Supervisors info:
Διαμάντης Σίδερης, Αναπληρωτής Καθηγητής, Τμήμα Βιολογίας, ΕΚΠΑ
Σκορίλας Ανδρέας, Καθηγητής, Τμήμα Βιολογίας, ΕΚΠΑ
Κοντός Χρήστος, Επίκουρος Καθηγητής, Τμήμα Βιολογίας, ΕΚΠΑ
Summary:
Acute lymphoblastic leukemia (ALL) is a form of lymphocytic malignancy. It is
characterized by the accumulation of immature blood cells in the bone marrow. Acute lymphoblastic leukemia is one of the most important malignancies in childhood, with the highest incidence occurring in children between the ages of 2 and 5 years. Over the years, ALL has been a field of research for this and there are several indicators used to diagnose and differentiate it. Ribonucleases, which in recent years have been shown to be involved in many carcinogenesis breakdowns, belong to the category of nucleases, which are the degradable molecules of RNAs in smaller segments. The purpose of this postgraduate study is to increase the number of samples and to continue the study of expression levels of variants 1, 4, and 14 and to re-study variants 9 and 19 of the ribonuclease κ gene in pediatric patients. ALL. A total of 70 patients with childhood ALL were studied, from which total RNA was isolated from marrow samples (whole blood) and cDNA synthesized by RT-PCR reaction. The expression levels of the 5 transcripts were studied by Real-Time PCR analysis using SYBR-GREEN dye followed by statistical analysis of the results to correlate the expression levels with different clinical characteristics.
The results of the statistical analysis show that the expression levels of the three
variants (1,4 and 14) are decreased in the patients compared to the healthy (pclas <0.001, pv4 <0.001, pv14 <0.001), respectively for the pairs of patients. between the day of diagnosis and day 33, there were no significant differences in expression levels at the end of the onset treatment (pclas = 0.614, pv4 = 0.627 pv14 = 0.548). Regarding the classical variant, there is increased expression in the presence of adverse markers, such as the B-ALL and T-ALL phenotype (pclas = 0.366), the number of white WBCs> 50,000 cells / μL (pclas = 0.032), the absence of hyperdiploidy (pclas = 0.048). In addition, in cases of positive MRD and high-risk patients, transcript 1 shows slightly increased expression with pclas = 0.185 and pclas = 0.191, respectively. Kaplan Meier survival analysis and Cox regression regression analysis showed that patients overexpressing the classic variant had an increased risk of death (HR = 1.908 with p = 0.293 and 95% confidence interval: 0.573-6.357). Respectively, 14 and 4 have not shown any statistically significant correlation with the above markers, it is worth noting though that patients with positive MRD at day 15 had elevated levels of var.4 expression (p = 0.064), result with high significance trend. However, the same patients did not have elevated levels of var.14 (p = 0.852). According to the Danger Score, variant 14 of RNase κ appears to have increased expression, with a significant tendency (p = 0.079) for high risk patients, but not for 4 (p = 0.807). In general, however, variants 4 and 14 appear to have a similar expression pattern compared to the clinicopathological data of patients, which is also demonstrated by Spearman's correlation analysis (RS = 0.695, p <0.001). In total, 31 patients were screened for transcript 19, whose expression was examined for patient age and white cell count at the day of diagnosis. Patients over 10 years of age showed increased expression of transcript 19, which was statistically significant (p = 0.039). In addition, patients with a WBC count greater than 50,000 on the day of diagnosis also showed elevated levels of transcript 19, a result that was highly significant (p = 0.076). For the transcript 9 study, multiple denaturation curves were observed, indicating the presence of by-products other than transcript 9. In all the patients examined, the result was the same. In any case, the results require clarification with Sequencing.
In conclusion, the expression levels of transcripts 1 and 19 appear to have a
significant correlation with poor prognostic markers for ALL. The classic transcript can also provide information on overall survival. With regard to transcripts 4 and 14 beyond two almost statistically significant findings, there was no other remarkable observation. In the general context of the study most of the results are not statistically significant due to the small number of samples analyzed. After trying to increase the cohort of the patients studied, some remarkable and even statistically significant observations were received while others indicated where the research should be moved. The only sure thing is that a larger number of samples are needed to obtain safer and more reliable results.
