Skip to main content
. Author manuscript; available in PMC: 2013 Dec 29.
Published in final edited form as: Cancer Lett. 2012 Jul 25;326(1):8–16. doi: 10.1016/j.canlet.2012.07.026

Figure 2. Examples of the biomodulatory effects of a differentiation-promoting agent (1,25 dihydroxy-vitamin D3; calcitriol) upon a solid tumor.

Figure 2

The A431 squamous cell carcinoma line was implanted subcutaneously in nude mice. Mice were preconditioned with daily i.p. injections of calcitriol (1 μg/kg body weight) for 3 days, and on the 4th day, ALA was administered for 4 hr prior to tumor harvest (A–C) or illumination with 635 nm light (D). Compare to inert saline controls (A–C), the calcitriol preconditioned tumors (A' – C') exhibited higher PpIX levels by confocal microscopy (A, A') in sections with equal cellularity (B, B'), and also showed stronger staining of a differentiation-associated molecule, ECadherin (C, C'). Scale bars, 50 μm. At various times after 635 nm illumination, histological H&E staining revealed significantly more cell death in the calcitriol-pretreated tumors (D). Scale bar, 250 μm. Adapted from ref. [28], with permission.