ABSTRACT
This chapter describes a modified organ culture method where tumor biopsy specimens are maintained as spheroids. Surgically removed tissue specimens from human gliomas and from transitional cell carcinomas of the urinary bladder easily form spheroids in agar-overlay culture. Tumor tissue cultured as spheroids from biopsy specimens displays several biological features of the corresponding tumor tissue in vivo. The chapter demonstrates that spheroids maintain their histiotypic architecture and a karyotype stability that is often lost during monolayer subculture. Genetic instability in the tumor cell population is a common feature, and this may lead to great cellular heterogeneity. Such spheroid cultures may be of interest in designing therapy regimens tailored to the specific biological characteristics of the tumor. The spheroids show similar histiotypic features, the same ploidy, and the same amount of proliferating cells, as observed in the original tumor. The morphology of each tumor expiant usually remains similar to the morphology of the original tumor tissue.
