Heat shock protein 90 as a molecular target for therapy in oral squamous cell carcinoma: Inhibitory effects of 17­DMAG and ganetespib on tumor cells.

Heat shock protein 90 (HSP90) expression is upregulated in numerous types of cancer. However, its role as a candidate for molecular targeted therapy in oral squamous cell carcinoma (OSCC) cells is poorly understood. In the present study, a common upstream search was performed using molecular network analysis software for proteins with expression abnormalities that were found in a proteomic analysis of six OSCC cell lines. HSP90 was identified as a target protein. In clinical samples, high frequencies of HSP90­high expression were detected via immunohistochemistry (26/58; 45%). Furthermore, the HSP90 expression status was associated with cervical lymph node metastasis (P=0.015). Furthermore, the potential of HSP90 as a candidate for molecular targeted therapy in OSCC cells was investigated using the HSP90 inhibitors 17­dimethylaminoethylamino­17­demethoxygeldanamycin (17­DMAG) and ganetespib. KON cells, which strongly express HSP90, were treated with the HSP90 inhibitors. The numbers of living cells in the 17­DMAG and ganetespib­treated groups were lower than those in the non­treated group. The cells treated with the inhibitors demonstrated reduced cell viability and migration, and this was associated with markedly decreased levels of the HSP90 target proteins EGFR, phospho­EGFR, phospho­MEK and phospho­MAPK in the treated groups compared with the non­treated group. To the best of our knowledge, this was the first study to investigate the effects of 17­DMAG and ganetespib on OSCC cells. The present results indicated the potential of HSP90 as a useful candidate for molecular targeted therapy in OSCC. However, additional studies with larger sample sizes are required to confirm these findings.

Differential proteome analysis in adolescent idiopathic scoliosis patients with thoracolumbar/lumbar curvatures.

BACKGROUND: Although the pathogenesis of adolescent idiopathic scoliosis (AIS) remains unclear, there are little evidences of the pathogenesis in patients with thoracolumbar/lumbar AIS. The purpose of this study was to identify proteins or proteomes that may be causally related to the pathogenesis of AIS with structured thoracolumbar/lumbar curvature using two-dimensional fluorescence difference gel electrophoresis (2D-DIGE). METHODS: A total of 20 control volunteers and 61 AIS in patients with thoracolumbar/lumbar curvature were included. First, the plasma samples of each five AIS with pure thoracolumbar/lumbar curvature and control samples were subjected to 2D-DIGE analysis. Protein spots that were expressed differently by the AIS and control groups were selected and identified by nanoscale liquid chromatography-tandem mass spectrometry (nanoLC-MS/MS) analysis. To characterize the differently-expressed proteins in AIS patients, we performed functional pathway analysis using the Protein ANalysis THrough Evolutionary Relationships (PANTHER) system. Additionally, the proteins were compared between control and AIS using western blotting. Lastly, prospectively collected 15 control and 41 AIS with thoracolumbar/lumbar curvature samples were compared to the differentially expressed proteins. RESULTS: A total of 3862 ± 137 spots were detected, of which 11 spots met the criteria when compared with controls. Nine proteins were identified by nanoLC-MS/MS. Functional analysis showed the association of the proteins in AIS patients with blood coagulation using the PANTHER system. Of the proteins, vitamin D binding protein (DBP) significantly correlated with Cobb angle in thoracolumbar/lumbar curvatures. DBP expression of the prospectively collected AIS samples were significantly higher than those of controls (P < 0.05). CONCLUSIONS: This study suggests that DBP and several coagulation-related proteins may play a role in the pathogenesis of AIS. DBP appears to be a marker of severity of AIS with thoracolumbar/lumbar curvature.

Comparative Serum Proteomic Analysis of the Effects of Sodium Selenate on a Mouse Model of Alzheimer's Disease.

Selenium (Se), as a nutritionally essential trace element, has been shown to decrease with age and is closely related to Alzheimer's disease (AD). To probe the effects of Se on AD pathology, two-dimensional fluorescence difference gel electrophoresis was applied to the serum samples collected from the wild-type (WT) mice and the triple transgenic (PS1M146V/AßPPSwe/TauP301L) AD mice (3xTg-AD), treated with or without sodium selenate in drinking water for 4 months beginning at 2 months of age. Proteomics results revealed 17 differentially expressed proteins between WT and 3xTg-AD mice. It was found that the administration of selenate reversed the alterations of the differentially expressed serum proteins by up-regulating 13 proteins and down-regulating 2 proteins which were reported to be involved in the key pathogenesis of AD, including regulation of Aß production, lipid metabolism regulation, and anti-inflammation. These results suggested that a dietary supplement with selenate is effective for prevention and treatment of AD, and the mechanism was maybe related to its role in Aß regulation, lipid metabolism, and anti-inflammation. Moreover, we also presented that α-2 macroglobulin, transthyretin, haptoglobin, alpha-2-HS-glycoprotein, and alpha-1-antitrypsin in the serum can be used to evaluate the effect of selenate on AD pathology.

Melatonin ameliorates anxiety and depression-like behaviors and modulates proteomic changes in triple transgenic mice of Alzheimer's disease.

Alzheimer's disease (AD) is a devastating neurodegenerative disease accompanied by neuropsychiatric symptoms, such as anxiety and depression. The levels of melatonin decrease in brains of AD patients. The potential effect of melatonin on anxiety and depression behaviors in AD and the underlying mechanisms remain unclear. In this study, we treated 10-month-old triple transgenic mice of AD (3xTg-AD) with melatonin (10 mg/kg body weight/day) for 1 month and explored the effects of melatonin on anxiety and depression-like behaviors in 3xTg-AD mice and the protein expression of hippocampal tissues. The behavioral test showed that melatonin ameliorated anxiety and depression-like behaviors of 3xTg-AD mice as measured by open field test, elevated plus maze test, forced swimming test, and tail suspension test. By carrying out two-dimensional fluorescence difference gel electrophoresis (2D-DIGE) coupled with mass spectrometry, we revealed a total of 46 differentially expressed proteins in hippocampus between the wild-type (WT) mice and non-treated 3xTg-AD mice. A total of 21 differentially expressed proteins were revealed in hippocampus between melatonin-treated and non-treated 3xTg-AD mice. Among these differentially expressed proteins, glutathione S-transferase P 1 (GSTP1) (an anxiety-associated protein) and complexin-1 (CPLX1) (a depression-associated protein) were significantly down-regulated in hippocampus of 3xTg-AD mice compared with the WT mice. The expression of these two proteins was modulated by melatonin treatment. Our study suggested that melatonin could be used as a potential candidate drug to improve the neuropsychiatric behaviors in AD via modulating the expression of the proteins (i.e. GSTP1 and CPLX1) involved in anxiety and depression behaviors. © 2017 BioFactors, 43(4):593-611, 2017.

Identification of the key molecules involved in chronic copper exposure-aggravated memory impairment in transgenic mice of Alzheimer's disease using proteomic analysis.

Alzheimer's disease (AD) is the most common neurodegenerative disease characterized by a progressive impairment of cognitive functions including spatial learning and memory. Excess copper exposure accelerates the development of AD; however, the potential mechanisms by which copper exacerbates the symptoms of AD remain unknown. In this study, we explored the effects of chronic copper exposure on cognitive function by treating 6 month-old triple AD transgenic (3xTg-AD) mice with 250 ppm copper sulfate in drinking water for 6 months, and identified several potential key molecules involved in the effects of chronic copper exposure on memory by proteomic analysis. The behavioral test showed that chronic copper exposure aggravated memory impairment of 3xTg-AD mice. Two-dimensional fluorescence difference gel electrophoresis (2D-DIGE) coupled with mass spectrometry revealed a total of 44 differentially expressed proteins (18 upregulated and 26 down-regulated) in hippocampus between the wild-type (WT) mice and non-exposed 3xTg-AD mice. A total of 40 differentially expressed proteins were revealed (20 upregulated and 20 down-regulated) in hippocampus between copper exposed and non-exposed 3xTg-AD mice. Among these differentially expressed proteins, complexin-1 and complexin-2, two memory associated proteins, were significantly decreased in hippocampus of 3xTg-AD mice compared with the WT mice. Furthermore, the expression of these two proteins was further down-regulated in 3xTg-AD mice when exposed to copper. The abnormal expression of complexin-1 and complexin-2 identified by proteomic analysis was verified by western blot analysis. Taken together, our data showed that chronic copper exposure accelerated memory impairment and altered the expression of proteins in hippocampus in 3xTg-AD mice. The functional analysis on the differentially expressed proteins suggested that complexin-1 and complexin-2 may be the key molecules involved in chronic copper exposure-aggravated memory impairment in AD.

Examination of the leaf proteome during flooding stress and the induction of programmed cell death in maize.

BACKGROUND: Maize is a major economic crop worldwide, with substantial crop loss attributed to flooding. During a stress response, programmed cell death (PCD) can be an effective way for plants better adapt. To identify flooding stress related PCD proteins in maize leaves, proteomic analysis was performed using two-dimensional fluorescence difference gel electrophoresis (2D-DIGE) and mass spectrometry. RESULTS: Comparative proteomics was combined with physiological and biochemical analysis of maize leaves under flooding stress. Fv/Fm, qP, qN and relative water content (RWC) were found to be altered in response to flooding stress, with an increase in H2O2 content noted in vivo. Furthermore, DNA ladder detection indicated that PCD had occurred under flooding treatment. The maize leaf proteome was analyzed via 2D-DIGE gel, with a total of 32 differentially expressed spots isolated, 31 spots were successfully identified via MALDI-TOF/TOF MS which represent 28 proteins. The identified proteins were related to energy metabolism and photosynthesis, PCD, phytohormones and polyamines. To better characterize the role of translationally controlled tumor protein (TCTP) in PCD during a stress response, mRNA expression was examined in different plants by stress-induced PCD. These included heat stress induced rice protoplasts, Tobacco Mosaic Virus infected tobacco leaves and dark induced rice and Arabidopsis thaliana leaves, all of which showed active PCD, and TCTP expression was increased in different degrees. Moreover, S-adenosylmethionine synthase 2 (SAMS2) and S-adenosylmethionine decarboxylase (SAMDC) mRNA expression were also increased, but ACC synthase (ACS) and ACC oxidase (ACO) mRNA expression were not found in maize leaves following flooding. Lastly, ethylene and polyamine concentrations were increased in response to flooding treatment in maize leaves. CONCLUSIONS: Following flooding stress, the photosynthetic systems were damaged, resulting in a disruption in energy metabolism, with the noted photosynthetic decline also possibly attributed to ROS production. The observed PCD could be regulated by TCTP with a possible role for H2O2 in TCTP induction under flooding stress. Additionally, increased SAMS2 expression was closely associated with an increased polyamine synthesis during flooding treatment.

Proteomic analysis of serum proteins in triple transgenic Alzheimer's disease mice: implications for identifying biomarkers for use to screen potential candidate therapeutic drugs for early Alzheimer's disease.

Alzheimer's disease (AD) is the most common fatal neurodegenerative disease affecting the elderly worldwide. There is an urgent need to identify novel biomarkers of early AD. This study aims to search for potential early protein biomarkers in serum from a triple transgenic (PS1M146V/APPSwe/TauP301L) mouse model. Proteomic analysis via two-dimensional fluorescence difference gel electrophoresis was performed on serum samples from wild-type (WT) and triple transgenic mice that were treated with or without coenzyme Q10 (CoQ10) (800 mg/kg body weight/day), a powerful endogenous antioxidant displaying therapeutic benefits against AD pathology and cognitive impairment in multiple AD mouse models, for a period of three months beginning at two months of age. A total of 15 differentially expressed serum proteins were identified between the WT and AD transgenic mice. The administration of CoQ10 was found to alter the changes in the differentially expressed serum proteins by upregulating 10 proteins and down-regulating 10 proteins. Among the proteins modulated by CoQ10, clusterin and α-2-macroglobulin were validated via ELISA assay. These findings revealed significant changes in serum proteins in the AD mouse model at an early pathological stage and demonstrated that administration of CoQ10 could modulate these changes in serum proteins. Our study suggested that these differentially expressed serum proteins could serve as potential protein biomarkers of early AD and that screening for potential candidate AD therapeutic drugs and monitoring of therapeutic effects could be performed via measurement of the changes in these differentially expressed serum proteins.

Plasma Proteomic Analysis of Early Diabetic Nephropathy Patients with Kidney Yang Deficiency / 广州中医药大学学报

Objective To screen the sensitive plasma molecular markers in diabetic nephropathy ( DN) patients with kidney yang deficiency. Methods Two-dimensional fluorescence difference gel electrophoresis (2-D DIGE) was used to analyze the plasma which was sampled from 4 early DN patients with kidney yang deficiency and 4 healthy adult volunteers. Proteins that showed differential expression with an over 1.5-fold change were analyzed by MALDI-TOF/TOF mass spectrometry. Results Two-dimensional electrophoresis (2-DE) maps of plasma proteins in DN patients with kidney yang deficiency and healthy adults were established successfully. We validated 9 differentially expressed proteins, including complements C3 and C4, apolipoprotein E and ubiquitination factor. Conclusion Proteomic analysis by 2-D DIGE can objectively reveal the differences of plasma protein expression in DN patents with kidney yang deficiency and healthy adult volunteers. The obtained 9 proteins have potential to provide plasma molecular markers for the early clinical diagnosis and for the research of traditional Chinese medical patterns of DN.

Expression and significance of glutathione S-transferase mu 3 in prostate cancer / 中华泌尿外科杂志

Objective To explore the role and clinical significance of GSTM 3 ( glutathione S-trans-ferase mu 3) expression in prostate cancer (PCa). Methods We had used the two-dimensional fluores-cence difference gel electrophoresis ( 2D-DIGE) and mass spectral analysis to further verify the microarray data of mRNA expression profiling discovered .GSTM3 mRNA level was detected by Rael-time Quantitative PCR ( RT-QPCR) in 28 pairs of prostate cancer tissue and benign tissue .The relationship of GSTM 3 level with the serum PSA level and the clinical feature of PCa were analyzed . Results In 2D-DIGE study, we found that the expression of GSTM 3 protein in adjacent tissues was significantly higher than that in PCa tis-sues (P0.05) and prostate cancer clinical pathological parameters ( P>0.05). Conclusions GSTM3 expression is down-regulated in PCa tissues, and we may identify PCa by detecting the GSTM 3 expression .

Protein from the fraction remaining after RNA extraction is useful for proteomics but care must be exercised in its application.

Simultaneous isolation of mRNA and proteins from a single small biopsy specimen can be useful for integrated omics studies. Here, we have improved the method for extracting protein from the fraction remaining after RNA isolation by TRIzol reagent, for application in protein and proteome analyses. Protein yield was reduced by half, but the patterns developed on 2D gels were equivalent to conventional urea extractions. Thus, although quantitative profiles of individual proteins were different from conventionally-isolated samples, overall profiles were similar. Therefore, this particular protein source is useful for proteomics but care must be exercised in its application.

Stathmin is involved in the cooperative effect of Zoledronic acid and gefitinib on bone homing breast cancer cells in vitro.

Zoledronic acid (Zol) is the most potent inhibitor of bone resorption among the bisphosphonates and is commonly used for inhibiting bone metastasis. However, it remains unclear whether Zol provides a survival benefit. Recent findings indicate that epidermal growth factor (EGF) signaling is an important mediator of bone metastasis. Thus, we examined the combined effects of Zol and an EGF receptor-tyrosine kinase inhibitor, gefitinib, on the proliferation and invasion of a bone-seeking clone and the breast cancer cell line MDA-MB-231. Combined treatment with Zol and gefitinib synergistically inhibited both invasion and cell proliferation of the bone-seeking clone, but not those of the MDA-MB-231 cells. Two-dimensional difference gel electrophoresis and mass spectrometry demonstrated that stathmin was down-regulated during these cooperative effects. Stathmin is a signal transduction regulatory factor which plays an important role in cell division and malignant tumor development. Our data suggest that stathmin may be a promising target molecule for blocking bone metastasis of breast cancer.

Screening for methylation-silenced genes in acute myeloid leukemia HL-60 cell line by a quantitative proteomic approach / 中南大学学报(医学版)

Objective To screen for new methylation association genes in HL-60 to reveal the pathogenesis of leukemia, and provide important theoretical and scientific basis for the prevention and cure of leukemia. Methods Two-dimensional fluorescence difference gel electrophoresis (F-2D-DIGE) was performed to separate the total proteins from acute myelogenous leukemia (AML) cell line HL-60 cells with or without 5-aza-2-deoxycytidine (5-aza-2-dC) treatment. Imaging software Decyder 6.5 and PDQuest were used to detect the differential expression protein spots, and matrix-assisted laser desorption/ionizaion time-of-flight mas spectrometer (MALDI-TOF MS) was adopted to identify the differential expression proteins. Results F-2D-DIGE maps of 5-aza-2-dC-untreated HL-60 and-treated HL-60 cells were established. A total of 53 differential protein spots were detected, and 35 differential proteins were successfully identified. Of the identified proteins, 32 proteins were up-regulated, and 3 proteins were down-regulated in HL-60 cells after 5-aza-2-dC treatment.Conclusion Thirty-five differential proteins may be associated with methylation in HL-60 cell line, which provides the important clues for epigenetic study of leukemia.

Quantitative Proteomics Analysis of LCM Purified Stroma of Nasopharyngeal Carcinoma and Normal Nasopharyngeal Mucosa / 生物化学与生物物理进展

The mechanism of how stroma plays an important role in tumor carcinogenesis is now a hotspot. To delineate the features of stromal protein between nasopharyngeal carcinoma (NPC) and normal nasopharyngeal mucosa(NNM), laser capture microdissection (LCM) was performed to purify stromal cells from the NPC and NNM, respectively. The protein expressed profiles of the stroma of NPC and NNM were compared using fluorescent two-dimensional difference gel electrophoresis (2D-DIGE) and 34 differential protein spots between tumor stroma and normal stroma were chosen to be identified by mass spectrometry (MS). A total of 20 differential proteins were identified, and three differential proteins (CapG, L-plastin and S100A9) were selectively further validated by Western blotting and immunohistochemical analysis to confirm the results of 2D-DIGE. 2D-DIGE patterns of the stroma of NPC and NNM were established for the first time, the results suggested that differentially expressed proteins in the stroma of NPC and NNM may be useful for understanding the relationship between NPC cells and their surrounding microenvironment. Further studying of these proteins will be helpful to elucidate the mechanisms of NPC carcinogenesis and provide new thoughts on therapy of NPC through stroma.