Mast Cell: A Mysterious Character in Skin Cancer.

Cutaneous malignancies represent a real concern and burden for the healthcare system, not only due to their increased frequency, but also due to the significant number of deaths attributed to these types of cancer. The genesis of tumors, their progression and metastasis are highly complex and researched subjects; apparently, mast cells (MCs) constitute an important piece in the complicated jigsaw puzzle of cancer. This article reviews the current knowledge of the roles MCs might play in the development of cutaneous malignancies. Besides their well-known and studied role in allergic reactions, MCs are linked to multiple and various disorders, including cancer. MCs exhibit incredible heterogeneity, being able to secrete numerous mediators that influence the tumor microenvironment and tumor cells. They are involved in many physiological and pathological processes, such as inflammation and angiogenesis. In this context, it is paramount to explore the advancements made so far in elucidating the roles that MCs have in skin cancer because they might provide valuable therapeutic targets in the future. Controversial and conflicting results were obtained across the studies examined.

The Follicular Dendritic Cells and HPV 18 Interrelation in Head and Neck Squamous Cell Carcinomas of the Larynx.

Background and Objectives: Even if they are cells of controversial origin (mesenchymal, perivascular, or fibroblastic), follicular dendritic cells (FDC) are present in all organs. The aim of this study was to establish the FDC expression pattern and its interrelation with HPV 18 expression in laryngeal squamous cell carcinoma (LSCC). Materials and Methods: Fifty-six cases of LSCC were evaluated by simple and double immunostaining. The following score was used: 0 (negative or few positive cells), 1 (10-30% of positive cells), 2 (30-50% of cells), and 3 (over 50% of cells). Results: The expression of CD 21-positive cells with dendritic morphology (CDM) was noticed in the intratumoral area of conventional (well and poorly differentiated types and HPV 18 positive cases with a value of 2 for the score) and papillary types (HPV-18 negative cases with a score of 1). The highest value of 2 for the score of CDM in HPV-18 positive cases was found in the peritumoral area of well- and poorly-differentiated conventional LSCCs. A significant correlation was found between scores of CDM from the intratumoral area and those of the peritumoral area (p = 0.001), between CDM and non-dendritic morphology cells (NDM) of the intratumoral area (p = 0.001), and between HPV-18 status and peritumoral NDM cells (p = 0.044). Conclusions: The FDC and NDM cell score values of intratumoral and peritumoral areas may represent important parameters of LSCCs. This may contribute to a better stratification of laryngeal carcinoma cases and the individualized selection of clinical treatment protocols.

Chloride Intracellular Channel Protein 1 Expression and Angiogenic Profile of Liver Metastasis of Digestive Origin.

Chloride intracellular channel 1 (CLIC1) is involved in cell migration and metastasis. The histological growth patterns of liver metastasis are as follows: desmoplastic (d-HGP), replacement (r-HGP), pushing (p-HGP), and mixed. The aim of this study was to evaluate the relation between HGP, angiogenesis, and CLIC1 expression. Materials and Methods: A total of 40 cases of primary tumors and their LM: d-HGP (12 cases), r-HGP (13 cases), and p-HGP (15 cases), were evaluated through simple and double immunostaining. CLIC1 assessment was conducted as follows: scores of 0 (less than 10% of positive cells), 1 (10-30%), 2 (30-50%), or 3 (more than 50%) were assigned. Heterogeneous CLIC1 expression was found. CLIC1 in primary tumors correlated with grade G for all cases of LM with a p-HGP (p = 0.004). The CLIC1 score for LMs with an r-HGP correlated with grade G of the corresponding primary tumor (p = 0.027). CLIC1 and CD34+/Ki67+ vessels (p = 0.006) correlated in primary tumors. CLIC1 in primary tumors correlated with CD34+/Ki67+ vessels of LMs with a d HGP (p = 0.024). Conclusions: The CLIC1 score may have prognostic value, mainly for LMs with a p-HGP and r-HGP, and therapeutic value for LMs with a d-HGP.

Mast Cells as an Indicator and Prognostic Marker in Molecular Subtypes of Breast Cancer.

BACKGROUND/AIM: Mast cells (MCs) represent the most controversial non-malignant element of the tumor microenvironment. Our aim was to study how MCs density and distribution (intratumoral-MCit versus peritumoral-MCpt) relate to tumor grade and molecular subtypes. MATERIALS AND METHODS: MCs tryptase immunohistochemistry was performed on 80 cases of breast carcinomas. RESULTS: For Luminal A tumors, a partial correlation was detected between MCit and progesterone receptor (PR) (p=0.005). Luminal B tumors showed a significant correlation between MCpt and age (p=0.009), estrogen receptor (ER) (p=0.017) and PR (p=0.035). MCit and MCpt were strongly interrelated in this subtype (p=0.002) and in triple-negative breast cancers (p=0.002). In HER2 subtype, MCpt tumors were significantly correlated with HER2 (p=0.044). In G2 tumors, MCpt correlated with ER (p=0.015) and PR (p=0.038) while in G3 tumors ER correlated with both MCit (p=0.009) and MCpt (p=0.000487) tumors. CONCLUSION: MCs dynamics are strongly influenced by hormone receptors and HER2 status. MCit increased in aggressive tumor types and is a worse prognostic factor.

Mast Cells: Key Players in the Shadow in Oral Inflammation and in Squamous Cell Carcinoma of the Oral Cavity.

Although mast cells (MCs) have been discovered over 130 years ago, their function was almost exclusively linked to allergic affections. At the time being, it is well known that MCs possess a great variety of roles, in both physiologic and pathologic conditions. In the oral tissues, MCs release different proinflammatory cytokines, tumor necrosis factor alpha (TNF-α), that promote leukocyte infiltration in various inflammatory states of the oral cavity. These cells play a key role in the inflammatory process and, as a consequence, their number changes in different pathologic conditions of the oral cavity, like gingivitis, periodontitis, and so on. MCs also represent a rich source of proteases, especially of mast cell tryptase and chymase, which directly degrade the extracellular matrix through their proteolytic activity and thus indirectly stimulate angiogenesis and facilitate invasion and metastasis. It may be stated that mast cells could have an impact on primary tumor development, progression, and metastases in oral squamous cell carcinoma. By understanding the role of mast cells in the pathogenesis of different inflammatory and tumor diseases of the oral cavity, these cells may become therapeutic targets that could possibly improve the prognosis and survival of these patients.

Epidermal Growth Factor Receptor (EGFR) and Keratin 5 (K5): Versatile Keyplayers Defining Prognostic and Therapeutic Sub-classes of Head and Neck Squamous Cell Carcinomas.

Molecular classifications of several malignancies are already accepted and applied in clinical practice. For head and neck squamous cell carcinomas (HNSCCs) there exist few and controversial data regarding their stratification on distinct groups or sub-groups and thus, none of them are validated as useful tools for diagnosis and therapy. Starting from the highly expressed markers in HNSCC (epidermal growth factor receptor, keratin 5 and E cadherin) we proposed to identify distinct HNSCC sub-groups with a potential impact on prognosis and therapy. Complex analysis of immunohistochemical expression for six surrogate markers (EGFR, p53, Bcl2, CD117, keratin 5 and E-cadherin) defined three distinct sub-classes amongst EGFR-positive cases, based on the association and differential expression of p53 and Bcl2 (EGFR(+)/p53(-)/bcl2(-), EGFR(+)/p53(+)/bcl2(-) and EGFR(+)/p53(+)/bcl2(+)). Amongst them, only the EGFR(+)/p53+/bcl2(-) sub-class showed significant correlations with grade and TNM parameters. Keratin 5-positive cases were grouped in a special "basal like" group with a particular sub-class rich in CD117(+)/p63(+) cells also highly expressing EGFR. Presence of K5(+)/CD117(+)/p63(+) cells was correlated with all TNM staging parameters defining a particular sub-class with high aggressiveness and particular behavior. Our data sustain EGFR as the key player in the pathogenesis of HNSCCs, but its diagnostic value may be improved by association with other prognostic or therapeutic markers. We herein defined two distinct HNSCCs groups (EGFR(+) and K5(+)) with several sub-classes, identifiable by the additional assessment of p53, Bcl2 and CD117.

Mast cells stimulate lymphangiogenesis in the gingiva of patients with periodontal disease.

The presence and distribution of lymphatic vessels and mast cells in the gingiva under normal and pathological conditions have been reported by several studies, but the relationship between them during inflammatory lymphangiogenesis is virtually unknown. The aim of the present study was to investigate the lymphatic microvessel density (LMVD) and mast cell density (MCD) in the gingiva of patients with periodontal disease compared to normal-like gingiva. Gingival punch biopsies from 51 patients with periodontal disease were investigated. MCs and LVs were detected by double-immunohistochemistry, using primary antibodies against mast cell tryptase and D2-40. The inflammatory infiltrate was evaluated on a scale from 0 (absent) to +3 (severe inflammation). MCs and LVs were counted in the same microscopic field for each case at ×200 magnification. We found a significant increase in the number of both MCs and LVs in cases with mild and moderate inflammatory changes, followed by a slight decrease in cases with severe inflammation. We have shown a particular association between MCs and LVs that may support the contribution of MCs to the development of the lymphatic vasculature in inflammatory conditions. MCD correlated with LMVD in all cases with mild and moderate inflammatory changes, but not in cases with severe inflammation. No correlation was found between MCD/LMVD and the density of the inflammatory infiltrate. Our results suggest the potential involvement of MCs in the induction and maintenance of lymphangiogenesis in the gingiva of patients with periodontal disease in the early steps of evolution.

Lymphangiogenesis as a prerequisite in the pathogenesis of lung fibrosis.

Despite increasing knowledge on the cellular and molecular mechanisms involved in pulmonary fibrosis, its therapeutic options are still limited. The study of lymphangiogenesis has contributed to a better understanding of tumor growth and metastasis, with a major impact upon changes in therapeutic strategies and this was followed by the research of lymphatic vessels in other pathological conditions. Some data support the possible role of lymphangiogenesis in the pathogenesis of lung fibrosis. However, at the time of diagnosis for each patient with a fibrotic interstitial lung disease, it is necessary to predict the prognosis and to choose for individual targeted-therapy. Our aim was the characterization of lymphangiogenesis as a useful tool to stratify patients with lung fibrosis. We evaluated the presence, morphology and density of D2-40-positive lymphatic vessels and co-localization of D2-40/Ki67 in pulmonary fibrosis with different degrees of severity and without a specific etiology. Lymphatic vessel density did not correlate with severity grade and ranged between 4.66 to 38.33 vessels/×40 field, with the highest value in degree III of fibrosis. An intense proliferative activity of lymphatic endothelial cells was found in 24% (6 out of 25) of cases. The morphology of lymphatics and the presence of splitting combined with the proliferative activity of endothelial cell pillars suggested two different mechanisms in the formation new lymphatic vessels. Our results support the hypothesis that the activity and ongoing evolution of fibrosis can be predicted through the characterization of lymphangiogenesis but its presence or absence cannot predict the severity of fibrosis.

Everolimus dual effects of an area vasculosa angiogenesis and lymphangiogenesis.

Recently approved as treatment for astrocytoma, kidney and pancreatic cancer, everolimus acts on tumor cells by inhibiting tumor cell growth and proliferation, as well as by inhibition of angiogenic activity by both direct effects on vascular cell proliferation and indirect effects on growth factor production. The effects of everolimus on early stages of normal vasculogenesis, angiogenesis and lymphangiogenesis are not yet available. We found increased development of intravascular pillars by using area vasculosa of the chick chorioallantoic membrane treated with everolimus. An active lymphangiogenic response was highlighted by the expression of Prospero homeobox protein 1 (Prox1) and podoplanin, together with vascular endothelial growth factor receptor C (Vegf-C) and vascular endothelial growth factor receptor 3 (Vegfr-3) expression on day 4 in the treated group. These findings suggest a potential role of everolimus in the activation of lymphangiogenesis.

Platelet-derived growth factor and platelet-derived growth factor receptor-α expression in the normal human thymus and thymoma.

Platelet-derived growth factor (PDGF) and its receptors (PDGFRs) are strongly involved in the normal development of several organs, tumour angiogenesis and malignant progression and metastasis. Few studies concerning their expression, distribution and role in normal and pathological human thymus are available in the literature. The aim of this study has been to analyse the immunohistochemical expression of PDGF and PDGFR-α in prenatal and postnatal normal human thymus and thymomal biopsy specimens. The results demonstrated immunoreactivity to both PDGF and PDGFR-α in all specimens, but the intensity, distribution and number of positive cells were different in normal thymus and thymomas, and also among different tumour types. PDGF and PDGFR-α were weakly expressed in foetal and postnatal humans with a different distribution between cortex and medulla in both blood vessels and epithelial cells, whereas they were overexpressed in thymoma, especially in type B2 and B3, in the tumour epithelial cells. Overall, these data suggest that PDGF and PDGFR-α may be involved in the pathophysiology of the human thymus.