Isolation and Morphologic Characterization of Human Ovarian Carcinoma Cell Clusters Present in Effusions

Abstract

Serous, mucinous, endometrioid and clear cell human ovarian carcinoma cells were isolated as multicellular aggregates from patient effusions by filtration on nylon mesh of defined porosity and examined by light microscopy. The cell clusters ranged from compact to loosely adherent groups of cells to spheroids with a central lumen surrounded by a cell monolayer. There was considerable variation in cluster morphology between effusions from different patients as well as within effusion from the same patient. Apparent budding of clusters was observed as well as different stages of cluster growth and development. This was observed for all histologic types studied. Electron microscopy of serous, mucinous and clear cell types showed that cells forming clusters were attached to each other by desmosomes, demonstrating that cluster formation did not result from a nonspecific stickiness of cells. Irregular micro villi were present on the external periphery of the various carcinoma cells and a prominent glycocalyx was present on the surface of mucinous carcinoma cells. Extensive interdigitation of cytoplasmic extensions and extended villi was present in mucinous and serous clusters which appeared to strengthen cluster cohesiveness. Nuclei were irregular with prominent nucleoli frequently present. The cell clusters usually remained intact and viable in culture but generally did not attach to glass or plastic substrata, whereas mesothelial cells and nonactivated histiocytes rapidly attached. When carcinoma cell clusters did attach, they were resistant to detachment by trypsin-EDTA treatment, in contrast to the nonmalignant cells.

Telomerase activity in human ovarian carcinoma.

“…Sometimes it was possible to obtain enough cells for analysis by filtering ascites cells through a 30-pm nylon mesh (Spectrum), which retains tumor clumps but not the smaller leukocytes, fibroblasts, or mesothelial cells. Filters were backwashed to yield essentially only tumor cell clumps (29,31). Results with this technique were similar to those obtained by fractionating cells by differential attachment.…”

“…Fibroblasts and mesothelial cells (the nonmalignant fraction) were separated from the tumor cells based on their ability to adhere to plastic more readily than tumor cells or most leukocytes (31,32 Protein concentration in the tumor cell extract was 3.3 mg/ml, and in the normal cell extracts 2.1 and 1.9 mg/ml, respectively. Consequently, the 293 cell extract was diluted and assayed at 1.5 mg/ml for proper comparison with the negative extracts.…”

Models of ovarian cancer metastasis: Murine models

“…However, a significant proportion of malignant cells in the ascites of ovarian cancer patients exist as multicellular aggregates. These can differ in size and morphology ranging from compact or loosely adherent groups of cells to spheroids with a central lumen surrounded by a cell monolayer [9]. Multicellular aggregates are particularly important from a clinical standpoint because they exhibit a high level of resistance to radiation and chemotherapy [10,11].…”

Oncolysis of human ovarian cancers by echovirus type 1

“…the multicellular aggregates commonly found in the ascitic fluid of patients with advanced-stage ovarian carcinoma. 36 Having established that monolayer cultures of ovarian cancer cells are highly susceptible to lytic infection by EV1, we next challenged multi-ovarian cancer cell spheroids with EV1. Flow-cytometric analysis determined that surface expression levels of the EV1 cellular receptor a 2 b 1 were comparable, whether DOV13 cells were grown in monolayer or spheroid formation (Fig.…”