title: Proteomic analysis of lanthanum citrate-induced apoptosis in human cervical carcinoma SiHa cells.
abstract: Lanthanides possess diverse biological effect and have been shown to promote cell proliferation and induce apoptosis. Our previous studies showing that lanthanide citrate complex has significant antitumor activity in human cervical cancer HeLa cells. This study aims at determining if [LaCit(2)](3-) have the activity against another type of human cervical cancer cell line SiHa and the changes in protein expression that contribute to the mechanism(s) of [LaCit(2)](3-)-mediated apoptosis in SiHa cells. Cell growth inhibition was measured by MTT method, and apoptosis was detected by means of Hoechst 33258 staining and flow cytometry analysis. After [LaCit(2)](3-)-treatment the results show that the growth of SiHa cells was inhibited, the cells displayed typical apoptosis morphological changes, and increase in the rates of apoptosis. Using proteomics approaches, a variety of differentially expressed proteins were identified in SiHa cells before and after treatment with [LaCit(2)](3-). There were profound changes in 10 proteins relating to mitochondrial function and oxidative stress, suggesting that mitochondrial dysfunction plays a key role in [LaCit(2)](3-)-induced apoptosis. This was confirmed by a decrease in the mitochondrial transmembrane potential (Δψ(m)), and increases in H(2)O(2) generation in [LaCit(2)](3-)-treated cells. Among them the alerted proteins, Prx I, ANXA1 and TRAF5 were validated by western blotting analyses. These results suggest that there is an intrinsic molecular pathway of cell apoptosis in [LaCit(2)](3-)-treated SiHa cells. This observation is in accordance with our previous reports about the effects of [LaCit(2)](3-) and [YbCit(2)](3-) on HeLa cells and it provide a molecular mechanism underlying lanthanide citrate complex-mediated cell apoptosis.
authors.affiliation: College of Life Sciences, Shenzhen University, Shenzhen, 518060, People's Republic of China.
authors.forename: Liming
authors.initials: L
authors.lastname: Shen
authors.forename: Ziyao
authors.initials: Z
authors.lastname: Lan
authors.forename: Xiaohong
authors.initials: X
authors.lastname: Sun
authors.forename: Lei
authors.initials: L
authors.lastname: Shi
authors.forename: Qiong
authors.initials: Q
authors.lastname: Liu
authors.forename: Jiazuan
authors.initials: J
authors.lastname: Ni
mesh_terms: D017209:Apoptosis / Q000187:drug effects*; D045744:Cell Line, Tumor; D049109:Cell Proliferation / Q000187:drug effects; D002951:Citrates / Q000494:pharmacology*; D005260:Female; D006801:Humans; D007811:Lanthanum / Q000494:pharmacology*; D053078:Membrane Potential, Mitochondrial / Q000187:drug effects; D008928:Mitochondria / Q000187:drug effects / Q000378:metabolism; D018384:Oxidative Stress / Q000187:drug effects; D040901:Proteomics; D017382:Reactive Oxygen Species / Q000378:metabolism; D002583:Uterine Cervical Neoplasms / Q000473:pathology
chemical_list: D002951:Citrates; D017382:Reactive Oxygen Species; C556091:lanthanum citrate; D007811:Lanthanum