Isolation and culture of hamster ectoplacental cone trophoblasts: an in vitro study on the cell types and their growth pattern

The method of isolation of trophoblast cell types from ectoplacental cone of hamster embryo of day 8 post coitum (plug day as day 1) and examination of their growth pattern in vitro is presented in this study. Based on their size, three types of trophoblast cells were identified: (1) the smaller cells having clear cytoplasm formed the major portion (70% to 80%) of the total cell population (2) moderately bigger cells having mono or binucleated appearance and containing minute granules in the nuclear region formed 5% to 10% and (3) extra large and multinucleated cells shared 10% to 20% of the total cell number. While the smaller and slightly bigger cells showed moderate growth the larger ones had extensive growth and were seen to acquire different shapes on extending the duration of culture, such as fusiform, dumb-bell, polygonal, rectangular or flowery. The extremities of the cytoplasmic growth of these cells were seen to be thickened at one end giving the impression of a pad-like structure. The significance of these adaptations are not known at present.     

Surface morphology of hamster (Mesocricetus auratus) decidual cells in vitro

Cell surface morphology of hamster decidual cells isolated from day 8 implantation swellings was studied, using both phase-contrast and scanning electron microscopy. Two kinds of cells, fibroblastic and epithelioid, were identified in cultures examined by phase-contrast microscopy. Fibroblastic cells were spindle-shaped, having pointed or blunt terminals on one end and bifid or webbed projections at the other end. Epithelioid cells, on the other hand, were flat and discoid, having a distinctively ruffled plasma membrane. Further, the plasma membrane of epithelioid cells formed rope-like or flange-like processes. The significance of such adaptations is discussed. © 1995 Wiley-Liss, Inc.     

The Malignant Pleural Effusion as a Model to Investigate Intratumoral Heterogeneity in Lung Cancer

Malignant Pleural Effusions (MPE) may be useful as a model to study hierarchical progression of cancer and/or intratumoral heterogeneity. To strengthen the rationale for developing the MPE-model for these purposes, we set out to find evidence for the presence of cancer stem cells (CSC) in MPE and demonstrate an ability to sustain intratumoral heterogeneity in MPE-primary cultures. Our studies show that candidate lung CSC-expression signatures (PTEN, OCT4, hTERT, Bmi1, EZH2 and SUZ12) are evident in cell pellets isolated from MPE, and MPE-cytopathology also labels candidate-CSC (CD44, cMET, MDR-1, ALDH) subpopulations. Moreover, in primary cultures that use MPE as the source of both tumor cells and the tumor microenvironment (TME), candidate CSC are maintained over time. This allows us to live-sort candidate CSC-fractions from the MPE-tumor mix on the basis of surface markers (CD44, c-MET, uPAR, MDR-1) or differences in xenobiotic metabolism (ALDH). Thus, MPE-primary cultures provide an avenue to extract candidate CSC populations from individual (isogenic) MPE-tumors. This will allow us to test whether these cells can be discriminated in functional bioassays. Tumor heterogeneity in MPE-primary cultures is evidenced by variable immunolabeling, differences in colony-morphology, and differences in proliferation rates of cell subpopulations. Collectively, these data justify the ongoing development of the MPE-model for the investigation of intratumoral heterogeneity, tumor-TME interactions, and phenotypic validation of candidate lung CSC, in addition to providing direction for the pre-clinical development of rational therapeutics.