Kang-Ai Injection Inhibits Gastric Cancer Cells Proliferation through IL-6/STAT3 Pathway.

OBJECTIVE: To explore the mechanisms underlying the proliferative inhibition of Chinese herbal medicine Kang-Ai injection (KAI) in gastric cancer cells. METHODS: Gastric cancer cell lines MGC803 and BGC823 were treated by 0, 0.3%, 1%, 3% and 10% KAI for 24, 48 and 72 h, respectively. The cell proliferation was evaluated by 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2-H-tetrazolium bromide (MTT) assay. The apoptosis and cell cycle were evaluated by flow cytometry. Interleukin (IL)-6 mRNA and protein expression levels were detected by quantitative real-time polymerase chain reaction (qRT-PCR) and enzyme-linked immune sorbent assay (ELISA), respectively. The protein expression levels of cyclin A, cyclin E, cyclin B1, cyclin D1, p21, retinoblastoma (RB), protein kinase B (AKT), extracellular regulated protein kinases (ERK), signal transducer and activator of transcription (STAT) 1 and STAT3 were detected by Western blot. RESULTS: KAI inhibited the proliferation of MGC803 and BGC823 gastric cancer cells in dose- and time-dependent manner. After treated with KAI for 48 h, the proportion of G1 phase was increased, expression level of cyclin D1 and phosphorylation-RB were down-regulated, whereas the expression of p21 was up-regulated (all P<0.01). Furthermore, 48-h treatment with KAI decreased the phosphorylation level of STAT3, inhibited the mRNA and protein expressions of IL-6 (all P<0.01). IL-6 at dose of 10 ng/mL significantly attenuated the proliferative effect of both 3% and 10% KAI, and recovered KAI-inhibited STAT3 phosphorylation and cyclin D1 expression level (all P<0.01). CONCLUSION: KAI exerted an anti-proliferative function by inhibiting IL-6/STAT3 signaling pathway followed by the induction of G1 phase arrest in gastric cancer cells.

Kang-Ai Injection Inhibits Gastric Cancer Cells Proliferation through IL-6/STAT3 Pathway / 中国结合医学杂志

OBJECTIVE@#To explore the mechanisms underlying the proliferative inhibition of Chinese herbal medicine Kang-Ai injection (KAI) in gastric cancer cells.@*METHODS@#Gastric cancer cell lines MGC803 and BGC823 were treated by 0, 0.3%, 1%, 3% and 10% KAI for 24, 48 and 72 h, respectively. The cell proliferation was evaluated by 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2-H-tetrazolium bromide (MTT) assay. The apoptosis and cell cycle were evaluated by flow cytometry. Interleukin (IL)-6 mRNA and protein expression levels were detected by quantitative real-time polymerase chain reaction (qRT-PCR) and enzyme-linked immune sorbent assay (ELISA), respectively. The protein expression levels of cyclin A, cyclin E, cyclin B1, cyclin D1, p21, retinoblastoma (RB), protein kinase B (AKT), extracellular regulated protein kinases (ERK), signal transducer and activator of transcription (STAT) 1 and STAT3 were detected by Western blot.@*RESULTS@#KAI inhibited the proliferation of MGC803 and BGC823 gastric cancer cells in dose- and time-dependent manner. After treated with KAI for 48 h, the proportion of G1 phase was increased, expression level of cyclin D1 and phosphorylation-RB were down-regulated, whereas the expression of p21 was up-regulated (all P<0.01). Furthermore, 48-h treatment with KAI decreased the phosphorylation level of STAT3, inhibited the mRNA and protein expressions of IL-6 (all P<0.01). IL-6 at dose of 10 ng/mL significantly attenuated the proliferative effect of both 3% and 10% KAI, and recovered KAI-inhibited STAT3 phosphorylation and cyclin D1 expression level (all P<0.01).@*CONCLUSION@#KAI exerted an anti-proliferative function by inhibiting IL-6/STAT3 signaling pathway followed by the induction of G1 phase arrest in gastric cancer cells.

FEN1 is a prognostic biomarker for ER+ breast cancer and associated with tamoxifen resistance through the ERα/cyclin D1/Rb axis.

BACKGROUND: Tamoxifen is an important choice in endocrine therapy for patients with oestrogen receptor-positive (ER+) breast cancer, and disease progression-associated resistance to tamoxifen therapy is still challenging. Flap endonuclease-1 (FEN1) is used as a prognostic biomarker and is considered to participate in proliferation, migration, and drug resistance in multiple cancers, especially breast cancer, but the prognostic function of FEN1 in ER+ breast cancer, and whether FEN1 is related to tamoxifen resistance or not, remain to be explored. METHODS: On-line database Kaplan-Meier (KM) plotter, GEO datasets, and immunohistochemistry were used to analyse the prognostic value of FEN1 in ER+ breast cancer from mRNA and protein levels. Cell viability assay and colony formation assays showed the response of tamoxifen in MCF-7 and T47D cells. Microarray data with FEN1 siRNA versus control group in MCF-7 cells were analysed by Gene Set Enrichment Analysis (GSEA). The protein levels downstream of FEN1 were detected by western blot assay. RESULTS: ER+ breast cancer patients who received tamoxifen for adjuvant endocrine therapy with poor prognosis showed a high expression of FEN1. MCF-7 and T47D appeared resistant to tamoxifen after FEN1 over-expression and increased sensitivity to tamoxifen after FEN1 knockdown. Importantly, FEN1 over-expression could activate tamoxifen resistance through the ERα/cyclin D1/Rb axis. CONCLUSIONS: As a biomarker of tamoxifen effectiveness, FEN1 participates in tamoxifen resistance through ERα/cyclin D1/Rb axis. In the future, reversing tamoxifen resistance by knocking-down FEN1 or by way of action as a small molecular inhibitor of FEN1 warrants further investigation.

Biological and clinical significance of flap endonuclease­1 in triple­negative breast cancer: Support of metastasis and a poor prognosis.

Flap endonuclease­1 (FEN1), a structure­specific nuclease participating in DNA replication and repair processes, has been confirmed to promote the proliferation and drug resistance of tumor cells. However, the biological functions of FEN1 in cancer cell migration and invasion have not been defined. In the present study, using online database analysis and immunohistochemistry of the specimens, it was found that FEN1 expression was associated with a highly invasive triple­negative breast cancer (TNBC) subtype in both breast cancer samples from the Oncomine database and from patients recruited into the study. Furthermore, FEN1 was an important biomarker of lymph node metastasis and poor prognosis in patients with TNBC. FEN1 promoted migration of TNBC cell lines and FEN1 knockdown reduced the number of spontaneous lung metastasis in vivo. Ingenuity Pathway Analysis of FEN1­related transcripts in 198 patients with TNBC demonstrated that the polo­like kinase family may be the downstream target of FEN1. PLK4 was further identified as a critical target of FEN1 mediating TNBC cell migration, by regulating actin cytoskeleton rearrangement. The results of the present study validate FEN1 as a therapeutic target in patients with TNBC and revealed a new role for FEN1 in regulating TNBC invasion and metastasis.

Real-time burn depth assessment using artificial networks: a large-scale, multicentre study.

INTRODUCTION: Early judgment of the depth of burns is very important for the accurate formulation of treatment plans. In medical imaging the application of Artificial Intelligence has the potential for serving as a very experienced assistant to improve early clinical diagnosis. Due to lack of large volume of a particular feature, there has been almost no progress in burn field. METHODS: 484 early wound images are collected on patients who discharged home after a burn injury in 48 h, from five different levels of hospitals in Hunan Province China. According to actual healing time, all images are manually annotated by five professional burn surgeons and divided into three sets which are shallow(0-10 days), moderate(11-20 days) and deep(more than 21 days or skin graft healing). These ROIs were further divided into 5637 patches sizes 224 × 224 pixels, of which 1733 shallow, 1804 moderate, and 2100 deep. We used transfer learning suing a Pre-trained ResNet50 model and the ratio of all images is 7:1.5:1.5 for training:validation:test. RESULTS: A novel artificial burn depth recognition model based on convolutional neural network was established and the diagnostic accuracy of the three types of burns is about 80%. DISCUSSION: The actual healing time can be used to deduce the depth of burn involvement. The artificial burn depth recognition model can accurately infer healing time and burn depth of the patient, which is expected to be used for auxiliary diagnosis improvement.

Integrated bioinformatics analysis for the identification of potential key genes affecting the pathogenesis of clear cell renal cell carcinoma.

Clear cell renal cell carcinoma (CCRCC) is a typical type of RCC with the worst prognosis among the common epithelial neoplasms of the kidney. However, its molecular pathogenesis remains unknown. Therefore, the aim of the present study was to screen for effective and potential pathogenic biomarkers of CCRCC. The gene expression profile of the GSE16441, GSE36895, GSE40435, GSE46699, GSE66270 and GSE71963 datasets were downloaded from the Gene Expression Omnibus database. First, the limma package in R language was used to identify differentially expressed genes (DEGs) in each dataset. The robust and strong DEGs were explored using the robust rank aggregation method. A total of 980 markedly robust DEGs were identified (429 upregulated and 551 downregulated). According to Gene Ontology and Kyoto Encyclopedia of Genes and Genomes pathway enrichment analysis, these DEGs exhibited an obvious enrichment in various cancer-related biological pathways and functions. The Search Tool for the Retrieval of Interacting Genes/Proteins database was used for the construction of a protein-protein interaction (PPI) network, the Cytoscape MCODE plug-in for module analysis and the cytoHubba plug-in to identify hub genes from the aforementioned DEGs. A total of four key modules were identified in the PPI network. A total of six hub genes, including C-X-C motif chemokine ligand 12, bradykinin receptor B2, adenylate cyclase 7, calcium sensing receptor (CASR), kininogen 1 and lysophosphatidic acid receptor 5, were identified. The DEG results of the hub genes were verified using The Cancer Genome Atlas database, and CASR was found to be significantly associated with the prognosis of patients with CCRCC. In conclusion, the present study provided new insight and potential biomarkers for the diagnosis and prognosis of CCRCC.

Inhibition of FEN1 Increases Arsenic Trioxide-Induced ROS Accumulation and Cell Death: Novel Therapeutic Potential for Triple Negative Breast Cancer.

Triple-negative breast cancer (TNBC) is an aggressive subtype of breast cancer, which is very difficult to treat and commonly develops resistance to chemotherapy. The following study investigated whether the inhibition of Flap Endonuclease 1 (FEN1) expression, the key enzyme in the base excision repair (BER) pathway, could improve the anti-tumor effect of arsenic trioxide (ATO), which is a reactive oxygen species (ROS) inducer. Our data showed that ATO could increase the expression of FEN1, and the knockdown of FEN1 could significantly enhance the sensitivity of TNBC cells to ATO both in vitro and in vivo. Further mechanism studies revealed that silencing FEN1 in combination with low doses of ATO might increase intracellular ROS and reduce glutathione (GSH) levels, by reducing the nuclear translocation of nuclear factor erythroid 2-related factor 2 (Nrf2); elevating ROS leaded to apoptosis and p38 and JNK pathway activating. In conclusion, our study suggested the combination of FEN1 knockdown and ATO could induce TNBC cell death by promoting ROS production. FEN1 knockdown can effectively decrease the application concentrations of ATO, thus providing a possibility for the treatment of TNBC with ATO.

DNMT3a promotes proliferation by activating the STAT3 signaling pathway and depressing apoptosis in pancreatic cancer.

BACKGROUND: Although aberrant DNA methyltransferase 3a (DNMT3a) expression is important to the tumorigenesis of pancreatic ductal adenocarcinoma (PDAC), the role of DNMT3a in PDAC prognosis is not clarified yet due to the limited studies and lacking of underlying molecular mechanism. METHODS: The expression of DNMT3a was examined by immunohistochemistry in PDAC tissues. Gene expression profiles assays were conducted to explore the impact of DNMT3a on biological processes and signal pathways. Cell cycle and apoptosis were measured by flow cytometry. Western blotting and real-time qPCR assays were used to explore the impact of DNMT3a on expression of protein and mRNA related to cell cycle, STAT3 signaling pathway and apoptosis. RESULTS: DNMT3a was overexpressed and closely associated with poor outcomes of PDAC. DNMT3a knockdown restrained PDAC cell proliferation, induced cell cycle arrest and promoted apoptosis in vitro. Affymetrix GeneChip Human Transcriptome Array identified that the cell cycle-related process was most significantly associated with DNMT3a. DNMT3a knockdown induced G1-S phase transition arrest by decreasing the expression of cyclin D1, which was mediated by the reduction of IL8 and the subsequent inactivation of STAT3 signaling pathway. Furthermore, exogenous apoptosis was also promoted after DNMT3a knockdown, probably via up-regulation of DNA transcription and expression in CASP8. CONCLUSION: These findings indicate that DNMT3a plays an important role in PDAC progression. DNMT3a may serve as a prognostic biomarker and a therapeutic strategy candidate in PDAC.

Bufalin induces protective autophagy by Cbl-b regulating mTOR and ERK signaling pathways in gastric cancer cells.

Bufalin, a natural small-molecule compound derived from the traditional Chinese medicine Chan su, has shown promising anti-cancer effects against a broad variety of cancer cells through different mechanisms. It has been reported to induce autophagy in gastric cancer cells. However, the molecular mechanism involved is not fully elucidated. In the present study, we aimed to investigate the molecular mechanism by which bufalin induce autophagy in human gastric cancer cells. We found that bufalin induced apoptosis and autophagy in gastric cancer cells, and autophagy prevented human gastric cancer cells from undergoing apoptosis. Bufalin treatment changed the expression of autophagy-related proteins. Moreover, phosphorylated Akt, mTOR, and p70S6K were all significantly decreased, while phosphorylated ERK1/2 was increased by bufalin. Pretreatment of MGC803 cells with the ERK1/2-specific inhibitor PD98059 led to the down-regulation of LC3 II. Further study showed that Cbl-b positively regulated autophagy by suppressing mTOR and enhancing ERK1/2 activation. Therefore, our data provide evidence that bufalin induces autophagy in MGC803 cells via both Akt/mTOR/p70S6K and ERK signaling pathways, and Cbl-b-mediated suppression of mTOR and activation of ERK1/2 might play an important role.

FEN1 knockdown improves trastuzumab sensitivity in human epidermal growth factor 2-positive breast cancer cells.

Trastuzumab has been widely applied as a treatment for human epidermal growth factor 2 (HER2)-overexpressing breast cancer. However, the therapeutic efficacy of trastuzumab is limited. Flap endonuclease 1 (FEN1) is a multifunctional endonuclease that has a crucial role in DNA recombination and repair. Inhibition of FEN1 is associated with the reversal of anticancer drug resistance. However, it is unclear whether FEN1 is involved in trastuzumab resistance. In the present study, it was demonstrated that trastuzumab increases the expression of FEN1, and FEN1 knockdown significantly enhanced the sensitivity of BT474 cells to trastuzumab (P<0.05). It was also revealed that trastuzumab induced HER receptor activation, increased binding with FEN1 and estrogen receptor α (ERα), and upregulated ERα-target gene transcription (P<0.05). Upon silencing of FEN1 expression with siRNA, activation of HER receptor and FEN1 binding to ERα were decreased, and trastuzumab-induced ERα target gene upregulation was partially ameliorated (P<0.05). These results suggest that FEN1 may mediate trastuzumab resistance via inducing HER receptor activation and enhancing ERα-target gene transcription. The findings of the present study indicate a novel role of FEN1 in trastuzumab resistance, suggesting that targeting FEN1 may enhance the efficiency of trastuzumab as a treatment for HER2-positive breast cancer.

Correlation between androgen receptor expression and surrogate molecular subtypes in invasive breast carcinoma / 中华病理学杂志

Objective@#To investigate androgen receptor(AR)expression in invasive breast carcinoma and the correlation with surrogate molecular breast carcinoma subtypes.@*Methods@#Immunohistochemical staining of AR and other biomarkers was performed in a cohort of 870 cases of primary invasive breast carcinomas collected from August to December, 2016. The association of AR expression with different histological and surrogate molecular subtypes was analyzed.@*Results@#The positive expression rate of AR in the immunohistochemistry-based surrogate subtypes was 96.3%(207/215) for Luminal A, 89.8%(378/421) for Luminal B, 82.4%(75/91) for HER2 overexpression and 37.1%(53/143) for triple negative breast carcinoma, with significant differences among the four groups (P<0.01). AR correlated positively with the expression of ER(P<0.01), PR(P<0.01), HER2(P=0.007), GATA3(P<0.01), GCDFP15(P<0.01)and mammaglobin(P<0.01), while negatively with the expression of Ki-67(P<0.01), CK5/6(P<0.01)and CK14(P<0.01).@*Conclusions@#AR exhibits a high expression in invasive breast carcinoma, which is mainly correlated with ER-positive breast carcinoma. Regardless of the relatively low expression rate, AR is a potential therapeutic target in triple negative breast carcinoma.

SPARC expression in gastric cancer predicts poor prognosis: Results from a clinical cohort, pooled analysis and GSEA assay.

BACKGROUND: The prognostic role of Secreted Protein Acidic and Rich in Cysteine (SPARC) in gastric cancer (GC) remains controversial. We investigated the clinical significance, the survival relevance, and potential function of SPARC in GC with resected samples, online gene set GSE62254, and cell line SGC7901. RESULTS: High immunostaining of SPARC significantly correlated with tumor differentiation (P = 0.004), and independently predicted shorter overall survival (OS) (HR = 1.446, P = 0.022), based on the current IHC evaluation. The accuracy of the results was further validated with 1000 times bootstrapping and the time-dependent receiver-operating characteristics (ROC) curves. The meta-analysis (pooled HR = 1.60, 95% CI: 1.01-2.53) confirmed SPARC as the predictor for reduced OS in GC. Moreover, the association between enhanced SPARC expression and Adriamycin (Adr) sensitivity was revealed by GSEA, and then confirmed by comparative cellular experiments, such as the protein level analysis of SGC7901and SGC7901/Adr cell line. MATERIALS AND METHODS: Immunohistochemistry (IHC) method was used to detect SPARC expression in 137 GC cases. Meta-analysis was performed based on 5 studies published in English on PubMed up to March 2016. GSEA was performed using online data set GSE62254 and GC-related functional gene sets derived from molecular signatures database (MSigDB). Western Blot was carried out to compare protein-level differences between gastric carcinoma SGC7901 cell line and Adr resistant SGC7901/Adr cell line. MTT assay was done to confirm the induction of SPARC on Adr sensitivity. CONCLUSIONS: Increased SPARC expression in GC led to a worse clinical outcome of patients and might induce Adr sensitivity of GC cells.

Molecular recognition mechanism and motion of HCV NS3/4A protease with Faldaprevir analogue / 生物工程学报

Faldaprevir analogue molecule (FAM) has been reported to effectively inhibit the catalytic activity of HCV NS3/4A protease, making it a potential lead compound against HCV. A series of HCV NS3/4A protease crystal structures were analyzed by bioinformatics methods, and the FAM-HCV NS3/4A protease crystal structure was chosen for this study. A 20.4 ns molecular dynamics simulation of the complex consists of HCV NS3/4A protease and FAM was conducted. The key amino acid residues for interaction and the binding driving force for the molecular recognition between the protease and FAM were identified from the hydrogen bonds and binding free energy analyses. With the driving force of hydrogen bonds and van der Waals, FAM specifically bind to the active pocket of HCV NS3/4A protease, including V130-S137, F152-D166, D77-D79 and V55, which agreed with the experimental data. The effect of R155K, D168E/V and V170T site-directed mutagenesis on FAM molecular recognition was analyzed for their effect on drug resistance, which provided the possible molecular explanation of FAM resistance. Finally, the system conformational change was explored by using free energy landscape and conformational cluster. The result showed four kinds of dominant conformation, which provides theoretical basis for subsequent design of Faldaprevir analogue inhibitors based on the structure of HCV NS3/4A protease.

Molecular simulation study on the recognition between hydroxy isoindolin ketone derivatives and HIV-1 integrase / 中国药科大学学报

@#To discuss the conformational change and the recognition mechanism of hydroxy isoindol ketone derivatives with HIV-1 integrase, fifty-eight hydroxy isoindol ketone derivatives were docked to the integrase using AutoDock program. Molecular dynamics simulation with 16 ns was carried out for the two complex modes, respectively, in which the corresponding small molecules exhibited strong inhibition ability. Main force acting on the association of small molecules with integrase was explored based on the docking complex model. After analyzing the hydrogen-bond and conformational changes, it was found that the hydrogen-bond between N155 and D64 was the key factor maintaining the DDE motif stability. Furthermore, the hydrophobic interactions between the loop region where Y143 located and the hydroxy isoindol ketone derivatives were found to play an important role for their recognition.

Clinicopathologic characteristics of membranous nephropathy with crescents / 医学研究生学报

Objective Membranous nephropathy ( MN) is rarely complicated by crescents.This study was to observe the clinicopathologic characteristics of MN with crescents. Methods This retrospective study included 53 cases of biopsy-proven idiopathic MN with crescents in the absence of immunologic and clinical etiologic factors and another 100 MN patients without histological crescents as controls.The clinicopathologic features, treatment response, and out-comes were analyzed and compared between the two groups of pa-tients. Results Significantly higher percentages of hypertension and decreased eGFR were observed in the MN +crescents group than in the control (47.2%vs 19.0%, P<0.05;28.3%vs 40.%, P<0.05).Circulating autoantibodies against the M-type phospholipase A2 receptor (PLA2R) were found in 66.7%(30/45) of the patients.The glomeruli exhibited a median of 4.6%(1.8%-35.3%) involvement of crescents.Compared with the controls, the MN +crescents group showed remarkably higher rates of segmental glomer-ulosclerosis lesions (16.0%vs 49.1%, P<0.05), capillary loops necrosis (0.0%vs 11.3%, P<0.05), interstitial fibrosis/tubu-lar atrophy (IFTA) (54.0%vs 86.8%, P<0.05) and afferent arterial lesions (65.0%vs 92.5%, P<0.05).No significant differ-ences were found in the outcomes of the two groups of patients. Conclusion MN with crescents is rare, and secondary MN and cres-centic glomerulonephritis should be considered.Crescentic MN usually presents with hypertension and renal dysfunction clinically and high rates of severe segmental and global glomerulosclerosis, capillary loops necrosis, and IFTA histologically.The condition has a fa-vorable short-term prognosis.

Uchl1 and its associated proteins were involved in spermatocyte apoptosis in mouse experimental cryptorchidism / 生理学报

Uchl1 was found to be involved in spermatocyte apoptosis. The aim of the present study was to test whether Uchl1 and its associated proteins Jab1 and p27(kip1) were involved in spermatogenic damages in response to heat-stress in cryptorchidism. Hematoxylin and eosin (HE) staining and DNA end labeling (TUNEL) were used to observe morphological and apoptotic characteristics of spermatogenic cells; Immunohistochemical analysis was used to detect changes of Uchl1 and its associated proteins Jab1 and p27(kip1) in response to heat-stress from cryptorchidism leading to spermatocyte losses; And protein affinity analysis (pull-down) and immunofluorescence co-localization were used to verify the relevance among the three proteins in spermatocytes. The results showed that, Jab1 and p27(kip1), in parallel to Uchl1, increased in spermatocytes of apoptotic appearances in response to heat-stress, but not in multinucleated giant cells; Jab1 bound to Uchl1 in testis protein extracts, and co-localized with Uchl1 and p27(kip1) specifically in spermatocytes with apoptotic appearances. These results suggest that the accumulation of Uchl1 protein is involved in the heat-stress-induced spermatocyte apoptosis through a new pathway related with Jab1 and p27(kip1), but not the formation of multinucleated giant cells.

The role of E3 ubiquitin ligase Cbl proteins in interleukin-2-induced Jurkat T-cell activation.

Interleukin- (IL-) 2 is the major growth factor for T-cell activation and proliferation. IL-2 has multiple functions in the regulation of immunological processes. Although most studies focus on T-cell immunomodulation, T-cell activation by IL-2 is the foundation of priming the feedback loop. Here, we investigated the effect of MAPK/ERK and PI3K/Akt signaling pathways on IL-2-induced cell activation and the regulatory mechanisms of upstream ubiquitin ligase Cbl-b and c-Cbl. Morphological analysis of Jurkat T cells was performed by cytospin preparations with Wright-Giemsa stain. CD25 expression on Jurkat T cells was determined by flow cytometry. Changes in cell activation proteins such as p-ERK, ERK, p-Akt, Akt, and ubiquitin ligase Casitas B-cell Lymphoma (Cbl) proteins were analyzed by western blot. Following IL-2-induced activation of Jurkat T cells, p-ERK expression was upregulated, while there was no change in p-Akt, ERK, or Akt expression. Thus, the MAPK/ERK signaling pathway, but not PI3K/Akt, was involved in IL-2-induced T-cell activation. Either using PD98059 (a specific inhibitor for p-ERK) or depletion of ERK with small interfering RNA (siRNA) reduced the expression of CD25. This study also showed that ubiquitin ligase proteins Cbl-b and c-Cbl might be involved in IL-2-induced Jurkat T-cell activation by negatively regulating the MAPK/ERK signaling pathway.

ß-Elemene induces apoptosis in human renal-cell carcinoma 786-0 cells through inhibition of MAPK/ERK and PI3K/Akt/ mTOR signalling pathways.

BACKGROUND: Renal-cell carcinoma (RCC) is resistant to almost all chemotherapeutics and radiation therapy. ß-Elemene, a promising anticancer drug extracted from a traditional Chinese medicine, has been shown to be effective against various tumors. In the present study, anti-tumor effects on RCC cells and the involved mechanisms were investigated. METHODS: Human RCC 786-0 cells were treated with different concentrations of ß-elemene, and cell viability and apoptosis were measured by 3-(4, 5-dimethylthiazol-2-yl)-2, 5-diphenyl tetrazolium bromide (MTT) assay and flow cytometry, respectively. Protein expression was assayed by western blotting. Autophagy was evaluated by transmission electron microscopy. RESULTS: ß-Elemene inhibited the viability of 786-0 cells in a dose- and time-dependent manner. The anti-tumor effect was associated with induction of apoptosis. Further study showed that ß-elemene inhibited the MAPK/ERK as well as PI3K/Akt/mTOR signalling pathways. Moreover, robust autophagy was observed in cells treated with ß-elemene. Combined treatment of ß-elemene with autophagy inhibitors 3-methyladenine or chlorochine significantly enhanced the anti-tumor effects. CONCLUSIONS: Our data provide first evidence that ß-elemene can inhibit the proliferation of RCC 786- 0 cells by inducing apoptosis as well as protective autophagy. The anti-tumor effect was associated with the inhibition of MAPK/ERK and PI3K/Akt/mTOR signalling pathway. Inhibition of autophagy might be a useful way to enhance the anti-tumor effect of ß -elemene on 786-0 cells.

ß-Elemene induces apoptosis as well as protective autophagy in human non-small-cell lung cancer A549 cells.

OBJECTIVES: ß-Elemene, a novel traditional Chinese medicine, has been shown to be effective against a wide range of tumours. In this study, the antitumour effect of ß-elemene on human non-small-cell lung cancer (NSCLC) A549 cells and the mechanism involved have been investigated. METHODS: Cell viability and apoptosis were measured by the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay and flow cytometry, respectively. Protein expression was assayed by Western blotting. Autophagy was evaluated under fluorescence microscopy and transmission electron microscopy. KEY FINDINGS: ß-Elemene inhibited the viability of A549 cells in a dose-dependent manner. This suppression of cell viability was due to the induction of apoptosis. Further study showed that ß-elemene inhibited the activity of the PI3K/Akt/mTOR/p70S6K1 signalling pathway, and at the same time it triggered a robust autophagy. The autophagy was characterized by the accumulation of punctate LC3 dots in the cytoplasm, morphological changes, and the increased levels of LC3-II as well as Atg5-Atg12 conjugated proteins. Inhibition of autophagy with chlorochine significantly enhanced the antitumour effect of ß-elemene. CONCLUSIONS: Our data indicated that ß-elemene inhibited the activity of the PI3K/Akt/mTOR/p70S6K1 signalling pathway in human NSCLC A549 cells, which resulted in apoptosis as well as protective autophagy. A combination of ß-elemene with autophagy inhibitor might be an effective therapeutic option for advanced NSCLC.

[Cisplatin enhances TRAIL-induced apoptosis in gastric cancer cells through clustering death receptor 4 into lipid rafts].

OBJECTIVE: Gastric cancer cells are insensitive to tumor necrosis factor-related apoptosis-inducing ligand (TRAIL). To sensitize gastric cancer cells to TRAIL, we treated gastric cancer MGC803 cells with TRAIL and cisplatin. METHODS: Cell proliferation was measured using MTT assay. Cell apoptosis was determined by flow cytometry. Expression of proteins was analyzed by Western blot. The distribution of lipid rafts and death receptors was analyzed by immunofluorescence microscopy. MGC803 cells were pretreated with 50 mg/L nystatin for 1 h, and followed by the treatment of cisplatin and TRAIL. RESULTS: 100 µg/L TRAIL resulted in (8.51 ± 3.45)% inhibition of cell proliferation and caused (3.26 ± 0.89)% cell apoptosis in MGC803 cells. Compared with the treatment with cisplatin alone, treatment with TRAIL (100 µg/L) and cisplatin (8.49 mg/L, IC(50) dose of 24 h) led to a dramatic increase in both inhibition of cell proliferation [(52.58 ± 4.57)% vs. (76.43 ± 5.35)%, P < 0.05] and cell apoptosis [(23.10 ± 3.41)% vs. (42.56 ± 4.11)%, P < 0.05]. Moreover, cleavage of caspase-8 and caspase-3 was detected. TRAIL (100 µg/L) did not induce obvious lipid rafts aggregation and death receptor 4 (DR4) clustering, while cisplatin (8.49 mg/L) significantly promoted the localization of DR4 in aggregated lipid rafts. Pretreatment with 50 mg/L nystatin, a cholesterol-sequestering agent, triggered (3.66 ± 0.52)% cell apoptosis after 24 h. Pretreatment with nystatin for 1 h before the addition of 8.49 mg/L cisplatin for 24 h caused a decreased tendency to cell apoptosis [(25.74 ± 3.28)% vs. (22.76 ± 2.97)%]. While, pretreatment with nystatin before the addition of cisplatin and TRAIL, the proportion of apoptotic cells decreased from (43.16 ± 4.26)% to (31.52 ± 3.99)% (P < 0.05). CONCLUSION: Cisplatin enhances TRAIL-induced apoptosis in gastric cancer MGC803 cells through clustering death receptors into lipid rafts.