Specific intensity imaging for glioblastoma and neural cell cultures with 5-aminolevulinic acid-derived protoporphyrin IX

Abstract

The fluorescence of protophorphyrin IX (PpIX) synthesized after incubation with 5-aminolevulinic acid (5-Ala) is used for the intraoperative visualisation of glioma cells in vivo. Such fluorescence may also be useful for the photodynamic therapy (PTD) of gliomas. A significant difference of fluorescence intensity in tumor cells compared to neurons is required for this application. To explore this, eight human glioma cell lines (LN-18, LN-428, U87MG, U373MG, D247MG, U251MG, LN-308, T98G) were compared with human astrocytes (SV-FHAS) and rat neurons after incubation for different periods of time in vitro with 5-Ala (1 mg/ml). Fluorescence intensity profiles were measured by a digital camera comparing glioma cell lines with control cells. All glioma cell lines could be discriminated from neural cells by their intensity of fluorescence by post-hoc tests for pairwise comparisons using Tukey's honestly significant difference test, at the global significance level of 5%. The glioma cell lines showed significant variation in this possibly limiting clinical use of fluorescence as a guide for resection.

Photodynamic therapy of malignant glioma with hypericin: Comprehensive in vitro study in human glioblastoma cell lines

“…This intermediate of porphyrin biosynthesis is converted to protoporphyrin IX (PP IX) in most cell types. Quite selective accumulation of 5-ALA-induced PP IX has been demonstrated for malignant glioma cells in vitro (23,24) and in vivo (25,26) as well as for many other tumour cells. In addition, due to the photosensitizing properties of PP IX, photodynamic treatment of malignant glioma might be considered as a promising additional therapeutic option, which is currently investigated in vitro (27,28) and in vivo (29)(30)(31)(32).…”

Hypericin uptake: A prognostic marker for survival in high-grade glioma

“…Seven patients did not receive chemotherapy. In four patients (1,5,8,10) the Karnofsky index was lower than 70%. One patient (6) refused chemotherapy.…”

“…10 The fluorescence intensity was measured in at least three experiments. Care was taken that there was a monolayer of cells in which fluorescence was determined.…”

Dose limited fluorescence microscopy of 5-aminolevulinic acid induced protoporphyrin IX in living cells

“…For about 20 years [2,3] 5-aminolevulinic acid (5-ALA) has been applied successfully to cells and patients, since it leads to an accumulation of protoporphyrin IX (PP IX) which appears to occur to a larger extent in tumour than in normal cells. Quite selective accumulation of 5-ALA-induced PP IX has been demonstrated in malignant glioma cells [4,5] as well as in patients suffering from malignant glioma [6] . This fact has been used for fluorescence-guided tumour resection [7] and appears to present a therapeutic option in neurosurgery.…”