[Retracted] MicroRNA­520a attenuates proliferation of Raji cells through inhibition of AKT1/NF­κB and PERK/eIF2α signaling pathway.

Following the publication of this paper, it was drawn to the Editors' attention by a concerned reader that a pair of the lanes featured in the western blot gel for Fig. 3B on p. 1705 were strikingly similar, suggesting that the same data may have been imported into the figure to represent data that were intended to show the results from differently performed experiments. In addition, the western data shown in Fig. 6 on p. 1706 for the GRP78 and the p­PERK proteins also appeared to be strikingly similar, such that the same data may have also been inserted into this figure to show the results from different experiments. Finally, certain of the data in this paper were shown to have appeared in a previous publication that featured some of the same authors, albeit in different form [Zhang L, Huang D, Wang Q, Shen D, Wang Y, Chen B, Zhang J and Gai L: MiR­132 inhibits expression of SIRT1 and induces pro­inflammatory processes of vascular endothelial inflammation through blockade of the SREBP­1c metabolic pathway. Cardiovasc Drugs Ther 8: 303­311, 2014]. Owing to the fact that some of the contentious data in the above article had already been published elsewhere prior to its submission to Oncology Reports, and because of an overall lack of confidence in the presented data, the Editor has decided that this paper should be retracted from the Journal. The authors were asked for an explanation to account for these concerns, but the Editorial Office did not receive a reply. The Editor apologizes to the readership for any inconvenience caused. [Oncology Reports 36: 1702­1708, 2016; DOI: 10.3892/or.2016.4975].

P19 a Parthenin Analog Induces Cell Lineage Dependent Apoptotic and Immunomodulatory Signaling in Acute Lymphoid Leukemia Cells.

Leukemia is a type of cancer that affects the blood and bone marrow. Acute lymphoid leukaemia, also known as ALL, is regarded as one of the deadliest forms of cancer. Due to the rapid increase in various cancer cases and the development of resistance in cancer cells, it is necessary to identify novel lead molecules with more potent anticancer properties. There is a growing interest in using herbal products/analogs as multi-component agents (as anticancer agents and immunomodulators) for cancer treatment. In the present investigation, an attempt has been made to explore the anticancer and immunomodulatory activity of P19, an analog of parthenin in ALL. P19 was reported to exhibit anticancer efficacy by triggering apoptotic signaling events in human leukaemia HL-60 cells by significant NO production. In contrast to this finding, ROS and NO were not required for P19-mediated apoptosis in Raji cells. The mechanism of action of P19 was observed to be cancer cell lineage dependent. P19 demonstrated very effective anticancer properties against ALL (IC50 3µM). Molecular investigations revealed that P19 induced mitochondrion mediated apoptosis by Bax localization to mitochondria and enhanced cytosolic calcium in the cytoplasm. Further activation of the caspase 3, caspase 8 and PARP cleavage suggested the involvement of the caspase-mediated apoptosis. Anti-proliferative activity revealed the telomerase inhibition and cell cycle arrest in G0/G1 phase after P19 treatment. Immunomodulatory effects of the P19 revealed the enhanced INFÉ£ and NO production in Jurkat and THP cells. Owing to its antiproliferative and immunomodulatory potential against leukemia cells P19 can further be explored as effective therapeutics against leukemia.

Effect of Pulsatilla Saponin A on Proliferation and Apoptosis of Burkitt Lymphoma Cells Based on JAK2/STAT3 Signaling Pathway / 中国实验方剂学杂志

ObjectiveTo investigate the effect of pulsatilla saponin A （PSA） on proliferation and apoptosis of human Burkitt lymphoma （BL） cell line Raji cells and expression of related pathway proteins. MethodWith Raji cells as the research object， the cell proliferation was detected by cell counting kit-8 （CCK-8） method， and the half-maximal inhibitory concentration （IC50） values of 24 h， 48 h and 72 h were calculated to be 19.77， 18.31， 16.70 μmol·L-1， respectively. In subsequent related experiments， 0， 8， 16， 32 μmol·L-1 PSA were selected according to the IC50 value of Raji cells treated with PAS for 72 h. After 0， 8， 16， 32 μmol·L-1 PSA acted on Raji cells for 24， 48， 72 h， the optical density values of cell growth curve were detected by CCK-8 method. The zymogen activities of cysteine aspartate-specific protease （Caspase）-3， Caspase-8 and Caspase-9 in Raji cells treated with 0， 8， 16 and 32 μmol·L-1 PSA for 24 h were measured by Caspase-3， Caspase-8 and Caspase-9 colorimetric assay kit. The apoptosis rate and cell cycle of Raji cells treated with different concentrations of PSA after 24 h were detected by flow cytometry. The expression of B-cell lymphoma 2 （Bcl-2）， Bcl-2-associated X protein （Bax）， cleaved poly（ADP-ribose） polymerase （cleaved PARP）， cleaved cysteinyl aspartate-specific protease-3 （cleaved Caspase-3） apoptosis related protein and Janus kinase 2 （JAK2）， signal transducer and activator of transcription 3 （STAT3）， phosphorylated-JAK2 （p-JAK2）， and phosphorylated- STAT3 （p-STAT3） pathway proteins in Raji cells after 24 h of treatment with 0， 8， 16 and 32 μmol·L-1 PSA were tested by Western blot. ResultCompared with control group， decreased cell survival rate， inhibited cell proliferation， activated zymogens of Caspase-3， Caspase-8 and Caspase-9 （P<0.01）， increased apoptosis （P<0.05， P<0.01）， and enhanced cell cycle arrest in Gap phase 2 （G2） were observed in 8， 16 and 32 μmol·L-1 PSA groups（P<0.05， P<0.01）. Compared with control group， cells treated with 8， 16 and 32 μmol·L-1 PSA had lower expression of Bcl-2， p-JAK2， p-STAT3 proteins （P<0.05， P<0.01）， and higher expression of Bax， cleaved PARP and cleaved Caspase-3 protein （P<0.01）， while no significant change was found in the expression of JAK2 and STAT3 proteins. ConclusionPSA could inhibit proliferation and induce apoptosis of Raji cells， and its potential mechanism might be related to the regulation of JAK2/STAT3 signaling pathway.

Characterization of a xenograft model for anti-CD19 CAR T cell studies

Purpose Chimeric antigen receptor (CAR) T cell development for B cell malignancies treatment has triggered a paradigm shift in oncology. The development of anti-CD19 CAR T cells relies primarily on a panel of cell line-derived xenograft models, including Raji cells; however, the behavior of this model is under debate. We attempted to characterize this lymphoma model and propose outcome measures for CAR T cell studies Methods Raji cell line was inoculated into NOG mice via intra-venous (IV), intra-peritoneal (IP), and subcutaneous (SC) routes with different inoculum sizes, and consequent clinical and histopathological outcomes were assessed. Results Inoculum sizes of 105–106 resulted in a complete take rate. The mice with IV and SC-inoculated Raji cells presented the shortest and longest survival among lymphoma-bearing mice, respectively (P < 0.01). The IP group had the highest number of both infiltrated organs (P < 0.05; compared to SC) and involvement of lymphatic sites (P < 0.05; compared to IV). The number of lymphoma lesions on the liver was higher in the IV compared to IP (P < 0.001) and SC (P < 0.05). Conclusion We demonstrate that the Raji cell line inoculation route could determine the xenograft model system behavior in terms of survival, tumor burden, and dissemination pattern and gives the model the specific features suitable for testing the specific hypothesis in CAR T cell therapy. We also conclude outcome measures for CAR T cell studies that do not require imaging techniques (AU)

In vitro assessment of the efficiency of the PIM-1 kinase pharmacological inhibitor as a potential treatment for Burkitt's lymphoma.

Burkitt's lymphoma is an aggressive form of lymphoma affecting B lymphocytes. It occurs endemically in Africa and sporadically in the rest of the world. Due to the high proliferation rate of this tumor, intensive multi-drug treatment is required; however, the risk of tumor syndrome lysis is high. Overexpression of the proto-oncogene proviral integration of the Moloney murine leukemia virus (PIM-1) kinase is associated with the development of hematological abnormalities, including Burkitt's lymphoma (BL). PIM-1 primarily exerts anti-apoptotic activities through BAD phosphorylation. The aim of the present study was to investigate the in vitro efficiency of a PIM-1 kinase pharmacological inhibitor (PIM1-1) in BL. The impact of PIM1-1 was evaluated in terms of the viability and apoptosis status of the BL B cell lines, Raji and Daudi, compared with K562 leukemia cells, which highly express PIM-1. Cell viability and apoptotic status were assessed with western blotting, and PIM-1 gene expression was assessed with reverse transcription-quantitative PCR. After 48 h of treatment, PIM1-1 inhibited the Daudi, Raji and K562 cell viability with a half-maximal inhibitory concentration corresponding to 10, 20 and 30 µM PIM1-1, respectively. A significant decrease of ERK phosphorylation was detected in PIM1-1-treated Daudi cells, confirming the antiproliferative effect. The addition of 10 µM PIM1-1 significantly decreased the PIM-1 protein and gene expression in Daudi cells. An inhibition of the pro-apoptotic BAD phosphorylation was observed in the Daudi cells treated with 0.1-1 µM PIM1-1 and 10 µM PIM1-1 decreased BAD phosphorylation in the Raji cells. The apoptotic status of both PIM1-1-treated cells lines were confirmed with the detection of cleaved capase-3. However, no change in cell viability and PIM-1 protein expression was observed in the 10 µM PIM1-1-treated K562 cells. In conclusion, the findings indicated that the PIM1-1 pharmacological inhibitor may have therapeutic potential in BL, but with lower efficiency in leukemia.

Characterization of a xenograft model for anti-CD19 CAR T cell studies.

PURPOSE: Chimeric antigen receptor (CAR) T cell development for B cell malignancies treatment has triggered a paradigm shift in oncology. The development of anti-CD19 CAR T cells relies primarily on a panel of cell line-derived xenograft models, including Raji cells; however, the behavior of this model is under debate. We attempted to characterize this lymphoma model and propose outcome measures for CAR T cell studies METHODS: Raji cell line was inoculated into NOG mice via intra-venous (IV), intra-peritoneal (IP), and subcutaneous (SC) routes with different inoculum sizes, and consequent clinical and histopathological outcomes were assessed. RESULTS: Inoculum sizes of 105-106 resulted in a complete take rate. The mice with IV and SC-inoculated Raji cells presented the shortest and longest survival among lymphoma-bearing mice, respectively (P < 0.01). The IP group had the highest number of both infiltrated organs (P < 0.05; compared to SC) and involvement of lymphatic sites (P < 0.05; compared to IV). The number of lymphoma lesions on the liver was higher in the IV compared to IP (P < 0.001) and SC (P < 0.05). CONCLUSION: We demonstrate that the Raji cell line inoculation route could determine the xenograft model system behavior in terms of survival, tumor burden, and dissemination pattern and gives the model the specific features suitable for testing the specific hypothesis in CAR T cell therapy. We also conclude outcome measures for CAR T cell studies that do not require imaging techniques.

Anticancer Activity of Pasak Bumi Root Extract (Eurycoma longifolia Jack) on Raji Cells.

<b>Background and Objective:</b> The use of the roots of the pasak bumi (<i>E. longifolia</i> Jack) to treat cancer has been studied widely, however, the scientific basis of these plants used as an anticancer drug is widely unknown. The purpose of this study was to examine the anticancer activity of ethyl acetate and non-ethyl acetate fractions of pasak bumi roots in Raji cells. <b>Materials and Methods:</b> The cytotoxicity test is using the direct cell count method with trypan blue staining. The growth inhibition is using doubling time analysis of Raji cells. Observation of the apoptotic events of Raji cells used ethidium bromide staining, while observing the expression of p53 protein in Raji cells was done by immunohistochemical staining. <b>Results:</b> The results of the cytotoxicity and doubling time test showed that the activity of the non-ethyl acetate fraction was greater than that of the roots of pasak bumi. The lower concentration of non-ethyl acetate fraction of pasak bumi roots was able to delay the multiplication time of Raji cells which was greater than that of ethyl acetate. The results of the cytotoxicity and doubling time test showed that the activity of the non-ethyl acetate fraction was greater than that of the roots of pasak bumi. <b>Conclusion:</b> It can be concluded that the ethyl acetate and non-ethyl acetate fractions of the roots of pasak bumi have cytotoxic and antiproliferative activity on Raji cells, however they cannot induce apoptosis in Raji cells. The death of Raji cells is through the mechanism of inhibiting Raji cell proliferation as evidenced by an increase in p53 protein expression.

A specific inhibitor of polo-like kinase 1, GSK461364A, suppresses proliferation of Raji Burkitt's lymphoma cells through mediating cell cycle arrest, DNA damage, and apoptosis.

Polo-like kinase 1 (PLK1) is a prominent mediatory player during the cell cycle, mitosis, and cytokinesis in eukaryotic cells. Besides its physiological roles, PLK1 expression is upregulated in a wide range of human malignant tumors and its overexpression worsens prognosis, therefore, specific inhibition of PLK1 in tumor cells is a fascinating approach for the development of novel chemotherapeutics. The present study elucidated the potential cytotoxic effects of a PLK1 inhibitor, GSK461364A, in five cancer cell lines including Raji, K562, PC3, MCF-7, MDA-MB-231, along with noncancerous L929 cells by XTT assay. The cells were treated for 24 h with GSK461364A at different concentrations ranged between 0.5 and 40 µM and significant cytotoxicity was observed in all treated groups with the IC50 values between 2.36 and 4.08 µM. GSK461364A was also found to be safer with lower cytotoxicity against L929 cells and the IC50 value was found to be greater than 40 µM. Raji cells were identified as the most sensitive cell line against GSK461364A with the lowest IC50 values, hence it was selected for further studies to evaluate the underlying mechanism of cytotoxic activity. The treatment of Raji cells with GSK461364A caused a cell cycle arrest at the G2/M phase, also altered TOS, which is an indicator of oxidative stress, and DNA damage response, significantly. The Annexin V binding assay revealed that GSK461364A treatment significantly increased in the percentage of early and late apoptotic cells. Fluorescence imaging also showed that GSK461364A treatment significantly induced apoptosis of Raji cells. The apoptotic effect of the compound has also been confirmed by increased expressions of Bax and cleaved caspase 3 and along with the decreased expression of BCL-2. The results demonstrated that GSK461364A induced anticancer effects which was mainly promoted by cell cycle arrest, oxidative stress, DNA damage, and finally apoptosis in Burkitt's lymphoma cells. Taken together, the present results emphasized that GSK461364A could be a useful therapeutic agent in patients with Burkitt's lymphoma. However, further studies are required to consolidate the anticancer activity of this promising compound.

An Integrative In Silico Mathematical Modelling Study of The Anti-Cancer Effect of Clove Extract ( Syzygium aromaticum ) Combined with In Vitro Metabolomics Study Using 1HNMR Spectroscopy.

BACKGROUND: Clove oil is known for its medicinal properties. The mechanism of anti-cancer properties of Syzygium aromaticum were investigated by mathematical modelling on the genome scale with metabolomics using 1H Nuclear Magnetic Resonance spectroscopy on Raji cells. OBJECTIVES: An integrative analysis correlated the metabolites identified by 1HNMR and genes with the detected pathways. MATERIALS AND METHODS: Raji cells treated with clove oil were collected and sent for 1HNMR spectroscopy and the spectra analyzed by MATLAB and Human Metabolome Database for metabolite identification. Pathway and topology analysis was implemented using the genes and metabolites in the integrative analysis of Metaboanalyst software. RESULTS: 50% inhibitory concentration of clove oil was 50 µg/ml and the model anticipated 74 genes with differentiating metabolites being some amino acids, cholesterol and fucose. CONCLUSION: The integrative study predicted that the anti cancer mechanism of clove oil involves novel enzymes, as likely drug targets, 24-dehydrocholesterol reductase and 7-dehydrocholesterol reductase in cholesterol biosynthesis, dehydrofolate reductase in one carbon metabolism and serine palmitoyl-transferase long chain in sphingolipid biosynthesis.

Knockdown of long non-coding RNA PVT1 inhibits the proliferation of Raji cells through cell cycle regulation.

Long non-coding RNA plasmacytoma variant translocation 1 (PVT1) has been reported to be associated with oncogenesis. However, the functional role of PVT1 in Burkitt lymphoma has not yet been addressed. The purpose of the present study was to investigate the effect of PVT1 knockdown by small interfering RNA (siRNA) on the proliferation of Burkitt lymphoma Raji cells and to explore its possible mechanism of action. An effective siRNA targeting PVT1 was screened and the corresponding short hairpin RNA (shRNA) was reconstructed into a lentiviral vector. Cell proliferation and cell cycle distribution were assessed by Cell Counting kit-8 assay and flow cytometry, respectively. Protein expression levels of c-Myc, cyclin-dependent kinase inhibitor1A (CDKN1A, P21) and cyclin E1 (CCNE1) were detected by western blotting. A polymerase chain reaction (PCR) array was used to analyse the expression of genes associated with the cell cycle. PVT1 knockdown markedly suppressed proliferation, and induced cell cycle arrest at the G0/G1 phase in Raji cells. Protein expression levels of c-Myc and CCNE1 were reduced, whereas P21 protein expression was markedly increased following downregulation of PVT1 in Raji cells. The cell cycle PCR array revealed that 54 genes were upregulated and 26 genes were downregulated in Raji cells following PVT1 knockdown. Reverse transcription-quantitative PCR demonstrated that cyclin G2 (CCNG2), CDKN1A, Retinoblastoma-like 2 (RBL2, p130), HUS1 checkpoint homolog, cyclin dependent kinase inhibitor 3 (CDKN3) and cyclin dependent kinase inhibitor 1B (CDKN1B) expression were upregulated, whereas the expression levels of CCNE1, cyclin D1 (CCND1) and cell division cycle 20 (CDC20) were downregulated in Raji cells with PVT1 knockdown. In conclusion, PVT1 knockdown may inhibit the proliferation of Raji cells by arresting cells in G0/G1 phase. Furthermore, inhibition of cell proliferation may be associated with a reduction inc-Myc expression and alterations in the expression levels of cell cycle-associated genes.

Effects of PTEN Combined with Adriamycin on the Proliferation, Migration and Invasion of Adriamycin in Non Hodgkin lymphoma Raji Cells / 中国药学杂志

OBJECTIVE: To investigate the inhibitiom effect of PTEN(gene of phosphate and tension homology deleted on chromsome ten) combined with adriamycin on proliferation, migration and invasion of non-Hodgkin lymphoma cell line Raji in vitro. METHODS: Cell proliferation was determined by MTT in Raji cells response to adriamycin with different concentrations. Transwell assay was performed to evaluate the effects of adriamycin and PTEN on migration and invasion of Raji cells. RT-qPCR was conducted to measure the expression of PTEN in Raji cells after adriamycin treatment. RESULTS: Adriamycin significantly inhibited the proliferation of Raji cells in a concentration dependent manner (r=-0.925, P<0.001). Adriamycin inhibited invasion and migration in Raji cells. Moreover, adriamycin promoted the expression of PTEN. Overexpression of PTEN markedly suppressed invasion and migration in Raji cells. The combination of adriamycin and PTEN strikingly decreased the proliferation, invasion and migration of Raji cells. CONCLUSION: Adriamycin and PTEN would inhibite the proliferation, invasion and migration of Raji cells. PTEN drastically enhances the inhibition of adriamycin on the proliferation, migration and invasion of Raji cells.

The sequential switch from macroautophagy to chaperone-mediated autophagy in Raji cells induced by starvation / 中国药理学通报

Aim To research the cross-talk and conversion between macroautophagy and chaperone-media-ted autophagy ( CMA) in cultured Burkitt lymphoma Raji cells induced by starvation. Methods The autophagic vacuoles were observed by fluorescence microscopy and confocal laser-scanning microscopy with monodansylcadaverine staining. The expression of autophagy associated-proteins were determined by West-em blot. Results Both macroautophagy and CMA were activated sequentially instead of simultaneously in starvation-induced Raji cells, and macroautophagy was quickly activated and peaked during the first hours of near baseline. With starvation persisted, CM A progressively increased along with the decline of macroautoph- A gy. Conclusions Macroautophagy and CMA are maximally activated during different stages of starvation. Activation of these two pathways is often sequential. The sequential switch from macroautophagy to CMA might be conducive to the adaption of cancer cells to miscellaneous intracellular or extracellular changes, maintaining their own growth and proliferation.

TRIM65 is a potential oncogenic protein via ERK1/2 on Jurkat and Raji cells: A therapeutic target in human lymphoma malignancies.

In human lung cancer, Tripartite motif 65 (TRIM65) is documented as an important regulator in carcinogenesis. Knockdown of TRIM65 prevents the tumorigenesis of lung cancer cells, while TRIM65 overexpression presents the opposite effect. However, the roles of TRIM65 in human lymphocyte malignancies have reported little. Herein, we found that Jurkat (T-lymphocyte) and Raji (B-lymphocyte) expressed TRIM65. We aimed to investigate whether TRIM65 was a potential oncogenic protein that regulated the tumorigenesis of Jurkat and Raji cells. In our present study, cells were transfected with siRNA-TRIM65 or TRIM65 overexpression vector, Cell counting kit-8 (CCK-8), Flow cytometry and Annexin V-FITC/propidium iodide (PI) staining was carried out to detect cell viability, cell cycle profile and cell apoptosis, respectively. Extracellular signal-regulated kinases 1/2 (ERK1/2) pathway-associated proteins, such as Bcl2, cleaved-caspase 3, vascular endothelial growth factor (VEGF), and phosphorylated ERK1/2 (p-ERK1/2) were assessed. Our data indicated that knockdown of TRIM65 prevented the tumorigenesis of Jurkat and Raji cells. TRIM65 silencing inhibited cell proliferation, promoted cell apoptosis and arrested cell cycle, highly like through blocking ERK1/2 pathway. However, TRIM65 overexpression enhanced cell viability, increased the protein levels of Bcl2, VEGF, p-ERK1/2 while decreased cleaved-caspase 3 expression, suggesting the promoted effect of TRIM65 overexpression in the tumorigenesis of those two lymphoma cells. To validate the involvement of ERK1/2 pathway, ERK1/2 inhibitor AZD8330 (1 µmol/L) was introduced. We found that AZD8330 significantly prevented TRIM65 overexpression-induced tumorigenesis. We concluded that TRIM65 served as a potential oncogenic protein on Jurkat and Raji cells, and ERK1/2 pathway was the underlying mechanism. Approaches targeting TRIM65 provided a novel strategy for the treatment of lymphoma.

Synthesis and Functional Investigations of Computer Designed Novel Cladribine-Like Compounds for the Treatment of Multiple Sclerosis.

Cladribine (2-CdA) is used as an anti-cancer drug but is currently studied as a potential treatment for use in relapsing-remitting multiple sclerosis (MS). In this study, we computer designed, synthesized, and characterized two novel derivatives of 2-CdA, K1-5d and K2-4c, and investigated their underlying mechanism of beneficial effect using the CCRF-CEM and RAJI cell lines. For this purpose, we first determined their effect on MS and DNA damage and repair-related gene expression profiles using custom arrays along with 2-CdA treatment at non-toxic doses. Then, we determined whether cells underwent apoptosis after treatment with 2-CdA, K1-5d, and K2-4c in CCRF-CEM and RAJI cells, using the DNA fragmentation assay. It was found that both derivatives modulated the expression of the pathway-related genes that are important in inflammatory signaling, apoptosis, ATM/ATR, double-strand break repair, and the cell cycle. Furthermore, 2-CdA, K1-5d, and K2-4c significantly activated apoptosis in both cell lines. In summary, our data demonstrate that although both derivatives act as anti-inflammatory and apoptotic agents, inducing the accumulation of DNA strand breaks and activating the ultimate tumor suppressor p53 in T and B lymphocytes, the K1-5d derivative has shown more promising activities for further studies.

Evaluation of various glyphosate concentrations on DNA damage in human Raji cells and its impact on cytotoxicity.

Glyphosate is a highly used active compound in agriculturally based pesticides. The literature regarding the toxicity of glyphosate to human cells has been highly inconsistent. We studied the resulting DNA damage and cytotoxicity of various glyphosate concentrations on human cells to evaluate DNA damaging potential. Utilizing human Raji cells, DNA damage was quantified using the comet assay, while cytotoxicity was further analyzed using MTT viability assays. Several glyphosate concentrations were assessed, ranging from 15 mM to 0.1 µM. We found that glyphosate treatment is lethal to Raji cells at concentrations above 10 mM, yet has no cytotoxic effects at concentrations at or below 100 µM. Treatment concentrations of 1 mM and 5 mM induce statistically significant DNA damage to Raji cells following 30-60 min of treatment, however, cells show a slow recovery from initial damage and cell viability is unaffected after 2 h. At these same concentrations, cells treated with additional compound did not recover and maintained high levels of DNA damage. While the cytotoxicity of glyphosate appears to be minimal for physiologically relevant concentrations, the compound has a definitive cytotoxic nature in human cells at high concentrations. Our data also suggests a mammalian metabolic pathway for the degradation of glyphosate may be present.

[Effects of dihydroartemisinin on radiosensitivity of Raji cells].

OBJECTIVE: To study the effects of dihydroartemisinin (DHA) on radiation sensitivity of Raji cells, and explore its mechanisms. METHODS: CCK8 was used to determine the effect of DHA on cell viability of Raji cells; apoptosis, intracellular reactive oxygen speies(ROS) and mitochondrial membrane potential of Raji cells were detected by flow cytometry; and the protein expressions of protein kinase B(AKT), phospho-rylated-protein kinase B(p-AKT), Bcl-2 and Bax were determined by Western blot. RESULTS: The cells were randomly divided into four groups:control group, DHA(5µmol/L DHA), irradiation(IR, 4 Gy), IR+DHA group (4 Gy IR+5 µmol/L DHA). Compared with the other three groups, cells in DHA+IR group exhibited lower mitochondrial membrane potential (P<0.01). While the intracellular ROS content and apoptosis rate of Raji cells in DHA+IR group were increased significantly(P<0.01). In addition, compared with the other three groups, there was no significant difference in the expression of AKT, but the phosphorylation of AKT protein were significantly inhibited and the expression of Bcl-2 protein was markedly decreased. However, the expressions of Bax and Cleaved-Caspase-3 protein were markedly increased. CONCLUSIONS: DHA might activate the mitochondrial apoptotic signal via inhibiting phosphoinositide 3-kinase (PI3K/AKT) pathway and increase oxidative stress to enhance the radiosensitivity of Raji cells.

Human B cells have an active phagocytic capability and undergo immune activation upon phagocytosis of Mycobacterium tuberculosis.

The paradigm that B cells are nonphagocytic was taken for granted for a long time until phagocytic B cells were found in early vertebrate animals. Thereafter, limited evidence has shown that human B cells may also internalize bacteria. However, whether human B cells can actively phagocytose bacteria has been less extensively investigated; in particular, the mechanisms and significance of the phagocytosis require clarification. Here, we show that the human Raji B cell line can phagocytose both live and dead Mycobacterium tuberculosis (Mtb), and the phagocytosed Mtb in turn affects the immune functions of the B cells. After incubation of Raji cells with Mtb, our confocal microscopy, electron microscopy and flow cytometry data showed that Raji cells effectively engulfed Mtb as well as latex beads. The phagocytic rate was proportional to the incubation time and the amount of Mtb or beads added. Additionally, we found that normal human serum could enhance the ability of Raji cells to phagocytose Mtb, while heat-inactivated serum reversed this promoting effect. The phagocytic process of B cells could partially be inhibited by cytochalasin B, an actin inhibitor. Importantly, the phagocytosed Mtb could regulate B cell immune functions, such as stimulating IgM production and upregulating the expression of the antigen-presenting costimulatory molecules CD80 and CD86. Therefore, our results provide the first evidence that human B cells can phagocytose Mtb in an active manner that is independent of bacterial viability, and phagocytosed Mtb can in turn regulate the immune activation of B cells.

Marsdenia tenacssima extract and its functional components inhibits proliferation and induces apoptosis of human Burkitt leukemia/lymphoma cells in vitro and in vivo.

Burkitt lymphoma is a fast growing non-Hodgkin lymphoma that occurs primarily in young males. The causes of Burkitt lymphoma include chromosome rearrangement and virus infection, but accurate and complete reasons remain to be discovered. The available treatment for Burkitt lymphoma is chemotherapy and radiation therapy. It is a highly aggressive B-cell neoplasm with not all patients cured, in spite of current therapies. This study evaluated the effects of traditional Chinese medicine Marsdenia tenacssima (MTE) and its component compound Tenacigenoside A (TGTA) and 11α-O-benzoyl-12ß-O-acetyltenacigenin B (TGTB) on human Burkitt lymphoma growth. It was observed that MTE, TGTA or TGTB inhibited cell growth and induced apoptosis of Burkitt lymphoma cells in culture. In lymphoma bearing NOD/SCID nude mice, both TGTA and TGTB inhibited tumor growth and improved animal survival. TGTA and TGTB significantly increased tumor cell apoptosis on lymphoma bearing mice, primarily through down-regulation of BCL2 and BCL-XL and up-regulation of BID.

A rapid and sensitive method to measure the functional activity of Shiga toxins in human serum.

Shiga toxins (Stx) have a definite role in the development of hemolytic uremic syndrome in children with hemorrhagic colitis caused by pathogenic Stx-producing Escherichia coli (STEC) strains. The dramatic effects of these toxins on the microvasculature of different organs, particularly of the kidney, are well known, whereas there is no consensus on the mechanism by which Stx reach the endothelia of target organs and/or indirectly injure these body sites. We hereby describe a quick (4 h), radioactive, Raji cell-based method designed for the detection of Stx in human sera. The assay monitors the translation impairment induced by these powerful inhibitors of protein synthesis, which are identified properly by neutralizing their activity with specific monoclonal antibodies. By this method, we detected for the first time the functional activity of Stx in sera of STEC-infected patients during hemorrhagic colitis. Recent research has pointed to a dynamic process of Stx-induced renal intoxication in which concurrent and interactive steps are involved. Our rapid and specific method could be useful for studying the kinetics of Stx during the natural course of STEC infection and the interplay between Stx activity in serum and Stx presence in different blood fractions (neutrophils, monocytes, platelets, leukocyte-platelet aggregates, microvesicles, lipoproteins).

DNA damage caused by inorganic particulate matter on Raji and HepG2 cell lines exposed to ultraviolet radiation.

Epidemiological studies have correlated exposure to ultraviolet-irradiated particulate matter with cardiovascular, respiratory, and lung diseases. This study investigated the DNA damage induced by two major inorganic particulate matter compounds found in diesel exhaust, ammonium nitrate and ammonium sulfate, on Burkitt's lymphoma (Raji) and hepatocellular carcinoma (HepG2) cell lines. We found a dose-dependent positive correlation of accumulated DNA damage at concentrations of ammonium nitrate (25 µg/ml, 50 µg/ml, 100 µg/ml, 200 µg/ml, 400 µg/ml) with ultraviolet exposure (250 J/m(2), 400 J/m(2), 600 J/m(2), 850 J/m(2)), as measured by the comet assay in both cell lines. There was a significant difference between the treated ammonium nitrate samples and negative control samples in Raji and HepG2 cells (p<0.001). Apoptosis was shown in Raji and HepG2 cells when exposed to high concentrations of ammonium nitrate (200 µg/ml and 400 µg/ml) for 1h in samples without ultraviolet exposure, as assessed by the comet assay. However, the level of apoptosis greatly diminished after ultraviolet exposure at these concentrations. Over a 24h period, at intervals of 1, 4, 8, 12, 18, and 24h, we also observed that ammonium nitrate decreased viability in Raji and HepG2 cell lines and inhibited cell growth. Ammonium sulfate-induced DNA damage was minimal in both cell lines, but there remained a significant difference (p<0.05) between the ultraviolet radiation treated and negative control samples. These results indicate that the inorganic particulate compound, ammonium nitrate, induced DNA strand breaks at all concentrations, and indications of apoptosis at high concentrations in Raji and HepG2 cells, with ultraviolet radiation preventing apoptosis at high concentrations. We hypothesize that ultraviolet radiation may inhibit an essential cellular mechanism, possibly involving p53, thereby explaining this phenomenon. Further studies are necessary to characterize the roles of apoptosis inhibition induced by DNA damage caused by inorganic particulate matter.