Made available in DSpace on 2014-12-17T15:32:24Z (GMT). No. of bitstreams: 1 JoaoAVGF.pdf: 1413564 bytes, checksum: f5d8ea2da8907cd551169a4091430007 (MD5) Previous issue date: 2006-02-17 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior / Squamous cell carcinoma is the most common malignant neoplasm in the oral cavity, accounting for more than 90% of all malignancies in this location. Cyclooxygenases (COX s) are key enzymes on arachidonic acid metabolism and prostaglandin synthesis, being expressed basically in two forms: the constitutive (COX-1) and the inducible (COX-2). Increased levels on the expression of COX-2 have been implicated in the pathogenesis tumor progression of various forms of human cancer, including oral squamous cell carcinoma, some of what suggesting a possible interaction between COX-2 and the protein expressed by the tumor suppressor gene p53, mutated in more than 50% of all human cancers. The mean of the present research consisted in analyze the correlation between the expression of COX-2 and p53, at the protein level, as well as evaluate the difference on the expression of these two proteins with the histological grading of malignancy. 34 cases of oral squamous cell carcinoma were selected and graded according to the histological grading system proposed by Bryne (1998) and the labeling indexes (LI s) for COX-2 and p53 evaluated using immunohistochemistry method. The results revealed that COX-2 was expressed in increased levels in most of the specimens, although there was no statistic significant correlation between LI s from COX-2 and p53 (p>0.05), and there were no statistical differences on the expression of these proteins between tumors of high and low grade of malignancy (p>0.05). Interestingly, the expression of COX-2 and p53 was detected in fragments of dysplastic oral epithelium adjacent to tumor areas, on basal and suprabasal layers. The absence of statistical correlation between the expression of COX-2 and p53 proteins do not rule ot the existence of a relation between them, were it may reflect the diversity of regulatory pathways between both, different direct and indirect inhibitory effects of COX-2 over p53, as well as the wide range of activation macheenisms for COX-2 and mutational status of the p53 gene Another conclusion point that the increased expression of COX-2 observed in oral squamous cell carcinomas suggest a role for this protein in the processes of pathogenesis and tumoral evolution of this malignant neoplasm / O carcinoma epiderm?ide ? a neoplasia maligna mais comum na cavidade oral, representando mais de 90% das malignidades nesta localiza??o. As cicloxigenases (COX s) s?o enzimas chave no metabolismo do ?cido aracd?nico e s?ntese de prostaglandinas, sendo expressas basicamente sob duas formas: uma constitutiva (COX-1) e uma induzida (COX-2). N?veis elevados na express?o da COX-2 t?m sido implicados na patog?nese e progress?o tumoral em diversos tipos de c?ncer em humanos, incluindo o carcinoma epiderm?ide oral, alguns dos quais sugerindo uma poss?vel intera??o entre a COX-2 e a prote?na expressa pelo gene supressor tumoral p53, mutado em mais de 50% de todos c?nceres humanos. O prop?sito da presente pesquisa consistiu em analisar a correla??o entre a express?o de COX-2 e p53, em n?vel de prote?na, bem como avaliar a diferen?a na express?o destas duas prote?nas em rela??o ao grau histol?gico de malignidade. Para tal, foram selecionados 34 casos de carcinoma epiderm?ide oral, os quais foram classificados de acordo com o sistema de grada??o histol?gica de malignidade proposto por Bryne (1998) e cujos ?ndices de positividade para COX-2 e p53 foram avaliados atrav?s da t?cnica imuno-histoqu?mica. O resultados revelaram que a COX-2 esteve expressa em n?veis elevados na maior parte dos esp?cimes analisados, embora n?o se tenha verificado correla??o estatisticamente significativa entre os IP s da COX-2 e da p53 (p>0,05), tampouco diferen?a estatisticamente significativa entre a express?o destas prote?nas entre tumores de alto e baixo grau de malignidade (p>0,05). Interessantemente, foi detectada a express?o da COX-2 e da p53 em fragmentos de epit?lio oral displ?sico, nas camadas basal e parabasal, adjacentes ao tumor. A aus?ncia de correla??o estat?stica entre a express?o das prote?nas COX-2 e p53 n?o descarta a exist?ncia de uma rela??o entre as mesmas, podendo refletir a diversidade de vias regulat?rias entre ambas, os diferentes efeitos inibit?rios diretos e indiretos da COX-2 sobre a p53, bem como os in?meros mecanismos de ativa??o da COX-2 e o estado mutacional do gene p53. Conclui-se ainda que a elevada express?o da COX-2 observada em carcinomas epiderm?ides orais sugere um papel desta prote?na dentro dos processos de patog?nese e evolu??o tumoral desta neoplasia maligna

Made available in DSpace on 2014-12-17T15:32:25Z (GMT). No. of bitstreams: 1 AndreaFS_tese.pdf: 610478 bytes, checksum: 22934e3fba7a401686d3b0057e0e7f35 (MD5) Previous issue date: 2007-07-11 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior / The expression of bone morphogenetic proteins (BMPs) is altered in a variety of human canceres. The BMP-2/4 and BMPR-IA were recently shown to be overexpressed in high-risk premalignant and malignant lesions of oral epithelium. The present study analysed the expression of BMP-2/4 and BMPR-IA in Oral Squamous Cell Carcinoma (OSCC) such as their implications in disease prognostic using munohistochemistry. Ten cases of Oral Fibroepithelial Hiperplasia were selected as a control group. The experimental group included 16 cases of OSCC without metastases and 7 cases of OSCC metastatic. The presence or absence of nodal metastases was used as parameter to evaluated the disease prognostic. The results demonstrated weak immunoreactivity for BMP-2/4 and BMPR-IA in every case of the control group. In the cases of OSCC with metastases an overexpression of BMP-2/4 (71,4%) was observed while the BMPR-IA showed weak expression (85,7%). In the cases of OSCC without metastases BMP-2/4 (62,5%) and BMPR-IA showed strong immunostaining standing out an overexpression of the receptor in all the specimens. Observed statistical significance for correlation between the oral cancer prognostic and the staining intensity of the BMP-2/4 (p=0,002). There wasn t statistical significance for association between the staining intensity of the BMPR-IA and the disease prognostic (p<0,001). In conclusion, this findings suggest that the overexpression of BMP-2/4 associated with the loss of expression of the BMPR-IA in OSCC metastatic has prognostic relevance, as the loss of sensitivity to BMPs can be an indicative of metastases development in OSCC / A express?o das prote?nas morfogen?ticas ?sseas (BMPs) est? alterada em v?rios c?nceres humanos. A BMP-2/4 e o BMPR-IA foram recentemente encontrados superexpressos em les?es malignas e pr?-malignas de alto risco em epit?lio oral. Este estudo analisou a express?o da BMP-2/4 e seu receptor BMPR-IA em 23 esp?cimes de Carcinoma Epiderm?ide Oral (CEO), utilizando a imuno-histoqu?mica. O grupo controle constou de 10 casos de Hiperplasia Fibro-epitelial da mucosa oral. O grupo experimental foi constitu?do por 16 casos de CEO n?o metast?tico e 7 casos de CEO metast?tico. Utilizou-se o par?metro presen?a ou aus?ncia de met?stase nodal para avaliar o progn?stico da doen?a. Os resultados demonstraram imunorreatividade fraca para a BMP-2/4 e o BMPR-IA em todos os esp?cimes do grupo controle. No grupo experimental com met?stase, a BMP-2/4 exibiu forte expressividade (71,4%), enquanto que o BMPR-IA mostrou fraca express?o (85,7%). No grupo experimental sem met?stase, evidenciou-se forte express?o para a BMP-2/4 (62,5%) e para o BMPR-IA (100%). Encontrou-se signific?ncia estat?stica para a associa??o entre o progn?stico do CEO e a intensidade de marca??o da BMP-2/4 (p=0,002). Para o BMPR-IA n?o houve signific?ncia estat?stica ? sua associa??o com o progn?stico da doen?a (p<0,001), em fun??o do tamanho da amostra. Portanto, os resultados sugerem que a fraca expressividade do BMPR-IA associada ? forte express?o da BMP-2/4, no grupo experimental com met?stase, tem relev?ncia progn?stica, j? que a perda de sensibilidade ?s BMPs, atrav?s da perda de express?o de seus receptores pode ser indicativo de desenvolvimento de met?stase em CEO

Made available in DSpace on 2014-12-17T15:32:28Z (GMT). No. of bitstreams: 1 MartaRP.pdf: 1904281 bytes, checksum: 2912c6b8ea9a773c553d0776245f93a5 (MD5) Previous issue date: 2009-02-27 / Conselho Nacional de Desenvolvimento Cient?fico e Tecnol?gico / The Oral Epithelial Dysplasia (OED) is the lesion that precedes or co-exists with the Oral Squamous Cell Carcinoma (OSCC), presenting molecular and/or histological similar alterations. The divergences about the malignization potential of OEDs and the role of inflammation in this process make hard the early diagnosis and evaluation of OSCCs aggressiveness. Thus, it became the goal of this study to evaluate the role of inflammation in oral carcinogenesis and tumoral aggressiveness. For this purpose a morphological study was performed in 20 OED cases and 40 OSCC cases to detect the malignization potential of OEDs and the histologic malignancy grading (HMG) of OSCCs, analyzing superficial masses for dismorphism evaluation and the invasive front for evaluation of tumoral growing; and immunohistochemical, using anti-CD8, anti-FOXP3, anti-TGF?, anti-TNF? and anti-NF-?B antibodies, comparing their with the types lesion, histological degree and intensity of the inflammatory infiltrate. The results were statistically significant for the parameters: cell maturity (p=0,0001), masses presence (p=0,038) and dismorphism (p=0,037), when associated to HMG. To compare the expression of the markers with the types lesion, a significantly higher expression of CD8 (p=0,001) and NF-?B (p=0,002) in the OED, and also a smaller expression of the epithelial TGF? in the severe OEDs (p=0,011), without significant expression between OSCC degrees. By relating the expression of the studied markers with the inflammatory infiltrate intensity, a positive relation was observed with: inflammatory TNF?(p=0,003), epithelial TNF? and NF-?B (p=0,051 and p=0,004), in OEDs; and with CD8 (p=0,021) and TNF? (p=0,015) in conjunctive OSCCs; and a negative relation with epithelial TNF? (p=0,034) in OSCCs. No significant relation was found between FOXP3 with any of the studied variables. These findings lead to the conclusion that, the study of the invasive front is as important as the study of superficial masses for the evaluation of tumoral aggressiveness; the intensity of the inflammatory infiltrate has no use as a parameter for prognostic evaluation of OSCC in routine exams, but, the molecular events detected in this study may be necessary to give basis for determining the malignant potential in OEDs and aggressiveness in OSCCs / A Displasia Epitelial Oral (DEO) ? a les?o que precede ou co-existe com o Carcinoma Epiderm?ide Oral (CEO), apresentando altera??es moleculares e/ou histol?gicas semelhantes. As diverg?ncias sobre o potencial de maligniza??o das DEO e o papel da inflama??o nestes processos t?m dificultado o diagn?stico precoce e a avalia??o da agressividade dos CEO. Sendo assim, tornou-se objetivo deste estudo avaliar o papel da inflama??o na carcinog?nese oral e agressividade tumoral. Para isso foi realizado estudo morfol?gico em 20 casos de DEO e 40 casos de CEO para detectar o potencial de maligniza??o das DEO e o Grau Histol?gico de Malignidade (GHM) dos CEO, analisando as massas superficiais para avalia??o do dismorfismo e o front invasivo para avalia??o do crescimento tumoral; e imuno-histoqu?mico, utilizando os anticorpos anti-CD8, anti-FOXP3, anti-TGF?, anti-TNF-? e anti-NF-?B, para comparar a express?o dos mesmos com o tipo de les?o, grau histol?gico e intensidade do infiltrado inflamat?rio. Os resultados foram estatisticamente significantes para os par?metros, maturidade celular (p=0,0001), presen?a de massas (p=0,038) e dismorfismo (p=0,037), quando associados aos GHM. Ao comparar a express?o dos marcadores com o tipo de les?o, encontrou-se uma express?o significativamente maior do CD8 (p=0,001) e do NF-?B (p=0,002) nas DEO, assim como uma menor express?o do TGF? epitelial nas DEO severas (p=0,011), n?o tendo express?o significativa entre os graus dos CEO. Ao relacionar a express?o dos marcadores estudados com a intensidade do infiltrado inflamat?rio, observou-se uma rela??o positiva com o TNF? inflamat?rio (p=0,003), o TNF? e o NF-?B epiteliais (p=0,051 e p=0,004), nas DEO; com o CD8 (p=0,021) e o TNF? (p=0,015) no conjuntivo dos CEO; e uma rela??o negativa com o TNF? (p=0,034) epitelial dos CEO. N?o foi encontrada rela??o significativa da FOXP3 com nenhuma das vari?veis estudadas. Esses achados levaram a concluir que, o estudo do front invasivo ? t?o importante quanto o estudo das massas superficiais para avalia??o da agressividade tumoral; a intensidade do infiltrado inflamat?rio n?o pode ser utilizado como par?metro para avalia??o progn?stica do CEO no exame de rotina; mas os eventos moleculares detectados neste estudo podem ser necess?rios para embasar a determina??o do potencial de malignidade nas DEO e da agressividade nos CEO

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / A proteína óxido nítrico sintase induzível (iNOS) é a mais importante proteína da família das óxido nítrico sintases, a qual é capaz de produzir grandes quantidades de óxido nítrico. A indução permanente de iNOS foi levantada como potencialmente mutagênica, apresentando um papel central na biologia tumoral. O objetivo deste estudo é investigar o papel da iNOS no desenvolvimento de carcinomas de células escamosas bucais (CCEB), usando um modelo experimental de carcinogênese lingual em camundongos knockouts para NOS2 e amostras humanas derivadas da mucosa normal, leucoplasia bucal e CCEB. Camundongos selvagens (iNOS+/+) e knockout (iNOS-/-) para iNOS foram desafiados com 4-nitroquinolina-1-óxido (4NQO) diluída em água potável por 16 semanas e sacrificados após 0, 8 e 16 semanas de acompanhamento. As línguas foram removidas e o número de displasias e carcinomas foram contados. Sangue periférico destes camundongos foram analisados, por citometria de fluxo, em busca de células tumorais circulantes. Amostras humanas derivadas da mucosa normal, leucoplasia e CCEB, foram utilizadas para quantificar o RNA mensageiro (mRNA) de NOS2. As amostras humanas também foram imuno-coradas com anticorpos anti-iNOS e anti-nitrotirosina. Em ambos os grupos, foram observadas uma redução no número de displasias e um aumento de carcinomas da 16 semana até a 32 semanas. Camundongos iNOS-/- demonstraram menor número de lesões displásicas e neoplásicas em todos os períodos de avaliação, sendo menores e menos invasivas, quando comparados aos animais selvagens. Aparentemente, há uma tendência em ascensão nos níveis do mRNA e da proteína iNOS durante a carcinogênese bucal humana. Dados similares foram obtidos com a imuno-detecção de nitrotirosina. Além disso, as imuno-marcações de iNOS e nitrotirosina foram associadas a várias características clínicopatológicas dos CCEB (tamanho, presença de metástase, estadiamento e recidiva). Nossos resultados demonstraram que iNOS afeta o processo de carcinogênese bucal experimental e humana, estando associada com a gênese e progressão dos CCEB. Mais estudos devem ser feitos, para nos fornecer, uma compreensão profunda das funções de iNOS no desenvolvimento de câncer bucal. / Inducible nitric oxide synthase (iNOS) is most important protein of nitric oxide synthases family, which is capable to produce huge amounts of nitric oxide. Permanent induction of iNOS has been raised as potentially mutagenic; presenting pivotal roles in tumor biology. The aim of this study is to investigate the role of iNOS in the development of oral squamous cells carcinomas (OSCC), using a mouse model of oral carcinogenesis in NOS2 knockout animals and human samples derived from normal mucosa, leukoplakia and OSCC. Wild-type (iNOS+/+) and NOS2-knockout (iNOS-/-) mices, were challenged with 4- nitroquinoline- 1-oxide (4NQO) in drinking water for 16 weeks and killed after 0, 8 and 16 weeks of after treatment. Tongues were removed and the number of dysplasias and carcinomas was counted. Mice’s peripheral blood were analyzed by flux cytometry in search of circulating tumor cells. Human samples derived from normal mucosa, leukoplakia and OSCC, were utilized to relative quantify the amount of NOS2-mRNA. The human samples were also immune-stained with anti-iNOS and anti- Nitrotyrosine antibodies. In both groups, a reduction of dysplasias and an increase of carcinomas from week 16 to week 32 were observed. iNOS-/- mices had shown a small number of dysplastic and neoplastic lesion in all evaluated periods, moreover these lesions were usually smaller and less invasive when compared to wild type animals. Apparently, there is a rising tendency in the iNOS mRNA and protein levels during human oral carcinogenesis. Similar findings were obtained in the nitrotyrosine staining. Furthermore, iNOS and nitrotyrosine imuno-stained is associated with several clinic-pathological features of OSCC (site, presence of metastasis, staging and recidive). Our results shows that, iNOS affects the process of experimental and human oral carcinogenesis, being associated with OSCC genesis and progression. More studies should be done to provide us a deep understanding of the iNOS functions in oral cancer development. / Tese (Doutorado)

Made available in DSpace on 2014-07-29T15:21:56Z (GMT). No. of bitstreams: 1 DIS J V S FILHO 2006.pdf: 804840 bytes, checksum: 74be1a5db70d292dc48c7621acb661f3 (MD5) Previous issue date: 2006-11-27 / Squamous cell carcinoma (SCC) is the most common malignant neoplasm of the bucal cavity, and one of its variants is verrucous carcinoma (VC), of low degree malignancy. The diagnosis of VC is difficult from the clinical as well as from the histopathological point of view, and an effective diagnosis is vital when deciding on the treatment and prognosis of this tumor. The aim of this research was to evaluate cell proliferation and investigate the presence of HPV in spindle cell carcinoma of the mouth so as to check for possible differences in the aetiopathogenesis and biological behavior of these lesions. Forty-seven samples were selected and divided as follows: 39 SCCs, 8 VCs and 9 control (CT). Cell proliferation was qualitatively evaluated according to the location of the expression of the immunomarker in the cell and epithelium layers and by quantitatively considering the percentage of positive cells expressed. The analysis of HPV+ carcinomas was undertaken by means of the polymerase chain reaction (PCR), having GP5+/6+ as primers for identification of the virus. The qualitative analysis showed that the immunomarking in the VC as well as in the control group was concentrated mainly in the basal and parabasal layers and the counting of the positive cells at the base of the epithelium showed a significant statistical difference in the expressions of all three markers (p<0,05). The quantitative analysis of the cell proliferation markers was calculated by means of the Mann-Whitney and Kruskal Wallis tests and through the Pearson and Spermans correlation. They pointed to differences between the SCC and VC groups for the PCNA and cyclin B1 markers (p<0,05). On considering the three groups, it was proved that there was a positive correlation between Ki67 and the cyclin B1 (r=0,56) but not between the PCNA and the Ki67. The PCNA immunomarking was greater in the control group (average=100%), and the Ki67 showed itself to be effective as a proliferation cell marker although it showed no significant difference between the carcinoma variants. Whereas the cyclin B1 showed a significant difference in the comparison between the SCC and the VC groups (p<0,05), and a positive correlation to the extent that the histological grading of the malignancy (WHO model) of the carcinomas increased (r=0,44). All tumor samples were negative for HPV. Although the lesions showed different biological behaviors, the cell proliferation index in both types of mouth carcinoma was higher than in the control group, as shown by the analysis of the Ki67 and cyclin B1 markers. On considering the total sample of carcinomas, independently of the tumor variety, cyclin B1 showed a positive correlation with the histological degree of malignancy according to WHO. There is a need for further study to be carried out in the field of cell proliferation and detection of HPV especially with regard to VC, because it is a rare variant of SCC. / O carcinoma espinocelular (CEC) é a neoplasia maligna mais comum na cavidade bucal, e uma de suas variantes é o carcinoma verrucoso (CV), considerado de baixo grau de malignidade. O diagnóstico do CV é difícil, tanto do ponto de vista clínico quanto histopatológico e um efetivo diagnóstico é fundamental para estabelecer o tratamento e o prognóstico desse tumor. Neste estudo foi avaliada a proliferação celular e investigada a presença de HPV em carcinomas espinocelulares de boca com intuito de verificar possíveis diferenças na etiopatogênese e comportamento biológico destas lesões. Foram selecionadas 47 amostras de CEC assim distribuídas: 39 CECs, 8 CVs e 9 controles (CT). A proliferação celular foi avaliada qualitativamente de acordo com a localização da expressão do imunomarcador na célula e nas camadas do epitélio e quantitativamente considerando o percentual de células positivas expressas. A análise de carcinomas HPV+ foi realizada por meio da reação em cadeia da polimerase (PCR), tendo como primers GP5+/6+ na identificação do vírus. A análise qualitativa revelou que a imunomarcação tanto no CV como no controle concentrava se principalmente nas camadas basal e parabasal e a contagem das células positivas na base do epitélio mostraram diferença estatisticamente significativa na expressão dos três marcadores (p<0,05). A análise quantitativa dos marcadores de proliferação celular foi calculada pelos testes estatísticos Mann-Whitney, Kruskal Wallis, correlação de Pearson e Spermans, que revelaram diferenças entre o grupo CEC e CV para os marcadores PCNA e ciclina B1 (p<0,05). Considerando os três grupos, verificou-se correlação positiva entre Ki67 e a ciclina B1 (r=0,56) e inexistência de correlação entre o PCNA e Ki67. A imunomarcação do PCNA foi maior no grupo controle (média=100%), e o Ki67, mostrou-se efetivo como marcador de proliferação celular, entretanto, não mostrou diferença significativa entre as variantes de carcinomas. Já a ciclina B1 apresentou diferença significativa na comparação entre o grupo CEC e o grupo CV (p<0,05) e correlação positiva na medida em que a gradação histológica de malignidade (padrão OMS) dos carcinomas aumentava (r=0,44). Todas as amostras de tumores foram negativas para o HPV. Embora as lesões apresentem comportamento biológico diferente, o índice de proliferação celular nos dois tipos de carcinomas de boca mostrou ser superior ao do grupo controle, por meio da análise dos marcadores Ki67 e ciclina B1. Quando considerada a amostra total de carcinomas, independente da variante tumoral, a ciclina B1 mostrou correlação positiva com o grau histológico de malignidade segundo a OMS. Há necessidade que mais estudos possam ser empreendidos na área de proliferação celular e detecção de HPV em especial com relação ao CV, por se tratar de uma variante rara do CEC.

No description available.

Autosomal recessive primary microcephaly (MCPH) is a congenital neurodevelopmental disorder characterised by a reduced occipital-frontal head circumference (OFC) of less than -3 SDs below the population mean for age and sex. It is a genetically heterogeneous disorder caused by mutations in one of the following 10 MCPH genes: MCPH1 (microcephalin 1), WDR62 (WD repeat domain 62), CDK5RAP2 (cyclin-dependent kinase 5 regulatory associated protein 2), CASC5 (cancer susceptibility candidate 5), CEP152 (centrosomal protein 152 kDa), ASPM (asp [abnormal spindle] homolog, microcephaly associated [Drosophila]), CENPJ (centromeric protein J), STIL (SCL/TAL1-interrupting locus), CEP135 (centrosomal protein 135 kDa) and CEP63 (centrosomal protein 135 kDa). The MCPH1 (microcephalin 1) gene is located on chromosome 8p23.1. Microsatellite analysis has previously shown LOH at the markers D8S518 and D8S277 flanking the MCPH1 locus in 1/21 oral tumors. Furthermore, LOH at the markers D8S1742 and D8S277 flanking the MCPH1 locus has also been observed in 2/32 hepatocellular carcinomas. MCPH1 has been found to be mutated in breast and endometrial cancers. Additionally, it was found to be downregulated at the transcript level in 19/30 ovarian cancer tissues and the protein level in 93/319 breast cancer tissues. Decreased MCPH1 protein levels are associated with triple negative breast cancers and a lower transcript level of MCPH1 correlates with lesser time for metastasis to occur in breast cancer patients. Interestingly, MCPH1 knockout mice in a null TP53 background show susceptibility to cancer.So far, studies have indicated that MCPH1 is a DNA repair protein. MCPH1 is required for the formation of DNA repair foci, chromatin relaxation, HR and NHEJ. It regulates G1/S and G2/M cell cycle checkpoints. Also, depletion of MCPH1 leads to genomic instability and centrosome amplification. Hence, the defect in the function of MCPH1 can lead to plethora of anomalies including cancer. Based on these observations, we hypothesized that MCPH1 may also function as a tumor suppressor (TS) gene, in addition to its role in the brain development. The purpose of this study was to test if MCPH1 also functions as a TS gene using different approaches in OSCC (oral squamous cell carcinoma). OSCC is the sixth most common type of cancer. It includes the cancer of the lips, anterior 2/3rd of the tongue, buccal mucosa, floor of the mouth, retromolar trigone and gingiva. Despite the advances in the treatment of oral cancer, the five-yr survival rate has not increased. Hence, the effective treatment of OSCC requires the identification of molecular targets to design appropriate therapeutic strategies. LOH, mutations and promoter methylation in tumors are the hallmarks of TS genes. In order to ascertain the TS roles of MCPH1, we carried out LOH analysis in 81 matched blood/normal and tumor oral tissues using D8S1819, D8S277 and D8S1798 markers flanking the MCPH1 locus. The results showed LOH at one or more markers in 14/71 (19.72%) informative samples across the tumor stages from T1 to T4. The entire coding region and the exon-intron junctions of the MCPH1 gene were sequenced for mutations in 15 OSCC samples and 5 cancer cell lines (viz., A549, HeLa, KB, SCC084 and SCC131). In total, three mutations namely c.1561G>T(p.Glu521X), c.321delA(p.Lys107fsX39) and c.1402delA(p.Thr468fsX32) were identified. The expression of MCPH1 was analysed at both the transcript and protein levels by real-time quantitative RT-PCR and immunohistochemistry, respectively, in OSCC samples. MCPH1 was downregulated in 51.22% (21/41) of OSCC samples at the transcript level. The MCPH1 protein was downregulated in 76% (19/25) of the OSCC samples. In order to elucidate if the MCPH1 promoter was methylated in OSCC tissues, we retrieved the MCPH1 promoter from the database TRED (Transcriptional Regulatory Element Database). The promoter was analysed for the presence of CpG islands using the CpG Plot/CpG Report program. Two CpG islands (CpGI and CpGII) were identified within the MCPH1 promoter. Both the CpG islands were analysed for methylation in 40 OSCC samples by COBRA (Combined Bisulfite Restriction Analysis). CpGI showed no methylation in 40 OSCC samples. However, CpGII showed methylation in 4/40 (10%) OSCC samples and the methylation was absent in their corresponding normal oral tissues. To analyse the methylation of the MCPH1 promoter in cancer cell lines, HeLa, KB, SCC084 and SCC131 cells were treated with 5’-2-deoxy azacytidine (AZA), a methyltrasferase inhibitor. HeLa and KB cells did not show any change in the MCPH1 transcript level after the AZA treatment. However, SCC084 and SCC131 cells showed upregulation of MCPH1 after the treatment, suggesting methylation of the MCPH1 promoter. To validate these observations, we examined the methylation status of both the CpG islands in these cell lines. We found methylation of CpGII only in SCC084 cells. HeLa, KB and SCC131 cells showed no methylation of CpGI and CpGII. The results obtained by COBRA in these cell lines were further confirmed by bisulfite sequencing of CpGI and CpGII islands. Further, the upregulation of MCPH1 after azacytidine treatment in SCC131 cells can be attributed to a promoter independent mechanism or due to methylation of the CpG sites not examined by us. To elucidate the biological effects of MCPH1 in a cancer cell line, we generated stable clones overexpressing MCPH1 in KB cells. The results showed that MCPH1 overexpression decreased cellular proliferation, cell invasion, anchorage-independent growth in soft-agar and tumor growth in nude mice. Further, MCPH1 overexpression lead to apoptosis. A low frequency of LOH, mutations and promoter methylation suggested that they might not be the major mechanisms of downregulation of MCPH1 in OSCC. We then speculated that MCPH1 could be regulated by miRNAs. We therefore used five miRNA target prediction softwares to identify miRNAs targeting MCPH1. The programs identified two binding sites for miR-27a within the 5.4 kb region of the 3’-UTR of MCPH1. The luciferase assay showed that both the seed regions of MCPH1 were binding to miR-27a. In addition, transient transfection of the premiR-27a construct in KB cells decreased the protein level of MCPH1. Additionally, in a small panel of 10 OSCC samples, there was a negative correlation between the levels of miR-27a and MCPH1. To the best of our knowledge, this is the first report showing any miRNA regulating the MCPH1 gene. It is important to note that tumor suppressors can serve as potential biomarkers with prognostic value. Hence, we analysed the correlation of the expression levels of MCPH1 with clinico-pathological parameters such as TNM, gender, age and site of the cancer by Fischer’s exact test. No statistical correlation was observed between the transcript or protein levels with any of the clinico-pathological parameters. In summary, the results of the present study have suggested that the primary microcephaly gene MCPH1 shows several hallmarks of TS genes and functions as a tumor suppressor in OSCC, in addition to its role in brain development. We have for the first time shown that miR-27a targets MCPH1 and regulates its level. It is interesting to note that none of the other 10 MCPH genes have been shown to be regulated by any miRNA yet. Our study will be useful in designing novel therapeutic methods for the treatment of OSCC either by overexpression of MCPH1 or reducing the level of miR-27a by an antagomir.

Background: Standardized staging procedures and presentation of oral squamous cell carcinoma (OSCC) patients in multidisciplinary tumor boards (MDTB) before treatment and utilization of elective neck dissection (ND) are expected to improve the outcome, especially in local advanced LAOSCC (UICC stages III–IVB). As standardized diagnostics but also increased heterogeneity in treatment applied so far have not been demonstrated to improve outcome in LAOSCC, a retrospective study was initiated. Methods: As MDTB was introduced into clinical routine in 2007, 316 LAOSCC patients treated during 1991-2017 in our hospital were stratified into cohort 1 treated before (n=104) and cohort 2 since 2007 (n=212). Clinical characteristics, diagnostic procedures and treatment modality of patients were compared using Chi-square tests and outcome analyzed applying Kaplan-Meier plots and log-rank tests as well as Cox proportional hazard regression. Propensity scores (PS) were used to elucidate predictors for impaired distant metastasis-free survival (DMFS) in PS-matched patients. Results: Most patient characteristics and treatment modalities applied showed insignificant alteration. Surgical treatment included significantly more often resection of the primary tumor plus neck dissection, tracheostomy and percutaneous endoscopic gastrostomy tube use. Cisplatin-based chemo-radiotherapy was the most frequent. Only insignificant improved disease- (DFS), progression- (PFS) and event-free (EFS) as well as tumor-specific (TSS) and overall survival (OS) were found after 2006 as local (LC) and locoregional control (LRC) were significantly improved but DMFS significantly impaired. Cox regression applied to PS-matched patients elucidated N3, belonging to cohort 2 and cisplatin-based chemo-radiotherapy as independent predictors for shortened DMFS. The along chemo-radiotherapy increased dexamethasone use in cohort 2 correlates with increased DM. Conclusions: Despite standardized diagnostic procedures, decision-making considering clear indications and improved therapy algorithms leading to improved LC and LRC, shortened DMFS hypothetically linked to increased dexamethasone use had a detrimental effect on TSS and OS.

No description available.

Objective: In many countries the access to high quality medical service depends on socioeconomic factors. Therefore, these factors are associated with the treatment and prognosis of many diseases. In Germany health care is claimed to be independent from such factors due to obligatory health insurance and a well-developed medical infrastructure. Thus, socioeconomically caused health disparities should be absent. The aim of this study was to analyze the association between socioeconomic factors and the survival of oral cavity cancer in Germany. Patients and methods: In this descriptive cohort study socioeconomic status related factors as well as demographic, tumor-specific, and comorbidity factors of 500 patients treated for oral cavity cancer were obtained in the university hospital of Dresden. Pearson correlation was used to describe associations between continuous variables. Associations between categorical variables were assessed using the chi-square test. Overall and recurrence-free survival were studied using the Kaplan-Meier method. Log-rank test was carried out to test between-group differences. Cox proportional hazard models were used to estimate the risk of death and the risk of recurrence. Results: Significant differences in overall survival were found between the different educational levels and sex. Seventy-nine percent of the patients did not have a university degree or master craftsman/craftswoman. Less discrepancy was observed according to the marital status (49.4% married/engaged vs. 47.8% single, divorced, or widowed). In the multivariable analysis only sex, age at diagnosis, the Charlson score, the number of positive lymph nodes, and the nodal status were identified as independent predictors for overall survival whereas sex and the age at diagnosis were identified as independent predictors for recurrence-free survival. Conclusion: Despite the equitable health system in Germany, significant associations between overall survival of oral cavity cancer and different socioeconomic factors could be found. For elimination of these disparities, health education programs should be established in socially deprived areas. Furthermore, clinicians should keep these factors in mind when determining recall periods for dental check-ups.