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Therapy targeting immune checkpoints represents an integral part of the treatment for patients suffering from advanced melanoma. However, the mechanisms of resistance are responsible for a lower therapeutic outcome than expected. Concerning melanoma, insufficient stimulation of the immune system by tumour neoantigens is a likely explanation. As shown previously, radiotherapy is a known option for increasing the production of tumour neoantigens and their release into the microenvironment. Consequently, neoantigens could be recognized by antigen presenting cells (APCs) and subjected to effector T lymphocytes. Enhancing the immune reaction can trigger the therapeutic response also at distant metastases, a phenomenon known as an abscopal effect (from "ab scopus", that is, away from the target). To illustrate this, we present the case of a 78-year old male treated by anti-CTLA-4/ipilimumab for metastatic melanoma. The patient received the standard four doses of ipilimumab administered every three weeks. However, the control CT scans detected disease progression in the form of axillary lymph nodes metastasis and liver metastasis two months after ipilimumab. At this stage, palliative cryotherapy of the skin metastases was initiated to alleviate the tumour burden. Surprisingly, the effect of cryotherapy was also observed in untreated metastases and deep subcutaneous metastases on the back. Moreover, we observed the disease remission of axillary lymph nodes and liver metastasis two months after the cryotherapy. The rarity of the abscopal effect suggests that even primed anti-tumour CD8 + T cells cannot overcome the tumour microenvironment's suppressive effect and execute immune clearance. However, the biological mechanism underlying this phenomenon is yet to be elucidated. The elicitation of a systemic response by cryotherapy with documented abscopal effect was rarely reported, although the immune response induction is presumably similar to a radiotherapy-induced one. The report is a combination case study and review of the abscopal effect in melanoma treated with checkpoint inhibitors.

The incidence of cutaneous malignant melanoma has been steadily increasing worldwide for several decades. This phenomenon seems to follow the trend observed in many types of malignancies caused by multiple significant factors, including ageing. Despite the progress in cutaneous malignant melanoma therapeutic options, the curability of advanced disease after metastasis represents a serious challenge for further research. In this review, we summarise data on the microenvironment of cutaneous malignant melanoma with emphasis on intercellular signalling during the disease progression. Malignant melanocytes with features of neural crest stem cells interact with non‑malignant populations within this microenvironment. We focus on representative bioactive factors regulating this intercellular crosstalk. We describe the possible key factors and signalling cascades responsible for the high complexity of the melanoma microenvironment and its premetastatic niches. Furthermore, we present the concept of melanoma early becoming a systemic disease. This systemic effect is presented as a background for the new horizons in the therapy of cutaneous melanoma.

The steadily increasing incidence of malignant melanoma (MM) and its aggressive behaviour makes this tumour an attractive cancer research topic. The tumour microenvironment is being increasingly recognised as a key factor in cancer biology, with an impact on proliferation, invasion, angiogenesis and metastatic spread, as well as acquired therapy resistance. Multiple bioactive molecules playing cooperative roles promote the chronic inflammatory milieu in tumours, making inflammation a hallmark of cancer. This specific inflammatory setting is evident in the affected tissue. However, certain mediators can leak into the systemic circulation and affect the whole organism. The present study analysed the complex inflammatory response in the sera of patients with MM of various stages. Multiplexed proteomic analysis (Luminex Corporation) of 31 serum proteins was employed. These targets were observed in immunohistochemical profiles of primary tumours from the same patients. Furthermore, these proteins were analysed in MM cell lines and the principal cell population of the melanoma microenvironment, cancer‑associated fibroblasts. Growth factors such as hepatocyte growth factor, granulocyte‑colony stimulating factor and vascular endothelial growth factor, chemokines RANTES and interleukin (IL)‑8, and cytokines IL‑6, interferon‑α and IL‑1 receptor antagonist significantly differed in these patients compared with the healthy controls. Taken together, the results presented here depict the inflammatory landscape that is altered in melanoma patients, and highlight potentially relevant targets for therapy improvement.

Melanoma represents a malignant disease with steadily increasing incidence. UV-irradiation is a recognized key factor in melanoma initiation. Therefore, the efficient prevention of UV tissue damage bears a critical potential for melanoma prevention. In this study, we tested the effect of UV irradiation of normal keratinocytes and their consequent interaction with normal and cancer-associated fibroblasts isolated from melanoma, respectively. Using this model of UV influenced microenvironment, we measured melanoma cell migration in 3-D collagen gels. These interactions were studied using DNA microarray technology, immunofluorescence staining, single cell electrophoresis assay, viability (dead/life) cell detection methods, and migration analysis. We observed that three 10 mJ/cm 2 fractions at equal intervals over 72 h applied on keratinocytes lead to a 50% increase (p < 0.05) in in vitro invasion of melanoma cells. The introduction cancer-associated fibroblasts to such model further significantly stimulated melanoma cells in vitro invasiveness to a higher extent than normal fibroblasts. A panel of candidate gene products responsible for facilitation of melanoma cells invasion was defined with emphasis on IL-6, IL-8, and CXCL-1. In conclusion, this study demonstrates a synergistic effect between cancer microenvironment and UV irradiation in melanoma invasiveness under in vitro condition.

The incidence of malignant melanoma is rapidly increasing and current medicine is offering only limited options for treatment of the advanced disease. For B‑Raf mutated melanomas, treatment with mutation‑specific drug inhibitors may be used. Unfortunately, tumors frequently acquire resistance to the treatment. Tumor microenvironment, namely cancer‑associated fibroblasts, largely influence this acquired resistance. In the present study, fibroblasts were isolated from a patient suffering from acrolentiginous melanoma (Breslow, 4.0 mm; Clark, IV; B‑Raf V600E mutated). The present study focused on the expression of structural and functional markers of fibroblast activation in melanoma‑associated fibroblasts (MAFs; isolated prior to therapy initiation) as well as in autologous control fibroblasts (ACFs) of the same patient isolated during B‑Raf inhibitor therapy, yet before clinical progression of the disease. Analysis of gene transcription was also performed, as well as DNA methylation status analysis at the genomic scale of both isolates. MAFs were positive for smooth muscle actin (SMA), which is a marker of myofibroblasts and the hallmark of cancer stoma. Surprisingly, ACF isolated from the distant uninvolved skin of the same patient also exhibited strong SMA expression. A similar phenotype was also observed in control dermal fibroblasts (CDFs; from different donors) exclusively following stimulation by transforming growth factor (TGF)‑β1. Immunohistochemistry confirmed that melanoma cells potently produce TGF‑β1. Significant differences were also identified in gene transcription and in DNA methylation status at the genomic scale. Upregulation of SMA was observed in ACF cells at the protein and transcriptional levels. The present results support recent experimental findings that tumor microenvironment is driving resistance to B‑Raf inhibition in patients with melanoma. Such an activated microenvironment may be viable for the growth of circulating melanoma cells.

Melanoma represents a cancer with increasing incidence worldwide and limited curability of advanced stages of the disease. Similarly to other types of tumors, the microenvironment is an important factor that participates in the control of melanoma biological properties. This review summarizes data regarding the role of the microenvironment, namely fibroblasts, keratinocytes and infiltrating immune cells, on melanoma growth and spreading. The role of embryonic microenvironment on melanoma cell biological properties is also discussed. The potential of therapeutic targeting of the melanoma microenvironment is demonstrated.

Background: The authors present a technical variation of the standard cannulation for cardiopulmonary bypass perfusion during hyperthermic isolated limb perfusion (ILP) procedures in selected patients with unresectable soft tissue sarcoma or malignant melanoma., Patients: Of 55 ILP procedures performed at our institution since the procedure was established in 2009, nine were performed at the upper extremity. Standard single venous cannulation was used in five cases, and extended, double venous cannulation in the last four. The standard technique for brachial vein cannulation in a small compartment of the upper extremity entails a problematic and longer perfusion of the upper extremity. This is due to the lower flow rate in the venous system and relatively large surface area with respect to weight. We present a simple technique based on a "Y" cannulation of the venous system via the deep brachial vein and superficial venous system via the basilic vein, delivering a 20% increase in flow rate in the extracorporeal circulation. Faster heating of the upper extremity and a stable thermal environment throughout upper-extremity ILP are essential for successful treatment., Conclusion: Extended technique of venous cannulation for extracorporeal circulation setting, due to their advantages, became standard in the upper limb ILP procedure at our institution.Key words: isolated limb perfusion - malignant melanoma - soft tissue sarcoma - upper limb - extracorporeal circulation The authors declare they have no potential conflicts of interest concerning drugs, products, or services used in the study. The Editorial Board declares that the manuscript met the ICMJE recommendation for biomedical papers.Submitted: 8. 1. 2017Accepted: 15. 1. 2017.

Incidence of malignant melanoma is increasing globally. While the initial stages of tumors can be easily treated by a simple surgery, the therapy of advanced stages is rather limited. Melanoma cells spread rapidly through the body of a patient to form multiple metastases. Consequently, the survival rate is poor. Therefore, emphasis in melanoma research is given on early diagnosis and development of novel and more potent therapeutic options. The malignant melanoma is arising from melanocytes, cells protecting mitotically active keratinocytes against damage caused by UV light irradiation. The melanocytes originate in the neural crest and consequently migrate to the epidermis. The relationship between the melanoma cells, the melanocytes, and neural crest stem cells manifests when the melanoma cells are implanted to an early embryo: they use similar migratory routes as the normal neural crest cells. Moreover, malignant potential of these melanoma cells is overdriven in this experimental model, probably due to microenvironmental reprogramming. This observation demonstrates the crucial role of the microenvironment in melanoma biology. Indeed, malignant tumors in general represent complex ecosystems, where multiple cell types influence the growth of genetically mutated cancer cells. This concept is directly applicable to the malignant melanoma. Our review article focuses on possible strategies to modify the intercellular crosstalk in melanoma that can be employed for therapeutic purposes.

Tumour microenvironment plays a critical role in cell invasion and metastasis. To investigate the role of cancer-associated fibroblasts (CAFs) in melanoma cell invasiveness, we used 3D spheroid invasion assay. The effect of conditioned media from normal fibroblasts and CAFs cultivated alone or co-cultivated with melanoma cells on BLM or A2058 melanoma spheroid invasion was analysed. We found that conditioned media from CAFs and CAFs co-cultured with melanoma cells, especially, promote invasion and migration, without significant effect on melanoma cell proliferation. We further analysed the expression of pro-invasive cytokines IL-8 and IL-6 in media and found that melanoma cells are dominant producers of IL-8 and fibroblasts are dominant producers of IL-6 in 2D monocultures, while co-cultivation of CAFs with melanoma cells induces production/secretion of IL-6 and IL-8 into the media. The analyses of IL-6 levels in 3D cultures and human melanoma samples, however, revealed that at least in some cases IL-6 is also produced directly by melanoma cells. Analysis of the role of IL-6 and IL-8 in CAF-induced melanoma invasion, using neutralising antibodies, revealed that simultaneous blocking of IL-6 and IL-8 is sufficient to fully inhibit CAF-induced human melanoma cell invasiveness. In summary, these experiments indicate the important role of CAFs and IL-8 and IL-6 cytokines in melanoma cell invasiveness.

Epidermal stem cells (ESCs) are crucial for maintenance and self- renewal of skin epithelium and also for regular hair cycling. Their role in wound healing is also indispensable. ESCs reside in a defined outer root sheath portion of hair follicle-also known as the bulge region. ECS are also found between basal cells of the interfollicular epidermis or mucous membranes. The non-epithelial elements such as mesenchymal stem cell-like elements of dermis or surrounding adipose tissue can also contribute to this niche formation. Cancer stem cells (CSCs) participate in formation of common epithelial malignant diseases such as basal cell or squamous cell carcinoma. In this review article, we focus on the role of cancer microenvironment with emphasis on the effect of cancer-associated fibroblasts (CAFs). This model reflects various biological aspects of interaction between cancer cell and CAFs with multiple parallels to interaction of normal epidermal stem cells and their niche. The complexity of intercellular interactions within tumor stroma is depicted on example of malignant melanoma, where keratinocytes also contribute the microenvironmental landscape during early phase of tumor progression. Interactions seen in normal bulge region can therefore be an important source of information for proper understanding to melanoma. The therapeutic consequences of targeting of microenvironment in anticancer therapy and for improved wound healing are included to article.

Background: Nodular melanoma is one of the most life threatening tumors with still poor therapeutic outcome. Similarly to other tumors, permissive microenvironment is essential for melanoma progression. Features of this microenvironment are arising from molecular crosstalk between the melanoma cells (MC) and the surrounding cell populations in the context of skin tissue. Here, we study the effect of melanoma cells on human primary keratinocytes (HPK). Presence of MC is as an important modulator of the tumor microenvironment and we compare it to the effect of nonmalignant lowly differentiated cells also originating from neural crest (NCSC)., Methods: Comparative morphometrical and immunohistochemical analysis of epidermis surrounding nodular melanoma (n = 100) was performed. Data were compared to results of transcriptome profiling of in vitro models, in which HPK were co-cultured with MC, normal human melanocytes, and NCSC, respectively. Differentially expressed candidate genes were verified by RT-qPCR. Biological activity of candidate proteins was assessed on cultured HPK., Results: Epidermis surrounding nodular melanoma exhibits hyperplastic features in 90% of cases. This hyperplastic region exhibits aberrant suprabasal expression of keratin 14 accompanied by loss of keratin 10. We observe that MC and NCSC are able to increase expression of keratins 8, 14, 19, and vimentin in the co-cultured HPK. This in vitro finding partially correlates with pseudoepitheliomatous hyperplasia observed in melanoma biopsies. We provide evidence of FGF-2, CXCL-1, IL-8, and VEGF-A participation in the activity of melanoma cells on keratinocytes., Conclusion: We conclude that the MC are able to influence locally the differentiation pattern of keratinocytes in vivo as well as in vitro. This interaction further highlights the role of intercellular interactions in melanoma. The reciprocal role of activated keratinocytes on biology of melanoma cells shall be verified in the future.

Malignant melanoma is a highly aggressive tumor with increasing incidence and high mortality. The importance of immunohistochemistry in diagnosis of the primary tumor and in early identification of metastases in lymphatic nodes is enormous; however melanoma phenotype is frequently variable and thus several markers must be employed simultaneously. The purposes of this study are to describe changes of phenotype of malignant melanoma in vitro and in vivo and to investigate whether changes of environmental factors mimicking natural conditions affect the phenotype of melanoma cells and can revert the typical in vitro loss of diagnostic markers. The influence of microenvironment was studied by means of immunocytochemistry on co-cultures of melanoma cells with melanoma-associated fibroblast and/or in conditioned media. The markers typical for melanoma (HMB45, Melan-A, Tyrosinase) were lost in malignant cells isolated from malignant effusion; however, tumor metastases shared identical phenotype with primary tumor (all markers positive). The melanoma cell lines also exerted reduced phenotype in vitro. The only constantly present diagnostic marker observed in our experiment was S100 protein and, in lesser extent, also Nestin. The phenotype loss was reverted under the influence of melanoma-associated fibroblast and/or both types of conditioned media. Loss of some markers of melanoma cell phenotype is not only of diagnostic significance, but it can presumably also contribute to biological behavior of melanoma. The presented study shows how the conditions of cultivation of melanoma cells can influence their phenotype. This observation can have some impact on considerations about the role of microenvironment in tumor biology.

It is widely recognized that stromal fibroblasts significantly influence biological properties of multiple tumors including breast cancer. However, these epithelial-mesenchymal interactions seem to be essential in tumor biology and it is not fully clear whether this interaction is tumor type-specific or has a more general non-specific character. To elucidate this question, we tested the effect of cancer-associated fibroblasts (CAFs) isolated from different types of tumors (breast cancer skin metastasis, cutaneous basal cell carcinoma and melanoma, squamous cell carcinoma arising from oral cavity mucous membrane) on the EM-G3 breast cancer cell line. The results were compared with control experiments using normal human dermal fibroblasts, 3T3 mouse fibroblasts, and 3T3 fibroblasts influenced by the fibroblasts prepared from the basal cell carcinoma. Our results demonstrated that expression of luminal marker keratin 8 was influenced only by CAFs prepared from any tested tumors. In contrast, all tested types of fibroblasts showed a strong stimulatory effect on the expression of basal/myoepithelial marker keratin 14. The CAFs also elevated the number of cells with positivity for both keratins 8 and 14 that are similar to ductal originated precursor cells. The expression of proliferation marker Ki67 was not influenced by any of the tested fibroblasts. In conclusion, our data indicate that CAFs are able to influence the phenotype of a breast cancer cell line and this effect is based on a tumor type-unspecific mechanism. Finally, a clear functional difference between normal and CAFs was demonstrated.

Hyperthermic isolated limb perfusion (HILP) is a standardized method of treatment in selected patients with in-transient locoregional recurrence/methastasis of melanoma or, some other soft tissue tumors (incl. sarcoma etc.) Authors present history and current status of this treatment modality in General University Hospital in Prague. During one year period (7/2009-6/2010) 10 patients were indicated for this procedure. We performed 13 procedures (3x redo), 11 in lower extremity and 2 in upper extremity. There was no serious complication in this cohort of patiens. Multidisciplinar approach is indicated in melanoma patients care.