OBJECTIVETo investigate the relationship between PTEN gene expression and Akt phosphorylation (p-Akt) in myelodysplastic syndrome (MDS) and to explore the progression of MDS and the mechanism of high risk transformation to acute myeloid leukemia.

METHODSRT-PCR was used to detect the PTEN mRNA expression in leukemia cell lines K562 (as negative control) and Jurkat (as positive control) and 65 MDS and MDS/AML patients. Flow cytometry was used to detect p-Akt in HL-60 and Jurkat cells and 30 MDS patients.

RESULTS(1) K562 cells present PTEN gene expression while Jurkat cells did not. Of 65 MDS and MDS/AML patients, 27 (41.5%) expressed PTEN mRNA, being significantly lower than that in normal group (85.7%) (P < 0.01). (2) Jurkat cell showed high expression (86.9%) of p-Akt, while HL-60 cell as negative control did not express. P-Akt levels of 30 MDS patients were increased (1.35% - 58.23%), being much higher as compared with that of the normal contrast group (0.54% - 2.34%) (P < 0.01). Moreover, with the rate of blast cells increasing, the p-Akt level was rising up. There is a positive correlation (r = 0.93, P < 0.01) between the low expression rate of PTEN and the positive rate of p-Akt.

CONCLUSIONThe loss of PTEN gene expression is one of the important factors of p-Akt high expression in MDS patients, moreover, it may speed up the progress of the MDS or transformation to acute myeloid leukemia.