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.

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.

miR-195 inhibits cell proliferation via targeting AEG-1 in hepatocellular carcinoma.

Emerging evidence has indicated that microRNAs (miRNAs) are frequently dysregulated and are fundamental in the pathogenesis of hepatocellular carcinoma (HCC). However, the roles of miR-195 in HCC have not been well elucidated. In the present study, the expression of miR-195 was determined to be markedly downregulated in HCC tissues and cell lines, as compared with normal liver cells. Restoration of miR-195 expression resulted in significant inhibition of the proliferation and tumorigenicity of HCC cells in vitro and in vivo. Gene expression data and luciferase reporter assays revealed that miR-195 is able to directly inhibit the expression of astrocyte elevated gene 1 (AEG-1) through interaction with its 3' untranslated region. Consistently, an inverse correlation between miR-195 and AEG-1 expression was observed in HCC tissues. Furthermore, the overexpression of AEG-1 was able to partially attenuate the miR-195-induced inhibition of cell growth and promotion of apoptosis. Taken together, these findings indicate that miR-195 functions as a tumor suppressor by inhibiting AEG-1. This pathway may provide new insights into the potential molecular mechanisms of HCC.

Gold nanoparticles delivered miR-375 for treatment of hepatocellular carcinoma.

MiR-375 is a tumor suppressor miRNA that is downregulated in hepatocellular carcinoma (HCC). However, due to the lack of effective delivery strategies, miR-375 replacement as a therapy for HCC has not been investigated. In the present study, we have developed a straightforward strategy to deliver miR-375 into HCC cells by assembling miR-375 mimics on the surface of AuNPs and forming AuNP-miR-375 nanoparticles. AuNP-miR-375 exhibits high cellular uptake and preserves miR-375's activities to suppress cellular proliferation, migration/invasion, and colony formation, and to induce apoptosis in HCC cells. Furthermore, AuNP-delivered miR-375 efficiently downregulated its target genes through RNA interference. In primary and xenograft tumor mouse models, AuNP-miR-375 showed high tumor uptake, therapeutic efficacy, and no apparent toxicity to the host mice. In conclusion, our findings indicate that AuNPs is a reliable strategy to deliver miR-375 into HCC cells and tissue, and that AuNP-miR-375 has the potential in the clinic for treatment of unresectable HCC.

Mcl-1 as a potential therapeutic target for human hepatocelluar carcinoma.

Hepatocellular carcinoma (HCC) is a major cause of cancer-related mortality in part due to its high resistance to chemotherapeutic drugs. The anti-apoptotic Mcl-1 expression has been reported as a resistance factor in various types of tumors. Here, we investigated the expression of Mcl-1 in hepatoma cells and HCC tissues and its relationship with p53, and analyzed the possibility of the gene as a molecular target for HCC therapy. HCC specimens of 30 patients were examined by immunohistochemistry for Mcl-1 and p53 expression. Mcl-1 expression in hepatoma cell lines was measured by RT-PCR and Western blotting. The suppression of Mcl-1 by RNA interference or specific phosphatidylinositol-3 kinase (PI3K) inhibitor, LY294002, was evaluated as monotherapy, and it was combined with mitomycin C (MMC) in treating hepatoma cell line HepG2. Cell viability and apoptosis were assessed by MTT and FACS analysis. Finally, changes of Mcl-1 or p53 expression in various hepatoma cell lines were examined after transfection with Mcl-1 siRNA, the Mcl-1 expression plasmid, or the wide-type p53 expression plasmid, respectively. Mcl-1 protein was remarkably enhanced in HCC tissues as compared with adjacent non-tumor liver tissues. In addition, Mcl-1 was prominently expressed in HepG2 and Hep3B cells, weakly in SMMC7721 cells, and not in L02 cells. P53 protein was also overexpressed in HCC tissues and there was a significant correlation between the expression of p53 and Mcl-1. Silencing Mcl-1 by RNAi or LY294002 downregulated Mcl-1 expression and led to decreased cell viability and increased apoptosis. Combination of MMC and Mcl-1 RNAi or LY294002 exhibited a significant chemosensitizing effect. The expression of p53 was not influenced by Mcl-1 siRNA in HepG2 cells or transfection with the Mcl-1 expression plasmid in L02 cells. Furthermore, the expression of Mcl-1 in Hep3B cells was also not significantly changed after transfection with the wild-type p53 expression plasmid. It is concluded that Mcl-1 is overexpressed in HCC tissues. The mechanisms by which silencing Mcl-1 sensitizes hepatoma cells towards chemotherapy may be not attributed to the upregulated expression of p53 but the dysfunction of p53 through Mcl-1/p53 interaction. Mcl-1 may be a potential target of gene therapy for HCC.

MiR-497 suppresses angiogenesis and metastasis of hepatocellular carcinoma by inhibiting VEGFA and AEG-1.

Hepatocellular carcinoma (HCC) is a worldwide malignance and displays marked vascular abnormalities and active metastasis. MicroRNAs (miRNAs) have been shown to play important roles in regulating tumor properties in cancer, however, whether miR-497 contributes to HCC angiogenesis or metastasis remains unclear. In this study, we found that miR-497 was significantly down-regulated in HCC tissue samples and cell lines. Gain-of-function and loss-of-function studies revealed that miR-497 could repress both the pro-angiogenic and metastatic ability of HCC cells. Subsequent investigations disclosed that miR-497 directly inhibited the 3'-untranslated regions (UTRs) of vascular endothelial growth factor A (VEGFA) and astrocyte elevated gene-1 (AEG-1). Furthermore, overexpression of these targets antagonized the function of miR-497. Based on nude mouse models, we demonstrated that overexpression of miR-497 significantly repressed microvessel densities in xenograft tumors and reduced pulmonary metastasis. In conclusion, our findings indicate that miR-497 downregulation contributes to angiogenesis and metastasis in HCC.

The regulation of microRNA expression by DNA methylation in hepatocellular carcinoma.

UNLABELLED: Emerging evidence indicates that microRNAs (miRNAs) are often dysregulated and play a fundamental role in hepatocellular carcinoma (HCC). However, the mechanism underlying miRNA dysregulation is still elusive. In the present study, we adopted an integrated analysis strategy combining data from genome-wide methylated DNA immunoprecipitation chip and miRNA expression microarray to study the regulation of DNA methylation on miRNA expression in HCC. We first characterized 864 differentially methylated regions (DMRs) located in 236 miRNA regions between cancerous and normal hepatocytes in HCC. We observed that the occurrence of miRNA DNA hypomethylation was more common than its hypermethylation while miRNA DNA hypermethylation was usually found in CpG islands. Then through correlation analysis between miRNA methylation and expression data, we identified 10 dysregulated miRNAs under the potential regulation of DNA methylation in HCC. Five of them (miR-148a, miR-375, miR-195, miR-497 and miR-378) were in hypermethylation and down-regulation status, while another five (miR-106b, miR-25, miR-93, miR-23a and miR-27a) were in hypomethylation and up-regulation status in HCC. Bioinformatics analysis showed that miR-148a may form a negative feedback loop with its targets DNMT1 and DNMT3B and the expression of the miR-195/497 cluster may be affected not only by their hypermethylated promoter region but also by their hypermethylated transcription factors NEUROG2 and DDIT3. CONCLUSION: our preliminary data and bioinformatics analysis suggest that DNA methylation plays an important and complex role in the regulation of miRNA expression in HCC, which may provide insights into the pathogenesis of HCC and thus may be used for diagnosis and intervention.

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.

Bioinformatics analysis identifies miR-221 as a core regulator in hepatocellular carcinoma and its silencing suppresses tumor properties.

Hepatocellular carcinoma (HCC) is a worldwide malignancy; however, there is a lack of effective targeted therapies. We and others have found that miR-221 is one of the most consistently overexpressed miRNAs in liver cancer. However, the roles of miR-221 in hepatocellular carcinogenesis are still not fully elucidated. In the present study, we used bioinformatics tools, gain- and loss-of-function methods to determine the roles of miR-221 in HCC. Bioinformatics analysis showed that miR-221 is a core miRNA which targets a large number of HCC-related genes and has formed many feed-forward regulatory loops combining transcription factors (TFs) to regulate HCC-related genes. Inhibition of miR-221 in liver cancer cells decreased cell proliferation, clonogenicity, migration/invasion and also induced G1 arrest and apoptosis. In addition, we demonstrated that miR-221 bound directly to the 3'-untranslated region of BMF, BBC3 and ANGPTL2, and inhibited the expression of BMF, BBC3 and ANGPTL2. In a mouse model, lentivirus­mediated miR-221 silencing could significantly suppress the growth of hepatoma xenografts in nude mice. In conclusion, we showed that miR-221 is a critical modulator in the HCC signaling pathway, and miR-221 silencing inhibits liver cancer malignant properties in vitro and in vivo, which may benefit the treatment for patients with unresectable HCC.

Influence of cytotoxic T lymphocyte-associated antigen 4 polymorphisms on the outcomes of hepatitis B virus infection.

Cytotoxic T lymphocyte-associated antigen 4 (CTLA-4) regulates T-cell activation and Th1/Th2 cytokine production and is involved in the immune response against Hepatitis B virus (HBV) infection. To detect the association of the CTLA-4 gene polymorphisms with susceptibility to HBV infection a hospital-based case-control study was conducted. A total of 1,119 unrelated individuals were recruited. The CTLA-4 variants rs5742909, rs231775 and rs3087243 were genotyped via the TaqMan method in this cohort. A comparison with a chronic active hepatitis B group revealed that the SNP rs231775 exhibited significant susceptibility to HBV progression, with the highest odds ratio (OR) reaching 1.659 and P=0.009-0.049. Although an HBV clearance group was used as a control, results of the present study demonstrated an association of rs5742909 with viral persistence [OR=1.694, 95% confidence intervals (CI)=1.124-2.553 and P=0.012]. Subsequent analyses revealed risk haplotypes (C-A-A and T-A-G, for which the highest OR reached 1.865) compared with the protective haplotype C-G-G. Therefore, SNPs in the CTLA-4 gene may be associated with HBV progression and viral persistence which is consistent with its emerging role in the T regulatory cells in the pathogenesis of disease.

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.

Association of Ephrin receptor A3 gene polymorphism with susceptibility to chronic severe hepatitis B.

AIM: Previous research has suggested that Ephrin receptor A3 (EphA3) plays signaling roles in the processes of inflammation by regulating lymphocyte migration and proliferation. In this study, we investigated whether the EphA3 gene polymorphism was associated with disease progression of chronic hepatitis B virus (HBV) infection. METHODS: The EphA3 variant rs9310117 was genotyped in 1245 unrelated Han Chinese HBV carriers including 800 cases and 445 controls. χ(2) test was used to examine the difference in allele frequencies and genotype distributions between groups. The association between the polymorphism and disease progression of HBV infection was conducted by unconditional logistic regression analysis. RESULTS: Statistical analysis revealed that the genetic variant was significantly associated with the occurrence of chronic severe hepatitis B (CSHB). We observed that subjects bearing at least one T allele (C/T or T/T genotype) had a decreased susceptibility to chronic severe hepatitis B compared with those bearing C/C genotype (P = 0.003, odds ratio = 0.560; 95% confidence interval, 0.381-0.824, recessive model). Genotype C/T had also been confirmed to protect subjects from suffering chronic severe hepatitis B (P = 0.001, odds ratio = 0.498; 95% confidence interval, 0.330-0.752, additive model). CONCLUSION: Our results suggest that the genetic alteration at EphA3 locus plays a role in the occurrence of chronic severe hepatitis B.

Association of a TANK gene polymorphism with outcomes of hepatitis B virus infection in a Chinese Han population.

The host genetic compound plays a vital role in determining clinical outcomes of hepatitis B virus (HBV) infection. The tumor necrosis factor receptor-associated factor family member-associated nuclear factor-κB (NF-κB) activator (TANK) takes part in the tumor necrosis factor-α (TNF-α)-mediated NF-κB signaling pathway and the interferon (IFN)-induction pathways that have relevance to HBV-related liver disease. In this report, we explored whether the intronic polymorphism rs3820998 of the TANK gene was associated with outcomes of HBV infection by binary logistic regression analysis. A total of 1305 unrelated Han Chinese patients recruited from Wuhan, including 180 acute-on-chronic hepatitis B liver failure (ACLF-HBV) patients, 331 HBV-related liver cirrhosis (LC) patients, 308 HBV-related hepatocellular carcinoma (HCC) patients, and 486 asymptomatic HBV carriers (AsC) were genotyped using the TaqMan probe method. Logistic analysis revealed that the single-nucleotide polymorphism (SNP) rs3820998 was significantly associated with susceptibility to ACLF-HBV (dominant model, OR 0.643, 95% CI 0.428,0.964, p=0.033; additive model, OR 0.640, 95% CI 0.414,0.990, p=0.045), and LC (recessive model, OR 0.398, 95% CI 0.164,0.966, p=0.042; additive model, OR 0.379, 95% CI 0.155,0.928, p=0.034). These results indicate that the G > T variant is a protective factor in the development of ACLF-HBV and LC, and that the SNP rs3820998 in the TANK gene may play a role in mediating susceptibility to ACLF-HBV and LC in a Chinese Han population.

[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.

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.