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1.
Invest New Drugs ; 40(3): 565-575, 2022 06.
Artigo em Inglês | MEDLINE | ID: mdl-35312943

RESUMO

Glioblastoma multiforme (GBM) is a malignant CNS tumor with a poor prognosis. GBM shows aberrant glycosylation with hypersialylation. This property is a potential target for therapy. This study investigates the growth inhibitory efficacy of poly-guanidine (GuaDex), with an affinity for sialic acid (Sia). Glioma cell cultures and patient-derived glioma cell lines (PDGCLs) expressing Prominin-1 (CD133) were used. Human fibroblasts and astrocyte-derived cells were used as controls. Temozolomide (standard GBM drug, TMZ) and DMSO were used as a comparison. GuaDex at 1-10 µM concentrations, were incubated for 3.5-72 h and with PDGCLs cells for 6-24 h. The cytotoxicity was estimated with a fluorometric cytotoxicity assay (FMCA). Fluorescence-labelled GuaDex was used to study the cell interactions. Sia expression was confirmed with a fluorescence labelled Sia binding lectin. Expression of glial fibrillary acidic protein was determined. GuaDex induction of growth inhibition was fast, showing after less than 5 min incubation while the control cells were not affected even after 50 min incubation. The growth inhibitory effect on PDGCLs spheroids was persistent still showing after 4 weeks post-treatment. The growth inhibition of GuaDex was induced at low µM concentrations while TMZ induced only a slight inhibition at mM concentrations. GuaDex efficacy appears significant and warrants further studies.


Assuntos
Neoplasias Encefálicas , Glioblastoma , Glioma , Neoplasias Encefálicas/patologia , Técnicas de Cultura de Células , Linhagem Celular Tumoral , Resistencia a Medicamentos Antineoplásicos , Glioblastoma/tratamento farmacológico , Glioma/metabolismo , Guanidina/farmacologia , Guanidina/uso terapêutico , Humanos , Células-Tronco Neoplásicas , Temozolomida/farmacologia , Temozolomida/uso terapêutico
2.
Endocrine ; 62(2): 361-370, 2018 11.
Artigo em Inglês | MEDLINE | ID: mdl-30171518

RESUMO

PURPOSE: To review incidence, treatment and outcome of pediatric pituitary adenomas (PAs). METHODS: A follow-up study patients with the age of ≤19 years old who were treated from 1995 to 2015 in Mexico. RESULTS: Out of 1244 diagnosed PA, 43 patients were children (35 females, 8 males) with a mean age of 17.2 years. The majority were macroadenomas (70%) with prolactinomas (PRL) dominating (63%) followed by non-functioning adenomas (21%). In total, 40% were diagnosed as invasive. Growth hormone (GH) secreting adenomas, adrenocorticotropic hormone secreting and mixed GH-PRL secreting were rare. The treatment modalities were dopamine agonists and surgery. The average treatment time was 44 months with an average follow-up period of 104 months. Sixty-eight percent (27/40) of the patients had complete response after long time follow-up. Thirty-one percent did not respond to treatment whereof three patients died due to advanced disease and late intervention. The principal causes for treatment failure were treatment resistance, late intervention and poor patient compliance. CONCLUSIONS: Sixty eight percent had complete treatment response without any sign of disease, while ~31% did not respond to treatment or did not comply to follow up/treatment. Optimized early diagnose, treatment methods with early intervention, long time follow-up and with better measures for patient compliance should improve outcomes.


Assuntos
Adenoma , Neoplasias Hipofisárias , Adenoma/diagnóstico , Adenoma/epidemiologia , Adenoma/patologia , Adenoma/terapia , Adolescente , Idade de Início , Criança , Feminino , Seguimentos , Humanos , Masculino , México/epidemiologia , Neoplasias Hipofisárias/diagnóstico , Neoplasias Hipofisárias/epidemiologia , Neoplasias Hipofisárias/patologia , Neoplasias Hipofisárias/terapia , Prolactinoma/epidemiologia , Prolactinoma/patologia , Prolactinoma/terapia
3.
Anticancer Res ; 38(3): 1531-1537, 2018 03.
Artigo em Inglês | MEDLINE | ID: mdl-29491082

RESUMO

BACKGROUND/AIM: Prostate-specific membrane antigen (PSMA) is emerging as a target for treatment of castration-resistant prostate cancer (CRPC) while its up-regulated in the majority of CRPC tumors. The most common approach is targeted radionuclide therapy. MATERIALS AND METHODS: The PSMA binding pharmacophore Glu-Urea-Lysine (GUL) and lysine were conjugated to oxidized dextran with reductive amination and subsequently labelled with fluorosceinisothiocyanate (FITC). Three prostate cancer cell lines were used for binding studies, 22Rv1 (PSMA positive), DU145 (PSMA negative) and PC3 (PSMA negative). Binding images were obtained by fluorescence microscopy. RESULTS: PDC binding was recorded on the 22Rv1 cell line while the negative cell lines showed no or slight background binding. PDC binding could be inhibited by pre-incubation with a molar excess of unlabelled PDC. CONCLUSION: This is a novel template for PSMA targeted CRPC therapy, either using cytostatics or radionuclides.


Assuntos
Antígenos de Superfície/metabolismo , Glutamato Carboxipeptidase II/antagonistas & inibidores , Glutamato Carboxipeptidase II/metabolismo , Compostos Radiofarmacêuticos/metabolismo , Compostos Radiofarmacêuticos/farmacologia , Linhagem Celular Tumoral , Dextranos/química , Fluoresceína-5-Isotiocianato/química , Ácido Glutâmico/química , Humanos , Lisina/química , Masculino , Microscopia de Fluorescência , Terapia de Alvo Molecular/métodos , Neoplasias de Próstata Resistentes à Castração/tratamento farmacológico , Neoplasias de Próstata Resistentes à Castração/metabolismo , Neoplasias de Próstata Resistentes à Castração/patologia , Ligação Proteica/efeitos dos fármacos , Compostos Radiofarmacêuticos/síntese química , Ureia/química
4.
Anticancer Res ; 36(12): 6499-6504, 2016 12.
Artigo em Inglês | MEDLINE | ID: mdl-27919973

RESUMO

BACKGROUND: Osteodex (ODX) is a cytotoxic bone-targeting polybisphosphonate, intended for treatment of bone metastasis from castration-resistant prostate cancer (CRPC). The primary objective of this study was to describe the tolerability and toxicity of such treatment by defining its maximum tolerated dose (MTD) and dose-limiting toxicity (DLT). PATIENTS AND METHODS: Twenty-eight patients with castration-resistant prostate cancer and confirmed bone metastasis were assigned to seven infusions of ODX every third week, divided in seven ascending dose cohorts. RESULTS: No DLT's were observed and as pre-specified, the highest dose administered was defined as MTD. In total, 206 adverse events (AE) were recorded and 13,6% were classified as treatment-related, while none were serious or severe (SAE). No cumulative toxicity and no renal toxicity were recorded. CONCLUSION: ODX was well tolerated, with few and mild side-effects and with apparent treatment efficacy in the highest dose cohort. Further clinical development is currently in progress.


Assuntos
Antineoplásicos/uso terapêutico , Neoplasias Ósseas/secundário , Difosfonatos/uso terapêutico , Orquiectomia , Neoplasias da Próstata/patologia , Antineoplásicos/efeitos adversos , Neoplasias Ósseas/tratamento farmacológico , Difosfonatos/efeitos adversos , Humanos , Masculino
5.
Int J Oncol ; 47(3): 817-39, 2015 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-26134040

RESUMO

Women from ethnic minority groups, including immigrants and refugees are reported to have low breast cancer (BC) screening rates. Active, culturally-sensitive outreach is vital for increasing participation of these women in BC screening programs. Women at high BC risk and who belong to an ethnic minority group are of special concern. Such women could benefit from ongoing trials aimed at optimizing screening strategies for early BC detection among those at increased BC risk. Considering the marked disparities in BC survival in Europe and its enormous and dynamic ethnic diversity, these issues are extremely timely for Europe. We systematically reviewed the literature concerning European surveillance studies that had imaging in the protocol and that targeted women at high BC risk. The aim of the present review was thereby to assess the likelihood that women at high BC risk from minority ethnic groups were adequately included in these surveillance programs. Twenty-seven research groups in Europe reported on their imaging surveillance programs for women at increased BC risk. The benefit of strategies such as inclusion of magnetic resonance imaging and/or more intensive screening was clearly documented for the participating women at increased BC risk. However, none of the reports indicated that sufficient outreach was performed to ensure that women at increased BC risk from minority ethnic groups were adequately included in these surveillance programs. On the basis of this systematic review, we conclude that the specific screening needs of ethnic minority women at increased BC risk have not yet been met in Europe. Active, culturally-sensitive outreach is needed to identify minority women at increased BC risk and to facilitate their inclusion in on-going surveillance programs. It is anticipated that these efforts would be most effective if coordinated with the development of European-wide, population-based approaches to BC screening.


Assuntos
Neoplasias da Mama/diagnóstico , Neoplasias da Mama/etnologia , Detecção Precoce de Câncer/métodos , Diagnóstico por Imagem/métodos , Europa (Continente)/etnologia , Feminino , Equidade em Saúde , Humanos , Grupos Minoritários/estatística & dados numéricos
6.
Anticancer Res ; 34(10): 5537-42, 2014 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-25275052

RESUMO

AIM: A descriptive study was developed in an entire Argentine rural community considering breast cancer risk factors, preventive strategies and breast cancer incidence. PATIENTS AND METHODS: the study comprised of 83 women. A questionnaire of 34 items was employed; a mammogram and a breast ultrasound were performed. ANOVA and Pearson correlation were employed. RESULTS: Mean age was 54.5 years; 69% of women were postmenopausal; 96% had children; breastfeeding was X=10 months/child; Body Mass Index (BMI) was X=27.8 kg/m(2); 13% had first-degree relatives with breast cancer; 90% of women considered mammographic screening a necessary study. One woman had presented breast cancer. Argentine screening guidelines were not followed and an inverse relationship between education level and age of first mammogram was found (p<0.05). Mammographic and ultrasound studies did not reveal potential abnormalities. CONCLUSION: Peculiar social and cultural characteristics may be relevant to evaluate breast cancer risk factors in Argentina.


Assuntos
Neoplasias da Mama/epidemiologia , Neoplasias da Mama/prevenção & controle , População Rural , Argentina/epidemiologia , Detecção Precoce de Câncer , Feminino , Conhecimentos, Atitudes e Prática em Saúde , Humanos , Incidência , Mamografia , Programas de Rastreamento , Fatores de Risco
7.
Cancer Genomics Proteomics ; 11(1): 39-49, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-24633318

RESUMO

BACKGROUND: Osteodex is a novel bi-functional macromolecular polybisphosphonate developed for treatment of bone metastases in prostate and breast cancer. High efficacy of osteodex has been demonstrated both in vitro and in vivo. The present study investigates whether osteodex is also efficacious on soft tissue tumor lesions. MATERIALS AND METHODS: Twelve female nude mice were injected with MDA-MB-231 cells orthotopically. Osteodex was administered i.v. at 2.5 mg/kg, once per week for five weeks. Tumor volumes were measured during the treatment period, the animals were sacrificed, and samples collected for proteomic analysis. RESULTS: The non-treated mice developed multiple tumors greater than 4 cm with pronounced ulceration, while the treated mice had tumors smaller than 1 cm, without ulceration. While general condition of treated mice was good, non-treated animals were in poor condition. Sixteen out of 300 identified proteins were differentially expressed, with statistically significant expression changes of more than two-fold differences between treated and non-treated groups. These proteins were identified using non-gel based nano-liquid chromatography coupled with a Synapt G2 instrument. CONCLUSION: We conclude that osteodex showed significant treatment efficacy on soft tissue tumor implants. The study provides a global view of changes in protein expression profiles following osteodex treatment. Some functions of the identified proteins might be used to explain the specific treatment efficacy of osteodex.


Assuntos
Antineoplásicos/farmacologia , Neoplasias Ósseas/tratamento farmacológico , Neoplasias Ósseas/secundário , Neoplasias da Mama/tratamento farmacológico , Neoplasias da Mama/metabolismo , Difosfonatos/farmacologia , Animais , Neoplasias Ósseas/metabolismo , Neoplasias da Mama/patologia , Linhagem Celular Tumoral , Progressão da Doença , Feminino , Humanos , Camundongos , Camundongos Nus , Proteômica/métodos , Ensaios Antitumorais Modelo de Xenoenxerto
8.
Int J Biochem Cell Biol ; 45(7): 1399-409, 2013 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-23608519

RESUMO

Loss of skeletal muscle is a serious consequence of cancer as it leads to weakness and increased risk of death. To better understand the interplay between urothelial carcinoma and skeletal muscle wasting, cancer-induced catabolic profile and its relationship with muscle mitochondria dynamics were evaluated using a rat model of chemically induced urothelial carcinogenesis by the administration of N-butyl-N-(4-hydroxybutyl)-nitrosamine (BBN). The histologic signs of non-muscle-invasive bladder tumors observed in BBN animals were related to 17% loss of body weight and high serum levels of IL-1ß, TNF-α, TWEAK, C-reactive protein, myostatin and lactate and high urinary MMPs activities, suggesting a catabolic phenotype underlying urothelial carcinoma. The 12% loss of gastrocnemius mass was related to mitochondrial dysfunction, manifested by decreased activity of respiratory chain complexes due to, at least partially, the impairment of protein quality control (PQC) systems involving the mitochondrial proteases paraplegin and Lon. This was paralleled by the accumulation of oxidatively modified mitochondrial proteins. In overall, our data emphasize the relevance of studying the regulation of PQC systems in cancer cachexia aiming to identify therapeutic targets to counteract muscle wasting.


Assuntos
Mitocôndrias Musculares/metabolismo , Músculo Esquelético/patologia , Atrofia Muscular/metabolismo , Neoplasias da Bexiga Urinária/metabolismo , 1-Naftilamina/análogos & derivados , Animais , Proteínas Reguladoras de Apoptose/sangue , Ácidos Borônicos , Proteína C-Reativa/análise , Citocina TWEAK , Modelos Animais de Doenças , Interleucina-1beta/sangue , Ácido Láctico/sangue , Masculino , Proteínas de Membrana/sangue , Miostatina/sangue , Ratos , Ratos Wistar , Fator de Necrose Tumoral alfa/sangue , Fatores de Necrose Tumoral/sangue , Neoplasias da Bexiga Urinária/induzido quimicamente , Urotélio/metabolismo
9.
Int J Oncol ; 42(1): 109-17, 2013 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-23151842

RESUMO

The aim of this study was to investigate the role of 70 Gy salvage radiotherapy (SRT) combined with short-term neoadjuvant hormonal therapy (NHT) in the treatment of recurrent disease after radical prostatectomy (RP), and to consider quality of life (QoL), survival outcomes and impact of co-morbidities on treatment-related rectal-genitourinary toxicity. Electronic records of 184 SRT patients treated consecutively between October 2001 and February 2007 were analyzed. Median age was 64 years (median follow-up 48 months). NHT was given to 165 patients (median 3 months). Pre-RP and pre-SRT PSA, PSA doubling time, Gleason score (GS), seminal vesicle invasion (SVI) and detectable post-SRT PSA were recorded. Any detectable PSA or PSA >0.1 ng/ml + nadir was considered biochemical failure (BcF). The Charlson co-morbidity index was used to correlate co-morbidities and rectal-genitourinary toxicity. Scores from the health-related QoL EORTC QLQ-C30 and PR-25 questionnaires were also evaluated. In 116 (63%) patients, a long-lasting curative effect was indicated by undetectable PSA levels. In univariate analysis, using BcF as an outcome variable, p<0.001 was found for GS, pre-SRT PSA, SVI and detectable post-SRT PSA. Multivariate analysis showed p=0.01 for SVI, p=0.09 for GS, and detectable post-SRT PSA (p=0.01); with metastases as an outcome variable, only SVI was significant (p=0.007). Cancer-specific and overall survival were 99 and 95%, respectively. Although microscopy showed SVI or GS 8-10 in the prostatectomy specimens 17/40 (43%) and 13/29 (45%), respectively, of patients still showed undetectable PSA at long-term follow-up (median 55 months) after SRT. Likewise, 11/31 (36%) patients with pre-SRT PSA >1.0 ng/ml and 80/134 (60%) patients with PSA doubling time (PSADT) <10 still showed undetectable PSA after 50 months. Slightly elevated acute and late rectal-genitourinary grade 3-4 toxicity was observed. No association with co-morbidity/toxicity was found. EORTC QLQ-C30 scores were similar to or slightly better than reference values. SRT with 70 Gy combined with 3-month NHT results in long-term undetectable PSA in >50% of patients with recurrence after RP with acceptable rectal-genitourinary toxicity and without negatively affecting long-term QoL. Non-metastatic patients should not be disqualified from receiving SRT although presenting with poor prognostic factors at surgery.


Assuntos
Adenocarcinoma/terapia , Antineoplásicos Hormonais/uso terapêutico , Quimiorradioterapia , Recidiva Local de Neoplasia/terapia , Prostatectomia , Neoplasias da Próstata/terapia , Qualidade de Vida , Terapia de Salvação , Adenocarcinoma/mortalidade , Adenocarcinoma/secundário , Adulto , Idoso , Comorbidade , Seguimentos , Humanos , Masculino , Pessoa de Meia-Idade , Recidiva Local de Neoplasia/mortalidade , Recidiva Local de Neoplasia/patologia , Estadiamento de Neoplasias , Prognóstico , Neoplasias da Próstata/mortalidade , Neoplasias da Próstata/patologia , Dosagem Radioterapêutica , Taxa de Sobrevida
10.
Anticancer Res ; 31(12): 4141-5, 2011 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-22199272

RESUMO

AIM: To investigate the in vivo efficacy of a novel polybisphosphonate (ODX) in the treatment of bone metastasis from prostate cancer. MATERIAL AND METHODS: A rat prostatic carcinoma model was used. Forty-two rats (21 control, 21 treatment) had induction of bone lesions through injection of AT6.1 cells into the distal medullar cavity of long bones (right femur). At day 21 post injection, radiographs were taken and tumor score (severity of lesions, 0-4) and tumor incidence (score >0) were determined. Treatment started at day 23 and lasted until day 49 (four i.v. administrations of ODX during four weeks). RESULTS: ODX reduced the severity of the lesions compared to the control group. Forty-seven percent of the treated rats had regression of their lesions at the study end, including four rats showing disappearance of the lesions i.e. score 0. Osteocondensation at the growth plate was only observed in the treatment group, indicating osteoclast inhibition. CONCLUSION: In spite of a relatively short treatment period with only four administrations, ODX showed significant efficacy (p=0.0023), with inhibition of tumor progression and osteolysis. The results are encouraging, confirming previous in vitro studies. Clinical research is pending on patients with bone metastasis from castration-resistant prostate cancer.


Assuntos
Antineoplásicos/farmacologia , Neoplasias Ósseas/tratamento farmacológico , Neoplasias Ósseas/secundário , Difosfonatos/farmacologia , Neoplasias da Próstata/patologia , Animais , Progressão da Doença , Desenho de Fármacos , Fêmur/patologia , Masculino , Metástase Neoplásica , Transplante de Neoplasias , Osteólise , Neoplasias da Próstata/tratamento farmacológico , Ratos , Ratos Sprague-Dawley , Fatores de Tempo
11.
Rapid Commun Mass Spectrom ; 25(17): 2453-8, 2011 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-21818805

RESUMO

Data on the use of accelerator mass spectrometry (AMS) in conjunction with in vivo studies of macromolecular drugs are scarce. The present study shows the versatility of this technique when investigating the pharmacokinetics (PK) of a macromolecular drug candidate, a polybisphosphonate conjugate (ODX). The aforementioned is a polymer (molecular weight ~30 kDa) constituting a carbohydrate backbone with covalently linked ligands (aldendronate and aminoguanidine) and is intended for treatment of osteoporosis and the therapy of bone metastasis from prostate cancer. The conjugate is prepared through partial oxidation of the carbohydrate and sequential coupling of the ligands by reductive amination. (14)C was incorporated in the conjugate by means of coupling a commercially available (14)C-lysine in the conjugation sequence. Fifteen rats were injected intravenously with (14)C-labelled ODX (150 µg, 14 Bq/rat) and blood samples were collected at 1, 2, 4, 6, and 24 h post-injection (3 rats/time point). Liver, spleen and kidney samples were collected at 4 and 24 h post-injection. Blood from each time point (triplicate) were collected for AMS measurement determining the isotopic ratio ((14)C/(12)C) and consequently the drug concentration in blood. ODX showed a transient presence in blood circulation; 93% of the total dose was cleared from the circulation within 1 h. The half-life after 1 h was estimated to be about 3 h; 0.7% of the administered (14)C dose of ODX remained in circulation after 24 h. The major (14)C accumulation was in the liver, the spleen and the kidneys indicating the probable route of metabolism and excretion. This study demonstrates the versatility of AMS for pharmacological in vivo studies of macromolecules. Labelling with (14)C is relatively simple, inexpensive and the method requires minimal radioactivity, eliminating the need for radioprotection precautions in contrast to methods using scintillation counting.


Assuntos
Difosfonatos/farmacocinética , Avaliação Pré-Clínica de Medicamentos/métodos , Substâncias Macromoleculares/farmacocinética , Espectrometria de Massas/métodos , Polímeros/farmacocinética , Alendronato/química , Animais , Isótopos de Carbono/química , Difosfonatos/administração & dosagem , Difosfonatos/química , Guanidinas/química , Substâncias Macromoleculares/administração & dosagem , Substâncias Macromoleculares/química , Masculino , Polímeros/administração & dosagem , Polímeros/química , Ratos , Ratos Sprague-Dawley , Distribuição Tecidual
12.
BMC Microbiol ; 11: 84, 2011 Apr 26.
Artigo em Inglês | MEDLINE | ID: mdl-21521527

RESUMO

BACKGROUND: The entomopathogenic anamorphic fungus Beauveria bassiana is currently used as a biocontrol agent (BCA) of insects. Fifty-seven Beauveria bassiana isolates -53 from Spain- were characterized, integrating group I intron insertion patterns at the 3'-end of the nuclear large subunit ribosomal gene (LSU rDNA) and elongation factor 1-alpha (EF1-α) phylogenetic information, in order to assess the genetic structure and diversity of this Spanish collection of B. bassiana. RESULTS: Group I intron genotype analysis was based on the four highly conserved insertion sites of the LSU (Ec2653, Ec2449, Ec2066, Ec1921). Of the 16 possible combinations/genotypes, only four were detected, two of which were predominant, containing 44 and 9 members out of 57 isolates, respectively. Interestingly, the members of the latter two genotypes showed unique differences in their growth temperatures. In follow, EF1-α phylogeny served to classify most of the strains in the B. bassiana s.s. (sensu stricto) group and separate them into 5 molecular subgroups, all of which contained a group I intron belonging to the IC1 subtype at the Ec1921 position. A number of parameters such as thermal growth or origin (host, geographic location and climatic conditions) were also examined but in general no association could be found. CONCLUSION: Most Spanish B. bassiana isolates (77.2%) are grouped into a major phylogenetic subgroup with word-wide distribution. However, high phylogenetic diversity was also detected among Spanish isolates from close geographic zones with low climatic variation. In general, no correlation was observed between the molecular distribution and geographic origin or climatic characteristics where the Spanish B. bassiana isolates were sampled.


Assuntos
Beauveria/classificação , Beauveria/genética , Genes de RNAr , Insetos/microbiologia , Fator 1 de Elongação de Peptídeos/genética , Polimorfismo Genético , Animais , Beauveria/isolamento & purificação , Análise por Conglomerados , DNA Fúngico/química , DNA Fúngico/genética , Íntrons , Dados de Sequência Molecular , Filogenia , Análise de Sequência de DNA , Espanha
13.
Int J Oncol ; 37(3): 563-7, 2010 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-20664925

RESUMO

Advanced stage prostate and breast cancer frequently metastasize to the skeleton (approximately 75%). An additional complication in these patients, that further affects the bones, is that their hormonal treatment, induces osteoporosis. Bisphosphonates (bpns) are standard drugs against osteoporosis and have been shown to have clinically significant anti-tumor effects. This study describes the development of a new polybisphosphonate conjugate (ODX) with enhanced dual efficacy i.e. with anti-bone resorption and anti-tumor properties. Zoledronic acid (Zometa) was used as a positive control (at equimolar concentrations). Alendronic acid and aminoguanidine were conjugated to oxidized dextran with subsequent reductive amination (on average approximately 8 alendronate and approximately 50 guanidine moieties per conjugate). ODX was tested in a bone resorption assay for its capacity to inhibit bone resorbing osteoclasts (bone organ culture from neonatal mice, 45Ca labelled bone mineral). Tumor cell toxicity was studied on prostate (PC3) and breast cancer (MDA231, MDA453) cell cultures. Two methods were employed, a fluorescent cytotoxicity assay (FMCA) and an apoptosis assay (Annexin V assay). In the bone resorption assay, Zometa and ODX showed very similar potency with 50% osteoclast inhibition at approximately 20 nM and 100% at 0.2 microM. In the FMCA, IC50 for ODX was at approximately 2 microM and 25 microM for Zometa (PC3). In the apoptosis assay, ODX induced approximately 85-97% apoptosis at 10 microM in both cell lines, while Zometa failed to induce any significant apoptosis in any of the cell lines at the tested concentration range (10 nM-10 microM). ODX appears to be a promising drug candidate with high dual efficacy for the treatment of bone metastasis and osteoporosis. It has both potent osteoclast inhibiting properties and enhanced anti-tumor efficacy.


Assuntos
Neoplasias Ósseas/tratamento farmacológico , Neoplasias Ósseas/secundário , Difosfonatos/farmacologia , Osteoporose/tratamento farmacológico , Animais , Reabsorção Óssea/tratamento farmacológico , Neoplasias da Mama/tratamento farmacológico , Neoplasias da Mama/patologia , Difosfonatos/química , Difosfonatos/uso terapêutico , Feminino , Humanos , Masculino , Camundongos , Neoplasias da Próstata/tratamento farmacológico , Neoplasias da Próstata/patologia
14.
Oncol Rep ; 22(6): 1451-8, 2009 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-19885599

RESUMO

The mechanisms underlying prostate cancer progression are poorly understood. Proteins responsive to androgens may be involved in the development and progression of prostate cancer and the ultimate failure of androgen-ablation therapy. Therapy with somatostatin (sms) analogues could be a possible therapeutic alternative to chemotherapy in hormone refractory prostate cancer patients. We used two prostate cancer cell-lines, LNCaP (androgen-dependent) and DU145 (androgen-independent), to compare the protein expressions. Both cell lines were treated with sms and its derivative smsdx. Smsdx is a glycosylated poly sms with high stability suitable for clinical use. A comparison study of protein expression was analyzed by means of two-dimensional gel electrophoresis (2DE) followed by mass spectrometric analysis. Marked quantitative differences were observed in the protein expression profiles in sms/smsdx treated LNCaP and DU145 cells compared to the control cells. One third of the detected proteins were differentially expressed (PRDXs, hnRNPs, HSPs, RKIP). Concordance in protein expression patterns was observed between smsdx and sms treated cells with strong agreement between the up- and down-regulation of proteins. Fifty-eight (isoforms of 49 proteins) protein spots were identified and found differentially expressed at 2-fold change between LNCaP and DU145 cells. Thirty-one proteins in LNCaP have higher expressions than in DU145. Twenty-seven proteins in DU145 have higher expressions than in LNCaP. Most of the differentially expressed proteins (2-fold) between LNCaP and DU145 cells were affected by sms/smsdx treatment (1.2- to 2.6-fold change). Sms/smsdx affects the mitochondria of prostate cancer cells in a way that eventually triggers mitochondrial-mediated apoptosis. Regulation of certain proteins (e.g., RKIP, VDACs) by sms/smsdx suggests that sms/smsdx exerts its effects on prostate cancer cells via MAPK pathway and by regulating the activities of phosphotyrosine phosphatases.


Assuntos
Regulação Neoplásica da Expressão Gênica , Neoplasias da Próstata/tratamento farmacológico , Neoplasias da Próstata/metabolismo , Somatostatina/farmacologia , Biomarcadores Tumorais , Linhagem Celular Tumoral , Relação Dose-Resposta a Droga , Perfilação da Expressão Gênica , Regulação Enzimológica da Expressão Gênica , Humanos , Sistema de Sinalização das MAP Quinases , Masculino , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Transdução de Sinais , Fatores de Tempo
15.
Int J Oncol ; 35(2): 281-5, 2009 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-19578741

RESUMO

Guanidine compounds have important biochemical properties. Aminoguanidine, as an example, is an anti-oxidant, a nitric oxide synthase inhibitor (NOS) which prevents nitric oxide formation, and an inhibitor of advanced glycosylation end products (AGEs). As an anti-oxidant, aminoguanidine may affect the formation of atherosclerotic lesions through protection from LDL oxidation. Inhibition of AGEs could have a preventive effect on the tissue damage caused by diabetes where AGEs are considered to be an important factor. The role of NO in cancer is complex and not fully understood, but it may have influence on growth and progression. In this study, the tumor growth inhibitory effect of conjugated guanidine (i.e. a polyguanidine) was investigated. The effect on tumor cell growth was studied in cultures of prostate, breast, bladder and renal cell cancer, and a fluorometric cytotoxicity assay was performed. Guanidine conjugates were prepared by reacting aminoguanidine or agmatine with periodate oxidized dextran followed by reductive amination. The cytotoxic effect was compared with an anthracycline (adriamycin). The dextran-guanidine conjugates were cytotoxic at low micromolar concentrations, and the dextran-aminoguanidine conjugate (GDC) had the highest efficacy, being more efficient than adriamycin, in all of the tested tumor cell lines. Breast and prostate cancer cells were the most sensitive. At 0.5 microM, GDC killed >95% of the breast cancer cells compared to 25% for Adriamycine. In prostate cancer cells, GDC killed approximately 55% of the cells at 0.1 microM and 100% of the cells at 0.5 microM compared to approximately 22 and approximately 62%, respectively, for adriamycin. Unconjugated aminoguanidine and agmatine did not seem to affect tumor cell growth even at high concentrations (mM). Polymer- conjugated guanidine is a potentially useful template for the construction of therapeutic tumor targeting cytotoxic agents.


Assuntos
Antineoplásicos/farmacologia , Dextranos/farmacologia , Guanidina/farmacologia , Linhagem Celular Tumoral , Humanos , Poliaminas/farmacologia
16.
Oncol Rep ; 20(1): 151-4, 2008 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-18575731

RESUMO

Somatostatin (SMS), binds to its specific receptors (SSTRs) and transduces growth inhibitory, anti-secretory and apoptotic signals. Several human cancers express SSTRs, including prostate cancer, and therefore SMS is of interest for anti-cancer therapy. DNA methylation and histone modifications are involved in normal cell development, gene imprinting and human carcinogenesis. Reversing DNA methylation is an attractive therapeutic possibility, since epigenetic modifications change gene expression without changing the gene function. DNA methylation inhibitors such as 5-aza-2'-deoxycytidine (5'-aza, decitabine) have been used to treat several types of haematological malignancies. Histone deacetylase inhibitors such as trichostatin (TSA), are a new class of 'targeted anti-cancer agents'. TSA and decitabine can induce growth arrest, apoptosis or terminal differentiation in a variety of solid and haematological cancers in advanced disease patients. In the present study, the LNCaP cell line (prostate cancer) was incubated with SMS or Somadex (an SMS polymer conjugate) for three days, 1 nM per day, and the untreated cells were the negative control. For DNA demethylation, cells were grown in the presence of 2.5 microM 5-aza for 120 h, and re-fed with 5-aza-containing fresh medium at day 3. The total incubation time with 5-aza was 120 h. TSA at 1.0 microM was added into the cultured cells for 24 h. The combined treatment of 5-aza and TSA was performed by incubating the cells with 5-aza for 120 h followed by a 24-h exposure to TSA. Using cDNA obtained from these cell lines, the difference in the expression level of SSTR mRNA transcripts before and after 5-aza and TSA treatments was analyzed by RT-PCR. An increased induction of mRNA expression of the five SSTR subtypes was observed in the LNCaP cells when incubated with SMS/Somadex (dose-dependent). The inhibition of DNA methylation and histone acetylation resulted in the up-regulation of SSTR5 mRNA expression. The results demonstrate a positive feedback loop between SMS and its receptors. This regulation pathway may enhance the anti-tumor activity of somatostatin. To benefit from this effect in a clinical setting, the dose, dose frequency and pan affinity of the SMS derivative are important factors. The epigenetic manipulation with DNA methylation or histone deacetylase inhibitors, combined with SMS, may offer a novel alternative for the treatment of advanced prostate cancer.


Assuntos
Azacitidina/análogos & derivados , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Ácidos Hidroxâmicos/farmacologia , Neoplasias da Próstata/tratamento farmacológico , Receptores de Somatostatina/genética , Somatostatina/farmacologia , Azacitidina/farmacologia , Linhagem Celular Tumoral , Metilação de DNA , Decitabina , Inibidores de Histona Desacetilases , Humanos , Masculino , Neoplasias da Próstata/metabolismo , Neoplasias da Próstata/patologia , RNA Mensageiro/análise , Regulação para Cima
17.
Int J Oncol ; 30(5): 1173-9, 2007 May.
Artigo em Inglês | MEDLINE | ID: mdl-17390019

RESUMO

Some clinical results indicate that somatostatin (sms) might be useful in the treatment of advanced prostate cancer (HRPC). Because of its transient in vivo half-life only more stable derivatives of sms are of interest in this context. Recent studies have shown that natural sms can be conjugated to a carbohydrate (smsdx) with preservation of sms-like effects on the prostatic tumor cell proteome. The present study identifies some of the affected proteins in an effort to elucidate pathways and proteins that might be of importance for the potential usefulness of sms treatment in HRPC. After incubating the LNCaP cell-line with sms14/smsdx, comparative proteomics was used for analysing and identifying affected proteins. Protein expression patterns were analysed with two-dimensional polyacrylamide gel electrophoresis and mass spectrometry. Catalytic mitochondrial and mitochondrial-associated proteins were significantly affected (fold change approximately 2 or higher) and they were in general up-regulated. Apoptosis-related proteins were both up-regulated (VDAC1, VDAC2) and down-regulated (PRDX2, TCTP). The fold change was >2 for PRDX2 and <2 for the others. There was a strong agreement between sms and smsdx on the up- and down-regulation of proteins. Sms/smsdx triggered up-regulation of catalytic mitochondrial proteins and seemed to affect apoptosis-related proteins. This could indicate important pathways on which smsdx might be able to curb the progression of HRPC. The results encourage a pending clinical phase II study.


Assuntos
Regulação Neoplásica da Expressão Gênica , Neoplasias da Próstata/tratamento farmacológico , Proteoma , Proteômica/métodos , Somatostatina/farmacologia , Catálise , Linhagem Celular Tumoral , Progressão da Doença , Eletroforese em Gel Bidimensional , Humanos , Masculino , Mitocôndrias/metabolismo , Proteínas de Neoplasias/química , Espectrometria de Massas por Ionização e Dessorção a Laser Assistida por Matriz , Proteína Tumoral 1 Controlada por Tradução
18.
Anticancer Res ; 27(6C): 4325-38, 2007.
Artigo em Inglês | MEDLINE | ID: mdl-18214040

RESUMO

BACKGROUND: Initial U.S.A. breast cancer screening rates have risen, but not repeat screening, especially among low-income minority populations. Latinas are particularly at-risk of underscreening. Consequently, late-detection is common, with increased risk of dying after diagnosis. Why women with low-income, particularly Latinas, who had initial mammography, were not regularly screened was examined. PATIENTS AND METHODS: An expanded model was tested, incorporating the Theory of Planned Behavior (TPB), cultural factors, potential facilitators and barriers. Participants were 112 women, 72 of whom were Latinas, who had contacted an Early-Detection Program and received a mammogram 3-4 years earlier. RESULTS: The TPB did not explain mammography rescreening behavior among Latinas. The cultural factors: high familism and low fatalism showed significant multivariate associations with recent mammogram among Latinas. A major barrier for Latinas was "distorted familism": neglecting own health because family was first priority. CONCLUSION: A cultural model is proposed, which can guide interventions for improving on-time mammography among Latinas.


Assuntos
Neoplasias da Mama/prevenção & controle , Hispânico ou Latino/etnologia , Mamografia/estatística & dados numéricos , Programas de Rastreamento/estatística & dados numéricos , Pobreza/etnologia , Cultura , Feminino , Conhecimentos, Atitudes e Prática em Saúde , Hispânico ou Latino/psicologia , Hispânico ou Latino/estatística & dados numéricos , Humanos , Mamografia/psicologia , Programas de Rastreamento/psicologia , Pobreza/psicologia , Pobreza/estatística & dados numéricos , Psicologia , Fatores Socioeconômicos , Tempo
19.
BMC Microbiol ; 6: 77, 2006 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-16978412

RESUMO

BACKGROUND: The entomopathogenic anamorphic fungus Metarhizum anisopliae is currently used as a biocontrol agent (BCA) of insects. In the present work, we analyzed the sequence data obtained from group I introns in the large subunit (LSU) of rDNA genes with a view to determining the genetic diversity present in an autochthonous collection of twenty-six M. anisopliae isolates selected as BCAs. RESULTS: DNA fragments corresponding to the 3'-end of the nuclear LSU rDNA genes of 26 M. anisopliae isolates were amplified by PCR. The amplicon sizes ranged from 0.8 to 3.4-kb. Four intron insertion sites, according to Escherichia coli J01695 numbering, were detected--Ec1921, Ec2066, Ec2449 and Ec2563--after sequencing and analysis of the PCR products. The presence/absence of introns allowed the 26 isolates to be distributed into seven genotypes. Nine of the isolates tested showed no introns, 4 had only one, 3 two, and 10 displayed three introns. The most frequent insertion sites were Ec1921 and Ec2449. Of the 26 isolates, 11 showed insertions at Ec2563 and a 1754-bp sequence was observed in ten of them. The most-parsimonious (MP) tree obtained from parsimony analysis of the introns revealed a main set containing four-groups that corresponded to the four insertion sites. CONCLUSION: Four insertion sites of group I introns in the LSU rDNA genes allowed the establishment of seven genotypes among the twenty-six biocontrol isolates of M. anisopliae. Intron insertions at the Ec2563 site were observed for first time in this species.


Assuntos
DNA Fúngico/genética , DNA Ribossômico/genética , Hypocreales/genética , Íntrons , Polimorfismo Genético , Regiões 3' não Traduzidas , Sequência de Bases , Primers do DNA , Genes Fúngicos , Reação em Cadeia da Polimerase
20.
Anticancer Res ; 24(3a): 1347-51, 2004.
Artigo em Inglês | MEDLINE | ID: mdl-15274294

RESUMO

BACKGROUND: Many previous studies show that cell surface sialylation of malignant cells is enhanced compared to normal tissue. The carboxyl group of the sialic acid yields, a negative surface charge of the tumor cells. This study investigates how tumor cell growth is affected when a cationic polymer is incubated with six different tumor cell lines. MATERIALS AND METHODS: Cationic dextran (CatDex) was prepared by periodate oxidation and subsequent coupling of cationic sidegroups by reductive amination. A fluorimetric cytotoxicity assay (FMCA) was used for the cell survival assay. Six different tumor cell lines (lung, breast, ovarian, prostate, colon, urinary bladder) were seeded into 96-well microtiter plates. CatDex was added at different microM concentrations and incubated for 72 h. Additionally, CatDex was fluorescence-labeled (FITC) and the interaction with the tumor cells was studied using fluorescence microscopy. The presence of sialic acid in the different cell lines was confirmed by using a FITC-labeled sialic acid binding lectin. RESULTS: CatDex showed a concentration-dependent growth inhibitory effect (i.e. the number of cationic side groups/dextran molecule and the molarity used). If the substitution was <20%, the growth inhibitory effect was small and difficult to reproduce. With 20-22% substitution, the growth inhibition varied between 20-95% depending on the molarity and the tumor type. Higher substitution resulted in complete cell death in all the cell lines. The fluorescent images showed intensive cell membrane interaction. CONCLUSION: Incubation with cationic dextran caused cell death in all six tumor cell lines. Our hypothesis is that CatDex binds to the anionic sialic acid residues and causes fatal disturbances in the cell membrane. However the exact mechanism remains to be elucidated. The results may indicate a new method of general interest for intra/local/regiolocal treatment of cancer. Clinical studies to explore this concept are pending.


Assuntos
Dextranos/farmacologia , Neoplasias/patologia , Cátions , Divisão Celular/efeitos dos fármacos , Linhagem Celular Tumoral , Relação Dose-Resposta a Droga , Feminino , Humanos , Masculino , Microscopia de Fluorescência , Ácido N-Acetilneuramínico/metabolismo , Neoplasias/tratamento farmacológico , Neoplasias/metabolismo
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