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The development of brain metastases hallmarks disease progression in 20-40% of melanoma patients and is a serious obstacle to therapy. Understanding the processes involved in the development and maintenance of melanoma brain metastases (MBM) is critical for the discovery of novel therapeutic strategies. Here, we generated transcriptome and methylome profiles of MBM showing high or low abundance of infiltrated Iba1high tumor-associated microglia and macrophages (TAMs). Our survey identified potential prognostic markers of favorable disease course and response to immune checkpoint inhibitor (ICi) therapy, among them APBB1IP and the interferon-responsive gene ITGB7. In MBM with high ITGB7/APBB1IP levels, the accumulation of TAMs correlated significantly with the immune score. Signature-based deconvolution of MBM via single sample GSEA revealed enrichment of interferon-response and immune signatures and revealed inflammation, stress and MET receptor signaling. MET receptor phosphorylation/activation maybe elicited by inflammatory processes in brain metastatic melanoma cells via stroma cell-released HGF. We found phospho-METY1234/1235 in a subset of MBM and observed a marked response of brain metastasis-derived cell lines (BMCs) that lacked druggable BRAF mutations or developed resistance to BRAF inhibitors (BRAFi) in vivo to MET inhibitors PHA-665752 and ARQ197 (tivantinib). In summary, the activation of MET receptor in brain colonizing melanoma cells by stromal cell-released HGF may promote tumor self-maintenance and expansion and might counteract ICi therapy. Therefore, therapeutic targeting of MET possibly serves as a promising strategy to control intracranial progressive disease and improve patient survival.
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Neoplasias Encefálicas , Melanoma , Humanos , Melanoma/tratamiento farmacológico , Melanoma/genética , Proteínas Proto-Oncogénicas B-raf , Neoplasias Encefálicas/tratamiento farmacológico , Neoplasias Encefálicas/genética , Progresión de la Enfermedad , InterferonesRESUMEN
Background and Aims: Hepatocellular ballooning is a common finding in chronic liver disease, mainly characterized by rarefied cytoplasm that often contains Mallory-Denk bodies (MDB). Ballooning has mostly been attributed to degeneration but its striking resemblance to glycogenotic/steatotic changes characterizing preneoplastic hepatocellular lesions in animal models and chronic human liver diseases prompts the question whether ballooned hepatocytes (BH) are damaged cells on the path to death or rather viable cells, possibly involved in neoplastic development. Methods: Using specimens from 96 cirrhotic human livers, BH characteristics were assessed for their glycogen/lipid stores, enzyme activities, and proto-oncogenic signaling cascades by enzyme- and immunohistochemical approaches with serial paraffin and cryostat sections. Results: BH were present in 43.8% of cirrhotic livers. Particularly pronounced excess glycogen storage of (glycogenosis) and/or lipids (steatosis) were characteristic, ground glass features and MDB were often observed. Decreased glucose-6-phosphatase, increased glucose-6-phosphate dehydrogenase activity and altered immunoreactivity of enzymes involved in glycolysis, lipid metabolism, and cholesterol biosynthesis were discovered. Furthermore, components of the insulin signaling cascade were upregulated along with insulin dependent glucose transporter glucose transporter 4 and the v-akt murine thymoma viral oncogene homolog/mammalian target of rapamycin signaling pathway associated with de novo lipogenesis. Conclusions: BH are hallmarked by particularly pronounced glycogenosis with facultative steatosis, many of their features being reminiscent of metabolic aberrations documented in preneoplastic hepatocellular lesions in experimental animals and chronic human liver diseases. Hence, BH are not damaged entities facing death but rather viable cells featuring metabolic reprogramming, indicative of a preneoplastic nature.
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Selenoproteins play important roles in many cellular functions and biochemical pathways in mammals. Our previous study showed that the deficiency of the 15 kDa selenoprotein (Selenof) significantly reduced the formation of aberrant crypt foci (ACF) in a mouse model of azoxymethane (AOM)-induced colon carcinogenesis. The objective of this study was to examine the effects of Selenof on inflammatory tumorigenesis, and whether dietary selenium modified these effects. For 20 weeks post-weaning, Selenof-knockout (KO) mice and littermate controls were fed diets that were either deficient, adequate or high in sodium selenite. Colon tumors were induced with AOM and dextran sulfate sodium. Surprisingly, KO mice had drastically fewer ACF but developed a similar number of tumors as their littermate controls. Expression of genes important in inflammatory colorectal cancer and those relevant to epithelial barrier function was assessed, in addition to structural differences via tissue histology. Our findings point to Selenof's potential role in intestinal barrier integrity and structural changes in glandular and mucin-producing goblet cells in the mucosa and submucosa, which may determine the type of tumor developing.
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Focos de Criptas Aberrantes/dietoterapia , Focos de Criptas Aberrantes/metabolismo , Carcinogénesis/efectos de los fármacos , Neoplasias del Colon/sangre , Neoplasias del Colon/dietoterapia , Mucosa Intestinal/metabolismo , Selenoproteínas/metabolismo , Selenito de Sodio/administración & dosificación , Oligoelementos/administración & dosificación , Focos de Criptas Aberrantes/genética , Animales , Azoximetano/efectos adversos , Carcinogénesis/genética , Neoplasias del Colon/inducido químicamente , Neoplasias del Colon/genética , Citocinas/sangre , Sulfato de Dextran/efectos adversos , Dieta/métodos , Modelos Animales de Enfermedad , Regulación Neoplásica de la Expresión Génica/efectos de los fármacos , Mucosa Intestinal/efectos de los fármacos , Masculino , Ratones , Ratones Noqueados , Selenoproteínas/genética , Transducción de Señal/efectos de los fármacos , Transducción de Señal/genéticaRESUMEN
Clear cell foci (CCF) of the liver are considered to be pre-neoplastic lesions of hepatocellular adenomas and carcinomas. They are hallmarked by glycogen overload and activation of AKT (v-akt murine thymoma viral oncogene homolog)/mTOR (mammalian target of rapamycin)-signaling. Here, we report the transcriptome and proteome of CCF extracted from human liver biopsies by laser capture microdissection. We found 14 genes and 22 proteins differentially expressed in CCF and the majority of these were expressed at lower levels in CCF. Using immunohistochemistry, the reduced expressions of STBD1 (starch-binding domain-containing protein 1), USP28 (ubiquitin-specific peptidase 28), monad/WDR92 (WD repeat domain 92), CYB5B (Cytochrome b5 type B), and HSPE1 (10 kDa heat shock protein, mitochondrial) were validated in CCF in independent specimens. Knockout of Stbd1, the gene coding for Starch-binding domain-containing protein 1, in mice did not have a significant effect on liver glycogen levels, indicating that additional factors are required for glycogen overload in CCF. Usp28 knockout mice did not show changes in glycogen storage in diethylnitrosamine-induced liver carcinoma, demonstrating that CCF are distinct from this type of cancer model, despite the decreased USP28 expression. Moreover, our data indicates that decreased USP28 expression is a novel factor contributing to the pre-neoplastic character of CCF. In summary, our work identifies several novel and unexpected candidates that are differentially expressed in CCF and that have functions in glycogen metabolism and tumorigenesis.
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Biomarcadores de Tumor , Perfilación de la Expresión Génica , Glucógeno/metabolismo , Neoplasias Hepáticas/etiología , Neoplasias Hepáticas/metabolismo , Proteómica , Transformación Celular Neoplásica/genética , Transformación Celular Neoplásica/metabolismo , Biología Computacional/métodos , Humanos , Inmunohistoquímica , Hepatopatías/complicaciones , Hepatopatías/patología , Neoplasias Hepáticas/patología , TranscriptomaRESUMEN
Selenocysteine-containing proteins (selenoproteins) have been implicated in the regulation of various cell signaling pathways, many of which are linked to colorectal malignancies. In this in-depth excurse into the selenoprotein literature, we review possible roles for human selenoproteins in colorectal cancer, focusing on the typical hallmarks of cancer cells and their tumor-enabling characteristics. Human genome studies of single nucleotide polymorphisms in various genes coding for selenoproteins have revealed potential involvement of glutathione peroxidases, thioredoxin reductases, and other proteins. Cell culture studies with targeted down-regulation of selenoproteins and studies utilizing knockout/transgenic animal models have helped elucidate the potential roles of individual selenoproteins in this malignancy. Those selenoproteins, for which strong links to development or progression of colorectal cancer have been described, may be potential future targets for clinical interventions.
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Transformación Celular Neoplásica/metabolismo , Neoplasias Colorrectales/metabolismo , Selenoproteínas/metabolismo , Animales , Humanos , Oxidación-ReducciónRESUMEN
Pancreatic ductal adenocarcinoma (PDAC) is a highly lethal and disseminating cancer resistant to therapy, including checkpoint immunotherapies, and early tumor resection and (neo)adjuvant chemotherapy fails to improve a poor prognosis. In a transgenic mouse model of resectable PDAC, we investigated the coordinated activation of T and natural killier (NK) cells in addition to gemcitabine chemotherapy to prevent tumor recurrence. Only neoadjuvant, but not adjuvant treatment with a PD-1 antagonist effectively supported chemotherapy and suppressed local tumor recurrence and improved survival involving both NK and T cells. Local T-cell activation was confirmed by increased tumor infiltration with CD103+CD8+ T cells and neoantigen-specific CD8 T lymphocytes against the marker neoepitope LAMA4-G1254V. To achieve effective prevention of distant metastases in a complementary approach, we blocked the NK-cell checkpoint CD96, an inhibitory NK-cell receptor that binds CD155, which was abundantly expressed in primary PDAC and metastases of human patients. In gemcitabine-treated mice, neoadjuvant PD-1 blockade followed by adjuvant inhibition of CD96 significantly prevented relapse of PDAC, allowing for long-term survival. In summary, our results show in an aggressively growing transgenic mouse model of PDAC that the coordinated activation of both innate and adaptive immunity can effectively reduce the risk of tumor recurrence after surgery, facilitating long-term remission of this lethal disease.Significance: Coordinated neoadjuvant and adjuvant immunotherapies reduce the risk of disease relapse after resection of murine PDAC, suggesting this concept for future clinical trials. Cancer Res; 78(2); 475-88. ©2017 AACR.
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Linfocitos T CD8-positivos/inmunología , Carcinoma Ductal Pancreático/prevención & control , Desoxicitidina/análogos & derivados , Inmunoterapia , Células Asesinas Naturales/inmunología , Recurrencia Local de Neoplasia/prevención & control , Neoplasias Pancreáticas/prevención & control , Animales , Antimetabolitos Antineoplásicos/farmacología , Apoptosis , Biomarcadores de Tumor/metabolismo , Carcinoma Ductal Pancreático/inmunología , Carcinoma Ductal Pancreático/patología , Carcinoma Ductal Pancreático/cirugía , Proliferación Celular , Terapia Combinada , Desoxicitidina/farmacología , Humanos , Activación de Linfocitos , Ratones , Recurrencia Local de Neoplasia/inmunología , Recurrencia Local de Neoplasia/patología , Recurrencia Local de Neoplasia/cirugía , Neoplasias Pancreáticas/inmunología , Neoplasias Pancreáticas/patología , Neoplasias Pancreáticas/cirugía , Atención Perioperativa , Pronóstico , Tasa de Supervivencia , Células Tumorales Cultivadas , GemcitabinaRESUMEN
AIMS: The intraportal pancreatic islet transplantation (IPIT) model of diabetic rats is an insulin mediated model of hepatocarcinogenesis characterized by the induction of clear cell foci (CCF) of altered hepatocytes, which are pre-neoplastic lesions excessively storing glycogen (glycogenosis) and exhibiting activation of the AKT/mTOR protooncogenic pathway. In this study, we transferred the IPIT model to the mouse and combined it with the knockout of the transcription factor carbohydrate responsive element binding protein (chREBP). METHODS: C57BL/6J Wild-type (WT) and chREBP-knockout (chREBP-KO) mice (n = 297) were matched to 16 groups (WT/ chREBP-KO, experimental/control, streptozotocine-induced diabetic/not diabetic, one/four weeks). Experimental groups received the intraportal transplantation of 70 pancreatic islets. Liver and pancreatic tissue was examined using histology, morphometry, enzyme- and immunohistochemistry and electron microscopy. RESULTS: CCF emerged in the liver acini downstream of the transplanted islets. In comparison to WT lesions, CCF of chREBP-KO mice displayed more glycogen accumulation, reduced activity of the gluconeogenic enzyme glucose-6-phosphatase, decreased glycolysis, lipogenesis and reduced levels of the AKT/mTOR cascade members. Proliferative activity of CCF was â¼two folds higher in WT mice than in chREBP-KO mice. CONCLUSIONS: The IPIT model is applicable to mice, as murine CCF resemble preneoplastic liver lesions from this hepatocarcinogenesis model in the rat in terms of morphological, metabolic and molecular alterations and proliferative activity, which is diminished after chREBP knockout. chREBP appears to be an essential component of AKT/mTOR mediated cell proliferation and the metabolic switch from a glycogenotic to lipogenic phenotype in precursor lesions of hepatocarcinogenesis.
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Activation of the epidermal growth factor receptor (EGFR) signaling pathway promotes the development of hepatocellular adenoma (HCA) and carcinoma (HCC). The selective EGFR inhibitor Gefitinib was found to prevent hepatocarcinogenesis in rat cirrhotic livers. Thus, Gefitinib might reduce progression of pre-neoplastic liver lesions to HCC. In short- and long-term experiments, administration of N-Nitrosomorpholine (NNM) or intrahepatic transplantation of pancreatic islets in diabetic (PTx), thyroid follicles in thyroidectomized (TTx) and ovarian fragments in ovariectomized (OTx) rats was conducted for the induction of foci of altered hepatocytes (FAH). Gefitinib was administered for two weeks (20 mg/kg) or three and nine months (10 mg/kg). In NNM-treated rats, Gefitinib administration decreased the amount of FAH when compared to controls. The amount of HCA and HCC was decreased, but development was not prevented. Upon all transplantation models, proliferative activity of FAH was lower after administration of Gefitinib in short-term experiments. Nevertheless, the burden of HCA and HCC was not changed in later stages. Thus, EGFR inhibition by Gefitinib diminishes chemical and hormonal also induced hepatocarcinogenesis in the initiation stage in the non-cirrhotic liver. However, progression to malignant hepatocellular tumors was not prevented, indicating only a limited relevance of the EGFR signaling cascade in later stages of hepatocarcinogenesis.