Aberrant Expression of Tetraspanin Molecules in B-CLL

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Leukemia. 2005 Jun 2; [Epub ahead of print]

Aberrant expression of tetraspanin molecules in B-cell chronic

lymphoproliferative disorders and its correlation with normal B-cell

maturation.

Barrena S, Almeida J, Yunta M, A, Fernandez-Mosteirin N, Giralt

M, Romero M, Perdiguer L, Delgado M, Orfao A, Lazo PA.

[1] 1Instituto de Biologia Molecular y Celular del Cancer, Centro de

Investigacion del Cancer, Consejo Superior de Investigaciones

Cientificas-Universidad de Salamanca, Salamanca, Spain [2] 2Servicio

de Citometria, Universidad de Salamanca and Hospital Universitario de

Salamanca, Salamanca, Spain.

Tetraspanin proteins form signaling complexes between them and with

other membrane proteins and modulate cell adhesion and migration

properties.

The surface expression of several tetraspanin antigens (CD9, CD37,

CD53, CD63, and CD81), and their interacting proteins (CD19, CD21,

and HLA-DR) were analyzed during normal B-cell maturation and

compared to a group of 67 B-cell neoplasias.

Three patterns of tetraspanin expression were identified in normal B

cells. The first corresponded to bone marrow CD10(+) B-cell

precursors (BCP) which showed high expression of CD81 and CD9, low

reactivity for CD53 and negativity for CD37. CD10(-) B-lymphocytes

showed downregulation of CD9/CD81 and upregulation of CD53/CD37.

Plasma cells showed re-expressed CD9 and downregulated CD37.

Hierarchical clustering analysis of flow cytometry immunophenotypic

data showed a good correlation between the tumor differentiation

stage and the pattern of tetraspanin expression, with all analyzed

individual samples classified into three major groups, independently

of their normal or neoplastic origin. Despite this, neoplastic B-

cells frequently showed aberrantly high/low expression of the

different markers analyzed.

Interestingly, in B-cell chronic lymphocytic leukemia, abnormal

expression of CD53 and CD9 were associated with different patterns of

disease infiltration, which would support the role of these molecules

on modulating adhesion and migration of neoplastic B cells.

Leukemia advance online publication, 2 June 2005;

doi:10.1038/sj.leu.2403822.

PMID: 15931266 [PubMed - as supplied by publisher]