Thesis (Ph. D.)--University of Hong Kong, 2008. / Includes bibliographical references (leaf 132-174) Also available in print.

Thesis (Ph. D.)--University of Hong Kong, 2008. / Includes bibliographical references (leaf 132-174) Also available online.

Yes / Recently a sub-population of cells with stem cell characteristics, reported to be associated with initiation, growth, spread and recurrence, has been identified in several solid tumors including oral tongue squamous cell carcinoma (OTSCC). The aim of our pilot study was to isolate CD44+ cancer stem cells from primary cultures of OTSCC and neck node Level I (node-I) biopsies, grow cell spheres and observe their characteristics in primary cultures. Parallel cultures of hyperplastic lesions of tongue (non-cancer) were set up as a control. Immunohistochemistry was used to detect CD44/CD24 expression and magnetic activated cell sorting to isolate CD44+ cell populations followed by primary cell culturing. Both OTSCC and node-I biopsies produced floating spheres in suspension, however those grown in hyperplastic and node-I primary cultures did not exhibit self-renewal properties. Lymph node metastatic OTSCC, express higher CD44/CD24 levels, produce cancer cell spheres in larger number and rapidly (24 hours) compared to node negative OTSCC (1 week) and non-cancer specimens (3 weeks). In addition, metastatic OTSCC have the capacity for proliferation for up to three generations in primary culture. This in vitro system will be used to study cancer stem cell behavior, therapeutic drug screening and optimization of radiation dose for elimination of resistant cancer cells. / SKMCH&RC, Yorkshire Cancer Research

Head and neck cancer is a heterogeneous group of tumours, of which certain subgroups such as cancer of the mobile tongue frequently are associated with a relatively poor prognosis due to the high risk of regional failure and mortality rates that haven’t improved in a significant way over the last 3 decades, despite advancements in both diagnostics and treatment. Today we lack means to assess the biological aggressiveness of each individual tumour, which varies largely. Treatment comprises of surgery with additional radiotherapy and medical therapies in more advanced tumours. The focus in this thesis is on molecular biomarker expression in head and neck cancer and especially in association with radiotherapy. Increased knowledge paves the way to a more individualized cancer treatment aiming for better outcome and less overtreatment and sequelae. The aims of this thesis was: To map the effects of radiotherapy in both tumour and adjacent tissue for the possible markers hyaluronan, EGFR and mast cells. To investigate whether the expression of hyaluronan in the epithelium and connective tissue stroma and EGFR in the tumour correlates with the risk for developing cervical metastasis in N0 patients, and to find out whether the 3-year tumour-specific survival rates correlates with the expression of HA in the epithelium and EGFR in the tumour. To establish an animal model for radiation-induced mucositis and to use that model to examine the pattern of invading inflammatory cells. To investigate whether the expression of podoplanin in tongue cancer correlates with the risk for cervical metastasis and to determine whether the total amount of lymph vessels in the diagnostic biopsy has any impact on the clinical outcome. To investigate the differences in the metabolome of tongue cancer cell lines with different radiosensitivity. The most important findings of this thesis were: The expression of EGFR and hyaluronan hade the same pattern of expression in both tumour and adjacent tissues before radiotherapy. The expression of EGFR was increased in the epithelium of the adjacent tissue close to the tumour after radiotherapy. The intensity of the staining of hyaluronan was correlated to the 3-year survival rates in patients with tongue cancer. An experimental model for radiation-induced oral mucositis in rat was established and in this model a temporal pattern of macrophage invasion with two different subtypes of macrophages was found. There were no correlation between the expression of podoplanin in the tumour tissue and the cervical metastasis rate in patients with tongue cancer, but the younger patients were more likely to have a higher expression of podoplanin in their tumour than elder patients. Tongue cancer cell lines with different radiosensitivity respond to irradiation with different patterns of metabolic expressions.

Made available in DSpace on 2014-12-17T15:32:27Z (GMT). No. of bitstreams: 1 CristinaRFA.pdf: 1625942 bytes, checksum: 99d50db14437c5ea0e3022e4da576321 (MD5) Previous issue date: 2009-03-06 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior / Bone morphogenetic proteins (BMPs) are cytokines involved in proliferation and angiogenesis of many kind of human cancer. The present study analyzed the immunohistochemical expression of BMP-2, BMPR-II, BMPR-IA and endoglin (CD105) and their relationship with the biological behavior and local angiogenesis in tongue oral squamous cells carcinoma (SCC). The sample consisted of 25 cases of tongue SCC without metastasis, 25 tongue SCC with metastasis and 25 cases of Inflamatory Fibrous Hyperplasia (IFH).The histological grade of malignancy proposed by Bryne (1998), adapted by Miranda (2002) was used to classify all tongue SCC cases. Score 0 was attributed to absent-weak immunoexpression and score 1 for strong immunostaning and pattern of distribution was focal or diffuse. Microvessel counts (MVC) was established for CD105. Most of the patients with tongue SCC was male. The principal age in tongue SCC without metastasis was over 65 years and in tongue SCC with metastasis was between 45-65 years. There were predominance of stage II in TNM and in the specimens with high-grade, independent of studied group. For BMP-2, 56% of tongue SCC without metastasis and 72% tongue SCC with metastasis exhibited score 1 while the IFH showed secore 0 in 72% of the cases, with statistical association (p=0,007). Considering the BMPR-II, 52% of tongue SCC without metastasis exhibited score 0; 56% tongue SCC with metastasis and 60% IFH showed score 1. The majority cases of BMPR-IA demonstrated score 1 and 100% of CD105 exhibited strong immunoexpression in tongue SCC. Regarding the pattern distribution, it was noted a tendency to diffuse pattern for the proteins in all groups. The means of MVC were similar in tongue SCC without metastasis (32,91) and in tongue SCC with metastasis (32,05), however existed statistical difference with IFH (p<0,001). There was statistical association of BMP-2 expression with BMPR-II (p=0,008), BMPR-IA (p=0,006) and CD105 (p=0,046). An association between TNM and BMP-2 immunoexpression and their receptors was not detected, nevertheless this association was found with MVC (p=0,047) whose averages were higher for the stages II (35,97) e IV (35,69). No association between histological grading and these proteins was observed. This study suggests that the superexpression of BMP-2 signaling pathways acts on cell proliferation in tongue SCC and can be implicated with more invasive potential. Additionaly, the CD105 is a potent biological marker of neovascularization in this neoplasm and their association with BMP-2 and BMPR-IA receptor, showed that this type of cancer in BMP-2 is presented as pro-angiogenic in the metastatic process / As BMPs (prote?nas morfogen?ticas ?sseas) s?o citocinas relacionadas com a prolifera??o e angiog?nese em diversos tipos de c?ncer humano. Com este trabalho foi analisada a express?o imunoistoqu?mica das prote?nas BMP-2, BMPR-IA, BMPR-II e endoglina (CD105), correlacionando-a com o comportamento biol?gico e a angiog?nese local nos carcinomas epiderm?ides de l?ngua (CEL). A amostra foi composta de 25 casos de CEL sem met?stase (CELSM), 25 CEL com met?stase (CELCM) graduados segundo Bryne (1998) e adaptado por Miranda (2002), al?m de 25 casos de hiperplasia fibrosa inflamat?ria (HFI), utilizado como grupo controle. Foi utilizado escore 0 para marca??o ausente-fraca e 1 para forte; tipo de distribui??o focal ou difuso. Adicionalmente, para o CD105 foi realizada a contagem microvascular (MVC). A maior parte dos pacientes com CEL foi do sexo masculino, no grupo CELSM a faixa et?ria foi maior que 65 anos e o CELCM se encontrou entre 45-65 anos; houve predom?nio do est?gio II do TNM, assim como de esp?cimes de alto grau, independente do grupo estudado. Para BMP-2, 56% dos CELSM e 72% dos CELCM exibiram escore 1, enquanto a HFI exibiu 72% de escore 0, apresentando associa??o estat?stica (p=0,007). Para BMPR-II 52% dos CELSM exibiram escore 0; 56% CELCM e 60% da HFI escore 1 e no BMPR-IA ocorreu uma predomin?ncia de escore 1 e para o CD105 100% de marca??o forte nos CEL. Quanto ao tipo de distribui??o notou-se tend?ncia de distribui??o difusa de todas as prote?nas, em todos os grupos. Observaram-se, para MVC, m?dias muito semelhantes entre os CELSM (32,91) e os CELCM (32,05) exibindo, contudo, diferen?a estat?stica com as HFI (p<0,001).Observa-se uma associa??o estat?stica da BMP-2 com a BMPR-II (P=0,008), BMPR-IA (p=0,006) e o CD105 (0,046). N?o se observou associa??o entre o TNM e a imunoexpress?o da BMP-2 e seus receptores, por?m foi encontrada com a MVC (p=0,047), cujas maiores m?dias foram para os est?gios II (35,97) e IV (35,69), tal como n?o ocorreu associa??o entre a grada??o histol?gica e as prote?nas. Conclui-se que a superexpress?o da via de sinaliza??o da BMP-2 atua na prolifera??o celular, contribuindo para maior invasividade do CEL. O CD105 ? um potente marcador de neovasculariza??o deste neoplasma e sua associa??o com a BMP-2 e o receptor BMPR-IA, mostra que neste tipo de neoplasia a BMP-2 se apresenta como pr?-angiog?nico no processo metast?tico