AIM: To identify the protein expression differences related to the CagA-induced ERK pathway activation in AGS cells. METHODS: Human AGS cells transfected with cagA and blank vector were treated with specific mitogen-a...AIM: To identify the protein expression differences related to the CagA-induced ERK pathway activation in AGS cells. METHODS: Human AGS cells transfected with cagA and blank vector were treated with specific mitogen-activated protein kinase kinase (MEK) inhibitor. Total cell proteins were combined by strong anion exchange (SAX2) and weak cation exchange (CM10) ProteinChip arrays and analyzed using surface-enhanced laser desorption/ ionization time-of-flight mass spectrometry (SELDI-TOF-MS) proteomics technology. Protein expression profi les were compared with those of inhibitor-untreated cagA transfectants. SwissProt/TrEMBL database searching for differentially expressed proteins was carried out using the TagIdent tool with the pI and mass information. RESULTS: When a total of 16 proteins that showed expression differences in inhibitor-untreated cagA transfectants were compared with vector transfectants,three proteins with m/z 4229,8162 and 9084 were found to have no expression differences after treatment with MEK inhibitor,while the other 13 maintained the same expression differences after inhibitor treatment. Seven pieces of meaningful matching information for the three proteins were obtained from database searching. CONCLUSION: Biomarkers with m/z 4229,8162 and 9084 are ERK1/2 phosphorylation dependent,and therefore are the downstream molecules of ERK1/2 in the ERK/MAPK signaling pathway. The three biomarkers may be important cancer-associated proteins according to SwissProt/TrEMBL database information.展开更多
Objective: To detect differential protein expression in malignant and normal liver cell lines in vitro using the SELDI ProteinChip platform, for investigating the pathogenesis of liver cancer. Methods: Two cell lines,...Objective: To detect differential protein expression in malignant and normal liver cell lines in vitro using the SELDI ProteinChip platform, for investigating the pathogenesis of liver cancer. Methods: Two cell lines, human normal liver cell line L02 and hepatoma cell line SMMC-7721 were cultured routinely, harvested in good condition and lysed. After quantification, the supernatant of the lysate was tested by IMAC3 (Immobilized Mental Affinity Capture) and WCX2 (Weak Cation Exchange) chips on the SELDI-TOF-MS ProteinChip reader. Results: Protein expression differed between the malignant and normal liver cell lines. A total of 20 differentially expressed proteins were found, among which, 7 were captured by the IMAC3 chip and 14 by the WCX2 chip. Peaks at 5,419, 7,979 and 11,265 Da were higher and at 8,103, 8,492, 10,160 and 11,304 Da lower in SMMC-7721 cells by the IMAC3 chip; peaks at 7,517, 7,945 and 7,979 Da were higher and at 5,061, 5,551, 5,818, 7,439, 9,401,10,100, 10,312, 11,621, 11,662, 11,830 and 12,772 Da lower in SMMC-7721 cells by the WCX2 chip. Interestingly, both chips captured the 7,979 Da peak. In addition, the 11,081 Da peak corresponded precisely with the molecular mass of the calcium binding protein S100A10, which may participate in the formation of liver cancer in association with p36. Conclusion: Detecting differential protein expression in malignant and normal liver cell lines using the SELDI ProteinChip platform was simple, sensitive and repeatable. The results we obtained can serve as a basis for investigating the pathogenesis of liver cancer and aid the discovery of new therapeutic targets.展开更多
Tumor metastasis is the dominant cause of death in cancer patients. However, the molecular and cellular mechanisms underlying tumor metastasis are still elusive. The identi?cation of protein molecules with their expre...Tumor metastasis is the dominant cause of death in cancer patients. However, the molecular and cellular mechanisms underlying tumor metastasis are still elusive. The identi?cation of protein molecules with their expressions correlated to the metastatic process would help to understand the metastatic mechanisms and thus facilitate the development of strategies for the therapeutic interventions and clini- cal management of cancer. Proteomics is a systematic research approach aiming to provide the global characterization of protein expression and function under given conditions. Proteomic technology has been widely used in biomarker discovery and pathogenetic studies including tumor metastasis. This article provides a brief review of the application of proteomics in identifying molecular factors in tumor metastasis process. The combination of proteomics with other experimental ap- proaches in biochemistry, cell biology, molecular genetics and chemistry, together with the development of new technologies and improvements in existing method- ologies will continue to extend its application in studying cancer metastasis.展开更多
基金National High Technology 2006AA02Z341 & NSFC 30430730
文摘AIM: To identify the protein expression differences related to the CagA-induced ERK pathway activation in AGS cells. METHODS: Human AGS cells transfected with cagA and blank vector were treated with specific mitogen-activated protein kinase kinase (MEK) inhibitor. Total cell proteins were combined by strong anion exchange (SAX2) and weak cation exchange (CM10) ProteinChip arrays and analyzed using surface-enhanced laser desorption/ ionization time-of-flight mass spectrometry (SELDI-TOF-MS) proteomics technology. Protein expression profi les were compared with those of inhibitor-untreated cagA transfectants. SwissProt/TrEMBL database searching for differentially expressed proteins was carried out using the TagIdent tool with the pI and mass information. RESULTS: When a total of 16 proteins that showed expression differences in inhibitor-untreated cagA transfectants were compared with vector transfectants,three proteins with m/z 4229,8162 and 9084 were found to have no expression differences after treatment with MEK inhibitor,while the other 13 maintained the same expression differences after inhibitor treatment. Seven pieces of meaningful matching information for the three proteins were obtained from database searching. CONCLUSION: Biomarkers with m/z 4229,8162 and 9084 are ERK1/2 phosphorylation dependent,and therefore are the downstream molecules of ERK1/2 in the ERK/MAPK signaling pathway. The three biomarkers may be important cancer-associated proteins according to SwissProt/TrEMBL database information.
基金the grant from the National Natural Science Foundation of China(No.30471527, No. 30540075)Mt. Tai Scholar Construction Engineering Foundation
文摘Objective: To detect differential protein expression in malignant and normal liver cell lines in vitro using the SELDI ProteinChip platform, for investigating the pathogenesis of liver cancer. Methods: Two cell lines, human normal liver cell line L02 and hepatoma cell line SMMC-7721 were cultured routinely, harvested in good condition and lysed. After quantification, the supernatant of the lysate was tested by IMAC3 (Immobilized Mental Affinity Capture) and WCX2 (Weak Cation Exchange) chips on the SELDI-TOF-MS ProteinChip reader. Results: Protein expression differed between the malignant and normal liver cell lines. A total of 20 differentially expressed proteins were found, among which, 7 were captured by the IMAC3 chip and 14 by the WCX2 chip. Peaks at 5,419, 7,979 and 11,265 Da were higher and at 8,103, 8,492, 10,160 and 11,304 Da lower in SMMC-7721 cells by the IMAC3 chip; peaks at 7,517, 7,945 and 7,979 Da were higher and at 5,061, 5,551, 5,818, 7,439, 9,401,10,100, 10,312, 11,621, 11,662, 11,830 and 12,772 Da lower in SMMC-7721 cells by the WCX2 chip. Interestingly, both chips captured the 7,979 Da peak. In addition, the 11,081 Da peak corresponded precisely with the molecular mass of the calcium binding protein S100A10, which may participate in the formation of liver cancer in association with p36. Conclusion: Detecting differential protein expression in malignant and normal liver cell lines using the SELDI ProteinChip platform was simple, sensitive and repeatable. The results we obtained can serve as a basis for investigating the pathogenesis of liver cancer and aid the discovery of new therapeutic targets.
基金supported by Hong Kong Research Grants Council Grants HKU 7227/02M(to Q.Y.H.),HKU 7218/02M and HKU 7395/03M(toJ.F.C.)the Department of Chemistry,and the Areasof Excellence scheme of Hong Kong University GrantsCommittee
文摘Tumor metastasis is the dominant cause of death in cancer patients. However, the molecular and cellular mechanisms underlying tumor metastasis are still elusive. The identi?cation of protein molecules with their expressions correlated to the metastatic process would help to understand the metastatic mechanisms and thus facilitate the development of strategies for the therapeutic interventions and clini- cal management of cancer. Proteomics is a systematic research approach aiming to provide the global characterization of protein expression and function under given conditions. Proteomic technology has been widely used in biomarker discovery and pathogenetic studies including tumor metastasis. This article provides a brief review of the application of proteomics in identifying molecular factors in tumor metastasis process. The combination of proteomics with other experimental ap- proaches in biochemistry, cell biology, molecular genetics and chemistry, together with the development of new technologies and improvements in existing method- ologies will continue to extend its application in studying cancer metastasis.
