RESUMO
Tumor-derived extracellular vesicles are important mediators of cell-to-cell communication during tumorigenesis. Here, we demonstrated that hepatocellular carcinoma (HCC)-derived ectosomes remodel the tumor microenvironment to facilitate HCC progression in an ectosomal PKM2-dependent manner. HCC-derived ectosomal PKM2 induced not only metabolic reprogramming in monocytes but also STAT3 phosphorylation in the nucleus to upregulate differentiation-associated transcription factors, leading to monocyte-to-macrophage differentiation and tumor microenvironment remodeling. In HCC cells, sumoylation of PKM2 induced its plasma membrane targeting and subsequent ectosomal excretion via interactions with ARRDC1. The PKM2-ARRDC1 association in HCC was reinforced by macrophage-secreted cytokines/chemokines in a CCL1-CCR8 axis-dependent manner, further facilitating PKM2 excretion from HCC cells to form a feedforward regulatory loop for tumorigenesis. In the clinic, ectosomal PKM2 was clearly detected in the plasma of HCC patients. This study highlights a mechanism by which ectosomal PKM2 remodels the tumor microenvironment and reveals ectosomal PKM2 as a potential diagnostic marker for HCC.
Assuntos
Proteínas de Transporte/metabolismo , Micropartículas Derivadas de Células/metabolismo , Proteínas de Membrana/metabolismo , Hormônios Tireóideos/metabolismo , Adulto , Idoso , Idoso de 80 Anos ou mais , Animais , Carcinoma Hepatocelular/genética , Carcinoma Hepatocelular/metabolismo , Proteínas de Transporte/genética , Diferenciação Celular/genética , Linhagem Celular Tumoral , Proliferação de Células/genética , Micropartículas Derivadas de Células/genética , Micropartículas Derivadas de Células/patologia , Quimiocina CCL1/metabolismo , Progressão da Doença , Células Hep G2 , Humanos , Neoplasias Hepáticas/genética , Neoplasias Hepáticas/metabolismo , Macrófagos/metabolismo , Masculino , Proteínas de Membrana/genética , Camundongos , Camundongos Endogâmicos C57BL , Pessoa de Meia-Idade , Monócitos/metabolismo , Prognóstico , Fator de Transcrição STAT3/metabolismo , Hormônios Tireóideos/genética , Microambiente Tumoral , Proteínas de Ligação a Hormônio da TireoideRESUMO
Wnt signalling through ß-catenin and the lymphoid-enhancing factor 1/T-cell factor (LEF1/TCF) family of transcription factors maintains stem cell properties in both normal and malignant tissues; however, the underlying molecular pathway involved in this process has not been completely defined. Using a microRNA microarray screening assay, we identified let-7 miRNAs as downstream targets of the Wnt-ß-catenin pathway. Expression studies indicated that the Wnt-ß-catenin pathway suppresses mature let-7 miRNAs but not the primary transcripts, which suggests a post-transcriptional regulation of repression. Furthermore, we identified Lin28, a negative let-7 biogenesis regulator, as a novel direct downstream target of the Wnt-ß-catenin pathway. Loss of function of Lin28 impairs Wnt-ß-catenin-pathway-mediated let-7 inhibition and breast cancer stem cell expansion; enforced expression of let-7 blocks the Wnt-ß-catenin pathway-stimulated breast cancer stem cell phenotype. Finally, we demonstrated that the Wnt-ß-catenin pathway induces Lin28 upregulation and let-7 downregulation in both cancer samples and mouse tumour models. Moreover, the delivery of a modified lin28 siRNA or a let-7a agomir into the premalignant mammary tissues of MMTV-wnt-1 mice resulted in a complete rescue of the stem cell phenotype driven by the Wnt-ß-catenin pathway. These findings highlight a pivotal role for Lin28/let-7 in Wnt-ß-catenin-pathway-mediated cellular phenotypes. Thus, the Wnt-ß-catenin pathway, Lin28 and let-7 miRNAs, three of the most crucial stem cell regulators, connect in one signal cascade.
Assuntos
Regulação Neoplásica da Expressão Gênica , MicroRNAs/metabolismo , Células-Tronco Neoplásicas/metabolismo , Proteínas de Ligação a RNA/metabolismo , Transdução de Sinais/genética , Proteína Wnt1/metabolismo , beta Catenina/metabolismo , Animais , Linhagem Celular Tumoral , Proliferação de Células , Feminino , Genes Reporter , Humanos , Luciferases/genética , Luciferases/metabolismo , Glândulas Mamárias Animais/metabolismo , Glândulas Mamárias Animais/patologia , Camundongos , Camundongos Knockout , MicroRNAs/genética , Células-Tronco Neoplásicas/patologia , Proteínas de Ligação a RNA/genética , Ativação Transcricional , Proteína Wnt1/genética , beta Catenina/genéticaRESUMO
BACKGROUND/AIMS: In the injured liver, hepatic stellate cells (HSCs) induce immunosuppression activity and thus participate in the pathogenesis of liver disease, including HCC. Therefore, finding new drugs to inhibit their immunosuppression activity is necessary. This study tests whether bear bile can affect the immunosuppression activities of HSCs. METHODOLOGY: The mice were gavaged with bear bile for 4 weeks. The expression of HSCs was detected through desmin and ±-smooth muscle antibody immunohistochemistry. HSCs were isolated from these mice liver and then cultured with T cells in a mixed leukocyte reaction for 3 days. Stellate cell surface makers, T-cell apoptosis, regulatory T cells and the ability of T cells to kill hepatocellular carcinoma were determined via flow cytometry. Cytokines were determined by a mouse cytokine array panel and T-cell proliferation was determined through a BrdU kit. RESULTS: Bear bile decreased HSCs and their surface molecules, and affected cytokine secretion. Interestingly, HSCs from the mice gavaged with bear bile promoted T-cell proliferation, inhibited T-cell apoptosis, decreased CD4+CD25+Foxp3+ regulatory T cells and enhanced the activation of T cells killing hepatocellular carcinoma. CONCLUSIONS: Bear bile can inhibit the immunosuppression activity of HSCs and enhance immune response especial anti-tumor immune response.
Assuntos
Bile/imunologia , Células Estreladas do Fígado/imunologia , Tolerância Imunológica/efeitos dos fármacos , Linfócitos T Reguladores/efeitos dos fármacos , Actinas/metabolismo , Análise de Variância , Animais , Apoptose/efeitos dos fármacos , Carcinoma Hepatocelular/imunologia , Proliferação de Células/efeitos dos fármacos , Células Cultivadas , Citocinas/efeitos dos fármacos , Citocinas/metabolismo , Desmina/metabolismo , Células Estreladas do Fígado/metabolismo , Masculino , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Endogâmicos C57BL , UrsidaeRESUMO
Salient Object Detection (SOD) simulates the human visual perception in locating the most attractive objects in the images. Existing methods based on convolutional neural networks have proven to be highly effective for SOD. However, in some cases, these methods cannot satisfy the need of both accurately detecting intact objects and maintaining their boundary details. In this paper, we present a Multiresolution Boundary Enhancement Network (MRBENet) that exploits edge features to optimize the location and boundary fineness of salient objects. We incorporate a deeper convolutional layer into the backbone network to extract high-level semantic features and indicate the location of salient objects. Edge features of different resolutions are extracted by a U-shaped network. We designed a Feature Fusion Module (FFM) to fuse edge features and salient features. Feature Aggregation Module (FAM) based on spatial attention performs multiscale convolutions to enhance salient features. The FFM and FAM allow the model to accurately locate salient objects and enhance boundary fineness. Extensive experiments on six benchmark datasets demonstrate that the proposed method is highly effective and improves the accuracy of salient object detection compared with state-of-the-art methods.
Assuntos
Redes Neurais de Computação , Percepção Visual , Humanos , Atenção , Semântica , BenchmarkingRESUMO
Extracellular vesicles play crucial roles in intercellular communication in the tumor microenvironment. Here we demonstrate that in hepatic fibrosis, TGF-ß stimulates the palmitoylation of hexokinase 1 (HK1) in hepatic stellate cells (HSCs), which facilitates the secretion of HK1 via large extracellular vesicles in a TSG101-dependent manner. The large extracellular vesicle HK1 is hijacked by hepatocellular carcinoma (HCC) cells, leading to accelerated glycolysis and HCC progression. In HSCs, the nuclear receptor Nur77 transcriptionally activates the expression of depalmitoylase ABHD17B to inhibit HK1 palmitoylation, consequently attenuating HK1 release. However, TGF-ß-activated Akt functionally represses Nur77 by inducing Nur77 phosphorylation and degradation. We identify the small molecule PDNPA that binds Nur77 to generate steric hindrance to block Akt targeting, thereby disrupting Akt-mediated Nur77 degradation and preserving Nur77 inhibition of HK1 release. Together, this study demonstrates an overlooked function of HK1 in HCC upon its release from HSCs and highlights PDNPA as a candidate compound for inhibiting HCC progression.
Assuntos
Carcinoma Hepatocelular , Vesículas Extracelulares , Neoplasias Hepáticas , Humanos , Carcinoma Hepatocelular/metabolismo , Carcinoma Hepatocelular/patologia , Células Estreladas do Fígado/metabolismo , Hexoquinase/metabolismo , Neoplasias Hepáticas/metabolismo , Proteínas Proto-Oncogênicas c-akt/metabolismo , Proliferação de Células , Linhagem Celular Tumoral , Vesículas Extracelulares/metabolismo , Fator de Crescimento Transformador beta/metabolismo , Receptores Citoplasmáticos e Nucleares/metabolismo , Microambiente TumoralRESUMO
In the title compound, [Zn(2)(C(10)H(2)O(8))(C(16)H(20)N(4))(H(2)O)(2)](n), the Zn(II) atom is in a distorted tetra-hedral environment, being coordinated by one N atom from a 1,4-bis-(3-pyridyl-meth-yl)piperazine (3-bpmp) ligand, two O atoms from two carboxyl-ate groups of the pyromellitate anion and one water mol-ecule. The distortion of the tetrahedral coordination may be ascribed to the hydrogen bonds between the carboxyl-ate groups and the adjacent water mol-ecules. Each Zn(II) atom links to three organic ligands and each pyromellitate ligand coordinates to four Zn(II) atoms, forming a (3,4)-connected infinite three-dimensional framework. O-Hâ¯N inter-actions also occur.
RESUMO
Hepatocellular carcinoma (HCC) is one of the leading causes of cancer-related mortality worldwide. Orphan nuclear receptor Nur77, which is low expressed in HCC, functions as a tumor suppressor to suppress HCC. However, the detailed mechanism is still not well understood. Here, we demonstrate that Nur77 could inhibit HCC development via transcriptional activation of the lncRNA WAP four-disulfide core domain 21 pseudogene (WFDC21P). Nur77 binds to its response elements on the WFDC21P promoter to directly induce WFDC21P transcription, which inhibits HCC cell proliferation, tumor growth, and tumor metastasis both in vitro and in vivo. In clinical HCC samples, WFDC21P expression positively correlated with that of Nur77, and the loss of WFDC21P is associated with worse prognosis. Mechanistically, WFDC21P could inhibit glycolysis by simultaneously interacting with PFKP and PKM2, two key enzymes in glycolysis. These interactions not only abrogate the tetramer formation of PFKP to impede its catalytic activity but also prevent the nuclear translocation of PKM2 to suppress its function as a transcriptional coactivator. Cytosporone-B (Csn-B), an agonist for Nur77, could stimulate WFDC21P expression and suppress HCC in a WFDC21P-dependent manner. Therefore, our study reveals a new HCC suppressor and connects the glycolytic remodeling of HCC with the Nur77-WFDC21P-PFKP/PKM2 axis.
Assuntos
Carcinoma Hepatocelular/metabolismo , Neoplasias Hepáticas/metabolismo , Membro 1 do Grupo A da Subfamília 4 de Receptores Nucleares/metabolismo , RNA Longo não Codificante/metabolismo , Animais , Carcinogênese , Carcinoma Hepatocelular/genética , Carcinoma Hepatocelular/patologia , Processos de Crescimento Celular , Linhagem Celular Tumoral , Glicólise , Células Hep G2 , Xenoenxertos , Humanos , Neoplasias Hepáticas/genética , Neoplasias Hepáticas/patologia , Masculino , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Nus , Membro 1 do Grupo A da Subfamília 4 de Receptores Nucleares/agonistas , Membro 1 do Grupo A da Subfamília 4 de Receptores Nucleares/genética , Fenilacetatos/farmacologia , Regiões Promotoras Genéticas , RNA Longo não Codificante/genética , Ativação Transcricional , Regulação para CimaRESUMO
The title Cd(II) coordination polymer, catena-poly[[{1,4-bis-[1-(2-pyridylmeth-yl)benzimidazol-2-yl]butane}cadmium(II)]-µ-benzene-1,3-dicarboxyl-ato], [Cd(C(8)H(4)O(4))(C(30)H(28)N(6))](n), was obtained by reaction of CdCO(3), benzene-1,3-dicarboxylic acid (H(2)btc) and 1,4-bis-[1-(2-pyridylmeth-yl)benzimidazol-2-yl]butane (L). The Cd(II) cation is six-coordinated by an N(2)O(4)-donor set. L acts as a bidentate ligand and btc anions link Cd(II) centers into a chain propagating parallel to [010].
RESUMO
Fat mass and obesity-associated protein (FTO) has been well known for a pivotal role in regulation of fat mass, adipogenesis and body weight. In recent years, increasing studies revealed a strong association between FTO and various types of cancer. Its role in human hepatocellular carcinoma, however, remains unclear. We aimed at investigating the expression pattern and clinical significance of FTO in hepatocellular carcinoma. We found that FTO mRNA levels were significantly lower in hepatocellular carcinoma tissues. Immunohistochemical analysis showed the expression of FTO was reduced in the nuclei in hepatocellular carcinoma, and was associated with AFP level (P < 0.001), tumor size (P < 0.001), metastasis (P = 0.025) and vascular invasion (P < 0.001). Patients with decreased FTO expression had a shorter overall and tumor-free survival time (P = 0.004 and P = 0.006) than those with normal FTO expression. Cox's proportional hazard regression model revealed that reduced expression of FTO was a risk factor associated with the prognosis of HCC patients (P = 0.022). These results indicated that decreased FTO expression is correlated with clinicopathological factors, implying that FTO could be a vital predictor of poor outcome in HCC patients and serves as a novel biomarker for HCC.
RESUMO
Acutely transforming retrovirus AKT8 in rodent T cell lymphoma (Akt) phosphorylates and regulates the function of many cellular proteins involved in processes such as metabolism, apoptosis and proliferation. However, the precise mechanisms by which Akt promotes cell survival and inhibits apoptosis have been characterized in part only. TR3, an orphan receptor, functions as a transcription factor that can both positively or negatively regulate gene expression. We have reported previously that the translocation of TR3 from the nucleus to the mitochondria can elicit a proapoptotic effect in gastric cancer cells. In our present study, we demonstrate that Akt phosphorylates cytoplasmic TR3 through its physical interaction with the N-terminus of TR3. When coexpressed with Akt, TR3 mitochondrial targeting was blocked and this protein adopted a diffuse expression pattern in the cytoplasm. Moreover, Akt displayed an ability to disrupt the interaction of TR3 with Bcl-2, which is thought to be a critical requirement for mitochondrial TR3 to elicit apoptosis. Consistently, insulin was also found to induce the phosphorylation of TR3 and abolish 12-O-tetradecanoylphorbol-13-acetate-induced mitochondrial localization, which was dependent upon the activation of the phophatidylinositol-3-OH-kinase-Akt signaling pathway. Taken together, our current data demonstrate a unique role for Akt in inhibiting TR3 functions that are not related to transcriptional activity but that correlate with the regulation of its mitochondrial association. This may represent a novel signal pathway by which Akt exerts its antiapoptotic effects in gastric cancer cells, i.e. by regulating the phosphorylation and redistribution of orphan receptors.
Assuntos
Mitocôndrias/metabolismo , Proteínas Proto-Oncogênicas c-akt/metabolismo , Receptores de Esteroides/metabolismo , Receptores dos Hormônios Tireóideos/metabolismo , Apoptose , Sequência de Bases , Sítios de Ligação , Western Blotting , Linhagem Celular Tumoral , Citocromos c/metabolismo , Citoplasma/metabolismo , Primers do DNA , Imunofluorescência , Humanos , Imunoprecipitação , Membro 1 do Grupo A da Subfamília 4 de Receptores Nucleares , Fosforilação , Proteínas Proto-Oncogênicas c-bcl-2/metabolismo , Receptores de Esteroides/química , Receptores dos Hormônios Tireóideos/químicaRESUMO
Acetylation modification regulates the functions of histone and nonhistone proteins, including transcriptional activity, protein interaction, and subcellular localization. Although many nuclear receptors have been shown to be modified by acetylation, whether retinoid X receptors (RXRs) are acetylated and how the acetylation is regulated remains unknown. Here, we provide the first evidence of RXRalpha acetylation by p300 on lysine 145. Acetylation of RXRalpha by p300 facilitated its DNA binding and subsequently increased its transcriptional activity. Furthermore, we discovered that TR3, an orphan receptor, exerted a negative regulation on p300-induced RXRalpha acetylation. TR3 significantly reduced the p300-induced RXRalpha acetylation and transcriptional activity, and such inhibition required the interaction of TR3 with RXRalpha. Binding of TR3 to RXRalpha resulted in the sequestration of RXRalpha from p300. 9-cis retinoic acid, a ligand for RXRalpha, enhanced the association of RXRalpha with TR3, rather than acetylation of RXRalpha by p300. Biological function analysis revealed that the mitogenic activity of RXRalpha stimulated by p300 was acetylation dependent and could be repressed by TR3. Upon the treatment of 9-cis retinoic acid, RXRalpha was translocated with TR3 from the nucleus to the mitochondria, and apoptosis was induced. Taken together, our data demonstrate the distinct regulatory mechanisms of p300 and TR3 on RXRalpha acetylation and reveal a previously unrecognized role for orphan receptor in the transcriptional control of retinoid receptors.
Assuntos
Proteína p300 Associada a E1A/metabolismo , Receptores de Esteroides/metabolismo , Receptores dos Hormônios Tireóideos/metabolismo , Receptores X de Retinoides/metabolismo , Acetilação , Alitretinoína , Apoptose , Linhagem Celular , DNA/metabolismo , Humanos , Lisina/genética , Lisina/metabolismo , Membro 1 do Grupo A da Subfamília 4 de Receptores Nucleares , Ligação Proteica , Transporte Proteico , Receptores de Esteroides/genética , Receptores dos Hormônios Tireóideos/genética , Receptores X de Retinoides/genética , Transcrição Gênica/efeitos dos fármacos , Transcrição Gênica/genética , Tretinoína/farmacologiaRESUMO
The content of total flavone in carthmus tinctorius L in Xinjiang was determined by ultraviolet spectrophotometry with scan from 200 to 400 nm where the maximum absorption wavelength was 267.00 nm. The contents of ten trace elements and constant elements in carthmus tinctorius L including potassium, sodium, calcium, magnesium, iron, chromium, nickel, manganese, copper and zinc were determined by flame atomic absorption spectrophotometry. The results showed that there were comparatively rich trace elements and high total flavone, among which are comparatively high calcium, magnesium, chromium, copper and zinc in carthmus tinctorius L. It provided useful data for discussing the relationship between the content of total flavone and the trace elements in carthmus tinctorius L, and for studing the relationship between the trace elements in carthmus tinctorius L and the cure for cardio-cerebral vascular disease.
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Gluconeogenesis, an essential metabolic process for hepatocytes, is downregulated in hepatocellular carcinoma (HCC). Here we show that the nuclear receptor Nur77 is a tumour suppressor for HCC that regulates gluconeogenesis. Low Nur77 expression in clinical HCC samples correlates with poor prognosis, and a Nur77 deficiency in mice promotes HCC development. Nur77 interacts with phosphoenolpyruvate carboxykinase (PEPCK1), the rate-limiting enzyme in gluconeogenesis, to increase gluconeogenesis and suppress glycolysis, resulting in ATP depletion and cell growth arrest. However, PEPCK1 becomes labile after sumoylation and is degraded via ubiquitination, which is augmented by the p300 acetylation of ubiquitin-conjugating enzyme 9 (Ubc9). Although Nur77 attenuates sumoylation and stabilizes PEPCK1 via impairing p300 activity and preventing the Ubc9-PEPCK1 interaction, Nur77 is silenced in HCC samples due to Snail-mediated DNA methylation of the Nur77 promoter. Our study reveals a unique mechanism to suppress HCC by switching from glycolysis to gluconeogenesis through Nur77 antagonism of PEPCK1 degradation.
Assuntos
Carcinoma Hepatocelular/metabolismo , Gluconeogênese , Neoplasias Hepáticas/metabolismo , Membro 1 do Grupo A da Subfamília 4 de Receptores Nucleares/metabolismo , Fosfoenolpiruvato Carboxiquinase (ATP)/metabolismo , Sumoilação , Acetilação , Animais , Carcinogênese/patologia , Carcinoma Hepatocelular/genética , Carcinoma Hepatocelular/patologia , Regulação para Baixo/genética , Proteína p300 Associada a E1A/metabolismo , Estabilidade Enzimática , Regulação Neoplásica da Expressão Gênica , Glucose/metabolismo , Células Hep G2 , Humanos , Neoplasias Hepáticas/genética , Neoplasias Hepáticas/patologia , Masculino , Metilação , Camundongos Endogâmicos C57BL , Camundongos Knockout , Modelos Biológicos , Membro 1 do Grupo A da Subfamília 4 de Receptores Nucleares/genética , Proteólise , Fatores de Transcrição da Família Snail/metabolismo , Proteínas Supressoras de Tumor/metabolismo , Enzimas de Conjugação de Ubiquitina/metabolismoRESUMO
The content of trace element manganese in aloe tea was determined by atomic absorption spectrophotometry. The contents of 17 kinds of amino acids in aloe tea were determined with amino acids instrumentation. The results showed that there are comparatively rich manganese and amino acids in aloe tea. The content of manganese in red tea is more than in green tea, and the dissolving ratio is more than 50% in boiled water, and first dissolving ratio is more than second dissolving ratio, which is more than third dissolving ratio. There are 7 kinds of amino acids essential to human body, among which are comparatively high aspartic acid, glutamic acid and leucine in aloe tea. It's outstanding characteristic is comparatively high content of manganese in aloe health tea. It has provided useful data for probing into the relationship between trace elements and amino acids in aloe health tea and health care function.
Assuntos
Aloe/química , Aminoácidos/análise , Camellia sinensis/química , Manganês/análise , Extratos Vegetais/análise , Chá/químicaRESUMO
Natural killer (NK) cells have been demonstrated to inhibit tumor growth. However, the role of NK cells in the inhibition of hepatocellular carcinoma metastasis is not well understood. The present study aimed to investigate the roles that NK cells may serve in inhibiting hepatocellular carcinoma metastasis. The role of isolated NK cells in the inhibition, proliferation, migration and invasion of the hepatoma cell line, MHCC97-H, was examined in vitro. Additionally, the survival rate of NK cells labeled with carboxyfluorescein diacetate-succinimidyl ester was assessed in vivo. An orthotopic implantation model was used to evaluate the role of NK cells in suppressing MHCC97-H cells in vivo. The effect of interleukin (IL)-2 stimulation on the tumor-inhibitory role of the NK cells was measured indirectly by analyzing the expression of various NK cell receptors and activated NK cell markers. It was observed that the NK cells inhibited the proliferation, migration and invasion of the MHCC97-H cells in vitro. Furthermore, the NK cells demonstrated long-term survival in the livers of the nude mice, and inhibited lung metastasis of hepatocellular carcinoma in vivo. However, liver tumor growth was not inhibited by the NK cells. IL-2 was identified to enhance the tumor-inhibitory effect of NK cells. The present study concludes that IL-2 may enhance the antitumor activity of the NK cells, and thereby inhibit the metastases of hepatocellular carcinoma in mice.
RESUMO
It has been reported that NKD1 was an antagonist of the canonical Wnt/ß-catenin pathway. While there is little information regarding NKD1 expression pattern in human hepatocellular carcinoma (HCC). The aim of this study was to investigate the clinicopathologic significance and expression pattern of NKD1 in HCC. NKD1 protein expressions in 69 paired HCC cancer/adjacent non-cancerous tissues were detected by Western blot. Immunohistochemical studies were performed on 58 cases of HCC with integrated clinical information. NKD1 protein expression was divided into normal and low expression group and correlations between NKD1 protein expression and clinicopathologic factors were then evaluated. Western blot results showed that NKD1 protein levels were significantly lower in cancerous tissues compared with corresponding normal tissue (p < 0.05). In addition, we found that the level of NKD1 protein expression in HCC was significantly associated with tumor size (p = 0.011), intra or extra-hepatic metastasis (p = 0.010) and differentiation (p = 0.003). This is to our knowledge the first report investigating NKD1 protein expression pattern in HCC. Our data show that decreased NKD1 protein expression is associated with clinicopathologic factors, and suggest that NKD1 may play an important role in the development of HCC and could serve as a novel biomarker for HCC after further investigation.
Assuntos
Carcinoma Hepatocelular/genética , Proteínas de Transporte/biossíntese , Regulação Neoplásica da Expressão Gênica , Neoplasias Hepáticas/genética , Proteínas Adaptadoras de Transdução de Sinal , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Biomarcadores Tumorais/biossíntese , Proteínas de Ligação ao Cálcio , Carcinoma Hepatocelular/metabolismo , Carcinoma Hepatocelular/patologia , Criança , Regulação para Baixo , Feminino , Humanos , Neoplasias Hepáticas/metabolismo , Neoplasias Hepáticas/patologia , Masculino , Pessoa de Meia-Idade , Prognóstico , Trombose/patologia , Proteínas Wnt/metabolismo , Via de Sinalização Wnt , Adulto Jovem , beta Catenina/metabolismoRESUMO
DLC1 has been shown to be downregulated or absent in hepatocellular carcinoma (HCC) and is associated with tumorigenesis and development. However, only a small number of studies have focused on genetic variations of DLC1. The present study performed exon sequencing for the DLC1 gene in HCC tissue samples from 105 patients to identify functional genetic variation of DLC1 and its association with HCC susceptibility, clinicopathological features and prognosis. A novel missense mutation and four nonsynonymous single nucleotide polymorphisms (SNPs; rs3816748, rs11203495, rs3816747 and rs532841) were identified. A significant correlation of rs3816747 polymorphisms with HCC susceptibility was identified. Compared to individuals with the GG genotype of rs3816747, those with the GA (odds ratio (OR)=0.486; P=0.037) or GA+AA genotype (OR=0.51; P=0.039) were associated with a significantly decreased HCC risk. Furthermore, patients with the GC+CC genotype of rs3816748, the TC+CC genotype of rs11203495 or the GA+AA genotype of rs3816747 had smallsized tumors compared with those carrying the wildtype genotype. No significant association of DLC1 SNPs with the patients' prognosis was found. These results indicated that genetic variations in the DLC1 gene may confer a risk for HCC.
Assuntos
Carcinoma Hepatocelular/genética , Proteínas Ativadoras de GTPase/metabolismo , Variação Genética , Neoplasias Hepáticas/genética , Proteínas Supressoras de Tumor/metabolismo , Alelos , Sequência de Aminoácidos , Animais , Carcinoma Hepatocelular/mortalidade , Carcinoma Hepatocelular/patologia , Intervalo Livre de Doença , Feminino , Proteínas Ativadoras de GTPase/química , Proteínas Ativadoras de GTPase/genética , Predisposição Genética para Doença , Genótipo , Humanos , Estimativa de Kaplan-Meier , Neoplasias Hepáticas/mortalidade , Neoplasias Hepáticas/patologia , Masculino , Razão de Chances , Polimorfismo de Nucleotídeo Único , Prognóstico , Análise de Sequência de DNA , Proteínas Supressoras de Tumor/química , Proteínas Supressoras de Tumor/genética , alfa-Fetoproteínas/análiseRESUMO
Cholangiocarcinoma (CCA), a devastating cancer with a poor prognosis, is resistant to the currently available chemotherapeutic agents. Capsaicin, the major pungent ingredient found in hot red chili peppers of the genus Capsicum, suppresses the growth of several malignant cell lines. Our aims were to investigate the role and mechanism of capsaicin with respect to the sensitivity of CCA cells to chemotherapeutic agents. The effect of capsaicin on CCA tumor sensitivity to 5-fluorouracil (5-FU) was assessed in vitro in CCA cells and in vivo in a xenograft model. The drug sensitivity of QBC939 to 5-FU was significantly enhanced by capsaicin compared with either agent alone. In addition, the combination of capsaicin with 5-FU was synergistic, with a combination index (CI) < 1, and the combined treatment also suppressed tumor growth in the CCA xenograft to a greater extent than 5-FU alone. Further investigation revealed that the autophagy induced by 5-FU was inhibited by capsaicin. Moreover, the decrease in AKT and S6 phosphorylation induced by 5-FU was effectively reversed by capsaicin, indicating that capsaicin inhibits 5-FU-induced autophagy by activating the phosphoinositide 3-kinase (PI3K)/protein kinase B (AKT)/mammalian target of rapamycin (mTOR) pathway in CCA cells. Taken together, these results demonstrate that capsaicin may be a useful adjunct therapy to improve chemosensitivity in CCA. This effect likely occurs via PI3K/AKT/mTOR pathway activation, suggesting a promising strategy for the development of combination drugs for CCA.
Assuntos
Antineoplásicos/uso terapêutico , Autofagia/efeitos dos fármacos , Capsaicina/uso terapêutico , Colangiocarcinoma/tratamento farmacológico , Animais , Antineoplásicos/farmacologia , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Apoptose/efeitos dos fármacos , Capsaicina/farmacologia , Linhagem Celular Tumoral , Colangiocarcinoma/patologia , Resistência a Múltiplos Medicamentos/efeitos dos fármacos , Resistencia a Medicamentos Antineoplásicos/efeitos dos fármacos , Fluoruracila/farmacologia , Fluoruracila/uso terapêutico , Humanos , Camundongos Endogâmicos BALB C , Camundongos Nus , Transdução de Sinais/efeitos dos fármacosRESUMO
Enoyl-coenzyme A hydratase short chain 1 (ECHS1) regulates fatty acid metabolism and is an essential factor in tumor development. The present study aimed to investigate the molecular mechanisms of ECHS1 in hepatocellular carcinogenesis by studying proliferation and survival in ECHS1 knocked-down hepatocellular carcinoma (HCC) cell lines, HepG2 and HuH7. The effect of ECHS1 on tumor development was investigated by tumor transplantation in nude mice, and the signaling pathways involved in the ECHS1-mediated regulation of HCC cell proliferation were identified by western blot analysis. The silencing of ECHS1 suppressed HCC cell proliferation in vitro and suppressed the growth of transplanted tumors in vivo. In addition, the phosphorylation of EGFR and its downstream effectors ERK1/2 and AKT was downregulated in ECHS1 knocked-down cells and tumor tissues. Furthermore, knockdown of ECHS1 in HCC suppressed cyclin D3 and cyclin dependent kinase 6 expression, whilst enhancing p16 and p21 expression. Therefore, ECHS1 may also be involved in cell cycle progression in HCC cells. These results suggested that ECHS1 may promote cell proliferation in HCC in an EGFR-dependent manner.
Assuntos
Carcinogênese , Carcinoma Hepatocelular/genética , Enoil-CoA Hidratase/genética , Receptores ErbB/genética , Neoplasias Hepáticas/genética , Animais , Carcinoma Hepatocelular/patologia , Proliferação de Células/genética , Enoil-CoA Hidratase/biossíntese , Receptores ErbB/biossíntese , Técnicas de Silenciamento de Genes , Células Hep G2 , Humanos , Neoplasias Hepáticas/patologia , Camundongos , Proteína Quinase 3 Ativada por Mitógeno/biossíntese , Proteína Oncogênica v-akt/biossíntese , Fosforilação , Transdução de SinaisRESUMO
Dysregulation of growth factor signaling plays a pivotal role in controlling the malignancy phenotype and progression of hepatocellular carcinoma (HCC). However, the precise oncogenic mechanisms underlying transcription regulation of certain tumor suppressor genes (TSGs) by growth factors are poorly understood. In the present study, we report a novel insulin-like growth factor 1 (IGF1) pathway that mediates de novo DNA methylation and TSG (such as DLC1 and CHD5) silencing by upregulation of the DNA methyltransferase 1 (DNMT1) via an AKT/ß-transducin repeat-containing protein (ßTrCP)-mediated ubiquitin-proteasome pathway in HCC. Analysis of DNA methylation in CpG islands of target genes revealed high co-localization of DNMT1 and DNMT3B on the promoters of TSGs associated with enhanced CpG hypermethylation. Our results point to a novel epigenetic mechanism for growth factor-mediated repression of TSG transcription that involves DNA methylation.