Melanoma: adjuvant therapy and other treatment options

Development of Personalized Strategies for Precisely Battling Malignant Melanoma

Melanoma is the most severe and fatal form of skin cancer, resulting from multiple gene mutations with high intra-tumor and inter-tumor molecular heterogeneity. Treatment options for patients whose disease has progressed beyond the ability for surgical resection rely on currently accepted standard therapies, notably immune checkpoint inhibitors and targeted therapies. Acquired resistance to these therapies and treatment-associated toxicity necessitate exploring novel strategies, especially those that can be personalized for specific patients and/or populations. Here, we review the current landscape and progress of standard therapies and explore what personalized oncology techniques may entail in the scope of melanoma. Our purpose is to provide an up-to-date summary of the tools at our disposal that work to circumvent the common barriers faced when battling melanoma.

Identification and validation of an epithelial mesenchymal transition-related gene pairs signature for prediction of overall survival in patients with skin cutaneous melanoma

BACKGROUND

We aimed to construct a novel epithelial-mesenchymal transition (EMT)-related gene pairs (ERGPs) signature to predict overall survival (OS) in skin cutaneous melanoma (CM) patients.

METHODS

Expression data of the relevant genes, corresponding clinicopathological parameters, and follow-up data were obtained from The Cancer Genome Atlas database. Univariate Cox regression analysis was utilized to identify ERGPs significantly associated with OS, and LASSO analysis was used to identify the genes used for the construction of the ERGPs signature. The optimal cutoff value determined by the receiver operating characteristic curve was used to classify patients into high-risk and low-risk groups. Survival curves were generated using the Kaplan-Meier method, and differences between the two groups were estimated using the log-rank test. The independent external datasets GSE65904 and GSE19234 were used to verify the performance of the ERGPs signature using the area under the curve (AUC) values. In addition, we also integrated clinicopathological parameters and risk scores to develop a nomogram that can individually predict the prognosis of patients with CM.

RESULTS

A total of 104 ERGPs related to OS were obtained, of which 21 ERGPs were selected for the construction of the signature. All CM patients were stratified into high-and low-risk groups based on an optimal risk score cutoff value of 0.281. According to the Kaplan-Meier analysis, the mortality rate in the low-risk group was lower than that in the high-risk group in the TCGA cohort (P < 0.001), GSE65904 cohort (P = 0.006), and GSE19234 cohort (P = 0.002). Multivariate Cox regression analysis indicated that our ERGP signature was an independent risk factor for OS in CM patients in the three cohorts (for TCGA: HR, 2.560; 95% CI [1.907-3.436]; P < 0.001; for GSE65904: HR = 2.235, 95% CI [1.492-3.347], P < 0.001; for GSE19234: HR = 2.458, 95% CI [1.065-5.669], P = 0.035). The AUC value for predicting the 5-year survival rate of patients with CM of our developed model was higher than that of two previously established prognostic signatures. Both the calibration curve and the C-index (0.752, 95% CI [0.678-0.826]) indicated that the developed nomogram was highly accurate. Most importantly, the decision curve analysis results showed that the nomogram had a higher net benefit than that of the American Joint Committee on Cancer stage system.

CONCLUSION

Our study established an ERGPs signature that could be potentially used in a clinical setting as a genetic biomarker for risk stratification of CM patients. In addition, the ERGPs signature could also predict which CM patients will benefit from PD-1 and PD-L1 inhibitors.

Response of human melanoma cell lines to interferon-beta gene transfer mediated by a modified adenoviral vector

Since melanomas often retain wild type p53, we developed an adenoviral vector, AdRGD-PG, which provides robust transduction and transgene expression in response to p53. Previously, this vector was used for interferon-β gene transfer in mouse models of melanoma, resulting in control of tumor progression, but limited cell killing. Here, the AdRGD-PG-hIFNβ vector encoding the human interferon-β cDNA (hIFNβ) was used to transduce human melanoma cell lines SK-MEL-05 and SK-MEL-147 (both wild type p53). In vitro, cell death was induced in more than 80% of the cells and correlated with elevated annexinV staining and caspase 3/7 activity. Treatment with hIFNβ promoted cell killing in neighboring, non-transduced cells, thus revealing a bystander effect. In situ gene therapy resulted in complete inhibition of tumor progression for SK-MEL-147 when using nude mice with no evidence of hepatotoxicity. However, the response in Nod-Scid mice was less robust. For SK-MEL-05, tumor inhibition was similar in nude and Nod-Scid mice and was less efficient than seen for SK-MEL-147, indicating both cell type and host specific responses. The AdRGD-PG-hIFNβ vector provides extensive killing of human melanoma cells in vitro and a potent anti-tumor effect in vivo. This study provides a critical advance in the development of our melanoma gene therapy approach.

MicroRNA-Directed Cancer Therapies: Implications in Melanoma Intervention

Acquired tumor resistance to cancer therapies poses major challenges in the treatment of cancers including melanoma. Among several signaling pathways or factors that affect neocarcinogenesis, cancer progression, and therapies, altered microRNAs (miRNAs) expression has been identified as a crucial player in modulating the key pathways governing these events. While studies in the miRNA field have grown exponentially in the last decade, much remains to be discovered, particularly with respect to their roles in cancer therapies. Since immune and nonimmune signaling cascades prevail in cancers, identification and evaluation of miRNAs, their molecular mechanisms and cellular targets involved in the underlying development of cancers, and acquired therapeutic resistance would help in devising new strategies for the prognosis, treatment, and an early detection of recurrence. Importantly, in-depth validation of miRNA-targeted molecular events could lead to the development of accurate progression-risk biomarkers, improved effectiveness, and improved patient responses to standard therapies. The current review focuses on the roles of miRNAs with recent updates on regulated cell cycle and proliferation, immune responses, oncogenic/epigenetic signaling pathways, invasion, metastasis, and apoptosis, with broader attention paid to melanomagenesis and melanoma therapies.

Expression levels of microRNA‑455 and its potential functions by targeting IGF‑1R in melanoma

Melanoma has the highest fatality and malignancy of all skin cancers. In cancer, microRNAs (miRNAs) act as tumor suppressors or oncogenes, and inactivation of oncogenic miRNAs or restoration of tumor suppressor miRNAs has potential for cancer treatment. In the present study, miR‑455 expression levels were examined in melanoma tissues and cell lines, and miR‑455 was significantly downregulated in melanoma compared with matched normal tissues or normal epidermal melanocytes. In addition, increasing miR‑455 expression in melanoma cells reduced cell proliferation and invasion. Bioinformatic analysis revealed that insulin‑like growth factor 1 receptor (IGF‑1R) was a putative target of miR‑455. Luciferase reporter assays, reverse transcription‑quantitative polymerase chain reaction and western blot confirmed that miR‑455 targeted the 3'‑untranslated region of IGF‑1R and thus regulated the biological processes of melanoma cells. IGF‑1R knockdown resulted in similar effects as miR‑455 overexpression in melanoma cells. In summary, these findings indicated that miR‑455 was downregulated in melanoma, and inhibited proliferation and invasion of melanoma cells through directly targeting IGF‑1R. This also suggested that the restoration of miR‑455 may be worth investigation as a therapeutic treatment for patients with melanoma.

MicroRNAs role as potential biomarkers and key regulators in melanoma

Malignant melanoma (MM) is a highly aggressive skin cancer with high incidence worldwide. It originates from melanocytes and is characterized by invasion, early metastasis and despite the use of new drugs it is still characterized by high mortality. Since an early diagnosis determines a better prognosis, it is important to explore novel prognostic markers in the management of patients with MM. microRNAs (miRNAs) are small (∼22 nucleotides) single-stranded non-coding RNAs that negatively regulate the expression of more than 60% of human genes.miRNAs alterations are involved in several cancers, including MM, where a differential expression for some of them has been reported between healthy controls and MM patients. Moreover, since miRNAs are stable and easily detectable in body fluids, they might be considered as robust candidate biomarkers useful to identify risk of MM, to diagnose an early lesion and/or an early metastatic disease. This review highlights the importance of miRNAs as risk factors, prognostic factors and their role as molecular regulator in the development and progression of MM. © 2016 Wiley Periodicals, Inc.

Mucin 1 and poly I:C activates dendritic cells and effectively eradicates pituitary tumors as a prophylactic vaccine

Pituitary tumors are the most common type of cancer within the central nervous system. In the present study, the expression levels of mucin 1 (Muc1) were examined in invasive and non‑invasive pituitary tumor samples, and the results of immunohistochemical staining and Western blot analysis demonstrated marked positive expression of Muc1. In addition, Muc1 + polyinosinic:polycytidylic acid (poly I:C) was found to stimulate the expression levels of the surface molecules cluster of differentiation (CD)40, CD83 and CD80, and HLA‑DRm and decreased the expression of CD14 in the dendritic cells, determined using fluorescence‑activated cell sorting. The secretions of interleukin (IL)‑6, tumor necrosis factor‑α and IL‑1β cytokines were also significantly induced, in a dose‑dependent manner. In in vivo experiments, a higher percentage of CD3+CD4+ T lymphocytes was detected, and the levels of interferon‑γ and IL‑2 in the splenocytes were also upregulated. Furthermore, the combination treatment of Muc1 with poly I:C increased anti‑Muc1 IgM and anti‑Muc1 IgG titers, and altered the balance of IgG2a and IgG1, all of which increased the T helper (Th)1 polarized immune response. Thus, the tumor antigen, Muc1, with poly I:C may produce potent protective effects, which polarize immune responses towards Th1, and elicit antitumor immunity to inhibit the progression of pituitary tumors.

Circulating miR-221 expression level and prognosis of cutaneous malignant melanoma

BACKGROUND

The aim of this study was to investigate the feasibility of using serum miR-221 as a noninvasive prognostic biomarker for cutaneous malignant melanoma (CMM).

MATERIAL/METHODS

We measured the expression levels of miR-221 in serum samples from 72 CMM patients and 54 healthy controls by real-time quantitative polymerase chain reaction (RT-PCR). The overall survival (OS) and disease-free survival (DFS) were calculated using the Kaplan-Meier method. The differences between the survival curves were tested by using the log-rank test. The COX proportional hazards regression model was used to determine the joint effects of several variables on survival.

RESULTS

The serum miR-221 levels were significantly higher in patients with CMM than in healthy controls (p<0.0001). Patients with high serum miR-221 levels had a significantly lower 5-year OS rate (22.1% vs. 54.6%; P=0.018) and RFS rate (12.5% vs. 45.2%; P=0.008) than those with low serum miR-221 level. In a multivariate Cox model, we found that miR-221 expression was an independent predictor of poor 5-year OS (hazards ratio [HR]=3.189, 95% confidence interval [CI]=1.782-6.777, P=0.007) and 5-year DFS (HR=2.119, CI=1.962-8.552, P=0.01) in CMM patients.

CONCLUSIONS

Our data indicate that serum miR-221 expression level has prognostic value in patients with CMM.

B16 cell lysates plus polyinosinic-cytidylic acid effectively eradicate melanoma in a mouse model by acting as a prophylactic vaccine

Th1 antigen-specific T cells secrete interferon-γ, which is able to kill antigen-specific cancer cells and is helpful for cancer vaccines. The aim of the present study was to explore whether B16 cell lysates plus polyinosinic-cytidylic acid (poly I:C) can effectively inhibit the progression of melanoma in an animal model. In the present study, C57BL/6 mice were divided into three groups, with each group containing more than six mice. The groups of mice were immunized twice with B16 cell lysates plus poly I:C, B16 cell lysates, or phosphate-buffered saline only, respectively. The in vivo results demonstrated that splenocytes from the mice immunized with B16 cell lysates plus poly I:C contained higher percentages of CD3+CD8+ T lymphocytes and CD3+CD4+ T lymphocytes, which were detected by a fluorescence-activated cell sorter, and produced higher levels of antigen-specific splenocyte proliferation activity, as detected by MTT assay. The splenocytes from the mice immunized with B16 cell lysates in combination with poly I:C produced higher levels of interferon‑γ, as detected by quantitative polymerase chain reaction and ELISA, as well as cytotoxic T lymphocyte activity when stimulated in vitro with B16 lysates. Additionally, subcutaneous immunization of the C57BL/6 mice with B16 cell lysates plus poly I:C conferred greater protection against tumor-forming B16 melanoma cells than that of the mice immunized with injection of B16 cell lysate alone. In conclusion, the cancer vaccine of B16 cell lysates plus poly I:C exerts potently protective effects that polarize responses toward Th1 and elicit antitumor immunity.

The status of microRNA-21 expression and its clinical significance in human cutaneous malignant melanoma

Dysregulation of microRNA-21 plays critical roles in tumor initiation and progression. The purpose of this study was to investigate the status of microRNA-21 expression in human cutaneous malignant melanoma and determine its clinical significance. TaqMan(®) real-time RT-PCR assay was performed to examine the expression of microRNA-21 in 10 cases of dysplastic nevi, 86 cases of primary cutaneous melanomas, 10 cases of melanoma metastases. The correlation of microRNA-21 expression with clinicopathological factors or prognosis of patients with cutaneous melanoma was statistically analyzed. Additionally, the effects of microRNA-21 expression on growth, apoptosis and chemo- or radiosensitivity of melanoma cells were also investigated by transfection of microRNA-21 inhibitor. We firstly showed that increased levels of microRNA-21 expression were shown from dysplastic nevi to primary cutaneous melanomas to melanoma metastases. Moreover, high miR-21 expression was found to be correlated with Breslow thickness and advanced clinical stage. Patients with high microRNA-21 expression showed shorter 5-year disease-free or overall survival than those with low microRNA-21 expression. Furthermore, multivariate regression analysis showed that the status of microRNA-21 expression was an independent prognostic factor for overall survival of patients. Antisense-mediated microRNA-21 inhibition could significantly suppress growth, increase apoptosis and enhance chemo- or radiosensitivity of human cutaneous melanoma cells by inducing the increased Bax/Bcl-2 ratio. Thus, the status of microRNA-21 might be an independent prognostic factor for patients with cutaneous melanoma, and microRNA-21 has the potential of being a novel molecular target for the treatment of human cutaneous melanoma.

Molecular markers of tumor progression in melanoma

Malignant melanoma represents one of the most aggressive malignancies but outcome is highly variable with early tumor lesions having an excellent prognosis following resection. We review here the data on identification of genes involved in the progression of melanoma as a result of expression array studies, genomic profiling, and genetic models. We focus on the role of tumor suppressors involved in cell cycle function, DNA repair, and genome maintenance. Highlighted are the roles of loss of p16 in promoting neoplasia in cooperation with deregulated MAPK signaling, and the role of loss of the RASSF1A protein in promoting chromosomal instability. The interactions between point mutation in growth signaling molecules and epigenetic changes in genes involved in DNA repair and cell division are discussed.

Functional and clinical relevance of chondroitin sulfate proteoglycan 4

The lack of effective conventional therapies for the treatment of advanced stage melanoma has stimulated interest in the development of novel strategies for the management of patients with malignant melanoma. Among them, immunotherapy has attracted much attention because of the potential role played by immunological events in the clinical course of melanoma. For many years, T cell-based immunotherapy has been emphasized in part because of the disappointing results of the monoclonal antibody (mAb)-based clinical trials conducted in the early 1980s and in part because of the postulated major role played by T cells in tumor growth control. More recently, mAb-based therapies have gained in popularity given their clinical and commercial success for a variety of malignant diseases. As a result, there has been increased interest in identifying and characterizing antibody-defined melanoma antigens. Among them, the chondroitin sulfate proteoglycan 4 (CSPG4), also known as high molecular weight-melanoma associated antigen (HMW-MAA) or melanoma chondroitin sulfate proteoglycan (MCSP), has attracted much attention in recent years because of the growing experimental evidence that it fulfills two requirements for immunotherapy to be therapeutically effective: (1) targeting of cancer stem cells (CSC) and (2) development of combinatorial therapies to counteract the escape mechanisms driven by the genetic instability of tumor cells. With this in mind, in this chapter, we have reviewed recent information related to the distribution of CSPG4 on various types of tumors, including CSC, its expression on pericytes in the tumor microenvironment, its recognition by T cells, its role in cell biology as well as the potential mechanisms underlying the ability of CSPG4-specific immunity to control malignant cell growth.

BRG1 expression is increased in human cutaneous melanoma

BACKGROUND

The SWI/SNF chromatin remodelling complex plays important roles in cellular processes including cell differentiation, cell cycle control and DNA repair. Aberrant expression of SWI/SNF subunits is involved in cancer development. The core subunit of the SWI/SNF complex, SNF5, has been shown to be inactivated in malignant rhabdoid tumours and has been defined as a tumour suppressor. However, the role of the catalytic subunit, BRG1, is not well defined in cancer.

OBJECTIVES

To investigate the role of BRG1 in melanoma development, we examined the expression of BRG1 in melanocytic lesions at different stages and analysed the correlation between BRG1 expression and clinicopathological variables and patient survival.

METHODS

Using tissue microarray and immunohistochemistry, we evaluated BRG1 staining in 48 dysplastic naevi, 90 primary melanomas and 47 metastatic melanomas. We studied melanoma cell proliferative ability with reduced BRG1 expression by small interfering RNA using cell proliferation assay and cell cycle analysis.

RESULTS

We found that BRG1 expression was increased in primary melanoma and metastatic melanoma compared with dysplastic naevi (P<0·0001). We did not find any correlation between BRG1 expression and melanoma patient survival. In addition, we demonstrated that knockdown of BRG1 in melanoma cell lines resulted in significantly reduced cell proliferative ability. This reduced cell proliferation is due to G(1) phase arrest as cyclin D(1) is downregulated upon BRG1 knockdown.

CONCLUSIONS

Our data indicate that BRG1 is significantly increased in human melanoma and is involved in melanoma initiation.

Loss of SNF5 expression correlates with poor patient survival in melanoma

PURPOSE

Aberrant expression of SWI/SNF chromatin remodeling complex is involved in cancer development. The tumor suppressor SNF5, the core subunit of SWI/SNF complex, has been shown to regulate cell differentiation, cell cycle control, and apoptosis. To investigate the role of SNF5 in the development of melanoma, we examined the expression of SNF5 in melanocytic lesions at different stages and analyzed the correlation between SNF5 expression and clinicopathologic variables and patient survival.

EXPERIMENTAL DESIGN

Using tissue microarray and immunohistochemistry, we evaluated SNF5 staining in 51 dysplastic nevi, 88 primary melanomas, and 48 metastatic melanomas. We studied chemosensitivity of melanoma cells with reduced SNF5 expression by siRNA using cell survival and apoptosis assays.

RESULTS

SNF5 expression was reduced in metastatic melanoma compared with dysplastic nevi (P = 0.005), in advanced primary melanoma (Clark's level V) compared with low risk Clark's level II melanoma (P = 0.019), and in melanoma at sun-exposed sites compared with sun-protected sites (P = 0.044). Furthermore, we showed a strong correlation between negative SNF5 expression and a worse 5-year survival in melanoma patients (P = 0.016). Multivariate Cox regression analysis revealed that negative SNF5 expression is an independent prognostic factor to predict patient outcome in primary melanomas (P = 0.031). Finally, we showed that knockdown of SNF5 in melanoma cell lines resulted in significant chemoresistance.

CONCLUSIONS

Our data indicate that SNF5 may be an important marker for human melanoma progression and prognosis as well as a potential therapeutic target.

The role of vaccine therapy in the treatment of melanoma

BACKGROUND

Melanoma is a tumour that is usually resistant to systemic therapy. Since it has been considered to be a highly immunogenic tumour, it has become an excellent target for the active specific immunotherapy. Vaccine therapy represents a novel approach to the treatment of melanoma.

OBJECTIVE

To evaluate different vaccines tested in stage III and/or IV melanoma patients.

METHODS

Systematic review of the published evidence on vaccine therapy in melanoma.

RESULTS

Melanoma vaccines can be classified into six groups: whole-cell vaccines, dendritic cell vaccines, peptide vaccines, ganglioside vaccines, DNA vaccines and viral vectors. The main characteristics of these vaccines including their advantages and disadvantages and the results from conducted trials are presented. Clinical responses to melanoma vaccines are still poor and currently there is no melanoma vaccine with a proven efficacy.

CONCLUSION

Vaccine therapy still remains an experimental therapy in patients with metastatic melanoma. Further research is required although a future therapy for advanced melanoma is probably a multimodal approach including vaccines, adjuvants and negative co-stimulatory blockade.

Interferon-induced hypothyroidism causing reversible pituitary enlargement

OBJECTIVE

To present the first reported case of interferon-induced hypothyroidism with radiographic confirmation of secondary pituitary hyperplasia.

METHODS

We describe the case of a woman with recurrent malignant melanoma, outline the details of her endocrine work-up, and illustrate the serial findings on magnetic resonance imaging of the head.

RESULTS

A 26-year-old woman underwent surgical excision of a melanoma of the left thigh and 10 years later had a second melanoma removed from her right knee. Metastatic work-up revealed evidence of tumor involvement in the cervical and mediastinal lymph nodes. After treatment with interferon for 1 year, persistent fatigue and menstrual irregularities led to the laboratory diagnosis of hypothyroidism, and magnetic resonance imaging revealed pituitary enlargement. Both her endocrinopathy and the pituitary hyperplasia resolved with discontinuation of the interferon treatment and with institution of thyroid replacement therapy.

CONCLUSION

Clinicians should be aware of the potential adverse effects of interferon therapy to avoid inappropriate diagnosis of a pituitary adenoma or metastatic lesion in patients with cancer who are treated with interferon. In addition, screening for hypothyroidism should be performed in patients receiving interferon.

Prognostic Significance of Nuclear ING3 Expression in Human Cutaneous Melanoma

PURPOSE

The novel tumor-suppressor ING3 has been shown to modulate transcription, cell cycle control, and apoptosis. Our previous study showed that ING3 promotes UV-induced apoptosis via the Fas/caspase-8-dependent pathway in melanoma cells. To investigate the putative role of ING3 in the development of melanoma, we examined the expression of ING3 in melanocytic lesions at different stages and analyzed the correlation between ING3 expression and clinicopathologic variables and patient survival.

EXPERIMENTAL DESIGN

Using tissue microarray and immunohistochemistry, we evaluated nuclear and cytoplasmic ING3 staining in 58 dysplastic nevi, 114 primary melanomas, and 50 metastatic melanomas.

RESULTS

Nuclear ING3 expression was remarkably reduced in malignant melanomas compared with dysplastic nevi (P<0.001), which was significantly correlated with the increased ING3 level in cytoplasm (P<0.05). Furthermore, the reduced nuclear ING3 expression was significantly correlated with a poorer disease-specific 5-year survival of patients with primary melanoma, especially for the high-risk melanomas (thickness >or=2.0 mm) with the survival rate reducing from 93% for patients with strong nuclear ING3 staining in their tumor biopsies to 44% for those with negative-to-moderate nuclear ING3 staining (P=0.004). Strikingly, our multivariate Cox regression analysis revealed that reduced nuclear ING3 expression is an independent prognostic factor to predict patient outcome in primary melanomas (P=0.038).

CONCLUSIONS

Our data indicate that ING3 may be an important marker for human melanoma progression and prognosis as well as a potential therapeutic target.

Potential side effects of dendritic cells pulsed with allogenic melanoma cell lysate in mice

An attempt has been made to investigate the toxicity of cancer immunotherapy based on the dendritic cells pulsed with lysate of allogenic melanoma cell, DM401. Dendritic cells pulsed with lysate of clone M3 were subcutaneously administered once a week eight times to C57BL/6 mice at 0, 2.5, 5, and 10 x 10(7) cells/kg. No changes attributable to the administration were observed in clinical signs and food and water consumption. The administration induced slight increases in body weights, white blood cells, total protein, total cholesterol, triglyceride, phospholipids, and absolute spleen weights, but a slight decrease in albumin/globulin ratio. Microscopic examinations revealed the infiltration of inflammatory cells in the lung, mainly in the pulmonary arteriole, in which the tunica media thickened, and in the pulmonary alveoli and alveolar space. Thickened tunica media of pulmonary arteriole was observed in both males and females at all selected doses. In addition, the subcutis at the test substance-application site showed inflammation and fibrosis. In conclusion, lung is a target organ of DM401, and most of the changes including the findings in lung are considered as the immunomodulatory functions of dendritic cells.

Gene Expression Changes and Signaling Events Associated with the Direct Antimelanoma Effect of IFN-γ

IFN-gamma plays a role in the response to melanoma indirectly through its effect on the immune system and directly through its antiproliferative and proapoptotic effects on melanoma cells. To understand the molecular basis for the direct antimelanoma effect of IFN-gamma, we studied IFN-induced changes in gene expression and signaling among three human melanoma cell lines (DM6, DM93, and 501mel). These were resistant to the antimelanoma effect of IFN-alpha, and only DM6 cells exhibited growth inhibition and apoptosis with IFN-gamma. Through DNA microarray analysis, we found that the antimelanoma effect of IFN-gamma in DM6 was associated with the down-regulation of multiple genes involved in G-protein signaling and phospholipase C activation (including Rap2B and calpain 3) as well as the down-regulation of genes involved in melanocyte/melanoma survival (MITF and SLUG), apoptosis inhibition (Bcl2A1 and galectin-3), and cell cycling (CDK2). The antimelanoma effect of IFN-gamma was also associated with the up-regulation of the proapoptotic dependence receptor UNC5H2 and the Wnt inhibitor Dkk-1. Whereas both IFNs were able to activate Stat1 in all cell lines, the delayed activation of the extracellular signal-regulated kinase, p38, and c-Jun NH2-terminal kinase mitogen-activated protein kinases occurred only in DM6 with IFN-gamma, and the effect of IFN-gamma on cell growth and survival as well as gene expression in DM6 was dependent on the coordinate activation of MEK1 and p38. These findings provide new insights into the signaling events and gene expression changes associated with growth inhibition and apoptosis in melanoma and may thereby assist in identifying new targets for the treatment of melanoma.

Successful treatment of malignant melanoma in situ with topical 5% imiquimod cream

BACKGROUND

Current treatment recommendations for malignant melanoma in situ include surgical excision with at least 0.5 cm margins. On the head or neck, obtaining adequate surgical margins for melanoma can be challenging and often disfiguring. In addition, some elderly patients may not be good surgical candidates and may request less aggressive interventions.

METHODS

We report herein three cases of malignant melanoma in situ on the face treated with topical imiquimod cream.

RESULTS

Complete regression of malignant melanoma in situ was observed on treatment with 5% topical imiquimod cream. The varied treatment regimens, rationale for using imiquimod rather than performing surgery, and the possible mechanisms of action are discussed.

CONCLUSIONS

Topical imiquimod can be used successfully for the treatment of malignant melanoma in situ on the face.

Molecular detection of circulating tumor cells is an independent prognostic factor in patients with high-risk cutaneous melanoma

Detection of circulating tumor cells (CTCs) might improve current staging procedures by identifying a subgroup of patients with minimal residual disease and thus a higher risk of disease recurrence. Forty patients with > or =2-mm-thick cutaneous melanoma with or without lymph node metastasis were enrolled. After standard radical surgery and adjuvant therapy in case of lymph node metastasis, patients were followed up with routine physical and radiologic assessments as well as serial PCR-based analysis of CTCs using 2 melanoma markers (tyrosinase and Melan-A/Mart-1). After a median follow-up of 30 months, 18 patients had disease recurrence and 28 were PCR-positive before the disease became clinically evident. The sensitivity of the molecular test was 83%. Median time to PCR positivity and median PCR-to-relapse time were 12 and 8 months, respectively. At multivariate analysis, PCR positivity was an independent predictor of disease recurrence (hazard ratio=2.06, 95% CI 1.07-3.35; p=0.03). Among high-risk melanoma patients, serial PCR-based analysis of CTCs can identify a subgroup at higher risk of disease recurrence, with clinically significant advance. Therefore, CTC detection might be employed for the selection of patients for adjuvant treatment and during follow-up for early indication of therapeutic failure.