Brevican, Neurocan, Tenascin-C and Versican are Mainly Responsible for the Invasiveness of Low-Grade Astrocytoma

The extent of tumor removal determines the effectiveness of postoperative oncotherapy. This is especially true for primary brain tumors, where peritumoral invasion usually makes radical resection impossible. The aim of the study was to determinate the specific expression pattern of invasion related molecules of different intracranial tumors and to identify molecules that are principally responsible for the peritumoral invasiveness of grade II astrocytoma mRNA expression of 26 extracellular matrix (ECM) molecules was determined in tissue samples from grade II astrocytoma, schwannoma, intracerebral metastases of non-small cell lung cancer and normal brain. Immunohistochemical staining for brevican, neurocan, tenascin-C and versican was also performed for each tumor group. Comparing astrocytoma to metastasis, schwannoma and normal brain; and metastasis and schwannoma to normal brain, 22, 17, 20, 21, and 19 molecules, respectively, were found to be significantly overexpressed at the mRNA level. Cluster analysis of mRNA expression showed a specific gene expression pattern for each histological group. Four molecules of 26 were found to be associated to astrocytoma. Immunohistochemical staining confirmed the results of the mRNA analysis at the protein level. Tumors of different origin have a specific invasive phenotype that can evidently determinate on gene expression level. This characteristic expression pattern of the invasion-related molecules might help to screen exact targets for anti-invasion drugs. In case of low-grade astrocytoma. brevican, neurocan, tenascin-C and versican were found to correlate principally with the invasive phenotype of low-grade astrocytoma, thus these molecules can potentially serve as targets for anti-invasion therapy in the future.