Selenium-Containing Protein From Selenium-Enriched Spirulina platensis Attenuates Cisplatin-Induced Apoptosis in MC3T3-E1 Mouse Preosteoblast by Inhibiting Mitochondrial Dysfunction and ROS-Mediated Oxidative Damage

Accumulated evidences have verified that cancer chemotherapy may increase the risk of osteoporosis and severely affected the life quality. Osteoclasts hyperactivation was commonly accepted as the major pathogenesis of osteoporosis. However, the role of osteoblasts dysfunction in osteoporosis was little investigated. Our previous study has confirmed that selenium-containing protein from selenium-enriched Spirulina platensis (Se-SP) exhibited enhanced hepatoprotective potential through inhibiting oxidative damage. Herein, the protective effect of Se-SP against cisplatin-induced osteoblasts dysfunction in MC3T3-E1 mouse preosteoblast was investigated, and the underlying mechanism was evaluated. The results indicated that cisplatin dramatically decreased cell viability of preosteoblast by triggering mitochondria-mediated apoptosis pathway. Cisplatin treatment also caused mitochondrial dysfunction and reactive oxide species (ROS)-mediated oxidative damage. However, Se-SP pre-treatment effectively prevented MC3T3-E1 cells from cisplatin-induced mitochondrial dysfunction by balancing Bcl-2 family expression and regulating the opening of mitochondrial permeability transition pore (MPTP), attenuated cisplatin-induced oxidative damage through inhibiting the overproduction of ROS and superoxide anion, and eventually reversed cisplating-induced early and late apoptosis by inhibiting PARP cleavage and caspases activation. Our findings validated that Se-SP as a promising Se species could be a highly effective way in the chemoprevention and chemotherapy of oxidative damage-mediated bone diseases.

The interplay between DNA repair and autophagy in cancer therapy

DNA is the prime target of anticancer treatments. DNA damage triggers a series of signaling cascades promoting cellular survival, including DNA repair, cell cycle arrest, and autophagy. The elevated basal and/or stressful levels of both DNA repair and autophagy observed in tumor cells, in contrast to normal cells, have been identified as the most important drug-responsive programs that impact the outcome of anticancer therapy. The exact relationship between DNA repair and autophagy in cancer cells remains unclear. On one hand, autophagy has been shown to regulate some of the DNA repair proteins after DNA damage by maintaining the balance between their synthesis, stabilization, and degradation. One the other hand, some evidence has demonstrated that some DNA repair molecular have a crucial role in the initiation of autophagy. In this review, we mainly discuss the interplay between DNA repair and autophagy in anticancer therapy and expect to enlighten some effective strategies for cancer treatment.

Combining a loop-stem aptamer sequence with methylene blue: a simple assay for thrombin detection by resonance light scattering technique

Schematic illustration of the RLS aptasensor for selective detection of human thrombin.

High-sensitivity determination of curcumin in human urine using gemini zwitterionic surfactant as a probe by resonance light scattering technique

INTRODUCTION

Curcumin is a popular plant medicine that is extracted from turmeric dry rhizomes of Curcuma longa Linn. The study of curcumin is well established and is currently becoming a centre of attention.

OBJECTIVE

To develop a steady and simple assay for curcumin determination at the nanogram level based on the intense resonance light scattering (RLS) enhancement due to the interaction between curcumin and phosphodiesters quaternary ammonium salt (PQAS).

METHODOLOGY

PQAS, a new kind of Gemini zwitterionic surfactant, was used as the probe for the determination of curcumin by the RLS technique. A series of validation experiments was also performed.

RESULTS

A linear relationship was constructed between the ΔI(RLS) and the concentration of curcumin. The linear regression equation was presented as ΔI(RLS)  = 8.37 + 44.92c (µg/mL) with the regression coefficient r = 0.9987 (n = 12) and the linear range was 0.08-60.0 µg/mL. The detection limit (3σ) was 2.6 ng/mL.

CONCLUSION

The proposed method can be used to detect the content of curcumin in human urine samples and this new assay using PQAS as a probe was more sensitive and displayed a wider linear range than that reported previously.

An aptamer based resonance light scattering assay of prostate specific antigen

Prostate specific antigen (PSA) is a valuable tumor marker for prostate cancer screening. In this work, a novel and sensitive resonance light scattering (RLS) spectral assay of PSA was proposed based on PSA aptamer modified gold nanoparticles (AuNPs). The sulfhydryl modified single-strand aptamer could interact with AuNPs, which made the AuNPs stable in high concentration of salt. In pH 7.0 BR buffer solution, the highly selective combination of PSA and AuNPs-labeling aptamer resulted in the aggregation of AuNPs which showed high RLS intensity. Under the optimal conditions, the magnitude of enhanced RLS intensity (ΔI(RLS)) was proportional to the concentration of PSA in the range from 0.13 to 110 ng/mL, with a detection limit (LOD, 3σ) of 0.032 ng/mL. This developed RLS assay as well as a commercially available enzyme-linked immunosorbent assay (ELISA) kit was successfully applied to the detection of PSA in 15 serum samples, and an excellent correlation of the levels of PSA measured was obtained. This is the first report of the aptamer based RLS assay for PSA and it is also a significant application of instrumental analysis technique.