Effects of ameloblastoma-associated fibroblasts on the proliferation and invasion of tumor cells

Context: Ameloblastoma is the most common odontogenic tumor, however, the molecular pathology, especially the role of the tumor stroma, is still unclear. Aims: To investigate the effects of the ameloblatoma-associated fibroblast (AAFs) on the proliferation and invasion of tumor cells. Settings and Design: Cell culture, ELISA, proliferation and invasion assays. Methods and Material: The cocultivations and three-dimensional organotypic cultures of the AAFs and the tumor cells were performed. The gingival fibroblasts (GFs) were used as the control. The levels of TGF- and HGF in the conditioned media were analyzed using ELISA technique. The MTT proliferation assays and Boyden chamber chemoinvasion assays were also performed. Statistical Analysis Used: ANOVA. Results: Both AAFs and GFs stimulated tumor cell growth. The TGF- level in the AAF group was more than those of GF group, whereas the HGF levels were not different. The AAF conditioned media also stimulated tumor cell proliferation and invasion more than the GF conditioned media. However, no difference in the thickness and morphology between the AAF and GF groups could be demonstrated in the organotypic models. Conclusions: Both AAFs and GFs support the proliferation of the tumor cells in cocultivation experiment and three-dimensional organotypic cultures. However, the AAFs have a tendency to stimulate the proliferation and induce the invasion more than GFs. Increased TGF- levels in the AAF condition media suggested the possible role of this growth factor in the ameloblastoma biology.