Project description:Despite increasing amounts of experimental evidence depicting the involvement of non-coding RNAs in cancer, the study of BRAFV600E-regulated genes has thus far focused mainly on protein-coding ones. Here, we identify and study the microRNAs that BRAFV600E regulates through the ERK pathway. By performing small RNA sequencing on A375 melanoma cells and a vemurafenib- resistant clone that was taken as negative control, we discover miR-204 and miR-211 as the miRNAs most induced by vemurafenib. We also demonstrate that, although belonging to the same family, these two miRNAs have distinctive features. miR-204 is under the control of STAT3 and its expression is induced in amelanotic melanoma cells, where it acts as an effector of vemurafenib’s anti-motility activity by targeting AP1S2. Conversely, miR-211, a known transcriptional target of MITF, is induced in melanotic melanoma cells, where it targets EDEM1 and consequently impairs the degradation of TYROSINASE (TYR) through the ER-associated degradation (ERAD) pathway. In doing so, miR-211 serves as an effector of vemurafenib’s pro-pigmentation activity. We also show that such an increase in pigmentation in turn represents an adaptive response that needs to be overcome using appropriate inhibitors in order to increase the ef cacy of vemurafenib. In summary, we unveil the distinct and context-dependent activities exerted by miR-204 family members in melanoma cells. Our work challenges the widely accepted “same miRNA family = same function” rule and provides a rationale for a novel treatment strategy for melanotic melanomas that is based on the combination of ERK pathway inhibitors with pigmentation inhibitors.
Project description:Despite increasing amounts of experimental evidence depicting the involvement of non-coding RNAs in cancer, the study of BRAFV600E-regulated genes has thus far focused mainly on protein-coding ones. Here, we identify and study the microRNAs that BRAFV600E regulates through the ERK pathway. By performing small RNA sequencing on A375 melanoma cells and a vemurafenib- resistant clone that was taken as negative control, we discover miR-204 and miR-211 as the miRNAs most induced by vemurafenib. We also demonstrate that, although belonging to the same family, these two miRNAs have distinctive features. miR-204 is under the control of STAT3 and its expression is induced in amelanotic melanoma cells, where it acts as an effector of vemurafenib’s anti-motility activity by targeting AP1S2. Conversely, miR-211, a known transcriptional target of MITF, is induced in melanotic melanoma cells, where it targets EDEM1 and consequently impairs the degradation of TYROSINASE (TYR) through the ER-associated degradation (ERAD) pathway. In doing so, miR-211 serves as an effector of vemurafenib’s pro-pigmentation activity. We also show that such an increase in pigmentation in turn represents an adaptive response that needs to be overcome using appropriate inhibitors in order to increase the ef cacy of vemurafenib. In summary, we unveil the distinct and context-dependent activities exerted by miR-204 family members in melanoma cells. Our work challenges the widely accepted “same miRNA family = same function” rule and provides a rationale for a novel treatment strategy for melanotic melanomas that is based on the combination of ERK pathway inhibitors with pigmentation inhibitors.
Project description:Purpose: Identification of miRNAs that enable resistance to BRAF inhibitors in melanoma suggests a mechanism-based strategy to limit resistance and improve clinical outcomes. Methods: We generated A375 melanoma cells resistant to Vemurafenib (VMF) with the goal of investigating changes in miRNA expression patterns that might contribute to resistance. Results: Increased expression of miR-204-5p and miR-211-5p occurring in VMF-resistant cells was determined to impact VMF response.
Project description:mRNA profiles generated from primary fibroblast upon treatment with miR-211, miR-302 or melanoma melanosomes. Abstract: Melanoma originates in the epidermis and enters the metastatic and lethal phase upon invasion into the dermis. However, the interactions between melanoma cells and the dermis prior to this invasion have been poorly studied. Here we uncover that melanoma cells directly affect the formation of the dermal tumor niche by microRNA (miRNA) trafficking prior to invading the dermis. Melanocytes, the cells of melanoma origin, are specialized in trafficking of pigment vesicles, termed melanosomes and, interestingly, melanoma cells retain this trafficking ability. In melanoma in-situ specimens, we found melanosome markers in distal fibroblasts prior to the invasion of melanoma cells into the dermis. Melanoma-derived melanosomes carry miRNAs into primary fibroblasts that trigger changes in the fibroblasts, including increased proliferation, migration, and expression of pro-inflammatory genes, all known features of cancer-associated fibroblasts (CAFs). Specifically, we found that melanosomal miRNA-211 directly targets IGF2R and leads to MAPK signaling activation in fibroblasts, which reciprocally encourages melanoma growth. Treatment of melanoma cells with a melanosome release-inhibitor prevented CAF formation. Since the first interaction of melanoma cells with blood vessels occurs in the dermis, our data suggest a promising opportunity to block melanoma cell invasion by preventing the formation of the dermal tumor niche. In the paper we showed the 10% of most differentially expressed mRNA upon miR-211, miR-320c and melanosomes treatment and overlap of 2000 downregulated mRNA upon miR-211 and melanosomes treatment with predicted target gene miR-211 and CAFs related genes Expresssion profiling was performed for primary fibroblasts transfected with miRNA-211 mimic and miRNA-320c mimic.
Project description:mRNA profiles generated from primary fibroblast upon treatment with miR-211, miR-302 or melanoma melanosomes. Abstract: Melanoma originates in the epidermis and enters the metastatic and lethal phase upon invasion into the dermis. However, the interactions between melanoma cells and the dermis prior to this invasion have been poorly studied. Here we uncover that melanoma cells directly affect the formation of the dermal tumor niche by microRNA (miRNA) trafficking prior to invading the dermis. Melanocytes, the cells of melanoma origin, are specialized in trafficking of pigment vesicles, termed melanosomes and, interestingly, melanoma cells retain this trafficking ability. In melanoma in-situ specimens, we found melanosome markers in distal fibroblasts prior to the invasion of melanoma cells into the dermis. Melanoma-derived melanosomes carry miRNAs into primary fibroblasts that trigger changes in the fibroblasts, including increased proliferation, migration, and expression of pro-inflammatory genes, all known features of cancer-associated fibroblasts (CAFs). Specifically, we found that melanosomal miRNA-211 directly targets IGF2R and leads to MAPK signaling activation in fibroblasts, which reciprocally encourages melanoma growth. Treatment of melanoma cells with a melanosome release-inhibitor prevented CAF formation. Since the first interaction of melanoma cells with blood vessels occurs in the dermis, our data suggest a promising opportunity to block melanoma cell invasion by preventing the formation of the dermal tumor niche. In the paper we showed the 10% of most differentially expressed mRNA upon miR-211, miR-320c and melanosomes treatment and overlap of 2000 downregulated mRNA upon miR-211 and melanosomes treatment with predicted target gene miR-211 and CAFs related genes
Project description:MicroRNAs (miRNAs) influence cancer development through post-transcriptional negative regulation of both tumor suppressors and oncogenes. We subjected melanoma cell lines, normal melanocytes, and keratinocytes to array based miRNA profiling, and identified several distinct miRNAs with differential expression. Specifically, miR-211 levels were depleted in all eight melanoma cell lines examined, and also in 23 of 30 distinct patient melanoma samples (graded as primary in situ, regional metastatic, distant metastatic and nodal metastatic). Putative target genes of miR-211 were identified, and their anticipated increased expression levels were confirmed in melanoma cell lines, which were reduced in two melanoma cell lines that artificially over-expressed miR-211. Four such target genes (TCF12, RAB22A, KCNMA1 and SLC37A3) were confirmed by a target cleavage assay. Stable over-expression of miR-211 in two melanoma cell lines caused significant growth inhibition and reduced invasiveness. The differential expression of miR-211 in a variety of melanoma cell lines and clinical samples, consistent inverse correlation between miR-211 and its target mRNA levels, and growth retardation and reduced invasiveness of melanoma cell lines by miR-211 are all consistent with the idea that the depletion of miR-211 is a key step in melanoma development and/or progression
Project description:MicroRNAs (miRNAs) influence cancer development through post-transcriptional negative regulation of both tumor suppressors and oncogenes. We subjected melanoma cell lines, normal melanocytes, and keratinocytes to array based miRNA profiling, and identified several distinct miRNAs with differential expression. Specifically, miR-211 levels were depleted in all eight melanoma cell lines examined, and also in 23 of 30 distinct patient melanoma samples (graded as primary in situ, regional metastatic, distant metastatic and nodal metastatic). Putative target genes of miR-211 were identified, and their anticipated increased expression levels were confirmed in melanoma cell lines, which were reduced in two melanoma cell lines that artificially over-expressed miR-211. Four such target genes (TCF12, RAB22A, KCNMA1 and SLC37A3) were confirmed by a target cleavage assay. Stable over-expression of miR-211 in two melanoma cell lines caused significant growth inhibition and reduced invasiveness. The differential expression of miR-211 in a variety of melanoma cell lines and clinical samples, consistent inverse correlation between miR-211 and its target mRNA levels, and growth retardation and reduced invasiveness of melanoma cell lines by miR-211 are all consistent with the idea that the depletion of miR-211 is a key step in melanoma development and/or progression The 15 Samples in this submission represent gene-level expression profiling of isolated total RNA from WM1552C, WM1552+miRNA211, A375, A375+miRNA211 and melanocytes hybridized to Affymetrix exon ararys.
Project description:Genome-wide expression analysis of MCF-10A and MCF-7 where miR-204 and miR-211 are overexpressed. The characteristics of differentially expressed genes in both cell lines derives the cells toward being oncogenic.