RESUMO
MLN2704 is an antibody-chemotherapeutic conjugate designed to target prostate-specific membrane antigen (PSMA). PSMA is a transmembrane receptor whose expression is largely restricted to prostatic epithelium and prostate cancer cells with its expression level increasing during the progression of malignancy. MLN2704 consists of a de-immunized, monoclonal antibody that is specific for PSMA conjugated to drug maytansinoid 1 (DM1), a microtubule-depolymerizing compound. After antibody binding to PSMA and the subsequent cellular internalization of this complex, DM1 is released leading to cell death. MLN2704 has an approximate half-life of 39 hours in scid mice bearing CWR22 tumor tissue, and the antibody effectively penetrates xenograft tumor tissue. Optimization of dosage and schedule of MLN2704 administration defined interdependency between these conditions that maximized efficacy with no apparent toxicity. Tumor growth delays of approximately 100 days could be achieved on the optimized schedule of one dose of 60 mg/kg MLN2704 every 14 days for five doses (q14dx5). The unconjugated antibody (MLN591) demonstrated essentially no antitumor activity and DM1 alone or a non-PSMA targeted antibody-DM1 conjugate was only weakly active. Furthermore, we show that MLN2704 is active in a novel model of osteoblastic prostate cancer metastasis.
Assuntos
Anticorpos Monoclonais/uso terapêutico , Antineoplásicos/uso terapêutico , Glutamato Carboxipeptidase II/antagonistas & inibidores , Imunotoxinas/uso terapêutico , Maitansina/análogos & derivados , Neoplasias da Próstata/terapia , Animais , Antígenos de Superfície , Neoplasias Ósseas/secundário , Humanos , Masculino , Maitansina/uso terapêutico , Camundongos , Transplante de Neoplasias , Transplante HeterólogoRESUMO
mTOR is a serine/threonine kinase that regulates cell growth, metabolism, proliferation, and survival. mTOR complex-1 (mTORC1) and mTOR complex-2 (mTORC2) are critical mediators of the PI3K-AKT pathway, which is frequently mutated in many cancers, leading to hyperactivation of mTOR signaling. Although rapamycin analogues, allosteric inhibitors that target only the mTORC1 complex, have shown some clinical activity, it is hypothesized that mTOR kinase inhibitors, blocking both mTORC1 and mTORC2 signaling, will have expanded therapeutic potential. Here, we describe the preclinical characterization of CC-223. CC-223 is a potent, selective, and orally bioavailable inhibitor of mTOR kinase, demonstrating inhibition of mTORC1 (pS6RP and p4EBP1) and mTORC2 [pAKT(S473)] in cellular systems. Growth inhibitory activity was demonstrated in hematologic and solid tumor cell lines. mTOR kinase inhibition in cells, by CC-223, resulted in more complete inhibition of the mTOR pathway biomarkers and improved antiproliferative activity as compared with rapamycin. Growth inhibitory activity and apoptosis was demonstrated in a panel of hematologic cancer cell lines. Correlative analysis revealed that IRF4 expression level associates with resistance, whereas mTOR pathway activation seems to associate with sensitivity. Treatment with CC-223 afforded in vivo tumor biomarker inhibition in tumor-bearing mice, after a single oral dose. CC-223 exhibited dose-dependent tumor growth inhibition in multiple solid tumor xenografts. Significant inhibition of mTOR pathway markers pS6RP and pAKT in CC-223-treated tumors suggests that the observed antitumor activity of CC-223 was mediated through inhibition of both mTORC1 and mTORC2. CC-223 is currently in phase I clinical trials.
Assuntos
Neoplasias/tratamento farmacológico , Pirazinas/farmacologia , Serina-Treonina Quinases TOR/antagonistas & inibidores , Ensaios Antitumorais Modelo de Xenoenxerto , Animais , Apoptose/efeitos dos fármacos , Western Blotting , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Relação Dose-Resposta a Droga , Feminino , Células HCT116 , Células HEK293 , Humanos , Alvo Mecanístico do Complexo 1 de Rapamicina , Alvo Mecanístico do Complexo 2 de Rapamicina , Camundongos SCID , Estrutura Molecular , Complexos Multiproteicos/antagonistas & inibidores , Complexos Multiproteicos/metabolismo , Neoplasias/irrigação sanguínea , Neoplasias/metabolismo , Neovascularização Patológica/prevenção & controle , Inibidores de Proteínas Quinases/química , Inibidores de Proteínas Quinases/farmacologia , Pirazinas/química , Serina-Treonina Quinases TOR/metabolismo , Carga Tumoral/efeitos dos fármacosRESUMO
We report here the synthesis and structure-activity relationship (SAR) of a novel series of triazole containing mammalian target of rapamycin (mTOR) kinase inhibitors. SAR studies examining the potency, selectivity, and PK parameters for a series of triazole containing 4,6- or 1,7-disubstituted-3,4-dihydropyrazino[2,3-b]pyrazine-2(1H)-ones resulted in the identification of triazole containing mTOR kinase inhibitors with improved PK properties. Potent compounds from this series were found to block both mTORC1(pS6) and mTORC2(pAktS473) signaling in PC-3 cancer cells, in vitro and in vivo. When assessed in efficacy models, analogs exhibited dose-dependent efficacy in tumor xenograft models. This work resulted in the selection of CC-115 for clinical development.
Assuntos
Desenho de Fármacos , Inibidores de Proteínas Quinases/química , Inibidores de Proteínas Quinases/farmacologia , Pirazinas/química , Pirazinas/farmacologia , Serina-Treonina Quinases TOR/antagonistas & inibidores , Triazóis/química , Triazóis/farmacologia , Animais , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Relação Dose-Resposta a Droga , Humanos , Simulação de Acoplamento Molecular , Conformação Proteica , Inibidores de Proteínas Quinases/metabolismo , Inibidores de Proteínas Quinases/farmacocinética , Pirazinas/metabolismo , Pirazinas/farmacocinética , Ratos , Transdução de Sinais/efeitos dos fármacos , Relação Estrutura-Atividade , Serina-Treonina Quinases TOR/química , Serina-Treonina Quinases TOR/metabolismo , Triazóis/metabolismo , Triazóis/farmacocinética , Ensaios Antitumorais Modelo de XenoenxertoRESUMO
We report here the synthesis and structure-activity relationship (SAR) of a novel series of mammalian target of rapamycin (mTOR) kinase inhibitors. A series of 4,6- or 1,7-disubstituted-3,4-dihydropyrazino[2,3-b]pyrazine-2(1H)-ones were optimized for in vivo efficacy. These efforts resulted in the identification of compounds with excellent mTOR kinase inhibitory potency, with exquisite kinase selectivity over the related lipid kinase PI3K. The improved PK properties of this series allowed for exploration of in vivo efficacy and ultimately the selection of CC-223 for clinical development.
Assuntos
Antineoplásicos/farmacologia , Descoberta de Drogas , Inibidores de Fosfoinositídeo-3 Quinase , Neoplasias da Próstata/tratamento farmacológico , Inibidores de Proteínas Quinases/farmacologia , Pirazinas/farmacologia , Transdução de Sinais/efeitos dos fármacos , Serina-Treonina Quinases TOR/antagonistas & inibidores , Animais , Antineoplásicos/síntese química , Humanos , Masculino , Modelos Moleculares , Estrutura Molecular , Inibidores de Proteínas Quinases/síntese química , Pirazinas/síntese química , Ratos , Relação Estrutura-Atividade , Células Tumorais CultivadasRESUMO
Using a high-throughput screening strategy, a series of 1-aryl-4,5-dihydro-1H-pyrazolo[3,4-d]pyrimidin-4-ones was identified that inhibit the cyclin-dependent kinase (CDK) 4/cyclin D1 complex-mediated phosphorylation of a protein substrate with IC(50)s in the low micromolar range. On the basis of preliminary structure-activity relationships (SAR), a model was proposed in which these inhibitors occupy the ATP-binding site of the enzyme, forming critical hydrogen bonds to the same residue (Val96) to which the amino group in ATP is presumed to bind. X-ray diffraction studies on a later derivative bound to CDK2 support this binding mode. Iterative cycles of synthesis and screening lead to a novel series of potent, CDK2-selective 6-(arylmethyl)pyrazolopyrimidinones. Placement of a hydrogen-bond donor in the meta-position on the 6-arylmethyl group resulted in approximately 100-fold increases in CDK4 affinity, giving ligands that were equipotent inhibitors of CDK4 and CDK2. These compounds exhibit antiproliferative effects in the NCI HCT116 and other cell lines. The potency of these antiproliferative effects is enhanced in anilide derivatives and translates into tumor growth inhibition in a mouse xenograft model.
Assuntos
Quinases Ciclina-Dependentes/antagonistas & inibidores , Proteínas Proto-Oncogênicas/antagonistas & inibidores , Pirazóis/síntese química , Pirimidinas/síntese química , Animais , Antineoplásicos/síntese química , Antineoplásicos/química , Antineoplásicos/farmacologia , Sítios de Ligação , Linhagem Celular Tumoral , Células Cultivadas , Cristalografia por Raios X , Ciclina D1/antagonistas & inibidores , Ciclina D1/metabolismo , Quinase 4 Dependente de Ciclina , Quinases Ciclina-Dependentes/metabolismo , Ensaios de Seleção de Medicamentos Antitumorais , Humanos , Camundongos , Modelos Moleculares , Estrutura Molecular , Fosforilação , Proteínas Proto-Oncogênicas/metabolismo , Pirazóis/química , Pirazóis/farmacologia , Pirimidinas/química , Pirimidinas/farmacologia , Relação Estrutura-Atividade , Transplante HeterólogoRESUMO
The recent clinical and commercial success of anticancer antibodies such as rituximab and trastuzumab has created great interest in antibody-based therapeutics for hematopoietic malignant neoplasms and solid tumors. Given the likelihood of lower toxic effects of antibodies that target tumor cells and have limited impact on nonmalignant bystander organs vs small molecules, the potential increased efficacy by conjugation to radioisotopes and other cellular toxins, and the ability to characterize the target with clinical laboratory diagnostics to improve the drug's clinical performance, current and future antibody therapeutics are likely to find substantial roles alone and in combination therapeutic strategies for treating patients with cancer. It also is likely that conjugation strategies will add new radiolabeled and toxin-linked products to the market to complement the recent approvals of ibritumomab tiuxetan and gemtuzumab ozogamicin. This review considers the structure of anticancer therapeutic antibodies and the techniques used to reduce their antigenicity. Efficacy and toxic effects, conjugation with isotopes and toxins, and validation of the antibody targets also are discussed. Antibodies approved by the Food and Drug Administration are described in detail, as are antibodies in late and early stages of clinical development.
Assuntos
Anticorpos Antineoplásicos/uso terapêutico , Antineoplásicos/uso terapêutico , Imunoterapia , Neoplasias/terapia , Animais , Anticorpos Monoclonais/uso terapêutico , Anticorpos Antineoplásicos/química , Anticorpos Antineoplásicos/imunologia , Especificidade de Anticorpos , Antineoplásicos/química , Antineoplásicos/imunologia , Terapia Combinada , Feminino , Humanos , Masculino , Neoplasias/imunologia , Engenharia de ProteínasRESUMO
The recent clinical and commercial success of anticancer antibodies, such as rituximab (Rituxan) and trastuzumab (Herceptin) has created great interest in antibody-based therapeutics for hematopoietic malignancies and solid tumors. Given the likely lower toxicity for antibodies versus small molecules, the potential increase in efficacy by conjugation to radioisotopes and other cellular toxins and the ability to characterize the target with clinical laboratory diagnostics to improve the drug's clinical performance, it is anticipated that current and future antibody therapeutics will find substantial roles alone and in combination therapy strategies for the treatment of patients with cancer. It is also likely that conjugation strategies will add new radiolabeled and toxin-linked products to the market to complement the recent approvals of ibritumomab tiuxetan (Zevalin) and gemtuzumab ozogamycin (Mylotarg). However, although there are a large number of agents in both early and later stages of clinical development, only a handful will make it through regulatory approval and become successful products. This review considers the structure of anticancer therapeutic antibodies, the techniques used to reduce their antigenicity, factors that influence efficacy and toxicity, conjugation with isotopes and toxins and antibody target validation.
Assuntos
Anticorpos Antineoplásicos/uso terapêutico , Imunoterapia , Neoplasias/terapia , Anticorpos Monoclonais/uso terapêutico , Anticorpos Antineoplásicos/efeitos adversos , Anticorpos Antineoplásicos/química , Ensaios Clínicos como Assunto , Sistemas de Liberação de Medicamentos , Neoplasias Hematológicas/terapia , Humanos , Imunotoxinas/uso terapêutico , Neoplasias/imunologia , Proteínas Recombinantes de Fusão/química , Proteínas Recombinantes de Fusão/uso terapêuticoRESUMO
Lenalidomide and pomalidomide have both been evaluated clinically for their properties as anticancer agents, with lenalidomide being available commercially. We previously reported that both compounds cause cell cycle arrest in Burkitt's lymphoma and multiple myeloma cell lines by increasing the level of p21(WAF-1) expression. In the present study, we unravel the molecular mechanism responsible for p21(WAF-1) up-regulation using Namalwa cells as a human lymphoma model. We show that the increase of p21(WAF-1) expression is regulated at the transcriptional level through a mechanism independent of p53. Using a combination of approaches, we show that several GC-rich binding transcription factors are involved in pomalidomide-mediated up-regulation of p21(WAF-1). Furthermore, we report that p21(WAF-1) up-regulation is associated with a switch from methylated to acetylated histone H3 on p21(WAF-1) promoter. Interestingly, lysine-specific demethylase-1 (LSD1) silencing reduced both pomalidomide and lenalidomide up-regulation of p21(WAF-1), suggesting that this histone demethylase is involved in the priming of the p21(WAF-1) promoter. Based on our findings, we propose a model in which pomalidomide and lenalidomide modify the chromatin structure of the p21(WAF-1) promoter through demethylation and acetylation of H3K9. This effect, mediated via LSD1, provides GC-rich binding transcription factors better access to DNA, followed by recruitment of RNA polymerase II and transcription activation. Taken together, our results provide new insights on the mechanism of action of pomalidomide and lenalidomide in the regulation of gene transcription, imply possible efficacy in p53 mutated and deleted cancer, and suggest new potential clinical uses as an epigenetic therapy.
Assuntos
Inibidor de Quinase Dependente de Ciclina p21/biossíntese , Linfoma/tratamento farmacológico , Mieloma Múltiplo/tratamento farmacológico , Oxirredutases N-Desmetilantes/metabolismo , Talidomida/análogos & derivados , Antineoplásicos/farmacologia , Linhagem Celular Tumoral , Cromatina/metabolismo , Inibidor de Quinase Dependente de Ciclina p21/genética , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Histona Desmetilases , Histonas/genética , Histonas/metabolismo , Humanos , Lenalidomida , Linfoma/genética , Linfoma/metabolismo , Mieloma Múltiplo/genética , Mieloma Múltiplo/metabolismo , Oxirredutases N-Desmetilantes/genética , Talidomida/farmacologia , Fatores de Transcrição/genética , Fatores de Transcrição/metabolismoRESUMO
BACKGROUND: Prostate cancer bone metastasis is distinguished by the predominance of osteoblastic lesions. This phenotype has been difficult to reproduce in animal models. Here, we describe a model utilizing the 22Rv1 human prostate cancer cell line that generates osteolytic lesions and a prominent spiculated periosteal osteoblastic response following intraosseous injection in scid mice. METHODS: We injected 22Rv1-luciferase prostate cancer cells directly into the tibiae of C.B-17 scid mice. We analyzed tumor growth and pathology every 2 weeks using radiographic and histologic techniques. RESULTS: X-ray analysis revealed that 22Rv1 tumors elicit a mixed-type lesion including some osteolysis and a robust induction of periosteal bone formation, in contrast to PC3M-luciferase intraosseous tumors which induce only extensive osteolysis. Micro-computerized tomographic imaging shows that 22Rv1 tumors exhibit both osteolytic and osteoblastic features which become apparent between 4 and 6 weeks post injection. There is initial disruption of the cortex and corresponding invasion of the periosteum which is associated with a vigorous osteoblastic response. Histological analysis of late stage tumors shows that the tumor has grown outside of the medullary cavity and surrounds the tibia underneath the periosteum and intermixed with spicules of woven bone which is detected in the radiographic analysis. CONCLUSIONS: The overall pattern of this model is suggestive of clinical cases of prostate cancer metastasis in which periosteal responses are noted, often in association with rapidly progressive disease. We expect that intraosseous injection of 22Rv1 cells will provide a new experimental model for the study of osteoblastic prostate cancer metastasis.