The methylation of arginine has been implicated in many cellular processes, such as regulation of transcription, mRNA splicing, RNA metabolism and transport. The enzymes responsible for this modification are the protein arginine methyltransferases. The most abundant methyltransferase in human cells is protein arginine methyltransferase 1. Methylation processes appear to interfere in the emergence of several diseases, including cancer. During our study, we examined the expression pattern of protein arginine methyltransferase 1 gene in colon cancer patients. The emerging results showed that the expression of one of the gene variants is associated with statistical significant probability to clinical and histological parameters, such as nodal status and stage. This is a first attempt to acquire an insight on the possible relation of the expression pattern of protein arginine methyltransferase 1 and colon cancer progression.

Methylation of arginine residues has been implicated in many cellular activities like mRNA splicing, transcription regulation, signal transduction and protein-protein interactions. Protein arginine methyltransferases are the enzymes responsible for this modification in living cells. The most commonly used methyltransferase in man is protein arginine methyltransferase 1 (PRMT1). Since methylation processes appear to interfere in the emergence of several diseases, including cancer, we investigated the localisation of the protein in cancer tissue and, for the first time, the relation that possibly exists between the expression of PRMT1 gene and breast cancer progression. We used tumour specimens from 62 breast cancer patients and semi-quantitative RT-PCR to determine the expression of PRMT1 gene and was found to be associated with patient's age (p = 0.002), menopausal status (p = 0.006), tumour grade (p = 0.03), and progesterone receptor status (p = 0.001). Survival curves revealed that PRMT1-v1 status-low expression relates to longer disease-free survival (DFS; p = 0.036). To the contrary, PRMT1-v2 status is not associated neither with the clinical or pathological parameters nor with DFS (p = 0.31). PRMT1-v3 was not statistically significantly expressed in breast cancer tissue. Selected cancer and normal breast samples were stained for PRMT1. In both normal and cancerous breast tissues, staining was in the cytoplasm and only in rare cases the cell nucleus appeared stained. Present results show a potential use for this gene as a marker of unfavourable prognosis for breast cancer patients.

Apoptosis is an active process regulated by a variety of genes. Recently, the molecular cloning, physical mapping and expression analysis of a novel gene of the Bcl-2 family, BCL2L12, was reported. Expression analysis of the BCL2L12 gene in breast cancer confirmed an association of BCL2L12 with favorable prognosis of patients. In the present study, the expression of the BCL2L12 gene was analyzed in colon cancer by RT-PCR. Two transcripts, BCL2L12 and BCL2L12-A, were overexpressed in the cancer tissues as compared to their paired normal mucosa. An association was found between BCL2L12-A transcript expression and nodal status, as well as Dukes' stage. The BCL2L12-A transcript appears to be of importance for colon cancer since its expression is associated with disease progression.

SR (serine-arginine) proteins are essential pre-mRNA splicing factors. Several SR proteins have been characterized in humans, among them SR-A1. It has been demonstrated by members of our group that the SR-A1 gene is constitutively expressed in most of the human tissues, while its transcription is increased in breast carcinoma cell lines. Moreover, the SR-A1 gene is overexpressed in a set of ovarian tumors, suggesting that it may be involved in the pathogenesis and/or progression of ovarian cancer. Therefore, in the present study we examined the expression of the SR-A1 gene in colon cancer tissues by RT-PCR and found that it is overexpressed as compared to normal mucosa (p=0.01). The SR-A1 gene was expressed more frequently in well-differentiated tumors than those with poor differentiation. Survival curves determined by the Kaplan-Meier method and univariate analysis demonstrated that SR-A1-positivity is associated with a long survival (p=0.044). However, when entered into a Cox multivariate model adjusted for other clinicopathological features studied, SR-A1 expression status was not found to be of independent prognostic significance. To the best of our knowledge, this is the first study examining the expression of the novel gene SR-A1 in colon cancer progression.

SummaryHuman tissue kallikrein-related peptidases are a family of 15 secreted serine proteases, located at chromosome 19q13.4. Most of them have been reported to be potential biomarkers for several carcinomas and other diseases. Human tissue kallikrein-related peptidase 7 (KLK7) has been purified from human stratum corneum and resembles a chymotryptic endopeptidase originally called stratum corneum chymotryptic enzyme (SCCE). In this study, we examined for the first time, the prognostic value of KLK7 mRNA expression, using a semi-quantitative RT-PCR method, in 105 colorectal cancer tissues for 54 of which, paired normal colonic mucosa were available. Furthermore, we analysed the expression of KLK7 in 10 adenomas, in 18 biopsies of inflamed colon mucosa, as well as in 22 human cancer cell lines of various origin, four of them being of colon. A defined number of colon cancer samples were also examined by immunohisto-chemistry. KLK7 expression was higher in cancerous than in normal tissues. Less differentiated tumors of more advanced stage showed higher KLK7 expression. Follow-up analysis revealed that KLK7 was significantly associated with shorter overall survival (OS) and disease-free survival (DFS). In addition, selected colon cancer samples highly expressing KLK7 gene, showed intense immunohistochemical staining for KLK7, enhancing RTPCR results. Present data suggest that KLK7 gene is up-regulated in colon cancer and its expression predicts poor prognosis for colon cancer patients.

In this present paper, a comparative study between the Spanish and Swiss primary educational systems took place, investigating whether WebQuests are used in the foreign language lesson for the instruction of critical literacy in multilingual environments. The modern learning environment requires student-centred teaching, with new technologies creating ideal learning conditions which, although they carry many risks, have advantages over traditional ones, creating a lively learning and collaborative environment. In the case of WebQuests, searching for information on the internet ceases to be an arduous process, since it is guided. In addition, it enhances and promotes reflection, critical thinking, creativity, discovery and presentation of new information, delving into real-life issues and situations which are key elements of critical literacy.

Ο καρκίνος είναι μια πολυπαραγοντική ασθένεια, με σημαντικά υψηλά ποσοστά θνησιμότητας. Ιδιαίτερα ο καρκίνος του παχέος εντέρου αποτελεί την τρίτη συχνότερα εμφανιζόμενη μορφή καρκίνου σε γυναίκες και άνδρες. Θεωρείται η ασθένεια του Δυτικού πολιτισμού, εφόσον πέραν των γενετικών αλλαγών που είναι υπεύθυνες για την εμφάνισή της, πολύ σημαντικό ρόλο παίζει ο τρόπος ζωής (κακή διατροφή, κάπνισμα, έλλειψη άσκησης). Η αναγκαιότητα ανακάλυψης νέων βιολογικών δεικτών έχει γίνει πλέον προφανής και γίνονται μεγάλες προσπάθειες προς αυτή την κατεύθυνση. Η ανακάλυψη τέτοιων μορίων θα μπορούσε να προσφέρει όχι μόνο έγκαιρη διάγνωση, αλλά και καθαρότερη εικόνα όσον αφορά την εξέλιξη της νόσου. Επιπρόσθετα, θα μπορούσε να συνεισφέρει στην εφαρμογή νέων θεραπευτικών προσεγγίσεων. Προς αυτή την κατεύθυνση κινήθηκε και η παρούσα διδακτορική διατριβή. Εκτός από τα γνωστά βιολογικά μονοπάτια που συνδέονται άμεσα με την εμφάνιση του καρκίνου του παχέος εντέρου, υπάρχουν γονίδια τα οποία ναι μεν δεν έχουν τόσο εμφανή σχέση με τον καρκίνο, αλλά μπορεί να δώσουν πληροφορίες για την πρόοδο της νόσου. Ένα τέτοιο γονίδιο θεωρήσαμε ότι είναι κι αυτό της πρωτεϊνικής μεθυλοτρανσφεράσης αργινίνης 1 (PRMT1). Το γονίδιο αυτό κωδικοποιεί μια πρωτεΐνη που εμπλέκεται σε ποικίλα και σημαντικά σημεία του κυτταρικού μεταβολισμού, μέσω της μεθυλίωσης καταλοίπων αργινίνης συγκεκριμένων μορίων. Η συμμετοχή του πρωτεϊνικού προϊόντος του PRMT1 στον μεταβολισμό έδωσε την ώθηση στο να μελετηθεί και να συσχετιστεί με τον καρκίνο του παχέος εντέρου. Η παρούσα μελέτη αφορά τα επίπεδα έκφρασης του mRNA του PRMT1 σε ιστούς ασθενών που πάσχουν από καρκίνο του παχέος εντέρου, ιστούς προερχόμενους από αδενώματα και φλεγμονές του παχέος εντέρου, καθώς και φυσιολογικούς ιστούς του παχέος εντέρου. Κατά τη διάρκεια της μελέτης ανακαλύφθηκε ένα επιπλέον μετάγραφο που προκύπτει από το εναλλακτικό μάτισμα του πρόδρομου mRNA του γονιδίου. Επίσης, κατά τη συσχέτιση της έκφρασης με κλινικοπαθολογικές παραμέτρους προέκυψε στατιστικά σημαντική σχέση μεταξύ των παραμέτρων και της έκφρασης ενός εκ των τεσσάρων εναλλακτικών μεταγράφων, του v1. Τέλος, πραγματοποιήθηκαν πειράματα ανοσοϊστοχημικού εντοπισμού της πρωτεΐνης, με αντίσωμα που φτιάχτηκε στο εργαστήριό μας, και υπέδειξαν την κατά κύριο λόγο κυτταροπλασματική παρουσία της πρωτεΐνης. Τα αποτελέσματα αυτής της μελέτης συγκλίνουν προς τον χαρακτηρισμό της υψηλής έκφρασης του μεταγράψου v1 ως δείκτη κακής πρόγνωσης όσον αφορά τους ασθενείς με καρκίνο του παχέος εντέρου.