Recent Advances in Melanoma and Melanocyte Biology

Cul4b Promotes Progression of Malignant Cutaneous Melanoma Patients by Regulating CDKN2A

Although several molecular targeted therapy and immunotherapy have been developed, cutaneous melanoma prognosis is still not satisfying. Cul4b promotes the progression of several malignant tumors by regulating cell proliferation. However, its prognostic role in malignant cutaneous melanoma has not been evaluated. In this study, immunohistochemistry was performed to assess the expression of Cul4b in a consecutive patient cohort. The prognostic role of Cul4b was estimated with univariate and multivariate analysis. Cul4b was knocked down in melanoma cell line to evaluate its role in promoting cell proliferation. The results revealed that Cul4b was highly expressed in some of the cutaneous malignant melanoma patients and high expression of Cul4b was associated with poor melanoma-specific overall survival and poor disease-free survival. Cul4b expression was associated with Breslow categories, Clark level, and Ki67 expression. Univariate and multivariate analysis revealed that Cul4b is an independent prognosis risk factor of cutaneous melanoma. Downregulation of Cul4b inhibited the proliferation ability of melanoma cells and downregulated the expression of CDKN2A. These results suggest that Cul4b plays an essential role in cutaneous melanoma progression and may serve as a promising treatment target.

Application of Animal Models in Cancer Research: Recent Progress and Future Prospects

Animal models refers to the animal experimental objects and related materials that can simulate human body established in medical research. As the second-largest disease in terms of morbidity and mortality after cardiovascular disease, cancer has always been the focus of human attention all over the world, which makes it a research hotspot in the medical field. At the same time, more and more animal models have been constructed and used in cancer research. With the deepening of research, the construction methods of cancer animal models are becoming more and more diverse, including chemical induction, xenotransplantation, gene programming, and so on. In recent years, patient-derived xenotransplantation (PDX) model has become a research hotspot because it can retain the microenvironment of the primary tumor and the basic characteristics of cells. Animal models can be used not only to study the biochemical and physiological processes of the occurrence and development of cancer in objects but also for the screening of cancer drugs and the exploration of gene therapy. In this paper, several main tumor animal models and the application progress of animal models in tumor research are systematically reviewed. Finally, combined with the latest progress and development trend in this field, the future research of tumor animal model was prospected.

Melanoma: clinical-pathological and molecular analysis in patients of Ibague city, Colombia

This study aimed to establish the clinicopathological characteristics of patients with melanoma and its association with BRAF gene mutations. The pathology reports and paraffin-embedded tumor samples from 47 women and 30 men with melanoma, with an average age of diagnosis of 60 years, were reviewed at the Hospital Federico Lleras Acosta of Ibague, between 2010 and 2016. The presence of V600E mutation at the exon 15 of BRAF gene, was analyzed in these tumoral samples by Sanger sequencing and visual inspection of the electropherograms. We also studied the clinicopathological variables with X2, t-Student and the Kaplan Meier index. Most of the lesions were located in the lower limbs (46.6%). The most frequent subtype was Acral Lentiginous Melanoma (41.8%). Most lesions were of poor prognosis: Breslow depth greater than 4.1 mm (52.7%), ulceration (61.4%) and medium or high mitotic rate (> 30 %). The V600E mutation was identified in five patients with large, deep and ulcerated tumors, four of them had less than four years of survival. In conclusion, there was a higher frequency of melanoma in women, V600E BRAF mutation was present in patients with advanced disease (high Breslow index) and, the probability of five-year survival was less than 40%.

Organization of the Skin Immune System and Compartmentalized Immune Responses in Infectious Diseases

The skin is an organ harboring several types of immune cells that participate in innate and adaptive immune responses. The immune system of the skin comprises both skin cells and professional immune cells that together constitute what is designated skin-associated lymphoid tissue (SALT). In this review, I extensively discuss the organization of SALT and the mechanisms involved in its responses to infectious diseases of the skin and mucosa. The nature of these SALT responses, and the cellular mediators involved, often determines the clinical course of such infections. I list and describe the components of innate immunity, such as the roles of the keratinocyte barrier and of inflammatory and natural killer cells. I also examine the mechanisms involved in adaptive immune responses, with emphasis on new cytokine profiles, and the role of cell death phenomena in host-pathogen interactions and control of the immune responses to infectious agents. Finally, I highlight the importance of studying SALT in order to better understand host-pathogen relationships involving the skin and detail future directions in the immunological investigation of this organ, especially in light of recent findings regarding the skin immune system.

Cell-state dynamics and therapeutic resistance in melanoma from the perspective of MITF and IFNγ pathways

Targeted therapy and immunotherapy have greatly improved the prognosis of patients with metastatic melanoma, but resistance to these therapeutic modalities limits the percentage of patients with long-lasting responses. Accumulating evidence indicates that a persisting subpopulation of melanoma cells contributes to resistance to targeted therapy or immunotherapy, even in patients who initially have a therapeutic response; however, the root mechanism of resistance remains elusive. To address this problem, we propose a new model, in which dynamic fluctuations of protein expression at the single-cell level and longitudinal reshaping of the cellular state at the cell-population level explain the whole process of therapeutic resistance development. Conceptually, we focused on two different pivotal signalling pathways (mediated by microphthalmia-associated transcription factor (MITF) and IFNγ) to construct the evolving trajectories of melanoma and described each of the cell states. Accordingly, the development of therapeutic resistance could be divided into three main phases: early survival of cell populations, reversal of senescence, and the establishment of new homeostatic states and development of irreversible resistance. On the basis of existing data, we propose future directions in both translational research and the design of therapeutic strategies that incorporate this emerging understanding of resistance.

Holistic view of patients with melanoma of the skin: how can health systems create value and achieve better clinical outcomes?

Patients with skin cancer should be treated in healthcare units that ensure holistic and multidisciplinary approaches. Current healthcare units, especially those dedicated to cancer care, must evolve to integrated patient-centred systems. The current review presents a holistic health services perspective towards managing patients with melanoma of the skin, based on a literature search. It includes a detailed discussion on how this could impact on the patient, his or her quality of life and on service providers. Data from a multidisciplinary integrated practice unit, specialised in skin cancer, were also discussed, namely, for outcomes measurements, access to innovative treatments, value-based healthcare, patient centricity and use of integrated systems. Epidemiology data, including disease determinants and risk factors, play an important role in defining measures, resources and management of these integrated cancer units. To optimise effective care and improve survival outcomes, integrated cancer clinics should comprise, in a patient-centred way, innovative treatments and technologies, along with continuous training and creation of multidisciplinary units of healthcare professionals. Measurement of outcomes, such as clinical, quality of life and cost, is decisive in determining affordability and access to the best available state-of-the-art care. Besides, treatment of melanoma has significantly improved over recent years, but with increasing costs, which brings a challenging mission to guarantee access to treatment and quality care. Value-based healthcare allows the achievement of better health outcomes and higher quality services while reducing the costs associated with the full-care cycle. Therefore, current healthcare systems should develop in line with health institutions' organisation and culture, increasing adherence to best practices and create value.

Inhibition of mouse RM-1 prostate cancer and B16F10 melanoma by the fusion protein of HSP65 & STEAP1 186-193

The research of tumor vaccine plays a crucial role in tumor immunotherapy. This study has constructed and prepared a fusion protein vaccine of heat shock protein 65 (HSP65) and the octapeptide epitope 186-193 of the six transmembrane epithelial antigen of the prostate 1 (STEAP1 _186-193), and investigated the inhibitory effect of the fusion protein on mouse RM-1 prostate cancer and B16F10 melanoma xenografts. The fusion protein His-HSP65-STEAP1 _186-193 (HHST1), His-HSP65-2×STEAP1 _186-193 (HHST2) and His-HSP65-6×STEAP1 _186-193 (HHST6) were obtained by setting different copy number of STEAP1 _186-193 and adding His purification tag before HSP65. Firstly the inhibitory effect of fusion protein on mouse RM-1 prostate cancer xenografts has been studied, which could be the basis of the study the inhibitory effect of the best fusion protein on mouse B16F10 melanoma xenografts. All studies compared with the fusion protein His-HSP65 (HHSP65), the fusion proteins HHST1, HHST2 and HHST6 all could significantly inhibit the growth of mouse RM-1 prostate cancer xenografts. In addition, the fusion protein HHST2 was proved to be the best compared with the fusion proteins HHST1 and HHST6 (P<0.05). Apart from this, compared with the fusion protein HHSP65, the fusion protein HHST2 also significantly inhibited the growth of mouse beared B16F10 melanoma. The results above indicate that HSP65 and STEAP1 _186-193 can significantly inhibit the growth of mouse RM-1 prostate cancer and B16F10 melanoma xenografts, and the appropriate increase of copy number can effectively improve that the fusion protein has an excellent anti-tumor ability.

Comparison of fusion protein and DC vaccine in inhibition of mouse B16F10 melanoma tumor

Dendritic cell (DC) vaccine and fusion protein vaccine have been put into clinical use in cancer immunotherapy. This study compared DC vaccine and fusion protein vaccine directly in their capability of inducing specific immune response. We used mouse Granulocyte Macrophage-Colony Stimulating Factor (mGM-CSF) fused with gastrin-releasing peptide (GRP) and Gonadotrophin Releasing Hormone (GnRH) respectively to obtain mGM-CSF/GRP6 (mG6) and mGM-CSF/mGGn (mGGn) fusion proteins. We prepared fusion protein vaccine and DC vaccine including mG6 protein vaccine (6P), mGGn protein vaccine (nP), mG6 DC vaccine (6D) and mGGn DC vaccine (nD), then the two proteins were mixed to prepare combination proteins vaccine (6nP) and DC vaccine (6nD). After that, C57BL/6 mice were injected with B16F10 cell line to build melanoma tumor model, and were immunized with vaccines to produce antibodies to inhibit and destruct melanoma tumor cells. The discoveries showed that anti- mGM-CSF-GRP6 and anti- mGM-CSF-mGGn antibody vaccines were successfully created as expected; this was deduced from significant inhibition of melanoma tumor in vivo and significant reduction of tumor weight and volume. The effects of DC groups were better than that of the protein groups and the combination of vaccines were more effective than vaccine given separately. Our results indicate that using combination vaccine provides a new strategy to inhibit melanoma tumor growth but a complete cure of melanoma needs further investigations.