Establishment of a homogeneous chemiluminescence immunoassay for cat dander sIgE antibody detection.

BACKGROUND: In vitro specific IgE (sIgE) testing has become an important tool for the diagnosis of IgE-mediated allergic diseases. Current methods used to detect allergen sIgE are time consuming and/or expensive. Therefore, a new method was developed for rapid quantitative detection of cat dander-sIgE antibody based on homogeneous chemiluminescence immunoassay. METHODS: Selection of chemibeads with different chemical groups, and the best Light-initiated chemiluminescence assay (LiCA) analytical mode for cat dander-sIgE detection. To validate and eliminate the interference of IgE on the detection of cat dander-sIgE, concentration of biotinylated anti-human IgE antibody was optimized. For quantification of cat dander-sIgE, a calibration curve was established, and the performance of the assay was evaluated according to clinical guidelines. RESULTS: Indirect LiCA is the best mode of analysis and biotinylated anti-human IgE antibody at a dilution ratio of 1:250 minimizes IgE interference. The coefficient of variation of the developed LiCA was 1.49% to 4.66%, with an intermediate precision of 6.90% to 8.21%. The LoB, LoD, and LoQ of the assay were 0.023 kUA/L, 0.056 kUA/L and 0.185 kUA/L. The coefficient of correlation (r) between LiCA and ImmounoCAP was 0.9478. CONCLUSIONS: A cat dander-sIgE quantitation assay based on homogeneous chemiluminescence immunoassay was established, which could be a new reliable analytical tool for the determination of cat dander-sIgE.

Ulinastatin inhibits the metastasis of nasopharyngeal carcinoma by involving uPA/uPAR signaling.

Distant metastasis is the primary reason for treatment failure in patients with nasopharyngeal carcinoma (NPC). In this study, we investigated the effect of ulinastatin (UTI) on NPC metastasis and its underlying mechanism. Highly-metastatic NPC cell lines S18 and 58F were treated with UTI and the effect on cell proliferation, migration, and invasion were determined by MTS and Transwell assays. S18 cells with luciferase-expressing (S18-1C3) were injected into the left hind footpad of nude mice to establish a model of spontaneous metastasis from the footpad to popliteal lymph node (LN). The luciferase messenger RNA (mRNA) was measured by quantitative polymerase chain reaction (qPCR), and the metastasis inhibition rate was calculated. Key molecular members of the UTI-related uPA, uPAR, and JAT/STAT3 signaling pathways were detected by qPCR and immunoblotting. UTI suppressed the migration and infiltration of S18 and 5-8F cells and suppressed the metastasis of S18 cells in vivo without affecting cell proliferation. uPAR expression decreased from 24 to 48 h after UTI treatment. The antimetastatic effect of UTI is partly due to the suppression of uPA and uPAR. UTI partially suppresses NPC metastasis by downregulating the expression of uPA and uPAR.

Potential inhibitors for blocking the interaction of the coronavirus SARS-CoV-2 spike protein and its host cell receptor ACE2.

BACKGROUND: The outbreak of SARS-CoV-2 continues to pose a serious threat to human health and social. The ongoing pandemic of COVID-19 caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has made a serious threat to public health and economic stability worldwide. Given the urgency of the situation, researchers are attempting to repurpose existing drugs for treating COVID-19. METHODS: We first established an anti-coronavirus drug screening platform based on the Homogeneous Time Resolved Fluorescence (HTRF) technology and the interaction between the coronavirus spike protein and its host receptor ACE2. Two compound libraries of 2,864 molecules were screened with this platform. Selected candidate compounds were validated by SARS-CoV-2_S pseudotyped lentivirus and ACE2-overexpressing cell system. Molecular docking was used to analyze the interaction between S protein and compounds. RESULTS: We identified three potential anti-coronavirus compounds: tannic acid (TA), TS-1276 (anthraquinone), and TS-984 (9-Methoxycanthin-6-one). Our in vitro validation experiments indicated that TS-984 strongly inhibits the interaction of the coronavirus S protein and the human cell ACE2 receptor. Additionally, tannic acid showed moderate inhibitory effect on the interaction of S protein and ACE2. CONCLUSION: This platform is a rapid, sensitive, specific, and high throughput system, and available for screening large compound libraries. TS-984 is a potent blocker of the interaction between the S-protein and ACE2, which might have the potential to be developed into an effective anti-coronavirus drug.

A Simple and Rapid Light-Initiated Chemiluminescence Assay for Quantitation of Artemisia-Specific Immunoglobulin E.

BACKGROUND: Light-initiated chemiluminescence assay (LICA) is a homogeneous assay that has been successfully used for the quantitation of food allergen-specific immunoglobulin E (sIgE), but not inhaled allergen-sIgE. Simultaneously, current assays used to detect allergen-sIgE are serum consuming and/or time consuming. Hence, we established a method for the quantitation of Artemisia-sIgE based on LICA and verified its performance according to the clinical guideline documents, laying a foundation for the quantitation of inhaled and food allergen-sIgE in parallel on LICA. METHODS: The assay was established after optimizing the first incubation time and the dilutions of Artemisia-coated chemibeads, biotinylated goat anti-human IgE, and serum. In order to quantitate Artemisia-sIgE, the calibration curve was established with a high positive serum of known concentration. The assay performance was confirmed per the clinical guideline documents. In addition, the correlation between the results of LICA and capture enzyme-linked immunosorbent assay was evaluated. RESULTS: The developed LICA's coefficients of variation of repeatability and intermediate precision were 3.20%, 2.14%, and 3.85% and 4.30%, 4.00%, and 4.40%, respectively. The limit of detection was 0.10 kUA/L, and the limit of quantitation was 0.11 kUA/L. The range of linearity was from 0.27 kUA/L to 97.53 kUA/L (r = 0.9968). The correlation coefficient (r) for the correlation analysis between results of LICA and capture ELISA was 0.9087. This assay was successfully applied in 64 human serum samples, showing good sensitivity (82.20%) and specificity (100%). CONCLUSION: An Artemisia-sIgE quantitation assay based on LICA was successfully established. Its performance satisfied the clinical requirements and could be widely used in clinical laboratories.

Performance evaluation of a laboratory-developed light-initiated chemiluminescence assay for quantification of egg white-specific IgE.

BACKGROUND: Specific IgE (sIgE) testing has become one of the most important tools for diagnosing IgE-mediated food allergy. Enzyme-linked immunosorbent assay (ELISA) and dot-enzyme-linked immunosorbent assay (Dot-ELISA) have been used to measure sIgE in clinical widely. Light-initiated chemiluminescence assay (LICA) is a new method for measuring allergen-sIgE. We aimed to establish a LICA method for quantitative detection of egg white-sIgE and evaluate its performances. METHODS: The best chemibeads coupling method in detecting egg white-sIgE was selected, and a LICA method for quantitative detection of egg white-sIgE was established. The precision study was performed according to Clinical and Laboratory Standards Institute (CLSI) EP5-A2. Detection capability which contains limit of blank (LoB), limit of detection (LoD), and limit of quantitation (LoQ) was evaluated according to National Health Commission of the People's Republic of China (NHC) WS/T 514-2017. Linear range was evaluated according to CLSI EP6-A. All data were analyzed using SPSS software. RESULTS: Precision contains repeatability and intermediate precision. The CV of repeatability ranged from 2.72% to 7.29%, and the CV of intermediate precision ranged from 4.93% to 8.64%. The LoB, LoD, and LoQ of the assay were 0.000 kUA/L, 0.053 kUA/L, and 0.076 kUA/L. The assay linear range was 0.076-34.125 kUA /L (r = 0.9979 ≥ 0.9900). CONCLUSION: This laboratory-developed LICA method can detect egg white-sIgE, and performance meets clinical requirements. This method shows rapid turnaround cycles and high sensitivity. It can be used as an alternative method for clinical detection of egg white-sIgE.

A systematic review and meta-analysis of children with coronavirus disease 2019 (COVID-19).

To provide a comprehensive and systematic analysis of demographic characteristics, clinical symptoms, laboratory findings, and imaging features of coronavirus disease 2019 (COVID-19) in pediatric patients. A meta-analysis was carried out to identify studies on COVID-19 from 25 December 2019 to 30 April 2020. A total of 48 studies with 5829 pediatric patients were included. Children of all ages were at risk for COVID-19. The main illness classification ranged as: 20% (95% confidence interval [CI]: 14%-26%; I2 = 91.4%) asymptomatic, 33% (95% CI: 23%-43%; I2 = 95.6%) mild and 51% (95% CI: 42%-61%; I2 = 93.4%) moderate. The typical clinical manifestations were fever 51% (95% CI: 45%-57%; I2 = 78.9%) and cough 41% (95% CI: 35%-47%, I2 = 81.0%). The common laboratory findings were normal white blood cell 69% (95% CI: 64%-75%; I2 = 58.5%), lymphopenia 16% (95% CI: 11%-21%; I2 = 76.9%) and elevated creatine-kinase MB 37% (95% CI: 25%-48%; I2 = 59.0%). The frequent imaging features were normal images 41% (95% CI: 30%-52%; I2 = 93.4%) and ground-glass opacity 36% (95% CI: 25%-47%; I2 = 92.9%). Among children under 1 year old, critical cases account for 14% (95% CI: 13%-34%; I2 = 37.3%) that should be of concern. In addition, vomiting occurred in 33% (95% CI: 18%-67%; I2 = 0.0%) cases that may also need attention. Pediatric patients with COVID-19 may experience milder illness with atypical clinical manifestations and rare lymphopenia. High incidence of critical illness and vomiting symptoms reward attention in children under 1 year old.

Postponing tumor onset and tumor progression can be achieved by alteration of local tumor immunity.

BACKGROUND: It has been known for years that the same genetic defects drive breast cancer formation, yet, the onset of breast cancer in different individuals among the same population differs greatly in their life spans with unknown mechanisms. METHODS: We used a MMTV-PyMT mouse model with different genetic backgrounds (FVB/NJ vs. C57BL/6J) to generate different cancer onset phenotypes, then profiled and analyzed the gene expression of three tumor stages in both Fvb.B6 and Fvb mice to explore the underlying mechanisms. RESULTS: We found that in contrast with the FVB/N-Tg (MMTV-PyMT) 634Mul mice (Fvb mice), mammary tumor initiation was significantly delayed and tumor progression was significantly suppressed in the Fvb.B6 mice (generated by crossing FVB/NJ with C57BL/6J mice). Transcriptome sequencing and analysis revealed that the differentially expressed genes were enriched in immune-related pathways. Flow cytometry analysis showed a higher proportion of matured dendritic cells in the Fvb.B6 mice. The plasma levels of interleukin-6 (IL-6) and vascular endothelial growth factor (VEGF) were significantly reduced in the Fvb.B6 mice. IL-6 also impaired the maturation of bone marrow dendritic cells (BMDCs) of the Fvb mice in vitro. CONCLUSION: All these findings suggest that immunity levels (characterized by a reduced IL-6 level and intact DC maturation in Fvb.B6 mice) are the key factors affecting tumor onset in a murine mammary cancer model.

Antioxidants suppress radiation-induced apoptosis via inhibiting MAPK pathway in nasopharyngeal carcinoma cells.

Nasopharyngeal carcinoma (NPC) is relatively sensitive to ionizing radiation, and radiotherapy is the main treatment modality for non-metastatic NPC. Radiation therapy generates overproduction of reactive oxygen species (ROS), which can cause DNA damage and induce apoptosis in tumors, thereby killing the malignant cells. Although dietary antioxidant supplementation reduces oxidative stress and promotes tumor progression, the effects of antioxidants on the NPC cells upon radiation have not been reported. In the present study, we showed that antioxidants (ß-Carotene, NAC, GSH) played an anti-apoptotic role in response to radiation via decreasing ROS production and inhibiting MAPK pathway in NPC cells. Based on that, we conclude that the use of supplemental antioxidants during radiotherapy should be avoided because of the possibility of tumor protection and reduced treatment efficacy.

IL-17A inhibits autophagic activity of HCC cells by inhibiting the degradation of Bcl2.

Hepatocellular carcinoma (HCC) is associated with poor prognosis due to many unknowns about its inflammatory microenvironment. As a pivotal proinflammatory cytokine, IL-17A exerts a protective effect on the survival and function of HCC cells. It is widely accepted that IL-17A plays an important role in regulating autophagy. Bcl2, a key molecule promoting the survival of HCC cells, also plays an indispensable role as an autophagy regulator. The aim of this study was to investigate the role of Bcl2 in IL-17A-regulated autophagy of HCC cells. The results showed that IL-17A not only inhibited autophagic activity, but also increased Bcl2 levels in HCC cells under starvation. Besides, IL-17A could prevent the dissociation of autophagy protein Beclin1 from Bcl2-Beclin1 complex upon starvation. Overexpression of Beclin1 rescued the autophagy deficiency of HCC cells in presence of IL-17A. Moreover, RNAi-induced Bcl2 silencing impaired the function of IL-17A in inhibiting the activation of autophagy, subsequently reducing the viability and migration of HCC cells, while the inhibition of Beclin1 by spautin-1 could reduce autophagic activity to a certain degree, thus restoring the viability and migration of HCC cells. In summary, it was suggested that the inhibition of Bcl2 degradation may be an important mechanism by which IL-17A inhibits autophagy response, subsequently maintaining the survival in HCC cells.

Association between iron metabolism markers and triglyceride-glucose index: A cross-sectional study in China Health and Nutrition Survey.

Iron metabolism plays an important role in insulin resistance, and the triglyceride-glucose (TyG) index has been proposed in recent years as a more accessible and cost-effective marker for insulin resistance. This study aims to evaluate the association between iron metabolism markers, including ferritin (FER), transferrin (TRF), and transferrin receptor (TFR), and the TyG index. A total of 6524 Chinese individuals aged between 18 and 75 years were included in this study. Multivariable linear models were used to investigate the association between FER, TRF, and TFR levels, and the TyG index. Further subgroup analyses stratified by age and sex were also performed. There was a positive association between FER and TRF levels and the TyG index in all 3 multivariable linear regression models, regardless of stratification by sex and age. Additionally, TFR was positively associated with the TyG index among females and those aged ≥45 years, but not among males and those aged <45 years. Our findings reveal a positive association between FER and TRF levels and the TyG index in a Chinese population, while the association between TFR levels and the TyG index showed different patterns depending on age and gender.

Quantitative Detection of House Dust Mites-Specific IgE by Light-Initiated Chemiluminescence Assay.

OBJECTIVE: To establish a new method for quantitative detection of house dust mite (HDM)-sIgE based on light-initiated chemiluminescence assay (LiCA). METHODS: The assay was established after optimizing the reaction conditions, and the assay performance was evaluated according to the clinical guidelines. Further, the results of LiCA were compared with those from the ELISA and ImmunoCAP methods. RESULTS: Coefficients of variation for repeatability ranged from 4.22% to 7.69%, and intermediate precision from 8.38% to 10.34%. The limit of blank (LoB), limit of detection (LoD), and limit of quantitation (LoQ) were 0.066 kUA/L, 0.165 kUA/L, and 0.171 kUA/L, respectively. The coefficient of correlation (r) between the results of LiCA and ELISA was 0.9263, and the r between the results of LiCA and ImmunoCAP was 0.8870. CONCLUSIONS: A HDM-sIgE quantitation assay based on LiCA was established, which could be used as a new reliable analytical tool for the determination of HDM-sIgE.

TSPAN1 inhibits metastasis of nasopharyngeal carcinoma via suppressing NF-kB signaling.

Nasopharyngeal carcinoma (NPC) originates in the epithelial cells of the nasopharynx and is a common malignant tumor in southern China and Southeast Asia. Metastasis of NPC remains the main cause of death for NPC patients even though the tumor is sensitive to radiotherapy and chemotherapy. Here, we found that the transmembrane protein tetraspanin1 (TSPAN1) potently inhibited the in vitro migration and invasion, as well as, the in vivo metastasis of NPC cells via interacting with the IKBB protein. In addition, TSPAN1 was essential in preventing the overactivation of the NF-kB pathway in TSPAN1 overexpressing NPC cells. Furthermore, reduced TSPAN1 expression was associated with NPC metastasis and the poor prognosis of NPC patients. These results uncovered the suppressive role of TSPAN1 against NF-kB signaling in NPC cells for preventing NPC metastasis. Its therapeutic value warrants further investigation.

Zinc finger protein 180 induces an apoptotic phenotype by activating METTL14 transcriptional activity in colorectal cancer.

Zinc finger protein 180 (ZNF180) is a multifunctional protein that interacts with nucleic acids and regulates various cellular processes; however, the function of ZNF180 in colorectal cancer (CRC) remains unclear. The present study investigated the role and function of ZNF180 in CRC, and aimed to reveal the underlying molecular mechanism. The results revealed that ZNF180 was downregulated in CRC tissues and was associated with a good prognosis in patients with CRC. Additionally, the expression of ZNF180 was downregulated by methylation in CRC. In vivo and in vitro experiments revealed that ZNF180 overexpression was functionally associated with the inhibition of cell proliferation and the induction of apoptosis. Mechanistically, chromatin immunoprecipitation­PCR and luciferase assays demonstrated that ZNF180 markedly regulated the transcriptional activity of methyltransferase 14, N6­adenosine­methyltransferase non­catalytic subunit (METTL14) by directly binding to and activating its promoter region. Simultaneous overexpression of ZNF180 and knockdown of METTL14 indicated that the reduction of METTL14 could suppress the effects of ZNF180 on the induction of apoptosis. Clinically, the present study observed a significant positive correlation between ZNF180 and METTL14 expression levels, and low expression of ZNF180 and METTL14 predicted a poor prognosis in CRC. Overall, these findings revealed a novel mechanism by which the ZNF180/METTL14 axis may modulate apoptosis and cell proliferation in CRC. This evidence suggests that this axis may serve as a prognostic biomarker and therapeutic target in patients with CRC.

Serum vitamin D3 deficiency can affect the efficacy of sublingual immunotherapy in children with allergic rhinitis: a retrospective cohort study.

Background: Sublingual immunotherapy (SLIT) is effective and convenient for many allergic patients but it is still ineffective for many children with allergic rhinitis (AR). In previous studies, most of the patients with poor efficacy of SLIT used the method of individualized adjustment of drug dosage. Currently, there are few reports on the relationship between serum vitamin D3 level and the efficacy of SLIT. Methods: In this study, 153 patients with AR who received SLIT were selected as the study objects. All patients collected serum for vitamin D3 test before treatment. The clinical characteristics of the patients were collected, and all patients were regularly followed up for at least 6 months. The improvement rates were assessed according to the combined symptom medication score (CSMS). A receiver operating characteristic (ROC) curve was drawn, and the optimal cut-off point was determined according to the Youden index. Univariate and multivariate logistic regression were used to analyze the relationship between serum vitamin D3 and SLIT efficacy. The odds ratios (ORs) and 95% confidence intervals (CIs) were computed by logistic regression. Results: Of 153 AR patients, 101 patients entered the final statistical analysis. According to CSMS, 29.7% of patients in low response (LR) group. The mean vitamin D3 level was (20.42±7.48) ng/mL. The optimal cutoff point for vitamin D3 was 22.25 ng/mL. Univariate logistic regression analysis of SLIT efficacy showed that whether the patient also had a food allergy (P<0.001) or asthma (P=0.011), whether they used acarid products (P=0.002), and whether vitamin D3 is sufficient (P=0.001) were significantly related to the efficacy of SLIT. Multivariate logistic regression analysis showed that after adjusting for whether the patient also had asthma and whether they had used acarid products, whether the patient also had a food allergy (OR: 12.13, 95% CI: 3.57-41.18, P<0.001) and whether vitamin D3 is sufficient (OR: 22.21, 95% CI: 4.04-122.30, P<0.001) were independent factors affecting the efficacy of SLIT. Conclusions: Serum Vitamin D3 deficiency can affect the efficacy of SLIT in children with AR. This study provided a new therapeutic approach for SLIT patients with poor efficacy.

IL-13RA2 downregulation in fibroblasts promotes keloid fibrosis via JAK/STAT6 activation.

Keloids are considered the manifestation of a fibroproliferative disease characterized by chronic inflammation that is induced following skin injury. Deciphering the underlying mechanism of keloid formation is essential for improving treatment outcomes. Here, we found that more macrophages were activated toward the M2 subtype in keloid dermis when compared with normal dermis. Western blotting revealed that the level of phosphorylated STAT6 (p-STAT6), a known inducer of M2 polarization, was higher in keloid fibroblasts as opposed to fibroblasts from normal dermis. Moreover, keloid fibrosis was shown to be positively correlated with the level of p-STAT6. Further, we identified downregulation of IL-13RA2, a decoy receptor for IL-13, in keloid fibroblasts compared with fibroblasts from normal dermis. Ectopic expression of IL-13RA2 in keloid fibroblasts resulted in inhibition of STAT6 phosphorylation, cell proliferation, migration, invasion, extracellular matrix secretion, and myofibroblast marker expression, as well as an increase in apoptosis. Consistently, knockdown of IL-13RA2 in normal fibroblasts induced a keloidal status. Furthermore, both in vitro application and intratumoral injection of p-STAT6 inhibitor AS1517499 in a patient-derived xenograft keloid-implantation mouse model resulted in proliferation inhibition and tissue necrosis, apoptosis, and myofibroblast marker reduction. Collectively, this study elucidates the key role of IL-13RA2 in keloid pathology and inspires further translational research of keloid treatment concerning JAK/STAT6 inhibition.

Correlated with better prognosis, CSTA inhibits metastasis of nasopharyngeal carcinoma cells via suppressing AKT signaling through promoting METTL3 degradation.

BACKGROUND: Metastasis is one of the main obstacles impeding the survival of nasopharyngeal carcinoma (NPC) patients, with the molecular mechanism underlying NPC metastasis still unclear. RESULTS: In this study, Cystatin A (CSTA) was found downregulated in NPC tissues with metastasis compared with those without metastasis. Shorter overall survival and distant metastasis-free survival were found in NPC patients with lower CSTA expression. Using functional assays, we found that CSTA prevented both the in vitro motility of NPC cells and their ability to metastasize in vivo. Transcriptome sequencing and western blot analysis revealed that CSTA inhibited the phosphorylation of AKT. Moreover, activating AKT using AKT agonist SG79 rescued the motility of CSTA-overexpressing NPC cells, whereas, treatment with AKT inhibitor MK2206 inhibited the motility of CSTA-knockdown NPC cells. Mechanically, immunoprecipitation coupled mass spectrometry found that CSTA interacted with the N6-adenosine-methyltransferase subunit METTL3 and promoted its ubiquitin-proteasome-mediated degradation following the upregulation of NKX3-1 and LHPP, which are negative regulators of AKT. Furthermore, knock-down of NKX3-1 and LHPP enhanced the motility of CSTA-overexpressing NPC cells. CONCLUSIONS: The inhibitory effect of CSTA upon NPC metastasis mainly depended on suppressing AKT signaling by the upregulation of NKX3-1 and LHPP expression resulting from the binding between CSTA and METLL3. Our study suggests that the CSTA-METLL3-NKX3-1/LHPP-AKT axis could be of therapeutic value for inhibiting NPC metastasis.

Development of a light-initiated chemiluminescence assay for the quantitative detection of cow's milk allergen-specific IgE.

BACKGROUND: Cow's milk allergy is a common food allergy in children. Clinically, cow's milk-specific IgE (CM-sIgE) antibody test is often used to diagnose milk allergy. An inexpensive light-initiated chemiluminescence assay (LICA), with fast detection speed and small sample volume demand, has application prospects in the field of quantitative detection of CM-sIgE. METHODS: Chemibeads coated with five major milk allergens, serum samples, biotinylated anti-human IgE antibodies, and streptavidin-coated sensibeads constitute a system to establish a LICA method for the quantitative detection of CM-sIgE. A series of experiments were performed to optimize its reaction conditions and evaluated its performance. RESULTS: The optimal conditions for LICA were 10:4 mass ratio of chemibeads to milk allergen, 20 µg/mL chemibeads, 1.0 µg/mL biotinylated anti-human IgE antibodies and a 1/10 dilution of serum for 30-min incubation. The limit of Quantitation (LoQ) was 0.22 kUA/L. For repeatability, the CV ranged from 3.71% to 8.11%. For intermediate precision, the CV ranged from 4.08% to 14.71%. It was linear within 0.20-18.20 kUA/L. This method did not interfere with common interfering substances and total IgE in serum, and there was no obvious cross-reaction with milk-specific IgG and non-milk-specific IgE. CONCLUSION: We have established a method to quantitatively detect CM-sIgE based on light-initiated chemiluminescence assay, which has good analytical performance and could meet the needs of clinical laboratories.

Euphorbia factor L1 reverses ABCB1-mediated multidrug resistance involving interaction with ABCB1 independent of ABCB1 downregualtion.

Euphorbia factor L1 (EFL1) belongs to diterpenoids of genus Euphorbia. In this article, its reversal activity against ABCB1-mediated MDR in KBv200 and MCF-7/adr cells was reported. However, EFL1 did not alter the sensitivity of KB and MCF-7 cells to chemotherapeutic agents. Meanwhile, EFL1 significantly increased accumulation of doxorubicin and rhodamine 123 in KBv200 and MCF-7/adr cells, showing no significant influence on that of KB and MCF-7 cells. Furthermore, EFL1 could enhance the ATP hydrolysis activity of ABCB1 stimulated by verapamil. At the same time, EFL1 inhibited the efflux of ABCB1 in KBv200 and MCF-7/adr cells. In addition, EFL1 did not downregulate expression of ABCB1 in KBv200 and MCF-7/adr cells either in mRNA or protein level.

Blockade of Her2/neu binding to Hsp90 by emodin azide methyl anthraquinone derivative induces proteasomal degradation of Her2/neu.

Overexpression of HER2/neu, a transmembrane tyrosine kinase acting as a coreceptor for other EGFR family members, is well-known to be associated with a poor prognosis in cancer. In the present study, we observed that emodin AMAD, a novel emodin azide methyl anthraquinone derivative, extracted from nature's giant knotweed rhizome of traditional Chinese herbs, potently decreased Her2/neu protein in dose- and time-dependent manners and also inhibited the downstream MAPK and PI3K-Akt signaling pathway. Intriguingly, reverse transcription-PCR and protein turnover assay revealed that the decrease of Her2/neu was independent of mRNA level but primarily owing to its protein stability. Meanwhile, proteasome inhibitor MG132 but not lysosome inhibitor chloroquine could restore Her2/neu and polyubiquitination of Her2/neu was augmented during emodin AMAD treatment. Furthermore, immunofluorescence study with anti-Her2/neu antibody showed that emodin AMAD disturbed the subcellular distribution of Her2/neu, with decreased location in the plasma membrane. Molecular docking studies predicted that AMAD can interact with the ATP-binding pocket of both Hsp90 and Her2/neu. Importantly, coimmunoprecipitation and immunofluorescence study revealed that emodin AMAD markedly impaired the binding between Hsp90 and Her2/neu and could bind to both Hsp90 and Her2/neu as reinforced by molecular modeling studies. In addition, combination of emodin AMAD treatment and siRNA against Her2 synergistically inhibited proliferation and induced apoptosis. Taken together, these data suggest that blockade of Her2/neu binding to Hsp90 and following proteasomal degradation of Her2/neu were involved in emodin AMAD-induced apoptosis in Her2/neu-overexpressing cancer cells. Our results provide suggestions that emodin AMAD could be promising as a new targeting therapeutic strategy in the treatment of Her2/neu-overexpressing cancers.

Structure identification of Euphorbia factor L3 and its induction of apoptosis through the mitochondrial pathway.

In this article, we have focused on the structure identification of Euphorbia factor L3 belonging to the lathyrane diterpenoids isolated from Caper Euphorbia Seed. Its anticancer activity in vitro against lung cancer A549 cells was also investigated and the IC(50) values were 34.04 ± 3.99 µM. Furthermore, Euphorbia factor L3 could induce apoptosis in A549 cells via the mitochondrial pathway including loss of mitochondrial potential and release of cytochrome c.