Critical role of miR-10b in B-RafV600E dependent anchorage independent growth and invasion of melanoma cells

Abstract

Recent high-throughput-sequencing of cancer genomes has identified oncogenic mutations in the B-Raf genetic locus as one of the critical events in melanomagenesis. B-Raf encodes a serine/threonine kinase that regulates the MAPK/ERK kinase (MEK) and extracellular signal-regulated kinase (ERK) protein kinase cascade. In normal cells, the activity of B-Raf is tightly regulated and is required for cell growth and survival. B-Raf gain-of-function mutations in melanoma frequently lead to unrestrained growth, enhanced cell invasion and increased viability of cancer cells. Although it is clear that the invasive phenotypes of B-Raf mutated melanoma cells are stringently dependent on B-Raf-MEK-ERK activation, the downstream effector targets that are required for oncogenic B-Raf-mediated melanomagenesis are not well defined. miRNAs have regulatory functions towards the expression of genes that are important in carcinogenesis. We observed that miR-10b expression correlates with the presence of the oncogenic B-Raf ( B-Raf V600E ) mutation in melanoma cells. While expression of miR-10b enhances anchorage-independent growth of B-Raf wild-type melanoma cells, miR-10b silencing decreases B-Raf V600E cancer cell invasion in vitro . Importantly, the expression of miR-10b is required for B-Raf V600E -mediated anchorage independent growth and invasion of melanoma cells in vitro . Taken together our results suggest that miR-10b is an important mediator of oncogenic B-Raf V600E activity in melanoma.

Multiomic analysis of microRNA-mediated regulation reveals a proliferative axis involving miR-10b in fibrolamellar carcinoma

“…MiR-483-5p (Figure 5B) and miR-10b (Figure 5C) exhibited the greatest decrease and increase in transcription, respectively, in FLC relative to NML (Figure 5A). It has been reported in other cancer types (35)(36)(37) that miR-10b is transcriptionally activated by the Twist1 transcription factor, and we identified a ~3-fold increase of TWIST1 expression in FLC (Supplemental Figure 3A). However, we observed that increasing patient age at the time of surgery.…”

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“…MiR-483-5p (Figure 5B) and miR-10b (Figure 5C) exhibited the greatest decrease and increase in transcription, respectively, in FLC relative to NML (Figure 5A). It has been reported in other cancer types (35)(36)(37) that miR-10b is transcriptionally activated by the Twist1 transcription factor, and we identified a ~3-fold increase of TWIST1 expression in FLC (Supplemental Figure 3A). However, we observed that increasing patient age at the time of surgery.…”

Untitled

“…MiR-483-5p (Figure 5B) and miR-10b (Figure 5C) exhibited the greatest decrease and increase in transcription, respectively, in FLC relative to NML (Figure 5A). It has been reported in other cancer types (35)(36)(37) that miR-10b is transcriptionally activated by the Twist1 transcription factor, and we identified a ~3-fold increase of TWIST1 expression in FLC (Supplemental Figure 3A). However, we observed that increasing patient age at the time of surgery.…”