Individualized approach based on Bcl-2/BCRP expression may improve PDT efficacy in lung cancers
THURSDAY, Sept. 1 (HealthDay News) -- NPe6-photodynamic therapy (PDT) is a better treatment for patients with lung cancer than photofrin-PDT, and the efficacy of PDT may improve based on individual expression status of the anti-apoptotic protein Bcl-2 and breast cancer-resistant protein (BCRP), according to a study published online Aug. 23 in Lasers in Surgery and Medicine.
Jitsuo Usuda, M.D., from the Tokyo Medical University, and colleagues analyzed the molecular mechanism of PDT using photofrin and NPe6, and compared the two treatments. The role of immunological reactions in the anti-tumor effects of PDT, using cytokine-over-expressing cells was assessed. In addition they evaluated whether Bcl-2 is a molecular target. The association between adenosine triphosphate-binding cassette transporter proteins such as BCRP and the efficacy of PDT was also evaluated using clinical samples from 81 early lung cancer lesions treated with PDT between 1998 and 2006.
The investigators found damaged Bcl-2 and rapidly induced apoptosis with photofrin-PDT but not NPe6-PDT. A strong anti-tumor effect was exerted by NPe6-PDT irrespective of Bcl-2 over-expression. Photofrin, and not NPe6, was found to be a substrate of BCRP, with all 81 lung cancer lesions found to be BCRP-positive. The expression of BCRP significantly affected the efficacy of photofrin-PDT. NPe6-PDT exerted a strong anti-tumor effect with much higher complete response rate after NPe6-PDT than after photofrin-PDT, irrespective of BCRP expression.
"NPe6-PDT may be superior to photofrin-PDT for the treatment of lung cancer, and individualized approaches to PDT based on the expression status of Bcl-2 and/or BCRP may improve the efficacy of PDT in patients with lung cancers," the authors write.
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