Gain-of-function mutant p53 together with ERG proto-oncogene drive prostate cancer by beta-catenin activation and pyrimidine synthesis.

Whether TMPRSS2-ERG fusion and TP53 gene alteration coordinately promote prostate cancer (PCa) remains unclear. Here we demonstrate that TMPRSS2-ERG fusion and TP53 mutation / deletion co-occur in PCa patient specimens and this co-occurrence accelerates prostatic oncogenesis. p53 gain-of-function (GOF) mutants are now shown to bind to a unique DNA sequence in the CTNNB1 gene promoter and transactivate its expression. ERG and ß-Catenin co-occupy sites at pyrimidine synthesis gene (PSG) loci and promote PSG expression, pyrimidine synthesis and PCa growth. ß-Catenin inhibition by small molecule inhibitors or oligonucleotide-based PROTAC suppresses TMPRSS2-ERG- and p53 mutant-positive PCa cell growth in vitro and in mice. Our study identifies a gene transactivation function of GOF mutant p53 and reveals ß-Catenin as a transcriptional target gene of p53 GOF mutants and a driver and therapeutic target of TMPRSS2-ERG- and p53 GOF mutant-positive PCa.

Androgen Receptor Variants Confer Castration Resistance in Prostate Cancer by Counteracting Antiandrogen-Induced Ferroptosis.

Androgen receptor (AR) inhibition by androgen deprivation and/or antiandrogen administration is the mainstay therapy for advanced prostate cancer. However, most prostate cancers ultimately become resistant to these therapies, indicating the importance of identifying mechanisms driving resistance to improve patient outcomes. Here we demonstrated that acute treatment with the antiandrogen enzalutamide (ENZ) decreased glutathione (GSH) production, increased lipid peroxidation, and induced ferroptosis in prostate cancer cells. Consistently, meta-analysis of transcriptomic data linked the androgen-AR axis to metabolism-related biological processes, including lipid metabolism. The cystine transporter gene SLC7A11 was a key AR target, and full-length AR (AR-FL) transactivated SLC7A11 transcription by directly occupying the SLC7A11 promoter and putative enhancer regions. AR variants (AR-V) preferentially bound the SLC7A11 enhancer and upregulated SLC7A11 expression, thereby conferring resistance to ferroptosis induced by ENZ treatment. However, this effect was abolished following downregulation of AR-Vs using the dual CBP/p300 and BET inhibitor NEO2734. These findings reveal ferroptosis induction as an anticancer mechanism of antiandrogens and SLC7A11 as a direct target gene of AR-FL and AR-Vs. AR-V-mediated SLC7A11 expression represents a mechanism coupling ferroptosis resistance to prostate cancer progression. SIGNIFICANCE: Upregulation of SLC7A11 can be induced by androgen receptor variants to inhibit antiandrogen-induced prostate cancer cell ferroptosis and to drive castration resistance in prostate cancer.

SETDB1 Modulates Degradation of Phosphorylated RB and Anticancer Efficacy of CDK4/6 Inhibitors.

Retinoblastoma (RB) protein can exert tumor suppressor functions even when it becomes phosphorylated. It is thus essential to understand how phosphorylated RB (p-RB) expression and function are regulated. Here, we demonstrated that RING finger domain protein TRIM28 bound and promoted ubiquitination and degradation of CDK4/6-phosphorylated RB protein. SETDB1, a known TRIM28 binding partner, protected p-RB from degradation through the binding of methylated RB by its Tudor domain independent of its methyltransferase activity. SETDB1 was found to be frequently overexpressed due to gene amplification and positively correlated with p-RB in prostate cancer patient specimens. Inhibition of SETDB1 expression using a gene-specific antisense oligonucleotide (ASO) reduced tumor growth but accelerated RB protein degradation, limiting the therapeutic efficacy. However, coadministration of the CDK4/6 inhibitor palbociclib blocked ASO-induced RB degradation and resulted in a much greater cancer-inhibitory effect than each inhibitor alone both in vitro and in vivo. This study identified CDK4/6-dependent, TRIM28-mediated proteasomal degradation as a mechanism of RB inactivation and reveals SETDB1 as a key inhibitor of this process. Our findings suggest that combined targeting of SETDB1 and CDK4/6 represents a viable approach for the treatment of cancers with SETDB1 gene amplification or overexpression. SIGNIFICANCE: The identification of a role for TRIM28 and SETDB1 in regulating CDK4/6-phosphorylated RB stability uncovers a combination strategy using CDK4/6 and SETDB1 inhibition to decrease RB degradation and inhibit cancer growth.

Retinoblastoma protein as an intrinsic BRD4 inhibitor modulates small molecule BET inhibitor sensitivity in cancer.

Bromodomain and extraterminal (BET) proteins including BRD4 play important roles in oncogenesis and immune inflammation. Here we demonstrate that cancer cells with loss of the retinoblastoma (RB) tumor suppressor became resistant to small molecule bromodomain inhibitors of BET proteins. We find that RB binds to bromodomain-1 (BD1) of BRD4, but binding is impeded by CDK4/6-mediated RB phosphorylation at serine-249/threonine-252 (S249/T252). ChIP-seq analysis shows RB knockdown increases BRD4 occupancy at genomic loci of genes enriched in cancer-related pathways including the GPCR-GNBIL-CREB axis. S249/T252-phosphorylated RB positively correlates with GNBIL protein level in prostate cancer patient samples. BET inhibitor resistance in RB-deficient cells is abolished by co-administration of CREB inhibitor. Our study identifies RB protein as a bona fide intrinsic inhibitor of BRD4 and demonstrates that RB inactivation confers resistance to small molecule BET inhibitors, thereby revealing a regulatory hub that converges RB upstream signaling onto BRD4 functions in diseases such as cancer.

CYCLIN K down-regulation induces androgen receptor gene intronic polyadenylation, variant expression and PARP inhibitor vulnerability in castration-resistant prostate cancer.

Androgen receptor (AR) messenger RNA (mRNA) alternative splicing variants (AR-Vs) are implicated in castration-resistant progression of prostate cancer (PCa), although the molecular mechanism underlying the genesis of AR-Vs remains poorly understood. The CDK12 gene is often deleted or mutated in PCa and CDK12 deficiency is known to cause homologous recombination repair gene alteration or BRCAness via alternative polyadenylation (APA). Here, we demonstrate that pharmacological inhibition or genetic inactivation of CDK12 induces AR gene intronic (intron 3) polyadenylation (IPA) usage, AR-V expression, and PCa cell resistance to the antiandrogen enzalutamide (ENZ). We further show that AR binds to the CCNK gene promoter and up-regulates CYCLIN K expression. In contrast, ENZ decreases AR occupancy at the CCNK gene promoter and suppresses CYCLIN K expression. Similar to the effect of the CDK12 inhibitor, CYCLIN K degrader or ENZ treatment promotes AR gene IPA usage, AR-V expression, and ENZ-resistant growth of PCa cells. Importantly, we show that targeting BRCAness induced by CYCLIN K down-regulation with the PARP inhibitor overcomes ENZ resistance. Our findings identify CYCLIN K down-regulation as a key driver of IPA usage, hormonal therapy-induced AR-V expression, and castration resistance in PCa. These results suggest that hormonal therapy-induced AR-V expression and therapy resistance are vulnerable to PARP inhibitor treatment.

3-Aminophthalic acid, a new cereblon ligand for targeted protein degradation by O'PROTAC.

In this study, we identified 3-aminophthalic acid as a new ligand of cereblon (CRBN) E3 ubiquitin ligase and developed a phthalic acid-based O'PROTAC for degradation of the ERG transcription factor. This phthalic acid-based O'PROTAC presented an efficacy in degrading ERG comparable to those displayed by pomalidomide-based ERG O'PROTACs. Moreover, phthalic acid-being more chemically stable and economical than classical immunomodulatory drugs (IMiDs)-represents, as a ligand, a new alternative for the development of PROTACs, especially O'PROTACs.

Destruction of DNA-Binding Proteins by Programmable Oligonucleotide PROTAC (O'PROTAC): Effective Targeting of LEF1 and ERG.

DNA-binding proteins, including transcription factors (TFs), play essential roles in various cellular processes and pathogenesis of diseases, deeming to be potential therapeutic targets. However, these proteins are generally considered undruggable as they lack an enzymatic catalytic site or a ligand-binding pocket. Proteolysis-targeting chimera (PROTAC) technology has been developed by engineering a bifunctional molecule chimera to bring a protein of interest (POI) to the proximity of an E3 ubiquitin ligase, thus inducing the ubiquitination of POI and further degradation through the proteasome pathway. Here, the development of oligonucleotide-based PROTAC (O'PROTACs), a class of noncanonical PROTACs in which a TF-recognizing double-stranded oligonucleotide is incorporated as a binding moiety of POI is reported. It is demonstrated that O'PROTACs of lymphoid enhancer-binding factor 1 (LEF1) and ETS-related gene (ERG), two highly cancer-related transcription factors, successfully promote degradation of these proteins, impede their transcriptional activity, and inhibit cancer cell growth in vitro and in vivo. The programmable nature of O'PROTACs indicates that this approach is also applicable to destruct other TFs. O'PROTACs not only can serve as a research tool but also can be harnessed as a therapeutic arsenal to target DNA binding proteins for effective treatment of diseases such as cancer.

ATM-phosphorylated SPOP contributes to 53BP1 exclusion from chromatin during DNA replication.

53BP1 activates nonhomologous end joining (NHEJ) and inhibits homologous recombination (HR) repair of DNA double-strand breaks (DSBs). Dissociation of 53BP1 from DSBs and consequent activation of HR, a less error-prone pathway than NHEJ, helps maintain genome integrity during DNA replication; however, the underlying mechanisms are not fully understood. Here, we demonstrate that E3 ubiquitin ligase SPOP promotes HR during S phase of the cell cycle by excluding 53BP1 from DSBs. In response to DNA damage, ATM kinase-catalyzed phosphorylation of SPOP causes a conformational change in SPOP, revealed by x-ray crystal structures, that stabilizes its interaction with 53BP1. 53BP1-bound SPOP induces polyubiquitination of 53BP1, eliciting 53BP1 extraction from chromatin by a valosin-containing protein/p97 segregase complex. Our work shows that SPOP facilitates HR repair over NHEJ during DNA replication by contributing to 53BP1 removal from chromatin. Cancer-derived SPOP mutations block SPOP interaction with 53BP1, inducing HR defects and chromosomal instability.

HDAC5 Loss Impairs RB Repression of Pro-Oncogenic Genes and Confers CDK4/6 Inhibitor Resistance in Cancer.

The tumor-suppressor protein RB acts as a transcription repressor via interaction of its pocket domain with an LXCXE motif in histone deacetylase (HDAC) proteins such as HDAC1. Here, we demonstrate that HDAC5 deficient for the LXCXE motif interacts with both RB-N (via an FXXXV motif) and RB-C segments, and such interactions are diminished by phosphorylation of RB serine-249/threonine-252 and threonine-821. HDAC5 was frequently downregulated or deleted in human cancers such as prostate cancer. Loss of HDAC5 increased histone H3 lysine 27 acetylation (H3K27-ac) and circumvented RB-mediated repression of cell-cycle-related pro-oncogenic genes. HDAC5 loss also conferred resistance to CDK4/6 inhibitors such as palbociclib in prostate and breast cancer cells in vitro and prostate tumors in vivo, but this effect was overcome by the BET-CBP/p300 dual inhibitor NEO2734. Our findings reveal an unknown role of HDAC5 in RB-mediated histone deacetylation and gene repression and define a new mechanism modulating CDK4/6 inhibitor therapeutic sensitivity in cancer cells. SIGNIFICANCE: This study defines a previously uncharacterized role of HDAC5 in tumor suppression and provides a viable strategy to overcome CDK4/6 inhibitor resistance in HDAC5-deficent cancer.

DNA Damage Promotes TMPRSS2-ERG Oncoprotein Destruction and Prostate Cancer Suppression via Signaling Converged by GSK3ß and WEE1.

TMPRSS2-ERG gene fusion occurs in approximately 50% of cases of prostate cancer (PCa), and the fusion product is a key driver of prostate oncogenesis. However, how to leverage cellular signaling to ablate TMPRSS2-ERG oncoprotein for PCa treatment remains elusive. Here, we demonstrate that DNA damage induces proteasomal degradation of wild-type ERG and TMPRSS2-ERG oncoprotein through ERG threonine-187 and tyrosine-190 phosphorylation mediated by GSK3ß and WEE1, respectively. The dual phosphorylation triggers ERG recognition and degradation by the E3 ubiquitin ligase FBW7 in a manner independent of a canonical degron. DNA damage-induced TMPRSS2-ERG degradation was abolished by cancer-associated PTEN deletion or GSK3ß inactivation. Blockade of DNA damage-induced TMPRSS2-ERG oncoprotein degradation causes chemotherapy-resistant growth of fusion-positive PCa cells in culture and in mice. Our findings uncover a previously unrecognized TMPRSS2-ERG protein destruction mechanism and demonstrate that intact PTEN and GSK3ß signaling are essential for effective targeting of ERG protein by genotoxic therapeutics in fusion-positive PCa.

NF90 stabilizes cyclin E1 mRNA through phosphorylation of NF90-Ser382 by CDK2.

Nuclear factor 90 (NF90), an RNA-binding protein, has been implicated in regulating interleukin-2 (IL-2) and the immune response. It was recently reported that NF90 is upregulated in hepatocellular carcinoma (HCC) tissues and promotes HCC proliferation through upregulating cyclin E1 at the posttranscription level. However, the regulation of NF90 in HCC remains unclear. We demonstrate here that cyclin-dependent kinase (CDK) 2 interacts with NF90 and phosphorylated it at serine382. Mechanistically, phosphorylation of NF90-Ser382 determines the nuclear export of NF90 and stabilization of cyclin E1 mRNA. We also demonstrate that the phosphorylation deficient mutant NF90-S382A inhibits cell growth and induces cell cycle arrest at the G1 phase in HCC cells. Moreover, an NF90-S382A xenograft tumor had a decreased size and weight compared with the wildtype NF90. The NF90-S382A xenograft contained a significantly lower level of the proliferation marker Ki-67. Additionally, in HCC patients, NF90-Ser382 phosphorylation was stronger in tumor than in non-tumor tissues. Clinically, phosphorylation of NF90-Ser382 is significantly associated with larger tumor sizes, higher AFP levels, and shorter overall survival rates. These results suggest NF90-Ser382 phosphorylation serves as a potential diagnosis and prognostic marker and a promising pharmacological target for HCC.

Phosphorylated RB Promotes Cancer Immunity by Inhibiting NF-κB Activation and PD-L1 Expression.

Aberrant expression of programmed death ligand-1 (PD-L1) in tumor cells promotes cancer progression by suppressing cancer immunity. The retinoblastoma protein RB is a tumor suppressor known to regulate the cell cycle, DNA damage response, and differentiation. Here, we demonstrate that RB interacts with nuclear factor κB (NF-κB) protein p65 and that their interaction is primarily dependent on CDK4/6-mediated serine-249/threonine-252 (S249/T252) phosphorylation of RB. RNA-seq analysis shows a subset of NF-κB pathway genes including PD-L1 are selectively upregulated by RB knockdown or CDK4/6 inhibitor. S249/T252-phosphorylated RB inversely correlates with PD-L1 expression in patient samples. Expression of a RB-derived S249/T252 phosphorylation-mimetic peptide suppresses radiotherapy-induced upregulation of PD-L1 and augments therapeutic efficacy of radiation in vivo. Our findings reveal a previously unrecognized tumor suppressor function of hyperphosphorylated RB in suppressing NF-κB activity and PD-L1 expression and suggest that the RB-NF-κB axis can be exploited to overcome cancer immune evasion triggered by conventional or targeted therapies.

DUB3 Promotes BET Inhibitor Resistance and Cancer Progression by Deubiquitinating BRD4.

The bromodomain and extra-terminal domain (BET) protein BRD4 is emerging as a promising anticancer therapeutic target. However, resistance to BET inhibitors often occurs, and it has been linked to aberrant degradation of BRD4 protein in cancer. Here, we demonstrate that the deubiquitinase DUB3 binds to BRD4 and promotes its deubiquitination and stabilization. Expression of DUB3 is transcriptionally repressed by the NCOR2-HDAC10 complex. The NCOR2 gene is frequently deleted in castration-resistant prostate cancer patient specimens, and loss of NCOR2 induces elevation of DUB3 and BRD4 proteins in cancer cells. DUB3-proficient prostate cancer cells are resistant to the BET inhibitor JQ1 in vitro and in mice, but this effect is diminished by DUB3 inhibitory agents such as CDK4/6 inhibitor in a RB-independent manner. Our findings identify a previously unrecognized mechanism causing BRD4 upregulation and drug resistance, suggesting that DUB3 is a viable therapeutic target to overcome BET inhibitor resistance in cancer.

MiR-608 rs4919510 is associated with prognosis of hepatocellular carcinoma.

Single nucleotide polymorphisms (SNPs) within microRNAs (miRNAs) are considered potential markers for risk and prognosis of various cancers. In the current study, we aimed to determine whether miR-608 rs4919510 affected hepatocellular carcinoma (HCC) prognosis. We genotyped rs4919510 using DNA from blood samples of 362 HCC patients receiving surgical resection of HCC tumor. Associations between rs4919510 and overall survival (OS) and demographic characteristics and clinical features were estimated using the Cox proportional hazards model. Results showed that HCC patients who carried the rs4919510 CC genotype had a significantly longer OS compared to those who carried the GG genotype (P = 0.013, hazard ratio [HR] = 0.600, 95 % confidence interval [CI] 0.402-0.897) and the CG + GG genotype (P = 0.033, HR = 0.681, 95 % CI 0.479-0.970) in univariate analysis. Similar results were obtained in multivariate analysis. Further stratification analysis indicated that rs4919510 was significantly associated with OS in patients who were satisfied with one of the following criteria: male gender, HbsAg-positive, α-fetoprotein (AFP)-positive, tumor size >5 cm, cirrhosis, solitary tumor, I + II pTNM stage, or no tumor capsule. Finally, a significantly higher frequency of rs4919510 CC genotype was observed in patients with cirrhosis (22.9 %, 55/240) than those without cirrhosis (14.0 %, 17/121) (P = 0.047). In conclusion, our results illustrated the potential role of miR-608 rs4919510 as a prognostic marker for HCC patients undergoing surgical resection of the tumor.

miR-492G>C polymorphism (rs2289030) is associated with overall survival of hepatocellular carcinoma patients.

Single-nucleotide polymorphisms (SNPs) of microRNAs (miRNAs) are considered potential markers of cancer risk and prognosis in various cancers. In the current study, the primary aim is to determine whether the miR-492G>C polymorphism (rs2289030) altered hepatocellular carcinoma (HCC) prognosis. The SNP rs2289030 of miR-492 was genotyped using DNA from blood samples of 362 HCC patients that had undergone surgical resection of a HCC tumor. The associations between overall survival and demographic characteristics, clinical features, and the SNP rs2289030 were estimated using the Cox proportional hazards model. Results showed that patients who carried the CG genotype (P = 0.015, hazard ratio [HR] = 0.704, 95 % confidence interval [CI] 0.530-0.934) and CG+GG genotype (P = 0.011, HR = 0.703, 95 % CI 0.536-0.924) had significantly decreased risk of death compared to those with the CC genotype. Similar results were found in the multivariate analysis adjusted by tumor size and venous invasion. Further stratification analysis indicated that the effect of rs2289030 had more prominence in patients ≤50 years old and that reported ever using alcohol, male gender, a family history of HCC, being HbsAg or alpha fetoprotein (AFP) positive, differentiation I + II, presence of venous invasion or cirrhosis, multiple tumors, and pTNM stage I + II. Results from this study illustrate the potential use of miR-492 rs2289030 as a prognostic marker for HCC patients that have undergone a surgical resection of the tumor.

Genetic polymorphisms in apoptosis-related genes and the prognosis of hepatocellular carcinoma.

The apoptotic pathway is important in the control of vital processes of hepatocellular carcinoma (HCC). In the current study, we aimed to determine whether apoptotic gene-related polymorphisms modified HCC prognosis. We genotyped 16 single nucleotide polymorphisms (SNPs) in 10 core genes (TP53, TP53INP1, TP53BP1, CDKN2A, CDKN1A, CDKN1B, MDM2, BAX, CCDN1 and BCL2) in the apoptotic pathway by using DNA from blood samples of 362 HCC patients receiving surgical resection of HCC tumor. The associations between genotypes/haplotypes of the 10 genes and overall survival (OS) of HCC patients were assessed using the Cox proportional hazards model. We found one CDKN1B haplotype CCT/ACT (constructed by rs36228499 C>A, rs34330 C>T and rs2066827 T>G) significantly associated with decreased OS of HCC patients, compared to the common haplotype ACT/CTT both in univariate analysis (P=0.013, HR=1.198, 95% CI: 1.039-1.381) and multivariate analysis (P=0.006, HR=1.224, 95% CI: 1.059-1.413). We also find two SNPs (rs560191 G>C and rs2602141 T>G) in TP53BP1 shown to be marginally significantly associated with decreased OS of HCC patients. However, none of the other SNPs or haplotypes were significantly associated with HCC OS. Our results illustrated the potential use of CDKN1B haplotype as a prognostic marker for HCC patients with surgical resection of tumor.

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

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

TRIM5α H43Y Polymorphism and Susceptibility to HIV-1 Infection: A Meta-Analysis.

TRIM5α is an antiviral factor that can greatly limit HIV-1 infection. Although several researchers have investigated whether TRIM5α H43Y polymorphism influences the risk of HIV-1 infection, no definite conclusion has ever been drawn. In this research, we performed a meta-analysis to generate a more robust estimate of the association between TRIM5α H43Y and susceptibility to HIV-1 infection. In total, six studies including 1,713 HIV-1 patients and 1,814 controls were included. TRIM5α H43Y polymorphisms of all individuals were genotyped. Odds ratios (ORs) with 95% confidence intervals were presented as the result of analysis. ORs for the main analysis were 0.82 (95% CI: 0.63-1.08) in the allelic comparison, 0.57 (95% CI: 0.34-0.95) in the homozygote comparison, 0.82 (95% CI: 0.57-1.16) in the dominant model, and 0.56 (95% CI: 0.33-0.93) in the recessive model. In the subgroup analysis by ethnicity, significantly decreased risks of infection were detected in the Asian population (homozygote comparison: 0.50, 95% CI: 0.28-0.89; recessive model: 0.49, 95% CI: 0.28-0.87), whereas such effects were not observed in the non-Asian population. Our meta-analysis indicates that TRIM5α H43Y polymorphism is associated with a decreased risk of HIV-1 infection in the homozygote comparison and recessive model. This polymorphism may act as a protective factor against HIV-1 infection, especially in Asians.

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

UNLABELLED: 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.

Epidermal growth factor receptor pathway polymorphisms and the prognosis of hepatocellular carcinoma.

The EGFR signaling pathway is important in the control of vital processes in the carcinogenesis of hepatocellular carcinoma (HCC), including cell survival, cell cycle progression, tumor invasion and angiogenesis. In the current study, we aim to assess if genetic variants in the genes of the EGFR signaling pathway are associated with the prognosis of HCC. We genotyped 36 single nucleotide polymorphisms (SNP) in four core genes (EGF, EGFR, VEGF, and VEGFR2) by using DNA from blood samples of 363 HCC patients with surgical resection. The associations between genotypes and overall survival (OS) and disease-free survival (DFS) were estimated using the Kaplan-Meier method. Hazard ratios (HRs) and 95% confident intervals (CIs) were estimated for the multivariate survival analyses by Cox proportional hazards regression models, adjusting for age, gender, family history, HBsAg and AFP. We found that five SNPs in the VEGFR2 gene were significantly associated with clinical outcomes of HCC patients. Among them, four SNPs (rs7692791, rs2305948, rs13109660, rs6838752) were associated with OS (p=0.035, 0.038, 0.029 and 0.028, respectively), and two SNPs (rs7692791 and rs2034965) were associated with DFS (p=0.039 and 0.017, respectively). Particularly, rs7692791 TT genotype was associated with both reduced OS (p=0.037) and DFS (p=0.043). However, only one SNP rs2034965 with the AA genotype was shown to be an independent effect on DFS (p=0.009) in the multivariate analysis. None of the other 31 polymorphisms or 9 haplotypes attained from the four genes was significantly associated with OS or DFS. Our results illustrated the potential use of VEGFR2 polymorphisms as prognostic markers for HCC patients.