title: Biological behaviors and proteomics analysis of hybrid cell line EAhy926 and its parent cell line A549.
abstract: BACKGROUND
  It is well established that cancer cells can fuse with endothelial cells to form hybrid cells spontaneously, which facilitates cancer cells traversing the endothelial barrier to form metastases. However, up to now, little is known about the biologic characteristics of hybrid cells. Therefore, we investigate the malignant biologic behaviors and proteins expression of the hybrid cell line EAhy926 with its parent cell line A549.
  
  
  METHODS
  Cell counting and flow cytometry assay were carried out to assess cell proliferation. The number of cells attached to the extracellular matrix (Matrigel) was measured by MTT assay for the adhesion ability of cells. Transwell chambers were established for detecting the ability of cell migration and invasion. Tumor xenograft test was carried out to observe tumorigenesis of the cell lines. In addition, two-dimensional electrophoresis (2-DE) and mass spectrometry were utilized to identify differentially expressed proteins between in Eahy926 cells and in A549 cells.
  
  
  RESULTS
  The doubling time of EAhy926 cell and A549 cell proliferation was 25.32 h and 27.29 h, respectively (P > 0.1). Comparing the phase distribution of cell cycle of EAhy926 cells with that of A549 cells, the percentage of cells in G0/G1 phase, in S phase and in G2/M phase was (63.7% +/- 2.65%) VS (60.0% +/- 3.17%), (15.4% +/- 1.52%) VS (13.8% +/- 1.32%), and (20.9% +/- 3.40%) VS (26.3% +/- 3.17%), respectively (P > 0.05). For the ability of cell adhesion of EAhy926 cells and A549 cells, the value of OD in Eahy926 cells was significantly higher than that in A549 cells (0.3236 +/- 0.0514 VS 0.2434 +/- 0.0390, P < 0.004). We also found that the migration ability of Eahy926 cells was stronger than that of A549 cells (28.00 +/- 2.65 VS 18.00 +/- 1.00, P < 0.01), and that the invasion ability of Eahy926 cells was significantly weak than that of A549 cells (15.33 +/- 0.58 VS 26.67 +/- 2.52, P < 0.01). In the xenograft tumor model, expansive masses of classic tumor were found in the A549 cells group, while subcutaneous inflammatory focuses were found in the EAhy926 cells group. Besides, twenty-eight proteins were identified differentially expressed between in EAhy926 cells and in A549 cells by proteomics technologies.
  
  
  CONCLUSIONS
  As for the biological behaviors, the ability of cell proliferation in Eahy926 cells was similar to that in A549 cells, but the ability in adhesion and migration of Eahy926 cells was higher. In addition, Eahy926 cells had weaker ability in invasion and could not form tumor mass. Furthermore, there were many differently expressed proteins between hybrid cell line Eahy926 cells and A549 cells, which might partly account for some of the differences between their biological behaviors at the molecular level. These results may help to understand the processes of tumor angiogenesis, invasion and metastasis, and to search for screening method for more targets for tumor therapy in future.
authors.affiliation: Cancer Center, State Key Laboratory of Biotherapy, West China Hospital of Sichuan University, Chengdu, PR China. luzejun.01@163.com
authors.forename: Ze Jun
authors.initials: ZJ
authors.lastname: Lu
authors.forename: Ya Qiong
authors.initials: YQ
authors.lastname: Ren
authors.forename: Guo Ping
authors.initials: GP
authors.lastname: Wang
authors.forename: Qi
authors.initials: Q
authors.lastname: Song
authors.forename: Mei
authors.initials: M
authors.lastname: Li
authors.forename: Sa Sa
authors.initials: SS
authors.lastname: Jiang
authors.forename: Tao
authors.initials: T
authors.lastname: Ning
authors.forename: Yong Song
authors.initials: YS
authors.lastname: Guan
authors.forename: Jin Liang
authors.initials: JL
authors.lastname: Yang
authors.forename: Feng
authors.initials: F
authors.lastname: Luo
mesh_terms: D000230:Adenocarcinoma / Q000378:metabolism / Q000473:pathology*; D000818:Animals; D015153:Blotting, Western; D002448:Cell Adhesion / Q000502:physiology; D002453:Cell Cycle / Q000502:physiology; D048708:Cell Growth Processes / Q000502:physiology; D045744:Cell Line, Tumor; D002465:Cell Movement / Q000502:physiology; D015180:Electrophoresis, Gel, Two-Dimensional; D042783:Endothelial Cells / Q000378:metabolism / Q000473:pathology*; D005260:Female; D006801:Humans; D006822:Hybrid Cells / Q000378:metabolism / Q000473:pathology*; D008175:Lung Neoplasms / Q000378:metabolism* / Q000473:pathology; D051379:Mice; D008807:Mice, Inbred BALB C; D008819:Mice, Nude; D009361:Neoplasm Invasiveness; D009363:Neoplasm Proteins / Q000096:biosynthesis; D040901:Proteomics; D014162:Transfection
chemical_list: D009363:Neoplasm Proteins