Previous studies had demonstrated the presence of the p70 (CAMAL) molecule in human myeloid leukemia cells and the promyelocytic leukemia cell line HL60, but not in equivalent preparations of normal cells (Malcolm et al., 1982, 1984; Shipman et al., 1983; Logan et al., 1984). Subsequent studies demonstrated that the p70 (CAMAL) protein was detectable and expressed in human myeloid leukemia cells and the leukemic cell lines HL60, KG1, K562 and U937. The association of p70 (CAMAL) expression with human myeloid leukemia cells prompted its consideration as a candidate leukemia-associated antigen. The demonstration, following CAMAL purification and peptide sequencing, that two tryptic peptides (tp27, tp31) displayed significant homology to sequences present in human serum albumin (HSA) and human alpha-1-fetoprotein (AFP), while one tryptic peptide (tp20) displayed unique peptide sequence, suggested that CAMAL might represent a protein that was structurally and functionally related to the albumins. Consequently, a comparative biochemical analysis of CAMAL and HSA was initiated. The results of the comparative studies demonstrated that although CAMAL and HSA shared conformational antigenic determinants, both proteins were also shown to be distinct molecules by a number of other criteria. The possibility that the CAMAL preparation, used for protein sequencing and comparative studies, was contaminated with HSA was thought likely, in view of the HSA/AFP-related peptide sequences from the CAMAL tryptic peptide sequence analysis. However, other results, particularly the antibody reactivity and ligand binding studies, showed that the CAMAL preparation was not contaminated with HSA. The unique CAMAL tryptic peptide (tp20) sequence supported further the contention that CAMAL was a distinct protein with regions homologous to HSA and AFP. Further analysis of the CAMAL molecule, through extensive protein sequencing, will be, in all likelihood, the only means by which to establish the degree of relatedness between CAMAL, HSA and AFP. / Science, Faculty of / Microbiology and Immunology, Department of / Graduate

We used flow cytometry in a retrospective study of pleomorphic adenoma and carcinoma arising in pleomorphic adenoma, using paraffin-embedded tissue, to assess the relationship among proliferative activity, ploidy, and recurrence or malignant transformation. Twenty-four specimens obtained from 22 tumors were acceptable for analysis (co-efficient of variation, < or = 7.0), including multiple samples from two tumors. Fourteen tumors (13 benign and one malignant) were diploid. Six tumors were aneuploid: four benign pleomorphic adenomas and two carcinomas arising in pleomorphic adenoma. Two tetraploid tumors were malignant recurrences from the same patient. Of the recurrent tumors (nine benign and four malignant), 54% were aneuploid. The highest S-phase fractions were observed in recurrent and malignant pleomorphic adenomas. Immunostaining with p105, a nuclear proliferation antigen, revealed increased proliferative activity in a majority of pleomorphic adenomas. Increased proliferative activity and aneuploidy occurred in benign pleomorphic adenomas.