RESUMO
Beyond their role in bone and lung homeostasis, mesenchymal stem cells (MSCs) are becoming popular in cell therapy. Various insults may disrupt the repair mechanisms involving MSCs. One such insult is smoking, which is a major risk factor for osteoporosis and respiratory diseases. Upon cigarette smoke-induced damage, a series of reparatory mechanisms ensue; one such mechanism involves Glycosaminoglycans (GAG). One of these GAGs, namely hyaluronic acid (HA), serves as a potential therapeutic target in lung injury. However, much of its mechanisms of action through its major receptor CD44 remains unexplored. Our previous studies have identified and functionally validated that both cortactin (CTTN: marker of motility) and Survivin (BIRC5: required for cell survival) act as novel HA/CD44-downstream transcriptional targets underpinning cell motility. Here, human MSCs were treated with "Water-pipe" smoke to investigate the effects of cigarette smoke condensate (CSC) on these HA-CD44 novel signaling pathways. Our results show that CSC decreased the expression of both CD44 and its downstream targets CTTN and BIRC5 in MSCs, and that HA reversed these effects. Interestingly, CSC inhibited migration and invasion of MSCs upon CD44-targeted RNAi treatment. This shows the importance of CD44-HA/CTTN and CD44-HA/BIRC5 signaling pathways in MSC motility, and further suggests that these signaling pathways may provide a novel mechanism implicated in migration of MSCs during repair of lung tissue injury. These findings suggest that one should use caution before utilizing MSC from donors with history of smoking, and further pave the way towards the development of targeted therapeutic approaches against CD44-associated diseases.
Assuntos
Fumar Cigarros/efeitos adversos , Cortactina/genética , Receptores de Hialuronatos/genética , Lesão Pulmonar/genética , Survivina/genética , Linhagem Celular , Movimento Celular/efeitos dos fármacos , Regulação da Expressão Gênica/efeitos dos fármacos , Glicosaminoglicanos/genética , Humanos , Ácido Hialurônico/genética , Lesão Pulmonar/induzido quimicamente , Lesão Pulmonar/patologia , Células-Tronco Mesenquimais/efeitos dos fármacos , Células-Tronco Mesenquimais/patologia , Transdução de Sinais/efeitos dos fármacos , Fumar/efeitos adversosRESUMO
Hypoxic-ischemic injury (HI) to the neonatal human brain results in myelin loss that, in some children, can manifest as cerebral palsy. Previously, we had found that neuronal overexpression of the bone morphogenic protein (BMP) inhibitor noggin during development increased oligodendroglia and improved motor function in an experimental model of HI utilizing unilateral common carotid artery ligation followed by hypoxia. As BMPs are known to negatively regulate oligodendroglial fate specification of neural stem cells and alter differentiation of committed oligodendroglia, BMP signaling is likely an important mechanism leading to myelin loss. Here, we showed that BMP signaling is upregulated within oligodendroglia of the neonatal brain. We tested the hypothesis that inhibition of BMP signaling specifically within neural progenitor cells (NPCs) is sufficient to protect oligodendroglia. We conditionally deleted the BMP receptor 2 subtype (BMPR2) in NG2-expressing cells after HI. We found that BMPR2 deletion globally protects the brain as assessed by MRI and protects motor function as assessed by digital gait analysis, and that conditional deletion of BMPR2 maintains oligodendrocyte marker expression by immunofluorescence and Western blot and prevents loss of oligodendroglia. Finally, BMPR2 deletion after HI results in an increase in noncompacted myelin. Thus, our data indicate that inhibition of BMP signaling specifically in NPCs may be a tractable strategy to protect the newborn brain from HI.
Assuntos
Proteínas Morfogenéticas Ósseas/metabolismo , Encéfalo/metabolismo , Hipóxia-Isquemia Encefálica/metabolismo , Atividade Motora/fisiologia , Células-Tronco Neurais/metabolismo , Animais , Animais Recém-Nascidos , Técnicas de Silenciamento de Genes , Hipóxia-Isquemia Encefálica/patologia , Camundongos , Camundongos Endogâmicos C57BL , Oligodendroglia/metabolismo , Transdução de Sinais/fisiologiaRESUMO
After nerve injury, Schwann cells (SCs) dedifferentiate, proliferate, and support axon regrowth. If axons fail to regenerate, denervated SCs eventually undergo apoptosis due, in part, to increased expression of the low-affinity neurotrophin receptor, p75(NTR). Merlin is the protein product of the NF2 tumor suppressor gene implicated in SC tumorigenesis. Here we explore the contribution of merlin to SC responses to nerve injury. We find that merlin becomes phosphorylated (growth permissive) in SCs following acute axotomy and following gradual neural degeneration in a deafness model, temporally correlated with increased p75(NTR) expression. p75(NTR) levels are elevated in P0SchΔ39-121 transgenic mice that harbor an Nf2 mutation in SCs relative to wild-type mice before axotomy and remain elevated for a longer period of time following injury. Replacement of wild-type, but not phospho-mimetic (S518D), merlin isoforms suppresses p75(NTR) expression in primary human schwannoma cultures which otherwise lack functional merlin. Despite elevated levels of p75(NTR), SC apoptosis following axotomy is blunted in P0SchΔ39-121 mice relative to wild-type mice suggesting that loss of functional merlin contributes to SC resistance to apoptosis. Further, cultured SCs from mice with a tamoxifen-inducible knock-out of Nf2 confirm that SCs lacking functional merlin are less sensitive to p75(NTR)-mediated cell death. Taken together these results point to a model whereby loss of axonal contact following nerve injury results in merlin phosphorylation leading to increased p75(NTR) expression. Further, they demonstrate that merlin facilitates p75(NTR)-mediated apoptosis in SCs helping to explain how neoplastic SCs that lack functional merlin survive long-term in the absence of axonal contact.
Assuntos
Apoptose/fisiologia , Neurofibromina 2/metabolismo , Traumatismos dos Nervos Periféricos/metabolismo , Receptor de Fator de Crescimento Neural/metabolismo , Células de Schwann/metabolismo , Transdução de Sinais/fisiologia , Animais , Axônios/metabolismo , Axônios/patologia , Axotomia , Desdiferenciação Celular/fisiologia , Proliferação de Células , Células Cultivadas , Humanos , Camundongos , Camundongos Transgênicos , Regeneração Nervosa/fisiologia , Neuroma Acústico/metabolismo , Neuroma Acústico/patologia , Traumatismos dos Nervos Periféricos/patologia , Ratos Sprague-Dawley , Células de Schwann/patologiaRESUMO
Spirulina (SP) (Arthrospira platensis; previously Spirulina platensis) is a filamentous blue-green microalga (cyanobacterium) with potent dietary phytoantioxidant and anticancerous properties. We investigated the chemopreventive effect of SP against 7,12-dimethylbenz[a]anthracene (DMBA)-induced rat breast carcinogenesis, and further studied its underlying mechanisms of action in vitro. Remarkably, SP cleared DMBA-induced rat mammary tumors, which was clearly confirmed by morphological and histological methods. SP supplementation reduced the incidence of breast tumors from 87% to 13%. At the molecular level, immunohistochemical analysis revealed that SP supplementation reduced expression of both Ki-67 and estrogen α. More interestingly, molecular analysis in the in vitro experiments indicated that SP treatment inhibited cell proliferation by 24 hours, which was accompanied by increased p53 expression, followed by increased expression of its downstream target gene, Cdkn1a (alias p21 or p21(Waf1/Cip1)). In addition, SP increased Bax and decreased Bcl-2 expression, indicating induction of apoptosis by 48 hours after SP treatment. To our knowledge, this is the first report of in vivo chemopreventive effect of SP against DMBA-induced breast carcinogenesis in rat, supporting its potential use in chemoprevention of cancer.
Assuntos
Quimioprevenção/métodos , Neoplasias Mamárias Experimentais/prevenção & controle , Spirulina , Animais , Western Blotting , Feminino , Expressão Gênica , Humanos , Imuno-Histoquímica , Células MCF-7 , Ratos , Ratos Sprague-DawleyRESUMO
Vestibular schwannomas (VSs) arise from Schwann cells (SCs) and result from the loss of function of merlin, the protein product of the NF2 tumor suppressor gene. In contrast to non-neoplastic SCs, VS cells survive long-term in the absence of axons. We find that p75(NTR) is overexpressed in VSs compared with normal nerves, both at the transcript and protein level, similar to the response of non-neoplastic SCs following axotomy. Despite elevated p75(NTR) expression, VS cells are resistant to apoptosis due to treatment with proNGF, a high affinity ligand for p75(NTR) . Furthermore, treatment with proNGF protects VS cells from apoptosis due to c-Jun N-terminal kinase (JNK) inhibition indicating that p75(NTR) promotes VS cell survival. Treatment of VS cells with proNGF activated NF-κB while inhibition of JNK with SP600125 or siRNA-mediated knockdown reduced NF-κB activity. Significantly, proNGF also activated NF-κB in cultures treated with JNK inhibitors. Thus, JNK activity appears to be required for basal levels of NF-κB activity but not for proNGF-induced NF-κB activity. To confirm that the increase in NF-κB activity contributes to the prosurvival effect of proNGF, we infected VS cultures with Ad.IκB.SerS32/36A virus, which inhibits NF-κB activation. Compared with control virus, Ad.IκB.SerS32/36A significantly increased apoptosis including in VS cells treated with proNGF. Thus, in contrast to non-neoplastic SCs, p75(NTR) signaling provides a prosurvival response in VS cells by activating NF-κB independent of JNK. Such differences may contribute to the ability of VS cells to survive long-term in the absence of axons.
Assuntos
NF-kappa B/metabolismo , Proteínas do Tecido Nervoso/metabolismo , Neuroma Acústico/fisiopatologia , Receptores de Fator de Crescimento Neural/metabolismo , Animais , Apoptose/fisiologia , Sobrevivência Celular/fisiologia , Células Cultivadas , Humanos , Proteínas Quinases JNK Ativadas por Mitógeno/antagonistas & inibidores , Proteínas Quinases JNK Ativadas por Mitógeno/metabolismo , Camundongos , NF-kappa B/agonistas , NF-kappa B/antagonistas & inibidores , Fator de Crescimento Neural/metabolismo , Precursores de Proteínas/metabolismo , Ratos , Receptores de Fatores de Crescimento , Células de Schwann/fisiologia , Nervo Isquiático/fisiologiaRESUMO
With their intricate design, nanoparticles (NPs) have become indispensable tools in the quest for precise cellular targeting. Among various NPs, gold NPs stand out with unique features such as chemical stability, biocompatibility, adjustable shape, and size-dependent optical properties, making them particularly promising for molecular detection by leveraging the surface-enhanced Raman scattering (SERS) effect. Their multiplexing abilities for the simultaneous identification of multiple biomarkers are important in the rapidly evolving landscape of diverse cellular phenotypes and biomolecular profiling. However, the challenge is ensuring that SERS NPs can effectively target specific cells and biomarkers among intricate cell types and biomolecules with high specificity. In this study, we improve the functionalization of SERS NPs, optimizing their targeting efficiency in cellular applications for ca. 160 nm NP-based probes. Spherical SERS NPs, conjugated with antibodies targeting epidermal growth factor receptor and human epidermal growth factor receptor 2, were incubated with cells overexpressing these proteins, and their specific binding potential was quantified at each stage by using flow cytometry to achieve optimal targeting efficiency. We determined that maintaining an average of 3.5 × 105 thiols per NP, 300 antibodies per NP, 18,000 NPs per cell, conducting a 15 min staining incubation at 4 °C in a shaker, and using SM(PEG)12 as a cross-linker for the NP conjugation were crucial to achieve the highest targeting efficiency. Fluorescence and Raman imaging were used with these parameters to observe the maximum ability of these NPs to efficiently target suspended cells. These highly sensitive contrast agents demonstrate their pivotal role in effective active targeting, making them invaluable for multiplexing applications across diverse biological environments.
Assuntos
Nanopartículas Metálicas , Nanopartículas , Humanos , Proteínas de Membrana , Nanopartículas/química , Análise Espectral Raman/métodos , Ouro/química , Anticorpos , Nanopartículas Metálicas/químicaRESUMO
Profiling the heterogeneous landscape of cell types and biomolecules is rapidly being adopted to address current imperative research questions. Precision medicine seeks advancements in molecular spatial profiling techniques with highly multiplexed imaging capabilities and subcellular resolution, which remains an extremely complex task. Surface-enhanced Raman spectroscopy (SERS) imaging offers promise through the utilization of nanoparticle-based contrast agents that exhibit narrow spectral features and molecular specificity. The current renaissance of gold nanoparticle technology makes Raman scattering intensities competitive with traditional fluorescence methods while offering the added benefit of unsurpassed multiplexing capabilities. Here, we present an expanded library of individually distinct SERS nanoparticles to arm researchers and clinicians. Our nanoparticles consist of a â¼60 nm gold core, a Raman reporter molecule, and a final inert silica coating. Using density functional theory, we have selected Raman reporters that meet the key criterion of high spectral uniqueness to facilitate unmixing of up to 26 components in a single imaging pixel in vitro and in vivo. We also demonstrated the utility of our SERS nanoparticles for targeting cultured cells and profiling cancerous human tissue sections for highly multiplexed optical imaging. This study showcases the far-reaching capabilities of SERS-based Raman imaging in molecular profiling to improve personalized medicine and overcome the major challenges of functional and structural diversity in proteomic imaging.
Assuntos
Ouro , Nanopartículas Metálicas , Humanos , Ouro/química , Nanopartículas Metálicas/química , Proteômica , Análise Espectral Raman/métodos , Diagnóstico por ImagemRESUMO
Providing physicians with new imaging agents to help detect cancer with better sensitivity and specificity has the potential to significantly improve patient outcomes. Development of new imaging agents could offer improved early cancer detection during routine screening or help surgeons identify tumor margins for surgical resection. In this study, we evaluate the optical properties of a colorful class of dyes and pigments that humans routinely encounter. The pigments are often used in tattoo inks and the dyes are FDA approved for the coloring of foods, drugs, and cosmetics. We characterized their absorption, fluorescence and Raman scattering properties in the hopes of identifying a new panel of dyes that offer exceptional imaging contrast. We found that some of these coloring agents, coined as "optical inks", exhibit a multitude of useful optical properties, outperforming some of the clinically approved imaging dyes on the market. The best performing optical inks (Green 8 and Orange 16) were further incorporated into liposomal nanoparticles to assess their tumor targeting and optical imaging potential. Mouse xenograft models of colorectal, cervical and lymphoma tumors were used to evaluate the newly developed nano-based imaging contrast agents. After intravenous injection, fluorescence imaging revealed significant localization of the new "optical ink" liposomal nanoparticles in all three tumor models as opposed to their neighboring healthy tissues (p < 0.05). If further developed, these coloring agents could play important roles in the clinical setting. A more sensitive imaging contrast agent could enable earlier cancer detection or help guide surgical resection of tumors, both of which have been shown to significantly improve patient survival.
Assuntos
Neoplasias , Tatuagem , Corantes , Meios de Contraste , Humanos , Tinta , Imagem ÓpticaRESUMO
CD146, also known as melanoma cell adhesion molecule or MCAM, is a key cell adhesion protein in vascular endothelial cell activity and angiogenesis. CD146 promotes tumor progression of many cancers including melanoma and prostate. Strikingly, its expression is frequently lost in breast carcinoma cells, and it may act as a suppressor of breast cancer progression. While upstream mechanisms regulating CD146 are well documented, our understanding of the downstream molecular events underlying its mode of action remains to be elucidated. This review aims to focus on the progress in understanding the signaling mechanisms and the functional relevance of CD146, a multifaceted molecule, in cancer with particular emphasis on its role in inhibiting breast cancer progression.
Assuntos
Antígeno CD146/fisiologia , Animais , Neoplasias da Mama/etiologia , Antígeno CD146/química , Células Endoteliais/fisiologia , Feminino , Humanos , Masculino , Melanoma/etiologia , Neoplasias da Próstata/etiologia , Transdução de Sinais/fisiologiaRESUMO
We have previously characterized the role of p16/Rb in coordinating the early events in UVB-irradiated skin. As an extension to this work, normal melanocytes and mutant p16-inducible melanoma cell models were employed to elucidate further the coordinated molecular mechanisms occurring during early UVB exposure. Our results showed that melanocytes expressed p16 only at a high UVB dose, with undetectable p53. The Bax/Bcl2 ratio increased at higher dose, indicating that the cells had selected apoptosis program. In the wt-p16 melanoma cells, while low UVB dose upregulated p16, the high dose suppressed it, and further abrogated Cdk6 but not Cdk4. Interestingly, while induction of mutant-p16 increased Cdk4, cdk6 and pRb proteins, UVB exposure did not affect this increase. More interestingly, p16 mutant cells increased their resistance to apoptosis at high UVB-dose, associated with decreased Bax and increased Bcl2 expression. Thus, mutant-p16 appears to dictate a deregulation of cell cycle and increased resistance to apoptosis in melanoma cells. Together, the data indicate a deregulation of p16INK4/Rb pathway as an early event in UVB-induced melanomagenesis.
Assuntos
Inibidor p16 de Quinase Dependente de Ciclina/genética , Melanócitos/efeitos da radiação , Melanoma/etiologia , Proteína do Retinoblastoma/metabolismo , Apoptose , Ciclo Celular , Linhagem Celular Tumoral , Inibidor p16 de Quinase Dependente de Ciclina/metabolismo , Genes p16 , Humanos , Melanócitos/metabolismo , Raios Ultravioleta/efeitos adversosRESUMO
Previous data suggest that lipophilic statins such as fluvastatin and N-bisphosphonates such as zoledronic acid, both inhibitors of the mevalonate metabolic pathway, have anti-cancer effects in vitro and in patients. We have examined the effect of fluvastatin alone and in combination with zoledronic acid in the ATP-based tumour chemosensitivity assay (ATP-TCA) for effects on breast and ovarian cancer tumour-derived cells. Both zoledronic acid and fluvastatin showed activity in the ATP-TCA against breast and ovarian cancer, though fluvastatin alone was less active, particularly against breast cancer. The combination of zoledronic acid and fluvastatin was more active than either single agent in the ATP-TCA with some synergy against breast and ovarian cancer tumour-derived cells. Sequential drug experiments showed that pre-treatment of ovarian tumour cells with fluvastatin resulted in decreased sensitivity to zoledronic acid. Addition of mevalonate pathway components with zoledronic acid with or without fluvastatin showed little effect, while mevalonate did reduced inhibition due to fluvastatin. These data suggest that the combination of zoledronic acid and fluvastatin may have activity against breast and ovarian cancer based on direct anti-cancer cell effects. A clinical trial to test this is in preparation.
Assuntos
Trifosfato de Adenosina/metabolismo , Antineoplásicos/farmacologia , Neoplasias da Mama/tratamento farmacológico , Inibidores Enzimáticos/farmacologia , Ácido Mevalônico/antagonistas & inibidores , Neoplasias Ovarianas/tratamento farmacológico , Trifosfato de Adenosina/antagonistas & inibidores , Adulto , Idoso , Idoso de 80 Anos ou mais , Protocolos de Quimioterapia Combinada Antineoplásica , Neoplasias da Mama/enzimologia , Neoplasias da Mama/metabolismo , Difosfonatos/farmacologia , Ensaios de Seleção de Medicamentos Antitumorais , Ácidos Graxos Monoinsaturados/farmacologia , Feminino , Fluvastatina , Humanos , Imidazóis/farmacologia , Indóis/farmacologia , Pessoa de Meia-Idade , Neoplasias Ovarianas/enzimologia , Neoplasias Ovarianas/metabolismo , Transdução de Sinais/efeitos dos fármacos , Células Tumorais Cultivadas , Ácido ZoledrônicoRESUMO
BACKGROUND: Tumor resistance to chemotherapy may be present at the beginning of treatment, develop during treatment, or become apparent on re-treatment of the patient. The mechanisms involved are usually inferred from experiments with cell lines, as studies in tumor-derived cells are difficult. Studies of human tumors show that cells adapt to chemotherapy, but it has been largely assumed that clonal selection leads to the resistance of recurrent tumors. METHODS: Cells derived from 47 tumors of breast, ovarian, esophageal, and colorectal origin and 16 paired esophageal biopsies were exposed to anticancer agents (cisplatin; 5-fluorouracil; epirubicin; doxorubicin; paclitaxel; irinotecan and topotecan) in short-term cell culture (6 days). Real-time quantitative PCR was used to measure up- or down-regulation of 16 different resistance/target genes, and when tissue was available, immunohistochemistry was used to assess the protein levels. RESULTS: In 8/16 paired esophageal biopsies, there was an increase in the expression of multi-drug resistance gene 1 (MDR1) following epirubicin + cisplatin + 5-fluorouracil (ECF) chemotherapy and this was accompanied by increased expression of the MDR-1 encoded protein, P-gp. Following exposure to doxorubicin in vitro, 13/14 breast carcinomas and 9/12 ovarian carcinomas showed >2-fold down-regulation of topoisomerase IIalpha (TOPOIIalpha). Exposure to topotecan in vitro, resulted in >4-fold down-regulation of TOPOIIalpha in 6/7 colorectal tumors and 8/10 ovarian tumors. CONCLUSION: This study suggests that up-regulation of resistance genes or down-regulation in target genes may occur rapidly in human solid tumors, within days of the start of treatment, and that similar changes are present in pre- and post-chemotherapy biopsy material. The molecular processes used by each tumor appear to be linked to the drug used, but there is also heterogeneity between individual tumors, even those with the same histological type, in the pattern and magnitude of response to the same drugs. Adaptation to chemotherapy may explain why prediction of resistance mechanisms is difficult on the basis of tumor type alone or individual markers, and suggests that more complex predictive methods are required to improve the response rates to chemotherapy.
Assuntos
Tratamento Farmacológico/métodos , Regulação Neoplásica da Expressão Gênica , Neoplasias/tratamento farmacológico , Membro 1 da Subfamília B de Cassetes de Ligação de ATP/metabolismo , Antineoplásicos/farmacologia , Biópsia , Camptotecina/análogos & derivados , Camptotecina/farmacologia , Linhagem Celular Tumoral , Cisplatino/farmacologia , Regulação para Baixo , Doxorrubicina/farmacologia , Resistencia a Medicamentos Antineoplásicos , Epirubicina/farmacologia , Fluoruracila/farmacologia , Humanos , Imuno-Histoquímica , Irinotecano , Paclitaxel/farmacologia , Recidiva , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Fatores de Tempo , Topotecan/farmacologia , Resultado do Tratamento , Regulação para CimaRESUMO
Vestibular schwannomas (VSs) result from inactivating mutations in the merlin tumor suppressor gene. The merlin protein suppresses a variety of progrowth kinase-signaling cascades, including extracellular regulated kinase/mitogen-activated protein kinase (ERK/MAPK), c-Jun N-terminal kinase (JNK), and phosphatidyl-inositol 3-kinase (PI3-K)/Akt. Recent studies indicate that ERKs and Akt are active in human VSs, and here we show that JNKs are also persistently active in human VS cells. With use of cultures of human VSs, we investigated the contribution of each of these signals to the proliferative and survival response of VS cells. Inhibition of ERK or Akt signaling reduced VS cell proliferation but did not increase apoptosis, whereas inhibition of JNK with SP600125, I-JIP, or siRNA knock-down reduced VS cell proliferation and survival by inducing apoptosis. By contrast, JNK activity promotes apoptosis in normal Schwann cells. Inhibition of JNK increased the fluorescence intensity of VS cells loaded with 5-(and-6)-chloromethyl-2',7'-dichlorodihydrofluorescein diacetate (H(2)DCFDA), a fluorescent probe for reactive oxygen species (ROS). Furthermore, ebselen, a ROS scavenger, rescued VS cells with suppressed JNK from apoptosis, suggesting that JNK activity protects VS cells from apoptosis by limiting accumulation of ROS. VS cultures treated with JNK inhibitors demonstrated significantly higher levels of MitoSOX Red fluorescence, implying that persistent JNK activity specifically suppresses superoxide production in the mitochondria. Overexpression of superoxide dismutase 2 (MnSOD; mitochondrial SOD) prevented apoptosis in VS cells with suppressed JNK signaling. Taken together, these results indicate that persistent JNK activity enhances VS cell survival, at least in part, by suppressing accumulation of mitochondrial superoxides.
Assuntos
Apoptose , Proteínas Quinases JNK Ativadas por Mitógeno/metabolismo , Neuroma Acústico/metabolismo , Neuroma Acústico/patologia , Espécies Reativas de Oxigênio/metabolismo , Superóxidos/metabolismo , Western Blotting , Linhagem Celular Tumoral , Proliferação de Células , Humanos , Técnicas Imunoenzimáticas , Mitocôndrias , Proteínas Quinases Ativadas por Mitógeno/metabolismo , Fosforilação , Proteínas Proto-Oncogênicas c-akt/metabolismo , Transdução de SinaisRESUMO
OBJECTIVE: Acrylamide (ACR), a proven rodent carcinogen, is present at significantly high quantities in commonly consumed foods such as potato chips, raising a health concern worldwide. METHODS: The effects of ACR and fried potato chips (FPC) on pregnant mice and their offspring before and after birth were investigated and compared. RESULTS: In the pregnant mice, similar histologic abnormalities were found in various tissues for ACR intoxication and FPC supplementation. Drastic alterations were mainly seen in the liver, kidney, heart muscle, and epiphyseal cartilage of experimental dams. ACR and FPC increased the rate of abortion and neonatal mortality and decreased the total number, body weight, size, and crown-rump length of the offspring before and after birth. Interestingly, however, higher rates of congenital malformations were observed in the FPC-treated group. Although ossification of axial and appendicular bones was markedly retarded during fetal development, some ossified bones were missing in newly born offspring of treated groups. Furthermore, the incidence of missing ossification centers was higher in the FPC-treated than in the ACR-treated neonates. CONCLUSION: These results suggest that FPC can cause hazardous health effects and warrant a systematic study on the health effects of consumption of FPC and French fries in the general population.
Assuntos
Anormalidades Induzidas por Medicamentos/etiologia , Acrilamida/efeitos adversos , Carcinógenos/farmacologia , Desenvolvimento Fetal/efeitos dos fármacos , Contaminação de Alimentos , Gravidez/efeitos dos fármacos , Solanum tuberosum , Anormalidades Induzidas por Medicamentos/patologia , Aborto Espontâneo/induzido quimicamente , Animais , Peso Corporal/efeitos dos fármacos , Osso e Ossos/efeitos dos fármacos , Cartilagem/patologia , Culinária/métodos , Estatura Cabeça-Cóccix , Feminino , Rim/patologia , Tamanho da Ninhada de Vivíparos/efeitos dos fármacos , Fígado/patologia , Camundongos , Miocárdio/patologiaRESUMO
OBJECTIVE: Acrylamide (ACR), a proved rodent carcinogen and neurotoxic agent, is present in significant quantities in commonly consumed foods such as fried potato chips (FPC) and French fries, raising a health concern worldwide. We investigated and compared the neurotoxic effects of ACR and FPC on postnatal development. METHODS: Female rats were treated with ACR (30 mg/kg of body weight), fed a diet containing approximately 30% of FPC during pregnancy, or fed a standard diet (control) and their offspring were examined. RESULTS: Female rats treated with ACR or fed a diet containing FPC during pregnancy gave birth to litters with delayed growth and decreased body and brain weights. Light microscopic studies of the cerebellar cortex of treated animals revealed drastic decreases in Purkinje cells and internal granular layers. Different patterns of cell death were detected in Purkinje cells and neurons in the brains of pups born to treated mothers. Ultrastructural analysis of Purkinje cells revealed changes in the endoplasmic reticulum, loss of the normal arrangement of polyribosomes, swollen mitochondria with abnormally differentiated cristae, and an abnormal Golgi apparatus. The gastrocnemius muscle in the ACR and FPC groups showed extensive degeneration of myofibrils as evidenced by poorly differentiated A, H, and Z bands. CONCLUSION: The present study reveals for the first time that rat fetal exposure to ACR, as a pure compound or from a maternal diet of FPC, causes cerebellar cortical defects and myodegeneration of the gastrocnemius muscle during the postnatal development of pups. These results warrant a systematic study of the health effects of the consumption of FPC and French fries in the general population.
Assuntos
Acrilamida/efeitos adversos , Encéfalo/efeitos dos fármacos , Contaminação de Alimentos , Transtornos do Crescimento/etiologia , Neurotoxinas/efeitos adversos , Efeitos Tardios da Exposição Pré-Natal , Solanum tuberosum , Animais , Peso Corporal/efeitos dos fármacos , Encéfalo/crescimento & desenvolvimento , Encéfalo/ultraestrutura , Morte Celular/efeitos dos fármacos , Culinária , Dieta , Feminino , Masculino , Camundongos , Camundongos Endogâmicos , Músculo Esquelético/efeitos dos fármacos , Músculo Esquelético/crescimento & desenvolvimento , Músculo Esquelético/patologia , Miofibrilas/efeitos dos fármacos , Miofibrilas/patologia , Tamanho do Órgão/efeitos dos fármacos , Organelas/efeitos dos fármacos , Organelas/ultraestrutura , Tubérculos , Gravidez , RatosRESUMO
The incidence of skin cancer has been rising at an astonishing rate, particularly that of the deadliest skin cancer, melanoma. While the molecular mechanisms of sunlight ultraviolet radiation (UV)-induced non-melanoma skin cancer (NMSC) have been well documented, there is a major gap in our current knowledge of how UV initiates melanoma. However, the components of the retinoblastoma (Rb) pathway, the p53 and the p16 pathways are considered the major targets of UV-induced NMSC and melanoma, respectively. Our recent study has revealed that these two pathways coordinate the early responses to UV radiation in the skin. Here, we review the value of studies targeting these early events of skin carcinogenesis, with specific focus on the critical role of the components of the Rb pathway.
Assuntos
Apoptose/efeitos dos fármacos , Dano ao DNA/efeitos da radiação , Melanoma/etiologia , Neoplasias Induzidas por Radiação/etiologia , Neoplasias Cutâneas/etiologia , Luz Solar/efeitos adversos , Raios Ultravioleta/efeitos adversos , Inibidor p16 de Quinase Dependente de Ciclina , Humanos , Proteínas de Neoplasias/metabolismo , Proteína Supressora de Tumor p53/metabolismoRESUMO
Sodium nitrite (NaNO2), a food color fixative and preservative, contributes to carcinogenesis. We investigated the protective role of garlic oil against NaNO2-induced abnormalities in metabolic biochemical parameters and oxidative status in male albino rats. NaNO2 treatment for a period of three months induced a significant increase in serum levels of glucose, aspartate aminotransferase (AST), alanine aminotransferase (ALT), alkaline phosphatase (ALP), bilirubin, urea and creatinine as well as hepatic AST and ALT. However, significant decrease was recorded in liver ALP activity, glycogen content, and renal urea and creatinine levels. In parallel, a significant increase in lipid peroxidation, and a decrease in glutathione content and catalase activity were observed in the liver and the kidney. However, garlic oil supplementation showed a remarkable amelioration of these abnormalities. Our data indicate that garlic is a phytoantioxidant with powerful chemopreventive properties against chemically-induced oxidative stress.
Assuntos
Compostos Alílicos/farmacologia , Rim/efeitos dos fármacos , Fígado/efeitos dos fármacos , Nitratos/toxicidade , Estresse Oxidativo/efeitos dos fármacos , Sulfetos/farmacologia , Alanina Transaminase/sangue , Alanina Transaminase/metabolismo , Fosfatase Alcalina/sangue , Animais , Anticarcinógenos/farmacologia , Aspartato Aminotransferases/sangue , Aspartato Aminotransferases/metabolismo , Bilirrubina/sangue , Glicemia/análise , Carcinógenos/toxicidade , Catalase/análise , Creatinina/sangue , Creatinina/metabolismo , Gorduras Insaturadas na Dieta/administração & dosagem , Glutationa/análise , Rim/metabolismo , Peroxidação de Lipídeos/efeitos dos fármacos , Fígado/metabolismo , Glicogênio Hepático/metabolismo , Masculino , Ratos , Ureia/sangue , Ureia/metabolismoRESUMO
Spirulina platensis (SP) is a filamentous cyanobacterium microalgae with potent dietary phyto-antioxidant, anti-inflammatory and anti-cancerous properties. The present study aimed to investigate the chemopreventive effect of SP against rat liver toxicity and carcinogenesis induced by dibutyl nitrosamine (DBN) precursors, and further characterized its underlying mechanisms of action in HepG2 cell line. Investigation by light and electron microscopy showed that DBN treatment induced severe liver injury and histopathological abnormalities, which were prevented by SP supplementation. The incidence of liver tumors was significantly reduced from 80 to 20% by SP. Immunohistochemical results indicated that both PCNA and p53 were highly expressed in the liver of DBN-treated rats, but were significantly reduced by SP supplementation. Molecular analysis indicated that SP treatment inhibited cell proliferation, which was accompanied by increased p21 and decreased Rb expression levels at 48hrs post-treatment. In addition, SP increased Bax and decreased Bcl-2 expression, indicating induction of apoptosis by 48hrs. This is the first report of the in vivo chemopreventive effect of SP against DBN-induced rat liver cytotoxicity and carcinogenesis, suggesting its potential use in chemoprevention of cancer.
Assuntos
Carcinoma Hepatocelular/prevenção & controle , Neoplasias Hepáticas/prevenção & controle , Fígado/efeitos dos fármacos , Fígado/patologia , Nitrosaminas/toxicidade , Probióticos , Spirulina/química , Animais , Antioxidantes/farmacologia , Apoptose/efeitos dos fármacos , Western Blotting , Peso Corporal/efeitos dos fármacos , Carcinoma Hepatocelular/metabolismo , Ciclo Celular/efeitos dos fármacos , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Quimioprevenção/métodos , Humanos , Imuno-Histoquímica , Fígado/ultraestrutura , Neoplasias Hepáticas/induzido quimicamente , Neoplasias Hepáticas/metabolismo , Neoplasias Hepáticas/ultraestrutura , Masculino , Microscopia Eletrônica de Transmissão , RatosRESUMO
Riboflavin carrier protein (RCP) is a growth- and development-specific protein. Here, we characterized the expression of this protein in prostate cancer by polyclonal and monoclonal antibodies against chicken RCP. RCP was localized to both androgen-dependent and independent prostate cancer cell lines. Compared to controls, RCP was over-expressed in all 45 prostate adenocarcinomas, irrespective of the Gleason's score or the stage of the disease. The identified RCP had a molecular weight of 38 kDa, similar to RCP purified from chicken. Presence of this protein was also confirmed by siRNA inhibition analysis. Antibodies to chicken RCP inhibited incorporation of tritiated thymidine into DNA and prevented riboflavin uptake in PC3 prostate cancer cells, suggesting a critical function of this protein in prostate cancer cell growth. These data suggest that RCP can be used as a tumor biomarker in prostate cancer.