Mechanistic Understanding of Dexamethasone-Mediated Protection against Remdesivir-Induced Hepatotoxicity.

Remdesivir (RDV), a broad-spectrum antiviral agent, is often used together with dexamethasone (DEX) for hospitalized COVID-19 patients requiring respiratory support. Potential hepatic adverse drug reaction is a safety concern associated with the use of RDV. We previously reported that DEX cotreatment effectively mitigates RDV-induced hepatotoxicity and reduces elevated serum alanine aminotransferase and aspartate aminotransferase levels in cultured human primary hepatocytes (HPH) and hospitalized COVID-19 patients, respectively. Yet, the precise mechanism behind this protective drug-drug interaction remains largely unknown. Here, we show that through the activation of p38, c-Jun N-terminal kinase (JNK), and extracellular signal-regulated kinases 1 and 2 (ERK1/2) signaling, RDV induces apoptosis (cleavage of caspases 8, 9, and 3), autophagy (increased autophagosome and LC3-II), and mitochondrial damages (decreased membrane potential, respiration, ATP levels, and increased expression of Bax and the released cytosolic cytochrome C) in HPH. Importantly, cotreatment with DEX partially reversed RDV-induced apoptosis, autophagy, and cell death. Mechanistically, DEX deactivates/dephosphorylates p38, JNK, and ERK1/2 signaling by enhancing the expression of dual specificity protein phosphatase 1 (DUSP1), a mitogen-activated protein kinase (MAPK) phosphatase, in a glucocorticoid receptor (GR)-dependent manner. Knockdown of GR in HPH attenuates DEX-mediated DUSP1 induction, MAPK dephosphorylation, as well as protection against RDV-induced hepatotoxicity. Collectively, our findings suggest a molecular mechanism by which DEX modulates the GR-DUSP1-MAPK regulatory axis to alleviate the adverse actions of RDV in the liver. SIGNIFICANCE STATEMENT: The research uncovers the molecular mechanisms by which dexamethasone safeguards against remdesivir-associated liver damage in the context of COVID-19 treatment.

Effect of Different Edible Trichosanthes Germplasm on Its Seed Oil to Enhance Antioxidant and Anti-Aging Activity in Caenorhabditis elegans.

The seeds of various Trichosanthes L. plants have been frequently used as snacks instead of for traditional medicinal purposes in China. However, there is still a need to identify the species based on seeds from Trichosanthes germplasm for the potential biological activities of their seed oil. In this study, 18 edible Trichosanthes germplasm from three species were identified and distinguished at a species level using a combination of seed morphological and microscopic characteristics and nrDNA-ITS sequences. Seed oil from the edible Trichosanthes germplasm significantly enhanced oxidative stress tolerance, extended lifespan, delayed aging, and improved healthspan in Caenorhabditis elegans. The antioxidant activity of the seed oil exhibits a significant positive correlation with its total unsaturated fatty acid content among the 18 edible Trichosanthes germplasm, suggesting a genetic basis for this trait. The biological activities of seed oil varied among species, with T. kirilowii Maxim. and T. rosthornii Harms showing stronger effects than T. laceribractea Hayata.

NCOA5 Haploinsufficiency in Myeloid-Lineage Cells Sufficiently Causes Nonalcoholic Steatohepatitis and Hepatocellular Carcinoma.

BACKGROUND & AIMS: The nuclear receptor coactivator 5 (NCOA5) is a putative type 2 diabetes susceptibility gene. NCOA5 haploinsufficiency results in the spontaneous development of nonalcoholic fatty liver disease (NAFLD), insulin resistance, and hepatocellular carcinoma (HCC) in male mice; however, the cell-specific effect of NCOA5 haploinsufficiency in various types of cells, including macrophages, on the development of NAFLD and HCC remains unknown. METHODS: Control and myeloid-lineage-specific Ncoa5 deletion (Ncoa5ΔM/+) mice fed a normal diet were examined for the development of NAFLD, nonalcoholic steatohepatitis (NASH), and HCC. Altered genes and signaling pathways in the intrahepatic macrophages of Ncoa5ΔM/+ male mice were analyzed and compared with those of obese human individuals. The role of platelet factor 4 (PF4) in macrophages and the underlying mechanism by which PF4 affects NAFLD/NASH were explored in vitro and in vivo. PF4 expression in HCC patient specimens and prognosis was examined. RESULTS: Myeloid-lineage-specific Ncoa5 deletion sufficiently causes spontaneous NASH and HCC development in male mice fed a normal diet. PF4 overexpression in Ncoa5ΔM/+ intrahepatic macrophages is identified as a potent mediator to trigger lipid accumulation in hepatocytes by inducing lipogenesis-promoting gene expression. The transcriptome of intrahepatic macrophages from Ncoa5ΔM/+ male mice resembles that of obese human individuals. High PF4 expression correlated with poor prognosis of HCC patients and increased infiltrations of M2 macrophages, regulatory T cells, and myeloid-derived suppressor cells in HCCs. CONCLUSIONS: Our findings reveal a novel mechanism for the onset of NAFLD/NASH and HCC initiated by NCOA5-deficient macrophages, suggesting the NCOA5-PF4 axis in macrophages as a potential target for developing preventive and therapeutic interventions against NAFLD/NASH and HCC.

Liensinine and neferine exert neuroprotective effects via the autophagy pathway in transgenic Caenorhabditis elegans.

BACKGROUND: Liensinine and neferine are the main bisbenzylisoquinoline alkaloids obtained from the seeds of Nelumbo nucifera, which commonly used as edible food and traditional medicine in Asia. It was reported that liensinine and neferine could inhibit the activities of acetylcholinesterase and cross the blood-brain barriers, suggesting their therapeutic potential for the management of Alzheimer's disease. METHODS: Here, we employed SH-SY5Y human neuroblastoma cells stably transfected with the human Swedish amyloid precursor protein (APP) mutation APP695 (APP695swe SH-SY5Y) as an in vitro model and transgenic Caenorhabditis elegans as an in vivo model to investigate the neuroprotective effects and underlying mechanism of liensinine and neferine. RESULTS: We found that liensinine and neferine could significantly improve the viability and reduce ROS levels in APP695swe SH-SY5Y cells, inhibit ß-amyloid and tau-induced toxicity, and enhance stress resistance in nematodes. Moreover, liensinine and neferine had obviously neuroprotective effects by assaying chemotaxis, 5-hydroxytryptamine sensitivity and the integrity of injured neurons in nematodes. Preliminary mechanism studies revealed that liensinine and neferine could upregulate the expression of autophagy related genes (lgg-1, unc-51, pha-4, atg-9 and ced-9) and reduce the accumulation of ß-amyloid induced autophagosomes, which suggested autophagy pathway played a key role in neuroprotective effects of these two alkaloids. CONCLUSIONS: Altogether, our findings provided a certain working foundation for the use of liensinine and neferine to treat Alzheimer's disease based on neuroprotective effects.

Hyperpolarization-activated cyclic nucleotide-gated cation channel 3 promotes HCC development in a female-biased manner.

Sex differences in hepatocellular carcinoma (HCC) development are regulated by sex and non-sex chromosomes, sex hormones, and environmental factors. We previously reported that Ncoa5+/- mice develop HCC in a male-biased manner. Here we show that NCOA5 expression is reduced in male patient HCCs while the expression of an NCOA5-interacting tumor suppressor, TIP30, is lower in female HCCs. Tip30 heterozygous deletion does not change HCC incidence in Ncoa5+/- male mice but dramatically increases HCC incidence in Ncoa5+/- female mice, accompanied by hepatic hyperpolarization-activated cyclic nucleotide-gated cation channel 3 (HCN3) overexpression. HCN3 overexpression cooperates with MYC to promote mouse HCC development, whereas Hcn3 knockout preferentially hinders HCC development in female mice. Furthermore, HCN3 amplification and overexpression occur in human HCCs and correlate with a poorer prognosis of patients in a female-biased manner. Our results suggest that TIP30 and NCOA5 protect against female liver oncogenesis and that HCN3 is a female-biased HCC driver.

Ribosome Heterogeneity in Development and Disease.

The functional ribosome is composed of ∼80 ribosome proteins. With the intensity-based absolute quantification (iBAQ) value, we calculate the stoichiometry ratio of each ribosome protein. We analyze the ribosome ratio-omics (Ribosome R ), which reflects the holistic signature of ribosome composition, in various biological samples with distinct functions, developmental stages, and pathological outcomes. The Ribosome R reveals significant ribosome heterogeneity among different tissues of fat, spleen, liver, kidney, heart, and skeletal muscles. During tissue development, testes at various stages of spermatogenesis show distinct Ribosome R signatures. During in vitro neuronal maturation, the Ribosome R changes reveal functional association with certain molecular aspects of neurodevelopment. Regarding ribosome heterogeneity associated with pathological conditions, the Ribosome R signature of gastric tumors is functionally linked to pathways associated with tumorigenesis. Moreover, the Ribosome R undergoes dynamic changes in macrophages following immune challenges. Taken together, with the examination of a broad spectrum of biological samples, the Ribosome R barcode reveals ribosome heterogeneity and specialization in cell function, development, and disease. One-Sentence Summary: Ratio-omics signature of ribosome deciphers functionally relevant heterogeneity in development and disease.

Clinical analysis of tubular stapler-assisted nested anastomosis in the prevention of postoperative esophageal cancer complications.

Background: Esophageal cancer (EC) is one of the most common malignant tumor types. Surgery is considered the treatment of choice for patients with early- and mid-stage EC. However, because of the traumatic nature of EC surgery and the need for gastrointestinal reconstruction, high rates of postoperative complications such as anastomotic leakage or stenosis, esophageal reflux, and pulmonary infection exist. Its time to explore a novel esophagogastric anastomosis method for McKeown EC surgery to reduce the postoperative complication. Methods: This study recruited a total of 544 patients who underwent McKeown resection for EC between January 2017 and August 2020. The tubular stapler-assisted nested anastomosis was taken as the time node, including 212 patients in the traditional tubular mechanical anastomosis group and 332 patients in the tubular stapler-assisted nested anastomosis group. The 6-month postoperative incidence of anastomotic fistula and anastomotic stenosis was recorded. Anastomosis in McKeown operation for EC and the influence of different anastomosis methods on clinical efficacy were investigated. Results: Compared with traditional mechanical anastomosis, tubular stapler-assisted nested anastomosis had a lower incidence of anastomotic fistula (0% vs. 5.2%), lung infection (3.3% vs. 11.8%), gastroesophageal reflux (6.9% vs. 16.0%), anastomotic stenosis (3.0% vs. 10.4%), neck incision infection (0.9% vs. 7.1%), anastomositis (16.6% vs. 23.6%), and a shorter surgical duration (11.02±1.54 vs. 18.53±3.20 min). Statistical significance was indicated at P<0.05. No significant difference was detected in the incidence of arrhythmia, recurrent laryngeal nerve injury, or chylothorax between the 2 groups. Due to its good effect in McKeown surgery for EC, stapler-assisted nested anastomosis has been widely used in McKeown surgery for EC, and has become a common anastomosis method in our department for McKeown surgery for EC. However, large sample-sized studies and long-term efficacy observation are still needed. Conclusions: The use of tubular stapler-assisted nested anastomosis can significantly reduce the incidence of complications such as anastomotic fistula, anastomotic stricture, gastroesophageal reflux, and pulmonary infection; therefore, it constitutes the preferred technique for cervical anastomosis in McKeown esophagogastrectomy.

Prognostic values of the prognostic nutritional index, geriatric nutritional risk index, and systemic inflammatory indexes in patients with stage IIB-III cervical cancer receiving radiotherapy.

Background: Growing evidence suggests that nutritional status and inflammation are associated with survival in various cancers. This study aimed to evaluate the prognostic value of the prognostic nutritional index (PNI), geriatric nutritional risk index (GNRI), and systemic inflammatory indexes (neutrophil/lymphocyte ratio [NLR], monocyte/lymphocyte ratio [MLR], and platelet/lymphocyte ratio [PLR]) in patients with stage IIB-III cervical cancer receiving radiotherapy. Results: The ideal cutoff values for the PNI, GNRI, NLR, MLR, and PLR were 48.3, 97.04, 2.8, 0.41, and 186.67, respectively. Low PNI and GNRI scores were associated with poor OS and PFS. High NLR, MLR, and PLR also predicted inferior 5-year OS and PFS rates in patients with stage IIB-III cervical cancer. Multivariate Cox regression analysis identified tumor size, histological type, stage, number of metastatic lymph nodes, PNI, GNRI, NLR, PLR, and MLR as significant prognostic factors for OS and PFS. Conclusions: The current findings suggest that the PNI, GNRI, NLR, PLR, and MLR are essential parameters for predicting prognosis in patients with stage IIB-III cervical cancer receiving radiotherapy.

Phenobarbital in Nuclear Receptor Activation: An Update.

Phenobarbital (PB) is a commonly prescribed anti-epileptic drug that can also benefit newborns from hyperbilirubinemia. Being the first drug demonstrating hepatic induction of cytochrome P450 (CYP), PB has since been broadly used as a model compound to study xenobiotic-induced drug metabolism and clearance. Mechanistically, PB-mediated CYP induction is linked to a number of nuclear receptors, such as the constitutive androstane receptor (CAR), pregnane X receptor (PXR), and estrogen receptor α, with CAR being the predominant regulator. Unlike prototypical agonistic ligands, PB-mediated activation of CAR does not involve direct binding with the receptor. Instead, dephosphorylation of threonine 38 in the DNA-binding domain of CAR was delineated as a key signaling event underlying PB-mediated indirect activation of CAR. Further studies revealed that such phosphorylation sites appear to be highly conserved among most human nuclear receptors. Interestingly, while PB is a pan-CAR activator in both animals and humans, PB activates human but not mouse PXR. The species-specific role of PB in gene regulation is a key determinant of its implication in xenobiotic metabolism, drug-drug interactions, energy homeostasis, and cell proliferation. In this review, we summarize the recent progress in our understanding of PB-provoked transactivation of nuclear receptors with a focus on CAR and PXR. SIGNIFICANCE STATEMENT: Extensive studies using PB as a research tool have significantly advanced our understanding of the molecular basis underlying nuclear receptor-mediated drug metabolism, drug-drug interactions, energy homeostasis, and cell proliferation. In particular, CAR has been established as a cell signaling-regulated nuclear receptor in addition to ligand-dependent functionality. This mini-review highlights the mechanisms by which PB transactivates CAR and PXR.

An immune infiltration-related long non-coding RNAs signature predicts prognosis for hepatocellular carcinoma.

Background: With a high incidence and dismal survival rate, hepatocellular carcinoma (HCC) tops the list of the world's most frequent malignant tumors. Immunotherapy is a new approach to cancer treatment, and its effect on prolonging overall survival (OS) varies from patient to patient. For a more effective prognosis and treatment of HCC, we are committed to identifying immune infiltration-related long non-coding RNAs (IIRLs) with prognostic value in hepatocellular carcinoma. Methods: In our study, we calculated immune scores of 369 hepatocellular carcinoma samples from the Cancer Genome Atlas (TCGA) database by using an estimation algorithm, and obtained long non-coding RNAs (lncRNAs) associated with immune infiltration by using Weighted Gene Co-expression Network analysis (WGCNA). For training cohort, univariate Cox, least absolute shrinkage and selection operator (Lasso) and multivariate Cox regression analysis were used to determine prognostic IIRLs, we established a prognostic IIRLs signature. By testing cohort and entire cohort, we confirmed that the signature is practical. The prognosis of people with different clinicopathological stages and risk scores were predicted by the nomogram we constructed. In addition, Immune cell infiltration analysis and prediction of therapeutic drugs were performed. Results: 93 IIRLs were obtained by WGCNA. Furthermore, the prognostic value of these IIRLs were evaluated by using univariate Cox, Lasso and multivariate Cox analysis. Four IIRLs were used to create a signature with a prognosis. Time-related receiver operating characteristic (ROC) curve revealed that this model had an acceptable prognostic value for HCC patients. By using univariate and multivariate Cox regression analysis, this risk score has been shown to be an independent prognostic factor for HCC. The nomogram we made showed good predictions. Except for that, the treatment with immune checkpoint inhibitors (ICI) was likely to be more effective for low-risk patients. Conclusion: Based on four IIRLs, a prognostic signature was created in this research showed good accuracy in predicting OS. This study also provided valuable references for Immunotherapy of hepatocellular carcinoma.

Comparison of rectus sheath block and local anesthetic for analgesia in pediatric umbilical hernia repair: A systematic review and meta-analysis.

BACKGROUND: Pediatric umbilical hernia repair could cause considerable postoperative discomfort. This study aimed to compare the analgesia between rectus sheath block and local anesthetic infiltration in child pediatric umbilical hernia repair. METHODS: The relevant randomized controlled trials were searched from PubMed, Embase, Web of Science, EBSCO, and Cochrane library databases from its inception to October 2020. The random-effects model was used for meta-analysis. RESULTS: Four randomized controlled trials were included in the meta-analysis. The 4 studies were published between 2006 and 2017, with sample sizes ranging from 13 to 52 and a total of 143 individuals across the 4 studies. The Jadad scores of the 4 included studies ranged from 4 to 5, and all 4 studies were considered high quality based on quality assessment. There was no difference in analgesic effect at 10 minutes (standardized mean difference [SMD] = -0.19; 95% confidence interval [CI] = -1.52 to 1.16; P = .78), 30 minutes (SMD = -0.37; 95% CI = -1.53 to 0.78; P = .52), 1 hour (SMD = -0.73; 95% CI = -2.00 to 0.53; P = .26) after surgery. Besides, there was no significant difference in postoperative nausea (risk ratio = 0.95; 95% CI = 0.18 to 5.02; P = .95) and postoperative morphine use in morphine equivalents (mean difference = -0.95; 95% CI = -0.06 to 0.01; P = .12). CONCLUSION: Rectus sheath block and local anesthetic are effective methods for analgesia in pediatric umbilical hernia repair.

Lymph node metastasis as the initial symptom of a germ cell tumor in an adult: A case report.

RATIONALE: Germ cell tumors in the head and neck are very rare. In cases of germ cell tumors, it is uncommon for lymph node metastasis to be the only and initial symptom, and this can easily lead to a misdiagnosis. Herein, we report about a 28-year-old woman with lymph node metastasis, in whom a primary tumor appeared in the nasal cavity. PATIENT CONCERNS: A 28-year-old woman presented with enlarged left submandibular lymph nodes. No other mass was found on whole-body screening using positron emission tomography-computed tomography. DIAGNOSIS: After partial submandibular lymphadenectomy was performed, histopathological and immunohistochemical examinations revealed a metastatic germ cell tumor. However, it was difficult to further classify and affirm the origin. INTERVENTIONS: As the patient was receiving four cycles of bleomycin, etoposide, and cisplatin chemotherapy, a primary tumor emerged in the nasal cavity, which was finally confirmed as an immature teratoma of a high World Health Organization histological grade and Norris grade 3. This tumor was found to contain similar components to lymph nodes with respect to histopathological and immunohistochemical characteristics, especially the immature neural tubes or nervous tissue in the nasal cavity. Fortunately, the patient recovered well with no signs of relapse, and the size of residual lymph nodes remained unchanged after she received another four cycles of bleomycin, etoposide, and cisplatin chemotherapy and two cycles of doxorubicin and ifosfamide (AI) chemotherapy. OUTCOMES: Unfortunately, 11 months later, during the coronavirus disease pandemic, the patient died owing to respiratory failure and pulmonary infection. CONCLUSIONS: In cases of malignant tumor in the submandibular lymph nodes of adults, the metastasis of a germ cell tumor should be considered an important differential diagnosis even if a primary tumor does not emerge. In this case, adequate postoperative chemotherapy is necessary.

Sec-O-Glucosylhamaudol Inhibits RANKL-Induced Osteoclastogenesis by Repressing 5-LO and AKT/GSK3ß Signaling.

Sec-O-glucosylhamaudol (SOG), an active flavonoid compound derived from the root of Saposhnikovia divaricata (Turcz. ex Ledeb.) Schischk., exhibits analgesic, anti-inflammatory, and high 5-lipoxygenase (5-LO) inhibitory effects. However, its effect on osteoclastogenesis was unclear. We demonstrated that SOG markedly attenuated RANKL-induced osteoclast formation, F-actin ring formation, and mineral resorption by reducing the induction of key transcription factors NFATc1, c-Fos, and their target genes such as TRAP, CTSK, and DC-STAMP during osteoclastogenesis. Western blotting showed that SOG significantly inhibited the phosphorylation of AKT and GSK3ß at the middle-late stage of osteoclastogenesis without altering calcineurin catalytic subunit protein phosphatase-2ß-Aα expression. Moreover, GSK3ß inhibitor SB415286 partially reversed SOG-induced inhibition of osteoclastogenesis, suggesting that SOG inhibits RANKL-induced osteoclastogenesis by activating GSK3ß, at least in part. 5-LO gene silencing by small interfering RNA in mouse bone marrow macrophages markedly reduced RANKL-induced osteoclastogenesis by inhibiting NFATc1. However, it did not affect the phosphorylation of AKT or GSK3ß, indicating that SOG exerts its inhibitory effects on osteoclastogenesis by suppressing both the independent 5-LO pathway and AKT-mediated GSK3ß inactivation. In support of this, SOG significantly improved bone destruction in a lipopolysaccharide-induced mouse model of bone loss. Taken together, these results suggest a potential therapeutic effect for SOG on osteoclast-related bone lysis disease.

Targeting CAR and Nrf2 improves cyclophosphamide bioactivation while reducing doxorubicin-induced cardiotoxicity in triple-negative breast cancer treatment.

Cyclophosphamide (CPA) and doxorubicin (DOX) are key components of chemotherapy for triple-negative breast cancer (TNBC), although suboptimal outcomes are commonly associated with drug resistance and/or intolerable side effects. Through an approach combining high-throughput screening and chemical modification, we developed CN06 as a dual activator of the constitutive androstane receptor (CAR) and nuclear factor erythroid 2-related factor 2 (Nrf2). CN06 enhances CAR-induced bioactivation of CPA (a prodrug) by provoking hepatic expression of CYP2B6, while repressing DOX-induced cytotoxicity in cardiomyocytes in vitro via stimulating Nrf2-antioxidant signaling. Utilizing a multicellular coculture model incorporating human primary hepatocytes, TNBC cells, and cardiomyocytes, we show that CN06 increased CPA/DOX-mediated TNBC cell death via CAR-dependent CYP2B6 induction and subsequent conversion of CPA to its active metabolite 4-hydroxy-CPA, while protecting against DOX-induced cardiotoxicity by selectively activating Nrf2-antioxidant signaling in cardiomyocytes but not in TNBC cells. Furthermore, CN06 preserves the viability and function of human iPSC-derived cardiomyocytes by modulating antioxidant defenses, decreasing apoptosis, and enhancing the kinetics of contraction and relaxation. Collectively, our findings identify CAR and Nrf2 as potentially novel combined therapeutic targets whereby CN06 holds the potential to improve the efficacy/toxicity ratio of CPA/DOX-containing chemotherapy.

Human constitutive androstane receptor represses liver cancer development and hepatoma cell proliferation by inhibiting erythropoietin signaling.

The constitutive androstane receptor (CAR) is a nuclear receptor that plays a crucial role in regulating xenobiotic metabolism and detoxification, energy homeostasis, and cell proliferation by modulating the transcription of numerous target genes. CAR activation has been established as the mode of action by which phenobarbital-like nongenotoxic carcinogens promote liver tumor formation in rodents. This paradigm, however, appears to be unrelated to the function of human CAR (hCAR) in hepatocellular carcinoma (HCC), which remains poorly understood. Here, we show that hCAR expression is significantly lower in HCC than that in adjacent nontumor tissues and, importantly, reduced hCAR expression is associated with a worse HCC prognosis. We also show overexpression of hCAR in human hepatoma cells (HepG2 and Hep3B) profoundly suppressed cell proliferation, cell cycle progression, soft-agar colony formation, and the growth of xenografts in nude mice. RNA-Seq analysis revealed that the expression of erythropoietin (EPO), a pleiotropic growth factor, was markedly repressed by hCAR in hepatoma cells. Addition of recombinant EPO in HepG2 cells partially rescued hCAR-suppressed cell viability. Mechanistically, we showed that overexpressing hCAR repressed mitogenic EPO-EPO receptor signaling through dephosphorylation of signal transducer and activator of transcription 3, AKT, and extracellular signal-regulated kinase 1/2. Furthermore, we found that hCAR downregulates EPO expression by repressing the expression and activity of hepatocyte nuclear factor 4 alpha, a key transcription factor regulating EPO expression. Collectively, our results suggest that hCAR plays a tumor suppressive role in HCC development, which differs from that of rodent CAR and offers insight into the hCAR-hepatocyte nuclear factor 4 alpha-EPO axis in human liver tumorigenesis.

Oncogenic magnesium transporter 1 upregulates programmed death-1-ligand 1 expression and contributes to growth and radioresistance of glioma cells through the ERK/MAPK signaling pathway.

Radiotherapy has been established as a major therapeutic modality for glioma, whereas new therapeutic targets are needed to prevent tumor recurrence. This study intends to explore the regulatory role of magnesium transporter 1 (MAGT1) in radiotherapy resistance of glioma through modulating ERK and programmed death-1-ligand 1 (PD-L1). Our bioinformatics analysis identified differentially expressed MAGT1 in glioma, expression of which was subsequently determined in cohort data of TCGA database and microarray dataset as well as glioma cell lines. Artificial modulation of MAGT1, ERK, and PD-L1 expression was performed to examine their effects on glioma cell proliferation and radioresistance, as reflected by MTT and colony formation assays under irradiation. Mouse glioma cells with manipulated MAGT1 and ERK inhibitors were further injected into mice to assess the in vivo tumor formation ability of glioma cells. It was noted that MAGT1 expression was highly expressed in glioma tissues of TCGA data and microarray dataset, which was then validated in glioma cell lines. Ectopic expression of MAGT1 was revealed to promote the proliferation and radioresistance of glioma cells, which was attributed to the MAGT1-mediated activation of the ERK/MAPK signaling pathway. It was illuminated that MAGT1 stimulated PD-L1 expression through the ERK/MAPK pathway and thus facilitated glioma cell growth. Additionally, MAGT1 overexpression accelerated the in vivo tumor formation of glioma cells, while the ERK inhibitor negated its effect. In conclusion, MAGT1 enhances the growth and radioresistance of glioma cells through the ERK/MAPK signaling pathway-mediated upregulation of PD-L1 expression.

Clinical Relevance of the Constitutive Androstane Receptor.

Constitutive androstane receptor (CAR) (NR1I3), a xenobiotic receptor, has long been considered a master mediator of drug disposition and detoxification. Accumulating evidence indicates that CAR also participates in various physiologic and pathophysiological pathways regulating the homeostasis of glucose, lipid, and bile acids, and contributing to cell proliferation, tissue regeneration and repair, as well as cancer development. The expression and activity of CAR can be regulated by various factors, including small molecular modulators, CAR interaction with other transcription factors, and naturally occurring genetic variants. Given that the influence of CAR has extended beyond the realm of drug metabolism and disposition and has expanded into a potential modulator of human diseases, growing efforts have centered on understanding its clinical relevance and impact on human pathophysiology. This review highlights the current information available regarding the contribution of CAR to various metabolic disorders and cancers and ponders the possible challenges that might arise from pursuing CAR as a potential therapeutic target for these diseases. SIGNIFICANCE STATEMENT: The growing importance of the constitutive androstane receptor (CAR) in glucose and lipid metabolism as well as its potential implication in cell proliferation emphasizes a need to keenly understand the biological function and clinical impact of CAR. This minireview captures the clinical relevance of CAR by highlighting its role in metabolic disorders and cancer development.

Targeting Squalene Epoxidase Interrupts Homologous Recombination via the ER Stress Response and Promotes Radiotherapy Efficacy.

Over 50% of all patients with cancer are treated with radiotherapy. However, radiotherapy is often insufficient as a monotherapy and requires a nontoxic radiosensitizer. Squalene epoxidase (SQLE) controls cholesterol biosynthesis by converting squalene to 2,3-oxidosqualene. Given that SQLE is frequently overexpressed in human cancer, this study investigated the importance of SQLE in breast cancer and non-small cell lung cancer (NSCLC), two cancers often treated with radiotherapy. SQLE-positive IHC staining was observed in 68% of breast cancer and 56% of NSCLC specimens versus 15% and 25% in normal breast and lung tissue, respectively. Importantly, SQLE expression was an independent predictor of poor prognosis, and pharmacologic inhibition of SQLE enhanced breast and lung cancer cell radiosensitivity. In addition, SQLE inhibition enhanced sensitivity to PARP inhibition. Inhibition of SQLE interrupted homologous recombination by suppressing ataxia-telangiectasia mutated (ATM) activity via the translational upregulation of wild-type p53-induced phosphatase (WIP1), regardless of the p53 status. SQLE inhibition and subsequent squalene accumulation promoted this upregulation by triggering the endoplasmic reticulum (ER) stress response. Collectively, these results identify a novel tumor-specific radiosensitizer by revealing unrecognized cross-talk between squalene metabolites, ER stress, and the DNA damage response. Although SQLE inhibitors have been used as antifungal agents in the clinic, they have not yet been used as antitumor agents. Repurposing existing SQLE-inhibiting drugs may provide new cancer treatments. SIGNIFICANCE: Squalene epoxidase inhibitors are novel tumor-specific radiosensitizers that promote ER stress and suppress homologous recombination, providing a new potential therapeutic approach to enhance radiotherapy efficacy.

H3K27ac-activated EGFR-AS1 promotes cell growth in cervical cancer through ACTN4-mediated WNT pathway.

BACKGROUND: Recently, extensive studies unveiled that lncRNAs exert critical function in the development and progression of cervical cancer (CC). EGFR-AS1 is a novel lncRNA which has not been well-explored in CC. AIMS: Our study aimed to research the function and molecular mechanism of EGFR-AS1 in CC cells. qRT-PCR analysis was performed to detect gene expression. Colony formation, EdU, flow cytometry, TUNEL, western blot and transwell assays were performed to assess the effect of EGFR-AS1 on CC cell growth. The regulatory mechanism of EGFR-AS1 was dug out through mechanism experiments. RESULTS: EGFR-AS1 was notably overexpressed in CC cell lines. Loss-of-functional experiments revealed that EGFR-AS1 promoted CC cell proliferation, migration and invasion, and suppressed cell apoptosis. Mechanistically, up-regulation of EGFR-AS1 was attributed to the activation of H3K27 acetylation (H3K27ac). Further, EGFR-AS1 was revealed to function as miR-2355-5p sponge. Additionally, miR-2355-5p was down-regulated in CC cells and ACTN4 was identified as a target gene of miR-2355-5p. Ultimately, overexpressed ACTN4 could reserve the suppressive role of EGFR-AS1 silencing in CC cell growth. Last but not least, EGFR-AS1 facilitated CC cell growth via ACTN4-mediated WNT pathway. CONCLUSIONS: H3K27ac-activated EGFR-AS1 sponged miR-2355-5p and promoted CC cell growth through ACTN4-mediated WNT pathway.

Hayatine inhibits amino acid-induced mTORC1 activation as a novel mTOR-Rag A/C interaction disruptor.

Abnormal activation of the mechanistic target of rapamycin (mTOR) signaling is commonly observed in many cancers and attracts extensive attention as an oncology drug discovery target, which is encouraged by the success of rapamycin and its analogs (rapalogs) in treatment of mTORC1-hyperactive cancers in both pre-clinic models and clinical trials. However, rapamycin and existing rapalogs have typically short-lasting partial responses due to drug resistance, thereby triggering our interest to investigate a potential mTORC1 inhibitor that is mechanistically different from rapamycin. Here, we report that hayatine, a derivative from Cissampelos, can serve as a potential mTORC1 inhibitor selected from a natural compound library. The unique properties owned by hayatine such as downregulation of mTORC1 activities, induction of mTORC1's translocation to lysosomes followed by autophagy, and suppression on cancer cell growth, strongly emphasize its role as a potential mTORC1 inhibitor. Mechanistically, we found that hayatine disrupts the interaction between mTORC1 complex and its lysosomal adaptor RagA/C by binding to the hydrophobic loop of RagC, leading to mTORC1 inhibition that holds great promise to overcome rapamycin resistance. Taken together, our data shed light on an innovative strategy using structural interruption-based mTORC1 inhibitors for cancer treatment.