Exposure to UV light causes increased biotinylation of histones in Jurkat cells

2002 ◽  
Vol 283 (3) ◽  
pp. C878-C884 ◽  
Author(s):  
Dorothea M. Peters ◽  
Jacob B. Griffin ◽  
J. Steven Stanley ◽  
Mary M. Beck ◽  
Janos Zempleni
Keyword(s):  
Dna Damage ◽  
Confocal Microscopy ◽  
Western Blot ◽  
Blot Analysis ◽  
Western Blot Analysis ◽  
Caspase 3 ◽  
Uv Light ◽  
Jurkat Cells ◽  
Uv Exposure ◽  
Thymine Dimers

Biotin in breakdown products of biotinylated carboxylases serves as substrate for biotinylation of histones by biotinidase. Here we determined whether biotinylation of histones might play a role in repair of damaged DNA and in apoptosis. Jurkat cells were exposed to UV light to induce DNA damage. Abundance of thymine dimers increased about three times in response to UV exposure, consistent with DNA damage. Biotin-containing carboxylases were degraded in response to UV exposure, as judged by Western blot analysis and carboxylase activities. Mitochondrial integrity decreased in response to UV exposure (as judged by confocal microscopy), facilitating the release of breakdown products of carboxylases from mitochondria. Biotinylation of histones increased in response to UV exposure; biotinylation of histones did not occur specifically at sites of newly repaired DNA. UV exposure triggered apoptosis, as judged by caspase-3 activity and analysis by confocal microscopy. In summary, this study provided evidence that increased biotinylation of histones in DNA-damaged cells might either be a side product of carboxylase degradation or a step during apoptosis.

scholarly journals DIAPH1 Is Upregulated and Inhibits Cell Apoptosis through ATR/p53/Caspase-3 Signaling Pathway in Laryngeal Squamous Cell Carcinoma

2019 ◽  
Vol 2019 ◽  
pp. 1-10 ◽  
Author(s):  
Jiechao Yang ◽  
Liang Zhou ◽  
Yanping Zhang ◽  
Juan Zheng ◽  
Jian Zhou ◽  
...  
Keyword(s):  
Squamous Cell Carcinoma ◽  
Western Blot ◽  
Cell Carcinoma ◽  
Squamous Cell ◽  
Blot Analysis ◽  
Western Blot Analysis ◽  
Molecular Mechanisms ◽  
Caspase 3 ◽  
Laryngeal Squamous Cell Carcinoma ◽  
Poor Overall Survival

Cancer bioinformatics has been used to screen possible key cancer genes and pathways. Here, through bioinformatics analysis, we found that high expression of diaphanous related formin 1 (DIAPH1) was associated with poor overall survival in head and neck squamous cell carcinoma and laryngeal squamous cell carcinoma (LSCC). The effect of DIAPH1 in LSCC has not been previously investigated. Therefore, we evaluated the expression, function, and molecular mechanisms of DIAPH1 in LSCC. Immunohistochemistry and western blot analysis confirmed the significant upregulation of DIAPH1 in LSCC. We used DIAPH1 RNA interference to construct two DIAPH1-knockdown LSCC cell lines, AMC-HN-8 and FD-LSC-1, and validated the knockdown efficiency. Flow cytometry data showed that DIAPH1 inhibited apoptosis. Further, western blot analysis revealed that DIAPH1 knockdown increased the protein levels of ATR, p-p53, Bax, and cleaved caspase-3, -8, and -9. Thus, DIAPH1 is upregulated in LSCC and may act as an oncogene by inhibiting apoptosis through the ATR/p53/caspase-3 pathway in LSCC cells.

Abstract 255: Cytoprotective Effects of Erythropoietin and Erythropoietin-derivatives in Ischaemic Human Myotubes and the Role of Pi3k/akt Signalling Pathway

2013 ◽  
Vol 33 (suppl_1) ◽  
Author(s):  
Rebekah Sian Hwee Yu ◽  
Daryll Baker ◽  
David Abraham ◽  
Janice Tsui
Keyword(s):  
Skeletal Muscle ◽  
Western Blot ◽  
Blot Analysis ◽  
Western Blot Analysis ◽  
Caspase 3 ◽  
Signalling Pathway ◽  
Critical Limb Ischaemia ◽  
Human Myotubes ◽  
Muscle Biopsies

Objectives Erythropoietin (Epo) has tissue-protective effects in response to injury, acting through the EpoR-βcR heteroreceptor. We have previously demonstrated the presence and interaction of the EpoR and βcR in human skeletal muscle. Here we aim to investigate the potential cytoprotective effects of Epo and an Epo-derivative (ARA-290) in a human in vitro model of skeletal muscle and establish a potential downstream signalling pathway utilised in protecting cells from apoptosis (including Jak-2, PI3k/Akt, NFkB). Methods Gastrocnemius muscle biopsies were obtained from patients with critical limb ischaemia and control samples were obtained from non-ischaemic patients. Human myoblasts were isolated from muscle biopsies, cultured, and allowed to differentiate into myotubes in order to investigate the cytoprotective effects of Epo and ARA-290 on myotubes subjected to simulated ischaemia. The PI3k inhibitors, LY294002 and wortmannin, were then used to determine the role of PI3k/Akt pathway in mediating cytoprotection. Following this, inhibitors against the upstreatm (Jak-2) and downstream (NFkB) molecules were also investigated. Western blot analysis, using the pro-apoptotic marker cleaved caspase-3 was performed and compared with levels of Akt and phosphorylated-Akt, using western blot analysis. Results Exogenous administration of Epo and ARA-290 were able to ameliorate the ischaemia-induced apoptosis on isolated human myotubes as shown by a significant reduction in cleaved caspase-3 expression. Addition of all inhibitors, to ARA-290 or Epo pre-treated cells, abolished the reduction in apoptosis. Conclusion The ability of ARA-290 to attenuate apoptosis in human myotubes undergoing ischaemic insult suggests a potential role in tissue protection in skeletal muscle injury. We propose that the PI3k/Akt signalling pathway is involved in mediating this cytoprotection.

Pan-BCL-2 Family Small Molecule Inhibitor GX015-070 (GeminX, Inc.) Exhibits Single Agent Cytotoxicity, Is Synergistic with Select Anti-Leukemia Cytotoxic Agents, and Induces Apoptosis in Cell Lines with t(4;11)(q21;q23) Translocations.

Blood ◽  
2005 ◽  
Vol 106 (11) ◽  
pp. 3368-3368 ◽  
Author(s):  
Jessicca M. Rege ◽  
Blaine W. Robinson ◽  
Manish Gupta ◽  
Jeffrey S. Barrett ◽  
Peter C. Adamson ◽  
...  
Keyword(s):  
Cell Death ◽  
Western Blot ◽  
Family Member ◽  
Cell Lines ◽  
Blot Analysis ◽  
Western Blot Analysis ◽  
Caspase 3 ◽  
Single Agent ◽  
Cytotoxic Agents ◽  
Response Surface Modeling

Abstract Background: Leukemias with MLL translocations, especially t(4;11), often are resistant to common chemotherapeutic agents, which may be due to abnormal apoptosis regulation. Pro- and anti-apoptotic BCL-2 family member interactions govern initiation of the intrinsic apoptosis pathway. GX015-070, which currently is in Phase I/IIA clinical trials, mimics the BH3 domain on pro-apoptotic BCL-2 family proteins and can bind the BH3 binding pocket of anti-apoptotic BCL-2 family members and modulate apoptosis. We performed comprehensive protein expression profiling of BCL-2 family member proteins and evaluated in vitro activity and mechanism of action of GX015-070 in cell lines with t(4;11). Methods: Baseline expression of BCL-2 family proteins was determined by Western blot analysis. Cytotoxicity was assessed by MTT after a 3 day exposure of RS4:11, SEM-K2 and MV4-11 cells in log phase growth to single agent GX015-070 at concentrations from 5 nM to 7.5 μM. Combined effects of fixed-concentration GX015-070 with cytotoxic agents over a range of concentrations were assayed by MTT, and the results were analyzed by pharmacostatistical response surface modeling. Disruption of specific pro- and anti-apoptotic BCL-2 family member interactions was investigated by co-immunoprecipitation/Western blot analysis. Flow cytometry and/or Western blot analysis of Caspase-3 activation, and a FACS TUNEL assay, were used to assess apoptosis in GX015-070 treated and untreated cells. Results: The three cell lines had similar baseline levels of expression of BCL-2 family proteins. BCL-2 and BAX were most abundant followed by PUMA, BAK, BCL-XL, BIM-EL, MCL-1, BIK and NOXA. Results of assays of GX015-070 activity and mechanism of action are in shown in the table. Conclusions: These data indicate that GX015-070 has potent cytotoxic activity in cell lines with t(4;11) as a single agent and that the cytotoxicity results from apoptosis. Response surface modeling in RS4:11 cells suggested ability to achieve effective doses with GX015-070 combined with cytosine arabinoside (Ara-C), dexamethasone (Dex) or doxorubicin (ADR) that are lower than projected from the single agents, but synergy was not suggested when GX015-070 was combined with etoposide, methotrexate or 6-thioguanine. The co-IP experiments give proof of principle that GX015-070 disrupts pro- and anti-apoptotic BCL-2 family protein interactions in cell lines with t(4;11). Additional pre-clinical experiments directed at overcoming drug resistance from abnormal cell death regulation in leukemias with t(4;11) using GX015-070 are in progress. These studies provide a framework to understand the cell death/survival machinery in primary leukemias with t(4;11) translocations more completely and manipulate that machinery to achieve better treatments. GX015-070 Activity and Mechanism Cell Line Single Agent Activity Synergy Inhibition Caspase-3 Activation TUNEL RS4:11 IC50=43.5 nM Ara-C, Dex, ADR Mcl1:Bak; Bcl2:Bak + + SEM-K2 IC50=156 nM In progress Mcl1:Bak; Bcl2:Bak + In Progress MV4-11 IC50=123 nM In progress Mcl1:Bak In progress +

scholarly journals Ovarian Cancer HO-8910 Cell Apoptosis Induced by Crocin in vitro

2015 ◽  
Vol 10 (2) ◽  
pp. 1934578X1501000 ◽  
Author(s):  
Dan Xia
Keyword(s):  
Ovarian Cancer ◽  
Flow Cytometry ◽  
Western Blot ◽  
Blot Analysis ◽  
Cell Apoptosis ◽  
Western Blot Analysis ◽  
Caspase 3 ◽  
Cell Cycle Distribution ◽  
Apoptotic Pathway ◽  
Apoptosis Rate

The effect and mechanism of ovarian cancer HO-8910 cell apoptosis induced by crocin. MTT assay was performed to detect the inhibitory action of crocin on the proliferation of HO-8910 cells. Flow cytometry was used to test the cell cycle distribution and apoptosis rate of ovarian cancer HO-8910 cells. Western blot analysis was utilized to measure the levels of apoptotic proteins such as p53, Fas/APO-1, and Caspase-3. MTT analysis revealed that crocin significantly inhibited the growth of HO-8910 cells. Additionally, flow cytometry illustrated that crocin raised the proportion of HO-8910 cells in the G0/G1 phase and increased their apoptosis rate. Furthermore, Western blot analysis revealed that crocin up-regulated the expression of p53, Fas/APO-1, and Caspase-3. The results of this study showed that crocin can significantly inhibit the growth of HO-8910 cells and arrest them in the G0/G1 phase. Crocin can also promote ovarian cancer HO-8910 cell apoptosis, most likely by increasing p53 and Fas/APO-1 expression, and then activating the apoptotic pathway regulated by Caspase-3.

106. NUCLEOSOME RETENTION DURING CHROMATIN PACKAGING IN HUMAN SPERMATOZOA

2010 ◽  
Vol 22 (9) ◽  
pp. 24
Author(s):  
S. D. Roman ◽  
A. T. Reid ◽  
K. McEwan ◽  
D. M. Campbell ◽  
D. A. Jans
Keyword(s):  
Dna Damage ◽  
Western Blot ◽  
Blot Analysis ◽  
Chromatin Immunoprecipitation ◽  
Western Blot Analysis ◽  
Human Spermatozoa ◽  
Tiling Arrays ◽  
Histone 3 ◽  
Exon 1 ◽  
Or Genes

In contrast to the histone packaging of somatic cells, spermatozoa are predominantly packaged by the protamine proteins. However, human spermatozoa retain ~15% histone packaging. Regions that are left nucleosome bound could be: either genes that are active shortly after fertilisation or genes that are transcribed late during spermatogenesis. DNA damage at histone bound loci would be of consequence to spermatogenesis and/or to a resulting embryo post-fertilisation. Western blot analysis confirmed the presence of acetylated H3 and H4 in sperm. Interestingly, we identified the presence of these modified histones in isolated good quality sperm considered to have complete packaging. This indicates that histone retention is not a consequence of aberrant chromatin remodelling. Using a combination of ChIP (chromatin immunoprecipitation) and tiling arrays we have identified regions bound by acetylated histone 3 (H3). ChIP-PCR confirmed histone retention at several of these loci. For the previously identified loci in exon 1 of the TNP-2 gene we were able to narrow the region bound to the size of one nucleosome only. Using a modified form of ChIP known as carrier ChIP we examined histone retention in individual ejaculates. We demonstrate that humans consistently retain acetylated H3 at the same loci. Retention of one nucleosome at the TNP-2 loci was maintained across ejaculates and donors. In conclusion, retention of acetylated H3 is consistently maintained during packaging of the genome in spermiogenesis.

Proteasome Inhibitors Can Induce Caspase-3 Activation and Apoptosis in Human CML Cell Lines.

Blood ◽  
2004 ◽  
Vol 104 (11) ◽  
pp. 4681-4681
Author(s):  
Byung-Su Kim ◽  
Chang Up Kim ◽  
Young-Ju Kim ◽  
Eun Kyung Bae ◽  
Jinhee Kim ◽  
...  
Keyword(s):  
Cell Cycle ◽  
Western Blot ◽  
Cell Lines ◽  
Blot Analysis ◽  
Proteasome Inhibitor ◽  
Western Blot Analysis ◽  
Caspase 3 ◽  
Expression Patterns ◽  
Proteasome Inhibitors ◽  
Acridine Orange Staining

Abstract The proteasome is a multi-enzyme complex that provides the ubiquitin-dependent degradation of many cytoplasmic and nuclear proteins involved in cell cycle progression and apoptosis. Inhibition of the proteasome represents a promising approach for the treatment of cancer because it can lead to cell cycle arrest and activation of caspases in tumor cells. There are several proteasome inhibitors that have been reported to induce apoptosis in various tumors. However, the effect of proteasome inhibition in human myeloid leukemia has not been reported so far. In this study, we tested two peptide-aldehyde proteasome inhibitors (MG115, MG132) on two human CML cell lines (K562, KCL22). At first, we treated both cell lines for 24, 48 and 72 hours with different doses of MG115 and MG132 and cell viability was tested by MTT assay. It showed substantial time and dose dependent cytotoxicity in both CML cell lines. Acridine orange staining also revealed DNA fragmentation. We then performed caspase-3 colorimetric assay after treating both cell lines for 6, 12 and 24 hours with 0.78μM of MG115, MG132. K562 showed the continuous rising of caspase-3 activity, while KCL22 exhibited the initial increase and subsequent mild decrease of caspase-3 activity. In addition, western blot analysis showed the reduction of procaspase-3 expression. The expression of Bcl-2 and Bcl-XL was reduced by western blot. p21 expression was slightly increased and that of cyclin D1 was decreased. Additionally, the treatment of proteasome inhibitor in CML cell lines initially induced phosphorylation of Jun kinase. We next examined the expression of heat shock proteins (Hsp70, Hsp90) after treating for 6, 12, 24 hours with the same proteasome inhibitors. Western blot analysis results indicated that expression patterns were different between MG115 and MG132. MG115 induced the slight increase of Hsp70 and Hsp90 in K562, but the reduction of both in KCL22. Meanwhile, MG132 produced the decrease of Hsp70 and Hsp90 in both K562, KCL22. In summary, our work supports that a proteasome inhibitor can induce apoptosis in human CML cell lines. We are currently focusing on the combined effect of proteasome inhibitor and Hsp90 inhibitor on CML. IC50 of Proteasome Inhibitors Cell line Proteasome Inhibitor 24hr 48hr 72hr K562 MG115 3.01 μM 1.14 μM 0.59 μM K562 MG132 μ 2.13 M 1.03 μM 0.57 μM KCL22 MG115 156.92 μM 1.36 μM 0.73 μM KCL22 MG132 1.56 μM 0.93 μM μ 0.75 M

scholarly journals Proteins PblA and PblB of Streptococcus mitis, Which Promote Binding to Human Platelets, Are Encoded within a Lysogenic Bacteriophage

2001 ◽  
Vol 69 (10) ◽  
pp. 6186-6192 ◽  
Author(s):  
Barbara A. Bensing ◽  
Ian R. Siboo ◽  
Paul M. Sullam
Keyword(s):  
Western Blot ◽  
Mitomycin C ◽  
Blot Analysis ◽  
Western Blot Analysis ◽  
Uv Light ◽  
Human Platelets ◽  
Surface Proteins ◽  
Lytic Cycle ◽  
Virulence Determinants ◽  
Streptococcus Mitis

ABSTRACT The binding of platelets by bacteria is a proposed central mechanism in the pathogenesis of infective endocarditis. Platelet binding by Streptococcus mitis strain SF100 (an endocarditis isolate) was recently shown to be mediated in part by the surface proteins PblA and PblB. The genes encoding PblA and PblB are clustered with genes nearly identical to those of streptococcal phages r1t, 01205, and Dp-1, suggesting that pblA andpblB might reside within a prophage. To address this possibility, cultures of SF100 were exposed to either mitomycin C or UV light, both of which are known to induce the lytic cycle of many temperate phages. Both treatments caused a significant increase in the transcription of pblA. Treatment with mitomycin C or UV light also caused a substantial increase in the expression of PblA and PblB, as detected by Western blot analysis of proteins in the SF100 cell wall. By electron microscopy, phage particles were readily visible in the supernatants from induced cultures of SF100. The phage, designated SM1, had a double-stranded DNA genome of approximately 35 kb. Southern blot analysis of phage DNA indicated thatpblA and pblB were contained within the SM1 genome. Furthermore, Western blot analysis of phage proteins revealed that both PblA and PblB were present in the phage particles. These findings indicate that PblA and PblB are encoded by a lysogenic bacteriophage, which could facilitate the dissemination of these potential virulence determinants to other bacterial pathogens.

Inhibition of PRAME Expression Causes Cell Cycle Arrest and Apoptosis In Leukemic Cells

Blood ◽  
2010 ◽  
Vol 116 (21) ◽  
pp. 1695-1695
Author(s):  
Norina Tanaka ◽  
Yan-Hua Wang ◽  
Masayuki Shiseki ◽  
Minoko Takanashi ◽  
Toshiko Motoji
Keyword(s):  
Cell Cycle ◽  
Acute Leukemia ◽  
Western Blot ◽  
Real Time ◽  
Blot Analysis ◽  
Western Blot Analysis ◽  
Caspase 3 ◽  
S Phase ◽  
Leukemic Cells ◽  
Rt Pcr

Abstract Abstract 1695 Introduction: The preferentially expressed antigen of melanoma (PRAME) was originally described as a tumor-associated antigen recognized by autologous cytotoxic T cells against a melanoma surface antigen. PRAME seems to act as a dominant repressor of retinoic acid receptor (RAR) signaling, but the function of PRAME in leukemia remains unclear. In the present study, we clarified the function of PRAME in leukemia, by the method of small interfering RNA (siRNA)-induced knockdown of PRAME using a leukemic cell line. To elucidate the clinical significance of PRAME expression in acute leukemia, especially its role at the relapse of disease, expression of PRAME mRNA levels and cell cycle profiles were analyzed in acute leukemia at the time of diagnosis and relapse in paired samples. Methods: The K562 cell line was used in siRNA experiments. After PRAME siRNA transfection, the effect on cell growth was examined by colony formation assay and cell counts in liquid culture. Furthermore, cell cycle analysis and apoptotic assays (annexinV assay and caspase-3 activity assay) were performed to assess the time course from day 1 to day 6. At the same time, the possible changes in various gene expressions and protein levels were analyzed by quantitative real-time RT-PCR and western blot analysis. As clinical samples, PRAME mRNA levels were measured in a total of 44 acute leukemia patients. We also examined the relationship between PRAME expression and the percentages of S phase in leukemic cells taken from 35 paired acute leukemia patients from whom sufficient blast cells were obtained. Results: A significant decrease in cell growth was observed in liquid culture and colony formation assay of the PRAME-inhibited cells. At the same time, cell cycle analysis showed a significant decrease of cells in the S phase and increase of cells in the G0/G1 phase in PRAME siRNA-treated cells. Among the cell cycle related genes analyzed with quantitative real-time RT-PCR, a clear increase of p27 expression was observed between day 3 and day 6 in PRAME siRNA-treated cells. Increase of p27 protein expression was also confirmed with western blot analysis. Furthermore, PRAME siRNA-treated cells showed a change of erythroid regulatory genes. Our result observed an increase in GATA-1 protein from day 3 to day 6, a decrease in GATA-2 protein from day 1 to day 5, and a decrease in PU.1 protein from day 2 to day 6, as well as quantitative real-time RT-PCR. On annexin V assay, the percentage of apoptotic cells gradually increased from day 3 to day 6 in PRAME siRNA-treated cells. The total percentage of apoptotic cells on day 6 was 45.5% (early apoptotic cells 33.1%, late apoptotic/necrotic cells 12.4%) in PRAME siRNA-treated cells and only 10.1% (early apoptosis 8.0%, late apoptosis 2.1%) in control cells. Caspase-3 was activated on day 3 in PRAME siRNA-treated cells, then increased gradually with the maximum activity being observed on day 6 (33.4%) using antibody against cleaved caspase-3 by flow cytometory. Western blot analysis showed that a faint band of cleaved caspase-3 protein was detected after day 3, and then an obviously augmented band was observed on days 5–6. In 51.4% of clinical samples in our study, the PRAME expression level was higher at relapse than at diagnosis. In the group in which PRAME expression was higher at relapse, the percentage of S phase cells at relapse was significantly increased compared to that at diagnosis (median, 2.4% at diagnosis vs. 6.8% at relapse, P = 0.02, n = 18). Conclusions: Inhibition of PRAME by siRNA in K562 cells suggested that PRAME expression is associated with cell cycle progression from the G0/G1 phase to S phase, inhibition of apoptosis and blocking of cell differentiation. Furthermore, we found cell cycle progression in leukemia patients in whom PRAME was highly expressed at relapse. The PRAME gene may be one of the important genes influencing proliferation of leukemic cells. Insights into the function of PRAME are expected to provide a new perspective on characteristics at relapse in acute leukemia, making it an attractive molecular target for potential therapy. Disclosures: No relevant conflicts of interest to declare.

scholarly journals Chrysophanol Prevents Lipopolysaccharide-Induced Hepatic Stellate Cell Activation by Upregulating Apoptosis, Oxidative Stress, and the Unfolded Protein Response

2020 ◽  
Vol 2020 ◽  
pp. 1-11
Author(s):  
Jiunn-Sheng Wu ◽  
Valeria Chiu ◽  
Chou-Chin Lan ◽  
Ming-Chieh Wang ◽  
I.-Shiang Tzeng ◽  
...  
Keyword(s):  
Western Blot ◽  
Dna Fragmentation ◽  
Hepatic Stellate Cell ◽  
Blot Analysis ◽  
Western Blot Analysis ◽  
Cell Activation ◽  
Caspase 3 ◽  
Stellate Cell ◽  
Unfolded Protein ◽  
Protein Response

Hepatic stellate cell (HSC) activation is a vital driver of liver fibrosis. Recent research efforts have emphasized the clearance of activated HSCs by apoptosis, senescence, or reversion to the quiescent state. LPS induces human HSC activation directly and contributes to liver disease progression. Chrysophanol is an anthraquinone with hepatoprotective and anti-inflammatory effects. This study aimed to investigate the pharmacological effects and mechanisms of chrysophanol in an LPS-induced activated rat HSC cell line (HSC-T6). The fibrosis phenotype was identified from the expression of α-smooth muscle actin (α-SMA), connective tissue growth factor (CTGF), and integrin β1 by western blot analysis. We examined DNA fragmentation by terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) staining. We detected the apoptotic markers p53 and cleaved caspase-3 by western blot analysis. Intracellular ROS were labeled with 2′,7′-dichlorofluorescein diacetate (DCF-DA) and the levels were measured by flow cytometry. Finally, we evaluated the ER stress markers binding immunoglobulin protein (BiP) and C/EBP homologous protein (CHOP) by Western blot analysis. Our results showed that chrysophanol decreased HSC-T6 cell viability in LPS-induced activated HSCs. Chrysophanol increased the expression of α-SMA, CTGF, integrin βI, p53, cleaved caspase-3, and DNA fragmentation. Chrysophanol also elevated ROS levels and increased the expression of BiP and CHOP. Pretreatment with chrysophanol prevented LPS-induced HSC-T6 cell activation by upregulating apoptosis, ROS accumulation, unfolded protein response (UPR) activation, and the UPR proapoptotic effect.

Caspase-Dependent Anti-Tumor Effects of ONC201/TIC10 on Acute Myeloid Leukemia (AML) and Multiple Myeloma (MM)

Blood ◽  
2014 ◽  
Vol 124 (21) ◽  
pp. 5224-5224
Author(s):  
Amriti R. Lulla ◽  
Christina Leah B Kline ◽  
Liz J. Hernandez-Borrero ◽  
Varun Vijay Prabhu ◽  
Jessica M Wagner ◽  
...  
Keyword(s):  
Western Blot ◽  
Tumor Cells ◽  
Cell Lines ◽  
Blot Analysis ◽  
Western Blot Analysis ◽  
Caspase 3 ◽  
Therapeutic Potential ◽  
Fold Induction ◽  
Dose Dependent Decrease ◽  
Resistant Cells

Abstract PI3K/Akt and Ras/MAPK pathways are attractive therapeutic targets in almost all tumor types, including AML and MM. Apo2L/TRAIL has been deemed a promising therapeutic given its selectivity towards cancer cells although its clinical development has been hampered by various limitations including short half-life and general shortcoming of protein-based therapeutics. ONC201/TIC10 (Oncoceutics, Inc.) is a first-in-class small molecule inducer of TRAIL expression. ONC201/TIC10 has previously been shown to up-regulate TRAIL and its death inducing receptor DR5 in HCT116 colon cancer cells, in part through the inhibition of Foxo3a phosphorylation mediated by dual inhibition of Akt and ERK (Allen JE et al, Sci Transl Med., 2013). Currently, ONC201/TIC10 is set to enter clinical trials for patients with advanced malignancies after the IND was approved by the FDA in March, 2014. We thus investigated the therapeutic potential of ONC201/TIC10 in AML and MM given a major unmet need when conventional therapy fails. We explored the possibility that ONC201/TIC10 induces apoptosis in MM and AML in part through dual inhibition of the PI3K/Akt and Ras/MAPK pathways. We tested a panel of four human MM cell lines (KMS18, MM.1S, MM.1S 33X and RPMI-8226) and three human AML cell lines (Kasumi-1, HL60, HL60/VCR). The Cell-titer Glo assay demonstrated a time and dose-dependent decrease in viability in the entire panel of MM and AML cells. EC50 values ranged from 1-2.5 µM for the MM and 2-5µM for the AML cell lines, respectively. Bortezomib-resistant cells MM.1S 33X and vincristine- resistant cells HL60/VCR were also significantly sensitive to ONC201/ TIC10 as a single agent with EC50s on par with the corresponding parental cell lines. Given the previously reported pro-apoptotic effects of ONC201/TIC10 against solid tumor cells, we assessed apoptosis by performing Sub-G1 analyses and assessing caspase-3 cleavage as two widely used methods to analyze apoptotic cell death. We observed an average of 10-fold induction of ONC201/TIC10–mediated apoptosis in MM cells at 5 mM at 48 hrs post-treatment. Rescue of ONC201/TIC10-mediated apoptosis was demonstrated using the pan-caspase inhibitor (Z-VAD-FMK). In addition, western blot analysis in MM cells indicated a dose-dependent decrease in the anti-apoptotic protein XIAP which is a key mediator of apoptosis inhibition and is reported to be highly up-regulated in MM cells. Dose and time dependent induction of apoptosis was noted in western blot analysis of caspase-3 cleavage in AML cell lines treated with 2.5 µM or 5 µM of ONC201/TIC10 for 48 hrs prior to analysis. Western Blot analysis further demonstrated inhibition of Akt and Foxo3a phosphorylation in Kasumi-1 cells, in line with the previously proposed mechanism of ONC201/TIC10 against solid tumor cells. To further investigate the therapeutic potential of ONC201/TIC10 in the context of AML, fresh AML cells were treated with ONC201/TIC10. The primary cells were also found to be sensitive to ONC201/TIC10 (60% decrease in cell viability 72 hrs post 5mM ONC201/TIC10 treatment). Similarly, caspase 3/7 activity was significantly increased as assessed by the Caspase Glo 3/7 assay (~5 fold induction in activity 72 hrs post 5mM ONC201/TIC10 treatment). To explore further the therapeutic potential of ONC201/TIC10, we performed combinatorial experiments with bortezomib and vincristine using the MM.1S 33X MM cells and the HL60/VCR AML cell lines. ONC201/ TIC10 showed an additive effect with both these compounds against the MM and AML lines. Our work demonstrates activity of ONC201/TIC10 against AML and MM cell lines including fresh AML tumor cells. The efficacy data with resistant cells is in par with the applicability of TIC10 in patients with refractory/relapsed hematological malignancies. The long-term goal of this project is to provide a rationale for a phase 1b trial of ONC201/TIC10 for refractory/relapsed MM and AML in combination with existing therapies. Figure 1: Efficacy of ONC201/TIC10 in AML and MM cells Figure 1:. Efficacy of ONC201/TIC10 in AML and MM cells Disclosures Allen: Oncoceutics, Inc.: Employment, Equity Ownership, Patents & Royalties. El-Deiry:Oncoceutics, Inc.: Equity Ownership, Patents & Royalties.

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