The authors previously sought to identify novel markers of glioma invasion and recurrence. Their research demonstrated that brain gliomas overexpressed a subset of vascular basement components, laminins, that contained the α4 chain. One of these laminins, laminin-8, was found to be present in highly invasive and malignant glioblastoma multiforme (GBM) (Grade 4 astrocytoma); its expression was associated with a decreased time to tumor recurrence, and it was found in vitro to promote invasion of GBM cell lines.
In the current study, the authors studied glial tumors of different grades in an attempt to correlate laminin-8 expression with tumor recurrence and patient survival. Immunohistochemistry and Western blot analysis were used to detect laminin isoforms of interest.
Using immunohistochemistry and Western blot analysis, the authors confirmed high levels of laminin-8 expression in approximately 75% of the GBM cases examined and in their adjacent tissues, whereas astrocytomas of lower grades expressed for the most part a different isoform, laminin-9, which also was found in low amounts in normal brain tissue and benign meningiomas. Overexpression of laminin-8 in GBM was found to be associated with a statistically significant shorter time to tumor recurrence (P < 0.0002) and a decreased patient survival time (P < 0.015).
The data suggest that laminin-8, which may facilitate tumor invasion, contributes to tumor regrowth after therapy. Laminin-8 may be used as a predictor of tumor recurrence and patient survival and as a potential molecular target for glioma therapy. Cancer 2004. © 2004 American Cancer Society.