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Oncogenic Phenotype (oncogenic + phenotype)
Selected AbstractsBlockade of AP-1 activity by dominant-negative TAM67 can abrogate the oncogenic phenotype in latent membrane protein 1-positive human nasopharyngeal carcinomaMOLECULAR CARCINOGENESIS, Issue 11 2007Xin Jin Abstract Although activating protein-1 (AP-1) transcription factors play an important role in mediating metastasis for nasopharyngeal carcinoma (NPC), the biological and physiological functions of AP-1, in relation to the oncogenic phenotype of NPC, are not fully understood. Our previous study showed that the latent membrane protein 1 (LMP1) mediated a primary dimer form of c- jun and jun B. In this study, we used a NPC cell line that express a specific inhibitor of AP-1, a dominant-negative c- jun mutant (TAM67), to investigate the role of AP-1 in regulating the NPC oncogenic phenotype. First, we observed that TAM67 inhibited cell growth in vitro and in vivo. Next, with Western blotting, we discovered that TAM67 impaired the cyclin D1/cdk4 complex but had little effect on the cyclin E/cdk2 complex, concomitantly with inhibiting Rb phosphorylation. RT-PCR and luciferase assay results demonstrated that the levels of cyclin D1 mRNA and the promoter activity in TAM67 transfectants were reduced as compared with control cells. Thereby, we show that blockade of AP-1 transcriptional activity has a negative impact on cyclin D1 transcription. We obtained the first evidence that TAM67 prevented NPC growth both in vitro and in vivo. AP-1 appears to be a novel target for treating or preventing LMP1-positive NPC effectively. © 2007 Wiley-Liss, Inc. [source] Nuclear STK15 expression is associated with aggressive behaviour of oral carcinoma cells in vivo and in vitro,THE JOURNAL OF PATHOLOGY, Issue 1 2010Shou-Yen Kao Abstract Oral squamous cell carcinoma (OSCC) is one of the most commonly diagnosed cancers worldwide. Chromosome 20q is a hotspot for gene amplification in OSCC and the serine/threonine kinase STK15 (also named Aurora-A) maps to 20q13. The amplification and over-expression of STK15 is common in neoplasia but the functional and clinical impact of STK15 in OSCC remains poorly understood. STK15 copy number is amplified in 12% of OSCCs and nuclear STK15 protein expression increases with tumour progression. In vivo elevated nuclear STK15 protein expression is significantly associated with the worse prognosis of OSCC patients. The combination of high nuclear STK15 and Ki-67 expression has a 2.55-fold hazard for cancer-associated mortality. In vitro knockdown of STK15 reduced the oncogenic phenotypes of OECM-1 cells. Injection of lentivirus carrying shRNA vectors against STK15 significantly reduced the growth of SAS xenografts on nude mice. Knockdown of STK15 also induced autophagy and apoptosis of OSCC cells. Our data provide evidence that STK15 is oncogenic for OSCC and that its nuclear expression is a predictor of clinical behaviour. Knockdown of STK15 could be a potential therapeutic option in OSCC and other tumours. Copyright © 2010 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd. [source] | ||||||||||