustaining life, and its downstream proteins are involved in diverse novel functions beyond mRNA translational regulation.

eIF3a sustains non-small cell lung cancer stem cell-like properties by promoting YY1-mediated transcriptional activation of ß-catenin.

Cancer stem cells (CSCs) are the leading cause of recurrence and poor prognosis in non-small cell lung cancer (NSCLC). Eukaryotic translation initiation factor 3a (eIF3a) participates in many tumor development processes, such as metastasis, therapy resistance, and glycolysis, all of which are closely associated with the presence of CSCs. However, whether eIF3a maintains NSCLC-CSC-like properties remains to be elucidated. In this study, eIF3a was highly expressed in lung cancer tissues and was linked to poor prognosis. eIF3a was also highly expressed in CSC-enriched spheres compared with adherent monolayer cells. Moreover, eIF3a is required for NSCLC stem cell-like traits maintenance in vitro and in vivo. Mechanistically, eIF3a activates the Wnt/ß-catenin signaling pathway, promoting the transcription of cancer stem cell markers. Specifically, eIF3a promotes the transcriptional activation of ß-catenin and mediates its nuclear accumulation to form a complex with T cell factor 4 (TCF4). However, eIF3a has no significant effect on protein stability and translation. Proteomics analysis revealed that the candidate transcription factor, Yin Yang 1 (YY1), mediates the activated effect of eIF3a on ß-catenin. Overall, the findings of this study implied that eIF3a contributes to the maintenance of NSCLC stem cell-like characteristics through the Wnt/ß-catenin pathway. eIF3a is a potential target for the treatment and prognosis of NSCLC.

Human PARP1 substrates and regulators of its catalytic activity: An updated overview.

Poly (ADP-ribose) polymerase 1 (PARP1) is a key DNA damage sensor that is recruited to damaged sites after DNA strand breaks to initiate DNA repair. This is achieved by catalyzing attachment of ADP-ribose moieties, which are donated from NAD+, on the amino acid residues of itself or other acceptor proteins. PARP inhibitors (PARPi) that inhibit PARP catalytic activity and induce PARP trapping are commonly used for treating BRCA1/2-deficient breast and ovarian cancers through synergistic lethality. Unfortunately, resistance to PARPi frequently occurs. In this review, we present the novel substrates and regulators of the PARP1-catalyzed poly (ADP-ribosyl)ation (PARylatison) that have been identified in the last 3 years. The overall aim is the presentation of protein interactions of potential therapeutic intervention for overcoming the resistance to PARPi.

PARPi treatment enhances radiotherapy-induced ferroptosis and antitumor immune responses via the cGAS signaling pathway in colorectal cancer.

In cancer cells, poly (ADP-ribose) polymerase (PARP)-1 and PARP2 initiate and regulate DNA repair pathways to protect against DNA damage and cell death caused by radiotherapy or chemotherapy. Radiotherapy and PARP inhibitors (PARPis) have been combined in clinical trials, but their action mechanisms remain unclear. Here, we show that activated by ionizing radiation (IR) generated dsDNA, cyclic GMP-AMP synthase (cGAS) signaling promoted regulated cell death, specifically ferroptosis, via the activating transcription factor 3 (ATF3)-solute carrier family 7 member 11 axis and the antitumor immune response via the interferon-ß-CD8+ T cell pathway. Niraparib, a widely used PARPi, augmented cGAS-mediated ferroptosis and immune activation. In colorectal cancer models, cGAS knockdown (KD) compromised IR-induced ferroptosis via downregulation of ATF3 (key ferroptosis regulator) expression. cGAS depletion reversed IR-induced infiltration of CD8+ T or CD8+GZMB+ T cells in the cGAS KD group. Survival analysis of paired tumor samples before and after standard radiotherapy revealed that high expression levels of cGAS, ATF3, and PTGS2 and high density of CD8+ T cells resulted in a significantly high disease-free survival rate in patients with rectal cancer. Therefore, PARPi treatment increases the cytoplasmic accumulation of dsDNA caused by IR, triggering the cGAS signaling-mediated tumor control in cancer cell lines and mouse xenograft models.

Effects of Glycolysis-Related Genes on Prognosis and the Tumor Microenvironment of Hepatocellular Carcinoma.

Background: Hepatocellular carcinoma (HCC) is a common and deadly malignancy worldwide. Current treatment methods for hepatocellular carcinoma have many disadvantages; thus, it is urgent to improve the efficacy of these therapies. Glycolysis is critical in the occurrence and development of tumors. However, survival and prognosis biomarkers related to glycolysis in HCC patients remain to be fully identified. Methods: Glycolysis-related genes (GRGs) were downloaded from "The Molecular Signatures Database" (MSigDB), and the mRNA expression profiles and clinical information of HCC patients were obtained from TCGA. Consensus clustering was performed to classify the HCC patients into two subgroups. We used the least absolute shrinkage and selection operator (LASSO) regression analysis to construct the risk signature model. Kaplan-Meier (K-M) survival analysis was performed to evaluate the prognostic significance of the risk model, and the receiver operating characteristic (ROC) curve analysis was used to evaluate the prediction accuracy. The independent prediction ability of the risk model was validated by univariate and multivariate Cox regression analyses. The differences of immune infiltrates and relevant oncogenic signaling between different risk groups were compared. Finally, biological experiments were performed to explore the functions of screened genes. Results: HCC patients were classified into two subgroups, according to the expression of prognostic-related GRGs. Almost all GRGs categorized in cluster 2 showed upregulated expressions, whereas GRGs in cluster 1 conferred survival advantages. GSEA identified a positive correlation between cluster 2 and the glycolysis process. Ten genes were selected for risk signature construction. Patients were assigned to high-risk and low-risk groups based on the median risk score, and K-M survival analysis indicated that the high-risk group had a shorter survival time. Additionally, the risk gene signature can partially affect immune infiltrates within the HCC microenvironment, and many oncogenic pathways were enriched in the high-risk group, including glycolysis, hypoxia, and DNA repair. Finally, in vitro knockdown of ME1 suppressed proliferation, migration, and invasion of hepatocellular carcinoma cells. Conclusion: In our study, we successfully constructed and verified a novel glycolysis-related risk signature for HCC prognosis prediction, which is meaningful for classifying HCC patients and offers potential targets for the treatment of hepatocellular carcinoma.

Midazolam Ameliorates Impairment of the Blood-Brain Barrier (BBB) Against LPS.

Central nervous system (CNS) dysfunction induced by sepsis and pathogenic microbial infections is reported to be closely associated with increased permeability of the blood-brain barrier (BBB), which is mainly mediated by the stimulation of lipopolysaccharide (LPS) on inflammatory signaling. Midazolam is a novel sedative acting on the benzodiazepine receptor, which is recently reported to exert a neuroprotective effect by inhibiting inflammation. The present study will explore the potential repair capacity of Midazolam on LPS-induced damage to the BBB. The in vivo mice model was established by intraperitoneal injection of LPS, while the in vitro model was constructed by stimulating endothelial cells utilizing LPS. We found that the increased malondialdehyde (MDA) level and reduced superoxide dismutase (SOD) activity in the brain cortices, promoted serum concentration of inflammatory factors, and elevated BBB permeability were found in the LPS group, all of which were dramatically reversed by 1 mg/kg and 2 mg/kg Midazolam. Interestingly, Midazolam increased the expression of the tight junction protein zonula occludens-1 (ZO-1). In LPS-challenged in vitro human brain microvascular endothelial cells (HBMECs), the increased concentration of inflammatory factors, reduced trans-endothelial electrical resistance (TEER) level, elevated relative value of trans-endothelial permeability, and downregulated ZO-1 were observed, all of which were pronouncedly alleviated by Midazolam, accompanied by the inhibition on the Ras homolog family member A/ Rho-kinase 2 (RhoA/ROCK-2) pathway. Furthermore, the regulatory effects of Midazolam on ZO-1 expression and the endothelial monolayer permeability in LPS-challenged HBMECs were abolished by the overexpression of RhoA. Collectively, our data imply that Midazolam ameliorated the impairment of the BBB against LPS by regulating the RhoA/ROCK2 pathway.

ETV4 promotes breast cancer cell stemness by activating glycolysis and CXCR4-mediated sonic Hedgehog signaling.

Cancer stem cells (CSCs) are a major cause of tumor treatment resistance, relapse and metastasis. Cancer cells exhibit reprogrammed metabolism characterized by aerobic glycolysis, which is also critical for sustaining cancer stemness. However, regulation of cancer cell metabolism rewiring and stemness is not completely understood. Here, we report that ETV4 is a key transcription factor in regulating glycolytic gene expression. ETV4 loss significantly inhibits the expression of HK2, LDHA as well as other glycolytic enzymes, reduces glucose uptake and lactate release in breast cancer cells. In human breast cancer and hepatocellular carcinoma tissues, ETV4 expression is positively correlated with glycolytic signaling. Moreover, we confirm that breast CSCs (BCSCs) are glycolysis-dependent and show that ETV4 is required for BCSC maintenance. ETV4 is enriched in BCSCs, its knockdown and overexpression suppresses and promotes breast cancer cell stem-like traits, respectively. Mechanistically, on the one hand, we find that ETV4 may enhance glycolysis activity to facilitate breast cancer stemness; on the other, ETV4 activates Sonic Hedgehog signaling by transcriptionally promoting CXCR4 expression. A xenograft assay validates the tumor growth-impeding effect and inhibition of CXCR4/SHH/GLI1 signaling cascade after ETV4 depletion. Together, our study highlights the potential roles of ETV4 in promoting cancer cell glycolytic shift and BCSC maintenance and reveals the molecular basis.

Construction and validation of an immunity-related prognostic signature for breast cancer.

Breast cancer is one of the most lethal malignancies among women, and understanding the effects of host immunity on disease progression offers the potential to improve immunotherapies against it. Here, we constructed an immunity-related gene (IRG)-based prognostic signature to stratify breast cancer patients and predict their survival. We identified differentially-expressed genes by analyzing the breast cancer transcriptome data from The Cancer Genome Atlas. Univariate Cox regression revealed 179 survival-correlated IRGs, 12 of which we used to construct an immunity-based prognostic signature that stratified breast cancer patients into high- and low-risk groups. The signature was an independent predictor for survival and was validated in an independent dataset. We also investigated the correlations between our prognostic signature and immune infiltrates and found that signature-derived risk scores correlated negatively with infiltration of B cells, CD4+ T cells, CD8+ T cells, neutrophils and dendritic cells. Our results show that the proposed prognostic signature reflects the tumor immune microenvironment, which makes it a potential indicator for survival that warrants further research to assess its clinical utility.

Comprehensive elaboration of the cGAS-STING signaling axis in cancer development and immunotherapy.

Cellular recognition of microbial DNA is an evolutionarily conserved mechanism by which the innate immune system detects pathogens. Cyclic GMP-AMP synthase (cGAS) and its downstream effector, stimulator of interferon genes (STING), are involved in mediating fundamental innate antimicrobial immunity by promoting the release of type I interferons (IFNs) and other inflammatory cytokines. Accumulating evidence suggests that the activation of the cGAS-STING axis is critical for antitumor immunity. The downstream cytokines regulated by cGAS-STING, especially type I IFNs, serve as bridges connecting innate immunity with adaptive immunity. Accordingly, a growing number of studies have focused on the synthesis and screening of STING pathway agonists. However, chronic STING activation may lead to a protumor phenotype in certain malignancies. Hence, the cGAS-STING signaling pathway must be orchestrated properly when STING agonists are used alone or in combination. In this review, we discuss the dichotomous roles of the cGAS-STING pathway in tumor development and the latest advances in the use of STING agonists.

Two new steroidal glycosides with unique structural feature of 14α-hydroxy-5ß-steroids from Reineckia carnea.

Two new steroidal glycosides (1-2) were isolated from the roots of Reineckia carnea, together with three known compounds (3-5). Their structures were determined on the basis of chemical methods and spectral data. Compounds 1-2 were the unique steroidal glycosides possessing structural feature of 14α-hydroxy-5ß-steroids, and compounds 4-5 were isolated from R. carnea for the first time. The isolated compounds (1-5) were tested in vitro for their cytotoxic activities against the A549, HepG 2 and Caski cancer cell lines. Among them, the compounds 2 and 3 showed cytotoxicity against Caski cancer cell line with IC50 values of 34.4 and 3.7µM, respectively.

Anti-proliferative effect of RCE-4 from Reineckia carnea on human cervical cancer HeLa cells by inhibiting the PI3K/Akt/mTOR signaling pathway and NF-κB activation.

Cervical cancer is the second leading cause of cancer deaths in women worldwide. In recent years, the studies find that inflammation is a critical component of tumor progression, and the ideal therapeutic methods should be aimed at the inflammation reaction triggers. (1ß,3ß,5ß,25S)-spirostan-1,3-diol1-[α-L-rhamnopyranosyl-(1 → 2)-ß-D-xylopyranoside] (RCE-4) was the main active composition of Reineckia carnea (Andr.) Kunth. It significantly induced apoptosis in cervical cancer Caski cells through the mitochondrial pathway in our previous studies; however, its underlying mechanism remains poorly understood. This study aimed to further evaluate the effect of RCE-4 on human cervical cancer HeLa cells. Based on this observation, we investigated the anti-cervical cancer effect of RCE-4 by modulating phosphatidylinositol 3-kinase/protein kinase-B/mammalian target of rapamycin (PI3K/Akt/mTOR) signaling pathway, nuclear factor-kappa B (NF-κB) activation, and inflammation-related key factors in HeLa cells. The results indicated that the HeLa cell was the most sensitive with an IC50 of 7.01 µM; RCE-4 significantly promoted the release of cellular lactate dehydrogenase (LDH); increased DNA fragmentation and apoptosis; reduced PI3K, Akt, mTOR, and NF-κBp65 phosphorylation levels; increased the Bax and cleaved poly (ADP-ribose) polymerase (PARP) protein levels; suppressed Bcl-2 protein expression; elevated the Bax/Bcl-2 expression ratio; and decreased the interleukin-1 beta (IL-1ß) and interleukin-6 (IL-6) mRNA expressions in HeLa cells in a concentration-dependent manner. These findings suggest that RCE-4 exerted beneficially anti-cervical cancer effect on HeLa cells, mainly inhibiting PI3K/Akt/mTOR signaling pathway phosphorylation and NF-κB activation, promoting HeLa cell apoptosis. Graphical abstract Anti-tumor effect of RCE-4 on HeLa cells.

[Study on Quality Standard for Panax japonicus Rhizome].

OBJECTIVE: To establish a quality standard for Panax japonicus rhizome. METHODS: Ginsenoside Ro and Chikusetsusaponin IVa were used as reference substances in the TLC identification and HPLC method. Additionally, acid insoluble ash and moisture were determined according to the procedures recorded in the Appendix of Chinese Pharmacopeia (2010 edition). RESULTS: The TLC identification with GF, showed a good resolution with clear spots and its optimum developer was the underlayer of chloroform-methanol-formic acid-water = 4.5:1.5: 0.1:0.3. The content of Ginsenoside Ro and Chikusetsusaponin N a were determined by HPLC. The mixture of acetonitrile and water (0.15% phosphate) with gradient elution as the mobile phase was used at a flow rate of 1.0 mL/min, the detection wavelength at 203 nm and the column temperature at 40 °C. The calibration curve was linear in the range of 31.25-2,000 g/mL for Ginsenoside Ro and Chikusetsusaponin IVa (r = 0.9999, respectively). The average recovery was 101.19% and 102.50%, and RSD was 1.59% and 1.80% respectively. The content of Ginsenoside Ro and Chikusetsusaponin IVa was no less than 1.5% respectively. An average content of moisture was 7.36% and acid insoluble ash was 0.84%. CONCLUSION: These methods are producible, sensitive and simple, which can be used to control the quality of Panax japonicus rhizome.