Cancer letters
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Photodynamic therapy (PDT) effectiveness can be improved by employing combined modality approaches involving pharmaceuticals targeting the tumor microenvironment and/or tumor cell death pathways. In one approach, combining PDT with celecoxib improves long-term tumoricidal activity without increasing normal tissue photosensitization. However, side effects arising from the use of coxib based cyclooxygenase-2 (COX-2) inhibitors, including cardiovascular injury, decreases the clinical applications of this class of compounds. ⋯ DMC enhanced the in vivo tumoricidal responsiveness of PDT without altering PGE2 levels. Our data demonstrates that DMC improved PDT by increasing apoptosis and tumoricidal activity without modulating COX-2 catalytic activity. Our results also suggest that celecoxib mediated enhancement of PDT may involve both COX-2 dependent and independent mechanisms.