scholarly journals Evaluation of ATAD2 As a Potential Target in Hepatocellular Carcinoma

Author(s):  
Umut Ekin ◽  
Haluk Yuzugullu ◽  
Cigdem Ozen ◽  
Peyda Korhan ◽  
Ezgi Bagirsakci ◽  
...  

Abstract Purpose Hepatocellular carcinoma (HCC) is one of the leading causes of cancer-related death worldwide with. lack of effective systemic chemotherapy. In this study, we aimed to evaluate the value of ATPase family AAA domain-containing protein 2 (ATAD2) as a biomarker and potential therapeutic target for HCC. Methods The expression of ATAD2 was tested in different HCC patient cohorts by immunohistochemistry and comparative transcriptional analysis. The co-expression of ATAD2 and proliferation markers was compared during liver regeneration and malignancy with different bioinformatics tools. The cellular effects of ATAD2 inactivation in liver malignancy was tested on cell cycle, apoptosis and colony formation ability as well as tumor formation using RNA interference. The genes affected by ATAD2 inactivation in three different HCC cell lines were identified by global gene expression profiling and bioinformatics tools. Results ATAD2 is overexpression is closely correlated with HCC tumor stage. There was gradual increase from dysplasia, well differentiated and poorly differentiated HCC, respectively. We also observed transient upregulation of ATAD2 expression during rat liver regeneration in parallel to changes in Ki-67 expression. ATAD2 knockdown resulted in apoptosis and decreased cell survival in vitro and decreased tumor formation in some HCC cell lines. However, three other HCC cell lines tested where not affected. Similarly, gene expression response to ATAD2 inactivation in different HCC cell lines was highly heterogeneous. Conclusions ATAD2 is a potential proliferation marker for liver regeneration and HCC. It may also serve as a therapeutic target despite heterogeneous response of malignant cells.

Author(s):  
Masumeh Sanaei ◽  
Fraidoon Kavoosi ◽  
Mohammad Amin Moezzi

Backgrounds: Epigenetic regulation such as DNA methylation plays a major role in chromatin organization and gene transcription. Additionally, histone modification is an epigenetic regulator of chromatin structure and influences chromatin organization and gene expression. The relationship between DNA methyltransferase (DNMTs) expression and promoter methylation of the tumor suppressor genes (TSGs) has been reported in various cancers. Previously, the effect of 5-aza-2'-deoxycytidine (5-AZA-CdR), trichostatin A (TSA), and valproic acid (VPA) was shown on various cancers. This study aimed to investigate the effect of 5'-fluoro-2'-deoxycytidine (FdCyd) and sodium butyrate on the genes of the intrinsic apoptotic pathway, p21, p53, cell viability, and apoptosis in human hepatocellular carcinoma SNU449, SNU475, and SNU368 cell lines. Materials and Methods: In this lab trial study, the SNU449, SNU475, and SNU368 cells were cultured and treated with 5'-fluoro-2'-deoxycytidine and sodium butyrate. To determine cell viability, cell apoptosis, and the relative gene expression level, MTT assay, flow cytometry assay, and qRT-PCR were done respectively. Results: 5'-fluoro-2'-deoxycytidine and sodium butyrate changed the expression level of the BAX, BAK, APAF1, Bcl-2, Bcl-xL, p21, and p53 gene (P<0.0001) by which induced cell apoptosis and inhibit cell growth in all three cell lines, SNU449, SNU475, and SNU368.  Conclusion: Both compounds played their roles through the intrinsic apoptotic pathway to induce cell apoptosis.


Blood ◽  
2009 ◽  
Vol 114 (22) ◽  
pp. 832-832 ◽  
Author(s):  
Michael A Chapman ◽  
Jean-Philippe Brunet ◽  
Jonathan J Keats ◽  
Angela Baker ◽  
Mazhar Adli ◽  
...  

Abstract Abstract 832 We hypothesized that new therapeutic targets for multiple myeloma (MM) could be discovered through the integrative computational analysis of genomic data. Accordingly, we generated gene expression profiling and copy number data on 250 clinically-annotated MM patient samples. Utilizing an outlier statistical approach, we identified HOXA9 as the top candidate gene for further investigation. HOXA9 expression was particularly high in patients lacking canonical MM chromosomal translocations, and allele-specific expression analysis suggested that this overexpression was mono-allelic. Indeed, focal copy number amplifications at the HOXA locus were observed in some patients. Outlier HOXA9 expression was further validated in both a collection of 52 MM cell lines and 414 primary patient samples previously described. To further verify the aberrant expression of HOXA9 in MM, we performed quantitative RT-PCR, which confirmed expression in all MM patients and cell lines tested, with high-level expression in a subset. To further investigate the mechanism of aberrant HOXA9 expression, we interrogated the pattern of histone modification at the HOXA locus because HOXA gene expression is particularly regulated by such chromatin marks. Accordingly, immunoprecipitation studies showed an aberrantly low level of histone 3 lysine 27 trimethylation marks (H3K27me3) at the HOXA9 locus. H3K27me3 modification is normally associated with silencing of HOXA9 in normal B-cell development. As such, it appears likely that the aberrant expression of HOXA9 in MM is due at least in part to defects in histone modification at this locus. To determine the functional consequences of HOXA9 expression in MM, we performed RNAi-mediated knock-down experiments in MM cell lines. Seven independent HOXA9 shRNAs that diminished HOXA9 expression resulted in growth inhibition of 12/14 MM cell lines tested. Taken together, these experiments indicate that HOXA9 is essential for survival of MM cells, and that the mechanism of HOXA9 expression relates to aberrant histone modification at the HOXA9 locus. The data thus suggest that HOXA9 is an attractive new therapeutic target for MM. Disclosures: No relevant conflicts of interest to declare.


2018 ◽  
Vol 36 (4_suppl) ◽  
pp. 284-284
Author(s):  
Yu Bin Tan ◽  
Timothy Shuen ◽  
Han Chong Toh

284 Background: Hepatocellular carcinoma (HCC) is the 2nd leading global cause of cancer death. Recently, we have discovered previously undescribed deletion and germline mutation of GATA4 and showed that GATA4 is a key differentiation driver and metabolic regulator in HCC. However, as GATA4 is mostly deleted in HCC, targeting GATA4-downstream molecules is ideal. In this study, proof-of-concept experiments were conducted to show that introduction of HNF4A, which is a GATA4-regulated downstream target, could partially rescue the impaired phenotypes in GATA4-deficient HCC cell line. Methods: Correlation analysis using gene expression microarray of human HCC samples was conducted to identify the genes that are positively correlated with GATA4. A transgenic mouse model with a liver-specific conditional GATA4 knockout was designed to identify liver morphology and gene expression changes which are correlated with the loss of Gata4 in the mouse liver. CRISPR-mediated knockout of GATA4 and lentiviral HNF4A overexpression was carried out in a GATA4-deficient HCC cell lines, PLC/PRF/5 and Hep3B, followed by proliferation, apoptosis, cell cycle and senescence functional assays. Results: Pearson correlation analysis from human HCC samples showed that expression of HNF4A is positively correlated with that of GATA4. Livers from conditional Gata4 knockout mice had lower Hnf4a gene expression when compared to age-matched control mice. Loss of function analysis by CRISPR-mediated GATA4 knockout further showed downregulation of HNF4A in GATA4-deficient PLC/PRF/5 cell line. Lentiviral HNF4A overexpression in PLC/PRF/5 and Hep3B demonstrated reduced proliferation and increased apoptosis while PLC/PRF/5 also showed cell cycle arrest at G2/M phase when compared to control. However, no senescence induction was detected in HNF4A-overexpressing cells. Conclusions: Transgenic mouse data, CRISPR-mediated knockout and analysis of HCC samples showed that HNF4A is a key GATA4-downstream target. HNF4A overexpression decreases proliferation, increases apoptosis and cell cycle arrest in GATA4-deficient HCC cell lines, thus representing a possible therapeutic target for HCC.


Blood ◽  
2006 ◽  
Vol 108 (11) ◽  
pp. 254-254
Author(s):  
Michele Milella ◽  
Maria Rosaria Ricciardi ◽  
Chiara Gregorj ◽  
Fabiana De Cave ◽  
Steven L. Abrams ◽  
...  

Abstract The Raf/MEK/ERK signaling module plays a pivotal role in the regulation of cell proliferation, survival, and differentiation. Our group, among others, has recently demonstrated that this pathway is frequently dysregulated in hematological malignancies and may constitute an attractive therapeutic target, particularly in AML. Here we investigated the effects of PD0325901, a novel MEK inhibitor, on phospho-protein expression, gene expression profiles, cell proliferation, and apoptosis in cell line models of AML, ALL, multiple myeloma (MM), ex vivo-cultured primary AML blasts, and oncogene-transformed hematopoietic cells. AML cell lines (OCI-AML2, OCI-AML3, HL-60) were strikingly sensitive to PD0325901 (IC50: 5–19 nM), NB4 (APL) and U266 (MM) showed intermediate sensitivity (IC50: 822 and 724 nM), while all the lymphoid cell lines tested and the myeloid cell lines U937 and KG1 were resistant (IC50 > 1000 nM). Cell growth inhibition was due to inhibition of cell cycle progression and induction of apoptosis. A statistically significant reduction in the proportion of S-phase cells (p=0.01) and increase in the percentage of apoptotic cells (p=0.019) was also observed in 18 primary AML samples in response to 100 nM PD0325901. Analysis of the correlation between sensitivity/resistance to PD0325901 and Ras/Raf mutation status is currently ongoing. PD0325901 effects were also examined in a panel of IL-3-dependent murine myeloid FDC-P1 cell lines transformed to grow in response to 11 different oncogenes in the absence of IL-3. Fms-, Ras-, Raf-1-, B-Raf-, MEK1-, IGF-1R-, and STAT5a-transformed FDC-P1 cells were very sensitive to PD0325901 (IC50: ~ 1 nM), while A-Raf-, BCR-ABL-, EGFR- or Src-transformed cells were 10 to 100 fold less sensitive (IC50: 10 to 100 nM); the parental, IL-3 dependent FDC-P1 cell line had an IC50 > 1000 nM. Analysis of the phosphorylation levels of 18 different target proteins after treatment with 10 nM PD0325901 showed a 5- to 8-fold reduction in ERK-1/2, observed only in sensitive cell lines, and a 2-fold reduction in JNK and STAT3 phosphorylation. PD0325901 (10 nM) treatment also profoundly altered the gene expression profile of the sensitive cell line OCI-AML3: 96 genes were modulated after 24 h (37 up- and 59 down-regulated), most of which involved in cell cycle regulation. Changes in cyclin D1 and D3, cyclin E, and cdc 25A were also validated at the protein level. Overall, PD0325901 shows potent growth-inhibitory and pro-apoptotic activity, indicating that MEK may be an appropriate therapeutic target in an array of different hematological malignancies. Further preclinical/clinical development of this compound is warranted, particularly in myeloid leukemias.


2018 ◽  
Vol Volume 10 ◽  
pp. 5691-5708 ◽  
Author(s):  
Li Yin ◽  
Yahao Wang ◽  
Xueqiang Guo ◽  
Cunshuan Xu ◽  
Guoying Yu

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Yasutoshi Nozaki ◽  
Hayato Hikita ◽  
Satoshi Tanaka ◽  
Kenji Fukumoto ◽  
Makiko Urabe ◽  
...  

AbstractHepatocellular carcinoma highly occurs in chronic hepatitis livers, where hepatocyte apoptosis is frequently detected. Apoptosis is a mechanism that eliminates mutated cells. Hepatocyte apoptosis induces compensatory liver regeneration, which is believed to contribute to tumor formation. Hepatocyte-specific Mcl-1 knockout mice (Mcl-1Δhep mice) developed persistent hepatocyte apoptosis and compensatory liver regeneration with increased oxidative stress in adulthood but had not yet developed hepatocyte apoptosis at the age of 2 weeks. When diethylnitrosamine (DEN) was administered to 2-week-old Mcl-1Δhep mice, multiple liver tumors were formed at 4 months, while wild-type mice did not develop any tumors. These tumors contained the B-Raf V637E mutation, indicating that DEN-initiated tumorigenesis was promoted by persistent hepatocyte apoptosis. When N-acetyl-L-cysteine was given from 6 weeks of age, DEN-administered Mcl-1Δhep mice had reduced oxidative stress and suppressed tumorigenesis in the liver but showed no changes in hepatocyte apoptosis or proliferation. In conclusion, enhanced tumor formation from DEN-transformed hepatocytes by persistent hepatocyte apoptosis is mediated by increased oxidative stress, independent of compensatory liver regeneration. For patients with livers harboring transformed cells, the control of oxidative stress may suppress hepatocarcinogenesis based on chronic liver injury.


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