Expression of LECAM-1 and LFA-1 on pre-B lymphoma cells but not on preneoplastic pre-B cells in SL/Kh mice

The pre-B lymphoma-prone inbred strain SL/Kh mice showed a polyclonal expansion of BP-1⁺ pre-B cells in bone marrow early in life. Preneoplastic pre-B cells did not express adhesion molecules LECAM-1 and LFA-1, whereas neoplastic pre-B cells consistently expressed both molecules. There were two types of pre-B lymphomas in SL/Kh with distinct in vivo behavior. One infiltrated lymph nodes and spleen and another, predominantly bone marrow. However, lymphoma cells of both types expressed BP-1, LECAM-1 and LFA-1. Expression of these adhesion molecules on BP-1⁺ cells, therefore, may represent an important consequence of pre-B lymphomagenesis in SL/Kh strain, but is not sufficient to explain the in vivo behavior of the pre-B lymphoma cells.