Infrequent Mutation of Lysophosphatidic Acid Receptor-1 Gene in Hamster Pancreatic Duct Adenocarcinomas and Established Cell Lines

To evaluate the involvement of lysophosphatidic acid receptor-1 (LPA1) gene alteration in pancreatic carcinogenesis, we investigated mutations in the LPA1 gene in hamster pancreatic duct adenocarcinomas (PDAs) and established cell lines. Female Syrian golden hamsters received 30 mg/kg of N-nitrosobis(2-oxopropyl)amine (BOP) followed by repeated exposure to an augmentation pressure regimen consisting of a choline-deficient diet combined with DL-ethionine and then L-methionine and a further administration of 20 mg/kg BOP. A total of 10 PDAs obtained 10 weeks after beginning the experiment and three cell lines established from subcutaneously transplantable PDAs in syngeneic hamsters were examined for mutations using reverse transcription-polymerase chain reaction-single strand conformation polymorphism (RT-PCR-SSCP) analysis. A mutation was detected in only one PDA (1/10, 10%) in the form of a GGA to GTA (Gly to Val) transversion at codon 355, and no mutations were detected in the three cell lines. These results suggest that the LPA1 gene mutation may play roles in a limited fraction of BOP-induced pancreatic duct carcinogenesis in hamsters

Genetic variants in antioxidant pathway: Risk factors for hepatotoxicity in tuberculosis patients

Tuberculosis (TB) treatment can cause serious sequelae including adverse effects such as anti-TB drug-induced hepatotoxicity (ATDH). We performed a candidate gene-based association study between single nucleotide polymorphisms (SNPs) in 10 genes in the antioxidant pathway and ATDH susceptibility. The subjects comprised 100 Japanese patients with pulmonary TB who received a treatment regimen including isoniazid and rifampicin. Out of them, 18 patients had ATDH. Thirty-four tag SNPs in 10 genes were analyzed by PCR-restriction fragment length polymorphism or PCR-direct DNA sequencing. The frequencies of alleles and genotypes between patients with and without ATDH were compared in three different genetic models. Statistical analyses revealed that a C/C genotype at rs11080344 in NOS2A, a C/C genotype at rs2070401 in BACH1, and a G/A or A/A genotype at rs4720833 in MAFK independently conferred ATDH susceptibility. Remarkably, the association of the latter two tag SNPs with ATDH susceptibility was highly statistically significant (P = 0.0006) with an odds ratio of 9.730. This study is the first report to demonstrate that NOS2A, BACH1, and MAFK appear to be genetic determinants of ATDH in Japanese patients with TB. Furthermore, a combination of BACH1 and MAFK polymorphisms may be useful as new biomarkers to identify high-risk Japanese TB patients for ATDH

SLIM1 Transcription Factor Promotes Sulfate Uptake and Distribution to Shoot, Along with Phytochelatin Accumulation, Under Cadmium Stress in Arabidopsis thaliana

Sulfur (S) assimilation, which is initiated by sulfate uptake, generates cysteine, the substrate for glutathione (GSH) and phytochelatin (PC) synthesis. GSH and PC contribute to cadmium (Cd) detoxification by capturing it for sequestration. Although Cd exposure is known to induce the expression of S-assimilating enzyme genes, including sulfate transporters (SULTRs), mechanisms of their transcriptional regulation are not well understood. Transcription factor SLIM1 controls transcriptional changes during S deficiency (−S) in Arabidopsis thaliana. We examined the potential involvement of SLIM1 in inducing the S assimilation pathway and PC accumulation. Cd treatment reduced the shoot fresh weight in the sulfur limitation1 (slim1) mutant but not in the parental line (1;2PGN). Cd-induced increases of sulfate uptake and SULTR1;2 expressions were diminished in the slim1 mutant, suggesting that SLIM1 is involved in inducing sulfate uptake during Cd exposure. The GSH and PC levels were lower in slim1 than in the parental line, indicating that SLIM1 was required for increasing PC during Cd treatment. Hence, SLIM1 indirectly contributes to Cd tolerance of plants by inducing −S responses in the cell caused by depleting the GSH pool, which is consumed by enhanced PC synthesis and sequestration to the vacuole

SLIM1 Transcription Factor Promotes Sulfate Uptake and Distribution to Shoot, Along with Phytochelatin Accumulation, Under Cadmium Stress in Arabidopsis thaliana

Sulfur (S) assimilation, which is initiated by sulfate uptake, generates cysteine, the substrate for glutathione (GSH) and phytochelatin (PC) synthesis. GSH and PC contribute to cadmium (Cd) detoxification by capturing it for sequestration. Although Cd exposure is known to induce the expression of S-assimilating enzyme genes, including sulfate transporters (SULTRs), mechanisms of their transcriptional regulation are not well understood. Transcription factor SLIM1 controls transcriptional changes during S deficiency (-S) in Arabidopsis thaliana. We examined the potential involvement of SLIM1 in inducing the S assimilation pathway and PC accumulation. Cd treatment reduced the shoot fresh weight in the sulfur limitation1 (slim1) mutant but not in the parental line (1;2PGN). Cd-induced increases of sulfate uptake and SULTR1;2 expressions were diminished in the slim1 mutant, suggesting that SLIM1 is involved in inducing sulfate uptake during Cd exposure. The GSH and PC levels were lower in slim1 than in the parental line, indicating that SLIM1 was required for increasing PC during Cd treatment. Hence, SLIM1 indirectly contributes to Cd tolerance of plants by inducing -S responses in the cell caused by depleting the GSH pool, which is consumed by enhanced PC synthesis and sequestration to the vacuole