Kenneth R. Stone

Changes in membrane polypeptides that occur when chick embryo fibroblasts and NRK cells are transformed with avian sarcoma viruses

Abstract Studies were designed to detect changes in the plasma membrane polypeptide composition of chick embryo fibroblasts (CEF) and Normal rat kidney (NRK) cells following infection with avian RNA tumor viruses. A method capable of isolating large fragments of plasma cell membranes, based on fractionation in a two-phase polymer system, was developed for this purpose. Infection with the Prague (subgroup C) or SR (subgroup A) strains of RSV, or with ts 68 of SR-RSV-A or ts 339 of B77 at the permissive temperature, caused CEF to transform morphologically; simultaneously a limited number of changes occurred in their plasma cell membrane composition. They were: (a) a large increase in the rate of labeling with 14 C-valine and in the total amount of a polypeptide with an apparent MW of 73,000; a similar small increase occurred with respect to a polypeptide with an MW of 95,000; neither could be labeled with 14 C-glucosamine; (b) a decrease in the rate of labeling and in the total amount of high molecular weight glycopoly-peptides with MWs of about 250,000; (c) a decrease in the rate of labeling and in the total amount of a polypeptide with an MW of 39,000. Infection with ts 68 and ts 339 at the nonpermissive temperature, or with a nontransforming mutant of SR-RSV-A, or with RAV-7, did not cause alterations (a) and (b), but did cause alteration (c). Identical membrane polypeptide changes were observed in NRK cells infected with the Prague strain of RSV or with ts 339 of B77 at the permissive but not at the nonpermissive temperature. The significance of the fact that these changes, in particular the increases in the amounts of the 73,000 and 95,000 dalton polypeptides, occurred to the same extent in the membranes of both avian and mammalian cells is discussed.

In vitro culture of epithelial cells derived from urogenital tissues

SummaryA tissue culture procedure is described which yields a high percentage of successful longterm cultures of epithelial cells derived from malignant and non-malignant human urogenital tissues.

Scanning and transmission electron microscopy of human prostatic acinar cells

SummaryBenign hyperplastic and neoplastic human prostate tissue samples were obtained by needle biopsy, transurethral resection or open prostatectomy. Acinar cells of both types of tissues were examined in the scanning electron microscope. It had been reported previously that adenocarcinoma acinar cells were more heterogenous in size and shape than BPH acinar cells; the purpose of this study was to determine if there were surface morphology differences between the two types of tissues. Acinar cells were found to be extremely heterogeneous in their surface morphologies; three major types of surface morphologies were present-microvillous, ruffled, and bare. Within each class of surface morphology there was heterogeneity, both in the size and density, of surface structures present. Microvillous, ruffled, and bare cells appeared to be present in normal, BPH, and neoplastic acini with no significant qualitative or quantitative differences in surface morphologies. Infrequently, it was possible to distinguish between well-differentiated and poorly-differentiated carcinomas because cells of the latter tissues were present in sheets rather than acini and appeared flat and totally devoid of surface detail. The SEM studies also sought to determine a marker to establish the origin of prostate tissue culture cells as normal, BPH or cancerous. Surface morphologies from tissues could be traced into the tissue cultures; again, three types of cells are presentbare, microvillous, and ruffled. However, since surface morphology does not appear to be a distinguishing feature of the pathology of the tissue if cannot provide a distinguishing marker for the origin of tissue culture cells.Scanning electron microscopy also provided an opportunity to observe possible secretory mechanisms and products in the prostate acinar cells.

Correlation of apparent molecular weight and antigenicity of viral proteins: An SDS-PAGE separation followed by acrylamide-agarose electro-phoresis and immunoprecipitation☆

A simple method is described which combines a sodium dodecyl sulfate polyacrylamide gel electrophoresis (SOS-PAGE) in the first demension with a second electrophoresis, at right angles to the first, into an agarose matrix. The proteins, separated by SDS-PAGE, are exposed to appropriate antisera after the second stage electrophoresis and immunoprecipitates form in the agarose corresponding to the relative electrophoretic mobilities of proteins in the first stage SDS-PAGE separation. The method thus provides a simple, reproducible means for correlating antigenicity with apparent molecular weight of proteins. The technique is qualtitative, but requires smaller quantities of antisera than more conventional immunoelectrophoretic methods such as rocket electrophoresis.

Surface proteins of a transitional carcinoma cell line (KS-31E).

SummaryBiosynthetic and post-synthetic labeling procedures have been used to examine the cell surface proteins of a cell line (KS-31) originating from a human transitional cell carcinoma. One isolate of this cell line (KS-31E) is epithelial in appearance and has retained the characteristic of the original tumour with regard to synthesis of a viscous mucin-like material. A 220–250, 000 (250K) dalton large external transformationsensitive (LETS) glycoprotein, and often a 95, 000 (95K) dalton glycoprotein, is released into the medium of KS-31E in association with the mucinlike material produced by the cell line. The finding of LETS and a 95K glycoprotein expressed on the cell surface and extruded into the growth medium of epithelial cells originating from a spontaneous human carcinoma is of interest in relation to the role of cell surface glycoproteins in normal cellular association and the antisocial behaviour exhibited by cancer cells.

Scanning Electron Microscopy of Hyperplastic and Neoplastic Human Prostate

SummaryAcinar cells of neoplastic prostate tissues are more heterogeneous in size and shape than benign hyperplastic cells when observed by scanning electron microscopy. Three types of acinar cells are recognizable by surface structure, cells with microvilli, cells without microvilli, and cells with membrane ruffles. The pitted cells previously seen in BPH tissues are probably artifactual. The identity of the crater cells is still in question.