Receiver operating characteristic (ROC) analysis demonstrated for first time that KLK5 expression had significant discriminatory values between cancer and adenoma tissues (area under the curve [AUC] 0.77; 95% confidence interval [CI]=0.69-0.85, p=0.03).
Kallikrein-related peptidases KLK5, KLK7 and KLK14 are important proteases in skin desquamation and aberrant KLK activity is associated with inflammatory skin diseases such as Netherton syndrome but also with various serious forms of cancer.
The KLK5 mRNA expression levels were significantly upregulated in CRC tissues compared with the paired normal tissues, and were higher in Dukes' stage C/D cancer than in stage A/B (P<0.001).
Here, we show that reconstitution of KLK5 expression in non-expressing MDA-MB-231 breast cancer cells suppresses malignancy in vitro and in vivo dose-dependently.
A trend for upregulation in tumors was observed for (CANFA)KLK5, (CANFA)KLK7, and (CANFA)KLK8, whereas (CANFA)KLK8 variant 1 tended to be downregulated in cancer.
KLK5-SV1 may have clinical utility in various malignancies and should be further explored as a potential new biomarker for prostate and ovarian cancer.
KLK5 should be further studied as a potential new prognostic marker in prostate cancer, whose expression is negatively correlated with cancer aggressiveness.