5970

RELA

v-rel avian reticuloendotheliosis viral oncogene homolog A;RELA;v-rel avian reticuloendotheliosis viral oncogene homolog A

NF-kappa-B p65delta3|nuclear factor NF-kappa-B p65 subunit|nuclear factor of kappa light polypeptide gene enhancer in B-cells 3|transcription factor p65|v-rel reticuloendotheliosis viral oncogene homolog A

11q13

protein-coding

metastasis of cancer cells is a complex process involving multiple steps including invasion, angiogenesis, and trafficking of cancer cells through blood vessels, extravasations, organ-specific homing, and growth. While matrix metalloproteinases, urokinase-type plasminogen activator, and cytokines play a major role in invasion and angiogenesis, chemokines such as stromal derived factor-1alpha (SDF-1alpha) and their receptors such as CXCR4 are thought to play a critical role in motility, homing, and proliferation of cancer cells at specific metastatic sites. We and others have previously reported that the extracellular signal-activated transcription factor NF-kappaB up-regulates the expression of matrix metalloproteinases, urokinase-type plasminogen activator, and cytokines in highly metastatic breast cancer cell lines. In this report, we demonstrate that NF-kappaB regulates the motility of breast cancer cells by directly up-regulating the expression of CXCR4. Overexpression of the inhibitor of kappaB (IkappaB) in breast cancer cells with constitutive NF-kappaB activity resulted in reduced expression of CXCR4 and a corresponding loss of SDF-1alpha-mediated migration in vitro. Introduction of CXCR4 cDNA into IkappaB-expressing cells restored SDF-1alpha-mediated migration. Electrophoretic mobility shift assays and transient transfection assays revealed that the NF-kappaB subunits p65 and p50 bind directly to sequences within the -66 to +7 region of the CXCR4 promoter and activate transcription. We also show that the cell surface expression of CXCR4 and the SDF-1alpha-mediated migration are enhanced in breast cancer cells isolated from mammary fat pad xenografts compared with parental cells grown in culture. A further increase in CXCR4 cell surface expression and SDF-1alpha-mediated migration was observed with cancer cells that metastasized to the lungs. Taken together, these results implicate NF-kappaB in the migration and the organ-specific homing of metastatic breast cancer cells.

Hyperactivation of beta-catenin-T-cell-factor (TCF)-regulated gene transcription is a hallmark of colorectal cancer (CRC). The cell-neural adhesion molecule L1CAM (hereafter referred to as L1) is a target of beta-catenin-TCF, exclusively expressed at the CRC invasive front in humans. L1 overexpression in CRC cells increases cell growth and motility, and promotes liver metastasis. Genes induced by L1 are also expressed in human CRC tissue but the mechanisms by which L1 confers metastasis are still unknown. We found that signaling by the nuclear factor kappaB (NF-kappaB) is essential, because inhibition of signaling by the inhibitor of kappaB super repressor (IkappaB-SR) blocked L1-mediated metastasis. Overexpression of the NF-kappaB p65 subunit was sufficient to increase CRC cell proliferation, motility and metastasis. Binding of the L1 cytodomain to ezrin - a cytoskeleton-crosslinking protein - is necessary for metastasis because when binding to L1 was interrupted or ezrin gene expression was suppressed with specific shRNA, metastasis did not occur. L1 and ezrin bound to and mediated the phosphorylation of IkappaB. We also observed a complex containing IkappaB, L1 and ezrin in the juxtamembrane region of CRC cells. Furthermore, we found that L1, ezrin and phosphorylated p65 are co-expressed at the invasive front in human CRC tissue, indicating that L1-mediated activation of NF-kappaB signaling involving ezrin is a major route of CRC progression.

Activation of nuclear factor-kappa B (NF-kappaB) has been detected in various malignant tumors, including gastric carcinoma, and is associated with tumor growth, metastasis, resistance to chemotherapeutic agents and poor prognosis. Therefore, NF-kappaB is a potential target for antitumor therapy. In this study, we used a small interfering RNA (siRNA) to knockdown NF-kappaB p65 expression and determined whether intraperitoneal administration of NF-kappaB p65 siRNA and paclitaxel was effective for treating peritoneal metastasis of gastric cancer. Western blot analysis revealed that NF-kappaB p65 expression was diminished by NF-kappaB p65 siRNA. Apoptotic cells were increased after transfection of NF-kappaB p65 siRNA compared with control siRNA in the treatment with paclitaxel. In a murine xenograft model, abundant fluorescence was observed on the surface of intraperitoneal nodules of gastric cancer after siRNA administration. Moreover, intraperitoneal administration of NF-kappaB p65 siRNA reduced NF-kappaB expression in intraperitoneal nodules of gastric cancer. Finally, mice treated by intraperitoneal administration of NF-kappaB p65 siRNA and paclitaxel survived for a significantly longer time than mice treated by intraperitoneal administration of paclitaxel alone (p = 0.0002). Taken together, the present results demonstrate that intraperitoneal administration of NF-kappaB p65 siRNA and paclitaxel inhibited cancer growth in mice with peritoneal metastasis of gastric cancer. Therefore, intraperitoneal administration of NF-kappaB p65 siRNA and paclitaxel may provide a breakthrough in the treatment of peritoneal metastasis of gastric cancer.

OBJECTIVE: To evaluate expressions of NF-kappaB p65 in laryngeal carcinoma and normal mucous membrane and its clinical significance. METHOD: The immunohistochemical method and the in situ hybridization were employed in detecting the NF-kappaB p65 expressions in surgical specimen from 48 laryngeal carcinoma and 20 normal mucous membrane. RESULT: (1) The expression of NF kappaB p65 was higher than in normal laryngeal mucous membrane. (2) Positive expression of NF-kappaB p65 correlated with the development of distant metastasis. CONCLUSION: The results of the study show that the NF-kappaB p65 protein is a significant predictor of survival in laryngeal carcinoma patients.

Nuclear factor kappa B (NFkappaB) is an essential regulator of gene transcription for hundreds of genes, including many critically involved in apoptosis. NFkappaB complexes containing cRel generally activate pro-apoptotic genes, while those with RelA activate anti-apoptotic genes. We have previously shown that NFkappaB binding by RelA is constitutively elevated in human metastatic melanoma cultures relative to normal melanocytes. Here we extended our investigation to immunohistochemical analysis of human tissue biopsies. We found that RelA expression is significantly elevated in melanocytes of human naevi and melanomas relative to normal skin, but expression of its inhibitor IkappaB-alpha is significantly lower in metastatic melanomas than in intradermal naevi. Antibodies specific for the nuclear localization signal of RelA also showed significantly increased staining in metastatic melanoma biopsies. Notably, in melanomas and in naevi, we also found that RelA is phosphorylated at serine 529, and this activated form accumulates in the nuclei of melanomas. This suggests that increased expression and phosphorylation of RelA occurs at the stage of the benign naevus, but IkappaB-alpha is able to sequester RelA in the cytoplasm and regulate RelA transcriptional transactivation. We also found that antibodies against cRel show a progressive increase in staining from naevi to melanoma. However, staining for IkappaB-epsilon, which primarily inhibits the nuclear localization of cRel was also progressively increased, and cRel expression was predominantly cytoplasmic in melanomas. These results confirm that the altered expression of RelA found in metastatic melanoma cells in tissue culture is relevant to human tumors and offer new insights into the deregulation of NFkappaB signaling.

NF-kappaB has been recognized as one of the factors responsible for the development of cancer; however, the mechanism by which high expression of NF-kappaB contributes to the progression of human oesophageal squamous cell cancer (ESCC) is not fully understood. In our investigations, NF-kappaBP65 was overexpressed in human ESCC tissues, especially in ESCC tissues with deep invasion and lymph node metastasis. Suppression of NF-kappaBP65 by siRNA decreased the invasion and proliferation ability of EC9706 cells in vitro. Furthermore, siRNA-mediated NF-kappaBP65 knock-down could lead to the downregulation of MMP-9, a metastasis-related gene. Reduced E-cadherin is a hallmark of invasive carcinomas that have acquired epithelial-mesenchymal transition (EMT) phenotypes and Vimentin is another molecule that is used widely as a marker of the EMT. We found upregulation of E-cadherin expression and downregulation of Vimentin was induced by NF-kappaBP65 siRNA, which suggests that NF-kappaBP65 siRNA could inhibit the invasion and proliferation ability of ECSS through attenuating the expression of MMP-9 and EMT. Thus, ESCC NF-kappaBP65 could be a useful target for cancer prevention and therapy.

OBJECTIVE: To test the expression of NF-kappaB/p65, MMP-3 and MMP-9 in nasopharyngeal carcinoma (NPC), and analyze their relationship and the clinical significance. METHOD: All samples were examined for the expression of NF-kappaB/p65, MMP-3 and MMP-9 by streptavidin-peroxidase immunohistochemistry. Chi2-test and Spearman-test were used to exam the correlation within them and the expression difference between nasopharyngeal carcinoma and normal nasopharyngeal mucosa. RESULT: Positive expression rate of NF-kappaB/p65 in nasopharyngeal carcinoma was 78.0%; positive expressions rate of MMP-3 and MMP-9 in nasopharyngeal carcinoma were 75.6%. There was positive relationship between NF-kappaB/p65, MMP-3, MMP-9 and N stage. The expression of NF-kappaB/p65 showed a significant positive correlation with the expression of MMP-3 and MMP-9. MMP-3 also had a significant positive correlation with MMP-9. CONCLUSION: The result suggests that NF-kappaB/p65, MMP-3 and MMP-9 are highly expressed in nasopharyngeal carcinoma cells. Their expression is correlated with lymph nodes metastasis, but do not have relationship with sex, age, pathological classification and clinical stage. Each of them has positive correlation with the others.

AKT plays an important role in malignant behavior of tumors. The purpose of the present study was to determine the expression of phosphorylated AKT (P-AKT) and nuclear factor-kappaB (NF-kappaB) p65 and their association with clinicopathological parameters and prognosis in epithelial ovarian tumor. On immunohistochemistry 115 samples of ovarian tissue that included 68 specimens of epithelial ovarian cancer, 12 of borderline tumor, 24 of epithelial benign tumor and 11 of normal ovary, were evaluated. Sixty-three patients with ovarian cancer were followed up from 7 to 68 months. The positive expression rate of P-AKT and NF-kappaB p65 were higher in epithelial ovarian cancer than in normal ovarian tissue (P<0.01). Elevated P-AKT or NF-kappaB p65 expression was significantly correlated with late clinical stage (P<0.05 and P<0.01) and poor histological differentiation (both P<0.01). P-AKT expression was significantly correlated with NF-kappaB p65 immunostaining (phi=0.272, P<0.05). Elevated expression of P-AKT was negatively correlated with the survival of ovarian cancer patients, but it was not an independent prognostic factor after multivariate analysis. Overexpression of P-AKT and NF-kappaB p65 were involved in the carcinogenesis and metastasis of ovarian cancer. P-AKT might contribute to the malignant transformation through NF-kappaBp65 upregulation.