Revista de citología e histología

Immuno Expression of PAKs in Actinic Cheilitis and in Lip Squamous Cell Carcinoma

Abstract

Nayara Rubio Diniz Del Nero, Nanci Mendes Pinheiro, Leopoldo Henrique Barboza Martins, Simone de Sales Costa Moreira Carboni, Ana Cristina Araújo Lemos da Silva and Virgínia Oliveira Crema

Lip squamous cell carcinoma (LSCC) may develop from a potentially malignant disorder known as Actinic cheilitis (AC). The p21-activated kinases (PAKs) are possible targets for cancer therapeutics. The LSSC and AC samples were analyzed by immunohistochemistry in order to detects endogenous levels PAKs group I (PAK1 and PAK2) and group II (PAK4, PAK5 and PAK6) only when they were in phosphorylated form (active). Keratinocytes of the basals stratum showed intense staining for phosphoPAKs 1/2, while the most superficial cells of the stratum spinosum and the surface layer showed moderate immunostaining for PAKs 4/5/6 phosphorylated in the epithelium adjacent to injured area. AC did not immunoexpress actives PAKs 1/2 and PAKs 4/5/6. LSSC did not immunoexpress phosphoPAKs 1/2, but some degenerating cells and cells in the necrotic area showed intense staining. Our results suggest that PAKs 1/2 not participate in the regulation of AC and LSCC pathogenesis, while PAKs 4/5/6 are involved in the regulation of cell death in LSCC.