Background: Understanding in vitro expansion of OKF6/TERT-2 oral epithelial cells is important for studying molecular biology of disease and pathology affecting the oral cavity. The media used for any cell culture is paramount in terms of efficient output. Therefore, this study aims to compare two different media for OKF6/TERT-2 cultures: Keratinocyte Serum-Free Medium (KSFM) and a composite medium comprised of DMEM/F-12 mixed with KSFM (referred to as DFK). For application purposes, this investigation also compares the toxicological effects of flavored electronic cigarette liquids (E-liquids) on OKF6/TERT-2 cultures grown in both media. Methods: Cells were grown in KSFM and DFK media and cellular growth, morphology, gene expression of mucins and tight junctions, as well as wound-healing were determined. Additionally, cellular viability and cytotoxicity were indexed after E-liquid exposures. Results: While overall cellular morphologies remained unaltered, cells grown in DFK reached confluency faster. Except for claudin-1, there is no appreciable difference in expression of the other genes tested. Additionally, cultures in DFK appear more sensitive to E-liquids ± flavors. Conclusions: DFK is an alternative medium for cultivation of OKF6/TERT-2 cells to study molecular biology of disease and pathology, such as their responses to E-liquids ± flavors.

Background: Expansion of OKF6/TERT-2 oral epithelial cells in vitro is important for studying the molecular biology of disease and pathology affecting the oral cavity. Keratinocyte Serum-Free Medium (KSFM) is the medium of choice for this cell line. This study compares three media for OKF6/TERT-2 cultures: KSFM, Dulbecco’s Modified Eagle Medium/Nutrient Mixture of Hams F-12 (DMEM/F12) and a composite medium comprised of DMEM/F-12 and KSFM (1:1 v/v), referred as DFK. The toxicological effects of electronic cigarette liquids (E-liquids) on OKF6/TERT-2 cells cultured in these media were also compared. Methods: Cells were cultured in KSFM, DMEM/F12 or DFK and cellular morphology, growth, wound healing and gene expression of mucins and tight junctions were evaluated. Additionally, cytotoxicity was determined after E-liquid exposures. Results: Switching from KSFM to DMEM/F12 or DFK 24-hours post-seeding leads to typical cellular morphologies, and these cultures reach confluency faster than those in KSFM. Wound-healing recovery occurred fastest in DFK. Except for claudin-1, there is no difference in expression of the other genes tested. Additionally, E-liquid cytotoxicity appears to be amplified in DFK cultures. Conclusions: DMEM/F12 and DFK are alternative media for OKF6/TERT-2 cell culture to study molecular biology of disease and pathology, provided cells are initially seeded in KSFM.