The correlation between the level of GRAF transcript and the sex, age, hematologic parameters, FAB subtypes and karyotypic groups was calculated by Spearman’s rho correlation analyses. A P-value < 0.05 was considered significant. Results GRAF expression in controls and AML patients The level of GRAF transcript in
controls was 14.49-126.85 (median 56.04). The significantly decreased level of GRAF transcript was observed in different myeloid malignancies (Table 1, Figure 1). There was no correlation between GRAF mRNA amount and the sex, age, peripheral white blood cell count, hemoglobin level, and platelet count (P > 0.05). The association of GRAF levels with cytogenetic abnormalities or CD34 antigen expression was also not observed in AML patients (P > STI571 supplier 0.05). Within AML, there was no difference in the level of GRAF transcript among different FAB subtypes (P > 0.05). Figure 1 Scatterplot showing varying levels of GRAF transcript in patients Ruxolitinib purchase with different myeloid malignancies and controls. GRAF expression in CML patients The median levels of GRAF transcript in CML patients at CP and BC
were 46.82 (1.08-157.42) and 10.69 (0.01-23.51), respectively (Figure 2). There was no difference in GRAF transcript amount between CML patients at CP and controls (P > 0.05). However, the amount of GRAF mRNA in CML at BC was significantly lower than that in cases at CP and that in controls (P = 0.028 and <0.001, respectively). Figure 2 Expression level of GRAF transcript in CML. GRAF expression in MDS patients Among MDS patients, three cases were identified with deletions of 5q (5q-) (Table 2). The level of GRAF transcript was lower in these cases (0.49-1.02, median 0.76) than Osimertinib the other four cases without 5q- (0.25-45.90, median 2.99), however, statistical difference was not observed (P > 0.05). Table 2 Clinical and laboratory characteristics of patients with MDS No. Sex Age (year) Diagnosis Karyotype GRAF level 1 F
51 RAEB-2 46, XX 2.76 2 F 63 RCMD 46, XX, del(20)(q11) 45.90 3 M 67 RAEB-1 46, XY 3.22 4 M 74 RARS 46, XY, del(5)(q13q33) 0.49 5 M 85 RAEB-1 46, XY, del(5)(q13q33) 0.76 6 M 39 RCMD 46, XY 0.25 7 M 41 RAEB-1 44-45, XY, del(5)(q13q33), -7, -15, -21[cp] 1.02 Discussion In this study, we demonstrated that the expression level of GRAF transcript was decreased in primary leukemic cells of all types of myeloid malignancies. Bojesen et al  found that GRAF promoter was hypermethylated in 38% cases with AML and MDS but not in healthy individuals, however, they did not detect the GRAF transcript in primary leukemic cells of AML and MDS. GRAF contains a centrally located GTPase-activating protein (GAP) domain, followed by a serine/proline rich domain and a carboxy-terminal Srchomology 3 (SH3) domain. GRAF acts as a negative regulator of RhoA because the GRAF GAP domain enhances GTP hydrolysis of both Cdc42 and RhoA in vitro .