Tumor.tissue obtained from seven human malignant gliomas was minced
and explanted into agarose-coated culture plates. After five to seven days, these
microtumor fragments emerged as spheroids in four tumors and were maintained as
multicellular organotypic spheroids for more than eight weeks. The morphological
features and growth characteristics of different spheroids were studied and compared
with the histology of the original tumor specimens. Light microscopic and
ultrastructural studies of the spheroids demonstrated that morphological structures
were similar to those of the original tumor tissue in vivo. The microtumor spheroids
contained connective tissue, blood vessels, and macrophages, maintaining a three
dimensional-architectural resemblance to the original tumors. Volumetric measurement
of the spheroids showed that the size decreased initially and did not change thereafter
over a period of time. This growth pattern of the spheroids was consistent with that of
tumors in vivo, suggesting the linkage of cell proliferation and loss. This in vitro culture
system for surgically removed brain tumor specimens may serve as an alternative to
the in vivo xenograft model for the research of brain tumor biology, invasion and immunology
and provide a valuable technique for the evaluation of new therapies, such
as biologic response modifiers
