ANP differentiates between primary Submandibular Gland Squamous Cell Carcinoma and Oral Squamous Cell Carcinoma: Preliminary data

The natriuretic peptide system consists of three ligands, Atrial Natriuretic Peptide (ANP), Brain Natriuretic peptide (BNP) and C-type Natriuretic peptide (CNP), and three natriuretic peptide receptors (NPR’s), NPRA, NPRB and NPRC. We investigated the expression levels of NPPA (encoding ANP) and NPR1 (encoding NPRA, the main receptor for ANP) in primary benign (pleomorphic adenoma) and malignant (squamous cell carcinoma, SCC) submandibular salivary gland (SMG) tumors, as well as in primary oral squamous cell carcinoma (OSCC). We found that the NPPA and NPR1 expression levels were significantly different in SMG SCC versus OSCC, exhibiting a significant increase in NPPA and absence of NPR1 expression in SMG SCC compared to OSCC whereby a decrease in NPPA expression was noted. These data strongly suggest that NPPA-NPRA expression levels could help in differentiating between SMG malignancies and more specifically discriminate between primary and secondary SMG malignancies.