Predictive Perspectives of Disease-Transformed Protein Biomarkers.

With advancement in instrumentation, computation and understanding of disease etiology, proteomics has been expanded to harness the knowledge of change in protein folding and misfolding, protein-protein interaction, protein modification, etc. during progression of disease which is a source of discovery for various biomarkers including predictive biomarkers. Various methodologies for disease prediction are reported using ‘omics’ technology; however, advancement in proteomics with discovery of protein biomarker allows for the estimation of disease risk from years to decades before any disease even manifests internally. Specific proteins as disease biomarkers that appear in the body fluid/diseased tissues are generally measured. Recently, new proteomics technologies are also being developed in order to facilitate both the highthroughput and high-sensitivity requirements of diseaserelated applications of proteomics and possibly providing the framework for prediction of diseases. Therefore, there is a growing interest in proteomics technologies to discover processes that are involved in various diseases, to discover new biomarkers that correlates with the prediction and early detection of diseases. Now there is change in research thinking where already known biomarkers alone or in combination of others are under investigation for advanced application like in prediction and early detection of chronic diseases. In this review, we have emphasized the prediction perspective of some of the protein biomarkers like CA-125, Lp-PLA2 and tau protein for diseases like cancers, cardiovascular diseases, and Alzheimer’s respectively.

In vitro toxicity of melamine against Tetrahymena pyriformis cells

This study assessed the toxicity of melamine against the unicellular eukaryotic system of Tetrahymena (T.) pyriformis exposed to 0, 0.05, 0.25, 0.5, 2.5, and 5 mg/mL of melamine. Cell growth curves of different cultures, the half maximum inhibition concentration (IC50) value of melamine, and morphological changes in cells were obtained via optical and transmission electron microscopic observation. The effects of eleven melamine concentrations, 0.25, 0.5, 1, 1.5, 2, 2.5, 3, 3.5, 4, 4.5 and 5 mg/mL, on protein expression levels of T. pyriformis were examined using matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF-MS). The results showed an obvious inhibitory effect of melamine on the growth of eukaryotic cells. Cell growth dynamics indicated that the IC50 value of melamine on T. pyriformis was 0.82 mg/mL. The cellular morphology was also affected in a concentration-dependent manner, with characteristics of atrophy or cell damage developing in the presence of melamine. The relative contents of the top four main proteins corresponding to peak mass-to-charge ratios (m/z) of 4466, m/z 6455, m/z 6514, and m/z 7772 in the MALDI-TOF-MS spectra were all found to be closely correlated with the melamine concentrations. In conclusion, exposure of eukaryotic cells to melamine could inhibit cell growth, cause changes in cytomorphology and even disturb the expression of proteins in a concentration-dependent manner. The described method of examining four sensitive proteins affected by melamine was also proposed to be used in a preliminary study to identify protein biomarkers in T. pyriformis.

Variabilities of serum proteomic spectra in patients with nasopharyngeal carcinoma before and after radiotherapy / 中华放射医学与防护杂志

Objective To study the changes of serum proteomic spectra in patients with nasopharyngeal carcinoma(NPC) before and after treatment in order to detect the protein biomarkers.Methods Proteomic spectra from serum of 50 NPC patients before radiotherapy,25 NPC patients who achieved complete remission(CR) after radiotherapy, and 40 persons from normal control subjects were analyzed by CM-10 protein chip and surface-enhanced laser desorption ionization time of flight mass spectrometry. Results Expressed proteins in serum were screened by analysis of the proteomic spectra of pre-radiotherapy patients and normal individuals. 4 kinds of proteins with the relative molecular masses of 2931,4098,5343,13 766 made up markers pattern which was able to classify the patients and normal individuals. The sensitivity and specificity results were 90.0% and 90. 0% , respectively. The twenty differential expression protein peaks of patients before and after radiotherapy were obviously different. The relative molecular masses of 2931 , 4182, 4688 and 13 766 were up-regulated in untreated NPC, while were close to the normal levels in CR group. Two other protein peaks of 4098 and 5343 were down-regulated in untreated NPC group, which were close to normal levels in CR group. Conclusions The expressions of protein levels are different before and after radiotherapy in NPC patients. Protein signatures of NPC may be screened using SELDI-TOF-MS. Those signatures may be helpful in assessing the minimal residual disease and predicting the treatment efficacy.