Modulation of cystatin C expression impairs the invasive and tumorigenic potential of human glioblastoma cells

Abstract

Increases in the abundance of cathepsin B transcript and protein with increased tumor grade and changes in subcellular localization and activity of this enzyme. We observed progressive reductions in levels of the protease inhibitor cystatin C, an inhibitor of cathepsin B with corresponding increases in the malignancy of glioma cell lines, implying an inverse correlation between cystatin C and tumor grade. To investigate the role of cystatin C in the invasion of brain tumor cells, we stably transfected SNB19 glioblastoma cells with either a 0.4-kb cDNA construct of human cystatin C in the sense orientation or an empty vector. Clones expressing sense-cystatin C cDNA had higher cystatin C mRNA and protein levels than did control cells. Sense-transfected cells were also markedly less invasive than control cells in a Matrigel invasion assay and in a coculture assay of SNB19 spheroids and fetal rat brain aggregates. Finally, the sense-transfected cells did not form tumors in nude mice upon intracerebral injection. These results strongly implicate cystatin C in the invasiveness of human glioblastoma cells and suggest that sense transcripts of cystatin C may prove useful in cancer therapy.

Proteomic analysis of cerebrospinal fluid discriminates malignant and nonmalignant disease of the central nervous system and identifies specific protein markers

“…In our study, cystatin C was not detected by SELDI analysis in neoplastic CSF samples. These findings are supported by a recent quantitative study of cystatin C in CSF derived from leptomeningeal metastasis, which showed low levels compared to controls [41]. By contrast, we found that cystatin C was present in the large majority of nondiagnostic and reactive/inflammatory samples, with the highest-intensity bands noted in inflammatory disease.…”

“…Most importantly, cystatin C is a potent inhibitor of cathepsins B, H, L, and S. In GBM, these cathepsins are thought to promote invasive behavior at the leading edge of the tumor [41]. In contrast, cystatin C expression is typically low in neoplastic cells where levels are inversely correlated with tumor grade [41]. In our study, cystatin C was not detected by SELDI analysis in neoplastic CSF samples.…”

“…Its main function is to protect tissue integrity by inhibiting extracellular cystein proteinases that are often up-regulated in neoplastic and non-neoplastic CNS diseases. Most importantly, cystatin C is a potent inhibitor of cathepsins B, H, L, and S. In GBM, these cathepsins are thought to promote invasive behavior at the leading edge of the tumor [41]. In contrast, cystatin C expression is typically low in neoplastic cells where levels are inversely correlated with tumor grade [41].…”

Cysteine proteinase inhibitor cystatin C in squamous cell carcinoma of the head and neck: relation to prognosis

“…Similarly, the overproduction of active recombinant cystatin C resulted in a pronounced reduction in Matrigel invasion of murine squamous carcinoma cells (Coulibaly et al, 1999). In human glioblastoma cells, inverse correlation between cystatin C and tumour grade was observed (Konduri et al, 2002). The sencecystatin C transfected cells were also markedly less invasive than the control cells and, in nude mice, did not form tumours upon intracerebral injection.…”

Cystatin C: current position and future prospects

“…Cathepsin B in particular has been widely shown to have a role through a correlation between expression of cathepsin B in tumour tissues, disease progression and adverse clinical prognosis in several types of tumour: gastric (238), pulmonary (239), breast (240), and head and neck carcinoma (241). Conversely, expression correlates with poorer in vivo and in vitro invasive potential for glioblastomas (242), improved survival of patients suffering from upper respiratory tract tumours (243) and a lower Gleason score in prostate tumours (244). The anti-tumour effect of CysC may also be due to a ''cytokine-like'' role independent of its protease inhibitor function.…”