Extracellular matrix in paediatric GBM

Purpose: In the last few decades, multiple studies have been addressed at assessing specific factors related to glioblastoma multiforme (GBM) invasion. However, few studies have evaluated the interaction of tumor cells with specific extracellular matrix (ECM) components; moreover, there is a lack of information regarding the occurrence of these phenomena in pediatric GBM. Methods: ECM proteins were evaluated in six cases of pediatric GBM assessing the immunohistochemical expression of laminin, fibronectin, and type IV collagen. We used a semiquantitative scale, ranging from not detected (zero) to marked (3). Results: Laminin expression was minimal in 3 cases, moderate in 1 case, markedly generalized in 1 patient and markedly focal in the remaining case. Fibronectin expression was minimal in 3 patients and moderate immunoreactivity was documented in 1 case. Conversely, 1 case was classified as marked with generalized distribution and the remaining case as marked with focal immunostaining. Type IV collagen expression was minimal in 3 cases, moderate in 1, marked with focal reaction in 1 and marked with generalized reaction in the remaining case. Conclusions: This study provides additional insights into tumor invasion features of pediatric GBMs, as ECM plays a pivotal role in numerous cellular functions during normal and pathological processes. Although based on a limited number of patients, this investigation may serve as a challenge for the management of pediatric GBM, stimulating trials with larger patient numbers aimed at documenting specific factors influencing GBM prognosis