Gene expression analysis of human hepatocellular carcinoma by using full-length cDNA library

Elevated expression of sepiapterin reductase, regulator of G protein signaling 1, hypothetical protein CXorf58 homolog, and zinc finger and BTB domain-containing protein 21 isoform X2 is associated with progression of hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is one of the most common cancers associated with high mortality rate. Understanding of events leading to HCC pathophysiology is essential for its better management. We earlier reported development of a novel rodent model by administrating chemical carcinogens, DEN, and 2-AAF for study of HCC at very early stage. 2D-Electrophoresis analysis of total serum proteins identified several differentially expressed proteins in animals undergoing tumorigenesis. MALDI-TOF-MS/MS analyses were performed to characterize the differentially expressed proteins. Further real-time PCR analyses were taken place to quantify the transcript expression for the identified proteins at HCC initiation and tumor stages. Considering protein-protein interactions among the experimentally identified proteins and their interacting neighbors, a protein network has been analyzed that provided further insight into molecular events taking place during HCC development. Histological changes confirmed HCC initiation and hepatotumorigenesis at 1 and 4 months post carcinogen treatment, respectively. Four differentially expressed proteins were identified which were further characterized as regulator of G protein signaling 1 (RGS1), sepiapterin reductase (SPR), similar to zinc finger and BTB domain-containing protein 21 isoform X2 (ZNF295), and a hypothetical protein CXorf58 homolog. Quantification of transcripts for these proteins revealed elevation in their expression both at initiation and tumorigenesis stages. The study deciphers the regulatory role of these proteins during HCC progression.

Elevated Expression of A-Raf and FA2H in Hepatocellular Carcinoma is Associated with Lipid Metabolism Dysregulation and Cancer Progression

BACKGROUND

Identification of events leading to hepatocellular carcinoma (HCC) progression is essential for understanding its pathophysiology. The aims of this study are to identify and characterize differentially expressed proteins in serum of HCC-bearing rats and the corresponding controls during cancer initiation, progression and tumorigenesis.

METHODS

Chemical carcinogens, N-Nitrosodiethylamine and 2-aminoacetylfluorine are administered to induce HCC to male Wistar rats. The 2D-Electrophoresis and PD-Quest analyses are performed to identify several differentially expressed proteins in serum of HCC-bearing animals. These proteins are further characterized by MALDI-TOF-MS/MS analyses. Using pathwaylinker a HCC-specific network is analyzed among the MALDITOF- MS/MS characterized proteins and their interactors.

RESULTS

Carcinogen administration caused inflammation leading to liver injury and HCC development. Liver inflammation was confirmed by increase in the levels of TNF-α and IL-6 in carcinogen treated rats. We report significant increase in expression of two differentially expressed proteins, namely, A-Raf and Fatty Acid 2- Hydroxylase (FA2H), at early stage of HCC initiation, during its progression and at tumor stage. Real-time PCR analysis of mRNA for these proteins confirmed up-regulation of their transcripts. Further, we validated our experimental data with sera of clinically confirmed liver cancer patients.

CONCLUSION

The study suggests that FA2H and A-Raf play a major role in the progression of HCC.

In silico analysis of differential gene expressions in biliary stricture and hepatic carcinoma

In-silico attempt was made to identify the key hub genes which get differentially expressed in biliary stricture and hepatic carcinoma. Gene expression data, GSE34166, was downloaded from the GEO database, which contains 10 biliary stricture samples (4 benign control and 6 malignant carcinoma), for screening of key hub genes associated with the disease. R packages scripts were identified 85 differentially expressed genes. Further these genes were uploaded in WebGestalt database and identified nine key genes. Using STRING database and Gephi software, the protein-protein interaction networks were constructed and also studied gene ontology through WebGestalt. Finally, we identified four key genes (CXCR4, ADH1C, ABCB1 and ADH1A) are associated with liver carcinoma and further cross-validated with Liverome, Protein Atlas database and bibliography. In addition, transcription factors and their binding sites also studied. These identified hub genes and their transcription factors are the probable potential targets for possible future drug design.

Biology of Hepatocellular Carcinoma

This chapter focuses on the identification of hepatocellular carcinoma (HCC) molecular signatures and the potentials of these signatures in prediction of HCC prognosis and driving of HCC therapeutic treatments. Progress in molecular profiling studies using DNA-microarray-based gene expression profiling has provided new insight about HCC pathogenesis, and gene signatures that can distinguish tumor subtypes assist clinical staging and predict patient outcomes. This provides the possibility to improve the stratification of HCC patients at a molecular level and, in the near future, will be potential in paving the way for tailored medicine in HCC patients.

New cathepsin D inhibitor library utilizing hydroxyethyl isosteres with cyclic tertiary amines

The design and synthesis of hydroxyethylamine isosteres as inhibitors of cathepsin D based on SAR data have been accomplished. A library of 96 of these hydroxyethylamine isosteres are described and many have proven to be very potent inhibitors of human cathepsin D activity as measured using a fluorometric assay technique, via peptide substrate Ac-Glu-Glu(Edans)-Lys-Pro-Ile-Cys-Phe-Phe-Arg-Leu-Gly-Lys(Methyl Red)-Glu-NH(2). Compounds showing strongest inhibition of cathepsin D activity were those that contain a hydroxyethyl-N'-2- or N'-(4-chlorophenyl)piperazine moiety (IC(50) values range from 0.55 to 8.5 nM), with N'-(2-pyrimidyl)piperizine (IC(50) values range from 0.5 to 21.6 nM), with N-N'- L-piperazinocolinamide (IC(50) values range from 0.001 - 0.25 nM), or N-N'-L-piperazinocolin-N-methylamide (IC(50) values range from 0.015 - 7.3 nM).

Microarray-based gene expression analysis of hepatocellular carcinoma

Microarray studies have successfully shed light on various aspects of the molecular mechanisms behind the development of hepatocellular carcinoma (HCC), such as the identification of novel molecular subgroups and the genetic profiles associated with metastasis and venous invasion. These experiments, mainly comprising genome wide profiling, potentially represent the basis of novel targeted therapeutic strategies in HCC. In response, we summarize the multiple reported expression profiles in HCC associated with HCC development, novel subgroups, venous invasion and metastasis.

Genetic variations in the regulator of G-protein signaling genes are associated with survival in late-stage non-small cell lung cancer

The regulator of G-protein signaling (RGS) pathway plays an important role in signaling transduction, cellular activities, and carcinogenesis. We hypothesized that genetic variations in RGS gene family may be associated with the response of late-stage non-small cell lung cancer (NSCLC) patients to chemotherapy or chemoradiotherapy. We selected 95 tagging single nucleotide polymorphisms (SNPs) in 17 RGS genes and genotyped them in 598 late-stage NSCLC patients. Thirteen SNPs were significantly associated with overall survival. Among them, rs2749786 of RGS12 was most significant. Stratified analysis by chemotherapy or chemoradiation further identified SNPs that were associated with overall survival in subgroups. Rs2816312 of RGS1 and rs6689169 of RGS7 were most significant in chemotherapy group and chemoradiotherapy group, respectively. A significant cumulative effect was observed when these SNPs were combined. Survival tree analyses identified potential interactions between rs944343, rs2816312, and rs1122794 in affecting survival time in patients treated with chemotherapy, while the genotype of rs6429264 affected survival in chemoradiation-treated patients. To our knowledge, this is the first study to reveal the importance of RGS gene family in the survival of late-stage NSCLC patients.

Regulator of G-protein signaling (RGS) proteins in cancer biology

The regulator of G-protein signaling (RGS) family is a diverse group of multifunctional proteins that regulate cellular signaling events downstream of G-protein coupled receptors (GPCRs). In recent years, GPCRs have been linked to the initiation and progression of multiple cancers; thus, regulators of GPCR signaling are also likely to be important to the pathophysiology of cancer. This review highlights recent studies detailing changes in RGS transcript expression during oncogenesis, single nucleotide polymorphisms in RGS proteins linked to lung and bladder cancers, and specific roles for RGS proteins in multiple cancer types.

Molecular mechanisms of hepatocellular carcinoma

Hepatocellular carcinoma (HCC) typically has poor prognosis, because it is often diagnosed at an advanced stage. Heterogeneous phenotypic and genetic traits of affected individuals and a wide range of risk factors have classified it a complex disease. HCC is not amenable to standard chemotherapy and is resistant to radiotherapy. In most cases, surgical resection and liver transplantation remain the only curative treatment options. Therefore, development of novel, effective therapies is of prime importance. Extensive research over the past decade has identified a number of molecular biomarkers as well as cellular networks and signaling pathways affected in liver cancer. Recent studies using a combination of "omics" technologies, microRNA studies, combinatorial chemistry, and bioinformatics are providing new insights into the gene expression and protein profiles during various stages of the disease. In this review, we discuss the contribution of these newer approaches toward an understanding of molecular mechanisms of HCC and for the development of novel cancer therapeutics.