Phosphoproteome is the whole complement of phosphorylated proteins in a cell, tissue or organism, and has become an interesting study subject since the discovery of phosphorylation as a key regulatory mechanism of cell life. Phosphoproteomics is a method which studies the compact of the phosphorylated proteins, expression and modification, interaction and association, rule of the regulatory and so on. Recently, phosphoproteomics is widely used in cancer research. It will provide important information in cancer research, cancer diagnosis, and therapy.
ErbB Receptors ; genetics ; Humans ; Neoplasms ; genetics ; metabolism ; Phosphoproteins ; genetics ; metabolism ; Phosphorylation ; Proteomics ; methods ; Signal Transduction

OBJECTIVETo examine the expression patterns of short palate, lung and nasal epithelium clone 1 (SPLUNC1) gene in human tissues.

METHODSIn situ hybridization was used to detect the expression of SPLUNC1 gene in 37 different human tissues.

RESULTSWe found that SPLUNC1 gene was not expressed in squamous epithelial cells of the palate, epidermis, esophagus, or the esophagus-cardia junction, metaplastic squamous cells in the nasopharynx, trachea, or uterus cervix, or tumor cells of esophageal squamous cell carcinoma or lung squamous cell carcinoma. SPLUNC1 gene was not expressed in the single layer columnar epithelia cells in the stomach, gallbladder, jejunum, colon, endometrium, or uterus cervix. SPLUNC1 expression was detected mainly in pseudostratified columnar epithelial cells in the nasopharynx, trachea and bronchi, and was gradually down-regulated from the upper to lower end of the respiratory tract, but was not detected in the lung tissues. SPLUNC1 expression was detected not only in the duct and serous gland cells in the parotid and submandibular glands, but also in cells of submucosal serous glands in the nasopharynx and lung, but not in the cells of the mucosal glands. The parietal cells of the gastric submucosa and epithelial cells of the lobula and ducts of the mammary glands expressed SPLUNC1. The adenocarcinoma cells in the lung, stomach, colon, mammary gland, uterus endometrium and cervix showed strong expressions of SPLUNC1 gene.

CONCLUSIONSPLUNC1 expression is highly cell-specific in association with the cell functions.

Epithelial Cells ; metabolism ; Gene Expression ; Glycoproteins ; genetics ; metabolism ; Humans ; Organ Specificity ; Phosphoproteins ; genetics ; metabolism

Carcinoma, Hepatocellular ; metabolism ; pathology ; DNA-Binding Proteins ; genetics ; metabolism ; Humans ; Liver Neoplasms ; metabolism ; pathology ; Phosphoproteins ; genetics ; metabolism ; RNA, Messenger ; genetics

Animals ; Carrier Proteins ; genetics ; metabolism ; Cell Line, Tumor ; Insulinoma ; genetics ; metabolism ; pathology ; Mice ; Neoplasm Proteins ; genetics ; metabolism ; Pancreatic Neoplasms ; genetics ; metabolism ; pathology ; Phosphoproteins ; genetics ; metabolism

BACKGROUNDOral squamous cell carcinoma (OSCC) is one of the most common malignancies in the oral and maxillofacial region. Yes-associated protein 1 (YAP1) has been implicated as a bona fide oncogene in solid tumors. We seek to elucidate the role of YAP1 in OSCC tissue.

METHODSWe identified YAP1 gene and protein overexpression in 30 OSCC patients and 10 normal oral mucosa tissues by immunohistochemistry, Western blotting and reverse transcription polymerase chain reaction (RT-PCR).

RESULTSIn the normal oral mucosa by immunohistochemical staining, YAP1 mainly located in both the cytoplasm and nucleus mainly the nuclei of the basal cells. In OSCC, the expression of YAP1 translocated from the nucleus to cytoplasm; YAP1 being mainly located in both the cytoplasm and nucleus of the adjacent mucosa. The expression of YAP1 gradual increased in normal oral mucosa, tumor adjacent mucosa and low grade, middle grade, high grade OSCC tissue by Western blotting. Significant difference was found between the expressions of the normal oral mucosa and OSCC tissue (P < 0.05). The coincidence was detected between the normal oral mucosa and OSCC tissue by RT-PCR (P < 0.05).

CONCLUSIONSYAP1 is involved in the carcinogenesis and development of OSCC. There is a transformation between nucleus and cytoplasm.

Adaptor Proteins, Signal Transducing ; genetics ; metabolism ; Blotting, Western ; Carcinoma, Squamous Cell ; genetics ; metabolism ; Humans ; In Vitro Techniques ; Mouth Neoplasms ; genetics ; metabolism ; Phosphoproteins ; genetics ; metabolism ; Reverse Transcriptase Polymerase Chain Reaction

Leupaxin (LPXN) is a new member of the Paxillin superfamily, mainly located in focal adhesion plaques, involved in the transduction of multiple signaling pathways, and regulating the proliferation, adhesion and migration of tumor cells. In prostate cancer cells, LPXN is not only involved in the integrin signaling transduction pathway, regulating the proliferation, adhesion and migration of prostate cancer cells, but is also a new androgen receptor (AR) coactivator, regulating the transcription of nuclear AR effect genes, participating in AR signal transduction, and regulating the differentiation and invasion of prostate cancer cells. This review focuses on the molecular structure, special roles and molecular mechanisms of LPXN involved in prostatic carcinoma metastasis.
Cell Adhesion Molecules ; genetics ; metabolism ; Humans ; Male ; Neoplasm Metastasis ; Phosphoproteins ; genetics ; metabolism ; Prostatic Neoplasms ; genetics ; metabolism ; pathology ; Receptors, Androgen ; metabolism ; Signal Transduction

PRAS40, a proline-rich Akt substrate of 40 kD, is 14-3-3 binding protein. To study the interaction between PRAS40 and 14-3-3 isoforms, We constructed the expression vector pEG-PRAS40 (DNA-binding plasmid) and pJG-PRAS40 (transcriptional activity plasmid) in yeast using gateway cloning technology, then the plasmid of pEG-PRAS40/pJG-PRAS40 was co-transformed into yeast EGY48 strain with each pJG-14-3-3 /pEG-14-3-3 isoform plasmid. The co-transformation were tested by nutrition limitation growth analysis, beta-galactosidase color assay was used to study the interaction degree between PRAS40 and 14-3-3 isoforms. We confirmed successfully the construction of pJG-PRAS40 and pEG-PRAS40 with enzyme digestion. four 14-3-3 isoforms were found interacting with PRAS40 using yeast two-hybrid assay, the interaction degree of Epsilon was stronger than beta and zeta, tau was the weakest. Our result will be used to further study the biological function of PRAS40 and 14-3-3 as new drug target.
14-3-3 Proteins ; genetics ; metabolism ; Adaptor Proteins, Signal Transducing ; Humans ; Phosphoproteins ; genetics ; metabolism ; Protein Binding ; Protein Isoforms ; genetics ; metabolism ; Two-Hybrid System Techniques

Binding of clathrin assembly protein to clathrin triskelia induces their assembly into clathrin-coated vesicle (CCV) in neurons. The clathrin assembly protein gene (rCALM) was cloned from rat brain cDNA library. rCALM deduced 69 kD molecule has overall 73% amino acid homology compared with that of AP180 protein. The N-terminal domain, where amino acid sequences are very similar with AP180, harbours binding sites for clathrin and inositides, as well as possible phosphorylation sites, but the proline rich C-terminal domain is different from that of AP180. The mRNA expression of rCALM and AP180 by in situ hybridization histochemistry revealed that the rCALM mRNA was more intensely expressed than that of AP180, and the distribution patterns were different from each other. These results suggest that the rCALM mediates the assembly of clathrin in neural and supporting cells of brain, and regulates the clathrin coated-vesicle formation through phosphorylation and inositide metabolism. Copyright 2000 Academic Press.
Age Factors ; Alternative Splicing ; Amino Acid Sequence ; Animal ; Base Sequence ; Brain/physiology* ; Cloning, Molecular ; Gene Expression Regulation, Developmental ; Molecular Sequence Data ; Nerve Tissue Proteins/metabolism ; Nerve Tissue Proteins/genetics* ; Phosphoproteins/metabolism ; Phosphoproteins/genetics* ; Rats ; Sequence Homology, Amino Acid

OBJECTIVETo explore ZO-1 gene expression and methylation in leukemia cells and the involvement of ZO-1 gene in leukemogenesis.

METHODSRestriction landmark genomic scanning (RLGS) was used to identify new leukemia related gene, and methylation specific PCR (MSP) for ZO-1 methylation status. ZO-1 specific siRNA was designed and prepared by in vitro transcription and transfected into K562 cells, the transfected cells were cultured for 48 hours before harvesting. The effect of ZO-1 siRNA was monitored by Northern blot. Cellular proliferation capacity was assayed by CCK-8, cell apoptosis by Annexin V-fluorescence in isothiocyanate (FITC) assay, and cell cycle by phosphatidylinositol (PI).

RESULTSThe intensified spots in RLGS gel were subjected to bioinformatics analysis and one of the candidate spots was proved to be ZO-1 gene. In fresh leukemia cells, Molt4 cells and HL-60 cells, ZO-1 was hypermethylated, causing it reduced or silenced. ZO-1 gene was highly expressed with no methylation in normal peripheral blood MNC and K562 cells. There was a good correlation between promoter methylation and the gene silence. The silenced gene can be re-activated by demethylation treatment with 5-AZA-dC in most leukemia cell lines. RNA interference for ZO-1 gene in K562 cells did not interfere with cell proliferation, cell cycle and apoptosis.

CONCLUSIONZO-1 gene methylation might be involved in the tumorigenesis of acute leukemia.

Animals ; DNA Methylation ; HL-60 Cells ; Humans ; K562 Cells ; Leukemia ; genetics ; pathology ; Membrane Proteins ; genetics ; metabolism ; Mice ; Phosphoproteins ; genetics ; metabolism ; Zonula Occludens-1 Protein

OBJECTIVE: To investigate the effects of Yes-associated protein 1 (YAP1) knockdown on the proliferation, migration and invasion in human nasopharyngeal carcinoma (NPC) cells. METHODS: We detected the expression of YAP1 mRNA and protein in different NPC cell lines and an immortalized nasopharyngeal epithelial cell line using RT-PCR and Western blotting. Two YAP1-targeting small interfering RNAs (siRNA) were transfected into NPC cell lines S26 and S18, and the knockdown efficiency was confirmed by RT-PCR and Western blotting. The effect of YAP1 knockdown on the proliferation of the NPC cells was determined by cell counting and colony formation assay; wound healing assay and Transwell assay were used to analyze the changes in the cell migration and invasion abilities in each group. Western blotting was used to analyze the changes in the expressions of c-myc, E-cadherin, N-cadherin and vimentin in the NPC cells after YAP1 knockdown. RESULTS: YAP1 was highly expressed in the NPC cell lines. Compared with the negative control group, the NPC cell lines with YAP1 knockdown showed significantly lowered YAP1 expressions at both the mRNA and protein levels ( < 0.05). YAP1 knockdown significantly suppressed the growth, cloning formation, migration and invasion of the NPC cells as compared with control cells ( < 0.01). YAP1 knockdown obviously decreased the expression levels of c-myc, N-cadherin and vimentin and increased E-cadherin expression in the NPC cells. CONCLUSIONS YAP1 knockdown siRNA suppresses the proliferation, migration and invasion of NPC cells , suggesting that YAP1 may serve as a therapeutic target for NPC.
Adaptor Proteins, Signal Transducing ; genetics ; metabolism ; Cell Line, Tumor ; Cell Movement ; Cell Proliferation ; Gene Expression Regulation, Neoplastic ; Humans ; Nasopharyngeal Carcinoma ; genetics ; Neoplasm Invasiveness ; Phosphoproteins ; genetics ; metabolism