Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UMLS:C0019204 (hepatocellular carcinoma)
 71,386 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

High concentrations of nitric oxide (NO) are generated by the inducible form of the enzyme nitric oxide synthase (iNOS), which is expressed in activated macrophages and in hepatocytes. Increased expression of iNOS in hepatocytes or macrophages might be expected in chronic HCV liver disease and HIV infections. This might in turn be reflected in increased serum NO levels in these two conditions. In view of the discrepant findings in published reports, we measured serum NO levels in a large number of chronic HCV-infected patients and patients with chronic HIV infections with or without AIDS-related opportunistic infection. We also localized HCV and iNOS antigens by immunohistochemistry, in liver biopsy tissue from patients with chronic HCV-related hepatitis, HCV-related cirrhosis, and HCV-related hepatocellular carcinoma. A group of 121 subjects with serological evidence of HCV with or without HIV infection were studied. These were compared with 14 controls without HIV or HCV disease (group A). Among the subjects with HCV, 35 were negative for HIV (group B), 66 were HIV positive (group C), and 20 had AIDS-related opportunistic infection (group D). The serum NO concentration was determined by the Brucine method. A well-characterized commercially available antibody (HCV88) directed against a synthetic NS3 peptide fragment of HCV, which localizes to the hepatocyte nuclei, and an antibody to human macrophage iNOS, were both used to detect these proteins in liver biopsy tissue by immunohistochemistry. Mean serum NO values in HIV negative/HCV negative control patients (group A) (54.6+/-12 microM) were similar to those in HIV negative/HCV positive patients (group B) (55.0+/-13 microM) and HIV positive without AIDS-related disease/HCV positive patients (group C) (47.2+/-25 microM). By contrast, the mean serum NO (70.1+/-24 microM) was significantly increased in HCV-positive patients with AIDS-related infection (group D) compared to controls (P = 0.02). HCV NS3 and iNOS antibody staining hepatocytes were not detected in any of the control non-HCV-infected biopsy samples. In early chronic HCV hepatitis (fibrosis scores F0-F2), HCV NS3 antigen localized focally to only a small number of hepatocytes. In cirrhosis (fibrosis score F4) with or without hepatocellular carcinoma, the majority of hepatocyte nuclei stained positively with HCV NS3 antibody. The majority of hepatocytes in chronic HCV hepatitis expressed iNOS, irrespective of histological disease severity. The staining was present uniformly in the cytoplasm. In chronic HCV and HIV coinfection, the pattern and number of iNOS staining cells were similar to that in patients with chronic HCV infection alone. In conclusion, there is widespread expression of iNOS in hepatocytes in chronic HCV liver disease, irrespective of liver disease stage. However, elevated NO levels in serum were related only to active AIDS-related bacterial, protozoan, and fungal infections, rather than to chronic viral infection with HCV or HIV alone. NO may play a role in the local control of chronic viral infections at tissue level, but this is not reflected in serum levels.
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PMID:Nitric oxide and chronic HCV and HIV infections. 1134 51

To screen the anti-tumor effects of the four alkaloids: brucine, strychnine, brucine N-oxide and isostrychnine from the seed of Strychnos nux-vomica, MTT assay was used to examine the growth inhibitory effects of these alkaloids on human hepatoma cell line (HepG2). Brucine, strychnine and isostrychnine revealed significant inhibitory effects against HepG2 cell proliferation, whereas brucine N-oxide didn't have such an effect. In addition, brucine caused HepG2 cell shrinkage, membrane blebbing, apoptotic body formation, all of which are typical characteristics of apoptotic programmed cell death. The results of flow cytometric analysis demonstrated that brucine caused dose-dependent apoptosis of HepG2 cells through cell cycle arrest at G0/G1 phase, thus preventing cells entering S or G2/M phase. Immunoblot results revealed that brucine significantly decreased the protein expression level of cyclooxygenase-2, whereas increased the expression caspase-3 as well as the caspase-3-like protease activity in HepG2 cells, suggesting the involvement of cyclooxygenase-2 and caspase-3 in the pro-apoptotic effects exerted by brucine. Therefore, this paper indicate that the major alkaloids present in the seed of Strychnos nux-vomica are effective against HepG2 cells proliferation, among which brucine proceed HepG2 cells death via apoptosis, probably through the participation of caspase-3 and cyclooxygenase-2.
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PMID:The anti-tumor effects of alkaloids from the seeds of Strychnos nux-vomica on HepG2 cells and its possible mechanism. 1644 63

In an attempt to dissect the mechanism of Strychnos nux-vomica, a commonly used Chinese folk medicine in the therapy of liver cancer, the cytotoxic effects of four alkaloids in Strychnos nux-vomica, brucine, brucine N-oxide, strychnine, and isostrychnine, on human hepatoma cells (HepG2) were screened by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-tetrasolium bromide (MTT) assay. Brucine, among the four alkaloids, exhibited the strongest toxic effect, the mechanism of which was found to cause HepG2 cell apoptosis, since brucine caused HepG2 cell shrinkage, the formation of apoptotic bodies, DNA fragmentation, cell cycle arrest, as well as phosphatidylserine externalization, all of which are typical characteristics of apoptotic programmed cell death. Brucine-induced HepG2 cell apoptosis was caspase dependent, with caspase-3 activated by caspase-9. Brucine also caused the proteolytic processing of caspase-9. In addition, brucine caused depolarization of the mitochondrial membrane of HepG2 cells, the inhibition of which by cyclosporine A completely abrogated the activation of casapses and release of cytochrome c in brucine-treated HepG2 cells. These findings suggested a pivotal role of mitochondrial membrane depolarization in HepG2 cell apoptosis elicited by brucine. Furthermore, brucine induced a rapid and sustained elevation of intracellular [Ca2+], which compromised the mitochondrial membrane potential and triggered the process of HepG2 cell apoptosis. Finally, Bcl-2 was found to predominately control the whole event of cell apoptosis induced by brucine. The elevation of [Ca2+]i caused by brucine was also suppressed by overexpression of Bcl-2 protein in HepG2 cells. From the facts given above, Ca2+ and Bcl-2 mediated mitochondrial pathway were found to be involved in brucine-induced HepG2 cell apoptosis.
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PMID:The apoptotic effect of brucine from the seed of Strychnos nux-vomica on human hepatoma cells is mediated via Bcl-2 and Ca2+ involved mitochondrial pathway. 1644 26

Brucine is an alkaloid derived from the seeds of Strychnos nux-vomica Linn. which have long been used as a traditional medicine for the treatment of hepatocellular carcinoma (HCC) in China. HCC prognosis can be greatly influenced by metastasis. There has thus far been little research into brucine as a source of anti-metastasis activity against HCC. In this study, we revealed that brucine dramatically repressed HepG2 and SMMC-7721 HCC cell migration with few cytotoxic effects. Hypoxia inducible factor 1 (HIF-1) is a key transcription factor mediating cell migration and invasion. Brucine suppressed HIF-1-dependent luciferase activity in HepG2 cells. The transcriptions of four known HIF-1 target genes involved in HCC metastasis, i.e., fibronectin, matrix metallopeptidase 2, lysyl oxidase, and cathepsin D, were also attenuated after brucine treatment. Experiments in vivo showed that an intraperitoneal injection of 5 and 15 mg/kg of brucine resulted in dose-dependent decreases in the lung metastasis of H22 ascitic hepatoma cells. Moreover, a dosage of brucine at 15 mg/kg exhibited very low toxic effects to tumor-bearing mice. Consistently, brucine downregulated expression levels of HIF-1 responsive genes in vivo. Our current study demonstrated the capacity of brucine in suppressing HCC cell migration in vitro and lung metastasis in vivo. The inhibition of the HIF-1 pathway is implicated in the anti-metastasis activity of brucine.
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PMID:Brucine, an alkaloid from seeds of Strychnos nux-vomica Linn., represses hepatocellular carcinoma cell migration and metastasis: the role of hypoxia inducible factor 1 pathway. 2393 19

We evaluated the effects of brucine on N-nitrosodiethylamine (DENA)-induced hepatocarcinogenesis in rats. Initiation of hepatocarcinogenesis was done by intraperitoneal injection of diethylnitrosamine (DENA) followed by promotion with phenobarbital. The rats were exposed to dietary brucine for 4 weeks prior to initiation, and the treatment was continued for 22 consecutive weeks. Brucine decreased the incidence, total number, multiplicity, size and volume of preneoplastic hepatic nodules in a dose-dependent manner. Administration of DENA induced hepatocellular carcinoma (HCC), as evidenced by changes in histopathological architecture, increased activity of cytochrome P450, decreased activity of glutathione Stransferase (GST) as well as decreased antioxidant status, enhanced lipid peroxidation, increased liver marker enzymes. Western blot analysis showed decreased expression of cyclin D1 and Bcl-2 with activation of caspase-3 and increased expression of Bax. Immunohistochemical demonstrated the decreased expression of the PCNA and VEGF. These results indicate that brucine prevents lipid peroxidation and hepatic cell damage and also protects the antioxidant system in DENA-induced hepatocarcinogenesis.
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PMID:Anticarcinogenic effect of brucine in diethylnitrosamine initiated and phenobarbital-promoted hepatocarcinogenesis in rats. 2406 Jun 83

Vasculogenic mimicry (VM) with the pattern of endothelial independent tubular structure formation lined by aggressive tumor cells mimics regular tumor blood vessels to ensure robust blood supply and correlates with the proliferation, invasion, metastasis, and poor prognosis of malignant tumors, which was demonstrated to be a major obstacle for resistance to antiangiogenesis therapy. Therefore, it is urgent to discover methods to abrogate the VM formation of tumors, which possesses important practical significance for improving tumor therapy. Brucine is a traditional medicinal herb extracted from seeds of Strychnos nux-vomica L. (Loganiaceae) exhibiting antitumor activity in a variety of cancer models. In the present study, the effect of brucine on vasculogenic mimicry and the related mechanism are to be investigated. We demonstrated that, in a triple-negative breast cancer cell line MDA-MB-231, brucine induced a dose-dependent inhibitory effect on cell proliferation along with apoptosis induction at higher concentrations. The further study showed that brucine inhibited cell migration and invasion with a dose-dependent manner. Our results for the first time indicated that brucine could disrupt F-actin cytoskeleton and microtubule structure, thereby impairing hallmarks of aggressive tumors, like migration, invasion, and holding a possibility of suppressing vasculogenic mimicry. Hence, the inhibitory effect of brucine on vasculogenic mimicry was further verified. The results illustrated that brucine significantly suppressed vasculogenic mimicry tube formation with a dose-dependent effect indicated by the change of the number of tubules, intersections, and mean length of tubules. The in-depth molecular mechanism of vasculogenic mimicry suppression induced by brucine was finally suggested. It was demonstrated that brucine inhibited vasculogenic mimicry which might be through the downregulation of erythropoietin-producing hepatocellular carcinoma-A2 and matrix metalloproteinase-2 and metalloproteinase-9.
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PMID:Brucine Suppresses Vasculogenic Mimicry in Human Triple-Negative Breast Cancer Cell Line MDA-MB-231. 3072 42