Genetic variants in STAT4 and HLA-DQ genes confer risk of hepatitis B virus-related hepatocellular carcinoma

To identify genetic susceptibility loci for hepatitis B virus (HBV)-related hepatocellular carcinoma (HCC) in the Chinese population, we carried out a genome-wide association study (GWAS) in 2,514 chronic HBV carriers (1,161 HCC cases and 1,353 controls) followed by a 2-stage validation among 6 independent populations of chronic HBV carriers (4,319 cases and 4,966 controls). The joint analyses showed that HCC risk was significantly associated with two independent loci: rs7574865 at STAT4, P(meta) = 2.48 × 10(-10), odds ratio (OR) = 1.21; and rs9275319 at HLA-DQ, P(meta) = 2.72 × 10(-17), OR = 1.49. The risk allele G at rs7574865 was significantly associated with lower mRNA levels of STAT4 in both the HCC tissues and nontumor tissues of 155 individuals with HBV-related HCC (P(trend) = 0.0008 and 0.0002, respectively). We also found significantly lower mRNA expression of STAT4 in HCC tumor tissues compared with paired adjacent nontumor tissues (P = 2.33 × 10(-14)).

Cbx4 governs HIF-1α to potentiate angiogenesis of hepatocellular carcinoma by its SUMO E3 ligase activity

Cbx4 is a polycomb group protein that is also a SUMO E3 ligase, but its potential roles in tumorigenesis remain to be explored. Here, we report that Cbx4, but not other members of the Cbx family, enhances hypoxia-induced vascular endothelial growth factor (VEGF) expression and angiogenesis in hepatocellular carcinoma (HCC) cells through enhancing HIF-1α sumoylations at K391 and K477 in its two SUMO-interacting motifs-dependent mechanisms and increasing transcriptional activity of HIF-1. The Cbx4 expression is significantly correlated with VEGF expression, angiogenesis, and the overall survival of HCC patients and also in subcutaneously and orthotopically transplanted mice HCC models. Collectively, our findings demonstrate that Cbx4 plays a critical role in tumor angiogenesis by governing HIF-1α protein.

Genetic variants in five novel loci including CFB and CD40 predispose to chronic hepatitis B

Hepatitis B virus affects more than 2 billion people worldwide, 350 million of which have developed chronic hepatitis B (CHB). The genetic factors that confer CHB risk are still largely unknown. We sought to identify genetic variants for CHB susceptibility in the Chinese population. We undertook a genome-wide association study (GWAS) in 2,514 CHB cases and 1,130 normal controls from eastern China. We replicated 33 of the most promising signals and eight previously reported CHB risk loci through a two-stage validation totaling 6,600 CHB cases and 8,127 controls in four independent populations, of which two populations were recruited from eastern China, one from northern China and one from southern China. The joint analyses of 9,114 CHB cases and 9,257 controls revealed significant association of CHB risk with five novel loci. Four loci are located in the human leukocyte antigen (HLA) region at 6p21.3, including two nonsynonymous variants (rs12614 [R32W] in complement factor B [CFB], Pmeta =1.28 × 10(-34) ; and rs422951 [T320A] in NOTCH4, Pmeta  = 5.33 × 10(-16) ); one synonymous variant (rs378352 in HLA-DOA corresponding to HLA-DOA*010101, Pmeta  = 1.04 × 10(-23) ); and one noncoding variant (rs2853953 near HLA-C, Pmeta  = 5.06 × 10(-20) ). Another locus is located at 20q13.1 (rs1883832 in the Kozak sequence of CD40, Pmeta  = 2.95 × 10(-15) ). Additionally, we validated seven of eight previously reported CHB susceptibility loci (rs3130542 at HLA-C, rs1419881 at TCF19, rs652888 at EHMT2, rs2856718 at HLA-DQB1, rs7453920 at HLA-DQB2, rs3077 at HLA-DPA1, and rs9277535 at HLA-DPA2, which are all located in the HLA region, 9.84 × 10(-71)  ≤ Pmeta  ≤ 9.92 × 10(-7) ).

CONCLUSION

Our GWAS identified five novel susceptibility loci for CHB. These findings improve the understanding of CHB etiology and may provide new targets for prevention and treatment of this disease.

The polymorphisms of GSTM1, GSTT1, HYL1*2, and XRCC1, and aflatoxin B1-related hepatocellular carcinoma in Guangxi population, China

AIM

High incidence rates of hepatocellular carcinoma (HCC) in Guangxi, China, are primarily due to heavy aflatoxin B1 (AFB1) exposure via corn and groundnut consumption. This study was designed to examine the polymorphisms associated of three carcinogen-metabolizing genes (namely: GSTM1, GSTT1, and HYL1*2) and one DNA-repair gene (namely: XRCC1), and investigate their role as susceptibility markers for HCC.

METHODS

We conducted a case-control study including 257 cases of cancer and 649 hospital-based age, sex, ethnicity, and hepatitis B virus infection-matched controls to examine the role of genetic polymorphisms of four genes (GSTM1, GSTT1, HYL1*2, and XRCC1) in the context of HCC risk for the Guangxi population. Genomic DNA isolated from 2ml whole blood was used to genotype GSTM1, GSTT1, HYL1*2, and XRCC1 by means of polymerase chain reaction (PCR) and restriction fragment length polymorphism (RFLP) analysis.

RESULTS

GSTT1-null genotype was not significantly associated with the risk of HCC, but GSTM1-null genotype [adjusted odds ratio (OR)=2.29, 95% confidence interval (CI)=1.59-3.31], HYL1*2 genotypes with 113 His allele (namely: YH/HH, adjusted OR=2.55, CI=1.78-3.65), and XRCC1 genotypes with 399 Gln allele (namely: AG/GG, adjusted OR=2.47, CI=1.72-3.54) increased the HCC risk. Compared with those individuals who did not express any putative risk genotypes as reference (OR=1), individuals featuring all of the putative risk genotypes [GSTM1-null, HYL1*2-YH/HH, and XRCC1-AG/GG] did experience a significantly greater cancer risk (adjusted OR=10.83, CI=5.44-21.59, P(interaction)<0.01). Additionally, the risk of HCC did appear to differ more significantly among individuals featuring risk genotypes and high-level or long-term AFB1 exposure, whose adjusted ORs (CIs) were 52.44 (17.51-157.08) and 326.93 (38.58-2770.52), respectively.

CONCLUSIONS

The results suggest that carcinogen metabolism and DNA-repair pathways may simultaneously modulate the risk of HCC for Guangxi population, and, particularly for these having high-level or long-term AFB1 exposure.

Metformin decreases IL-22 secretion to suppress tumor growth in an orthotopic mouse model of hepatocellular carcinoma

Epidemiological, preclinical and cellular studies in the last 5 years have shown that metformin exerts anti-tumoral properties, but its mode of action in cancer remains unclear. Here, we investigated the effects of metformin on a mouse hepatocellular carcinoma (HCC) model and tumor-associated T cell immune responses. Oral metformin administration led to a significant reduction of tumor growth, which was accompanied by decreased interleukin-22 (IL-22). Meanwhile, IL-22-induced STAT3 phosphorylation and upregulation of downstream genes Bcl-2 and cyclin D1 were inhibited by metformin. At the cellular level, metformin attenuated Th1- and Th17-derived IL-22 production. Furthermore, metformin inhibited de novo generation of Th1 and Th17 cells from naive CD4(+) cells. These observations were further supported by the fact that metformin treatment inhibited CD3/CD28-induced IFN-γ and IL-17A expression along with the transcription factors that drive their expression (T-bet [Th1] and ROR-γt [Th17], respectively). The effects of metformin on T cell differentiation were mediated by downregulated STAT3 and STAT4 phosphorylation via the AMP-activated kinase-mammalian target of rapamycin complex 1 pathway. Notably, metformin led to a reduction in glucose transporter Glut1 expression, resulting in less glucose uptake, which is critical to regulate CD4(+) T cell fate. Taken together, these findings provide evidence for the growth-inhibitory and immune-modulatory effects of metformin in HCC and thus, broaden our understanding about the action of metformin in liver cancer treatment.

Polymorphism in xeroderma pigmentosum complementation group C codon 939 and aflatoxin B1-related hepatocellular carcinoma in the Guangxi population

Genetic polymorphisms in DNA repair genes may influence individual variations in DNA repair capacity, and this may be associated with the risk and outcome of hepatocellular carcinoma (HCC) related to aflatoxin B1 (AFB1) exposure. In this study, we focused on the polymorphism of xeroderma pigmentosum complementation group C (XPC) codon 939 (rs#2228001), which is involved in nucleotide excision repair. We conducted a case-control study including 1156 HCC cases and 1402 controls without any evidence of hepatic disease to evaluate the associations between this polymorphism and HCC risk and prognosis in the Guangxi population. AFB1 DNA adduct levels, XPC genotypes, and XPC protein levels were tested with a comparative enzyme-linked immunosorbent assay, TaqMan polymerase chain reaction for XPC genotypes, and immunohistochemistry, respectively. Higher AFB1 exposure was observed among HCC patients versus the control group [odds ratio (OR) = 9.88 for AFB1 exposure years and OR = 6.58 for AFB1 exposure levels]. The XPC codon 939 Gln alleles significantly increased HCC risk [OR = 1.25 (95% confidence interval = 1.03-1.52) for heterozygotes of the XPC codon 939 Lys and Gln alleles (XPC-LG) and OR = 1.81 (95% confidence interval = 1.36-2.40) for homozygotes of the XPC codon 939 Gln alleles (XPC-GG)]. Significant interactive effects between genotypes and AFB1 exposure status were also observed in the joint-effects analysis. This polymorphism, moreover, was correlated with XPC expression levels in cancerous tissues (r = -0.369, P < 0.001) and with the overall survival of HCC patients (the median survival times were 30, 25, and 19 months for patients with homozygotes of the XPC codon 939 Lys alleles, XPC-LG, and XPC-GG, respectively), especially under high AFB1 exposure conditions. Like AFB1 exposure, the XPC codon 939 polymorphism was an independent prognostic factor influencing the survival of HCC. Additionally, this polymorphism multiplicatively interacted with the xeroderma pigmentosum complementation group D codon 751 polymorphism with respect to HCC risk (OR(interaction) = 1.71).

CONCLUSION

These results suggest that the XPC codon 939 polymorphism may be associated with the risk and outcome of AFB1-related HCC in the Guangxi population and may interact with AFB1 exposure in the process of HCC induction by AFB1.

Genetic polymorphisms in DNA repair genes XRCC4 and XRCC5 and aflatoxin B1-related hepatocellular carcinoma

BACKGROUND

Genetic polymorphisms in DNA repair genes may influence individual variation in DNA repair capacity and may play an important role in carcinogenesis. We investigated the role of genetic polymorphisms at XRCC4 codon 247 (rs3734091, XRCC4P) and XRCC5 codon 180 (rs80309960, XRCC5P) in liver cancer (hepatocellular carcinoma) caused by aflatoxin B1 (AFB1).

METHODS

A hospital-based case-control study, including 1499 liver cancer cases and 2045 controls without any liver disease, was conducted in a high aflatoxin exposure area in the Guangxi region of China to assess the relationship between these two polymorphisms and aflatoxin-related liver cancer risk and prognosis. Genotypes, mRNA levels, and the hot-spot mutation of TP53 gene (TP53M) related to AFB1 exposure was tested using TaqMan-PCR technique. XRCC4 protein level was analyzed by immunohistochemistry.

RESULTS

For XRCC4P and XRCC5P, only XRCC4P modified liver cancer risk. Compared with the homozygote of XRCC4 codon 247 Ala alleles (XRCC4-AA), the genotypes of XRCC4 codon 247 Ser alleles (namely XRCC4-AS or -SS) increased liver cancer risk (odds ratio [OR] = 1.35 and 2.02, respectively). Significant interactive effects between risk genotypes (OR > 1) and aflatoxin exposure status were also observed in the joint effects analysis. Moreover, this polymorphism was associated not only with lower XRCC4 expression levels but also with higher AFB1-DNA adduct levels and increasing TP53M and portal vein tumor risk. Additionally, XRCC4P modified the recurrence-free survival and overall survival of cases, especially under conditions of high aflatoxin exposure.

CONCLUSION

XRCC4P may be a genetic modifier for the risk and outcome of hepatocellular carcinoma induced by AFB1 exposure.

Long noncoding RNA HAGLROS promotes cell proliferation, inhibits apoptosis and enhances autophagy via regulating miR-5095/ATG12 axis in hepatocellular carcinoma cells

In this research, we planned to dig the possible influences and mechanism of long noncoding (lnc) RNA HAGLROS in the development and progression of hepatocellular carcinoma (HCC). The levels of lncRNA HAGLROS in HCC tumor samples and their relationship with clinicopathological characteristics and prognosis of patients with HCC were studied. Subsequently, overexpression and silenced approaches were used in HCC cells for detecting the effects of lncRNA HAGLROS on cell viability, apoptosis, and autophagy. Furthermore, we investigated whether HAGLROS could function as a competing endogenous RNA (ceRNA) to regulate miR-5095 expression in HCC cells, and explored the correlation between miR-5095 and ATG12. Besides, the correlation of HAGLROS, the consequent PI3K/AKT/mTOR signaling pathway was further explored. The level of HAGLROS was higher in HCC tissues and correlated with clinical performances including tumor stages or tumor differentiation. In contrast to the lower level, a higher level of HAGLROS correlated with a shorter survival time of patients with HCC. The suppression of HAGLROS decreased cell viability, promoted apoptosis, and inhibited autophagy. Moreover, HAGLROS negatively regulated miR-5095 expression, which further regulated HCC cell viability, apoptosis, and autophagy. In addition, ATG12 was targeted by miR-5095 and was then involved in miR-5095-regulated HCC cell biological processes including viability, apoptosis, and autophagy. Furthermore, overexpression of HAGLROS activated PI3K/AKT/mTOR signals. Our results revealed that HAGLROS is highly expressed in HCC, and its high level may correlate with the progression and development of HCC involving the processes of cell viability, apoptosis, and autophagy through the miR-5095/ATG12 axis and PI3K/AKT/mTOR signals.

XPD codon 312 and 751 polymorphisms, and AFB1 exposure, and hepatocellular carcinoma risk

BACKGROUND

Genetic polymorphisms in DNA repair genes may influence individual variation in DNA repair capacity, which may be associated with risk of hepatocellular carcinoma (HCC) related to the exposure of aflatoxin B1 (AFB1). In this study, we have focused on the polymorphisms of xeroderma pigmentosum complementation group D (XPD) codon 312 and 751 (namely Asp312Asn and Lys751Gln), involved in nucleotide excision repair.

METHODS

We conducted a case-control study including 618 HCC cases and 712 controls to evaluate the associations between these two polymorphisms and HCC risk for Guangxi population by means of TaqMan-PCR and PCR-RFLP analysis.

RESULTS

We found that individuals featuring the XPD genotypes with codon 751 Gln alleles (namely XPD-LG or XPD-GG) were related to an elevated risk of HCC compared to those with the homozygote of XPD codon 751 Lys alleles [namely XPD-LL, adjusted odds ratios (ORs) were 1.75 and 2.47; 95% confidence interval (CIs) were 1.30-2.37 and 1.62-3.76, respectively]. A gender-specific role was evident that showed an higher risk for women (adjusted OR was 8.58 for XPD-GG) than for men (adjusted OR = 2.90 for XPD-GG). Interestingly, the interactive effects of this polymorphism and AFB1-exposure information showed the codon 751 Gln alleles increase the risk of HCC for individuals facing longer exposure years (Pinteraction = 0.011, OR = 0.85). For example, long-exposure-years (> 48 years) individuals who carried XDP-GG had an adjusted OR of 470.25, whereas long-exposure-years people with XDP-LL were at lower risk (adjusted OR = 149.12). However, we did not find that XPD codon 312 polymorphism was significantly associated with HCC risk.

CONCLUSION

These findings suggest that XPD Lys751Gln polymorphism is an important modulator of AFB1 related-HCC development in Guangxi population.

SIRT2 regulates extracellular vesicle-mediated liver-bone communication

The interplay between liver and bone metabolism remains largely uncharacterized. Here, we uncover a mechanism of liver-bone crosstalk regulated by hepatocyte SIRT2. We demonstrate that hepatocyte SIRT2 expression is increased in aged mice and elderly humans. Liver-specific SIRT2 deficiency inhibits osteoclastogenesis and alleviates bone loss in mouse models of osteoporosis. We identify leucine-rich α-2-glycoprotein 1 (LRG1) as a functional cargo in hepatocyte-derived small extracellular vesicles (sEVs). In SIRT2-deficient hepatocytes, LRG1 levels in sEVs are upregulated, leading to increased transfer of LRG1 to bone-marrow-derived monocytes (BMDMs), and in turn, to inhibition of osteoclast differentiation via reduced nuclear translocation of NF-κB p65. Treatment with sEVs carrying high levels of LRG1 inhibits osteoclast differentiation in human BMDMs and in mice with osteoporosis, resulting in attenuated bone loss in mice. Furthermore, the plasma level of sEVs carrying LRG1 is positively correlated with bone mineral density in humans. Thus, drugs targeting hepatocyte-osteoclast communication may constitute a promising therapeutic strategy for primary osteoporosis.

The polymorphism of XRCC3 codon 241 and AFB1-related hepatocellular carcinoma in Guangxi population, China

PURPOSE

The relationship between aflatoxin B1 (AFB1) exposure and hepatocellular carcinoma (HCC) has been previously demonstrated and supported with strong epidemiological evidence. However, the role of genetic polymorphism of X-ray cross-complementing group 3 (XRCC3) codon 241 (namely: Thr241Met), which may be involved in the repair of DNA double-strand breaks caused by carcinogens such as AFB1, been less well elaborated.

METHODS

We conducted a case-control study including 491 cases and 862 controls to evaluate the associations between this polymorphism and HCC risk for Guangxi population by means of polymerase chain reaction-restriction fragment length polymorphism analysis.

RESULTS

We found that individuals with the XRCC3 genotypes with codon 241 Met (namely XRCC3-TM or XRCC3-MM) had an increased risk of HCC than those with the homozygote of XRCC3 codon 241 Thr alleles (namely XRCC3-TT, adjusted odds ratios 2.22 and 7.19; 95% confidence intervals 1.72-2.88 and 4.52-11.42, respectively). The risk of HCC, moreover, did appear to differ more significantly among individuals featuring high-level AFB1-DNA adducts, whose adjusted odds ratios (95% confidence intervals) were 11.59 (5.73-23.47) and 37.54 (16.32-86.32), respectively.

CONCLUSIONS

These findings support the hypothesis that the XRCC3 Thr241Met polymorphism may be associated with the risk of AFB1-related HCC among the Guangxi population.

hsa_circ_0000092 promotes hepatocellular carcinoma progression through up-regulating HN1 expression by binding to microRNA-338-3p

Circular RNAs (circRNAs) have been identified in diverse cancers for their role in regulating multiple cellular processes by antagonizing microRNAs (miRNAs or miRs). However, the role of circRNA hsa_circ_0000092 in hepatocellular carcinoma (HCC) still remains enigmatic. Therefore, we aimed to investigate the specific mechanism of hsa_circ_0000092 in HCC. Differentially expressed circRNAs associated to HCC were initially analysed. The expression of hsa_circ_0000092, miR-338-3p and HN1 in HCC tissues and cell lines was examined. Next, the interaction among hsa_circ_0000092, miR-338-3p and HN1 was determined by dual-luciferase reporter, RNA pull-down and northern blot assays. Subsequently, a series of mimic, inhibitor or siRNA plasmids were delivered into HCC cells to validate the effects of hsa_circ_0000092, miR-338-3p and HN1 in controlling cell proliferation, migration, invasion and angiogenesis in vitro. Furthermore, the role of hsa_circ_0000092 in tumour growth of HCC in vivo was assessed with hsa_circ_0000092 depleted with siRNA. The hsa_circ_0000092/miR-338-3p/HN1 axis was predicted to participate in the development of HCC. hsa_circ_0000092 and HN1 were highly expressed while miR-338-3p was poorly expressed in HCC tissues and cell lines. hsa_circ_0000092 could competitively bind to miR-338-3p to up-regulate HN1 expression. Moreover, depleted hsa_circ_0000092 or elevated miR-338-3p was shown to suppress HCC cell proliferation, migration, invasion and angiogenesis in vitro via down-regulation of HN1. Furthermore, silencing hsa_circ_0000092 was demonstrated to suppress tumour growth in HCC in vivo. The results of this study suggested that hsa_circ_0000092 impaired miR-338-3p-mediated HN1 inhibition to aggravate the development of HCC, indicating that hsa_circ_0000092 is a potential candidate marker and therapeutic target for HCC.

MicroRNA-24 modulates aflatoxin B1-related hepatocellular carcinoma prognosis and tumorigenesis

MicroRNA-24 (miR-24) may be involved in neoplastic process; however, the role of this microRNA in the hepatocellular carcinoma (HCC) related to aflatoxin B1 (AFB1) has not been well elaborated. Here, we tested miR-24 expression in 207 pathology-diagnosed HCC cases from high AFB1 exposure areas and HCC cells. We found that miR-24 was upregulated in HCC tumor tissues relative to adjacent noncancerous tissue samples, and that the high expression of miR-24 was significantly correlated with larger tumor size, higher microvessel density, and tumor dedifferentiation. Additionally, this microRNA overexpression modified the recurrence-free survival (relative hazard ratio [HR], 4.75; 95% confidence interval [CI], 2.66-8.47) and overall survival (HR = 3.58, 95% CI = 2.34-5.46) of HCC patients. Furthermore, we observed some evidence of joint effects between miR-24 and AFB1 exposure on HCC prognosis. Functionally, miR-24 overexpression progressed tumor cells proliferation, inhibited cell apoptosis, and developed the formation of AFB1-DNA adducts. These results indicate for the first time that miR-24 may modify AFB1-related HCC prognosis and tumorigenesis.

MicroRNA-429 Modulates Hepatocellular Carcinoma Prognosis and Tumorigenesis

MicroRNA-429 (miR-429) may modify the development and progression of cancers; however, the role of this microRNA in the hepatocellular carcinoma (HCC) has not been well elaborated. Here, we tested miR-429 expression in 138 pathology-diagnosed HCC cases and SMMC-7721 cells. We found that miR-429 was upregulated in HCC tumor tissues and that the high expression of miR-429 was significantly correlated with larger tumor size (odd ratio (OR), 2.70; 95% confidence interval (CI), 1.28-5.56) and higher aflatoxin B1-DNA adducts (OR = 3.13, 95% CI = 1.47-6.67). Furthermore, this microRNA overexpression modified the recurrence-free survival and overall survival of HCC patients. Functionally, miR-429 overexpression progressed tumor cells proliferation and inhibited cell apoptosis. These results indicate for the first time that miR-429 may modify HCC prognosis and tumorigenesis and may be a potential tumor therapeutic target.

Polymorphisms in the coding region of X-ray repair complementing group 4 and aflatoxin B1-related hepatocellular carcinoma

X-ray repair complementing group 4 (XRCC4) is very important in maintaining overall genome stability and may play an important role in carcinogenesis. We aimed to investigate the role of polymorphisms in the coding region of this gene in hepatocellular carcinoma (HCC) caused by aflatoxin B1 (AFB1). A hospital-based case-control study, including 1,499 HCC cases and 2,045 controls without any liver diseases or tumors, was conducted in a high AFB1 exposure area (the Guangxi region) to assess the relationship between 21 polymorphisms in the coding region of XRCC4 and AFB1-related HCC risk and prognosis. Among these 21 polymorphisms, only rs28383151 modified HCC risk. These individuals with the genotypes of rs28383151 A alleles (rs28383151-GA/AA), compared with the homozygote of rs28383151 G alleles (rs28383151-GG), faced increasing risk of HCC (odds ratio [OR]: 2.17; 95% confidence interval: 1.77-2.67). Significant interactive effects between risk genotypes (OR, >1) and AFB1 exposure status were also observed in the joint-effects analysis. Furthermore, this polymorphism was correlated not only with lower XRCC4-expressing levels, but also with higher AFB1-DNA adducts levels and increasing TP53M and portal vein tumor risk. The rs28383151 polymorphism modified the recurrence-free survival and overall survival of HCC patients, especially under high AFB1 exposure conditions. Additionally, this polymorphism multiplicatively interacted with the glutathione S-transferase M1 polymorphism with respect to HCC risk (ORinteraction = 2.13).

CONCLUSION

Genetic polymorphisms in the coding region of XRCC4 may be risk and prognostic biomarkers of AFB1-related HCC, and rs28383151 is such a potential candidate.

SIRT2-mediated deacetylation and deubiquitination of C/EBPβ prevents ethanol-induced liver injury

Protein acetylation has emerged to play pivotal roles in alcoholic liver disease (ALD). Sirutin 2 (SIRT2) is a nicotinamide adenine dinucleotide (NAD+)-dependent deacetylase involved in the regulation of aging, metabolism, and stress. However, the role of SIRT2 in ALD remains unclear. Here, we report that the SIRT2-mediated deacetylation-deubiquitination switch of CCAAT/enhancer-binding protein beta (C/EBPβ) prevents ALD. Our results showed that hepatic SIRT2 protein expression was negatively correlated with the severity of alcoholic liver injury in ALD patients. Liver-specific SIRT2 deficiency sensitized mice to ALD, whereas transgenic SIRT2 overexpression in hepatocytes significantly prevented ethanol-induced liver injury via normalization of hepatic steatosis, lipid peroxidation, and hepatocyte apoptosis. Mechanistically, we identified C/EBPβ as a critical substrate of SIRT2 implicated in ALD. SIRT2-mediated deacetylation at lysines 102 and 211 decreased C/EBPβ ubiquitination, resulting in enhanced protein stability and subsequently increased transcription of C/EBPβ-target gene LCN2. Importantly, hepatic deacetylated C/EBPβ and LCN2 compensation reversed SIRT2 deletion-induced ALD aggravation in mice. Furthermore, C/EBPβ protein expression was positively correlated with SIRT2 and LCN2 expression in the livers of ALD patients and was inversely correlated with ALD development. Therefore, activating SIRT2-C/EBPβ-LCN2 signaling pathway is a potential therapy for ALD.

Prognostic significance of Cbx4 expression and its beneficial effect for transarterial chemoembolization in hepatocellular carcinoma

Our recent investigations showed that polycomb chromobox 4 (Cbx4) promotes angiogenesis and metastasis of hepatocellular carcinoma (HCC) through its sumoylating action on hypoxia-inducible factor-1α protein. Here, we attempt to identify the prognostic significances of Cbx4 by a retrospective analyses in 727 cases of HCC patients with and without postoperative transarterial chemoembolization (TACE) or transarterial embolization (TAE). Binary logistic regression tests indicated that Cbx4 is correlated with histological grading, tumor-node-metastasis stage, microvessel density, distant metastasis and hematogenous metastasis of HCC. By univariate and multivariate analyses, we show that Cbx4 is an independent prognostic factor of HCC, and both TAE and TACE treatments have no effects on the overall survival in HCC patients with low Cbx4 expression. More intriguingly, TACE prolongs, while TAE shortens, the overall survival of HCC patients with high Cbx4 expression, indicating that Cbx4 is a good biomarker on decision-making to perform postoperative TACE in HCC patients. Moreover, Cbx4 overexpression enhances while Cbx4 silencing antagonizes doxorubicin-induced cell death of HCC cell lines. In conclusion, Cbx4 is an independent prognostic factor for HCC patients, and the patients with high Cbx4 expression should receive postoperative TACE treatment to improve their survival.

Diagnostic and prognostic potential of serum microRNA-4651 for patients with hepatocellular carcinoma related to aflatoxin B1

BACKGROUND

The serum microRNAs have been reported as potential biomarkers for hepatitis virus-related hepatocellular carcinoma (HCC); however, their role in aflatoxin B1 (AFB1)-related HCC to has not yet been evaluated.

MATERIALS AND METHODS

We conducted a case-control study, including 366 HCC cases and 662 controls without any evidence of tumors, to identify and assess diagnostic and prognostic potential of serum microRNAs for AFB1-related HCC. The sensitivity, specificity, and area under the receiver operating characteristic curve (AUC) were used to elucidate diagnostic performance, and to compare the microRNAs with α-fetoprotein (AFP) at a cutoff of 20 ng/mL (AFP20) and 400 ng/mL (AFP400).

RESULTS

We found 8 differentially expressed microRNAs via the microRNA array analysis; however, only microRNA-4651 was further identified to detect AFB1-positive HCC but not AFB1-negative HCC. For AFB1-positive HCC, microRNA-4651 showed higher accuracy and sensitivity than AFP400 (AUC, 0.85 vs. 0.72; Sensitivity, 78.1% vs. 43.0%). Compared to AFP20, microRNA-4651 exhibited higher potential in identifying small-size (0.68 vs. 0.84 for AUC and 36.7% vs. 75.5% for sensitivity, respectively) and early-stage HCC (0.69 vs. 0.84 for AUC and 38.7% vs. 75.7% for sensitivity, respectively). Additionally, miR-4651 was also associated with HCC prognosis (hazard risk value, 2.67 for overall survival and 3.62 for tumor recurrence analysis).

CONCLUSIONS

These data suggest that serum microRNA-4651 may be a useful marker for HCC diagnosis and prognosis, especially AFB1-positive cases.

DNA repair gene XRCC7 polymorphisms (rs#7003908 and rs#10109984) and hepatocellular carcinoma related to AFB1 exposure among Guangxi population, China

AIM

  The X-ray repair cross-complementing group 7 (XRCC7) plays an important role in the repair of DNA double-strand breaks by nonhomologous end-joining repair (NEJR) pathway. However, the role of XRCC7 polymorphisms (rs#7003908 and rs#10109984) possibly influencing NEJR capacity in hepatocellular carcinoma (HCC) induced by aflatoxin B1 (AFB1) has not been well elaborated.

METHODS

  This hospital-based case-control study, including 348 patients with newly diagnosed HCC and 597 controls without any evidence of liver diseases, was conducted to elucidate the association between these two polymorphisms and the risk of HCC related to AFB1 exposure among a Guangxi population from a high AFB1-exposure area by means of TaqMAN-polymerase chain reaction technique.

RESULTS

  We observed that HCC patients featured higher AFB1 exposure than control group (odds ratios [OR] = 6.49 and 6.75 for exposure years and exposure levels, respectively). Furthermore, these individuals with the genotypes of XRCC7 rs#7003908 G alleles (namely XRCC7-TG or -GG), compared the homozygote of XRCC7 rs#7003908 T alleles (XRCC7-TT), faced increasing risk of HCC (OR, 3.45 and 5.04; 95% confidence intervals [CIs], 2.40-4.94 and 3.28-7.76, respectively). We also found some evidence that this polymorphism interacted with AFB1-expousure years or levels in the process of HCC carcinogenesis. Additionally, XRCC7 rs#7003908 polymorphism was correlated with the levels of AFB1-DNA adducts (r = 0.142, P < 0.001). XRCC7 rs#10109984 polymorphism, however, did not modify the risk of HCC related to AFB1 exposure (P > 0.05).

CONCLUSION

  These data suggest that XRCC7 rs#7003908 polymorphism may be one of the genetic modifiers for AFB1-related HCC among Guangxi population.

Genetic polymorphisms in DNA repair genes XPC, XPD, and XRCC4, and susceptibility to Helicobacter pylori infection-related gastric antrum adenocarcinoma in Guangxi population, China

Genetic polymorphisms in DNA repair genes may influence individual variation in DNA repair capacity, which may be associated with risk of gastric antrum adenocarcinoma (GAA) related to Helicobacter pylori infection. This study, including 361 GAAs and 616 controls without any evidence of tumors, was designed to evaluate the association between the polymorphisms of DNA repair genes XPC Ala499Val (RS#2228000) and Lys939Gln (RS#2228001), XPD Lys751Gln (RS#13181), and XRCC4 Ala247Ser (RS#3734091) and Ser298Asn (RS#1805377), and GAA risk for Guangxi population by means of TaqMan-PCR analysis. Increased risks of GAA were found for individuals with H. pylori positive [odds ratio (OR), 2.48; 95% confidence interval (CI), 1.84-3.33] or cagA positive (OR, 7.34; 95% CI, 5.46-9.87). No differences were observed among the studied groups with regard to the genotype distribution of XPC codons 499 and 939 and of XRCC4 codon 247; but XPD codon 751 genotypes with Gln [ORs (95% CI) were 2.67 (1.98-3.58) and 3.97 (2.64-5.99) for Lys/Gln and Gln/Gln, respectively] and XRCC4 codon 298 genotypes with Asn [ORs (95% CI) were 3.01 (2.21-4.10) and 4.78 (3.24-7.05) for Ser/Asn and Asn/Asn, respectively] increased the risk of GAA. Interestingly, there was an interactive effect between the risk genotypes of these two genes and cagA-positive status in the GAA risk (OR(interact) = 2.05 and 2.08, respectively). However, we did not find the gene-H. pylori-status interaction effects on the risk of GAA (P(interact) > 0.05). The results suggested that the polymorphisms of XPD codon 751 and XRCC4 codon 298 are associated with an increased risk of developing H. pylori-related GAA among Guangxi population.

Polymorphisms in the precursor microRNAs and aflatoxin B1-related hepatocellular carcinoma

The altered expression of some microRNAs (miRNAs) is observed in hepatocellular carcinoma (HCC); however, the genetic polymorphisms in the precursor miRNAs (pre-miRNAs) in aflatoxin B1 (AFB1)-related HCC have not yet been investigated. A hospital-based case-control study, including 1,706 HCC cases and 2,270 controls without any liver diseases or tumors, was conducted in a high AFB1 exposure area of China to assess the relationship between 48 polymorphisms in the pre-miRNAs and AFB1-related HCC risk and prognosis. Among 48 polymorphisms, only rs28599926 (in the miRNA 1268a) affected HCC risk. Compared with the homozygote of rs28599926C alleles (rs28599926-CC), the genotypes of rs28599926 T alleles (namely rs28599926-CT or -TT) increased HCC risk (odds ratio [OR]: 1.63 and 5.52, 95% confidence interval [CI]: 1.40-1.90 and 4.27-7.14, respectively). Significant interactive effects between risk genotypes and AFB1 exposure status were also observed in the joint effects analysis. This polymorphism was associated not only with larger tumor size, higher portal vein tumor risk, and tumor dedifferentiation, but also with higher AFB1 adducts levels and increasing the mutation risk of TP53 gene. Furthermore, rs28599926 modified the tumor recurrence-free survival (hazard ratio [HR]: 2.86, 95% CI: 2.36-3.43) and overall survival (HR: 2.12, 95% CI: 1.86-2.41) of cases. Additionally, one target of miR-1268a was show to be the ADAMTS4 mRNA and rs28599926 polymorphism might modify ADAMTS4 expression. These findings indicate that polymorphisms in the pre-miRNAs may be risk and prognostic biomarkers of AFB1-related HCC, and rs28599926 in miR-1268a is such a potential candidate. © 2015 Wiley Periodicals, Inc.

Prognostic significance of miR-1268a expression and its beneficial effects for post-operative adjuvant transarterial chemoembolization in hepatocellular carcinoma

Our recent investigation has shown that the variables of microRNA-1268a may involve in hepatocellular carcinoma (HCC) tumorigenesis. Here, we attempted to identify the prognostic significance of microRNA-1268a expression in tumor tissues by a retrospective analysis in 411 patients with HCC, and analyze its effects on post-operative adjuvant transarterial chemoembolization (TACE) improving HCC prognosis. All cases received tumor resection or tumor resection plus post-operative adjuvant TACE as an initial treatment. Logistical regression analysis exhibited that microRNA-1268a expression was significantly correlated with tumor stage, tumor grade, tumor size, and microvessel density. Cox regression analysis showed that microRNA-1268a expression was an independent prognostic factor for HCC, and TACE treatment had no effects on prognosis of HCC patients with high microRNA-1268a expression. More intriguingly, TACE improved the prognosis of HCC patients with low microRNA-1268a expression. Functionally, overexpression of microRNA-1268a inhibited while its inhibitor enhanced doxorubicin-induced the death of cancer cells. These results suggest that microRNA-1268a may be an independent prognostic factor for HCC patients, and that decreasing microRNA-1268a expression may be beneficial for post-operative adjuvant TACE treatment in HCC.

Spautin-1 Ameliorates Acute Pancreatitis via Inhibiting Impaired Autophagy and Alleviating Calcium Overload

Acute pancreatitis is characterized by zymogen pre-activation. Severe inflammation caused by zymogen activation can eventually lead to multiple organ dysfunctions, which contributes to the high mortality rate of severe acute pancreatitis. However, there is no specific treatment available for acute pancreatitis therapy. Here, we show that spautin-1, which effectively inhibits autophagy flux, ameliorated the pathogenesis of acute pancreatitis induced by cerulein or L-Arginine. CaMKII phosphorylation due to cytosolic calcium oeverload was revealed in this paper. It was also demonstrated that autophagic protein aggregates degradation blockade accompanying with impaired autophagy correlated positively to intra acinar cells digestive aymogen activation sitimulated by cerulein or L-Arginine. The role of spautin-1 in ameliorating acute pancreatitis was shown here to be associated with impaired autophagy inhibition and Ca2+ overload alleviation. We provided a promising therapy for acute pancreatitis here through targeting both impaired autophagy and increased cytosolic calcium.

Prognostic significance of XRCC4 expression in hepatocellular carcinoma

BACKGROUND

Our previous investigations have shown that the variants of X-ray repair complementing 4 (XRCC4) may be involved in hepatocellular carcinoma (hepatocarcinoma) tumorigenesis. This study aimed to investigate the possible prognostic significance of XRCC4 expression for hepatocarcinoma patients and possible value for the selection of transarterial chemoembolization (TACE) treatment.

MATERIALS AND METHODS

We conducted a hospital-based retrospective analysis (including 421 hepatocarcinoma cases) to analyze the effects of XRCC4 on hepatocarcinoma prognosis and TACE. The levels of XRCC4 expression were tested using immunohistochemistry. The sensitivity of cancer cells to anti-cancer drug doxorubicin was evaluated using the half-maximal inhibitory concentration (IC50).

RESULTS

XRCC4 expression was significantly correlated with pathological features including tumor stage, liver cirrhosis, and micro-vessel density. XRCC4 expression was an independent prognostic factor of hepatocarcinoma, and TACE treatments had no effects on prognosis of hepatocarcinoma patients with high XRCC4 expression. More intriguingly, TACE improved the prognosis of hepatocarcinoma patients with low XRCC4 expression. Functionally, XRCC4 overexpression increased while XRCC4 knockdown reduced the IC50 of cancer cells to doxorubicin.

CONCLUSIONS

These results suggest that XRCC4 may be an independent prognostic factor for hepatocarcinoma patients, and that decreasing XRCC4 expression may be beneficial for post-operative adjuvant TACE treatment in hepatocarcinoma.

Tonsillar CD4+CD25+ regulatory T cells from IgA nephropathy patients have decreased immunosuppressive activity in experimental IgA nephropathy rats

BACKGROUND/AIM

CD4+CD25+ regulatory T (Treg) cells are of critical importance for maintenance of tolerance. We showed that the number of CD4+CD25+ Treg cells was significantly lower in tonsils of patients with IgA nephropathy (IgAN); however, the function of tonsillar CD4+CD25+ Treg cells in IgAN has not been reported. The aim of this study was to investigate the effect of tonsillar CD4+CD25+ Treg cells of IgAN patients on experimental IgAN in rats.

METHODS

Tonsillar CD4+CD25+ Treg cells were isolated by magnetic beads. A total of 2 × 10(6) CD4+CD25+ Treg cells were transferred into rats that were previously orally immunized over a period of 14 weeks and subsequently received an injection of BSA into the tail vein on 3 consecutive days. Urine protein and erythrocytes were measured. Glomerular injury was assessed by histopathology. Plasminogen activator inhibitor type 1 (PAI-1), interleukin (IL)-6 and transforming growth factor (TGF)-β1 in mesangial cells of rats were examined by reverse transcription PCR. Serum IgA and C3 and supernatants of IL-2, IL-4 and IL-6 in splenic cells were analysed by ELISA. Transferred tonsillar CD4+CD25+ Treg cells were tracked by reverse transcription PCR and flow cytometry.

RESULTS

IgA deposition in the mesangial region and the glomerular planar area and the number of cells, levels of serum IgA and supernatant IL-2, IL-4 and IL-6 in splenic cells and PAI-1, IL-6 and TGF-β1 expression in renal mesangial cells of rats that received CD4+CD25+ Treg cells from IgAN patients were significantly higher than in rats that received CD4+CD25+ Treg cells from the control group, although they were dramatically lower compared with rats treated without CD4+CD25+ Treg cells. Transferred tonsillar CD4+CD25+ Treg cells migrated predominantly to secondary lymphoid organs but not to the kidneys.

CONCLUSION

Dysfunction of tonsillar CD4+CD25+ Treg cells may be an important cause of IgAN progression.