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1.
Int J Surg Pathol ; 30(2): 167-169, 2022 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-34142902

RESUMO

Nodular hyperplasia of the Bartholin's gland is an underreported and extremely rare entity that presents as a solid lesion potentially raising concern for malignancy clinically, most solid lesions at this location are carcinomas. They may also be mistaken for a Bartholin cyst clinically. Nodular hyperplasia is rarer than carcinoma of the Bartholin gland, and hence pathologists may not be familiar with this entity, making it a pitfall in pathologic as well as a clinical diagnosis. Here we report a case originally considered a Bartholin cyst, but raising intraoperative concern due to solid elements. Histological examination of the lesion revealed nodular hyperplasia of Bartholin's gland. Recognition of this entity is important, as it is something that may be encountered by the pathologist.


Assuntos
Glândulas Vestibulares Maiores , Carcinoma , Cistos , Neoplasias Vulvares , Glândulas Vestibulares Maiores/patologia , Carcinoma/patologia , Cistos/diagnóstico , Cistos/patologia , Cistos/cirurgia , Feminino , Humanos , Hiperplasia/patologia , Neoplasias Vulvares/diagnóstico
2.
Cancer Metab ; 9(1): 31, 2021 Aug 16.
Artigo em Inglês | MEDLINE | ID: mdl-34399819

RESUMO

BACKGROUND: Metabolic reprogramming is a central feature in many cancer subtypes and a hallmark of cancer. Many therapeutic strategies attempt to exploit this feature, often having unintended side effects on normal metabolic programs and limited efficacy due to integrative nature of metabolic substrate sourcing. Although the initiating oncogenic lesion may vary, tumor cells in lymphoid malignancies often share similar environments and potentially similar metabolic profiles. We examined cells from mouse models of MYC-, RAS-, and BCR-ABL-driven lymphoid malignancies and find a convergence on de novo lipogenesis. We explore the potential role of MYC in mediating lipogenesis by 13C glucose tracing and untargeted metabolic profiling. Inhibition of lipogenesis leads to cell death both in vitro and in vivo and does not induce cell death of normal splenocytes. METHODS: We analyzed RNA-seq data sets for common metabolic convergence in lymphoma and leukemia. Using in vitro cell lines derived in from conditional MYC, RAS, and BCR-ABL transgenic murine models and oncogene-driven human cell lines, we determined gene regulation, metabolic profiles, and sensitivity to inhibition of lipogenesis in lymphoid malignancies. We utilize preclinical murine models and transgenic primary model of T-ALL to determine the effect of lipogenesis blockade across BCR-ABL-, RAS-, and c-MYC-driven lymphoid malignancies. Statistical significance was calculated using unpaired t-tests and one-way ANOVA. RESULTS: This study illustrates that de novo lipid biogenesis is a shared feature of several lymphoma subtypes. Using cell lines derived from conditional MYC, RAS, and BCR-ABL transgenic murine models, we demonstrate shared responses to inhibition of lipogenesis by the acetyl-coA carboxylase inhibitor 5-(tetradecloxy)-2-furic acid (TOFA), and other lipogenesis inhibitors. We performed metabolic tracing studies to confirm the influence of c-MYC and TOFA on lipogenesis. We identify specific cell death responses to TOFA in vitro and in vivo and demonstrate delayed engraftment and progression in vivo in transplanted lymphoma cell lines. We also observe delayed progression of T-ALL in a primary transgenic mouse model upon TOFA administration. In a panel of human cell lines, we demonstrate sensitivity to TOFA treatment as a metabolic liability due to the general convergence on de novo lipogenesis in lymphoid malignancies driven by MYC, RAS, or BCR-ABL. Importantly, cell death was not significantly observed in non-malignant cells in vivo. CONCLUSIONS: These studies suggest that de novo lipogenesis may be a common survival strategy for many lymphoid malignancies and may be a clinically exploitable metabolic liability. TRIAL REGISTRATION: This study does not include any clinical interventions on human subjects.

3.
Case Rep Obstet Gynecol ; 2020: 8892014, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32802533

RESUMO

Surgical correction is considered in women with symptomatic pelvic organ prolapse (POP). There is an expected increase in the prevalence of surgical correction due to an aging population within the United States. Individuals with previous colorectal surgery present a unique challenge considering the changes in pelvic anatomy. This case discusses the challenges of posterior colporrhaphy in a patient with previous, remote J-pouch surgery. In traditional posterior colporrhaphy, randomized controlled trials have not shown any benefit of graft augmentation (Maher, 2016). However, the utilization of a biologic graft to improve anatomical correction is discussed in this unique case. Short term anatomical success was obtained without immediate complications in the postoperative period. In a patient with a history of ulcerative colitis with colorectal resection and a J-pouch, surgery can be challenging due to alterations of pelvic anatomy. Modification of the standard surgical approach may be required to achieve success.

4.
Front Immunol ; 11: 832, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32457754

RESUMO

Inhibitors that block the programmed cell death-1 (PD-1) pathway can potentiate endogenous antitumor immunity and have markedly improved cancer survival rates across a broad range of indications. However, these treatments work for only a minority of patients. The efficacy of anti-PD-1 inhibitors may be extended by cytokines, however, the incorporation of cytokines into therapeutic regimens has significant challenges. In their natural form when administered as recombinant proteins, cytokine treatments are often associated with low response rates. Most cytokines have a short half-life which limits their exposure and efficacy. In addition, cytokines can activate counterregulatory pathways, in the case of immune-potentiating cytokines this can lead to immune suppression and thereby diminish their potential efficacy. Improving the drug-like properties of natural cytokines using protein engineering can yield synthetic cytokines with improved bioavailability and tissue targeting, allowing for enhanced efficacy and reduced off-target effects. Using structure guided engineering we have designed a novel class of antibody-cytokine fusion proteins consisting of a PD-1 targeting antibody fused together with an interleukin-21 (IL-21) cytokine mutein. Our bifunctional fusion proteins can block PD-1/programmed death-ligand 1 (PD-L1) interaction whilst simultaneously delivering IL-21 cytokine to PD-1 expressing T cells. Targeted delivery of IL-21 can improve T cell function in a manner that is superior to anti-PD-1 monotherapy. Fusion of engineered IL-21 variants to anti-PD1 antibodies can improve the drug-like properties of IL-21 cytokine leading to improved cytokine serum half-life allowing for less frequent dosing. In addition, we show that targeted delivery of IL-21 can minimize any potential detrimental effect on local antigen-presenting cells. A highly attenuated IL-21 mutein variant (R9E:R76A) fused to a PD-1 antibody provides protection in a humanized mouse model of cancer that is refractory to anti-PD-1 monotherapy. Collectively, our preclinical data demonstrate that this approach may improve upon and extend the utility of anti-PD-1 therapeutics currently in the clinic.


Assuntos
Anticorpos Monoclonais/uso terapêutico , Antígeno B7-H1/antagonistas & inibidores , Linfócitos T CD8-Positivos/imunologia , Imunoterapia , Interleucinas/uso terapêutico , Neoplasias/terapia , Animais , Anticorpos Monoclonais/imunologia , Antígeno B7-H1/imunologia , Modelos Animais de Doenças , Feminino , Humanos , Interleucinas/imunologia , Camundongos , Camundongos Endogâmicos BALB C , Camundongos SCID , Neoplasias/imunologia , Engenharia de Proteínas , Proteínas Recombinantes de Fusão/imunologia , Proteínas Recombinantes de Fusão/uso terapêutico
5.
Cureus ; 11(6): e4913, 2019 Jun 17.
Artigo em Inglês | MEDLINE | ID: mdl-31417833

RESUMO

We report on the treatment of a Basal Cell Carcinoma of the skin with high-dose-rate (HDR) brachytherapy using a 3D-printed surface mold. The lesion was treated with 40 Gy in 10 fractions, administered every second day. The treatment was well tolerated and there were no significant toxicities. The patient had a complete response to radiation therapy. So it can concluded that 3D printed surface molds can be effectively used in the context of HDR skin brachytherapy.

6.
Cureus ; 11(12): e6412, 2019 Dec 18.
Artigo em Inglês | MEDLINE | ID: mdl-31988814

RESUMO

Purpose To report on skin tumor treatment with surface mould brachytherapy at our institution. Methods This was a retrospective review for all patients with skin tumors treated using Ir-192 high dose rate (HDR) surface mould brachytherapy from January 1, 2010 to December 31, 2017 in British Columbia. We identified 65 lesions (59 patients). Median age at diagnosis was 83 (range = 45-97). The majority were basal cell (54%, n = 35) or squamous cell carcinomas (31%, n = 20). Most lesions were located in the head and neck region. The most commonly used RT dose was 40 Gy/10 fractions; all patients had individualized CT-based planning. Results The two-year overall survival (OS) was 77.6% and two-year progression-free survival (PFS) was 71.5%. Most deaths were from unrelated causes. Response was assessed in clinic 2-4 months post-treatment. Our complete response (CR) rate was 96.8%, with partial response in two patients; two patients could not be assessed for response. We report a two-year local control (LC) rate of 84.9%, and local recurrence in five patients. The procedure was well tolerated, with no grade 3-5 acute or late toxicities. There was one case of grade 2 radionecrosis (Common Terminology Criteria for Adverse Events (CTCAE) v. 4.03). The 100% isodose line median depth was 0.5 cm, and median surface dose = 126.5%. The median V90 = 92.3%. Conclusion Surface mould brachytherapy for skin tumors is a safe and effective modality, with excellent response rates. It is well-tolerated and a non-invasive option for elderly patients with comorbidities.

8.
Blood ; 131(18): 2007-2015, 2018 05 03.
Artigo em Inglês | MEDLINE | ID: mdl-29514782

RESUMO

The MYC proto-oncogene is a gene product that coordinates the transcriptional regulation of a multitude of genes that are essential to cellular programs required for normal as well as neoplastic cellular growth and proliferation, including cell cycle, self-renewal, survival, cell growth, metabolism, protein and ribosomal biogenesis, and differentiation. Here, we propose that MYC regulates these programs in a manner that is coordinated with a global influence on the host immune response. MYC had been presumed to contribute to tumorigenesis through tumor cell-intrinsic influences. More recently, MYC expression in tumor cells has been shown to regulate the tumor microenvironment through effects on both innate and adaptive immune effector cells and immune regulatory cytokines. Then, MYC was shown to regulate the expression of the immune checkpoint gene products CD47 and programmed death-ligand 1. Similarly, other oncogenes, which are known to modulate MYC, have been shown to regulate immune checkpoints. Hence, MYC may generally prevent highly proliferative cells from eliciting an immune response. MYC-driven neoplastic cells have coopted this mechanism to bypass immune detection. Thus, MYC inactivation can restore the immune response against a tumor. MYC-induced tumors may be particularly sensitive to immuno-oncology therapeutic interventions.


Assuntos
Regulação da Expressão Gênica , Imunidade/genética , Proteínas Proto-Oncogênicas c-myc/genética , Animais , Antígeno B7-H1/genética , Antígeno B7-H1/metabolismo , Biomarcadores Tumorais , Regulação Neoplásica da Expressão Gênica , Humanos , Imunomodulação/genética , Neoplasias/genética , Neoplasias/imunologia , Neoplasias/metabolismo , Neoplasias/patologia , Oncogenes , Proto-Oncogene Mas
9.
Trends Immunol ; 38(4): 298-305, 2017 04.
Artigo em Inglês | MEDLINE | ID: mdl-28233639

RESUMO

Cancers are often initiated by genetic events that activate proto-oncogenes or inactivate tumor-suppressor genes. These events are also crucial for sustained tumor cell proliferation and survival, a phenomenon described as oncogene addiction. In addition to this cell-intrinsic role, recent evidence indicates that oncogenes also directly regulate immune responses, leading to immunosuppression. Expression of many oncogenes or loss of tumor suppressors induces the expression of immune checkpoints that regulate the immune response, such as PD-L1. We discuss here how oncogenes, and in particular MYC, suppress immune surveillance, and how oncogene-targeted therapies may restore the immune response against tumors.


Assuntos
Carcinogênese , Tolerância Imunológica , Neoplasias/metabolismo , Proteínas Proto-Oncogênicas c-myc/imunologia , Proteínas Supressoras de Tumor/imunologia , Animais , Antígeno B7-H1/genética , Antígeno B7-H1/metabolismo , Carcinogênese/genética , Proliferação de Células , Regulação Neoplásica da Expressão Gênica , Humanos , Vigilância Imunológica , Imunomodulação , Terapia de Alvo Molecular , Neoplasias/tratamento farmacológico , Neoplasias/genética , Evasão Tumoral
10.
Cureus ; 8(9): e767, 2016 Sep 04.
Artigo em Inglês | MEDLINE | ID: mdl-27725923

RESUMO

PURPOSE: Non-melanotic skin cancers remain the most commonly diagnosed cancers. Radiotherapy and surgery are the most common treatment options. Radiotherapy has a recurrence rate of up to 20% for basal or squamous cell cancers. One of the difficulties is to determine the extent of disease for poorly demarcated tumors. This study utilizes protoporphyrin (PpIX) fluorescence to provide information on the extent of subclinical disease for poorly demarcated tumors treated with radiotherapy. MATERIALS AND METHODS: For 33 patients, PpIX photo-delineation was used to determine the clinical target volume (CTV2), which was compared to current conventional margins used to account for microscopic disease. RESULTS: The use of PpIX photo-delineation demonstrated a significantly larger CTV of 15 mm compared to the conventional 10 mm (p = 0.03) for poorly demarcated lesions. A larger CTV was also demonstrated with PpIX photo-delineation for all basal cell carcinomas (13 mm, p = 0.03) as well as for non-nasal lesions (14 mm, p = 0.04). A trend towards an increased CTV was also noted for squamous cell carcinomas (16 mm, p = 0.19) and nasal primary sites (14 mm, p = 0.11). Nasal primary malignancies had multifocal PpIX uptake in 94% of cases. There was one case of local recurrence and one case of distant recurrence, with an average follow-up time of 22 months. CONCLUSIONS: The margins currently used to account for subclinical disease may underestimate the extent of microscopic spread for poorly demarcated tumors. Longer follow-up with larger pools of patients are necessary to determine if using PpIX photo-delineation translates into significantly improved clinical outcomes.

11.
Science ; 352(6282): 227-31, 2016 Apr 08.
Artigo em Inglês | MEDLINE | ID: mdl-26966191

RESUMO

The MYC oncogene codes for a transcription factor that is overexpressed in many human cancers. Here we show that MYC regulates the expression of two immune checkpoint proteins on the tumor cell surface: the innate immune regulator CD47 (cluster of differentiation 47) and the adaptive immune checkpoint PD-L1 (programmed death-ligand 1). Suppression of MYC in mouse tumors and human tumor cells caused a reduction in the levels of CD47 and PD-L1 messenger RNA and protein. MYC was found to bind directly to the promoters of the Cd47 and Pd-l1 genes. MYC inactivation in mouse tumors down-regulated CD47 and PD-L1 expression and enhanced the antitumor immune response. In contrast, when MYC was inactivated in tumors with enforced expression of CD47 or PD-L1, the immune response was suppressed, and tumors continued to grow. Thus, MYC appears to initiate and maintain tumorigenesis, in part, through the modulation of immune regulatory molecules.


Assuntos
Antígeno B7-H1/genética , Antígeno CD47/genética , Transformação Celular Neoplásica/imunologia , Regulação Neoplásica da Expressão Gênica , Tolerância Imunológica/genética , Proteínas Proto-Oncogênicas c-myc/metabolismo , Animais , Linhagem Celular Tumoral , Transformação Celular Neoplásica/genética , Regulação para Baixo , Técnicas de Silenciamento de Genes , Humanos , Células Jurkat , Linfoma/genética , Linfoma/imunologia , Camundongos , Leucemia-Linfoma Linfoblástico de Células T Precursoras/genética , Leucemia-Linfoma Linfoblástico de Células T Precursoras/imunologia , Regiões Promotoras Genéticas , Proteínas Proto-Oncogênicas c-myc/genética , RNA Interferente Pequeno/genética
12.
Semin Cancer Biol ; 35 Suppl: S276-S304, 2015 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-26590477

RESUMO

Targeted therapies and the consequent adoption of "personalized" oncology have achieved notable successes in some cancers; however, significant problems remain with this approach. Many targeted therapies are highly toxic, costs are extremely high, and most patients experience relapse after a few disease-free months. Relapses arise from genetic heterogeneity in tumors, which harbor therapy-resistant immortalized cells that have adopted alternate and compensatory pathways (i.e., pathways that are not reliant upon the same mechanisms as those which have been targeted). To address these limitations, an international task force of 180 scientists was assembled to explore the concept of a low-toxicity "broad-spectrum" therapeutic approach that could simultaneously target many key pathways and mechanisms. Using cancer hallmark phenotypes and the tumor microenvironment to account for the various aspects of relevant cancer biology, interdisciplinary teams reviewed each hallmark area and nominated a wide range of high-priority targets (74 in total) that could be modified to improve patient outcomes. For these targets, corresponding low-toxicity therapeutic approaches were then suggested, many of which were phytochemicals. Proposed actions on each target and all of the approaches were further reviewed for known effects on other hallmark areas and the tumor microenvironment. Potential contrary or procarcinogenic effects were found for 3.9% of the relationships between targets and hallmarks, and mixed evidence of complementary and contrary relationships was found for 7.1%. Approximately 67% of the relationships revealed potentially complementary effects, and the remainder had no known relationship. Among the approaches, 1.1% had contrary, 2.8% had mixed and 62.1% had complementary relationships. These results suggest that a broad-spectrum approach should be feasible from a safety standpoint. This novel approach has potential to be relatively inexpensive, it should help us address stages and types of cancer that lack conventional treatment, and it may reduce relapse risks. A proposed agenda for future research is offered.


Assuntos
Heterogeneidade Genética , Terapia de Alvo Molecular , Neoplasias/terapia , Medicina de Precisão , Antineoplásicos Fitogênicos/uso terapêutico , Resistencia a Medicamentos Antineoplásicos/genética , Humanos , Neoplasias/genética , Neoplasias/patologia , Neoplasias/prevenção & controle , Transdução de Sinais , Microambiente Tumoral/genética
13.
Regul Toxicol Pharmacol ; 73(3): 1007-17, 2015 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-26239693

RESUMO

We present a detailed response to the critique of "State of the Science of Endocrine Disrupting Chemicals 2012" (UNEP/WHO, 2013) by financial stakeholders, authored by Lamb et al. (2014). Lamb et al.'s claim that UNEP/WHO (2013) does not provide a balanced perspective on endocrine disruption is based on incomplete and misleading quoting of the report through omission of qualifying statements and inaccurate description of study objectives, results and conclusions. Lamb et al. define extremely narrow standards for synthesizing evidence which are then used to dismiss the UNEP/WHO 2013 report as flawed. We show that Lamb et al. misuse conceptual frameworks for assessing causality, especially the Bradford-Hill criteria, by ignoring the fundamental problems that exist with inferring causality from empirical observations. We conclude that Lamb et al.'s attempt of deconstructing the UNEP/WHO (2013) report is not particularly erudite and that their critique is not intended to be convincing to the scientific community, but to confuse the scientific data. Consequently, it promotes misinterpretation of the UNEP/WHO (2013) report by non-specialists, bureaucrats, politicians and other decision makers not intimately familiar with the topic of endocrine disruption and therefore susceptible to false generalizations of bias and subjectivity.


Assuntos
Disruptores Endócrinos/toxicidade , Animais , Humanos
14.
Carcinogenesis ; 36 Suppl 1: S160-83, 2015 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-26106136

RESUMO

Potentially carcinogenic compounds may cause cancer through direct DNA damage or through indirect cellular or physiological effects. To study possible carcinogens, the fields of endocrinology, genetics, epigenetics, medicine, environmental health, toxicology, pharmacology and oncology must be considered. Disruptive chemicals may also contribute to multiple stages of tumor development through effects on the tumor microenvironment. In turn, the tumor microenvironment consists of a complex interaction among blood vessels that feed the tumor, the extracellular matrix that provides structural and biochemical support, signaling molecules that send messages and soluble factors such as cytokines. The tumor microenvironment also consists of many host cellular effectors including multipotent stromal cells/mesenchymal stem cells, fibroblasts, endothelial cell precursors, antigen-presenting cells, lymphocytes and innate immune cells. Carcinogens can influence the tumor microenvironment through effects on epithelial cells, the most common origin of cancer, as well as on stromal cells, extracellular matrix components and immune cells. Here, we review how environmental exposures can perturb the tumor microenvironment. We suggest a role for disrupting chemicals such as nickel chloride, Bisphenol A, butyltins, methylmercury and paraquat as well as more traditional carcinogens, such as radiation, and pharmaceuticals, such as diabetes medications, in the disruption of the tumor microenvironment. Further studies interrogating the role of chemicals and their mixtures in dose-dependent effects on the tumor microenvironment could have important general mechanistic implications for the etiology and prevention of tumorigenesis.


Assuntos
Exposição Ambiental/efeitos adversos , Substâncias Perigosas/efeitos adversos , Microambiente Tumoral/efeitos dos fármacos , Animais , Carcinogênese/induzido quimicamente , Humanos , Neoplasias/induzido quimicamente
15.
Proc Natl Acad Sci U S A ; 112(21): 6539-44, 2015 May 26.
Artigo em Inglês | MEDLINE | ID: mdl-25964345

RESUMO

The MYC oncogene is frequently mutated and overexpressed in human renal cell carcinoma (RCC). However, there have been no studies on the causative role of MYC or any other oncogene in the initiation or maintenance of kidney tumorigenesis. Here, we show through a conditional transgenic mouse model that the MYC oncogene, but not the RAS oncogene, initiates and maintains RCC. Desorption electrospray ionization-mass-spectrometric imaging was used to obtain chemical maps of metabolites and lipids in the mouse RCC samples. Gene expression analysis revealed that the mouse tumors mimicked human RCC. The data suggested that MYC-induced RCC up-regulated the glutaminolytic pathway instead of the glycolytic pathway. The pharmacologic inhibition of glutamine metabolism with bis-2-(5-phenylacetamido-1,2,4-thiadiazol-2-yl)ethyl sulfide impeded MYC-mediated RCC tumor progression. Our studies demonstrate that MYC overexpression causes RCC and points to the inhibition of glutamine metabolism as a potential therapeutic approach for the treatment of this disease.


Assuntos
Carcinoma de Células Renais/genética , Carcinoma de Células Renais/metabolismo , Genes myc , Glutamina/metabolismo , Neoplasias Renais/genética , Neoplasias Renais/metabolismo , Animais , Carcinoma de Células Renais/patologia , Linhagem Celular Tumoral , Modelos Animais de Doenças , Progressão da Doença , Inibidores Enzimáticos/farmacologia , Genes ras , Glutaminase/antagonistas & inibidores , Glutaminase/metabolismo , Humanos , Neoplasias Renais/patologia , Metabolismo dos Lipídeos , Camundongos , Camundongos SCID , Camundongos Transgênicos , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , RNA Neoplásico/genética , RNA Neoplásico/metabolismo , Espectrometria de Massas por Ionização por Electrospray , Sulfetos/farmacologia , Tiadiazóis/farmacologia , Regulação para Cima
16.
Semin Cancer Biol ; 35 Suppl: S199-S223, 2015 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-25865775

RESUMO

Cancer arises in the context of an in vivo tumor microenvironment. This microenvironment is both a cause and consequence of tumorigenesis. Tumor and host cells co-evolve dynamically through indirect and direct cellular interactions, eliciting multiscale effects on many biological programs, including cellular proliferation, growth, and metabolism, as well as angiogenesis and hypoxia and innate and adaptive immunity. Here we highlight specific biological processes that could be exploited as targets for the prevention and therapy of cancer. Specifically, we describe how inhibition of targets such as cholesterol synthesis and metabolites, reactive oxygen species and hypoxia, macrophage activation and conversion, indoleamine 2,3-dioxygenase regulation of dendritic cells, vascular endothelial growth factor regulation of angiogenesis, fibrosis inhibition, endoglin, and Janus kinase signaling emerge as examples of important potential nexuses in the regulation of tumorigenesis and the tumor microenvironment that can be targeted. We have also identified therapeutic agents as approaches, in particular natural products such as berberine, resveratrol, onionin A, epigallocatechin gallate, genistein, curcumin, naringenin, desoxyrhapontigenin, piperine, and zerumbone, that may warrant further investigation to target the tumor microenvironment for the treatment and/or prevention of cancer.


Assuntos
Carcinogênese/efeitos dos fármacos , Neoplasias/tratamento farmacológico , Neovascularização Patológica/tratamento farmacológico , Microambiente Tumoral/genética , Antineoplásicos/uso terapêutico , Carcinogênese/genética , Proliferação de Células/efeitos dos fármacos , Humanos , Terapia de Alvo Molecular , Neoplasias/genética , Neoplasias/prevenção & controle , Neovascularização Patológica/genética , Neovascularização Patológica/prevenção & controle , Transdução de Sinais , Microambiente Tumoral/efeitos dos fármacos
17.
PLoS One ; 10(3): e0119177, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-25749104

RESUMO

Steroid and xenobiotic receptor (SXR) and its murine ortholog, pregnane X receptor (PXR), are nuclear receptors that are expressed at high levels in the liver and the intestine where they function as xenobiotic sensors that induce expression of genes involved in detoxification and drug excretion. Recent evidence showed that SXR and PXR are also expressed in bone tissue where they mediate bone metabolism. Here we report that systemic deletion of PXR results in aging-dependent wearing of articular cartilage of knee joints. Histomorphometrical analysis showed remarkable reduction of width and an enlarged gap between femoral and tibial articular cartilage in PXR knockout mice. We hypothesized that genes induced by SXR in chondrocytes have a protective effect on articular cartilage and identified Fam20a (family with sequence similarity 20a) as an SXR-dependent gene induced by the known SXR ligands, rifampicin and vitamin K2. Lastly, we demonstrated the biological significance of Fam20a expression in chondrocytes by evaluating osteoarthritis-related gene expression of primary articular chondrocytes. Consistent with epidemiological findings, our results indicate that SXR/PXR protects against aging-dependent wearing of articular cartilage and that ligands for SXR/PXR have potential role in preventing osteoarthritis caused by aging.


Assuntos
Envelhecimento/metabolismo , Cartilagem Articular/metabolismo , Condrócitos/metabolismo , Osteoartrite do Joelho/metabolismo , Receptores de Esteroides/deficiência , Envelhecimento/genética , Envelhecimento/patologia , Animais , Cartilagem Articular/patologia , Condrócitos/patologia , Proteínas do Esmalte Dentário , Articulação do Joelho/metabolismo , Articulação do Joelho/patologia , Camundongos , Camundongos Knockout , Osteoartrite do Joelho/genética , Osteoartrite do Joelho/patologia , Receptor de Pregnano X , Proteínas/genética , Proteínas/metabolismo
18.
PLoS One ; 9(9): e107589, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-25208064

RESUMO

The Cre/loxP system is a powerful tool for generating conditional genomic recombination and is often used to examine the mechanistic role of specific genes in tumorigenesis. However, Cre toxicity due to its non-specific endonuclease activity has been a concern. Here, we report that tamoxifen-mediated Cre activation in vivo induced the regression of primary lymphomas in p53-/- mice. Our findings illustrate that Cre activation alone can induce the regression of established tumors.


Assuntos
Antineoplásicos Hormonais/farmacologia , Integrases/genética , Linfoma/tratamento farmacológico , Linfoma/genética , Tamoxifeno/farmacologia , Proteína Supressora de Tumor p53/genética , Animais , Apoptose/efeitos dos fármacos , Carcinogênese/genética , Ativação Enzimática/efeitos dos fármacos , Terapia Genética , Integrases/metabolismo , Linfoma/metabolismo , Linfoma/patologia , Imageamento por Ressonância Magnética , Camundongos , Camundongos Knockout , Regiões Promotoras Genéticas , Carga Tumoral/efeitos dos fármacos , Proteína Supressora de Tumor p53/deficiência , Ubiquitina C/genética , Ubiquitina C/metabolismo
19.
Cancer Res ; 74(21): 6205-15, 2014 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-25217519

RESUMO

Cancers due to germline mutations in the BRCA1 gene tend to lack targets for approved chemoprevention agents. This study aimed at a targeted chemoprevention strategy for BRCA1-associated malignancies. Mutant BRCA1 limits the base-excision DNA repair activity that addresses oxidative DNA damage, the accumulation of which heightens one's risk for cancer. Therefore, we conducted a high-throughput chemical screen to identify drug candidates that could attenuate the inhibitory effects of mutant BRCA1 on this repair activity, thereby describing a new class of DNA repair-activating chemopreventive agents. In the screen design, such drugs functioned by enhancing base-excision DNA repair of oxidative DNA damage in the presence of mutant BRCA1, with minimal cytotoxicity. We identified at least one new agent that decreased malignant properties associated with tumorigenesis, including anchorage-independent growth and tumor progression. This work offers a preclinical proof-of-concept for a wholly new approach to chemoprevention in carriers of BRCA1 mutations as a strategy to reduce the prevalence of BRCA1-associated malignancy.


Assuntos
Proteína BRCA1/antagonistas & inibidores , Neoplasias da Mama/genética , Terapia de Alvo Molecular , Bibliotecas de Moléculas Pequenas/administração & dosagem , Proteína BRCA1/genética , Neoplasias da Mama/tratamento farmacológico , Neoplasias da Mama/patologia , Reparo do DNA/efeitos dos fármacos , Reparo do DNA/genética , Feminino , Mutação em Linhagem Germinativa , Humanos , Células MCF-7 , Bibliotecas de Moléculas Pequenas/química
20.
Cancer Cell ; 26(2): 262-72, 2014 Aug 11.
Artigo em Inglês | MEDLINE | ID: mdl-25117713

RESUMO

The MYC oncogene regulates gene expression through multiple mechanisms, and its overexpression culminates in tumorigenesis. MYC inactivation reverses turmorigenesis through the loss of distinguishing features of cancer, including autonomous proliferation and survival. Here we report that MYC via miR-17-92 maintains a neoplastic state through the suppression of chromatin regulatory genes Sin3b, Hbp1, Suv420h1, and Btg1, as well as the apoptosis regulator Bim. The enforced expression of miR-17-92 prevents MYC suppression from inducing proliferative arrest, senescence, and apoptosis and abrogates sustained tumor regression. Knockdown of the five miR-17-92 target genes blocks senescence and apoptosis while it modestly delays proliferative arrest, thus partially recapitulating miR-17-92 function. We conclude that MYC, via miR-17-92, maintains a neoplastic state by suppressing specific target genes.


Assuntos
Proliferação de Células , Sobrevivência Celular , Linfoma/metabolismo , MicroRNAs/genética , Proteínas Proto-Oncogênicas c-myc/fisiologia , Animais , Apoptose , Regulação Neoplásica da Expressão Gênica , Linfoma/genética , Linfoma/patologia , Camundongos , Família Multigênica , Transplante de Neoplasias , Interferência de RNA , Carga Tumoral , Células Tumorais Cultivadas
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