Prognostic Value of IGF2 mRNA-Binding Protein 3 (IGF2BP3) Intratumoral Expression in Melanoma Patients at the Time of Diagnosis: Comparative Analysis of RT-qPCR Versus Immunohistochemistry.

Screening for prognostic biomarkers is crucial for clinical melanoma management. Insulin-like growth factor-II mRNA-binding protein 3 (IGF2BP3) has emerged as a potential melanoma diagnostic and prognostic biomarker. It is commonly tested by immunohistochemistry (IHC). Our study retrospectively examines IGF2BP3 mRNA and protein expression in primary melanomas, their correlation with clinicopathologic factors, clinical outcome, and selected miRNAs expression, and their efficiency in predicting melanoma progression and survival. RT-qPCR and IHC on IGF2BP3 expression were performed in 61 cryopreserved and 63 formalin-fixed paraffin-embedded primary melanomas, respectively, and correlated to clinicopathologic factors, distant metastasis-free survival (DMFS), and melanoma -specific survival (MSS). The correlation between RT-qPCR and IHC was significant but moderate. IGF2BP3 mRNA showed a stronger association with clinicopathologic factors (Breslow thickness, ulceration, mitosis rate, growth phase, development of metastasis, and melanoma-specific survival) than its protein counterpart. Interestingly, higher IGF2BP3 mRNA expression was detected in primary melanomas that further metastasized to distant sites and was an independent prognostic factor for the risk of unfavorable DMFS and MSS. RT-qPCR outperformed IHC in sensitivity and in predicting worse clinical outcomes. Therefore, RT-qPCR may successfully be implemented for routine IGF2BP3 assessing for the selection of melanoma patients with a higher risk of developing distant metastasis and dying of melanoma.

The Prognostic Value of miR-125b, miR-200c and miR-205 in Primary Cutaneous Malignant Melanoma Is Independent of BRAF Mutational Status.

BRAF mutations are present in around 50% of cutaneous malignant melanomas and are related to a poor outcome in advanced-stage melanoma patients. miRNAs are epigenetic regulators that modulate different cellular processes in cancer, including melanoma development and progression. However, there are no studies on the potential associations of the genetic alterations of the BRAF gene with miRNA expression in primary cutaneous melanomas. Here, in order to analyze the influence of BRAF mutations in the ability of selected miRNAs to predict clinical outcome and patient survival at the time of diagnosis, we studied the prognostic value of miR-125b, miR-200c and miR-205 expression depending on the BRAF mutational status in fresh, frozen primary tumor specimens. For this purpose, RNA was extracted for studying both BRAF mutations by Sanger sequencing and miRNA expression. Our results indicate that, although there seems to be a slight preference for their predictive ability in the BRAF mutated group, the expression of these three miRNAs serves effectively to predict the clinical outcome of melanoma patients independently of BRAF mutational status at the time of primary tumor diagnosis.

Cutaneous Lymphadenoma Is a Distinct Trichoblastoma-like Lymphoepithelial Tumor With Diffuse Androgen Receptor Immunoreactivity, Notch1 Ligand in Reed-Sternberg-like Cells, and Common EGFR Somatic Mutations.

The term "cutaneous lymphadenoma" was coined in this journal for an unusual lymphoepithelial cutaneous adnexal neoplasm, possibly with immature pilosebaceous differentiation. Some authors further proposed that cutaneous lymphadenoma was an adamantinoid trichoblastoma. However, although a hair follicle differentiation is widely accepted, the fact that this is a lymphoepithelial tumor is not appropriately explained by the trichoblastoma hypothesis. Our goal was to further clarify the phenotypic and genotypic features of cutaneous lymphadenoma in a series of 11 cases. Histologically, a lobular architecture surrounded by a dense fibrous stroma was present in all cases. The lobules were composed of epithelial cells admixtured with small lymphocytes and isolated or clustered large Reed-Sternberg-like (RS-L) cells. The epithelial cells were diffusely positive for the hair follicle stem cell markers CK15, PHLDA1, and for androgen receptor. No immunostaining for markers of sebaceous differentiation was found. Intraepithelial lymphocytes were predominantly CD3+, CD4+, FoxP3+ T cells. RS-L cells showed both strong Jagged-1 and Notch1 cytoplasmic immunostaining. Androgen-regulated NKX3.1 nuclear immunostaining was present in a subset of large intralobular cells in all cases. Double immunostaining showed coexpression of NKX3.1 and CD30 in a subset of RS-L cells. No immunostaining for lymphocytic or epithelial markers was present in RS-L cells. EGFR, PIK3CA, and FGFR3 somatic mutations were found by next-generation sequencing in 56% of the cases. We consider that cutaneous lymphadenoma is a distinct benign lymphoepithelial tumor with androgen receptor and hair follicle bulge stem cell marker expression, RS-L cell-derived Notch1 ligand, and common EGFR gene mutations.

Transcriptomic identification of miR-205 target genes potentially involved in metastasis and survival of cutaneous malignant melanoma.

Cutaneous melanoma is an aggressive neoplasm and is responsible for the majority of skin cancer deaths. Several miRNAs are involved in melanoma tumor progression. One of them is miR-205, the loss of which contributes to the development of melanoma metastasis. We evaluated whole-genome mRNA expression profiling associated with different miR-205 expression levels in melanoma cells. Differential expression analysis identified 243 differentially expressed transcripts including inositol polyphosphate 5'-phosphatase-like protein-1 (INPPL1) and BTB/POZ Domain-Containing Protein 3 (BTBD3). INPPL1 and BTBD3 were downregulated when melanoma cells expressed miR-205, indicating that these genes are potential miR-205 targets. Additionally, the target prediction algorithm TargetScan revealed that INPPL1 and BTBD3 genes had predicted target sites of miR-205 in their 3'UTRs and functional analysis demonstrated that these genes were directly linked to miR-205. Interestingly, our clinical data showed that INPPL1 was significantly associated with lymph node metastasis-free survival (LNMFS), distant metastasis-free survival (DMFS) and melanoma specific survival (MSS). This study supports INPPL1 as a miR-205 target gene and, therefore, that the involvement of miR-205 in the metastatic dissemination of malignant melanoma is, at least in part, via INPPL1.

Downregulation of intratumoral expression of miR-205, miR-200c and miR-125b in primary human cutaneous melanomas predicts shorter survival.

While only 15-25 percent of melanoma patients develop distant metastasis and die, this disease is still responsible for the majority of skin cancer-related deaths. The availability of adjuvant therapies makes the selection of high-risk patients essential. We evaluated the intratumoral expression of ten miRNAs in primary melanomas in relation to its ability to predict melanoma survival. To this end, we correlated miRNA expression in 132 cryopreserved primary and metastatic tumors with clinicopathological factors and clinical outcome. We found sequential downregulation of intratumoral expression of miR-125b, miR-182, miR-200c and miR-205 over the full spectrum of melanoma progression. Moreover, downregulation of these miRNAs occurred in primary melanomas that further disseminated to distant sites. Furthermore, miR-125b, miR-200c and miR-205 correlated as independent factors with shorter survival. Our in vitro findings demonstrate that loss of miR-205 potentiates the invasive ability of melanoma cells. We conclude that the downregulation of miR-205 in primary melanomas is an intrinsic property that might contribute to distant metastasis. In particular, the interaction of melanoma cells with the extracellular matrix is one of the key mechanisms by which miR-205 influences melanoma metastasis. In conclusion, miR-125b, miR-200c and miR-205 are useful prognostic biomarkers at the time of diagnosis to select high-risk patients.