Relationship between Chromosomal Aberrations and Gene Expressions in the p53 Pathway in Chronic Lymphocytic Leukemia.

Chronic lymphocytic leukemia (CLL) is a neoplasm characterized by excessive accumulation of B lymphocytes in the peripheral blood, bone marrow and lymph nodes. We assessed the expressions of 22 genes in the p53 pathway in 30 CLL patients and 15 healthy subjects by a RT2 Profiler PCR (polymerase chain reaction) Array technique and their relation to cytogenetic aberrations detected by fluorescent in situ hybridization (FISH). Our Student's t-test results indicated that ATM, ATR, BAX, CASP9, CDK4, CDKN2A, CHEK1, CHEK2, E2F3, MCL1, MDM2, MDM4, PCNA, RB1, P53 and BCL2 genes were statistically significant (p <0.001). For six genes (APAF1, CDKN1A, E2F1, GADD45A, PTEN and PTX3) were not statistically significant. The ATM, ATR, BAX, CASP9, CDK4, CDKN1A, CDKN2A, CHEK1, CHEK2, MDM2, MDM4, PCNA, RB1, P53, E2F1, GADD45A and BCL2 genes were found to be upregulated by the 2-ᐃᐃCt (relative fold change in gene expression) method. The highest up-regulation was detected in CDKN2A and BCL2 genes, 10.22- and 8.51-fold, respectively. On the other hand, the PTX3 gene with a fold regulation of 1.84 was found to the highest downregulation. Overall, the CDNK2A BCL2 and PTX3 genes are related to the mechanism of the disease in the p53 pathway and may be an important predictor of the prognosis of the disease. The BCL2 gene may be associated with increased risk of developing CLL. We suggest that the PTX3 gene may be considered as a marker associated with CLL disease. The CDKN2A gene expression seems to play a protective role in CLL.

The frequency of C609T polymorphism in the NQO1 gene and its relation to cytogenetic abnormalities in patients with myelodysplastic syndrome.

The aim of the present study is to evaluate the frequency of C609T polymorphism in the NQO1 (NAD(P)H) quinon oxydoreductase) gene and its relation to cytogenetic abnormalities in patients with Myelodysplastic Syndrome (MDS). The study group consisted of 80 patients MDS with 13 of them in the pediatric age group. The frequency of the NQO1 gene polymorphism was compared with a healthy control group involving 423 individuals. Cytogenetic abnormalities were detected in 43 patients (54%). In patients with MDS the overall frequency of the C609T polymorphism was not different than controls. Also, although the frequency of the C609T polymorphism was higher in patients with secondary MDS (sMDS) (OR: 1.893, 95% CI: 0.840-4.265, p=0.238) , 5/del(5q) (OR:1.298, 95% CI: 0.331-5.086,p=0.124), +21(OR:1.817, 95% CI:0.429-7698,p=0.124) and t(8;21) (OR:3.028, 95% CI: 0.604-15.172,p=0.137) groups, the difference did not reach statistical significiance. Our results do not support the view that the C609T polymorphism has a role in the pathogenesis of MDS. Also the frequency of the C609T allele did not seem to be associated with cytogenetic abnormalities.