Purpose:Malignant pleural mesothelioma (MPM) is an aggressive and therapy-resistant neoplasm arising from the pleural mesothelial cells, without established indicators to predict responsiveness to chemotherapy. Experimental Design:Our present study involving 79 MPM patients demonstrated that 73.4% of MPM expressed CD26 on cell membrane. Results:The majority of epithelioid and biphasic type of MPM expressed CD26 on the cell membrane, whereas the sarcomatoid type demonstrated a lack of CD26 surface expression. Although the sarcomatoid type was associated with poor prognosis (p<0.0001), no significant relationship between CD26 expression and survival was observed. On the other hand, there was a trend for an association between response rate to chemotherapy and CD26 expression (p=0.053), with higher level of CD26 expression more likely to be linked to better response to chemotherapy. Moreover, CD26 expression was a significant factor associated with improved survival in patients who received chemotherapy (MST, 18.6 vs 10.7 months, p=0.0083). Furthermore, CD26 expression was significantly associated with better prognosis in patients receiving non-pemetrexed (PEM)-containing regimens (MST, 14.2 vs 7.4 months, p=0.0042), while there was no significant association between CD26 expression and survival time for patients receiving PEM-containing regimens. Our in vitro and microarray studies showed that mesothelioma cells expressing high CD26 displayed high proliferative activity, and CD26 expression was closely linked to cell cycle regulation, apoptosis, and chemotherapy resistance. Conclusions:Our results strongly suggest that CD26 is a clinically significant biomarker for predicting response to chemotherapy for MPM.
- Received August 3, 2011.
- Revision received October 4, 2011.
- Accepted January 7, 2012.
- Copyright © 2012, American Association for Cancer Research.