Trends in Peptide and Protein Sciences
Volume:1 Issue: 2, Jan 2016

Hypoxia is due to imbalance in oxygen supply and oxygen demand compromising biological functions of cells. Since tumor hypoxia results in angiogenesis, apoptosis, metastasis, tumor aggressiveness and treatment failure, in vivo measurement is required. Nuclear imaging can provide information about tissue oxygen levels. 2-nitroimidazole containing compounds selectively accumulate in hypoxic cells. They have been radiolabeled with 18F, 123/124I, and 99mTc and used in clinical trial stages using PET and SPECT techniques. 62/64Cu-ATSM is a non-imidazole imaging agent, which is trapped in hypoxic cells. There is a great interest in the development of 99mTc-labeled 2-nitroimidazole compounds. Though novel compounds based on molecular mechanisms of hypoxia would be developed in future.

Conventional cancer management is directly associated with many problems, including accurate therapeutic delivery to tumours and serious side effects of chemotherapeutics. A specific and efficient anticancer delivery to the tumour site without damaging normal tissues is the ultimate goal of all cancer treatment strategies. Nanomedicine has immense potential for cancer therapy that focuses on improving treatment efficacy, while reducing toxicity to normal tissues as well. However, the biodistribution and targeting capability of nanoparticles lacking targeting ligands rely solely on their physicochemical properties and the pathophysiological parameters of the body. Targeting is a promising strategy for selective and efficient therapeutic delivery to tumour cells with reduced detrimental side effects. Taking advantage of the fact that molecular markers and receptors over-express on the tumour cell surface as compared to a normal cell, the active targeting approach would be beneficial for cancer therapy. The epidermal growth factor receptors (EGFR), abnormally overexpressed in many epithelial tumours, have received much attention for molecular targeting in cancer diagnostics and therapeutics. This review presents the role of EGFR targeting in cancer imaging and therapy, and some recent researches on treatment of EGFR overexpressing cancers by using targeted nanoparticulate platforms. It also discusses illustrative examples of various ligands, including antibodies, antibody fragments, nanobodies, and peptides.

Persian Gulf Stonefish (Pseudosynanceia melanostigma) is one of the poisonous fish which is naturally found in Indian Ocean and Persian Gulf. The venom, which is isolated from this species, is suspected to use as an anticancer agent. In this study, we showed the cytotoxic effect of stonefish crude venom on lymphocytes, which obtained from acute lymphoblastic leukemia (ALL) patients and normal donors. Our results demonstrated that crude venom of Persian Gulf Stonefish could affect cancerous lymphocytes by reactive oxygen species (ROS) generation and mitochondrial membrane damage without any significant effect on normal cells.

The use of the methylotrophic yeast, Pichia pastoris, as one of the most effective and versatile systems for the expression of heterologous proteins in biopharmaceutical manufacturing has become increasingly popular in recent years. The impurity caused by residual host cell DNA is one of the major concerns in production of recombinant therapeutics. The aim of the present study was to develop a semi-quantitative, multiplex PCR method to determine the level of impurity in biopharmaceuticals produced in Pichia pastoris as the host. Primers were designed based on the rDNA repeat region and optimized to achieve the limit of detection in a multiplex PCR following by analyzing with MYImageAnalysis (Thermo Fisher Scientific, USA) software to quantify the concentration of Pichia pastoris genomic DNA in pertinent controls and drug samples. The multiplex PCR were able to detect up to 1 femtogram (fg) of genomic DNA under optimized conditions. Moreover, achieved concentration of DNA in controls and samples through relevant standard curve indicates the feasibility of this method in the presence of inhibitory effects. In comparison with other methods such as real-time PCR and Threshold assay, the assay shows acceptable sensitivity, precision and linearity along with ease of use, low equipment costs and analyte flexibility. We thus propose this method to be considered as a useful tool to estimate host cell residual DNA in biopharmaceuticals produced in Pichia pastoris.

The secondary structure of recombinant proteins can change through complex formation with other proteins. Here, we have determined the spatial structure of two proteins, including core protein of hepatitis C virus and HbsAg of hepatitis B virus, without the effect of human HSP90 as well as with the effect of this recombinant chaperone. As a result, the increase in intensity from 297.5 to 346.64 was accompanied by different folding and being non-polar protein in complex with the chaperone. HbsAg protein, combined with HSP90, showed a reduction in the maximum peak wavelength from 385 to 369.07 nm. The property of protein of being non-polar and hydrophobic, as well as having an increase in intensity from 200 to 219, indicates the protein folding. The shift from 342 to 337 nm along with blue shift indicates hydrophobic properties and the removal of protein from the water environment.

Determination of the levels of endotoxins in injectable products has always been one of the concerns of regulatory authorities and manufacturers. Since a number of pharmaceuticals interfere with the LAL test to some degree, overcoming the inhibition or enhancement properties of a product is required as part of the validation of the LAL test for use in the final release testing of parenteral products. In this study, interference profile of Heparin injection in quantitative chromogenic LAL test was evaluated and the method of overcoming was investigated and validated. The results indicate that dilution as the most widely used technique for overcoming interference could not eliminate LAL interference in the aforementioned medicinal product. The inhibitory nature of heparin occurs due to its anticoagulant properties and can be overcome by using divalent cations such as magnesium. Three concentrations of magnesium chloride were evaluated for elimination of heparin’s inhibitory effect. All three concentrations studied (5, 10 and 25 mM) could effectively eliminate the inhibitory effects of heparin. Hence, one-way analysis of variance was used to determine statistically significant differences between these three concentrations. The results of ANOVA statistical method showed the optimal recovery of spiked endotoxin was at a concentration of 10 mM of magnesium chloride. In consequence, chromogenic LAL test using 10 mM of magnesium chloride as diluent could be a validated method of choice for heparin LAL assay.

Lectins are believed to act as modulations of cell substratum interactions and to be essential for the normal differentiation and growth of all multicellular humans and animals. Although several lectins have been reported from microfungi, many more genera remain unexplored and their physiological role is also uncertain. The aim of this laboratory work was to make a comparison between self-made lectins (Indigenous) and commercial ones, following High Resolution Cell Synchronization technique (HRCS). Cytogenetic studies were performed in 175 normal healthy blood donor individuals of both genders and statistical analysis was performed. Our results indicated that the preparation of fresh phytohemagglutinin at the time of cell division and cell culture procedure reveals a satisfactory score. The overall frequency of mitotic index in our study was higher when compared with commercial imported Lectins (p