Behavior of HO-1-N-1, buccal mucosa carcinoma derived cells, on [Ca²⁺] i responses to stimulants Malignant potential of the reticular form of oral lichen planus over a 25-year observation period in 55 patients from Slovenia

Abstract

Buccal mucosa carcinoma-derived cell line, HO-1-N-1, epithelial-like cells, was obtained in order to investigate the characteristics of oral cancer cells and examine the [Ca²⁺] i responses to stimulants, such as bradykinin (BK), histamine (HIST), thapsigargin (TG), epidermal growth factor (EGF) and transforming growth factor α (TGF α). Intracellular Ca²⁺ influx was observed by all stimulants that enhanced the [Ca²⁺] i response. However, intracellular Ca²⁺ release was not observed in response to growth factors. The [Ca²⁺] i response of BK (100 nM) was inhibited by 10 μ M of the BKB₂ antagonist, D-Arg- [Hyp³, Thi^{5, 8}, D-Phe⁷] -BK, and HIST (1 mM) was completely inhibited by 100nM of the H₁ antagonist, (+) -chlorpheniramine, in the presence and absence of extracellular Ca²⁺ (1.5mM).A retrospective evaluation of the reticular form of oral lichen planus was made on the basis of clinical and histopathological observations in 55 patients. Patients were re-examined once every six months over a 25-year period. Biopsies were taken from all lesions. No cases of complete remission and no cases of malignant transformation were recorded. Our findings suggest that the reticular form of oral lichen planus is not a precancerous lesion.