Topical therapy for regression and melanoma prevention of congenital giant nevi.

Giant congenital melanocytic nevi are NRAS-driven proliferations that may cover up to 80% of the body surface. Their most dangerous consequence is progression to melanoma. This risk often triggers preemptive extensive surgical excisions in childhood, producing severe lifelong challenges. We have presented preclinical models, including multiple genetically engineered mice and xenografted human lesions, which enabled testing locally applied pharmacologic agents to avoid surgery. The murine models permitted the identification of proliferative versus senescent nevus phases and treatments targeting both. These nevi recapitulated the histologic and molecular features of human giant congenital nevi, including the risk of melanoma transformation. Cutaneously delivered MEK, PI3K, and c-KIT inhibitors or proinflammatory squaric acid dibutylester (SADBE) achieved major regressions. SADBE triggered innate immunity that ablated detectable nevocytes, fully prevented melanoma, and regressed human giant nevus xenografts. These findings reveal nevus mechanistic vulnerabilities and suggest opportunities for topical interventions that may alter the therapeutic options for children with congenital giant nevi.

Melanoma Cell-Intrinsic PD-1 Receptor Functions Promote Tumor Growth.

Therapeutic antibodies targeting programmed cell death 1 (PD-1) activate tumor-specific immunity and have shown remarkable efficacy in the treatment of melanoma. Yet, little is known about tumor cell-intrinsic PD-1 pathway effects. Here, we show that murine and human melanomas contain PD-1-expressing cancer subpopulations and demonstrate that melanoma cell-intrinsic PD-1 promotes tumorigenesis, even in mice lacking adaptive immunity. PD-1 inhibition on melanoma cells by RNAi, blocking antibodies, or mutagenesis of melanoma-PD-1 signaling motifs suppresses tumor growth in immunocompetent, immunocompromised, and PD-1-deficient tumor graft recipient mice. Conversely, melanoma-specific PD-1 overexpression enhances tumorigenicity, as does engagement of melanoma-PD-1 by its ligand, PD-L1, whereas melanoma-PD-L1 inhibition or knockout of host-PD-L1 attenuate growth of PD-1-positive melanomas. Mechanistically, the melanoma-PD-1 receptor modulates downstream effectors of mTOR signaling. Our results identify melanoma cell-intrinsic functions of the PD-1:PD-L1 axis in tumor growth and suggest that blocking melanoma-PD-1 might contribute to the striking clinical efficacy of anti-PD-1 therapy.

Loss of 5-hydroxymethylcytosine is an epigenetic hallmark of melanoma.

DNA methylation at the 5 position of cytosine (5-mC) is a key epigenetic mark that is critical for various biological and pathological processes. 5-mC can be converted to 5-hydroxymethylcytosine (5-hmC) by the ten-eleven translocation (TET) family of DNA hydroxylases. Here, we report that "loss of 5-hmC" is an epigenetic hallmark of melanoma, with diagnostic and prognostic implications. Genome-wide mapping of 5-hmC reveals loss of the 5-hmC landscape in the melanoma epigenome. We show that downregulation of isocitrate dehydrogenase 2 (IDH2) and TET family enzymes is likely one of the mechanisms underlying 5-hmC loss in melanoma. Rebuilding the 5-hmC landscape in melanoma cells by reintroducing active TET2 or IDH2 suppresses melanoma growth and increases tumor-free survival in animal models. Thus, our study reveals a critical function of 5-hmC in melanoma development and directly links the IDH and TET activity-dependent epigenetic pathway to 5-hmC-mediated suppression of melanoma progression, suggesting a new strategy for epigenetic cancer therapy.

A Novel Multi-Component Formulation Reduces Inflammation In Vitro and Clinically Lessens the Symptoms of Chronic Eczematous Skin.

Long-term treatments for inflammatory skin diseases like atopic dermatitis or eczema can cause adverse effects. Super Protein Multifunction (SPM) was investigated as a potential treatment for managing skin inflammation by monitoring the expression of pro-inflammatory cytokines induced using LPS and poly(I:C)/TNFα in HaCaT keratinocytes and Hs27 fibroblasts as measured via RT-PCR. SPM solution was also assessed for its effect on cytokine release, measured using ELISA, in a UVB-irradiated 3D human skin model. To evaluate the efficiency of SPM, 20 patients with mild eczematous skin were randomized to receive SPM or vehicle twice a day for three weeks in a double-blind controlled trial. In vitro studies showed SPM inhibited inflammation-induced IL-1ß, IL-6, IL-33, IL-1α, TSLP, and TNFα expression or release. In the clinical study, the SPM group showed significant improvements in the IGA, PA, and DLQI scores compared to the vehicle group. Neither group showed significant differences in VAS (pruritus). Histological analysis showed reduced stratum corneum thickness and inflammatory cell infiltration. The results suggest that SPM may reduce inflammation in individuals with chronic eczematous skin.

Photochemical Tissue Passivation Prevents Contracture of Full Thickness Wounds in Mice.

BACKGROUND AND OBJECTIVES: Wound contracture formation from excessive myofibroblast activity can result in debilitating morbidities. There are currently no treatments to prevent contracture. Photochemical tissue passivation (PTP), an established, safe, and user-friendly treatment modality, crosslinks collagen by a light-activated process, thus modulating the wound healing response and scarring. We hypothesised that PTP treatment would reinforce wounds by blunting the fibrotic response thus limiting contracture. STUDY DESIGN/MATERIALS AND METHODS: Full-thickness, 1 cm × 1 cm excisional wounds were created on the dorsum of 32 C57BL/6 mice. Treated wounds were painted with photosensitizing dye and exposed to visible light. Wounds were serially photographed over 6 weeks to measure wound contracture. At 7, 14, 21, and 42 days after wound creation, mice were euthanized and wounds were harvested for histologic review by a dermatopathologist. RESULTS: By Day 7, control wounds had significantly more contracture than those treated with PTP (33.0 ± 17.1% and 19.3 ± 9.0%, respectively; P = 0.011). PTP-treated wounds maintained approximately 20% less contracture than controls from Day 14 and on (P < 0.05). By Day 42, wounds had contracted by 86.9 ± 5.5% in controls and 64.2 ± 3.2% in PTP-treated wounds (P < 0.03). Histologically, PTP wounds had earlier growth and development of dermal collagen, neovascularization, and development of skin appendages, compared with control wounds. CONCLUSIONS: PTP significantly limits contracture of full-thickness wounds and improves wound healing. PTP-treated wounds histologically demonstrate more mature structural organization than untreated wounds and closely resemble native skin. PTP treatment may be applicable not only for excisional wounds, but also for wounds with a high incidence of contracture and associated morbidity. Lasers Surg. Med. © 2019 Wiley Periodicals, Inc.

The Pathogenesis of Port Wine Stain and Sturge Weber Syndrome: Complex Interactions between Genetic Alterations and Aberrant MAPK and PI3K Activation.

Port wine stain (PWS) is a congenital vascular malformation involving human skin. Approximately 15-20% of children a facial PWS involving the ophthalmic (V1) trigeminal dermatome are at risk for Sturge Weber syndrome (SWS), a neurocutaneous disorder with vascular malformations in the cerebral cortex on the same side of the facial PWS lesions. Recently, evidence has surfaced that advanced our understanding of the pathogenesis of PWS/SWS, including discoveries of somatic genetic mutations (GNAQ, PI3K), MAPK and PI3K aberrant activations, and molecular phenotypes of PWS endothelial cells. In this review, we summarize current knowledge on the etiology and pathology of PWS/SWS based on evidence that the activation of MAPK and/or PI3K contributes to the malformations, as well as potential futuristic treatment approaches targeting these aberrantly dysregulated signaling pathways. Current data support that: (1) PWS is a multifactorial malformation involving the entire physiological structure of human skin; (2) PWS should be pathoanatomically re-defined as "a malformation resulting from differentiation-impaired endothelial cells with a progressive dilatation of immature venule-like vasculatures"; (3) dysregulation of vascular MAPK and/or PI3K signaling during human embryonic development plays a part in the pathogenesis and progression of PWS/SWS; and (4) sporadic low frequency somatic mutations, such as GNAQ, PI3K, work as team players but not as a lone wolf, contributing to the development of vascular phenotypes. We also address many crucial questions yet to be answered in the future research investigations.

Histological features and outcome of inverted type-A melanocytic nevi.

The presence of enlarged epithelioid/spindled nests located deep in the reticular dermis of a biphasic melanocytic neoplasm can mimic melanoma arising in a pre-existing nevus, causing over-interpretation of malignancy. We aimed to define the clinicopathologic significance of epithelioid/spindled nests in melanocytic nevi. Retrospectively using clinical and histologic information, we characterized 121 patients with a single lesion showing epithelioid/spindled melanocytes in the reticular dermis or subcutaneous fat, surrounded by melanophages, sometimes blending in with the adnexa. The majority of nevi occurred in women in the ages of 10 to 39 years, where the most frequent presentation was a changing mole. While 78% of the lesions displayed an anatomic (Clark's) level of IV-V, there was no ulceration, significant regression or inflammation. Up to 2 mitoses were found in only 12% of the cases, not correlating with the severity of cytological atypia. No recurrence or metastasis occurred during 45.5 months (mean) of clinical follow up in 26 patients. Notwithstanding the deep dermal extension, these findings suggest a benign histopathology and clinical outcome. Having compared the overlapping histopathology and clinical features between deep penetrating/clonal nevus and combined nevus, we posit that "inverted type-A nevus" might be considered a variant of the two.

An ultraviolet-radiation-independent pathway to melanoma carcinogenesis in the red hair/fair skin background.

People with pale skin, red hair, freckles and an inability to tan--the 'red hair/fair skin' phenotype--are at highest risk of developing melanoma, compared to all other pigmentation types. Genetically, this phenotype is frequently the product of inactivating polymorphisms in the melanocortin 1 receptor (MC1R) gene. MC1R encodes a cyclic AMP-stimulating G-protein-coupled receptor that controls pigment production. Minimal receptor activity, as in red hair/fair skin polymorphisms, produces the red/yellow pheomelanin pigment, whereas increasing MC1R activity stimulates the production of black/brown eumelanin. Pheomelanin has weak shielding capacity against ultraviolet radiation relative to eumelanin, and has been shown to amplify ultraviolet-A-induced reactive oxygen species. Several observations, however, complicate the assumption that melanoma risk is completely ultraviolet-radiation-dependent. For example, unlike non-melanoma skin cancers, melanoma is not restricted to sun-exposed skin and ultraviolet radiation signature mutations are infrequently oncogenic drivers. Although linkage of melanoma risk to ultraviolet radiation exposure is beyond doubt, ultraviolet-radiation-independent events are likely to have a significant role. Here we introduce a conditional, melanocyte-targeted allele of the most common melanoma oncoprotein, BRAF(V600E), into mice carrying an inactivating mutation in the Mc1r gene (these mice have a phenotype analogous to red hair/fair skin humans). We observed a high incidence of invasive melanomas without providing additional gene aberrations or ultraviolet radiation exposure. To investigate the mechanism of ultraviolet-radiation-independent carcinogenesis, we introduced an albino allele, which ablates all pigment production on the Mc1r(e/e) background. Selective absence of pheomelanin synthesis was protective against melanoma development. In addition, normal Mc1r(e/e) mouse skin was found to have significantly greater oxidative DNA and lipid damage than albino-Mc1r(e/e) mouse skin. These data suggest that the pheomelanin pigment pathway produces ultraviolet-radiation-independent carcinogenic contributions to melanomagenesis by a mechanism of oxidative damage. Although protection from ultraviolet radiation remains important, additional strategies may be required for optimal melanoma prevention.

New insights into naevoid melanomas: a clinicopathological reassessment.

AIMS: Because the term 'naevoid melanoma' has variable clinical and pathological interpretations, we aimed to clarify the features of melanomas referred to as naevoid. METHODS AND RESULTS: A review was undertaken of 102 melanomas diagnosed histopathologically as naevoid melanomas and ascertained by European Organization for Research and Treatment of Cancer Melanoma Group Subcommittee pathologists from their records. We found these could be classified morphologically into three groups. Thirteen melanomas were overlying genuine naevi and were therefore excluded. Of the 89 melanomas considered to be naevoid, 11 presented clinically as exophytic papillomatous nodules with little junctional component and composed of small atypical cells showing numerous mitoses and no change with depth; we termed these 'papillomatous naevoid' melanomas. The other 78 were flat or only slightly raised, and had a superficial spreading melanoma-like component with maturation to a small cell, but still an atypical, dermal component; we termed these 'maturing naevoid' melanomas. We showed that papillomatous and maturing naevoid melanomas also have differing immunochemical profiles. Preliminary clinical follow-up suggested different outcomes for these two naevoid melanoma types. CONCLUSIONS: Melanomas that have been classified as naevoid melanomas comprise two types with distinct clinical, histopathological and immunohistochemical features that may also be prognostically significant.

5-Hydroxymethylcytosine is a nuclear biomarker to assess biological potential in histologically ambiguous heavily pigmented melanocytic neoplasms.

BACKGROUND: 5-Hydroxymethylcytosine (5-hmC) is an epigenetic marker detectable through immunohistochemistry (IHC) that has been shown to distinguish benign nevi from melanoma with high sensitivity and specificity. The purpose of the study was to explore its diagnostic utility in a subset of histologically challenging, heavily pigmented cutaneous melanocytic neoplasms. METHODS: 5-hmC IHC was performed on 54 heavily pigmented melanocytic tumors. Semi-quantitative analysis of immunoreactivity was correlated with clinical, pathologic and follow-up data. RESULTS: Benign melanocytic neoplasms (4 of 4 blue nevi with epithelioid change; 12 of 12 combined nevi; 5 of 5 deep penetrating nevi, DPN) exhibited strong 5-hmC nuclear reactivity. Eight heavily pigmented blue nevus-like melanomas and 7 of 8 pigmented epithelioid melanocytomas (PEM) showed significant 5-hmC loss. Five of 7 atypical DPN cases and 8 of 10 melanocytic tumors of uncertain malignant potential (MELTUMP) showed low to intermediate 5-hmC immunoreactivity. These differences were statistically significant (P-value <.0001). CONCLUSIONS: Loss of 5-hmC may be helpful in differentiating benign, diagnostically challenging, heavily pigmented melanocytic tumors from those with malignant potential. The intermediate to low 5-hmC immunoreactivity in atypical DPNs, PEMs and so-called MELTUMP categories further underscores the need to consider these neoplasms as having some potential for lethal biological behavior.

The correlation of the standard 5 probe FISH assay with melanocytic tumors of uncertain malignant potential.

BACKGROUND: FISH has recently emerged as a technique to better assess the malignant potential of histologically ambiguous melanocytic lesions. However, the usefulness of FISH has not been conclusively established. The purpose of this study was to further explore the diagnostic value of FISH in distinguishing the borderline melanocytic tumor (BMT) from melanoma. METHOD: 73 cases with BMT were analyzed retrospectively from a dermatopathology database between 2010-2015. FISH studies were conducted in each case using probes targeting 5 loci including CCND1 on 11q13, RREB1 on 6p25, MYB on 6q23, CDKN2A on 9p21, and CEP 6 control probe for chromosome 6. RESULTS: The study was composed of 50 females and 23 males with an age range of 1-73 and a mean age of 35years. Of the 6 cases in the superficial atypical Spitz tumor (AST) category, 2 had indeterminate results due to polyploidy. In the conventional atypical Spitz tumor cases, FISH was positive in 3 of 15 cases. Of the 27 cases in the borderline nevoid tumor (BNM) category, 3 showed positive FISH and 3 were equivocal due to the possibility of polyploidy. 3 of 13 cases of the borderline tumor of deep penetrating nevus variant (B-DPN) were positive for FISH. Neither of the 2 pigmented epithelioid melanocytoma (PEM) cases had positive FISH result. Of the 4 cases in the superficial atypical dermoepidermal nevomelanocytic proliferation group, only 1 met the FISH diagnostic criteria for melanoma. None of the 6 borderline tumors with overlapping features met FISH criteria diagnostic of melanoma. Clinical follow up was available on 55 patients. None of the patients had recurrence nor died of the disease. Lymph node biopsy was performed on five patients without evidence of metastasis. CONCLUSION: Despite the benefits of FISH, it is limited by the fact that melanomas are not genetically identical whereby certain genetic abnormalities are only seen in specific subtypes. Additionally, FISH only targets specific chromosomes resulting in limitations in sensitivity and specificity. Although FISH has proven to be highly sensitive and specific in distinguishing unequivocally benign from malignant lesions, in cases of histopathological ambiguity, these parameters cannot be assessed with great confidence because the histopathological diagnosis (gold standard) is not without uncertainty. The 4-probe set (excluding 9p21) consistently showed chromosomal aberrations throughout all groups, but only 10 of the 73 total cases (13%) met the diagnostic criteria for melanoma. Moreover, it would be wise to establish new cytogenetic reference values that incorporate these borderline lesions in an effort to better assess the possibility of malignant behavior and or define a cytogenetic profile supportive of its categorization as an indeterminate proliferation. Polyploidy is another inherent limitation, which leads to false positives due to the absolute signal counts incorrectly reflecting relative imbalances in the tumor genome.

Evaluation of 122 advanced-stage cutaneous squamous cell carcinomas by comprehensive genomic profiling opens the door for new routes to targeted therapies.

BACKGROUND: The authors hypothesized that comprehensive genomic profiling of advanced-stage cutaneous squamous cell carcinoma (cSCC) could identify genomic-derived drug targets of therapy for patients with conventional therapy-resistant disease. METHODS: Comprehensive genomic profiling of 315 cancer genes was applied to 50 ng of DNA from 122 cSCC cases for the evaluation of all classes of genomic alterations (GAs). Clinically relevant genomic alterations (CRGAs) were defined as those identifying anticancer drugs on the market or in registered clinical trials. RESULTS: There were 21 women (17%) and 101 men (83%) with a median age of 64.9 years (range, 21-87 years). Eleven cSCC cases (9%) were histologic AJCC grade 1, 69 (57%) were grade 2, and 42 (34%) were grade 3. The primary cSCC was used for sequencing in 77 cases (63%). Metastatic lesions were sequenced in 37% of cases. There were 1120 total GAs identified (average of 9.2 GAs per tumor), with 100% of cases harboring at least 1 alteration. Of the 122 cSCCs, 107 (88%) harbored at least 1 CRGA (2.5 CRGAs per cSCC) includingNOTCH1 (43%); patched 1 (PTCH1) (11%); BRCA2 (10%); HRAS (8%); ataxia telangiectasia mutated (ATM) (7%); erb-B2 receptor tyrosine kinase 4 (ERBB4) (7%); neurofibromatosis type 1 (NF1) (7%); erb-B2 receptor tyrosine kinase 2 (ERBB2) (6%); phosphatidylinositol-4,5-bisphosphate 3-kinase, catalytic subunit alpha (PIK3CA) (6%); cyclin D1 (CCND1) (6%); epidermal growth factor receptor (EGFR) (5%); and F-box and WD repeat domain containing 7, E3 ubiquitin protein ligase (FBXW7) (5%). CONCLUSIONS: In the current study, approximately 88% of patients with cSCC were found to harbor clinically relevant GAs that have the potential to guide the treatment of patients with advanced-stage tumors with targeted therapeutic agents. Cancer 2016;122:249-257. © 2015 American Cancer Society.

Evaluation of the Melanocytic Pathology Assessment Tool and Hierarchy for Diagnosis (MPATH-Dx) classification scheme for diagnosis of cutaneous melanocytic neoplasms: Results from the International Melanoma Pathology Study Group.

BACKGROUND: Pathologists use diverse terminology when interpreting melanocytic neoplasms, potentially compromising quality of care. OBJECTIVE: We sought to evaluate the Melanocytic Pathology Assessment Tool and Hierarchy for Diagnosis (MPATH-Dx) scheme, a 5-category classification system for melanocytic lesions. METHODS: Participants (n = 16) of the 2013 International Melanoma Pathology Study Group Workshop provided independent case-level diagnoses and treatment suggestions for 48 melanocytic lesions. Individual diagnoses (including, when necessary, least and most severe diagnoses) were mapped to corresponding MPATH-Dx classes. Interrater agreement and correlation between MPATH-Dx categorization and treatment suggestions were evaluated. RESULTS: Most participants were board-certified dermatopathologists (n = 15), age 50 years or older (n = 12), male (n = 9), based in the United States (n = 11), and primary academic faculty (n = 14). Overall, participants generated 634 case-level diagnoses with treatment suggestions. Mean weighted kappa coefficients for diagnostic agreement after MPATH-Dx mapping (assuming least and most severe diagnoses, when necessary) were 0.70 (95% confidence interval 0.68-0.71) and 0.72 (95% confidence interval 0.71-0.73), respectively, whereas correlation between MPATH-Dx categorization and treatment suggestions was 0.91. LIMITATIONS: This was a small sample size of experienced pathologists in a testing situation. CONCLUSION: Varying diagnostic nomenclature can be classified into a concise hierarchy using the MPATH-Dx scheme. Further research is needed to determine whether this classification system can facilitate diagnostic concordance in general pathology practice and improve patient care.

A Hyalinized Trichilemmoma of the Eyelid in a Teenager.

A 16-year-old African American male, the youngest patient to date, presented with a well-circumscribed upper eyelid lesion. On excision, the dermal nodule was contiguous with the epidermis, displayed trichohyalin-like bodies in an expanded outer root sheath, and was composed chiefly of small cellular clusters separated by a prominent network of periodic acid Schiff -positive hyaline bands of basement membrane material. The tumor cells were positive for high molecular weight cytokeratins (CK) 5/6, CK14, and CK34ßE12 and were negative for CK7, carcinoembryonic antigen and epithelial membrane antigen. Negative S100, glial fibrillary acidic protein, and smooth muscle actin immunoreactions ruled out a myoepithelial lesion. The Ki-67 proliferation index was <10%. The diagnosis was a hyalinized trichilemmoma, contrasting with the more common lobular type. As an isolated lesion, trichilemmoma does not portend Cowden syndrome.

An automated image processing method to quantify collagen fibre organization within cutaneous scar tissue.

Standard approaches to evaluate scar formation within histological sections rely on qualitative evaluations and scoring, which limits our understanding of the remodelling process. We have recently developed an image analysis technique for the rapid quantification of fibre alignment at each pixel location. The goal of this study was to evaluate its application for quantitatively mapping scar formation in histological sections of cutaneous burns. To this end, we utilized directional statistics to define maps of fibre density and directional variance from Masson's trichrome-stained sections for quantifying changes in collagen organization during scar remodelling. Significant increases in collagen fibre density are detectable soon after burn injury in a rat model. Decreased fibre directional variance in the scar was also detectable between 3 weeks and 6 months after injury, indicating increasing fibre alignment. This automated analysis of fibre organization can provide objective surrogate endpoints for evaluating cutaneous wound repair and regeneration.

Use of Photodynamic Therapy and Sterile Water to Target Adipose Tissue.

BACKGROUND: Neither photodynamic therapy (PDT) nor sterile water has not been well studied for the treatment of adipose tissue. OBJECTIVE: This investigation studied 2 different modalities, verteporfin PDT and sterile water, on adipose tissue compared with control. MATERIALS AND METHODS: Four light-skinned pigs were used. Test sites received verteporfin PDT or sterile water injection. Control sites received injection of verteporfin without PDT, normal saline injection, no intervention, exposure to laser only, or insertion of a needle or cannula only. Sites were evaluated clinically, by ultrasound, and with histology 4 to 6 weeks after treatment. RESULTS: There was a decrease in adipose tissue by ultrasound after verteporfin PDT (15%, p < .001) and sterile water (2%, p = .23). Verteporfin without PDT showed a decrease in adipose tissue (17%, p = .21). All other control sites showed an increase in adipose tissue. Histologically, verteporfin PDT and sterile water showed moderate damage (median Grade 2, p < .001) 4 to 6 weeks after intervention. CONCLUSION: Verteporfin decreased adipose tissue after treatment. Sterile water injection had a statistically significant effect on adipose tissue histologically but did not substantially decrease the adipose tissue by ultrasound 4 to 6 weeks after intervention. Longer follow-up may be needed.

CXCR4 pathway associated with family history of melanoma.

PURPOSE: Genetic predisposition plays a major role in the etiology of melanoma, but known genetic markers only account for a limited fraction of family-history-associated melanoma cases. Expression microarrays have offered the opportunity to identify further genomic profiles correlated with family history of melanoma. We aimed to distinguish mRNA expression signatures between melanoma cases with and without a family history of melanoma. METHODS: Based on the Nurses' Health Study, family history was defined as having one or more first-degree family members diagnosed with melanoma. Melanoma diagnosis was confirmed by reviewing pathology reports, and tumor blocks were collected by mail from across the USA. Genomic interrogation was accomplished through evaluating expression profiling of formalin-fixed paraffin-embedded tissues from 78 primary cutaneous invasive melanoma cases, on either a 6K or whole-genome (24K) Illumina gene chip. Gene set enrichment analysis was performed for each batch to determine the differentially enriched pathways and key contributing genes. RESULTS: The CXC chemokine receptor 4 (CXCR4) pathway was consistently up-regulated within cases of familial melanoma in both platforms. Leading edge analysis showed four genes from the CXCR4 pathway, including MAPK1, PLCG1, CRK, and PTK2, were among the core members that contributed to the enrichment of this pathway. There was no association between the enrichment of CXCR4 pathway and NRAS, BRAF mutation, or Breslow thickness of the primary melanoma cases. CONCLUSIONS: We found that the CXCR4 pathway might constitute a novel susceptibility pathway associated with family history of melanoma in first-degree relatives.

Loss of 5-hydroxymethylcytosine correlates with increasing morphologic dysplasia in melanocytic tumors.

DNA methylation is the most well-studied epigenetic modification in cancer biology. 5-hydroxymethylcytosine is an epigenetic mark that can be converted from 5-methylcytosine by the ten-eleven translocation gene family. We recently reported the loss of 5-hydroxymethylcytosine in melanoma compared with benign nevi and suggested that loss of this epigenetic marker is correlated with tumor virulence based on its association with a worse prognosis. In this study, we further characterize the immunoreactivity patterns of 5-hydroxymethylcytosine in the full spectrum of melanocytic lesions to further validate the potential practical application of this epigenetic marker. One hundred and seventy-five cases were evaluated: 18 benign nevi, 20 dysplastic nevi (10 low-grade and 10 high-grade lesions), 10 atypical Spitz nevi, 20 borderline tumors, 5 melanomas arising within nevi, and 102 primary melanomas. Progressive loss of 5-hydroxymethylcytosine from benign dermal nevi to high-grade dysplastic nevi to borderline melanocytic neoplasms to melanoma was observed. In addition, an analysis of the relationship of nuclear diameter with 5-hydroxymethylcytosine staining intensity within lesional cells revealed a significant correlation between larger nuclear diameter and decreased levels of 5-hydroxymethylcytosine. Furthermore, borderline lesions uniquely exhibited a diverse spectrum of staining of each individual case. This study further substantiates the association of 5-hydroxymethylcytosine loss with dysplastic cytomorphologic features and tumor progression and supports the classification of borderline lesions as a biologically distinct category of melanocytic lesions.

Evaluation of stromal HGF immunoreactivity as a biomarker for melanoma response to RAF inhibitors.

Of more than 150 000 published studies evaluating new biomarkers, fewer than 100 biomarkers have been implemented for patient care. One reason for this is lack of rigorous testing by the medical community to validate claims for biomarker clinical relevance, and potential reluctance to publish negative results when confirmation is not obtained. Here we sought to determine the utility and reproducibility of immunohistochemical detection of hepatocyte growth factor (HGF) in melanoma tissue, an approach of potential assistance in defining patients with innate resistance to BRAF inhibitor therapy. To this end, a published and a revised method that retained sensitivity but with greater specificity for HGF detection, were evaluated in cells known to endogenously express HGF, and in models where HGF is upregulated via cytokine induction and via overexpression by gene transfection. Consequent patient evaluation in collaboration with the Melanoma Institute Australia of a cohort of 41 melanoma specimens with extensive clinical annotation failed to validate HGF immunohistochemistry as a predictor of response to BRAF inhibitors. Targeted therapies for advanced melanoma and other cancers show great promise, and rigorous validation studies are thus indicated for approaches that seek to personalize such therapies to maximize therapeutic efficacy.