Expression of epithelial–mesenchymal transition-associated proteins and proliferating cell nuclear antigen in dihydropyridine-induced gingival overgrowth fibroblasts: A preliminary study

Background/purpose: The clinical features of dihydropyridine-induced gingival overgrowth (DIGO), including extracellular matrix accumulation and cell hyperplasia, are regulated by inflammatory factors (e.g., Interleukin-1β [IL-1β]) in combination with calcium channel blockers (e.g., nifedipine [Nif]). We speculated that IL-1β and Nif (IL-1β/Nif) may be the main factor modulating the proliferative potential and turnover of fibroblasts in DIGO. Materials and methods: We cultured four DIGO fibroblast strains and analysed the possible effects of IL-1β/Nif treatments on epithelial–mesenchymal transition (EMT)-associated proteins. We developed short hairpin ribonucleic acids (shRNAs) and used them to explore the role of IL-1β/Nif in regulating proliferating cell nuclear antigen (PCNA) levels in DIGO tissues. Results: Our results revealed that compared with control cells, DIGO cells stimulated with IL-1β/Nif had higher levels of the EMT-associated proteins Snail, Slug, and Twist. Moreover, both drugs enhanced androgen receptor (AR), Slug, and PCNA expression. Conclusion: Taken together, our data indicate that proinflammatory cytokines in combination with calcium channel blockers can regulate the expression of EMT-associated proteins and increase the proliferative potential of DIGO fibroblasts.