Effect of Vismodegib on Dermal Fibroblasts in Three-dimensional Collagen Scaffolds

Objectives: Sonic Hedgehog (SHh) pathway inhibitors, such as Vismodegib, have proven to be clinically effective in reducing tumor burden in Basal Cell Carcinoma Nevoid Syndrome (BCCNS) patients, who develop multiple BCCs and keratocystic odontogenic tumors throughout their life. However, cancer recurrence and emergence of epithelial drug-resistant tumors in these patients emphasize the contribution of multiple molecular mechanisms to the development of these tumors. Since the tissue microenvironment play critical roles in tumor development, we used three-dimensional collagen scaffolds to investigate the effect of Vismodegib on the behavior of dermal fibroblasts within an in vivo-like tissue microenvironment.
Methods: Human dermal fibroblasts were embedded in multiple collagen scaffolds and treated with DMSO (control), 10 nM, 1 uM, 10 uM, or 100 uM Vismodegib for 14 days. Collagen-embedded fibroblasts and tissue constructs were imaged throughout the study. Measurements of collagen scaffolds were performed using Infinity Analyze software by two independent investigators.
Results: Embedded fibroblasts spread in the collagen scaffolds and demonstrated a characteristic spindle cell morphology. Overtime, intertwined cell networks developed within the tissues under all treatment conditions. Preliminary data showed that control, 10 nM, 1 uM and 10 uM Vismodegib-treated tissues exhibited a rapid, similar shrinkage during the first 8 days of the study, followed by slower, continuous shrinkage through day 14. However, in 100 uM Vismodegib-treated tissues, collagen shrinkage was completely inhibited during the first 10 days. Although rapid collagen shrinkage was exhibited in 100 uM Vismodegib-treated tissues between days 10 and 14, the inhibition of tissue shrinkage was evident relative to all other tissues.
Conclusions: Using three-dimensional tissues, the study revealed that the chemotherapeutic drug Vismodegib can affect the activity of dermal fibroblasts and their ability to modify their collagen-rich surrounding environment in vitro. In vivo, altered fibroblast behavior may modify the epithelial tumor microenvironment and further support tumor development.