PATTERN OF EXPRESSION OF TETRASPANIN ANTIGEN GENES IN BURKITT-LYMPHOMA CELL-LINES

Tetraspanin antigens are implicated in the prognosis of different type s of tumours. In this study we determine by semiquantitative reverse t ranscriptase-polymerase chain reaction (RT-PCR) the level of 13 tetras pan messages in 21 Burkitt lymphoma (BL) cell lines. All tumour cell l ines have a common pattern of tetraspanin gene expression. There are f ive antigens which are detected in 90% of cell lines at high levels, C D53, CD81, CD63, SAS and CD82. Another two, CD9 and CD37, were detecte d in 608 of cell lines, and have a very variable level of expression. The remaining antigens, A15, CoO29, KRAG, L6, TI-1 and il-TMP, are exp ressed at low levels in very few cell lines without any specific patte rn. The level of gene expression corresponds with the level of cell su rface antigen determined by flow cytometry. The average number of tetr aspan proteins expressed per cell line is six. These proteins may form subunits of an oligomeric structure with 24 transmembrane domains. Th ere are no major differences in tetraspan expression pattern among spo radic or endemic tumours, type of translocation or Epstein-Barr virus status, suggesting the original cell of these tumours is the same, pro bably a late pre-B cell, at the CD9 to CD37 transition point. Tetraspa nin gene expression is consistent with BL being a single entity, despi te variations in other parameters.