Hisashi Matsuoka

5-Aminolevulinic acid-induced fluorescence diagnosis of pleural malignant tumor

BACKGROUND It is known that endogenously synthesized protoporphyrin IX (PpIX) following the administration of 5-aminolevulinic acid (5-ALA) is an effective photosensitizer for photodynamic diagnosis (PDD). We tested in vivo and in vitro susceptibility of human lung cancer and mesothelioma cells to photodynamic diagnosis (PDD) using 5-aminolevulinic acid (5-ALA) as a photosensitizer. METHODS Human lung cancer cell lines A549, Ma44-3, FT821 and human mesothelioma cell lines MSTO-211H, NCI-H290, Y-MESO-14 were incubated with 0.03% 5-ALA for 4 h. After incubation, protoporphyrin IX (PpIX) fluorescence was detected using a fluorescence microscope. Pleural carcinosis was induced in severe combined immunodeficiency disease mice using the previous cell lines to test the efficacy of PDD in vivo. The mice were sacrificed 4 h after oral administration of 400 mg/kg of 5-ALA. We counted the visible tumors under white light then fluorescence light. RESULTS In vitro, clear red fluorescence was observed in all cell lines. The mean fluorescence intensity was stronger in A549 and FT821 cells than Ma44-3 cells (165.59±26.49, 157.62±18.93 vs. 104.01±17.58). Also, MSTO-211H and NCI-H290 cells had stronger fluorescence intensity than Y-MESO-14 cells (142.51±26.85, 165.16±12.91 vs. 92.31±8.69). In vivo, the tumor detection rate of fluorescence diagnosis was 1.1-4.5 times higher than that of white light. The mean number of metastases detected by the PDD was significantly higher than that of white light for FT821 (p=0.004), Ma44-3 (p=0.006) and Y-MESO-14 cell lines (p=0.005), but not for A549, NCI-H290 and MSTO-211H cell lines. Small lesions were detected by fluorescence diagnosis even though the lesions were invisible macroscopically under white light. CONCLUSION Our results suggest the possibility of clinical application of fluorescence diagnosis with intrapleural malignant tumors.

Comprehensive evaluation of the response of genes to the administration of the antitumor drug S-1 using a low density array

S-1 is a newly developed dihydropyrimidine dehydrogenase inhibitory fluoropyrimidine that exhibits high clinical efficacy against non-small cell lung cancers. To identify genes that may be associated with chemosensitivity to the antitumor drug S-1, we used a low density array representing 93 genes to analyze expression profiles in 4 orthotopically implanted lung cancers derived from human lung cancer cell lines (Lu99, Lu130, LC6 and A549). The tumor growth inhibition (TGI) rates of S-1 in orthotopically implanted tumors of the Lu99, Lu130, LC6 and A549 cell lines were 34.6, 37.5, 32.1 and 3.6%, respectively. The expression of the PRSS3, ABCC4, TXN, SHMT1 and CMPK genes was significantly promoted in the orthotopically implanted SCID mouse model of the 4 lung cancer cell lines by the administration of S-1, while the expression of the LMO7 and FOLH1 genes was significantly suppressed. The expression of the ABCC1, 2 and TST genes was negatively correlated with TGI. The expression of the TK1 and ERCC2 genes was positively correlated with TGI. The results of the present study suggest that the expression of the ABCC1, 2, TST, TK1 and ERCC2 genes is related to resistance to the antitumor drug S-1.