State of the science 60th anniversary review: 60 Years of advances in cutaneous melanoma epidemiology, diagnosis, and treatment, as reported in the journal Cancer

DNA methylation-induced E-cadherin silencing is correlated with the clinicopathological features of melanoma

E-cadherin, a calcium-dependent cell-cell adhesion molecule, has an important role in epithelial cell function, maintenance of tissue architecture and cancer suppression. Loss of E-cadherin promotes tumor metastatic dissemination and predicts poor prognosis. The present study investigated the clinicopathological significance of E-cadherin expression in cutaneous, mucosal and uveal melanoma related to epigenetic mechanisms that may contribute to E-cadherin silencing. E-cadherin expression was reduced in 55/130 cutaneous (42.3%), 49/82 mucosal (59.7%) and 36/64 uveal (56.2%) melanoma samples as compared to normal skin controls and was inversely associated with promoter methylation. Of the 10 different CpG sites studied (nt 863, 865, 873, 879, 887, 892, 901, 918, 920 and 940), two sites (nt 892 and 940) were 90-100% methylated in all the melanoma specimens examined and the other ones were partially methylated (range, 53-86%). In contrast, the methylation rate of the E-cadherin gene was low in normal tissues (range, 5-24%). In all the three types of melanoma studied, a significant correlation was found between reduced levels of E-cadherin and reduced survival, high mitotic index and metastasis, accounting for the predilection of lymph nodal localization. In cutaneous and mucosal melanoma, low E-cadherin expression was positively correlated also with head/neck localization and ulceration. A high frequency of reduced E-cadherin levels occurred in choroid melanomas. In vitro experiments showed that E-cadherin transcription was restored following 5-aza-2'-deoxycytidine (5-aza-dC) treatment or DNMT1 silencing and was negatively correlated with the invasive potential of melanoma cells. The significant relationship between E-cadherin silencing and several poor prognostic factors indicates that this adhesion molecule may play an important role in melanomagenesis. Therefore, the inverse association of E-cadherin expression with promoter methylation raises the intriguing possibility that reactivation of E-cadherin expression through promoter demethylation may represent a potential therapeutic strategy for the treatment of melanoma.

Prognostic Significance of CD169+ Lymph Node Sinus Macrophages in Patients with Malignant Melanoma

CD169 (sialoadhesin) is a sialic acid receptor that is specifically expressed on macrophages, including lymph node sinus macrophages. Animal studies suggest that CD169(+) macrophages in lymph nodes have properties in preventing cancers. In order to determine the significance of CD169(+) macrophages in patients with malignant melanoma, we evaluated tissue samples from 93 patients to investigate CD169 expression in regional lymph nodes (RLN) and determine the relationship of this expression with overall survival and various clinicopathologic factors. Higher densities of CD169(+) cells were significantly associated with longer overall survival (P = 0.001). A multivariate analysis showed that the density of CD169(+) cells was an independent prognostic factor, with higher densities correlating with higher density of CD8(+) cytotoxic T cells within tumor sites. High CD169 expression in macrophages could be stimulated by IFNα in vitro, and in RLNs, IFNα-producing macrophages and CD303(+) plasmacytoid dendritic cells were identified surrounding CD169(+) macrophages. These data suggest that IFNα-stimulated CD169(+) macrophages in RLNs are closely involved in T-cell-mediated antitumor immunity and may be a useful marker for assessing the clinical prognosis and monitoring antitumor immunity in patients with malignant melanoma.

Nectin like-5 overexpression correlates with the malignant phenotype in cutaneous melanoma

NECL-5 is involved in regulating cell–cell junctions, in cooperation with cadherins, integrins and platelet-derived growth factor receptor, that are essential for intercellular communication. Its role in malignant transformation was previously described. It has been reported that transformation of melanocytes is associated with altered expression of adhesion molecules suggesting the potential involment of NECL-5 in melanoma development and prognosis. To shed light on this issue, the expression and the role of NECL-5 in melanoma tissues was investigated by bioinformatic and molecular approaches. NECL-5 was up-regulated both at the mRNA and the protein levels in WM35, M14 and A375 cell lines compared with normal melanocytes. A subsequent analysis in primary and metastatic melanoma specimens confirmed “in vitro” findings. NECL-5 overexpression was observed in 53 of 59 (89.8%) and 12 of 12 (100%), primary melanoma and melanoma metastasis, respectively; while, low expression of NECL-5 was detected in 12 of 20 (60%) benign nevi. A significant correlation of NECL-5 overexpression was observed with most of known negative melanoma prognostic factors, including lymph-node involvement (P = 0.009) and thickness (P = 0.004). Intriguingly, by analyzing the large series of melanoma samples in the Xu dataset, we identified the transcription factor YY1 among genes positively correlated with NECL-5 (r = 0.5). The concordant computational and experimental data of the present study indicate that the extent of NECL-5 expression correlates with melanoma progression.

Primary oral melanoma: a histopathological and immunohistochemical study of 22 cases of Latin America

OBJECTIVE

The aim of this study was to analyze the histopathological and immunohistochemical characteristics of 22 cases of primary oral melanomas (OM).

STUDY DESIGN

Twenty two cases of primary oral melanoma were analyzed by description of their histopathological features and immunohistochemical study using the antibodies S-100, HMB-45, Melan-A and Ki-67.

RESULTS

The mean age was 58 years and 14 cases were female. The main affected sites were the hard palate, followed by the upper gingiva. Microscopically, 15 cases presented level III of invasion, 2 cases were amelanotic and 13 showed a mixed epithelioid and plasmacytoid or spindle cells composition. Some cases showed necrosis, perivascular and perineural invasion. S-100 and HMB-45 were positive in all cases, but 3 cases were negative for Melan-A. The proliferative index with Ki-67 was high, with labeling index ranging from 15.51% to 63% of positive cells.

CONCLUSION

S-100 and HMB-45 are more frequently expressed than Melan-A in primary oral melanomas and these markers are helpful to confirm the diagnosis.

Surgical management of primary disease

Despite advancements in the treatment of melanoma, surgical management remains the cornerstone for treatment and long-term survival. The authors present their surgical approach to the patient with melanoma including evaluation, treatment, and reconstruction. In addition, management of melanoma occurring in difficult anatomic areas and in special patient populations is reviewed.

Patterns of GRP78 and MTJ1 expression in primary cutaneous malignant melanoma

Cell surface expression of glucose-regulated protein 78 (GRP78) occurs in several types of cancer; however, its role in the behavior of primary cutaneous melanoma is not well studied. The association of cell surface GRP78 with other proteins such as MTJ1 stimulates cell proliferation. In this study, we characterized the pattern of expression of GRP78 and MTJ1 in invasive primary cutaneous melanomas and analyzed the relationships between the pattern of expression and various clinicopathological parameters. We found two patterns of GRP78 expression in invasive primary cutaneous melanoma. One pattern showed a gradual fading of protein expression from superficial to deeper levels within the same tumor. The second pattern of expression showed a similar fading with an abrupt regaining of expression at the deep invasive edge of the melanoma. These two distinct patterns of GRP78 expression correlated with both patient survival and depth of tumor invasion. A moderate MTJ1 expression was found to be associated with decreased patient survival; however, no significant associations were observed between patterns of GRP78 and MTJ1 expression. Our study (1) describes two distinct patterns of GRP78 in invasive primary cutaneous melanoma, (2) inversely correlates regain of GRP78 expression with patient survival, and (3) suggests a modifying effect of MTJ1 on GRP78 in enhancing tumor aggressiveness.

Glypican-3 protein expression in primary and metastatic melanoma: a combined immunohistochemistry and immunocytochemistry study

BACKGROUND

The incidence of melanoma is increasing. Fine-needle aspiration (FNA) is critical in documenting recurrent/metastatic disease in established cases. The potential of metastatic melanoma (MM) to mimic epithelial tumors presents a diagnostic dilemma. In liver FNA, the distinction between hepatocellular carcinoma (HCC) and MM is a frequent challenge. Glypican-3 (GPC3), a heparan sulfate proteoglycan, is a highly sensitive and specific marker for HCC. Serum GPC3 was shown to be expressed in 40% of primary melanomas (PMs), but to the authors' knowledge no tissue studies to date have assessed GPC3 expression in MM. In this study, GPC3 protein expression was investigated in FNAs from MM, and in corresponding histologic sections from the primary tumors.

METHODS

Sixty archival, direct FNA smears or CytoLyt-fixed samples from 50 patients with MM were retrieved together with formalin-fixed, paraffin-embedded specimens available from 17 corresponding PMs. All cases were stained with anti-GPC3 antibody. FNA and core biopsy specimens from HCCs and benign liver were used as positive and negative controls. GPC3 expression was divided into 2 categories: negative (negative or weak cytoplasmic staining) and positive (moderate or strong cytoplasmic with membranous accentuation).

RESULTS

All FNAs from MM cases were negative (0 of 60) for GPC3. The exact 95% Clopper-Pearson confidence interval was 0.0% to 5.96%. Only 1 case of PM (1 of 17; 5.9%) demonstrated weak focal cytoplasmic staining (regarded as negative).

CONCLUSIONS

In the current study, all MM and PM cases in archival FNAs and tissue sections were found to be negative for GPC3. These data suggest that GPC3 is not expressed in melanoma using the 1G12 clone.