RESUMO
Little is known regarding the molecular differences between basal cell carcinoma (BCC) subtypes, despite clearly distinct phenotypes and clinical outcomes. In particular, infiltrative BCCs have poorer clinical outcomes in terms of response to therapy and propensity for dissemination. In this project, we aimed to use exome sequencing and RNA sequencing to identify somatic mutations and molecular pathways leading to infiltrative BCCs. Using whole-exome sequencing of 36 BCC samples (eight infiltrative) combined with previously reported exome data (58 samples), we determine that infiltrative BCCs do not contain a distinct somatic variant profile and carry classical UV-induced mutational signatures. RNA sequencing on both datasets revealed key differentially expressed genes, such as POSTN and WISP1, suggesting increased integrin and Wnt signaling. Immunostaining for periostin and WISP1 clearly distinguished infiltrative BCCs, and nuclear ß-catenin staining patterns further validated the resulting increase in Wnt signaling in infiltrative BCCs. Of significant interest, in BCCs with mixed morphology, infiltrative areas expressed WISP1, whereas nodular areas did not, supporting a continuum between subtypes. In conclusion, infiltrative BCCs do not differ in their genomic alteration in terms of initiating mutations. They display a specific type of interaction with the extracellular matrix environment regulating Wnt signaling.
Assuntos
Carcinoma Basocelular/genética , Neoplasias Cutâneas/genética , Idoso , Proteínas de Sinalização Intercelular CCN/análise , Carcinoma Basocelular/classificação , Carcinoma Basocelular/patologia , Moléculas de Adesão Celular/análise , Feminino , Humanos , Masculino , Mutação , Proteínas Proto-Oncogênicas/análise , Neoplasias Cutâneas/classificação , Neoplasias Cutâneas/patologiaRESUMO
To better understand the influence of ultraviolet (UV) irradiation on the initial steps of skin carcinogenesis, we examine patches of labeled keratinocytes as a proxy for clones in the interfollicular epidermis (IFE) and measure their size variation upon UVB irradiation. Multicolor lineage tracing reveals that in chronically irradiated skin, patches near hair follicles (HFs) increase in size, whereas those far from follicles do not change. This is explained by proliferation of basal epidermal cells within 60 µm of HF openings. Upon interruption of UVB, patch size near HFs regresses significantly. These anatomical differences in proliferative behavior have significant consequences for the cell of origin of basal cell carcinomas (BCCs). Indeed, a UV-inducible murine BCC model shows that BCC patches are more frequent, larger, and more invasive near HFs. These findings have major implications for the prevention of field cancerization in the epidermis.
Assuntos
Epiderme/metabolismo , Neoplasias Induzidas por Radiação/patologia , Raios Ultravioleta , Animais , Carcinoma Basocelular/metabolismo , Carcinoma Basocelular/patologia , Proliferação de Células , Ciclina D1/metabolismo , Modelos Animais de Doenças , Epiderme/efeitos da radiação , Folículo Piloso/patologia , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Transgênicos , Neoplasias Induzidas por Radiação/metabolismo , Neoplasias Cutâneas/metabolismo , Neoplasias Cutâneas/patologia , Células-Tronco/citologia , Células-Tronco/metabolismo , Proteína Supressora de Tumor p53/genética , Proteína Supressora de Tumor p53/metabolismoRESUMO
BACKGROUND: Basal Cell Carcinoma is the most common tumour and yet much remains to be determined regarding the molecular mechanisms that leads to its development. Hedgehog signal activation is sufficient for BCC induction, but the molecular mediators of BCC growth are not well understood. SoxF transcription factor Sox18 has been identified in human BCC, but its role in growth of the tumour is as yet unknown. OBJECTIVE: To determine if Sox18 is involved in the regulation of Basal Cell Carcinoma growth. METHODS: We analysed the function of Sox18 by combining a dominant negative Sox18 mouse model, Sox18+/OP with murine BCC RESULTS: We determine that Sox18 is ectopically expressed in the epidermal cells of a murine model of Basal Cell Carcinoma. We then show that dominant negative mutation of Sox18 increases the severity of murine Basal Cell Carcinoma. Finally, decreased Hey1 in Sox18+/OP BCC suggests Sox18 may negatively regulate BCC progression via Notch signaling. CONCLUSIONS: These data suggest that Sox18 is a hedgehog regulated mediator of tumour suppression within Basal Cell Carcinoma epidermis.
Assuntos
Carcinoma Basocelular/genética , Epiderme/patologia , Regulação Neoplásica da Expressão Gênica , Fatores de Transcrição SOXF/metabolismo , Neoplasias Cutâneas/genética , Animais , Carcinoma Basocelular/diagnóstico , Carcinoma Basocelular/patologia , Modelos Animais de Doenças , Expressão Ectópica do Gene , Proteínas Hedgehog/metabolismo , Humanos , Camundongos , Camundongos Transgênicos , Mutação , Receptor Patched-1/genética , Receptores Notch/metabolismo , Fatores de Transcrição SOXF/genética , Índice de Gravidade de Doença , Transdução de Sinais/genética , Neoplasias Cutâneas/diagnóstico , Neoplasias Cutâneas/patologiaRESUMO
Most chemotherapeutics elevate intracellular levels of reactive oxygen species (ROS), and many can alter redox-homeostasis of cancer cells. It is widely accepted that the anticancer effect of these chemotherapeutics is due to the induction of oxidative stress and ROS-mediated cell injury in cancer. However, various new therapeutic approaches targeting intracellular ROS levels have yielded mixed results. Since it is impossible to quantitatively detect dynamic ROS levels in tumors during and after chemotherapy in clinical settings, it is of increasing interest to apply mathematical modeling techniques to predict ROS levels for understanding complex tumor biology during chemotherapy. This review outlines the current understanding of the role of ROS in cancer cells during carcinogenesis and during chemotherapy, provides a critical analysis of the methods used for quantitative ROS detection and discusses the application of mathematical modeling in predicting treatment responses. Finally, we provide insights on and perspectives for future development of effective therapeutic ROS-inducing anticancer agents or antioxidants for cancer treatment.
Assuntos
Neoplasias/tratamento farmacológico , Espécies Reativas de Oxigênio/metabolismo , Humanos , Neoplasias/patologia , Estresse OxidativoRESUMO
Natural killer T (NKT) cells are prominent innate-like lymphocytes in the liver with critical roles in immune responses during infection, cancer, and autoimmunity. Interferon gamma (IFN-γ) and IL-4 are key cytokines rapidly produced by NKT cells upon recognition of glycolipid antigens presented by antigen-presenting cells (APCs). It has previously been reported that the transcriptional coactivator ß-catenin regulates NKT cell differentiation and functionally biases NKT cell responses toward IL-4, at the expense of IFN-γ production. ß-Catenin is not only a central effector of Wnt signaling but also contributes to other signaling networks. It is currently unknown whether Wnt ligands regulate NKT cell functions. We thus investigated how Wnt ligands and ß-catenin activity shape liver NKT cell functions in vivo in response to the glycolipid antigen, α-galactosylceramide (α-GalCer) using a mouse model. Pharmacologic targeting of ß-catenin activity with ICG001, as well as myeloid-specific genetic ablation of Wntless (Wls), to specifically target Wnt protein release by APCs, enhanced early IFN-γ responses. By contrast, within several hours of α-GalCer challenge, myeloid-specific Wls deficiency, as well as pharmacologic targeting of Wnt release using the small molecule inhibitor IWP-2 impaired α-GalCer-induced IFN-γ responses, independent of ß-catenin activity. These data suggest that myeloid cell-derived Wnt ligands drive early Wnt/ß-catenin signaling that curbs IFN-γ responses, but that, subsequently, Wnt ligands sustain IFN-γ expression independent of ß-catenin activity. Our analyses in ICG001-treated mice confirmed a role for ß-catenin activity in driving early IL-4 responses by liver NKT cells. However, neither pharmacologic nor genetic perturbation of Wnt production affected the IL-4 response, suggesting that IL-4 production by NKT cells in response to α-GalCer is not driven by released Wnt ligands. Collectively, these data reveal complex temporal roles of Wnt ligands and ß-catenin signaling in the regulation of liver NKT cell activation, and highlight Wnt-dependent and -independent contributions of ß-catenin to NKT cell functions.
Assuntos
Interferon gama/imunologia , Células T Matadoras Naturais/imunologia , Via de Sinalização Wnt/imunologia , beta Catenina/imunologia , Animais , Benzotiazóis/farmacologia , Compostos Bicíclicos Heterocíclicos com Pontes/farmacologia , Feminino , Interleucina-4/imunologia , Peptídeos e Proteínas de Sinalização Intracelular/antagonistas & inibidores , Peptídeos e Proteínas de Sinalização Intracelular/imunologia , Camundongos , Pirimidinonas/farmacologia , Receptores Acoplados a Proteínas G/antagonistas & inibidores , Receptores Acoplados a Proteínas G/imunologia , Via de Sinalização Wnt/efeitos dos fármacosRESUMO
Giant congenital nevi are associated with clinical complications such as neurocutaneous melanosis and melanoma. Virtually nothing is known about why some individuals develop these lesions. We previously identified the sonic hedgehog (Shh) pathway regulator Cdon as a candidate nevus modifier gene. Here we validate this by studying Cdon knockout mice, and go on to establishing the mechanism by which Shh exacerbates nevogenesis. Cdon knockout mice develop blue nevi without the need for somatic melanocyte oncogenic mutation. In a mouse model carrying melanocyte NRASQ61K, we found that strain backgrounds that carry genetic variants that cause increased keratinocyte Shh pathway activity, as measured by Gli1 and Gli2 expression, develop giant congenital nevi. Shh components are also active adjacent to human congenital nevi. Mechanistically, this exacerbation of nevogenesis is driven via the release of the melanocyte mitogen endothelin-1 from keratinocytes. We then suppressed nevus development in mice using Shh and endothelin antagonists. Our work suggests an aspect of nevus development whereby keratinocyte cytokines such as endothelin-1 can exacerbate nevogenesis, and provides potential therapeutic approaches for giant congenital nevi. Furthermore, it highlights the notion that germline genetic variation, in addition to somatic melanocyte mutation, can strongly influence the histopathological features of melanocytic nevi.
Assuntos
Endotelina-1/metabolismo , Regulação Neoplásica da Expressão Gênica , Proteínas Hedgehog/genética , Queratinócitos/metabolismo , Neoplasias Experimentais , Nevo Pigmentado/genética , Neoplasias Cutâneas/genética , Regulação para Cima , Animais , Feminino , Proteínas Hedgehog/biossíntese , Humanos , Queratinócitos/patologia , Masculino , Melanócitos/metabolismo , Melanócitos/patologia , Camundongos , Camundongos Knockout , Nevo Pigmentado/metabolismo , Nevo Pigmentado/patologia , Transdução de Sinais , Neoplasias Cutâneas/metabolismo , Neoplasias Cutâneas/patologia , Ativação Transcricional , Células Tumorais CultivadasRESUMO
Epidemiological studies suggest that ultraviolet B exposure (UVR) during childhood is the most important environmental risk factor for melanoma. In accordance, neonatal, but not adult, UVR exacerbates melanoma incidence in mouse models. The inability of neonates, as opposed to adults, to mount a proper neutrophil inflammatory response in the skin upon UVR exposure has been one of the driving hypotheses explaining this observation for the past decade. However, this aspect remains controversial. Here, we evaluated the UVR-induced inflammatory response in neonatal versus adult mice. In neonates, a significant neutrophil infiltration could be identified and quantified using three different antibodies by flow cytometry or immunohistochemistry. On day 1 after UVR, neutrophils were increased by 84-fold and on day 4 macrophages increased by 37-fold compared with nonexposed age-matched skin. When compared with adults, neonatal skin harbored a higher proportion of neutrophils in the myeloid compartment without significant differences in absolute counts. This response was reproduced with different kinetics in C57Bl/6 and FVB mice with a more rapid attenuation of neutrophil counts in the latter. Overall, our results suggest that the greatly increased sensitivity to melanomagenesis in neonates does not result from their incompetence in terms of myeloid inflammatory response to UVR.
Assuntos
Macrófagos/patologia , Melanoma/patologia , Neoplasias Induzidas por Radiação/patologia , Neutrófilos/patologia , Neoplasias Cutâneas/patologia , Raios Ultravioleta/efeitos adversos , Fatores Etários , Animais , Animais Recém-Nascidos , Proliferação de Células/efeitos da radiação , Citometria de Fluxo , Macrófagos/efeitos da radiação , Melanoma/epidemiologia , Melanoma/imunologia , Camundongos , Camundongos Endogâmicos C57BL , Células Mieloides/patologia , Células Mieloides/efeitos da radiação , Neoplasias Induzidas por Radiação/epidemiologia , Neoplasias Induzidas por Radiação/imunologia , Neutrófilos/efeitos da radiação , Fatores de Risco , Neoplasias Cutâneas/epidemiologia , Neoplasias Cutâneas/imunologiaRESUMO
The Patched 1 (Ptch1) receptor has a pivotal role in inhibiting the activity of the Hedgehog (Hh) pathway and is therefore critical in preventing the onset of many human developmental disorders and tumor formation. However, the functional role of the mammalian Ptch2 paralogue remains elusive, particularly the extent to which it contributes to regulating the spatial and temporal activity of Hh signaling. Here we demonstrate in three independent mouse models of epidermal development that in vivo ablation of both Ptch receptors results in a more severe phenotype than loss of Ptch1 alone. Our studies indicate that concomitant loss of Ptch1 and Ptch2 activity inhibits epidermal lineage specification and differentiation. These results reveal that repression of Hh signaling through a dynamic Ptch regulatory network is a crucial event in lineage fate determination in the skin. In general, our findings implicate Ptch receptor redundancy as a key issue in elucidating the cellular origin of Hh-induced tumors.
Assuntos
Células Epidérmicas , Receptores de Superfície Celular/metabolismo , Transdução de Sinais/fisiologia , Neoplasias Cutâneas , Animais , Animais não Endogâmicos , Diferenciação Celular/fisiologia , Linhagem da Célula/fisiologia , Epiderme/embriologia , Epiderme/metabolismo , Feminino , Folículo Piloso/citologia , Folículo Piloso/embriologia , Folículo Piloso/metabolismo , Proteínas Hedgehog/metabolismo , Humanos , Queratinócitos/citologia , Queratinócitos/metabolismo , Camundongos , Camundongos da Linhagem 129 , Camundongos SCID , Receptores Patched , Receptor Patched-1 , Receptor Patched-2 , Gravidez , Receptores de Superfície Celular/genética , Neoplasias Cutâneas/genética , Neoplasias Cutâneas/metabolismo , Neoplasias Cutâneas/patologia , Transplante de PeleRESUMO
The intrinsic properties underlying cancer development are extensively studied while the effect of a cancer on the host is often overlooked. Activation of the Hedgehog (Hh) signaling pathway underlies a number of types of common human cancers, yet little is known concerning endocrine signaling in such tumors. Here, we investigated endocrine signaling in a murine model of basal cell carcinoma (BCC) of the skin, the most common cancer. BCCs were generated by the activation of Hh signaling resulting from the specific deletion of the Ptch1 gene in the developing epidermis. Subsequently, a severe growth deficiency was observed in the murine BCC model, and we identified a deficiency of circulating IGF1 (Igf1). We demonstrate that Hh pathway activation in murine BCC induces IGF binding proteins, thereby regulating Igf1 sequestration into the skin and skewing Igf endocrine signaling. Significantly, these results show that Hh-induced tumors can have endocrine effects on normal tissues that in turn can greatly impact the host. This study not only identifies that Igf is important in Hh-associated skin tumors but also exemplifies the need to consider endocrine signaling when interpreting complex in vivo tumor models.
Assuntos
Carcinoma Basocelular/metabolismo , Proteínas Hedgehog/metabolismo , Fator de Crescimento Insulin-Like I/metabolismo , Neoplasias Cutâneas/metabolismo , Animais , Carcinoma Basocelular/genética , Carcinoma Basocelular/patologia , Feminino , Integrases/metabolismo , Queratina-14/metabolismo , Masculino , Camundongos , Camundongos Transgênicos , Receptores Patched , Receptor Patched-1 , Receptores de Superfície Celular/genética , Transdução de Sinais , Neoplasias Cutâneas/genética , Neoplasias Cutâneas/patologia , Timo/metabolismo , Timo/patologiaRESUMO
Basal cell carcinoma (BCC) of the skin is the most common form of cancer, with the majority being caused by mutations in the Patched1 (Ptch1) gene, leading to activation of the Hedgehog (Hh) signaling pathway. Hh signaling is implicated in many tumor types; thus, defining the mechanisms by which Ptch1 regulates tissue proliferation is of paramount importance. Here, we show that the key role of Ptch1 in the skin is to limit the size of the epidermal stem/progenitor compartment and allow hair follicle differentiation. Specifically, loss of Ptch1 leads to the promotion of progenitor cell fate by increasing basal cell proliferation and limiting the progression of basal cells into differentiated hair follicle cell types. Our data indicate that BCCs likely result from hair follicle progenitor cells that, due to Hh signal activation, cannot progress through normal hair follicle differentiation. These data confirm the role of Ptch1 as a negative regulator of epidermal progenitor turnover and also show for the first time that Ptch1 plays a role in the differentiation of the hair follicle lineage. In addition, we show that insulin-like growth factor binding protein 2 (Igfbp2) is upregulated in both murine and human BCCs and that blocking Igfbp2 activity reduces the Hh-mediated expansion of epidermal progenitor cells. We propose that Igfbp2 mediates epidermal progenitor cell expansion and therefore represents an epidermal progenitor cell-specific target of Hh signaling that promotes BCC development.
Assuntos
Carcinoma Basocelular/genética , Transformação Celular Neoplásica/genética , Proteína 2 de Ligação a Fator de Crescimento Semelhante à Insulina/genética , Receptores de Superfície Celular/genética , Neoplasias Cutâneas/genética , Células-Tronco/metabolismo , Animais , Western Blotting , Carcinoma Basocelular/metabolismo , Carcinoma Basocelular/patologia , Proliferação de Células , Transformação Celular Neoplásica/metabolismo , Transformação Celular Neoplásica/patologia , Células Epiteliais/metabolismo , Células Epiteliais/patologia , Expressão Gênica , Perfilação da Expressão Gênica , Folículo Piloso/patologia , Proteínas Hedgehog/metabolismo , Humanos , Imuno-Histoquímica , Hibridização In Situ , Proteína 2 de Ligação a Fator de Crescimento Semelhante à Insulina/metabolismo , Camundongos , Camundongos Knockout , Receptores Patched , Receptor Patched-1 , Receptores de Superfície Celular/metabolismo , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Transdução de Sinais/fisiologia , Neoplasias Cutâneas/metabolismo , Neoplasias Cutâneas/patologia , Células-Tronco/patologia , Regulação para CimaRESUMO
Hedgehog (Hh) ligands bind to the Patched1 (Ptch1) receptor, relieving repression of Smoothened, which leads to activation of the Hh signaling pathway. Using conditional Ptch1 knockout mice, the aim of this study was to determine the effects of activating the Hh signaling pathway in hematopoiesis. Surprisingly, hematopoietic-specific deletion of Ptch1 did not lead to activation of the Hh signaling pathway and, consequently, had no phenotypic effect. In contrast, deletion of Ptch1 in nonhematopoietic cells produced 2 distinct hematopoietic phenotypes. First, activation of Hh signaling in epithelial cells led to apoptosis of lymphoid progenitors associated with markedly elevated levels of circulating thymic stromal lymphopoietin. Second, activation of Hh signaling in the bone marrow cell niche led to increased numbers of lineage-negative c-kit(+) Sca-1(+) bone marrow cells and mobilization of myeloid progenitors associated with a marked loss of osteoblasts. Thus, deletion of Ptch1 leads to hematopoietic effects by distinct cell-extrinsic mechanisms rather than by direct activation of the Hh signaling pathway in hematopoietic cells. These findings have important implications for therapeutics designed to activate the Hh signaling pathway in hematopoietic cells including hematopoietic stem cells.