Kallikrein-Related Peptidase mRNA Expression in Adenoid Cystic Carcinoma of Salivary Glands: A Polymerase Chain Reaction Study

Kallikrein-related peptidases (KLKs) are a group of 15 serine proteases implicated in a variety of biological processes. Aberrant expression of KLKs has been associated with the development of certain cancers. However, the role of KLKs in salivary tumors has not been extensively studied. This study evaluated the expression of KLKs in both adenoid cystic carcinoma (ACC) and normal salivary gland tissue. We isolated total RNA from 39 formalin-fixed, paraffin-embedded samples, which included 24 ACCs and 15 normal salivary gland tissues. Complementary DNA, synthesized by reverse transcription, was combined with gene specific kallikrein primers (KLK1–KLK15) to allow for quantitative real-time PCR. Data was normalized to a β-actin housekeeping gene. Relative quantification analysis was performed using the ΔCq method. KLK1–KLK15 expression was observed in both tissue types. However, KLK1, KLK8, KLK11, and KLK14 were found to be downregulated in ACC. We propose that this may represent a multi-parametric panel providing diagnostic and prognostic information.