Kai-Fu Tang

Controlled attenuation parameter for the detection of steatosis severity in chronic liver disease: a meta-analysis of diagnostic accuracy.

Controlled attenuation parameter (CAP) is a novel ultrasound‐based elastography method for detection of steatosis severity. This meta‐analysis aimed to assess the performance of CAP.

Performance of Shear Wave Elastography for Differentiation of Benign and Malignant Solid Breast Masses

Objectives To perform a meta-analysis assessing the ability of shear wave elastography (SWE) to identify malignant breast masses. Methods PubMed, the Cochrane Library, and the ISI Web of Knowledge were searched for studies evaluating the accuracy of SWE for identifying malignant breast masses. The diagnostic accuracy of SWE was evaluated according to sensitivity, specificity, and hierarchical summary receiver operating characteristic (HSROC) curves. An analysis was also performed according to the SWE mode used: supersonic shear imaging (SSI) and the acoustic radiation force impulse (ARFI) technique. The clinical utility of SWE for identifying malignant breast masses was evaluated using analysis of Fagan plot. Results A total of 9 studies, including 1888 women and 2000 breast masses, were analyzed. Summary sensitivities and specificities were 0.91 (95% confidence interval [CI], 0.88–0.94) and 0.82 (95% CI, 0.75–0.87) by SSI and 0.89 (95% CI, 0.81–0.94) and 0.91 (95% CI, 0.84–0.95) by ARFI, respectively. The HSROCs for SSI and ARFI were 0.92 (95% CI, 0.90–0.94) and 0.96 (95% CI, 0.93–0.97), respectively. SSI and ARFI were both very informative, with probabilities of 83% and 91%, respectively, for correctly differentiating between benign and malignant breast masses following a “positive” measurement (over the threshold value) and probabilities of disease as low as 10% and 11%, respectively, following a “negative” measurement (below the threshold value) when the pre-test probability was 50%. Conclusions SWE could be used as a good identification tool for the classification of breast masses.

Clinical utility of endoscopic ultrasound elastography for identification of malignant pancreatic masses: A meta-analysis

Endoscopic ultrasound (EUS) elastography is not used for detection but rather for characterization of solid pancreatic masses. A meta‐analysis was used to assess the accuracy of EUS elastography for identification of malignant pancreatic masses.

Dicer interacts with SIRT7 and regulates H3K18 deacetylation in response to DNA damaging agents.

Dicer participates in heterochromatin formation in fission yeast and plants. However, whether it has a similar role in mammals remains controversial. Here we showed that the human Dicer protein interacts with SIRT7, an NAD+-dependent H3K18Ac (acetylated lysine 18 of histone H3) deacetylase, and holds a proportion of SIRT7 in the cytoplasm. Dicer knockdown led to an increase of chromatin-associated SIRT7 and simultaneously a decrease of cytoplasmic SIRT7, while its overexpression induced SIRT7 reduction in the chromatin-associated fraction and increment in the cytoplasm. Furthermore, DNA damaging agents promoted Dicer expression, leading to decreased level of chromatin-associated SIRT7 and increased level of H3K18Ac, which can be alleviated by Dicer knockdown. Taken together with that H3K18Ac was exclusively associated with the chromatin, our findings suggest that Dicer induction by DNA damaging treatments prevents H3K18Ac deacetylation, probably by trapping more SIRT7 in the cytoplasm.

Relationship between IL-10 gene −1082A/G and −592C/A polymorphisms and the risk of hepatitis C infection: a meta-analysis

Increasing evidence suggests that interleukin‐10 (IL‐10) gene promoter polymorphisms may be associated with chronic hepatitis C virus (HCV) infection and HCV clearance. To more precisely estimate the association between these variants and the risk of HCV infection, we performed a meta‐analysis of 26 studies describing the IL‐10–1082A/G, –819C/T, –592C/A genotypes, including 4039 chronic HCV infection cases and 2902 controls. When compared with a healthy population, the –1082GG allele had a 43% increased risk of chronic HCV infection in combined populations (GG vs GA + AA: odds ratio (OR) = 1.433, 95% confidence interval (CI) = 1.052–1.952, P = 0.023). In subgroup analysis by ethnicity, a significant increased risk was associated with the −1082GG genotype in the Caucasian population (GG vs AA: OR = 1.390, 95% CI: 1.108–1.744, P = 0.004; GG vs GA + AA: OR = 1.621, 95% CI: 1.267–2.075, P = 0.000). However, no significant association was found in Asian, African or Chinese populations. Moreover, a higher distribution of −592A was found in the spontaneously recovered population (AA vs CC: OR = 0.585, 95% CI = 0.387–0.884, P = 0.011; AA + AC vs CC: OR = 0.738, 95% CI = 0.551–0.988, P = 0.041; AA vs AC + CC: OR = 0.788, 95% CI = 0.664–0.935, P = 0.006) than that in the chronic HCV infection population. In conclusion, the IL‐10–1082GG allele may increase the risk of chronic HCV infection in Caucasian population, and people carrying the IL‐10–592A allele are more likely to clear HCV spontaneously.

MicroRNA-581 Promotes Hepatitis B Virus Surface Antigen Expression by Targeting Dicer and EDEM1

Hepatitis B virus surface antigen (HBsAg) is an important risk factor for hepatocellular carcinoma (HCC) and is downregulated during hepatocarcinogenesis. MicroRNAs (miRNAs) are frequently deregulated in HCC tissues. However, whether the deregulation of certain miRNAs in HCC has an impact on HBsAg expression remains unclear. We found here that microRNA-581 (miR-581), which is deregulated during hepatocarcinogenesis, promoted HBsAg expression. Additionally, miR-581 targeted Dicer and endoplasmic reticulum degradation-enhancing alpha-mannosidase-like protein 1 (EDEM1) and repressed their expression. Although Dicer cannot process HBV transcripts, Dicer knockdown led to increased HBsAg secretion, most likely due to a reduction in the levels of Dicer-processed 7SL RNA fragments. Moreover, Dicer-processed 7SL RNA fragments partially inhibited the ability of miR-581 to stimulate HBsAg expression. Furthermore, we found that forced EDEM1 expression inhibited miR-581-mediated induction of HBsAg. Finally, transfection of miR-581 into HepG2.2.15 cells promoted cell proliferation and led to upregulation of genes involved in development, cell proliferation and protein secretion. Altogether, we conclude that miR-581 promotes HBsAg expression by targeting Dicer and EDEM1. Our findings suggest that downregulation of miR-581 during hepatocarcinogenesis may lead to a reduction in HBsAg expression and impede HCC development.

Meta-Analysis of the Association between a Polymorphism in MicroRNA-196a2 and Susceptibility to Colorectal Cancer

Background/Aims: To accurately evaluate the impact of the C/T polymorphism in microRNA (miRNA)-196a2 on the colorectal cancer (CRC) risk, by meta-analysis. Methods: An electronic search for articles was conducted in PubMed, EMBASE, ISI Web of Science, and the Cochrane Library. The pooled odds ratio (OR) and its 95% confidence interval (CI) were used to assess the association through meta-analysis. Results: 5 studies were used for analysis. The results showed a significant association between the miRNA-196a2 C/T polymorphism and CRC risk in the genetic models (C vs. T: OR = 1.168, 95% CI = 1.106-1.282, p = 0.001; CC vs. TT: OR = 1.368, 95% CI = 1.132-1.654, p = 0.001; TC/CC vs. TT: OR = 1.206, 95% = CI 1.035-1.405, p = 0.016; CC vs. TC/TT: OR = 1.254, 95% CI = 1.077-1.461, p = 0.004), with the exception of the TC-versus-TT model (TC vs. TT: OR = 1.130, 95% CI = 0.961-1.329, p = 0.138). In a subgroup analysis based on ethnicity, we identified a significant overrepresentation of the polymorphism in individuals of Asian ethnicity. Conclusion: This meta-analysis indicates a significant association between the miRNA-196a2 polymorphism and CRC risk.

The Fra-1–miR-134–SDS22 feedback loop amplifies ERK/JNK signaling and reduces chemosensitivity in ovarian cancer cells

The Fra-1 transcription factor is frequently upregulated in multiple types of tumors. Here we found that Fra-1 promotes miR-134 expression. miR-134 activates JNK and ERK by targeting SDS22, which in turn induces Fra-1 expression and leads to miR-134 upregulation. In addition, miR-134 augmented H2AX S139 phosphorylation by activating JNK and promoted non-homologous end joining (NHEJ)-mediated DNA repair. Therefore, ectopic miR-134 expression reduced chemosensitivity in ovarian cancer cells. Furthermore, miR-134 promotes cell proliferation, migration and invasion of ovarian cancer cells, and enhances tumor growth in vivo. Of particular significance, both Fra-1 and miR-134 are upregulated in ovarian cancer tissues, and Fra-1 and miR-134 expression is positively correlated. High levels of miR-134 expression were associated with a reduced median survival of ovarian cancer patients. Our study revealed that a Fra-1-miR-134 axis drives a positive feedback loop that amplifies ERK/JNK signaling and reduces chemosensitivity in ovarian cancer cells.

The interferon-gamma (IFN-γ) +874T allele reduces the risk of hepatitis B infection in an Asian population.

Increasing evidence suggests that polymorphism of the interferon‐gamma (IFN‐γ) gene in the first intron at position +874 may be associated with chronic hepatitis B virus (HBV) infection and/or HBV clearance. However, the results of relevant studies have been inconsistent. To derive a more precise estimation of the association, we performed a meta‐analysis. In total, 10 independent studies including 1661 chronic HBV‐infected patients and 1142 controls were included in this meta‐analysis. In studies following Hardy–Weinberg equilibrium (HWE), a significantly decreased risk of chronic HBV infection was associated with the IFN‐γ + 874TT genotype in the overall population (TT vs AA: odds ratio (OR) = 0.714, 95% confidence interval (CI) = 0.526–0.969, P = 0.031) when compared with a spontaneously recovered population. Subgroup analysis by ethnicity revealed a similar association in Asian individuals (TT vs AA: OR = 0.706, 95% CI = 0.518–0.962, P = 0.028). Moreover, when compared with a healthy control group, the 874T allele was associated with a significant lower risk of chronic HBV infection in the overall populations (TA vs AA: OR = 0.439, 95% CI = 0.193–0.997, P = 0.049; TT + TA vs AA: OR = 0.475, 95% CI = 0.271–0.832, P = 0.009) and in Asian individuals (TA vs AA: OR = 0.862, 95% CI = 0.744–0.999, P = 0.048). In conclusion, the IFN‐γ + 874TT genotype and 874T allele reduce the risk of chronic HBV infection in Asian individuals.

Association between a Polymorphism in miR-34b/c and Susceptibility to Cancer - a Meta-analysis

MicroRNAs (miRNAs) act as tumor suppressors or promoters in neoplasia by regulating relative gene expression. The association between a single nucleotide polymorphism (SNP) rs4938723 in miR-34b/c and susceptibility to cancers was inconsistent in previous studies. In this study, we conducted a literature search of PubMed, Web of Science and Embase to identify all relevant studies in this meta-analysis with 6,036 cases and 6,204 controls. We found that the miR-34b/c rs4938723 polymorphism was significantly associated with increased risk of cancers in the heterozygous model (TC versus TT, OR=1.09, 95% CI=1.01-1.18, P=0.02). Subgroup analysis also revealed increased risk for Asian ethnicity in the heterozygous model (TC versus TT, OR=1.12, 95% CI=1.02-1.22, P=0.02), but decreased risk of colorectal cancer in homozygote model (CC versus TT, OR=0.66, 95% CI=0.47-0.92, P=0.02) and in the recessive model (CC versus TC+TT, OR=0.67, 95% CI=0.48-0.93, P=0.02) by cancer type. The current meta-analysis indicated that the miR-34b/c rs4938723 polymorphism may decrease susceptibility to colorectal cancer. Well-designed studies with larger sample size are required to further validate the results.