Author/Editor		Trinkaus, M; Vranič, A; Dolenc, VV; Lah, TT
Title		Cathepsin B and L and their inhibitors stefin B and cystatin C as markers for malignant progression of benign meningiomas
Type		članek
Source		Int J Biol Markers
Vol. and No.		Letnik 20, št. 1
Publication year		2005
Volume		str. 50-9
Language		eng
Abstract		Meningiomas are, in general, slowly growing benign tumors attached to the dura mater and composed of neoplastic meningothelial (arachnoidal) cells. They have a wide range of histopathological appearances and are classified, according to the aggressiveness of their growth and the risk of recurrence, as WHO grade I (benign) meningiomas, WHO grade II (atypical) meningiomas and WHO grade III anaplastic (malignant) meningiomas. As invasion of normal tissue may occur in all grades, independent biological markers are needed to identify the more aggressive and recurrent meningiomas. The lysosomal cysteine proteinases, cathepsins B and L, have been associated with tumor invasiveness and the aim of this study was therefore to evaluate them, together with their endogenous inhibitors stefin B and cystatin C, as potential markers for the aggressiveness of meningiomas. The expression of cathepsins B and L and their inhibitors stefin B and cystatin C in 21 benign (grade I) and 9 atypical (grade II) meningiomas has been compared by immunohistochemical staining, QRT PCR and Northern blot analysis. The protein levels of cathepsins B (p=0.050) and L (p=0.019) were found to be significantly higher in atypical than in benign meningiomas. In contrast, their mRNA levels did not differ, indicating that the synthesis of cathepsins was accelerated at the translational level. Protein and mRNA levels of stefin B (p= 0.007), but not cystatin C, were significantly lower in atypical compared with benign meningiomas. The expression of cathepsins and inhibitors was not different between central and peripheral meningioma tissue or between histological subtypes of meningiomas, with the exception of cathepsin L, the level of which was significantly lower in transitional meningiomas. We conclude that higher protein levels of cathepsins B and L and lower mRNA levels of stefin B are potential diagnostic markers for invasive and aggressive behavior of meningiomas. (Abstract truncated at 2000 characters).
Descriptors		MENINGIOMA NEOPLASM STAGING NEOPLASM INVASIVENESS CATHEPSINS CYSTEINE PROTEINASE INHIBITORS POLYMERASE CHAIN REACTION BLOTTING, WESTERN RNA, MESSENGER RECEPTORS, PROGESTERONE IMMUNOHISTOCHEMISTRY KI-67 ANTIGEN