We have established 3 new EBV-negative cell lines, designated Sc-I, Ri-I and Ci-I, from patients with 8-cell lymphoma/ leukemia. We characterized them by cytogenetics and by study of surface membrane antigens with a panel of monoclonal antibodies (MAbs), surface and cytoplasmic immunoglobulin (Ig) expression and Ig heavy-and light-chain genes. All 3 lines had a 14q+ abnormality. Ri-l also had translocations involving chromosomes 2, 8 and 18. Ci-l also had abnormalities involving chromosomes 2.8 and 22 and its karyotype was 46, XX, t(2;8), t( l4;22). The t(2;8) had the same breakpoints as those reported in some cases of Burkitt's lymphoma. We also studied a classical Ph'-positive cell line previously established by Pegoraro et a/. (1983) and designated BV173. The phenotypes of these 4 lines based on Ig expression and marker studies correlated well with their respective genotypes. Our results are in keeping with the notion that leukaemic cell populations are clonal expansions of cells "frozen" at a particular stage in their differentiation. Specifically, BV I73 cells are at an early stage of B-cell differentiation, Ri-I and Ci-l cells are at intermediate stages and Sc-l cells are at a relatively late stage in the B-cell lineage.
A large number of cell lines have been established from patients with lymphoma-leukaemia. Some are positive and others negative for Epstein-Barr viral (EBV) expression (Magrath et al., 1980;Minowada et al., 1982). The 14q+ abnormality was initially identified in Burkitt's lymphoma (Manolov and Manolova, 1972) and later was also found in other lymphomas (Zech et al., 1976;Fukuhara and Rowley, 1978). In Burkitt's lymphoma the 14q+ abnormality is almost invariably associated with a reciprocal translocation involving chromosomes 8 and 14 that usually includes translocation to 14q of the c-myc oncogene localized at 8q24. The resulting juxtaposition of c-myc with the locus for the constant region of the immunoglobulin (Ig) heavy chain on chromosome 14 could be relevant in the pathogenesis of the malignant change (Lenoir and Taub, 1985).
We report here details of the establishment of 3 new EBVnegative B-cell lines with 14qf derived from the ascitic fluid or peripheral blood of patients with lymphoma-leukaemia. We also studied a known Ph'-positive cell line, BV173 (Pegoraro et al., 1983). On the basis of immunological, cytogenetic and molecular genetic analyses, we have tried to place the cells from these lines at the corresponding stages in the maturation pathway of normal B-cells.
MATERIAL AND METHODS
Patients
Case 1 (Ci). A 38-year-old woman presented in October 1981 with abdominal swelling and ankle oedema. On laparotomy she proved to have massive ascites and infiltration of ileum, mesentery, omentum and uterus by tumour which histologically was a non-convoluted-cell lymphoblastic lymphoma. The patient was treated with chemotherapy and responded well.