Search results for " Raf-1 kinase inhibitor protein"

Alteration of the YY1/RKIP ratio is a frequent event in hepatocellular carcinoma

2009

Mechanisms of Raf-1 Kinase Inhibitor Protein Dysregulation in Triple-Negative Breast Cancers and Identification of Possible Novel Therapeutic Approac…

2014

Triple-negative breast cancers (TNBCs) are a heterogenous group of breast cancers characterized by poor prognosis because they are not amenable to targeted therapies. We have taken into account that altered expression of Raf-1 kinase inhibitor protein (RKIP), a tumor and metastasis suppressor and a promoter of drug-induced apoptosis, is frequent in TNBCs and may be involved in their aggressive biology. Interestingly, the analysis of the possible mechanisms of RKIP downregulation in TNBCs permits the identification and recapitulation of different possible approaches, including epigenetic modulation, e.g., by DNA demethylating agents or histone deacetylase inhibition, and NF-κB inhibition. Th…

Frequent Alteration of the Yin Yang 1/Raf-1 Kinase Inhibitory Protein Ratio in Hepatocellular Carcinoma

2011

The transcription factor Yin Yang 1 (YY1) can favor several aspects of tumorigenesis. In turn, Raf-1 Kinase Inhibitor Protein (RKIP) inhibits the oncogenic activities of MAPK and NF-κB pathways and promotes drug-induced apoptosis. Mutual influences between YY1 and RKIP may exist, and there are already separate evidences that relevant increases in YY1 and reductions in RKIP occur in hepatocellular carcinoma (HCC). However, the levels of the two factors have never been concomitantly examined in HCC. We evaluated by RT-PCR the mRNA levels of YY1, YY1AP, RKIP, and survivin in 35 clinical HCCs (91% HCV-related), in their adjacent cirrhotic tissues and in 6 healthy livers. Immunohistochemical ana…

Epigenetic changes and nuclear factor-κB activation, but not microRNA-224, downregulate Raf-1 kinase inhibitor protein in triple-negative breast canc…

2015

Raf-1 kinase inhibitor protein (RKIP) is a tumor suppressor and metastasis inhibitor, which enhances drug-induced apoptosis of cancer cells. Downregulation of RKIP may be significant in the biology of highly aggressive and drug-resistant tumors, for example triple-negative breast cancers (TNBCs). Potential causes for the low levels of RKIP expressed by SUM 159 TNBC cells were investigated in the present study. Bisulphite modification, methylation specific-polymerase chain reaction (PCR) and a TransAM NF-κB assay were performed and the results suggested that various mechanisms, including methylation of the gene promoter, histone deacetylation and nuclear factor-κB (NF-κB) activation, but not…

Induction of Apoptosis and Chemosensitization by the Histone Deacetylase Inhibitor Trichostatin in Hepatocellular Carcinoma Cells: Molecular Analysis…

2011

The mRNA and protein levels of RKIP are reduced and those of YY1 increased in clinical HCC. Loss, mutation, or promoter hypermethylation of the RKIP gene may not account for the downregulation of RKIP in HCC. Histone deacetylation can silence gene expression and play a significant role in hepatocarcinogenesis. The histone deacetylase inhibitor (HDACI) trichostatin induced cell growth inhibition and proapoptotic effects in HA22T/VGH and HepG2 HCC cells; it also exhibited synergy with doxorubicin. Treatment with trichostatin caused histone hyperacetylation and down- or upregulated expression of different genes (such as β-catenin, cyclin D1, hTERT, XIAP, and IL-6). These changes might, at leas…