Elevated expression of CD30 in adult T-cell leukemia cell lines: possible role in constitutive NF-kappaB activation.
BACKGROUND
Human T-cell leukemia virus type 1 (HTLV-1) is associated with the development of adult T-cell leukemia (ATL). HTLV-1 encoded Tax1 oncoprotein activates the transcription of genes involved in cell growth and anti-apoptosis through the NF-kappaB pathway, and is thought to play a critical role in the pathogenesis of ATL. While Tax1 expression is usually lost or minimal in ATL cells, these cells still show high constitutive NF-kappaB activity, indicating that genetic or epigenetic changes in ATL cells induce activation independent of Tax1. The aim of this study was to identify the molecules responsible for the constitutive activation of NF-kappaB in ATL cells using a retroviral functional cloning strategy.


RESULTS
Using enhanced green fluorescent protein (EGFP) expression and blasticidin-resistance as selection markers, several retroviral cDNA clones exhibiting constitutive NF-kappaB activity in Rat-1 cells, including full-length CD30, were obtained from an ATL cell line. Exogenous stable expression of CD30 in Rat-1 cells constitutively activated NF-kappaB. Elevated expression of CD30 was identified in all ATL lines examined, and primary ATL cells from a small number of patients (8 out of 66 cases).


CONCLUSIONS
Elevated CD30 expression is considered one of the causes of constitutive NF-kappaB activation in ATL cells, and may be involved in ATL development.
Higuchi
Masaya
M
Division of Virology, Niigata University Graduate School of Medical and Dental Sciences, Niigata 951-8510, Japan. mhiguchi@med.niigata-u.ac.jp
Matsuda
Takehiro
T
Mori
Naoki
N
Yamada
Yasuaki
Y
Horie
Ryouichi
R
Watanabe
Toshiki
T
Takahashi
Masahiko
M
Oie
Masayasu
M
Fujii
Masahiro
M
D000818:Animals; D002460:Cell Line; D005347:Fibroblasts; D015368:Human T-lymphotropic virus 1 / Q000472:pathogenicity; D006801:Humans; D019169:Jurkat Cells; D017730:Ki-1 Antigen / Q000378:metabolism*; D015459:Leukemia-Lymphoma, Adult T-Cell / Q000378:metabolism*; D016328:NF-kappa B / Q000378:metabolism*; D051381:Rats; D013601:T-Lymphocytes; D014407:Tumor Cells, Cultured; D015854:Up-Regulation
D017730:Ki-1 Antigen; D016328:NF-kappa B