pp32在前列腺癌细胞中的作用研究

目的研究pp32在前列腺癌细胞中的作用。方法将本实验室先前保存的pcDNA3．1和pcDNA3．1一pp32质粒,转染至Pc3M细胞,构建Pc3M—pp32稳定细胞株。吉姆萨染色实验观察Pc3M细胞的形态变化,通过Transwell小室法检测细胞迁移能力。黏附测定实验鉴定细胞的黏附能力,采用MTr法测定细胞生长曲线。最后,Western印迹检测N一钙黏蛋白（N—cadherin）在细胞中的表达。结果成功筛选并获得了稳定过表达pp32的细胞株（Pc3M．pp32）,pp32能引起Pc3M细胞形状的显著改变,引起人前列腺癌细胞Pc3M迁移和黏附能力的增加,明显促进Pc3M细胞的生长,并有效抑制N一钙黏蛋白在Pc3M细胞中的表达。结论过表达pp32可引起Pc3M细胞的形状改变,并可促进Pc3M细胞的迁移、黏附以及生长。     

抗博尔纳病病毒磷蛋白单克隆抗体的制备及鉴定

目的以重组的博尔纳病病毒(BDV)磷蛋白(p24)为免疫原制备单克隆抗体,并鉴定其特异性。方法以纯化后的重组BDVp24免疫小鼠,将骨髓瘤细胞与其脾细胞进行融合,经ELISA法筛选出分泌抗p24单抗的细胞株,并对其进行克隆与亚克隆培养,将最终获得的其中2株细胞株分别注入小鼠腹腔制备单抗,经亲和纯化法纯化后,采用ELISA法测定效价,利用蛋白免疫印迹和免疫荧光鉴定其特异性。结果建立了2株稳定分泌抗p24单抗的杂交瘤细胞株,抗体亚类均为IgG1型。纯化后的腹水抗p24单抗纯度为98%和93%,ELISA效价在1∶81 000以上,该抗体均能识别重组p24蛋白和BDV感染人类少突胶质细胞(Oligodendroglia cell,OL细胞)所表达的p24蛋白。结论成功制备了灵敏性高、特异性好的抗BDVp24单抗,为博尔纳病病毒诊断方法的研制及感染机理的研讨提供依据。     

Effect of neural activity on skeletal muscle phosphoproteins

A number of phosphoproteins were found in the soluble fraction of rat skeletal muscle by two-dimensional polyacrylamide gel electrophoresis (PAGE). The pattern of some of these phosphoproteins differed in fast (extensor digitorum longus, EDL) or slow (soleus) muscles, was dependent on normal innervation, and was altered with denervation. In order to determine if the pattern was maintained by electrical activity or trophic factors, we compared the effect of electrical block by local neural application of tetrodotoxin with the effect of complete nerve section. Both methods produced similar alterations in phosphoproteins, indicating that the pattern is dependent on nerve activity, not trophic factors. Such phosphoproteins are possible mediators of neural activity on gene expression.     

Increased phosphate content of fibrinogen in vivo correlates with alteration in fibrinogen behaviour.

Fibrinogen was purified from five patients admitted for hip-replacement surgery the day before (day 0), the day after (day 2) and and one week after the operation (day 8). The behaviour of each patient's three fibrinogens was compared in thrombin gelation assays and plasmin degradation experiments to investigate whether the reported increase in protein-bound phosphate at day 2 and day 8 had any effecton the functional behaviour of fibrinogen as has been demonstrated in vitro. It was found that the thickness of the fibrin fibres produced by thrombin increased markedly at day 2 and declined thereafter. Susceptibility to plasmin appeared to decrease post-operatively by 50% and remained at that level on day 8 despite the phosphate content returning to normal. This has also been shown for fibrinogen phosphorylated in vitro. We conclude, after testing the fibrinogens with and without alkaline phosphatase pretreatment, that our data most resemble the published findings for in vitro phosphorylation of fibrinogen by casein kinase II.     

Alternations of 14-3-3 θ and β protein levels in brain during experimental sepsis

The 14-3-3 family members play a crucial role in the determination of cell fate, exerting their antiapoptotic activity through directly interfering with the critical function of the mitochondrial core proapoptotic machinery. Dimerization of 14-3-3 is vital for the interaction with many of its client proteins and is regulated by phosphorylation. In a previous study, we observed time-dependent neuronal apoptosis during sepsis. Therefore, in the present study, we sought to evaluate the expression of 14-3-3 θ and β isoforms in septic brain and their association with apoptosis. Sepsis was induced by a CLP model in Wistar rats that were sacrificed at predefined time points. Flow cytometric analysis showed a sepsis-induced, time-dependent alteration of 14-3-3 θ and β isoforms in both Neun(+) and GFAP(+) cells. 14-3-3 θ was linearly correlated with apoptosis, and stratified analysis for alive and apoptotic neuronal cells demonstrated a gradual down-regulation of θ isoform in alive neurons and astrocytes. The phospho-P38 (pP38) MAP kinase levels were altered in a time-dependent manner during sepsis, presenting a peak at 6 hr post-CLP. A significant correlation between the two isoforms of 14-3-3 was observed in septic rats, with the θ isoform predominant at all time points. The hippocampus, Purkinje cells, and glia-like cells showed intense immunohistochemical reactivity for 14-3-3 θ isoform, whereas the choroid plexus showed constantly increased β isoform expression. Our results showed that sepsis alters the expression of both 14-3-3 θ and β isoforms in a time-, cell-, and topography-dependent manner.     

Matrix Proteins and Mineralization: An Overview

There is a wealth of information on the mineral and matrix components in bones and teeth, in the exoskeletons of invertebrates, and in dystrophic calcific deposits. This information includes detailed characterization of their physical and chemical composition and details on the gene localization and regulation of gene expression for the major and minor protein constituents. The reason that mineral deposition occurs in some tissues and not in others remains unclear. In this review, studies in solution, cell culture studies, and investigations in mutant animals will be surveyed to indicate which matrix proteins may affect mineralization. Most of the molecules that appear to be involved in initiation and regulation of biological mineral formation are anionic; they have structural features that facilitate interaction with mineral, cells, and other matrix molecules, and they can have more than one function. Despite extensive data it is not yet clear which of these molecules is absolutely essential for physiologic calcification in each of the calcified tissues.     

Cerebrospinal Fluid Biomarkers for Major Depression Confirm Relevance of Associated Pathophysiology

Individual characteristics of pathophysiology and course of depressive episodes are at present not considered in diagnostics. There are no biological markers available that can assist in categorizing subtypes of depression and detecting molecular variances related to disease-causing mechanisms between depressed patients. Identification of such differences is important to create patient subgroups, which will benefit from medications that specifically target the pathophysiology underlying their clinical condition. To detect characteristic biological markers for major depression, we analyzed the cerebrospinal fluid (CSF) proteome of depressed vs control persons, using two-dimensional polyacrylamide gel electrophoresis and time-of-flight (TOF) mass spectrometry peptide profiling. Proteins of interest were identified by matrix-assisted laser desorption ionization TOF mass spectrometry (MALDI-TOF-MS). Validation of protein markers was performed by immunoblotting. We found 11 proteins and 144 peptide features that differed significantly between CSF from depressed patients and controls. In addition, we detected differences in the phosphorylation pattern of several CSF proteins. A subset of the differentially expressed proteins implicated in brain metabolism or central nervous system disease was validated by immunoblotting. The identified proteins are involved in neuroprotection and neuronal development, sleep regulation, and amyloid plaque deposition in the aging brain. This is one of the first hypothesis-free studies that identify characteristic protein expression differences in CSF of depressed patients. Proteomic approaches represent a powerful tool for the identification of disease markers for subgroups of patients with major depression.     

Relationship between tyrosine phosphorylation and protein expression of insulin receptor and insulin resistance in gestational diabetes mellitus

Summary： The relationship between tyrosine phosphorylation （TP） and protein expression of insulin receptor （InsR） and insulin resistance （IR） in patients with gestational diabetes mellitus （GDM） was investigated. The InsR expression and TP in skeleton muscle tissue were determined by Western blotting and immunoprecipitation in women with GDM （GDM group, n=22）, normal pregnant women （normal pregnancy group, n=22） and normal non-pregnant women （normal non-pregnant group, n=13）. Fasting plasma glucose （FPG） and fasting insulin （FINS） were measured by oxidase assay and immunoradioassay. The results showed that the levels of FPG （5.61±0.78 mmol/L）, FINS （15.42±5.13 mU/L） and Ho- meostasis model assessment-IR （HOMA-IR） （1.21±0.52） in GDM group were significantly higher than those in normal pregnancy group （4.43±0.46 mmol/L, 10.56±3.07 mU/L and 0.80±0.31 respectively） （P〈0.01）. The levels of FINS and HOMA-IR in normal pregnancy group were significantly higher than those in normal non-pregnant group （7.56±2.31 mU/L and 0.47±0.26 respectively） （P〈0.01）. There was no significant difference in the InsR expression level among the three groups （P〉0.05）. TP of InsR with insulin stimulation was significantly decreased in GDM group （0.20±0.05） as compared with normal pregnancy group （0.26±0.06） （P〈0.01）. TP of InsR with insulin stimulation in normal pregnancy group was lower than that in normal non-pregnant group （0.31±0.06） （P〈0.01）. TP of InsR with insulin stimu- lation was negatively related with HOMA-IR in GDM group （r=-0.525, P〈0.01）. There was no correlation between the protein expression of InsR and HOMA-IR in GDM group （r=-0.236, P〉0.05）. It was suggested that there is no significant correlation between the protein expression of InsR in skeletal muscle and IR in GDM, but changes in TP of InsR are associated with IR in GDM.     

Surgical procedures and postsurgical tissue processing significantly affect expression of genes and EGFR-pathway proteins in colorectal cancer tissue

An understanding of tissue data variability in relation to processing techniques during and postsurgery would be desirable when testing surgical specimens for clinical diagnostics, drug development, or identification of predictive biomarkers.Specimens of normal and colorectal cancer (CRC) tissues removed during colon and liver resection surgery were obtained at the beginning of surgery and postsurgically, tissue was fixed at 10, 20, and 45 minutes. Specimens were analyzed from 50 patients with primary CRC and 43 with intrahepatic metastasis of CRC using a whole genome gene expression array. Additionally, we focused on the epidermal growth factor receptor pathway and quantified proteins and their phosphorylation status in relation to tissue processing timepoints.Gene and protein expression data obtained from colorectal and liver specimens were influenced by tissue handling during surgery and by postsurgical processing time. To obtain reliable expression data, tissue processing for research and diagnostic purposes needs to be highly standardized.     

Expression of pEGFR and pAKT as response-predictive biomarkers for RAS wild-type patients to anti-EGFR monoclonal antibodies in metastatic colorectal cancers

Background:

RAS wild-type (RAS_w/t) tumours have been associated with better outcomes in patients with metastatic colorectal cancer (mCRC) treated with anti-EGFR monoclonal antibodies (mAb). We investigated the expression of EGFR downstream proteins under their active phosphorylated forms as potential markers in response to these patients.

Methods:

One-hundred tumour samples were collected from patients with mCRC refractory to FOLFOX and/or FOLFIRI and treated by a combination of chemotherapy with anti-EGFR mAb. The outcomes were measured on response evaluation criteria in solid tumour (RECIST), progression-free survival (PFS) and overall survival (OS). All samples were assessed for RAS and BRAF mutations, and the key phosphorylated proteins of EGFR downstream signalling were quantitatively analysed using the BioPlex Protein array.

Results:

Among the 60 RAS_w/t patients, 45.0% achieved a complete or partial response when treated with anti-EGFR mAb. Expression of pAKT, pERK1/2 and pMEK1 was significantly lower in RAS_w/t patients (P=0.0246; P=0.004; P=0.0110, respectively). The response rate was significantly higher for RAS_w/t patients who express pEGFR and pAKT (P=0.0258; P=0.0277, respectively).

Conclusions:

Overexpression of pEGFR and pAKT may predict the response rate in RAS_w/t patients treated with anti-EGFR mAb. On the basis of our results, we hypothesise that the association of anti-EGFR mAb and anti-AKT therapies could be of interest.