Possible role of CA IX in chalcedony (a crystalline variety of silica) formation in human glioblastoma multiforme from aged patients

PRADO FIGUEROA, M.; CASAVILCA, S.

Bruselas, Bélgica

Simposio; CA IX Symposium; 2007

Wilex

    Possible role of CA IX in chalcedony (a crystalline variety of silica) formation in human glioblastoma multiforme from aged patients.   María Prado Figueroa1, Sandro Casavilca2 1Instituto de Investigación Bioquímica (CONICET - Universidad Nacional del Sur) cc 857, FWB8000, Bahía Blanca, Argentina. e-mail: inprado@criba.edu.ar  2Departamento de Patología, Instituto de Enfermedades Neoplásicas, Lima, Perú   Chalcedony is a microcrystalline fibrous form of silica and actually consists of nanoscale intergrowths of quartz and the optically length-slow fibrous silica polymorph moganite. Chalcedony formation is due to the relationship between pH and oxidation potential (Eh) (Krumbein and Garrels, 1952). A biogenically produced crystalline mineral phase (i.e. chalcedony) has been observed in electric organs (cholinergic nerves and electrocytes) from living electric fish (Prado Figueroa et al., 2005; 2007). Chalcedony (SiO2) was also detected in human brain from aged patients (Prado Figueroa et al., 2006). Glioblastoma is the most aggressive type of primary brain tumor and it involves overexpression of the enzyme carbonic anhidrase IX (CA IX). From these evidences, we decided to document the presence of chalcedony in human astrocytoma II and glioblastoma multiforme from autopsy derived and also biopsy. In those sections, naturally occurring fluorescent mineral was observed by confocal laser scanning microscopy.. Our data showed that there is a green fluorescent chalcedony in astrocytoma II with a crystalline mineral phase, it was about 1-2 mm in size. In glioblastoma, green fluorescent chalcedony appeared infiltrating all the tissue. CA IX is involved in physiological pH regulation and may be in the polymerization - depolymerization of silica in the human brain.