Ο TGF-β στην λευκοπλακία και το Ακανθοκυτταρικό Καρκίνωμα Στόματος
Creators: name: Μαυρουδής, Στέργιος Γεωργίου
Publisher: name: Aristotle University of Thessaloniki
Year: 2018
Subjects: TGF-β
Λευκοπλακία
Καρκίνος
Leucoplacia
Carcinoma

description: Τα καρκινικά κύτταρα εμφανίζουν συγκεκριμένα διαφοροποιητικά χαρακτηριστικά κεντρικό ρόλο στην επίτευξη των οποίων διαδραματίζουν οι αυξητικοί παράγοντες. Στην παρούσα διπλωματική διατρηβή θα ασχοληθούμε με τον TGF-β. Επι του παρόντως θεωρείται πως ο TGF-β εμφανίζει ογκοκατασταλτική δράση στα αρχικά στάδια της νόσου, ενώ σε μεταγενέστερα στάδια μπορεί να είναι βοηθητικός στην επέκταση του καρκίνου. Σκοπός αυτής της έρευνας είναι η μελέτη του ανοσοιστοχημικού προφίλ έκφρασης του TGFβ σε φυσιολογικό επιθήλιο στο στοματικό βλεννογόνο, και η μεταβολή σε προκαρκινικές δυσπλαστικές βλάβες έως και ΑΚΚ. Στην πειραματική εργασία την οποία πραγματοποιήσαμε, απεδείχθη ότι η ομάδα καρκίνου διαφέρει με την ομάδα ελέγχου και της λευκοπλακίας τόσο στον αριθμό των κυττάρων θετικών ως προς την χρώση, όσο και ως προς την ένταση χρώσης Τα αποτελέσματα αυτά αποτυπώνονται και στο συνδυαστικό σκορ όπου η ομάδα του καρκίνου διαφοροποιείται από την ομάδα ελέγχου και της λευκοπλακίας. Αξιοσημείωτο είναι ότι σε καμία από τις συγκρίσεις δεν εντοπίστηκε στατιστικά σημαντική διαφορά μεταξύ της ομάδας ελέγχου και λευκοπλακίας .
description: Cancer cells are characterized by self-sufficiency in growth signals, insensitivity to growth-inhibitory (antigrowth) signals, evasion of programmed cell death (apoptosis), limitless replication potential, sustained angiogenesis, and tissue invasion and metastasis. All of these abnormal characteristics are controlled by a complex mesh of oncogenes, tumor suppressor genes, and in part by growth factors, and cytokines. TGF-β has been described as a “Dr. Jeckyl and Mr Hyde” growth factor due to its dual and paradoxical function in carcinogenesis as both tumor suppressor as well as tumor promoter. In the early stages it inhibits cellular transformation and prevents cancer progression by inhibiting the proliferation of epithelial cells, inhibiting cell division by arresting healthy cells in the G1 phase through increasing expression of the cyclin dependent kinase (cdk) inhibitors an activity that most tumor cells must learn to overcome during cancer progression. In later stages TGF-β plays a key role in promoting tumor progression facilitating epithelial to mesenchymal transition (EMT), stimulating angiogenesis inducing immunosuppression and promotes the metastatic phenotype by enhancing tumour cell migration. Aim: Our aim concerning this thesis is to study the immunohistochemical expression profile of TGF-β in healthy oral tissue, compared to precancerous lesions such as leukoplakia and oral squamous cell carcinoma. Currently, unlike other types of malignancies there is a distinct lack research concerning the level of TGF-β expression in oral squamous cell carcinoma while studies including both cancerous and pre-cancerous lesions are rare. Methods: Biopsy samples were retrieved from the A.U.T.H, School of Dentistry, Department of Oral Medicine and Pathology’s archive. A total of 26 patients were included in our study. 5 patients with non precancerous or malignant lesions, 8 patients with oral leukoplakia of various degrees of dysplasia and 13 oral squamous cell carcinoma patients. Inclusion criteria was the presence of precancerous lesions or oral malignancy while patients with malignancies who had previously undergone radiotherapy, chemotherapy or surgical treatment were excluded from the study. Patients whose biopsy samples did not include sufficient quantites of epithelial or stromal tissue were excluded from the study in a preliminary examination of the sample. Deparaffinated and appropreatly treated selected speciments were sliced in 4μm sections by use of microtome and mounted on slides. After mounting samples were stained with Anti-TGF beta antibody (ab66043) rabbit polyclonal to TGF beta 1 in accordance to the manufacturer’s (Abcam) instructions. After staining the sample was examined by optical microscopy and analysed as to its clinical and histological characteristics. The examination and sample evaluation was done by means optical microscopy in 100X, 200X, and 400X magnification and each sample was graded for Staining Intensity and Percentage of Positive staining cells From the SI and PP a combined immunoreactivity scored was produced. Sample evaluation was conducted by examination of 5 randomised hot – spots in each sample in 100X, 200X, 400X magnification. Hypothesis testing and Statistical analysis of the collected data was conducted appropriately by specialized in Biostatistics personel. Significance level was put at 0.05. RESULTS: In our study it was shown that the OSCC group differed significantly from the control group (p-value = 0.018) and the leukoplakia group (p-value = 0.042) in Percentage of Percentage of Positive staining cells and in Staining Intensity from the control group (p-value = 0.002) and the leukoplakia group (p-value = 0.031)]. These results were also shown in the Compined Immunoreactivity Score were the oral squamous cell carcinoma group differed significantly from the control group (p-value = 0.002) and the leukoplakia group (p-value 0.048). In our study the leukoplakia group did not differ significantly from the control group either in Percentage of Positive staining cells (p-value 0.557), or Staining intensity (p-value 0.233) To be noted is that in our study strong staining was only noted in OSCC group samples, and as a results only OSCC samples received a CIS score of 3. DISCUSSION: In our study we found a continuous progression in staining intensity and percentage of positive staining cells spanning from health to malignancy. This progression did not surpass the limit of statistical difference when examining samples of oral leukoplakia in contrast to healthy samples but was far more pronounced in OSCC samples. Unfortunately we encountered a number of limitation in our research such as the size of the sample that did not permit us to further classify and analyse the leukoplakia samples according to the grade of dysplasia, or the oral squamous cell carninoma samples according to grade of differentiantion. Furthermore lack of patient follow up prevented us from reaching further conclusions concerning sample immunoreactivity and predicted patient outcome. In order to finally achieve new and highly targeted molecular treatments for OSCC, further and more analytical studies are needed in our field.