Expression and immunohistochemical localization of cathepsin L during the progression of human gliomas

✍ Scribed by Marupudi Sivaparvathi; Masaaki Yamamoto; Garth L. Nicolson; Ziya L. Gokaslan; Gregory N. Fullert; Lance A. Liotta; Raymond Sawaya; Jasti S. Rao

• Publisher: Springer
• Year: 1996
• Tongue: English
• Weight: 785 KB
• Volume: 14
• Category: Article
• ISSN: 0262-0898
• DOI: 10.1007/bf00157683

✦ Synopsis

Recent studies suggest that cysteine proteinase cathepsin L is involved in the process of tumor invasion and metastasis. We examined cathepsin L activity in brain tumor tissue samples by an enzymatic assay, and cathepsin L protein content by enzyme-linked immunoadsorbent assays and Western blotting to determine whether increased levels of cathepsin L correlate with the progression of human gliomas. Native and acid-activatable cathepsin L activities were highest in glioblastomas followed by anaplastic astrocytomas and were lowest in low-grade gliomas and normal brain tissues. Significantly higher amounts of an M(r) 29,000 cathepsin L were present in glioblastomas and anaplastic astrocytomas than in normal brain tissues and low-grade glioma tissue extracts. Using specific antibodies to cathepsin L, we also studied its cellular distribution by immunohistochemical procedures. Higher diffuse cathepsin L immunoreactivity was found in glioblastomas than in low-grade gliomas and normal brain tissue samples. Finally, the addition of cathepsin L antibody inhibits the invasion of glioblastoma cell lines through Matrigel invasion assay. These results suggest the expression of cathepsin L is dramatically upregulated in malignant gliomas and correlates with the malignant progression of human gliomas in vivo.