Solasonine Causes Redox Imbalance and Mitochondrial Oxidative Stress of Ferroptosis in Lung Adenocarcinoma.

Ferroptosis, a type of iron-dependent oxidative cell death caused by excessive lipid peroxidation, is emerging as a promising cancer therapeutic strategy. Solasonine has been reported as a potential compound in tumor suppression, which is closely linked to ferroptosis. However, ferroptosis caused by solasonine is insufficiently identified and elaborated in lung adenocarcinoma, a fatal disease with high morbidity and mortality rates. First, the biochemical and morphological changes in Calu-1 and A549 cells exposed to solasonine are observed using a cell death assay and a microscope. The cell viability assay is performed after determining the executive concentration of solasonine to assess the effects of solasonine on tumor growth in Calu-1 and A549 cells. The ferroptosis is then identified by using ferroptosis-related reagents on CCK-8, lipid peroxidation assessment, Fe2+, and ROS detection. Furthermore, the antioxidant system, which includes GSH, Cys, GPx4, SLC7A11, and mitochondrial function, is measured to identify the potential pathways. According to the results, solasonine precisely exerts antitumor ability in lung adenocarcinoma cells. Ferroptosis is involved in the solasonine-induced cell death, as well as the accumulation of lipid peroxide, Fe2+, and ROS. Moreover, the failures of antioxidant defense and mitochondrial damage are considered to make a significant contribution to the occurrence of ferroptosis caused by solasonine. The study describes the potential process of ferroptosis caused by solasonine when dealing with lung adenocarcinoma. This encouraging evidence suggests that solasonine may be useful in the treatment of lung cancer.

Ir doping-induced superconductivity in the SmFeAsO system.

The 5d transition metal Ir is successfully doped for Fe in SmFeAsO to induce superconductivity with T(c) = 16 K at a doping level of approximately 15 atom %. Ir doping decreases the As-Fe-As bond angle, beta; this behavior is different from the change in beta for the system with doping charges in the charge-reservoir layers.

[Association of thymidylate synthase polymorphism with esophageal squamous-cell carcinoma].

OBJECTIVE: To explore the influence of 5'UTR tandem repeat and 3'UTR 6 bp deletion polymorphism of thymidylate synthase (TS) gene on the development and lymphatic metastases of esophageal squamous-cell carcinoma (ESCC). METHODS: Peripheral leucocyte DNA was extracted from 232 ESCC patients and 348 age- and sex-matched healthy controls. TS 5'UTR and 3'UTR genotyping in all study subjects was performed by PCR fragment analysis and PCR-RFLP analysis, respectively. RESULTS: The distribution of TS 5'UTR and 3'UTR variants in ESCC patients was not significantly different from that in healthy controls. However, individuals with 6 bp+/6 bp+ and 3R/3R genotypes significantly reduced the risk to ESCC development compared to those with other genotype combinations (adjusted OR = 0.32, 95% CI = 0.08-0.92). In addition, the frequency of 2R/3R genotype in ESCC patients with lymphatic metastases (40%) was significantly higher than that in lymph node negative cases (14.7%) (chi(2) = 10.11, P = 0.001). Compared to 3R/3R genotype, the 2R/3R genotype significantly increased the risk of lymphatic metastases in ESCC (adjusted OR = 3.68, 95% CI = 1.54-8.93). CONCLUSION: The genotyping of TS 5'UTR and 3'UTR polymorphisms might be used as a stratification maker for predicting susceptibility to ESCC. The TS 5'UTR 2R/3R genotype might be a candidate molecular marker to predict the potential of lymphatic metastases in ESCC.

[Association of polymorphisms of p21cip1 and p27kip1 genes with susceptibilities of esophageal squamous cell carcinoma and gastric cardiac adenocarcinoma].

BACKGROUND & OBJECTIVE: Researches showed that polymorphisms of p21(cip1) and p27(kip1) genes have associations with susceptibilities of breast cancer, lung cancer, prostate cancer, and so on. This study was to investigate the possible association of functional polymorphisms of p21(cip1) and p27(kip1) genes with susceptibilities of esophageal squamous cell carcinoma (ESCC) and gastric cardiac adenocarcinoma (GCA) in a population from a high incidence region in north China. METHODS: The single nucleotide polymorphisms (SNPs) in the 3'-untranslated region of p21(cip1) gene and in codon 109 of p27(kip1) gene were analyzed by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) in 299 ESCC patients, 256 GCA patients, and 437 healthy controls from a high incidence region of north China. RESULTS: The frequency of p21(cip1) T allelotype was significantly higher in ESCC patients than in healthy controls (42.8% vs. 36.7%, P=0.02). The frequency of p27(kip1) V allelotype was significantly higher in ESCC and GCA patients than in healthy controls (96.8% and 96.1% vs. 92.9%, P=0.001, P=0.02). The distribution of p21(cip1) genotypes among ESCC patients was significantly different from that among healthy controls (P=0.04); compared with the combination of the C/C and C/T genotypes, the T/T genotype significantly elevated the risk of developing ESCC [adjusted odds ratio (OR)=1.93, 95% confidence interval (CI)=1.12-3.94]. The distribution of p27(kip1) genotypes among ESCC and GCA patients were significantly different from that among healthy controls (P=0.002, P=0.01); compared with the combination of V/G and G/G genotypes, the V/V genotype significantly elevated the risk of developing ESCC and GCA (adjusted OR=2.44, 95% CI=1.21-4.02; adjusted OR=2.01, 95% CI=1.12-3.68). When stratified for smoking and family history of upper gastrointestinal cancers (UGIC), compared with the combination of V/G and G/G genetypes, the V/V genotype significantly elevated the risk of developing both ESCC and GCA in smokers (adjusted OR=2.24, 95% CI=1.14-4.03; adjusted OR=2.61, 95% CI=1.25-3.82) and ESCC in individuals with positive family history of UGIC (adjusted OR =2.04, 95% CI=1.04-3.43). The combination of p21(cip1) T/T and p27(kip1) V/V genotypes significantly elevated the risk of developing ESCC and GCA (adjusted OR=3.78, 95% CI=1.46-5.89; adjusted OR=2.56, 95% CI=1.06-4.78). CONCLUSION: In north China, p21(cip1) polymorphisms might be correlated with the susceptibility of ESCC, p27(kip1) polymorphisms might be correlated with the susceptibilities of ESCC and GCA, and they might have synergetic effect on ESCC and GCA development.

[Polymorphisms of thymidylate synthase gene and correlation of its protein expression to lymph node metastasis of esophageal squamous cell carcinoma].

BACKGROUND & OBJECTIVE: Thymidylate synthase (TS) is a key enzyme in DNA synthesis. The 28-bp tandem repeat in the 5'-untranslated region (UTR) of TS gene and the G/C single nucleotide polymorphism (SNP) of TS gene may modify the expression and activity of TS protein, therefore, may change the susceptibility and prognosis of tumors. This study was to explore the correlations of TS 5'-UTR polymorphism to lymph node metastasis of esophageal squamous cell carcinoma (ESCC) and the expression of TS protein. METHODS: Peripheral leucocyte DNA was extracted from 232 ESCC patients and 348 age-and gender-matched healthy controls. TS 5'-UTR tandem repeat and the G/C SNP genotype was detected by polymerase chain reaction (PCR) and PCR-restriction fragment length polymorphism (PCR-RFLP), respectively. TS expression in 51 specimens of ESCC was detected by SP immunohistochemistry. RESULTS: The frequencies of 3G/3G, 3G/3C, 3C/3C, 2R/3G, 2R/3C, 2R/2R, and other genotypes were 17.5%, 17.3%, 29.3%, 12.9%, 17.8%, 3.7%, and 1.5% in the healthy controls, and 16.0%, 16.0%, 29.3%, 13.8%, 17.6%, 4.3%, and 3.0% in the ESCC patients; whereas the frequencies of 3G, 3C, 2R, and other alleles were 32.8%, 47.0%, 19.5%, and 0.7% in the healthy controls, and 31.2%, 46.8%, 20.5%, and 1.5% in the ESCC patients, respectively. Compared with 3G/3G genotype, 2R/3G genotype significantly increased the risk of lymph node metastasis of ESCC [age and gender adjusted odds ratio (OR), 11.53; 95% confidence interval (CI), 2.67-49.74]. TS protein expression was significantly related to TS 5'-UTR genotype (P<0.05), but was not related to gender, age, lymph node metastasis and clinicopathologic stage. CONCLUSION: TS 5'-UTR tandem repeat and G/C SNP genotype, but not TS expression, might be a candidate molecular marker to predict lymph node metastasis of ESCC.