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Dopaminergic neurons express a heteromer composed of the dopamine D3 receptor and the α4ß2 nicotinic acetylcholine receptor, the D3R-nAChR heteromer, activated by both nicotine and dopamine D2 and D3 receptors agonists, such as quinpirole, and crucial for dopaminergic neuron homeostasis. We now report that D3R-nAChR heteromer activity is potentiated by 17-ß-estradiol which acts as a positive allosteric modulator by binding a specific domain on the α4 subunit of the nicotinic receptor protomer. In mouse dopaminergic neurons, in fact, 17-ß-estradiol significantly increased the ability of nicotine and quinpirole in promoting neuron dendritic remodeling and in protecting neurons against the accumulation of α-synuclein induced by deprivation of glucose, with a mechanism that does not involve the classical estrogen receptors. The potentiation induced by 17-ß-estradiol required the D3R-nAChR heteromer since either nicotinic receptor or dopamine D3 receptor antagonists and interfering TAT-peptides, but not the estrogen receptor antagonist fulvestrant, specifically prevented 17-ß-estradiol effects. Evidence of estrogens neuroprotection, mainly mediated by genomic mechanisms, have been provided, which is in line with epidemiological data reporting that females are less likely to develop Parkinson's Disease than males. Therefore, potentiation of D3R-nAChR heteromer activity may represent a further mechanism by which 17-ß-estradiol reduces dopaminergic neuron vulnerability.
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Neurônios Dopaminérgicos , Estradiol , Fármacos Neuroprotetores , Receptores de Dopamina D3 , Receptores Nicotínicos , Receptores de Dopamina D3/metabolismo , Receptores de Dopamina D3/agonistas , Estradiol/farmacologia , Animais , Neurônios Dopaminérgicos/efeitos dos fármacos , Neurônios Dopaminérgicos/metabolismo , Receptores Nicotínicos/metabolismo , Camundongos , Fármacos Neuroprotetores/farmacologia , Feminino , MasculinoRESUMO
BACKGROUND: The delayed diagnosis of skin tumors is associated with a worsened prognosis. The impact of the interruption of clinical and surgical health services during the COVID-19 pandemic lockdowns has been documented among many pathologies. The impact of delayed diagnoses on patients with cutaneous squamous cell carcinomas (cSCCs) is poorly defined. OBJECTIVE: To compare patient and lesion characteristics and the surgical management of excised cSCCs prior to the pandemic shutdown of services (2018-2019) with the phase following the pandemic's second wave (2021-2022). METHODS: An observational, single-center, cross-sectional study of 416 surgically excised cSCCs over the course of two years was performed. Only patients with histologically confirmed cSCC were enrolled. Data collection included patient demographics and lesion characteristics, time to surgery, surgical approach, and histological data. RESULTS: More cSCC lesions were excised prior to the interruption of services (n = 312 vs. n = 186). Lesions were significantly larger (1.7 ± 1.2 vs. 2.1 ± 1.5 cm; p = 0.006) and more invasive (52% vs. 89%; p < 0.001), in the period 2021-2022. Surgical reconstructive techniques were significantly different (p = 0.001). Metastatic involvement was confirmed in three subjects (one in 2018-2019 and two in 2021-2022). There were no significant differences in the time to surgery or patient characteristics. Multivariable regression analysis identified a 4.7-times higher risk of tumor invasion (OR 4.69, 95%CI 2.55-8.16, p < 0.001), a two-times higher chance of dermo-epidermal grafts (OR 2.06, 95%CI 1.09-3.88, p = 0.025), and a 3.2-times higher risk of positive surgical margins (OR 3.21, 95%CI 1.44-7.17, p = 0.004). CONCLUSIONS: Diagnostic delays of cutaneous SCCs associated with reduced patient access to clinical and diagnostic services are associated with a 4.7-times increased risk of more severe invasion, a three-times increased risk of positive surgical margins, and a significant impact on surgical management, compared to the pre-pandemic period. Comparable patient cohort characteristics and time to surgery remained unchanged.
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BACKGROUND: MatriDerm and Integra are both widely used collagenic acellular dermal matrices (ADMs) in the surgical setting, with similar characteristics in terms of healing time and clinical indication. The aim of the present study is to compare the two ADMs in terms of clinical and histological results in the setting of dermato-oncological surgery. METHODS: Ten consecutive patients with medical indications to undergo surgical excision of skin cancers were treated with a 2-step procedure at our Dermatologic Surgery Unit. Immediately after tumor removal, both ADMs were positioned on the wound bed, one adjacent to the other. Closure through split-thickness skin grafting was performed after approximately 3 weeks. Conventional histology, immunostaining and ELISA assay were performed on cutaneous samples at different timepoints. RESULTS: No significant differences were detected in terms of either final clinical outcomes or in extracellular matrix content of the neoformed dermis. However, Matriderm was observed to induce scar retraction more frequently. In contrast, Integra was shown to carry higher infectious risk and to be more slowly reabsorbed into the wound bed. Sometimes foreign body-like granulomatous reactions were also observed, especially in Integra samples. CONCLUSIONS: Even in the presence of subtle differences between the ADMs, comparable global outcomes were demonstrated after dermato-oncological surgery.
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BACKGROUND: Hereditary epidermolysis bullosa (EB) is a rare genodermatosis characterized by skin fragility and blistering of the skin and mucous membranes in reaction to minimal traumas. The development of cutaneous squamous cell carcinomas (cSCCs) is one of the most common medical complications in junctional and dystrophic forms of the disease. Complete surgical excision of cutaneous tumors represents the gold standard of treatment. However, not only recognition of cSCCs can be challenging in the affected skin but also wound closure after surgical excision poses a great therapeutic challenge in EB patients. The aim of our study was to analyze the postoperative outcomes of such patients in order to have a better knowledge of the main critical issues in their surgical management and oncological follow-up. METHODS: We retrospectively identified a cohort of five EB patients treated at Modena University Hospital. Collected data included patient age and sex, date of cSCC diagnosis, relapses/recurrences, site of the neoplasm, number of surgical interventions, use of dermal substitutes, and postoperative infections. RESULTS: A total of 26 cSCCs were detected in our cohort. Forty-one surgical interventions were necessary to achieve excision of cSCCs with clear margins, varying from 1 to 4 surgical sessions per cSCC. Dermal substitutes were used in most cases but carried a higher infectious risk. CONCLUSIONS: EB patients tend to develop numerous cSCCs that often relapse even after complete excision with clear margins. These results stress the importance of early cSCC diagnosis and strict postsurgical follow-up.
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Carcinoma de Células Escamosas , Epidermólise Bolhosa , Neoplasias Cutâneas , Carcinoma de Células Escamosas/complicações , Carcinoma de Células Escamosas/cirurgia , Epidermólise Bolhosa/complicações , Epidermólise Bolhosa/patologia , Epidermólise Bolhosa/cirurgia , Seguimentos , Humanos , Margens de Excisão , Recidiva Local de Neoplasia , Estudos Retrospectivos , Neoplasias Cutâneas/etiologia , Neoplasias Cutâneas/patologia , Neoplasias Cutâneas/cirurgiaRESUMO
We have previously shown that the heteromer composed by the dopamine D3 receptor (D3R) and the nicotinic acetylcholine receptor (nAChR) (D3R-nAChR heteromer) is expressed in dopaminergic neurons, activated by nicotine and represents the molecular unit that, in these neurons, contributes to the modulation of critical events such as structural plasticity and neuroprotection. We now extended this study by investigating the D3R-nAChR heteromer properties using various cell models such as transfected HEK293 cells, primary cultures of mouse dopaminergic neurons and human dopaminergic neurons derived from induced pluripotent stem cells.We found that the D3R-nAChR heteromer is the molecular effector that transduces the remodeling properties not only associated with nicotine but also with D3R agonist stimulation: neither nAChR nor D3R, in fact, when express as monomers, are able to elicit these effects. Moreover, strong and sustained activation of the PI3K-ERK1/2/Akt pathways is coupled with D3R-nAChR heteromer stimulation, leading to the expression of the immediate-early gene c-Fos and to sustained phosphorylation of cytosolic p70 ribosomal S6 kinase (p70S6K), critical for dendritic remodeling. By contrast, while D3R stimulation results in rapid and transient activation of both Erk1/2 and Akt, that is PI3K-dependent, stimulation of nAChR is associated with persistent activation of Erk1/2 and Akt, in a PI3K-independent way. Thus, the D3R-nAChR heteromer and its ability to trigger the PI3K-ERK1/2/Akt signaling pathways may represent a novel target for preserving dopaminergic neurons healthy and for conferring neuronal protection against injuries.
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Receptores de Dopamina D3 , Receptores Nicotínicos , Animais , Neurônios Dopaminérgicos/metabolismo , Células HEK293 , Humanos , Sistema de Sinalização das MAP Quinases , Camundongos , Nicotina/farmacologia , Fosfatidilinositol 3-Quinases/metabolismo , Proteínas Proto-Oncogênicas c-akt/metabolismo , Proteínas Proto-Oncogênicas c-fos/metabolismo , Receptores de Dopamina D3/metabolismo , Receptores Nicotínicos/metabolismo , Proteínas Quinases S6 Ribossômicas 70-kDa/metabolismo , Transdução de SinaisRESUMO
Mitotane is the only approved drug for treating adrenocortical carcinoma (ACC). The regimen added to mitotane is chemotherapy with etoposide, doxorubicin, and cisplatin. This pharmacological approach, however, has a limited efficacy and significant toxicity. Target-therapy agents represent a new promising approach to cancer therapy. Among these, a preeminent role is played by agents that interfere with cell-cycle progression, such as CDK4/6-inhibitors. Here, we investigate whether ribociclib could induce a cytotoxic effect both in ACC cell line and patient-derived primary cell cultures, alone or in combined settings. Cell viability was determined by 3-(4,5-dimethyl-2-thiazol)-2,5-diphenyl-2H-tetrazolium bromide assay, whereas cell proliferation was evaluated by direct count. Binary combination experiments were performed using Chou and Talalay method. Gene expression was analyzed by quantitative RT-PCR, whereas protein expression was evaluated by immunofluorescence. A double staining assay revealed that ribociclib induced a prevalent apoptotic cell death. Cell-cycle analysis was performed to evaluate the effect of ribociclib treatment on cell-cycle progression in ACC cell models. Our results indicate that ribociclib was cytotoxic and reduced the cell proliferation rate. The effect on cell viability was enhanced when ribociclib was combined with progesterone and/or mitotane. The effect of ribociclib on cell-cycle progression revealed a drug-induced cell accumulation in G2 phase. The positive relationship underlined by our results between ribociclib, progesterone, and mitotane strengthen the clinical potential of this combination.
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Neoplasias do Córtex Suprarrenal/tratamento farmacológico , Carcinoma Adrenocortical/tratamento farmacológico , Aminopiridinas/administração & dosagem , Antineoplásicos/administração & dosagem , Mitotano/administração & dosagem , Progesterona/administração & dosagem , Purinas/administração & dosagem , Neoplasias do Córtex Suprarrenal/patologia , Carcinoma Adrenocortical/patologia , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Apoptose/efeitos dos fármacos , Ciclo Celular/efeitos dos fármacos , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Células Cultivadas , HumanosRESUMO
The progressive neuropathological damage seen in Parkinson's disease (PD) is thought to be related to the spreading of aggregated forms of α-synuclein. Clearance of extracellular α-synuclein released by degenerating neurons may be therefore a key mechanism to control the concentration of α-synuclein in the extracellular space. Several molecular chaperones control misfolded protein accumulation in the extracellular compartment. Among these, clusterin, a glycoprotein associated with Alzheimer's disease, binds α-synuclein aggregated species and is present in Lewy bodies, intraneuronal aggregates mainly composed by fibrillary α-synuclein. In this study, using murine primary astrocytes with clusterin genetic deletion, human-induced pluripotent stem cell (iPSC)-derived astrocytes with clusterin silencing and two animal models relevant for PD we explore how clusterin affects the clearance of α-synuclein aggregates by astrocytes. Our findings showed that astrocytes take up α-synuclein preformed fibrils (pffs) through dynamin-dependent endocytosis and that clusterin levels are modulated in the culture media of cells upon α-synuclein pffs exposure. Specifically, we found that clusterin interacts with α-synuclein pffs in the extracellular compartment and the clusterin/α-synuclein complex can be internalized by astrocytes. Mechanistically, using clusterin knock-out primary astrocytes and clusterin knock-down hiPSC-derived astrocytes we observed that clusterin limits the uptake of α-synuclein pffs by cells. Interestingly, we detected increased levels of clusterin in the adeno-associated virus- and the α-synuclein pffs- injected mouse model, suggesting a crucial role of this chaperone in the pathogenesis of PD. Overall, our observations indicate that clusterin can limit the uptake of extracellular α-synuclein aggregates by astrocytes and, hence, contribute to the spreading of Parkinson pathology.
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Doença de Parkinson , alfa-Sinucleína , Animais , Astrócitos , Clusterina/genética , Humanos , Corpos de Lewy , Camundongos , alfa-Sinucleína/genéticaRESUMO
Perioperative antibiotic treatment duration in skin reconstruction with dermal substitutes is not well established. This study compares the incidence of infective complications after two different durations of perioperative antibiotic treatment in patients undergoing surgical reconstruction with skin dermal substitutes (SDS) after excision of skin cancer. Infective complications at the site of SDS were compared in subjects undergoing surgical reconstruction who received either a > 24-hour (extended protocol) or a ≤ 24-hour (short protocol) perioperative antibiotic treatment. Of 116 patients undergoing SDS surgical reconstruction, 62 (53.4%) received an extended schedule, and 54 (46.6%) received a short schedule. The two groups were similar for gender, age, comorbidities, American Society of Anesthesiologists score, and type of skin cancer. Overall incidence rate of infection was 20.7% (24/116). No differences in terms of risk of infection were observed between the two groups (OR: 1.04, 95% CI: 0.42-2.55; P = .937). Patients undergoing SDS reconstruction in the limb/foot had a higher risk of infection in comparison with those undergoing SDS reconstruction in the chest/head (OR: 2.69, 95% CI: 1.06-6.86; P = .038). The short protocol was demonstrated to be beneficial to patients undergoing surgical reconstruction with SDS. A ≤ 24-hour perioperative antibiotic schedule did not increase the infection rate, potentially allowing a reduction of antibiotic exposure.
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Antibacterianos/uso terapêutico , Antibioticoprofilaxia/métodos , Assistência Perioperatória/métodos , Procedimentos de Cirurgia Plástica/métodos , Neoplasias Cutâneas/cirurgia , Transplante de Pele/métodos , Infecção da Ferida Cirúrgica/prevenção & controle , Derme Acelular/estatística & dados numéricos , Adulto , Idoso , Idoso de 80 Anos ou mais , Antibioticoprofilaxia/estatística & dados numéricos , Feminino , Humanos , Itália/epidemiologia , Masculino , Pessoa de Meia-Idade , Assistência Perioperatória/estatística & dados numéricos , Procedimentos de Cirurgia Plástica/estatística & dados numéricos , Neoplasias Cutâneas/epidemiologia , Transplante de Pele/estatística & dados numéricosAssuntos
Bandagens , Carcinoma de Células Escamosas/cirurgia , Epidermólise Bolhosa/complicações , Neoplasias Cutâneas/cirurgia , Cicatrização/fisiologia , Adulto , Carcinoma de Células Escamosas/etiologia , Humanos , Masculino , Pessoa de Meia-Idade , Neoplasias Cutâneas/etiologia , Resultado do TratamentoRESUMO
We recently found that in mouse dopaminergic neurons, the heteromer formed by the dopamine D3 receptor (D3R) and the ß2 subunit of acetylcholine nicotinic receptor (nAChR) exerts neurotrophic effects when activated by nicotine, leading to neurons with enlarged cell bodies and increased dendrite arborization. Beside this action, we now show that nicotine, by activating the D3R-nAChR heteromer, protects dopaminergic neurons against neuronal injury. In primary cultures of mouse dopaminergic neurons, in fact, the ability of nicotine to inhibit both the pathological accumulation of alpha-synuclein induced by glucose deprivation and the consequent morphological defects were strongly prevented by disrupting the D3R-nAChR heteromer with specific interfering TAT-peptides; the relevance of the phosphoinositide 3-kinase (PI3K) intracellular signaling in mediating nicotine prevention of alpha-synuclein aggregation has been also demonstrated. Moreover, the ability of nicotine in restoring the ubiquitin-proteasome system has been found as a mechanism contributing to the neuroprotective properties of nicotine. By using the proximity ligation assay, we have shown that the D3R-nAChR heteromer is also expressed in human dopaminergic neurons derived from induced pluripotent stem cells. In this human cell model, nicotine exerts neuroprotective effects specifically acting through the D3R-nAChR complex thus indicating that this heteromer is a relevant molecular effector involved in the protection of human dopaminergic neurons.
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Neurônios Dopaminérgicos/metabolismo , Nicotina/farmacologia , Receptores de Dopamina D3/metabolismo , Receptores Nicotínicos/metabolismo , alfa-Sinucleína/efeitos dos fármacos , Animais , Células Cultivadas , Neurônios Dopaminérgicos/efeitos dos fármacos , Humanos , Células-Tronco Pluripotentes Induzidas/efeitos dos fármacos , Células-Tronco Pluripotentes Induzidas/metabolismo , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Fármacos Neuroprotetores/farmacologia , Receptores de Dopamina D3/efeitos dos fármacos , Receptores Nicotínicos/efeitos dos fármacosRESUMO
Adrenocortical carcinoma (ACC) is a rare, highly aggressive cancer, often insensitive to conventional chemotherapeutics agents. Early diagnosis, followed by radical surgical resection plus/minus adjuvant mitotane therapy, is nowadays the only valuable option. Unfortunately, one out of four patients has metastatic disease at diagnosis and most of radically resected ACC patients are destined to recur with local or metastatic disease. Numerous efforts aimed at identifying molecular alterations crucial for ACC pathogenesis have been extensively conducted, with the hope to develop new treatments. Indeed, multiple genes and pathways have been identified as potentially targetable in ACC patients; however, despite the strong preclinical rationale, translational findings to clinical trials led to date to disappointing results. The immunotherapeutic intervention targeting T-cell checkpoint molecules has been proposed as well, but results obtained in early studies indicate that ACC patients would be unlikely to benefit from immunotherapy. Genetic alterations of different pathways involved in ACC carcinogenesis are also known substrates of resistance to immunotherapy. Among them, ß-catenin gene CTNNB1 and TP53 gene are frequently mutated in ACC samples. Overactivation of the ß-catenin pathway and loss of p53 protein function are potential tumor-intrinsic factors that, impacting on the ability of ACC cells to recruit dendritic cells, leading to T-cell exclusion, put this tumor among those that are potentially resistant to immunotherapy. Moreover, the steroid phenotype, which implies glucocorticoids hypersecretion in a subset of ACC, contributes to generating an immunosuppressive microenvironment. Here, we review clinical results of immunotherapy in ACC and we highlight molecular mechanisms driving immunotherapy failure in ACC, suggesting possible approaches to overcome resistance.
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PURPOSE: The management of patients with adrenocortical carcinoma (ACC) is challenging. As mitotane and chemotherapy show limited efficacy, there is an urgent need to develop therapeutic approaches. The aim of this study was to investigate the antitumor activity of progesterone and explore the molecular mechanisms underlying its cytotoxic effects in the NCI-H295R cell line and primary cell cultures derived from ACC patients. METHODS: Cell viability, cell cycle, and apoptosis were analyzed in untreated and progesterone-treated ACC cells. The ability of progesterone to affect the Wnt/ß-catenin pathway in NCI-H295R cells was investigated by immunofluorescence. Progesterone and mitotane combination experiments were also performed to evaluate their interaction on NCI-H295R cell viability. RESULTS: We demonstrated that progesterone exerted a concentration-dependent inhibition of ACC cell viability. Apoptosis was the main mechanism, as demonstrated by a significant increase of apoptosis and cleaved-Caspase-3 levels. Reduction of ß-catenin nuclear translocation may contribute to the progesterone cytotoxic effect. The progesterone antineoplastic activity was synergically increased when mitotane was added to the cell culture medium. CONCLUSIONS: Our results show that progesterone has antineoplastic activity in ACC cells. The synergistic cytotoxic activity of progesterone with mitotane provides the rationale for testing this combination in a clinical study.
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Neoplasias do Córtex Suprarrenal/tratamento farmacológico , Carcinoma Adrenocortical/tratamento farmacológico , Progesterona/uso terapêutico , Progestinas/uso terapêutico , Neoplasias do Córtex Suprarrenal/metabolismo , Carcinoma Adrenocortical/metabolismo , Antineoplásicos Hormonais/uso terapêutico , Apoptose/efeitos dos fármacos , Ciclo Celular/efeitos dos fármacos , Linhagem Celular Tumoral , Ensaios de Seleção de Medicamentos Antitumorais , Sinergismo Farmacológico , Humanos , Proteínas de Membrana/metabolismo , Mitotano/uso terapêutico , Cultura Primária de Células , Progesterona/farmacologia , Progestinas/farmacologia , Receptores de Progesterona/metabolismo , beta Catenina/metabolismoRESUMO
Immunotherapy is widely used in the treatment of different cancer types, including metastatic melanoma, non-small cell lung cancer, renal cell carcinoma and urothelial cancer. The results of the phase I JAVELIN study failed to demonstrate a substantial activity of the PDL-1 inhibitor Avelumab in advanced adrenocortical carcinoma (ACC). This editorial focus on the possible mechanisms of ACC immunoevasion and suggests strategies to overcome the intrinsic immunotherapy resistance of this disease.
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The reconstruction of complex wounds in patients with comorbidities in the lower extremities is a challenging problem for surgeons. Skin grafting is frequently used to cover large skin defects, but it has several limits, including unwanted outcomes resulting from scars, poor elasticity and limitations in joint movement due to contractures. Locoregional flaps, particularly in the lower limbs, have limited application due to the size of the defect. Tissue engineering of the skin has offered major improvements in the coverage of large defects. Dermal matrix can be applied in order to generate a new dermis that allows good re-epithelialisation or skin grafting at a later stage. The reconstruction of large lower limb defects is more complicated in the case of chronic wounds showing no tendency to heal due to chronic infection. For all surgeons, it is very important to prevent the formation of a biofilm or manage it when it is already established before undertaking surgical procedures that involve a dermal matrix. We report our reconstruction strategy of chronic infected neoplastic ulcers of the lower extremities with a dermal matrix and our postoperative dressing protocol.
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Complicações Pós-Operatórias/cirurgia , Transplante de Pele/métodos , Lesões dos Tecidos Moles/cirurgia , Retalhos Cirúrgicos/transplante , Coxa da Perna/cirurgia , Engenharia Tecidual/métodos , Cicatrização/fisiologia , Idoso , Humanos , Masculino , Pessoa de Meia-Idade , Resultado do TratamentoAssuntos
Neoplasias do Córtex Suprarrenal/patologia , Carcinoma Adrenocortical/patologia , Proliferação de Células/efeitos dos fármacos , Piperazinas/farmacologia , Piridinas/farmacologia , Neoplasias do Córtex Suprarrenal/genética , Carcinoma Adrenocortical/genética , Proliferação de Células/genética , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Humanos , Cultura Primária de Células , Células Tumorais CultivadasRESUMO
Glycaemic index (GI) and glycaemic load (GL) are indicators of dietary carbohydrate quantity and quality and have been associated with increased risk of certain cancers and type 2 diabetes. Insulin resistance has been associated with increased melanoma risk. However, GI and GL have not been investigated for melanoma. We present the first study to examine the possible association of GI and GL with melanoma risk. We carried out a population-based, case-control study involving 380 incident cases of cutaneous melanoma and 719 age- and sex-matched controls in a northern Italian region. Dietary GI and GL were computed for each subject using data from a self-administered, semi-quantitative food frequency questionnaire. We computed the odds ratio (OR) for melanoma according to quintiles of distribution of GL and GL among controls. A direct association between melanoma risk and GL emerged in females (OR 2·38; 95 % CI 1·25, 4·52 for the highest v. the lowest quintile of GL score, P for trend 0·070) but not in males. The association in females persisted in the multivariable analysis after adjusting for several potential confounders. There was no evidence of an association between GI and melanoma risk. GL might be associated with melanoma risk in females.
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Glicemia/metabolismo , Carboidratos da Dieta/efeitos adversos , Índice Glicêmico , Carga Glicêmica , Melanoma/etiologia , Adulto , Idoso , Estudos de Casos e Controles , Inquéritos sobre Dietas , Carboidratos da Dieta/sangue , Feminino , Humanos , Resistência à Insulina , Masculino , Melanoma/sangue , Pessoa de Meia-Idade , Razão de Chances , Autorrelato , Fatores Sexuais , Neoplasias Cutâneas , Melanoma Maligno CutâneoRESUMO
Activation of nicotinic acetylcholine receptors (nAChR) promotes the morphological remodeling of cultured dopamine (DA) neurons, an effect requiring functional DA D3 receptors (D3R). The aim of this study was to investigate the mechanisms mediating D3R-nAChR cross-talk in the modulation of DA neuron structural plasticity. By using bioluminescence resonance energy transfer2 (BRET2) and proximity ligation assay (PLA), evidence for the existence of D3R-nAChR heteromers has been obtained. In particular, BRET2 showed that the D3R directly and specifically interacts with the ß2 subunit of the nAChR. The D3R-nAChR complex was also identified in cultured DA neurons and in mouse Substantia Nigra/Ventral Tegmental Area by PLA. Cell permeable interfering peptides, containing highly charged amino acid sequences from the third intracellular loop of D3R (TAT-D3R) or the second intracellular loop of the ß2 subunit (TAT-ß2), were developed. Both peptides, but not their scrambled counterparts, significantly reduced the BRET2 signal generated by D3R-GFP2 and ß2-Rluc. Similarly, the PLA signal was undetectable in DA neurons exposed to the interfering peptides. Moreover, interfering peptides abolished the neurotrophic effects of nicotine on DA neurons. Taken together these data first demonstrate that a D3R-nAChR heteromer is present in DA neurons and represents the functional unit mediating the neurotrophic effects of nicotine.
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Neurônios Dopaminérgicos/fisiologia , Mesencéfalo/citologia , Plasticidade Neuronal/genética , Receptores de Dopamina D3/deficiência , Receptores Nicotínicos/metabolismo , Animais , Técnicas de Transferência de Energia por Ressonância de Bioluminescência , Células Cultivadas , Proteínas de Fluorescência Verde/genética , Proteínas de Fluorescência Verde/metabolismo , Células HEK293 , Humanos , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Plasticidade Neuronal/efeitos dos fármacos , Nicotina/farmacologia , Agonistas Nicotínicos/farmacologia , Multimerização Proteica/genética , Multimerização Proteica/fisiologia , Receptores de Dopamina D3/genética , Receptores Nicotínicos/genética , Transfecção , Tirosina 3-Mono-Oxigenase/metabolismoRESUMO
CONTEXT: Patients with adrenocortical carcinoma (ACC) frequently suffer from cortisol excess, which portends a negative prognosis. Rapid control of cortisol hypersecretion and tumor growth are the main goals of ACC therapy. Abiraterone acetate (AA) is a potent inhibitor of 17alpha-hydroxylase/17,20-lyase, a key enzyme of adrenal steroidogenesis. OBJECTIVE: This study sought to investigate the therapeutic use of AA in preclinical models of ACC. DESIGN: AA antisecretive and antiproliferative effects were investigated in vitro using NCI-H295R and SW13 ACC cell lines and human primary ACC cell cultures, as well as in vivo using immunodeficient mice. METHODS: Steroid secretion, cell viability, and proliferation were analyzed in untreated and AA-treated ACC cells. The ability of AA to affect the Wnt/beta-catenin pathway in NCI-H295R cells was also analyzed. Progesterone receptor (PgR) gene was silenced by the RNA interference approach. The antitumor efficacy of AA was confirmed in vivo in NCI-H295R cells xenografted in immunodeficient mice. RESULTS: AA reduced the secretion of both cortisol and androgens, increased production of progesterone, and induced a concentration-dependent decrease of cell viability in the NCI-H295R cells and primary secreting ACC cultures. AA also reduced beta-catenin nuclear accumulation in NCI-H295R cells. AA administration to NCI-H295R-bearing mice enhanced progesterone levels and inhibited tumor growth. The cytotoxic effect of AA was prevented by either blocking PgR or by gene silencing. CONCLUSION: AA is able to inhibit hormone secretion and growth of ACC both in vitro and in vivo. It also reduces beta-catenin nuclear accumulation. The cytotoxic effect of AA seems to require PgR.
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Acetato de Abiraterona/farmacologia , Neoplasias do Córtex Suprarrenal/tratamento farmacológico , Carcinoma Adrenocortical/tratamento farmacológico , Androgênios/metabolismo , Antineoplásicos/farmacologia , Hidrocortisona/metabolismo , Progesterona/metabolismo , Animais , Linhagem Celular Tumoral , Feminino , Humanos , CamundongosRESUMO
BACKGROUND: Some results from laboratory and epidemiologic studies suggest that diet may influence the risk of melanoma, but convincing evidence for a role of single nutrients or food items is lacking. Diet quality, which considers the combined effect of multiple food items, may be superior for examining this relation. OBJECTIVE: We sought to assess whether diet quality, evaluated with the use of 4 different dietary indexes, is associated with melanoma risk. METHODS: In this population-based case-control study, we analyzed the relation between 4 diet quality indexes, the Healthy Eating Index 2010 (HEI-2010), Dietary Approaches to Stop Hypertension (DASH) index, Greek Mediterranean Index (GMI), and Italian Mediterranean Index (IMI), and melanoma risk in a northern Italian community, with the use of data from 380 cases and 719 matched controls who completed a semiquantitative food frequency questionnaire. RESULTS: In the overall sample, we found an inverse association between disease risk and the HEI-2010 and DASH index, but not the Mediterranean indexes, adjusting for potential confounders (skin phototype, body mass index, energy intake, sunburn history, skin sun reaction, and education). However, in sex stratified analyses, the association appeared only in women (P-trend: 0.10 and 0.04 for the HEI-2010 and DASH index, respectively). The inverse relations were stronger in women younger than age 50 y than in older women, for whom the GMI and IMI scores also showed an inverse association with disease risk (P-trend: 0.05 and 0.02, respectively). CONCLUSIONS: These results suggest that diet quality may play a role in cutaneous melanoma etiology among women.