scholarly journals A Novel RAD51 Inhibitor, CYT01B, Shows Anti-Cancer Activity in Preclinical Models of Aid Expressing Lymphomas

Blood ◽  
2018 ◽  
Vol 132 (Supplement 1) ◽  
pp. 2944-2944
Author(s):  
Muneer G Hasham ◽  
Darryl Patrick ◽  
Leanne Bedard ◽  
Joseph Vacca ◽  
Casey McComas ◽  
...  

Abstract Activation Induced Cytidine Deaminase (AID) is a DNA directed cytidine deaminase that is normally only expressed in activated B-cells to promote somatic hypermutations and immunoglobulin class switching. Unlike site-specific recombinases (e.g. RAG1/2), AID lacks target site specificity and can generate DNA damage at widespread locations throughout the genome. In cancer cells, AID expression promotes high levels of DNA replication stress, and results in dependency upon the homologous recombination factor RAD51. We have shown previously that a novel RAD51 inhibitor, CYT01B, functions by disrupting RAD51 focus formation which reduces the nuclear concentration of RAD51 and promotes RAD51 protein degradation. Here we present the in vitro and in vivo pharmacological characterization of CYT01B. We first analyzed the permeability and stability of the compound using Caco-2 and liver microsome assays. CYT01B shows low efflux and is stable with low intrinsic clearance rates (< 30 ml/min/mg protein) in mouse, rat, dog, and human, but not in cynomolgus monkey liver microsomes. In vivo, CYT01B showed oral bioavailability that correlated well with Caco-2 permeability (36.9% in monkeys up to 86.5% in rats). Additionally, CYT01B exhibited a minimum half-life of 4 hours in all species tested (mouse, rat, dog, and monkey). We then examined off target liabilities by performing kinome inhibition and Panlabs safety panel screens. CYT01B showed negligible (<50%) inhibition across 371 kinases tested, while only two targets showed greater than 50% inhibition in the Panlabs panel. CYT01B displayed activity in several human-to-mouse cell line xenograft models. In a systemic model of chronic lymphoblastic leukemia (CLL), the tumor burden in the bone marrow of CYT01B-treated mice was reduced by approximately 30%. In two different subcutaneous engraftment models of either a Burkitt's lymphoma cell line (Daudi) or an acute lymphoblastic leukemia cell line (CCRF-SB), mice treated with CYT01B showed tumor growth inhibition of 49% and 88%, respectively. Lastly, CYT01B was well tolerated in rat 7-day dose range finding studies. Rats were treated with 20, 80, and 240 mg/kg once per day by oral gavage. There were no observed changes in hematology or clinical chemistry, and no observed histopathological toxicities. Taken together, these data demonstrate that CYT01B is a cell permeable, metabolically stable, and orally bioavailable small molecule, with anti-cancer activity in multiple preclinical lymphoid cancer models. Overall, this provides the basis for continued preclinical development of an AID/RAD51 synthetic lethal therapeutic paradigm that may be applicable to various hematologic malignancies. Disclosures Patrick: Cyteir Therapeutics: Consultancy. Bedard:Cyteir Therapeutics: Consultancy. Vacca:Cyteir Therapeutics: Consultancy. McComas:Cyteir Therapeutics: Consultancy. Castro:Cyteir Therapeutics: Consultancy. Day:Cyteir Therapeutics: Employment. Mills:Cyteir Therapeutics: Employment, Equity Ownership, Membership on an entity's Board of Directors or advisory committees.

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Kotaro Sakamoto ◽  
Teruaki Masutani ◽  
Takatsugu Hirokawa

AbstractRas mutations (e.g., occur in K-Ras, N-Ras, and H-Ras) are one of the most desirable and promising drug targets in chemotherapy treatments for cancer. However, there are still no approved drugs directly targeting mutated Ras. In 2017, an artificial cyclic peptide, KRpep-2d, was discovered as the first selective inhibitor of K-Ras(G12D), the most frequent K-Ras mutation. Here, we report the generation of KS-58, a KRpep-2d derivative that is identified as a bicyclic peptide and possess unnatural amino acid structures. Our in vitro data and molecular dynamics simulations suggest that KS-58 enters cells and blocks intracellular Ras–effector protein interactions. KS-58 selectively binds to K-Ras(G12D) and suppresses the in vitro proliferation of the human lung cancer cell line A427 and the human pancreatic cancer cell line PANC-1, both of which express K-Ras(G12D). Moreover, KS-58 exhibits anti-cancer activity when given as an intravenous injection to mice with subcutaneous or orthotropic PANC-1 cell xenografts. The anti-cancer activity is further improved by combination with gemcitabine. To the best of our knowledge, this is the first report of K-Ras(G12D)-selective inhibitory peptide presenting in vivo anti-cancer activity. KS-58 is an attractive lead molecule for the development of novel cancer drugs that target K-Ras(G12D).


Author(s):  
MARIMUTHU GOKUL ◽  
UMARANI G. ◽  
AYYAMPERUMAL ESAKKI

Objective: An Eco-friendly process of Green Synthesis of Copper Nano-particles (CuNPs) is an important aspect in the field of Nanotechnology using alternative feedstock, energy minimization, the design of less toxic and inherently safer chemicals. Methods: In this study, Copper Nano-Particles were synthesized by using isolated flavonoids to induce the reduction of Cu2+ions to CuNPs and also act as a capping and stabilizing agent. The solutions of CuSO4 and flavonoid were used as stock solutions for the preparation of CuNPs. Aqueous flavonoid(Quercetin) solution was mixed with CuSO4 solution separately. The reaction mixtures were immediately placed in a hot plate magnetic stirrer at 2000 rpm, 50-60 °C temperature and observed the change in colour of the solution from colourless to coloured solution. The synthesized CuNPs were characterized by various spectral methods for structural analysis of Nano-particles and In vitro and In vivo evaluation for anti-cancer activity. Results: The results described that the Copper Nano-particles are crystalline and amorphous with an average size of 295.4 nm and highly stable and having good hydrogen peroxide scavenging effect, reducing power and total antioxidant activity with the IC50value of 59.24μg/ml, 24.35μg/ml and16.83μg/ml respectively. The in vitro (HepG2 and MCF-7 cell lines) anti-cancer activity showing good results with IC50 values of 57.56 µg/ml for HepG2 cell line and 56.41 µg/ml for MCF-7 cell line. The in vivo anti-cancer activity also showing good results.


Blood ◽  
1985 ◽  
Vol 65 (1) ◽  
pp. 21-31 ◽  
Author(s):  
RC Stong ◽  
SJ Korsmeyer ◽  
JL Parkin ◽  
DC Arthur ◽  
JH Kersey

Abstract A cell line, designated RS4;11, was established from the bone marrow of a patient in relapse with an acute leukemia that was characterized by the t(4;11) chromosomal abnormality. The cell line and the patient's fresh leukemic cells both had the t(4;11)(q21;q23) and an isochromosome for the long arm of No. 7. Morphologically, all cells were lymphoid in appearance. Ultrastructurally and cytochemically, approximately 30% of the cells possessed myeloid features. The cells were strongly positive for terminal deoxynucleotidyl transferase. They were HLA-DR positive and expressed surface antigens characteristic for B lineage cells, including those detected by anti-B4, BA-1, BA-2, and PI153/3. Immunoglobulin gene analysis revealed rearrangements of the heavy chain and kappa chain genes. The cells lacked the common acute lymphoblastic leukemia antigen and antigenic markers characteristic of T lineage cells. The cells reacted with the myeloid antibody 1G10 but not with other myeloid monoclonal antibodies. Treatment with 12-O-tetradecanoyl- phorbol-13-acetate induced a monocyte-like phenotype demonstrated by cytochemical, functional, immunologic, and electron microscopic studies. The expression of markers of both early lymphoid and early myeloid cells represents an unusual phenotype and suggests that RS4;11 represents a cell with dual lineage capabilities. To our knowledge, RS4;11 is the first cell line established from t(4;11)-associated acute leukemia.


2012 ◽  
Vol 31 (4) ◽  
pp. 337-347 ◽  
Author(s):  
Susan R. Meier-Davis ◽  
Min Meng ◽  
Weiwei Yuan ◽  
Lisa Diehl ◽  
Fatima M. Arjmand ◽  
...  

Donepezil hydrochloride is a reversible acetyl cholinesterase inhibitor approved for Alzheimer disease treatment. As an alternate therapy, a donepezil hydrochloride transdermal patch is in development. Recommended nonclinical safety studies include a 3-month Good Laboratory Practice (GLP) dose-range finding (DRF) study prior to conducting the 2-year dermal carcinogenicity study in rats. Demonstration of systemic exposure is necessary to interpret the in vivo data. Previous nonclinical reports supporting oral dosing have utilized liquid chromatography tandem mass spectrometry (LC/MS/MS) to quantify donepezil concentrations in plasma. Smaller species with limited blood volumes do not allow serial sampling to derive the full pharmacokinetic profile from a single animal. Therefore, the option of another analytical method requiring decreased sample volumes is desirable as it would decrease the required number of animals while obtaining the complete profile. The dried blood spot (DBS) technique allows drug level measurement from a few microliters; however, the method is still not widely utilized in GLP studies. Because donepezil plasma levels are known by the oral route, DBS was used to bridge the previous oral data and to support a 13-week GLP DRF study for repeated topical application in rats, comparing oral administration with 4 topical formulations. The DBS method was validated and demonstrated robustness and reproducibility for application to the DRF study. The assay results were comparable to a previously reported plasma LC/MS/MS assay-derived pharmacokinetic profile and provided justification for selection of the topical formulation and dose levels for the subsequent dermal carcinogenicity study.


RSC Advances ◽  
2017 ◽  
Vol 7 (6) ◽  
pp. 3408-3412 ◽  
Author(s):  
Long Ma ◽  
Haiyan Liu ◽  
Lingpei Meng ◽  
Ping Qin ◽  
Botao Zhang ◽  
...  

Triterpenoidal saponins fraction isolated from a traditional Chinese medicine Conyza blinii H. Lév. demonstrates anti-cancer activity both in vitro and in vivo.


2003 ◽  
Vol 37 (1) ◽  
pp. 84-91 ◽  
Author(s):  
Roderick A.F. MacLeod ◽  
Stefan Nagel ◽  
Maren Kaufmann ◽  
Johannes W.G. Janssen ◽  
Hans G. Drexler

2020 ◽  
Vol 10 (6) ◽  
pp. 315-324
Author(s):  
Fahmi Radityamurti ◽  
Fauzan Herdian ◽  
Tiara Bunga Mayang Permata ◽  
Handoko Handoko ◽  
Henry Kodrat ◽  
...  

Introduction: Vitamin D has been shown to have anti-cancer properties such as antioxidants, anti-proliferative, and cell differentiation. The property of vitamin D as an anticancer agent triggers researchers to find out whether vitamin D is useful as a radiosensitizer. Multiple studies have been carried out on cell lines in various types of cancer, but the benefits of vitamin D as a radiosensitizer still controversial. This paperwork aims to investigate the utilization of Vitamin D3 (Calcitriol) as radiosensitizer in various cell line through literature review.Methods: A systematic search of available medical literature databases was performed on in-vitro studies with Vitamin D as a radiosensitizer in all types of cell lines. A total of 11 in-vitro studies were evaluated.Results: Nine studies in this review showed a significant effect of Vitamin D as a radiosensitizer agent by promoting cytotoxic autophagy, increasing apoptosis, inhibiting of cell survival and proliferation, promoting gene in ReIB inhibition, inducing senescene and necrosis. The two remaining studies showed no significant effect in the radiosensitizing mechanism of Vitamin D due to lack of evidence in-vitro settings.Conclusion: Vitamin D have anticancer property and can be used as a radiosensitizer by imploring various mechanism pathways in various cell lines. Further research especially in-vivo settings need to be evaluated.


Blood ◽  
2020 ◽  
Vol 136 (Supplement 1) ◽  
pp. 21-21
Author(s):  
Gisele Olinto Libanio Rodrigues ◽  
Julie Hixon ◽  
Hila Winer ◽  
Erica Matich ◽  
Caroline Andrews ◽  
...  

Mutations of the IL-7Rα chain occur in approximately 10% of pediatric T-cell acute lymphoblastic leukemia cases. While we have shown that mutant IL7Ra is sufficient to transform an immortalized thymocyte cell line, mutation of IL7Ra alone was insufficient to cause transformation of primary T cells, suggesting that additional genetic lesions may be present contributing to initiate leukemia. Studies addressing the combinations of mutant IL7Ra plus TLX3 overexpression indicates in vitro growth advantage, suggesting this gene as potential collaborative candidate. Furthermore, patients with mutated IL7R were more likely to have TLX3 or HOXA subgroup leukemia. We sought to determine whether combination of mutant hIL7Ra plus TLX3 overexpression is sufficient to generate T-cell leukemia in vivo. Double negative thymocytes were isolated from C57BL/6J mice and transduced with retroviral vectors containing mutant hIL7R plus hTLX3, or the genes alone. The combination mutant hIL7R wild type and hTLX3 was also tested. Transduced thymocytes were cultured on the OP9-DL4 bone marrow stromal cell line for 5-13 days and accessed for expression of transduced constructs and then injected into sublethally irradiated Rag-/- mice. Mice were euthanized at onset of clinical signs, and cells were immunophenotyped by flow cytometry. Thymocytes transduced with muthIL-7R-hTLX3 transformed to cytokine-independent growth and expanded over 30 days in the absence of all cytokines. Mice injected with muthIL7R-hTLX3 cells, but not the controls (wthIL7R-hTLX3or mutIL7R alone) developed leukemia approximately 3 weeks post injection, characterized by GFP expressing T-cells in blood, spleen, liver, lymph nodes and bone marrow. Furthermore, leukemic mice had increased white blood cell counts and presented with splenomegaly. Phenotypic analysis revealed a higher CD4-CD8- T cell population in the blood, bone marrow, liver and spleen compared in the mutant hIL7R + hTLX3 mice compared with mice injected with mutant IL7R alone indicating that the resulting leukemia from the combination mutant hIL7R plus hTLX3 shows early arrest in T-cell development. Taken together, these data show that oncogenic IL7R activation is sufficient for cooperation with hTLX3 in ex vivo thymocyte cell transformation, and that cells expressing the combination muthIL7R-hTLX3 is sufficient to trigger T-cell leukemia in vivo. Figure Disclosures No relevant conflicts of interest to declare.


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