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Query: UMLS:C0043167 (
pertussis
)
19,595
document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)
Human breast cancer cells have been recently reported to produce endothelin (ET) 1. To investigate the potential regulation of ET production in breast cancer cells, we have measured the release of ET-like immunoreactivity from the T47D cell line in response to various paracrine/endocrine factors. Bombesin (0.1 microM) and cortisol (1 microM) stimulated maximal respective increases in IR-ET release to 580 and 369% of basal values after 6 h. The responses to cortisol and bombesin were additive. The response to bombesin was dose dependent with a median effective dose around 1 nM and was inhibited by the receptor antagonist [Leu13-psi-CH2NH-Leu14]bombesin. Pretreatment of T47D cells with
pertussis
toxin had no effect on bombesin-induced inositol lipid hydrolysis but inhibited ET-like immunoreactivity release in response to bombesin in the presence of glucocorticoid, by 56%. ET-1 (10 nM) and
insulin-like growth factor
(10 ng/ml) stimulated modest separate increases in DNA synthesis in human breast fibroblasts of 35 and 71%, respectively, but together exhibited a strong synergistic response to 905% of control values. This in vitro study demonstrates the potential for bombesin and glucocorticoid to regulate ET production in human breast cancer cells, which may in turn have a paracrine influence on neighboring stromal cell function.
...
PMID:Bombesin and glucocorticoids stimulate human breast cancer cells to produce endothelin, a paracrine mitogen for breast stromal cells. 155 Nov 9
PC-3 human prostatic tumor sublines have been previously isolated which exhibit striking differences in their invasive and metastatic phenotypes. This work has been extended here to measure and compare the levels of kinesin, a microtubule-dependent translocator molecule, in the PC-3 sublines. Western blots, slot blots, radiolabeling, and immunoprecipitation analysis showed that kinesin was expressed in the highly invasive and metastatic sublines at levels which were elevated above the base-line levels observed in the parent PC-3 cells. In comparison, kinesin was not expressed in detectable amounts in the noninvasive cell lines. The conditioned medium of the metastatic PC-3 sublines contained a heat- and trypsin-sensitive protein which exhibited a dosage-dependent capacity to stimulate increased kinesin expression, type IV collagenase secretion, and invasion of Matrigel by the metastatic sublines. The noninvasive sublines failed to secrete a similar stimulatory factor(s) or respond to the conditioned medium of metastatic sublines. Various growth factors and cytokines tested (platelet-derived growth factor, epidermal growth factor,
insulin-like growth factor
, formylmethionineleucinephenylalanine) had no significant effect on either kinesin expression or protease secretion and invasion.
Pertussis
toxin blocked the stimulatory effects of the conditioned medium, but other agents known to interfere with adenylate cyclase pathways (i.e., cholera toxin, forskolin, 8-bromoadenosine) failed to block stimulation. The data show for the first time that kinesin, protease secretion, and the resulting invasion process may be regulated in a coordinated manner by an autocrine factor(s) which activates G-protein-dependent processes.
...
PMID:Regulation of kinesin expression and type IV collagenase secretion in invasive human prostate PC-3 tumor sublines. 165 72
Mastoparan, a basic tetradecapeptide isolated from wasp venom, is a novel mitogen for Swiss 3T3 cells. This peptide induced DNA synthesis in synergy with insulin in a concentration-dependent manner; half-maximum and maximum responses were achieved at 14 and 17 microM, respectively. Mastoparan also stimulated DNA synthesis in the presence of other growth promoting factors including bombesin,
insulin-like growth factor
-1, and platelet-derived growth factor. The synergistic mitogenic stimulation by mastoparan can be dissociated from activation of phospholipase C. Mastoparan did not stimulate phosphoinositide breakdown, Ca2+ mobilization or protein kinase C-mediated phosphorylation of a major cellular substrate or transmodulation of the epidermal growth factor receptor. In contrast, mastoparan stimulated arachidonic acid release, prostaglandin E2 production, and enhanced cAMP accumulation in the presence of forskolin. These responses were inhibited by prior treatment with
pertussis
toxin. Hence, mastoparan stimulates arachidonic acid release via a
pertussis
toxin-sensitive G protein in Swiss 3T3 cells. Arachidonic acid, like mastoparan, stimulated DNA synthesis in the presence of insulin. The ability of mastoparan to stimulate mitogenesis was reduced by
pertussis
toxin treatment. These results demonstrate, for the first time, that mastoparan stimulates reinitiation of DNA synthesis in Swiss 3T3 cells and indicate that this peptide may be a useful probe to elucidate signal transduction mechanisms in mitogenesis.
...
PMID:Mastoparan, a novel mitogen for Swiss 3T3 cells, stimulates pertussis toxin-sensitive arachidonic acid release without inositol phosphate accumulation. 170 71
We previously reported that
insulin-like growth factor
-II (IGF-II) stimulates both calcium influx and DNA synthesis by acting on the cell surface IGF-II receptor (IGF-IIR) in a manner sensitive to
pertussis
toxin, and recently demonstrated that IGF-II binding to the IGF-IIR gives rise to functional changes of purified Gi-2, a GTP-binding protein (G protein) in phospholipid vesicles as well as in broken cell membranes. On the other hand, a variety of evidence indicates that the IGF-IIR binds mannose 6-phosphate (man6P) with high affinity probably at a receptor extracellular region different from the IGF-II-binding site. In the present study, we examined whether man6P stimulation of the IGF-IIR evokes the activation of Gi-2 in phospholipid vesicles and in native cell membranes. In vesicles reconstituted with purified rat IGF-IIR and bovine Gi-2, man6P did not stimulate GDP dissociation from Gi-2 even in concentrations up to 10 mM, while IGF-II dose-dependently facilitated GDP release from Gi-2 with an EC50 of 6 nM. The stimulatory effect of IGF-II was not observed in vesicles reconstituted with Gi-2 alone. In addition, also in a native environment of cell membranes, man6P did not affect an endogenous 40-kDa protein or exogenously added purified Gi-2 as assessed with reduction of the
pertussis
toxin-catalyzed ADP-ribosylation. These results indicate that the IGF-IIR does not activate Gi-like proteins upon man6P binding in phospholipid vesicles and in native cellular membranes, whereas the receptor activates Gi-like proteins upon IGF-II binding in both environments. Thus, we postulate that the IGF-IIR dissimilarly responds to the two structurally unrelated ligands, IGF-II and man6P, in the linkage function with G proteins.
...
PMID:Insulin-like growth factor-II/mannose 6-phosphate receptor is incapable of activating GTP-binding proteins in response to mannose 6-phosphate, but capable in response to insulin-like growth factor-II. 216 Dec 18
In mouse Balb/c3T3 fibroblasts,
insulin-like growth factor
(IGF)-II activates a calcium-permeable cation channel through a cell surface IGF-II receptor (Kojima, I., Nishimoto, I., Iiri, T., Ogata, E., and Rosenfeld, R. G. (1988) Biochem. Biophys. Res. Commun. 154, 9-19; Matsunaga, H., Nishimoto, I., Kojima, I., Yamashita, N., Kurokawa, K., and Ogata, E. (1988) Am. J. Physiol. 255, C442-C446). In the action of IGF-II, a
pertussis
toxin (or islet-activating protein; IAP)-sensitive GTP-binding protein (G protein) is inferred to be involved (Nishimoto, I., Hata, Y., Ogata, E., and Kojima, I. (1987) J. Biol. Chem. 262, 12120-12126). In the present study, we examined the direct coupling of the IGF-II receptor with G proteins. In broken Balb/c3T3 cell membranes, 10 nM IGF-II rapidly attenuated the IAP-catalyzed ADP-ribosylation of a 40-kDa protein in a manner requiring magnesium ion. The IGF-II-mediated attenuation in the IAP substrate activity was 80% recovered after washing off IGF-II and inhibited by coexisting guanosine 5'-O-(2-thiodiphosphate), while either aluminum fluoride solution (10 mM NaF plus 100 microM AlCl3) or 100 microM guanosine 5'-O-(3-thiotriphosphate) (GTP gamma S) reproduced the action of IGF-II. When purified IAP substrate G proteins (Gi1, Gi2, G0) were incubated with IGF-II in the presence of membranes from IAP-treated Balb/c3T3 cells, the attenuation in the IAP substrate activity was evident in Gi2, but not in Gi1 or G0. On the other hand, 10 nM insulin had no effect on the modification of the 40-kDa IAP substrate in Balb/c3T3 cell membranes, whereas 10 nM IGF-I elicited a slow onset of the IAP sensitivity attenuation from the 40-kDa protein. However, the specific involvement of the IGF-II receptor in the modification of the IAP substrate induced by low concentrations of IGF-II was suggested by the observations that (i) IGF-I receptor-lacking cell membranes were effective for the Gi2 modification by IGF-II, (ii) the ability of membranes to mediate the action of IGF-II was markedly attenuated in IGF-II receptor-lacking cell membranes, and (iii) agonistic anti-IGF-II receptor antibody mimicked the action of IGF-II on the 40-kDa protein in Balb/c3T3 cell membranes in a dose-dependent manner similar to that observed in the antibody-induced blocking of membrane IGF-II binding.(ABSTRACT TRUNCATED AT 400 WORDS)
...
PMID:Possible direct linkage of insulin-like growth factor-II receptor with guanine nucleotide-binding proteins. 254 80
Insulin and insulin-like growth factors stimulate motility in the highly metastatic human melanoma cell line, A2058. Insulin-like growth factor-I (IGF-I) is the most potent with a maximal response at a concentration of 10 nM compared to the activities of insulin and
insulin-like growth factor
-II (IGF-II) which peak at 300-400 nM. Using checkerboard analysis, the responses to IGF-I and insulin are predominantly chemotactic, although insulin had a significant chemokinetic component.
Pertussis
toxin does not inhibit the response to any of these polypeptides. However, in previous studies, it was shown that the motile response to autocrine motility factor from these same A2058 cells was markedly inhibited by
pertussis
toxin. 125I-labelled IGF-I binds saturably and specifically to the A2058 cells. Scatchard analysis indicates a high binding affinity (Kd approximately 3 x 10(-10) M) and an estimated 5000 receptors/cell. These studies indicate that in addition to their mitogenic properties, certain growth factors may profoundly enhance metastasis of tumor cells by their ability to induce motility.
...
PMID:Insulin-like growth factors stimulate chemotaxis in human melanoma cells. 329 67
Rat granulosa cell-derived
insulin-like growth factor
(IGF) binding proteins (BPs) have been found subject to biphasic dose-dependent regulation by FSH under in vitro circumstances. Since cAMP may play an intermediary role in FSH hormonal action, we have undertaken to characterize the A kinase-mediated regulation of the elaboration of IGFBPs by cultured rat granulosa cells. Treatment with increasing concentrations of prostaglandin E2 or choleragen, both established cAMP-generating agonists, produced biphasic dose-dependent regulation of the release of the major 28-29 kilodalton (kDa) IGFBP species while promoting the release of their minor 24 (and 19) kDa counterparts. Similar effects were noted for other cAMP-generating agonists including vasoactive intestinal peptide and forskolin (a potent activator of adenylate cyclase). Moreover, concomitant treatment with a functionally inert low dose (10(-7) M) of forskolin, substantially potentiated the FSH (10 ng/ml)-mediated inhibition of the elaboration of the 28-29 kDa IGFBPs. Application of decreasing dilutions of the invasive adenylate cyclase toxin of bordetella
pertussis
(but not of an inactive mutant strain) yielded monophasic dose-dependent modulation of the release of the 28-29 kDa IGFBPs while effecting biphasic regulation of the 24 kDa moiety. Concurrent treatment with 1-methyl-3-isobutylxanthine (a potent inhibitor of cAMP phosphodiesterase activity) at the 10(-4) M level resulted in profound (P < 0.05) inhibition of the (low dose) FSH (3 ng/ml)-supported accumulation of the major 28-29 kDa IGFBP species, an effect associated with modest (2.5-fold) induction (P < 0.05) of the minor 24 kDa IGFBP moiety. Lastly, provision of increasing concentrations of nondegradable lipophilic analogs of cAMP (i.e. (Bu)2cAMP and 8-bromoadenosine cAMP resulted in biphasic dose-dependent modulation of the release of the major 28-29 kDa IGFBP doublet while producing an increase in the accumulation of the minor 24 kDa IGFBP species. Taken together, these observations suggest that the ability of low dose FSH to stimulate and of high dose FSH to inhibit the elaboration of the 28-29 kDa IGFBP species may entail activation of the A-kinase transduction pathway. Similar conclusions appear to apply for the ability of FSH to regulate (albeit at a lower response sensitivity level) the biphasic elaboration of the 24 kDa IGFBP moiety. As such, these observations point out the disparate response sensitivities of distinct IGFBP species, thereby suggesting a novel potent mechanism through which FSH may determine the relative distribution pattern of granulosa cell-derived IGFBPs and the consequent overall IGF responsiveness of this cell type.
...
PMID:A kinase-mediated regulation of granulosa cell-derived insulin-like growth factor binding proteins (IGFBPs): disparate response sensitivities of distinct IGFBP species. 768 61
Effects of insulin and IGF-1 (
insulin-like growth factor
-1) on K+ channel opener-induced/glibenclamide-sensitive K+ currents were studied using follicle-enclosed Xenopus oocytes. Both insulin (4 x 10(-9)-4 x 10(-6) M) and IGF-1 (4 x 10(-10)-4 x 10(-7) M) increased the cromakalim-induced K+ currents in a concentration-dependent manner. The current-facilitating effect of IGF-1 was about ten times as potent as that of insulin. Treatment of the oocyte with
pertussis
toxin (2 micrograms/ml) suppressed the current-potentiating effects of insulin and IGF-1 by about 60%. Although phenylarsine oxide (1-100 microM), a putative inhibitor of protein tyrosine phosphatase, also facilitated the K+ currents, the current enhancing effects were not affected by
pertussis
toxin. These results suggest that insulin and IGF-1 potentiate the glibenclamide-sensitive K+ current by activating IGF-1 receptor and that
pertussis
toxin-sensitive G-protein may be associated with these effects.
...
PMID:Potentiation by insulin and insulin-like growth factor-1 of glibenclamide-sensitive K+ currents in follicle-enclosed Xenopus oocytes. 780 61
Tyrosine kinases are involved in cell signalling of growth factors such as insulin and
insulin-like growth factor
(IGF-I) and others. Insulin and IGF-I receptors which possibly feedback on insulin release are established in insulin-secreting cells. The role of tyrosine kinase in insulin secretion is controversial. Both the tyrosine kinase inhibitors tyrphostin 25 (TYR) and genistein (GEN), but not its structurally similar albeit biologically inactive analogue daidzein, increase insulin release at 16.7 mM glucose in INS-1 cells, an insulin secreting cell line. Tyrosine kinase activity is inhibited by GEN, but not diadzein. The inhibitory effects of either insulin or IGF-I on insulin release are abolished by 10(-4) M GEN but not by daidzein indicating an involvement of tyrosine kinase in the inhibitory effect of both insulin and IGF-I on insulin release. Since GEN was argued not to be specific for tyrosine kinase, several second messengers were investigated. cAMP is not influenced. The insulinotropic effect of acutely administered TPA is not influenced by GEN while in protein kinase C (PKC)-downregulated cells the insulinotropic effect of GEN is preserved: both indicate no involvement of PKC in GEN effect. Since
pertussis
toxin (PT) pretreatment has no effect on the inhibitory effects of IGF-I on insulin release, a PT-sensitive G-protein is not likely to be involved. The data indicate that tyrosine kinase is involved in the inhibitory effects of insulin and IGF on insulin release in INS-1 cells, possibly mediating the negative feedback effect.
...
PMID:Role of tyrosine kinase in insulin release in an insulin secreting cell line (INS-1). 856 11
Long chain saturated fatty acids are known to inhibit breast cancer cell proliferation; however, the mechanism of this inhibition is not known. Treatment of Hs578T breast cancer cells with long chain saturated fatty acids (0.15 mmol/L for 6 hours) before epidermal growth factor (EGF) treatment inhibited EGF-induced cell proliferation in a chain-length-dependent manner. Stearate (C:18) completely inhibited the EGF-induced cell proliferation, whereas palmitate (C:16) inhibited by 67 +/- 8% and myristate (C:14) had no effect. In contrast, stearate had little effect on
insulin-like growth factor
-1-stimulated cell proliferation. The inhibitory effect of stearate on cell proliferation was dose and time dependent and independent of EGF receptor (EGFR) tyrosine phosphorylation. Pretreatment of cells with
pertussis
toxin (0.1 microgram/ml for 24 hours) inhibited the EGF-induced cell growth by 50 +/- 8%, also independent of EGFR tyrosine phosphorylation. A
pertussis
-toxin-sensitive, 41-kd G-protein was specifically co-immunoprecipitated with the EGFR. Pretreatment of cells with 0.15 mmol/L stearate from 0 to 6 hours inhibits, in parallel, both the EGF-induced cell proliferation and
pertussis
-toxin-catalyzed ADP ribosylation of the G-protein associated with the EGFR. These studies suggest that long chain saturated fatty acids inhibit EGF-induced breast cancer cell growth via a mechanism involving an EGFR-G-protein signaling pathway.
...
PMID:Stearate inhibition of breast cancer cell proliferation. A mechanism involving epidermal growth factor receptor and G-proteins. 877 53
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