A NEW METHOD FOR THE 3-D IN-VITRO GROWTH OF HUMAN RT112 BLADDER-CARCINOMA CELLS USING THE ALGINATE CULTURE TECHNIQUE

We studied the response to different in vitro culture conditions and t he ability for polarization in three-dimensional (3-D) and two-dimensi onal (2-D) cell culture systems of the commonly used human bladder car cinoma cell line RT112. In the case of 2-D culture the cells were grow n on glass or plastic coverslips, filter membranes, or bovine lens cap sules. The alginate culture technique (ACT) was used to test the effec ts of 3-D cell culture on the polarization of the RT112 epithelial cel ls. Our studies show clear differences in the arrangement of the cells depending on the cultivation procedure. The RT112 cells cultured on g lass and plastic supports were irregular and flattened in shape wherea s the cells grown on filters or on lens capsules developed into 2-3 la yers consisting of markedly polarized cells. However, ACT was superior to cell culture on either artificial supports or even on lens capsule . During the 3-D cultivation the transformed epithelial cells regenera ted multicellular spheroids which maintained a tissue-like, geometrica lly well-ordered and highly prismatic organization. This ACT-induced m orphogenesis is novel and distinct from that reported with conventiona l culture conditions. Microscopic investigations showed that RT112 cel ls grown in alginate were both much more tightly packed and more regul arly organized compared to 2-D cultures. In addition, the spheroidal o rganized cells exhibited well developed cell-cell contacts, a distinct endoplasmatic reticulum, and a marked Golgi apparatus. In summary, AC T can he used for 3-D in vitro growth of the transformed human epithel ial cell line RT112 that offers substantial advantages over convention al cell culture methods.