Showing papers by "Howard H. Sussman published in 1980"

Expression of Human Placental Cell Surface Antigens on Peripheral Blood Lymphocytes and Lymphoblastoid Cell Lines

Abstract: The expression of human placental cell surface antigens was examined in cells of lymphoid origin, including peripheral blood lymphocytes and cultured lymphoblastoid cells of bone marrow or thymus derivation. A select group of this defined set of surface antigens was detected on all three cell preparations. The most remarkable observation was the conspicuous absence of three subunits previously demonstrated to be present on all human cell surfaces examined to date. Antiserum directed against several placental components prevents adhesion and spreading of cells which grow attached to surfaces. These results suggest a role for these three glycoproteins in mediating cellular adhesion.

Distribution and characterization of alpha hCG in the serum and tumor cytosol of patients with breast cancer.

Abstract: Serum and tumor tissue from breast cancer patients were evaluated for the presence of alpha subunit of hCG, by means of the specific radioimmunoassay. Elevated serum levels occurred in 0/50 (0%) of normal female controls, 1/17 (6%) of patients with benign breast disease, 3/53 (6%) of patients with primary breast cancer, and 12/84 (14%) of patients with metastatic breast cancer. Cytosols from 10/56 (18%) primary tumors and 10/37 (28%) metastatic tumors were found to contain the alpha subunit. Comparison of serum and tumor cytosol levels in nine patients with metastatic disease showed a correspondence between elevated cytosol levels and elevated serum levels. No similar correspondence in 25 patients with primary disease was observed. Alpha subunit was isolated from one tumor cytosol and was characterized with respect to its immunochemical cross-reactivity and molecular weight as compared with native alpha subunit from hCG. For both parameters, the native and ectopic alpha subunit were found to be identical.

Independent expression of alpha-HCG and placental alkaline phosphatase in clonal human cell lines.

Abstract: The expression of the placental isoenzyme of alkaline phosphatase and the alpha subunit of chorionic gonadotropin was examined in a series of cloned lines of Chang liver cells. both placental gene products show large quantitative variation in the amounts made (over 30-fold) among the various clones. This variation occurs independently for both proteins. These results suggest that these placental-specific genes are discordantly regulated. Because karyologic analysis of several clones shows significant variation in the chromosome content, we cannot determine whether such expression results from true independent mechanisms controlling expression or from variation in gene dosage.