Growth inhibitory effects of somatostatin on human leukemia cell lines mediated by somatostatin receptor subtype 1.
Reverse transcription polymerase chain reaction analysis revealed that only somatostatin receptor (SSTR) 1 mRNA was expressed in Ball-1 B-, Jurkat T-, and HL60 leukemia cell lines. In contrast, human normal mononuclear cells expressed the mRNA of all five subtypes of SSTR, although the expression level of SSTR1 was the highest. A binding study, revealed that [125I]-somatostatin bound specifically to HL60 cells and this binding was inhibited concentration-dependently by unlabeled somatostatin (SS). A [3H]thymidine incorporation study showed that SS significantly and concentration-dependently inhibited HL60 and BALL-1 leukemia cell growth. Furthermore, this inhibition of leukemia cell growth was associated with reduces c-fos gene expression. These data indicate that leukemia cells express SSTR1 and SS reduce c-fos gene expression with resultant suppression of leukemia cell growth, possibly mediated by the SSTRI.
Ishihara
S
S
2nd Division of Internal Medicine, Shimane Medical University, Japan.
Hassan
S
S
Kinoshita
Y
Y
Moriyama
N
N
Fukuda
R
R
Maekawa
T
T
Okada
A
A
Chiba
T
T
D002455:Cell Division / Q000187:drug effects; D018922:HL-60 Cells; D006727:Hormone Antagonists / Q000494:pharmacology*; D006801:Humans; D019169:Jurkat Cells; D007938:Leukemia / Q000378:metabolism / Q000473:pathology*; D017481:Receptors, Somatostatin / Q000378:metabolism*; D015398:Signal Transduction / Q000187:drug effects; D013004:Somatostatin / Q000494:pharmacology*
D006727:Hormone Antagonists; D017481:Receptors, Somatostatin; D013004:Somatostatin