RESUMO
CXC ligand (L)12 is a chemokine implicated in the migration, invasion and metastasis of cancer cells via interaction with its receptors CXC chemokine receptor (CXCR)4 and CXCR7. In the present study, CXCL12-mediated Ca2+ signalling was compared with two basal-like breast cancer cell lines, MDA-MB-231 and MDA-MB-468, which demonstrate distinct metastatic potential. CXCL12 treatment induced Ca2+ responses in the more metastatic MDA-MB-231 cells but not in the less metastatic MDA-MB-468 cells. Assessment of mRNA levels of CXCL12 receptors and their potential modulators in both cell lines revealed that CXCR4 and CXCR7 levels were increased in MDA-MB-231 cells compared with MDA-MB-468 cells. Cluster of differentiation (CD)24, the negative regulator of CXCL12 responses, demonstrated increased expression in MDA-MB-468 cells compared with MDA-MB-231 cells, and the two cell lines expressed comparable levels of hypoxia-inducible factor (HIF)2α, a CXCR4 regulator. Induction of epithelial-mesenchymal transition (EMT) by epidermal growth factor exhibited opposite effects on CXCR4 mRNA levels compared with hypoxia-induced EMT. Neither EMT inducer exhibited an effect on CXCR7 expression, however hypoxia increased HIF2α expression levels in MDA-MB-468 cells. Analysis of the gene expression profiles of breast tumours revealed that the highest expression levels of CXCR4 and CXCR7 were in the Claudin-Low molecular subtype, which is markedly associated with EMT features.
RESUMO
BACKGROUND: Epithelial-to-mesenchymal transition (EMT) is associated with downregulated E-cadherin and frequently with decreased proliferation. Proliferation may be restored in secondary metastases by mesenchymal-to-epithelial transition (MET). We tested whether E-cadherin maintains epithelial proliferation in MDA-MB-468 breast cancer cells, facilitating metastatic colonization in severe combined immunodeficiency (SCID) mice. METHODS: EMT/MET markers were assessed in xenograft tumors by immunohistochemistry. Stable E-cadherin manipulation was effected by transfection and verified by Western blotting, immunocytochemistry, and quantitative polymerase chain reaction (qPCR). Effects of E-cadherin manipulation on proliferation and chemomigration were assessed in vitro by performing sulforhodamine B assays and Transwell assays, respectively. Invasion was assessed by Matrigel outgrowth; growth in vivo was assessed in SCID mice; and EMT status was assessed by qPCR. Hypoxic response of E-cadherin knockdown cell lines was assessed by qPCR after hypoxic culture. Repeated measures analysis of variance (ANOVA), one- and two-way ANOVA with posttests, and paired Student's t tests were performed to determine significance (p < 0.05). RESULTS: EMT occurred at the necrotic interface of MDA-MB-468 xenografts in regions of hypoxia. Extratumoral deposits (vascular and lymphatic inclusions, local and axillary nodes, and lung metastases) strongly expressed E-cadherin. MDA-MB-468 cells overexpressing E-cadherin were more proliferative and less migratory in vitro, whereas E-cadherin knockdown (short hairpin CDH1 [shCDH1]) cells were more migratory and invasive, less proliferative, and took longer to form tumors. shCDH1-MDA-MB-468 xenografts did not contain the hypoxia-induced necrotic areas observed in wild-type (WT) and shSCR-MDA-MB-468 tumors, but they did not exhibit an impaired hypoxic response in vitro. Although vimentin expression was not stimulated by E-cadherin knockdown in 2D or 3D cultures, xenografts of these cells were globally vimentin-positive rather than exhibiting regional EMT, and they expressed higher SNA1 than their in vitro counterparts. E-cadherin suppression caused a trend toward reduced lung metastasis, whereas E-cadherin overexpression resulted in the reverse trend, consistent with the increased proliferation rate and predominantly epithelial phenotype of MDA-MB-468 cells outside the primary xenograft. This was also originally observed in WT xenografts. Furthermore, we found that patients with breast cancer that expressed E-cadherin were more likely to have metastases. CONCLUSIONS: E-cadherin expression promotes growth of primary breast tumors and conceivably the formation of metastases, supporting a role for MET in metastasis. E-cadherin needs to be reevaluated as a tumor suppressor.
Assuntos
Neoplasias da Mama/genética , Caderinas/genética , Proliferação de Células/genética , Transição Epitelial-Mesenquimal/genética , Animais , Neoplasias da Mama/patologia , Linhagem Celular Tumoral , Células Epiteliais/patologia , Feminino , Regulação Neoplásica da Expressão Gênica/genética , Humanos , Camundongos , Metástase Neoplásica , Ensaios Antitumorais Modelo de XenoenxertoRESUMO
Within the field of cancer research, focus on the study of minimal residual disease (MRD) in the context of carcinoma has grown exponentially over the past several years. MRD encompasses circulating tumour cells (CTCs)-cancer cells on the move via the circulatory or lymphatic system, disseminated tumour cells (DTCs)-cancer cells which have escaped into a distant site (most studies have focused on bone marrow), and resistant cancer cells surviving therapy-be they local or distant, all of which may ultimately give rise to local relapse or overt metastasis. Initial studies simply recorded the presence and number of CTCs and DTCs; however recent advances are allowing assessment of the relationship between their persistence, patient prognosis and the biological properties of MRD, leading to a better understanding of the metastatic process. Technological developments for the isolation and analysis of circulating and disseminated tumour cells continue to emerge, creating new opportunities to monitor disease progression and perhaps alter disease outcome. This review outlines our knowledge to date on both measurement and categorisation of MRD in the form of CTCs and DTCs with respect to how this relates to cancer outcomes, and the hurdles and future of research into both CTCs and DTCs.
Assuntos
Neoplasias da Mama/patologia , Neoplasia Residual/patologia , Células Neoplásicas Circulantes/patologia , Feminino , Humanos , PrognósticoRESUMO
Mammographic density (MD) adjusted for age and body mass index is one of the strongest known risk factors for breast cancer. Given the high attributable risk of MD for breast cancer, chemoprevention with a safe and available agent that reduces MD and breast cancer risk would be beneficial. Cox-2 has been implicated in MD-related breast cancer risk, and was increased in stromal cells in high MD tissues in one study. Our study assessed differential Cox-2 expression in epithelial and stromal cells in paired samples of high and low MD human breast tissue, and in a validated xenograft biochamber model of MD. We also examined the effects of endocrine treatment upon Cox-2 expression in high and low MD tissues in the MD xenograft model. Paired high and low MD human breast tissue samples were immunostained for Cox-2, then assessed for differential expression and staining intensity in epithelial and stromal cells. High and low MD human breast tissues were separately maintained in biochambers in mice treated with Tamoxifen, oestrogen or placebo implants, then assessed for percentage Cox-2 staining in epithelial and stromal cells. Percentage Cox-2 staining was greater for both epithelial (p = 0.01) and stromal cells (p < 0.0001) of high compared with low MD breast tissues. In high MD biochamber tissues, percentage Cox-2 staining was greater in stromal cells of oestrogen-treated versus placebo-treated tissues (p = 0.05).
Assuntos
Neoplasias da Mama/metabolismo , Neoplasias da Mama/patologia , Ciclo-Oxigenase 2/metabolismo , Células Epiteliais/metabolismo , Células Estromais/metabolismo , Adulto , Animais , Mama/metabolismo , Mama/patologia , Densidade da Mama , Ciclo-Oxigenase 2/genética , Modelos Animais de Doenças , Feminino , Expressão Gênica , Xenoenxertos , Humanos , Imuno-Histoquímica , Glândulas Mamárias Humanas/anormalidades , Camundongos , Pessoa de Meia-IdadeRESUMO
The medicinal use of aspirin stretches back to ancient times, before it was manufactured in its pure form in the late 19th century. Its accepted mechanistic target, cyclooxygenase (COX), was discovered in the 1970s and since this landmark discovery, the therapeutic application of aspirin and other non-steroidal anti-inflammatory drugs (NSAIDs) has increased dramatically. The most significant benefits of NSAIDs are in conditions involving chronic inflammation (CI). Given the recognized role of CI in cancer development, the use of long-term NSAID treatment in the prevention of cancer is an enticing possibility. COX-2 is a key driver of CI, and here we review COX-2 expression as a predictor of survival in various cancer types, including breast. Obesity and post-partum involution are natural inflammatory states that are associated with increased breast cancer risk. We outline the COX-2 mediated mechanisms contributing to the growth of cancers. We dissect the cellular mechanism of epithelial-mesenchymal transition (EMT) and how COX-2 may induce this to facilitate tumor progression. Finally we examine the potential regulation of COX-2 by c-Myb, and the possible interplay between c-Myb/COX-2 in proliferation, and hypoxia inducible factor-1 alpha (HIF1α)/COX-2 in invasive pathways in breast cancer.
Assuntos
Neoplasias da Mama/metabolismo , Neoplasias da Mama/patologia , Ciclo-Oxigenase 2/metabolismo , Inflamação/metabolismo , Proteínas Proto-Oncogênicas c-myb/metabolismo , Neoplasias da Mama/mortalidade , Doença Crônica , Transição Epitelial-Mesenquimal , Feminino , Humanos , Subunidade alfa do Fator 1 Induzível por Hipóxia/metabolismo , Invasividade Neoplásica , Metástase Neoplásica , Transdução de SinaisRESUMO
Mammographic density (MD) is a strong risk factor for breast cancer. It is altered by exogenous endocrine treatments, including hormone replacement therapy and Tamoxifen. Such agents also modify breast cancer (BC) risk. However, the biomolecular basis of how systemic endocrine therapy modifies MD and MD-associated BC risk is poorly understood. This study aims to determine whether our xenograft biochamber model can be used to study the effectiveness of therapies aimed at modulating MD, by examine the effects of Tamoxifen and oestrogen on histologic and radiographic changes in high and low MD tissues maintained within the biochamber model. High and low MD human tissues were precisely sampled under radiographic guidance from prophylactic mastectomy fresh specimens of high-risk women, then inserted into separate vascularized murine biochambers. The murine hosts were concurrently implanted with Tamoxifen, oestrogen or placebo pellets, and the high and low MD biochamber tissues maintained in the murine host environment for 3 months, before the high and low MD biochamber tissues were harvested for histologic and radiographic analyses. The radiographic density of high MD tissue maintained in murine biochambers was decreased in Tamoxifen-treated mice compared to oestrogen-treated mice (p = 0.02). Tamoxifen treatment of high MD tissue in SCID mice led to a decrease in stromal (p = 0.009), and an increase in adipose (p = 0.023) percent areas, compared to placebo-treated mice. No histologic or radiographic differences were observed in low MD biochamber tissue with any treatment. High MD biochamber tissues maintained in mice implanted with Tamoxifen, oestrogen or placebo pellets had dynamic and measurable histologic compositional and radiographic changes. This further validates the dynamic nature of the MD xenograft model, and suggests the biochamber model may be useful for assessing the underlying molecular pathways of Tamoxifen-reduced MD, and in testing of other pharmacologic interventions in a preclinical model of high MD.
Assuntos
Neoplasias da Mama/diagnóstico por imagem , Neoplasias da Mama/patologia , Estrogênios/farmacologia , Glândulas Mamárias Humanas/anormalidades , Mamografia , Tamoxifeno/farmacologia , Animais , Antineoplásicos Hormonais/farmacologia , Densidade da Mama , Neoplasias da Mama/tratamento farmacológico , Feminino , Humanos , Glândulas Mamárias Humanas/efeitos dos fármacos , Glândulas Mamárias Humanas/patologia , Camundongos , Camundongos SCID , Engenharia Tecidual , Transplante de Tecidos , Transplante HeterólogoRESUMO
There has been considerable recent interest in the genetic, biological and epidemiological basis of mammographic density (MD), and the search for causative links between MD and breast cancer (BC) risk. This report will critically review the current literature on MD and summarize the current evidence for its association with BC. Keywords 'mammographic dens*', 'dense mammary tissue' or 'percent dens*' were used to search the existing literature in English on PubMed and Medline. All reports were critically analyzed. The data were assigned to one of the following aspects of MD: general association with BC, its relationship with the breast hormonal milieu, the cellular basis of MD, the generic variations of MD, and its significance in the clinical setting. MD adjusted for age, and BMI is associated with increased risk of BC diagnosis, advanced tumour stage at diagnosis and increased risk of both local recurrence and second primary cancers. The MD measures that predict BC risk have high heritability, and to date several genetic markers associated with BC risk have been found to also be associated with these MD risk predictors. Change in MD could be a predictor of the extent of chemoprevention with tamoxifen. Although the biological and genetic pathways that determine and perhaps modulate MD remain largely unresolved, significant inroads are being made into the understanding of MD, which may lead to benefits in clinical screening, assessment and treatment strategies. This review provides a timely update on the current understanding of MD's association with BC risk.
Assuntos
Neoplasias da Mama/diagnóstico por imagem , Neoplasias da Mama/patologia , Mama/patologia , Glândulas Mamárias Humanas/anormalidades , Mamografia , Densidade da Mama , Neoplasias da Mama/tratamento farmacológico , Neoplasias da Mama/etiologia , Neoplasias da Mama/mortalidade , Feminino , Terapia de Reposição Hormonal , Humanos , Recidiva Local de Neoplasia , Prognóstico , Fatores de RiscoRESUMO
Signals from the tumor microenvironment trigger cancer cells to adopt an invasive phenotype through epithelial-mesenchymal transition (EMT). Relatively little is known regarding key signal transduction pathways that serve as cytosolic bridges between cell surface receptors and nuclear transcription factors to induce EMT. A better understanding of these early EMT events may identify potential targets for the control of metastasis. One rapid intracellular signaling pathway that has not yet been explored during EMT induction is calcium. Here we show that stimuli used to induce EMT produce a transient increase in cytosolic calcium levels in human breast cancer cells. Attenuation of the calcium signal by intracellular calcium chelation significantly reduced epidermal growth factor (EGF)- and hypoxia-induced EMT. Intracellular calcium chelation also inhibited EGF-induced activation of signal transducer and activator of transcription 3 (STAT3), while preserving other signal transduction pathways such as Akt and extracellular signal-regulated kinase 1/2 (ERK1/2) phosphorylation. To identify calcium-permeable channels that may regulate EMT induction in breast cancer cells, we performed a targeted siRNA-based screen. We found that transient receptor potential-melastatin-like 7 (TRPM7) channel expression regulated EGF-induced STAT3 phosphorylation and expression of the EMT marker vimentin. Although intracellular calcium chelation almost completely blocked the induction of many EMT markers, including vimentin, Twist and N-cadherin, the effect of TRPM7 silencing was specific for vimentin protein expression and STAT3 phosphorylation. These results indicate that TRPM7 is a partial regulator of EMT in breast cancer cells, and that other calcium-permeable ion channels are also involved in calcium-dependent EMT induction. In summary, this work establishes an important role for the intracellular calcium signal in the induction of EMT in human breast cancer cells. Manipulation of calcium-signaling pathways controlling EMT induction in cancer cells may therefore be an important therapeutic strategy for preventing metastases.
Assuntos
Neoplasias da Mama/metabolismo , Neoplasias da Mama/patologia , Sinalização do Cálcio , Cálcio/metabolismo , Transição Epitelial-Mesenquimal/fisiologia , Hipóxia Celular , Linhagem Celular Tumoral , Fator de Crescimento Epidérmico/metabolismo , Fator de Crescimento Epidérmico/farmacologia , Transição Epitelial-Mesenquimal/efeitos dos fármacos , Transição Epitelial-Mesenquimal/genética , Feminino , Humanos , Proteína Quinase 1 Ativada por Mitógeno/metabolismo , Proteína Quinase 3 Ativada por Mitógeno/metabolismo , Fosforilação , Proteínas Serina-Treonina Quinases , RNA Interferente Pequeno/genética , Fator de Transcrição STAT3/metabolismo , Canais de Cátion TRPM/antagonistas & inibidores , Canais de Cátion TRPM/genética , Canais de Cátion TRPM/metabolismo , Vimentina/biossínteseRESUMO
Mammographic density (MD) is a strong heritable risk factor for breast cancer, and may decrease with increasing parity. However, the biomolecular basis for MD-associated breast cancer remains unclear, and systemic hormonal effects on MD-associated risk is poorly understood. This study assessed the effect of murine peripartum states on high and low MD tissue maintained in a xenograft model of human MD. Method High and low MD human breast tissues were precisely sampled under radiographic guidance from prophylactic mastectomy specimens of women. The high and low MD tissues were maintained in separate vascularised biochambers in nulliparous or pregnant SCID mice for 4 weeks, or mice undergoing postpartum involution or lactation for three additional weeks. High and low MD biochamber material was harvested for histologic and radiographic comparisons during various murine peripartum states. High and low MD biochamber tissues in nulliparous mice were harvested at different timepoints for histologic and radiographic comparisons. Results High MD biochamber tissues had decreased stromal (p = 0.0027), increased adipose (p = 0.0003) and a trend to increased glandular tissue areas (p = 0.076) after murine postpartum involution. Stromal areas decreased (p = 0.042), while glandular (p = 0.001) and adipose areas (p = 0.009) increased in high MD biochamber tissues during lactation. A difference in radiographic density was observed in high (p = 0.0021) or low MD biochamber tissues (p = 0.004) between nulliparous, pregnant and involution groups. No differences in tissue composition were observed in high or low MD biochamber tissues maintained for different durations, although radiographic density increased over time. Conclusion High MD biochamber tissues had measurable histologic changes after postpartum involution or lactation. Alterations in radiographic density occurred in biochamber tissues between different peripartum states and over time. These findings demonstrate the dynamic nature of the human MD xenograft model, providing a platform for studying the biomolecular basis of MD-associated cancer risk.
Assuntos
Neoplasias da Mama/patologia , Mama/crescimento & desenvolvimento , Glândulas Mamárias Humanas/anormalidades , Engenharia Tecidual , Animais , Mama/patologia , Densidade da Mama , Neoplasias da Mama/genética , Feminino , Humanos , Mamografia , Camundongos , Período Periparto , GravidezRESUMO
Gene expression profiling using microarrays and xenograft transplants of human cancer cell lines are both popular tools to investigate human cancer. However, the undefined degree of cross hybridization between the mouse and human genomes hinders the use of microarrays to characterize gene expression of both the host and the cancer cell within the xenograft. Since an increasingly recognized aspect of cancer is the host response (or cancer-stroma interaction), we describe here a bioinformatic manipulation of the Affymetrix profiling that allows interrogation of the gene expression of both the mouse host and the human tumour. Evidence of microenvironmental regulation of epithelial mesenchymal transition of the tumour component in vivo is resolved against a background of mesenchymal gene expression. This tool could allow deeper insight to the mechanism of action of anti-cancer drugs, as typically novel drug efficacy is being tested in xenograft systems.
Assuntos
Biomarcadores Tumorais/genética , Transição Epitelial-Mesenquimal , Perfilação da Expressão Gênica , Neoplasias/genética , Neoplasias/patologia , Animais , Biologia Computacional , Regulação Neoplásica da Expressão Gênica , Humanos , Camundongos , Análise de Sequência com Séries de Oligonucleotídeos , Especificidade da Espécie , Transplante Heterólogo , Microambiente TumoralRESUMO
Mammographic density (MD) is the area of breast tissue that appears radiologically white on mammography. Although high MD is a strong risk factor for breast cancer, independent of BRCA1/2 mutation status, the molecular basis of high MD and its associated breast cancer risk is poorly understood. MD studies will benefit from an animal model, where hormonal, gene and drug perturbations on MD can be measured in a preclinical context. High and low MD tissues were selectively sampled by stereotactic biopsy from operative specimens of high-risk women undergoing prophylactic mastectomy. The high and low MD tissues were transferred into separate vascularised biochambers in the groins of SCID mice. Chamber material was harvested after 6 weeks for histological analyses and immunohistochemistry for cytokeratins, vimentin and a human-specific mitochondrial antigen. Within-individual analysis was performed in replicate mice, eliminating confounding by age, body mass index and process-related factors, and comparisons were made to the parental human tissue. Maintenance of differential MD post-propagation was assessed radiographically. Immunohistochemical staining confirmed the preservation of human glandular and stromal components in the murine biochambers, with maintenance of radiographic MD differential. Propagated high MD regions had higher stromal (p = 0.0002) and lower adipose (p = 0.0006) composition, reflecting the findings in the original human breast tissue, although glands appeared small and non-complex in both high and low MD groups. No significant differences were observed in glandular area (p = 0.4) or count (p = 0.4) between high and low MD biochamber tissues. Human mammary glandular and stromal tissues were viably maintained in murine biochambers, with preservation of differential radiographic density and histological features. Our study provides a murine model for future studies into the biomolecular basis of MD as a risk factor for breast cancer.
Assuntos
Neoplasias da Mama/patologia , Mama/patologia , Mamografia , Engenharia Tecidual , Animais , Mama/fisiologia , Mama/transplante , Neoplasias da Mama/diagnóstico por imagem , Feminino , Humanos , Camundongos , Camundongos SCID , Células Estromais , Transplante de Tecidos , Transplante HeterólogoRESUMO
Regenerative endodontics aims to preserve, repair or regenerate the dental pulp tissue. Dental pulp stem cells, have a potential use in dental tissue generation. However, specific requirements to drive the dental tissue generation are still obscured. We established an in vivo model for studying the survival of dental pulp cells (DPC) and their potential to generate dental pulp tissue. DPC were mixed with collagen scaffold with or without slow release bone morphogenic protein 4 (BMP-4) and fibroblast growth factor 2 (FGF2). The cell suspension was transplanted into a vascularized tissue engineering chamber in the rat groin. Tissue constructs were harvested after 2, 4, 6, and 8 weeks and processed for histomorphological and immunohistochemical analysis. After 2 weeks newly formed tissue with new blood vessel formation were observed inside the chamber. DPC were found around dentin, particularly around the vascular pedicle and also close to the gelatin microspheres. Cell survival, was confirmed up to 8 weeks after transplantation. Dentin Sialophosphoprotein (DSPP) positive matrix production was detected in the chamber, indicating functionality of dental pulp progenitor cells. This study demonstrates the potential of our tissue engineering model to study rat dental pulp cells and their behavior in dental pulp regeneration, for future development of an alternative treatment using these techniques.
Assuntos
Polpa Dentária/citologia , Neovascularização Fisiológica , Regeneração , Engenharia Tecidual/instrumentação , Animais , Proteína Morfogenética Óssea 4/metabolismo , Sobrevivência Celular , Colágeno/metabolismo , Polpa Dentária/metabolismo , Dentina/irrigação sanguínea , Dentina/metabolismo , Dentina/fisiologia , Proteínas da Matriz Extracelular/metabolismo , Fator 2 de Crescimento de Fibroblastos/metabolismo , Virilha/irrigação sanguínea , Virilha/fisiologia , Humanos , Imuno-Histoquímica , Masculino , Fosfoproteínas/metabolismo , Ratos , Ratos Sprague-Dawley , Sialoglicoproteínas/metabolismo , Transplante de Células-Tronco , Células-Tronco/metabolismo , Células-Tronco/fisiologia , Engenharia Tecidual/métodos , Alicerces TeciduaisRESUMO
Epithelial-to-mesenchymal transition (EMT) processes endow epithelial cells with enhanced migratory/invasive properties and are therefore likely to contribute to tumor invasion and metastatic spread. Because of the difficulty in following EMT processes in human tumors, we have developed and characterized an animal model with transplantable human breast tumor cells (MDA-MB-468) uniquely showing spontaneous EMT events to occur. Using vimentin as a marker of EMT, heterogeneity was revealed in the primary MDA-MB-468 xenografts with vimentin-negative and vimentin-positive areas, as also observed on clinical human invasive breast tumor specimens. Reverse transcriptase-PCR after microdissection of these populations from the xenografts revealed EMT traits in the vimentin-positive zones characterized by enhanced 'mesenchymal gene' expression (Snail, Slug and fibroblast-specific protein-1) and diminished expression of epithelial molecules (E-cadherin, ZO-3 and JAM-A). Circulating tumor cells (CTCs) were detected in the blood as soon as 8 days after s.c. injection, and lung metastases developed in all animals injected as examined by in vivo imaging analyses and histology. High levels of vimentin RNA were detected in CTCs by reverse transcriptase-quantitative PCR as well as, to a lesser extent, Snail and Slug RNA. Von Willebrand Factor/vimentin double immunostainings further showed that tumor cells in vascular tumoral emboli all expressed vimentin. Tumoral emboli in the lungs also expressed vimentin whereas macrometastases displayed heterogenous vimentin expression, as seen in the primary xenografts. In conclusion, our data uniquely demonstrate in an in vivo context that EMT occurs in the primary tumors, and associates with an enhanced ability to intravasate and generate CTCs. They further suggest that mesenchymal-to-epithelial phenomena occur in secondary organs, facilitating the metastatic growth.
Assuntos
Neoplasias da Mama/patologia , Transição Epitelial-Mesenquimal , Células Neoplásicas Circulantes/patologia , Animais , Linhagem Celular Tumoral , Feminino , Humanos , Camundongos , Camundongos SCID , Metástase NeoplásicaRESUMO
The orphan nuclear receptor liver receptor homologue-1 (LRH-1) has roles in the development, cholesterol and bile acid homeostasis, and steroidogenesis. It also enhances proliferation and cell cycle progression of cancer cells. In breast cancer, LRH-1 expression is associated with invasive breast cancer; positively correlates with ERα status and aromatase activity; and promotes oestrogen-dependent cell proliferation. However, the mechanism of action of LRH-1 in breast cancer epithelial cells is still not clear. By silencing or over-expressing LRH-1 in ER-positive MCF-7 and ER-negative MDA-MB-231 breast cancer cells, we have demonstrated that LRH-1 promotes motility and cell invasiveness. Similar effects were observed in the non-tumourigenic mammary epithelial cell line, MCF-10A. Remodelling of the actin cytoskeleton and E-cadherin cleavage was observed with LRH-1 over-expression, contributing to increased migratory and invasive properties. Additionally, in LRH-1 over-expressing cells, the truncation of the 120âkDa E-cadherin to the inactive 97âkDa form was observed. These post-translational modifications in E-cadherin may be associated with LRH-1-dependent changes to matrix metalloproteinase 9 expression. These findings suggest a new role of LRH-1 in promoting migration and invasion in breast cancer, independent of oestrogen sensitivity. Therefore, LRH-1 may represent a new target for breast cancer therapeutics.
Assuntos
Neoplasias da Mama/metabolismo , Invasividade Neoplásica/genética , Receptores Citoplasmáticos e Nucleares/metabolismo , Análise de Variância , Western Blotting , Neoplasias da Mama/genética , Caderinas/genética , Caderinas/metabolismo , Contagem de Células , Linhagem Celular Tumoral , Movimento Celular/genética , Proliferação de Células , Citoesqueleto/genética , Citoesqueleto/metabolismo , Receptor alfa de Estrogênio/genética , Receptor alfa de Estrogênio/metabolismo , Feminino , Humanos , Metaloproteinase 9 da Matriz/genética , Metaloproteinase 9 da Matriz/metabolismo , Processamento de Proteína Pós-Traducional , Receptores Citoplasmáticos e Nucleares/genética , TransfecçãoAssuntos
Neoplasias da Mama/fisiopatologia , Transdiferenciação Celular , Células Epiteliais/fisiologia , Glândulas Mamárias Humanas/fisiologia , Glândulas Mamárias Humanas/fisiopatologia , Células-Tronco Mesenquimais/fisiologia , Animais , Antígenos de Diferenciação , Neoplasias da Mama/patologia , Desdiferenciação Celular , Feminino , Humanos , Glândulas Mamárias Animais/patologia , Glândulas Mamárias Animais/fisiologia , Glândulas Mamárias Animais/fisiopatologia , Glândulas Mamárias Humanas/patologia , Neoplasias Mamárias Experimentais/patologia , Neoplasias Mamárias Experimentais/fisiopatologiaRESUMO
OBJECTIVE: To investigate the role of matrix metalloproteinase 13 (MMP-13; collagenase 3) in osteoarthritis (OA). METHODS: OA was surgically induced in the knees of MMP-13-knockout mice and wild-type mice, and mice were compared. Histologic scoring of femoral and tibial cartilage aggrecan loss (0-3 scale), erosion (0-7 scale), and chondrocyte hypertrophy (0-1 scale), as well as osteophyte size (0-3 scale) and maturity (0-3 scale) was performed. Serial sections were stained for type X collagen and the MMP-generated aggrecan neoepitope DIPEN. RESULTS: Following surgery, aggrecan loss and cartilage erosion were more severe in the tibia than femur (P<0.01) and tibial cartilage erosion increased with time (P<0.05) in wild-type mice. Cartilaginous osteophytes were present at 4 weeks and underwent ossification, with size and maturity increasing by 8 weeks (P<0.01). There was no difference between genotypes in aggrecan loss or cartilage erosion at 4 weeks. There was less tibial cartilage erosion in knockout mice than in wild-type mice at 8 weeks (P<0.02). Cartilaginous osteophytes were larger in knockout mice at 4 weeks (P<0.01), but by 8 weeks osteophyte maturity and size were no different from those in wild-type mice. Articular chondrocyte hypertrophy with positive type X collagen and DIPEN staining occurred in both wild-type and knockout mouse joints. CONCLUSION: Our findings indicate that structural cartilage damage in a mouse model of OA is dependent on MMP-13 activity. Chondrocyte hypertrophy is not regulated by MMP-13 activity in this model and does not in itself lead to cartilage erosion. MMP-13 deficiency can inhibit cartilage erosion in the presence of aggrecan depletion, supporting the potential for therapeutic intervention in established OA with MMP-13 inhibitors.
Assuntos
Artrite Experimental/enzimologia , Cartilagem Articular/patologia , Condrócitos/patologia , Metaloproteinase 13 da Matriz/deficiência , Osteoartrite/enzimologia , Agrecanas/metabolismo , Animais , Artrite Experimental/genética , Artrite Experimental/patologia , Calcinose/patologia , Cartilagem Articular/metabolismo , Fêmur/patologia , Hipertrofia , Articulações/metabolismo , Articulações/patologia , Articulações/cirurgia , Masculino , Metaloproteinase 13 da Matriz/genética , Metaloproteinase 13 da Matriz/metabolismo , Camundongos , Camundongos Knockout , Osteoartrite/genética , Osteoartrite/patologia , Osteófito/patologia , Tíbia/patologiaRESUMO
Epithelial mesenchymal transition (EMT) has long been associated with breast cancer cell invasiveness and evidence of EMT processes in clinical samples is growing rapidly. Genome-wide transcriptional profiling of increasingly larger numbers of human breast cancer (HBC) cell lines have confirmed the existence of a subgroup of cell lines (termed Basal B/Mesenchymal) with enhanced invasive properties and a predominantly mesenchymal gene expression signature, distinct from subgroups with predominantly luminal (termed Luminal) or mixed basal/luminal (termed Basal A) features (Neve et al Cancer Cell 2006). Studies providing molecular and cellular analyses of EMT features in these cell lines are summarised, and the expression levels of EMT-associated factors in these cell lines are analysed. Recent clinical studies supporting the presence of EMT-like changes in vivo are summarised. Human breast cancer cell lines with mesenchymal properties continue to hold out the promise of directing us towards key mechanisms at play in the metastatic dissemination of breast cancer.
Assuntos
Neoplasias da Mama/genética , Neoplasias da Mama/patologia , Células Epiteliais/patologia , Mesoderma/patologia , Invasividade Neoplásica/genética , Invasividade Neoplásica/patologia , Linhagem Celular Tumoral , Feminino , Expressão Gênica , Regulação Neoplásica da Expressão Gênica , HumanosRESUMO
OBJECTIVE: To investigate the potential of inflammation to induce new adipose tissue formation in the in vivo environment. METHODS AND RESULTS: Using an established model of in vivo adipogenesis, a silicone chamber containing a Matrigel and fibroblast growth factor 2 (1 microg/ml) matrix was implanted into each groin of an adult male C57Bl6 mouse and vascularized with the inferior epigastric vessels. Sterile inflammation was induced in one of the two chambers by suspending Zymosan-A (ZA) (200-0.02 microg/ml) in the matrix at implantation. Adipose tissue formation was assessed at 6, 8, 12 and 24 weeks. ZA induced significant adipogenesis in an inverse dose-dependent manner (P<0.001). At 6 weeks adipose tissue formation was greatest with the lowest concentrations of ZA and least with the highest. Adipogenesis occurred both locally in the chamber containing ZA and in the ZA-free chamber in the contralateral groin of the same animal. ZA induced a systemic inflammatory response characterized by elevated serum tumour necrosis factor-alpha levels at early time points. Aminoguanidine (40 microg/ml) inhibited the adipogenic response to ZA-induced inflammation. Adipose tissue formed in response to ZA remained stable for 24 weeks, even when exposed to the normal tissue environment. CONCLUSIONS: These results demonstrate that inflammation can drive neo-adipogenesis in vivo. This suggests the existence of a positive feedback mechanism in obesity, whereby the state of chronic, low-grade inflammation, characteristic of the condition, may promote further adipogenesis. The mobilization and recruitment of a circulating population of adipose precursor cells is likely to be implicated in this mechanism.
Assuntos
Adipogenia/efeitos dos fármacos , Tecido Adiposo/efeitos dos fármacos , Inibidores Enzimáticos/toxicidade , Inflamação/induzido quimicamente , Zimosan/toxicidade , Animais , Materiais Biocompatíveis/farmacologia , Colágeno/farmacologia , Combinação de Medicamentos , Imuno-Histoquímica , Laminina/farmacologia , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Proteoglicanas/farmacologia , Resultado do TratamentoRESUMO
Collagen synthesis inhibition potentially can reduce adhesion formation after tendon injury but also may affect cutaneous wound healing. We hypothesized that a novel orally administered collagen synthesis inhibitor (CPHI-I) would substantially reduce flexor tendon adhesions after injury, without any clinically important effect on cutaneous wound healing. The experiments were performed in a rat model with an in-continuity crush injury model in the rat hindfoot flexor tendon to provoke adhesion formation. Assays of dermal collagen production and the rate of healing of an excised wound were performed to assess cutaneous wound healing. Animals in the treatment groups received CPHI-I for 1, 2, or 6 weeks and were assessed at either 2 or 6 weeks. The work of flexion in the injured digit was reduced in the CPHI-I-treated animals compared with control animals, (0.188 J versus 0.0307 J at 2 weeks, and 0.0231 J versus 0.0331 J at 6 weeks) The cutaneous wound healing rate was similar in all animals, but dermal collagen synthesis was reduced in the treated animals. The CPHI-I seems to reduce tendon adhesion, and although collagen synthesis was reduced in cutaneous wounds, CPHI-I did not retard wound healing.