RESUMO
BACKGROUND: We previously reported the results of a phase II study for patients with newly diagnosed primary central nervous system lymphoma treated with autologous peripheral blood stem-cell transplantation (aPBSCT) and response-adapted whole-brain radiotherapy (WBRT). Now, we update the initial results. PATIENTS AND METHODS: From 1999 to 2004, 23 patients received high-dose methotrexate. In case of at least partial remission, high-dose busulfan/thiotepa (HD-BuTT) followed by aPBSCT was carried out. Patients refractory to induction or without complete remission after HD-BuTT received WBRT. Eight patients still alive in 2011 were contacted and Mini-Mental State Examination (MMSE) and the European Organisation for Research and Treatment of Cancer quality-of-life questionnaire (QLQ)-C30 were carried out. RESULTS: Of eight patients still alive, median follow-up is 116.9 months. Only one of nine irradiated patients is still alive with a severe neurologic deficit. In seven of eight patients treated with HD-BuTT, health condition and quality of life are excellent. MMSE and QLQ-C30 showed remarkably good results in patients who did not receive WBRT. All of them have a Karnofsky score of 90%-100%. CONCLUSIONS: Follow-up shows an overall survival of 35%. In six of seven patients where WBRT could be avoided, no long-term neurotoxicity has been observed and all patients have an excellent quality of life.
Assuntos
Antimetabólitos Antineoplásicos/administração & dosagem , Neoplasias do Sistema Nervoso Central/terapia , Linfoma/terapia , Metotrexato/administração & dosagem , Transplante de Células-Tronco , Adolescente , Adulto , Idoso , Neoplasias do Sistema Nervoso Central/mortalidade , Terapia Combinada , Irradiação Craniana , Feminino , Seguimentos , Humanos , Avaliação de Estado de Karnofsky , Linfoma/mortalidade , Masculino , Pessoa de Meia-Idade , Qualidade de Vida , Transplante AutólogoAssuntos
Mobilização de Células-Tronco Hematopoéticas/métodos , Transplante de Células-Tronco Hematopoéticas , Compostos Heterocíclicos/uso terapêutico , Antígenos CD34/sangue , Benzilaminas , Ciclamos , Feminino , Fator Estimulador de Colônias de Granulócitos/efeitos adversos , Humanos , Masculino , Pessoa de Meia-Idade , Mieloma Múltiplo/cirurgia , Irmãos , Transplante HomólogoAssuntos
Antivirais/uso terapêutico , Diarreia/tratamento farmacológico , Diarreia/virologia , Ganciclovir/uso terapêutico , Transplante de Células-Tronco Hematopoéticas , Herpesvirus Humano 6/isolamento & purificação , Infecções por Roseolovirus/tratamento farmacológico , Adulto , Humanos , Adulto JovemRESUMO
BACKGROUND: We investigated the efficacy and safety of tandem high-dose methotrexate (HD-MTX) induction followed by high-dose busulfan/thiotepa (HD-BuTT) with autologous peripheral blood stem-cell transplantation (aPBSCT) and response-adapted whole-brain radiation therapy (WBRT) in patients with newly diagnosed primary central nervous system lymphoma. PATIENTS AND METHODS: Twenty-three patients were treated with HD-MTX on days 1 and 10. In case of at least a partial remission (PR), HD-BuTT followed by aPBSCT was given. Patients without response to induction or without complete remission (CR) after HD-BuTT received WBRT. RESULTS: Sixteen patients received HD-MTX and HD-BuTT achieving a CR/PR rate of 69%/13%. CR/PR rates for all patients (n = 23) were 70%/13%. There were three deaths during therapy. With longer follow-up three neurotoxic deaths occurred in irradiated patients (n = 9), while no persistent neurotoxicity was seen after HD-BuTT without subsequent WBRT. At a median follow-up of 15 months (range 1-69) median event-free survival (EFS) and overall survival (OS) for all patients were 17 and 20 months (Kaplan-Meier), after HD-BuTT 27 months and "not reached", respectively. Estimated 2-year EFS and OS were 45% and 48% for all patients versus 56% and 61% for the HD-BuTT group, respectively. CONCLUSION: MTX induction followed by HD-BuTT is an effective and very short time-on-treatment regimen. Median survival for patients treated with high-dose chemotherapy is not reached yet. The induction regimen needs optimisation. In this study WBRT was associated with a high incidence of severe neurotoxicity.
Assuntos
Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Neoplasias do Sistema Nervoso Central/terapia , Irradiação Craniana , Linfoma/terapia , Transplante de Células-Tronco de Sangue Periférico , Adolescente , Adulto , Idoso , Bussulfano/administração & dosagem , Neoplasias do Sistema Nervoso Central/mortalidade , Terapia Combinada , Feminino , Humanos , Linfoma/mortalidade , Masculino , Metotrexato/administração & dosagem , Pessoa de Meia-Idade , Tiotepa/administração & dosagemRESUMO
HISTORY: A 22-year old man was admitted with a large pericardial effusion after he had been successfully treated for tuberculosis of the right lung for 6 months. Treatment had been discontinued according to plan 4 months before the current admission. The patient was only mildly symptomatic with exertional dyspnea of 3 weeks duration. Body temperature, pulse rate and blood pressure were within normal limits. The neck veins were not distended. INVESTIGATIONS AND DIAGNOSIS: Laboratory data were unremarkable. The patient underwent thoracoscopy for pericardial drainage. A large chylous effusion was removed. CLINICAL COURSE: Drainage ceased over the following months after the patient had been on a medium-chain triglyceride diet. On follow-up 9 months later, the patient was asymptomatic and without evidence of cardiopulmonary disease. CONCLUSION: We presume (A) that the tuberculous infection had affected the mediastinal lymph nodes and (B) that the fibrous contraction of perinodal tissue caused a temporary obstruction of the thoracic duct at a later stage in the course of the healing process with subsequent reflux of chyle into the pericardial cavity via lymphatic vessels that normally drain the pericardium.
Assuntos
Derrame Pericárdico/etiologia , Derrame Pericárdico/terapia , Tuberculose Pulmonar/complicações , Adulto , Antituberculosos/uso terapêutico , Gorduras na Dieta/administração & dosagem , Gorduras na Dieta/classificação , Drenagem , Dispneia/etiologia , Humanos , Masculino , Derrame Pericárdico/cirurgia , Toracoscopia/métodos , Resultado do Tratamento , Triglicerídeos/administração & dosagem , Triglicerídeos/química , Tuberculose Pulmonar/tratamento farmacológicoRESUMO
Infections during neutropaenia contribute still significantly to mortality and morbidity after high-dose therapy and autologous stem cell transplantation. Further acceleration of haemopoietic recovery seems impossible for biological reasons. Another approach to shorten neutropaenia could be to remove drugs from high-dose therapy protocols with strong contribution to immunosuppression and neutropaenia and unproven antineoplastic activity. In this retrospective matched-pair analysis, conventional busulphan/cyclophosphamide (Bu/Cy) high-dose therapy was compared to single-agent busulphan conditioning before autologous stem cell transplantation. This modification led to a significant shorter neutropaenic interval by protraction of cell decrease and to a significant mitigation of neutropaenia. After single-agent busulphan conditioning, leucocytes dropped below 1/nl at median 1.5 days later when compared to the patients from the busulphanBu/Cy control group (P=0.001). In a significant percentage of patients (n=6, 60%) leucocytes did not fall below 0.5 cells/nl at any time. In contrast, all patients from the Bu/Cy control group experienced deep neutropaenia (P=0.004). Thrombocytopaenia and requirement for transfusions of platelets or red cells were not influenced. Antineoplastic activity seemed to be preserved as determined by survival analysis. In conclusion, modification of high-dose regimen with the intention to shorten neutropaenia with preserved antitumour activity could be an approach to reduce infection-related morbidity and mortality and to consider economic necessities.
Assuntos
Transtornos Linfoproliferativos/terapia , Neutropenia , Transplante de Células-Tronco , Condicionamento Pré-Transplante , Adolescente , Adulto , Idoso , Bussulfano/administração & dosagem , Bussulfano/efeitos adversos , Bussulfano/economia , Ciclofosfamida/administração & dosagem , Ciclofosfamida/efeitos adversos , Ciclofosfamida/economia , Feminino , Humanos , Imunossupressores/administração & dosagem , Imunossupressores/efeitos adversos , Imunossupressores/economia , Infecções/economia , Infecções/etiologia , Infecções/mortalidade , Infecções/patologia , Contagem de Leucócitos , Transtornos Linfoproliferativos/sangue , Transtornos Linfoproliferativos/complicações , Transtornos Linfoproliferativos/economia , Transtornos Linfoproliferativos/mortalidade , Masculino , Pessoa de Meia-Idade , Neutropenia/sangue , Neutropenia/induzido quimicamente , Neutropenia/prevenção & controle , Transfusão de Plaquetas , Estudos Retrospectivos , Transplante de Células-Tronco/economia , Transplante de Células-Tronco/mortalidade , Trombocitopenia/sangue , Trombocitopenia/induzido quimicamente , Trombocitopenia/economia , Trombocitopenia/mortalidade , Trombocitopenia/terapia , Condicionamento Pré-Transplante/efeitos adversos , Condicionamento Pré-Transplante/economia , Condicionamento Pré-Transplante/métodos , Transplante AutólogoAssuntos
Dermatoses Faciais/diagnóstico , Foliculite/diagnóstico , Doença Enxerto-Hospedeiro/diagnóstico , Ácaros , Mielofibrose Primária/terapia , Transplante de Células-Tronco/efeitos adversos , Doença Aguda , Adulto , Animais , Medula Óssea/patologia , Diagnóstico Diferencial , Dermatoses Faciais/parasitologia , Dermatoses Faciais/patologia , Feminino , Foliculite/tratamento farmacológico , Foliculite/parasitologia , Doença Enxerto-Hospedeiro/patologia , Doença Enxerto-Hospedeiro/terapia , Hexaclorocicloexano/uso terapêutico , Humanos , Indução de Remissão , Condicionamento Pré-Transplante , Transplante Homólogo , Resultado do TratamentoRESUMO
A significant increase in tumor regression was induced in N-nitroso-N-methylurea-induced mammary tumors in rats treated with the combination of melatonin and 9-cis-retinoic acid (9cRA). Treatment groups included: control (ethanolic saline), 9cRA (30 mg/kg chow/day), melatonin 500 microg/day, melatonin 1000 microg/day, melatonin 500 microg/day+9cRA and melatonin 1000 microg/day+9cRA. Rats treated with the lower dose of melatonin 500 microg+9cRA show the greatest degree of tumor regression (78%), with 54% undergoing complete regression and a significant increase in apoptotic cells observed by TUNEL Assay. Furthermore, tumor multiplicity and burden were significantly decreased by the combination of melatonin and 9cRA.
Assuntos
Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Neoplasias Mamárias Experimentais/tratamento farmacológico , Melatonina/administração & dosagem , Tretinoína/administração & dosagem , Alitretinoína , Animais , Apoptose/efeitos dos fármacos , Receptor alfa de Estrogênio/genética , Feminino , Neoplasias Mamárias Experimentais/induzido quimicamente , Neoplasias Mamárias Experimentais/patologia , Metilnitrosoureia , RNA Mensageiro/análise , Ratos , Ratos Sprague-DawleyRESUMO
Patients undergoing cancer chemotherapy frequently suffer from mucositis, particularly if they become leukopenic (leucocytes <1000/microL). To identify a possible benefit from antiseptic rinsing of the oral cavity, 47 patients were randomized to rinse either with a chlorhexidine-based product (chlorhexidine concentration 0.3%; N=24) or with an amine-stannous fluoride combination (control group; N=23). Patients were asked to rinse three times a day for 30s from the beginning of chemotherapy until the end of leukopenia. Before rinsing, as well as during and after leukopenia, aerobic and anaerobic bacteria in the oral cavity were counted. At the same time, the patients were assessed for mucositis. In the chlorhexidine-based group, a significant decrease of the aerobic (P=0.042) and anaerobic (P=0.008) bacterial flora was identified. In the control group, the numbers of aerobic and anaerobic bacteria remained unchanged (P>0.05). Fifteen patients in the chlorhexidine-based group had a C-reactive protein (CRP) increase >50mg/L, compared with only eight patients in the control group [odds ratio: 3.13, confidence interval (CI) 0.82-12.39]. Nine patients in the chlorhexidine-based group but only two patients in the control group developed severe mucositis. This difference was statistically significant with an odds ratio of 6.30 (CI: 1.02-49.67). As not all of the 47 patients developed severe leukopenia, a separate analysis was carried out for patients with <1000 leucocytes/microL for a minimum of three days. The results of the microbial counts were very similar, with a clear reduction in the chlorhexidine group and no major alterations in the control group. Twelve of 15 patients in the chlorhexidine-based group had a CRP >50mg/L whereas only eight of 15 patients did so in the control group, which can be regarded as a slightly elevated risk for a CRP increase in the former group. Seven of 15 patients developed severe mucositis in the chlorhexidine-based group, but only two of 15 patients in the control group. These differences were not significant, but patients treated with chlorhexidine-based product seemed to have more problems with inflammation of the oral mucous membranes, resulting in an elevated mucositis score and a CRP increase. Other parameters such as body temperature or application of antibiotics did not differ between the two groups. We conclude that treatment with the chlorhexidine-based product did not provide a clinical benefit for cancer chemotherapy patients. On the contrary, the risk of mucositis and clinical sequelae seems to be enhanced, although the counts of micro-organisms on the oral mucous membranes are significantly reduced.
Assuntos
Anti-Infecciosos Locais/uso terapêutico , Clorexidina/uso terapêutico , Leucopenia/complicações , Antissépticos Bucais , Estomatite/prevenção & controle , Adolescente , Adulto , Idoso , Antineoplásicos/efeitos adversos , Método Duplo-Cego , Feminino , Humanos , Leucopenia/induzido quimicamente , Masculino , Pessoa de Meia-Idade , Mucosa Bucal , Neoplasias/complicações , Neoplasias/tratamento farmacológico , Risco , Estatísticas não Paramétricas , Estomatite/induzido quimicamente , Estomatite/etiologiaRESUMO
Overexpression of the MT1 melatonin receptor in MCF-7 human breast cancer cells significantly enhances the response of these cells to the growth-inhibitory actions of melatonin. Athymic nude mice implanted with MT1-overexpressing MCF-7 cells developed significantly fewer palpable tumors (60% reduction) compared to mice receiving vector-transfected MCF-7 cells (vt-MCF-7). In response to exogenous melatonin, tumor incidence in the mice receiving the MT1-overexpressing MCF-7 cells was decreased by 80% compared to mice receiving vt-MCF-7 cells. Interestingly, daily melatonin administration did not decrease tumor incidence in mice receiving vt-MCF-7 cells, but rather stimulated overall tumor formation.
Assuntos
Neoplasias da Mama/prevenção & controle , Receptores de Superfície Celular/fisiologia , Receptores Citoplasmáticos e Nucleares/fisiologia , Animais , Feminino , Humanos , Melatonina/farmacologia , Camundongos , Camundongos Nus , Transplante de Neoplasias , Receptores de Superfície Celular/genética , Receptores de Superfície Celular/metabolismo , Receptores Citoplasmáticos e Nucleares/genética , Receptores Citoplasmáticos e Nucleares/metabolismo , Receptores de Melatonina , Transfecção , Transplante Heterólogo , Células Tumorais CultivadasRESUMO
Our laboratory has demonstrated that treatment of MCF-7 breast cancer cells with melatonin (Mlt) followed 24h later with physiological concentrations of all-trans retinoic acid (atRA) results in apoptosis. These studies were extended into trials using the N-nitroso-N-methylurea (NMU)-induced rat mammary tumor model. Initial studies conducted by feeding the animals 9-cis-retinoic acid (9cRA in the chow) and administering melatonin by subcutaneous injection in the late afternoon demonstrated that the combination of Mlt and 9cRA was able to significantly prevent tumor development, and that the combination was more efficacious that either Mlt or 9cRA alone. In this report, we conducted studies to determine if lower doses of 9cRA could be used in combination with Mlt while still maintaining anti-tumor activity and if the route of administration of 9cRA (bolus (gavage) v.s. chronic (chow) routes) affected its interaction with Mlt. The studies presented here demonstrate that significantly reduced doses of 9cRA can be used in combination with Mlt while maintaining anti-tumor efficacy. Furthermore, our studies demonstrate that 9cRA is equally effective when it is administered chronically (chow) or as a bolus (gavage). These data demonstrate that the combined use of Mlt and 9cRA produces additive or synergistic effects, which are more efficacious than 9cRA alone. This combination of Mlt and 9cRA could be a potentially useful clinical treatment regimen for breast cancer since it allows the use of lower doses of retinoic acid, thus, avoiding the toxic side effects associated with the use of high dose retinoids.
Assuntos
Antineoplásicos/farmacologia , Apoptose/efeitos dos fármacos , Neoplasias Mamárias Experimentais/prevenção & controle , Melatonina/farmacologia , Tretinoína/farmacologia , Administração Oral , Alitretinoína , Animais , Antineoplásicos/administração & dosagem , Antineoplásicos/uso terapêutico , Neoplasias da Mama/tratamento farmacológico , Modelos Animais de Doenças , Relação Dose-Resposta a Droga , Ensaios de Seleção de Medicamentos Antitumorais , Sinergismo Farmacológico , Feminino , Injeções Subcutâneas , Neoplasias Mamárias Experimentais/induzido quimicamente , Neoplasias Mamárias Experimentais/patologia , Melatonina/administração & dosagem , Melatonina/uso terapêutico , Metilnitrosoureia , Ratos , Ratos Sprague-Dawley , Tretinoína/administração & dosagem , Tretinoína/uso terapêuticoRESUMO
Two putative melatonin receptors have been described including the cell surface G-protein-linked receptors, mt1 and MT2, and the nuclear retinoic orphan receptor alpha (RORalpha). The mt1 receptor, but not the MT2 receptor, is expressed in human breast tumor cell lines, and melatonin-induced growth suppression can be mimicked by the mt1 and MT2 agonist, AMMTC, and blocked by the antagonist, CBPT. RORalpha receptors are also expressed in MCF-7 breast cancer cells and the putative RORalpha agonist CPG-52608 inhibits MCF-7 cell growth but with a very different dose-response than melatonin. Finally, melatonin and AMMTC, but not CPG-52608, can repress RORalpha transcriptional activity in MCF-7 cells.
Assuntos
Neoplasias da Mama/patologia , Receptores de Superfície Celular/metabolismo , Receptores Citoplasmáticos e Nucleares/metabolismo , Neoplasias da Mama/genética , Neoplasias da Mama/metabolismo , Carbazóis/farmacologia , Divisão Celular/efeitos dos fármacos , Relação Dose-Resposta a Droga , Humanos , Immunoblotting , Luciferases/efeitos dos fármacos , Luciferases/genética , Luciferases/metabolismo , Melatonina/farmacologia , Membro 1 do Grupo F da Subfamília 1 de Receptores Nucleares , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Receptores de Superfície Celular/efeitos dos fármacos , Receptores de Superfície Celular/genética , Receptores Citoplasmáticos e Nucleares/efeitos dos fármacos , Receptores Citoplasmáticos e Nucleares/genética , Receptores de Melatonina , Proteínas Recombinantes de Fusão/efeitos dos fármacos , Proteínas Recombinantes de Fusão/genética , Proteínas Recombinantes de Fusão/metabolismo , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Tiazóis/farmacologia , Tiossemicarbazonas/farmacologia , Transativadores/genética , Transativadores/metabolismo , Células Tumorais CultivadasRESUMO
We have previously demonstrated that the pineal hormone, melatonin, can inhibit the growth of estrogen receptor-alpha (ERalpha)-positive breast cancer cells and suppress ERalpha gene transcription. To investigate the relationship between the estrogen response pathway and melatonin's growth inhibition, ERalpha-positive MCF-7 human breast cancer cells were transiently transfected with an estrogen response element (ERE) luciferase reporter construct and then treated with melatonin (10(-9)-10(-6) M) for 30 min followed by 10(-9) M 17-beta-estradiol (E2) or treated with each compound alone. Melatonin pre-treatment significantly reduced E2-induced ERalpha transactivation and ERalpha-ERE binding activity. We also conducted experiments to determine if melatonin modulates cAMP levels in MCF-7 cells. Melatonin inhibited the forskolin-induced and E2-induced elevation of cAMP levels by 57 and 45%, respectively. These data indicate that melatonin can act as a biological modifier to affect ERalpha transcriptional activity by regulating signal transduction pathways which impinge on the ERalpha and by altering E2-mediated ERalpha transactivation and ERalpha DNA binding activity.
Assuntos
Adjuvantes Imunológicos/farmacologia , Neoplasias da Mama/patologia , AMP Cíclico/biossíntese , Regulação Neoplásica da Expressão Gênica , Melatonina/farmacologia , Receptores de Estrogênio/biossíntese , Estradiol/farmacologia , Receptor alfa de Estrogênio , Feminino , Humanos , Transdução de Sinais , Transfecção , Células Tumorais CultivadasRESUMO
In experimental trials using the N-nitroso-N-methylurea (NMU)-induced rat mammary tumor model, a significant decrease in tumor incidence (to 5%) was observed in rats treated with melatonin and 9-cis-retinoic acid (9 cRA) compared to controls (55%). Although 9cRA alone decreased tumor incidence to 26%, this response did not reach statistical significance. Tumor incidence was significantly inhibited to 20% in the animals that received melatonin and 9cRA on alternating days. Latency to tumor onset was prolonged in animals receiving either of the combination treatments compared with controls, and tumor multiplicity was also significantly decreased.
Assuntos
Adenocarcinoma/prevenção & controle , Anticarcinógenos/farmacologia , Neoplasias Mamárias Experimentais/prevenção & controle , Melatonina/farmacologia , Tretinoína/farmacologia , Adenocarcinoma/induzido quimicamente , Adenocarcinoma/patologia , Alitretinoína , Animais , Antioxidantes/farmacologia , Peso Corporal/efeitos dos fármacos , Carcinógenos/antagonistas & inibidores , Sinergismo Farmacológico , Quimioterapia Combinada , Estradiol/sangue , Receptor alfa de Estrogênio , Feminino , Sequestradores de Radicais Livres/farmacologia , Neoplasias Mamárias Experimentais/induzido quimicamente , Neoplasias Mamárias Experimentais/patologia , Metilnitrosoureia , Tamanho do Órgão/efeitos dos fármacos , Ratos , Ratos Sprague-Dawley , Receptores de Estrogênio/biossíntese , Receptores do Ácido Retinoico/biossíntese , Receptor alfa de Ácido Retinoico , Útero/anatomia & histologia , Útero/efeitos dos fármacosRESUMO
Energy restriction (ER) extends the life span and slows aging and age-related diseases in short-lived mammalian species. Although a wide variety of physiological systems have been studied using this paradigm, little is known regarding the effects of ER on skeletal health and reproductive aging. Studies in rhesus monkeys have reported that ER delays sexual and skeletal maturation in young male monkeys and reduces bone mass in adult males. No studies have examined the chronic effects on bone health and reproductive aging in female rhesus monkeys. The present cross-sectional study examined the effects of chronic (6 y) ER on skeletal and reproductive indices in 40 premenopausal and perimenopausal (7-27 y old) female rhesus macaques (Macaca mulatta). Although ER monkeys weighed less and had lower fat mass, ER did not alter bone mineral density, bone mineral content, osteocalcin, 25-hydroxyvitamin D, 1,25-hydroxyvitamin D or parathyroid hormone concentrations, menstrual cycling or reproductive hormone concentrations. Body weight and lean mass were significantly related to bone mineral density and bone mineral content at all skeletal sites (total body, lumbar spine, mid and distal radius; P: < or = 0.04). The number of total menstrual cycles over 2 y, as well as the percentage of normal-length cycles (24-31 d), was lower in older than in younger monkeys (P: < or = 0.05). Older monkeys also had lower estradiol (P: = 0.02) and higher follicle-stimulating hormone (P: = 0.02) concentrations than did younger monkeys. We conclude that ER does not negatively affect these indices of skeletal or reproductive health and does not alter age-associated changes in the same variables.
Assuntos
Envelhecimento/fisiologia , Calcificação Fisiológica/fisiologia , Privação de Alimentos/fisiologia , Macaca mulatta/fisiologia , Reprodução/fisiologia , Vitamina D/análogos & derivados , Animais , Peso Corporal , Estudos Transversais , Ingestão de Energia/fisiologia , Estradiol/sangue , Feminino , Hormônio Foliculoestimulante/sangue , Modelos Lineares , Macaca mulatta/metabolismo , Ciclo Menstrual , Osteocalcina/sangue , Hormônio Paratireóideo/sangue , Vitamina D/sangueRESUMO
It has been established that melatonin (Mlt) and retinoic acid, individually, inhibit the proliferation of the estrogen receptor-alpha (ER alpha)-positive MCF-7 breast cancer cell line. Our laboratory has previously demonstrated that Mlt and all-trans-retinoic acid (atRA) not only inhibit the proliferation, but also induce apoptosis of MCF-7 cells when used in a sequential regimen of Mlt followed 24 h later by atRA. Using this same MCF-7 breast cancer cell line, we investigated the potential pathways through which apoptosis is being induced. We found that treatment of MCF-7 cells with Mlt for 24 h before the addition of atRA decreased the protein levels of the death suppressor, Bcl-2, and increased, although with different time courses, the levels of the death promoters, Bax and Bak; however, there was no change in the levels of the tumor suppressor gene, p53. MCF-7 cells treated sequentially with Mlt and atRA also demonstrated an enhanced sensitivity to the apoptotic effects of atRA, which did not appear to be due to increased expression of the retinoic acid receptors, RAR alpha or RXR alpha, but rather to enhanced transcriptional activity of the RAR alpha. These data suggest that the sequential treatment regimen of Mlt and atRA may induce apoptosis by modulation of members of the Bcl-2 family of proteins. Thus, this combinatorial regimen, which reduces the concentration of atRA needed for clinical efficacy while enhancing its anti-tumorigenic activity, could be of great therapeutic benefit, and may, in fact, specifically induce the regression of established breast tumors due to its apoptosis-promoting effects.
Assuntos
Apoptose/efeitos dos fármacos , Neoplasias da Mama/patologia , Melatonina/farmacologia , Tretinoína/farmacologia , Western Blotting , Neoplasias da Mama/metabolismo , Relação Dose-Resposta a Droga , Feminino , Humanos , Luciferases/biossíntese , Proteínas de Membrana/metabolismo , Microscopia de Contraste de Fase , Proteínas Proto-Oncogênicas/metabolismo , Proteínas Proto-Oncogênicas c-bcl-2/metabolismo , Receptores de Estrogênio/metabolismo , Receptores do Ácido Retinoico/metabolismo , Transdução de Sinais/efeitos dos fármacos , Fatores de Tempo , Células Tumorais Cultivadas , Proteína Supressora de Tumor p53/metabolismo , Proteína Killer-Antagonista Homóloga a bcl-2 , Proteína X Associada a bcl-2RESUMO
The estrogen receptor (ER)-positive MCF-7 human breast cancer cell line has been used extensively for the study of estrogen-responsive human breast cancer. However, various levels of estrogen responsiveness have been described in different stocks of MCF-7 cells. Because we have previously shown that the pineal hormone, melatonin, inhibits proliferation of MCF-7 cells and can modulate ER expression and transactivation, we investigated if various stocks of MCF-7 cells exhibit a differential responsiveness to the anti-proliferative effects of melatonin and the possible mechanisms involved. The MCF-7 stocks (M, O, H) were examined for: (1) mitogenic response to estradiol; (2) steady-state ER mRNA levels; (3) expression of the mt1 melatonin membrane receptor; (4) growth inhibition by melatonin; and (5) melatonin's modulation of expression of the ER and the estrogen-regulated genes, PgR, TGFbeta and pS2. For all of these parameters, there was a stock-specific response which showed: MCF-7M > MCF-7O > MCF-7H. These results demonstrate that there are significant differences in the responsiveness of various stocks of MCF-7 breast cancer cells to the growth-inhibitory effects of melatonin which can be correlated with both the level of ER mRNA expression and the degree of estrogen-responsiveness. These findings suggest that not only may these differences have some impact on the cells' estrogen-response pathway, but also that the primary growth-inhibitory effects of melatonin are transduced through the membrane-associated G-protein coupled mt1 melatonin receptor.