RESUMO
Rectal cancer represents one third of the colorectal cancers that are diagnosed. Neoadjuvant chemoradiation is a well-established protocol for rectal cancer treatment reducing the risk of local recurrence. However, a pathologic complete response is only achieved in 10-40% of cases and the mechanisms associated with resistance are poorly understood. To identify potential targets for preventing therapy resistance, a proteomic analysis of biopsy specimens collected from stage II and III rectal adenocarcinoma patients before neoadjuvant treatment was performed and compared with residual tumor tissues removed by surgery after neoadjuvant therapy. Three proteins, Ku70, Ku80, and Rab5C, exhibited a significant increase in expression after chemoradiation. To better understand the role of these proteins in therapy resistance, a rectal adenocarcinoma cell line was irradiated to generate a radiotherapy-resistant lineage. These cells overexpressed the same three proteins identified in the tissue samples. Furthermore, radiotherapy resistance in this in vitro model was found to involve modulation of epidermal growth factor receptor (EGFR) internalization by Rab5C in response to irradiation, affecting expression of the DNA repair proteins, Ku70 and Ku80, and cell resistance. Taken together, these findings indicate that EGFR and Rab5C are potential targets for the sensitization of rectal cancer cells and they should be further investigated. KEY MESSAGES: ⢠Rab5C orchestrates a mechanism of radioresistance in rectal adenocarcinoma cell. ⢠Rab5C modulates EGFR internalization and its relocalization to the nucleus. ⢠In the nucleus, EGFR can modulate the expression of the DNA repair proteins, Ku70 and Ku80. ⢠Rab5C, Ku70, and Ku80 are overexpressed in tumor tissues that contain tumor cells that are resistant to chemoradiation treatment.
Assuntos
Tolerância a Radiação/efeitos da radiação , Radiação Ionizante , Neoplasias Retais/metabolismo , Neoplasias Retais/radioterapia , Proteínas rab5 de Ligação ao GTP/metabolismo , Linhagem Celular Tumoral , Quimiorradioterapia , Endocitose/efeitos da radiação , Receptores ErbB/metabolismo , Humanos , Modelos Biológicos , Proteínas de Neoplasias/metabolismo , Neoplasias Retais/patologiaRESUMO
Follicular lymphoid hyperplasia is a very rare though benign reactive process of an unknown pathogenesis that may resemble a follicular lymphoma, clinically and histologically. Oral reactive follicular hyperplasia (RFH) has been described on the hard or soft palate and at the base of the tongue. We describe here the first case of RFH presenting as an aggressive tumor on the right posterior side of the maxilla in a 24-year-old male patient. The lesion had a clinical evolution of 18 months and was noticed after the surgical extraction of the right third molar, although we cannot assume a cause-effect relation with that surgical event whatsoever. His medical history was unremarkable. Following an incisional biopsy, histological examination revealed lymphoid follicles comprised by germinal centers surrounded by well-defined mantle zones. The germinal centers were positive for Bcl-6, CD10, CD20, CD21, CD23, CD79a, and Ki-67, while negative for Bcl-2, CD2, CD3, CD5, and CD138. The mantle and interfollicular zones were positive for Bcl-2, CD2, CD3, CD5, CD20, and CD138. Both areas were diffusively positive for kappa and lambda, showing polyclonality. The patient underwent a vigorous curettage of the lesion with no reoccurrences at 36 months of follow-up. This case report demonstrates that morphologic and immunohistochemical analyses are crucial to differentiate RFH from follicular lymphoma, leading to proper management.
Assuntos
Hiperplasia do Linfonodo Gigante/diagnóstico por imagem , Tomografia Computadorizada de Feixe Cônico , Doenças Maxilares/diagnóstico por imagem , Radiografia Panorâmica , Adulto , Biópsia , Hiperplasia do Linfonodo Gigante/patologia , Hiperplasia do Linfonodo Gigante/cirurgia , Curetagem , Diagnóstico Diferencial , Seguimentos , Humanos , Imuno-Histoquímica , Masculino , Doenças Maxilares/patologia , Doenças Maxilares/cirurgia , Seio Maxilar/diagnóstico por imagem , Seio Maxilar/patologia , Seio Maxilar/cirurgia , Dente Serotino/cirurgia , Complicações Pós-Operatórias/diagnóstico por imagem , Complicações Pós-Operatórias/patologia , Complicações Pós-Operatórias/cirurgia , Extração DentáriaRESUMO
Colorectal cancer (CRC) is one of the most frequently diagnosed malignancies. The generation of conventional treatments has improved, but approximately 50 % of patients with CRC who undergo potentially curative surgery ultimately relapse and die, usually as a consequence of metastatic disease. Our previous findings showed that engagement of the cellular prion protein (PrP(C)) to its ligand HSP70/90 heat shock organizing protein (HOP) induces proliferation of glioblastomas. In addition, PrP(C) has been described as an important modulator of colorectal tumor growth. Here, we investigated the biological relevance of the PrP(C)-HOP interaction in CRC cells. We demonstrate that HOP induced the migration and invasion of CRC cell lines in a PrP(C)-dependent manner and that phosphorylation of the ERK1/2 pathway is a downstream mediator of these effects. Additionally, we show that a HOP peptide with the ability to bind PrP(C) and abolish the PrP(C)-HOP interaction inhibited the migration and invasion of CRC cells. Together, these data indicate that the disruption of the PrP(C)-HOP complex could be a potential therapeutic target for modulating the migratory and invasive cellular properties that lead to metastatic CRC.
Assuntos
Neoplasias Colorretais/genética , Proteínas de Homeodomínio/genética , Metástase Neoplásica/genética , Proteínas Priônicas/genética , Proteínas Supressoras de Tumor/genética , Linhagem Celular Tumoral , Movimento Celular/genética , Proliferação de Células/genética , Neoplasias Colorretais/patologia , Proteínas de Homeodomínio/metabolismo , Humanos , Sistema de Sinalização das MAP Quinases/genética , Invasividade Neoplásica/genética , Metástase Neoplásica/patologia , Recidiva Local de Neoplasia/genética , Recidiva Local de Neoplasia/patologia , Fosforilação , Proteínas Priônicas/metabolismo , Ligação Proteica , Mapas de Interação de Proteínas/genética , Proteínas Supressoras de Tumor/metabolismoRESUMO
BACKGROUND: Celecoxib, a non-steroidal anti-inflammatory drug that selectively inhibits cyclooxygenase-2 (COX-2), has shown an important anticarcinogenic effect for the treatment of squamous cell carcinoma. The use of COX-2 inhibitors has effectively inhibited the growth of Head and Neck Squamous Cell Carcinoma (HNSCC) cell lines, while a recent phase 1 trial demonstrated good response rate of cancer cells to this drug with minimal toxicity. Possible targets of celecoxib include proteins involved in cell proliferation and apoptosis control. Additionally, celecoxib antitumoral activity has been linked with a COX-2-independent event. METHODS: To better understand which cellular mechanisms are targeted by celecoxib, its effects upon the Akt signaling pathway using two different HNSCC cell lines were analyzed through cell viability assay, immunofluorescence, and Western blotting. RESULTS: The results showed decreased levels of Cyclin D1 and pAkt protein expression in vitro. The number of viable cells was also diminished after celecoxib treatment. CONCLUSION: As Akt pathway seems to be a valuable target for the HNSCC therapy, the results presented herein confirm that celecoxib can be considered as an alternative adjuvant drug for HNSCC treatment.
Assuntos
Antineoplásicos/farmacologia , Carcinoma de Células Escamosas/patologia , Inibidores de Ciclo-Oxigenase 2/farmacologia , Neoplasias de Cabeça e Pescoço/patologia , Proteínas Proto-Oncogênicas c-akt/efeitos dos fármacos , Pirazóis/farmacologia , Transdução de Sinais/efeitos dos fármacos , Sulfonamidas/farmacologia , Apoptose/efeitos dos fármacos , Western Blotting , Celecoxib , Técnicas de Cultura de Células , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Ciclina D1/efeitos dos fármacos , Relação Dose-Resposta a Droga , Imunofluorescência , Humanos , Fosfatidilinositol 3-Quinases/efeitos dos fármacosRESUMO
Paracoccidioidomycosis (PCM) is caused by a dimorphic fungus called Paracoccidioides brasiliensis and is a disseminated, systemic disorder that involves the lungs and other organs but presents characteristic oral lesions as the prominent feature. This article reports an unusual case of a 56-year-old man who had symptomatic granulomatous lesions in the oral cavity. The patient had received a nystatin-based treatment that masked the presence of fungi and made the diagnosis of PCM difficult. Although nystatin is normally used to treat oral fungal infections such as candidiasis, its topical usage is not appropriate for management of PCM. Once the patient received the correct treatment, he demonstrated a full recovery.
Assuntos
Antibacterianos/uso terapêutico , Antifúngicos/uso terapêutico , Candidíase Bucal/tratamento farmacológico , Doenças da Boca/microbiologia , Nistatina/uso terapêutico , Paracoccidioidomicose/diagnóstico , Anti-Inflamatórios não Esteroides/uso terapêutico , Biópsia , Diagnóstico Diferencial , Dipirona/uso terapêutico , Seguimentos , Humanos , Itraconazol/uso terapêutico , Masculino , Pessoa de Meia-IdadeRESUMO
Cell therapy is a therapeutic strategy used to replace or repair damaged tissue. The epithelium transplantation of cultivated keratinocytes has been applied to several modalities of reconstruction, like oral, urethra and ocular surface. Life and death signals work coordinately to ensure cellular quality control and the viability of an organism. The aim of this study is to verify that culture conditions did not induce genetic mutations through the analysis of the key genes: pAKT, Pten, p53 and MDM2 and investigate the presence of the related proteins in human oral keratinocytes obtained by primary culture and in vitro cultivated. Formalin fixed and paraffin embedded tissues from the oral cavity were utilized as control for normal expression of the related markers and two oral squamous cell carcinoma cell lines provided the expression pattern of the proposed markers in the event of cellular transformation. Akt, PTEN, p53 and MDM2 immunohistochemistry and Western-Blotting analyzes were performed. The results showed the expression levels and intracellular localizations of the four proteins evaluated. These analyzes confirmed that the produced in vitro epithelium is bio-compatible for its utilization as reconstruction and reparatory tissue, however further analyses and additional research on other biomarkers should be performed to analyse the long term engraftment of transplantable primary culture of oral keratinocytes and the long term resistance to cellular transformation.
Assuntos
Transformação Celular Neoplásica/patologia , Epitélio/patologia , Neoplasias Bucais/patologia , Boca/patologia , Western Blotting , Carcinoma de Células Escamosas/patologia , Técnicas de Cultura de Células , Linhagem Celular Tumoral , Células Cultivadas , Humanos , Espaço Intracelular/metabolismo , Queratinócitos/enzimologia , Queratinócitos/patologia , Queratinócitos/transplante , PTEN Fosfo-Hidrolase/metabolismo , Transporte Proteico , Proteínas Proto-Oncogênicas c-akt/metabolismo , Proteínas Proto-Oncogênicas c-mdm2/metabolismo , Proteína Supressora de Tumor p53/metabolismoRESUMO
Modificações nas histonas são conhecidas por regular a estrutura conformacional da cromatina e a expressão gênica em células adultas e células-tronco pluripotentes. Tem sido postulado que a acetilação e deacetilação das histonas podem influenciar a expressão de genes envolvidos na iniciação, progressão e metástase tumoral, além de contribuir para o desenvolvimento de resistência à quimioterapia. Assim, buscou-se avaliar a influência das modificações nas histonas sobre a biologia do carcinoma epidermoide de cabeça e pescoço (CECP) e sua respectiva subpopulação de células semelhantes às células-tronco (CSC). Inicialmente, foi checado os níveis de acetilação da histona H3 (membro das histonas nucleares associado à compactação da cromatina) em um painel representativo de linhagens celulares de CECP. Posteriormente, para estudar a influência do estroma tumoral no padrão de acetilação da histona H3, o microambiente do tumor foi mimetizado através da utilização de meio condicionado derivado do cultivo de fibroblastos e cultura primária de células endoteliais humanas. Além disso, validamos esses resultados in vitro por meio de amostras humanas de CECP. Finalmente, a acetilação e deacetilação da cromatina foi induzida, respectivamente, pela administração dos inibidores das enzimas histona deacetilase tricostatina A (TSA) e histona acetiltransferase curcumina, em linhagens celulares de CECP. Foi feita a análise da formação de esferas (ensaio funcional de células-tronco), juntamente com a verificação dos níveis de ALDH, marcador de células-tronco (citometria de fluxo - FACS), além da determinação do índice de proliferação tumoral (Ki-67) e realização dos ensaios de invasão e migração celular. Linhagens celulares de CECP apresentaram níveis baixos de acetilação da histona H3 e demonstraram capacidade de retenção de uma subpopulação de CSC. Apenas o meio condicionado de células endoteliais humanas foi capaz de alterar a conformação da cromatina, uma vez que induziu o aumento da acetilação da histona H3. Interessantemente, foi também notado um concomitante aumento da agressividade de linhagens celulares de CECP (aumento dos níveis de BMI-1 e vimentina). Esses resultados foram confirmados em amostras humanas de CECP que mostraram, apenas no fronte de invasão, células com cromatina acetilada. Curiosamente, essas mesmas células também expressaram vimentina. Os tratamentos com TSA e curcumina resultaram na diminuição significativa da subpopulação de CSC, interrompendo a formação de esferas e reduzindo os níveis de ALDH. Além disso, o tratamento com curcumina mostrou resultados muito interessantes, uma vez que gerou uma redução evidente da invasão celular e impactou por completo o potencial de migração tumoral, sendo nesse sentido mais eficiente que a cisplatina, droga antineoplásica bem estabelecida. Por outro lado, o tratamento com TSA induziu a transição epitélio-mesenquimal nas linhagens celulares de CECP, detectada pelo aumento da expressão de vimentina e indução de um fenótipo fusiforme, juntamente com o aumento da invasão tumoral e os níveis de BMI-1.
Histone modifications are known to regulate chromatin conformation structure and gene expression in adult cells and pluripotent stem cells. It has been postulated that histone acetylation and deacetylation could influence the expression of genes involved in cancer initiation, progression, metastasis, and development of resistance to chemotherapies. Here, we sought to evaluate the influence of histone modifications over the biology of head and neck squamous cell carcinoma (HNSCC) and its stem cell-like subpopulation (CSC). Initially, we checked the status of histone H3 acetylation (a member of the core histones associated to chromatin compaction) in a representative set of HNSCC cell lines. Subsequently, to analyze the influence of tumor stroma over the histone H3 acetylation, we mimicked the tumor microenvironment by using conditioned medium from fibroblasts and primary human endothelial cells. Further we validated these in vitro findings through human samples of HNSCC. Finally, we induced chromatin acetylation and deacetylation by the administration of the histone deacetylase inhibitor trichostatin A (TSA) and histone acetyltransferase inhibitor curcumin, respectively, in HNSCC cell lines. The analysis of spheres formation (stem cell functional assay), along with the levels of stem cells marker ALDH (showed by flow cytometry - FACS), tumor proliferation index (Ki-67), invasion and migration cellular potencial were verified. HNSCC cell lines showed lower levels of histone H3 acetylation and ability to retain a subpopulation of CSC.
Assuntos
Humanos , Masculino , Feminino , Carcinoma de Células Escamosas/diagnóstico , Células-Tronco/fisiologia , Cromatina/ultraestruturaRESUMO
Vimentin is a cytoeskeletal intermediate filament protein commonly observed in mesenchymal cells; however, it can also be found in malignant epithelial cells. It is demonstrated in several carcinomas, such as those of the cervix, breast and bladder, in which it is widely used as a marker of the epithelial to mesenchymal transition that takes place during embryogenesis and metastasis. Vimentin is associated with tumors that show a high degree of invasiveness, being detected in invasion front cells. Its expression seems to be influenced by the tumor microenvironment. The aim of this study was to evaluate vimentin expression in head and neck squamous cell carcinoma (HNSCC) cell lines, and to investigate the contribution of the microenvironment to its expression. HNSCC cell lines (HN6, HN30 and HN31) and an immortalized nontumorigenic cell line (HaCaT) were submitted to a three-dimensional assay with Matrigel. Cytoplasmatic staining of the HN6 cell line cultured without Matrigel and of the HN30 and HN31 cell lines cultured with Matrigel was demonstrated through immunohistochemistry. Western Blotting revealed a significant decrease in vimentin expression for the HN6 cell line and a significant increase for the HN30 and HN31 cell lines cultured with Matrigel. The results suggest that vimentin can be expressed in HNSCC cells and its presence is influenced by the microenvironment of a tumor.
Assuntos
Carcinoma de Células Escamosas/metabolismo , Colágeno/farmacologia , Neoplasias de Cabeça e Pescoço/metabolismo , Laminina/farmacologia , Proteínas de Neoplasias/metabolismo , Proteoglicanas/farmacologia , Vimentina/metabolismo , Western Blotting , Carcinoma de Células Escamosas/patologia , Linhagem Celular Tumoral , Combinação de Medicamentos , Matriz Extracelular , Neoplasias de Cabeça e Pescoço/patologia , Humanos , Imuno-Histoquímica , Proteínas de Neoplasias/análise , Vimentina/análiseRESUMO
Vimentin is a cytoeskeletal intermediate filament protein commonly observed in mesenchymal cells; however, it can also be found in malignant epithelial cells. It is demonstrated in several carcinomas, such as those of the cervix, breast and bladder, in which it is widely used as a marker of the epithelial to mesenchymal transition that takes place during embryogenesis and metastasis. Vimentin is associated with tumors that show a high degree of invasiveness, being detected in invasion front cells. Its expression seems to be influenced by the tumor microenvironment. The aim of this study was to evaluate vimentin expression in head and neck squamous cell carcinoma (HNSCC) cell lines, and to investigate the contribution of the microenvironment to its expression. HNSCC cell lines (HN6, HN30 and HN31) and an immortalized nontumorigenic cell line (HaCaT) were submitted to a three-dimensional assay with Matrigel. Cytoplasmatic staining of the HN6 cell line cultured without Matrigel and of the HN30 and HN31 cell lines cultured with Matrigel was demonstrated through immunohistochemistry. Western Blotting revealed a significant decrease in vimentin expression for the HN6 cell line and a significant increase for the HN30 and HN31 cell lines cultured with Matrigel. The results suggest that vimentin can be expressed in HNSCC cells and its presence is influenced by the microenvironment of a tumor.
Assuntos
Humanos , Carcinoma de Células Escamosas/metabolismo , Colágeno/farmacologia , Neoplasias de Cabeça e Pescoço/metabolismo , Laminina/farmacologia , Proteínas de Neoplasias/metabolismo , Proteoglicanas/farmacologia , Vimentina/metabolismo , Western Blotting , Linhagem Celular Tumoral , Carcinoma de Células Escamosas/patologia , Combinação de Medicamentos , Matriz Extracelular , Neoplasias de Cabeça e Pescoço/patologia , Imuno-Histoquímica , Proteínas de Neoplasias/análise , Vimentina/análiseRESUMO
Células-tronco adultas já foram encontradas em uma variedade de tecidos humanos. Nos tecidos dentais essas células já foram isoladas da polpa de dentes permanentes e decíduos, do ligamento periodontal, da papila apical e do folículo dentário. A engenharia de tecidos mostra a utilização das células-tronco dentais como futura alternativa promissora para tratamentos restauradores. A construção de estruturas complexas como polpa e periodonto, por exemplo, poderá revolucionar a odontologia moderna. De modo geral, as células-tronco de origem dental são de fácil acesso e podem ser caracterizadas com base em propriedades específicas. Esta revisão de literatura trouxe um breve panorama sobre as células-tronco de origem dentária, mostrando as principais diferenças encontradas entre suas populações e discutindo conceitos básicos a seu respeito
Assuntos
Humanos , Polpa Dentária , Saco Dentário , Ligamento Periodontal , Células-Tronco , Biologia Celular , Papila Dentária , Neurogênese , Odontogênese , Dente DecíduoRESUMO
BACKGROUND: Several signaling pathways are involved in the progression of squamous cell carcinoma. Among them, activated PI3K/Akt may result in NF-κB nuclear translocation, thus leading to the transcription of genes enrolled in cellular invasion and proliferation, such as cyclin D1. This study sought to evaluate the expression of pAkt, NF-κB and cyclin D1 proteins in head and neck squamous cell carcinoma cell lines and their respective in vitro-obtained invasive clones. METHODS: Squamous cell carcinoma cell lines originating from the tongue, pharynx and the metastatic lymph node were submitted to an in vitro invasion assay to select invasive clones. All experimental groups were submitted to immunofluorescence and Western blot assays. Statistical analysis was performed through a Student's t-test with a significance level of 5%. RESULTS: The pAkt and NF-κB expression differed from cytoplasm and nucleus depending on the studied cell line. The invasive clone from the tongue presented a network-like structure of pAkt's cytoplasmic expression. This lineage as well as the invasive clone from pharynx also showed pAkt and NF-κB nuclear transportation. Significant pAkt and NF-κB increases were observed in the tongue and pharynx invasive clones. Cyclin D1 was detected in the nucleus of all studied cells and was significantly enhanced in the invasive clones from tongue and pharynx. CONCLUSION: This study suggests the participation of pAkt, NF-κB and cyclin D1 in the invasion process of head and neck squamous cell carcinoma. Moreover, cytoplasmic pAkt network-like structure was probably related to cytoskeleton changes presented during invasion.
Assuntos
Carcinoma de Células Escamosas/metabolismo , Ciclina D1/biossíntese , NF-kappa B/biossíntese , Invasividade Neoplásica/genética , Neoplasias Faríngeas/metabolismo , Proteínas Proto-Oncogênicas c-akt/biossíntese , Neoplasias da Língua/metabolismo , Transporte Ativo do Núcleo Celular , Carcinoma de Células Escamosas/genética , Linhagem Celular Tumoral , Células Clonais , Citoesqueleto/metabolismo , Transição Epitelial-Mesenquimal , Regulação Neoplásica da Expressão Gênica , Humanos , Neoplasias Faríngeas/genética , Transdução de Sinais , Neoplasias da Língua/genética , Regulação para CimaRESUMO
BACKGROUND: Myoepitheliomas are rare tumours that may generally arise from the minor or major salivary glands. The differential diagnosis of this tumour should be performed along with several benign and malignant soft tissue neoplasms. The present case report describes an asymptomatic mass that arose in the soft palate of 42 year old black woman with duration of the six months. METHODS: An incisional biopsy of soft palate lesion was carried out and submitted for histological evaluation under the clinical hypothesis of salivary gland tumour. To confirm the myoepithelial nature of neoplastic cells the immunohistochemical reactions for smooth-muscle actin, cytokeratins and S100 were performed. RESULTS: The histological examination revealed the presence of tumour originating from a minor salivary gland and covered by a stratified squamous oral epithelium. The tumour cells were arranged in order to form a myxoid pattern and, individually, small and/or medium spindle-shaped cells with predominantly round or ovoid nuclei, as well as epithelioid and plasmocytoid cells were noted. The stroma was myxomatous and no ductal or syringomatous epithelial structures were observed. Following the histological and immunohistochemical diagnosis of myoepithelioma, the lesion was surgically removed. After the surgery, a follow-up of one year showed no signs and symptoms of reccurrence. CONCLUSIONS: The myoepithelioma should be carefully distinguished from the other soft tissue tumours, especially those arising from salivary glands, such as pleomorphic adenoma and adenoid-cystic carcinoma.