title: Knockdown of hTERT alters biophysical properties of K562 cells resulting in decreased migration rate in vitro.
abstract: It has been shown that 90% of tumors, including hematological malignant tumors and leukemia, have much higher levels of telomerase expression than normal cells. To investigate the effect of telomerase on leukemia cells, we transfected K562, a human erythroleukemia cell line with an antisense-hTERT (human telomerase reverse transcriptase) cDNA vector, and examined the biological and biophysical properties of the stably transfected cells (referred to as KAT). Un-transfected cells (K562) and cells transfected with the empty vector (referred to as KC) were used as controls. Cell growth curve and (3)H-TdR test showed that the growth rate and DNA synthesis of KAT decreased compared with those of K562 and KC cells. Apoptosis and cell cycle distribution in KAT cells under normal culture condition were similar to those of K562 and KC cells, but changed after serum deprivation. KAT cells had significantly different biophysical characteristics from K562 and KC in terms of cell electrophoresis, membrane fluidity, membrane fluidity, and viscoelasticity. Furthermore, the transendothelial migration rate of KAT was much lower than those of K562 and KC cells. Confocal microscopy showed that KAT cells had higher F-actin content, suggesting the reorganization of cytoskeleton. Flow cytometry analysis revealed a lowered intracellular calcium concentration and CD71 expression, explaining the high F-actin content in KAT cells. In conclusion, we found that the knockdown of hTERT in K562 cells changed their cytoskeleton and biophysical features, and reduced the cell migration.
authors.affiliation: Hemorheology Center, Peking University Health Science Center, Beijing 100191, People's Republic of China.
authors.forename: Yingyu
authors.initials: Y
authors.lastname: Zhang
authors.forename: Xiaopeng
authors.initials: X
authors.lastname: Chen
authors.forename: Xiaofeng
authors.initials: X
authors.lastname: Xu
authors.forename: Xianwei
authors.initials: X
authors.lastname: Wang
authors.forename: Xifu
authors.initials: X
authors.lastname: Wang
authors.forename: Guihong
authors.initials: G
authors.lastname: Yuan
authors.forename: Dagong
authors.initials: D
authors.lastname: Sun
authors.forename: Weibo
authors.initials: W
authors.lastname: Ka
authors.forename: Dongqi
authors.initials: D
authors.lastname: He
authors.forename: Zongyao
authors.initials: Z
authors.lastname: Wen
authors.forename: Weijuan
authors.initials: W
authors.lastname: Yao
mesh_terms: D000199:Actins / Q000378:metabolism; D015703:Antigens, CD / Q000378:metabolism; D017209:Apoptosis / Q000235:genetics; D002118:Calcium / Q000378:metabolism; D002453:Cell Cycle / Q000235:genetics; D002465:Cell Movement / Q000235:genetics*; D049109:Cell Proliferation; D003593:Cytoplasm / Q000378:metabolism; D016373:DNA, Antisense / Q000235:genetics; D018076:DNA, Complementary / Q000235:genetics; D004548:Elasticity; D015972:Gene Expression Regulation, Neoplastic / Q000235:genetics; D055785:Gene Knockdown Techniques; D005822:Genetic Vectors / Q000235:genetics; D006801:Humans; D020014:K562 Cells; D011990:Receptors, Transferrin / Q000378:metabolism; D019098:Telomerase / Q000172:deficiency* / Q000235:genetics*; D014162:Transfection; D014783:Viscosity
chemical_list: D000199:Actins; D015703:Antigens, CD; C068126:CD71 antigen; D016373:DNA, Antisense; D018076:DNA, Complementary; D011990:Receptors, Transferrin; D019098:Telomerase; D002118:Calcium