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.

• Keywords
• melanoma, cancer microenvironment, cancer-associated fibroblast, cytokine, chemokine, growth factor,
• MeSH
• Skin cytology   pathology   MeSH
• Humans MeSH
• Melanocytes pathology   MeSH
• Melanoma secondary   MeSH
• Cell Communication * MeSH
• Disease Models, Animal MeSH
• Mice MeSH
• Tumor Microenvironment * MeSH
• Skin Neoplasms pathology   MeSH
• Brain Neoplasms secondary   MeSH
• Lung Neoplasms secondary   MeSH
• Disease Progression MeSH
• Animals MeSH
• Check Tag
• Humans MeSH
• Mice MeSH
• Animals MeSH
• Publication type
• Journal Article MeSH
• Review MeSH

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.

• Keywords
• Cancer-associated fibroblast, Cytokine, Keratinocyte, Melanocyte, Melanoma cells, Melanoma ecosystem,
• MeSH
• Early Detection of Cancer methods   MeSH
• Neural Crest cytology   pathology   MeSH
• Indoles therapeutic use   MeSH
• Keratinocytes MeSH
• Humans MeSH
• Melanoma, Cutaneous Malignant MeSH
• Melanocytes pathology   MeSH
• Melanoma drug therapy   epidemiology   pathology   MeSH
• Tumor Microenvironment physiology   MeSH
• Skin Neoplasms MeSH
• Antineoplastic Agents therapeutic use   MeSH
• Sulfonamides therapeutic use   MeSH
• Ultraviolet Rays adverse effects   MeSH
• Vemurafenib MeSH
• Check Tag
• Humans MeSH
• Publication type
• Journal Article MeSH
• Review MeSH
• Names of Substances
• Indoles MeSH
• Antineoplastic Agents MeSH
• Sulfonamides MeSH
• Vemurafenib MeSH

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.

• Keywords
• cancer microenvironment, cancer-associated fibroblast, niche, stem cell, wound healing,
• MeSH
• Epidermal Cells MeSH
• Epithelial Cells pathology   MeSH
• Fibroblasts pathology   MeSH
• Wound Healing physiology   MeSH
• Keratinocytes pathology   MeSH
• Humans MeSH
• Melanoma pathology   MeSH
• Mesenchymal Stem Cells pathology   MeSH
• Neoplastic Stem Cells pathology   MeSH
• Tumor Microenvironment physiology   MeSH
• Skin Neoplasms pathology   MeSH
• Stem Cell Niche physiology   MeSH
• Hair Follicle cytology   MeSH
• Animals MeSH
• Check Tag
• Humans MeSH
• Animals MeSH
• Publication type
• Journal Article MeSH
• Research Support, Non-U.S. Gov't MeSH
• Review MeSH

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.

• MeSH
• Cell Differentiation * genetics   MeSH
• Chemokine CXCL1 pharmacology   MeSH
• Adult MeSH
• Epidermal Cells * MeSH
• Epidermis pathology   MeSH
• Fibroblast Growth Factor 2 pharmacology   MeSH
• Interleukin-8 pharmacology   MeSH
• Keratin-10 metabolism   MeSH
• Keratin-14 metabolism   MeSH
• Keratinocytes cytology   drug effects   metabolism   MeSH
• Middle Aged MeSH
• Humans MeSH
• Melanocytes metabolism   MeSH
• Melanoma metabolism   pathology   MeSH
• Neoplasm Metastasis MeSH
• Cell Communication * MeSH
• Cell Line, Tumor MeSH
• S100 Proteins metabolism   MeSH
• Aged MeSH
• Gene Expression Profiling MeSH
• Vascular Endothelial Growth Factor A pharmacology   MeSH
• Check Tag
• Adult MeSH
• Middle Aged MeSH
• Humans MeSH
• Male MeSH
• Aged MeSH
• Female MeSH
• Publication type
• Journal Article MeSH
• Research Support, Non-U.S. Gov't MeSH
• Names of Substances
• Chemokine CXCL1 MeSH
• Fibroblast Growth Factor 2 MeSH
• Interleukin-8 MeSH
• Keratin-10 MeSH
• Keratin-14 MeSH
• S100 Proteins MeSH
• Vascular Endothelial Growth Factor A MeSH

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.

• MeSH
• Models, Biological MeSH
• Cell Culture Techniques MeSH
• Fibroblasts cytology   drug effects   metabolism   MeSH
• Immunophenotyping MeSH
• Immunohistochemistry MeSH
• Coculture Techniques MeSH
• Culture Media, Conditioned pharmacology   MeSH
• Cells, Cultured MeSH
• Humans MeSH
• MART-1 Antigen metabolism   MeSH
• Melanoma metabolism   pathology   MeSH
• Melanoma-Specific Antigens metabolism   MeSH
• gp100 Melanoma Antigen MeSH
• Biomarkers, Tumor metabolism   MeSH
• Cell Line, Tumor MeSH
• Tumor Cells, Cultured MeSH
• Tumor Microenvironment drug effects   MeSH
• Skin Neoplasms metabolism   pathology   MeSH
• Nestin metabolism   MeSH
• S100 Proteins metabolism   MeSH
• Monophenol Monooxygenase metabolism   MeSH
• Check Tag
• Humans MeSH
• Publication type
• Journal Article MeSH
• Research Support, Non-U.S. Gov't MeSH
• Names of Substances
• Culture Media, Conditioned MeSH
• MART-1 Antigen MeSH
• Melanoma-Specific Antigens MeSH
• gp100 Melanoma Antigen MeSH
• Biomarkers, Tumor MeSH
• Nestin MeSH
• PMEL protein, human MeSH Browser
• S100 Proteins MeSH
• Monophenol Monooxygenase MeSH

Regulation of organ growth is critical during embryogenesis. At the cellular level, mechanisms controlling the size of individual embryonic organs include cell proliferation, differentiation, migration, and attrition through cell death. All these mechanisms play a role in cardiac morphogenesis, but experimental studies have shown that the major determinant of cardiac size during prenatal development is myocyte proliferation. As this proliferative capacity becomes severely restricted after birth, the number of cell divisions that occur during embryogenesis limits the growth potential of the postnatal heart. We summarize here current knowledge concerning regional control of myocyte proliferation as related to cardiac morphogenesis and dysmorphogenesis. There are significant spatial and temporal differences in rates of cell division, peaking during the preseptation period and then gradually decreasing toward birth. Analysis of regional rates of proliferation helps to explain the mechanics of ventricular septation, chamber morphogenesis, and the development of the cardiac conduction system. Proliferation rates are influenced by hemodynamic loading, and transduced by autocrine and paracrine signaling by means of growth factors. Understanding the biological response of the developing heart to such factors and physical forces will further our progress in engineering artificial myocardial tissues for heart repair and designing optimal treatment strategies for congenital heart disease.

• MeSH
• Models, Biological MeSH
• Cell Differentiation genetics   MeSH
• Myocytes, Cardiac metabolism   physiology   MeSH
• Humans MeSH
• Morphogenesis genetics   physiology   MeSH
• Myocardium metabolism   MeSH
• Cell Proliferation * MeSH
• Heart embryology   growth & development   MeSH
• Gene Expression Regulation, Developmental MeSH
• Animals MeSH
• Check Tag
• Humans MeSH
• Animals MeSH
• Publication type
• Journal Article MeSH
• Research Support, Non-U.S. Gov't MeSH
• Review MeSH
• Research Support, N.I.H., Extramural MeSH