Dihydroartemisinin Ameliorates Decreased Neuroplasticity-Associated Proteins and Excessive Neuronal Apoptosis in APP/PS1 Mice

2020 ◽  
Vol 17 ◽  
Author(s):  
Yueyang Zhao ◽  
Zhimin Long ◽  
Yuanjie Liu ◽  
Min Luo ◽  
Yu Qiu ◽  
...  
Keyword(s):  
Western Blot ◽  
Blot Analysis ◽  
Western Blot Analysis ◽  
Neuronal Apoptosis ◽  
Caspase 3 ◽  
Senile Plaques ◽  
Autophagic Flux ◽  
Neuron Loss ◽  
Associated Proteins

Objective: Alzheimer’s disease (AD) is one of the worst neurodegenerative disorders worldwide, with extracellular senile plaques (SP), subsequent intracellular neurofibrillary tangles (NFTs) and final neuron loss and synaptic dysfunction as the main pathological characteristics. Excessive apoptosis is the main cause of irreversible neuron loss. Thus, therapeutic intervention for these pathological features has been considered a promising strategy to treat or prevent AD. Dihydroartemisin (DHA) is a widely used first-line drug for malaria. Our previous study showed that DHA treatment significantly accelerated Aβ clearance, improved memory and cognitive deficits in vivo and restored autophagic flux both in vivo and in vitro. Methods: The present study intended to explore the neuroprotective effect of DHA on neuron loss in APP/PS1 double-transgenic mice and the underlying mechanisms involved. Transmission electron microscope (TEM) analysis showed that DHA significantly reduced the swollen endoplasmic reticulum (ER) in APP/PS1 mice. Western blot analysis indicated that DHA upregulated the level of NeuN, NeuroD, MAP2, and synaptophysin and promoted neurite outgrowth. Meanwhile, DHA greatly corrected the abnormal levels of Brain-derived neurotrophic factor (BDNF) and rescued the neuronal loss in the hippocampal CA1 area. Western blot analysis revealed that DHA notably down-regulated the protein expression of full length caspase-3, cleaved caspase-3 and Bax. Results: In parallel, the expression of the antiapoptotic protein Bcl-2 increased after oral DHA treatment. Altogether, these results indicate that DHA protected AD mice from neuron loss via promoting the expression of BDNF and other neuroplasticity-associated proteins and suppressing the inhibition of neuronal apoptosis.

Radiosensitivity of glioma to Gamma Knife treatment enhanced in vitro and in vivo by RNA interfering Ku70 that is mediated by a recombinant adenovirus

2010 ◽  
Vol 113 (Special_Supplement) ◽  
pp. 228-235 ◽  
Author(s):  
Qiang Jia ◽  
Yanhe Li ◽  
Desheng Xu ◽  
Zhenjiang Li ◽  
Zhiyuan Zhang ◽  
...  
Keyword(s):  
Western Blot ◽  
Gamma Knife ◽  
Blot Analysis ◽  
Western Blot Analysis ◽  
Glioma Cells ◽  
C6 Glioma ◽  
C6 Glioma Cells ◽  
C6 Cells

Object The authors sought to evaluate modification of the radiation response of C6 glioma cells in vitro and in vivo by inhibiting the expression of Ku70. To do so they investigated the effect of gene transfer involving a recombinant replication-defective adenovirus containing Ku70 short hairpin RNA (Ad-Ku70shRNA) combined with Gamma Knife treatment (GKT). Methods First, Ad-Ku70shRNA was transfected into C6 glioma cells and the expression of Ku70 was measured using Western blot analysis. In vitro, phenotypical changes in C6 cells, including proliferation, cell cycle modification, invasion ability, and apoptosis were evaluated using the MTT (3′(4,5-dimethylthiazol-2-yl)2,5-diphenyltetrazolium bromide) assay, Western blot analysis, and cell flow cytometry. In vivo, parental C6 cells transfected with Ad-Ku70shRNA were implanted stereotactically into the right caudate nucleus in Sprague-Dawley rats. After GKS, apoptosis was analyzed using the TUNEL (terminal deoxynucleotidyl transferase–mediated deoxyuridine triphosphate nick-end labeling) method. The inhibitory effects on growth and invasion that were induced by expression of proliferating cell nuclear antigen and matrix metalloproteinase–9 were determined using immunohistochemical analyses. Results The expression of Ku70 was clearly inhibited in C6 cells after transfection with Ad-Ku70shRNA. In vitro following transfection, the C6 cells showed improved responses to GKT, including suppression of proliferation and invasion as well as an increased apoptosis index. In vivo following transfection of Ad-Ku70shRNA, the therapeutic efficacy of GKT in rats with C6 gliomas was greatly enhanced and survival times in these animals were prolonged. Conclusions Our data support the potential for downregulation of Ku70 expression in enhancing the radiosensitivity of gliomas. The findings of our study indicate that targeted gene therapy–mediated inactivation of Ku70 may represent a promising strategy in improving the radioresponsiveness of gliomas to GKT.

The Antitumor Effects of Britanin on Hepatocellular Carcinoma Cells and its Real-Time Evaluation by In Vivo Bioluminescence Imaging

2020 ◽  
Vol 20 (9) ◽  
pp. 1147-1156
Author(s):  
Hanrui Li ◽  
GeTao Du ◽  
Lu Yang ◽  
Liaojun Pang ◽  
Yonghua Zhan
Keyword(s):  
Hepatocellular Carcinoma ◽  
Western Blot ◽  
Blot Analysis ◽  
Tumor Size ◽  
Hepg2 Cells ◽  
Western Blot Analysis ◽  
Bioluminescence Imaging ◽  
Antitumor Effects ◽  
In Vivo Bioluminescence Imaging

Background: Hepatocellular carcinoma is cancer with many new cases and the highest mortality rate. Chemotherapy is the most commonly used method for the clinical treatment of hepatocellular carcinoma. Natural products have become clinically important chemotherapeutic drugs due to their great potential for pharmacological development. Many sesquiterpene lactone compounds have been proven to have antitumor effects on hepatocellular carcinoma. Objective: Britanin is a sesquiterpene lactone compound that can be considered for the treatment of hepatocellular carcinoma. The present study aimed to investigate the antitumor effect of britanin. Methods: BEL 7402 and HepG2 cells were used to study the cytotoxicity and antitumor effects of britanin. Preliminary studies on the nuclear factor kappa B pathway were conducted by western blot analysis. A BEL 7402-luc subcutaneous tumor model was established for the in vivo antitumor studies of britanin. In vivo bioluminescence imaging was conducted to monitor changes in tumor size. Results: The results of the cytotoxicity analysis showed that the IC50 values for britanin in BEL 7402 and HepG2 cells were 2.702μM and 6.006μM, respectively. The results of the colony formation demonstrated that the number of cells in a colony was reduced significantly after britanin treatment. And the results of transwell migration assays showed that the migration ability of tumor cells was significantly weakened after treatment with britanin. Tumor size measurements and staining results showed that tumor size was inhibited after britanin treatment. The western blot analysis results showed the inhibition of p65 protein expression and reduced the ratio of Bcl-2/Bax after treatment. Conclusion: A series of in vitro and in vivo experiments demonstrated that britanin had good antitumor effects and provided an option for hepatocellular carcinoma treatment.

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.

scholarly journals 9-PAHSA Improves Cardiovascular Complications by Promoting Autophagic Flux and Reducing Myocardial Hypertrophy in Db/Db Mice

2021 ◽  
Vol 12 ◽  
Author(s):  
Yan-Mei Wang ◽  
Shou-Ling Mi ◽  
Hong Jin ◽  
Qi-Lin Guo ◽  
Zhong-Yu Yu ◽  
...  
Keyword(s):  
Cardiovascular Disease ◽  
Blood Glucose ◽  
Western Blot ◽  
Vascular Calcification ◽  
Blot Analysis ◽  
Western Blot Analysis ◽  
Myocardial Hypertrophy ◽  
Autophagic Flux ◽  
Glucose Levels ◽  
Blood Glucose Levels

Atherosclerotic cardiovascular disease is a common and severe complication of diabetes. There is a large need to identify the effective and safety strategies on diabetic cardiovascular disease (DCVD). 9-PAHSA is a novel endogenous fatty acid, and has been reported to reduce blood glucose levels and attenuate inflammation. We aim to evaluate the effects of 9-PAHSA on DCVD and investigate the possible mechanisms underlying it. Firstly, serum 9-PAHSA levels in human were detected by HPLC-MS/MS analysis. Then 9-PAHSA was synthesized and purified. The synthesized 9-PAHSA was gavaged to db/db mice with 50 mg/kg for 4 weeks. The carotid arterial plaque and cardiac structure was assessed by ultrasound. Cardiac autophagy was tested by western blot analysis, electron microscope and iTRAQ. The results showed that 9-PAHSA, in patients with type 2 diabetes mellitus (T2DM), was significantly lower than that in non-diabetic subjects. Administration of 9-PAHSA for 2 weeks reduced blood glucose levels. Ultrasound observed that continue administration of 9-PAHSA for 4 weeks ameliorated carotid vascular calcification, and attenuated myocardial hypertrophy and dysfunction in db/db mice. Electron microscopy showed continue 9-PAHSA treatment significantly increased autolysosomes, while dramatically decreased greases in the myocardial cells of the db/db mice. Moreover, iTRAQ analysis exhibited that continue 9-PAHSA treatment upregulated BAG3 and HSPB8. Furthermore, western blot analysis confirmed that 9-PAHSA down-regulated Akt/mTOR and activated PI3KIII/BECN1 complex in diabetic myocardium. Thus, 9-PAHSA benefits DCVD in diabetic mice by ameliorating carotid vascular calcification, promoting autophagic flux and reducing myocardial hypertrophy.

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.

Interfering With Hyaluronic Acid Metabolism Suppresses Glioma Cell Proliferation by Regulating Autophagy

2020 ◽  
Author(s):  
Tao Yan ◽  
Xin Chen ◽  
Hua Zhan ◽  
Penglei Yao ◽  
Ning Wang ◽  
...  
Keyword(s):  
Cell Cycle ◽  
Hyaluronic Acid ◽  
Tumor Microenvironment ◽  
Western Blot ◽  
Blot Analysis ◽  
Western Blot Analysis ◽  
Glioma Cell ◽  
Glioma Cells

Abstract BackgroundThe tumor microenvironment plays an important role in tumor progression. Hyaluronic acid (HA), an important component of the extracellular matrix in the tumor microenvironment, abnormally accumulates in a variety of tumors. Whereas the role of abnormal HA metabolism in glioma remains unclear. MethodsThe expression level of hyaluronic acid (HA) was analyzed by ELISA assay and proteins such as HAS3, CD44, P62, LC3, CCND1 and CCNB1 were measured with Western blot analysis. The cell viability and proliferation were measured by MTT and KI67 immunofluorescence staining respectively. Autophagic vesicles and autophagosomes were quantified by transmission electron microscopy (TEM) and GFP-RFP-LC3 fluorescence analysis respectively. Cell cycle was analyzed by flowcytometry and Western blot analysis. Immunohistochemical (IHC) staining was used to detect expression levels of HA, Ki67, HAS3 and CD44 in human and mouse tumor tissues. Lentivirus constructed HAS3 and CD44 knockout stable glioma cells were transplanted to BALB/C nude mice for in vivo experiments. 4-Methylumbelliferone (4MU) was also used to treat glioma bearing mice for verifing its anti-tumor ability. The expression curve of HAS3, CD44 and the disease-free survival (DFS) curves for HAS3, CD44 in patients with LGG and GBM was performed based on TCGA database. ResultsAs shown in the present study, HA, hyaluronic acid synthase 3 (HAS3) and a receptor of HA named CD44 are expressed at high levels in human glioma tissues and negatively correlated with the prognosis of patients with glioma. Silencing HAS3 or blocking CD44 inhibited the proliferation of glioma cells in vitro and in vivo. The underlying mechanism was attributed to the inhibition of autophagy flux and further maintaining glioma cell cycle arrest in G1 phase. More importantly, 4-Methylumbelliferone (4-MU), a small competitive inhibitor of UDP with the ability to penetrate the blood-brain barrier (BBB), also inhibited the proliferation of glioma cells in vitro and in vivo. ConclusionApproaches that interfere with HA metabolism by altering the expression of HAS3 and CD44 and the administration of 4-MU potentially represent effective strategies for glioma treatment.

scholarly journals In Vitro and In Vivo Effects of Fermented Oyster-Derived Lactate on Exercise Endurance Indicators in Mice

2020 ◽  
Vol 17 (23) ◽  
pp. 8811
Author(s):  
Storm N. S. Reid ◽  
Joung-Hyun Park ◽  
Yunsook Kim ◽  
Yi Sub Kwak ◽  
Byeong Hwan Jeon
Keyword(s):  
Lactate Dehydrogenase ◽  
Protein Expression ◽  
Western Blot ◽  
Blot Analysis ◽  
Western Blot Analysis ◽  
Biochemical Analysis ◽  
Positive Control ◽  
Exercise Endurance

Exogenous lactate administration has more recently been investigated for its various prophylactic effects. Lactate derived from potential functional foods, such as fermented oyster extract (FO), may emerge as a practical and effective method of consuming exogenous lactate. The current study endeavored to ascertain whether the lactate derived from FO may act on muscle cell biology, and to what extent this may translate into physical fitness improvements. We examined the effects of FO in vitro and in vivo, on mouse C2C12 cells and exercise performance indicators in mice, respectively. In vitro, biochemical analysis was carried out to determine the effects of FO on lactate content and muscle cell energy metabolism, including adenosine triphosphate (ATP) activity. Western blot analysis was also utilized to measure the protein expression of total adenosine monophosphate-activated protein kinase (AMPK), p-AMPK (Thr172), lactate dehydrogenase (LDH), succinate dehydrogenase (SDHA) and peroxisome proliferator-activated receptor gamma coactivator-1α (PGC-1α) in response to FO administration. Three experimental groups were formed: a positive control (PC) treated with 1% horse serum, FO10 treated with 10 μg/mL and FO50 treated with 50 μg/mL. In vivo, the effects of FO supplementation on exercise endurance were measured using the Rota-rod test, and Western blot analysis measured myosin heavy-chain 2 (MYH2) to assess skeletal muscle growth, alongside p-AMPK, total-AMPK, PGC-1α, cytochrome C and UCP3 protein expression. Biochemical analysis was also performed on muscle tissue to measure the changes in concentration of liver lactate, lactate dehydrogenase (LDH), glycogen and citrate. Five groups (n = 10/per group) consisted of a control group (CON), exercise group (Ex), positive control treated with Ex and 500 mg/kg Taurine (Ex-Tau), Ex and 100 mg/kg FO supplementation (Ex-FO100) and Ex and 200 mg/kg FO supplementation (Ex-FO200) orally administered over the 4-week experimental period.FO50 significantly increased PGC-1α expression (p < 0.001), whereas both FO10 and FO50 increased the expression of p-AMPK (p < 0.001), in C2C12 muscle cells, showing increased signaling important for mitochondrial metabolism and biogenesis. Muscle lactate levels were also significantly increased following FO10 (p < 0.05) and FO50 (p < 0.001). In vivo, muscle protein expression of p-AMPK (p < 0.05) and PGC-1α were increased, corroborating our in vitro results. Cytochrome C also significantly increased following FO200 intake. These results suggest that the effects of FO supplementation may manifest in a dose-response manner. FO administration, in vitro, and supplementation, in vivo, both demonstrate a potential for improvements in mitochondrial metabolism and biogenesis, and even for potentiating the adaptive effects of endurance exercise. Mechanistically, lactate may be an important molecule in explaining the aforementioned positive effects of FO.

scholarly journals Expression and subcellular localization of BNIP3 in hypoxic hepatocytes and liver stress

2009 ◽  
Vol 296 (3) ◽  
pp. G499-G509 ◽  
Author(s):  
Mallikarjuna R. Metukuri ◽  
Donna Beer-Stolz ◽  
Rajaie A. Namas ◽  
Rajeev Dhupar ◽  
Andres Torres ◽  
...  
Keyword(s):  
Cell Death ◽  
Western Blot ◽  
Blot Analysis ◽  
Western Blot Analysis ◽  
Ischemia Reperfusion ◽  
Redox Stress ◽  
No Donor ◽  
Interacting Protein

We have previously demonstrated that the Bcl-2/adenovirus EIB 19-kDa interacting protein 3 (BNIP3), a cell death-related member of the Bcl-2 family, is upregulated in vitro and in vivo in both experimental and clinical settings of redox stress and that nitric oxide (NO) downregulates its expression. In this study we sought to examine the expression and localization of BNIP3 in murine hepatocytes and in a murine model of hemorrhagic shock (HS) and ischemia-reperfusion (I/R). Freshly isolated mouse hepatocytes were exposed to 1% hypoxia for 6 h followed by reoxygenation for 18 h, and protein was isolated for Western blot analysis. Hepatocytes grown on coverslips were fixed for localization studies. Similarly, livers from surgically cannulated C57Bl/6 mice and from mice cannulated and subjected to 1–4 h of HS were processed for protein isolation and Western blot analysis. In hepatocytes, BNIP3 was expressed constitutively but was upregulated under hypoxic conditions, and this upregulation was countered by treatment with a NO donor. Surprisingly, BNIP3 was localized in the nucleus of normoxic hepatocytes, in the cytoplasm following hypoxia, and again in the nucleus following reoxygenation. Upregulation of BNIP3 partially required p38 MAPK activation. BNIP3 contributed to hypoxic injury in hepatocytes, since this injury was diminished by knockdown of BNIP3 mRNA. Hepatic BNIP3 was also upregulated in two different models of liver stress in vivo, suggesting that a multitude of inflammatory stresses can lead to the modulation of BNIP3. In turn, the upregulation of BNIP3 appears to be one mechanism of hepatocyte cell death and liver damage in these settings.

ADAMTS13 Binds VWF Via its C-Terminal CUB2 Domain.

Blood ◽  
2004 ◽  
Vol 104 (11) ◽  
pp. 126-126 ◽  
Author(s):  
Weirui Zhang ◽  
David Motto ◽  
David Ginsburg
Keyword(s):  
Fusion Protein ◽  
Western Blot ◽  
Blot Analysis ◽  
Western Blot Analysis ◽  
Expression Vector ◽  
Full Length ◽  
Mammalian Expression ◽  
Partial Denaturation

Abstract Thrombotic thrombocytopenic purpura (TTP) is a life threatening illness due to a deficiency of the VWF-cleaving protease, ADAMTS13. The ADAMTS13 protein is composed of a propeptide, followed by a typical zinc metalloprotease domain. The C-terminal 2/3 of the molecule contains disintegrin-like, cystine-rich, and spacer domains, as well as a total of eight TSP1 motifs and two CUB domains. The function of this C-terminal portion of the molecule and its composite motifs is unknown, though TSP1 and CUB domains of other proteins have been shown to mediate protein-protein interactions. To further explore the interaction between ADAMTS13 and VWF, we cloned full length human cDNAs for both ADAMTS13 and VWF into the mammalian expression vector pcDNA3.1. These constructs were transiently transfected into 293T cells and COS cells respectively, and conditioned media collected for analysis. Using an anti-myc antibody, myc-tagged VWF co-immunoprecipitated (co-IP) with ADAMTS13, as demonstrated by western blot analysis using antisera raised against a C-terminal peptide derived from the predicted ADAMTS13 sequence. This direct interaction required partial denaturation of VWF in 1M urea, with no co-IP observed in the absence of urea. To map the segment within ADAMTS13 responsible for VWF binding, we cloned a series of overlapping ADAMTS13 fragments into the bacterial expression vector, Pet44b. Fusion proteins were purified by binding of the included His-tag to Ni-NTA beads and incubated with recombinant myc-VWF in the presence of 1M urea. Association with VWF was analyzed by co-IP with anti-myc followed by western blot analysis using an antibody to the C-terminal HSV-tag present in each fusion protein. The CUB2 (Glu1298- Thr1427) fusion protein co-IP’d with full-length VWF and also demonstrated concentration-dependent competition with full-length ADAMTS13 for VWF binding. In summary, we have demonstrated a direct protein-protein interaction between VWF and ADAMTS13. Binding requires partial denaturation of VWF and appears to be mediated primarily through contacts with the ADAMTS13 CUB2 domain. This interaction may account for the previously observed co-purification of VWF and ADAMTS13 from human plasma. Furthermore, the requirement for 1M urea suggests that this interaction may only occur physiologically under conditions of high shear. Though others have shown that the C-terminal domains of ADAMTS13, including CUB2, are not required for VWF cleavage in vitro, our data, together with several C-terminal mutations previously reported in TTP patients, suggest that interactions between VWF and the ADAMTS13 CUB2 domain may be important in vivo.

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 +

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