scholarly journals OP0034 STP938, A NOVEL, POTENT AND SELECTIVE INHIBITOR OF CTP SYNTHASE 1 (CTPS1) DEMONSTRATES EFFICACY IN RODENT MODELS OF INFLAMMATION AND ARTHRITIS

2021 ◽  
Vol 80 (Suppl 1) ◽  
pp. 18.1-19
Author(s):  
H. Asnagli ◽  
A. Novak ◽  
L. Birch ◽  
R. Lane ◽  
N. Minet ◽  
...  

Background:The final rate-limiting step in pyrimidine synthesis is the conversion of UTP to CTP which is catalyzed by cytidine triphosphate synthase 1 (CTPS1) or CTPS2. A hypomorphic mutation in the CTPS1 gene has highlighted the essential and non-redundant role of CTPS1 in T and B lymphocyte proliferation1. These patients exhibit no effects on non-hematopoietic tissues. Thus, selective inhibition of CTPS1 represents a novel targeted approach to dampen pathological T- and B-cell lympho-proliferation. STP938 is an orally bioavailable, small molecular weight, selective inhibitor of CTPS1 developed by Step Pharma.Objectives:To demonstrate the in vitro effects of CTPS1 inhibition on T and B cell proliferation and the therapeutic potential of STP938 using in vivo models of disease.Methods:The in vitro anti-proliferative activity of STP938 was investigated using cell lines and primary human PBMCs. STP938 was assessed in vivo using the DTH-KLH rat model and the mouse collagen-induced arthritis (CIA) model. For the KLH-DTH model, Lewis rats were immunized with KLH, a week later, challenged locally at the ear with KLH antigen, ear swelling was assessed after 24 hours. Blood samples were collected for detection of KLH-specific IgG levels at day 8. STP938 was given orally one-hour prior to immunization and then b.i.d. for 7 days. For the CIA model, DBA-1 mice were immunized with Collagen type II and complete Freund’s adjuvant and received a booster immunization three weeks later. STP938 was administered to mice developing signs of arthritis from Day 28 to 45 orally daily b.i.d.Results:STP938 inhibited in vitro proliferation of HEKwt but not HEK-CTPS1KO cells as well as Jurkat and human PBMCs. STP938 demonstrated a significant and dose-dependent inhibition of KLH-specific T and B cell responses in vivo. STP938 significantly reduced the disease severity in the CIA model in a dose-dependent manner as determined by clinical and histopathological readouts.Conclusion:Our preliminary in vitro and in vivo results indicate that inhibition of CTPS1 specifically blocks proliferation of cells derived from the lymphocyte lineage and reduces the T cell driven inflammatory response. These data highlight the therapeutical potential of STP938 in treating patients with autoimmune diseases such as rheumatoid arthritis.References:[1]Martin et al, JCI Insight. 2020, 12;5(5):133880Disclosure of Interests:Hélène ASNAGLI Employee of: Step Pharma, Andrew Novak: None declared, Louise Birch Shareholder of: Step Pharma, Rebecca Lane: None declared, Norbert Minet Employee of: employee as Ph D student under CIFRE grant, David Laughton: None declared, Pascal George Shareholder of: Step Pharma, Geoffroy de Ribains Shareholder of: as former employee of Step Pharma, Employee of: former employee of Step Pharma, Sylvain Latour: None declared, Alain Fischer: None declared, Tim Bourne Shareholder of: UCB, Step Pharma, Sitryx Therapeutics, Consultant of: a range of biotech companies, Employee of: former employee of Step Pharma and Sitryx Therapeutics, Andrew Parker Employee of: Step Pharma

Blood ◽  
2005 ◽  
Vol 106 (11) ◽  
pp. 3470-3470 ◽  
Author(s):  
Li Long ◽  
Xia Tong ◽  
Montesa Patawaran ◽  
Sharon L. Aukerman ◽  
Bahija Jallal ◽  
...  

Abstract CD40 is expressed on all B-cell malignancies, including multiple myeloma, and represents an attractive target for antibody therapy. CHIR-12.12 is a fully human, highly potent, IgG1 antagonistic anti-CD40 monoclonal antibody generated using XenoMouse® mice (Abgenix, Inc). CHIR-12.12 can mediate antitumor activity by at least two mechanisms: blocking CD40-ligand-mediated survival signals and killing tumor cells by antibody-dependent cellular cytotoxicity (ADCC). We have previously reported that CHIR-12.12 mediates stronger in vitro killing of CD40+- and CD20+-expressing human non-Hodgkin’s lymphoma and lymphoblastoid B cells by ADCC than rituximab and significantly inhibits the growth of rituximab-responsive (Daudi) and rituximab-resistant (Namalwa) human lymphoma and lymphoblastoid B-cell (IM-9) xenografts in vivo. In this study, we examined the in vitro and in vivo efficacy of CHIR-12.12 against the human multiple myeloma cell line KMS-12-BM. CHIR-12.12 induced lysis of KMS-12-BM cells by ADCC in a dose-dependent manner, reaching maximum cell lysis at 0.1μg/ml with an EC50 of 17.5 pM. CHIR-12.12 efficacy in vivo was evaluated in orthotopic and subcutaneous KMS-12-BM xenograft models. In the staged orthotopic model, tumor cells were delivered intravenously and treatment was initiated 7 days post cell implantation. CHIR-12.12 significantly prolonged the median survival of tumor-bearing mice in a dose-dependent manner, with a median survival of 78 and 98 days in the groups treated with 1 mg/kg and 10 mg/kg CHIR-12.12 weekly, respectively, compared to a median survival time of 68 days in the control IgG1 group (P<0.0001). Bortezomib administered i.v. twice weekly at 0.5 or 1 mg/kg showed no survival benefit. In the staged subcutaneous model, CHIR-12.12 was administered weekly at 1 and 10 mg/kg after the mean tumor volume reached 100mm3. CHIR-12.12 significantly inhibited tumor growth, with a tumor volume reduction of 42% (P<0.05) and 63% (P<0.01), respectively. Bortezomib and melphalan/prednisone did not inhibit KMS-12-BM tumor growth at the doses and schedules reported for other human multiple myeloma xenograft models. Western blot analysis and immunohistochemical staining showed significantly increased levels of cleaved PARP in KMS-12-BM s.c. tumors 7 days after the initiation of CHIR-12.12 treatment, suggesting the induction of cell death by CHIR-12.12. Taken together, these data demonstrate that the anti-CD40 mAb CHIR-12.12 has potent activity against human multiple myeloma cells in vitro and in xenograft models in vivo. Currently CHIR-12.12 is in Phase I clinical trials for the treatment of B-cell malignancies.


Toxins ◽  
2021 ◽  
Vol 13 (4) ◽  
pp. 271
Author(s):  
Enrique García-Pérez ◽  
Dojin Ryu ◽  
Chan Lee ◽  
Hyun Jung Lee

Ochratoxin A (OTA) is a mycotoxin frequently found in raw and processed foods. While it is considered a possible human carcinogen, the mechanism of action remains unclear. OTA has been shown to be hepatotoxic in both in vitro and in vivo models and oxidative stress may be one of the factors contributing to its toxicity. Hence, the effect of OTA on human hepatocellular carcinoma, HepG2 cells, was investigated on oxidative stress parameters. The cytotoxicity of OTA on HepG2 was time- and dose-dependent within a range between 0.1 and 10 µM; while 100 μM of OTA increased the intracellular reactive oxygen species (ROS) in a time-dependent manner. Additionally, the levels of glutathione (GSH) were increased by 9.7% and 11.3% at 10 and 100 nM of OTA, respectively; while OTA at 100 μM depleted GSH by 40.5% after 24 h exposure compared with the control. Finally, the mRNA level of catalase (CAT) was downregulated by 2.33-, 1.92-, and 1.82-fold after cells were treated with 1, 10, and 10 μM OTA for 24 h, respectively; which was linked to a decrease in CAT enzymatic activity. These results suggest that oxidative stress is involved in OTA-mediated toxicity in HepG2 cells.


Gene Therapy ◽  
2021 ◽  
Author(s):  
Ian W. Luecke ◽  
Gloria Lin ◽  
Stephanie Santarriaga ◽  
K. Matthew Scaglione ◽  
Allison D. Ebert

AbstractProtein misfolding and aggregation are shared features of neurodegenerative diseases, including amyotrophic lateral sclerosis (ALS), and protein quality control disruption contributes to neuronal toxicity. Therefore, reducing protein aggregation could hold therapeutic potential. We previously identified a novel chaperone protein, serine-rich chaperone protein 1 (SRCP1), that effectively prevents protein aggregation in cell culture and zebrafish models of Huntington’s disease. Here we tested whether this benefit extends to aggregated proteins found in ALS. We used viral-mediated expression of SRCP1 in in vitro and in vivo models of ALS. We found that SRCP1 reduced insoluble SOD1 protein levels in HEK293T cells overexpressing either the A4V or G93R mutant SOD1. However, the reduction of insoluble protein was not observed in either mutant C9orf72 or SOD1 ALS iPSC-derived motor neurons infected with a lentivirus expressing SRCP1. SOD1-G93A ALS mice injected with AAV-SRCP1 showed a small but significant reduction in insoluble and soluble SOD1 in both the brain and spinal cord, but SRCP1 expression did not improve mouse survival. These data indicate that SRCP1 likely reduces insoluble protein burden in a protein and/or context-dependent manner indicating a need for additional insight into SRCP1 function and therapeutic potential.


Biology ◽  
2021 ◽  
Vol 10 (7) ◽  
pp. 610
Author(s):  
Robin Park ◽  
Andrew L. Coveler ◽  
Ludimila Cavalcante ◽  
Anwaar Saeed

Glycogen synthase kinase-3 beta is a ubiquitously and constitutively expressed molecule with pleiotropic function. It acts as a protooncogene in the development of several solid tumors including pancreatic cancer through its involvement in various cellular processes including cell proliferation, survival, invasion and metastasis, as well as autophagy. Furthermore, the level of aberrant glycogen synthase kinase-3 beta expression in the nucleus is inversely correlated with tumor differentiation and survival in both in vitro and in vivo models of pancreatic cancer. Small molecule inhibitors of glycogen synthase kinase-3 beta have demonstrated therapeutic potential in pre-clinical models and are currently being evaluated in early phase clinical trials involving pancreatic cancer patients with interim results showing favorable results. Moreover, recent studies support a rationale for the combination of glycogen synthase kinase-3 beta inhibitors with chemotherapy and immunotherapy, warranting the evaluation of novel combination regimens in the future.


Pharmaceutics ◽  
2021 ◽  
Vol 13 (4) ◽  
pp. 498
Author(s):  
Mariaevelina Alfieri ◽  
Antonietta Leone ◽  
Alfredo Ambrosone

Plants produce different types of nano and micro-sized vesicles. Observed for the first time in the 60s, plant nano and microvesicles (PDVs) and their biological role have been inexplicably under investigated for a long time. Proteomic and metabolomic approaches revealed that PDVs carry numerous proteins with antifungal and antimicrobial activity, as well as bioactive metabolites with high pharmaceutical interest. PDVs have also been shown to be also involved in the intercellular transfer of small non-coding RNAs such as microRNAs, suggesting fascinating mechanisms of long-distance gene regulation and horizontal transfer of regulatory RNAs and inter-kingdom communications. High loading capacity, intrinsic biological activities, biocompatibility, and easy permeabilization in cell compartments make plant-derived vesicles excellent natural or bioengineered nanotools for biomedical applications. Growing evidence indicates that PDVs may exert anti-inflammatory, anti-oxidant, and anticancer activities in different in vitro and in vivo models. In addition, clinical trials are currently in progress to test the effectiveness of plant EVs in reducing insulin resistance and in preventing side effects of chemotherapy treatments. In this review, we concisely introduce PDVs, discuss shortly their most important biological and physiological roles in plants and provide clues on the use and the bioengineering of plant nano and microvesicles to develop innovative therapeutic tools in nanomedicine, able to encompass the current drawbacks in the delivery systems in nutraceutical and pharmaceutical technology. Finally, we predict that the advent of intense research efforts on PDVs may disclose new frontiers in plant biotechnology applied to nanomedicine.


2021 ◽  
Vol 12 (5) ◽  
Author(s):  
Xuxing Shen ◽  
Chao Wu ◽  
Meng Lei ◽  
Qing Yan ◽  
Haoyang Zhang ◽  
...  

AbstractCarfilzomib, a second-generation proteasome inhibitor, has significantly improved the survival rate of multiple myeloma (MM) patients, but its clinical application is still restricted by drug resistance and cardiotoxicity. Here, we identified a novel proteasome inhibitor, D395, and assessed its efficacy in treating MM as well as its cardiotoxicity at the preclinical level. The activities of purified and intracellular proteasomes were measured to determine the effect of D395 on the proteasome. CCK-8 and flow cytometry experiments were designed to evaluate the effects of D395 on cell growth and apoptosis. The effects of D395 and carfilzomib on serum enzyme activity, echocardiography features, cardiomyocyte morphology, and hERG channels were also compared. In our study, D395 was highly cytotoxic to MM cell lines and primary MM cells but not normal cells, and it was well tolerated in vivo. Similar to carfilzomib, D395 inhibited osteoclast differentiation in a dose-dependent manner. In particular, D395 exhibited lower cardiotoxicity than carfilzomib in all experiments. In conclusion, D395 is a novel irreversible proteasome inhibitor that has remarkable anti-MM activity and mild cardiotoxicity in vitro and in vivo.


Pharmaceutics ◽  
2021 ◽  
Vol 13 (3) ◽  
pp. 386
Author(s):  
Tung-Hu Tsai ◽  
Yu-Jen Chen ◽  
Li-Ying Wang ◽  
Chen-Hsi Hsieh

This study was performed to evaluate the interaction between conventional or high-dose radiotherapy (RT) and the pharmacokinetics (PK) of regorafenib in concurrent or sequential regimens for the treatment of hepatocellular carcinoma. Concurrent and sequential in vitro and in vivo studies of irradiation and regorafenib were designed. The interactions of RT and regorafenib in vitro were examined in the human hepatoma Huh-7, HA22T and Hep G2 cell lines. The RT–PK phenomenon and biodistribution of regorafenib under RT were confirmed in a free-moving rat model. Regorafenib inhibited the viability of Huh-7 cells in a dose-dependent manner. Apoptosis in Huh-7 cells was enhanced by RT followed by regorafenib treatment. In the concurrent regimen, RT decreased the area under the concentration versus time curve (AUC)regorafenib by 74% (p = 0.001) in the RT2 Gy × 3 fraction (f’x) group and by 69% (p = 0.001) in the RT9 Gy × 3 f’x group. The AUCregorafenib was increased by 182.8% (p = 0.011) in the sequential RT2Gy × 1 f’x group and by 213.2% (p = 0.016) in the sequential RT9Gy × 1 f’x group. Both concurrent regimens, RT2Gy × 3 f’x and RT9Gy × 3 f’x, clearly decreased the biodistribution of regorafenib in the heart, liver, lung, spleen and kidneys, compared to the control (regorafenib × 3 d) group. The concurrent regimens, both RT2Gy × 3 f’x and RT9Gy × 3 f’x, significantly decreased the biodistribution of regorafenib, compared with the control group. The PK of regorafenib can be modulated both by off-target irradiation and stereotactic body radiation therapy (SBRT).


2007 ◽  
Vol 53 (3) ◽  
pp. 380-390 ◽  
Author(s):  
Pious Thomas ◽  
Sima Kumari ◽  
Ganiga K. Swarna ◽  
T.K.S. Gowda

Fourteen distinct bacterial clones were isolated from surface-sterilized shoot tips (~1 cm) of papaya (Carica papaya L. ‘Surya’) planted on Murashige and Skoog (MS)-based papaya culture medium (23/50 nos.) during the 2–4 week period following in vitro culturing. These isolates were ascribed to six Gram-negative genera, namely Pantoea ( P. ananatis ), Enterobacter ( E. cloacae ), Brevundimonas ( B. aurantiaca ), Sphingomonas , Methylobacterium ( M. rhodesianum ), and Agrobacterium ( A. tumefaciens ) or two Gram-positive genera, Microbacterium ( M. esteraromaticum ) and Bacillus ( B. benzoevorans ) based on 16S rDNA sequence analysis. Pantoea ananatis was the most frequently isolated organism (70% of the cultures) followed by B. benzoevorans (13%), while others were isolated from single stocks. Bacteria-harboring in vitro cultures often showed a single organism. Pantoea, Enterobacter, and Agrobacterium spp. grew actively on MS-based normal papaya medium, while Microbacterium, Brevundimonas, Bacillus, Sphingomonas, and Methylobacterium spp. failed to grow in the absence of host tissue. Supplying MS medium with tissue extract enhanced the growth of all the organisms in a dose-dependent manner, indicating reliance of the endophyte on its host. Inoculation of papaya seeds with the endophytes (20 h at OD550 = 0.5) led to delayed germination or slow seedling growth initially. However, the inhibition was overcome by 3 months and the seedlings inoculated with Pantoea, Microbacterium, or Sphingomonas spp. displayed significantly better root and shoot growths.


2014 ◽  
Vol 26 (8) ◽  
pp. 1084 ◽  
Author(s):  
Yu-Ting Shen ◽  
Yue-Qiang Song ◽  
Xiao-Qin He ◽  
Fei Zhang ◽  
Xin Huang ◽  
...  

Meiosis produces haploid gametes for sexual reproduction. Triphenyltin chloride (TPTCL) is a highly bioaccumulated and toxic environmental oestrogen; however, its effect on oocyte meiosis remains unknown. We examined the effect of TPTCL on mouse oocyte meiotic maturation in vitro and in vivo. In vitro, TPTCL inhibited germinal vesicle breakdown (GVBD) and first polar body extrusion (PBE) in a dose-dependent manner. The spindle microtubules completely disassembled and the chromosomes condensed after oocytes were exposed to 5 or 10 μg mL–1 TPTCL. γ-Tubulin protein was abnormally localised near chromosomes rather than on the spindle poles. In vivo, mice received TPTCL by oral gavage for 10 days. The general condition of the mice deteriorated and the ovary coefficient was reduced (P < 0.05). The number of secondary and mature ovarian follicles was significantly reduced by 10 mg kg–1 TPTCL (P < 0.05). GVBD decreased in a non-significant, dose-dependent manner (P > 0.05). PBE was inhibited with 10 mg kg–1 TPTCL (P < 0.05). The spindles of in vitro and in vivo metaphase II oocytes were disassembled with 10 mg kg–1 TPTCL. These results suggest that TPTCL seriously affects meiotic maturation by disturbing cell-cycle progression, disturbing the microtubule cytoskeleton and inhibiting follicle development in mouse oocytes.


2011 ◽  
Vol 2011 ◽  
pp. 1-9 ◽  
Author(s):  
Ting-Yeu Dai ◽  
Chih-Hua Wang ◽  
Kun-Nan Chen ◽  
I-Nung Huang ◽  
Wei-Sheng Hong ◽  
...  

We assayed the effects of velvet antler (VA) of Formosan sambar deer (Cervus unicolor swinhoei) and its extracts on the anti-infective activity against pathogenicStaphylococcus aureus in vitroandin vivoin this study.In vitrodata indicated that the VA extracts stimulated the proliferation of resting splenocytes and macrophages in a dose-dependent manner up to the highest concentration used (150 μg mL−1). The production of proinflammatory cytokines (TNF-α, IL-6, IL-12) by lipoteichoic acid was significantly suppressed after being cocultured with the VA extracts in a dose-dependent manner. Animal test inS. aureus-infected mice demonstrated that the numbers of bacteria determined in the kidneys and peritoneal lavage fluid ofS. aureus-infected mice were significantly higher than those found in the same organs of mice pretreated with the VA samples. Moreover, the highly enhanced phagocytic activity of macrophages was further verified afterin vitrotreatment with the VA samples. The protective mechanisms of the VA samples might include an immune enhancer and an inflammatory cytokine suppressor.


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