Abstract
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.