Synthesis, DNA binding of bis-naphthyl ferrocene derivatives and the application as new electroactive indicators for DNA biosensor.

A series of bis-naphthyl ferrocene derivatives were synthesized and characterized. Based on the results obtained from UV-visible absorption titration and ethidium bromide (EB) displacement experiments, it was observed that the synthesized compounds exhibited a strong binding ability to dsDNA. In comparison to the viscosity curve of EB, the tested compounds demonstrated a bisintercalation binding mode when interacting with CT-DNA. Differential pulse voltammetry (DPV) was employed to assess the binding specificity of these indicators towards ssDNA and dsDNA. All tested indicators displayed more pronounced signal differences before and after hybridization between probe nucleic acids and target nucleic acids compared to Methylene Blue (MB). Among the evaluated compounds, compound 3j containing an ether chain showed superior performance as an indicator, making it suitable for constructing DNA-based biosensors. Under optimized conditions including probe ssDNA concentration and indicator concentration, this biosensor exhibited good sensitivity, reproducibility, stability, and selectivity. The limit of detection was calculated as 4.53 × 10-11 mol/L. Furthermore, when utilizing 3j as the indicator in serum samples, the biosensor achieved satisfactory recovery rates for detecting the BRCA1 gene.

Smoking, green tea consumption, genetic polymorphisms in the insulin-like growth factors and lung cancer risk.

Insulin-like growth factors (IGFs) are mediators of growth hormones; they have an influence on cell proliferation and differentiation. In addition, IGF-binding protein (IGFBP)-3 could suppress the mitogenic action of IGFs. Interestingly, tea polyphenols could substantially reduce IGF1 and increase IGFBP3. In this study, we evaluated the effects of smoking, green tea consumption, as well as IGF1, IGF2, and IGFBP3 polymorphisms, on lung cancer risk. Questionnaires were administered to obtain the subjects' characteristics, including smoking habits and green tea consumption from 170 primary lung cancer cases and 340 healthy controls. Genotypes for IGF1, IGF2, and IGFBP3 were identified by polymerase chain reaction. Lung cancer cases had a higher proportion of smoking, green tea consumption of less than one cup per day, exposure to cooking fumes, and family history of lung cancer than controls. After adjusting the confounding effect, an elevated risk was observed in smokers who never drank green tea, as compared to smokers who drank green tea more than one cup per day (odds ratio (OR) = 13.16, 95% confidence interval (CI) = 2.96-58.51). Interaction between smoking and green tea consumption on lung cancer risk was also observed. Among green tea drinkers who drank more than one cup per day, IGF1 (CA)(19)/(CA)(19) and (CA)(19)/X genotypes carriers had a significantly reduced risk of lung cancer (OR = 0.06, 95% CI = 0.01-0.44) compared with IGF1 X/X carriers. Smoking-induced pulmonary carcinogenesis could be modulated by green tea consumption and their growth factor environment.