title: Thymosin alpha1 suppresses proliferation and induces apoptosis in human leukemia cell lines.
abstract: Thymosin alpha1 (Talpha1), a 28-amino acid peptide, is a well-known immune system enhancer for the treatment of various diseases. In the present investigation, the effects of Talpha1 on the proliferation and apoptosis of human leukemia cell lines (HL-60, K562 and K562/ADM) were studied. The proliferation was significantly depressed after 96 h of treatment with Talpha1, and obvious signs of apoptosis, i.e., cell morphology, nuclei condensation and Annexin V binding, were observed thereafter. Moreover, the up-regulation of Fas/Apol (CD95) and decrease in bcl-2 anti-apoptotic gene expression were observed in apoptotic cells. The expression and the function of P-glycoprotein (P-gp) can be slightly inhibited by Talpha1. It is noteworthy that K562 and K562/ADM were more sensitive than HL-60 cells when subjected to Talpha1. Furthermore, HepG-2, the human hepatoma cell line, displayed significant less sensitivity to Talpha1 than all the human leukemia cell lines. D-Tubocurarine (TUB), a nicotinic acetylcholine receptors (nAChRs) antagonist, significantly antagonized the inhibition effects induced by Talpha1, whereas atropine, a muscarinic acetylcholine receptor antagonist, did not exhibit such effects. All the results indicate that Talpha1 was able to significantly suppress proliferation and induce apoptosis in human leukemia cell lines.
authors.affiliation: Department of Biochemistry and Molecular Biology, School of Life Sciences, Lanzhou University, Lanzhou 73000, PR China.
authors.forename: Ying-zhe
authors.initials: YZ
authors.lastname: Fan
authors.forename: Hui
authors.initials: H
authors.lastname: Chang
authors.forename: Ye
authors.initials: Y
authors.lastname: Yu
authors.forename: Jing
authors.initials: J
authors.lastname: Liu
authors.forename: Rui
authors.initials: R
authors.lastname: Wang
mesh_terms: D020168:ATP Binding Cassette Transporter, Subfamily B, Member 1 / Q000378:metabolism; D017304:Annexin A5 / Q000378:metabolism; D000970:Antineoplastic Agents / Q000494:pharmacology* / Q000627:therapeutic use; D017209:Apoptosis; D045744:Cell Line, Tumor; D049109:Cell Proliferation / Q000187:drug effects; D004305:Dose-Response Relationship, Drug; D018432:Drug Resistance, Multiple; D019254:Genes, bcl-2; D018922:HL-60 Cells; D006801:Humans; D020014:K562 Cells; D007938:Leukemia / Q000188:drug therapy* / Q000378:metabolism; D011950:Receptors, Cholinergic / Q000378:metabolism; D000077596:Thymalfasin; D013947:Thymosin / Q000031:analogs & derivatives* / Q000494:pharmacology / Q000627:therapeutic use; D013997:Time Factors; D014403:Tubocurarine / Q000378:metabolism / Q000494:pharmacology; D019014:fas Receptor / Q000378:metabolism
chemical_list: D020168:ATP Binding Cassette Transporter, Subfamily B, Member 1; D017304:Annexin A5; D000970:Antineoplastic Agents; D011950:Receptors, Cholinergic; D019014:fas Receptor; D013947:Thymosin; D000077596:Thymalfasin; D014403:Tubocurarine