Genetic and epigenetic control of molecular alterations in hepatocellular carcinoma

Titolo rivista: Exp Biol Me

Autoantibody responses in autoimmune ovarian insufficiency and in Addison's disease are IgG1 dominated and suggest a predominant, but not exclusive, Th1 type of response

none13noneBrozzetti A;Marzotti S;La Torre D;Bacosi ML;Morelli S;Bini V;Ambrosi B;Giordano R;Perniola R;De Bellis A;Betterle C;Falorni A;Italian Addison NetworkBrozzetti, A; Marzotti, S; La Torre, D; Bacosi, Ml; Morelli, S; Bini, V; Ambrosi, B; Giordano, R; Perniola, R; De Bellis, A; Betterle, Corrado; Falorni, A; Italian Addison, Networ

Role of transcriptional and postttranscriptional regulation of methionine adenosyltransferases in liver cancer progression.

Down-regulation of liver-specific MAT1Agene, encoding S-adenosylmethionine (SAM) synthesizing isozymes MATI/III, and upregulation of widely expressedMAT2A, encoding MATII isozyme, known as MAT1A:MAT2A switch, occurs in hepatocellular carcinoma (HCC). Here, we found Mat1A:Mat2A switch and low SAM levels, associated with CpG hypermethylation and histone H4 deacetylation of Mat1A promoter, and prevalent CpG hypomethylation and histone H4 acetylation in Mat2A promoter of fast growing HCC of F344 rats, genetically susceptible to hepatocarcinogenesis. In HCC of genetically resistant BN rats, very low changes in Mat1A:Mat2A ratio, CpG methylation, and histone H4 acetylation occurred. Highest MAT1A promoter hypermethylation and MAT2A promoter hypomethylation occurred in human HCC with poorer prognosis. Furthermore, levels of AUF1 protein, which destabilizes MAT1A mRNA, MAT1A-AUF1 ribonucleoprotein, HuR protein, which stabilizes MAT2AmRNA, and MAT2A-HuR ribonucleoprotein, sharply increased in F344 and human HCC, and underwent low/no increase in BN HCC. In human HCC, MAT1A:MAT2Aexpression and MATI/III:MATII activity ratios correlated negatively with cell proliferation and genomic instability, and positively with apoptosis and DNA methylation. Noticeably, MATI/III:MATII ratio strongly predicted patients' survival length. Forced MAT1A overexpression in HepG2 and HuH7 cells led to rise in SAM level, decreased cell proliferation, increased apoptosis, downregulation of Cyclin D1, E2F1, IKK, NF-kB,and antiapoptotic BCL2and XIAP genes, and upregulation of BAX and BAK proapoptotic genes. In conclusion, we found for the first time a post-transcriptional regulation of MAT1A and MAT2A by AUF1 and HuR in HCC. Low MATI/III:MATII ratio is a prognostic marker that contributes to determine a phenotype susceptible to HCC and patients' survival. Interference with cell cycle progression and IKK/NF-kB signaling contributes to the anti-proliferative and pro-apoptotic effect of high SAM levels in HCC

Deregulation of DNA-dependent protein kinase catalytic subunit contributes to human hepatocarcinogenesis development and has a putative prognostic value

Background:The DNA-repair gene DNA-dependent kinase catalytic subunit (DNA-PKcs) favours or inhibits carcinogenesis, depending on the cancer type. Its role in human hepatocellular carcinoma (HCC) is unknown.Methods:DNA-dependent protein kinase catalytic subuni, H2A histone family member X (H2AFX) and heat shock transcription factor-1 (HSF1) levels were assessed by immunohistochemistry and/or immunoblotting and qRT-PCR in a collection of human HCC. Rates of proliferation, apoptosis, microvessel density and genomic instability were also determined. Heat shock factor-1 cDNA or DNA-PKcs-specific siRNA were used to explore the role of both genes in HCC. Activator protein 1 (AP-1) binding to DNA-PKcs promoter was evaluated by chromatin immunoprecipitation. Kaplan-Meier curves and multivariate Cox model were used to study the impact on clinical outcome.Results:Total and phosphorylated DNA-PKcs and H2AFX were upregulated in HCC. Activated DNA-PKcs positively correlated with HCC proliferation, genomic instability and microvessel density, and negatively with apoptosis and patient's survival. Proliferation decline and massive apoptosis followed DNA-PKcs silencing in HCC cell lines. Total and phosphorylated HSF1 protein, mRNA and activity were upregulated in HCC. Mechanistically, we demonstrated that HSF1 induces DNA-PKcs upregulation through the activation of the MAPK/JNK/AP-1 axis.Conclusion:DNA-dependent protein kinase catalytic subunit transduces HSF1 effects in HCC cells, and might represent a novel target and prognostic factor in human HCC

Robotic Versus Open Pancreaticoduodenectomy: A Comparative Study at a Single Institution

Minimally invasive pancreaticoduodenectomy (PD) remains one of the most challenging abdominal procedures, and its application is poorly reported in the literature so far. To date, few data are available comparing a minimally invasive approach to open PD. The aim of the present study is to compare the robotic and open approaches for PD at a single institution