OBJECTIVETo investigate the significance of DARPP-32 protein expression in gastric carcinoma tissue and cell lines.

METHODSThe expression of DARPP-32 protein in normal gastric mucosa and gastric carcinoma tissue was evaluated by immunohistochemical staining using streptavidin-biotin complex technique. The expression in gastric carcinoma tissue and cell lines was evaluated by Western blotting.

RESULTSThe expression rate of DARPP-32 protein in gastric adenocarcinoma tissue (92.7%) was significantly higher than that in normal gastric mucosa (52.6%, P < 0.05). There was no significant association between DARPP-32 protein expression and degree of tumor differentiation, local invasion and distant metastasis. As compared with adjacent non-carcinomatous gastric mucosa, both DARPP-32 and its truncated isoform t-DARPP were overexpressed in gastric adenocarcinoma tissue (t = 2.45, P = 0.015); and t-DARPP overexpression was more frequently seen. Expression of DARPP-32 and t-DARPP could also be detected in human gastric cancer cell lines. The expression of DARPP-32 protein was obviously reduced in SGC7901 drug-resistant cell strains.

CONCLUSIONSDARPP-32 is overexpressed in gastric carcinoma. It may play an important role in gastric carcinogenesis. The underlying signal pathways in neoplastic gastric epithelium may also be related to the multi-drug resistance property of gastric cancer cells.

Adenocarcinoma ; metabolism ; Aged ; Antibiotics, Antineoplastic ; pharmacology ; Antineoplastic Agents, Phytogenic ; pharmacology ; Cell Line, Tumor ; Dopamine and cAMP-Regulated Phosphoprotein 32 ; Doxorubicin ; pharmacology ; Drug Resistance, Multiple ; Drug Resistance, Neoplasm ; Female ; Gastric Mucosa ; metabolism ; Humans ; Male ; Middle Aged ; Nerve Tissue Proteins ; metabolism ; Phosphoproteins ; metabolism ; Stomach Neoplasms ; metabolism ; Vincristine ; pharmacology

Objective To investigate the expression level of serine/threonine phosphoprotein phosphatase 4C(PPP4C)in gastric cancer,and analyze its relationship with prognosis and the underlying regulatory mechanism.Methods The clinical data of 104 gastric cancer patients admitted to the First Affiliated Hospital of Bengbu Medical College between January 2012 and August 2016 were collected.Immunohistochemical staining was employed to determine the expression levels of PPP4C and Ki-67 in the gastric cancer tissue.The gastric cancer cell lines BGC823 and HGC27 were cultured and transfected with the vector for PPP4C knockdown,the vector for PPP4C overexpression,and the lentiviral vector(control),respectively.The effects of PPP4C on the cell cycle and proliferation were analyzed and the possible regulatory mechanisms were explored.Results PPP4C was highly expressed in gastric cancer(P<0.001),and its expression promoted malignant progression of the tumor(all P<0.01).Univariate and Cox multivariate analysis clarified that high expression of PPP4C was an independent risk factor affecting the 5-year survival rate of gastric cancer patients(P=0.003).Gene ontology and Kyoto encyclopedia of genes and genomes enrichment analysis suggested that PPP4C may be involved in the cell cycle.The correlation analysis showed that the expression of PPP4C was positively correlated with that of Ki-67 in gastric cancer(P<0.001).The up-regulation of PPP4C expression increased the proportion of tumor cells in the S phase,alleviated the G2/M phase arrest,and promoted the proliferation of gastric cancer cells and the expression of cyclin D1 and cyclin-dependent kinase 6(CDK6)(all P<0.05).The down-regulation of PPP4C decreased the proportion of gastric cancer cells in the S phase,promoted G2/M phase arrest,and inhibited cell proliferation and the expression of cyclin D1,CDK6,and p53(all P<0.05).p53 inhibitors promoted the proliferation of BGC823 and HGC27 cells in the PPP4C knockdown group(P<0.001,P<0.001),while p53 activators inhibited the proliferation of BGC823 and HGC27 cells in the PPP4C overexpression group(P<0.001,P=0.002).Conclusions PPP4C is highly expressed in gastric cancer and affects the prognosis of the patients.It may increase the proportion of gastric cancer cells in the S phase and alleviate the G2/M phase arrest by inhibiting p53 signaling,thereby promoting cell proliferation.
Humans ; Stomach Neoplasms/genetics* ; Cyclin D1/metabolism* ; Tumor Suppressor Protein p53 ; Phosphoproteins/metabolism* ; Ki-67 Antigen ; Cell Line, Tumor ; Prognosis ; Cell Proliferation ; Phosphoprotein Phosphatases/metabolism* ; Threonine ; Serine

In eukaryotes protein phosphorytion is a key event. By reversible protein phosphorylation eukaryotes control many cellular processes including signal transduction, gene expression, the cell cycle etc. Phosphoproteomics involves identification of phosphoproteins and phosphopeptides, localization of the exact residues that are phosphorylated and quantitation of phosphorylation. Because protein phosphorylation is a dynamic process, and it is present at low abundance within cells, and the phosphorylated sites on proteins might vary, and mass spectrometry (MS) signals from phosphopeptides are usually suppressed etc., so phosphoprotein analysis have more difficulties than nonphosphoprotein. In this article, we outline several analysis techniques for separation, identification and quantitation of phosphorylated proteins and peptides, and discuss the progress in these techniques. At present, MS is still an essential core identification technology for phosphoproteomic studies, To search better enrichment strategies are the main challenges in this rapidly evolving field. A major goal of quantitative proteomics is precise quantification and identification of proteins in complex mixtures. A common method for quantitative proteome analysis is the stable isotope labeling method. Today there is no single method that supersedes all others techniques for Phosphoproteomic studies. With continued development of sample preparation techniques and instrumentation, it should be possible to perform a global analysis of protein phosphorylation.
Animals ; Humans ; Mass Spectrometry ; Phosphoproteins ; analysis ; Phosphorylation ; Proteomics ; methods

OBJECTIVETo develop a method for ng quantitation of circulating DNA in serum and explore the value in the diagnosis of cancer.

METHODSSerum DNA was extracted by commercial "genomic DNA extraction kit" and detected by fluorescent dye (SYBR green I) staining. Loss of heterozygosity (LOH) at BRCA1 (D17S579, D17S855) and p53 (TP53, D17S786) in serum DNA was analyzed by PCR-based method.

RESULTSSYBR green I dot staining could detect DNA as low as 2 ng. Using this method, we detected serum samples from 483 patients with various types of cancer and 150 healthy individuals. The mean DNA concentration in the normal controls was 22.2 +/- 13.4 ng/ml, while that in cancer patients was 81.3 +/- 98.3 ng/ml (P < 0.001). In 33 ovarian cancer patients with increased DNA level, 27(81.8%) displayed LOH in at least one of the four loci analyzed.

CONCLUSIONCirculating DNA in serum may become additional tumor marker for the diagnosis of cancer.

BRCA1 Protein ; genetics ; Biomarkers, Tumor ; blood ; DNA, Neoplasm ; blood ; genetics ; Female ; Genes, BRCA1 ; Genes, p53 ; Humans ; Loss of Heterozygosity ; Male ; Microsatellite Repeats ; Neoplasms ; blood ; genetics ; Tumor Suppressor Protein p53 ; genetics

OBJECTIVETo investigate the role of the tumor suppressor gene BRCA1 in response to DNA damage and to confirm that the function of the BRCA1 protein is regulated by a variety of mechanisms including transcriptional control, phosphorylation and protein-protein interaction.

METHODSWith the human breast cell line MCF7 as the positive control, we determined the subcellular distribution of BRCA1 in the prostate cancer cell lines LNCaP, DU145 and PC3 by immunohistochemical staining and Western blotting analyses.

RESULTSBRCA1 was present in the prostate cancer cell lines LNCaP, DU145 and PC3. Ionizing radiation induced BRCA1 nuclear export, increasing from 14% to 40% in the cytoplasma (P < 0.01) and decreasing from 46% to 21% in the nuclei (P < 0.01). This DNA damage-induced BRCA1 nuclear export occurred only in the p53 wild-type but not in the p53 mutant cell line. The apoptosis rate of LNCaP cells was as high as 40% after nuclear export, with an obvious increase of cleaved caspase-3, which was correlated with BRCA1 nuclear-cytoplasmic shuttling.

CONCLUSIONCytoplasmic relocalization of the BRCA1 protein may be a mechanism whereby the BRCA1 function is regulated in response to DNA damage. Its induction of a higher rate of cell apoptosis indicates BRCA1 to be another good biomarker for the treatment of prostate cancer.

BRCA1 Protein ; metabolism ; Blotting, Western ; Cell Line, Tumor ; DNA Damage ; Humans ; Immunohistochemistry ; Male ; Prostatic Neoplasms ; genetics ; metabolism ; pathology ; Tumor Suppressor Protein p53 ; metabolism

We have shown that hyaluronic acid stimulates the proliferation of quiescent NIH 3T3 cells. We have shown that treatment of 1 mg/ml hyaluronic acid results in increase of tyrosine phosphorylation of two proteins, MW 124 kDa and 60 kDa as detected by anti-tyrosine antibodies by Western blot analysis. Maximum phosphorylation occurred within 2 h after addition of 1 mg/ml hyaluronic acid. Stimulation of proliferation was also accompanied by increase in c-Myc protein, which was inhibited by amlloride, an inhibitor of Na+/H+ antiporter and EGTA and increase in the steady state level of pRb, the RB gene product. These results suggest that the intracellular signal transduction pathways that mediate the stimulatory effects of hyaluronic acid on cellular proliferation are similar to those of growth factors.
3T3 Cells ; Amiloride/pharmacology ; Animal ; Cell Division ; Dose-Response Relationship, Drug ; Egtazic Acid/pharmacology ; Hyaluronic Acid/pharmacology* ; Mice ; Mitogens/pharmacology* ; Phosphoproteins/metabolism* ; Phosphorylation ; Proto-Oncogene Proteins c-myc/metabolism* ; Retinoblastoma Protein/metabolism* ; Signal Transduction ; Sodium-Hydrogen Antiporter/antagonists & inhibitors ; Tyrosine

OBJECTIVETo investigate the effects of telocinobufagin on viability and apoptosis of colorectal cancer (CRC) cells and explore the mechanism of telocinobufagin-induced apoptosis.

METHODSMTT assay was performed to detect the viability of CRC cells exposed to telocinobufagin. Nuclear staining with Hoechst 33342 and flow cytometry were used to analyze the cell death of CRC cells. Expressions of proteins related with cell apoptosis and oxidative stress were determined with Western blotting.

RESULTSTelocinobufagin decreased the viability of CRC cells in a time- and dose-dependent manner. The presence of karyopycnosis and apoptotic bodies together with the results of flow cytometry suggested that telocinobufagin induced cell apoptosis to cause cell death. Western blotting showed that telocinobufagin exposure of the cells resulted in upregulated p53 and Bax protein expressions and promoted cleavage of caspase 9 and PARP. Telocinobufagin induced phosphorylation of Bad and PARP cleavage, and suppressed phosphorylation of IKBα and TAK1 and expression of survivin in the cells.

CONCLUSIONTelocinobufagin can decrease the viability of CRC cells by inducing cell apoptosis, which involves p53-mediated Bax activation and inhibition of the IAP pathway.

Apoptosis ; Bufanolides ; pharmacology ; Caspase 9 ; metabolism ; Cell Survival ; Colorectal Neoplasms ; pathology ; Humans ; MAP Kinase Kinase Kinases ; metabolism ; NF-KappaB Inhibitor alpha ; metabolism ; Oxidative Stress ; Poly (ADP-Ribose) Polymerase-1 ; metabolism ; Tumor Cells, Cultured ; Tumor Suppressor Protein p53 ; metabolism ; bcl-2-Associated X Protein ; metabolism ; bcl-Associated Death Protein ; metabolism

OBJECTIVETo study the related proteins of apoptosis initiation induced by homoharringtonine (HHT) in HL-60 cells.

METHODSAfter establishment of an apoptosis initiation model induced by HHT in HL-60 cells, proteins of untreated and HHT treated HL-60 cells were extracted, and the two-dimensional polyacrylamide gel electrophoresis (2-DE) maps of the extracted proteins were established by using the immobilized pH gradient (IPG) two-dimensional electrophoresis respectively. The alteration protein spots were identified with assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF-MS) and database searching.

RESULTSProteomics analysis showed that proteins including MHC class I antigen, calbindin D-28K, chloride channel protein 6, oncoprotein 18, zinc finger protein Helios and apoptosis inhibitor like protein 2 were involved in apoptosis initiation induced by HHT.

CONCLUSIONThe present study might conduce to the researches of HL-60 cells carcinogenesis and pave the way to exploit drug precursor related to HHT and initiation of apoptosis in HL-60 cells.

Antineoplastic Agents, Phytogenic ; pharmacology ; Apoptosis ; drug effects ; Calbindins ; Chloride Channels ; analysis ; DNA-Binding Proteins ; analysis ; Electrophoresis, Gel, Two-Dimensional ; methods ; HL-60 Cells ; Harringtonines ; pharmacology ; Histocompatibility Antigens Class I ; analysis ; Humans ; Ikaros Transcription Factor ; Inhibitor of Apoptosis Proteins ; Microtubule Proteins ; Phosphoproteins ; analysis ; Proteins ; analysis ; Proteome ; analysis ; S100 Calcium Binding Protein G ; analysis ; Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization ; Stathmin ; Transcription Factors ; analysis

To explore differentially expressed genes in leukemia gene expression profile and identify main related genes in acute leukemia, gene expression profiles were analyzed in bone marrow/leucopheresis peripheral blood stem cells samples from 9 acute leukemia patients and their sibling donors with the use of oligonucleotide microarrays. 163 reported leukemia-related genes were involved in the study. The oligonucleotide primers were designed, synthesized and spotted on the chemical-material-coated-glass plates in array. The total RNAs were isolated from nine patients' bone marrow or leucopheresis peripheral blood cells and from nine their sibling donors peripheral blood stem cells treated by G-CSF, then collected by CS-3000 cell selection machine, and were reversely transcribed to cDNAs with the incorporations of fluorescent dUTP. The mixed probes were then hybridized to the oligonucleotide microarray. The results showed that in four patient/donor pairs with B-ALL, 5 up-regulated (RIZ, STK-1, T-cell leukemia/lymphoma 1A, Cbp/p300, Op18) and 1 down-regulated genes (hematopoietic proteoglycan core protein) were identified; In five patient/donor pairs with AML-M(4) and AML-M(5), 6 up-regulated (STAT5B, ligand p62 for the Lck SH2, CST3, LTC4S, myeloid leukemia factor 2 and epb72) and 1 down-regulated genes (CCR5) were identified. In conclusion, on the basis of distinguishing study of specific genetic related recipient/sibling donor pairs, screening leukemia-related genes with oligonucleotide microarrays, a set of 13 up-regulated or down-regulated genes among 163 leukemia-related genes has been identified. The result has further confirmed that above genes play critical role in the molecular mechanism of acute leukemia.
Blood Donors ; DNA-Binding Proteins ; genetics ; Gene Expression Profiling ; Glutathione Transferase ; genetics ; Humans ; Leukemia, Myeloid, Acute ; genetics ; Microtubule Proteins ; genetics ; Milk Proteins ; genetics ; Oligonucleotide Array Sequence Analysis ; Peripheral Blood Stem Cell Transplantation ; Phosphoproteins ; genetics ; Precursor Cell Lymphoblastic Leukemia-Lymphoma ; genetics ; STAT5 Transcription Factor ; Siblings ; Stathmin ; Trans-Activators ; genetics

Good progress has been made in the researches on correlating genes of breast cancer in recent years. Quite a few kinds of genes such as susceptibility gene, oncogene and tumor suppressor genes have been found with implications for diagnosis, therapy and prognosis. Abnormality of breast cancer susceptibility gene (BRCA) is of great significance, especially in the development of breast cancer.
BRCA1 Protein ; genetics ; BRCA2 Protein ; genetics ; Breast Neoplasms ; genetics ; Cyclin-Dependent Kinase Inhibitor p16 ; genetics ; Cyclin-Dependent Kinase Inhibitor p21 ; Cyclins ; genetics ; Female ; Humans ; Mutation ; Neoplasm Proteins ; genetics ; Proto-Oncogene Proteins ; genetics ; Tumor Suppressor Protein p53 ; genetics