Survivin and SIRT1: can be two prognostic factors in chronic myeloid leukemia?

Antiapoptotic molecules are important in the development, progression, and prognosis of malignant disorders. The aim of this study was to determine the expression of two distinct antiapoptotic molecules, SIRT1 and Survivin (SVV), in chronic myeloid leukemia (CML) and to compare them with hematological prognostic factors. In this study, we measured the expression of SVV and SIRT1 in 18 patients with typical Ph-positive chronic myeloid leukemia in chronic phases of the disease as well as in 18 matched healthy donors. SVV, SIRT1, and BCR/ABL expression were determined by quantitative-real-time polymerase chain reaction (Q-RT-PCR). HPRT was used as a reference gene to calculate SVV/HPRT and SIRT1/HPRT ratio, and ABL was used as an internal control for BCR/ABL expression. SVV was between 0.00 and 2.39-fold (median 0.204) and SIRT1 was between 0.00 and 33.32-fold (median 0.186). In our study, both SVV and SIRT1 were lower in patients than in the controls (p = 0.001 and 0.001, respectively). Although the expression of SVV and SIRT1 was decreased in patients with chronic phase (0.043 and 0.043-fold, respectively), a potent expression upregulation of both genes was found in K562, Jurkat, and U937 cell lines. Despite lower expression of both SVV and SIRT1 at chronic phase, a significant correlation was found between SVV expression levels and minor Hb concentration (<10) (p = 0.005). In addition, there was important correlation between BCR/ABL copy number and older age (≥60) and PLT count (p = 0.027 and p = 0.001, respectively). Of course, no specific clinicohematological or prognostic profile was associated with SIRT1 expression. In contrast with SIRT1 expression, high SVV expression and high BCR/ABL copy number could be introduced as prognostic factors in chronic phase of CML, but this finding must be evaluated in other phase of CML and with a higher number of subjects.