|M.Sc Student||Shehadeh Mbariki Therese|
|Subject||The Role of Endothelial Protein C Receptor (EPCR) in Early|
Non-Small Cell Lung Carcinoma (NSCLC) Progression
|Department||Department of Medicine||Supervisor||DR. Galit Sarig|
|Full Thesis text|
There is a close correlation between thrombotic complications, hypercoagulation, tumor progression and poor outcome in cancer patients. The protein C pathway and the endothelial protein C receptor (EPCR) play major roles in anticoagulant and cytoprotective mechanisms in malignancy. However, the effect of EPCR A6936G polymorphism on tumor progression has not been clarified yet.
In order to determine the association between EPCR A6936G polymorphism and EPCR expression levels on tumor cells from Non-Small Cell Lung Carcinoma (NSCLC), and to study the association between EPCR A6936G polymorphism and EPCR expression levels with stage of disease, time to disease progression and survival in NSCLC patients after surgery, a total of 293 patients with NSCLC, which were histologically characterized with lung adenocarcinoma, were included in this research. DNA samples were extracted from archival formalin fixed paraffin embedded (FFPE) tissue blocks preserved from the operation time. Fluorescent Resonance Energy Transfer (FRET) real time PCR and Sanger sequencing reactions were used to determine the EPCR A6936G polymorphism. Sections from 83 lung adenocarcinoma patients were strictly matched according to age, gender and stage of disease between sections from patients with EPCR 6936 AG/GG polymorphism versus AA polymorphism. These sections were immunohistochemically stained with anti EPCR antibodies in matched paired of sections from EPCR 6936 AG/GG vs. AA on the same slide. Quantitation of EPCR expression and co-localization was evaluated by pathologist scoring which incorporate both intensity scores and extent (percentage of positive immunostained cells) scores. Statistical Package for the Social Sciences (SPSS) was used for data statistical analysis.
EPCR expression level in tissue sections with EPCR 6963 AA polymorphism were significantly higher than in tissues sections with AG/GG polymorphism ( P=0.048 ). Patients whose tissues sections were strongly positive immunostained with the EPCR antibody had shorter survival time than those who had less EPCR expression on their tumor cells. (P=0.044). Most patients with EPCR 6936 AG/GG (72%) were diagnosed at the lower stage of lung adenocarcinoma, with a 3 fold probability to be at the lower stage (<2a) rather that higher stages of the disease (P=0.03).
In conclusion: EPCR 6936 AG/GG polymorphisms were found to be associated with low expression levels of EPCR on lung adenocarcinoma cells and with low stages (1a, 1b) of disease. Low expression levels of EPCR were associated with prolonged survival time in the studied lung adenocarcinoma patients. These results and the role of EPCR in malignancy should be further studied.