The distribution of nuclear DNA from human brain-tumor cells

Abstract

Flow cytometry (FCM) is a technique that measures the quantity of DNA contained in individual nuclei and records a frequency distribution of the DNA content per nucleus in the sampled cell population. Nuclei from a variety of human brain-tumor types were isolated by means of tissue grinding, purified by centrifugation through 40% sucrose (15 minutes at 4000 rpm), fixed with 10% formalin, stained with acriflavin-Feulgen, and analyzed by FCM. Profiles of DNA distribution in histologically benign tumors, such as meningiomas, pituitary adenomas, neuroblastomas, and low-grade astrocytomas, revealed a large diploid population (2C) with a few nuclei in DNA synthesis, as well as a small premitotic population (G2 cells) that contains a 4C DNA complement. In contrast, malignant gliomas, including glioblastomas, consist of more cells in DNA synthesis; these tumor cells show a highly variable distribution of ploidy consisting not only of diploid, and/or aneuploid, but also of triploid, tetraploid, and possibly octaploid populations. Also, a large variability between different regions of each tumor was always observed. In contrast, metastatic brain tumors, despite the fact that they contain a considerable number of cells undergoing DNA synthesis, demonstrate little variability within each individual tumor. The ability to rapidly characterize the cell populations of human brain tumors with FCM may enhance the effectiveness of their clinical management.

Ploidy and Proliferative Activity of Human Brain Tumors

“…These results are in keeping with those obtained by Mork and Laerum [17] and by Borchersand Beck [18]. Hoshinoet al [19], Kawamo to et al [13] and Frederiksen ct al. [20] have reported even higher percentages (>85% ) of aneuploidy in malignant brain tumors.…”

“…Among factors influencing FCM detection of aneuploidy, the method for tumor cell disaggregation must be taken into account. We employed a mechanical disaggrega tion technique, which has been proved [21,22] to furnish unicellular suspensions and DNA resolutions better than enzymatic procedures used by others [13,19,20],…”

Intraoperative flow cytometry analysis of glioma tissue for rapid determination of tumor presence and its histopathological grade

“…3,6,9 Nevertheless, even in glioblastoma various patterns of DNA content can be observed; therefore, it might be inaccurate to determine the histopathological grade of the tumor based only on the presence of aneuploid cells. 6,16 In our analysis the differences in the frequency of aneuploidy and the DNA index in gliomas of various degrees of malignancy did not reach the level of statistical significance. Therefore, these parameters have limited effectiveness for the intraoperative determination of brain tumor grade.…”

Genetic Diversity of Glioblastoma Multiforme: Impact on Future Therapies

“…Using flow cytometry data analysis Hoshino et al (1978) reported that different tumor regions of one glioblastoma showed a highly variable distribution of ploidy. By use of a DNA fingerprinting technique Misra et al (2000) analysed genetic alterations within two or three tumor areas from seven glioblastomas.…”