In order to study the effect of estrogens and antiestrogens on the adhesive properties of human breast cancer cells, the attachment on endothelial cells (EC), on subendothelial extracellular matrix (ECM) and on ECM components (collagen I and IV, laminin, fibronectin) of estrogen-dependent (MCF-7, ZR75-1) and estrogen-independent (BT-20) breast cancer cell lines was investigated. The cells were grown under conditions of controlled exposure to estrogen [17 beta-estradiol (E2)] and/or antiestrogens [tamoxifen (Tam) or 4-hydroxytamoxifen (OH-Tam)]. Treatment by E2 enhanced the ability of ZR75-1 cells to adhere to the various substrates, which contrasts with the observed absence of effects with the BT-20 cells. Similarly, Tam or OH-Tam induced a reduction of the adhesion of ZR75-1 tumor cell, but not of BT-20 cells. This effect was reversed by competing concentrations of E2. The effects on MCF-7 cell adhesion were similar to those described for ZR75-1 cells, but could not be reproducibly observed. Adhesion assays carried out with ZR75-1 cells grown in the absence or presence of phenol red, a pH indicator which behaves as a weak estrogen, led to a similar pattern of cell attachment. Conditioned media harvested from E2- or Tam-treated ZR75-1 cells failed to induce any effect on adhesion of other ZR75-1 cells grown in E2-deprived medium, suggesting that secretory activities are not required for the control of cell adhesiveness. The results suggest that estrogens and antiestrogens can control the adhesive behavior of breast tumor cells through their hormone responsive structures possibly by regulating expression of cell adhesion proteins and/or their cell surface receptors.

Breast Neoplasms↗

PubMedDate not supplied

Nine days post-thawing red cell conservation in a synthetic medium. Biochemical studies.

The expiration of thawed red cells (RBC) currently is 24 hours. This leads to problems in current transfusion practice, and often wastes rare and costly products. To remedy this situation, we developed a synthetic medium containing 0.085 g per l adenine, 5 g per l glucose, 48.0 g per l sucrose, 0.75 g per l NaH2PO4.H2O, 4 g per l Na2HPO4.2H2O, and 2.5 g per l NaCl, with a pH of 7.40, and an osmolarity of 320 mOsm. After 15 days post-thawing storage at 4 degrees C in our medium, the viability and function of RBC were maintained. We propose the storage of thawed RBC at 4 degrees C in our medium for up to 9 days: sterility was maintained, pH was 6.80, and 2,3-diphosphate glycerate was 50 percent, and adenosine triphosphate 100 percent of the original values. Free hemoglobin was 122 mg per unit, adenylate energy charge was 0.90, and RBC labeled 7 days after thawing showed 89 percent survival 24 hours after transfusion and a one-half disappearance of 22 days.

Adenosine Triphosphate↗

PubMedDate not supplied