Reference

Ultrastructural and enzymic modulation of HeLa cells induced by sodium butyrate and the effects of cytochalasin B and colcemid

Ultrastructural and enzymic modulation of HeLa cells induced by sodium butyrate and the effects of cytochalasin B and colcemid. Deutsch, S. I.; Silvers, D. N.; Cox, R. P.; Griffin, M. J.; Ghosh, N. K. (Med. Cent., New York Univ., New York, N. Y., USA). J. Cell Sci., 21(2), 391-406 (English) 1976. CODEN: JNCSAI. ISSN: 0021-9533. DOCUMENT TYPE: Journal CA Section: 3 (Biochemical Interactions) Sodium butyrate [156-54-7] caused HeLa cells to assume an elongated and jagged shape, this change being assocd. with the formation of bundles of microfilaments. Desmosomes were present between adjacent cells, but no increase in microtubules was obsd. in the butyrate-treated cells. Butyrate increased the activity of 2 membrane-bound enzymes, alk. phosphatase [9001-78-9] and 5'-nucleotidase [9027-73-0]; however, the activity of a 3rd membrane enzyme, acetylcholinesterase [9000-81-1], was reduced. The activities of several other enzymes with different subcellular localizations were not significantly increased. Colcemid [477-30-5] and cytochalasin B [14930-96-2] prevented or reversed the butyrate-mediated change in HeLa cell morphol. and also partially inhibited the induction of alk. phosphatase activity in these cells. The effect of cytochalasin B on alk. phosphatase induction may be caused by a decrease in protein synthesis produced by this fungal metabolite.

Differentiation-inducing agents decrease cryptic prolactin receptors in cultured rat mammary tumor cells

Differentiation-inducing agents decrease cryptic prolactin receptors in cultured rat mammary tumor cells. Costlow, Mark E. (Dep. Biochem., St. Jude Children's Res. Hosp., Memphis, TN 48101, USA). Exp. Cell Res., 155(1), 17-23 (English) 1984. CODEN: ECREAL. ISSN: 0014-4827. DOCUMENT TYPE: Journal CA Section: 2 (Mammalian Hormones) Section cross-reference(s): 13 The effects of DMSO [67-68-5] and Na butyrate [156-54-7] (inducers of differentiation in other cell systems) were examd. in primary cultures of 7,12-dimethylbenzanthracene-induced rat mammary tumors. These substances decreased cryptic prolactin [9002-62-4] receptor levels and inhibited growth. Na butyrate (5 mM) decreased receptor levels within 3 h; by 24 h, receptor levels averaged 11% of the controls. Similarly, DMSO (1-5%) caused a dose-dependent decrease in receptor levels. With 4% DMSO, there was a progressive decrease in prolactin binding to a nadir of 22% of the controls at 12-24 h. Receptor levels returned to pretreatment values by 24 h after the removal of Na butyrate or DMSO. In addn., Na butyrate and DMSO increased the formation of the multicellular structures called domes and the accumulation of lipid droplets. Since Na butyrate and DMSO decreased cryptic sites, inhibited cell growth, and evoked the expression of some morphol. features of differentiation, the loss of cryptic prolactin receptors may thus be involved in the acquisition of a differentiated phenotype in mammary cells.