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microRNA-155, induced by interleukin-1ß, represses the expression of microphthalmia-associated transcription factor (MITF-M) in melanoma cells.

Arts N, Cané S, Hennequart M, Lamy J, Bommer G, Van den Eynde B, De Plaen E - PLoS ONE (2015)

Bottom Line: We previously reported that interleukin-1ß (IL-1ß) can downregulate MITF-M levels.Notably, we also observed a strong negative correlation between MITF-M and miR-155 levels in a mouse model of melanoma.Taken together, our results indicate that MITF-M downregulation by inflammatory stimuli might be partly due to miR-155 upregulation.

View Article: PubMed Central - PubMed

Affiliation: Ludwig Institute for Cancer Research, Brussels and Université Catholique de Louvain, Brussels, Belgium.

ABSTRACT
Loss of expression of surface antigens represents a significant problem for cancer immunotherapy. Microphthalmia-associated transcription factor (MITF-M) regulates melanocyte fate by driving expression of many differentiation genes, whose protein products can be recognized by cytolytic T lymphocytes. We previously reported that interleukin-1ß (IL-1ß) can downregulate MITF-M levels. Here we show that downregulation of MITF-M expression by IL-1ß was paralleled by an upregulation of miR-155 expression in four melanoma lines. We confirmed that miR-155 was able to target endogenous MITF-M in melanoma cells and demonstrated a role for miR-155 in the IL-1ß-induced repression of MITF-M by using an antagomiR. Notably, we also observed a strong negative correlation between MITF-M and miR-155 levels in a mouse model of melanoma. Taken together, our results indicate that MITF-M downregulation by inflammatory stimuli might be partly due to miR-155 upregulation. This could represent a novel mechanism of melanoma immune escape in an inflammatory microenvironment.

No MeSH data available.


Related in: MedlinePlus

miR-155 downregulates MITF-M in LB2201-MEL melanoma cell line.(A) MITF-M and (B) Tyrosinase expression was analyzed by quantitative RT-PCR in melanoma cell line LB2201-MEL 24h and 48h after the transfection with a mimic of miR-155 (30 nM). ß-actin expression was used to normalize MITF-M expression (means ± SD for 3 independent experiments). (C) MITF-M and Tyrosinase protein expression was analyzed by Western Blot in the same cell line 24h and 48h after the transfection with the mimic of miR-155 (30 nM) (1 of 3 independent experiments).
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pone.0122517.g003: miR-155 downregulates MITF-M in LB2201-MEL melanoma cell line.(A) MITF-M and (B) Tyrosinase expression was analyzed by quantitative RT-PCR in melanoma cell line LB2201-MEL 24h and 48h after the transfection with a mimic of miR-155 (30 nM). ß-actin expression was used to normalize MITF-M expression (means ± SD for 3 independent experiments). (C) MITF-M and Tyrosinase protein expression was analyzed by Western Blot in the same cell line 24h and 48h after the transfection with the mimic of miR-155 (30 nM) (1 of 3 independent experiments).

Mentions: Then, to test whether miR-155 was able to target endogenous MITF-M transcripts, we transfected a miR-155 mimic in the melanoma cell line LB2201-MEL. We then evaluated the expression of MITF-M and its target gene tyrosinase at the mRNA and protein levels. On RNA level, we observed a decrease in the abundance of MITF-M mRNA after 24h and 48h (Fig 3A) followed by a decrease of tyrosinase mRNA (Fig 3B). This repression of MITF-M and tyrosinase expression was even stronger at the protein level, in particular at 48h when both proteins were almost undetectable (Fig 3C).


microRNA-155, induced by interleukin-1ß, represses the expression of microphthalmia-associated transcription factor (MITF-M) in melanoma cells.

Arts N, Cané S, Hennequart M, Lamy J, Bommer G, Van den Eynde B, De Plaen E - PLoS ONE (2015)

miR-155 downregulates MITF-M in LB2201-MEL melanoma cell line.(A) MITF-M and (B) Tyrosinase expression was analyzed by quantitative RT-PCR in melanoma cell line LB2201-MEL 24h and 48h after the transfection with a mimic of miR-155 (30 nM). ß-actin expression was used to normalize MITF-M expression (means ± SD for 3 independent experiments). (C) MITF-M and Tyrosinase protein expression was analyzed by Western Blot in the same cell line 24h and 48h after the transfection with the mimic of miR-155 (30 nM) (1 of 3 independent experiments).
© Copyright Policy
Related In: Results  -  Collection

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Show All Figures
getmorefigures.php?uid=PMC4390329&req=5

pone.0122517.g003: miR-155 downregulates MITF-M in LB2201-MEL melanoma cell line.(A) MITF-M and (B) Tyrosinase expression was analyzed by quantitative RT-PCR in melanoma cell line LB2201-MEL 24h and 48h after the transfection with a mimic of miR-155 (30 nM). ß-actin expression was used to normalize MITF-M expression (means ± SD for 3 independent experiments). (C) MITF-M and Tyrosinase protein expression was analyzed by Western Blot in the same cell line 24h and 48h after the transfection with the mimic of miR-155 (30 nM) (1 of 3 independent experiments).
Mentions: Then, to test whether miR-155 was able to target endogenous MITF-M transcripts, we transfected a miR-155 mimic in the melanoma cell line LB2201-MEL. We then evaluated the expression of MITF-M and its target gene tyrosinase at the mRNA and protein levels. On RNA level, we observed a decrease in the abundance of MITF-M mRNA after 24h and 48h (Fig 3A) followed by a decrease of tyrosinase mRNA (Fig 3B). This repression of MITF-M and tyrosinase expression was even stronger at the protein level, in particular at 48h when both proteins were almost undetectable (Fig 3C).

Bottom Line: We previously reported that interleukin-1ß (IL-1ß) can downregulate MITF-M levels.Notably, we also observed a strong negative correlation between MITF-M and miR-155 levels in a mouse model of melanoma.Taken together, our results indicate that MITF-M downregulation by inflammatory stimuli might be partly due to miR-155 upregulation.

View Article: PubMed Central - PubMed

Affiliation: Ludwig Institute for Cancer Research, Brussels and Université Catholique de Louvain, Brussels, Belgium.

ABSTRACT
Loss of expression of surface antigens represents a significant problem for cancer immunotherapy. Microphthalmia-associated transcription factor (MITF-M) regulates melanocyte fate by driving expression of many differentiation genes, whose protein products can be recognized by cytolytic T lymphocytes. We previously reported that interleukin-1ß (IL-1ß) can downregulate MITF-M levels. Here we show that downregulation of MITF-M expression by IL-1ß was paralleled by an upregulation of miR-155 expression in four melanoma lines. We confirmed that miR-155 was able to target endogenous MITF-M in melanoma cells and demonstrated a role for miR-155 in the IL-1ß-induced repression of MITF-M by using an antagomiR. Notably, we also observed a strong negative correlation between MITF-M and miR-155 levels in a mouse model of melanoma. Taken together, our results indicate that MITF-M downregulation by inflammatory stimuli might be partly due to miR-155 upregulation. This could represent a novel mechanism of melanoma immune escape in an inflammatory microenvironment.

No MeSH data available.


Related in: MedlinePlus