Expression of Smoothened protein in CD34-positive cells of chronic myeloid leukemia and its significance / 白血病·淋巴瘤

ABSTRACT

Objective To detect the expression of Hedgehog signaling pathway receptor Smoothened (Smo) protein in chronic myeloid leukemia (CML) CD34-positive (CD34+) cells, and to explore the role of Hedgehog signaling pathway in CML stem/progenitor cells. Methods Seventeen chronic phase (CP) and 6 advanced phase (AP) CML patients who were diagnosed in West China Hospital of Sichuan University from September 2010 to March 2011 and 10 People (healthy people and patients without hematologic malignances) as control were included in this study. The expression levels of Smo protein were detected by the protocol of indirect immunofluorescence labeling for cytometry and analyzed statistically. Results The mean of relative fluorescence intensity of Smo protein was 282.5±102.4, 188.8±55.4 and 354.0±297.9 in the CML-CP, CML-AD and control groups, respectively. The difference between CML-CP and CML-AD groups was statistically significant (P= 0.032). However, there were no significant differences between the CML-CP, CML-AD groups and control group (both P>0.05). The percentage of CD34+Smo+cells was (58.9±24.2)％, (42.6±17.6)％and (55.9±29.7) ％ in the CML-CP, CML-AD and control groups, respectively. There were still no significant differences between the CML-CP, CML-AD groups and control group (F= 0.950, P= 0.398). The mean of relative fluorescence intensity of Smo protein in the CML-CP patients with tyrosine kinase inhibitor (TKI) (9 cases) administered and without TKI (8 cases) were 282.3 ±122.6 and 282.6 ±82.4, respectively. There were no significant differences between the two groups(P=0.157). Conclusions Flow cytometry can qualitatively and quantitatively detect the expression level of Smo protein in CML CD34+cells. Smo expression is associated with stage of CML;TKI could not inhibit the activation of the Hedgehog signaling pathway in CML CD34+cells.