ABSTRACT
Non-melanoma skin cancer (NMSC) has risen dramatically as a result of chronic exposure to sunlight ultraviolet (UV) radiation, climatic changes and clinical conditions associated with immunosuppression. In spite of considerable progress, our understanding of the mechanisms that control NMSC development and their associated molecular and immunological landscapes is still limited. Here we demonstrated a critical role for galectin-7 (Gal-7), a ß-galactoside-binding protein preferentially expressed in skin tissue, during NMSC development. Transgenic mice (Tg46) overexpressing Gal-7 in keratinocytes showed higher number of papillomas compared to WT mice or mice lacking Gal-7 (Lgals7-/-) when subjected to a skin carcinogenesis protocol, in which tumor initiator 7,12-dimethylbenz[a]anthracene (DMBA) and tumor promoter 12-O-tetradecanoyl-phorbol-13-acetate (TPA) were sequentially administered. RNAseq analysis of Tg46 tumor lesions revealed a unique profile compatible with cells of the myelomonocytic lineage infiltrating these tumors, an effect that was substantiated by a higher number of CD11b+Gr1+ cells in tumor-draining lymph nodes. Heightened c-Met activation and Cxcl-1 expression in Tg46 lesions suggested a contribution of this pathway to the recruitment of these cells. Remarkably, Gal-7 bound to the surface of CD11b+Ly6ChiLy6Glo monocytic myeloid cells and enhanced their immunosuppressive activity, as evidenced by increased IL-10 and TGF-ß1 secretion, and higher T-cell inhibitory activity. In vivo, carcinogen-treated Lgals7-/- animals adoptively transferred with Gal-7-conditioned monocytic myeloid cells developed higher number of papillomas, whereas depletion of these cells in Tg46-treated mice led to reduction in the number of tumors. Finally, human NMSC biopsies showed increased LGALS7 mRNA and Gal-7 protein expression and displayed transcriptional profiles associated with myeloid programs, accompanied by elevated CXCL1 expression and c-Met activation. Thus, Gal-7 emerges as a critical mediator of skin carcinogenesis and a potential therapeutic target in human NMSC.
Subject(s)
Papilloma , Skin Neoplasms , Mice , Animals , Humans , Carcinogens , Skin Neoplasms/pathology , Papilloma/pathology , Carcinogenesis/genetics , Mice, Transgenic , Galectins/genetics , Skin/metabolism , Immunity, InnateABSTRACT
The relevance of glycan-binding proteins in immune tolerance and inflammation has been well established, mainly by studies of C-type lectins, siglecs and galectins, both in experimental models and patient samples. Galectins, a family of evolutionarily conserved lectins, are characterized by sequence homology in the carbohydrate-recognition domain, atypical secretion via an endoplasmic reticulum-Golgi-independent pathway and by the ability to recognize ß-galactoside-containing saccharides. Galectin-1 (Gal-1), a prototype member of this family, displays mainly anti-inflammatory and immunosuppressive activities, although, similar to many cytokines and growth factors, it may also trigger paradoxical pro-inflammatory effects under certain circumstances. These dual effects could be associated to tissue-, time- or context-dependent regulation of galectin expression and function, including particular pathophysiologic settings and/or environmental conditions influencing the structure of this lectin, as well as the availability of glycosylated ligands in immune cells during the course of inflammatory responses. Here, we discuss the tissue-specific role of Gal-1 as a master regulator of inflammatory responses across different pathophysiologic settings, highlighting its potential role as a therapeutic target. Further studies designed at analyzing the intrinsic and extrinsic pathways that control Gal-1 expression and function in different tissue microenvironments may contribute to delineate tailored therapeutic strategies aimed at positively or negatively modulating this glycan-binding protein in pathologic inflammatory conditions.
Subject(s)
Galectin 1 , Galectins , Carbohydrates , Galectin 1/genetics , Galectins/metabolism , Humans , Inflammation/metabolism , Polysaccharides/metabolismABSTRACT
INTRODUCCIÓN La transmisión vertical del virus Zika (ZIKV) puede provocar microcefalia y/u otras anomalías cerebrales. Desde 2016 hay brotes de ZIKV. OBJETIVOS Evaluar prevalencia al nacimiento de microcefalia y/u otras anomalías cerebrales sus variaciones geográficas y temporales y estimar el riesgo asociado a infecciones congénitas. MÉTODOS Se incluyeron recién nacidos de la RENAC desde 4/2017 a 3/2018. Caso; recién nacido con perímetro cefálico (PC) < a percentilo 3. Control; recién nacido con PC normal sin anomalías nacido en la misma maternidad. Se analizó sangre y orina de madre y recién nacido en casos y controles. Para ZIKV se realizó PCR, ELISA IgM y PRNT. Se evaluó infección por toxoplasmosis, herpes simple, lúes, citomegalovirus (CMV), con estudios serológicos y directos. RESULTADOS Se detectaron 98 casos en 110,540 nacimientos, prevalencia 8,9 por 10.000 (IC 95%;7,2-10,8) con causa definida en 21 casos, microcefalia por anomalía cerebral específica 2 y sin causa 75. En 4 casos se detectó serología positiva para ZIKV, en 5 infección por CMV, 9 por toxoplasmosis, 1 caso coinfección por toxoplasmosis y CMV y 1 caso por lúes. Se detectó por el método de sumas acumulativas un aumento de los casos observados en noviembre y diciembre de 2017. La presencia de infecciones congénitas confirmadas en los recién nacidos, en su conjunto, mostró una asociación para el total de casos OR;5.91 (IC95%1.31-26.57), casos solo con microcefalia; OR;5.24 (IC95%1.65-16.59) y casos solo con anomalías cerebrales OR;8.10 (IC95%2.50-26.23). La infección materna por ZIKV se asoció con la presencia de anomalía cerebral (P=0.026), no fue significativa al ajustar por variables maternas. Toxoplasmosis se asoció a microcefalia OR;8.03 (IC95%1.23-∞). DISCUSIÓN Las infecciones congénitas fueron la causa reconocida más frecuente de microcefalia, ZIKV en la madre se asoció a anomalías cerebrales específicas en la descendencia. Futuros estudios son necesarios para definir más adecuadamente la magnitud del riesgo
