Human cell culture: morphology of the Detroit strains.

The isolation of increasing numbers of human cell strains has stirred up old problems and created new ones. For example, continuously maintained transferable cells lose their resemblance to those of the original explanted tissues, and there are many similarities among cultured cells derived from different sources. Furthermore, in vitro the cells may acquire features pathologists rely on for recognition of malignancy. This occurs in cells derived from noncancerous as well as cancerous sources. During the past few years we have studied thir teen strains of human cells developed in our lab oratories from bone marrow (Detroit-6,-32,-34,-52,-98,-1431), carcinomatous ascitic fluid (De-troit-30A,-56A), lymphomatous pleural fluid (Detroit-166P), nonleukemic peripheral blood (Detroit-173B,-B16,1-B171), and a hamartoma of liver (Detroit-5011). Others have had similar results with various normal and malignant tissues These strains grow as networks of spindle-shaped or in timately attached polygonal cells and are often referred to as fibroblastic or epithelial. Many were derived from tissues containing mixtures of cells of ectodermal, mesodermal, and entodermal ori gins, but it is not known whether they are descendents of epithelial cells or fibroblasts originally present. For these reasons we refer to cells as epi-thelial-like (Ep-L) or fibroblast-like (Fb-L). The latter are especially interesting because of their tendency to transform to Ep-L cells. The Detroit * These investigations were supported by grants from the strains have been maintained in continuous cul ture by repeated transfers for 8-26 months. Their use for virologie studies has been reported (6, 42, 44, 45). This paper deals mainly with morphology as observed by bright-field microscopy. For maintenance of strains we use Eagle's basal medium2 (11), to which serum of human or animal origin is added. Suspensions of cells from marrow, blood, ascitic or pleural fluid, or one prepared by mincing and trypsin-treatment of solid tissues, are placed in ordinary prescription bottles3 lying on their flat sides. Cells settle on the glass and prolif erate. Morphologic studies of fixed and stained preparations at high magnifications are made on films prepared on removable coverslips placed in 5-ml. Beckman beakers or Leighton tubes.2 The details of isolation, maintenance, and transfer of cells were given in previous papers (5, 6, 45). Addi tional special technics will be described in connec tion with related observations. OBSERVATIONS There are subtle differences among the Ep-L Detroit strains, but their significance is not clear. Morphologic findings exhibited in common will be emphasized. Variances shown to have functional meaning will …