RESUMO
The Guide for the Care and Use of Laboratory Animals strongly encourages the use of pharmaceutical-grade chemicals and analgesics. Sustained-release buprenorphine (SRB) is administered extralabel to rodents to mitigate moderate to severe pain. An FDA-indexed buprenorphine formulation-extended-release buprenorphine (XRB)-has recently become available and is currently the only pharmaceutical-grade slow-release buprenorphine formulation approved for use in mice and rats. However, no studies have directly compared the pharmacokinetic parameters of SRB and XRB in surgically catheterized mice. To this end, we compared the plasma buprenorphine concentrations and pharmacokinetic parameters of SRB and XRB in mice after surgical catheterization. We hypothesized that mice treated before surgery with SRB or XRB would have circulating buprenorphine concentrations that exceeded the therapeutic threshold for as long as 72 h after surgery. Male and female C57Bl/6J mice were anesthetized, treated with a single dose of either SRB (1 mg/kg SC) or XRB (3.25 mg/kg SC), and underwent surgical catheterization. Arterial blood samples were collected at 6, 24, 48, and 72 h after administration. Weight loss after surgery (mean ± SEM) was similar between groups (SRB: males, 12% ± 2%; females, 8% ± 2%; XRB: males, 12% ± 1%; females, 8% ± 1%). Both SRB and XRB maintained circulating buprenorphine concentrations above the therapeutic level of 1.0 ng/mL for 72 h after administration. Plasma buprenorphine concentrations at 6, 24, and 48 h were significantly greater (3- to 4-fold) with XRB than SRB, commensurate with XRB's higher dose. These results support the use of either SRB or XRB for the alleviation of postoperative pain in mice. The availability of FDA-indexed XRB increases options for safe and effective pharmaceutical-grade analgesia in rodents.
Assuntos
Buprenorfina , Analgésicos/uso terapêutico , Analgésicos Opioides , Animais , Cateterismo/veterinária , Preparações de Ação Retardada , Feminino , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Dor Pós-Operatória/tratamento farmacológico , Dor Pós-Operatória/veterinária , RatosRESUMO
A growing body of evidence has demonstrated the promising anti-tumor effects of resveratrol in ovarian cancer cells, including its inhibitory effects on STAT3 activation. Nonetheless, the low bioavailability of resveratrol has reduced its attractiveness as a potential anti-cancer treatment. In contrast, pterostilbene, a stilbenoid and resveratrol analog, has demonstrated superior bioavailability, while possessing significant antitumor activity in multiple solid tumors. In this study, the therapeutic potential of pterostilbene was evaluated in ovarian cancer cells. Pterostilbene reduces cell viability in several different ovarian cancer cell lines by suppressing cell cycle progression and inducing apoptosis. Further molecular study has shown that pterostilbene effectively suppressed phosphorylation of STAT3, as well as STAT3 downstream genes that regulate cell cycle and apoptosis, indicating that inhibition of STAT3 pathway may be involved in its anti-tumor activity. The addition of pterostilbene to the commonly used chemotherapy cisplatin demonstrated synergistic antiproliferative activity in several ovarian cancer cell lines. Pterostilbene additionally inhibited cell migration in multiple ovarian cancer cell lines. The above results suggest that pterostilbene facilitates significant anti-tumor activity in ovarian cancer via anti-proliferative and pro-apoptotic mechanisms, possibly via downregulation of JAK/STAT3 pathway. Pterostilbene thus presents as an attractive non-toxic alternative for potential adjuvant or maintenance chemotherapy in ovarian cancer.
Assuntos
Antineoplásicos/farmacologia , Neoplasias Ovarianas/metabolismo , Fator de Transcrição STAT3/metabolismo , Estilbenos/farmacologia , Ciclo Celular/efeitos dos fármacos , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Feminino , Humanos , Neoplasias Ovarianas/tratamento farmacológico , Transdução de Sinais/efeitos dos fármacosRESUMO
Endometrial cancer is the most common gynecologic cancer in the United States and its incidence and mortality has been rising over the past decade. Few treatment options are available for patients with advanced and recurring endometrial cancers. Novel therapies, which are frequently toxic, are difficult to establish in this patient population which tends to be older and plagued by comorbidities such as diabetes mellitus and hypertension. Therefore, novel, non-toxic therapies are urgently needed. Megestrol acetate is a frequently used drug in endometrial cancer patients. However, its response rate is only 20-30%. To enhance the activity of megestrol acetate in endometrial cancer patients, we explored the potential of combining natural supplements with megestrol acetate and found that the addition of the natural phenolic compound, pterostilbene, to megestrol acetate resulted in a synergistic inhibition of cancer cell growth in vitro and an enhanced reduction of tumor growth in a xenograft mouse model. In addition, dual treatment led to attenuation of signaling pathways, as well as cell cycle and survival pathways. Our results demonstrated for the first time that the anti-tumor activity of megestrol acetate can be enhanced by combining with pterostilbene, providing an insight into the potential application of pterostilbene and megestrol acetate combination for the treatment of endometrial cancer.
Assuntos
Antineoplásicos/uso terapêutico , Produtos Biológicos/uso terapêutico , Neoplasias do Endométrio/tratamento farmacológico , Acetato de Megestrol/uso terapêutico , Fenóis/uso terapêutico , Estilbenos/uso terapêutico , Animais , Antineoplásicos/farmacologia , Protocolos de Quimioterapia Combinada Antineoplásica/farmacologia , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Produtos Biológicos/farmacologia , Ciclo Celular/efeitos dos fármacos , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Sinergismo Farmacológico , Neoplasias do Endométrio/patologia , Feminino , Humanos , Sistema de Sinalização das MAP Quinases/efeitos dos fármacos , Acetato de Megestrol/farmacologia , Camundongos Nus , Fenóis/farmacologia , Fator de Transcrição STAT3/metabolismo , Transdução de Sinais/efeitos dos fármacos , Estilbenos/farmacologia , Ensaios Antitumorais Modelo de XenoenxertoRESUMO
Epithelial ovarian cancer (EOC) is the most deadly gynecologic malignancy on account of its late stage at diagnosis and frequency of drug resistant recurrences. Novel therapies to overcome these barriers are urgently needed. TWIST is a developmental transcription factor reactivated in cancers and linked to angiogenesis, metastasis, cancer stem cell phenotype, and drug resistance, making it a promising therapeutic target. In this work, we demonstrate the efficacy of TWIST siRNA (siTWIST) and two nanoparticle delivery platforms to reverse chemoresistance in EOC models. Polyamidoamine dendrimers and mesoporous silica nanoparticles (MSNs) carried siTWIST into target cells and led to sustained TWIST knockdown in vitro. Mice treated with cisplatin plus MSN-siTWIST exhibited lower tumor burden than mice treated with cisplatin alone, with most of the effect coming from reduction in disseminated tumors. This platform has potential application for overcoming the clinical challenges of metastasis and chemoresistance in EOC and other TWIST overexpressing cancers.
Assuntos
Nanopartículas/química , Neoplasias Epiteliais e Glandulares/terapia , Neoplasias Ovarianas/terapia , RNA Interferente Pequeno/administração & dosagem , RNA Interferente Pequeno/uso terapêutico , Terapêutica com RNAi/métodos , Dióxido de Silício/química , Proteína 1 Relacionada a Twist/genética , Animais , Carcinoma Epitelial do Ovário , Linhagem Celular Tumoral , Dendrímeros/química , Feminino , Humanos , Camundongos , Camundongos Endogâmicos NOD , Nanopartículas/ultraestrutura , Neoplasias Epiteliais e Glandulares/genética , Neoplasias Epiteliais e Glandulares/patologia , Neoplasias Ovarianas/genética , Neoplasias Ovarianas/patologia , Ovário/metabolismo , Ovário/patologia , Porosidade , RNA Interferente Pequeno/genéticaRESUMO
Although essential to professional competence in psychology, quantitative research methods are a known area of weakness for many undergraduate psychology students. Students find selecting appropriate statistical tests and procedures for different types of research questions, hypotheses and data types particularly challenging, and these skills are not often practiced in class. Decision trees (a type of graphic organizer) are known to facilitate this decision making process, but extant trees have a number of limitations. Furthermore, emerging research suggests that mobile technologies offer many possibilities for facilitating learning. It is within this context that we have developed StatHand, a free cross-platform application designed to support students' statistical decision making. Developed with the support of the Australian Government Office for Learning and Teaching, StatHand guides users through a series of simple, annotated questions to help them identify a statistical test or procedure appropriate to their circumstances. It further offers the guidance necessary to run these tests and procedures, then interpret and report their results. In this Technology Report we will overview the rationale behind StatHand, before describing the feature set of the application. We will then provide guidelines for integrating StatHand into the research methods curriculum, before concluding by outlining our road map for the ongoing development and evaluation of StatHand.
RESUMO
An important task facing both researchers and animal core facilities is producing sufficient mice for a given project. The inherent biologic variability of mouse reproduction and litter size further challenges effective research planning. A lack of precision in project planning contributes to the high cost of animal research, overproduction (thus waste) of animals, and inappropriate allocation of facility resources. To examine the extent daily prepartum maternal weight gain predicts litter size in 2 commonly used mouse strains (BALB/cJ and C57BL/6J) and one mouse stock (Swiss Webster), we weighed ≥ 25 pregnant dams of each strain or stock daily from the morning on which a vaginal plug (day 0) was present. On the morning when dams delivered their pups, we recorded the weight of the dam, the weight of the litter itself, and the number of pups. Litter sizes ranged from 1 to 7 pups for BALB/cJ, 2 to 13 for Swiss Webster, and 5 to 11 for C57BL/6J mice. Linear regression models (based on weight change from day 0) demonstrated that maternal weight gain at day 9 (BALB/cJ), day 11 (Swiss Webster), or day 14 (C57BL/6J) was a significant predictor of litter size. When tested prospectively, the linear regression model for each strain or stock was found to be accurate. These data indicate that the number of pups that will be born can be estimated accurately by using maternal weight gain at specific or stock-specific time points.
Assuntos
Peso Corporal , Tamanho da Ninhada de Vivíparos , Camundongos/fisiologia , Prenhez/fisiologia , Animais , Feminino , Modelos Lineares , Camundongos/classificação , Camundongos Endogâmicos BALB C , Camundongos Endogâmicos C57BL , Gravidez , Reprodução , Aumento de PesoRESUMO
Growth and progression of solid tumors depend on the integration of multiple pro-growth and survival signals, including the induction of angiogenesis. TWIST1 is a transcription factor whose reactivation in tumors leads to epithelial to mesenchymal transition (EMT), including increased cancer cell stemness, survival, and invasiveness. Additionally, TWIST1 drives angiogenesis via activation of IL-8 and CCL2, independent of VEGF signaling. In this work, results suggest that chemically modified siRNA against TWIST1 reverses EMT both in vitro and in vivo. siRNA delivery with a polyethyleneimine-coated mesoporous silica nanoparticle (MSN) led to reduction of TWIST1 target genes and migratory potential in vitro. In mice bearing xenograft tumors, weekly intravenous injections of the siRNA-nanoparticle complexes resulted in decreased tumor burden together with a loss of CCL2 suggesting a possible anti-angiogenic response. Therapeutic use of TWIST1 siRNA delivered via MSNs has the potential to inhibit tumor growth and progression in many solid tumor types. FROM THE CLINICAL EDITOR: Tumor progression and metastasis eventually lead to patient mortality in the clinical setting. In other studies, it has been found that TWIST1, a transcription factor, if reactivated in tumors, would lead to downstream events including angiogenesis and result in poor prognosis in cancer patients. In this article, the authors were able to show that when siRNA against TWIST1 was delivered via mesoporous silica nanoparticle, there was tumor reduction in an in-vivo model. The results have opened up a new avenue for further research in this field.
Assuntos
Nanopartículas/administração & dosagem , Neoplasias/terapia , Neovascularização Patológica/terapia , Proteínas Nucleares/genética , RNA Interferente Pequeno/administração & dosagem , Proteína 1 Relacionada a Twist/genética , Animais , Linhagem Celular Tumoral , Técnicas de Transferência de Genes , Humanos , Camundongos , Nanopartículas/química , Neoplasias/genética , Neoplasias/patologia , Neovascularização Patológica/genética , Proteínas Nucleares/antagonistas & inibidores , RNA Interferente Pequeno/química , Dióxido de Silício/administração & dosagem , Dióxido de Silício/química , Carga Tumoral/genética , Proteína 1 Relacionada a Twist/antagonistas & inibidores , Ensaios Antitumorais Modelo de XenoenxertoRESUMO
Breast cancer is the leading cause of cancer-related deaths among women in the United States, and survival rates are lower for patients with metastases and/or triple-negative breast cancer (TNBC; ER, PR, and Her2 negative). Understanding the mechanisms of cancer metastasis is therefore crucial to identify new therapeutic targets and develop novel treatments to improve patient outcomes. A potential target is the TWIST1 transcription factor, which is often overexpressed in aggressive breast cancers and is a master regulator of cellular migration through epithelial-mesenchymal transition (EMT). Here, we demonstrate an siRNA-based TWIST1 silencing approach with delivery using a modified poly(amidoamine) (PAMAM) dendrimer. Our results demonstrate that SUM1315 TNBC cells efficiently take up PAMAM-siRNA complexes, leading to significant knockdown of TWIST1 and EMT-related target genes. Knockdown lasts up to one week after transfection and leads to a reduction in migration and invasion, as determined by wound healing and transwell assays. Furthermore, we demonstrate that PAMAM dendrimers can deliver siRNA to xenograft orthotopic tumors and siRNA remains in the tumor for at least four hours after treatment. These results suggest that further development of dendrimer-based delivery of siRNA for TWIST1 silencing may lead to a valuable adjunctive therapy for patients with TNBC.
Assuntos
Neoplasias da Mama/tratamento farmacológico , Neoplasias da Mama/genética , Dendrímeros/farmacologia , Metástase Neoplásica/tratamento farmacológico , Proteínas Nucleares/antagonistas & inibidores , RNA/genética , Proteína 1 Relacionada a Twist/antagonistas & inibidores , Linhagem Celular Tumoral , Movimento Celular/efeitos dos fármacos , Movimento Celular/genética , Transição Epitelial-Mesenquimal/efeitos dos fármacos , Transição Epitelial-Mesenquimal/genética , Feminino , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Regulação Neoplásica da Expressão Gênica/genética , Humanos , Invasividade Neoplásica/genética , Metástase Neoplásica/genética , Proteínas Nucleares/genética , RNA Interferente Pequeno/genética , Fatores de Transcrição/genética , Transfecção/métodos , Proteína 1 Relacionada a Twist/genéticaRESUMO
BACKGROUND: Metastasis is the primary cause of death for cancer patients. TWIST1, an evolutionarily conserved basic helix-loop-helix (bHLH) transcription factor, is a strong promoter of metastatic spread and its expression is elevated in many advanced human carcinomas. However, the molecular events triggered by TWIST1 to motivate dissemination of cancer cells are largely unknown. RESULTS: Here we show that TWIST1 induces the production of interleukin 8 (IL8), which activates matrix metalloproteinases and promotes invasion of breast epithelial and cancer cells. In this novel mechanism, TWIST1-mediated IL8 transcription is induced through the TWIST1 carboxy-terminal WR (Trp-Arg) domain instead of the classic DNA binding bHLH domain. Co-immunoprecipitation analyses revealed that the WR domain mediates the formation of a protein complex comprised of TWIST1 and the nuclear factor-kappaB (NF-κB) subunit RELA (p65/NF-κB3), which synergistically activates the transcriptional activity of NF-κB. This activation leads to increased DNA binding affinity of RELA to the IL8 promoter and thus induces the expression of the cytokine. Blockage of IL8 signaling by IL8 neutralizing antibodies or receptor inhibition reduced the invasiveness of both breast epithelial and cancer cells, indicating that TWIST1 induces autonomous cell invasion by establishing an IL8 antocrine loop. CONCLUSIONS: Our data demonstrate that the TWIST1 WR domain plays a critical role in TWIST1-induced IL8 expression through interactions with and activation of NF-κB. The produced IL8 signals through an autocrine loop and promotes extracellular matrix degradation to enable cell invasion across the basement membrane.
Assuntos
Interleucina-8/metabolismo , NF-kappa B/metabolismo , Proteínas Nucleares/metabolismo , Fator de Transcrição RelA/metabolismo , Proteína 1 Relacionada a Twist/metabolismo , Neoplasias da Mama/metabolismo , Linhagem Celular Tumoral , Feminino , Humanos , Interleucina-8/genética , NF-kappa B/química , Invasividade Neoplásica , Proteínas Nucleares/genética , Regiões Promotoras Genéticas , Estrutura Terciária de Proteína , Fator de Transcrição RelA/genética , Proteína 1 Relacionada a Twist/genéticaRESUMO
Marek's disease virus (MDV) is ubiquitous within commercial poultry flocks because current vaccines do not prevent MDV infection or transmission. In order for newly-evolved MDV strains to become established within a flock, it seems inevitable that any new strain would need to infect and replicate in chickens previously infected with resident MDV strains. This phenomenon is difficult to detect and there is no clear evidence that it is even possible. Four experiments were performed to demonstrate superinfection and evaluate the effect of time between challenges on the effect of superinfection with the use of two pairs of fully virulent MDV strains that could be discriminated by novel technology: 1) JM/102W and rMd5//38CVI, and 2) rMd5 and rMd5//38CVI. Feather follicle epithelium (FFE), spleen, and tumor samples were collected at single or multiple time points from the same bird to determine the frequency and distribution of each virus present following superinfection, with the use of pyrosequencing and immunohistochemistry. Superinfection was observed in 82 of 149 (55%) FFE samples following short-interval challenge (24 hr) compared to only 6 of 121 (5%) samples following long-interval challenge (13 days), indicating a strong influence of challenge interval. In cases where the first inoculated virus was weak or delayed, the second inoculated virus was detected in 42 of 95 (44%) birds. In tumors from dually challenged birds, the second virus was again present much more often following short-interval challenge (68%) compared to long-interval challenge (11%). Virus mixtures in tumors were less common compared to those in FFE samples. Vaccination with turkey herpesvirus had no significant effect on the virus frequency for either virus pair or challenge time interval, suggesting these conclusions may be applicable to vaccinated chickens in the field. These studies demonstrated superinfection for the first time with two fully virulent MDV strains and suggest that short-interval challenge exposure and/or weak initial exposures may be important factors leading to superinfection--a prerequisite for the establishment of a second virus strain in the population. This model system should be useful to elucidate this important phenomenon further.
Assuntos
Galinhas , Mardivirus/imunologia , Doença de Marek/prevenção & controle , Superinfecção/veterinária , Vacinas Virais/imunologia , Animais , Feminino , Esquemas de Imunização , Masculino , Mardivirus/patogenicidade , Doença de Marek/imunologia , Organismos Livres de Patógenos Específicos , Superinfecção/virologia , Fatores de Tempo , VirulênciaRESUMO
During a videofluoroscopic swallowing study (VFSS), speech and language pathologists (SLPs) are potentially exposed to radiation. To effectively limit unnecessary exposure, SLPs performing VFSS are encouraged to actively shield themselves and to be monitored by radiation-monitoring badges. The aim of this research was to assess the level of current knowledge and practice of radiation protection among SLPs performing this procedure. A questionnaire was distributed via Speech Pathology Australia (SPA) and the Australasian Dysphagia Newsletter (ADN). Sixty-nine questionnaires were returned. The results revealed that participants had received some radiation protection training, which provided them with general knowledge on radiation protection. Participants indicated a lack of formal education and were unsure of the adequacy of the information provided. Ninety-seven percent of participants always wore lead aprons, 76% always wore thyroid shields, and 36% wore radiation-monitoring badges. The researchers recommend that education on radiation protection and safety be provided for SLPs at university level to educate them before they enter the workplace. It is also recommended that SLPs always wear lead aprons, thyroid shields, and radiation-monitoring badges.