An in vitro three-dimensional co-culture system for ameloblastoma modelling

• Main Authors: Lee, Soo Leng, Zainal Ariff Abdul Rahman,, Tsujigiwa, Hidetsugu, Hamada, Mei, Takabatake, Kiyofumi, Nakano, Keisuke, Nagatsuka, Hitoshi, Chong, Huat Siar
• Format: Article
• Language: English
• Published: Penerbit Universiti Kebangsaan Malaysia 2019
• Online Access: http://journalarticle.ukm.my/13892/1/15%20Soo%20Leng%20Lee.pdf; http://journalarticle.ukm.my/13892/; http://www.ukm.my/jsm/malay_journals/jilid48bil8_2019/KandunganJilid48Bil8_2019.html

Ameloblastoma, the most clinically significant odontogenic epithelial tumor, is a locally-invasive and destructive lesion in the jawbones. However, the nature of this infiltrativeness and destructive behavior remains ill-understood. To address this, we established an in vitro three-dimensional (3D) co-culture system to simulate an amelobastoma disease model aimed at investigating the interactions between tumor cells and osteoblasts. Osteoblastic cell lines (KUSA/A1 and MC3T3-E1) and one stromal cell line (ST2) were separately co-seeded with ameloblastoma-derived cell line (AM-1) in a collagen scaffold (representing the extracellular bone matrix) and incubated with mineralization medium. Immunohistochemistry, double immunofluorescence and mineralization assay were performed. Only AM-1/KUSA-A1 co-culture showed a significant increase in AM-1 cell count, suggesting that heterotypic cell-cell interaction promotes tumoral cell growth, while formation of visible AM-1 epithelial nest-like structures resembling ameloblastoma cells in their native state, suggest morphodifferentiation. A RANK-high, RANKL-low and osteoprotegerin-low immunoprofile in co-culture AM-1 cells implies deregulated osteoclastogenesis. Mineralization assays showed diminished calcification in AM-1/KUSA-A1 co-culture extracellular matrix suggesting an altered local bone metabolism. In contrast, KUSA/A1 monocultures showed abundant extracellular matrix calcification. Taken together, these results suggest that a 3D co-culture system as an amelobastoma disease model provides insights that bidirectional ameloblastoma-osteoblastic interactions might play a role in modulating tumor growth and osteoclastogenesis.