APOBEC3B Is Co-Expressed with PKCα/NF-κB in Oral and Oropharyngeal Squamous Cell Carcinomas

The enzymatic activity of APOBEC3B (A3B) has been implicated as a prime source of mutagenesis in head and neck squamous cell carcinoma (HNSCC). The expression of Protein Kinase C a (PKCa) and Nuclear Factor -KB p65 (NF-kappa B p65) has been linked to the activation of the classical and the non-canonical NF -KB signaling pathways, respectively, both of which have been shown to lead to the upregulation of A3B. Accordingly, the aim of the present study was to evaluate the expression of PKC alpha, NF-kappa B p65 and A3B in non-HPV related oral and oropharyngeal squamous cell carcinomas (SCC), by means of immunohistochemistry and in silico methods. PKC alpha was expressed in 29/36 (80%) cases of oral and oropharyngeal SCCs, with 25 (69%) cases showing a PKC alpha+/A3B+ phenotype and only 6/36 (17%) cases showing a PKC alpha-/A3B+ phenotype. Expression of NF-kappa B p65 was seen in 33/35 (94%) cases of oral and oropharyngeal SCCs, with 30/35 (86%) cases showing an NF-kappa B p65+/A3B+ phenotype and only 2/35 (6%) cases showing an NF-kappa B p65-/A3B+ phenotype. In addition, mRNA expression analysis, using the UALCAN database, revealed strong expression of all three genes. These findings indicate that the expression of A3B is associated with PKC alpha/NF-kappa B p65 expression and suggest a potential role for the PKC/NF-kappa B signaling pathway in the development of oral and oropharyngeal cancer.

Automated summary

The enzymatic activity of APOBEC3B has been implicated as a main cause of mutagenesis in head and neck squamous cell carcinoma. The expression of PKC alpha and NF-kappa B p65 has been linked to the upregulation of A3B. The study evaluated the expression of PKC alpha, NF-kappa B p65, and A3B in non-HPV related oral and oropharyngeal squamous cell carcinomas and found that A3B expression is associated with PKC alpha/NF-kappa B p65 expression, suggesting a potential role for the PKC/NF-kappa B signaling pathway in the development of oral and oropharyngeal cancer.