KLK7 expression in human tumors: a tissue microarray study on 13,447 tumors.

Area of Science:

• Oncology
• Biochemistry
• Dermatology

Background:

• Kallikrein-related peptidase 7 (KLK7) is a serine protease vital for skin homeostasis by regulating corneocyte desquamation.
• Overexpression of KLK7 in cancer is implicated in metastasis through the degradation of cell junctions and extracellular matrix proteins.

Purpose of the Study:

• To comprehensively map KLK7 protein expression across a wide range of normal and neoplastic human tissues.
• To investigate the correlation between KLK7 expression and clinicopathological features in various cancers.

Main Methods:

• Utilized immunohistochemistry to analyze KLK7 protein expression.
• Examined a large-scale tissue microarray with 13,447 tumor samples (147 types/subtypes) and 608 normal tissue samples (76 types).

Main Results:

• KLK7 was detected in 64 out of 147 tumor categories, with notable high positivity in squamous cell carcinomas, ovarian, endometrium, salivary gland, bilio-pancreatic, and upper gastrointestinal cancers.
• KLK7 expression correlated with metastasis (nodal, blood, and lymph vessel infiltration) in colorectal adenocarcinoma, nodal metastasis in hepatocellular carcinoma, advanced tumor stage in thyroid cancer, and lower malignancy grade in squamous cell carcinomas.

Conclusions:

• This study provides a comprehensive atlas of KLK7 expression in human tissues.
• The prognostic significance and potential of KLK7 as a drug target warrant further investigation.