RESUMO
The gut microbiota is altered in epilepsy and is emerging as a potential target for new therapies. We studied the effects of rifaximin, a gastrointestinal tract-specific antibiotic, on seizures and neuropathology and on alterations in the gut and its microbiota in a mouse model of temporal lobe epilepsy (TLE). Epilepsy was induced by intra-amygdala kainate injection causing status epilepticus (SE) in C57Bl6 adult male mice. Sham mice were injected with vehicle. Two cohorts of SE mice were fed a rifaximin-supplemented diet for 21 days, starting either at 24 h post-SE (early disease stage) or at day 51 post-SE (chronic disease stage). Corresponding groups of SE mice (one each disease stage) were fed a standard (control) diet. Cortical ECoG recording was done at each disease stage (24/7) for 21 days in all SE mice to measure the number and duration of spontaneous seizures during either rifaximin treatment or control diet. Then, epileptic mice ± rifaximin and respective sham mice were sacrificed and brain, gut and feces collected. Biospecimens were used for: (i) quantitative histological analysis of the gut structural and cellular components; (ii) markers of gut inflammation and intestinal barrier integrity by RTqPCR; (iii) 16S rRNA metagenomics analysis in feces. Hippocampal neuronal cell loss was assessed in epileptic mice killed in the early disease phase. Rifaximin administered for 21 days post-SE (early disease stage) reduced seizure duration (p < 0.01) and prevented hilar mossy cells loss in the hippocampus compared to epileptic mice fed a control diet. Epileptic mice fed a control diet showed a reduction of both villus height and villus height/crypt depth ratio (p < 0.01) and a decreased number of goblet cells (p < 0.01) in the duodenum, as well as increased macrophage (Iba1)-immunostaining in the jejunum (p < 0.05), compared to respective sham mice. Rifaximin's effect on seizures was associated with a reversal of gut structural and cellular changes, except for goblet cells which remained reduced. Seizure duration in epileptic mice was negatively correlated with the number of mossy cells (p < 0.01) and with villus height/crypt depth ratio (p < 0.05). Rifaximin-treated epileptic mice also showed increased tight junctions (occludin and ZO-1, p < 0.01) and decreased TNF mRNA expression (p < 0.01) in the duodenum compared to epileptic mice fed a control diet. Rifaximin administered for 21 days in chronic epileptic mice (chronic disease stage) did not change the number or duration of seizures compared to epileptic mice fed a control diet. Chronic epileptic mice fed a control diet showed an increased crypt depth (p < 0.05) and reduced villus height/crypt depth ratio (p < 0.01) compared to respective sham mice. Rifaximin treatment did not affect these intestinal changes. At both disease stages, rifaximin modified α- and ß-diversity in epileptic and sham mice compared to respective mice fed a control diet. The microbiota composition in epileptic mice, as well as the effects of rifaximin at the phylum, family and genus levels, depended on the stage of the disease. During the early disease phase, the abundance of specific taxa was positively correlated with seizure duration in epileptic mice. In conclusion, gut-related alterations reflecting a dysfunctional state, occur during epilepsy development in a TLE mouse model. A short-term treatment with rifaximin during the early phase of the disease, reduced seizure duration and neuropathology, and reversed some intestinal changes, strengthening the therapeutic effects of gut-based therapies in epilepsy.
Assuntos
Modelos Animais de Doenças , Epilepsia do Lobo Temporal , Microbioma Gastrointestinal , Camundongos Endogâmicos C57BL , Rifaximina , Convulsões , Animais , Rifaximina/uso terapêutico , Rifaximina/farmacologia , Camundongos , Masculino , Microbioma Gastrointestinal/efeitos dos fármacos , Convulsões/tratamento farmacológico , Epilepsia do Lobo Temporal/tratamento farmacológico , Estado Epiléptico/tratamento farmacológico , Encéfalo/efeitos dos fármacos , Encéfalo/metabolismo , Hipocampo/efeitos dos fármacos , Hipocampo/metabolismo , Hipocampo/patologia , Epilepsia/tratamento farmacológicoRESUMO
Pelvic radiation disease (PRD), a frequent side effect in patients with abdominal/pelvic cancers treated with radiotherapy, remains an unmet medical need. Currently available preclinical models have limited applications for the investigation of PRD pathogenesis and possible therapeutic strategies. In order to select the most effective irradiation protocol for PRD induction in mice, we evaluated the efficacy of three different locally and fractionated X-ray exposures. Using the selected protocol (10 Gy/day × 4 days), we assessed PRD through tissue (number and length of colon crypts) and molecular (expression of genes involved in oxidative stress, cell damage, inflammation, and stem cell markers) analyses at short (3 h or 3 days after X-ray) and long (38 days after X-rays) post-irradiation times. The results show that a primary damage response in term of apoptosis, inflammation, and surrogate markers of oxidative stress was found, thus determining a consequent impairment of cell crypts differentiation and proliferation as well as a local inflammation and a bacterial translocation to mesenteric lymph nodes after several weeks post-irradiation. Changes were also found in microbiota composition, particularly in the relative abundance of dominant phyla, related families, and in alpha diversity indices, as an indication of dysbiotic conditions induced by irradiation. Fecal markers of intestinal inflammation, measured during the experimental timeline, identified lactoferrin, along with elastase, as useful non-invasive tools to monitor disease progression. Thus, our preclinical model may be useful to develop new therapeutic strategies for PRD treatment.
Assuntos
Lesões por Radiação , Camundongos , Animais , Raios X , Modelos Animais de Doenças , Apoptose/efeitos da radiação , InflamaçãoRESUMO
Oxidized form of avidin, named AvidinOX, provides stable fixation of biotinylated molecules in tissues thus representing a breakthrough in topical treatment of cancer. AvidinOX proved to be a stable receptor for radiolabeled biotin, biotinylated antibodies and cells. In order to expand applicability of the AvidinOX-based delivery platform, in the present study we investigated the possibility to hold biotinylated chemotherapeutics in AvidinOX-treated sites. A novel biotinylated gimatecan-derived camptothecin, coded ST8161AA1, was injected at suboptimal doses into human tumors xenografted in mice alone or pre-complexed to AvidinOX. Significantly higher growth inhibition was observed when the drug was anchored to AvidinOX suggesting the potential utility of this delivery modality for the local treatment of inoperable tumors.
Assuntos
Antineoplásicos/uso terapêutico , Biotina/análogos & derivados , Biotina/uso terapêutico , Camptotecina/análogos & derivados , Carcinoma/tratamento farmacológico , Neoplasias Ovarianas/tratamento farmacológico , Animais , Antineoplásicos/síntese química , Antineoplásicos/metabolismo , Avidina/metabolismo , Biotina/síntese química , Biotina/metabolismo , Camptotecina/síntese química , Camptotecina/metabolismo , Camptotecina/uso terapêutico , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Feminino , Humanos , Camundongos , Ligação ProteicaRESUMO
Despite the marked improvements in the treatment of lymphomas, there is still a need for new therapeutic agents. Synthetic retinoids represent a class of compounds with anti-cancer activity. Here, we report the preclinical activity of a new member of this class, the ST1926-derivative ST5589, in lymphomas. ST5589 presented a dose-dependent anti-proliferative activity in almost all of the 25 lymphoma cell lines analysed, with a median 50% inhibitory concentration of 433 nM. Apoptosis was observed in 8/11 cell lines. ST5589 induced changes in the gene expression profiles of the cell lines, including the down-regulation of Aurora Kinase A (AURKA). Specific gene expression signatures were associated with a higher sensitivity to the compound and combination of ST5589 with carfilzomib revealed the importance of proteasome activity in mediating the anti-tumour activity of ST5589. In conclusion, we have identified a new mechanism of action of atypical retinoids as anti-cancer compounds, and the encouraging results obtained with the new ST1926-derivative ST5589 provide the basis for further developments of the compound.
Assuntos
Aurora Quinase A/biossíntese , Regulação para Baixo/efeitos dos fármacos , Regulação Enzimológica da Expressão Gênica/efeitos dos fármacos , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Linfoma/tratamento farmacológico , Proteínas de Neoplasias/biossíntese , Retinoides/farmacologia , Apoptose/efeitos dos fármacos , Linhagem Celular Tumoral , Ensaios de Seleção de Medicamentos Antitumorais , Humanos , Linfoma/enzimologia , Linfoma/patologiaRESUMO
A series of alternative Zn-binding groups were explored in the design of phenyl-4-yl-acrylohydroxamic acid derivatives as histone deacetylase (HDAC) inhibitors. Most of the synthesized compounds were less effective than the parent hydroxamic acid. However, the profile of activity shown by the analog bearing a hydroxyurea head group, makes this derivative promising for further investigation.
Assuntos
Histona Desacetilase 2/antagonistas & inibidores , Inibidores de Histona Desacetilases/farmacologia , Ácidos Hidroxâmicos/farmacologia , Compostos Organometálicos/farmacologia , Zinco/farmacologia , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Relação Dose-Resposta a Droga , Histona Desacetilase 2/metabolismo , Inibidores de Histona Desacetilases/síntese química , Inibidores de Histona Desacetilases/química , Humanos , Ácidos Hidroxâmicos/química , Modelos Moleculares , Estrutura Molecular , Compostos Organometálicos/síntese química , Compostos Organometálicos/química , Relação Estrutura-Atividade , Zinco/químicaRESUMO
A series of SAHA-like molecules were prepared introducing different lactam-carboxyamides in position 7 of the suberoylanilide skeleton. The activity against different HDAC isoforms was tested and the data compared with the corresponding linear products, without substituent in position 7. In general, this modification provided an effective reinforcement of in vitro activity. While the lactam size or the CO/NH group orientation did not strongly influence the inhibition, the contemporary modification of the suberoylamide fragment gave vary active variants in the lactam series, with compound 28 (ST8078AA1) that showed IC50 values between 2 and 10nM against all Class I HDAC isoforms, demonstrating it to be a large spectrum pan-inhibitor. This strong affinity with HDAC was also confirmed by the value of IC50=0.5µM against H460 cells, ranking 28 as one of the most potent HDAC inhibitors described so far.
Assuntos
Inibidores de Histona Desacetilases/farmacologia , Histona Desacetilases/metabolismo , Ácidos Hidroxâmicos/farmacologia , Lactamas/química , Linhagem Celular Tumoral , Relação Dose-Resposta a Droga , Inibidores de Histona Desacetilases/síntese química , Inibidores de Histona Desacetilases/química , Humanos , Ácidos Hidroxâmicos/síntese química , Ácidos Hidroxâmicos/química , Estrutura Molecular , Relação Estrutura-AtividadeRESUMO
Poly(ADP-ribose)polymerase-I (PARP-1) enzyme is involved in maintaining DNA integrity and programmed cell death. A virtual screening of commercial libraries led to the identification of five novel scaffolds with inhibitory profile in the low nanomolar range. A hit-to-lead optimization led to the identification of a group of new potent PARP-1 inhibitors, acyl-piperazinylamides of 3-(4-oxo-3,4-dihydro-quinazolin-2-yl)-propionic acid. Molecular modeling studies highlighted the preponderant role of the propanoyl side chain.
Assuntos
Antineoplásicos/química , Inibidores de Poli(ADP-Ribose) Polimerases , Quinazolinonas/química , Animais , Antineoplásicos/farmacologia , Linhagem Celular Tumoral , Inibidores Enzimáticos/química , Inibidores Enzimáticos/farmacologia , Feminino , Humanos , Camundongos , Camundongos SCID , Poli(ADP-Ribose) Polimerase-1 , Poli(ADP-Ribose) Polimerases/metabolismo , Quinazolinonas/farmacologia , Relação Estrutura-Atividade , Ensaios Antitumorais Modelo de Xenoenxerto/métodosRESUMO
7-Azaindole-1-carboxamides were designed as a new class of PARP-1 inhibitors. The compounds displayed a variable pattern of target inhibition profile that, in part, paralleled the antiproliferative activity in cell lines characterized by homologous recombination defects. A selected compound (1l; ST7710AA1) showed significant in vitro target inhibition and capability to substantially bypass the multidrug resistance mediated by Pgp. In antitumor activity studies against the MX1 human breast carcinoma growth in nude mice, the compound exhibited an effect similar to that of Olaparib in terms of tumor volume inhibition when used at a lower dose than the reference compound. Treatment was well tolerated, as no deaths or significant weight losses were observed among the treated animals.
Assuntos
Antineoplásicos/farmacologia , Resistencia a Medicamentos Antineoplásicos/efeitos dos fármacos , Inibidores Enzimáticos/química , Inibidores Enzimáticos/farmacologia , Inibidores de Poli(ADP-Ribose) Polimerases , Membro 1 da Subfamília B de Cassetes de Ligação de ATP/genética , Animais , Antineoplásicos/síntese química , Antineoplásicos/química , Proteína BRCA1/genética , Proteína BRCA2/genética , Neoplasias da Mama/tratamento farmacológico , Neoplasias da Mama/genética , Resistência a Múltiplos Medicamentos/efeitos dos fármacos , Inibidores Enzimáticos/síntese química , Feminino , Células HeLa/efeitos dos fármacos , Recombinação Homóloga , Humanos , Indóis/química , Camundongos , Camundongos Nus , Modelos Moleculares , Poli(ADP-Ribose) Polimerase-1 , Células Tumorais Cultivadas , Ensaios Antitumorais Modelo de XenoenxertoRESUMO
Crohn's and ulcerative colitis are common conditions associated with inflammatory bowel disease as well as intestinal flora and epithelial barrier dysfunction. A novel fermented Lactobacillus brevis (AL0035) herein assayed in a trinitro benzene sulfonic acid (TNBS)-induced colitis mice model after oral administration significantly counteracted the body weight loss and improves the disease activity index and histological injury scores. AL0035 significantly decreased the mRNA and protein expression of different pro-inflammatory cytokines (TNFalpha, IL-1beta, IL-6, IL-12, IFN-gamma) and enhanced the expression of IL-10. In addition, the probiotic promoted the expression of tight junction proteins, such as ZO-1, keeping the intestinal mucosal barrier function to attenuate colitis symptoms in mice. Markers of inflammation cascade such as myeloperoxidase (MPO) and PPAR-gamma measured in the colon were also modified by AL0035 treatment. AL0035 was also able to reduce different lymphocyte markers' infiltration in the colon (GATA-3, T-Bet, NK1.1) and monocyte chemoattractant protein-1 (MCP-1/CCL2), a key chemokine involved in the migration and infiltration of monocytes/macrophages in the immunological surveillance of tissues and inflammation. In colonic microbiota profile analysis through 16S rRNA sequencing, AL0035 increased the microbial diversity depleted by TNBS administration and the relative abundance of the Lactobacillaceae and Lachnospiraceae families, whereas it decreased the abundance of Proteobacteria. Altogether, these data indicated that AL0035 could lower the severity of colitis induced by TNBS by regulating inflammatory cytokines, increasing the expression of tight junction proteins and modulating intestinal microbiota, thus preventing tissue damage induced by colitis.
Assuntos
Colite , Microbioma Gastrointestinal , Levilactobacillus brevis , Humanos , Animais , Camundongos , Verduras , RNA Ribossômico 16S , Colite/induzido quimicamente , Inflamação , Citocinas , Proteínas de Junções Íntimas/genéticaRESUMO
Background: Chronic intestinal pseudo-obstruction (CIPO) is a type of intestinal dysfunction with symptoms of intestinal blockage but without the actual mechanical obstruction. Currently, there are no drugs available to treat this disease. Herein, we report the characterization of the PrP-SCA7-92Q transgenic (Tg) line as a valuable CIPO mouse model and investigated the tolerability and efficacy of the 5-hydroxytryptamine type-4 receptor (5HT4R) agonist velusetrag as a promising pharmacological treatment for CIPO. Methods: To test the pharmacodynamics of velusetrag, 8-week-old SCA7 Tg mice, which express human mutated Ataxin-7 gene containing 92 CAG repeats under the mouse prion protein promoter, were treated for 5 weeks by oral route with velusetrag at 1 and 3 mg/kg doses or vehicle. Body weight was monitored throughout the treatment. After sacrifice, the small intestine and proximal colon were collected for whole-mount immunostaining. Untreated, age-matched, C57BL/6J mice were also used as controls in comparison with the other experimental groups. Results: Analysis of SCA7 Tg mice showed tissue damage and alterations, mucosal abnormalities, and ulcers in the distal small intestine and proximal colon. Morphological changes were associated with significant neuronal loss, as shown by decreased staining of pan-neuronal markers, and with accumulation of ataxin-7-positive inclusions in cholinergic neurons. Administration of velusetrag reversed intestinal abnormalities, by normalizing tissue damage and re-establishing the normal level of glia/neuron's count in both the small and large intestines. Conclusion: We demonstrated that the PrP-SCA7-92Q Tg line, a model originally developed to mimic spinocerebellar ataxia, is suitable to study CIPO pathology and can be useful in establishing new therapeutic strategies, such as in the case of velusetrag. Our results suggest that velusetrag is a promising compound to treat patients affected by CIPO or intestinal dysmotility disease.
RESUMO
In patients with Parkinson's disease (PD), constipation is common, and it appears in a prodromal stage before the hallmark motor symptoms. The present study aimed to investigate whether Velusetrag, a selective 5HT4 receptor agonist, may be a suitable candidate to improve intestinal motility in a mouse model of PD. Five months old PrP human A53T alpha-synuclein transgenic (Tg) mice, which display severe constipation along with decreased colonic cholinergic transmission already at 3 months, were treated daily with the drug for 4 weeks. Velusetrag treatment reduced constipation by significantly stimulating both the longitudinal and circular-driven contractions and improved inflammation by reducing the level of serum and colonic IL1ß and TNF-α and by decreasing the number of GFAP-positive glia cells in the colon of treated mice. No significant downregulation of the 5-HT4 receptor was observed but instead Velusetrag seemed to improve axonal degeneration in Tgs as shown by an increase in NF-H and VAChT staining. Ultimately, Velusetrag restored a well-balanced intestinal microbial composition comparable to non-Tg mice. Based on these promising data, we are confident that Velusetrag is potentially eligible for clinical studies to treat constipation in PD patients.
RESUMO
A RGD peptide mimetic was conjugated to four camptothecins, with the purpose to improve their therapeutic index. The conjugate derivatives were evaluated against two tumor cell lines, one overexpressing integrins (human ovarian carcinoma, A2780) and a second one with a low integrin expression (human prostate cancer, PC3). The in vitro screening was completed with the adhesion behavior to vitronectin. Compound 8 (ST7456CL1) was selected for the in vivo investigation after stability tests over 24h, in PBS solution and in rat plasma, and compared to irinotecan. The former showed a prolonged half-life.
Assuntos
Antineoplásicos Fitogênicos/administração & dosagem , Camptotecina/administração & dosagem , Sistemas de Liberação de Medicamentos , Integrinas/imunologia , Oligopeptídeos/química , Neoplasias Ovarianas/tratamento farmacológico , Neoplasias da Próstata/tratamento farmacológico , Sequência de Aminoácidos , Animais , Antineoplásicos Fitogênicos/farmacologia , Camptotecina/farmacologia , Linhagem Celular Tumoral , Feminino , Humanos , Masculino , Oligopeptídeos/imunologia , Neoplasias Ovarianas/imunologia , Neoplasias da Próstata/imunologia , RatosRESUMO
Adarotene belongs to the so-called class of atypical retinoids. The presence of the phenolic hydroxyl group on Adarotene structure allows a rapid O-glucuronidation as a major mechanism of elimination of the drug, favoring a fast excretion of its glucuronide metabolite in the urines. A series of ether, carbamate and ester derivatives was synthesized. All of them were studied and evaluated for their stability at different pH. The cytotoxic activity in vitro on NCI-H460 non-small cell lung carcinoma and A2780 ovarian tumor cell lines was also tested. A potential back-up of Adarotene has been selected to be evaluated in tumor models.
Assuntos
Retinoides/química , Animais , Antineoplásicos/farmacologia , Carcinoma Pulmonar de Células não Pequenas/tratamento farmacológico , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Esterases/metabolismo , Humanos , Neoplasias Pulmonares/tratamento farmacológico , Camundongos , Camundongos Nus , Retinoides/farmacologia , Retinoides/toxicidade , Transplante HeterólogoRESUMO
Many severe human pathologies are related to alterations of the fine balance between histone acetylation and deacetylation; because not all such diseases involve hypoacetylation, but also hyperacetylation, compounds able to enhance or repress the activities of histone acetyltransferases (HATs) could be promising therapeutic agents. We evaluated in vitro and in cell the ability of eleven natural polyisoprenylated benzophenone derivatives to modulate the HAT activity of p300/CBP, an enzyme that plays a pivotal role in a variety of cellular processes. Some of the tested compounds bound efficiently to the p300/CBP protein: in particular, guttiferone A, guttiferone E and clusianone inhibit its HAT activity, whereas nemorosone showed a surprising ability to activate the enzyme. The ability of nemorosone to penetrate cell membranes and modulate histone acetylation into the cell together with its high affinity for the p300/CBP enzyme made this compound a suitable lead for the design of optimized anticancer drugs. Besides, the studies performed at a cellular and molecular level on both the inhibitors and the activator provided new insights into the modulation mechanism of p300/CBP by small molecules.
Assuntos
Benzofenonas/química , Fatores de Transcrição de p300-CBP/agonistas , Acetilação , Benzofenonas/farmacologia , Benzoquinonas , Compostos Bicíclicos com Pontes/química , Compostos Bicíclicos com Pontes/farmacologia , Linhagem Celular Tumoral , Ensaios de Seleção de Medicamentos Antitumorais , Fase G1 , Histonas/metabolismo , Humanos , Cinética , Termodinâmica , Fatores de Transcrição de p300-CBP/metabolismoRESUMO
Eight conjugates of a novel camptothecin derivative (Namitecan, NMT) with RGD peptides have been synthesized and biologically evaluated. This study focused on factors that optimize the drug linkage to the transport vector. The different linkages investigated consist of heterofunctional glycol fragments and a lysosomally cleavable peptide. The linkage length and conformation were systematically modified with the purpose to understand their effect on receptor affinity, systemic stability, cytotoxicity, and solubility of the corresponding conjugates. Among the new conjugates prepared, C6 and C7 showed high receptor affinity and tumor cell adhesion, acceptable stability in murine blood, and high cytotoxic activity (IC50 = 8 nM). The rationale, synthetic strategy, and preliminary biological results will be presented.
Assuntos
Antineoplásicos/química , Antineoplásicos/farmacologia , Camptotecina/análogos & derivados , Integrina alfaVbeta3/metabolismo , Oligopeptídeos/química , Oligopeptídeos/metabolismo , Animais , Antineoplásicos/sangue , Antineoplásicos/metabolismo , Camptotecina/sangue , Camptotecina/química , Camptotecina/farmacologia , Proliferação de Células/efeitos dos fármacos , Ensaios de Seleção de Medicamentos Antitumorais , Humanos , Ligantes , Camundongos , Conformação Molecular , Oligopeptídeos/sangue , Estereoisomerismo , Relação Estrutura-Atividade , Células Tumorais CultivadasRESUMO
A series of 3,5-diaryl-4,5-dihydropyrazole regioisomers, and their 1-acetylated derivatives, bearing a 3,4,5-trimethoxyphenyl moiety combined with a variety of substituted phenyl rings, was synthesized and evaluated for antitumor activity. Results of the in vitro assay against a non-small cell lung carcinoma cell line (NCI-H460) showed several compounds to be endowed with cytotoxicity in micromolar to sub-micromolar range, depending on substitution pattern and position of aryl rings on 4,5-dihydropyrazole core. Potent and selective activity was also observed in the NCI 60 human cancer cell line panel. 5-(3,4,5-Trimethoxyphenyl)pyrazolines 31 and 39 were found to possess potent antiproliferative activity against SR and MDA-MB-435, with GI(50) inhibitory values in nanomolar range. Structure-activity relationships revealed that introduction of a (hydroxy)acetyl group at N-1 of inactive 5-(3,4,5-trimethoxyphenyl)pyrazolines, results in a clear in vitro activating effect. Compound 31 (IC(50)=5.16 microM) showed inhibition of tubulin polymerization comparable to that of CA-4 (IC(50)=4.92 microM).
Assuntos
Antineoplásicos/síntese química , Pirazóis/síntese química , Pirazóis/farmacologia , Antineoplásicos/farmacologia , Linhagem Celular Tumoral , Ensaios de Seleção de Medicamentos Antitumorais , Humanos , Relação Estrutura-Atividade , Moduladores de Tubulina , Células Tumorais CultivadasRESUMO
Five RGD peptide-camptothecin (CPT) conjugates were designed and synthesized with the purpose to improve the therapeutic index of this antitumoral drug family. New RGD cyclopeptides were selected on the basis of their high affinity to alpha(v) integrin receptors overexpressed by tumor cells and their metabolic stability. The conjugates can be divided in two groups: in the first the peptide was attached to the drug through an amide bond, in the second through a hydrazone bond. The main difference between the two spacers lies in their acid stability. Affinity to the receptors was maintained for all conjugates and their internalization into tumor cells was demonstrated. The first group conjugates showed lower in vitro and in vivo activity than the parent drug, probably due to the excessive stability of the amide bond, even inside the tumor cells. Conversely, the hydrazone conjugates exhibited in vitro tumor cell inhibition similar to the parent drug, indicating high conversion in the culture medium and/or inside the cells, but their poor solubility hampered in vivo experiments. On the basis of these results, information was acquired for additional development of derivatives with different linkers and better solubility for in vivo evaluation.
Assuntos
Antineoplásicos Fitogênicos/administração & dosagem , Antineoplásicos Fitogênicos/uso terapêutico , Camptotecina/administração & dosagem , Camptotecina/uso terapêutico , Sistemas de Liberação de Medicamentos , Oligopeptídeos/química , Animais , Antineoplásicos Fitogênicos/química , Antineoplásicos Fitogênicos/farmacocinética , Camptotecina/química , Camptotecina/farmacocinética , Carcinoma/tratamento farmacológico , Linhagem Celular Tumoral , Sobrevivência Celular/efeitos dos fármacos , Feminino , Humanos , Camundongos , Camundongos Nus , Estrutura Molecular , Neoplasias Ovarianas/tratamento farmacológicoRESUMO
A series of mold metabolites of Ascomycetes, structurally belonging to the class of azaphilones, were found to inhibit the heat shock protein Hsp90. In particular, bulgarialactone B was tested for its binding to Hsp90 using surface plasmon resonance and limited proteolysis assays and for its effects on Hsp90 client proteins expression in a series of human tumor cell lines. This compound showed high affinity for Hsp90, interacting with the 90-280 region of the N-terminal domain and down-regulated the Hsp90 client proteins Raf-1, survivin, Cdk4, Akt, and EGFR. Bulgarialactone B and other natural azaphilones showed antiproliferative activity in a panel of human tumor cell lines; their conversion into semisynthetic derivatives by reaction with primary amines increased the antiproliferative activity. Preliminary results indicated in vivo activity of bulgarialactone B against an ascitic ovarian carcinoma xenograft, thus supporting the therapeutic potential of this novel series of Hsp90 inhibitors.
Assuntos
Antineoplásicos/química , Antineoplásicos/uso terapêutico , Ascomicetos/química , Benzopiranos/química , Benzopiranos/uso terapêutico , Proteínas de Choque Térmico HSP90/antagonistas & inibidores , Pigmentos Biológicos/química , Pigmentos Biológicos/uso terapêutico , Animais , Antineoplásicos/isolamento & purificação , Antineoplásicos/farmacologia , Benzopiranos/isolamento & purificação , Benzopiranos/farmacologia , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Feminino , Proteínas de Choque Térmico HSP90/metabolismo , Humanos , Camundongos , Camundongos Nus , Neoplasias/tratamento farmacológico , Pigmentos Biológicos/isolamento & purificação , Pigmentos Biológicos/farmacologiaRESUMO
With the aim to discover novel HDAC inhibitors with high potency and good safety profiles, we have designed a small library based on a N-hydroxy-(4-oxime)-cinnamide scaffold. We describe the synthesis of these novel compounds and some preliminary in vitro cytotoxic activity on three tumor cell lines, NB4, H460 and HCT116, as well as their inhibitory activity against class I, II and IV HDAC. Several 4-oxime derivatives demonstrated a promising inhibitory activity on HDAC6 and HDAC8 coupled to a good selectivity profile.
Assuntos
Cinamatos/síntese química , Inibidores de Histona Desacetilases , Antineoplásicos/síntese química , Antineoplásicos/farmacologia , Linhagem Celular Tumoral , Cinamatos/metabolismo , Cinamatos/farmacologia , Histona Desacetilases/classificação , Histona Desacetilases/metabolismo , Humanos , Isoenzimas/antagonistas & inibidores , Isoenzimas/classificação , Isoenzimas/metabolismo , Ligação Proteica/fisiologiaRESUMO
In order to gather further knowledge about the structural requirements on histone deacetylase inhibitors (HDACi), starting from the schematic model of the common pharmacophore that characterizes this class of molecules (surface recognition CAP group-connection unit-linker region-Zinc Binding Group), we designed and synthesized a series of hydroxamic acids containing a bis-(indolyl)methane moiety. HDAC inhibition profile and antiproliferative activity were evaluated.