KLF4 translation level is associated with differentiation stage of different pediatric leukemias in both cell lines and primary samples.

Biomarkers on malignant cells may confer prognostic significance. Krüppel-like factor 4 (KLF4) has been reported to be expressed variably on leukemia cells, but its expression patterns in leukemias with different differentiation stages and its relationships with clinical parameters remain to be elucidated. To examine the KLF4 expression pattern in human leukemias and its clinical significance, RT-PCR and real-time PCR were used to detect KLF4 expression in 9 leukemia cell lines and 96 pediatric leukemia patients. KLF4 mRNA expressed in 5/16 (31.25 %) of AML patients and 11/28 (39.29 %) ALL patients, significantly lower than that in control (9/11, 81.82 %, P < 0.05). The expressions of KLF4 mRNA were much lower in ALL (27/52) compared to AML (25/52) (P = 0.019), AML-M1 to other subtypes of AML (P = 0.001), C-ALL to Pre-B ALL (P = 0.004), Pro-T ALL to T-ALL (P = 0.048). Observation on leukemia cell lines showed the similar pattern. The relative expression of KLF4 mRNA was inversely associated with CD34-positive rates (r = -0.296, P = 0.037), but it was not associated with the blasts percentages in bone marrow (r = -0.222, P = 0.137) and the WBC counts (r = -0.058, P = 0.679). KLF4 mRNA expression level was not related to the overall survival (r = -0.063, P = 0.670), and the median survival times for the KLF4 (Lower) and KLF4 (Higher) groups were comparable (28 vs. 25 months, P = 0.265). Furthermore, no difference was found in KLF4 mRNA expression levels whether in leukemias with normal and abnormal karyotypes (P = 0.180), or in leukemias with normal and abnormal molecular cytogenetics (P = 0.591). We conclude that KLF4 translation level is associated with the differentiation stage of different leukemias and is independent of other parameters of risk stratification.