Expression Of Melanoma Markers Research Articles

Expression of HMB45, MelanA and SOX10 is rare in non-small cell lung cancer

BackgroundNon-small cell lung cancer (NSCLC) and melanoma are frequent entities in routine diagnostics. Whereas the differential diagnosis is usually straight forward based on histomorphology, it can be challenging in poorly differentiated tumors as melanoma may mimic various histological patterns. Distinction of the two entities is of outmost importance as both are treated differently. HMB45 and MelanA are recommended immunohistological markers for melanoma in this scenario. SOX10 has been described as an additional marker for melanoma. However, comprehensive large-scale data about the expression of melanoma markers in NSCLC tumor tissue specimen are lacking so far.MethodsTherefore, we analyzed the expression of these markers in 1085 NSCLC tumor tissue samples. Tissue microarrays of NSCLC cases were immunohistochemically stained for HMB45, MelanA, and SOX10. Positivity of a marker was defined as ≥1% positive tumor cells.ResultsIn 1027 NSCLC tumor tissue samples all melanoma as well as conventional immunohistochemical markers for NSCLC could be evaluated. HMB45, MelanA, and SOX10 were positive in 1 (< 1%), 0 (0%) and 5 (< 1%) cases. The HMB45 positive case showed co-expression of SOX10 and was classified as large cell carcinoma. Three out of five SOX10 positive cases were SqCC and one case was an adenosquamous carcinoma.ConclusionsExpression of HMB45, MelanA and SOX10 is evident but exceedingly rare in NSCLC cases. Together with conventional immunomarkers a respective marker panel allows a clear-cut differential diagnosis even in poorly differentiated tumors.

A case of desmoplastic melanoma that was difficult to distinguish from malignant peripheral nerve sheath tumor

The clinical and pathological diagnosis of desmoplastic melanoma is difficult, because almost 50% of desmoplastic melanoma cases involve non-pigmented lesions and the tumor cells can resemble fibroblasts or Schwannian cells based on their frequent amelanotic features. Moreover, desmoplastic melanoma typically has low positive rates for melanoma markers, with the exception of the S-100 protein. We report the case of an 81-year-old Japanese man with an 8-mm desmoplastic melanoma. He initially noticed a painless and non-pigmented skin lesion that did not grow noticeably for 6months. It was unlikely that he had von Recklinghausen disease, and the mass was initially considered a dermatofibroma. Excisional biopsy revealed an intradermal mass, with the superficial portion mimicking neurofibroma and the deeper portion exhibiting nodular growth of sarcomatoid spindle cells. The tumor region lacked intradermal proliferation of atypical melanocytic cells, intracytoplasmic melanin, and expression of melanoma markers (except S-100 protein and Sox10). Although a malignant peripheral nerve sheath tumor derived from neurofibroma was possible, the slow growth with diffuse and strong immunoreactivity to the S-100 protein and Sox10 favored a diagnosis of desmoplastic melanoma. Pathologists should recognize that desmoplastic melanoma may not involve in situ lesions or the immunohistochemical expression of standard melanoma markers.

Abstract 1714: Translating CTCs for clinical use: melanoma patient-derived CTCs evolution in xenografts

Abstract Circulating tumor cells (CTCs) are known to disseminate from primary/metastatic tumors, survive in the circulation, and develop competency to colonize distant organs. Dissecting CTC heterogeneity is therefore crucial to provide improve prognostic and diagnostic tools (concept of “liquid biopsy”). However, the clinical significance of CTC heterogeneity is still unknown. We hypothesized that melanoma patient blood-derived, lineage-negative cells (CD45-/CD34-/CD73-/CD90-/CD105-) contain melanoma cell subpopulations (Melan A+, S100+, CD146+ and NG2+ CTCs) that evolve in vivo and achieve metastatic potency when reaching an organ-specific niche. We enriched Lin-negative cells from peripheral blood of melanoma patients clinically diagnosed with or without brain metastasis (MBM) by multi-parametric flow cytometry; and analyzed CTC heterogeneity in xenografts by longitudinal capturing and interrogation at the single-cell level (DEPArrayTM platform). First, we evaluated the presence of melanoma CTC subpopulations in Lin-negative cells and developed Lin-negative murine xenograft models. Human-cell derived melanoma metastasis in xenografts confirmed that CTCs require metastasis-potentiating factors present in the Lin-negative population. Second, we performed multi-parametric flow cytometry to isolate human-derived HLA+/Melan A+/- CTCs/DTCs population from murine blood and bone marrow at T0, Tmid and Tend phases of metastasis. We interrogated the differential levels of CTCs/DTCs in HLA+/Melan A+ cell population and established their neoplastic identity by genetic profiling and the expression of melanoma markers at single-cell level. Third, we dissected longitudinal transcriptional signatures of CTCs vs DTCs in association with MBM onset. We assessed the comprehensive EMT scores of CTCs and DTCs transcriptomics and identified the pathways associated with CTC/DTCs dynamic functional states depending upon melanoma progression. Collectively, this study provide important insights to identify novel EMT-related biomarkers of MBM progression. Further elucidation of these CTC biomarkers and properties may provide novel therapeutic strategies that can be clinically useful in melanoma patients which are yet to develop MBM. Citation Format: Monika Vishnoi, Haowen N. Liu, Debasish Boral, Wei Yin, Marc L. Sprouse, Jean P. Thiery, Isabella C. Glitza, Dario Marchetti. Translating CTCs for clinical use: melanoma patient-derived CTCs evolution in xenografts [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 1714. doi:10.1158/1538-7445.AM2017-1714

Abstract 1564: Establishment and characterization of an orthotopic mouse model for human uveal melanoma hepatic metastasis.

Abstract Background: The survival of patients with metastatic uveal melanoma remains poor due to lack of effective treatment. Uveal melanoma patients preferentially develop hepatic metastasis, which is the major cause of death. Therefore, a suitable animal model of hepatic metastasis with human uveal melanoma is critical for the investigation of its biological behavior and designing an effective therapy. Methods: Human hepatic metastatic uveal melanoma cell line (UM001), established in our laboratory, and NOD scid gamma mice (NSG mice) were used for orthotopic hepatic metastasis model. The UM001 cell line has typical characters of human melanoma, including a GNAQ mutation and expression of IGF-1 receptors. 1.00 -1.25 x 106 of UM001 cells in 15-20μl suspension of RPMI1640 medium were implanted using 27G needles under the capsule of the liver through a 1.5 cm abdominal incision. After the development of liver tumors, the NSG mice were sacrificed and investigated the behavior of the tumor cells in the liver both macro- and microscopically. Immunohistochemical analysis was performed to confirm the expression of human melanoma markers (HMB45 and Melan-A), IGF-1R. Tumor specimens were also stained for mouse CD31 (constituent of the endothelial intercellular junction of the vessels) and human laminin (major basement component of the vessels) to investigate neovascularization and vasculogenic mimicry patterns in the tumor. In addition, we performed Western blot analysis and immunohistochemistry to investigate the activation of PI3K-Akt and MAPK signaling pathways. Results: We achieved 91% (10/11cases) success rate of tumor formation using the method described in the present report. UM001 cells formed localized macroscopic nodules in the mouse liver within 4 weeks and then developed intrahepatic and peritoneal metastases within 12 weeks after implantation. Immunohistochemical analysis showed the expression of melanoma markers, IGF-1R, neovascularization positive for mouse CD31, vasculogenic mimicry patterns composed of human laminin in the hepatic tumors. In addition, activation of phosphorylated Akt and Erk1/2 in the hepatic tumor specimens was also noted. Conclusion: This orthotopic mouse model of human uveal melanoma liver metastasis showed similar histological findings as those observed in human liver. Moreover, PI3K-Akt and MAPK signaling pathway are activated in the hepatic tumor tissue. Taken together, this model is a useful tool to investigate the biological behavior of metastatic uveal melanoma in vivo, and to test novel therapies for the treatment of human uveal melanoma metastasizing to liver. Citation Format: Shinji Ozaki, Makoto Yoshida, Mizue Terai, Senthamil Selvan, Michael J. Mastrangelo, Takami Sato. Establishment and characterization of an orthotopic mouse model for human uveal melanoma hepatic metastasis. [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr 1564. doi:10.1158/1538-7445.AM2013-1564

Quantitative detection of melanoma‐associated antigens by multimarker real‐time RT‐PCR for molecular staging: results of a 5 years study

Monitoring of circulating melanoma cells in the peripheral blood is a promising method for identifying a subgroup of patients with minimal residual disease. To evaluate the prognostic impact of melanoma-associated antigens by multimarker real-time RT-PCR for disease-specific survival time. Five melanoma markers: Melan-A, gp 100, MAGE-3, MIA and tyrosinase were detected by a quantitative multimarker real-time reverse transcription-PCR (RT-PCR). We included 65 patients with resected melanoma in stage II-III. Peripheral blood samples were examined every 3 months for 2 years. The expression of melanoma markers in 2925 RT-PCR assays was correlated with clinical staging results in total of 5 years. Twenty-seven patients relapsed during the study period and 26 of them revealed positive markers. MAGE-3 was the most sensitive progression marker in single occurrence or in combination with MIA and gp 100. The time distribution of metastases during the screened period was as follows: progression in the first year was observed in 40.7% patients, second year in 25.9%, third year in 18.6%, fourth and fifth year in 7.4% equally. Statistically significant tumor marker elevation during the first 2 years after the surgical treatment correlates with a worse prognosis of patients. In contrast, the group showing negative real-time RT-PCR results in 24 months serial blood testing was associated with prolonged 5-year disease-specific survival. Therefore, quantitative detection of melanoma-specific molecular markers in the presented setting represents a useful tool for selecting patients in a higher risk of disease recurrence.

BRAF and NRAS mutational status in clear cell sarcoma

9000 Background: Clear-cell-sarcoma (CCS) also known as melanoma of the soft parts (MSP) is a rare cancer of adolescents and young adults arising in the deep soft tissues. Several clinical and pathological data demonstrate features typical of melanoma (the propensity for lymph node metastasis, expression of melanoma markers:HMB45, S100. Conversely, deep location in the soft tissues and recurrent t(12;22) translocation coding for the fusion protein EWS-ATF1 are rather suggestive of soft tissue sarcoma (STM). Data comparing gene expression profiles of CCS, melanomas and STM showed that CCS clustered with melanoma rather than with STM. BRAF mutations are frequently found in cutaneous melanoma (40–60%) but are not found in distinct melanoma subtypes(mucosal or uveal). Upstream of BRAF, on the same MAP kinase pathway NRAS is also frequently mutated in melanoma, with a mutually exclusive spectrum of mutations for these two genes. Our objective was to evaluate the frequency of BRAF and NRAS mutations is CCS. Methods: DNA was prepared from paraffin-embeded tissues of 22 CCS carrying the t(12;22) translocation and six melanoma. PCR amplification of BRAF exons 11 and 15 as well as NRAS codons 12, 13 and 61 were performed and PCR products were sequenced. Phosphorylation of ERK was studied using an anti-phospho-ERK antibody SIGMA). Results: Only one of the 22 CCS harboured a BRAF mutation (V599E) (4.5%). Two mutations of NRAS (codon 61) were also found with no overlap with the BRAF mutation. Among the 6 melanomas, one had a BRAF (V599E) and three others had a NRAS mutation. Immunostaining with the anti phospho-ERK antibody showed faint positivity in 8/14 CCS. Among the 6 melanoma, 4 displayed ERK phosphorylation, which was strictly correlated to the presence of NRAS or BRAF activating mutations. Conclusions: BRAF and NRAS mutations are rarely present in CCS. Only 1/22 BRAF mutation and 2/22 NRAS mutation were found. in our serie. These results suggest that although genomic profiling showed that CCS clustered with melanoma, most of them occur independently of BRAF and NRAS mutations frequently found in cutaneous melanoma. No significant financial relationships to disclose.

Comparative Histopathology of Grey‐Horse‐Melanoma and Human Malignant Melanoma

Equine melanoma shows striking features particularly with regard to clinical development in grey horses: in contrast to malignant melanoma in humans and in solid coloured horses that are characterized by early onset of metastasis, pigment cell tumours display almost benign clinical features in ageing grey horses. Through evolution, grey horses appear to be in a favourable position in regard to the biological behaviour of melanomas. Yet unknown factors inhibiting or retarding early melanoma metastasis may be responsible for this phenomenon. In this study, immunostaining profiles and histopathologic patterns of equine vs. human melanotic tumours were compared. In addition, the expression of melanoma markers currently used in human melanoma detection and characterization were evaluated for their applicability in equine melanoma diagnosis. Immunohistopathologic investigations revealed that benign grey horse melanomas share common features with human blue nevi and with human malignant desmoplastic melanomas, whereas their resemblance to other types of human cutaneous malignant melanomas is less pronounced. Our data equally underline that S-100, proliferating cell nuclear antigen (PCNA), HMB-45, Ki-67, T-311 and CD44 can serve as reliable markers for horse melanomas. Further investigations aiming at identifying factors retarding metastasis in affected grey horses are needed, as they may contribute to the development of novel treatment strategies for human malignant melanoma.