TPX2 in malignantly transformed human bronchial epithelial cells by anti-benzo[a]pyrene-7,8-diol-9,10-epoxide.
In order to elucidate the function of the targeting protein for Xenopus kinesin-like protein 2 (Xklp2) (TPX2) in the malignant transformation of human bronchial epithelial cells induced by anti-benzo[a]pyrene-trans-7, 8-dihydrodiol-9, 10-epoxide (anti-BPDE), TPX2 was characterized in cells at both the gene and the protein levels. TPX2 was present at higher levels in 16HBE-C cells than in 16HBE cells as demonstrated by two-dimensional gel electrophoresis, immunocytochemistry, Western blot analysis and RT-PCR. TPX2 was also detected in lung squamous-cell carcinoma tissues by immunohistochemistry, but not in normal lung tissues. Depression of TPX2 by RNA interference in 16HBE-C cells led to a decrease in cell proliferation, S-phase cell cycle arrest and cell apoptosis. Abnormal TPX2 tyrosine phosphorylation was detected in 16HBE-C cells, and this could be inhibited, to different degrees, by tyrosine kinase inhibitors. Inhibiting tyrosine phosphorylation in 16HBE-C cells by three selected tyrosine protein kinase inhibitors, tyrphostin 47, AG112 and AG555, caused G(0)/G(1)-phase cell cycle arrest. Our results suggest that anti-BPDE can cause the over-expression of TPX2 and its aberrant tyrosine phosphorylation. Misregulation of TPX2 affects the cell cycle state, proliferation rates and apoptosis.
Zhang
Lijuan
L
Department of Toxicology, School of Public Health, Peking University, PR China.
Huang
He
H
Deng
Luyao
L
Chu
Ming
M
Xu
Lan
L
Fu
Juanling
J
Zhu
Yunlan
Y
Zhang
Xiuchun
X
Liu
Shulin
S
Zhou
Zongcan
Z
Wang
Yuedan
Y
D015123:7,8-Dihydro-7,8-dihydroxybenzo(a)pyrene 9,10-oxide / Q000633:toxicity*; D017209:Apoptosis / Q000187:drug effects; D015153:Blotting, Western; D001980:Bronchi / Q000166:cytology* / Q000187:drug effects; D002453:Cell Cycle / Q000187:drug effects; D018797:Cell Cycle Proteins / Q000235:genetics* / Q000378:metabolism*; D045744:Cell Line, Tumor; D049109:Cell Proliferation / Q000187:drug effects; D002471:Cell Transformation, Neoplastic / Q000235:genetics* / Q000378:metabolism*; D030562:Databases, Protein; D015180:Electrophoresis, Gel, Two-Dimensional; D004847:Epithelial Cells / Q000187:drug effects*; D015870:Gene Expression / Q000187:drug effects; D006801:Humans; D007150:Immunohistochemistry; D047468:Immunoprecipitation; D007525:Isoelectric Focusing; D008869:Microtubule-Associated Proteins / Q000235:genetics* / Q000378:metabolism*; D009153:Mutagens / Q000633:toxicity*; D009687:Nuclear Proteins / Q000235:genetics* / Q000378:metabolism*; D010766:Phosphorylation / Q000187:drug effects; D034622:RNA Interference; D034741:RNA, Small Interfering; D012854:Sister Chromatid Exchange / Q000187:drug effects; D014443:Tyrosine / Q000378:metabolism
D018797:Cell Cycle Proteins; D008869:Microtubule-Associated Proteins; D009153:Mutagens; D009687:Nuclear Proteins; D034741:RNA, Small Interfering; C122167:TPX2 protein, human; D014443:Tyrosine; D015123:7,8-Dihydro-7,8-dihydroxybenzo(a)pyrene 9,10-oxide