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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.
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PURPOSE: Smoothened(Smo) encodes a 1,024 amino acid transmembrane protein that acts as a transducer of the hedgehog(Hh) signal and maps to 7q31-q32 in humans. In the absence of Hh, Patched(Ptc) prevents Smo from signaling. When M-Hh-N binds to Ptc, however, Smo is free to upregulate downstream genes in the network. Activating mutations in Smo have been identified in sporadic basal cell carcinomas. This study was performed to evaluate the significance of Smo expression in humanzbladder cancer. MATERIALS AND METHODS: Tumor tissues were obtained from 140 patients with bladder cancer and normal bladder mucosa were acquired from 17 patients without bladder cancer as controls. Smo expression was assessed from paraffin sections of tissues using immunohistochemistry and graded on a scale of 0-12 according to the intensity and rate of staining. Differences of Smo expression between the bladder tumors and normal mucosa were compared. The relationships between their expression and the pathological or clinical characteristics such as tumor stage, grade, recurrence, and progression were also analyzed. RESULTS: There was no difference in the Smo expression in comparisons between the bladder cancers and the normal tissues(4.96+/-1.92 vs.4.52+/-0.87, p=0.111). Superficial bladder tumors had a higher Smo expression compared with normal tissues(0.005). Smo expression in the superficial and low-grade bladder tumors were higher than in the invasive and high-grade bladder tumors(p=0.002 and 0.001, respectively). The progression status was correlated with Smo expression but not the recurrence status(p=0.041 and 0.357, respectively). However, the Smo expression levels were not associated with the overall survival of patients(p=0.406). CONCLUSIONS: The results of this study showed that the enhanced expression of Smo was correlated with superficial, low-grade bladder cancer and tumors without progression. These results suggest that Smo is closely correlated with the differentiation and progression of bladder cancer and may, therefore, be useful as a prognostic marker for bladder cancer in the clinical setting.