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Up-regulated Dicer expression in patients with cutaneous melanoma.

Ma Z, Swede H, Cassarino D, Fleming E, Fire A, Dadras SS - PLoS ONE (2011)

Bottom Line: The expression of Dicer was significantly higher in melanomas compared to benign melanocytic nevi (P<0.0001).In patients with cutaneous melanomas, Dicer up-regulation was found to be significantly associated with an increased tumor mitotic index (P = 0.04), Breslow's depth of invasion (P = 0.03), nodal metastasis (P = 0.04) and a higher American Joint Committee on Caner (AJCC) clinical stage (P = 0.009).Understanding deregulation of Dicer and its influence on miRNA maturation is needed to predict the susceptibility of melanoma patients to miRNA-based therapy in the future.

View Article: PubMed Central - PubMed

Affiliation: Department of Genetics, Stanford University School of Medicine, Stanford, California, United States of America.

ABSTRACT

Background: MicroRNAs (miRNAs) are small non-coding RNAs (18-24 nucleotides) that have recently been shown to regulate gene expression during cancer progression. Dicer, a central enzyme in the multi-component miRNA biogenesis pathway, is involved in cutting precursor miRNAs to functionally mature forms. Emerging evidence shows that Dicer expression is deregulated in some human malignancies and it correlates with tumor progression, yet this role has not yet been investigated in skin cancers.

Methods and findings: Using an anti-human monoclonal antibody against Dicer and immunohistochemistry, we compared the expression of Dicer protein among 404 clinically annotated controls and skin tumors consisting of melanocytic nevi (n = 71), a variety of melanomas (n = 223), carcinomas (n = 73) and sarcomas (n = 12). Results showed a cell-specific up-regulated Dicer in 81% of cutaneous, 80% of acrolentiginous and 96% of metastatic melanoma specimens compared to carcinoma or sarcoma specimens (P<0.0001). The expression of Dicer was significantly higher in melanomas compared to benign melanocytic nevi (P<0.0001). In patients with cutaneous melanomas, Dicer up-regulation was found to be significantly associated with an increased tumor mitotic index (P = 0.04), Breslow's depth of invasion (P = 0.03), nodal metastasis (P = 0.04) and a higher American Joint Committee on Caner (AJCC) clinical stage (P = 0.009). Using western blot analysis, we confirmed the cell-specific up-regulation of Dicer protein in vitro. A pooled-analysis on mRNA profiling in cutaneous tumors showed up-regulation of Dicer at the RNA level in cutaneous melanoma, also showing deregulation of other enzymes that participate in the biogenesis and maturation of canonical miRNAs.

Conclusions: Increased Dicer expression may be a clinically useful biomarker for patients with cutaneous melanoma. Understanding deregulation of Dicer and its influence on miRNA maturation is needed to predict the susceptibility of melanoma patients to miRNA-based therapy in the future.

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Related in: MedlinePlus

Dicer expression was cancer-cell specific among cutaneous malignancies and was significantly higher in primary and metastatic melanoma compared to common melanocytic nevus.A) Primary cutaneous (n = 95) and metastatic (n = 52) melanomas had the highest levels of Dicer immunoreactivity vs. carcinomas (n = 73) and sarcomas (n = 12). B) Cutaneous (n = 95) and acrolentiginous (n = 40) melanomas had the highest levels of Dicer immunoreactivity vs. melanocytic nevi (n = 71), mucosal (n = 24) and desmoplastic (n = 8) melanomas. Dicer immunoreactivity is shown as mean (boxed) ±2 standard error (SE). The statistical significance was measured for all independent samples comparing to each other (Kruskal-Wallis Test, P<0.0001). C) Pooled analysis performed on publically available transcriptional profiling data showed significant changes in Dicer mRNA levels during melanoma progression. This analysis included 25,135 genes from 20 disease groups and 139 individual specimens of squamous cell carcinoma (SCC), basal cell carcinoma (BCC), primary melanoma (PM), common nevus (CN), dysplastic nevus with low (DNL), dysplastic nevus with high atypia (DNH), primary melanoma vertical growth phase (PM VGP), melanoma in situ (MIS), lymph node melanoma metastases (LNMM), dermal melanoma metastases (DMM), normal skin (NS) and melanoma metastases (MM) [21], [22]. Dicer1 ranked among the top 20% most significantly altered genes.
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pone-0020494-g003: Dicer expression was cancer-cell specific among cutaneous malignancies and was significantly higher in primary and metastatic melanoma compared to common melanocytic nevus.A) Primary cutaneous (n = 95) and metastatic (n = 52) melanomas had the highest levels of Dicer immunoreactivity vs. carcinomas (n = 73) and sarcomas (n = 12). B) Cutaneous (n = 95) and acrolentiginous (n = 40) melanomas had the highest levels of Dicer immunoreactivity vs. melanocytic nevi (n = 71), mucosal (n = 24) and desmoplastic (n = 8) melanomas. Dicer immunoreactivity is shown as mean (boxed) ±2 standard error (SE). The statistical significance was measured for all independent samples comparing to each other (Kruskal-Wallis Test, P<0.0001). C) Pooled analysis performed on publically available transcriptional profiling data showed significant changes in Dicer mRNA levels during melanoma progression. This analysis included 25,135 genes from 20 disease groups and 139 individual specimens of squamous cell carcinoma (SCC), basal cell carcinoma (BCC), primary melanoma (PM), common nevus (CN), dysplastic nevus with low (DNL), dysplastic nevus with high atypia (DNH), primary melanoma vertical growth phase (PM VGP), melanoma in situ (MIS), lymph node melanoma metastases (LNMM), dermal melanoma metastases (DMM), normal skin (NS) and melanoma metastases (MM) [21], [22]. Dicer1 ranked among the top 20% most significantly altered genes.

Mentions: Overall, when compared among all examined cutaneous malignancies, Dicer up-regulation was tumor-type specific by immunostaining, as Dicer was highly expressed by melanomas (metastatic and cutaneous) compared to carcinomas or sarcomas (P<0.0001, Fig. 3A). Furthermore Dicer up-regulation was specific to the melanoma subtype, i.e. cutaneous and acrolentiginous compared to mucosal and desmoplastic melanomas (P<0.0001, Fig. 3B). Importantly, higher Dicer levels were detected in cutaneous, acrolentiginous and metastatic melanomas compared to common melanocytic nevi. To confirm the up-regulation of Dicer in melanoma, we performed a pooled analysis by mining published whole genome oligo-microarray dataset on two recent large studies that profiled gene expression pattern in excisional specimens of cutaneous tumors (n = 139) [21], [22]. The combined dataset included 20 different disease groups consisting of cutaneous melanoma in various stages (in situ, Clark level I and II-radial growth phase, Clark level III, IV and V-vertical growth phase), melanoma metastases to skin and lymph node, common acquired melanocytic nevi, dysplastic nevi with low and high atypia, normal skin, basal cell carcinoma and squamous cell carcinoma (Table 2). The combined dataset provided 25,135 genes, which we interrogated for Dicer mRNA expression levels. Comparing cutaneous melanoma to other skin cancers, squamous and basal cell carcinoma, or normal skin (mostly consisting of keratinocytes) showed significantly higher levels Dicer mRNA in melanoma (Fig. 3C, Table 2), confirming our immunostaining results (Fig. 3A) and indicating an up-regulation at the level of mRNA accumulation. Furthermore, invasive and metastatic melanomas had significantly higher levels of Dicer mRNA than common melanocytic nevi (Fig. 3C, Table 2), again confirming our immunostaining results (Fig. 3B). Interestingly, the Dicer mRNA levels are decreased in dysplastic when compared common melanocytic nevi and in melanoma in situ when compared to invasive (Fig. 3C, Table 2). Overall, these results showed that Dicer up-regulation, at both the protein and the RNA levels, is specific to melanoma subtypes and that Dicer levels are higher in primary cutaneous and metastatic melanomas compared to common melanocytic nevi.


Up-regulated Dicer expression in patients with cutaneous melanoma.

Ma Z, Swede H, Cassarino D, Fleming E, Fire A, Dadras SS - PLoS ONE (2011)

Dicer expression was cancer-cell specific among cutaneous malignancies and was significantly higher in primary and metastatic melanoma compared to common melanocytic nevus.A) Primary cutaneous (n = 95) and metastatic (n = 52) melanomas had the highest levels of Dicer immunoreactivity vs. carcinomas (n = 73) and sarcomas (n = 12). B) Cutaneous (n = 95) and acrolentiginous (n = 40) melanomas had the highest levels of Dicer immunoreactivity vs. melanocytic nevi (n = 71), mucosal (n = 24) and desmoplastic (n = 8) melanomas. Dicer immunoreactivity is shown as mean (boxed) ±2 standard error (SE). The statistical significance was measured for all independent samples comparing to each other (Kruskal-Wallis Test, P<0.0001). C) Pooled analysis performed on publically available transcriptional profiling data showed significant changes in Dicer mRNA levels during melanoma progression. This analysis included 25,135 genes from 20 disease groups and 139 individual specimens of squamous cell carcinoma (SCC), basal cell carcinoma (BCC), primary melanoma (PM), common nevus (CN), dysplastic nevus with low (DNL), dysplastic nevus with high atypia (DNH), primary melanoma vertical growth phase (PM VGP), melanoma in situ (MIS), lymph node melanoma metastases (LNMM), dermal melanoma metastases (DMM), normal skin (NS) and melanoma metastases (MM) [21], [22]. Dicer1 ranked among the top 20% most significantly altered genes.
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Related In: Results  -  Collection

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getmorefigures.php?uid=PMC3117784&req=5

pone-0020494-g003: Dicer expression was cancer-cell specific among cutaneous malignancies and was significantly higher in primary and metastatic melanoma compared to common melanocytic nevus.A) Primary cutaneous (n = 95) and metastatic (n = 52) melanomas had the highest levels of Dicer immunoreactivity vs. carcinomas (n = 73) and sarcomas (n = 12). B) Cutaneous (n = 95) and acrolentiginous (n = 40) melanomas had the highest levels of Dicer immunoreactivity vs. melanocytic nevi (n = 71), mucosal (n = 24) and desmoplastic (n = 8) melanomas. Dicer immunoreactivity is shown as mean (boxed) ±2 standard error (SE). The statistical significance was measured for all independent samples comparing to each other (Kruskal-Wallis Test, P<0.0001). C) Pooled analysis performed on publically available transcriptional profiling data showed significant changes in Dicer mRNA levels during melanoma progression. This analysis included 25,135 genes from 20 disease groups and 139 individual specimens of squamous cell carcinoma (SCC), basal cell carcinoma (BCC), primary melanoma (PM), common nevus (CN), dysplastic nevus with low (DNL), dysplastic nevus with high atypia (DNH), primary melanoma vertical growth phase (PM VGP), melanoma in situ (MIS), lymph node melanoma metastases (LNMM), dermal melanoma metastases (DMM), normal skin (NS) and melanoma metastases (MM) [21], [22]. Dicer1 ranked among the top 20% most significantly altered genes.
Mentions: Overall, when compared among all examined cutaneous malignancies, Dicer up-regulation was tumor-type specific by immunostaining, as Dicer was highly expressed by melanomas (metastatic and cutaneous) compared to carcinomas or sarcomas (P<0.0001, Fig. 3A). Furthermore Dicer up-regulation was specific to the melanoma subtype, i.e. cutaneous and acrolentiginous compared to mucosal and desmoplastic melanomas (P<0.0001, Fig. 3B). Importantly, higher Dicer levels were detected in cutaneous, acrolentiginous and metastatic melanomas compared to common melanocytic nevi. To confirm the up-regulation of Dicer in melanoma, we performed a pooled analysis by mining published whole genome oligo-microarray dataset on two recent large studies that profiled gene expression pattern in excisional specimens of cutaneous tumors (n = 139) [21], [22]. The combined dataset included 20 different disease groups consisting of cutaneous melanoma in various stages (in situ, Clark level I and II-radial growth phase, Clark level III, IV and V-vertical growth phase), melanoma metastases to skin and lymph node, common acquired melanocytic nevi, dysplastic nevi with low and high atypia, normal skin, basal cell carcinoma and squamous cell carcinoma (Table 2). The combined dataset provided 25,135 genes, which we interrogated for Dicer mRNA expression levels. Comparing cutaneous melanoma to other skin cancers, squamous and basal cell carcinoma, or normal skin (mostly consisting of keratinocytes) showed significantly higher levels Dicer mRNA in melanoma (Fig. 3C, Table 2), confirming our immunostaining results (Fig. 3A) and indicating an up-regulation at the level of mRNA accumulation. Furthermore, invasive and metastatic melanomas had significantly higher levels of Dicer mRNA than common melanocytic nevi (Fig. 3C, Table 2), again confirming our immunostaining results (Fig. 3B). Interestingly, the Dicer mRNA levels are decreased in dysplastic when compared common melanocytic nevi and in melanoma in situ when compared to invasive (Fig. 3C, Table 2). Overall, these results showed that Dicer up-regulation, at both the protein and the RNA levels, is specific to melanoma subtypes and that Dicer levels are higher in primary cutaneous and metastatic melanomas compared to common melanocytic nevi.

Bottom Line: The expression of Dicer was significantly higher in melanomas compared to benign melanocytic nevi (P<0.0001).In patients with cutaneous melanomas, Dicer up-regulation was found to be significantly associated with an increased tumor mitotic index (P = 0.04), Breslow's depth of invasion (P = 0.03), nodal metastasis (P = 0.04) and a higher American Joint Committee on Caner (AJCC) clinical stage (P = 0.009).Understanding deregulation of Dicer and its influence on miRNA maturation is needed to predict the susceptibility of melanoma patients to miRNA-based therapy in the future.

View Article: PubMed Central - PubMed

Affiliation: Department of Genetics, Stanford University School of Medicine, Stanford, California, United States of America.

ABSTRACT

Background: MicroRNAs (miRNAs) are small non-coding RNAs (18-24 nucleotides) that have recently been shown to regulate gene expression during cancer progression. Dicer, a central enzyme in the multi-component miRNA biogenesis pathway, is involved in cutting precursor miRNAs to functionally mature forms. Emerging evidence shows that Dicer expression is deregulated in some human malignancies and it correlates with tumor progression, yet this role has not yet been investigated in skin cancers.

Methods and findings: Using an anti-human monoclonal antibody against Dicer and immunohistochemistry, we compared the expression of Dicer protein among 404 clinically annotated controls and skin tumors consisting of melanocytic nevi (n = 71), a variety of melanomas (n = 223), carcinomas (n = 73) and sarcomas (n = 12). Results showed a cell-specific up-regulated Dicer in 81% of cutaneous, 80% of acrolentiginous and 96% of metastatic melanoma specimens compared to carcinoma or sarcoma specimens (P<0.0001). The expression of Dicer was significantly higher in melanomas compared to benign melanocytic nevi (P<0.0001). In patients with cutaneous melanomas, Dicer up-regulation was found to be significantly associated with an increased tumor mitotic index (P = 0.04), Breslow's depth of invasion (P = 0.03), nodal metastasis (P = 0.04) and a higher American Joint Committee on Caner (AJCC) clinical stage (P = 0.009). Using western blot analysis, we confirmed the cell-specific up-regulation of Dicer protein in vitro. A pooled-analysis on mRNA profiling in cutaneous tumors showed up-regulation of Dicer at the RNA level in cutaneous melanoma, also showing deregulation of other enzymes that participate in the biogenesis and maturation of canonical miRNAs.

Conclusions: Increased Dicer expression may be a clinically useful biomarker for patients with cutaneous melanoma. Understanding deregulation of Dicer and its influence on miRNA maturation is needed to predict the susceptibility of melanoma patients to miRNA-based therapy in the future.

Show MeSH
Related in: MedlinePlus