RESUMEN
In laboratory studies, acquired resistance to long-term antihormonal therapy in breast cancer evolves through two phases over 5 y. Phase I develops within 1 y, and tumor growth occurs with either 17ß-estradiol (E(2)) or tamoxifen. Phase II resistance develops after 5 y of therapy, and tamoxifen still stimulates growth; however, E(2) paradoxically induces apoptosis. This finding is the basis for the clinical use of estrogen to treat advanced antihormone-resistant breast cancer. We interrogated E(2)-induced apoptosis by analysis of gene expression across time (2-96 h) in MCF-7 cell variants that were estrogen-dependent (WS8) or resistant to estrogen deprivation and refractory (2A) or sensitive (5C) to E(2)-induced apoptosis. We developed a method termed differential area under the curve analysis that identified genes uniquely regulated by E(2) in 5C cells compared with both WS8 and 2A cells and hence, were associated with E(2)-induced apoptosis. Estrogen signaling, endoplasmic reticulum stress (ERS), and inflammatory response genes were overrepresented among the 5C-specific genes. The identified ERS genes indicated that E(2) inhibited protein folding, translation, and fatty acid synthesis. Meanwhile, the ERS-associated apoptotic genes Bcl-2 interacting mediator of cell death (BIM; BCL2L11) and caspase-4 (CASP4), among others, were induced. Evaluation of a caspase peptide inhibitor panel showed that the CASP4 inhibitor z-LEVD-fmk was the most active at blocking E(2)-induced apoptosis. Furthermore, z-LEVD-fmk completely prevented poly (ADP-ribose) polymerase (PARP) cleavage, E(2)-inhibited growth, and apoptotic morphology. The up-regulated proinflammatory genes included IL, IFN, and arachidonic acid-related genes. Functional testing showed that arachidonic acid and E(2) interacted to superadditively induce apoptosis. Therefore, these data indicate that E(2) induced apoptosis through ERS and inflammatory responses in advanced antihormone-resistant breast cancer.
Asunto(s)
Apoptosis/efectos de los fármacos , Neoplasias de la Mama/metabolismo , Estrés del Retículo Endoplásmico/efectos de los fármacos , Estradiol/farmacología , Regulación Neoplásica de la Expresión Génica/efectos de los fármacos , Proteínas Reguladoras de la Apoptosis/metabolismo , Ácido Araquidónico/metabolismo , Área Bajo la Curva , Proteína 11 Similar a Bcl2 , Caspasas Iniciadoras/metabolismo , Línea Celular Tumoral , Estrés del Retículo Endoplásmico/fisiología , Ácidos Grasos/biosíntesis , Femenino , Humanos , Proteínas de la Membrana/metabolismo , Análisis por Micromatrices , Pliegue de Proteína/efectos de los fármacos , Proteínas Proto-Oncogénicas/metabolismoRESUMEN
BACKGROUND: Oncology has been facing increasing outpatient activity associated with higher cancer incidence, better survival rates, and more treatment options. Innovative technological solutions could help deal with this increasing demand. Using digital patient-reported outcome measures (PROMs) to identify patients who need a face-to-face (FTF) appointment is a potential approach. OBJECTIVE: This study aims to assess the feasibility of digital PROM questionnaires to enable remote symptom monitoring for patients undergoing cancer treatment and their ability to highlight the requirement for an FTF appointment. METHODS: This study was performed at a tertiary oncology center between December 2018 and February 2019. The Common Terminology Criteria for Adverse Events were adapted into patient-friendly language to form the basis of treatment-specific digital questionnaires covering specific cancer drugs and radiotherapy treatments. These treatment-specific digital PROM questionnaires were scored by both patients and their clinicians during FTF appointments. Patients and clinicians did not see each other's scored PROMs. Agreement between patients and clinicians was assessed using descriptive statistics. Patient and staff feedback was also obtained. RESULTS: In total, 90 patients participated in the study across 10 different treatment pathways. By comparing paired patient and clinician responses, the sensitivity of the patient-completed questionnaires in correctly highlighting the need for FTF review was 94% (44/47), and all patients with severe or grade 3+ symptoms were identified (6/6, 100%). Patient-completed PROMs appropriately revealed that 29% (26/90) of the participating patients did not need FTF review based on their symptoms alone. Certain oncological treatment pathways, such as immunotherapy, were found to have a larger proportion of patients with minimal symptoms than others, such as conventional chemotherapy. Patient and staff feedback showed high approval of digital PROMs and their potential for use in remote monitoring. CONCLUSIONS: Digital PROM questionnaires can feasibly highlight the need for FTF review in oncology clinics for treatment. Their use with specific treatments could safely reduce the requirement for FTF care, and future work should evaluate their application in the remote monitoring of patients.
RESUMEN
Aromatase inhibitors (AI) are being evaluated as long-term adjuvant therapies and chemopreventives in breast cancer. However, there are concerns about bone mineral density loss in an estrogen-free environment. Unlike nonsteroidal AIs, the steroidal AI exemestane may exert beneficial effects on bone through its primary metabolite 17-hydroexemestane. We investigated 17-hydroexemestane and observed it bound estrogen receptor alpha (ERalpha) very weakly and androgen receptor (AR) strongly. Next, we evaluated 17-hydroexemestane in MCF-7 and T47D breast cancer cells and attributed dependency of its effects on ER or AR using the antiestrogen fulvestrant or the antiandrogen bicalutamide. 17-Hydroexemestane induced proliferation, stimulated cell cycle progression and regulated transcription at high sub-micromolar and micromolar concentrations through ER in both cell lines, but through AR at low nanomolar concentrations selectively in T47D cells. Responses of each cell type to high and low concentrations of the non-aromatizable synthetic androgen R1881 paralleled those of 17-hydroexemestane. 17-Hydroexemestane down-regulated ERalpha protein levels at high concentrations in a cell type-specific manner similarly as 17beta-estradiol, and increased AR protein accumulation at low concentrations in both cell types similarly as R1881. Computer docking indicated that the 17beta-OH group of 17-hydroexemestane relative to the 17-keto group of exemestane contributed significantly more intermolecular interaction energy toward binding AR than ERalpha. Molecular modeling also indicated that 17-hydroexemestane interacted with ERalpha and AR through selective recognition motifs employed by 17beta-estradiol and R1881, respectively. We conclude that 17-hydroexemestane exerts biological effects as an androgen. These results may have important implications for long-term maintenance of patients with AIs.
Asunto(s)
Andrógenos/farmacología , Androstadienos/metabolismo , Androstadienos/farmacología , Antineoplásicos/farmacología , Andrógenos/química , Androstadienos/química , Unión Competitiva/efectos de los fármacos , Ciclo Celular/efectos de los fármacos , Línea Celular Tumoral , Proliferación Celular/efectos de los fármacos , Receptor alfa de Estrógeno/química , Receptor alfa de Estrógeno/genética , Humanos , Hidroxilación/efectos de los fármacos , Metribolona/farmacología , Modelos Moleculares , Receptores Androgénicos/química , Receptores Androgénicos/genética , Transcripción Genética/efectos de los fármacosRESUMEN
The ubiquitous application of selective oestrogen receptor modulators (SERMs) and aromatase inhibitors for the treatment and prevention of breast cancer has created a significant advance in patient care. However, the consequence of prolonged treatment with antihormonal therapy is the development of drug resistance. Nevertheless, the systematic description of models of drug resistance to SERMs and aromatase inhibitors has resulted in the discovery of a vulnerability in tumour homeostasis that can be exploited to improve patient care. Drug resistance to antihormones evolves, so that eventually the cells change to create novel signal transduction pathways for enhanced oestrogen (GPR30+OER) sensitivity, a reduction in progesterone receptor production and an increased metastatic potential. Most importantly, antihormone resistant breast cancer cells adapt with an ability to undergo apoptosis with low concentrations of oestrogen. The oestrogen destroys antihormone resistant cells and reactivates sensitivity to prolonged antihormonal therapy. We have initiated a major collaborative program of genomics and proteomics to use our laboratory models to map the mechanism of subcellular survival and apoptosis in breast cancer. The laboratory program is integrated with a clinical program that seeks to determine the minimum dose of oestrogen necessary to create objective responses in patients who have succeeded and failed two consecutive antihormonal therapies. Once our program is complete, the new knowledge will be available to translate to clinical care for the long-term maintenance of patients on antihormone therapy.
Asunto(s)
Inhibidores de la Aromatasa/farmacología , Neoplasias de la Mama/tratamiento farmacológico , Estrógenos/fisiología , Receptores de Estrógenos/efectos de los fármacos , Moduladores Selectivos de los Receptores de Estrógeno/farmacología , Apoptosis , Neoplasias de la Mama/fisiopatología , Resistencia a Antineoplásicos , Femenino , Humanos , Transducción de Señal/efectos de los fármacosRESUMEN
The incidence of breast cancer is rising throughout the world. Breast cancer is slowly becoming more prevalent in countries which previously had low rates of cancer as well as becoming a leading cause of cancer death in some countries. Fortunately, a large number of these tumors are estrogen receptor (ER) positive and respond to anti-hormonal adjuvant therapy which until recently has been 5 years of tamoxifen treatment. Unfortunately, a significant number of patients develop recurrent cancers and the recurrent tumors are resistant to tamoxifen treatment. In addition, because of tamoxifen's selective estrogenic actions, there have been reports of venous thrombosis, endometrial cancer, and strokes in patients receiving tamoxifen therapy. Thus, there are other novel therapies such as aromatase inhibitors that block estrogen production in postmenopausal women or fulvestrant that destroys the estrogen receptor. This paper will summarize the therapeutic options for anti-hormonal therapy, the role of anti-hormonal agents in advanced breast cancer, and adjuvant therapy and the current status of chemoprevention with selective ER modulators.
Asunto(s)
Neoplasias de la Mama/tratamiento farmacológico , Neoplasias de la Mama/prevención & control , Neoplasias Hormono-Dependientes/tratamiento farmacológico , Neoplasias Hormono-Dependientes/prevención & control , Inhibidores de la Aromatasa/uso terapéutico , Neoplasias de la Mama/metabolismo , Resistencia a Antineoplásicos , Neoplasias Endometriales/inducido químicamente , Femenino , Humanos , Neoplasias Hormono-Dependientes/metabolismo , Receptores de Estrógenos/metabolismo , Moduladores Selectivos de los Receptores de Estrógeno/uso terapéutico , Accidente Cerebrovascular/inducido químicamente , Tamoxifeno/uso terapéutico , Trombosis de la Vena/inducido químicamenteRESUMEN
Recent studies indicate that regulation of the actin cytoskeleton is important for protein trafficking, but its precise role is unclear. We have characterized the ARF1-dependent assembly of actin on the Golgi apparatus. Actin recruitment involves Cdc42/Rac and requires the activation of the Arp2/3 complex. Although the actin-binding proteins mAbp1 (SH3p7) and drebrin share sequence homology, they are differentially segregated into two distinct ARF-dependent actin complexes. The binding of Cdc42 and mAbp1, which localize to the Golgi apparatus, but not drebrin, is blocked by occupation of the p23 cargo-protein-binding site on coatomer. Exogenously expressed mAbp1 is mislocalized and inhibits Golgi transport in whole cells. The ability of ARF, vesicle-coat proteins, and cargo to direct the assembly of cytoskeletal structures helps explain how only a handful of vesicle types can mediate the numerous trafficking steps in the cell.
Asunto(s)
Actinas/fisiología , Aparato de Golgi/fisiología , Proteínas de la Membrana/fisiología , Proteínas de Microfilamentos/fisiología , Dominios Homologos src , Factor 1 de Ribosilacion-ADP/fisiología , Animales , Bovinos , Citoesqueleto/fisiología , Sustancias Macromoleculares , Ratas , Vesículas Secretoras/fisiología , Proteína de Unión al GTP cdc42/fisiología , Proteínas de Unión al GTP rho/fisiologíaRESUMEN
We seek to evaluate the clinical consequences of resistance to antihormonal therapy by studying analogous animal xenograft models. Two approaches were taken: (1) MCF-7 tumors were serially transplanted into selective estrogen receptor modulator (SERM)-treated immunocompromised mice to mimic 5 years of SERM treatment. The studies in vivo were designed to replicate the development of acquired resistance to SERMs over years of clinical exposure. (2) MCF-7 cells were cultured long-term under SERM-treated or estrogen withdrawn conditions (to mimic aromatase inhibitors), and then injected into mice to generate endocrine-resistant xenografts. These tumor models have allowed us to define Phase I and Phase II antihormonal resistance according to their responses to E(2) and fulvestrant. Phase I SERM-resistant tumors were growth stimulated in response to estradiol (E(2)), but paradoxically, Phase II SERM and estrogen withdrawn-resistant tumors were growth inhibited by E(2). Fulvestrant did not support growth of Phases I and II SERM-resistant tumors, but did allow growth of Phase II estrogen withdrawn-resistant tumors. Importantly, fulvestrant plus E(2) in Phase II antihormone-resistant tumors reversed the E(2)-induced inhibition and instead resulted in growth stimulation. These data have important clinical implications. Based on these and prior laboratory findings, we propose a clinical strategy for optimal third-line therapy: patients who have responded to and then failed at least two antihormonal treatments may respond favorably to short-term low-dose estrogen due to E(2)-induced apoptosis, followed by treatment with fulvestrant plus an aromatase inhibitor to maintain low tumor burden and avoid a negative interaction between physiologic E(2) and fulvestrant.
Asunto(s)
Antineoplásicos Hormonales/uso terapéutico , Neoplasias de la Mama/tratamiento farmacológico , Resistencia a Antineoplásicos , Estradiol/análogos & derivados , Estradiol/uso terapéutico , Neoplasias Hormono-Dependientes/tratamiento farmacológico , Moduladores Selectivos de los Receptores de Estrógeno/uso terapéutico , Animales , Neoplasias de la Mama/metabolismo , Neoplasias de la Mama/patología , Proliferación Celular/efectos de los fármacos , Modelos Animales de Enfermedad , Fulvestrant , Humanos , Ratones , Ratones Endogámicos BALB C , Ratones DesnudosRESUMEN
BACKGROUND: X-box binding protein 1 (XBP1), a transcription factor involved in unfolded protein response, is also an estrogen-regulated gene and strongly correlates with estrogen receptor alpha (ERα) expression in breast cancers. We investigated the functional role of XBP1 in estrogen responsive breast and endometrial cancer cells as its functions are not fully understood. MATERIALS AND METHODS: ERα positive breast (MCF7) and endometrial (ECC1) cancer cells were used to study XBP1 gene regulation by 17-ß-estradiol (E2) and to investigate the role of XBP1 in E2-mediated growth using short interfering RNA. Quantitative real-time PCR and Western blot were used to assess RNA and protein levels. Recruitment of ERα and other cofactors at the promoter and enhancer region of the XBP1 gene was investigated by chromatin immunoprecipitation. Estrogen responsive element (ERE)-mediated transcriptional activity was evaluated by a luciferase reporter assay. RESULTS: E2 induced the transcription of XBP1 in both MCF7 and ECC1 cells. E2-dependent recruitment of ERα, steroid receptor coactivator (SRC)-1 and SRC-3, and RNA polymerase II were observed at the promoter and/or enhancer region of the XBP1 gene. Depletion of XBP1 markedly inhibited the E2-induced growth in MCF7 and ECC1 cells. However, ERE-mediated transcription was not altered in XBP1-overexpressing or XBP1-depleted MCF7 cells. CONCLUSION: Our results confirm E2-induced transcription of XBP1 and demonstrate the crucial role of XBP1 in E2-induced growth of ERα positive breast and endometrial cancer cells without modulating the classical ERE-mediated transcription by ER. This knowledge creates new opportunities for therapeutic interventions.
RESUMEN
Intrinsic and acquired cellular resistance factors limit the efficacy of most targeted cancer therapeutics. Synthetic lethal screens in lower eukaryotes suggest that networks of genes closely linked to therapeutic targets would be enriched for determinants of drug resistance. We developed a protein network centered on the epidermal growth factor receptor (EGFR), which is a validated cancer therapeutic target, and used small interfering RNA screening to comparatively probe this network for proteins that regulate the effectiveness of both EGFR-targeted agents and nonspecific cytotoxic agents. We identified subnetworks of proteins influencing resistance, with putative resistance determinants enriched among proteins that interacted with proteins at the core of the network. We found that clinically relevant drugs targeting proteins connected in the EGFR network, such as protein kinase C or Aurora kinase A, or the transcriptional regulator signal transducer and activator of transcription 3 (STAT3), synergized with EGFR antagonists to reduce cell viability and tumor size, suggesting the potential for a direct path to clinical exploitation. Such a focused approach can potentially improve the coherent design of combination cancer therapies.
Asunto(s)
Citotoxinas/metabolismo , Descubrimiento de Drogas/métodos , Resistencia a Antineoplásicos/genética , Receptores ErbB/metabolismo , Neoplasias/tratamiento farmacológico , Mapeo de Interacción de Proteínas/métodos , Transducción de Señal/genética , Aurora Quinasa A , Aurora Quinasas , Citotoxinas/genética , Receptores ErbB/antagonistas & inhibidores , Receptores ErbB/genética , Proteína Quinasa C/metabolismo , Proteínas Serina-Treonina Quinasas/metabolismo , Interferencia de ARN , ARN Interferente Pequeño/genética , Factor de Transcripción STAT3/metabolismoRESUMEN
Previously we demonstrated that secondary products of plant mevalonate metabolism called isoprenoids attenuate 3-hydroxy-3-methylglutaryl coenzyme A reductase mRNA translational efficiency and cause tumor cell death. Here we compared effects of "pure" isoprenoids (perillyl alcohol and gamma-tocotrienol) and a "mixed" isoprenoid-genistein-on the PKB/Akt/mTOR pathway that controls mRNA translation and m(7)GpppX eIF4F cap binding complex formation. Effects were cell- and isoprenoid-specific. Perillyl alcohol and genistein suppressed 4E-BP1(Ser65) phosphorylation in prostate tumor cell lines, DU145 and PC-3, and in Caco2 adenocarcinoma cells. Suppressive effects were similar to or greater than that observed with a PI3 kinase inhibitor or rapamycin, an mTOR inhibitor. 4E-BP1(Thr37) phosphorylation was reduced by perillyl alcohol and genistein in DU145, but not in PC-3. Conversely, perillyl alcohol but not genistein decreased 4E-BP1(Thr37) phosphorylation in Caco2. PKB/Akt activation via Ser473 phosphorylation was enhanced in DU145 by perillyl alcohol and in PC-3 by gamma-tocotrienol, but was suppressed by genistein. Importantly, perillyl alcohol disrupted interactions between eIF4E and eIF4G, key components of eIF4F (m(7)GpppX) cap binding complex. These results demonstrate that "pure" isoprenoids and genistein differentially impact cap-dependent translation in tumor cell lines.
Asunto(s)
Proteínas Adaptadoras Transductoras de Señales/metabolismo , Factor 4E Eucariótico de Iniciación/metabolismo , Factor 4G Eucariótico de Iniciación/metabolismo , Genisteína/administración & dosificación , Monoterpenos/administración & dosificación , Neoplasias/metabolismo , Fosfoproteínas/metabolismo , Proteínas Proto-Oncogénicas c-akt/metabolismo , Proteínas de Ciclo Celular , Línea Celular Tumoral , Relación Dosis-Respuesta a Droga , Regulación Neoplásica de la Expresión Génica/efectos de los fármacos , Humanos , Fosforilación/efectos de los fármacos , Transducción de Señal/efectos de los fármacosRESUMEN
Tamoxifen and raloxifene are both selective estrogen receptor modulators (SERMs). The medicines can block estrogen mediated breast cancer growth and development but will also maintain bone density in postmenopausal women and lower circulating cholesterol. Tamoxifen has remained the antihormonal therapy of choice for the treatment of ER positive breast cancer for the last 30 years. However, although adjuvant tamoxifen produces profound increases in disease-free and overall survival in patients with ER positive breast cancer, concerns about drug resistance, blood clots and endometrial cancer have resulted in a change to the use of aromatase inhibitors for the treatment of postmenopausal women. Nevertheless, tamoxifen remains the antihormonal treatment of choice for premenopausal women with ER positive breast cancer and for risk reduction in premenopausal women who are at high risk for developing breast cancer. The risk of endometrial cancer and thromboembolic disorders during tamoxifen therapy is not elevated in premenopausal women. It is important to note that aromatase inhibitors or raloxifene should not be used in premenopausal women. Raloxifene is used to prevent osteoporosis in postmenopausal women and, unlike tamoxifen, does not increase the risk of endometrial cancer. However, raloxifene does reduce breast cancer risk by 50-70% in both low risk and high risk postmenopausal women. Comparisons of raloxifene with tamoxifen show equal efficacy as a chemopreventive for breast cancer but there is a reduction in thromboembolic disorders, fewer endometrial cancers, hysterectomies, cataracts and cataract surgeries in women taking raloxifene. Overall, SERMs continue to fulfill their promise as appropriate medicines that target specific populations for the treatment and prevention of breast cancer.