RESUMO
TTK protein kinase (TTK), also known as Monopolar spindle 1 (MPS1), is a key regulator of the spindle assembly checkpoint (SAC), which functions to maintain genomic integrity. TTK has emerged as a promising therapeutic target in human cancers, including triple-negative breast cancer (TNBC). Several TTK inhibitors (TTKis) are being evaluated in clinical trials, and an understanding of the mechanisms mediating TTKi sensitivity and resistance could inform the successful development of this class of agents. We evaluated the cellular effects of the potent clinical TTKi CFI-402257 in TNBC models. CFI-402257 induced apoptosis and potentiated aneuploidy in TNBC lines by accelerating progression through mitosis and inducing mitotic segregation errors. We used genome-wide CRISPR/Cas9 screens in multiple TNBC cell lines to identify mechanisms of resistance to CFI-402257. Our functional genomic screens identified members of the anaphase-promoting complex/cyclosome (APC/C) complex, which promotes mitotic progression following inactivation of the SAC. Several screen candidates were validated to confer resistance to CFI-402257 and other TTKis using CRISPR/Cas9 and siRNA methods. These findings extend the observation that impairment of the APC/C enables cells to tolerate genomic instability caused by SAC inactivation, and support the notion that a measure of APC/C function could predict the response to TTK inhibition. Indeed, an APC/C gene expression signature is significantly associated with CFI-402257 response in breast and lung adenocarcinoma cell line panels. This expression signature, along with somatic alterations in genes involved in mitotic progression, represent potential biomarkers that could be evaluated in ongoing clinical trials of CFI-402257 or other TTKis.
Assuntos
Ciclossomo-Complexo Promotor de Anáfase/metabolismo , Proteínas de Ciclo Celular/antagonistas & inibidores , Resistencia a Medicamentos Antineoplásicos , Inibidores de Proteínas Quinases/farmacologia , Proteínas Serina-Treonina Quinases/antagonistas & inibidores , Proteínas Tirosina Quinases/antagonistas & inibidores , Pirazóis/farmacologia , Pirimidinas/farmacologia , Neoplasias de Mama Triplo Negativas/enzimologia , Ciclossomo-Complexo Promotor de Anáfase/genética , Proteínas de Ciclo Celular/metabolismo , Linhagem Celular Tumoral , Feminino , Instabilidade Genômica/efeitos dos fármacos , Humanos , Mitose/efeitos dos fármacos , Proteínas Serina-Treonina Quinases/metabolismo , Proteínas Tirosina Quinases/metabolismo , Neoplasias de Mama Triplo Negativas/tratamento farmacológico , Neoplasias de Mama Triplo Negativas/genética , Neoplasias de Mama Triplo Negativas/fisiopatologiaRESUMO
BACKGROUND: Standard first-line treatment of metastatic triple-negative breast cancer (mTNBC) is chemotherapy. However, outcomes are poor, and new treatment options are needed. In cohort B of the phase II KEYNOTE-086 study, we evaluated pembrolizumab as first-line therapy for patients with PD-L1-positive mTNBC. PATIENTS AND METHODS: Eligible patients had centrally confirmed mTNBC, no prior systemic anticancer therapy for metastatic disease, measurable disease at baseline per RECIST v1.1 by central review, no radiographic evidence of central nervous system metastases, and a tumor PD-L1 combined positive score ≥1. Patients received pembrolizumab 200 mg intravenously every 3 weeks for up to 2 years. The primary end point was safety. Secondary end points included objective response rate, disease control rate (percentage of patients with complete or partial response or stable disease for ≥24 weeks), duration of response, progression-free survival and overall survival. RESULTS: All 84 patients enrolled were women, and 73 (86.9%) received prior (neo)adjuvant therapy. Fifty-three (63.1%) patients had treatment-related adverse events (AEs), including 8 patients (9.5%) with grade 3 severity; no patients experienced grade 4 AEs or died because of treatment-related AEs. Four patients had a complete response and 14 had a partial response, for an objective response rate of 21.4% (95% CI 13.9-31.4). Of the 13 patients with stable disease, 2 had stable disease lasting ≥24 weeks, for a disease control rate of 23.8% (95% CI 15.9-34.0). At data cut-off, 8 of 18 (44.4%) responses were ongoing, and median duration of response was 10.4 months (range 4.2 to 19.2+). Median progression-free survival was 2.1 months (95% CI 2.0-2.2), and median overall survival was 18.0 months (95% CI 12.9-23.0). CONCLUSIONS: Pembrolizumab monotherapy had a manageable safety profile and showed durable antitumor activity as first-line therapy for patients with PD-L1-positive mTNBC. CLINICAL TRIAL REGISTRATION: ClinicalTrials.gov, NCT02447003.
Assuntos
Anticorpos Monoclonais Humanizados/administração & dosagem , Antígeno B7-H1/genética , Neoplasias de Mama Triplo Negativas/tratamento farmacológico , Adulto , Idoso , Idoso de 80 Anos ou mais , Anticorpos Monoclonais Humanizados/efeitos adversos , Estudos de Coortes , Feminino , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Humanos , Masculino , Pessoa de Meia-Idade , Metástase Neoplásica , Intervalo Livre de Progressão , Neoplasias de Mama Triplo Negativas/genética , Neoplasias de Mama Triplo Negativas/patologiaRESUMO
BACKGROUND: Treatment options for previously treated metastatic triple-negative breast cancer (mTNBC) are limited. In cohort A of the phase II KEYNOTE-086 study, we evaluated pembrolizumab as second or later line of treatment for patients with mTNBC. PATIENTS AND METHODS: Eligible patients had centrally confirmed mTNBC, ≥1 systemic therapy for metastatic disease, prior treatment with anthracycline and taxane in any disease setting, and progression on or after the most recent therapy. Patients received pembrolizumab 200 mg intravenously every 3 weeks for up to 2 years. Primary end points were objective response rate in the total and PD-L1-positive populations, and safety. Secondary end points included duration of response, disease control rate (percentage of patients with complete or partial response or stable disease for ≥24 weeks), progression-free survival, and overall survival. RESULTS: All enrolled patients (N = 170) were women, 61.8% had PD-L1-positive tumors, and 43.5% had received ≥3 previous lines of therapy for metastatic disease. ORR (95% CI) was 5.3% (2.7-9.9) in the total and 5.7% (2.4-12.2) in the PD-L1-positive populations. Disease control rate (95% CI) was 7.6% (4.4-12.7) and 9.5% (5.1-16.8), respectively. Median duration of response was not reached in the total (range, 1.2+-21.5+) and in the PD-L1-positive (range, 6.3-21.5+) populations. Median PFS was 2.0 months (95% CI, 1.9-2.0), and the 6-month rate was 14.9%. Median OS was 9.0 months (95% CI, 7.6-11.2), and the 6-month rate was 69.1%. Treatment-related adverse events occurred in 103 (60.6%) patients, including 22 (12.9%) with grade 3 or 4 AEs. There were no deaths due to AEs. CONCLUSIONS: Pembrolizumab monotherapy demonstrated durable antitumor activity in a subset of patients with previously treated mTNBC and had a manageable safety profile. CLINICAL TRIAL REGISTRATION: ClinicalTrials.gov, NCT02447003.
Assuntos
Anticorpos Monoclonais Humanizados/administração & dosagem , Antígeno B7-H1/genética , Neoplasias de Mama Triplo Negativas/tratamento farmacológico , Adulto , Idoso , Idoso de 80 Anos ou mais , Antraciclinas/administração & dosagem , Anticorpos Monoclonais Humanizados/efeitos adversos , Hidrocarbonetos Aromáticos com Pontes/administração & dosagem , Estudos de Coortes , Feminino , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Humanos , Masculino , Pessoa de Meia-Idade , Metástase Neoplásica , Intervalo Livre de Progressão , Taxoides/administração & dosagem , Neoplasias de Mama Triplo Negativas/genética , Neoplasias de Mama Triplo Negativas/patologiaRESUMO
BACKGROUND: Phase III randomized clinical trials (RCTs) have become larger and are powered to detect small absolute benefits. Temporal changes in absolute benefits of experimental medical therapies reported in RCTs are unknown. METHODS: We identified all RCTs with sample size > or =200 evaluating experimental medical therapies for breast and colorectal cancer published from 1975 to 2007. We assessed changes over three decades in absolute differences in time-to-event end points between experimental and control arms by (i) the usual method (i.e. at one point) and (ii) as the area between time-to-event curves up to a predefined time. RESULTS: We identified 236 eligible RCTs of which 57% (N = 135) evaluated adjuvant treatments. Experimental treatments became more often compared with active treatments (48% versus 59% versus 81%; P < 0.0001). Median absolute benefits of experimental adjuvant treatments decreased but outcomes in control arms improved with time. For RCTs evaluating metastatic disease, there were no changes in absolute benefit over time but incremental monthly costs of new approved treatments increased with time by 100-fold (P < 0.0001). CONCLUSION: In RCTs of breast and colorectal cancer, new effective adjuvant treatments show decreasing absolute benefit, while new treatments of metastatic disease show unchanging levels of benefit at rapidly escalating costs.
Assuntos
Neoplasias da Mama/patologia , Neoplasias da Mama/terapia , Ensaios Clínicos Fase III como Assunto , Neoplasias Colorretais/patologia , Neoplasias Colorretais/terapia , Terapia Combinada , Análise Custo-Benefício , Feminino , Humanos , Metástase Neoplásica , Resultado do TratamentoRESUMO
p53 Arg72Pro, MDM2 T309G, and CCND1 G870A are functional single-nucleotide polymorphisms (SNPs) in key genes that regulate apoptosis and cell cycle. Variant genotypes of these SNPs have been associated with increased risk and earlier age of onset in some cancers. We investigated the association of these SNPs with susceptibility to esophageal adenocarcinoma in a large, North American case-control study. Three hundred and twelve cases and 454 cancer-free controls recruited in Boston, USA were genotyped for each of the three SNPs, and demographic and clinical data were collected. Genotype frequencies for each of the three SNPs did not deviate from the Hardy-Weinberg equilibrium, and did not differ between cases and controls. Odds ratios (OR), adjusted for clinical risk factors, for the homozygous variant genotypes were 0.99 (95% confidence interval [CI] 0.57-1.72) for p53 Pro/Pro, 0.81 (95% CI 0.52-1.28) for MDM2 G/G, and 0.97 (95% CI 0.64-1.49) for CCND1 A/A. The analysis was adequately powered (80%) to detect ORs of 1.37, 1.35, and 1.34 for each SNP, respectively. In contrast to the results of smaller published studies, no association between p53 Arg72Pro, MDM2 T309G, and CCND1 G870A SNPs and susceptibility to esophageal adenocarcinoma, age of onset, or stage of disease at diagnosis was detected.
Assuntos
Ciclina D1/genética , Neoplasias Esofágicas/genética , Predisposição Genética para Doença , Polimorfismo de Nucleotídeo Único , Proteínas Proto-Oncogênicas c-mdm2/genética , Proteína Supressora de Tumor p53/genética , Adenocarcinoma/genética , Adulto , Idoso , Idoso de 80 Anos ou mais , Estudos de Casos e Controles , Feminino , Genótipo , Humanos , Masculino , Pessoa de Meia-IdadeRESUMO
Deregulation of the cell cycle is a hallmark of cancer that enables limitless cell division. To support this malignant phenotype, cells acquire molecular alterations that abrogate or bypass control mechanisms in signaling pathways and cellular checkpoints that normally function to prevent genomic instability and uncontrolled cell proliferation. Consequently, therapeutic targeting of the cell cycle has long been viewed as a promising anti-cancer strategy. Until recently, attempts to target the cell cycle for cancer therapy using selective inhibitors have proven unsuccessful due to intolerable toxicities and a lack of target specificity. However, improvements in our understanding of malignant cell-specific vulnerabilities has revealed a therapeutic window for preferential targeting of the cell cycle in cancer cells, and has led to the development of agents now in the clinic. In this review, we discuss the latest generation of cell cycle targeting anti-cancer agents for breast cancer, including approved CDK4/6 inhibitors, and investigational TTK and PLK4 inhibitors that are currently in clinical trials. In recognition of the emerging population of ER+ breast cancers with acquired resistance to CDK4/6 inhibitors we suggest new therapeutic avenues to treat these patients. We also offer our perspective on the direction of future research to address the problem of drug resistance, and discuss the mechanistic insights required for the successful implementation of these strategies.
Assuntos
Antineoplásicos/farmacologia , Neoplasias da Mama/tratamento farmacológico , Ciclo Celular/efeitos dos fármacos , Animais , Antineoplásicos/uso terapêutico , Neoplasias da Mama/fisiopatologia , Proteínas de Ciclo Celular/antagonistas & inibidores , Quinases Ciclina-Dependentes/antagonistas & inibidores , Inibidores Enzimáticos/farmacologia , Inibidores Enzimáticos/uso terapêutico , Feminino , Humanos , Proteínas Serina-Treonina Quinases/antagonistas & inibidores , Proteínas Tirosina Quinases/antagonistas & inibidoresRESUMO
Isocitrate dehydrogenase-1 (Idh1) is an important metabolic enzyme that produces NADPH by converting isocitrate to α-ketoglutarate. Idh1 is known to reduce reactive oxygen species (ROS) induced in cells by treatment with lipopolysaccharide (LPS) in vitro. Here, we used Idh1-deficient knockout (Idh1 KO) mice to investigate the role of Idh1 in antioxidant defense in vivo. Idh1 KO mice showed heightened susceptibility to death induced by LPS and exhibited increased serum levels of inflammatory cytokines such as tumor necrosis factor-α and interleukin-6. The serum of LPS-injected Idh1 KO mice also contained elevated levels of AST, a marker of inflammatory liver damage. Furthermore, after LPS injection, livers of Idh1 KO mice showed histological evidence of elevated oxidative DNA damage compared with livers of wild-type (WT) mice. Idh1 KO livers showed a faster and more pronounced oxidative stress than WT livers. In line with that, Idh1 KO hepatocytes showed higher ROS levels and an increase in the NADP(+)/NADPH ratio when compared with hepatocytes isolated from WT mice. These results suggest that Idh1 has a physiological function in protecting cells from oxidative stress by regulating the intracellular NADP(+)/NADPH ratio. Our findings suggest that stimulation of Idh1 activity may be an effective therapeutic strategy for reducing oxidative stress during inflammatory responses, including the early stages of septic shock.