Down-regulation of S100A9 and S100A10 in manganese-resistant RBL-2H3 cells

• Published in: Journal of toxicological sciences 2013/10/01, Vol.38(5), pp.753-757
• Main Authors: Fujishiro, Hitomi, Ohashi, Toshinao, Takuma, Miki, Himeno, Seiichiro
• Format: Article
• Language: English
• Subjects: Animals; Annexin A2 - genetics; Annexin A2 - metabolism; Annexin A2 - physiology; Calgranulin B - genetics; Calgranulin B - metabolism; Calgranulin B - physiology; Down-Regulation - drug effects; Drug Resistance, Neoplasm - genetics; Gene Expression Regulation - drug effects; Leukemia, Basophilic, Acute - genetics; Leukemia, Basophilic, Acute - pathology; Manganese; Manganese - toxicity; Microarray; Protein Array Analysis; Rats; Resistance; Reverse Transcriptase Polymerase Chain Reaction; RNA, Messenger - metabolism; S100 Proteins - genetics; S100 Proteins - metabolism; S100 Proteins - physiology; S100A10; S100A9; Tumor Cells, Cultured
• ISSN: 0388-1350; 1880-3989
• DOI: 10.2131/jts.38.753

Exposure to excess amounts of manganese causes toxic effects, including neurological symptoms such as Parkinsonism. However, endogenous factors involved in the protection against manganese toxicity remain unclear. Previously, we showed that rat basophilic leukemia RBL-2H3 cells are highly sensitive to MnCl2 compared with other rat cell lines. To identify the genes involved in resistance to manganese toxicity, two lines of Mn-resistant cells showing resistance to 300 µM MnCl2 (RBL-Mnr300) and 1200 µM MnCl2 (RBL-Mnr1200) were developed from RBL-2H3 cells by a stepwise increase in MnCl2 concentration in the medium. Microarray analyses were carried out to compare gene expression between parental RBL-2H3 cells and RBL-Mnr300 or RBL-Mnr1200 cells. Five genes exhibited more than 10-fold up-regulation in both RBL-Mnr300 and RBL-Mnr1200 cells, and 24 genes exhibited less than 0.1-fold down-regulation in both Mn-resistant cell lines. The S100a9 and S100a10 genes, encoding the calcium-binding S100A9 and S100A10 proteins, respectively, were found among the three most down-regulated genes in both Mn-resistant cell lines. The marked decreases in mRNA levels of S100a9 and S100a10 were confirmed by real-time RT-PCR analyses. Further characterization and comparison of these Mn-resistant cells may enable the identification of novel genes that play important roles in the modification of manganese toxicity.