Grant-funded Project Nr. 002/2004/C/1.LF
Final Report

Project title:The expression of nitric oxide synthases in relation to cell proliferation and cell death: changes in cancer and inflammation
Research leader:MUDr. Tomáš Kučera, 2001
Co-researcher: Prof. MUDr. Jindřich Martínek, DrSc.; MUDr. Hana Pácová
Period of project:2004-2004
Overall grant:215 000 CZK

Project Results

The project focused on one important aspect of NO action in the human organism, which is its role in the intitiation and development of cancer. The factors determining NO pro- and anticancerogenic effects are mainly based on its chemical properties. In certain circumstances, NO can damage DNA and can also negatively influence DNA reparatory mechanisms. This can lead to the malignant transformation of the injured cell or it can cause the apoptotic cell death of already malignant cells via NO producing immune cells. There is also number of examples of NO-mediated antiapoptotic action in different organs and cells. The incresed NO production is reported during inflammation and could be the link between inflammation and malignancy.
The goal of this particular project was to elucidate the role of NO in these fundamental cellular processes. Immunohistochemical analysis of the expression of different NOS isoforms was performed in the inflammatory and malignant tissue of the same anatomical localization, specifically in chronic tonsillitis and oropharyngeal carcinoma. The expression of these isoenzymes was related to apoptosis and cell proliferation. Furthermore, the expression of NOS isoenzymes, cell proliferation and apoptosis was determined in the normal human nasal mucosa and nasal polyposis together with the detection of other  molecules involved in antimicrobial defense - human defensins beta.
The simultaneous presence of apoptotic and proliferative processes was determined but different cell types were involved in them. In chronic tonsillitis, it was B-lymphocytes, which were both highly proliferative and displayed frequent apoptosis. On the other hand, mostly malignant epithelial cells were subjected to cell death and at the same time were avidly proliferating in oropharyngeal carcinoma. Endothelial NOS was constantly detected in endothelial cells in all examined samples. The inducible isoform was in the case of chronic tonsillitis expressed by germinal center macrophages and epithelial cells in the basal layer of the surface epithelium. Several scattered malignat cells and some stromal cells were immunoreactive in the stroma of the oropharyngeal carcinoma. The level of NOS expression was not related to the presence of apoptotic and proliferative processes in any pathology. The detection of human beta defensin-2 revealed its expression by epithelia of both normal and pathological nasal mucosa. In the nasal polyposis defensin beta -3 was also detected in epithelial cells. Endothelial NOS isoform was expressed in endothelial cells in all samples. On the other hand, inducible isoform was variably present in the stroma.  No relation was found to the level of apoptotic and proliferative processes.