AIMS

Osteopontin (OPN) and LIM homeobox transcription factor 1, alpha (LMX1A) are important factors related to tumour progression, invasion and metastasis in human cancers. The aim of this study was to test the hypothesis that expression of OPN and of LMX1A correlate with the World Health Organization (WHO) grading system of primary brain tumours.

METHODS AND RESULTS

Immunohistochemical analyses of OPN and LMX1A expression were performed in 139 cases of brain tumour, including 65 meningiomas, 71 gliomas, and three central neurocytomas. More than 90% of WHO grade I meningiomas showed negative or weak staining for OPN and LMX1A. However, among all WHO grade II and III meningiomas, 100% and 66.7% showed moderate or strong staining for OPN and LMX1A, respectively. Similarly, higher percentages of WHO grade I and II gliomas than of WHO grade III and IV gliomas showed negative or weak staining for OPN. A higher intensity of immunoreactivity for LMX1A correlated with more advanced grade in WHO grade I-III gliomas, but not in WHO grade IV tumours.

CONCLUSIONS

Higher immunostaining intensity for OPN and LMX1A correlated with WHO grades for meningiomas and some gliomas. Contrary to our expectations, LMX1A staining in WHO grade IV gliomas was shown to be weaker than in WHO grade III tumours.