Oxidative stress: therapeutic approaches for cervical cancer treatment

OBJECTIVES: Oxidative stress results from an imbalance between the generation and elimination of oxidant species. This condition may result in DNA, RNA and protein damage, leading to the accumulation of genetic alterations that can favor malignant transformation. Persistent infection with high-risk human papillomavirus types is associated with inflammatory responses and reactive oxygen species production. In this context, oxidative stress, chronic inflammation and high-risk human papillomavirus can act in a synergistic manner. To counteract the harmful effects of oxidant species, protective molecules, known as antioxidant defenses, are produced by cells to maintain redox homeostasis. In recent years, the use of natural antioxidants as therapeutic strategies for cancer treatment has attracted the attention of the scientific community. This review discusses specific molecules and mechanisms that can act against or together with oxidative stress, presenting alternatives for cervical cancer prevention and treatment.

Redox Regulation of Cardiac Na and Ca Handling Protein / 天津医药

Cardiac contractile dysfunction and arrhythmic genesis are resulted from disturbed intracellular Na+and Ca2+ handling under condition of oxidation stress. Stress-induced intracellular signaling regulated mechanisms in which many activated stress kinases, such as cAMP-dependent protein kinase A, protein kinase C , Ca/calmodulin-dependent pro-tein kinaseⅡand classical pathways, are known to be involved. However, it is becoming increasingly evident that reactive oxygen species may directly oxidize these kinases, Na+and Ca2+channel protein and transporters, which lead to changing of intracellular Na+and Ca2+accumulation, and to trigger of arrhythmias.

Refolding of recombinant human granulocyte colony stimulating factor: Effect of cysteine/cystine redox system.

Granulocyte colony-stimulating factor (G-CSF) is a multi-functional cytokine which is widely used for treating neutropenia in humans. Evaluation of alternative to expensive components of redox buffer (reduced and oxidized glutathione) is an important step in reducing the cost of production of human biotherapeutic proteins. In the present study, refolding of recombinant human G-CSF expressed as inclusion bodies (IBs) in E. coli was optimized using cysteine and cystine redox agents. The refolding to correct native form of G-CSF was assessed by reverse phase high performance liquid chromatography (RP-HPLC). The optimized concentrations of cysteine and cystine for correct refolding of G-CSF were found to be 2 mM and 1 mM, respectively. The correctly refolded G-CSF was detected as early as 4 h of incubation in renaturation buffer containing optimized concentrations of cysteine (2 mM) and cystine (1 mM) redox agents. Refolding of G-CSF in optimized redox system increased with increase in shuffling time. Overall, the results suggested the use of cysteine/cystine redox pair could be an alternative to the costlier redox pairs for successful refolding of G-CSF and possibly other human biotherapeutic proteins of importance.

Structural model of the Plasmodium falciparum Thioredoxin reductase: a novel target for antimalarial drugs.

Background: Malaria, a scourge of mankind, imposes a huge socioeconomic burden in tropical countries. Emergence of multi-drug resistant malarial parasites impels us to explore novel drug targets. Thioredoxin reductase is a promising antimalarial drug target. Methods: The Thioredoxin reductase enzyme of Plasmodium falciparum was characterized in silico and protein disorder was predicted using available online tools. Since the crystal structure of Thioredoxin reductase of P. falciparum is not yet available, its three-dimensional structure was constructed by homology modeling using the high-resolution Thioredoxin reductase type 2 of mouse as a template. Obtained model was further refined by Molecular Dynamics (MD). Results: The model was stable during the simulation with the equilibrium root mean square deviation (RMSD) value of 1.2 Å. Stereochemical evaluation revealed that 99.1% residues of the constructed model lie in the most favoured and allowed regions, thus, indicating a good quality model. Conclusion: Results of this study will provide an insight into the structure of the Thioredoxin reductase of malarial parasite and aid in rational drug designing.