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. Author manuscript; available in PMC: 2010 May 15.
Published in final edited form as: Clin Cancer Res. 2009 May 15;15(10):3333–3343. doi: 10.1158/1078-0432.CCR-08-3054

Figure 4. MTX pretreatment increases PpIX levels in organotypic 3-D cultures of immortalized keratinocytes (REK cells).

Figure 4

Fully-stratified organotypic cultures of the REK cell line were pretreated with MTX or with media alone for 72 hr at the concentration indicated, followed by incubation with ALA (1 mM, 4 hr) prior to frozen-sectioning. (A) Frozen sections visualized for PpIX by confocal microscopy. Note the increased intensity of the bright PpIX-specific signal in cultures pretreated with methotrexate. (B) Quantification of PpIX signal. Integrated fluorescence was analyzed from 6 confocal images per condition, using IPLab image-processing software. (*), significant difference from control, p < 0.005 level.