RESUMEN
BACKGROUND: The National Cancer Institute-Molecular Analysis for Therapy Choice (NCI-MATCH) is a national precision medicine study incorporating centralized genomic testing to direct refractory cancer patients to molecularly targeted treatment subprotocols. This treatment subprotocol was designed to screen for potential signals of efficacy of ado-trastuzumab emtansine (T-DM1) in HER2-amplified histologies other than breast and gastroesophageal tumors. METHODS: Eligible patients had HER2 amplification at a copy number (CN) >7 based on targeted next-generation sequencing (NGS) with a custom Oncomine AmpliSeq™ (ThermoFisher Scientific) panel. Patients with prior trastuzumab, pertuzumab or T-DM1 treatment were excluded. Patients received T-DM1 at 3.6 mg/kg i.v. every 3 weeks until toxicity or disease progression. Tumor assessments occurred every three cycles. The primary end point was centrally assessed objective response rate (ORR). Exploratory end points included correlating response with HER2 CN by NGS. The impact of co-occurring genomic alterations and PTEN loss by immunohistochemistry were also assessed. RESULTS: Thirty-eight patients were enrolled and 36 included in efficacy analysis. Median prior therapies in the metastatic setting was 3 (range 0-9; unknown in one patient). Median HER2 CN was 17 (range 7-139). Partial responses were observed in two (5.6%) patients: one mucoepidermoid carcinoma of parotid gland and one parotid gland squamous cell cancer. Seventeen patients (47%) had stable disease including 8/10 (80%) with ovarian and uterine carcinomas, with median duration of 4.6 months. The 6-month progression-free survival rate was 23.6% [90% confidence interval 14.2% to 39.2%]. Common toxicities included fatigue, anemia, fever and thrombocytopenia with no new safety signals. There was a trend for tumor shrinkage with higher levels of gene CN as determined by the NGS assay. CONCLUSION: T-DM1 was well tolerated. While this subprotocol did not meet the primary end point for ORR in this heavily pre-treated diverse patient population, clinical activity was seen in salivary gland tumors warranting further study in this tumor type in dedicated trials.
Asunto(s)
Ado-Trastuzumab Emtansina/uso terapéutico , Antineoplásicos Inmunológicos/uso terapéutico , Biomarcadores de Tumor/genética , Neoplasias/tratamiento farmacológico , Receptor ErbB-2/genética , Ado-Trastuzumab Emtansina/farmacología , Adulto , Anciano , Anciano de 80 o más Años , Antineoplásicos Inmunológicos/farmacología , Resistencia a Antineoplásicos/genética , Femenino , Amplificación de Genes , Humanos , Persona de Mediana Edad , National Cancer Institute (U.S.) , Neoplasias/genética , Neoplasias/mortalidad , Neoplasias/patología , Medicina de Precisión/métodos , Supervivencia sin Progresión , Receptor ErbB-2/antagonistas & inhibidores , Estados Unidos/epidemiologíaRESUMEN
Range expansion in north-temperate fishes subsequent to the retreat of the Wisconsinan glaciers has resulted in the rapid colonization of previously unexploited, heterogeneous habitats and, in many situations, secondary contact among conspecific lineages that were once previously isolated. Such ecological opportunity coupled with reduced competition likely promoted morphological and genetic differentiation within and among post-glacial fish populations. Discrete morphological forms existing in sympatry, for example, have now been described in many species, yet few studies have directly assessed the association between morphological and genetic variation. Morphotypes of Lake Trout, Salvelinus namaycush, are found in several large-lake systems including Great Bear Lake (GBL), Northwest Territories, Canada, where several shallow-water forms are known. Here, we assess microsatellite and mitochondrial DNA variation among four morphotypes of Lake Trout from the five distinct arms of GBL, and also from locations outside of this system to evaluate several hypotheses concerning the evolution of morphological variation in this species. Our data indicate that morphotypes of Lake Trout from GBL are genetically differentiated from one another, yet the morphotypes are still genetically more similar to one another compared with populations from outside of this system. Furthermore, our data suggest that Lake Trout colonized GBL following dispersal from a single glacial refugium (the Mississippian) and support an intra-lake model of divergence. Overall, our study provides insights into the origins of morphological and genetic variation in post-glacial populations of fishes and provides benchmarks important for monitoring Lake Trout biodiversity in a region thought to be disproportionately susceptible to impacts from climate change.
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Evolución Biológica , Ecotipo , Simpatría , Trucha/genética , Animales , ADN Mitocondrial/genética , Agua Dulce , Variación Genética , Genética de Población , Lagos , Desequilibrio de Ligamiento , Repeticiones de Microsatélite , Modelos Genéticos , Territorios del Noroeste , Fenotipo , Análisis de Secuencia de ADN , Trucha/anatomía & histologíaRESUMEN
Three populations of Arctic charr Salvelinus alpinus from southern Baffin Island were previously identified to display variable migratory phenotypes, with an anadromous component of the population and another remaining resident in fresh water. In this study, 14 microsatellite markers were used to help distinguish between two alternative hypotheses to explain the co-existence of the two ecotypes: that the two ecotypes originate from a single population and are the result of a conditional mating tactic or that the migratory ecotypes are reproductively isolated populations utilizing alternative migratory strategies. In two of the three replicate systems, F(ST) values between the resident and anadromous individuals were non-significant, while they were significant in a third sampling location. Bayesian clustering analysis implemented in structure, however, failed to identify any within-location clustering in all three sampling locations. It is concluded from these analyses that the life-history ecotypes are most likely conditional mating tactics, rather than reproductively isolated populations. Other evidence in favour of the alternative mating tactic hypothesis is briefly reviewed, and implications for management of those populations are discussed.
Asunto(s)
Ecotipo , Aislamiento Reproductivo , Conducta Sexual Animal , Trucha/genética , Migración Animal , Animales , Teorema de Bayes , Análisis por Conglomerados , Genética de Población , Repeticiones de Microsatélite , Nunavut , Análisis de Secuencia de ADNRESUMEN
BACKGROUND: In early-stage breast cancer, adjuvant chemotherapy is associated with significant systemic toxicity with only a modest survival benefit. Therefore, there is considerable interest in identifying predictive markers of response to therapy. Doxorubicin, one of the most common drugs used to treat breast cancer, is an anthracycline chemotherapeutic agent, a class of drugs known to be affected by hypoxia. Accordingly, we examined whether expression of the endogenous hypoxia marker carbonic anhydrase IX (CA IX) is predictive of outcome in early-stage breast cancer patients treated with doxorubicin. METHODS: We obtained 209 early-stage pre-treatment surgically-resected breast tumours from patients, who received doxorubicin in their chemotherapeutic regimen and had >10 years of follow-up. Immunohistochemistry was used to detect CA IX, and we used fluorescence in situ hybridisation to detect both human epidermal growth factor receptor (HER2) and DNA topoisomerase II-alpha (TOP2A) gene amplification. RESULTS: Carbonic anhydrase IX intensity was significantly correlated with progression-free survival (PFS) and overall survival (OS) in patients receiving 300 mg m(-2) of doxorubicin (HR=1.82 and 3.77; P=0.0014 and 0.010, respectively). There was a significant, inverse correlation between CA IX score and oestrogen receptor expression, but no significant correlations were seen with either HER2 or TOP2A ratio. CONCLUSION: We demonstrate that CA IX expression is correlated with worse PFS and OS for breast cancer patients treated with doxorubicin, independent of HER2 or TOP2A gene amplification. This study provides evidence that using CA IX to detect hypoxia in surgically-resected breast tumours may be of clinical use in choosing an appropriate chemotherapy regimen.
Asunto(s)
Antibióticos Antineoplásicos/uso terapéutico , Antígenos de Neoplasias/metabolismo , Neoplasias de la Mama/tratamiento farmacológico , Anhidrasas Carbónicas/metabolismo , Doxorrubicina/uso terapéutico , Resistencia a Antineoplásicos , Adulto , Anciano , Antígenos de Neoplasias/genética , Biomarcadores de Tumor , Neoplasias de la Mama/patología , Neoplasias de la Mama/cirugía , Anhidrasa Carbónica IX , Hipoxia de la Célula , Quimioterapia Adyuvante , ADN-Topoisomerasas de Tipo II/genética , Proteínas de Unión al ADN/genética , Supervivencia sin Enfermedad , Femenino , Amplificación de Genes , Genes erbB-2 , Humanos , Persona de Mediana Edad , Proteínas de Unión a Poli-ADP-RibosaRESUMEN
In this study, the magnitude and direction of gene flow and estimates of effective population sizes (N(e) ) were quantified among two life-history types (lacustrine and anadromous) of broad whitefish Coregonus nasus in the lower Mackenzie River system. The data suggest that dispersal and subsequent gene flow occurs between these groups, with the former appearing to be asymmetrical. Gene flow may potentially be directionally biased as well, a result attributed to source-sink population dynamics and the ongoing process of post-glacial colonization and contemporary range expansion. Additionally, average N(e) estimates were consistently lower for lacustrine populations of C. nasus although confidence intervals for both contemporary and historical estimates broadly overlapped. The lower average estimates of N(e) for lacustrine populations was suggested to be the result of more recent founding events following post-glacial dispersal. This study provides one of the first assessments of gene flow and N(e) in an Arctic coregonine, results that may be relevant to other freshwater and anadromous Arctic species persisting in systems near the periphery of their range.
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Flujo Génico , Genética de Población , Salmonidae/genética , Alelos , Animales , Regiones Árticas , Canadá , Conservación de los Recursos Naturales , Variación Genética , Densidad de PoblaciónRESUMEN
The NCI-MATCH was designed to characterize the efficacy of targeted therapies in histology-agnostic driver mutation-positive malignancies. Sub-protocols F and G were developed to evaluate the role of crizotinib in rare tumors that harbored either ALK or ROS1 rearrangements. Patients with malignancies that progressed following at least one prior systemic therapy were accrued to the NCI-MATCH for molecular profiling, and those with actionable ALK or ROS1 rearrangements were offered participation in sub-protocols F or G, respectively. There were five patients who enrolled on Arm F (ALK) and four patients on Arm G (ROS1). Few grade 3 or 4 toxicities were noted, including liver test abnormalities, and acute kidney injury. For sub-protocol F (ALK), the response rate was 50% (90% CI 9.8-90.2%) with one complete response among the 4 eligible patients. The median PFS was 3.8 months, and median OS was 4.3 months. For sub-protocol G (ROS1) the response rate was 25% (90% CI 1.3-75.1%). The median PFS was 4.3 months, and median OS 6.2 months. Data from 3 commercial vendors showed that the prevalence of ALK and ROS1 rearrangements in histologies other than non-small cell lung cancer and lymphoma was rare (0.1% and 0.4% respectively). We observed responses to crizotinib which met the primary endpoint for ALK fusions, albeit in a small number of patients. Despite the limited accrual, some of the patients with these oncogenic fusions can respond to crizotinib which may have a therapeutic role in this setting.
RESUMEN
The contemporary distribution of genetic variation within and among high latitude populations cannot be fully understood without taking into consideration how species responded to the impacts of Pleistocene glaciations. Broad whitefish, Coregonus nasus, a species endemic to northwest North America and the Arctic coast of Russia, was undoubtedly impacted by such events because its geographic distribution suggests that it survived solely within the Beringian refuge from where it dispersed post-glacially to achieve its current range. We used microsatellite DNA to investigate the role of glaciations in promoting intraspecific genetic variation in broad whitefish (N = 14 localities, 664 fish) throughout their North American range and in one Russian sample. Broad whitefish exhibited relatively high intrapopulation variation (average of 11.7 alleles per locus, average H(E) = 0.61) and moderate levels of interpopulation divergence (overall F(ST) = 0.10). The main regions assayed in our study (Russia, Alaska, Mackenzie River and Travaillant Lake systems) were genetically differentiated from each other and there were declines in genetic diversity with distance from putative refugia. Additionally, Mackenzie River system populations showed less developed and more variable patterns of isolation-by-distance than populations occupying former Alaskan portions of Beringia. Finally, our data suggest that broad whitefish dispersed from Beringia using coastal environments and opportunistically via headwater stream connections that once existed between Yukon and Mackenzie River drainages. Our results illustrate the importance of history (e.g. glaciation) and contemporary dispersal ecology in shaping the current genetic population structure of Arctic faunas.
Asunto(s)
Cubierta de Hielo , Repeticiones de Microsatélite , Polimorfismo Genético , Salmonidae/genética , Migración Animal , Animales , Geografía , Dinámica Poblacional , Salmonidae/fisiologíaRESUMEN
There is a pressing need to identify new drug targets and novel approaches for treatment of non-small-cell lung carcinoma (NSCLC). Members of the epidermal growth factor receptor (EGFR) and Met receptor families have been identified as important molecular targets for NSCLC. Two EGFR tyrosine kinase inhibitors (TKIs; erlotinib and gefitinib) are in current clinical use, but a majority of patients do not respond to these targeted therapies. We used receptor TK (RTK) capture arrays to identify receptors active in NSCLC cell lines. As Met and ErbBs were active, we explored the potential therapeutic advantage of combined targeting of Met with ErbB receptor family inhibitors for treatment of NSCLC. We found that Met physically interacts with both EGFR and Her2 in a NSCLC cell line with overexpression/overactivation of Met. Combined use of a dual EGFR/Her2 inhibitor with a Met inhibitor yields maximal growth inhibition compared with the use of EGFR and/or Met inhibitors. This suggests that simultaneous inhibition of multiple RTKs may be needed to effectively abrogate tumour cell growth. Phosphoproteomic analysis by RTK capture arrays may be a valuable tool for identifying the subset of tumours with functional receptor activation, regardless of mechanism.
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Carcinoma de Pulmón de Células no Pequeñas/tratamiento farmacológico , Receptores ErbB/antagonistas & inhibidores , Neoplasias Pulmonares/tratamiento farmacológico , Inhibidores de Proteínas Quinasas/farmacología , Proteínas Proto-Oncogénicas/fisiología , Quinazolinas/farmacología , Receptor ErbB-2/antagonistas & inhibidores , Receptores de Factores de Crecimiento/fisiología , Carcinoma de Pulmón de Células no Pequeñas/patología , Línea Celular Tumoral , Resistencia a Antineoplásicos , Humanos , Neoplasias Pulmonares/patología , Proteínas Proto-Oncogénicas c-met , Cicatrización de Heridas/efectos de los fármacosRESUMEN
PURPOSE: This phase I study explored gefitinib (G) and capecitabine (C) in metastatic breast cancer (MBC). METHODS: Sequential cohorts (n = 3) received G and escalating C on a 14 day on/7 day off schedule, with a validation cohort (n = 10) at the maximum tolerated dose (MTD). Dose limiting toxicity (DLT) was defined in cycle 1. The primary endpoint was safety; secondary endpoints included response and adherence. RESULTS: About 19 patients were treated for a median of 5 cycles. No patients in sequential cohorts experienced DLT; C MTD was 2,000 mg/m(2)/day when paired with daily G 250 mg. In the validation cohort, four experienced serious toxicities, including diarrhea, mucositis, and palmarplantar dysesthesia. At the MTD, 6 (46%) required a C dose reduction, and 3 (23%) came off study for toxicity. One partial response was observed (8%, 95% CI 0.2-38.5%); five had stable disease >24 weeks (26, 95% CI 9-51%). Patients missed few drug doses, with the suggestion of overadherence to therapy. CONCLUSIONS: In this phase I study of G and C in MBC, a C MTD was identified, and significant toxicity was observed. About 8% demonstrated a response, with 26% maintaining stable disease. The possibility of overadherence, as suggested in this study, may have implications for other trials of oral antineoplastic therapy.
Asunto(s)
Protocolos de Quimioterapia Combinada Antineoplásica/efectos adversos , Neoplasias de la Mama/tratamiento farmacológico , Cumplimiento de la Medicación , Administración Oral , Adulto , Protocolos de Quimioterapia Combinada Antineoplásica/administración & dosificación , Neoplasias de la Mama/sangre , Neoplasias de la Mama/patología , Capecitabina , Desoxicitidina/administración & dosificación , Desoxicitidina/efectos adversos , Desoxicitidina/análogos & derivados , Relación Dosis-Respuesta a Droga , Receptores ErbB/sangre , Femenino , Fluorouracilo/administración & dosificación , Fluorouracilo/efectos adversos , Fluorouracilo/análogos & derivados , Gefitinib , Humanos , Dosis Máxima Tolerada , Persona de Mediana Edad , Quinazolinas/administración & dosificación , Quinazolinas/efectos adversosRESUMEN
BACKGROUND: The cell surface glycoprotein E-cadherin (CDH1) is a key regulator of adhesive properties in epithelial cells. Germline mutations in CDH1 are well established as the defects underlying hereditary diffuse gastric cancer (HDGC) syndrome, and an increased risk of lobular breast cancer (LBC) has been described in HDGC kindreds. However, germline CDH1 mutations have not been described in patients with LBC in non-HDGC families. This study aimed to investigate the frequency of germline CDH1 mutations in patients with LBC with early onset disease or family histories of breast cancer without DGC. METHODS: Germline DNA was analysed in 23 women with invasive lobular or mixed ductal and lobular breast cancers who had at least one close relative with breast cancer or had themselves been diagnosed before the age of 45 years, had tested negative for a germline BRCA1 or BRCA2 mutation, and reported no personal or family history of diffuse gastric cancer. The full coding sequence of CDH1 including splice junctions was amplified using PCR and screened for mutations using DHPLC and sequencing. RESULTS: A novel germline CDH1 truncating mutation in the extracellular portion of the protein (517insA) was identified in one woman who had LBC at the age of 42 years and a first degree relative with invasive LBC. CONCLUSIONS: Germline CDH1 mutations can be associated with invasive LBC in the absence of diffuse gastric cancer. The finding, if confirmed, may have implications for management of individuals at risk for this breast cancer subtype. Clarification of the cancer risks in the syndrome is essential.
Asunto(s)
Neoplasias de la Mama/genética , Cadherinas/genética , Carcinoma de Células Grandes/genética , Codón sin Sentido , Mutación de Línea Germinal , Síndromes Neoplásicos Hereditarios/genética , Adulto , Neoplasias de la Mama/química , Cadherinas/análisis , Cadherinas/deficiencia , Carcinoma Ductal de Mama/genética , Carcinoma de Células Grandes/química , Metilación de ADN , Femenino , Heterogeneidad Genética , Humanos , Pérdida de Heterocigocidad , Invasividad Neoplásica , Proteínas de Neoplasias/análisis , Proteínas de Neoplasias/genética , Linaje , Neoplasias Gástricas/genéticaRESUMEN
PURPOSE: HER-2 is overexpressed in 20% to 30% of human breast cancer and is associated with poor outcome. Studies suggest an association between HER-2 overexpression and resistance to alkylating agents. To further evaluate this relationship, we assessed the interaction of HER-2, measured by different methods, and outcome after dose intensification with alkylating agents in metastatic breast cancer. PATIENTS AND METHODS: From 1988 to 1995 at Duke University, 425 patients with metastatic breast cancer were enrolled in a study of high-dose alkylating agents (HDC) with autologous cellular support after doxorubicin-based therapy (AFM). HER-2 was measured in serum for shed extracellular domain (ECD) and in tissue by immunohistochemistry (IHC) and fluorescent in situ hybridization (FISH). RESULTS: HER-2 ECD was positive in 29% (19 of 65) of patients pre-AFM and in 11.7% (34 of 290) pre-HDC. Higher pre-AFM and higher pre-HDC HER-2 ECD predicted worse overall survival (P =.045 and P =.0096, respectively). HER-2 overexpression by IHC and FISH showed no correlation with worse disease-free survival or overall survival. FISH and ECD were highly specific for IHC (97.3% and 97.7% respectively). However, ECD had a low sensitivity for IHC-only 22% of patients with HER-2 in the primary tumor shed ECD into the serum. CONCLUSION: These data suggest that the method of measuring HER-2 is important in predicting clinical outcome. HER2 ECD may identify a poor prognosis subgroup of HER-2-positive tumors. Lack of association of HER2 by IHC/FISH with worse outcome suggests that therapy with AFM and/or HDC therapy may be able to overcome the effect of this prognostic factor or it may not be a prognostic factor in this setting.
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Antineoplásicos Alquilantes/farmacología , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapéutico , Biomarcadores de Tumor/análisis , Neoplasias de la Mama/genética , Regulación Neoplásica de la Expresión Génica , Genes erbB-2/genética , Receptor ErbB-2/biosíntesis , Adulto , Anciano , Protocolos de Quimioterapia Combinada Antineoplásica/farmacología , Neoplasias de la Mama/tratamiento farmacológico , Neoplasias de la Mama/patología , Supervivencia sin Enfermedad , Resistencia a Antineoplásicos , Femenino , Humanos , Hibridación Fluorescente in Situ , Persona de Mediana Edad , Valor Predictivo de las Pruebas , Pronóstico , Receptor ErbB-2/análisis , Estudios RetrospectivosRESUMEN
HER2 (erbB-2) proto-oncogene amplification and/or overexpression correlate with poor prognosis in many malignancies. The precise biological role of this oncogenic signaling pathway (which also involves the HER4 gene) in breast cancer is unclear. One property conferred by this oncogene relates to response to drug therapy. Clinical studies support an association between HER2 overexpression and resistance to alkylating agents (cisplatinum and cyclophosphamide). Data from the Cancer and Leukemia Group B 8869/8541 study indicate enhanced dose responsiveness to doxorubicin (Adriamycin) in patients who overexpress the HER2 receptor. Heregulin beta-2, a naturally occurring ligand that activates the HER2 receptor by inducing its heterodimerization with the HER4 receptor, has recently been cloned. The ability of this ligand to phosphorylate the HER2 receptor exogenously allows us to study the effect of HER2 activation on cancer cell behavior. To study the relationship between chemotherapy response and activation of HER2, MCF-7 cells expressing biologically active heregulin were assessed for response to doxorubicin and etoposide, both of which are topoisomerase IIalpha (topo IIalpha) inhibitors. Several clones show markedly increased sensitivity to these drugs. In addition, the same wild-type MCF-7 cells transfected with heregulin beta-2 under the control of an inducible promoter also show this dose-response relationship to doxorubicin after the expression of heregulin beta-2 is activated by zinc. The modulation of topo IIalpha was studied in the cell lines transfected with heregulin. topo IIalpha mRNA and protein (total protein and enzymatic decatenating activity) were found to be up-regulated in heregulin beta-2-transfected cells. Moreover, topo IIalpha promoter activity was also modestly increased in heregulin beta-2-transfected cells. Because up-regulation of topo IIalpha in vitro and in clinical specimens is associated with increased response to doxorubicin (presumptively by an increase in drug substrate), this may be the mechanism of the increased sensitivity to doxorubicin seen in heregulin beta-2-transfected cells. This implies that activation of HER2 or one of the other members of the receptor family may increase sensitivity to doxorubicin by up-regulation of topo IIalpha. This finding suggests the use of receptor/ligand expression to direct patient-specific therapeutic choices (e.g., doxorubicin versus alkylator-based regimens) and the use of biological agents (such as heregulin) in combination with certain chemotherapeutic agents to enhance response to treatment in breast cancer patients.
Asunto(s)
Antibióticos Antineoplásicos/farmacología , Antineoplásicos Fitogénicos/farmacología , Proteínas Portadoras/genética , ADN-Topoisomerasas de Tipo II , Doxorrubicina/farmacología , Etopósido/farmacología , Genes erbB-2/fisiología , Glicoproteínas/genética , Neurregulina-1 , Antígenos de Neoplasias , Neoplasias de la Mama/tratamiento farmacológico , Neoplasias de la Mama/genética , Neoplasias de la Mama/metabolismo , Proteínas Portadoras/metabolismo , Ciclo Celular/efectos de los fármacos , ADN-Topoisomerasas de Tipo II/metabolismo , Proteínas de Unión al ADN , Activación Enzimática , Amplificación de Genes , Glicoproteínas/metabolismo , Humanos , Isoenzimas/metabolismo , Pronóstico , Regiones Promotoras Genéticas/genética , Proto-Oncogenes Mas , Transfección , Células Tumorales Cultivadas/efectos de los fármacosRESUMEN
ErbB2 (HER-2) gene amplification and overexpression have been shown to predict a better outcome with doxorubicin-based chemotherapy as opposed to alkylator-based chemotherapy in early stage breast cancer. To understand the mechanism of differential response to these two regimens, we have evaluated the effect of signaling through the ErbB2 receptor on downstream enzymes that may affect drug response, using two different models. The first system employs breast cancer cells that have high levels of endogenous ErbB2 by gene amplification (BT-474 and SKBR3 cells). The second system allows us to isolate the effect of ErbB2 receptor-mediated intracellular signaling using an epidermal growth factor receptor-ErbB2 chimeric receptor activated by epidermal growth factor. Our experiments show that the cytotoxicity of doxorubicin is inhibited in ErbB2+ breast cancer cells by the anti-ErbB2 antibody, Herceptin. This is accompanied by a decrease in topoisomerase (topo) IIalpha protein and activity, suggesting that this is the mechanism of change in doxorubicin response. In addition, a 10-100-fold (1-2 log) decrease in the LD(50) of doxorubicin is seen after ErbB2 activation using the chimeric receptor model. Furthermore, we see a 100-fold decrease in the LD(50) of etoposide, another topo II inhibitor. This increase in doxorubicin sensitivity is associated with a 4.5-fold increase in the amount of topo IIalpha protein and an increase in topo II activity as measured by DNA decatenating and unknotting activities, as well as cleavable complex formation. In contradistinction to doxorubicin, we have observed an increased resistance to cyclophosphamide chemotherapy after chimeric receptor activation. We propose that the differential benefit seen with doxorubicin- versus alkylator-based chemotherapy in ErbB2+ breast cancer is due, in some cases, to ErbB2-mediated topo IIalpha activation. These data also suggest hypotheses for the optimal sequencing of Herceptin and chemotherapy agents in ErbB2+ breast cancer.
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Neoplasias de la Mama/tratamiento farmacológico , ADN-Topoisomerasas de Tipo II/metabolismo , Receptor ErbB-2/metabolismo , Células 3T3 , Animales , Antineoplásicos/farmacología , Antineoplásicos Alquilantes/farmacología , Western Blotting , Ciclo Celular , Núcleo Celular/metabolismo , Ciclofosfamida/farmacología , ADN/efectos de los fármacos , Doxorrubicina/farmacología , Activación Enzimática , Factor de Crecimiento Epidérmico/metabolismo , Etopósido/farmacología , Femenino , Humanos , Ratones , Inhibidores de la Síntesis del Ácido Nucleico/farmacología , Unión Proteica , Transducción de Señal , Factores de Tiempo , Transfección , Células Tumorales CultivadasRESUMEN
Following confirmation of the appropriate dosage, safety and potential efficacy of Herceptin(trastuzumab) in small-scale phase I and II trials involving patients with refractory disease, a large trial was conducted in 222 patients with breast cancer who had relapsed after one or two chemotherapy regimens for their metastatic disease. The results showed a positive and durable overall response rate (15% according to a response evaluation committee (REC) assessment) using trastuzumab monotherapy (initial dose 4 mg/kg intravenously (i.v.) followed by 2 mg/kg i.v. weekly). In another recently completed phase II trial, 113 patients were randomised to two dose levels (initial dose of 4 mg/kg i.v. dose followed by 2 mg/kg i.v. weekly, or initial dose of 8 mg/kg followed by 4 mg/kg i.v. weekly) of single-agent trastuzumab as first-line therapy for metastatic disease. The preliminary overall response rate was 23% based on investigator assessment, and tolerability was excellent as in previous trials; efficacy was similar in both dose groups, but the side-effects tended to be more frequent in the higher dose group. The preferred dosage is therefore the same as that currently recommended, i.e. an initial dose of 4 mg/kg i.v. followed by 2 mg/kg weekly i.v. until disease progression.
Asunto(s)
Anticuerpos Monoclonales/uso terapéutico , Antineoplásicos/uso terapéutico , Neoplasias de la Mama/tratamiento farmacológico , Adulto , Anciano , Anciano de 80 o más Años , Anticuerpos Monoclonales Humanizados , Femenino , Humanos , Persona de Mediana Edad , Estudios Multicéntricos como Asunto , Ensayos Clínicos Controlados Aleatorios como Asunto , Trastuzumab , Resultado del TratamientoRESUMEN
PURPOSE: Vinorelbine (Navelbine) is a semi-synthetic vinca alkaloid with documented activity in breast cancer. The major dose-limiting toxicity (DLT) when given weekly is myelosuppression with minimal neurologic toxicity. This phase I study attempted to define the maximally tolerated dose (MTD) and the DLT of vinorelbine on a daily x3 schedule with and without filgrastim support. METHODS: A total of 19 patients with stage IV breast cancer were enrolled in separate studies at Duke University Medical Center (DUMC) and the Dana-Farber Cancer Institute (DFCI). Eligible patients could have received up to two prior chemotherapy regimens in the metastatic setting and had to have an ANC > 1500/mm2, PLT > 100000 m3, creatinine < 2.0 mg/dl, bilirubin < 2.0 mg/dL, SGOT not more than three times normal, and performance status 0-1. Vinorelbine was administered using a daily x3 schedule every 3 weeks. The protocols were designed to study dose escalation with and without growth factor support. At DUMC, in the initial phase of the study, the starting dose was 15 mg/m2 per day and dose escalations of 5 mg/m2 were planned until DLT developed and the MTD was defined. DLT was defined as granulocytopenia < 500/mm3 for > 7 days, grade IV thrombocytopenia, febrile neutropenia, or grade III or greater nonhematologic toxicity. In the second phase of the study, growth factor support was given with vinorelbine at the MTD. Filgrastim at a dose of 5 microg/kg was started on day 4 of the 21-day cycle and was continued until the neutrophil count exceeded 10000 cells/ mm3. At DFCI, all patients received growth factor starting on day 4 and the starting dose of vinorelbine was 25 mg/m2. RESULTS: At DUMC, DLT was seen at 20 mg/m2 in three of three patients and included febrile neutropenia, grade IV neutropenia > 7 days, grade III neurotoxicity, and grade III vomiting. Despite the addition of filgrastim, DLT was again seen at 20 mg/m2 and included grade III neurotoxicity (jaw pain, abdominal pain, constipation, ileus) and grade IV mucositis. Three patients at DFCI were treated with vinorelbine at a dose of 25 mg/m2 with growth factor support, and two developed DLT including febrile neutropenia, neutropenia > 7 days, and grade III stomatitis. CONCLUSIONS: Our effort to escalate the dose intensity of vinorelbine on this schedule was not successful and was complicated by hematologic and nonhematologic toxicity. A daily x3 schedule of vinorelbine should not be pursued as an alternative treatment regimen in patients with previously treated metastatic breast cancer.
Asunto(s)
Antineoplásicos Fitogénicos/administración & dosificación , Neoplasias de la Mama/tratamiento farmacológico , Factor Estimulante de Colonias de Granulocitos/administración & dosificación , Vinblastina/análogos & derivados , Adulto , Anciano , Anciano de 80 o más Años , Antineoplásicos Fitogénicos/efectos adversos , Antineoplásicos Fitogénicos/uso terapéutico , Neoplasias de la Mama/patología , Esquema de Medicación , Quimioterapia Combinada , Femenino , Filgrastim , Estudios de Seguimiento , Factor Estimulante de Colonias de Granulocitos/efectos adversos , Factor Estimulante de Colonias de Granulocitos/uso terapéutico , Humanos , Masculino , Persona de Mediana Edad , Metástasis de la Neoplasia , Proteínas Recombinantes , Vinblastina/administración & dosificación , Vinblastina/efectos adversos , Vinblastina/uso terapéutico , VinorelbinaRESUMEN
Treatment with histone deacetylase inhibitors (HDACI) results in potent cytotoxicity of a variety of cancer cell types, and these drugs are used clinically to treat hematological tumors. They are known to repress the transcription of ERBB2 and many other oncogenes, but little is known about this mechanism. Using global run-on sequencing (GRO-seq) to measure nascent transcription, we find that HDACI cause transcriptional repression by blocking RNA polymerase II elongation. Our data show that HDACI preferentially repress the transcription of highly expressed genes as well as high copy number genes in HER2+ breast cancer genomes. In contrast, genes that are activated by HDACI are moderately expressed. We analyzed gene copy number in combination with microarray and GRO-seq analysis of expression level, in normal and breast cancer cells to show that high copy number genes are more likely to be repressed by HDACI than non-amplified genes. The inhibition of transcription of amplified oncogenes, which promote survival and proliferation of cancer cells, might explain the cancer-specific lethality of HDACI, and may represent a general therapeutic strategy for cancer.
Asunto(s)
Antineoplásicos/farmacología , Inhibidores de Histona Desacetilasas/farmacología , Ácidos Hidroxámicos/farmacología , Elongación de la Transcripción Genética/efectos de los fármacos , Neoplasias de la Mama , Línea Celular Tumoral , Femenino , Dosificación de Gen , Regulación Neoplásica de la Expresión Génica/efectos de los fármacos , Silenciador del Gen/efectos de los fármacos , Genoma Humano , Humanos , Análisis de Secuencia por Matrices de Oligonucleótidos , Oncogenes , ARN Polimerasa II/antagonistas & inhibidores , ARN Polimerasa II/metabolismo , ARN Mensajero/genética , ARN Mensajero/metabolismo , Receptor ErbB-2/genética , Receptor ErbB-2/metabolismo , Iniciación de la Transcripción Genética , TranscriptomaAsunto(s)
Protocolos de Quimioterapia Combinada Antineoplásica/uso terapéutico , Neoplasias de la Mama/tratamiento farmacológico , Neoplasias de la Mama/mortalidad , Doxorrubicina/administración & dosificación , Esquema de Medicación , Femenino , Fluorouracilo/administración & dosificación , Humanos , Metástasis de la Neoplasia , Tasa de SupervivenciaRESUMEN
Although social and ethical issues related to the storage and use of biologic specimens for genetic research have been discussed extensively in the medical literature, few empiric data exist describing patients' views. This qualitative study explored the views of 26 female breast cancer patients who had consented to donate blood or tissue samples for breast cancer research. Participants generally did not expect personal benefits from research and had few unprompted concerns. Few participants had concerns about use of samples for studies not planned at the time of consent. Some participants did express concerns about insurance or employment discrimination, while others believed that current privacy protections might actually slow breast cancer research. Participants were generally more interested in receiving individual genetic test results from research studies than aggregate results. Most participants did not want individual results of uncertain clinical significance, although others believed that they should be able to receive such information. These data examined the range of participants' views regarding the storage and use of biologic samples. Further research with different and diverse patient populations is critical to establishing an appropriate balance between protecting the rights of human subjects in genetic research and allowing research to progress.