scholarly journals Inhibition of Rho Is Required for cAMP-induced Melanoma Cell Differentiation

1998 ◽  
Vol 9 (6) ◽  
pp. 1367-1378 ◽  
Author(s):  
Roser Buscà ◽  
Corine Bertolotto ◽  
Patricia Abbe ◽  
Walter Englaro ◽  
Toshimasa Ishizaki ◽  
...  
Keyword(s):  
Cell Differentiation ◽  
Melanoma Cell ◽  
Active Form ◽  
Rho Kinase ◽  
Melanin Synthesis ◽  
Actin Organization ◽  
Melanocyte Stimulating Hormone ◽  
Tyrosinase Gene ◽  
Stimulation Of ◽  
Constitutively Active

Up-regulation of the cAMP pathway by forskolin or α-melanocyte stimulating hormone induces melanocyte and melanoma cell differentiation characterized by stimulation of melanin synthesis and dendrite development. Here we show that forskolin-induced dendricity is associated to a disassembly of actin stress fibers. Since Rho controls actin organization, we studied the role of this guanosine triphosphate (GTP)-binding protein in cAMP-induced dendrite formation.Clostridium botulinum C3 exotransferase, which inhibits Rho, mimicked the effect of forskolin in promoting dendricity and stress fiber disruption, while the Escherichia colitoxin cytotoxic necrotizing factor-1 (CNF-1), which activates Rho and the expression of a constitutively active Rho mutant, blocked forskolin-induced dendrite outgrowth. In addition, overexpression of a constitutively active form of the Rho target p160 Rho-kinase (P160ROCK) prevented the dendritogenic effects of cAMP. Our results suggest that inhibition of Rho and of its target p160ROCK are required events for cAMP-induced dendrite outgrowth in B16 cells. Furthermore, we present evidence that Rho is involved in the regulation of melanogenesis. Indeed, Rho inactivation enhanced the cAMP stimulation of tyrosinase gene transcription and protein expression, while Rho constitutive activation impaired these cAMP-induced effects. This reveals that, in addition to controlling dendricity, Rho also participates in the regulation of melanin synthesis by cAMP.

Stimulation of tyrosinase in human melanocytes by pro-opiomelanocortin-derived peptides

1995 ◽  
Vol 146 (3) ◽  
pp. 439-447 ◽  
Author(s):  
S D McLeod ◽  
C Smith ◽  
R S Mason
Keyword(s):  
Extracellular Matrix ◽  
Corneal Endothelium ◽  
Adrenocorticotropic Hormone ◽  
Test System ◽  
Tyrosinase Activity ◽  
Melanin Synthesis ◽  
Melanocyte Stimulating Hormone ◽  
Kinase C ◽  
Human Melanocytes ◽  
Stimulation Of

Abstract Human melanocytes, maintained on bovine corneal endothelium-derived extracellular matrix for at least 4 days in the absence of phorbol 12-myristate 13-acetate (PMA) and cholera toxin (CT), displayed increased tyrosinase activity when exposed to several pro-opiomelanocortinderived (POMC) peptides. Melanocytes from 9 of 14 donors showed significantly increased tyrosinase activity after treatment with adrenocorticotropic hormone (ACTH; mean increase 320±107 (s.e.m.)% of control, P<0·005), while melanocytes from 8 of 13 donors increased tyrosinase in the presence of diacetyl-melanocyte stimulating hormone (di-MSH; mean increase 223±31 (s.e.m.)% of control, P<0·005). Maximal increases in tyrosinase were seen after treatment with 10−10 m ACTH and with 10−6 m di-MSH. In two cell cultures which showed tyrosinase stimulation, melanin synthesis was similarly increased in the presence of added POMC peptides. PMA but not CT increased tyrosinase activity in melanocytes cultured under these conditions. In the presence of staurosporine, an inhibitor of protein kinase C (PKC), the magnitude of the increase in tyrosinase due to PMA, ACTH and di-MSH was significantly reduced. These results indicate that tyrosinase activity in melanocytes from most human donors, under appropriate conditions, is susceptible to the stimulatory effects of POMC peptides, that ACTH is considerably more potent than di-MSH in this test system and that in human cells the PKC pathway may be important in modulating melanogenesis. Journal of Endocrinology (1995) 146, 439–447

Stimulation of melanin synthesis of B16-F10 mouse melanoma cells by bufalin

Life Sciences ◽  
1992 ◽  
Vol 51 (1) ◽  
pp. 17-24 ◽  
Author(s):  
Lisha Zhang ◽  
Takemi Yoshida ◽  
Yukio Kuroiwa
Keyword(s):  
Melanoma Cells ◽  
Melanin Synthesis ◽  
Mouse Melanoma ◽  
Stimulation Of

Blood vessel formation in the tissue-engineered bone with the constitutively active form of HIF-1α mediated BMSCs

Biomaterials ◽  
2012 ◽  
Vol 33 (7) ◽  
pp. 2097-2108 ◽  
Author(s):  
Duohong Zou ◽  
Zhiyuan Zhang ◽  
Jiacai He ◽  
Kai Zhang ◽  
Dongxia Ye ◽  
...  
Keyword(s):  
Blood Vessel ◽  
Active Form ◽  
Blood Vessel Formation ◽  
Vessel Formation ◽  
Constitutively Active

scholarly journals Constitutively Active Protein Kinase A Qualitatively Mimics the Effects of Follicle-Stimulating Hormone on Granulosa Cell Differentiation

2008 ◽  
Vol 22 (8) ◽  
pp. 1842-1852 ◽  
Author(s):  
Rosalba Escamilla-Hernandez ◽  
Lynda Little-Ihrig ◽  
Kyle E. Orwig ◽  
Junming Yue ◽  
Uma Chandran ◽  
...  
Keyword(s):  
Cell Differentiation ◽  
Protein Kinase ◽  
Protein Kinase A ◽  
Granulosa Cell ◽  
Follicle Stimulating Hormone ◽  
Active Protein ◽  
Kinase A ◽  
Constitutively Active ◽  
Stimulating Hormone

Rho A and the Rho kinase pathway regulate fibroblast contraction: Enhanced contraction in constitutively active Rho A fibroblast cells

2010 ◽  
Vol 399 (2) ◽  
pp. 292-299 ◽  
Author(s):  
Koji Nobe ◽  
Hiromi Nobe ◽  
Hiroko Yoshida ◽  
Michael S. Kolodney ◽  
Richard J. Paul ◽  
...  
Keyword(s):  
Rho Kinase ◽  
Fibroblast Cells ◽  
Rho A ◽  
Kinase Pathway ◽  
Constitutively Active

5-Bromo-2-deoxyuridine regulates invasiveness and expression of integrins and matrix-degrading proteinases in a differentiated hamster melanoma cell

1993 ◽  
Vol 105 (1) ◽  
pp. 191-201 ◽  
Author(s):  
L. Thomas ◽  
P.W. Chan ◽  
S. Chang ◽  
C. Damsky
Keyword(s):  
Extracellular Matrix ◽  
Tumor Progression ◽  
Melanoma Cell ◽  
Critical Role ◽  
Terminal Differentiation ◽  
Cell System ◽  
Melanocyte Stimulating Hormone ◽  
Complex Processes ◽  
Differentiation Marker ◽  
Stimulating Hormone

Cell interactions with the extracellular matrix play a critical role in regulating complex processes such as terminal differentiation and tumor progression. In these studies we describe a melanoma cell system that should be useful in addressing the regulation of cell-matrix interactions and the roles they play in regulating differentiation and cell invasiveness. CS (suspension)-1 melanoma cells are relatively well differentiated: they are melanotic, responsive to melanocyte-stimulating hormone, and express TA99, a melanosome membrane differentiation marker. Their repertoire of integrin receptors for extracellular matrix ligands is limited; in particular, they lack receptors for vitronectin, accounting for the observation that they are nonadherent when cultured in the presence of serum. CS-1 cells are noninvasive as well, and express low levels of both metalloproteinases and activated plasminogen activators. Treatment of these cells with melanocyte-stimulating hormone causes them to increase melanin production and assume an arborized phenotype, suggesting that it promotes their further differentiation. In contrast, treatment of CS-1 with the thymidine analog 5-bromodeoxyuridine, converts them to a highly invasive cell population (termed BCS-1) that loses its differentiated properties and responsiveness to melanocyte-stimulating hormone, acquires a broad integrin repertoire (including vitronectin receptors), and expresses elevated levels of metalloproteinases and activated urokinase. From these observations and findings of others on BrdU treatment of other developmental lineages, we hypothesize that BrdU both suppresses differentiation and promotes invasiveness of CS-1 cells. The demonstrated manipulability of CS-1 cells should make them extremely useful for studying the regulation of both terminal differentiation and tumor progression in the melanocyte lineage.

The effect of exogenous RNA extract on chick embryo fibroblasts in vitro

Development ◽  
1970 ◽  
Vol 23 (2) ◽  
pp. 509-517
Author(s):  
A. Sann ◽  
D. Sharp ◽  
J. McKenzie
Keyword(s):  
Cell Differentiation ◽  
Chick Embryo ◽  
Morphological Changes ◽  
Bacterial Cells ◽  
Baby Hamster Kidney ◽  
Exogenous Rna ◽  
Embryo Fibroblasts ◽  
Stimulation Of ◽  
Rna Extract

It is extremely difficult, if not impossible, to reconcile the conflicting claims of those who have treated different cells and tissues with exogenous RNA. Some authors (e.g. Niu, Cordova & Niu, 1961; Niu, Cordova & Radbill, 1962) maintain that RNA extracts alter the course of cell differentiation to conform in morphological terms to the source of the RNA; in the same vein, Amos, Askonas & Soeiro (1964) have shown that, under certain conditions, RNA from mouse and bacterial cells can stimulate chick embryo fibroblasts to synthesize protein related antigenically to the origin of the RNA. Shepley, Ambrose & Kirby (1965), however, obtained stimulation of growth with permanent morphological changes in baby hamster kidney fibroblasts by the addition of RNA from a variety of sources.

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