Tissue culture plastic adhesivity was precisely varied by applying different concentrations of poly(2-hydroxyethyl methacrylate). The extent of cell spreading was thus accurately controlled so that cells cultured on these substrata could be held at any one of a graded series of quantitated cell shapes. Cell shape was found to be tightly coupled to DNA synthesis and growth in nontransformed cells. These findings suggest a mechanism that is important in growth control of mammalian cells, and provide a more fundamental interpretation of such phenomena as density dependent inhibition of cell growth and anchorage dependence.

Role of cell shape in growth control

A permanent human cell line, EA . hy 926, has been established that expresses at least one highly differentiated function of vascular endothelium, factor VIII-related antigen. This line was derived by fusing human umbilical vein endothelial cells with the permanent human cell line A549. Hybrid cells that survived in selective medium had more chromosomes than either progenitor cell type and included a marker chromosome from the A549 line. Factor VIII-related antigen can be identified intracellularly in the hybrids by immunofluorescence and accumulates in the culture fluid. Expression of factor VIII-related antigen by these hybrid cells has been maintained for more than 100 cumulative population doublings, including more than 50 passages and three cloning steps. This is evidence that EA . hy 926 represents a permanent line.

https://www.pnas.org/content/pnas/80/12/3734.full.pdf

Permanent cell line expressing human factor VIII-related antigen established by hybridization

Cancer metastasis. Organ colonization and the cell-surface properties of malignant cells.

The control of proliferation of mesoderm-derived cells by EGF and FGF has been examined taking, as an example, the vascular endothelium. The mechanisms by which cell proliferation can be brought to a stop in vivo and in vitro have been reviewed.

Factors involved in the modulation of cell proliferation in vivo and in vitro: the role of fibroblast and epidermal growth factors in the proliferative response of mammalian cells.

We have developed a method that permits analysis of neovascular responses in the mouse cornea. Using this method we have demonstrated that both allogeneic lymphocytes and a variety of tumors can induce angiogenesis, but that only the latter appear capable of eliciting secondary capillary sprouting.

http://science.sciencemag.org/content/sci/205/4413/1416.full.pdf

Angiogenesis in the Mouse Cornea

TUMOURS induce vascularisation into the neoplasm to provide needed cell nutrients and remove wastes1. The formation of tumour blood vessels seems to depend, in part, on the proliferation and movement of vascular endothelial cells which are, in turn, controlled by the secretion of tumour angiogenesis factor (TAP) (refs 2–4). Extracts of tumours2–4 and of established cell lines5 have TAF activity in vivo. But little is known about the molecular nature or mechanism of action of TAF. The proliferation, formation and integrity of vascular endothelium are also involved in normal host processes: wound healing, morphogenetic tissue rearrangements, as well as the prevention of various non-neoplastic diseases resulting from blood vessel wall injury depend on angiogenesis factors6. A convenient method to study angiogenesis and endothelial repair is with an in vitro endothelial cell system, but the lack of uniform, reliable cultured endothelial cell lines has delayed progress in this area. Most studies7–9 (with some exceptions10) have used uncloned vascular cells which are often slow growing and heterogeneous in cell type. We have recently established a cloned adult bovine aortic endothelial (ABAE) cell line which has maintained its endothelial properties for over 1 yr in culture, provided that fibroblast (growth factor (FGF) is present in the growth medium11. We report here the mitogenic effects of several untransformed and transformed cell lines on cloned ABAE cells and non-vascular endothelial cell controls.

C. R. Birdwell

Papers

Factors from 3T3 cells stimulate proliferation of cultured vascular endothelial cells.