ABSTRACT
This chapter focuses on the use of multicellular tumor spheroids as a model for studies of drug effects and recently published results. A general growth pattern can be described for the growth of tumor spheroids. The spheroids have an outer layer of proliferating cells and an inside layer of mainly quiescent cells. Spheroids contain an extensive extracellular matrix composed of fibronectin, laminin, and collagen in a proteoglycan gel. Two different methods have been described for spheroid culture: the liquid overlay culture method and the spinner flask technique. Cells growing as spheroids are generally less sensitive to the action of anticancer drugs than are the corresponding cells growing as monolayers. Growth curves have been measured to quantify the effects of anticancer drugs. Growth curves for liquid-overlay-cultured spheroids can be constructed from measurements with a reticle manipulated by a micrometer screw in the eyepiece of an inverted microscope.
