Search results for "c-MYC"

C-myc mRNA Expression in Epithelial Ovarian Carcinomas in Relation to Estrogen Receptor Status, Metastatic Spread, Survival Time, FIGO Stage, and His…

1998

Recently, it has been suggested that c-myc expression might correlate with estrogen receptor (ER) status and metastatic spread in ovarian cancer. In this study, expression of c-myc mRNA in 90 epithelial ovarian carcinomas was determined using the S1 nuclease protection assay. Expression of c-myc mRNA was detectable in 27 of 90 tumors. There was no significant association between c-myc mRNA expression and metastatic spread, survival time, FIGO stage, or histologic grade and type. C-myc mRNA was expressed in 45% of ER-positive tumors but only 24% of ER-negative tumors (p = 0.094; Fisher's exact test). Similarly, 44% of progesterone receptor (PR)-positive and 23% of PR-negative tumors expresse…

Theabrownin Inhibits Cell Cycle Progression and Tumor Growth of Lung Carcinoma through c-myc-Related Mechanism.

2017

Green tea, the fresh leaves of Camellia sinensis, is not only a health-promoting beverage but also a traditional Chinese medicine used for prevention or treatment of cancer, such as lung cancer. Theabrownin (TB) is the main fraction responsible for the medicinal effects of green tea, but whether it possesses anti-cancer effect is unknown yet. This study aimed to determine the in vitro and in vivo anti-lung cancer effect of TB and explore the underlying molecular mechanism, by using A549 cell line and Lewis lung carcinoma-bearing mice. In cellular experiment, MTT assay was performed to evaluate the inhibitory effect and IC50 values of TB, and flow cytometry was conducted to analyze the cell …

In silico pathway analysis in cervical carcinoma reveals potential new targets for treatment

2016

Abstract: An in silico pathway analysis was performed in order to improve current knowledge on the molecular drivers of cervical cancer and detect potential targets for treatment. Three publicly available Affymetrix gene expression data-sets (GSE5787, GSE7803, GSE9750) were retrieved, vouching for a total of 9 cervical cancer cell lines (CCCLs), 39 normal cervical samples, 7 CIN3 samples and 111 cervical cancer samples (CCSs). Predication analysis of microarrays was performed in the Affymetrix sets to identify cervical cancer biomarkers. To select cancer cell-specific genes the CCSs were compared to the CCCLs. Validated genes were submitted to a gene set enrichment analysis (GSEA) and Expre…

Role of THAP11 in the transcriptional regulation and chromatin structure of the human MYC locus

C-MYC è uno dei geni più frequentemente deregolati nei tumori umani. Una comprensione dettagliata della regolazione trascrizionale di questo gene è essenziale per comprendere meglio gli aspetti molecolari delle sue diverse funzioni. Usando diversi tipi di analisi (EMSA, 2D-IPG e analisi MALDI), nei nostri laboratori abbiamo caratterizzato un elemento con funzione di enhancer blocker (HB2.8) situato 32Kb valle del gene c-MYC . Saggi di trasfezione transiente e stabile hanno dimostrato che l'attività dell’elemento enhancer-blocker può essere attribuita esclusivamente ad un sub-regione di DNA di circa 400 bp chiamato AA0.4. Ulteriori test per valutare l'attività enhancer blocker di questa sequ…

Iron-mediated oxidative stress induces PD-L1 expression via activation of c-Myc in lung adenocarcinoma

2023

Introduction: The PD-1/PD-L1 axis is hijacked by lung adenocarcinoma (LUAD) cells to escape immune surveillance. PD-L1 expression in LUAD is affected, among others, by the metabolic trafficking between tumor cells and the tumor microenvironment (TME). Methods: Correlation between PD-L1 expression and iron content within the TME was established on FFPE LUAD tissue samples. The effects of an iron rich microenvironment on PD-L1 mRNA and protein levels were assessed in vitro in H460 and A549 LUAD by using qPCR, western blot and flow citometry. c-Myc knockdown was performed to validate the role of this transcription factor on PD-L1 expression. The effects of iron-induced PD-L1 on T cell immune f…

MYC Activates Stem-like Cell Potential in Hepatocarcinoma by a p53-Dependent Mechanism

2014

Activation of c-MYC is an oncogenic hallmark of many cancers including liver cancer, and is associated with a variety of adverse prognostic characteristics. Despite a causative role during malignant transformation and progression in hepatocarcinogenesis, consequences of c-MYC activation for the biology of hepatic cancer stem cells (CSCs) are undefined. Here, distinct levels of c-MYC over-expression were established by using two dose-dependent tetracycline inducible systems in 4 hepatoma cell lines with different p53 mutational status. The CSCs were evaluated using side-population approach as well as standard in vitro and in vivo assays. Functional repression of p53 was achieved by lentivira…

HSPH1 inhibition downregulates Bcl-6 and c-Myc and hampers the growth of human aggressive B-cell non-Hodgkin lymphoma

2015

We have shown that human B-cell non-Hodgkin lymphomas (B-NHLs) express heat shock protein (HSP)H1/105 in function of their aggressiveness. Here, we now clarify its role as a functional B-NHL target by testing the hypothesis that it promotes the stabilization of key lymphoma oncoproteins. HSPH1 silencing in 4 models of aggressive B-NHLs was paralleled by Bcl-6 and c-Myc downregulation. In vitro and in vivo analysis of HSPH1-silenced Namalwa cells showed that this effect was associated with a significant growth delay and the loss of tumorigenicity when 10(4) cells were injected into mice. Interestingly, we found that HSPH1 physically interacts with c-Myc and Bcl-6 in both Namalwa cells and pr…

In vivo GSH depletion induces c-myc expression by modulation of chromatin protein complexes.

2009

Abstract We hypothesize that glutathione (GSH) fluctuations could have a prominent role in the modulation of c-myc expression through a mechanism affecting chromatin remodeling complexes. This could lead to an open chromatin structure accessible to transcription factors. We studied the in vivo effect of GSH depletion on these complexes bound to the c-myc promoter in the liver of l-buthionine-(S,R)-sulfoximine (BSO)-treated rats. Using chromatin immunoprecipitation we found that 3 h after BSO treatment the repressing complexes Id2 and Sin3A (part of a histone–deacetylase complex) were released from the c-myc promoter. STAT3 was phosphorylated and associated with its coactivator p300 with int…

The apoptotic effects and synergistic interaction of sodium butyrate and MG132 in human retinoblastoma Y79 cells

1999

This study deals with the apoptotic effect exerted on human retinoblastoma Y79 cells by both sodium butyrate and an inhibitor of 26S proteasome [z-Leu-Leu-Leu-CHO (MG132)] and their synergistic effect. Exposure to sodium butyrate (1-4 mM) induced an accumulation of cells in the G2-M phase that was already visible after 24 h of treatment, when morphological and biochemical signs of apoptosis appeared only in a small number of cells (5-10%). Thereafter, the apoptotic effects increased progressively with slow kinetics, reaching a maximum after 72 h of exposure, when they concerned a large fraction of cells (>75% with 4 mM sodium butyrate). Sodium butyrate stimulated the conversion of procaspas…

Silencing of hepatic fate-conversion factors induce tumorigenesis in reprogrammed hepatic progenitor-like cells

2016

Abstract Background Several studies have reported the direct conversion of mouse fibroblasts to hepatocyte-like cells with different degrees of maturation by expression of hepatic fate-conversion factors. Methods We have used a combination of lentiviral vectors expressing hepatic fate-conversion factors with Oct4, Sox2, Klf4, and Myc to convert mouse embryonic fibroblasts into hepatic cells. Results We have generated hepatic cells with progenitor-like features (iHepL cells). iHepL cells displayed basic hepatocyte functions but failed to perform functions characteristic of mature hepatocytes such as significant Cyp450 or urea cycle activities. iHepL cells expressed multiple hepatic-specific …