Active radar guides missile to its target: receptor-based targeted treatment of hepatocellular carcinoma by nanoparticulate systems.

Patients with hepatocellular carcinoma (HCC) usually present at advanced stages and do not benefit from surgical resection, so drug therapy should deserve a prominent place in unresectable HCC treatment. But chemotherapy agents, such as doxorubicin, cisplatin, and paclitaxel, frequently encounter important problems such as low specificity and non-selective biodistribution. Recently, the development of nanotechnology led to significant breakthroughs to overcome these problems. Decorating the surfaces of nanoparticulate-based drug carriers with homing devices has demonstrated its potential in concentrating chemotherapy agents specifically to HCC cells. In this paper, we reviewed the current status of active targeting strategies for nanoparticulate systems based on various receptors such as asialoglycoprotein receptor, transferrin receptor, epidermal growth factor receptor, folate receptor, integrin, and CD44, which are abundantly expressed on the surfaces of hepatocytes or liver cancer cells. Furthermore, we pointed out their merits and defects and provided theoretical references for further research.

The emerging role of miR-375 in cancer.

MicroRNAs (miRNAs) are evolutionarily conserved, small noncoding RNAs that are believed to play fundamental roles in various biological processes through regulation of gene expression at the level of posttranscription. MiR-375 was first identified as a pancreatic islet-specific miRNA regulating insulin secretion. However, further study revealed that miR-375 is a multifunctional miRNA participating in pancreatic islet development, glucose homeostasis, mucosal immunity, lung surfactant secretion and more importantly, tumorigenesis. Recently, miR-375 has been found significantly downregulated in multiple types of cancer, and suppresses core hallmarks of cancer by targeting several important oncogenes like AEG-1, YAP1, IGF1R and PDK1. The alteration of miR-375 in cancer is caused by a variety of mechanisms, including the dysregulation of transcription factors, aberrant promoter methylation and so on. Reduced expression of miR-375 in tissue or circulation may indicate the presence of neoplasia as well as a poor prognosis of many malignant cancers. Moreover, miR-375 stands for a promising direction for developing targeted therapies due to its capacity to inhibit tumor cell growth in vitro and in vivo. Here, we summarize the present understanding of the tumor suppressive role of miR-375 in cancer progression; the mechanisms underlying the dysregulation of miR-375; the potential use of miR-375 in prognosis and diagnosis and the therapeutic prospects of miR-375 in cancer.

Pilot validation of the Boston Bowel Preparation Scale in China.

BACKGROUND AND AIM: The Boston Bowel Preparation Scale (BBPS) is a novel bowel cleanliness rating scale that has undergone validation at Boston University Medical Center, Boston, MA, USA. Thus far, there is no standard recognized bowel preparation scale in China. The aim of the present study was to analyze the reliability and validity of the BBPS for the assessment of bowel preparation quality (BPQ) in China. METHODS: A group of 49 participants from several hospitals in Guangdong province viewed a video demonstration of BBPS provided by Boston Medical Center and participated in a continuing education seminar. Inter-observer reliability was assessed for three testing colonoscopies in the video. Three months later, 13 of the participants repeated the test, and intra-observer reliability was assessed. The BBPS was then applied prospectively in 1012 screening colonoscopies and BBPS scores were compared with polyp-detection rate. Intraclass correlation coefficients (ICC) and weighted Kappa values assessed inter- and intra-rater reliability, respectively. The association of BBPS scores with polyp-detection rates was calculated by χ(2) tests. RESULTS: The inter-observer ICC of BBPS scores was 0.987 (95% CI, 0.949-1.0). The weighted Kappa for BBPS scores was 0.671 (95%CI, 0.507-0.841). For 1012 screening colonoscopies, the mean BBPS score was 6.9 ± 1.8. BBPS scores ≥ 5 were associated with a higher polyp-detection rate (35%) than scores < 5 (18%) (P < 0.05). CONCLUSION: The BBPS is a valid and reliable measure of BPQ, and this validity and reliability was maintained for Chinese physicians taught via video.

Downregulation of MiR-93 expression reduces cell proliferation and clonogenicity of HepG2 cells.

BACKGROUND/AIMS: MiR-93 was observed in various types of cancers. This study is to investigate a role of miR-93 in the carcinogenesis of HCC. METHODOLOGY: The expression of miR-93 in HepG2 cells and prima-ry human hepatocytes (PHHC) was measured by RT-PCR. HepG2 cells were transfected with miR-93 inhibitor or negative control. The cell proliferation was determined by using the CellTiter 96® Aqueous One Solution Cell Proliferation Assay kit. The migration and clonogenicity in vitro were measured by cell migration assay, colony formation analysis and anchorage-in-dependent growth assay. The apoptosis and cell cycle were detected by flow cytometry analysis. The mRNA and protein levels of transforming growth factor-beta type II receptor (TGFBR2) and integrin beta8 (ITGB8)were evaluated by RT-PCR and western blot analysis. RESULTS: MiR-93 was upregulated in HepG2 cells compared with PHHC and inhibition of miR-93 significantly suppressed HepG2 cell proliferation, migration and col-ony formation. The expressions of TGFBR2 and ITGB8 were upregulated when miR-93 was inhibited. CONCLUSIONS: Our results reveal an important contribution for miR-93 in hepatocarcinogenesis and suggest a role for TGFBR2 and ITGB8 dysregulation in this process. Thus,the use of synthetic inhibitor of miR-93 may prove to bea promising approach to liver cancer treatment.

MiR-192 inhibits nucleotide excision repair by targeting ERCC3 and ERCC4 in HepG2.2.15 cells.

Deficient DNA repair capacity is associated with genetic lesions accumulation and susceptibility to carcinogenesis. MicroRNAs (miRNAs) are small non-coding RNAs that regulate various cellular pathways including DNA repair. Here we hypothesized that the existence of HBV products may interfere with cellular nucleotide excision repair (NER) through microRNA-mediated gene regulation. We found that NER was impaired in HepG2.2.15 cells, a stable HBV-expressing cell line, compared with its parental cell line HepG2. Altered miRNA expression profile, in particular the significant upregulation of miR-192, was observed in HepG2.2.15 cells. Additionally, ERCC3 and ERCC4, two key factors implicated in NER, were identified as targets of miR-192 and over-expressing miR-192 significantly inhibited cellular NER. These results indicated that persistent HBV infection might trigger NER impairment in part through upregulation of miR-192, which suppressed the levels of ERCC3 and ERCC4. It provides new insight into the effect of chronic HBV infection on NER and genetic instability in cancer.

[HBx gene down-regulates miR-192 expression and inhibits apoptosis of human hepatoma cell line HepG2].

OBJECTIVE: To explore the mechanism by which HBV X gene(HBx) inhibits apoptosis of human hepatoma cell line HepG2 in terms of miRNA. METHODS: Three cell lines were prepared: HepG2 cells stably transfected with HBx (HepG2/HBx), HepG2 cells stably transfected with pcDNA3.1 (HepG2/pcDNA3.1) and HepG2 cells. Flow cytometry was adopted to measure the apoptosis of these three cells and Taqman fluorescence quantitative PCR was used to examine miR-192 expression. After HepG2 cells was transfected with miR-192, the apoptosis was analyzed by flow cytometry and the expressions of p53 and PUMA at mRNA and protein levels were evaluated by SYBR Green quantitative PCR and Western blot, respectively. RESULTS: Compared with HepG2/pcDNA3.1 cells (11.46% ± 0.69%) and HepG2 cells (12.5% ± 0.66%), the apoptosis rate of HepG2/HBx cells (2.37% ± 0.35%) was significantly reduced (F = 171.722, P < 0.01). The level of miR-192 was 49.1% ± 5.9% in HepG2 cells, which was dramatically down-regulated (F = 14.319, P = 0.019) as compared to the other two groups (HepG2/pcDNA3.1: 98.0% ± 8.9%; HepG2: 100%). Compared with HepG2 cells transfected with miR-NC (10.74% ± 1.15%), transfection of miR-192 into HepG2 cells led to increased apoptosis (15.74% ± 1.17%) (F = 18.415, P = 0.013) and higher p53 and PUMA expressions at mRNA (p53: 1.68 ± 0.12 vs 0.90 ± 0.09, F = 43.115, P = 0.003, PUMA: 1.66 ± 0.10 vs 0.98 ± 0.06, F = 22.541, P = 0.009) and protein (p53: 3.07 vs 1, PUMA: 2.13 vs 1) levels. CONCLUSION: HBx could inhibit apoptosis of HepG2 cells through down-regulation of miR-192 which induces apoptosis of HepG2 cells.

[The effect of hepatitis B virus X protein on the expression of CtIP in HepG2 Cells].

To investigate the effect of hepatitis B virus X protein(HBx) on CtBP-interacting protein(CtIP) which is an important repair factor of DNA double strand break damage in HepG2 cells induced by bleomycin. A HBx stably expressing HepG2 cell line and a control HepG2 cell line with empty vector transfected were established. After the double strand break (DSB) damage occurred, the mRNA and protein levels of CtIP were detected by Real-time PCR and Western blot assay respectively, cell cycle profiles and apoptotic cell death were determined by a flow cytometry, and the position of CtIP in cells was observed by confocal laser scanning microscopy. It showed that HepG2 cells transfected with hepatitis B virus X gene could stably express HBx protein. After being induced by bleomycin, the percentage of apoptotic cell was 16.90%+/-0.89% in HBx stably expressing HepG2 cell line and 15.30%+/-0.86% in control cell line, respectively (q = 2.074, P is more than to 0.05). While the percentage of death cell was 8.71%+/-0.74% in HBx stably expressing HepG2 cell line and 4.90%+/-0.46% in control cell line, respectively (q = 7.126, P is less than to 0.01). The two cell lines manifested the increase of G2/M arrest and significant difference existed between the two cell lines. HBx down regulated the expression levels of CtIP and its mRNA. The CtIP level was 0.66+/-0.04 in HepG2-HBx cell and 0.73+/-0.05 in HepG2-vec cell, respectively (t = 2.314, P is less than to 0.05). The relative mRNA level was 1.00+/-0.06 in HepG2-HBx cell and 1.23+/-0.08 in HepG2-vec cell, respectively (t = 2. 732, P is less than to 0.05). We also found that CtIP was concentrated in the cell nucleus. The research suggests that HBx may affect DNA-repair pathways by disrupting the expression of CtIP.

Hepatic stellate cell-specific gene silencing induced by an artificial microRNA for antifibrosis in vitro.

BACKGROUND: We previously reported that the anti-transforming growth factor-beta1 (TGF-beta1) ribozymes directed by T7 and CMV promoters could reverse the character of activated hepatic stellate cells (HSCs) in vitro and improve fibrotic pathology in vivo. However, nonspecific elimination of the effects of TGF-beta1 without selectivity might have unfavorable consequences, such as overwhelming inflammation, tissue necrosis, etc. AIMS: To establish an activated-HSC-specific gene silencing method and validate its feasibility for antifibrosis in vitro. METHODS: An artificial intronic microRNA (miRNA) expression system was established, containing three parts: (1) a 1,074-bp SM-alpha actin promoter SMP8, which is a kind of RNA polymerase II promoter and has no activity in normal liver-derived cells but is switched on during the activation of HSCs, (2) intron1 modified by inserting an artificial pre-miRNA sequence against TGF-beta1, and (3) report gene enhanced green fluorescent proteins (EGFP). The feasibility of this system for artificial microRNA expression was validated through microRNA detection by real-time polymerase chain reaction (PCR). Alteration of biological characteristics of HSCs with the anti-TGF-beta1 miRNAs was preliminarily evaluated by measuring the expression levels of TGF-beta1 and its downstream molecules, including collagen I, matrix metalloproteinase 2 (MMP2), tissue inhibitor of metalloproteinase 1 (TIMP-1), etc. RESULTS: The microRNA expression system could successfully produce mature anti-TGF-beta1 miRNAs in an activated-HSC-specific manner. The microRNA-induced inhibition rate of TGF-beta1 reached 70% and above. Accompanied by TGF-beta1 suppression, its downstream targets such as collagen I, MMP2, TIMP-1, etc. were also significantly downregulated in vitro. CONCLUSIONS: Activated-HSC-cell-specific gene silencing could be induced well by the artificial intronic microRNA expression system to realize antifibrosis in vitro.

[The imprinting status of genetic imprinted gene PEG10 in human hepatocellular carcinomas].

OBJECTIVE: To study the imprinting status of genetic imprinted gene PEG10 (perternally expressed gene 10) in human hepatocellular carcinoma (HCC) tissues and liver cancer cell lines. METHODS: Genomic DNA was extracted from 20 HCC tissues and its adjacent tissues, 15 normal liver tissues, 5 liver cancer cell lines (PLC/PRF/5, smmc-7721, HepG2, Hep3B, SK-HEP-1) and 2 normal human liver cell lines (changliver, HL7702). The DNA fragments containing single nucleotide polymorphism (SNP) site of PEG10 were amplified by polymerase chain reaction (PCR) and the genotype of samples was detected by DNA sequencing. Total RNA was extracted from heterozygous samples, the imprinting status and expression level of PEG10 were evaluated by quantitative real time reverse transcription-polymerase chain reaction (qRT-PCR) and DNA sequencing. RESULTS: It was found that 16/40 of HCC and its adjacent tissues were heterozygous, 3/15 of normal liver tissue were heterozygous. A site of heterozygous mutation was found in HepG2 cells by DNA sequencing. The other liver tissues and cell lines were all homozygous. PEG10 was biallelically expressed and showed loss of imprinting (LOI) in 82.4% (14/17) liver cancer samples (16 HCC tissues and HepG2), however it was a monoallelic expression and showed genomic imprinting in17.6% (3/17) liver cancer samples. In HCC, the expression levels of PEG10 were increased apparently, but it was negative expressed in cancer adjacent tissues and normal liver tissues. Expression levels of PEG10 were not significantly different between imprinted HCC tissues and HCC tissues with LOI (t = 1.311, P value is more than 0.05). CONCLUSION: PEG10 imprinting is lost in a majority of HCC and no correlation exists between the imprinting status of PEG10 and its expressions in HCC tissues.

[MiR-122 regulates the expression of PEG10 in hepatoma cell lines].

OBJECTIVE: Our previous work indicated that overexpression of imprinting gene PEG10 is associated with malignant phenotype of hepatocellular carcinoma. The aim of this study is to explore whether disregulation of PEG10 leads to dysregulation of microRNAs. METHODS: In silico analysis using TargetScan indicated that miR-122 could regulate the expression of PEG10. The expression of miR-122 in three hepatoma cell lines, Huh7, Hep3B and HepG2 and in primary human normal liver cell were compared using real time RT-PCR. After pre-miR-122 was transfected into HepG2 cell, the levels of PEG10 mRNA and protein were measured. RESULTS: In silico analysis revealed that miR-122 could regulate the expression of PEG10. Real time RT-PCR indicated that miR-122 was not expressed in Hep3B and HepG2 cells, and only weakly expressed in Huh7 cells, but highly expressed in primary human normal liver cells. The expression of miR-122 was negatively correlated with the expression of PEG10. After pre-miR122 was transfected into HepG2, the mRNA level of PEG10 was not increased, whereas the protein level of PEG10 was increased. CONCLUSION: miR-122 may be involved in regulation of PEG10 expression.

miR-30a-3p inhibits the proliferation of liver cancer cells by targeting DNMT3a through the PI3K/AKT signaling pathway.

MicroRNAs (miRNAs or miRs) are crucial for normal development and maintenance of homeostasis. Dysregulated miRNA expression contributes to numerous pathological conditions, including cancer tumorigenesis. However, a limited number of studies have examined the regulatory effects of miR-30a-3p in tumorigenesis. Therefore, the present study investigated the mechanistic process of tumorigenesis in liver cancer. The results revealed a high expression of DNA methyltransferase 3a (DNMT3a) and a low expression of miR-30a-3p in HepG2 cells compared with that in the L02 cell line. A luciferase reporter assay demonstrated that DNMT3a is a direct target of miR-30a-3p. In addition, DNMT3a overexpression significantly enhanced cell proliferation, which was reversed by a miR-30a-3p mimic. Similarly, the miR-30a-3p mimic blocked DNMT3a-triggered cell cycle processes and apoptosis by attenuating active p-AKT and p-PI3K in HepG2 cells. In summary, the results of the present study demonstrate that miR-30a-3p is essential for cell proliferation regulation via its association with AKT/PI3K signaling in liver cancer. These results provide insight into the molecular mechanism by which miR-30a-3p inhibits liver cancer cell proliferation and provides a foundation for its clinical development and application.

[Establishment of PEG10 transgenic mouse and effects of PEG10 on growth, metastasis of transplanted tumor in mice].

OBJECTIVE: To establish PEG10 transgenic mice model and study the effect of PEG10 transgene on tumor growth and metastasis in mice. METHODS: The linearized expression element of pALB-PEG10, which contained mouse albumin promoter, structural gene of PEG10, and polyaenylation signal sequence, was microinjected into 3741 KM mouse fertilized ova. The manipulated embryos were then transplanted into the oviducts of 94 pseudopregnant recipient mice. All the newborn mice were screened by PCR to detect genomic DNA in tail tissue, then PEG10 mRNA and protein expression were detected by RT-PCR and western blot, respectively in the positive mice. Hepatoma cell H22 was subcutaneously inoculated into the right armpit of wild type mice and No.17, No.33 transgenic mice. Tumor size was measured every week. Mice were sacrificed on day 12 and then the tumors were exercised and weighted. Tumors and livers were fixed in formaldehyde and sectioned. The sections were stained with hematoxylin/eosin and examined under microscope. The expression of PEG10 protein was detected with immunohistochemistry method. RESULTS: Among the 43 off-springs, 3 were positive for tail tissue PEG10 gene examination, PEG10 was successfully expressed in the liver of the randomly selected transgenic mouse. H22 tumor grew faster in all the transgenic mice than in wild type mice. The average size and weight of tumors between the transgenic mice and wild type mice were significantly different (P < 0.05). Most tumors in the transgenic mice invaded the surrounding tissues and showed liver metastasis, PEG10 protein was expressed in liver. In contrast, nearly all the tumors in wild type mice were capsulized and PEG10 was not expressed in liver. CONCLUSION: Our results showed that the PEG10 gene could be expressed in the liver of the transgenic mice. PEG10 promotes growth, invasion, and metastasis of transplanted H22 tumors in mice.

[Insertion of TC motif into hepatitis B virus core protein c/e1 site does not affect the expression of S and e antigen].

OBJECTIVE: To investigate whether insertion of TC motif into hepatitis B virus (HBV) core protein c/e1 site affects the expression of S and e antigen. METHODS: Different oligonucleotides encoding TC motif were inserted into the c/e1 site of the core gene of a 1.3 copy wild-type HBV genome vector. HepG2 cells were divided into several groups of cells to transiently transfect with the wild-type and mutant HBV vectors, respectively. In each group, the expression level of core protein inside cells was detected by western blotting, and the levels of S and e antigen in culture medium were analyzed by ELISA assay. RESULTS: Western blotting showed that these TC-tagged core proteins were expressed at similar level of wild-type one. ELISA assay indicated that the level of S and e antigen in culture medium of different groups were not significantly different. CONCLUSION: Insertion of TC motif into HBV core protein c/e1 site does not interference with the expression of viral protein encoded by HBV genome.

Inhibition of the replication of hepatitis B virus in vitro by a novel 2,6-diaminopurine analog, beta-LPA.

Antiviral therapy of chronic hepatitis B remains a major clinical problem worldwide. Like lamivudine, nucleoside analogs have become the focus of investigation of anti-hepatitis B virus (anti-HBV) drugs. Here, beta-LPA is a novel 2,6-diaminopurine analog found to possess potent anti-HBV activity. In HepG2.2.15 cell line, beta-LPA had a 50% effective concentration (EC(50)) of 0.01 microM against HBV, as determined by analysis of secreted and intracellular episomal HBV DNA. Levels of HBV surface antigen (HBsAg) and e antigen (HBeAg) in drug-treated cultures revealed that beta-LPA had no significant inhibitory effects on HBsAg and HBeAg. beta-LPA didn't show any cytotoxicity up to 0.4 microM with a 50% cytotoxic concentration (CC(50)) of 50 microM. Furthermore, treatment with beta-LPA resulted in no apparent inhibitory effects on mitochondrial DNA content. Considering the potent inhibition of HBV DNA synthesis and no obvious toxicity of beta-LPA, this compound should be further explored for development as an anti-HBV drug.

Efficacies of beta-L-D4A against Hepatitis B virus in 2.2.15 cells.

AIM: To investigate the antiviral effect of beta-L-enantiomer of 2',3'-didehydro-2',3'-dideoxyadenosine (beta-L-D4A) on 2.2.15 cells transfected with the hepatitis B virus (HBV) genome. METHODS: Lamivudine (3TC) as a positive control. Then, HBV DNA in treated 2.2.15 cells and the Hepatitis B surface antigen (HBsAg) in the culture supernatants were detected to determine the inhibitory effect of beta-L-D4A. At the same time, 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) was used to detect the survival ratio of 2.2.15 cells. RESULTS: beta-L-D4A has a dose-dependent inhibitory effect on HBV DNA replication; this effect was apparent when the concentration was above 1 mol/L. When beta-L-D4A was at the highest concentration, 100 mol/L, the HBsAg inhibition ratio was above 50%. The Therapeutic index (TI) of beta-L-D4A was above 2.1. CONCLUSION: beta-L-D4A has a dose-dependent inhibitory effect on the replication of HBV DNA and the secretion of HBsAg at low toxicity.

Effects of two novel nucleoside analogues on different hepatitis B virus promoters.

AIM: To explore the effects of the nucleoside analogues beta-L-D4A and beta-LPA on hepatitis B virus (HBV) promoters. METHODS: Four HBV promoters were amplified by polymerase chain reaction (PCR) and subcloned into the expression vector pEGFP-1. The four recombinants controlled by HBV promoters were confirmed by restriction analysis and sequencing. Human hepatoma HepG2 cells transfected with the recombinant plasmids were treated with various concentrations of beta-L-D4A and beta-LPA. Then, enhanced green fluorescent protein (EGFP)-positive cells were detected by fluorescence microscopy and using a fluorescence activated cell sorter (FACS). RESULTS: Four HBV promoters were separately obtained and successfully cloned into pEGFP-1. Expression of EGFP under the control of the surface promoter (Sp) and the X promoter (Xp) was inhibited by beta-L-D4A in a dose-dependent manner, while expression of EGFP under the control of the core promoter (Cp) and Xp was inhibited by beta-LPA in a dose-dependent manner. CONCLUSION: The two novel nucleoside analogues investigated here can inhibit the activities of HBV promoters in a dose-dependent manner. These findings may explain the mechanisms of action by which these two novel compounds inhibit HBV DNA replication.

[Establishment of an I-SceI system and its application to introduce DNA double-strand break into human hepatoma cell line HepG2].

OBJECTIVE: To construct a system of I-SceI and induce a site-specific DNA double-strand break (DSB) in the genome of HepG2 for using this system in future exploration of the potential mechanisms of HBV integration by DSB repair. METHODS: The eukaryotic expression plasmid pEGFP2 was constructed and transfected into human hepatoma cell line HepG2. The positive neomycin-resistant transfected cell clones were generated by G418 selection. Then the positive cells containing an 18-bp I-SceI endonuclease site were transfected transiently with pCMV(3NLS) I-SceI, an I-SceI expression plasmid. At 24 h post-transfection with pCMV (3NLS) I-SceI, gamma-H2AX, as an early cellular marker of DSB, was detected using immunocytochemistry and Western blot analysis. RESULTS: Restriction analysis and DNA sequencing verified that the plasmid pEGFP2 was successfully constructed. gamma-H2AX increased significantly in cells transfected with the I-SceI system. CONCLUSIONS: Genomic DSB can be induced into HepG2 by introducing an I-SceI system. The cell model could provide us with a practical tool for further study to see if DSB is a potential target for HBV integration.

The ASH1-miR-375-YWHAZ Signaling Axis Regulates Tumor Properties in Hepatocellular Carcinoma.

Hepatocellular carcinoma (HCC) is a worldwide malignance, and the underlying mechanisms of this disease are not fully elucidated. In this study, the existence and function of achaete-scute homolog-1 (ASH1)-miR-375-YWHAZ signaling axis in HCC were determined. Our experiments and the Cancer Genome Atlas (TCGA) sequencing data analyses showed that ASH1 and miR-375 were significantly downregulated, whereas YWHAZ was significantly upregulated in HCC. Furthermore, we found that ASH1 positively regulates miR-375, and miR-375 directly downregulates its target YWHAZ. Gain- and loss-of-function study demonstrated ASH1 and miR-375 function as tumor suppressors, whereas YWHAZ acts as an oncogene in HCC. Animal experiment indicated that YWHAZ small interfering RNAs (siRNAs) (si-YWHAZ) delivered by nanoliposomes could suppress the growth of hepatoma xenografts and was well tolerant by nude mice. Further studies revealed that YWHAZ was involved in several protein networks, such as cell autophagy, epithelial-mesenchymal transition (EMT), apoptosis, cell cycle, invasion, and migration. In addition, the patient group with ASH1-high-expression-miR-375-high-expression-YWHAZ-low-expression was correlated with a better clinical prognosis compared with the opposite expression group. In conclusion, we proved the existence of ASH1-miR-375-YWHAZ signaling axis and interpreted its important role in driving HCC tumor progression.

DNA methyltransferase 3B promoter polymorphism and its susceptibility to primary hepatocellular carcinoma in the Chinese Han nationality population: a case-control study.

AIM: To investigate the correlation between C/T single nucleotide polymorphism (SNP) in the promoter of the DNA methyltransferase 3B (DNMT3B) gene and risk for development and progression of primary hepatocellular carcinoma (HCC). METHODS: One hundred case subjects were selected consecutively from Tongji Hospital (Wuhan, China). from March to November 2006. They did not receive radiotherapy or chemotherapy for newly diagnosed and histopathologically confirmed HCC. One hundred and forty control subjects having no history of cancerous or genetic diseases were healthy volunteers to Wuhan Blood Center in the same period. Frequency was matched for sex, age, alcohol consumption and cigarette smoking status of the case subjects. C/T polymorphism of the DNMT3B promoter was analyzed using polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) and sequencing analysis. The association between genotypes of DNMT3B and clinicopathological parameters among cases was also studied. RESULTS: The CC genotype was not detected in both HCC patients and controls. In control subjects, the frequency of TT and CT genotypes was 99.3% and 0.7% respectively, and that of T and C alleles was 99.6% and 0.4% respectively. The frequency of CT genotype was higher in HCC (3.0%). The frequency of T and C alleles was 98.5% and 1.5% respectively. However, the genotype and allelotype distribution in HCC patients was not significantly different from that in controls. CONCLUSION: C/T polymorphism is not associated with the increased risk of HCC. DNMT3B genetic polymorphism is variable in different races, ethnic groups or geographic areas. Further study is needed to clarify the role of DNMT3B SNP in the development of HCC among other populations.

Effect and mechanism of beta-L-D4A on DNA polymerase alpha.

AIM: To investigate the safety of beta-L-D4A on DNA polymerase alpha. METHODS: Ion exchange chromatography was used to separate DNA polymerase alpha from crude extract of human Hela cells. Detailed kinetic parameters were determined for beta-L-D4A against DNA polymerase alpha. RESULTS: DNA polymerase alpha was purified with 4% yield and 31000 units/mg specific activity. The Michaelis constant (Km = 3.22 micromol/L), 50% inhibition concentration (IC50 = 178.49 micromol/L) and inhibition constant (Ki = 126 micromol/L) of beta-L-D4A were determined by kinetic analysis. CONCLUSION: beta-L-D4A is a more safe nucleoside for hepatitis B virus infection with a lower host toxicity.