Expression of NM23 protein in acquired melanocytic nevi, malignant melanoma and metastases of malignant melanoma: an immunohistological assessment in human skin

NDPKA is not just a metastasis suppressor - be aware of its metastasis-promoting role in neuroblastoma

NDPK-A, encoded by nm23-H1 (also known as NME1) was the first metastasis suppressor discovered. Much of the attention has been focused on the metastasis-suppressing role of NDPK-A in human tumors, including breast carcinoma and melanoma. However, compelling evidence points to a metastasis-promoting role of NDPK-A in certain tumors such as neuroblastoma and lymphoma. To balance attention on this contrariety of NDPK-A in different cancer types, this review addresses the metastasis-promoting role of NDPK-A in neuroblastoma. Neuroblastoma is an embryonic tumor, arising from neural crest cells that fail to differentiate into the sympathetic nervous system. We summarize and discuss nm23-H1 genetics and the prognosis of neuroblastoma, structural and functional changes associated with the S120G mutation of NDPK-A, as well as the evidence supporting the role of NDPK-A as a metastasis promoter. Also discussed are the NDPK-A relevant molecular determinants of neuroblastoma metastasis, and metastasis-relevant neural crest development. Because of NDPK-A's dichotomous role in tumor metastasis as both a suppressor and a promoter, tumor genome/exome profiles are necessary to identify the molecular drivers of metastasis in the NDPK-A network for developing tumor-specific therapies.

Reticulin and NM23 staining in the interpretation of lymph nodal nevus rests

Melanocytic nevus rests in lymph nodes are a known diagnostic challenge, especially in patients with a history of melanoma. Reticulin and NM23 have been studied in this context. The pattern of reticulin staining in melanomas surrounds groups/nests of melanocytes but individual cells in benign nevi. NM23, a metastasis-suppressor gene, has an association with metastatic potential in melanomas and some carcinomas. Twenty-eight cases (14 cases of metastatic melanoma to lymph nodes and 14 cases of lymph node nevus rests, all confirmed with Melan-A staining) were stained with reticulin and NM23. The pattern of reticulin staining was reported as surrounding groups if staining was noted in approximately 5-10 melanocytes in greater than 50% of the lesion but was otherwise reported as surrounding individual melanocytes. Cytoplasmic staining was considered to represent reactivity for NM23. Reticulin staining around groups of melanocytes was identified in all 14 cases of metastatic melanoma. Regarding nodal nevus rest cases, 12 of 14 cases (86%) demonstrated staining around individual melanocytes, whereas in 2 cases, reticulin surrounded melanocytic groups. NM23 staining was equivocal in all cases. Reticulin staining reliably invests groups of melanocytes in cases of metastatic melanoma, whereas in nodal nevus rests, it predominantly surrounds individual melanocytes. NM23 demonstrated no discriminatory value in this analysis. In cases in which a collection of melanocytes is present within a lymph node, reticulin deposition around individual melanocytes supports a diagnosis of lymph nodal nevus rest.

Dermatopathological indicators of poor melanoma prognosis are significantly inversely correlated with the expression of NM23 protein in primary cutaneous melanoma

BACKGROUND

Some dermatopathological parameters are recognized as dominant indicators of high metastatic potential in melanoma, especially Breslow thickness, ulceration, Clark's level of invasion and mitotic rate. Because NM23 protein is the product of a melanoma metastasis suppressor gene, the aim of this study was to compare such dermatopathological indicators of melanoma prognosis with NM23 protein expression in primary cutaneous melanoma.

METHODS

The immunohistochemical NM23 expression was semiquantitatively assessed in 30 primary cutaneous melanomas. Ten dermatopathological parameters were evaluated and compared with NM23 expression.

RESULTS

A significant inverse correlation was found for NM23 expression in comparison with Breslow thickness (p < 0.01), ulceration (p < 0.05), Clark's level (p < 0.01), mitotic rate (p < 0.05), and vertical growth phase (p < 0.05). By contrast, no significant correlation was found for NM23 expression in comparison with cell morphology, presence of adjacent nevus, pigmentation, tumor-infiltrating lymphocytes, and regression was impossible to evaluate.

CONCLUSIONS

The expression of NM23 protein in primary cutaneous melanoma is significantly inversely correlated with dermatopathological parameters currently recognized as powerful indicators of melanoma prognosis. NM23 may be therefore considered in the dermatopathological evaluation of primary cutaneous melanoma.

nm23 as a prognostic marker in primary cutaneous melanoma: evaluation using tissue microarray in a patient group with long-term follow-up

The accurate estimation of prognosis in patients with melanoma is of increasing importance with novel adjuvant therapies on the horizon. The current prediction of prognosis employs techniques involving sentinel lymph node biopsy, which carries an associated morbidity and is of little use in patients who develop direct distant metastases or direct in-transit metastases. New strategies or factors are therefore needed to improve the accuracy of determination of prognosis. nm23 is a putative metastasis suppressor; however, conflicting data exist as to its role in melanoma progression and its use as a potential prognostic marker. The purpose of this study was to use the technique of tissue microarray to study a cohort of melanoma patients with long-term follow-up data in order to ascertain its potential use as a prognostic marker. One hundred and twenty patients with primary cutaneous melanoma were included in the tissue microarray and a commercially available immunohistochemical marker for nm23 was used for protein detection. nm23 expression was strongly correlated with Clark's level (P<0.001), Breslow depth (P=0.002) and patient age (P=0.014). nm23 expression was significantly associated with a poor patient outcome (chi2=7.2219, P=0.0072). Further analysis revealed that the intensity of nm23 expression also correlated with patient outcome (chi2=11.3281, P=0.0035). However, on multivariate analysis, nm23 was shown not to be an independent marker of prognosis. The results of this study, when taken with the existing literature, suggest a role for nm23 in melanoma disease progression. However, its use as a prognostic marker in routine practice does not appear to be justified.

Immunohistochemical markers of melanocytic lesions: a review of their diagnostic usefulness

We critically reviewed recent literature reports of 25 melanocytic immunohistochemical markers. This review organizes and summarizes the many new studies of old and novel melanocytic markers and identifies the most promising diagnostic immunohistochemical markers that can be used to distinguish melanocytic from nonmelanocytic lesions and benign melanocytic from malignant melanocytic lesions.

Immunohistochemical expression of nm23 in primary invasive malignant melanoma is predictive of survival outcome

The objective of this study was to determine the utility of nm23 as an immunohistochemical indicator of prognosis in a large series (157 cases) of malignant melanoma and also in two subsets within this group: stage 1 tumours, whether in radial or vertical growth phase (140 cases); and stage 1 tumours in which a vertical growth phase component was positively identified (123 cases). A secondary objective was to explore the relationship between the immunohistochemical expression of nm23 and established clinical and histological indicators of prognosis in each of these three groups. In all groups it was found that strong immunoreactivity correlated positively with survival and inversely with indicators of poor prognosis, in keeping with transfection and mRNA studies and also with many immunohistochemical studies of other tumour types. That these findings are at variance with earlier reported immunohistochemical studies of melanoma highlights the importance of large case numbers of primary invasive tumours in studies which set out to explore the relationship between immunoreactivity and survival.

Differential expression of nm23 H-1 protein in conjunctival melanoma and potential precursor lesions

Loss of nm23 gene expression is believed to enhance metastatic spread in diverse human tumors, including skin melanoma. The purpose of this work was to determine the pattern and prognostic relevance of nm23 protein immunoexpression in conjunctival melanoma and potential precursor lesion. Formaldehyde-fixed, paraffin-embedded conjunctival specimens comprising 85 melanocytic lesions (nevi, primary aquired melanosis with and without atypia and primary and locally recurrent malignant melanomas) from 73 patients were used. Sections from all specimens were examined by light microscopy to assess diverse prognostic parameters. Additional sections were then immunostained for nm23 H-1 protein and the immunoreactivity was assessed semi-quantitatively. Survival data for all patients were retrieved from the National Causes of Death Registry of Sweden.Nm23 H-1 protein was differentially expressed in conjunctival melanocytic lesions, however loss of immunoexpression was not more common in melanocytic lesions asociated with a high risk of malignant transformation. Also, primary and recurrent conjunctival melanomas showed an essentially similar nm23 expression pattern and we could not associate the pattern of nm23 immunoexpression with an increased risk for malignant transformation or locally recurrent disease. While there was a tentative separation between cause-specific survival curves after excision for low and high nm23 expression conjunctival melanoma, there was no statistically significant association with metastatic death of patients. However, loss of nm23 protein immunoexpression may still be of some importance as a marker for prognosis in conjunctival melanoma because the present study could only detect large differences in survival. Our results suggest that any potential prognostic value of nm23 immunoexpression would be independent of other markers, underlining the importance of further studies.