RESUMO
BACKGROUND: The Aurora kinases are a family of serine/threonine kinases comprised of Aurora A, B, and C which execute critical steps in mitotic and meiotic progression. Alisertib (MLN8237) is an investigational Aurora A selective inhibitor that has demonstrated activity against a wide variety of tumor types in vitro and in vivo, including CRC. RESULTS: CRC cell lines demonstrated varying sensitivity to alisertib with IC50 values ranging from 0.06 to > 5 umol/L. Following exposure to alisertib we observed a decrease in pAurora A, B and C in four CRC cell lines. We also observed an increase in p53 and p21 in a sensitive p53 wildtype cell line in contrast to the p53 mutant cell line or the resistant cell lines. The addition of alisertib to standard CRC treatments demonstrated improvement over single agent arms; however, the benefit was largely less than additive, but not antagonistic. METHODS: Forty-seven CRC cell lines were exposed to alisertib and IC50s were calculated. Twenty-one PDX models were treated with alisertib and the Tumor Growth Inhibition Index was assessed. Additionally, 5 KRAS wildtype and mutant PDX models were treated with alisertib as single agent or in combination with cetuximab or irinotecan, respectively. CONCLUSION: Alisertib demonstrated anti-proliferative effects against CRC cell lines and PDX models. Our data suggest that the addition of alisertib to standard therapies in colorectal cancer if pursued clinically, will require further investigation of patient selection strategies and these combinations may facilitate future clinical studies.
Assuntos
Antineoplásicos/farmacologia , Aurora Quinase A/antagonistas & inibidores , Azepinas/farmacologia , Neoplasias Colorretais/tratamento farmacológico , Pirimidinas/farmacologia , Animais , Apoptose , Camptotecina/análogos & derivados , Camptotecina/farmacologia , Ciclo Celular , Linhagem Celular Tumoral , Proliferação de Células , Cetuximab/farmacologia , Inibidor de Quinase Dependente de Ciclina p21/metabolismo , Ensaios de Seleção de Medicamentos Antitumorais , Feminino , Humanos , Concentração Inibidora 50 , Irinotecano , Camundongos , Camundongos Nus , Transplante de Neoplasias , Inibidores de Proteínas Quinases/farmacologia , Proteínas Proto-Oncogênicas p21(ras)/metabolismo , Proteína Supressora de Tumor p53/metabolismo , Ensaios Antitumorais Modelo de XenoenxertoRESUMO
Glioblastoma remains a devastating disease for which novel therapies are urgently needed. Here, we report that the Aurora-A kinase inhibitor alisertib exhibits potent efficacy against glioblastoma neurosphere tumor stem-like cells in vitro and in vivo. Many glioblastoma neurosphere cells treated with alisertib for short periods undergo apoptosis, although some regain proliferative activity upon drug removal. Extended treatment, however, results in complete and irreversible loss of tumor cell proliferation. Moreover, alisertib caused glioblastoma neurosphere cells to partially differentiate and enter senescence. These effects were also observed in glioma cells treated with the Aurora-A inhibitor TC-A2317 or anti-Aurora-A siRNA. Furthermore, alisertib extended median survival of mice bearing intracranial human glioblastoma neurosphere tumor xenografts. Alisertib exerted similar effects on glioblastoma neurosphere cells in vivo and resulted in markedly reduced activated phosphoThr288Aurora-A and increased abnormal mitoses and cellular ploidy, consistent with on-target activity. Our results offer preclinical proof-of-concept for alisertib as a new therapeutic for glioma treatment.
Assuntos
Aurora Quinase A/antagonistas & inibidores , Neoplasias Encefálicas/tratamento farmacológico , Glioblastoma/tratamento farmacológico , Inibidores de Proteínas Quinases/uso terapêutico , Animais , Neoplasias Encefálicas/patologia , Diferenciação Celular/efeitos dos fármacos , Linhagem Celular Tumoral , Feminino , Glioblastoma/patologia , Humanos , Camundongos , Camundongos Nus , Inibidores de Proteínas Quinases/farmacologia , Ensaios Antitumorais Modelo de XenoenxertoRESUMO
Oncogene-induced senescence can provide a protective mechanism against tumour progression. However, production of cytokines and growth factors by senescent cells may contribute to tumour development. Thus, it is unclear whether induction of senescence represents a viable therapeutic approach. Here, using a mouse model with orthotopic implantation of metastatic melanoma tumours taken from 19 patients, we observed that targeting aurora kinases with MLN8054/MLN8237 impaired mitosis, induced senescence and markedly blocked proliferation in patient tumour implants. Importantly, when a subset of tumour-bearing mice were monitored for tumour progression after pausing MLN8054 treatment, 50% of the tumours did not progress over a 12-month period. Mechanistic analyses revealed that inhibition of aurora kinases induced polyploidy and the ATM/Chk2 DNA damage response, which mediated senescence and a NF-κB-related, senescence-associated secretory phenotype (SASP). Blockade of IKKß/NF-κB led to reversal of MLN8237-induced senescence and SASP. Results demonstrate that removal of senescent tumour cells by infiltrating myeloid cells is crucial for inhibition of tumour re-growth. Altogether, these data demonstrate that induction of senescence, coupled with immune surveillance, can limit melanoma growth.
Assuntos
Azepinas/farmacologia , Benzazepinas/farmacologia , Melanoma Experimental/tratamento farmacológico , NF-kappa B/antagonistas & inibidores , Proteínas Serina-Treonina Quinases/antagonistas & inibidores , Pirimidinas/farmacologia , Animais , Antineoplásicos/farmacologia , Proteínas Mutadas de Ataxia Telangiectasia , Aurora Quinases , Proteínas de Ciclo Celular/metabolismo , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Senescência Celular/efeitos dos fármacos , Quinase do Ponto de Checagem 2 , Dano ao DNA , Proteínas de Ligação a DNA/metabolismo , Humanos , Melanoma Experimental/metabolismo , Melanoma Experimental/patologia , Melanoma Experimental/secundário , Camundongos , Camundongos Nus , Poliploidia , Inibidores de Proteínas Quinases/farmacologia , Proteínas Serina-Treonina Quinases/metabolismo , Proteína Supressora de Tumor p53/metabolismo , Proteínas Supressoras de Tumor/metabolismo , Ensaios Antitumorais Modelo de XenoenxertoRESUMO
Aurora A kinase is a serine/threonine protein kinase responsible for regulating several mitotic processes including centrosome separation, spindle assembly, and chromosome segregation. Small molecule inhibitors of Aurora A kinase are being pursued as novel anticancer agents, some of which have entered clinical trials. Despite the progress in developing these agents, terminal outcomes associated with Aurora A inhibition are not fully understood. Although evidence exists that Aurora A inhibition leads to apoptosis, other therapeutically relevant cell fates have not been reported. Here, we used the small molecule inhibitor MLN8054 to show that inhibition of Aurora A induces tumor cell senescence both in vitro and in vivo. Treatment of human tumor cells grown in culture with MLN8054 showed a number of morphologic and biochemical changes associated with senescence. These include increased staining of senescence-associated beta-galactosidase, increased nuclear and cell body size, vacuolated cellular morphology, upregulation/stabilization of p53, p21, and hypophosphorylated pRb. To determine if Aurora A inhibition induces senescence in vivo, HCT-116 xenograft-bearing animals were dosed orally with MLN8054 for 3 weeks. In the MLN8054-treated animals, increased senescence-associated beta-galactosidase activity was detected in tissue sections starting on day 15. In addition, DNA and tubulin staining of tumor tissue showed a significant increase in nuclear and cell body area, consistent with a senescent phenotype. Taken together, this data shows that senescence is a terminal outcome of Aurora A inhibition and supports the evaluation of senescence biomarkers in clinic samples.