MSH Receptors and the Response of Human A375 Melanoma Cells to Interleukin-1β

Baumann, J. M.; Bagutti, Claudia; Siegrist, Walter; Christen, E.; Zumsteg, Urs; Eberlé, Alex N.

doi:10.3109/10799899709036604

Cited by 5 publications

(4 citation statements)

References 24 publications

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“…A375 malignant melanoma cells were transfected to stably overexpress MC1R for evaluation of the MC1R imaging probes both in vitro and in vivo. The A375 malignant melanoma cell line was chosen due to its very low endogenous expression of MC1R, , providing both low- and high-expressing cells for the in vitro as well as in vivo selectivity studies. qRT-PCR of A375 and A375/MC1R cells revealed the level of MC1R mRNA expression to be ∼100-fold higher in the engineered cells compared to the parental cell line.…”

Section: Resultsmentioning

confidence: 99%

Synthesis and Characterization of a Melanoma-Targeted Fluorescence Imaging Probe by Conjugation of a Melanocortin 1 Receptor (MC1R) Specific Ligand

Tafreshi¹,

Huang²,

Moberg³

et al. 2012

Bioconjugate Chem.

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The incidence of malignant melanoma is rising faster than that of any other cancer in the United States. The melanocortin 1 receptor (MC1R) is overexpressed in most human melanoma metastases, thus making it a promising target for imaging and therapy of melanomas. We have previously reported the development of a peptidomimetic ligand with high specificity and affinity for MC1R. Here, we have conjugated near-infrared fluorescent dyes to the C-terminus of this ligand via lysine-mercaptopropionic acid linkers to generate MC1R specific optical probes (MC1RL-800, 0.4 nM Ki and MC1RL-Cy5, 0.3 nM Ki). Internalization of the imaging probe was studied in vitro by fluorescence microscopy using engineered A375/MC1R cells and B16F10 cells with endogenous MC1R expression. The in vivo tumor targeting of MC1RL-800 was evaluated by intravenous injection of probe into nude mice bearing bilateral subcutaneous A375 xenograft tumors with low MC1R expression and engineered A375/MC1R tumors with high receptor expression. Melanotic B16F10 xenofgrafts were also studied. Fluorescence imaging showed that the agent has higher uptake values in tumors with high expression compared to low (p<0.05), demonstrating the effect of expression levels on image contrast-to-noise. In addition, tumor uptake was significantly blocked by co-injection of excess NDP-α-MSH peptide (p<0.05). In conclusion, the MC1R-specific imaging probe developed in this study displays excellent potential for the intraoperative detection of regional node involvement and for margin detection during melanoma metastasis resection.

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Section: Resultsmentioning

confidence: 99%

Synthesis and Characterization of a Melanoma-Targeted Fluorescence Imaging Probe by Conjugation of a Melanocortin 1 Receptor (MC1R) Specific Ligand

Tafreshi¹,

Huang²,

Moberg³

et al. 2012

Bioconjugate Chem.

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“…Five MC receptor subtypes have been cloned to date (MC-1R-MC-5R) with MC-1R reported to be the subtype expressed exclusively on the surface of melanocytes and melanoma cells (Mountjoy et al, 1992). The MSH receptor status for the cells used in this study have previously been investigated (Ghanem et al, 1988;Goodall et al, 1994;Baumann et al, 1997). The HBL cell line typically expresses 2000-3000 MSH binding sites per cell (Ghanem et al, 1988), in contrast with the A-375SM cell line where 600 sites per cell are usual (Baumann et al, 1997).…”

Section: Resultsmentioning

confidence: 99%

“…The MSH receptor status for the cells used in this study have previously been investigated (Ghanem et al, 1988;Goodall et al, 1994;Baumann et al, 1997). The HBL cell line typically expresses 2000-3000 MSH binding sites per cell (Ghanem et al, 1988), in contrast with the A-375SM cell line where 600 sites per cell are usual (Baumann et al, 1997). It is of note that a strong positive correlation exists between the proportion by which NF-κB was inhibited at a given α-MSH concentration in these two cell types and the above reported receptor numbers.…”

Section: Resultsmentioning

confidence: 99%

α-Melanocyte-Stimulating Hormone Inhibits NF-κB Activation in Human Melanocytes and Melanoma Cells

Haycock

Wagner

Neil

et al. 1999

Journal of Investigative Dermatology

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Alpha-melanocyte-stimulating hormone is produced by several different cell types including neural cells, endothelial cells, monocytes, and keratinocytes. A biologic role in melanocyte pigmentation is widely recognized, but more recent studies describe a part in modulating inflammatory and immune responses. The aim of the this study was to investigate the mechanism by which alpha-melanocyte-stimulating hormone antagonizes proinflammatory cytokine action. We report that alpha-melanocyte-stimulating hormone (10-9 M) was effective in opposing a tumor necrosis factor-alpha stimulated increase in NF-kappaB DNA binding activity in: (i) normal ocular melanocytes; (ii) cells cultured from ocular melanoma tumors; and (iii) two cutaneous melanoma cell lines. NF-kappaB is activated by many inflammatory mediators and controls transcription of genes required for immune and inflammatory responses. The transcription factor complex was positively identified as the p50/p65 heterodimer, recognized to have transcriptional activating potential. Maximum reduction of NF-kappaB DNA binding activity with alpha-melanocyte-stimulating hormone was detected 2 h after cellular stimulation and varied from between 53% and 18% depending on cell type. Whereas the acute inhibitory effects could be mimicked by elevating cyclic adenosine monophosphate, alpha-melanocyte-stimulating hormone was not found to have any effect on the relative level of IkappaBalpha protein expression over 24 h. These data show that alpha-melanocyte-stimulating hormone has a pronounced effect on NF-kappaB activity in melanocytes and melanoma cells, identifying a specific dimeric complex, and suggest this to be a key pathway by which immunomodulation/anti-inflammation may operate. The results may also be considered in the broader context of general inflammatory pathologies concerning cells which express alpha-melanocyte-stimulating hormone receptors and utilize the NF-kappaB signaling pathway.

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“…However, stable transfection of these cells with the wildtype MC-1R showed that these cells were then able to respond to a-MSH with a significant reduction in invasion. The HBL melanoma cell line has previously been demonstrated to express 1000 -3000 MSH receptor-binding sites per cell , and A375 and C8161 melanoma cell lines have also been demonstrated to have MSH receptors (Baumann et al, 1997) and MSH binding sites (Sharma et al, 1996). In comparison, normal human cutaneous melanocytes are reported to express between 300 and 1000 binding sites per cell (Donatien et al, 1992;De Luca et al, 1993).…”

Section: Discussionmentioning

confidence: 99%

Anti-inflammatory and anti-invasive effects of α-melanocyte-stimulating hormone in human melanoma cells

et al. 2003

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a-Melanocyte stimulating hormone (a-MSH) is known to have pleiotrophic functions including pigmentary, anti-inflammatory, antipyretic and immunoregulatory roles in the mammalian body. It is also reported to influence melanoma invasion with levels of a-, b-and g-MSH correlated clinically with malignant melanoma development, but other studies suggest a-MSH acts to retard invasion. In the present study, we investigated the action of a-MSH on three human melanoma cell lines (HBL, A375-SM and C8161) differing in metastatic potential. a-melanocyte-simulating hormone reduced invasion through fibronectin and also through a human reconstructed skin composite model for the HBL line, and inhibited proinflammatory cytokine-stimulated activation of the NF-kB transcription factor. However, A375-SM and C8161 cells did not respond to a-MSH. Immunofluorescent microscopy and Western blotting identified melanocortin-1 receptor (MC-1R) expression for all three lines and MC-2R on HBL and A375-SM lines. Receptor binding identified a similar affinity for a-MSH for all three lines with the highest number of binding sites on HBL cells. Only the HBL melanoma line demonstrated a detectable cyclic adenosine monophosphate (cAMP) response to a-MSH, although all three lines responded to acute a-MSH addition ( þ (À)-N 6 -(2-phenylisopropyl)-adenosine (PIA)) with an elevation in intracellular calcium. The nonresponsive lines displayed MC-1R polymorphisms (C8161, Arg (wt) 151/Cys 151; A375-SM, homozygous Cys 151), whereas the HBL line was wild type. Stable transfection of the C8161 line with wild-type MC-1R produced cells whose invasion was significantly inhibited by a-MSH. From this data, we conclude that a-MSH can reduce melanoma cell invasion and protect cells against proinflammatory cytokine attack in cells with the wild-type receptor (HBL).

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MSH Receptors and the Response of Human A375 Melanoma Cells to Interleukin-1β

Cited by 5 publications

References 24 publications

Synthesis and Characterization of a Melanoma-Targeted Fluorescence Imaging Probe by Conjugation of a Melanocortin 1 Receptor (MC1R) Specific Ligand

Synthesis and Characterization of a Melanoma-Targeted Fluorescence Imaging Probe by Conjugation of a Melanocortin 1 Receptor (MC1R) Specific Ligand

α-Melanocyte-Stimulating Hormone Inhibits NF-κB Activation in Human Melanocytes and Melanoma Cells

Anti-inflammatory and anti-invasive effects of α-melanocyte-stimulating hormone in human melanoma cells

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