GROWTH OF MAMMALIAN MULTICELLULAR TUMOR SPHEROIDS

  • 1 January 1983
    • journal article
    • research article
    • Vol. 43  (2) , 556-560
Abstract
The in vitro growth of small (0.05-3 mm diameter) avascular multicellular tumor spheroids from 6 rodent and 2 human tumor lines [mouse lung carcinoma 498 cells, mammary tumor MCA-11 cells, fibroblast tumor QTA-31 cells, KA-31 cells, rat squamous cell breast carcinoma 3M2N cells, nephroblastoma RLN-13-K2 cells, human breast carcinoma MDA-361 cells, neuroblastoma NB-100 cells] was analyzed. The radial increase of multicellular tumor spheroids is linear with time after a brief initial period of geometric growth. These multicellular tumor spheroids have a constant thickness of proliferative outer crust and of middle nonproliferative but viable mantle. An analytical model for their growth is developed which explains the growth pattern. This constant crust thickness model leads to a progressively diminishing growth fraction as radius increases and should be applicable to such early growth of micrometastases in vivo. The model also provides a procedure for determining cell cycle time.