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1.
Fam Cancer ; 19(2): 177-182, 2020 04.
Artigo em Inglês | MEDLINE | ID: mdl-31997047

RESUMO

To prevent endometrial carcinoma in Lynch syndrome (LS), regular gynecological surveillance visits and prophylactic surgery are recommended. Previous data have shown that prophylactic hysterectomy is an effective means of cancer prevention, while the advantages and disadvantages of surveillance are somewhat unclear. We aimed to evaluate female LS carriers' attitudes towards regular gynecological surveillance and factors influencing their decision-making on prophylactic surgery that have not been well documented. Pain experienced during endometrial biopsies was also evaluated. Postal questionnaires were sent to LS carriers undergoing regular gynecological surveillance. Questionnaires were sent to 112 women with LS, of whom 76 responded (68%). Forty-two (55%) had undergone prophylactic hysterectomy by the time of the study. The majority of responders (64/76; 84.2%) considered surveillance appointments beneficial. Pain level during endometrial biopsy was not associated with the decision to undergo prophylactic surgery. The level of satisfaction the women had with the information and advice provided during surveillance was significantly associated with the history of prophylactic hysterectomy (satisfaction rate of 73.2% versus 31.8% of nonoperated women, p = 0.003). The women who had undergone prophylactic surgery were older than the nonoperated women both at mutation testing (median of 42.3 years versus 31.6 years, p < 0.001) and at the time of the study (median of 56.9 years versus 46.0 years, respectively, p < 0.001). Women with LS pathogenic variants have positive experiences with gynecological surveillance visits, and their perception of the quality of the information and advice obtained plays an important role in their decision-making concerning prophylactic surgery.


Assuntos
Neoplasias Colorretais Hereditárias sem Polipose/genética , Tomada de Decisões , Neoplasias do Endométrio/prevenção & controle , Histerectomia/psicologia , Adulto , Idoso , Idoso de 80 Anos ou mais , Proteínas de Ligação a DNA/genética , Feminino , Finlândia , Testes Genéticos , Heterozigoto , Humanos , Histerectomia/estatística & dados numéricos , Pessoa de Meia-Idade , Proteína 1 Homóloga a MutL/genética , Proteína 2 Homóloga a MutS/genética , Dor Processual/psicologia , Satisfação do Paciente , Estudos Retrospectivos , Inquéritos e Questionários
2.
Arch Gynecol Obstet ; 299(5): 1345-1351, 2019 05.
Artigo em Inglês | MEDLINE | ID: mdl-30607583

RESUMO

PURPOSE: The two main etiological factors for vulvar squamous cell carcinoma (vSCC) are the vulvar dermatosis lichen sclerosus (LS) and high-risk human papillomavirus (hrHPV). Serpin A1 (α1-antitrypsin) is a serine protease inhibitor, which plays a role in the tumorigenesis of various cancer types. The aim of the study was to evaluate the expressions of Serpin A1 in LS, premalignant vulvar lesions, and vSCC using immunohistochemistry (IHC) and serum analysis, and to compare Serpin A1 stainings to the tumor markers p53 and p16. METHODS: In total, 120 samples from 74 patients were studied with IHC for Serpin A1, p53 and p16: 18 normal vulvar skin, 53 LS, 9 premalignant vulvar lesions (dVIN/HSIL) and 40 vSCC samples. Serum concentrations of Serpin A1 were analyzed from 30 LS, 44 vSCC and 10 control patients. Expressions were compared to clinical data. RESULTS: Tumor cell-specific Serpin A1 overexpression was detected in 88% of vSCC samples, independent of the etiology. The intensity of Serpin A1 expression was significantly higher in vSCC than in healthy vulvar skin, LS, or premalignant vulvar lesions. Serpin A1 showed an association with p53 positivity. No difference in overall survival was found between Serpin A1-, p53-, or p16-positive vSCC patients. Serum concentrations of Serpin A1 were equal in the LS, vSCC, and control groups. CONCLUSION: Tumor cell-specific Serpin A1 overexpression is a potential biomarker in vSCC.


Assuntos
Carcinoma de Células Escamosas/genética , Neoplasias Vulvares/genética , alfa 1-Antitripsina/metabolismo , Adulto , Idoso , Idoso de 80 Anos ou mais , Carcinoma de Células Escamosas/patologia , Feminino , Humanos , Pessoa de Meia-Idade , Neoplasias Vulvares/patologia
3.
Gynecol Oncol ; 139(3): 536-40, 2015 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-26499936

RESUMO

OBJECTIVE: ERRs (estrogen-related receptors) regulate energy metabolism, the cell cycle and inflammatory processes in both normal and cancer cells. Chronic inflammation induced by lichen sclerosus (LS) or human papilloma virus (HPV) precedes vulvar squamous cell carcinoma (vulvar SCC). We investigated the expression of ERRα, ERRß and ERRγ in normal vulvar skin, LS as well as LS-dependent and LS-independent/HPV-related vulvar SCC. METHODS: A total of 203 samples were analyzed for ERRα, ERRß and ERRγ by using immunohistochemistry. These included 37 normal vulvar skin samples, 110 LS samples, 6 vulvar intraepithelial neoplasia (VIN) samples and 50 vulvar SCC samples. RESULTS: A substantial reduction in or disappearance of ERRα was detected in all vulvar SCC samples. A total of 79% of childhood-onset LS and 51% of adulthood-onset LS lesions showed decreases in ERRα staining. A gradual reduction in ERRα cytoplasmic staining was observed from healthy vulvar skin to precursor lesions and further to SCC. Nuclear ERRα staining was observed in 8/33 (24%) LS-dependent and 10/17 (59%) LS-independent SCC samples. CONCLUSIONS: ERRα, a key regulator of cell energy metabolism, may play a role in the pathogenesis of both LS and vulvar SCC.


Assuntos
Carcinoma in Situ/química , Carcinoma de Células Escamosas/metabolismo , Receptores de Estrogênio/metabolismo , Líquen Escleroso Vulvar/metabolismo , Neoplasias Vulvares/metabolismo , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Carcinoma in Situ/etiologia , Carcinoma de Células Escamosas/etiologia , Criança , Pré-Escolar , Feminino , Humanos , Pessoa de Meia-Idade , Pele/química , Vulva/química , Líquen Escleroso Vulvar/complicações , Neoplasias Vulvares/etiologia , Adulto Jovem , Receptor ERRalfa Relacionado ao Estrogênio
4.
Ultrasound Obstet Gynecol ; 39(4): 466-72, 2012 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-21953858

RESUMO

OBJECTIVE: Preoperative evaluation of the depth of myometrial invasion in endometrial carcinoma is challenging. The objective of this study was to evaluate the usefulness of three-dimensional power Doppler angiography (3D-PDA) in this setting. METHODS: Sonographic and histological data on 100 consecutive cases of endometrial carcinoma were analyzed. The endometrial and myometrial vascular indices VI (vascularization index), FI (flow index) and VFI (vascularization flow index) were calculated by 3D-PDA. The results were compared with a complete surgical staging. RESULTS: The mean ( ± SD) age of patients was 67.1 ± 8.8 (range, 33-87) years. Forty-six patients had deep (≥ 50%) myometrial invasion. Eight patients had metastases, seven of them with deep invasion. Three patients were found to have carcinomas of non-uterine origin on histology, and these were excluded from further statistical analysis. The median endometrial and myometrial vascular indices were higher in the group with deep invasion than in the group without. Following multivariable analysis of the indices only the endometrial FI was independently associated with deep invasion (OR, 1.061; 95% CI, 1.023-1.099; P = 0.001). However, a greater endometrial volume was also an independent predictor of deep invasion (OR, 1.109; 95% CI, 1.011-1.215; P = 0.028). CONCLUSION: Our study suggests that endometrial and, to a lesser degree, myometrial vascular indices and endometrial volume correlate with the depth of myometrial invasion in endometrial carcinoma.


Assuntos
Angiografia/métodos , Neoplasias do Endométrio/diagnóstico por imagem , Imageamento Tridimensional/métodos , Cuidados Pré-Operatórios/métodos , Adulto , Idoso , Idoso de 80 Anos ou mais , Velocidade do Fluxo Sanguíneo , Neoplasias do Endométrio/patologia , Feminino , Humanos , Pessoa de Meia-Idade , Invasividade Neoplásica , Valor Preditivo dos Testes , Cuidados Pré-Operatórios/instrumentação , Ultrassonografia , Resistência Vascular
5.
Br J Cancer ; 89 Suppl 3: S29-34, 2003 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-14661044

RESUMO

Despite considerable progress over the past two decades in the management of advanced ovarian cancer, the majority of patients with this type of malignancy still die from their disease, and the search for new and improved first-line and salvage chemotherapy regimens continues. As part of this work, the antitumour activity and effect on survival of new chemotherapy combinations containing the novel taxane docetaxel are being explored. Dual therapy with docetaxel plus a camptothecin (a topoisomerase inhibitor) has shown promise in second-line treatment, and preliminary data indicate good activity of docetaxel in combination with gemcitabine. Triple-therapy studies have produced mixed results, but encouraging activity has been reported when the anthracycline, epirubicin, is added to docetaxel and carboplatin - sequential therapy with docetaxel, cisplatin and epirubicin is currently being assessed. Combinations of docetaxel, carboplatin and gemcitabine may also be of future interest. Early efficacy and tolerability results with novel combination chemotherapy regimens involving docetaxel thus offer the promise of additional progress in the chemotherapy of advanced ovarian cancer, and further trials should be encouraged.


Assuntos
Antineoplásicos/uso terapêutico , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Neoplasias Ovarianas/tratamento farmacológico , Taxoides/uso terapêutico , Antineoplásicos/administração & dosagem , Antineoplásicos/efeitos adversos , Protocolos de Quimioterapia Combinada Antineoplásica/efeitos adversos , Ensaios Clínicos como Assunto , Docetaxel , Feminino , Humanos , Taxoides/administração & dosagem , Taxoides/efeitos adversos
6.
Anticancer Drugs ; 9(2): 181-9, 1998 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-9510505

RESUMO

The purpose of the present study was to evaluate the tissue distribution of toremifene (TOR) in baboons following intra-tissue injections and to examine the effectiveness of intratumoral TOR therapy of baboons with various spontaneous neoplasms. Five healthy baboons (Papio sp.) were used to examine the distribution of TOR following intra-tissue injections. Twenty-three different tissue specimens were collected for HPLC analysis. In addition, four baboons with various spontaneous neoplasms (myxoma, squamous cell carcinoma, lymphosarcoma and adenocarcinoma) were treated with intratumoral TOR and their responses were evaluated. Tissue TOR distribution was also examined in these animals. In the tissue distribution study, target tissue/serum TOR concentration ratios ranged from 138 to 8873 and the target tissue/other tissue ratios ranged from 1.2 to 2428. The distribution of TOR was very favorable, with the highest concentrations outside the injection sites noted in adjacent organs. A marked response was observed in the myxoma and partial responses were observed in the other three cases. Drug level analysis data from these four animals revealed tissue concentrations similar to those seen in the TOR tissue distribution study. Intratumoral administration of TOR can achieve effective local tumor and tissue concentrations, while systemic distribution via circulation to other organs is limited.


Assuntos
Antineoplásicos Hormonais/administração & dosagem , Antineoplásicos Hormonais/farmacocinética , Neoplasias Experimentais/tratamento farmacológico , Neoplasias Experimentais/metabolismo , Toremifeno/administração & dosagem , Toremifeno/farmacocinética , Adenocarcinoma/tratamento farmacológico , Adenocarcinoma/metabolismo , Animais , Carcinoma de Células Escamosas/tratamento farmacológico , Carcinoma de Células Escamosas/metabolismo , Cromatografia Líquida de Alta Pressão , Feminino , Injeções Intralesionais , Neoplasias Hepáticas Experimentais/tratamento farmacológico , Neoplasias Hepáticas Experimentais/metabolismo , Linfoma não Hodgkin/tratamento farmacológico , Linfoma não Hodgkin/metabolismo , Masculino , Mixoma/tratamento farmacológico , Mixoma/metabolismo , Papio , Neoplasias Parotídeas/tratamento farmacológico , Neoplasias Parotídeas/metabolismo
7.
Drugs Aging ; 11(4): 261-70, 1997 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-9342556

RESUMO

Toremifene is a chlorinated tamoxifen analogue that is indicated for the treatment of postmenopausal hormone-dependent breast cancer. It competes with estradiol for estrogen receptors and has growth-inhibitory effects on MCF-7 breast cancer cells. At concentrations < 10(-6) mol/L, this growth inhibition can be reversed by estradiol, but at higher concentrations toremifene is cytotoxic. In dimethylbenzanthracene (DMBA)-induced mammary cancer in rats, toremifene has been shown to decrease the number of new tumours and to inhibit the growth of existing tumours. Toremifene causes growth inhibition by suppressing mitosis and inducing apoptosis. The mechanism by which these events occur may involve the induction of transforming growth factor-beta 1 and inhibition of insulin-like growth factor-1 (mecasermin). Toremifene is primarily an antiestrogen, but it has some estrogen agonist properties in postmenopausal women. The latter are reflected by the fall in luteinising hormone and follicle-stimulating hormone levels and the rise in sex hormone-binding globulin levels that are associated with its use in most women. After estrogen priming, toremifene 68mg administered orally has been found to exert a similar antiestrogenic effect on the vaginal epithelium in postmenopausal women as tamoxifen 60mg. The half-life of toremifene in plasma is 5 days, and the drug is > 99% bound to plasma proteins. The main metabolites of toremifene are N-demethyl-toremifene and deaminohydroxy-toremifene. Altered liver, but not kidney, function affects the pharmacokinetics of toremifene. Toremifene 60mg daily is as effective as tamoxifen 20mg daily in the treatment of postmenopausal hormone-dependent breast cancer, producing a response in about 50% of patients. Soft tissue and visceral metastases respond better to toremifene than bone metastases. Most of the adverse effects of toremifene are related to its activity at estrogen receptors and include hot flashes, vaginal discharge and nausea. Although toremifene decreases antithrombin III levels slightly, the incidence of thromboembolic complications is low. Thus far, no carcinogenic effects have been noted in humans, and preclinical data are mostly reassuring. Toremifene has favourable effects on serum lipids, and thus has potential in preventing coronary heart disease. Although toremifene is somewhat more expensive to use than tamoxifen, toremifene is an effective and well tolerated alternative to tamoxifen in the treatment of postmenopausal women with hormone-dependent breast cancer. No formal pharmacoeconomic comparisons of toremifene and tamoxifen have yet been published. Toremifene is potentially safer than tamoxifen in relation to carcinogenic effects and effects on serum lipids.


Assuntos
Antineoplásicos Hormonais/uso terapêutico , Neoplasias da Mama/tratamento farmacológico , Neoplasias Hormônio-Dependentes/tratamento farmacológico , Pós-Menopausa , Toremifeno/uso terapêutico , Antineoplásicos Hormonais/química , Antineoplásicos Hormonais/economia , Antineoplásicos Hormonais/farmacocinética , Ensaios Clínicos Fase I como Assunto , Ensaios Clínicos Fase II como Assunto , Feminino , Humanos , Tamoxifeno/uso terapêutico , Toremifeno/química , Toremifeno/economia , Toremifeno/farmacocinética
8.
Cancer Chemother Pharmacol ; 39(6): 513-20, 1997.
Artigo em Inglês | MEDLINE | ID: mdl-9118463

RESUMO

PURPOSE: Toremifene is an orally administered triphenylethylene derivative with antiestrogenic activity that is primarily used in the treatment of patients with metastatic breast cancer. The purpose of this study was to evaluate the therapeutic advantage of local (transdermal) administration of toremifene in several animal models. Local (subcutaneous and skin) versus systemic concentrations of toremifene were evaluated serially following transdermal application of the drug. With high local concentrations and minimal distribution to other organs via the circulation, topical toremifene may deliver maximal therapeutic effects to local tissue while avoiding the side effects seen with systemic therapy. METHODS: Three animal models (nude mice, baboons, and a horse) were used to examine topically administered toremifene for kinetic measurements. RESULTS: In nude mice implanted subcutaneously with MDA-MB-231 human breast tumors, topical toremifene (2.5 mg/day x 5 days) produced greater than 50-fold higher tumor concentrations compared with intraperitoneal (i.p.) administration (1.0 mg/day x 5 days). Systemic distribution in plasma, uterus, and liver was lower following topical than following i.p. administration. In nude mice inoculated subcutaneously with estrogen receptor-positive (ER +) MCF-7 human breast cancer cells, topical toremifene and 4-hydroxytoremifene (4-OH) prevented tumor growth in the presence of estradiol. In four nontumor-bearing baboons that were given transdermal toremifene, relatively high distribution of drug was noted in normal breast tissue and fat, compared with undetectable serum concentrations. Finally, a new topical formulation of toremifene (a gel preparation for human use, Orion-Farmos, Finland) achieved high local tumor toremifene concentrations in a horse melanoma, with minimal systemic distribution. CONCLUSIONS: Transdermal toremifene can achieve high local tissue concentrations with minimal systemic distribution.


Assuntos
Antagonistas de Estrogênios/farmacocinética , Toremifeno/farmacocinética , Administração Cutânea , Animais , Antagonistas de Estrogênios/administração & dosagem , Antagonistas de Estrogênios/uso terapêutico , Feminino , Cavalos , Humanos , Masculino , Camundongos , Camundongos Nus , Transplante de Neoplasias , Neoplasias Experimentais/tratamento farmacológico , Neoplasias Experimentais/prevenção & controle , Papio , Distribuição Tecidual , Toremifeno/administração & dosagem , Toremifeno/uso terapêutico , Células Tumorais Cultivadas
9.
Gynecol Oncol ; 57(3): 294-8, 1995 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-7774832

RESUMO

In order to find out whether the response rate and survival in epithelial ovarian cancer can be improved by aid of sensitivity testing with the subrenal capsule assay (SRCA), 196 patients with FIGO Stage II-IV epithelial ovarian cancer were randomized to be treated with either cyclophosphamide-doxorubicin-cisplatin (CAP) or SRCA-guided chemotherapy. The drug combinations tested with the SRCA were (1) cyclophosphamide-doxorubicin-carboplatin (CACAR), (2) CAP, (3) carboquone-methotrexate-tegafur (CQ-MTX-TEG), (4) cisplatin-etoposide-hexamethyl-melamine (P-VP-HXM), and (5) bleomycin-epirubicin-cisplatin (BEP). A total of 132 patients (CAP, 69; SRCA, 63) were eligible for efficacy analysis based on relaparotomy findings. The overall response rate was 59% in the CAP arm and 62% in the SRCA arm. In the SRCA arm, 16 patients were treated with CACAR, 24 with CAP, 10 with CQ-MTX-TEG, 11 with P-VP-HXM, and 2 with BEP. The response rate to CACAR was 63% and to SRCA-CAP was 75%. The number of complete responses was higher when CAP was given as guided by the assay than when given at random (14/24 vs 23/69; P = 0.03, Pearson chi 2). Survival curves as estimated by Kaplan-Meier method gave a median survival of 24 (SE = 4) months to the SRCA arm and 28 (SE = 5) for the CAP arm (P = 0.7; log-rank test). Because no survival benefit was achieved, the SRCA obviously needs further development before it can be routinely recommended in the choice of first-line chemotherapy for patients with ovarian cancer.


Assuntos
Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Neoplasias Ovarianas/tratamento farmacológico , Ensaio de Cápsula Sub-Renal , Idoso , Altretamine/administração & dosagem , Animais , Carbazilquinona/administração & dosagem , Carboplatina/administração & dosagem , Cisplatino/administração & dosagem , Ciclofosfamida/administração & dosagem , Doxorrubicina/administração & dosagem , Doxorrubicina/análogos & derivados , Etoposídeo/administração & dosagem , Feminino , Humanos , Metotrexato/administração & dosagem , Camundongos , Camundongos Endogâmicos , Pessoa de Meia-Idade , Estudos Prospectivos , Tegafur/administração & dosagem
10.
Important Adv Oncol ; : 175-85, 1995.
Artigo em Inglês | MEDLINE | ID: mdl-7672804

RESUMO

The tamoxifen chemoprevention trial in health women is ongoing in over 250 cancer treatment centers. The use of tamoxifen for the treatment of postmenopausal women with known breast cancer has been touted as a medical breakthrough by many physicians. However, the ongoing trial which enroll high-risk healthy women above the age of 34, has been controversial since its initiation in 1991. Congressional hearings, editorial, and statistical analyses concerning the scientific basis of the trial have emerged over the past year. This chapter presents the newest scientific facts, and speculates on the unknown risks of using tamoxifen as a chemopreventive in healthy women.


Assuntos
Neoplasias da Mama/prevenção & controle , Tamoxifeno/uso terapêutico , Densidade Óssea/efeitos dos fármacos , Neoplasias da Mama/tratamento farmacológico , Neoplasias da Mama/patologia , Doenças Cardiovasculares/prevenção & controle , Protocolos Clínicos , Ensaios Clínicos como Assunto , Resistência a Medicamentos , Neoplasias do Endométrio/induzido quimicamente , Feminino , Humanos , Neoplasias Hepáticas/induzido quimicamente , Seleção de Pacientes , Pré-Menopausa , Fatores de Risco , Tamoxifeno/efeitos adversos
11.
Breast Cancer Res Treat ; 32(1): 57-65, 1994.
Artigo em Inglês | MEDLINE | ID: mdl-7819587

RESUMO

Flow cytometric analysis of DNA ploidy and S-phase fraction are well recognized prognostic indicators in breast cancer. The present paper deals with the widening of the applications of flow cytometry to monitoring the effectiveness of antiestrogen therapy, detecting clonal selection and emergence of drug resistance, and monitoring chemosensitizing properties of drugs. Antiestrogen activity can be studied by DNA flow cytometry to address clinical research problems such as patient-specific pharmacokinetics, dosing compliance, and acquired antiestrogen resistance. Patient plasma specimens containing various concentrations of triphenylethylenes can be monitored for drug-induced effects using cell cycle measurements and correlated to in vivo drug levels. DNA flow cytometry has also been instrumental in the study of the effects of prolonged low-dose (0.5 microM for > 100 days) tamoxifen treatment on human estrogen receptor negative MDA-MB-231 cells, where it was shown that tamoxifen may significantly alter cell cycle kinetics and tumorigenicity of these cells, selecting a new, more aggressive, and rapidly growing clone. Lastly, it has been shown that the chemosensitizing properties of another triphenylethylene antiestrogen, toremifene, on estrogen receptor negative, multidrug resistant MDA-MB-231-A1 human breast cancer cells can be studied using flow cytometric analysis. Toremifene (and its metabolites N-desmethyltoremifene and toremifene IV) are able to "resensitize" MDA-MB-231-A1 cells to vinblastine and doxorubicin, as reflected in a marked shift of cells to G2/M phase of the cell cycle. Flow cytometry is a widely available technique that might be applied clinically to monitor, at the cellular level, drug effects on tumors, including the modulators of drug resistance.


Assuntos
Neoplasias da Mama/tratamento farmacológico , Neoplasias da Mama/patologia , DNA de Neoplasias/análise , Citometria de Fluxo , Antineoplásicos/uso terapêutico , Ciclo Celular/efeitos dos fármacos , Resistência a Múltiplos Medicamentos , Antagonistas de Estrogênios/uso terapêutico , Humanos
12.
Oncol Res ; 5(12): 461-6, 1993.
Artigo em Inglês | MEDLINE | ID: mdl-8086667

RESUMO

The in vivo growth rate and the chemosensitivity patterns of a cell clone selected by tamoxifen from the estrogen receptor-negative human breast cancer cell line MDA-MB-231 was studied in the nude mouse model and with flow cytometry. To investigate the growth rate of the wild-type and clone cells in vivo, the cells were inoculated into the opposite flanks of 5 male nude mice. Drug sensitivity to doxorubicin (10 ng/mL), vinblastine (1 ng/mL), and paclitaxel (1 ng/mL) was examined in wild-type/clone cell mixture using flow cytometry. Northern blot technique was used to study the expression of mdr-1 messenger RNA in both the wild-type and the clone cells. The tumors derived from the clone and wild-type cells were, following a 3-week growth period, 260.2 +/- 78.8 mm2 vs. 68.3 +/- 50.8 mm2 in size, respectively (P < 0.001). Following a 28-day continuous exposure, doxorubicin was selectively, toxic to the wild-type cells, while having no apparent effect on the clone population. However, paclitaxel- and vinblastine-treated wild-type/clone cell mixtures did not exhibit a differential cytotoxic effect on either cell population. It was concluded that the clone selected by tamoxifen shows an aggressive growth rate in vivo and an altered chemosensitivity pattern to doxorubicin in vitro.


Assuntos
Neoplasias da Mama/patologia , Doxorrubicina/farmacologia , Tamoxifeno/farmacologia , Animais , Divisão Celular/efeitos dos fármacos , Resistência a Medicamentos , Feminino , Humanos , Masculino , Camundongos , Camundongos Endogâmicos BALB C , Células Tumorais Cultivadas
14.
Eur J Cancer ; 29A(15): 2138-44, 1993.
Artigo em Inglês | MEDLINE | ID: mdl-8297653

RESUMO

The effects of long-term tamoxifen exposure on cell growth and cell cycle kinetics were compared between oestrogen receptor (ER)-positive (MCF-7) and ER-negative (MDA-MB-231) cell lines. In the MCF-7 cell line, prolonged tamoxifen exposure (0.5 mumol/l for > 100 days) blocked cells in G0-G1 of the cell cycle, and slowed the doubling time of cells from 30 to 59 h. These effects corresponded to an increase in the cellular accumulation of tamoxifen over time [mean area under concentration curve (AUC) = 77.92 mumoles/10(6)/cells/day]. In contrast, in the MDA-MB-231 cell line, long-term tamoxifen exposure had no obvious effect on the doubling time, and reduced cellular tamoxifen accumulation (mean AUC = 50.50 mumoles/10(6)/cells/day) compared to the MCF-7 cells. Flow cytometric analysis of MDA-MB-231 cells demonstrated that a new tetraploid clone emerged following 56 days of tamoxifen exposure. Inoculation of the MDA-MB-231 tetraploid clone and MDA-MB-231 wildtype cells into the opposite flanks of athymic nude mice resulted in the rapid growth of tetraploid tumours. The tetraploid tumours maintained their ploidy following tamoxifen treatment for nine consecutive serial transplantations. Histological examination of the fifth transplant generation xenografts revealed that the tetraploid tumour had a 25-30 times greater mass, area of haemorrhage and necrosis, a slightly higher mitotic index and was more anaplastic than the control neoplasm. The control wildtype MDA-MB-231 tumours maintained a stable ploidy following tamoxifen treatment until the eighth and ninth transplantation, when a tetraploid population appeared, suggesting that tamoxifen treatment may select for this clone in vivo. These studies suggest that prolonged tamoxifen exposure may select for new, stable, fast growing cell clones in vitro as well as in vivo.


Assuntos
Neoplasias da Mama/patologia , Células-Tronco Neoplásicas/efeitos dos fármacos , Tamoxifeno/farmacologia , Animais , Neoplasias da Mama/química , Divisão Celular/efeitos dos fármacos , Feminino , Citometria de Fluxo , Humanos , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Nus , Proteínas de Neoplasias/análise , Transplante de Neoplasias , Receptores de Estrogênio/análise , Fatores de Tempo , Transplante Heterólogo , Células Tumorais Cultivadas
15.
Oncol Res ; 5(6-7): 207-12, 1993.
Artigo em Inglês | MEDLINE | ID: mdl-8123940

RESUMO

The clinical study of compounds that modulate multidrug resistance has been hindered by both the toxicities of these agents and the inability to monitor their effectiveness at the level of the tumor cell. Previously, toremifene has been shown to be well tolerated clinically and to sensitize multidrug resistant cells to the effects of cytotoxic chemotherapeutic agents. The chemosensitizing properties of toremifene in estrogen receptor negative, multidrug resistant MDA-MB-A1 human breast cancer cells were studied using flow cytometric analysis and growth inhibition assays. Cell cycle kinetics of MDA-MB-A1 cells were not significantly affected by treatment with either toremifene, N-desmethyltoremifene, Toremifene IV or vinblastine alone, as the majority of cells remained in G0/G1. However, preincubation with toremifene or one of its metabolites for 72 hours followed by treatment for one hour with vinblastine caused a marked shift of cells to G2/M, as cells appeared to be blocked in that phase of the cell cycle. This result was nearly identical to the effect of vinblastine alone on vinblastine-sensitive MDA-MB-231 breast cancer cells and can be interpreted as a "resensitization" by toremifene of MDA-MB-A1 cells to vinblastine. This chemosensitizing effect of toremifene was accompanied by an enhanced inhibition of cell growth by vinblastine. The chemosensitizing effects of toremifene or one of its metabolites in combination with cytotoxic chemotherapy can be effectively monitored by flow cytometry, an easily accessible technique.


Assuntos
Neoplasias da Mama/patologia , Resistência a Medicamentos , Toremifeno/farmacologia , Vimblastina/farmacologia , Neoplasias da Mama/tratamento farmacológico , Ciclo Celular/efeitos dos fármacos , Divisão Celular/efeitos dos fármacos , Sinergismo Farmacológico , Feminino , Citometria de Fluxo , Humanos , Células Tumorais Cultivadas
17.
Breast Cancer Res Treat ; 24(1): 43-9, 1992.
Artigo em Inglês | MEDLINE | ID: mdl-1463871

RESUMO

The clinical study of compounds that modulate multidrug resistance in cancer cells has been hindered by both the toxicities of these agents and the inability to monitor their effectiveness at a cellular level. The non-steroidal triphenylethylene toremifene is well tolerated clinically and can sensitize multidrug resistant cells to the effects of doxorubicin in vitro. The chemosensitizing properties of toremifene in estrogen receptor negative, multidrug resistant MDA-A1 human breast cancer cells were studied using flow cytometric analysis. Cell cycle kinetics of MDA-A1 cells were not significantly affected by treatment with either toremifene or doxorubicin alone, as the majority of cells remained in G0/G1. However, preincubation with toremifene for 70 hours followed by treatment with doxorubicin caused a marked shift of cells to G2, as cells appeared to be blocked in that phase of the cell cycle. This result was nearly identical to the effect of doxorubicin alone on doxorubicin-sensitive MDA-MB-231 breast cancer cells and can be interpreted as a "resensitization" by toremifene of MDA-A1 cells to doxorubicin. This chemosensitizing effect of toremifene was accompanied by an enhanced accumulation of doxorubicin in MDA-A1 cells (+110% after 70 hours pre-incubation with toremifene), and by a depression in protein kinase C activity in MDA-A1 cells that was maximal following 70 hours incubation with toremifene. Flow cytometry is a widely available technique that might be applied clinically to monitor at the cellular level the chemosensitizing effects of toremifene and other modulators of multidrug resistance.


Assuntos
Neoplasias da Mama/patologia , Receptores de Estrogênio/análise , Toremifeno/farmacologia , Neoplasias da Mama/metabolismo , Ciclo Celular/efeitos dos fármacos , Doxorrubicina/farmacocinética , Resistência a Medicamentos , Citometria de Fluxo , Humanos , Proteína Quinase C/metabolismo , Células Tumorais Cultivadas/efeitos dos fármacos , Células Tumorais Cultivadas/metabolismo
18.
Eur J Cancer Clin Oncol ; 21(10): 1133-40, 1985 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-4076280

RESUMO

The subrenal capsule assay (SRCA) was used to study the sensitivity of breast cancer to cytostatic drug combinations. The results were compared with steroid receptor status. Forty-five of 46 SRCAs (98%) were macroscopically evaluable. However, a histological study implied that the transplants should also be evaluated histologically, because in only 14/21 (67%) of the control SRCAs examined were histologically viable tumor cells seen. An inflammatory cell reaction was noticed in half of the cases. In the groups treated with cytostatics only 3/21 (14%) had vital tumor cells, whereas inflammation was evident in 4/21 (19%) of the cases. The rate of resistance to A + CTX was 30%. By testing several drug combinations against each tumor the rate of chemoresistance was reduced to 10%. The differences between A + CTX and the best combination were statistically significant (P less than 0.05). Of the tumors 79% were ER-positive and 67% PR-positive. Receptor-negative tumors tended to be more sensitive to cytostatics than receptor-positive tumors (100 vs 85%). The difference was not, however, statistically significant. It can be concluded that the SRCA under standardized conditions is a good method for studying the response of individual breast cancers to chemotherapy.


Assuntos
Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Neoplasias da Mama/tratamento farmacológico , Receptores de Esteroides/metabolismo , Adulto , Idoso , Animais , Neoplasias da Mama/patologia , Ciclofosfamida/uso terapêutico , Doxorrubicina/uso terapêutico , Resistência a Medicamentos , Feminino , Humanos , Rim , Camundongos , Camundongos Endogâmicos , Pessoa de Meia-Idade , Transplante de Neoplasias , Receptores de Progesterona/metabolismo , Ensaio Tumoral de Célula-Tronco/métodos
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