Biomarkers as Indicators of Severity of Cerebral Damage in Postoperative Brain Tumor Patients

Abstract

Biomarkers have traditionally been used in clinical practice in order to support a diagnosis, or monitoring the progression of a disease by measuring their concentrations in serum. These serum biomarkers are often proteins, enzymes or hormones. They may be tumor specific while others are present in normal tissues but are produced at high concentration in cancer patients. Four biomarkers i.e. S100B, p53, C-reactive protein (CRP) and Creatine Kinase (CK) are included in this study. S100B is an EF-hand calcium binding protein family with increased intracellular and serum levels of the protein in a range of human tumors. P53 is a tumor suppressor and plays an important role in protecting the cell from malignant proliferation by inducing growth arrest or apoptosis. This function of p53 is lost, if its gene is mutated and consequently malignant transformation of cell may occur. Recent studies have shown that S100B protein can bind to P53, suppressing p53-dependent transcription of target genes including HDM2, P21 and c-BCL2 thus affecting a range of functions. S100B is primarily found in neuronal tissue and has been proposed as a neuro pathological biomarker with a similar impact as CRP which is an acute-phase reactant and indicator of underlying systemic inflammation. CK is a well defined marker for muscular damage which is released into the serum following muscle damage. The present study aimed to examine the role of these biomarkers in serum of patients with brain tumors including meningioma, glioma, pituitary tumor, ependymoma, medulloblastoma, lymphoma, acoustic neuroma and orbital neuroblastoma. Their 15concentrations in the serum of these patients were measured before and after brain tumor surgery. S100B levels were significantly increased in serum of patients with brain tumors than in healthy individuals. Significantly high levels of S100B were observed in all postoperative patients than preoperative patients with brain tumor. Also, no statistically significant difference was found between the levels of p53 and CRP in serum of normal healthy individuals and preoperative patients. In all postoperative patients the levels of serum CRP and p53 were increased significantly as compared with preoperative serum samples. CK concentrations were significantly lowered in preoperative patients than in normal healthy individuals. There was no significant correlation found between these biomarkers in the patients both pre- and post operative periods except on postoperative Day 1 where significant positive correlation between S100B and CRP proteins was observed. These findings suggest that these biomarkers may be considered as independent risk factors. However, these findings warrant further studies to investigate the potential role and relevance of these biomarkers to the disease process and prognosis.