By using decoy-oligodeoxynucleotides (decoy-ODNS) technique, the effects of Stathmin gene on the proliferation and differentiation of in vitro cultured precartilainous stem cells (PSCs) were investigated. The Stathmin decoy-ODNs were transfected into PSCs in rats by using gene transfection technique. Under the induction of cortisol (1 micromol/L), electrophoretic mobility shift assay was used the inhibitory effects of decoy-ODNS on Stathmin gene. MTT and cytometry were used to test the cell proliferation. The expression of collagen II and V and Stathmin protein was detected by using Western blot. The results showed that Stathmin decoy-ODNs inhibited the Stathmin activity in a dose-dependent manner. When the concentration of decoy-ODNs was 10 times of standard concentration, the proliferation of PSCs was obviously suppressed and the differentiation happened. Compared to the control group, the difference was significant (P<0.05). It was concluded that decoy-ODNs could inhibit the proliferation and promote the differentiation of PSCs by antagonizing Stathmin activity.
Cartilage/*cytology ; Cell Differentiation/*drug effects ; Cell Proliferation/drug effects ; Cells, Cultured ; Oligodeoxyribonucleotides/genetics ; Oligodeoxyribonucleotides/*pharmacology ; Rats, Sprague-Dawley ; Stathmin/*genetics ; Stathmin/pharmacology ; Stem Cells/*cytology

The purpose of this study was to compare the differences of the protein expression profiles between human myeloid leukemia K562 cells and adriamycin-resistant K562/A02 cells, as well as to select novel resistance-related proteins in myeloid leukemia by means of proteomics. The total cellular proteins were separated from K562 and adriamycin-resistant K562/A02 cells by using technique of two dimensional difference in gel electrophoresis (2D-DIGE). Differentially expressed proteins were analyzed by matrix-assisted laser desorption ionization/time of flight-mass spectrometry (MALDI-TOF/MS), and by protein database searching. Moreover, the differentially expressed proteins were verified at protein and mRNA levels by Western blot assay and quantitative real time PCR. The results showed that 8 proteins differentially expressed in adriamycin-resistant K562/A02 cells, among them 2 proteins were identified to be down-regulated and 6 to be up-regulated. These identified proteins involved in the cell energy metabolism, cell proliferation, cell apoptosis, signal transduction, gene transcription and translation respectively. The results assayed by Western blot were similar to those detected by 2D-PAGE. Two up-regulated proteins Stathmin and CrkL were selected for verification in K562 and K562/A02 cells. As a result, the results detected by Western blot were identical with results from 2D-DIGE; real time quantitative PCR assay showed that the changes of CrkL at mRNA level were identical with changes at protein level, but no complete identity of Stathmin changes at mRNA level and protein level was observed. It is concluded that the difference of protein expression profile exists in K562 and K562/A02 cells. Stathmin and CrkL proteins may be involved in the drug resistance and suggest a novel clue for the resistant mechanisms in myeloid leukemia, which is worth further to explore.
Adaptor Proteins, Signal Transducing ; metabolism ; Doxorubicin ; pharmacology ; Drug Resistance, Neoplasm ; Humans ; K562 Cells ; Leukemia ; metabolism ; Nuclear Proteins ; metabolism ; Stathmin ; metabolism

OBJECTIVE: To determine the biological activity of ellagic acid extracted from gallnut against nasopharyngeal carcinoma and its molecular mechanism. METHODS: Nasopharyngeal carcinoma 5-8F cells were treated with 2, 4, 6 μg/mL ellagic acid for 48 h in vitro. The cell proliferation and cell apoptosis were analyzed by MTT and Hoechst33258 stain. The cell cycle and protein expression were measured by flow cytometry and Western blot. RESULTS: Ellagic acid inhibited the proliferation of 5-8F cells. The inhibition rates were (29.35±4.95)%, (53.32 ±4.44)% and ( 61.75 + 6.93)%, respectively, with significant difference from the control group (P<0.01). S phase cells in the experimental groups were (25.47±0.74)%, (28.08±1.41)% and (35.49±0.66)%, respectively, with significant difference (P<0.01) from the control group (21.26±0.70)%. Cells in the experimental groups showed nuclear pyknosis, karyorrhexis and poptotic cell morphology. The expression of COX-2 and stathmin in 5-8F cells was down-regulated with increased drug concentration. CONCLUSION Ellagic acid extracted from gallnut has activity against nasopharyngeal carcinoma cells, and its mechanism may be related to down-regulated expression of COX-2 and stathmin.
Antineoplastic Agents, Phytogenic ; pharmacology ; Apoptosis ; drug effects ; Cell Line, Tumor ; Cell Proliferation ; drug effects ; Cyclooxygenase 2 ; genetics ; metabolism ; Down-Regulation ; drug effects ; Ellagic Acid ; pharmacology ; Humans ; Nasopharyngeal Neoplasms ; pathology ; Plant Extracts ; pharmacology ; Stathmin ; genetics ; metabolism

BACKGROUNDMultidrug resistance to chemotherapeutic agents is an important clinical problem during the treatment of leukemia. The resistance process is multifactorial. To realize the total factors involved in multidrug resistance, we analyzed the differentially expressed proteins of K562 and K562/ADM cells and we investigated one of the up-regulated proteins (CRKL) using siRNA to determine its role in K562/ADM cells.

METHODSAltered protein expressions between K562/S (K562 ADM-sensitive cell line) and K562/ADM (K562 multidrug resistant cell line induced by adriamycin) were identified by 2D-DIGE coupled with mass spectrometry. Meanwhile, we confirmed the differential expression of CRKL and Stathmin in both K562 and K562/ADM cells by Western blot analysis. Furthermore, we used RNA interference to silence the CRKL gene expression.

RESULTSAmong the 9 differentially expressed proteins, 3 were up-regulated in K562/ADM cells, while 6 were down-regulated in the K562/ADM cells compared with its parent cell line. The expression of CRKL was up-regulated significantly in K562/ADM cells, and it can be decreased by recombinant lentivirus. Moreover, the multidrug resistance of K562/ADM cells was efficiently reversed by silence of CRKL gene expression.

CONCLUSIONSThe data provided the differentially expressed proteins in K562 and its resistant cell line and highlights the power of 2D-DIGE for the discovery of resistance markers in cancer. We found CRKL may be a new protein involved in the multidrug resistance of leukaemia cells.

Adaptor Proteins, Signal Transducing ; analysis ; antagonists & inhibitors ; genetics ; Amino Acid Sequence ; Doxorubicin ; pharmacology ; Drug Resistance, Multiple ; Humans ; K562 Cells ; chemistry ; drug effects ; Molecular Sequence Data ; Neoplasm Proteins ; analysis ; Nuclear Proteins ; analysis ; antagonists & inhibitors ; genetics ; Proteomics ; Stathmin ; analysis

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