Enzymes: Tumour Associated Biomarker

Enzymes catalyse biochemical reactions and tightly regulate biophysical and metabolic pathways to maintain cellular homeostasis. However, the unregulated activity of these enzymes results in metabolic disorders and genetic diseases, including cancer. In cancer, significant alteration of enzyme levels and/or activity can be detected during malignant transformation, thus, it can be used as a potential biomarker in clinical applications. For example, serum levels of lactate dehydrogenase (LDH), neuron-specific enolase (NSE) and thymidine kinase 1(TK1), alkaline phosphatases (ALPs), tumour M2-PK, hexokinase (HK), etc., significantly increased in patients with various cancers, such as metastatic breast cancer, intracranial germ cell tumours, ovarian serous carcinomas, oesophagus, cervical, gastrointestinal, prostate, renal cell carcinoma, head and neck and lung cancers. Also, they are associated with various clinicopathological factors, such as stage, grade, lymph node metastasis, distant metastasis, etc. In addition, overexpression of carbonic anhydrase XII (CAXII), matrix metalloproteinases (MMPs) and aldehyde dehydrogenase 1 (ALDH1), in cancer tissues, is associated with the presence of several cancers and correlated with the progression of the diseases. Therefore, screening of these enzymes at the point-of-care settings could facilitate better management of patients with cancer. This chapter summarizes the roles of cancer associated-enzymes, especially emphasizing their clinical significance in patients with various cancers. 

Keywords: Alkaline phosphatase, Aldehyde dehydrogenase 1, Biosynthesis, Carbonic anhydrase XII, Cancer bioenergetics, Cancer metabolism, Ghrelin OAcyl Transferase, Glucose-6-phosphate dehydrogenase, Hexokinase, Lactate dehydrogenase, Matrix metalloproteinases, Metabolic enzymes, Neuron-specific enolase, Receptor-interacting protein kinase, Thymidine kinase, Tumour M2-PK, Urokinase-type plasminogen activator, Warburg effects.