Objective: To investigate the effects of Podoplanin on cell proliferation and cell cycle in oral leukoplakia cells.
Methods: Oral leukoplakia cell line (Leuk-1) transfected with pCMV-Podoplanin (A4-1) or pCMV (B4-1) was used in this study. The levels of mRNA and protein of Podoplanin were detected by real-time PCR and Western boltting in A4-1, B4-1 and Leuk-1 cells. The localization of Podoplanin was detected by confocal microscope. Cell growth and proliferation was examined by methyl thiazolyl tetrazolium (MTT) assay and cell cycle was detected by flow cytometry (FCM).
Results: The value of Podoplanin mRNA level in A4-1 cells was 0.022, which was significantly higher than the values in B4-1 (0.001) and Leuk-1 cells (0.002), P < 0.05. The gray scale of Podoplanin protein in A4-1 cells was significantly higher than in the control groups (P < 0.05). The expression of Podoplanin was observed in cell plasm and membrane of A4-1, B4-1 and Leuk-1 cells. But the expression level of Podoplanin in A4-1 cells was higher than in control groups. A4-1 cells grew faster than Leuk-1 cells. The proliferation rate after 3 days of culture in A4-1 cells was 40.4% higher than that in B4-1 cells (P < 0.05). The G₂-M phase (24.89 +/- 4.55)% and PI (0.57 +/- 0.06) of A4-1 cells were significantly higher than that in B4-1 cells [(4.13 +/- 5.24)%, (0.41 +/- 0.04)] and Leuk-1 cells [(4.69 +/- 7.42)%, (0.40 +/- 0.02)], P < 0.05.
Conclusions: Over expression of Podoplanin accelerated the growth and proliferation of oral leukoplakia cells. Podoplanin may be one of key genes in the malignant transformation of oral leukoplakia.