Chalcomoracin inhibits cell proliferation and increases sensitivity to radiotherapy in human non-small cell lung cancer cells via inducing endoplasmic reticulum stress-mediated paraptosis

Chalcomoracin promotes apoptosis and endoplasmic reticulum stress in hepatocellular carcinoma cells

Chalcomoracin (CMR), a Diels-Alder adduct obtained from mulberry leaves, demonstrated wide-spectrum anti-cancer activity. Herein, we aimed to explore the function of CMR and how it works in hepatocellular carcinoma (HCC). Human HCC cell lines Hep3B and SNU-387 were cultured and treated with various concentrations of CMR (1.5, 3, and 6 µM). Subsequently, the effects of CMR on cell viability, colony formation, apoptosis, migration, and invasion abilities were studied in vitro. Furthermore, the levels of endoplasmic reticulum (ER) stress-related proteins and mitogen-activated protein kinase (MAPK) pathway-related proteins in cells under CMR exposure were detected using western blot. Experiments in vivo were conducted to examine the effects of CMR on tumor growth in HCC. CMR administration inhibited the viability and clonogenic, migration, and invasion abilities, as well as promoted cell apoptosis and ER stress in Hep3B and SNU-387 cells. In addition, CMR treatment reduced the phosphorylation levels of ERK, P38, and JNK in the MAPK pathway. Moreover, an in vivo study showed that CMR administration could inhibit tumorigenesis and MAPK pathway activity in HCC. Our data indicate that CMR has the potential to inhibit the development of HCC, potentially through the inhibition of the MAPK pathway. These findings suggest that CMR may have promising applications as an anticancer agent in future therapeutics for HCC.

A Dual-Channel Ca2+ Nanomodulator Induces Intracellular Ca2+ Disorders via Endogenous Ca2+ Redistribution for Tumor Radiosensitization

Tumor cells harness Ca2+ to maintain cellular homeostasis and withstand external stresses from various treatments. Here, a dual-channel Ca2+ nanomodulator (CAP-P-NO) is constructed that can induce irreversible intracellular Ca2+ disorders via the redistribution of tumor-inherent Ca2+ for disrupting cellular homeostasis and thus improving tumor radiosensitivity. Stimulated by tumor-overexpressed acid and glutathione, capsaicin and nitric oxide are successively escaped from CAP-P-NO to activate the transient receptor potential cation channel subfamily V member 1 and the ryanodine receptor for the influx of extracellular Ca2+ and the release of Ca2+ in the endoplasmic reticulum, respectively. The overwhelming level of Ca2+ in tumor cells not only impairs the function of organelles but also induces widespread changes in the gene transcriptome, including the downregulation of a set of radioresistance-associated genes. Combining CAP-P-NO treatment with radiotherapy achieves a significant suppression against both pancreatic and patient-derived hepatic tumors with negligible side effects. Together, the study provides a feasible approach for inducing tumor-specific intracellular Ca2+ overload via endogenous Ca2+ redistribution and demonstrates the great potential of Ca2+ disorder therapy in enhancing the sensitivity for tumor radiotherapy.

Secondary metabolites of mulberry leaves exert anti-lung cancer activity through regulating the PD-L1/PD-1 signaling pathway

Lung cancer ranks the top of malignancies that cause cancer-related deaths worldwide. The leaves of Morus alba L are traditional Chinese medicine widely applied in respiratory diseases. Our previous work has demonstrated the anti-lung cancer effect of secondary metabolites of mulberry leaf, but their mechanism of action has still not fully elucidated. We synthesized Moracin N (MAN)-Probe conjugated with alkyne to label lung cancer cells and identified protein targets by chemical proteomic analysis. MAN and its probe exerted similar growth-inhibitory effect on human lung cancer cells. Chemical proteomic results showed that MAN targeted the programmed death ligand 1 (PD-L1) checkpoint pathway and T cell receptor (TCR) signaling pathway, indicating its immune-regulatory function. Cell-free surface plasmon resonance (SPR) results showed the direct interaction of MAN with PD-L1 protein. Molecular docking analysis demonstrated that MAN bound to E158 residue of PD-L1 protein. MAN downregulated the expression levels of PD-L1 in a time- and dose-dependent manner and disrupted the PD-L1/programmed death 1 (PD-1) binding, including other secondary metabolites of mulberry leaves Guangsangon E (GSE) and Chalcomoracin (CMR). Human peripheral blood mononuclear cells (PBMCs) co-cultured with MAN-treated A549 cells, resulting in the increase of CD8+ GZMB+ T cells and the decrease of CD8+ PD-1+ T cells. It suggested that MAN exerts anti-cancer effect through blocking the PD-L1/PD-1 signaling. In vivo, MAN combined with anti-PD-1 antibody significantly inhibited lung cancer development and metastasis, indicating their synergistic effect. Taken together, secondary metabolites of mulberry leaves target the PD-L1/PD-1 signaling, enhance T cell-mediated immunity and inhibit the tumorigenesis of lung cancer. Their modulatory effect on tumor microenvironment makes them able to enhance the therapeutic efficacy of immune checkpoint inhibitors in lung cancer.

Identification of PANoptosis-related signature reveals immune infiltration characteristics and immunotherapy responses for renal cell carcinoma

PANoptosis is a specific type of inflammatory programmed cell death (PCD) modality that can be involved in three key modes of cellular programmed cell death-pyroptosis, apoptosis and necroptosis. We analyzed PANoptosis activity in three common renal cell carcinoma subtypes (Clear cell renal cell carcinoma, Papillary renal cell carcinoma, and Chromophobe renal cell carcinoma) separately and constructed a new PANoptosis immunity index (PANII). In three renal cell carcinomas, we found that PANII was an effective predictor of immunotherapy efficacy in KIRC, KIRP and KICH, and the high PANII group was characterized by high immune infiltration and sensitivity to immunotherapy, while the low PANII group was prone to immune escape and immunotherapy resistance. We performed molecular docking prediction of each core protein comprising PANII and identified natural small molecule compounds with the highest affinity to target proteins. In addition, we found that down-regulation of PYCARD inhibited the proliferation and migration of renal clear cell carcinoma cells by in vitro functional assays, suggesting that PYCARD could be a novel target for renal clear cell carcinoma therapy. Our findings that the PANoptosis characterization-based index (PANII) helps to elucidate the tumor microenvironmental features of three common renal cell carcinoma subtypes and identify patient populations that will benefit from immunotherapy, providing a new tool for the clinical diagnosis and treatment of patients with intermediate- and advanced-stage renal cell carcinoma.

Targeting paraptosis in cancer: opportunities and challenges

Cell death can be classified into two primary categories: accidental cell death and regulated cell death (RCD). Within RCD, there are distinct apoptotic and non-apoptotic cell death pathways. Among the various forms of non-apoptotic RCD, paraptosis stands out as a unique mechanism characterized by distinct morphological changes within cells. These alterations encompass cytoplasmic vacuolization, organelle swelling, notably in the endoplasmic reticulum and mitochondria, and the absence of typical apoptotic features, such as cell shrinkage and DNA fragmentation. Biochemically, paraptosis distinguishes itself by its independence from caspases, which are conventionally associated with apoptotic death. This intriguing cell death pathway can be initiated by various cellular stressors, including oxidative stress, protein misfolding, and specific chemical compounds. Dysregulated paraptosis plays a pivotal role in several critical cancer-related processes, such as autophagic degradation, drug resistance, and angiogenesis. This review provides a comprehensive overview of recent advancements in our understanding of the mechanisms and regulation of paraptosis. Additionally, it delves into the potential of paraptosis-related compounds for targeted cancer treatment, with the aim of enhancing treatment efficacy while minimizing harm to healthy cells.

Paraptosis: a non-classical paradigm of cell death for cancer therapy

Due to the sustained proliferative potential of cancer cells, inducing cell death is a potential strategy for cancer therapy. Paraptosis is a mode of cell death characterized by endoplasmic reticulum (ER) and/or mitochondrial swelling and cytoplasmic vacuolization, which is less investigated. Considerable evidence shows that paraptosis can be triggered by various chemical compounds, particularly in cancer cells, thus highlighting the potential application of this non-classical mode of cell death in cancer therapy. Despite these findings, there remain significant gaps in our understanding of the role of paraptosis in cancer. In this review, we summarize the current knowledge on chemical compound-induced paraptosis. The ER and mitochondria are the two major responding organelles in chemical compound-induced paraptosis, which can be triggered by the reduction of protein degradation, disruption of sulfhydryl homeostasis, overload of mitochondrial Ca2+, and increased generation of reactive oxygen species. We also discuss the stumbling blocks to the development of this field and the direction for further research. The rational use of paraptosis might help us develop a new paradigm for cancer therapy.

Zearalenone Induces Blood-Testis Barrier Damage through Endoplasmic Reticulum Stress-Mediated Paraptosis of Sertoli Cells in Goats

Zearalenone (ZEA) is present worldwide as a serious contaminant of food and feed and causes male reproductive toxicity. The implication of paraptosis, which is a nonclassical paradigm of cell death, is unclear in ZEA-induced male reproductive disorders. In this study, the toxic effects of ZEA on the blood-testis barrier (BTB) and the related mechanisms of paraptosis were detected in goats. ZEA exposure, in vivo, caused a significant decrease in spermatozoon quality, the destruction of seminiferous tubules, and damage to the BTB integrity. Furthermore, ZEA exposure to Sertoli cells (SCs) in vitro showed similar dysfunction in structure and barrier function. Importantly, the formation of massive cytoplasmic vacuoles in ZEA-treated SCs corresponded to the highly swollen and dilative endoplasmic reticulum (ER), and paraptosis inhibition significantly alleviated ZEA-induced SC death and vacuolization, which indicated the important contribution of paraptosis in ZEA-induced BTB damage. Meanwhile, the expression of ER stress marker proteins was increased after ZEA treatment but decreased under the inhibition of paraptosis. The vacuole formation and SC death, induced by ZEA, were remarkably blocked by ER stress inhibition. In conclusion, these results facilitate the exploration of the mechanisms of the SC paraptosis involved in ZEA-induced BTB damage in goats.

Recent advances in natural compounds inducing non-apoptotic cell death for anticancer drug resistance

The induction of cell death is recognized as a potent strategy for cancer treatment. Apoptosis is an extensively studied form of cell death, and multiple anticancer drugs exert their therapeutic effects by inducing it. Nonetheless, apoptosis evasion is a hallmark of cancer, rendering cancer cells resistant to chemotherapy drugs. Consequently, there is a growing interest in exploring novel non-apoptotic forms of cell death, such as ferroptosis, necroptosis, pyroptosis, and paraptosis. Natural compounds with anticancer properties have garnered significant attention due to their advantages, including a reduced risk of drug resistance. Over the past two decades, numerous natural compounds have been discovered to exert anticancer and anti-resistance effects by triggering these four non-apoptotic cell death mechanisms. This review primarily focuses on these four non-apoptotic cell death mechanisms and their recent advancements in overcoming drug resistance in cancer treatment. Meanwhile, it highlights the role of natural compounds in effectively addressing cancer drug resistance through the induction of these forms of non-apoptotic cell death.

Phytoconstituent Profiles Associated with Relevant Antioxidant Potential and Variable Nutritive Effects of the Olive, Sweet Almond, and Black Mulberry Gemmotherapy Extracts

The extracts of whole plants or specific organs from different plant species are gaining increasing attention for their phytotherapy applications. Accordingly, we prepared standardized gemmotherapy extracts (GTEs) from young shoots/buds of olive (Olea europaea), sweet almond (Prunus amygdalus), and black mulberry (Morus nigra), and analyzed the corresponding phytonutrient profiles. We identified 42, 103, and 109 phytonutrients in the olive, almond, and black mulberry GTEs, respectively, containing amino acids, vitamins, polyphenols, flavonoids, coumarins, alkaloids, iridoids, carboxylic acids, lignans, terpenoids, and others. In order to assess the physiological effects generated by the GTEs, we developed a translational nutrition model based on Drosophila melanogaster and Cyprinus carpio. The results indicate that GTEs could influence, to a variable extent, viability and ATP synthesis, even though both are dependent on the specific carbohydrate load of the applied diet and the amino acid and polyphenol pools provided by the GTEs. It seems, therefore, likely that the complex chemical composition of the GTEs offers nutritional properties that cannot be separated from the health-promoting mechanisms that ultimately increase viability and survival. Such an approach sets the paves the way for the nutritional genomic descriptions regarding GTE-associated health-promoting effects.

Morusinol extracted from Morus alba induces cell cycle arrest and apoptosis via inhibition of DNA damage response in melanoma by CHK1 degradation through the ubiquitin-proteasome pathway

BACKGROUD

Flavonoids have a variety of biological activities, such as anti-inflammation, anti-tumor, anti-thrombosis and so on. Morusinol, as a novel isoprene flavonoid extracted from Morus alba root barks, has the effects of anti-arterial thrombosis and anti-inflammatory in previous studies. However, the anti-cancer mechanism of morusinol remains unclear.

PURPOSE

In present study, we mainly studied the anti-tumor effect of morusinol and its mode of action in melanoma.

METHODS

The anti-cancer effect of morusinol on melanoma were evaluated by using the MTT, EdU, plate clone formation and soft agar assay. Flow cytometry was used for detecting cell cycle and apoptosis. The ɣ-H2AX immunofluorescence and the alkaline comet assay were used to detect DNA damage and the Western blotting analysis was used to investigate the expressions of DNA-damage related proteins. Ubiquitination and turnover of CHK1 were also detected by using the immunoprecipitation assay. The cell line-derived xenograft (CDX) mouse models were used in vivo to evaluate the effect of morusinol on tumorigenicity.

RESULTS

We demonstrated that morusinol not only had the ability to inhibit cell proliferation, but also induced cell cycle arrest at G0/G1 phase, caspase-dependent apoptosis and DNA damage in human melanoma cells. In addition, morusinol effectively inhibited the growth of melanoma xenografts in vivo. More strikingly, CHK1, which played an important role in maintaining the integrity of cell cycle, genomic stability and cell viability, was down-regulated in a dose- and time-dependent manner after morusinol treatment. Further research showed that CHK1 was degraded by the ubiquitin-proteasome pathway. Whereafter, morusinol-induced cell cycle arrest, apoptosis and DNA damage were partially salvaged by overexpressing CHK1 in melanoma cell lines. Herein, further experiments demonstrated that morusinol increased the sensitivity of dacarbazine (DTIC) to chemotherapy for melanoma in vitro and in vivo.

CONCLUSION

Morusinol induces CHK1 degradation through the ubiquitin-proteasome pathway, thereby inducing cell cycle arrest, apoptosis and DNA damage response in melanoma. Our study firstly provided a theoretical basis for morusinol to be a candidate drug for clinical treatment of cancer, such as melanoma, alone or combinated with dacarbazine.

Identification of endoplasmic reticulum stress-related lncRNAs in lung adenocarcinoma by bioinformatics and experimental validation

BACKGROUND

Endoplasmic reticulum stress (ERs) is an important cellular self-defence mechanism, which is closely related to tumorigenesis and development. However, the role of endoplasmic reticulum stress state in the development of lung adenocarcinoma (LUAD) has not been clarified.

METHODS

The lncRNAs associated with endoplasmic reticulum stress were identified by co-expression analysis in public databases, and by the least absolute shrinkage and selection operator (LASSO) regression and multivariate Cox regression modelling, we constructed a prognostic model based on endoplasmic reticulum stress-related lncRNAs (ERs-related lncRNAs), performed immune analysis, TME, TMB and clinical drug prediction for model-related risk scores, and performed correlation validation in public databases and at the human tissue level.

RESULTS

Five ERs-related lncRNAs were used to construct an ERs-related lncRNA signature (ERs-related LncSig), which can predict the prognosis of LUAD. Patients in the high-risk group had worse survival, and differences existed in immune cell infiltration, immune function, immune checkpoint analysis, tumour microenvironment (TME), tumour mutational burden (TMB), immunotherapy efficacy, and sensitivity to some commonly used chemotherapeutic agents between high and low risk groups.

CONCLUSION

Our study demonstrated that ERs-related lncRNA signature can be used for the prognostic evaluation of LUAD patients and may provide new insights into clinical decision-making and personalised medicine for LUAD.

Traditional Chinese medicine suppressed cancer progression by targeting endoplasmic reticulum stress responses: A review

Cancer has a high morbidity and mortality; therefore, it poses a major global health concern. Imbalance in endoplasmic reticulum homeostasis can induce endoplasmic reticulum stress (ERS). ERS has been shown to play both tumor-promoting and tumor-suppressive roles in various cancer types by activating a series of adaptive responses to promote tumor cell survival and inducing ERS-related apoptotic pathways to promote tumor cell death, inhibit tumor growth and suppress tumor invasion. Because multiple roles of ERS in tumors continue to be reported, many studies have attempted to target ERS in cancer therapy. The therapeutic effects of traditional Chinese medicine (TCM) treatments on tumors have been widely recognized. TCM treatments can enhance the sensitivity of tumor radiotherapy, delay tumor recurrence and improve patients' quality of life. However, there are relatively few reports exploring the antitumor effects of TCM from the perspective of ERS. This review addresses the progress of TCM intervention in tumors via ERS with a view to providing a new direction for tumor treatment.

Guangsangon E triggers mitochondria dysfunction and mitophagy in triple-negative breast cancer and leads to non-apoptotic cell death

Guangsangon E (GSE) is a natural product separated from Morus alba L. It has been reported to treat lung cancer through autophagy. However, whether GSE is effective in repressing triple-negative breast cancer (TNBC) cells is yet to be elucidated. In the present study, GSE inhibited cell growth of MDA-MB-231, MDA-MB-453, and MDA-MB-468 cells. Moreover, GSE induced mitochondrial dysfunction, including membrane potential loss, mitochondria fission, and reactive oxygen species accumulation, and finally led to mitophagy-related non-apoptotic cell death. In the xenograft tumor nude mice, GSE treatment significantly reduced the size and weight of MDA-MB-231 tumors. The tumor inhibition rates of GSE treatment were 49.68% (low-dose) and 48.73% (high-dose). In summary, GSE is a potential anticancer drug available for treating TNBC with apoptosis resistance.

Isolation of Chalcomoracin as a Potential α-Glycosidase Inhibitor from Mulberry Leaves and Its Binding Mechanism

Diabetes is a chronic metabolic disease, whereas α-glucosidases are key enzymes involved in the metabolism of starch and glycogen. There is a long history of the use of mulberry leaf (the leaf of Morus alba) as an antidiabetic herb in China, and we found that chalcomoracin, one of the specific Diels–Alder adducts in mulberry leaf, had prominent α-glucosidase inhibitory activity and has the potential to be a substitute for current hypoglycemic drugs such as acarbose, which have severe gastrointestinal side effects. In this study, chalcomoracin was effectively isolated from mulberry leaves, and its α-glucosidase inhibition was studied via enzymatic kinetics, isothermal titration (ITC) and molecular docking. The results showed that chalcomoracin inhibited α-glucosidase through both competitive and non-competitive manners, and its inhibitory activity was stronger than that of 1-doxymycin (1-DNJ) but slightly weaker than that of acarbose. ITC analysis revealed that the combination of chalcomoracin and α-glucosidase was an entropy-driven spontaneous reaction, and the molecular docking results also verified this conclusion. During the binding process, chalcomoracin went into the “pocket” of α-glucosidase via hydrophobic interactions, and it is linked with residues Val544, Asp95, Ala93, Gly119, Arg275 and Pro287 by hydrogen bonds. This study provided a potential compound for the prevention and treatment of diabetes and a theoretical basis for the discovery of novel candidates for α-glycosidase inhibitors.

Mulberry Diels-Alder-type adducts: isolation, structure, bioactivity, and synthesis

Mulberry Diels-Alder-type adducts (MDAAs) are unique phenolic natural products biosynthetically derived from the intermolecular [4 + 2]-cycloaddition of dienophiles (mainly chalcones) and dehydroprenylphenol dienes, which are exclusively distributed in moraceous plants. A total of 166 MDAAs with diverse skeletons have been isolated and identified since 1980. Structurally, the classic MDAAs characterized by the chalcone-skeleton dienophiles can be divided into eight groups (Types A - H), while others with non-chalcone dienophiles or some variations of classic MDAAs are non-classic MDAAs (Type I). These compounds have attracted significant attention of natural products and synthetic chemists due to their complex architectures, remarkable biological activities, and synthetic challenges. The present review provides a comprehensive summary of the structural properties, bioactivities, and syntheses of MDAAs. Cited references were collected between 1980 and 2021 from the SciFinder, Web of Science, and China National Knowledge Internet (CNKI).

Nanosilver inhibits the progression of pancreatic cancer by inducing a paraptosis-like mixed type of cell death

Silver has been in clinical use since ancient times and silver nanoparticles (AgNPs) have attracted attention in cancer therapy. We investigated the mechanisms by which AgNPs inhibit pancreatic ductal adenocarcinoma (PDAC). AgNPs were synthesized and 3 human PDAC and 2 nonmalignant primary cell lines were treated with AgNPs. MTT, MAPK, colony, spheroid and scratch assays, Western blotting, TEM, annexin V, 7-AAD, and H2DCFDA staining, FACS analysis, mRNA array and bioinformatics analyses, tumor xenograft transplantation, and immunohistochemistry of the treated cells were performed. We found that minimal AgNPs amounts selectively eradicated PDAC cells within a few hours. AgNPs inhibited cell migration and spheroid and colony formation, damaged mitochondria, and induced paraptosis-like cell death with the presence of cytoplasmic vacuoles, dilation of the ER and mitochondria, ROS formation, MAPK activity, and p62 and LC3b expression, whereas effects on the nucleus, DNA fragmentation, or caspases were not detectable. AgNPs strongly decreased tumor xenograft growth without side effects and reduced the expression of markers for proliferation and DNA repair, but upregulated paraptosis markers. The results highlight nanosilver as complementary agent to improve the therapeutic efficacy in pancreatic cancer.

Clinical and Preclinical Outcomes of Combining Targeted Therapy With Radiotherapy

In the era of precision medicine, radiation medicine is currently focused on the precise delivery of highly conformal radiation treatments. However, the tremendous developments in targeted therapy are yet to fulfill their full promise and arguably have the potential to dramatically enhance the radiation therapeutic ratio. The increased ability to molecularly profile tumors both at diagnosis and at relapse and the co-incident progress in the field of radiogenomics could potentially pave the way for a more personalized approach to radiation treatment in contrast to the current ‘‘one size fits all’’ paradigm. Few clinical trials to date have shown an improved clinical outcome when combining targeted agents with radiation therapy, however, most have failed to show benefit, which is arguably due to limited preclinical data. Several key molecular pathways could theoretically enhance therapeutic effect of radiation when rationally targeted either by directly enhancing tumor cell kill or indirectly through the abscopal effect of radiation when combined with novel immunotherapies. The timing of combining molecular targeted therapy with radiation is also important to determine and could greatly affect the outcome depending on which pathway is being inhibited.

Swainsonine Triggers Paraptosis via ER Stress and MAPK Signaling Pathway in Rat Primary Renal Tubular Epithelial Cells

Swainsonine (SW), an indolizidine alkaloid extracted from locoweeds, was shown toxic effects in multiple studies, but the underlying action mechanism remains unclear. SW is known to cause autophagy and apoptosis, but there has been no report on paraptosis mediated cell death. Here, we showed that SW induced rat primary renal tubular epithelial cells (RTECs) death accompanied by vacuolation in vitro. The fluorescence with the endoplasmic reticulum (ER)-Tracker Red and transmission electron microscopy (TEM) results indicated that the vacuoles were of ER origin, typical of paraptosis. The level of ER stress markers, such as polyubiquitinated proteins, Bip, CHOP and cytoplasmic concentration of Ca²⁺ have drastically increased. Interestingly, autophagy inhibitor could not interrupt but enhanced the induction of cytoplasmic vacuolization. Furthermore, MAPK pathways were activated by SW and inhibitors of ERK and JNK pathways could prevent the formation of cytoplasmic vacuolization. In this study, we confirmed that SW induced cell paraptosis through ER stress and MAPK signaling pathway, thus further laying a theoretical foundation for the study of SW toxicity mechanism.

Potential use of the Diels-Alder reaction in biomedical and nanomedicine applications

The Diels-Alder reaction and its retro breakdown has garnered increasing research focus due to several of its advantageous properties including, atomic conservation, reversibility, and substituent retention. This is especially true in biomedical application and nanomedicine development which display a preference for rapid, efficient, and clean "click" chemistry reactions allowing for delivery of active ingredients and subsequent release upon temperature elevation. There are multiple variations on the Diels-Alder reaction based around substitution position and materials being coupled which can affect the temperature threshold for and rate of the retro reaction reversal. Hence, the Diels-Alder reaction offers a simple coupling reaction for active ingredients with tailorable release. In this review the incorporation of the Diels-Alder chemistries and linkers within the biomedical and nanomedicine field will be discussed, as well as its use in future potential technologies.

Long non-coding RNA CASC2 enhances irradiation-induced endoplasmic reticulum stress in NSCLC cells through PERK signaling

Radiotherapy is instrumental in the treatment of inoperable non-small cell lung cancer (NSCLC). Studies have revealed that radiotherapy induces endoplasmic reticulum (ER) stress, which consequently induces apoptosis and sensitization of cancer cells. A recent study has revealed that long non-coding RNA (lncRNA) CASC2 is negatively correlated with the malignancy of NSCLC cells. The present study investigated the effects and molecular mechanisms of CASC2 on radiosensitivity and ER stress in NSCLC cells. The overexpression of CASC2 markedly decreased cell survival and increased apoptosis, expression of PERK, phosphorylated-eIF2α and CHOP in irradiated human NSCLC cells, whereas knocking down PERK reversed these effects. Moreover, CASC2 considerably promoted the stability of PERK mRNA, but had no effect on the activity of PERK gene promoter in irradiated NSCLC cells. Strikingly, CASC2 exhibited no apparent effect on non-irradiated NSCLC cells. This study demonstrated that lncRNA CASC2 increases the stability of PERK mRNA, which consequently triggers the PERK/eIF2α/CHOP ER stress pathway and promotes radiosensitivity or apoptosis in irradiated NSCLC cells. Results of the present study suggest that CASC2 can act as an effective therapeutic target to enhance the efficacy of radiotherapy in the treatment of NSCLC.

Ethanol extract of Liriodendron chinense (Hemsl.) Sarg barks attenuates hyperuricemic nephropathy by inhibiting renal fibrosis and inflammation in mice

ETHNOPHARMACOLOGICAL RELEVANCE

Liriodendron chinense (Hemsl.) Sarg, known as the Chinese tulip tree, has a long history of cultivation and utilization in many Asia countries, especially in China to use in traditional Chinese medicine for expelling "wind and dampness", a term corresponding to rheumatic fever and rheumatoid arthritis. Interestingly, the barks of Liriodendron chinense (Hemsl.) Sarg was also found in folk to treat gout. However, further experimental studies remained to confirm its uric acid-lowering effects.

AIM OF THE STUDY

The aim of the study was to evaluate the protective effect of ethanol extract of the barks of Liriodendron chinense (Hemsl.) Sarg (EELC) in a mouse model of hyperuricemic nephropathy (HN) and the involved mechanisms.

MATERIALS AND METHODS

EELC at a respective dose of 250 mg/kg/d or 500 mg/kg/d were orally administered to HN mice induced by a mixture of adenine (160 mg/kg/d)/potassium oxonate (2.4 g/kg/d) for 21 days. At the end of the treatment, serum uric acid, kidney functions (serum creatinine, blood urea nitrogen and urine microalbumin), 24-h urine uric acid excretion, as well as kidney pathological changes were investigated by biochemical assay, histopathological score, immunofluorescence and histochemistry, RT-qPCR, and western blotting analysis.

RESULTS AND DISCUSSION

Oral administration of EELC significantly lowered serum uric acid level at 500 mg/kg (185.75 ± 15.49 μmol/L of EELC vs. 238.28 ± 20.97 μmol/L of HN model, p < 0.01) in HN mice. EELC at 500 mg/kg also remarkably reduced the levels of serum creatinine (82.92 ± 7.86 μmol/L of EELC vs. 92.08 ± 6.13 μmol/L of HN model, p < 0.0001), blood urea nitrogen (21.50 ± 1.87 mmol/L of EELC vs. 29.40 ± 3.95 mmol/L of HN model, p < 0.001) and urine microalbumin (4.25 ± 0.40 mg/L of EELC vs. 5.95 ± 0.33 mg/L of HN model, p < 0.001) to improve renal function. It also attenuated renal fibrosis, especially the high-dose of EELC. Furthermore, EELC could inhibit the activation of NF-κB, ASK1/JNK/c-Jun, JAK2/STAT3 signaling pathways and reduce the release of pro-inflammatory cytokine TNF-α in the kidneys of HN mice. Additionally, EELC remarkably increased urine uric acid excretion of HN mice, which may be achieved by the upregulation of organic anion transporter 1 (OAT1), OAT3 and ATP-binding cassette subfamily G member 2 (ABCG2) proteins.

CONCLUSIONS

EELC alleviated the progression of HN by suppressing the activation of NF-κB, ASK1/JNK/c-Jun and JAK2/STAT3 signaling pathway, reducing the infiltration of inflammatory factors and uric acid accumulation in the kidney.

Organelle-localized radiosensitizers

This feature article highlights the recent advances of organelle-localized radiosensitizers and discusses the current challenges and future directions.