The effects of growth factors and calcium concentrations present in different culture media on induction of terminal differentiation were investigated for four different epidermoid carcinoma cell lines, Hela, KB, A431...The effects of growth factors and calcium concentrations present in different culture media on induction of terminal differentiation were investigated for four different epidermoid carcinoma cell lines, Hela, KB, A431, and SCC-25, and their responses determined relative to those elicited by normal human keratinocytes subjected to these culture conditions. Differentiation status was determined cyto-chemically by a validated keratin protein staining method, and by autoradiographic analyses. Growth and differentiation promoting factors that influenced the direction of integrated control of growth and differentiation in normal human keratinocytes were found to be effective for some cell lines but not others. The factors examined were 1) high density arrest in serum-free and serum-containing media, 2) media shifts from high density culture in serum-containing media to low density growth factor-depleted or supplemented serum-free medium, and 3) the concentration of calcium in the media. The extent and degree of differentiation achieved varied among different cell lines depend on the presence or absence of serum, EGF and insulin protein growth factors. Certain growth media appear to sponsor keratin protein, cyto-chemically-detected differentiation, and evidence of quantal mitotic division in low density HeLa cell and SCC25 cell cultures. Epidermoid carcinoma cell lines retain limited capacity to commit to early stages of cell differentiation.展开更多
Applephenon®, a purified extract prepared from green apples, was examined for its cytotoxicity and inhibitory effects on the proliferation of cultures of normal human keratinocytes and several epidermoid cancer...Applephenon®, a purified extract prepared from green apples, was examined for its cytotoxicity and inhibitory effects on the proliferation of cultures of normal human keratinocytes and several epidermoid cancer cell lines. Our HPLC studies demonstrated a high content of phenolic compounds (>65%), including catechin, epicatechin, caffeic acid and phloretin as well as polyphenols such as proanthocyanidins. Applephenon® demonstrated a greater cytotoxic effect against HeLa, A431 cancer cell lines and HaCaT, an immortalized keratinocyte cell line than serum-free cultures of proliferating normal human keratinocytes (NHK). Proliferation of NHK was inhibited at concentrations above 0.0013% while concentrations above 0.005% were cytotoxic. By contrast, Applephenon® solutions above 0.00025% killed each of the cancer cell lines. Treated cells displayed increased intercellular separation and evidence of keratinizing stratification. We also tested the effect of epicatechin, and two isoflavonoids, genistein and daidzein, on cancer cell lines. Hela cells were more sensitive to epicatechin and genistein inhibition of cell growth and cytotoxicity than were NHK. Daidzein at these concentrations had little effect on cancer cells. These results indicate that Applephenon® and some of its phenolic components have selective anticancer activity.展开更多
文摘The effects of growth factors and calcium concentrations present in different culture media on induction of terminal differentiation were investigated for four different epidermoid carcinoma cell lines, Hela, KB, A431, and SCC-25, and their responses determined relative to those elicited by normal human keratinocytes subjected to these culture conditions. Differentiation status was determined cyto-chemically by a validated keratin protein staining method, and by autoradiographic analyses. Growth and differentiation promoting factors that influenced the direction of integrated control of growth and differentiation in normal human keratinocytes were found to be effective for some cell lines but not others. The factors examined were 1) high density arrest in serum-free and serum-containing media, 2) media shifts from high density culture in serum-containing media to low density growth factor-depleted or supplemented serum-free medium, and 3) the concentration of calcium in the media. The extent and degree of differentiation achieved varied among different cell lines depend on the presence or absence of serum, EGF and insulin protein growth factors. Certain growth media appear to sponsor keratin protein, cyto-chemically-detected differentiation, and evidence of quantal mitotic division in low density HeLa cell and SCC25 cell cultures. Epidermoid carcinoma cell lines retain limited capacity to commit to early stages of cell differentiation.
文摘Applephenon®, a purified extract prepared from green apples, was examined for its cytotoxicity and inhibitory effects on the proliferation of cultures of normal human keratinocytes and several epidermoid cancer cell lines. Our HPLC studies demonstrated a high content of phenolic compounds (>65%), including catechin, epicatechin, caffeic acid and phloretin as well as polyphenols such as proanthocyanidins. Applephenon® demonstrated a greater cytotoxic effect against HeLa, A431 cancer cell lines and HaCaT, an immortalized keratinocyte cell line than serum-free cultures of proliferating normal human keratinocytes (NHK). Proliferation of NHK was inhibited at concentrations above 0.0013% while concentrations above 0.005% were cytotoxic. By contrast, Applephenon® solutions above 0.00025% killed each of the cancer cell lines. Treated cells displayed increased intercellular separation and evidence of keratinizing stratification. We also tested the effect of epicatechin, and two isoflavonoids, genistein and daidzein, on cancer cell lines. Hela cells were more sensitive to epicatechin and genistein inhibition of cell growth and cytotoxicity than were NHK. Daidzein at these concentrations had little effect on cancer cells. These results indicate that Applephenon® and some of its phenolic components have selective anticancer activity.
