The Methylation State Of P15^INK4B And FHIT Genes Of Patients With Myelodysplatic Syndromes(MDS).

Objective1.To explore the relationship between hypermethylation of P15^INK4B and FHIT genes and the pathogenesis of myelodysplatic syndromes(MDS);2. To analyze the characteristic of immunophenotype in patients with myelodysplastic syndrome (MDS);3.To analyze the expression features of cellular immune function of patients with myelodysplastic syndrome (MDS).MethodsSelecting 50 patients with myelodysplastic syndrome (MDS) and 10 normal controls for the study, as the following detections:1.The metyhlation state of P15^INK4B gene and FHIT gene were detected by methylation-specific PCR;2.The metyhlation state of P15^INK4B gene and FHIT gene were detected by denaturing high-performance liquid chromatography (DHPLC);3.The immunophenotype of bone marrow cells in patients with MDS were detected by flow cytometric;4.The lymphocyte subsets of patients with MDS were detected by flow cytometry;5.The chromosome karyotype of patients with MDS were detected by R-banding;6.The cytogenetic state of patients with MDS were detected by Fluorescence in situ hybridization (FISH).Result1.According to the international prognostic scoring system (IPSS), all MDS patients were divided into low-risk group, inter-risk-1 group, inter-risk-2 group and high-risk group. P15^INK4B methylation positive rates of low-risk/inter-risk-1 group, inter-risk-2 group and high-risk group were 15.4%, 51.9% and 70.0%, respectively,the methylation positive rates of FHIT gene were 7.7%, 40.7% and 60.0%, respectively.The differences among three groups are significant(χ²=7.596,,P=0.022;χ²=7.285,P=0.026),the methylation level of low-risk/inter-risk-1 group is lower than high-risk group, and the differences between two groups are significan(tP<0.05/3); but the differences between low-risk/inter-risk-1 group and inter-risk-2 group , between inter-risk-2 group and high-risk group are not significant; the methylation between P15^INK4B gene and FHIT gene is not relevant.2. As the progression of the disease, CD34 positive cells gradually increased:refractory anemia /ring sideroblasts refractory anemia (RA/RAS) 7.43%,refractory anemia with excess of blasts (RAEB) 36.81%,refractory anemia with excess of blasts transformed (RAEB-T) 56.45%, and the differences were statistically significant (P <0.05); the expressions of CD33, CD13 and HLA-DR increased gradually, the expressions of CD14 and CD15 antigens gradually decreased,the difference of three groups was statistically significant (P<0.05); the expression of CD19 and CD10 were decreased as the progression of the disease , the expression of CD19 were 3.05%,2.04% and 1.05%,respectively;the difference of three groups was statistically significant (F=8.236,P=0.002), the differences between any other two groups were statistically significant (P<0.05); the expression of CD10 were 9.95%,8.07% and 3.67%,respectively;the difference of three groups was statistically significant (F=6.919,P=0.004), the differences between RA/RAS and RAEB-T, RAEB and RAEB-T were statistically significant (P<0.05); the expression of CD19 and CD10 were decreased and the expression of CD7 was increased(RA/RAS 2.63%,RAEB 10.79% and RAEB-T 11.00% ) with the progression of the disease, the difference of three groups was statistically significant (P <0.05), the differences between RA/RAS and RAEB, RA/RAS and RAEB-T were statistically significant (P<0.05).3. Compared with the control group,the expression of Th,Th/Ts and NK cells in patients with MDS were lower,they were 37.09%, 1.63% and 10.26% respectively ;the expression of Ts cells in patients with MDS are higher,it was 25.49%. As the progression of the disease,the Th cells expression of RA/RAS,RAEB and RAEB-T were 33.08%,34.19% and 46.58% respectively,the differences were not statistically significant.;the expression of Ts cells were 24.19%,28.69% and 27.50%,respectively,and only the difference between RA/RAS and RAEB was statistically significant (P = 0.027); the ratio of Th / Ts were 1.43,1.24 and 1.72, respectively; the expression of NK cells were 8.41%, 10.70% and 11.29% respectively.the differences of Th, Th / Ts and NK cells in each group were not statistically significant.Conclusion1. The methylation of P15^INK4B gene and FHIT gene may participate in the pathogenesis of MDS and may have a relationship with the deterioration of the disease;2. The detection of immunephenotype of bone marrow cells in patients with MDS contributed to the diagnosis, classification and prognosis of MDS and thus can provide the basis for treatment;3. The cellular immunity of MDS patients were disorders, in which abnormal expression of Ts cells was the most significant.