Joining S100 proteins and migration:for better or for worse, in sickness and in health

The vast diversity of S100 proteins has demonstrated a multitude of biological correlations with cell growth, cell differentiation and cell survival in numerous physiological and pathological conditions in all cells of the body. This review summarises some of the reported regulatory functions of S100 proteins (namely S100A1, S100A2, S100A4, S100A6, S100A7, S100A8/S100A9, S100A10, S100A11, S100A12, S100B and S100P) on cellular migration and invasion, established in both culture and animal model systems and the possible mechanisms that have been proposed to be responsible. These mechanisms involve intracellular events and components of the cytoskeletal organisation (actin/myosin filaments, intermediate filaments and microtubules) as well as extracellular signalling at different cell surface receptors (RAGE and integrins). Finally, we shall attempt to demonstrate how aberrant expression of the S100 proteins may lead to pathological events and human disorders and furthermore provide a rationale to possibly explain why the expression of some of the S100 proteins (mainly S100A4 and S100P) has led to conflicting results on motility, depending on the cells used. © 2013 Springer Basel

New angiogenic regulators produced by TAMs: perspective for targeting tumor angiogenesis

Angiogenesis is crucial to the supply of a growing tumor with nutrition and oxygen. Inhibition of angiogenesis is one of the main treatment strategies for colorectal, lung, breast, renal, and other solid cancers. However, currently applied drugs that target VEGF or receptor tyrosine kinases have limited efficiency, which raises a question concerning the mechanism of patient resistance to the already developed drugs. Tumor-associated macrophages (TAMs) were identified in the animal tumor models as a key inducer of the angiogenic switch. TAMs represent a potent source not only for VEGF, but also for a number of other pro-angiogenic factors. Our review provides information about the activity of secreted regulators of angiogenesis produced by TAMs. They include members of SEMA and S100A families, chitinase-like proteins, osteopontin, and SPARC. The COX-2, Tie2, and other factors that control the pro-angiogenic activity of TAMs are also discussed. We highlight how these recent findings explain the limitations in the efficiency of current anti-angiogenic therapy. Additionally, we describe genetic and posttranscriptional mechanisms that control the expression of factors regulating angiogenesis. Finally, we present prospects for the complex targeting of the pro-angiogenic activity of TAMs

S100A7 as a biomarker for predicting transformation in a potentially malignant lesion: lichen planus.

Oral Lichen Planus (OLP) is a potentially malignant disorder that has a malignant transformation rate of approximately 1%. Current management includes incisional biopsy and grading of dysplasia, if present. This may not be a reliable predictive tool for malignant transformation. Tissue biomarkers such as S100A7 may provide a more accurate method of risk determination. The proposed mechanism is an association between S100A7 and the MAPK signalling pathway. Paraffin embedded sections of OLP that progressed and did not progress on serial biopsy were selected. The tissues were stained via S100A7 immunohistochemistry. S100A7 was quantified using an Immunoreactivity score, QuPath and StraticyteÔ. Phosphorylated MAPK proteins and WNT proteins were also evaluated. Based on Pearson correlation coefficients, the Immunoreactivity score correlated well with both StraticyteÔ and Qupath scores. The 3 predictive scores can distinguish Lichen Planus from Normal tissue based on quantification of S100A7, however, S100A7 cannot predict which Lichen Planus lesion might progress to malignancy. Furthermore, the pathway involved in progression of this inflammatory lesion also remains uncertain. Biomarker S100A7 does not aid in the accurate prediction of transformation in Lichen Planus and hence should not be used to guide clinical management. Keywords: Potentially malignant disorder, Lichen planus, Dysplasia

Characterization of bitter taste receptors expression and function in the human blood-cerebrospinal fluid barrier

Bitter taste receptors (TR2) expression and functionality was recently reported in the rat choroid plexus (CP). CP epithelial cells establish a major brain barrier, the blood-cerebrospinal fluid barrier (BCSFB). Given their capacity to bind a large array of chemical compounds, we hypothesised that TR2 might be involved in monitoring the composition of blood and cerebrospinal fluid. Brain barriers play a critical role in the protection of the central nervous system (CNS) by hindering the access of toxic substances to the brain. Consequently, many drugs targeting neurological disorders are impaired to cross these barriers. This is explained through the expression of several membrane transporters in brain barriers cells that efflux drugs, thus impairing drug cell accumulation in the brain. A wide range of compounds that bind to TR2 show neuroprotective and anti-tumoral properties. However, their low bioavailability in the CNS restrains its therapeutic application. Additionally, bitter compounds might interact with transporters that are also found in brain barriers. Therefore, bitter compounds might be effluxed which explains their low bioavailability but can also regulate the action of these transporters in order to increase their or other drugs’ intracellular accumulation. Considering that bitter compounds are TR2 agonists it is possible that TR2 play an important role on the bioactive effects of bitter compounds in the CNS, as reported in other tissues. The main goal of this doctoral thesis was to analyse the expression and function of the bitter signalling pathway in the human BCSFB. Additionally, the role of human TR2 (TAS2Rs) as modulator of specific neuroactive bitter compounds on ABC transporters function and activity at the BCSFB was also evaluated. The first research work presented showed the expression of 13 TAS2Rs as well as of downstream effector proteins of the taste signalling pathway in the human BCSFB. Moreover, we demonstrated that TAS2R14 and TAS2R39 are functional in a human cell model of the BCSFB and respond to bitter compounds quercetin and chloramphenicol, respectively. The second research work evaluated resveratrol transport across the BCSFB and the involvement of TAS2Rs. Results showed that resveratrol is able to cross the BCSFB from blood to cerebrospinal fluid in a dependent manner of TAS2R14 expression at CP epithelial cells. Further, efflux transporters ABCC1, ABCC4 and ABCG2, which are expressed at CP epithelial cells, transport resveratrol. Additionally, resveratrol upregulated ABCG2 expression and regulated ABCC4 and ABCG2 efflux activity in TAS2R14 dependent way. In conclusion, the results obtained during this project demonstrate that TAS2Rs are expressed and functional at the human BCSFB and support their participation in the monitorization of chemical composition of the surrounding fluids. Furthermore, the major achievements of this thesis strongly support the role of BCSFB in the regulation of the transport of molecules into the brain. In the future, it is necessary to further exploit the role of other TAS2Rs as mediators of the effects of bitter compounds in the brain, as well as in the regulation of transport and detoxifying systems at the BCSFB. The knowledge hereby created has far-reaching potential for improving the challenging task of delivering therapeutic drugs into the CNS.(TR2) foi demonstrada recentemente nas células epiteliais do plexo coróide (PC) de rato. As células do PC formam a barreira sangue-líquido cefalorraquidiano, uma das principais barreiras cerebrais. A presença de TR2 no PC sugere que estes recetores possam estar envolvidos na monitorização da composição química do sangue e do líquido cefalorraquidiano. As barreiras do cérebro desempenham um papel crucial na proteção do sistema nervoso central (SNC) impedindo o acesso de substâncias nocivas ao cérebro. Consequentemente, muitos fármacos direcionados para o tratamento de patologias do SNC não conseguem ultrapassar estas barreiras. Isto deve-se, em grande parte, à presença de diversos transportadores nas células que constituem estas barreiras, os quais transportam os fármacos para fora das células e, portanto, impedem a sua acumulação nas células alvo. Diversos compostos amargos, ligandos dos TR2, possuem propriedades anti-tumorais e de neuroprotecção. Contudo, a biodisponibilidade destes compostos é, normalmente, muito baixa o que dificulta a sua aplicação terapêutica. Adicionalmente, sabe-se que estes compostos interagem com transportadores membranares nas células das barreiras do cérebro. Isto sugere que os compostos amargos com potencial terapêutico sejam transportados para fora das células, o que explica a sua baixa biodisponibilidade, mas também que podem regular a ação dos transportadores de membrana o que poderá contribuir para uma maior acumulação intracelular dos compostos. Uma vez que estes compostos amargos são agonistas dos TR2, é possível que estes tenham um papel crucial na regulação da biodisponibilidade desses compostos ao nível do SNC, tal como reportado em alguns órgãos. Como tal, o trabalho desenvolvido nesta tese de doutoramento teve como principal objetivo a análise da expressão e da função da via de sinalização gustativa do amargo na barreira sangue-líquido cefalorraquidiano humana. Adicionalmente, foi estudado o papel dos TR2 no transporte do composto resveratrol ao nível da barreira sangue-líquido cefalorraquidiano humana. Na primeira parte do trabalho, foi possível confirmar a expressão de 13 TAS2Rs e das proteínas efetoras da via de transdução de sinal gustativa num modelo humano da barreira sangue-líquido cefalorraquidiano. Além disto, foi também demonstrada a funcionalidade dos TAS2R14 e 39, em resposta aos compostos quercetina e cloranfenicol, respetivamente. Na segunda parte do trabalho, analisámos o transporte do composto amargo, resveratrol, num modelo in vitro da barreira sangue-líquido cefalorraquidiano humana, e avaliámos a possível envolvência dos TAS2Rs, que ligam o resveratrol, nesse transporte. Deste trabalho concluiu-se que o resveratrol atravessa a barreira sangue-líquido cefalorraquidiano na direção sangue - líquido cefalorraquidiano (basolateral – apical), de forma dependente do TAS2R14. Observámos também que os transportadores de efluxo ABCC1, ABCC4 e ABCG2 presentes nas células epiteliais do CP transportam o resveratrol, e que este aumenta a expressão do ABCG2 e modula a sua função, bem como a do ABCC4, de forma dependente do TAS2R14. Em suma, os resultados obtidos durante o desenvolvimento deste projeto permitem afirmar que os TAS2Rs são expressos e estão funcionais na barreira sangue-líquido cefalorraquidiano humana, podendo participar na monitorização da composição química dos fluidos que a circundam. Adicionalmente, reforçam o papel crucial que esta barreira desempenha na regulação do transporte de substâncias para o cérebro. No futuro, será importante continuar a explorar o papel de outros TAS2Rs após ativação pelos seus ligandos no cérebro, assim como, na regulação dos mecanismos de transporte e, também de destoxificação existentes na barreira sangue-líquido cefalorraquidiano. Este conhecimento irá certamente contribuir para uma melhoria dos processos terapêuticos utilizados para entrega de fármacos ao SNC

The integrated molecular and histological analysis defines subtypes of esophageal squamous cell carcinoma

Esophageal squamous cell carcinoma (ESCC) is highly heterogeneous. Our understanding of full molecular and immune landscape of ESCC remains limited, hindering the development of personalised therapeutic strategies. To address this, we perform genomic-transcriptomic characterizations and AI-aided histopathological image analysis of 120 Chinese ESCC patients. Here we show that ESCC can be categorized into differentiated, metabolic, immunogenic and stemness subtypes based on bulk and single-cell RNA-seq, each exhibiting specific molecular and histopathological features based on an amalgamated deep-learning model. The stemness subgroup with signature genes, such as WFDC2, SFRP1, LGR6 and VWA2, has the poorest prognosis and is associated with downregulated immune activities, a high frequency of EP300 mutation/activation, functional mutation enrichment in Wnt signalling and the highest level of intratumoural heterogeneity. The immune profiling by transcriptomics and immunohistochemistry reveals ESCC cells overexpress natural killer cell markers XCL1 and CD160 as immune evasion. Strikingly, XCL1 expression also affects the sensitivity of ESCC cells to common chemotherapy drugs. This study opens avenues for ESCC treatment and provides a valuable public resource to better understand ESCC

The HBP1 tumor suppressor is a negative epigenetic regulator of MYCN driven neuroblastoma through interaction with the PRC2 complex

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The Role of Extracellular Matrix in Cancer Development and Progression

The extracellular matrix (ECM) scaffold, which surrounds and supports the cells in tissues, consists of fibrillar proteins, proteoglycans, glycosaminoglycans, signaling molecules, and enzymes involved in its remodeling. The stages of cancer progression, e.g., local invasion, intravasation, extravasation, distant invasion and immunosuppression, are obligatorily perpetrated through interactions of these tumor cells with the ECM. Cancer-related ECM changes can be exploited for the evaluation of disease progression, anticancer therapy development, and monitoring of therapy response. Thus, in breast cancer, hyaluronan-mediated wound repair mechanisms are hijacked to promote tumor development. Altered mechanical properties of the pancreatic cancer ECM are immunosuppressive and prevent the penetration of cytotoxic chemotherapy agents. The expression of the proteoglycan syndecan-4 is modulated by anticancer drugs, suggesting its potential druggabilty capacity. Another proteoglycan, lumican, is proposed as a cancer prognosis marker, chemoresistance regulator, and cancer therapy target. Due to their remodeling properties, the MMPs are vital mediators and important therapeutic targets. Treatment of breast cancer cells with sulfated hyaluronan has been shown to attenuate tumor cell growth, migration, and invasion. Extracellular vesicles (EVs), comprising exosomes, microvesicles, and apoptotic bodies, are released by all cells into the ECM and body fluids and can be utilized as diagnostic markers in malignant pleural mesothelioma. These exciting developments encourage tumor biology scientists for further creative research