Expression of heat shock protein 70 and NKG2D ligands in acute myeloid leukemia cell lines.
Membrane-bound heat shock protein 70 (HSP70) was found to be tumor-specific and was proposed as a target for immunotherapy. In the present study, we analyzed cell surface and relative gene expression of HSP70 in cell lines established from patients with different acute myeloid leukemia (AML) subtypes, together with the expression of natural killer (NK) cell activation/inhibitory ligands.


METHODS
Six AML cell lines were included in this study. The relative gene expression of HSP70 was analyzed using the real-time reverse-transcriptase polymerase chain reaction. Surface expression of HSP70 and NK cell ligands was analyzed using flow cytometry.


RESULTS
All cell lines overexpressed HSP70; however, its mRNA levels were not elevated. The expression of NKG2D activation ligands was heterogeneous.


CONCLUSIONS
Our study is the first to describe long-term stationary cell surface expression of HSP70 in different subtypes of AML. Combined with the results of the gene expression experiments these data provide more evidence to the idea of a self-limiting mechanism for HSP70 expression.
Hromadnikova
Ilona
I
Department of Molecular Biology and Cell Pathology, Third Faculty of Medicine, Charles University, Prague, Czech Republic. ilona.hromadnikova@lf3.cuni.cz
Volchenkov
Roman
R
Sedlackova
Lucie
L
Spacek
Martin
M
Kozak
Tomas
T
D000293:Adolescent; D000328:Adult; D045744:Cell Line, Tumor; D002462:Cell Membrane / Q000378:metabolism; D015331:Cohort Studies; D005260:Female; D005434:Flow Cytometry / Q000379:methods; D015973:Gene Expression Regulation, Leukemic; D018922:HL-60 Cells; D018840:HSP70 Heat-Shock Proteins / Q000378:metabolism*; D006801:Humans; D007694:Killer Cells, Natural / Q000166:cytology; D015470:Leukemia, Myeloid, Acute / Q000378:metabolism*; D008024:Ligands; D008297:Male; D008875:Middle Aged; D055655:NK Cell Lectin-Like Receptor Subfamily K / Q000378:metabolism*
D018840:HSP70 Heat-Shock Proteins; C527085:KLRK1 protein, human; D008024:Ligands; D055655:NK Cell Lectin-Like Receptor Subfamily K