Effects of lactogenic hormones on morphological development and growth of human breast epithelial cells cultivated in collagen gels

A human combined hepatocellular and cholangiocarcinoma cell line (KMCH-2) that shows the features of hepatocellular carcinoma or cholangiocarcinoma under different growth conditions

BACKGROUND/AIMS

Combined hepatocellular and cholangiocarcinoma is a rare tumor of the liver, and its histogenesis remains unclear. The authors addressed this issue in the current article.

METHODS

A specimen aseptically obtained from the surgically resected combined hepatocellular and cholangiocarcinoma was processed for primary culture. The morphologic features of the established cell line cultured on a plastic dish and in type I collagen gel matrix, and transplanted in nude mice were examined.

RESULTS

The authors established a new human combined hepatocellular and cholangiocarcinoma cell line, designated KMCH-2, from a 40-year-old Japanese man. KMCH-2 cells on a plastic dish proliferated in a monolayered sheet with a population doubling time of 32 to 44 h. KMCH-2 expressed functional characteristics of hepatocellular carcinoma, such as albumin synthesis at protein and mRNA levels, but were poorly differentiated in morphology, showing an overlap of features with cholangiocarcinoma. KMCH-2 cells cultured within type I collagen gel matrix proliferated, forming compact to vaguely trabecular and pseudoglandular arrangements, and differentiated to show morphological characteristics of hepatocellular carcinoma unlike the cells on a plastic dish. Mucin production was not detected in KMCH-2 cells in vitro. Subcutaneous tumors which developed in nude mice injected with KMCH-2 cells represented features of adenocarcinoma with mucin production.

CONCLUSIONS

The present results revealed the presence of an albumin-producing human hepatic neoplastic cell, such as KMCH-2, that can differentiate to show not only the features of hepatocellular carcinoma but also those of cholangiocarcinoma under certain growth conditions.

Activity of interferon alpha, interleukin 6 and insulin in the regulation of differentiation in A549 alveolar carcinoma cells

The differentiation of A549, a human tumour cell line from type II pneumocytes, can be induced by a crude fibroblast-derived factor (FDF) isolated from the conditioned medium of glucocorticoid-treated lung fibroblasts. In the present report, we have used alkaline phosphatase as a differentiation marker to investigate the activity of a number of growth factors as potential candidates for this paracrine activity. This showed that insulin, interleukin 6 (IL-6), and interferon alpha (IFN-alpha) could simulate the activity of conditioned medium. Their effects were dexamethasone (DX) dependent, additive and reversible with a half-life of 1 week. Transforming growth factor alpha and beta, IL-1 alpha and epidermal growth factor, were all inhibitory, and inhibition was opposed, partially or completely, by DX. The most potent inducer was IL-6, but as DX was shown to decrease the concentration of IL-6 in lung fibroblast-conditioned medium it seems an unlikely candidate for FDF. Unlike FDF, all of the positive-acting factors were shown to induce plasminogen activator. FDF has also been shown to be active in the absence of DX. This suggests that differentiation-inducing activity may be present in several paracrine factors, but that so far a candidate for FDF has not been identified.

Morphological and biological changes of a hepatocellular carcinoma cell line cultured in a three-dimensional matrix of collagen

A human hepatocellular carcinoma (HCC) cell line, KIM-1, was cultured in three different concentrations (0.1, 0.2 and 0.3%) of type-I collagen gel matrix and its morphologic features, growth kinetics and alpha-fetoprotein and albumin productions were compared with each other or with those of cells growing on a plastic dish. KIM-1 cells in any concentration of collagen gel matrix formed various sized three-dimensional colonies with compact to trabecular cell arrangement. Larger colonies with a more definitive trabecular cell arrangement, resembling the in vivo structure of HCC, tended to form in the collagen gel matrix of a low concentration. The prolongation of doubling time was identified as the collagen concentration in the gel became higher. The cells on a plastic dish proliferated in a monolayered sheet with a shorter doubling time than others. Ultrastructurally, the cells in collagen gel matrix have more distinct cell membranes, junctional complexes and bile canaliculus-like structures, and less cytoskeletons than those on plastic dishes, similar to those in vivo. The productions of alpha-fetoprotein per 10(4) cells and albumin per 10(5) cells were much higher in the collagen gel matrix culture than on a plastic dish in a stationary phase. These data suggest that collagen gel matrix culture is suitable to monitor the morphologic features and protein production of the tumor cells in similar conditions to those in vivo, and tht the three-dimensional presence of an extracellular matrix is important in cellular proliferation and differentiation.

Effects of growth factors on cytokine production in serum-free cultures of human thymic epithelial cells

Human thymic epithelial cells (TEC) of medullary phenotype were cultured for 14 days in a growth factor-defined serum-free medium. The effects of added growth factors on cell numbers and the production of cytokines were investigated by separate exclusion of the various growth factors from the medium. We found that hydrocortisone stimulated cell proliferation but inhibited the differentiation of TEC and significantly reduced the production of interleukin-1 alpha, interleukin-6 and granulocyte-macrophage colony stimulating factor. Insulin was found to enhance the differentiation of TEC and the production of the three cytokines. Transferrin and choleratoxin were found to inhibit cell proliferation, but they did not affect production of the cytokines. Exclusion of epidermal growth factor, however, leads to cell death. We conclude that it is essential to exclude hydrocortisone from the medium to optimize production of cytokines, and that transferrin and choleratoxin seem to be unnecessary constituents in serum-free cultures of human TEC.

Increased drug resistance of cultured human cancer cell lines in three-dimensional cellular growth assay using collagen gel matrix

We have conducted a three-dimensional cellular growth assay using collagen gel matrix with an endpoint of the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-2H tetrazolium bromide (MTT) assay, on four human gastric and colonic cancer cell lines. Three-dimensionally growing cells in collagen gel matrix were 2- to 180-fold more resistant to mitomycin C, doxorubicin, 5-fluorouracil, and cisplatin than those in monolayer culture, and these resistances were increased further when the cells increased their three-dimensionality. Furthermore, the influence of fibroblasts in the collagen gel matrix on the chemosensitivity of cancer cells was less than that in monolayer culture. Since this new assay using collagen gel matrix with an endpoint of the MTT assay was able to detect the increase of drug resistance of human cancer cell lines by three-dimensional cellular growth using a simple and convenient procedure, it was considered to be more useful than conventional monolayer cultures for evaluating the chemosensitivity of cancer cells.