Growth-related glycogen levels of human intestine carcinoma cell lines grown in vitro and in vivo in nude mice.

The relationship known to exist in vitro between glycogen accumulation and the growth of malignant human intestine epithelial cells was investigated in vivo. The glycogen concentration of 7 human intestine carcinoma cell lines (Caco-2, HT-29, HRT-18, HCT-8R, CO-115, SW-480, and HuTu 80) was measured during cell growth for the in vitro series and during the course of tumor growth for the in vivo series. The glycogen stores were compared for these cells in vitro and after their injection in noninbred Swiss athymic nude mice. The tumors and cultured cells were ranked identically on the basis of glycogen level (Caco-2 > HRT-18 > HT-29 > HCT-8R > CO-115 > SW-480 > HuTu 80). Values for the tumors ranged from 128.8 +/- 10.8 micrograms glycogen/mg protein for Caco-2 tumors down to 2.9 +/- 0.9 micrograms for HuTu 80 tumors; similar values were found for the exponentially growing corresponding cultured cells. The tumor glycogen concentration was independent of the host's nutritional state: Glycogen concentration differed from one type of tumor to another despite its constant level in the liver; fasting did not cause tumor glycogenolysis. By the two experimental approaches, results varied during the growth phases: Stationary phase glycogen concentration increased threefold to fourfold for all cultured cell lines; tumor glycogen concentration, by contrast, was stable throughout the growth period. An inverse relationship was nonetheless found between the rate of tumor growth and tumor glycogen concentration; the highest glycogen content was associated with the slowest growing tumors, and conversely. Apparently, elevated glycogen concentration is regularly associated with decreased cell division rates in vitro and in vivo.