scholarly journals Alantolactone inhibits cell autophagy and promotes apoptosis via AP2M1 in acute lymphoblastic leukemia

2020 ◽  
Author(s):  
Ce Shi ◽  
Wenjia Lan ◽  
Zhenkun Wang ◽  
Dongguang Yang ◽  
Jia Wei ◽  
...  
Keyword(s):  
Acute Lymphoblastic Leukemia ◽  
Tumor Growth ◽  
Cell Lines ◽  
Lymphoblastic Leukemia ◽  
Dependent Manner ◽  
Nude Mouse Model ◽  
Hematopoietic Malignancy ◽  
Induced Apoptosis ◽  
Anti Tumor Activity

Abstract Background: Acute lymphoblastic leukemia (ALL) is an aggressive hematopoietic malignancy that is most commonly observed in children. Alantolactone (ALT) has been reported to exhibit anti-tumor activity in different types of cancer. The aim of the present study was to investigate the anti-tumor activity and molecular mechanism of ALT in ALL. Methods: ALL cell lines were treated with 1, 5 and 10 μM ALT, and cell viability was assessed using an MTT assay and RNA sequencing. Flow cytometry, JC-1 staining and immunofluorescence staining assays were used to measure cell apoptosis and autophagy. Additionally, western blot analysis was used to detect expression of apoptosis and autophagy related proteins. Finally, the effects of ALT on tumor growth were assessed in a BV173 xenograft nude mouse model. Results: ALT inhibited the proliferation of ALL cells in a dose-dependent manner. Additionally, it was demonstrated that ALT inhibited cell proliferation, colony formation, autophagy, induced apoptosis and reduced tumor growth in vivo through upregulating the expression of adaptor related protein complex 2 subunit mu 1 (AP2M1). Moreover, the autophagy activator rapamycin, attenuated the pro-apoptotic effects of ALT on BV173 and NALM6 cell lines. Overexpression of AP2M1 decreased the expression of Beclin1 and the LC3-II/LC3-1 ratio, and increased p62 expression. Knockdown of Beclin1 increased the levels of bax, cleaved caspase 3 and cytochrome C, and decreased bcl-2 expression. Conclusions: The present study demonstrated that ALT exerts anti-tumor activity through inducing apoptosis and inhibiting autophagy by upregulating AP2M1 in ALL, highlighting a potential therapeutic strategy for treatment of ALL.

scholarly journals Alantolactone inhibits cell autophagy and promotes apoptosis via AP2M1 in acute lymphoblastic leukemia

2020 ◽  
Vol 20 (1) ◽  
Author(s):  
Ce Shi ◽  
Wenjia Lan ◽  
Zhenkun Wang ◽  
Dongguang Yang ◽  
Jia Wei ◽  
...  
Keyword(s):  
Acute Lymphoblastic Leukemia ◽  
Tumor Growth ◽  
Cell Lines ◽  
Lymphoblastic Leukemia ◽  
Dependent Manner ◽  
Nude Mouse Model ◽  
Hematopoietic Malignancy ◽  
Induced Apoptosis ◽  
Anti Tumor Activity

Abstract Background Acute lymphoblastic leukemia (ALL) is an aggressive hematopoietic malignancy that is most commonly observed in children. Alantolactone (ALT) has been reported to exhibit anti-tumor activity in different types of cancer. The aim of the present study was to investigate the anti-tumor activity and molecular mechanism of ALT in ALL. Methods ALL cell lines were treated with 1, 5 and 10 μM ALT, and cell viability was assessed using an MTT assay and RNA sequencing. Flow cytometry, JC-1 staining and immunofluorescence staining assays were used to measure cell apoptosis and autophagy. Additionally, western blot analysis was used to detect expression of apoptosis and autophagy related proteins. Finally, the effects of ALT on tumor growth were assessed in a BV173 xenograft nude mouse model. Results ALT inhibited the proliferation of ALL cells in a dose-dependent manner. Additionally, it was demonstrated that ALT inhibited cell proliferation, colony formation, autophagy, induced apoptosis and reduced tumor growth in vivo through upregulating the expression of adaptor related protein complex 2 subunit mu 1 (AP2M1). Moreover, the autophagy activator rapamycin, attenuated the pro-apoptotic effects of ALT on BV173 and NALM6 cell lines. Overexpression of AP2M1 decreased the expression of Beclin1 and the LC3-II/LC3-1 ratio, and increased p62 expression. Knockdown of Beclin1 increased the levels of bax, cleaved caspase 3 and cytochrome C, and decreased bcl-2 expression. Conclusions The present study demonstrated that ALT exerts anti-tumor activity through inducing apoptosis and inhibiting autophagy by upregulating AP2M1 in ALL, highlighting a potential therapeutic strategy for treatment of ALL.

scholarly journals Alantolactone inhibits cell autophagy and promotes apoptosis through targeting AP2M1 in acute lymphotic leukemia

2020 ◽  
Author(s):  
Ce Shi ◽  
Zhenkun Wang ◽  
Dongguang Yang ◽  
Jia Wei ◽  
Zhiyu Liu ◽  
...  
Keyword(s):  
Antitumor Activity ◽  
Tumor Growth ◽  
Cell Lines ◽  
Lymphoblastic Leukemia ◽  
Dependent Manner ◽  
Nude Mouse Model ◽  
Hematopoietic Malignancy ◽  
Apoptotic Effect ◽  
Induced Apoptosis

Abstract Background: Acute lymphoblastic leukemia (ALL) is an aggressive hematopoietic malignancy that is most common in children. Alantolactone (ALT) has been reported to have antitumor activity in different types of cancers. This study aimed to investigate the antitumor activity and molecular mechanism of ALT in ALL. Methods: The ALL cell lines were treated with 1, 5 and 10μM of ALT, and then subjected to MTT assay and RNA sequencing. Flow cytometry, JC-1 staining and immunofluorescence staining assays were employed to measure cell apoptosis and autophagy. Meanwhile, Western blot analysis was used to detect apoptosis and autophagy related proteins. Finally, the effect of ALT on tumor growth was measured in BV173 xenograft nude mouse model. Results: In this study, we demonstrated that ALT inhibited the proliferation of ALL cells in does-dependent manner. A series of experiments demonstrated that ALT inhibited cell proliferation, colony formation, autophagy, induced apoptosis and restained tumor growth in vivo through upregulating adaptor related protein complex 2 subunit mu 1 (AP2M1). Moreover, autophagy activator rapamycin attenuated the pro-apoptotic effect of ALT on BV173 and NALM6 cell lines. Further, overexpressed AP2M1 decreased the expression of Beclin1, LC3-II/LC3-1 ratio and increased p62 expression. Fianally, knockdown of Beclin1 increased the levels of bax, cleaved caspase 3 and cytochrome C and decreased bcl-2 expression. Conclusions: This study demonstrated that ALT exerts antitumor activity through inducing apoptosis and inhibiting autophagy by upregulating AP2M1 in ALL, indicating a potential therapeutic strategy for ALL treatment.

scholarly journals Alantolactone inhibits cell autophagy and promotes apoptosis through targeting AP2M1 in acute lymphotic leukemia

2020 ◽  
Author(s):  
Ce Shi ◽  
Zhenkun Wang ◽  
Dongguang Yang ◽  
Jia Wei ◽  
Zhiyu Liu ◽  
...  
Keyword(s):  
Flow Cytometry ◽  
Acute Lymphoblastic Leukemia ◽  
Therapeutic Strategy ◽  
Molecular Mechanisms ◽  
Lymphoblastic Leukemia ◽  
Nude Mouse Model ◽  
Hematopoietic Malignancy ◽  
Different Types ◽  
Related Proteins ◽  
Anti Tumor Activity

Abstract Background: Acute lymphoblastic leukemia (ALL) is an aggressive hematopoietic malignancy and most commonly seen in children. Alantolactone (ATL) has been reported to have anti-tumor activities in different types of cancer. This study aimed to evaluate the anti-tumor activity and molecular mechanisms of ATL in ALL. Methods: The ALL cells were treated with 1, 5 and 10μM of of ALT, and then subjected to MTT assay and RNA sequencing. Flow cytometry, JC-1 staining and immunofluorescence staining assay were employed to measure cell apoptosis and autophagy. Meanwhile, western blot analysis was used to detect apoptosis and autophagy-related proteins. Finally, the effect of ALT on tumor growth was measured in BV173 xenograft nude mouse model. Results: In this study, we demonstrated that ALT could inhibit the proliferation of ALL cells by inducing apoptosis and inhibiting autophagy. Administration of rapamycin activated autophagy while reversing the effect of ALT on apoptosis. Mechanically, ALT could induce apoptosis and inhibit autophagy by promoting AM2P1 expression. Further, AM2P1 was figured to inhibit beclin1 phosphorylation so that the apartment between beclin1 and bcl-2 was alleviated to participate in the regulation of autophagy and apoptosis in ALL cell. Conclusions: This study disclosed that Alantolactone can inhibit cell autophagy and promote apoptosis through targeting AP2M1 in acute lymphotic leukemia, indicating a potential therapeutic strategy for ALLtreatment.

Curcumin Induces Apoptosis by Inhibiting the Expression of IAPs in Human Precursor B-Acute Lymphoblastic Leukemic (PreB-ALL) Cells.

Blood ◽  
2005 ◽  
Vol 106 (11) ◽  
pp. 883-883 ◽  
Author(s):  
Azhar R. Hussain ◽  
Abdul K. Siraj ◽  
Pulicat S. Manogaran ◽  
Khawla S. Al-Kuraya ◽  
Shahab Uddin
Keyword(s):  
Acute Lymphoblastic Leukemia ◽  
Cell Lines ◽  
Lymphoblastic Leukemia ◽  
Philadelphia Chromosome ◽  
Dependent Manner ◽  
Curcumin Treatment ◽  
Down Regulation ◽  
Term Survival ◽  
Childhood All ◽  
Induced Apoptosis

Abstract Acute lymphoblastic leukemia (ALL) is the most common cancer of childhood resulting from the clonal proliferation of lymphoid precursors with arrested maturation. Chemotherapy can induce complete remission in more than 95% of cases of childhood ALL and achieve long-term survival in 70–80% of cases. However, ALL with the t(9:22) BCR-ABL translocation or Philadelphia chromosome (Ph1) are still highly resistant to chemotherapy from the onset. Thus, new therapeutic approaches are required to improve their prognosis. Characterization of the growth requirement of ALL cells suggest that these cancers are dependent on various cytokines via paracrine and/or autocrine mechanism in which the JAK family of proteins are closely implicated. Accordingly, tyrosine kinase inhibitors against JAKs are expected to become a new class of anti-tumor agents against these cancers. Curcumin has been shown to inhibit JAK-STAT pathway in a variety of hematological malignancies including multiple myeloma and primary effusion lymphomas. We therefore sought to determine whether curcumin suppresses the growth of acute lymphoblastic leukemia. We tested a panel of preB-ALL cell lines with various translocations after treatment with different doses of curcumin. The cell lines included REH (t12:21), RS4:11 (t4:11), 697 (t1:19) and SupB15(t9:22). Cell viability decreased in a concentration-dependent manner in 697, REH and RS4:11 with curcumin (0–40mM) whereas only minimal changes in viability was detected in SupB15. Curcumin induced apoptosis in all preB-ALL cell lines except SupB15 that was found to be refractory to curcumin treatment. Curcumin induced apoptosis via truncation of BID, loss of mitochondrial potential as determined by JC1 staining with subsequent release of cytochrome c from the mitochondria, and activation of caspase 3 and PARP. Curcumin treatment also caused the down-regulation of the IAPs, cIAP1 and XIAP. All these events occured in the sensitive cell lines 697, REH and RS4:11, however, in SupB15, curcumin failed to inhibit the expression of cIAP1 and XIAP and remained refractory to treatment. These results suggest that the IAPs may play an important role in curcumin induced apoptosis in preB-ALL cells. Altogether, our findings suggests a novel function for curcumin, acting as a growth suppressor of most preB-ALL cells and inducing apoptosis via down-regulation of IAPs. Therefore, curcumin may have a future therapeutic role in preB-ALL and possibly other malignancies.

Mir∼17-92 Identifies BCL2 As a Therapeutic Target In BCR-ABL Positive B-Lineage Acute Lymphoblastic Leukemia

Blood ◽  
2013 ◽  
Vol 122 (21) ◽  
pp. 835-835
Author(s):  
Matthias Eder ◽  
Alex Elder ◽  
David Barzan ◽  
Karin Battmer ◽  
Simon Bomken ◽  
...  
Keyword(s):  
Acute Lymphoblastic Leukemia ◽  
Cell Lines ◽  
Therapeutic Target ◽  
Isotope Labeling ◽  
Lymphoblastic Leukemia ◽  
Luciferase Reporter ◽  
Dependent Manner ◽  
Over Expression ◽  
Specific Manner

Abstract Despite advances in both targeted therapies with ABL-specific tyrosine kinase inhibitors and in allogeneic stem cell transplantation, BCR-ABL positive acute lymphoblastic leukemia (ALL) remains a very high-risk disease, necessitating the development of novel treatment strategies. miRNAs are small non-coding RNAs which regulate gene expression posttranscriptionally in a sequence-specific manner. miRNAs usually repress the expression of many target genes. We hypothesized that miRNAs may help to identify potential therapeutic targets if (i) they are expressed in a disease-specific manner and if (ii) modulating their expression induces a desired phenotype, such as apoptosis of tumour cells, in appropriate experimental models. Based on our observation that miR∼17-92-encoded miRNAs are significantly less abundant in primary BCR-ABL-positive as compared to negative ALL-cells, we studied the expression and function of miRNAs encoded by the miR∼17-92 derivative miR∼17-19b in a murine pro-B-cell line with inducible BCR-ABL-expression (TonB). Induction of BCR-ABL expression in TonB cells reduced endogenous miR-17, miR-18a, and miR-19 by 2 to 3.5-fold, confirming that expression of the miR∼17-92 cluster is controlled by BCR-ABL. Interestingly, over-expression of miR∼17-19b by lentiviral gene transfer led to a substantial induction of apoptosis in TonB cells in a BCR-ABL-dependent manner. To identify potential miRNA targets, we used a proteomic approach based on stable isotope labeling of amino acids in cell culture (SILAC) followed by liquid chromatography and mass spectroscopy (LC-MS) in miR∼17-19b transgenic TonB cells. Several apoptosis-related proteins were differentially expressed including Bcl2, an established inhibitor of mitochondrial pro-apoptotic pathways. The miRNA target prediction program RNA22 predicted several miR∼17-19b miRNA-binding sites within both murine and human Bcl2 mRNA, and we demonstrated direct miRNA binding to Bcl2 mRNA by luciferase reporter and anti-AGO2 RIP chip analyses. As with miR∼17-19b over-expression, Bcl2 specific RNAi strongly induced apoptosis in murine TonB and the human BCR-ABL-positive cell lines BV-173, Tom1 and SupB15. BCR-ABL positive human ALL-cell lines were also more sensitive than negative ones to pharmacological BCL2 inhibition with the BH3 mimetic ABT 737. In addition, inhibition of BCL2 by ABT 737 and BCR-ABL kinase activity by Imatinib exert different anti-leukemic effects with differential impact on miR∼17-92 miRNA-expression. To assess the therapeutic potential of BCL2 inhibition we used a xenotransplantation assay with real time in vivo monitoring of drug therapies by bioluminescent imaging. ABT-737 treatment substantially inhibited expansion of luciferase-expressing human primary BCR-ABL-positive ALL xenografts in NOD/LtSz-scid IL-2Rγ null (NSG) mice and significantly lengthened their median survival. Taken together, our data identify BCL2 as a therapeutic target of particular relevance in BCR-ABL-positive ALL and indicate involvement of miR∼17-92-encoded miRNAs in regulation of apoptosis in these cells. The validity of this miRNA-based approach to identify potential drug targets is demonstrated by the efficacy of the BCL2 inhibitor ABT-737 in an in vivo model of human BCR-ABL positive ALL, suggesting that BCL2 inhibition should be considered for early phase clinical testing as a strategy to improve disease outcomes. Disclosures: No relevant conflicts of interest to declare.

Restraining the Proliferation of Acute Lymphoblastic Leukemia Cells by Genistein through Up-regulation of B-cell Translocation Gene-3 at Transcription Level

2019 ◽  
Vol 8 ◽  
Author(s):  
Masoumeh Abedi Nejad ◽  
Mohsen Nikbakht ◽  
Masoomeh Afsa ◽  
Kianoosh Malekzadeh
Keyword(s):  
Acute Lymphoblastic Leukemia ◽  
B Cell ◽  
Cancer Cells ◽  
Cell Lines ◽  
Lymphoblastic Leukemia ◽  
Suppressor Gene ◽  
Transcription Level ◽  
Hematopoietic Malignancy ◽  
Proliferative Effect ◽  
Cancer Agent

Background: Acute lymphoblastic leukemia (ALL) is a highly prevalent pediatric cancer accounting for approximately 78% of leukemia cases in patients younger than 15 years old. Different studies have demonstrated that B-cell translocation gene 3 (BTG3) plays a suppressive role in the progress of different cancers. Genistein is considered a natural and biocompatible compound and a new anti-cancer agent. In this study, we evaluate the effect of genistein on BTG3 expression and proliferation of ALL cancer cells. Materials and Methods: ALL cell lines (MOLT4, MOLT17, and JURKAT) were cultured in standard conditions. Cytotoxicity of genistein was detected using MTT assay. The cells were treated with different concentrations of genistein (10, 25, 40, and 55μM) for 24, 48, and 72 hours, and then cell viability and growth rate were measured. The quantitative real-time polymerase chain reaction was applied to investigate the effect of genistein on BTG3 expression. Results: The percentage of vital cells treated with genistein significantly decreased compared to the non-treated cells, showed an inverse relationship with an increasing genistein concentration. The present study suggests a dose of 40μM for genistein as a potent anticancer effect. Genistein could elevate BTG3 for 1.7 folds in MOLT4 and JURKAT and 2.7 folds in MOLT17 cell lines at transcription level conveged with 60 to 90% reduction in the proliferation rate of cancer cells. Conclusion: Up-regulation of BTG3 as a tumor suppressor gene can be induced by genistein. It seems that BTG3 reactivation can be introduced as another mechanism of anti-proliferative effect of genistein and could be considered as a retardant agent candidate against hematopoietic malignancy.[GMJ. 2019;inpress:e1229]

scholarly journals Opposing regulation of BIM and BCL2 controls glucocorticoid-induced apoptosis of pediatric acute lymphoblastic leukemia cells

Blood ◽  
2015 ◽  
Vol 125 (2) ◽  
pp. 273-283 ◽  
Author(s):  
Duohui Jing ◽  
Vivek A. Bhadri ◽  
Dominik Beck ◽  
Julie A. I. Thoms ◽  
Nurul A. Yakob ◽  
...  
Keyword(s):  
Acute Lymphoblastic Leukemia ◽  
Glucocorticoid Receptor ◽  
Lymphoblastic Leukemia ◽  
Leukemia Cells ◽  
Pediatric Acute Lymphoblastic Leukemia ◽  
Intronic Region ◽  
Key Points ◽  
Pediatric All ◽  
Induced Apoptosis

Key Points The glucocorticoid receptor coordinately regulates the antiapoptotic BCL2 and proapoptotic BIM genes in pediatric ALL cells in vivo. GR binding at a novel intronic region is associated with BIM transcription and dexamethasone sensitivity in pediatric ALL cells in vivo.

scholarly journals Isoquinolinamine FX-9 Exhibits Anti-Mitotic Activity in Human and Canine Prostate Carcinoma Cell Lines

2019 ◽  
Vol 20 (22) ◽  
pp. 5567
Author(s):  
Jan Torben Schille ◽  
Ingo Nolte ◽  
Eva-Maria Packeiser ◽  
Laura Wiesner ◽  
Jens Ingo Hein ◽  
...  
Keyword(s):  
Cell Lines ◽  
Lymphoblastic Leukemia ◽  
Leukemia Cell ◽  
In Vivo Studies ◽  
Mediated Effects ◽  
Multinucleated Cells ◽  
Prostate Carcinoma Cell ◽  
Castrate Resistant ◽  
Induced Apoptosis

Current therapies are insufficient for metastatic prostate cancer (PCa) in men and dogs. As human castrate-resistant PCa shares several characteristics with the canine disease, comparative evaluation of novel therapeutic agents is of considerable value for both species. Novel isoquinolinamine FX-9 exhibits antiproliferative activity in acute lymphoblastic leukemia cell lines but has not been tested yet on any solid neoplasia type. In this study, FX-9′s mediated effects were characterized on two human (PC-3, LNCaP) and two canine (CT1258, 0846) PCa cell lines, as well as benign solid tissue cells. FX-9 significantly inhibited cell viability and induced apoptosis with concentrations in the low micromolar range. Mediated effects were highly comparable between the PCa cell lines of both species, but less pronounced on non-malignant chondrocytes and fibroblasts. Interestingly, FX-9 exposure also leads to the formation and survival of enlarged multinucleated cells through mitotic slippage. Based on the results, FX-9 acts as an anti-mitotic agent with reduced cytotoxic activity in benign cells. The characterization of FX-9-induced effects on PCa cells provides a basis for in vivo studies with the potential of valuable transferable findings to the benefit of men and dogs.

Activation of the JNK Pathway Mediates Chemoresistance in T-Cell Acute Lymphoblastic Leukemia by Phosphorylation and Proteosomal Degradation of BimEL.

Blood ◽  
2007 ◽  
Vol 110 (11) ◽  
pp. 2372-2372
Author(s):  
Kam Tong Leung ◽  
Karen Kwai Har Li ◽  
Samuel Sai Ming Sun ◽  
Paul Kay Sheung Chan ◽  
Yum Shing Wong ◽  
...  
Keyword(s):  
Acute Lymphoblastic Leukemia ◽  
T Cell ◽  
Cytochrome C ◽  
Cell Lines ◽  
Caspase 3 ◽  
Lymphoblastic Leukemia ◽  
Chemotherapeutic Agents ◽  
Jnk Pathway ◽  
Cell Acute Lymphoblastic Leukemia ◽  
Induced Apoptosis

Abstract Despite progress in the development of effective treatments against T-cell acute lymphoblastic leukemia (T-ALL), about 20% of patients still exhibit poor response to the current chemotherapeutic regimens and the cause of treatment failure in these patients remains largely unknown. In this study, we aimed at finding mechanisms that drive T-ALL cells resistant to chemotherapeutic agents. By screening etoposide sensitivity of a panel of T-ALL cell lines using DNA content and PARP cleavage as apoptosis markers, we identified an apoptosis-resistant cell line, Sup-T1. Western blot analysis and caspase activity assay showed that Sup-T1 cells were deficient in etoposide-induced activation of caspase-3 and caspase-9. In addition, mitochondrial cytochrome c release was not evident in etoposide-treated Sup-T1 cells. However, addition of exogenous cytochrome c in cell-free apoptosis reactions induced prominent caspase-3 activation, indicating that the chemoresistance observed in Sup-T1 cells was due to its insusceptibility to the drug-induced mitochondrial alterations. Analysis of the basal expression of the Bcl-2 family proteins revealed that the levels of Bcl-2 was higher in Sup-T1 cells, while Bax and BimEL levels were lower, when compared to etoposide-sensitive T-ALL cell lines. Gene silencing using antisense oligonucleotide to Bcl-2 and overexpression of Bax did not resensitize cells to etoposide-induced apoptosis. On the contrary, transient transfection of BimEL into Sup-T1 cells significantly restored etoposide sensitivity. Further experiments revealed that the lack of BimEL expression in Sup-T1 cells was due to the rapid degradation of newly-synthesized BimEL by the proteosomal pathway, as treatment of Sup-T1 cells with a proteosome inhibitor significantly restored the protein level of BimEL. Moreover, treatment with proteosome inhibitor resulted in mobility shift of BimEL, which was sensitive to phosphatase digestion. Furthermore, treatment of Sup-T1 cells with JNK inhibitor resulted in accumulation of BimEL, and pretreatment with JNK inhibitor restored sensitivity of Sup-T1 cells to etoposide-induced apoptosis, indicating that constitutive activation of the JNK pathway in Sup-T1 cells was responsible for promoting BimEL phosphorylation, and this may serve as a signal targeting BimEL to the proteosome for degradation. Altogether, our findings provide the first evidence that JNK activation correlates inversely with BimEL level by promoting its phosphorylation and degradation. This, in turn, reduces the sensitivity of T-ALL cells to chemotherapeutic agents.

NPI-2358, a Novel Vascular Disrupting Agent Blocks Growth and Angiogenesis in Multiple Myeloma Cells.

Blood ◽  
2009 ◽  
Vol 114 (22) ◽  
pp. 3842-3842
Author(s):  
Dharminder Chauhan ◽  
Ajita V. Singh ◽  
Madhavi Bandi ◽  
Noopur Raje ◽  
Robert L Schlossman ◽  
...  
Keyword(s):  
Cell Lines ◽  
Annexin V ◽  
Vascular Endothelial ◽  
Caspase 9 ◽  
Migration Assays ◽  
Induced Apoptosis ◽  
Rpmi 8226 ◽  
Anti Tumor Activity

Abstract Abstract 3842 Poster Board III-778 Background and Rationale Vascular disrupting agents (VDAs) act via selectively disrupting established tumor vasculature and have shown remarkable clinical success as anti-cancer therapies. NPI-2358 is a novel VDA with a distinct structure and mechanism of action from other available VDAs. NPI-2358 binds to the colchicine-binding site of beta-tubulin preventing polymerization and disrupting the cytoplasmic microtubule network, thereby causing loss of vascular endothelial cytoskeletal function, and inducing cytotoxicity in cancer cells. Here, we examined the anti-angiogenic and anti-tumor activity of NPI-2358 in multiple myeloma (MM) cells using both in vitro and in vivo model systems. Material and Methods We utilized MM.1S, MM.1R, RPMI-8226, U266, and INA-6 human MM cell lines, as well as purified tumor cells from MM patients relapsing after prior anti-MM therapies. Cell viability/apoptosis assays were performed using MTT, trypan blue exclusion, and Annexin V/PI staining. Angiogenesis was measured in vitro using Matrigel capillary-like tube structure formation assays: Since human vascular endothelial cells (HUVECs) plated onto Matrigel differentiate and form capillary-like tube structures similar to in vivo neovascularization, this assay measures anti-angiogenic effects of drugs/agents. Migration assays were performed using transwell insert assays. Immunoblot analysis was performed using antibodies to caspase-8, caspase-9, caspase-3, PARP, Bcl-2, Bax, pJNK and GAPDH. Statistical significance was determined using a Student t test. Results Treatment of MM.1S, RPMI-8226, MM.1R, INA-6, and KMS-12BM with NPI-2358 for 24h induces a dose-dependent significant (P < 0.005) decrease in viability of all cell lines (IC50 range: 5-8 nM; n=3). To determine whether NPI-2358-induced decrease in viability is due to apoptosis, MM cell lines were treated with NPI-2358 for 24h; harvested, and analyzed for apoptosis using Annexin V/PI staining. A significant increase in NPI-2358-induced apoptosis was observed in all MM cell lines (% Annexin V+/PI- apoptotic cells: MM.1S, 48 ± 2.3%; MM.1R, 46.6 ± 3.1%; RPMI-8226, 61.7 ± 4.5%; and INA-6, 59.9 ± 3.2%; P < 0.05; n=3). Importantly, NPI-2358 decreased viability of freshly isolated MM cells from patients (IC50 range: 3-7 nM; P < 0.005), without affecting the viability of normal peripheral blood mononuclear cells, suggesting specific anti-MM activity and a favorable therapeutic index for NPI-2358. Examination of in vitro angiogenesis using capillary-like tube structure formation assay showed that even low doses of NPI-2358 (7 nM treatment for 12h; IC50: 20 nM at 24h) significantly decreased tubule formation in HUVECs (70-80% decrease; P < 0.05). Transwell insert assays showed a marked reduction in serum-dependent migration of NPI-2358-treated MM cells (42 ± 2.1% inhibition in NPI-2358-treated vs. control; P < 0.05). NPI-2358 at the concentrations tested (5 nM for 12h) in the migration assays did not affect survival of MM cells (> 95% viable cells). A similar anti-migration activity of NPI-2358 was noted against HUVEC cells (48 ± 1.7% decrease in migration; P < 0.05). Mechanistic studies showed that NPI-2358-induced apoptosis was associated with activation of caspase-8, caspase-9, caspase-3 and PARP. Importantly, treatment of MM.1S cells with NPI-2358 (5 nM) triggered phosphorylation of c-Jun amino-terminal kinase (JNK), a classical stress response protein, without affecting Bcl-2 family members Bax and Bcl-2. Blockade of JNK using dominant negative strategy markedly abrogated NPI-2358-induced apoptosis. Conclusion Our preclinical data provide evidence for remarkable anti-angiogenic and anti-tumor activity of NPI-2358 against MM cells, without significant toxicity in normal cells. Ongoing studies are examining in vivo anti-MM activity of NPI-2358 in animal models. Importantly, a Phase-1 study of NPI-2358 as a single agent in patients with advanced malignancies (lung, prostrate and colon cancer) has already established a favorable pharmacokinetic, pharmacodynamic and safety profile; and, a Phase-2 study of the combination of NPI-2358 and docetaxel in non-small cell lung cancer showed encouraging safety, pharmacokinetic and activity data. These findings, coupled with our preclinical studies, provide the framework for the development of NPI-2358-based novel therapies to improve patient outcome in MM. Disclosures: Chauhan: Nereus Pharmaceuticals, Inc: Consultancy. Lloyd:Nereus Pharmaceuticals, In: Employment. Palladino:Nereus Pharmaceuticals, Inc: Employment. Anderson:Nereus Pharmaceuticals, Inc: Consultancy.

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