In vitro and in vivo tumor growth inhibition by a p16-mimicking peptide in p16INK4A-defective, pRb-positive human melanoma cells

2004 ◽  
Vol 202 (3) ◽  
pp. 922-928 ◽  
Author(s):  
Douglas M. Noonan ◽  
Anna Severino ◽  
Monica Morini ◽  
Alessandra Tritarelli ◽  
Lucrezia Manente ◽  
...  
Blood ◽  
2019 ◽  
Vol 134 (Supplement_1) ◽  
pp. 1844-1844
Author(s):  
John Richards ◽  
Myriam N Bouchlaka ◽  
Robyn J Puro ◽  
Ben J Capoccia ◽  
Ronald R Hiebsch ◽  
...  

AO-176 is a highly differentiated, humanized anti-CD47 IgG2 antibody that is unique among agents in this class of checkpoint inhibitors. AO-176 works by blocking the "don't eat me" signal, the standard mechanism of anti-CD47 antibodies, but also by directly killing tumor cells. Importantly, AO-176 binds preferentially to tumor cells, compared to normal cells, and binds even more potently to tumors in their acidic microenvironment (low pH). Hematological neoplasms are the fourth most frequently diagnosed cancers in both men and women and account for approximately 10% of all cancers. Here we describe AO-176, a highly differentiated anti-CD47 antibody that potently targets hematologic cancers in vitro and in vivo. As a single agent, AO-176 not only promotes phagocytosis (15-45%, EC50 = 0.33-4.1 µg/ml) of hematologic tumor cell lines (acute myeloid leukemia, non-Hodgkin's lymphoma, multiple myeloma, and T cell leukemia) but also directly targets and kills tumor cells (18-46% Annexin V positivity, EC50 = 0.63-10 µg/ml) in a non-ADCC manner. In combination with agents targeting CD20 (rituximab) or CD38 (daratumumab), AO-176 mediates enhanced phagocytosis of lymphoma and multiple myeloma cell lines, respectively. In vivo, AO-176 mediates potent monotherapy tumor growth inhibition of hematologic tumors including Raji B cell lymphoma and RPMI-8226 multiple myeloma xenograft models in a dose-dependent manner. Concomitant with tumor growth inhibition, immune cell infiltrates were observed with elevated numbers of macrophage and dendritic cells, along with increased pro-inflammatory cytokine levels in AO-176 treated animals. When combined with bortezomib, AO-176 was able to elicit complete tumor regression (100% CR in 10/10 animals treated with either 10 or 25 mg/kg AO-176 + 1 mg/kg bortezomib) with no detectable tumor out to 100 days at study termination. Overall survival was also greatly improved following combination therapy compared to animals treated with bortezomib or AO-176 alone. These data show that AO-176 exhibits promising monotherapy and combination therapy activity, both in vitro and in vivo, against hematologic cancers. These findings also add to the previously reported anti-tumor efficacy exhibited by AO-176 in solid tumor xenografts representing ovarian, gastric and breast cancer. With AO-176's highly differentiated MOA and binding characteristics, it may have the potential to improve upon the safety and efficacy profiles relative to other agents in this class. AO-176 is currently being evaluated in a Phase 1 clinical trial (NCT03834948) for the treatment of patients with select solid tumors. Disclosures Richards: Arch Oncology Inc.: Employment, Equity Ownership, Other: Salary. Bouchlaka:Arch Oncology Inc.: Consultancy, Equity Ownership. Puro:Arch Oncology Inc.: Employment, Equity Ownership. Capoccia:Arch Oncology Inc.: Employment, Equity Ownership. Hiebsch:Arch Oncology Inc.: Employment, Equity Ownership. Donio:Arch Oncology Inc.: Employment, Equity Ownership. Wilson:Arch Oncology Inc.: Employment, Equity Ownership. Chakraborty:Arch Oncology Inc.: Employment, Equity Ownership. Sung:Arch Oncology Inc.: Employment, Equity Ownership. Pereira:Arch Oncology Inc.: Employment, Equity Ownership.


2016 ◽  
Vol 480 (4) ◽  
pp. 515-521 ◽  
Author(s):  
Lezi Chen ◽  
Quan Chen ◽  
Guosan Deng ◽  
Shifeng Kuang ◽  
Jihong Lian ◽  
...  

1996 ◽  
Vol 135 (6) ◽  
pp. 1889-1898 ◽  
Author(s):  
D Schadendorf ◽  
M A Kern ◽  
M Artuc ◽  
H L Pahl ◽  
T Rosenbach ◽  
...  

Human malignant melanoma is notoriously resistant to pharmacological modulation. We describe here for the first time that the synthetic retinoid CD437 has a strong dose-dependent antiproliferative effect on human melanoma cells (IC50: 5 x 10(-6) M) via the induction of programmed cell death, as judged by analysis of cell morphology, electron microscopical features, and DNA fragmentation. Programmed cell death was preceded by a strong activation of the AP-1 complex in CD437-treated cells as demonstrated by gel retardation and chloramphenicol transferase (CAT) assays. Northern blot analysis showed a time-dependent increase in the expression of c-fos and c-jun encoding components of AP-1, whereas bcl-2 and p53 mRNA levels remained constant. CD437 also exhibited a strong growth inhibitory effect on MeWo melanoma cells in a xenograft model. In tissue sections of CD437-treated MeWo tumors from these animals, apoptotic melanoma cells and c-fos overexpressing cells were colocalized by TdT-mediated deoxyuridine triphosphate-digoxigenin nick end labeling (TUNEL) staining and in situ hybridization. Taken together, this report identifies CD437 as a retinoid that activates and upregulates the transcription factor AP-1, leading eventually to programmed cell death of exposed human melanoma cells in vitro and in vivo. Further studies are needed to evaluate whether synthetic retinoids such as CD437 represent a new class of retinoids, which may open up new ways to a more effective therapy of malignant melanoma.


Blood ◽  
2008 ◽  
Vol 112 (11) ◽  
pp. 1592-1592 ◽  
Author(s):  
Jessica J Huck ◽  
Mengkun Zhang ◽  
Marc L Hyer ◽  
Mark G Manfredi

Abstract Aurora A kinase is a serine/threonine protein kinase that is essential for normal transit of cells through mitosis. In many tumor types the Aurora A gene is amplified and/or the protein is over-expressed. The Aurora A small-molecule inhibitor MLN8237 demonstrated robust tumor growth inhibition in xenograft models of solid tumors grown subcutaneously (S.C.) in immunocompromised mice. Here we explored the antitumor activity of MLN8237 in models of diffuse large B-cell lymphoma (DLBCL) both in vitro and in vivo. In vivo three established DLBCL xenograft models (OCI-Ly7, OCI-Ly19, and WSU-DLCL2; all cells expressing luciferase) and a primary DLBCL tumor model PHTX-22-06 were tested using MLN8237 at different doses. Rituximab, an anti-CD20 monoclonal antibody that is active against CD20+ malignant B cells and is a standard of care agent was used for comparison. Using these model systems, tumor cells were injected either I.V. (to evaluate disseminated disease), or S.C. in severe combined immunodeficient mice (SCID). Animals were dosed orally for 21 days with MLN8237 (QD or BID) at various doses, or Rituximab dosed at 10mg/kg IV (once/week) and tumor growth inhibition was monitored using either bioluminescent imaging for the disseminated models or vernier calipers for the S.C. models. Tumor growth inhibition by MLN8237 was dose dependent with 20 mg/kg bid being the most efficacious dose (TGI>100% in both disseminated OCI-Ly19 and WSU models). All animals in the OCI-Ly19 disseminated model 20 mg/kg BID treatment group demonstrated regressions and remained disease free until the end of the study, day 65. In this study the Rituximab treated animals were euthanized on day 31 due to a high level of tumor burden. In the primary tumor model, PHTX-22-06, MLN8237 dosed at 20 mg/kg BID was also the most efficacious with a TGI of 95%. Moreover, tumor growth inhibition was durable as determined by prolonged tumor growth delay (>50 days). Significant efficacy was achieved in all models tested, whether grown as disseminated or subcutaneous models. A noted increase in durability of response was observed with MLN8237 treatment when compared with previous data from solid tumor models. In vitro, MLN8237 treatment increased levels of apoptosis in the OCI-Ly19 cells in comparison to the solid tumor cell line HCT-116 (colon). Greater Annexin V positive cells and greater cleaved PARP and Caspase-3 signals were detected in the MLN8237 treated OCI-Ly19 cells when compared to HCT-116 cells. The demonstration of robust and durable anti-tumor activity in preclinical models treated with MLN8237 provides the basis for its clinical evaluation as a treatment option for DLBCL. MLN8237 is currently in multiple Phase I clinical trials.


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