Methods: OSCC cell lines PCI1, PCI4A, PCI9, PCI13, PCI52 were included in the analysis. NHEK and HOK cell lines served as controls. In order to qualitatively assess the localization/distribution of Arp2, immunofluoresence analysis was performed. Mouse monoclonal anti-human Arp2 antibody was used (Abcam, UK). The cells were visualized by confocal laser scanning microscopy. Quantitative assessment of Arp2 expression was done by qRT-PCR.
Results: Quantitative RT-PCR revealed high Arp2 expression in normal HOK cells and low expression in all OSCC cell lines. Arp2 seems to be widely distributed in the cytoplasm and at the cell periphery in NHEK cells. PCI1, PCI4A share a similar distribution pattern with NHEK. In contrast, PCI9, PCI52 show no distribution of Arp2 in cell periphery and cytoplasm, while the localization inside and around nucleus is intense and polarized. PCI13 shows nuclear and perinuclear Arp2 localization as well as diffuse weak cytoplasmic distribution.
Conclusion: Arp2 expression at mRNA level is significantly increased in normal oral keratinocytes compared to tumor cells. Comparing OSCC cells, it seems that higher levels of perinuclear-nuclear localization of Arp2 can be associated with low Arp2 mRNA expression and moderate or intense cytoplasmic and peripheral distribution is, on the other hand, associated with higher Arp2 mRNA expression. Our future goal is to clarify the functional impact of Arp2 in oral squamous cell carcinoma.