Epithelial-mesenchymal transition in oral squamous carcinoma cells

In epithelial-mesenchymal transition (EMT), epithelial cells acquire traits typical for mesenchymal cells, dissociate their cell-cell junctions and gain the ability to migrate. EMT is essential during embryogenesis, but may also mediate cancer progression. Basement membranes are sheets of extracellular matrix that support epithelial cells. They have a major role in maintaining the epithelial phenotype and, in cancer, preventing cell migration, invasion and metastasis. Laminins are the main components of basement membranes and may actively contribute to malignancy. We first evaluated the differences between cell lines obtained from oral squamous cell carcinoma and its recurrence. As the results indicated a change from epithelial to fibroblastoid morphology, E-cadherin to N-cadherin switch, and change in expression of cytokeratins to vimentin intermediate filaments, we concluded that these cells had undergone EMT. We further induced EMT in primary tumour cells to gain knowledge of the effects of transcription factor Snail in this cell model. The E-cadherin repressors responsible for the EMT in these cells were ZEB-1, ZEB-2 and Snail, and ectopic expression of Snail was able to augment the levels of ZEB-1 and ZEB-2. We produced and characterized two monoclonal antibodies that specifically recognized Snail in cell lines and patient samples. By immunohistochemistry, Snail protein was found in mesenchymal tissues during mouse embryonal development, in fibroblastoid cells of healing skin wounds and in fibromatosis and sarcoma specimens. Furthermore, Snail localized to the stroma and borders of tumour cell islands in colon adenocarcinoma, and in laryngeal and cervical squamous cell carcinomas. Immunofluorescence labellings, immunoprecipitations and Northern and Western blots showed that EMT induced a progressive downregulation of laminin-332 and laminin-511 and, on the other hand, an induction of mesenchymal laminin-411. Chromatin immunoprecipitation revealed that Snail could directly bind upstream to the transcription start sites of both laminin α5 and α4 chain genes, thus regulating their expression. The levels of integrin α6β4, a receptor for laminin-332, as well as the hemidesmosomal complex proteins HD1/plectin and BP180 were downregulated in EMT-experienced cells. The expression of Lutheran glycoprotein, a specific receptor for laminin-511, was diminished, whereas the levels of integrins α6β1 and α1β1 and integrin-linked kinase were increased. In quantitative cell adhesion assays, the cells adhered potently to laminin-511 and fibronectin, but only marginally to laminin-411. Western blots and immunoprecipitations indicated that laminin-411 bound to fibronectin and could compromise cell adhesion to fibronectin in a dose-dependent manner. EMT induced a highly migratory and invasive tendency in oral squamous carcinoma cells. Actin-based adhesion and invasion structures, podosomes and invadopodia, were detected in the basal cell membranes of primary tumour and spontaneously transformed cancer cells, respectively. Immunofluorescence labellings showed marked differences in their morphology, as podosomes organized a ring structure with HD1/plectin, αII-spectrin, talin, focal adhesion kinase and pacsin 2 around the core filled with actin, cortactin, vinculin and filamin A. Invadopodia had no division between ring and core and failed to organize the ring proteins, but instead assembled tail-like, narrow actin cables that showed a talin-tensin switch. Time-lapse live-cell imaging indicated that both podosomes and invadopodia were long-lived entities, but the tails of invadopodia vigorously propelled in the cytoplasm and were occasionally released from the cell membrane. Invadopodia could also be externalized outside the cytoplasm, where they still retained the ability to degrade matrix. In 3D confocal imaging combined with in situ gelatin zymography, the podosomes of primary tumour cells were large, cylindrical structures that increased in time, whereas the invadopodia in EMT-driven cells were smaller, but more numerous and degraded the underlying matrix in significantly larger amounts. Fluorescence recovery after photobleaching revealed that the substructures of podosomes were replenished more rapidly with new molecules than those of invadopodia. Overall, our results indicate that EMT has a major effect on the transcription and synthesis of both intra- and extracellular proteins, including laminins and their receptors, and on the structure and dynamics of oral squamous carcinoma cells.

Matrix metalloproteinases as biomarkers in premalignant and malignant tumors of the human skin

The incidence of non-melanoma skin cancer is increasing worldwide. Basal cell carcinoma followed by squamous cell carcinoma and malignant melanoma are the most frequent skin tumors. Immunosuppressed patients have an increased risk of neoplasia, of which non-melanoma skin cancer is the most common. Matrix metalloproteinases (MMPs) are proteolytic enzymes that collectively are capable of degrading virtually all components of the extracellular matrix. MMPs can also process substrates distinct from extracellular matrix proteins and influence cell proliferation, differentiation, angiogenesis, and apoptosis. MMP activity is regulated by their natural inhibitors, tissue inhibitors of metallopro-teinases (TIMPs). In this study, the expression patterns of MMPs, TIMPs, and certain cancer-related molecules were investigated in premalignant and malignant lesions of the human skin. As methods were used immunohistochemisty, in situ hybridization, and reverse transcriptase polymerase chain reaction (RT-PCR) from the cell cultures. Our aim was to evaluate the expression pattern of MMPs in extramammary Paget's disease in order to find markers for more advanced tumors, as well as to shed light on the origin of this rare neoplasm. Novel MMPs -21, -26, and -28 were studied in melanoma cell culture, in primary cutaneous melanomas, and their sentinel nodes. The MMP expression profile in keratoacanthomas and well-differentiated squamous cell carcinomas was analyzed to find markers to differentiate benign keratinocyte hyperproliferation from malignantly transformed cells. Squamous cell carcinomas of immunosuppressed organ transplant recipients were compared to squamous cell carcinomas of matched immunocompetent controls to investigate the factors explaining their more aggressive nature. We found that MMP-7 and -19 proteins are abundant in extramammary Paget's disease and that their presence may predict an underlying adenocarcinoma in these patients. In melanomas, MMP-21 was upregulated in early phases of melanoma progression, but disappeared from the more aggressive tumors with lymph node metastases. The presence of MMP-13 in primary melanomas and lymph node metastases may relate to more aggressive disease. In keratoacanthomas, the expression of MMP-7 and -9 is rare and therefore should raise a suspicion of well-differentiated squamous cell carcinomas. Furthermore, MMP-19 and p16 were observed in benign keratinocyte hyperproliferation of keratoacanthomas, whereas they were generally lost from malignant keratinocytes of SCCs. MMP-26 staining was significantly stronger in squamous cell carcinomas and Bowen s disease samples of organ transplant recipients and it may contribute to the more aggressive nature of squamous cell carcinomas in immunosuppressed patients. In addition, the staining for MMP-9 was significantly stronger in macrophages surrounding the tumors of the immunocompetent group and in neutrophils of those patients on cyclosporin medication. In conclusion, based on our studies, MMP-7 and -19 might serve as biomarkers for more aggressive extramammary Paget's disease and MMP-21 for malignant transformation of melanocytes. MMP -7, -9, and -26, however, could play an important role in the pathobiology of keratinocyte derived malignancies.

The Risk of Cancer Associated with Immunosuppressive Therapy for Skin Diseases

The possible carcinogenic risk of immunosuppressive therapies is an important issue in everyday clinical practise. Carcinogenesis is a slow multi step procedure, thus a long latency period is needed before cancer develops. PUVA therapy is used for many skin diseases including psoriasis, early stage cutaneous T cell lymphoma, atopic dermatitis, palmoplantar pustulosis and chronic eczema. There has been concern about the increased melanoma risk associated to PUVA therapy, which has previously been associated with an increased risk on non-melanoma skin cancer, especially squamous cell carcinoma. The increased risk of basal cell carcinoma (BCC) is also documented but it is modest compared to squamous cell carcinoma (SCC). This thesis evaluated melanoma and noncutaneous cancer risk associated to PUVA, and the persistence of nonmelanoma cancer risk after the cessation of PUVA treatment. Also, the influence of photochemotherapy to the development of secondary cancers in cutaneous T cell lymphoma and the role of short term cyclosporine in later cancer development in inflammatory skin diseases were evaluated. The first three studies were performed on psoriasis patients. The risk of melanoma started to increase 15 years after the first treatment with PUVA. The risk was highest among persons who had received over 250 treatments compared to those under 250 treatments. In noncutaneous cancer, the overall risk was not increased (RR=1.08,95% CI=0.93-1.24), but significant increases in risk were found in thyroid cancer, breast cancer and in central nervous system neoplasms. These cancers were not associated to PUVA. The increased risk of SCC was associated to high cumulative UVA exposure in the PUVA regimen. The patients with high risk had no substantial exposure to other carcinogens. In BCC there was a similar but more modest tendency. In the two other studies, the risk of all secondary cancers (SIR) in CTCL patients was 1.4 (95% CI=1.0-1.9). In separate sites, the risk of lung cancer, Hodgkin and non-Hodgkin lymphomas were increased. PUVA seemed not to contribute to any extent to the appearance of these cancers. The carcinogenity of short-term cyclosporine was evaluated in inflammatory skin diseases. No increased risk for any type of cancer including the skin cancers was detected. To conclude, our studies confirm the increased skin cancer risk related to PUVA treatment in psoriasis patients. In clinical practice, this has led to a close and permanent follow-up of patients treated with PUVA. In CTCL patients, PUVA treatment did not contribute to the development of secondary cancers. We could not detect any increase in the risk of cancer in patients treated with short term cyclosporine, unlike in organ transplant patients under such long-term therapy.

Microarrays in molecular profiling of cancer - focus on head and neck squamous cell carcinoma

Microarrays have a wide range of applications in the biomedical field. From the beginning, arrays have mostly been utilized in cancer research, including classification of tumors into different subgroups and identification of clinical associations. In the microarray format, a collection of small features, such as different oligonucleotides, is attached to a solid support. The advantage of microarray technology is the ability to simultaneously measure changes in the levels of multiple biomolecules. Because many diseases, including cancer, are complex, involving an interplay between various genes and environmental factors, the detection of only a single marker molecule is usually insufficient for determining disease status. Thus, a technique that simultaneously collects information on multiple molecules allows better insights into a complex disease. Since microarrays can be custom-manufactured or obtained from a number of commercial providers, understanding data quality and comparability between different platforms is important to enable the use of the technology to areas beyond basic research. When standardized, integrated array data could ultimately help to offer a complete profile of the disease, illuminating mechanisms and genes behind disorders as well as facilitating disease diagnostics. In the first part of this work, we aimed to elucidate the comparability of gene expression measurements from different oligonucleotide and cDNA microarray platforms. We compared three different gene expression microarrays; one was a commercial oligonucleotide microarray and the others commercial and custom-made cDNA microarrays. The filtered gene expression data from the commercial platforms correlated better across experiments (r=0.78-0.86) than the expression data between the custom-made and either of the two commercial platforms (r=0.62-0.76). Although the results from different platforms correlated reasonably well, combining and comparing the measurements were not straightforward. The clone errors on the custom-made array and annotation and technical differences between the platforms introduced variability in the data. In conclusion, the different gene expression microarray platforms provided results sufficiently concordant for the research setting, but the variability represents a challenge for developing diagnostic applications for the microarrays. In the second part of the work, we performed an integrated high-resolution microarray analysis of gene copy number and expression in 38 laryngeal and oral tongue squamous cell carcinoma cell lines and primary tumors. Our aim was to pinpoint genes for which expression was impacted by changes in copy number. The data revealed that especially amplifications had a clear impact on gene expression. Across the genome, 14-32% of genes in the highly amplified regions (copy number ratio >2.5) had associated overexpression. The impact of decreased copy number on gene underexpression was less clear. Using statistical analysis across the samples, we systematically identified hundreds of genes for which an increased copy number was associated with increased expression. For example, our data implied that FADD and PPFIA1 were frequently overexpressed at the 11q13 amplicon in HNSCC. The 11q13 amplicon, including known oncogenes such as CCND1 and CTTN, is well-characterized in different type of cancers, but the roles of FADD and PPFIA1 remain obscure. Taken together, the integrated microarray analysis revealed a number of known as well as novel target genes in altered regions in HNSCC. The identified genes provide a basis for functional validation and may eventually lead to the identification of novel candidates for targeted therapy in HNSCC.

Evaluation of regional and distant metastases in head and neck squamous cell carcinoma patients with special reference to the assessment of regional lymph nodes in oral cancer

For optimal treatment planning, a thorough assessment of the metastatic status of mucosal squamous cell carcinoma of the head and neck (HNSCC) is required. Current imaging methods do not allow the recognition of all patients with metastatic disease. Therefore, elective treatment of the cervical lymph nodes is usually given to patients in whom the risk of subclinical metastasis is estimated to exceed 15-20%. The objective of this study was to improve the pre-treatment evaluation of patients diagnosed with HNSCC. Particularly, we aimed at improving the identification of patients who will benefit from elective neck treatment. Computed tomography (CT) of the chest and abdomen was performed prospectively for 100 patients diagnosed with HNSCC. The findings were analysed to clarify the indications for this examination in this patient group. CT of the chest influenced the treatment approach in 3% of patients, while CT of the abdomen did not reveal any significant findings. Our results suggest that CT of the chest and abdomen is not indicated routinely for patients with newly diagnosed HNSCC but can be considered in selected cases. Retrospective analysis of 80 patients treated for early stage squamous cell carcinoma of the oral tongue was performed to investigate the potential benefits of elective neck treatment and to examine whether histopathological features of the primary tumour could be used in the prediction of occult metastases, local recurrence, or/and poor survival. Patients who had received elective neck treatment had significantly fewer cervical recurrences during the follow-up when compared to those who only had close observation of the cervical lymph nodes. Elective neck treatment did not result in survival benefit, however. Of the histopathological parameters examined, depth of infiltration and pT-category (representing tumour diameter) predicted occult cervical metastasis, but only the pT-category predicted local recurrence. Depth of infiltration can be used in the identification of at risk patients but no clear cut-off value separating high-risk and low-risk patients was found. None of the histopathological parameters examined predicted survival. Sentinel lymph node (SLN) biopsy was studied as a means of diagnosing patients with subclinical cervical metastases. SLN biopsy was applied to 46 patients who underwent elective neck dissection for oral squamous cell carcinoma. In addition, SLN biopsy was applied to 13 patients with small oral cavity tumours who were not intended to undergo elective neck dissection because of low risk of occult metastasis. The sensitivity of SLN biopsy for finding subclinical cervical metastases was found to be 67%, when SLN status was compared to the metastatic status of the rest of the neck dissection specimen. Of the patients not planned to have elective neck dissection, SLN biopsy revealed cervical metastasis in 15% of the patients. Our results suggest that SLN biopsy can not yet entirely replace elective neck dissection in the treatment of oral cancer, but it seems beneficial for patients with low risk of metastasis who are not intended for elective neck treatment according to current treatment protocols.

Merkel cell carcinoma : Epidemiological study with special reference to polyomavirus and vascular factors in pathogenesis

Merkel cell carcinoma (MCC) is a rare cutaneous malignancy that occurs predominantly on sun exposed skin areas. A new polyomavirus (MCPyV) was identified in MCC tumor tissues in 2008 suggesting that a viral infection might be an etiological factor. A typical MCC is a rapidly growing painless purple nodule. In its early stage it can be misjudged by its appearance as a cyst or abscess. Recurrences are common and approximately half of the patients will develop lymph node metastases and third of the patents will have distant metastases. It affects mostly elderly persons at an average age of 70 at the time of diagnosis. MCC was first described in 1972 and the first MCC patient in Finland was identified in 1983. MCC has been poorly recognized, but increased awareness and better diagnostic accuracy has increased the incidence since the early years. In this study, all cases with a notation of MCC during 1979 2008 were obtained from the Finnish Cancer Registry. Based on this data, the incidence is 0.11 for men and 0.12 for women. It is similar than that of other Nordic countries, but lower than in the USA. For clinical series, the files of patients diagnosed with MCC during 1983 2004 were reviewed, and the tissue samples were re-evaluated, if available (n=181). Third of the patients were men, and the most common site of the primary tumor was the head and neck (53%). The majority of the patients (86%) presented with a clinically node-negative (Stage I or II) disease, but the disease recurred in 38% of them. The treatment schemes were heterogeneous. No additional benefit from a wide margin (≥2 cm) was found compared to a margin of 0.1-1.9 cm, but intralesional excision was more often associated with local recurrence. None of the patients with Stage I-II disease who had received postoperative radiotherapy had local recurrence during the follow-up period. The 5-year relative survival ratio for Stage I disease was 68%, for Stage II 67%, for Stage III 16%, and for Stage IV 0%. The relative excess risk of death was significantly lower among women than among men. Some of these tissue samples were further analyzed for vascular invasion (n=126) by immunohistochemistry using vascular endothelial markers CD-31 and D2-40. Vascular invasion was seen in 93% of the samples and it was observed already in very small, <5mm tumors. The tissue samples were also analyzed for the presence of MCPyV by using a polymerase chain reaction (PCR) and quantitative PCR. MCPyV DNA was present in 80% of 114 samples studied. The patients with virus-positive tumors had better overall survival than patients with virus-negative tumors. Immunohistochemical analyses were performed for the expression of VEGFR-2 (n=21) and endostatin (n=19), but they had no prognostic value. Our results support the concept of treating MCC with margin-negative excision and radiotherapy to the tumor bed to reduce local recurrence. The finding of a high frequency of lymphovascular invasion reduces its value as a prognostic factor, but emphasizes the role of sentinel node biopsy even in very small primary MCC.

Stem Cell Markers in Cancer: Do They Have Clinical Significance?

In cancer, a subpopulation of malignant cells expresses markers of normal stem cells. These cells have the potential of initiating tumor growth and therefore also tumor recurrence. Thus, these cells are called cancer stem cells. A myriad of markers have been applied to identify these cells, but no single marker can be found exclusively in cancer stem cells. In many types of cancer, clinical recurrence and tumor progression are the main causes of mortality, despite intense oncological treatment. It has been proposed that the presence of cancer stem cells causes this resistance to therapy. The scope of this thesis is to investigate the role of stem cell markers and genes in the clinical setting. Especially, the aim was to elucidate the clinical significance of stem cell markers as novel prognostic and diagnostic tools in cancer. Tumor biopsy material from central nervous system tumors (oligodendroglioma, astrocytoma and glioblatoma), neural crest derived tumors (pheochromocytomas) and oral carcinoma was screened for stem cell markers. Initially, 15 stem cell markers were screened in a test series of gliomas. The markers applied for expanded tumor analyses (in 305 cases of glioma, 42 cases of pheochromocytoma, and 73 cases of oral carcinoma) were BMI-1, Snail, p16, mdm2, and c-Myc. Data on marker expression was compared with clinical and pathological parameters. In gliomas, BMI-1 expression was found in nearly all tumors analyzed, but the frequency of BMI-1 expressing cells was highly variable, ranging from 1 to 100%. In oligodendroglioma, BMI-1 expression was identified as a prognostic marker independent of tumor grade and clinical parameters. In pheochromocytoma, Snail expression was shown to distinguish between the metastatic and non-metastatic forms of the tumor. Snail expression was seen only in metastatic tumors, whereas non-metastatic tumors did not commonly express Snail. Finally, in oral carcinoma, BMI-1 expression was seen in roughly 80% of tumors, and Snail expression was high or very high in all cases. The lack of BMI-1 expression was associated with early relapse in oral carcinoma.

Associations among Emdogain®, human oral carcinoma cells and oral proteolytic enzymes

The Enamel matrix derivative Emdogain® (EMD) is a commercially available tissue extract preparation of porcine enamel origin. Studies have shown EMD to be clinically useful in promoting periodontal regeneration. EMD has been widely used in periodontal therapy for over ten years, but the mechanism of its action and the exact composition are not completely clear. EMD is predominantly amelogenin (>90%). However, unlike amelogenin, EMD has a number of growth factor-like effects and it has been shown to enhance the proliferation, migration and other cellular functions of periodontal ligament fibroblasts and osteoblasts. In contrast, the effects of EMD on epithelial cell lines and in particular on oral malignant cells have not been adequately studied. In addition, EMD has effects on the production of cytokines by several oral cell lines and the product is in constant interaction with different oral enzymes. Regardless of the various unknown properties of EMD, it is said to be clinically safe in regenerative procedures, also in medically compromised patients. The aim of the study was to examine whether gingival crevicular fluid (GCF), which contains several different proteolysis enzymes, could degrade EMD and alter its biological functions. In addition, the objective was to study the effects of EMD on carcinogenesis-related factors, in particular MMPs, using in vitro and in vivo models. This study also aimed to contribute to the understanding of the composition of EMD. GCF was capable of degrading EMD, depending on the periodontal status, with markedly more degradation in all states of periodontal disease compared to healthy controls. EMD was observed to stimulate the migration of periodontal ligament fibroblasts (PLF), whereas EMD together with GCF could not stimulate this proliferation. In addition, recombinant amelogenin, the main component of EMD, decreased the migration of PLFs. A comparison of changes induced by EMD and TGF-β1 in the gene profiles of carcinoma cells showed TGF-β1 to regulate a greater number of genes than EMD. However, both of the study reagents enhanced the expression of MMP-10 and MMP-9. Furthermore, EMD was found to induce several factors closely related to carcinogenesis on gene, protein, cell and in vivo levels. EMD enhanced the production of MMP-2, MMP-9 and MMP-10 proteins by cultured carcinoma cells. In addition, EMD stimulated the migration and in vitro wound closure of carcinoma cells. EMD was also capable of promoting metastasis formation in mice. In conclusion, the diseased GCF, containing various proteases, causes degradation of EMD and decreased proliferation of PLFs. Thus, this in vitro study suggests that the regenerative effect of EMD may decrease due to proteases present in periodontal tissues during the inflammation and healing of the tissues in vivo. Furthermore, EMD was observed to enhance several carcinoma-related factors and in particular the production of MMPs by benign and malignant cell lines. These findings suggest that the clinical safety of EMD with regard to dysplastic mucosal lesions should be further investigated.

Prognostic markers in head and neck carcinoma

Head and neck squamous cell carcinoma (HNSCC) is the sixth most common cancer worldwide. Well-known risk factors include tobacco smoking and alcohol consumption. Overall survival has improved, but is still low especially in developing countries. One reason for this is the often advanced stage of the disease at the time of diagnosis, but also lack of reliable prognostic tools to enable individualized patient treatment to improve outcome. To date, the TNM classification still serves as the best disease evaluation criterion, although it does not take into account the molecular basis of the tumor. The need for surrogate molecular markers for more accurate disease prediction has increased research interests in this field. We investigated the prevalence, physical status, and viral load of human papillomavirus (HPV) in HNSCC to determine the impact of HPV on head and neck carcinogenesis. The prevalence and genotyping of HPV were assessed with an SPF10 PCR microtiter plate-based hybridization assay (DEIA), followed by a line probe-based genotyping assay. More than half of the patients had HPV DNA in their tumor specimens. Oncogenic HPV-16 was the most common type, and coinfections with other oncogenic and benign associated types also existed. HPV-16 viral load was unevenly distributed among different tumor sites; the tonsils harbored significantly greater amounts of virus than other sites. Episomal location of HPV-16 was associated with large tumors, and both integrated and mixed forms of viral DNA were detected. In this series, we could not show that the presence of HPV DNA correlated with survival. In addition, we investigated the prevalence and genotype of HPV in laryngeal carcinoma patients in a prospective Nordic multicenter study based on fresh-frozen laryngeal tumor samples to determine whether the tumors were HPV-associated. These patients were also examined and interviewed at diagnosis for known risk factors, such as tobacco smoking and alcohol consumption, and for several other habituations to elucidate their effects on patient survival. HPV analysis was performed with the same protocols as in the first study. Only 4% of the specimens harbored HPV DNA. Heavy drinking was associated with poor survival. Heavy drinking patients were also younger than nonheavy drinkers and had a more advanced stage of disease at diagnosis. Heavy drinkers had worse oral hygiene than nonheavy drinkers; however, poor oral hygiene did not have prognostic significance. History of chronic laryngitis, gastroesophageal reflux disease, and orogenital sex contacts were rare in this series. To clarify why vocal cord carcinomas seldom metastasize, we determined tumor lymph vessel (LVD) and blood vessel (BVD) densities in HNSCC patients. We used a novel lymphatic vessel endothelial marker (LYVE-1 antibody) to locate the lymphatic vessels in HNSCC samples and CD31 to detect the blood microvessels. We found carcinomas of the vocal cords to harbor less lymphatic and blood microvessels than carcinomas arising from sites other than vocal cords. The lymphatic and blood microvessel densities did not correlate with tumor size. High BVD was strongly correlated with high LVD. Neither BVD nor LVD showed any association with survival in our series. The immune system plays an important role in tumorigenesis, as neoplastic cells have to escape the cytotoxic lymphocytes in order to survive. Several candidate HLA class II alleles have been reported to be prognostic in cervical carcinomas, an epithelial malignancy resembling HNSCC. These alleles may have an impact on head and neck carcinomas as well. We determined HLA-DRB1* and -DQB1* alleles in HNSCC patients. Healthy organ donors served as controls. The Inno-LiPA reverse dot-blot kit was used to identify alleles in patient samples. No single haplotype was found to be predictive of either the risk for head and neck cancer, or the clinical course of the disease. However, alleles observed to be prognostic in cervical carcinomas showed a similar tendency in our series. DRB1*03 was associated with node-negative disease at diagnosis. DRB1*08 and DRB1*13 were associated with early-stage disease; DRB1*04 had a lower risk for tumor relapse; and DQB1*03 and DQB1*0502 were more frequent in controls than in patients. However, these associations reached only borderline significance in our HNSCC patients.

Biology and Molecular Markers of Malignant Gonadal Germ Cell Tumors

Germ cell tumors occur both in the gonads of both sexes and in extra-gonadal sites during adoles-cence and early adulthood. Malignant ovarian germ cell tumors are rare neoplasms accounting for less than 5% of all cases of ovarian malignancy. In contrast, testicular cancer is the most common malignancy among young males. Most of patients survive the disease. Prognostic factors of gonadal germ cell tumors include histology, clinical stage, size of the primary tumor and residua, and levels of tumor markers. Germ cell tumors include heterogeneous histological subgroups. The most common subgroup includes germinomas (ovarian dysgerminoma and testicular seminoma); other subgroups are yolk sac tumors, embryonal carcinomas, immature teratomas and mixed tumors. The origin of germ cell tumors is most likely primordial germ cells. Factors behind germ cell tumor development and differentiation are still poorly known. The purpose of this study was to define novel diagnostic and prognostic factors for malignant gonadal germ cell tumors. In addition, the aim was to shed further light into the molecular mechanisms regulating gonadal germ cell tumorigenesis and differentiation by studying the roles of GATA transcription factors, pluripotent factors Oct-3/4 and AP-2γ, and estrogen receptors. This study revealed the prognostic value of CA-125 in malignant ovarian germ cell tumors. In addition advanced age and residual tumor had more adverse outcome. Several novel markers for histological diagnosis were defined. In the fetal development transcription factor GATA-4 was expressed in early fetal gonocytes and in testicular carcinoma precursor cells. In addition, GATA-4 was expressed in both gonadal germinomas, thus it may play a role in the development and differentiation of the germinoma tumor subtype. Pluripotent factors Oct-3/4 and AP-2γ were expressed in dysgerminomas, thus they could be used in the differential diagnosis of the germ cell tumors. Malignant ovarian germ cell tumors expressed estrogen receptors and their co-regulator SNURF. In addition, estrogen receptor expression was up-regulated by estradiol stimulation. Thus, gonadal steroid hormone burst in puberty may play a role in germ cell tumor development in the ovary. This study shed further light in to the molecular pathology of malignant gonadal germ cell tumors. In addition, some novel diagnostic and prognostic factors were defined. This data may be used in the differential diagnosis of germ cell tumor patients.

Non-small cell lung cancer : studies on pathogenesis, tumour targeting and treatment outcomes

Lung cancer accounts for more cancer-related deaths than any other cancer. In Finland, five-year survival ranges from 8% to 13%. The main risk factor for lung cancer is long-term cigarette smoking, but its carcinogenesis requires several other factors. The aim of the present study was to 1) evaluate post-operative quality of life, 2) compare clinical outcomes between minimally invasive and conventional open surgery, 3) evaluate the role of oxidative stress in the carcinogenesis of non-small lung cancer (NSCLC), and 4) to identify and characterise targeted agents for therapeutic and diagnostic use in surgery. For study I, pneumonectomy patients replied to 15D quality of life and baseline dyspnea questionnaires. Study III involved a prospective quality of life assessment using the 15D questionnaire after lobectomy or bi-lobectomy. Study IV was a retrospective comparison of clinical outcomes between 212 patients treated with open thoracotomy and 116 patients who underwent a minimally invasive technique. Study II measured parameters of oxidative metabolism (myeloperoxidase activity, glutathione content and NADPH oxidase activity) and DNA adducts. Study V employed the phage display method and identified a core motif for homing peptides. This method served in cell-binding, cell-localisation, and biodistribution studies. Following both pneumonectomy and lobectomy, NSCLC patients showed significantly decreased long-term quality of life. No significant correlation was noted between post-operative quality of life and pre-operative pulmonary function tests. Women suffered more from increased dyspnea after pneumonectomy which was absent after lobectomy or bi-lobectomy. Patients treated with video-assisted thoracoscopy showed significantly decreased morbidity and shorter periods of hospitalization than did open surgery patients. This improvement was achieved even though the VATS patients were older and suffered more comorbid conditions and poorer pulmonary function. No significant differences in survival were noted between these two groups. An increase in NADPH oxidase activity was noted in tumour samples of both adenocarcinoma and squamous cell carcinoma. This increase was independent from myeloperoxidase activity. Elevated glutathione content was noted in tumour tissue, especially in adenocarcinoma. After panning the clinical tumour samples with the phage display method, an amino acid sequence of ARRPKLD, the Thx, was chosen for further analysis. This method proved selective of tumour tissue in both in vitro and in vivo cell-binding assay, and biodistribution showed tumour accumulation. Because of the significantly reduced quality of life following pneumonectomy, other operative strategies should be implemented as an alternative (e.g. sleeve-lobectomy). To treat this disease, implementation of a minimally invasive surgical technique is safe, and the results showed decreased morbidity and a shorter period of hospitalisation than with thoracotomy. This technique may facilitate operative treatment of elderly patients with comorbid conditions who might otherwise be considered inoperable. Simultaneous exposure to oxidative stress and altered redox states indicates the important role of oxidative stress in the pathogenesis and malignant transformation of NSCLC. The studies showed with great specificity and with favourable biodistribution that Thx peptide is specific to NSCLC tumours. Thx thus shows promise in imaging, targeted therapy, and monitoring of treatment response.

Molecular studies on LIM-domain protein CRP1

Various intrinsic and external factors are constantly attacking the cells causing damage to DNA and to other cellular structures. Cells in turn have evolved with different kinds of mechanisms to protect against the attacks and to repair the damage. Ultraviolet radiation (UVR) is one of the major environmental genotoxic carcinogens that causes inflammation, mutations, immunosuppression, accelerated aging of the skin and skin cancers. Epidermis is the outermost layer of the skin consisting mostly of keratinocytes, whose primary function is to protect the skin against e.g. UV radiation. LIM domain proteins are a group of proteins involved in regulation of cell growth, damage signalling, cell fate determination and signal transduction. Despite their two zinc fingers, LIM domains do not bind to DNA, but rather mediate protein-protein interactions and function as modular protein binding interfaces. We initially identified CSRP1 as UVR-regulated transcript by using expression profiling. Here we have further studied the regulation and function of CRP1, a representative of cysteine rich protein- family consisting of two LIM domains. We find that CRP1 is increased by UVR in primary human keratinocytes and in normal human skin fibroblasts. Ectopic expression of CRP1 protected the cells against UVR and provided a survival advantage, whereas silencing of CRP1 rendered the cells more photosensitive. Actinic keratosis is a premalignant lesion of skin caused by excess exposure to sunlight and sunburn, which may lead to formation of squamous cell carcinoma. The expression of CRP1 was increased in basal keratinocytes of Actinic keratosis patient specimens suggesting that CRP1 may be increased by constant exposure to UVR and may provide survival advantage for the cells also in vivo. In squamous cell carcinoma, CRP1 was only expressed in the fibroblasts surrounding the tumour. Moreover, we found that ectopic expression of CRP1 suppresses cell proliferation. Transforming growth factor beta (TGFbeta) is a multifunctional cytokine that regulates several functions in cell including growth, apoptosis and differentiation, and plays important roles in pathological disorders like cancer and fibrosis. We found that TGFbeta-signalling pathway regulates CRP1 at protein, but not at transcriptional level. The increase was mediated both through Smad and non-Smad signalling pathways involving MAPK/p38. Furthermore, we found that TGFbeta-mediated increase in CRP1 was associated with myofibroblast differentiation, and that CRP1 was significantly more expressed in idiopathic pulmonary fibrosis as compared to normal lung specimens. Since cell contractility is a distinct feature of myofibroblasts, and CRP1 is associated with actin cytoskeleton, we studied the role of CRP1 in cell contractility. CRP1 was found to localize to stress fibres that mediate contractility and to mediate myofibroblast contraction. These studies identify CRP1 as a stress responsive and cytokine regulated cytoskeletal protein that participates in pathological processes involved in fibrotic diseases and cancer.