Detection of an intracellular transforming protein (v-Ki-ras p21) using the flow activated cell sorter (FACS)

Ploidy and Proliferation Evaluated by Flow Cytometry. An Overview of Techniques and Impact in Oncology

Flow cytometric methods for the assessment of nuclear and chromosomal DNA content and of cell proliferation (including methods based on pulse-chase of bromodeoxyuridine and on monoclonal antibodies against nuclear oncoproteins and proliferation-associated antigens) are illustrated by examples and analyzed critically. The impact of most of these techniques for the study of human solid tumors, with exception of nuclear DNA content evaluation, appears still limited. In particular, new studies of cell lines and clinical material from human tumors using new proliferation markers and multiparameter flow cytometry are necessary to solve a considerable number of methodologic and scientific problems.

Detection of the ras p21 gene product in human leukemias by flow cytometry

To date, the detection of oncogene products in human neoplasms has relied primarily upon immunoblot analysis of specimen homogenates. Herein are reported the results of a study using flow cytometry to evaluate the expression of the ras p21 gene product in both fresh and cryopreserved specimens of human acute leukemias. Cell lines known to express ras p21 were used as positive controls and normal peripheral blood was used as a negative control. Intensity of staining for ras p21 (Ip21) was expressed as the ratio of the peak channel numbers of the peak generated by staining with anti-ras p21 to the peak obtained by staining with an isotype control. Using this method, 21 out of 32 clinical specimens of acute leukemia were found to express ras p21 in elevated amounts compared to normal peripheral blood. Flow cytometry appears to be a practical method for routine screening of clinical specimens for the expression of oncogene products on individual cells rather than cell homogenates.