Creatine kinase activity and isoenzyme pattern in various normal tissues and neoplasms

Area of Science:

• Biochemistry
• Oncology
• Enzymology

Background:

• Creatine kinase (CK) is an enzyme crucial for cellular energy homeostasis.
• CK isoenzymes (CK-MM, CK-MB, CK-BB) have distinct tissue distributions.
• Altered CK expression is observed in various neoplastic conditions.

Purpose of the Study:

• To investigate total creatine kinase (CK) activity and isoenzyme patterns in normal and neoplastic tissues.
• To assess the potential of CK isoenzymes as tumor markers.

Main Methods:

• Measurement of total creatine kinase (CK) activity.
• Analysis of creatine kinase (CK) isoenzyme patterns (CK-MM, CK-BB).
• Comparison of CK levels and patterns between normal and tumor tissues.

Main Results:

• CK activity was detected in all examined normal and neoplastic tissues.
• No clear correlation was found between total CK activity and tumor growth rate or differentiation.
• An atypical CK-MM band was observed in 15 out of 53 cases, potentially indicating a nonspecific tumor marker.
• CK-BB isoenzyme was ubiquitous in neoplastic tissues, suggesting it as a nonspecific marker.
• Total CK activity was generally low in most tumor tissues.

Conclusions:

• The CK-BB isoenzyme is a nonspecific marker found ubiquitously in neoplastic tissues.
• An atypical CK-MM band may serve as an insensitive and nonspecific tumor marker.
• Detectable circulating CK-BB likely requires bulky tumors or advanced malignancy stages.