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.