Salivary Gland Adenocarcinoma Cell Line Research Articles

ヒト培養唾液腺癌細胞とその分化細胞における細胞分化に依存したコレラ毒素刺激細胞内ｃＡＭＰ産生の増強

We have already reported that a neoplastic human salivary intercalated duct cell line, HSG, which has ultrastructure and biological markers specific to the intercalated duct cells of human salivary gland, can differentiate into both myoepithelial cells and acinar cells after treatment with 5-azacytidine. In addition, these differentiated cells were found to carry decreased tumorigenicity and anchorage-independent growth potential as compared to their parental HSG cells.On the other hand, it has been suggested that cyclic adenosine 3', 5'-monophosphate (cAMP) plays essential roles in controlling cellular proliferation and/or differentiation. For example, in mouse fibroblast lines including 3T3 cells, the growth potentials of cells are inversely associated with the intracellular cAMP levels. In addition, it has been demonstrated that murine erythroleukemia cells and human or murine neuroblastoma cells can be induced to differentiate in response to cAMP. Moreover, an elevation of cAMP in murine neuroblastoma cells has been reported to cause loss of tumorigenicity. Therefore, we examined the differentiation-associated enhancement of cholera toxin-mediated intracellular cAMP production in HSG cells and their differentiated cells.Consequently, the intracellular cAMP levels in response to cholera toxin were higher in the differentiated cells than in their parental HSG cells. Autoradiographic analysis found that the cholera toxin-catalyzed [32P] ADP-ribosylation of Gs protein present in cytoplasmic membranes from the differentiated cells increased as compared to untreated controls. These findings suggest that the cellular proliferation and differentiation in human salivary gland adenocarcinoma cell line HSG are assessed by the levels of cholera toxin-stimulated intracellular cAMP.

Effect of dibutyryl cyclic AMP on morphologic features and biologic markers of a human salivary gland adenocarcinoma cell line in culture.

Dibutyryl cyclic AMP (dB-cAMP) has marked effects on the growth, morphologic features, and biologic markers of a human salivary gland adenocarcinoma cell line in culture. A cell line with ultrastructure and biologic markers specific to the intercalated duct cells of human salivary glands was cultivated in the presence of dB-cAMP. Major alterations, such as process formation and expression of myofilaments and oxytocin receptor in addition to myosin and S-100 protein, were observed in those cells with a phenotype similar to myoepithelial cells. Both the anchorage-independent and anchorage-dependent growths were markedly suppressed in the presence of dB-cAMP. After the removal of dB-cAMP from the culture, the treated cells returned rapidly to the phenotype of the untreated cells. These findings indicate that reversible differentiation into the myoepithelial cells of a human salivary gland adenocarcinoma cell line occurs in growth medium containing dB-cAMP.

Multiple functions of vitamin A.

Multiple functions of vitamin A.

Effects of 5-fluorouracil and the combination of 5-fluorouracil and human leukocyte interferon on human salivary gland adenocarcinoma cell line in culture

The growth inhibitory effects of 5-fluorouracil (5-Fu) and the combination of 5-Fu and human leukocyte interferon (HuIFN-α) on the human salivary gland adenocarcinoma cell line HSG in culture were examined by measuring colony formation in the semi-solid agar medium and cell proliferation in the monolayer culture. As a consequence, the colony-forming ability of HSG cells in the agar medium containing 5-Fu was found to be markedly inhibited as compared with the untreated control. The concentration of 5-Fu yielding 50% inhibition of colony-forming ability of HSG cells under the presence of 5-Fu was 0.08 μg/ml. When the growth inhibitory effects of the combination of 5-Fu and HuIFN-α on HSG cells were examined, the colony forming ability of HSG cells was synergistically inhibited, whereas effects of the combined treatment on HSG cells in the monolayer culture were less sensitive than those on the colony formation. These findings strongly suggest that the combination of 5-Fu and HuIFN-α or 5-Fu alone is selectively effective on the neoplastic cells of HSG cell population but not on the non-neoplastic cells.