Deke Jiang

Human tumor microRNA signatures derived from large‐scale oligonucleotide microarray datasets

The expression profiles of microRNAs (miRNAs) are associated with the initiation and progression of human tumors. DNA microarrays are widely used to explore the expression patterns of miRNAs. Because of the limited sample size and experimental expense, the statistical power of individual research projects is not sufficient to yield a robust conclusion. However, collected microarray datasets of expression profiles provide opportunities to compile the information of individual studies. Our study carried out a comprehensive meta‐analysis of miRNA expression microarray datasets from 28 published tumor studies; it comprises 33 comparisons and nearly 4,000 tumor and corresponding nontumorous samples. This work reports 52 miRNAs as common signatures that are dysregulated in tumors. In addition to the commonly altered miRNAs, five solid cancers displayed specific tissue patterns of altered miRNAs as well. The meta‐analysis also revealed some novel tumor‐related miRNAs such as hsa‐miR‐144, hsa‐miR‐130b, hsa‐miR‐132, hsa‐miR‐154, hsa‐miR‐192 and hsa‐miR‐345. We further validated the expression pattern of hsa‐miR‐154 in human hepatocellular carcinoma by RT‐PCR. Restoration of intracellular miR‐154 inhibited tumor cell malignance and the G1/S transition in cancer cells. Both bioinformatic prediction and western blotting demonstrated that miR‐154 could target CCND2. In addition, expression patterns of miR‐154 were inversely correlated with those of CCND2 in hepatocellular carcinoma. Overall, this study used a large‐scale data analysis to identify a qualified list of miRNAs that are consistently changed in tumors, which could lead to a better understanding of human tumor etiology.

An Insertion/Deletion Polymorphism within RERT-lncRNA Modulates Hepatocellular Carcinoma Risk

The Prolyl hydroxylase 1 (EGLN2) is known to affect tumorigenesis by regulating the degradation of hypoxia-inducible factor. Polymorphisms in EGLN2 may facilitate cancer cell survival under hypoxic conditions and directly associate with cancer susceptibility. Here, we examined the contribution of a 4-bp insertion/deletion polymorphism (rs10680577) within the distal promoter of EGLN2 to the risk of hepatocelluar carcinoma (HCC) in Chinese populations. The contribution of rs10680577 to HCC risk was investigated in 623 HCC cases and 1,242 controls and replicated in an independent case-control study consisting of 444 HCC cases and 450 controls. Logistic regression analysis showed that the deletion allele of rs10680577 was significantly associated with increased risk for HCC occurrence in both case-control studies [OR = 1.40; 95% confidence interval (CI) = 1.18-1.66, P < 0.0001; OR = 1.49; 95% CI = 1.18-1.88, P = 0.0007]. Such positive association was more pronounced in current smokers (OR = 3.49, 95% CI = 2.24-5.45) than nonsmokers (OR = 1.24, 95% CI = 1.03-1.50; heterogeneity P = 0.0002). Genotype-phenotype correlation studies showed that the deletion allele was significantly correlated with higher expression of both EGLN2 and RERT-lncRNA [a long noncoding RNA whose sequence overlaps with Ras-related GTP-binding protein 4b (RAB4B) and EGLN2)] in vivo and in vitro. Furthermore, RERT-lncRNA expression was also significantly correlated with EGLN2 expression in vivo, consistent with in vitro gain-of-function study that showed overexpressing RERT-lncRNA upregulated EGLN2. Finally, in silico prediction suggested that the insertion allele could disrupt the structure of RERT-lncRNA. Taken together, our findings provided strong evidence for the hypothesis that rs10680577 contributes to hepatocarcinogenesis, possibly by affecting RERT-lncRNA structure and subsequently EGLN2 expression, making it a promising biomarker for early diagnosis of HCC.

CYP1B1 and MYOC Mutations in 116 Chinese Patients With Primary Congenital Glaucoma

OBJECTIVES To clinically characterize 116 Chinese patients with primary congenital glaucoma and to determine the role of CYP1B1 and MYOC mutations in this cohort. METHODS This study included 116 unrelated patients with primary congenital glaucoma and 120 ethnically matched, unrelated, healthy controls in China. CYP1B1 and MYOC were amplified from genomic DNA, followed by direct DNA sequencing to identify disease-causing variants. RESULTS Twenty patients (17.2%) had CYP1B1 mutations. Five of these patients had homozygous mutant alleles and 4 had compound heterozygous mutations. Fourteen of the mutations were novel. Three patients (2.6%) had MYOC mutations, all of which were novel. CONCLUSIONS This study describes the spectrum of CYP1B1 and MYOC mutations in a large cohort of Chinese patients with primary congenital glaucoma. The role of mutations in CYP1B1 and MYOC varies, depending on the ethnic origin of the patients. Clinical Relevance Patients with primary congenital glaucoma and CYP1B1 mutations tend to have a more severe phenotype than those without mutations. Genetic testing of CYP1B1 mutations may help predict new cases and their prognoses.

MDM2 SNP309T>G Polymorphism with Hepatocellular Carcinoma Risk: A Meta-analysis

BACKGROUND AND AIMS The murine double minute 2 (MDM2) gene encodes a negative regulator of the tumor protein p53. A single nucleotide polymorphism (SNP) in MDM2 promoter, SNP309 T>G, has been reported to alter MDM2 protein expression and accelerate tumor formation in humans. Studies investigating the association between the polymorphism and human hepatocellular carcinoma (HCC) risk reported conflicting results. We performed a meta-analysis to explore the association of this polymorphism and HCC risk. METHODS All eligible studies published were searched for in PubMed. Crude odds ratios (ORs) with 95% confidence intervals (CIs) were assessed for the association using fixed- and random-effects models. RESULTS We identified five case-control studies including 738 cases and 1014 controls for the present meta-analysis. In studies with limited data, we detected significant associations for all genetic models in the overall analysis (OR = 2.51, 95% CI = 1.88-3.36 for GG vs. TT, p <0.001, P(het) = 0.666; OR = 1.71, 95% CI = 1.35-2.18 for TG vs. TT, p <0.001, P(het) = 0.925; OR = 1.94, 95% CI = 1.54-2.43 for dominant model TG + GG vs. TT, p <0.001, P(het) = 0.772; OR = 1.74, 95% CI = 1.39-2.20 for recessive model GG vs. TT + TG, p <0.001, P(het) = 0.656). Moreover, in the subgroup analysis based on Hardy-Weinberg equilibrium (HWE) in controls, sample size, and ethnicity, significant associations were observed in most genetic models. CONCLUSIONS This meta-analysis suggests that the MDM2 309 G allele probably acts as an important HCC risk factor. To further confirm our findings, well-designed studies with large sample sizes and representing different ethnicities are required.

Zinc finger transcription factor 191, directly binding to β‐catenin promoter, promotes cell proliferation of hepatocellular carcinoma

Activation of β‐catenin, the central effector of the canonical wingless‐type (Wnt) pathway, has been implicated in hepatocellular carcinoma (HCC). However, the transcription regulation mechanism of the β‐catenin gene in HCC remains unknown. Here we report that human zinc finger protein 191 (ZNF191) is a potential regulator of β‐catenin transcription. ZNF191, a Krüppel‐like protein, specifically interacts with the TCAT motif, which constitutes the HUMTH01 microsatellite in the tyrosine hydroxylase (TH) gene ex vivo. We demonstrate that ZNF191 is significantly overexpressed in human HCC specimens and is associated with growth of human HCC cells. Global profiling of gene expression in ZNF191 knockdown human hepatic L02 cells revealed that the important Wnt signal pathway genes β‐catenin and cyclin D1 messenger RNAs (mRNAs) are significantly down‐regulated. In agreement with transcription level, β‐catenin and cyclin D1 proteins are also down‐regulated in transient and stable ZNF191 knockdown L02 and hepatoma Hep3B cell lines. Moreover, significant correlation between ZNF191 and β‐catenin mRNA expression was detected in human HCCs. Promoter luciferase assay indicated that ZNF191 can increase transcription activity of the full‐length β‐catenin (CTNNB1) promoter, and nucleotide (nt)‐1407/‐907 of the CTNNB1 promoter exhibited the maximum transcriptional activity. Electrophoretic mobility shift assay showed that purified ZNF191 protein can directly bind to the CTNNB1 promoter, and the binding region is located at nt‐1254/‐1224. Finally, we demonstrate that the key binding sequence of ZNF191 in vivo is ATTAATT. Conclusion: ZNF191 can directly bind to the CTNNB1 promoter and activate the expression of β‐catenin and its downstream target genes such as cyclin D1 in hepatoma cell lines. This study uncovers a new molecular mechanism of transcription regulation of the β‐catenin gene in HCC. (HEPATOLOGY 2012;55:1830–1839)

HDGF-related protein-3 is required for anchorage-independent survival and chemoresistance in hepatocellular carcinomas

Objective Hepatoma-derived growth factor (HDGF)-related proteins (HRPs) comprise a family of six members and are characterised by a conserved HATH domain. Among the family members, HDGF was the first to be identified as a mitogenic factor and shown to play an important role in hepatocellular carcinoma pathogenesis. The aim of the present study is to examine the relevance of HDGF-related protein-3 (HRP-3), another member of the HRP family in hepatocellular carcinoma (HCC). Design HRP-3 expression in HCC tissues was measured by quantitative reverse transcriptase PCR, western blot and immunohistochemistry analysis. The biological consequences of overexpression and knockdown of HRP-3 in HCC cell lines were studied in vitro and in vivo. Results Expression of HRP-3 mRNA and protein was shown to be highly upregulated in HCC tissues. While knockdown of HRP-3 by small interference RNAs failed to affect anchorage-dependent growth of HCC cells, it inhibited anchorage-independent growth of HCC cells in vitro and xenograft tumour growth in vivo. Further, knockdown of HRP-3 was shown to sensitise HCC cells to anoikis. Moreover, HRP-3 specifically activated the extracellular-signal-regulated kinase (ERK) pathway without affecting c-Jun N-terminal kinase (JNK), p38, AKT and signal transducer and activator of transcription 3 (STAT3). Importantly, inhibition of the ERK pathway diminished HRP-3-mediated protection of HCC cells from anoikis. Finally, knockdown of HRP-3 was shown to enhance apoptosis of HCC cells induced by multiple chemotherapeutic drugs. Conclusion These findings indicate that HRP-3 plays an essential role in HCC pathogenesis and suggest that it may serve as a novel prognostic marker and molecular target for development of drugs for treatment of HCC.

Hepatitis B virus genotype, mutations, human leukocyte antigen polymorphisms and their interactions in hepatocellular carcinoma: a multi-centre case-control study.

Three genome-wide association studies (GWAS) have been conducted on the genetic susceptibility of hepatitis B virus (HBV)-related hepatocellular carcinoma (HCC), two of which consistently identified tagging single nucleotide polymorphisms (SNPs) around HLA-DQ/DR. In contrast, large multi-centre association studies between HBV genotype, mutations and the risk of HCC are relatively rare, and their interactions with host variants are even less. We performed a multi-centre study of 1,507 HBV-related HCC cases and 1,560 HBV persistent carriers as controls to evaluate the effects of HBV genotype, mutations, GWAS-identified HLA-DQ/DR SNPs (rs9272105 and rs9275319) and their interactions on HCC risk. We found HBV genotype C was more frequent in HBV-related HCC. And 11 HBV hotspot mutations were independently and significantly associated with HCC risk. We also detected significant interactions of rs9272105 with both the HBV genotype and mutations. Through stepwise regression analysis, HBV genotype, the 11 mutations, HLA-DQ/DR SNPs, and the interaction of rs9272105 with mutation A1752G were all entered into the HCC prediction model, and the area under the curve for the panel including the HLA-DQ/DR SNPs, HBV genotype and mutations was 0.840. The HBV genotype, the mutations and the HLA-DQ/DR SNPs may serve as biomarkers for the surveillance of HBV persistent carriers.

Genetic variations in STAT4,C2,HLA-DRB1 and HLA-DQ associated with risk of hepatitis B virus-related liver cirrhosis.

Recent genome-wide associated studies (GWASs) have revealed several common loci associated with the risk of hepatitis B virus (HBV)- or hepatitis C virus (HCV)-related hepatocellular carcinoma (HCC). We selected 15 single nucleotide polymorphisms (SNPs) identified through GWASs on HBV- or HCV-related HCC, and genotyped them in two independent Chinese cohorts of chronic HBV carriers, including 712 LC cases and 2601 controls. The association of each SNP with the risk of HBV-related LC was assessed by meta-analysis of the two cohorts. Of the 12 SNPs reported in HBV-related HCC GWASs, five SNPs (rs7574865 in STAT4, rs9267673 near C2, rs2647073 and rs3997872 near HLA-DRB1 and rs9275319 near HLA-DQ), were found to be significantly associated with the risk of HBV-related LC (rs7574865: P = 1.79 × 10−2, OR = 1.17, 95% CI = 1.03–1.34; rs9267673: P = 4.91 × 10−4, OR = 1.37, 95% CI = 1.15–1.63; rs2647073: P = 3.53 × 10−5, OR = 1.63, 95% CI = 1.29–2.06; rs3997872: P = 4.22 × 10−4, OR = 1.86, 95% CI = 1.32–2.62; rs9275319: P = 1.30 × 10−2, OR = 1.32, 95% CI = 1.06–1.64). However, among the three SNPs associated with the risk of HCV-related HCC in previous GWASs, none of them showed significant association with the risk of HBV-related LC. Our results suggested that genetic variants associated with HBV-related hepatocarcinogenesis may already play an important role in the progression from CHB to LC.

Murine double minute 2 promoter SNP309 polymorphism and prostate cancer risk: A meta-analysis

Objective:  The murine double minute 2 gene encodes a negative regulator of the tumor protein p53. A single nucleotide polymorphism in murine double minute 2 promoter, SNP309 T>G, has been reported to alter murine double minute 2 protein expression and to accelerate tumor formation in humans. We carried out a meta‐analysis to explore the association between this polymorphism and prostate cancer risk.

Characterization and expression of HLysG2, a basic goose-type lysozyme from the human eye and testis.

Lysozyme plays an important role in human innate immunity by causing bacterial cell lysis. We describe for the first time, the actual performance of human lysozyme g-like 2 (HLysG2), a mammalian g-type lysozyme. RT-PCR revealed that the HLysG2 gene was transcribed in eye and testis tissues. A spot was detected from human tears using 2D gel electrophoresis and was identified as HLysG2 using MALDI-TOF/TOF MS and a MASCOT search with a matching score of 140 and 27% sequence coverage of the whole amino acid sequence. To gain insight into the in vitro antimicrobial activities of HLysG2, the mature peptide-coding region was cloned into Pichia pastoris for heterogeneous expression. Recombinant HLysG2, had an optimal at pH 6.0 and 30 °C, reached the peak activity of 1.2 × 10(4)U/mg at the sodium ion concentration of 75 mM and showed a higher salt tolerance than human c-type lysozyme (HLysC). Recombinant HlysG2 inhibited Gram-positive bacterial growth and did not inhibit Gram-negative bacterial and Candida albicans growth. Results indicated that HLysG2 is a potent antibacterial protein that may play a role in the innate immunity of the human eye.