Primary mucinous adenocarcinoma of the urethra: A clinicopathological analysis of 35 cases

AIM

Primary mucinous adenocarcinoma of the urethra represents an extremely rare entity. We sought to characterise further these tumours' clinicopathological, immunohistochemical and molecular features.

METHODS AND RESULTS

Thirty-five cases were identified, occurring in 18 males and 17 females. The mean age at diagnosis was 65 years (28-89 years). The main presentation symptoms were haematuria and urinary outlet obstruction. Microscopic analysis revealed that all 35 tumours have stromal dissection by mucin. Ten tumours showed villoglandular dysplasia, nine showed mucinous metaplasia, two showed adenocarcinoma in situ and four showed signet ring cell features. All tumours were immunopositive for CEA, while immunonegative for nuclear β-catenin; 19 of 23 (83%) expressed high molecular weight cytokeratin; 19 of 33 (58%) CK7; 28 of 34 (82%) CK20; 32 of 35 (91%) CDX2; 22 of 27 (81%) cadherin-17 (CDH-17); 26 of 29 (90%) SATB2; and one of 31 (3%) GATA3. Mismatch repair gene products, including MLH1, PMS2, MSH2 and MSH6, were immunopositive, suggesting the MSI-low genotype of mucinous adenocarcinoma of the urethra. BRAF V600E and ALK rearrangements were not detected. During the mean follow-up of 20 months, nine patients either developed distant metastasis or succumbed to the illness.

CONCLUSION

Our study, encompassing the most extensive series of 35 cases of primary mucinous adenocarcinoma of the urethra, provides crucial insights into its precise diagnosis, management and potential targeted treatments. We found a greater CDX2, SATB2 and CDH17 sensitivity in these urethral tumours for the first time, to our knowledge. We identified characteristics such as an MSI-low profile, non-V600E BRAF mutations and an absence of ALK rearrangements.

Lacticaseibacillus rhamnosus GG Improves Periodontal Bone Repair via Gut-Blood Axis in Hyperlipidemia

Periodontal bone regeneration remains a clinical challenge, and hyperlipidemia can aggravate alveolar bone resorption. Probiotics have recently been reported to improve bone mass. We aimed to determine the role of Lacticaseibacillus rhamnosus GG (LGG) in periodontal bone regeneration improvement within the context of periodontitis with hyperlipidemia. A Sprague Dawley rat model for periodontitis, hyperlipidemia, and periodontal fenestration defect was constructed (n = 36) and administered LGG gavage for 6 wk (the rats were subsequently sacrificed). Fecal microbiota from donor rats 3 wk after LGG gavage was transplanted into recipient rats to evaluate the role of LGG-modulated gut microbiota in periodontal bone regeneration. Regenerated bone mass was detected using micro-computerized tomography and hematoxylin and eosin stain. Gut microbiota was analyzed using 16S ribosomal RNA sequencing. Serum metabolites were detected by liquid chromatography-mass spectrometry (6 wk after LGG gavage). The pro-osteogenic effects of screened serum metabolite were verified in vitro on bone marrow mesenchymal stem cells (BMMSCs). We found that the bone mineral density, bone volume (BV), trabecular bone volume fraction (BV/TV), and trabecular thickness of the regenerated periodontal bone increased after LGG gavage (P < 0.05) but had little effect on oral flora. After LGG gavage, Staphylococcus, Corynebacterium, and Collinsella in the gut of donors were significantly changed, and these differences were maintained in recipients, who also showed increased trabecular thickness of the regenerated periodontal bone (P < 0.05). These key genera were correlated with BV/TV and BV (P < 0.05). In addition, LGG gavage significantly regulated bone-related blood metabolites, of which selenomethionine promoted BMMSC osteogenesis. Notably, selenomethionine was associated with key gut genera (P < 0.05). Collectively, LGG improved periodontal bone regeneration in the context of periodontitis with hyperlipidemia by modulating gut microbiota and increasing pro-osteogenic metabolites in the blood. These results reveal new insights into the use of probiotics to promote periodontal bone regeneration via the gut-blood-bone axis.

Frequent Telomerase Reverse Transcriptase (TERT) Promoter and Fibroblast Growth Factor Receptor 3 (FGFR3) Mutations Support the Precursor Nature of Papillary Urothelial Hyperplasia of the Urinary Bladder

The precursor nature of papillary urothelial hyperplasia of the urinary bladder is uncertain. In this study, we investigated TERT promoter and FGFR3 mutations in 82 patients with papillary urothelial hyperplasia lesions. Thirty eight patients presented with papillary urothelial hyperplasia and concurrent non-invasive papillary urothelial carcinoma and 44 patients presented with de novo papillary urothelial hyperplasia. The prevalence of TERT promoter and FGFR3 mutation are compared between de novo papillary urothelial hyperplasia and those with concurrent papillary urothelial carcinoma. Mutational concordance between papillary urothelial hyperplasia and concurrent carcinoma were also compared. The TERT promoter mutations were detected in 44% (36/82) of papillary urothelial hyperplasia including 23 (23/38, 61%) papillary urothelial hyperplasia with urothelial carcinoma, and 13 (13/44, 29%) de novo papillary urothelial hyperplasia. The overall concordance of TERT promoter mutation status between papillary urothelial hyperplasia and concurrent urothelial carcinoma was 76%. Overall FGFR3 mutation rate of papillary urothelial hyperplasia was 23% (19/82). FGFR3 mutations were detected in 11 patients with papillary urothelial hyperplasia and concurrent urothelial carcinoma (11/38, 29%), and 8 patients with de novo papillary urothelial hyperplasia (8/44, 18%). Identical FGFR3 mutation status was detected in both papillary urothelial hyperplasia and urothelial carcinoma component in all 11 patients with FGFR3 mutations. Our findings provide strong evidence of genetic association between papillary urothelial hyperplasia and urothelial carcinoma. High frequency of TERT promoter and FGFR3 mutations suggests the precursor role of papillary urothelial hyperplasia in urothelial carcinogenesis.

[Expert consensus on the management of adverse events of CDK4/6 inhibitors in breast cancer]

Cyclin-dependent kinases 4/6 (CDK4/6) inhibitors are anti-tumor agents for the treatment of hormone receptor-positive breast cancer. Palbociclib, abemaciclib and dalpiciclib have been approved for the treatment of breast cancer in China. Common adverse effects of CDK4/6 inhibitors include bone marrow suppression, gastrointestinal toxicities, liver dysfunction, and skin or subcutaneous tissue adverse reactions (AEs). The Breast Cancer Expert Group of Chinese Society of Clinical Oncology (CSCO) summarized the incidence, clinical manifestations, and grading of the AEs. This expert consensus reports measures of AE management on the basis of experience of clinical practice and the latest advances worldwide, aiming to guide clinical practice by the way of managing AE and help to choose the best treatment regimen.

Tumor microenvironment heterogeneity an important mediator of prostate cancer progression and therapeutic resistance

Prostate cancer is characterized by a high degree of heterogeneity, which poses a major challenge to precision therapy and drug development. In this review, we discuss how nongenetic factors contribute to heterogeneity of prostate cancer. We also discuss tumor heterogeneity and phenotypic switching related to anticancer therapies. Lastly, we summarize the challenges targeting the tumor environments, and emphasize that continued exploration of tumor heterogeneity is needed in order to offer a personalized therapy for advanced prostate cancer patients.

[Analysis on the HIV-1 molecular transmission characteristics of newly confirmed HIV/AIDS in Jiaxing city, 2017-2018]

Objective: To analyze the relationship between infection and transmission of HIV/AIDS, explore the characteristics of the HIV-1 transmission network, and provide evidence for formulating targeted prevention and control measures. Methods: The newly confirmed HIV/AIDS in Jiaxing from 2017 to 2018 were selected for the study. The sociodemographic and infection transmission-related information was gathered. The blood samples were collected and RNA was extracted, RT-PCR and nested PCR amplified the pol gene of HIV-1. The phylogenetic tree was constructed by Mega 6.0 software for subtype analysis. The genetic distance between strains was calculated, and the molecular transmission network was drawn by using Cytoscape 3.6.0 software. The results of the epidemiological study based on the molecular transmission network were analyzed. Results: There were fifteen HIV-1 gene subtypes in 517 cases of HIV/AIDS. The main subtypes were CRF01_AE (37.1%)、CRF07_BC (36.2%) and CRF08_BC (11.8%). Under the 1.0% gene distance threshold, 87 molecular clusters were established, and the total clustering rate was 45.8% (237/517). The cluster risk factors were 60-81 age group (compared with 14-24 age group, OR=2.690, 95%CI:1.058-6.844), married (compared with unmarried, OR=1.698, 95%CI:1.003-2.875), CRF07_BC subtype (compared with CRF01_AE, OR=2.203, 95%CI:1.426-3.404). The largest molecular cluster, CRF07_BC-1, consisted of 50 cases (including 21 cases confirmed in 2017 cases and 29 confirmed in 2018). Multivariate analysis showed that characteristics of unmarried (compared with married, OR=2.482, 95%CI:1.140-5.402), gays (compared with heterosexual, OR=3.163, 95%CI:1.543-6.483), cases with high-risk transmission (compared with other cases, OR=7.631, 95%CI:1.783-32.654), confirmed in Nanhu and Pinghu districts of Jiaxing (compared with other districts, OR=2.225, 95%CI:1.074-4.608) were risks for entering the largest molecular cluster. There were seven suspected high-risk transmission MSM in the largest molecular cluster. The first debut of homosexual behavior was from 2010 to 2018, and the median number of gay partners was 20 (P₂₅, P₇₅：10, 100) within two years before being diagnosed. Six reported a recent history of looking for gay partners in an MSM dating place in Nanhu district. Conclusions: The HIV-1 subtypes of newly confirmed HIV/AIDS were diverse, mainly sporadic in Jiaxing from 2017 to 2018. There were geographical aggregation characteristics and suspected some high-risk transmission cases, suggesting that rapid transmission and targeted intensive intervention are needed.

[Clinicopathological features of polymorphous low-grade neuroepithelial tumor of the young]

Objective: To investigate the clinicopathological features, diagnosis and prognosis of polymorphous low-grade neuroepithelial tumor of the young (PLNTY). Methods: Two cases of PLNTY diagnosed during January 2016 to December 2019 were collected from Ningbo Diagnostic Pathology Center, Zhejiang, China. The clinical features, histopathological characteristics, immunohistochemical and molecular genetic findings were analyzed and the relevant literature was reviewed. Results: The two patients were both female, at the ages of 14 and 25 years, respectively. Both patients presented with seizure attacks. The imaging study showed a mixed signal in the cerebral cortex, located in the occipital and temporal lobes, respectively. Microscopically, the tumors were characterized by the invariable presence of oligodendroglioma-like appearance, often with calcification. Immunohistochemically, the tumors were diffusely and intensely CD34 positive with ramified, CD34-expressing neural elements in regional cortex. The tumors were positive for GFAP, Olig2 and ATRX, and negative for IDH1, Neu N, nestin and EMA. The Ki-67 labeling index was less than 2%. The case number 2 harbored the BRAF V600E mutation, while the case number 1 was negative for both the BRAF V600E mutation and 1p/19q codeletion. Both patients recovered very well and were free of seizures after the following-up of 2 and 24 months, respectively. Conclusions: PLNTY is an uncommon neuroepithelial tumor. Histopathologic and immunohistochemical examinations are necessary for establishing the diagnosis and for excluding oligodendroglioma. PLNTY should be considered as a benign tumor corresponding to WHO Grade I. The prognosis is overall good after complete tumor-resection.

Methylation of SRD5A2 promoter predicts a better outcome for castration-resistant prostate cancer patients undergoing androgen deprivation therapy

PURPOSE

To determine whether SRD5A2 promoter methylation is associated with cancer progression during androgen deprivation therapy (ADT) in CRPC.

PATIENTS AND METHODS

In a Local CRPC cohort, 42 prostatic specimens were collected from patients who were diagnosed as CRPC and underwent transurethral resection of the prostate (TURP) at Massachusetts General Hospital (MGH). In a metastatic CRPC (Met CRPC) cohort, 12 metastatic biopsies were collected from CRPC patients who would be treated with abiraterone plus dutasteride (Clinical Trial NCT01393730). As controls, 36 benign prostatic specimens were collected from patients undergoing prostate reduction surgery for symptoms of bladder outlet obstruction secondary to benign prostatic hyperplasia (BPH). The methylation status of cytosine-phosphate-guanine (CpG) site(s) at SRD5A2 promoter regions was tested.

RESULTS

Compared with benign prostatic tissue, CRPC samples demonstrated higher SRD5A2 methylation in the whole promoter region (Local CRPC cohort: P < 0.001; Met CRPC cohort: P <0.05). In Local CRPC cohort, a higher ratio of methylation was correlated with better OS (R2 = 0.33, P = 0.013). Hypermethylation of specific regions (nucleotides -434 to -4 [CpG# -39 to CpG# -2]) was associated with a better OS (11.3±5.8 vs 6.4±4.4 years, P = 0.001) and PFS (8.4±5.4 vs 4.5±3.9 years, P = 0.003) with cutoff value of 37.9%. Multivariate analysis showed that SRD5A2 methylation was associated with OS independently (whole promoter region: P = 0.035; specific region: P = 0.02).

CONCLUSION

Our study demonstrate that SRD5A2 methylation in promoter regions, specifically at CpG# -39 to -2, is significantly associated with better survival for CRPC patients treated with ADT. Recognition of epigenetic modifications of SRD5A2 may affect the choices and sequence of available therapies for management of CRPC.

[Epidemiological characteristics of molecular transmission cluster among reported HIV/AIDS cases in Jiaxing city, Zhejiang province, 2017]

Objective: To understand the epidemiological characteristics of one large HIV molecular transmission cluster in Jiaxing city, Zhejiang province, 2017 in order to select those people under high-risk and providing basis for programs on prevention. Methods: During 2017, newly diagnosed HIV/AIDS cases in this city were recruited. Plasma samples were collected from subjects, followed by RNA extraction, RT-PCR and nest-PCR for pol gene amplification, before being sequenced and aligned. Mega 6.0 software was used to construct phylogenetic tree, and Cytoscape 3.6.0 software was used to identify HIV molecular transmission clusters. Cases within the large transmission clusters were investigated, using a field-epidemiology-questionnaire. Data related to socio-demographics and previous sexual behaviors were collected and EpiData 3.0 and SPSS 20.0 software were used. Results: In the large transmission cluster with subtype identified as CRF07_BC, in Jiaxing, 2017, 26 cases of the total 30 cases were investigated. A total of 80.8% (21/26) could be identified as newly infected within the last two years and 30.8%(8/26) could be identified as newly infected within the last one year, including 22 cases infected locally. Among several infected cases who were at age 45 years or older, they admitted that they had experienced unprotected sexual contacts in local city for long time and having had more than 10 disclosed sexual contacts within the last two years at the local venues. Conclusions: This molecular cluster had been formed and scaled up quickly in recent two years, it has played an important role in promoting and scaling up the HIV transmission. Three cases identificed as high risk played an importantrde role in scaling up this cluster.

Design for a Nanoscale Single-Photon Spin Splitter for Modes with Orbital Angular Momentum

We propose using the effective spin-orbit coupling of light in Bragg-modulated cylindrical waveguides for the efficient separation of spin-up and spin-down photons emitted by a single photon emitter. Because of the spin and directional dependence of photonic stop bands in the waveguides, spin-up (-down) photon propagation in the negative (positive) direction along the waveguide axis is blocked while the same photon freely propagates in the opposite direction. Frequency shifts of photonic band structures induced by the spin-orbit coupling are verified by finite-difference time-domain numerical simulations.

Androgenic to oestrogenic switch in the human adult prostate gland is regulated by epigenetic silencing of steroid 5α-reductase 2

Benign prostatic hyperplasia is the most common proliferative abnormality of the prostate. All men experience some prostatic growth as they age, but the rate of growth varies among individuals. Steroid 5α-reductase 2 (SRD5A2) is a critical enzyme for prostatic development and growth. Previous work indicates that one-third of adult prostatic samples do not express SRD5A2, secondary to epigenetic modifications. Here we show that the level of oestradiol is dramatically elevated, concomitant with significant upregulation of oestrogen response genes, in prostatic samples with methylation at the SRD5A2 promoter. The phosphorylation of oestrogen receptor-α in prostatic stroma is upregulated when SRD5A2 expression is absent. We show that tumour necrosis factor (TNF)-α suppresses SRD5A2 mRNA and protein expression, and simultaneously promotes expression of aromatase, the enzyme responsible for conversion of testosterone to oestradiol. Concomitant suppression of SRD5A2 and treatment with TNF-α synergistically upregulate the aromatase levels. The data suggest that, in the absence of prostatic SRD5A2, there is an androgenic to oestrogenic switch. These findings have broad implications for choosing appropriate classes of medications for the management of benign and malignant prostatic diseases. Copyright © 2017 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.

Changes in IL-4 and IL-13 expression in allergic-rhinitis treated with hydrogen-rich saline in guinea-pig model

BACKGROUND

Medical gas hydrogen (H₂) has a special role in airway inflammation; however, the effect of H₂ on allergic rhinitis (AR) remains unclear. This study explored the possible roles of H2 on the pathogenesis of AR and observed the influences of H₂ on cytokines IL-4 and IL-13.

METHODS

An AR guinea pig model was established by nasal ovalbumin sensitisation. Eighteen guinea pigs were divided into three groups, namely, saline control, AR-sensitised, and hydrogen-rich saline (HRS)-treated groups, with each group having six guinea pigs. The frequencies of sneezing and scratching were recorded. The IgE level and cytokine (IL-4 and IL-13) levels in the serum were measured. The expression levels of IL-4 and IL-13 mRNA and protein in the nasal mucosa were also determined by real-time reverse transcriptase-polymerase chain reaction and Western blot. We also observed the infiltration of cytokine (IL-4 and IL-13) in nasal mucosa by immunofluorescence.

RESULTS

The frequencies of sneezing and scratching, as well as the levels of IgE, IL-4, and IL-13, in the serum were higher in the AR group than in the control group (p<0.01), whereas all these parameters were decreased significantly after HRS treatment (p<0.05). The expression levels of IL-4 and IL-13 mRNA and protein in the nasal mucosa were also lower in guinea pigs treated with HRS than those in the AR group (p<0.05).

CONCLUSIONS

HRS could affect anti-inflammation in AR and decreased the expression of IL-4 and IL-13.

Metformin inhibits the proliferation of benign prostatic epithelial cells

OBJECTIVE

Benign prostatic hyperplasia (BPH) is the most common proliferative abnormality of the prostate affecting elderly men throughout the world. Epidemiologic studies have shown that diabetes significantly increases the risk of developing BPH, although whether anti-diabetic medications preventing the development of BPH remains to be defined. We have previously found that stromally expressed insulin-like growth factor 1 (IGF-1) promotes benign prostatic epithelial cell proliferation through paracrine mechanisms. Here, we seek to understand if metformin, a first line medication for the treatment of type 2 diabetes, inhibits the proliferation of benign prostatic epithelial cells through reducing the expression of IGF-1 receptor (IGF-1R) and regulating cell cycle.

METHODS

BPE cell lines BPH-1 and P69, murine fibroblasts3T3 and primary human prostatic fibroblasts were cultured and tested in this study. Cell proliferation and the cell cycle were analyzed by MTS assay and flow cytometry, respectively. The expression of IGF-1R was determined by western-blot and immunocytochemistry. The level of IGF-1 secretion in culture medium was measured by ELISA.

RESULTS

Metformin (0.5-10mM, 6-48h) significantly inhibited the proliferation of BPH-1 and P69 cells in a dose-dependent and time-dependent manner. Treatment with metformin for 24 hours lowered the G2/M cell population by 43.24% in P69 cells and 24.22% in BPH-1 cells. On the other hand, IGF-1 (100ng/mL, 24h) stimulated the cell proliferation (increased by 28.81% in P69 cells and 20.95% in BPH-1 cells) and significantly enhanced the expression of IGF-1R in benign prostatic epithelial cells. Metformin (5mM) abrogated the proliferation of benign prostatic epithelial cells induced by IGF-1. In 3T3 cells, the secretion of IGF-1 was significantly inhibited by metformin from 574.31pg/ml to 197.61pg/ml. The conditioned media of 3T3 cells and human prostatic fibroblasts promoted the proliferation of epithelial cells and the expression of IGF-1R in epithelial cells. Metformin abrogated the proliferation of benign prostatic epithelial cells promoted by 3T3 conditioned medium.

CONCLUSIONS

Our study demonstrates that metformin inhibits the proliferation of benign prostatic epithelial cells by suppressing the expression of IGF-1R and IGF-1 secretion in stromal cells. Metformin lowers the G2/M cell population and simultaneously increases the G0/G1 population. Findings here might have significant clinical implications in management of BPH patients treated with metformin.

Metformin represses cancer cells via alternate pathways in N-cadherin expressing vs. N-cadherin deficient cells

Metformin has emerged as a potential anticancer agent. Here, we demonstrate that metformin plays an anti-tumor role via repressing N-cadherin, independent of AMPK, in wild-type N-cadherin cancer cells. Ectopic-expression of N-cadherin develops metformin-resistant cancer cells, while suppression of N-cadherin sensitizes cancer to metformin. Manipulation of AMPK expression does not alter sensitivity of cancer to metformin. We show that NF-kappaB is a downstream molecule of N-cadherin and metformin regulates NF-kappaB signaling via suppressing N-cadherin. Moreover, we also suggest that TWIST1 is an upstream molecule of N-cadherin/NF-kappaB signaling and manipulation of TWIST1 expression changes the sensitivity of cancer cells to metformin. In contrast to the cells that express N-cadherin, in N-cadherin deficient cells, metformin plays an anti-tumor role via activation of AMPK. Ectopic expression of N-cadherin makes cancer more resistant to metformin. Therefore, we suggest that metformin's anti-cancer therapeutic effect is mediated through different molecular mechanism in wild-type vs. deficient N-cadherin cancer cells. At last, we selected 49 out of 984 patients' samples with prostatic cancer after radical prostatectomy (selection criteria: Gleason score ≥ 7 and all patients taking metformin) and showed levels of N-cadherin, p65 and AMPK could predict post-surgical recurrence in prostate cancer after treatment of metformin.

Epigenetic silencing and variable expression of SRD5A2 in specific compartments of human prostate

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Background: The steroid-5α reductase type 2 gene (SRD5A2) and protein play a significant role in the development and growth of prostate tissue. SRD5A2 can be expressed in both the epithelial and stromal compartments of the prostate gland. Previously, we have shown that somatic suppression of SRD5A2 during adulthood is dependent on epigenetic changes associated with methylation of the promoter region of the SRD5A2 gene. Here we determined whether variability of SRD5A2 expression occurs in specific compartments of prostate tissues. Methods: Frozen and formalin-fixed sections of human adult prostate tissue was used. Laser capture microdissection (LCM) was performed to obtain a pure population of epithelial and stromal cells. Approximately 500–600 excised cells were captured, and the methylation pattern of SRD5A2 was determined by DNA methylation pull-down assay kit. The expression of SRD5A2 protein was identified with immunohistochemistry and quantitated by ELISA. Results: In the whole prostate tissue, samples with high SRD5A2 immunoreactivity had much lower levels of SRD5A2 promoter methylation compared to those with low SRD5A2 immunoreactivity. DNA methylation assay for the epithelial compartment closely resembled the findings of the whole prostate tissue. In contrast, the samples from the stromal compartment showed uniform methylation irrespective of the methylation pattern in the epithelial compartment or the whole tissue. The expression of SRD5A2 protein quantitated by ELISA further showed that the variable expression of SRD5A2 is better determined by epithelial compartment expression. Conclusions: Our data suggests that variability of SRD5A2 expression is dependent on the methylation pattern and expression of SRD5A2 in the epithelial compartment and not the stroma. Therefore, if epithelial expression of SRD5A2 is more representative of the whole prostatic tissue expression, then it is logical that SRD5A2 inhibitor’s efficacy is dependent on involution of the epithelial cells. Our findings will have broad implications for the use of 5ARIs in the treatment of BPH and for the chemoprevention of prostate cancer. Grant support: NIH/R01 DK091353

Gene expression profiling of prostate tissue based on variable expression of 5-alpha reductase 2

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Background: Androgen signaling plays a central role in the pathophysiology of both benign and malignant prostatic disease. We previously showed that some men carry epigenetic modifications of the 5-alpha reductase (AR) promoter that modulate gene expression, raising the hypothesis that there may be molecular heterogeneity underlying the variability in clinical response to 5-AR inhibitors for management of benign and malignant prostatic diseases. In this study, we performed whole-genome expression profiling of prostatic tissue based on variable expression of 5-AR2 to determine whether molecular subtypes of clinical relevance could be identified. Methods: Prostatic tissue specimens were obtained from 22 patients with symptomatic BPH undergoing prostate debulking surgery. 5-AR2 protein expression was measured by immunohistochemistry, and 5-AR2 promoter methylation determined by PCR. RNA was extracted from each specimen and whole-genome expression profiling was performed using Illumina Human BeadChip Arrays. Gene expression data was analyzed by unsupervised hierarchical clustering and Gene Set Enrichment Analysis. Results: Unsupervised hierarchical clustering identified two subtypes of patients with distinct gene expression signatures. Among the most differentially expressed genes were several notable androgen-regulated genes, including TMPRSS2, NKX3-1, AZGP1, KLK3 (encoding the PSA protein) and multiple other members of the kallikrein family of serine proteases (all P< 0.001, FDR < 0.02). Multiple gene sets composed of androgen-regulated genes and androgen receptor target genes were found to be significantly enriched in one of the two subtypes. Interestingly, patients from this Androgen-Up subtype were also noted to have a higher frequency of 5-AR2 promoter methylation (though not statistically significant). Conclusions: Our findings suggest that there are distinct molecular subtypes among prostatic tissues with variable expression of 5-AR2, driven by differences in androgen gene regulation. These differences may partially explain the variable response to 5-AR inhibitors and thereby inform clinical strategies for devising therapies for benign and malignant prostatic disease.

Regulation of steroid-5-alpha-reductase 2 (SRD5A2) in human prostate by epigenetic modifications

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Background: 5-alpha reductase type 2 (SRD5A2), an enzyme that is critical for prostatic development and growth. We have found that many aging prostate tissues do not express the enzyme. We previously showed that expression of SRD5A2 is not static and epigenetic modulations by DNA methyltransferase and pro-inflammatory cytokines play important roles in silencing of SRD5A2. Here we wished to define the methylation pattern and identify specific CpG dinucleotides that are methylated in the SRD5A2promoter region. Methods: Ninety six prostate samples from patients were obtained by transurethral resection of prostate (TURP). Methylation of SRD5A2 promoter was assessed using Methylated CpG Island Recovery Assay (MIRA). Bisulfide conversion of Genomic DNA was performed using Epimark bisulfide conversion kit. Primers for bisulfide sequencing were designed using MethPrimer software and bisulfide sequencing was performed using 3730XL DNA Sequencers. Binding of histone demethylase to promoter DNA was analyzed by ChiP assay. Results: We randomly selected 3 TURP samples with methylated SRD5A2 promoters and 3 TURP samples with un-methylated SRD5A2 promoters, and then bisulfide conversion and sequencing were performed to verify the methylation pattern of CpG dinucleotides on SRD5A2 promoter. We found that bisulfide sequencing analysis of SRD5A2 promoter was consistent with MIRA analysis. To further analyze the mediators of SRD5A2 promoter region, we show that TNF-alpha up-regulates expression of Snail protein, which is a central regulator of both DNA methylation and histone methylation, and increases the binding of H3K9me to SRD5A2promoter region, but not H3K27me or H4K20me. Conclusions: Methylation of SRD5A2 promoter, which is regulated by DNMT1, proinflammatory cytokines and the histone methylase, H3K9me, accounts for suppression of SRD5A2 in many adult human prostate tissues. Bisulfide conversion and sequencing confirm and focus the specified CpG dinucleotides that are methylated enabling us to evaluate mechanisms and patterns of SRD5A2 promoter methylation in order to study the functional significance of SRD5A2 methylation. Grant support: NIH/R01 DK091353.

Age and Obesity Promote Methylation and Suppression of 5α-Reductase 2: Implications for Personalized Therapy of Benign Prostatic Hyperplasia

PURPOSE

In men with symptomatic benign prostatic hyperplasia 5α-reductase inhibitors are a main modality of treatment. More than 30% of men do not respond to the therapeutic effects of 5α-reductase inhibitors. We have found that a third of adult prostate samples do not express 5α-reductase type 2 secondary to epigenetic modifications. We evaluated whether 5α-reductase type 2 expression in benign prostatic hyperplasia specimens from symptomatic men was linked to methylation of the 5α-reductase type 2 gene promoter. We also identified associations with age, obesity, cardiac risk factors and prostate specific antigen.

MATERIALS AND METHODS

Prostate samples from men undergoing transurethral prostate resection were used. We determined 5α-reductase type 2 protein expression and gene promoter methylation status by common assays. Clinical variables included age, body mass index, hypertension, hyperlipidemia, diabetes, prostate specific antigen and prostate volume. Univariate and multivariate statistical analyses were performed followed by stepwise logistic regression modeling.

RESULTS

Body mass index and age significantly correlated with methylation of the 5α-reductase type 2 gene promoter (p <0.05) whereas prostate volume, prostate specific antigen or benign prostatic hyperplasia medication did not correlate. Methylation highly correlated with 5α-reductase protein expression (p <0.0001). In a predictive model increasing age and body mass index significantly predicted methylation status and protein expression (p <0.01).

CONCLUSIONS

Increasing age and body mass index correlate with increased 5α-reductase type 2 gene promoter methylation and decreased protein expression in men with symptomatic benign prostatic hyperplasia. These results highlight the interplay among age, obesity and gene regulation. Our findings suggest an individualized epigenetic signature for symptomatic benign prostatic hyperplasia, which may be important to choose appropriate personalized treatment options.

DNA methyl transferase 1 reduces expression of SRD5A2 in the aging adult prostate

5-α Reductase type 2 (SRD5A2) is a critical enzyme for prostatic development and growth. Inhibition of SRD5A2 by finasteride is used commonly for the management of urinary obstruction caused by benign prostatic hyperplasia. Contrary to common belief, we have found that expression of SRD5A2 is variable and absent in one third of benign adult prostates. In human samples, absent SRD5A2 expression is associated with hypermethylation of the SRD5A2 promoter, and in vitro SRD5A2 promoter activity is suppressed by methylation. We show that methylation of SRD5A2 is regulated by DNA methyltransferase 1, and inflammatory mediators such as tumor necrosis factor α, NF-κB, and IL-6 regulate DNA methyltransferase 1 expression and thereby affect SRD5A2 promoter methylation and gene expression. Furthermore, we show that increasing age in mice and humans is associated with increased methylation of the SRD5A2 promoter and concomitantly decreased protein expression. Artificial induction of inflammation in prostate primary epithelial cells leads to hypermethylation of the SRD5A2 promoter and silencing of SRD5A2, whereas inhibition with tumor necrosis factor α inhibitor reactivates SRD5A2 expression. Therefore, expression of SRD5A2 is not static and ubiquitous in benign adult prostate tissues. Methylation and expression of SRD5A2 may be used as a gene signature to tailor therapies for more effective treatment of prostatic diseases.

5α-Reductase inhibitors and risk of high-grade or lethal prostate cancer

IMPORTANCE

5α-Reductase inhibitors (5ARIs) are widely used for benign prostatic hyperplasia despite controversy regarding potential risk of high-grade prostate cancer with use. Furthermore, the effect of 5ARIs on progression and prostate cancer death remains unclear.

OBJECTIVE

To determine the association between 5ARI use and development of high-grade or lethal prostate cancer.

DESIGN, SETTING, AND PARTICIPANTS

Prospective observational study of 38,058 men followed up for prostate cancer diagnosis and outcomes between 1996 and 2010 in the Health Professionals Follow-up Study.

EXPOSURES

Use of 5ARIs between 1996 and 2010.

MAIN OUTCOMES AND MEASURES

Cox proportional hazards models were used to estimate risk of prostate cancer diagnosis or development of lethal disease with 5ARI use, adjusting for possible confounders including prostate specific antigen testing.

RESULTS

During 448,803 person-years of follow-up, we ascertained 3681 incident prostate cancer cases. Of these, 289 were lethal (metastatic or fatal), 456 were high grade (Gleason sum [GS] 8-10), 1238 were GS 7, and 1600 were low grade (GS 2-6). A total of 2878 (7.6%) men reported use of 5ARIs between 1996 and 2010. After adjusting for confounders, men who reported ever using 5ARIs over the study period had a reduced risk of overall prostate cancer (hazard ratio [HR], 0.77; 95% CI, 0.65-0.91). 5ARI users had a reduced risk of GS 7 (HR, 0.67; 95% CI, 0.49-0.91) and low-grade (GS 2-6) prostate cancer (HR, 0.74; 95% CI, 0.57-0.95). 5ARI use was not associated with risk of high-grade (GS 8-10) prostate cancer (HR, 0.97; 95% CI, 0.64-1.46) or lethal disease (HR, 0.99; 95% CI, 0.58-1.69). Increased duration of use was associated with significantly lower risk of overall prostate cancer (HR for 1 year of additional use, 0.95; 95% CI, 0.92-0.99), localized (HR, 0.95; 95% CI, 0.90-1.00), and low-grade disease (HR, 0.92; 95% CI, 0.85-0.99). There was no association for lethal, high-grade, or grade 7 disease.

CONCLUSIONS AND RELEVANCE

While 5ARI use was not associated with developing high-grade or lethal prostate cancer, it was associated with a reduction in low-grade, GS 7, and overall prostate cancer. Because the number of patients with high-grade or lethal prostate cancer in our cohort was limited, we cannot rule out potential risk of harm with 5ARI use.

Isthmin targets cell-surface GRP78 and triggers apoptosis via induction of mitochondrial dysfunction

Isthmin (ISM) is a secreted 60-kDa protein that potently induces endothelial cell (EC) apoptosis. It suppresses tumor growth and angiogenesis in mice when stably overexpressed in cancer cells. Although αvβ5 integrin serves as a low-affinity receptor for ISM, the mechanism by which ISM mediates antiangiogenesis and apoptosis in ECs remain to be fully resolved. In this work, we report the identification of cell-surface glucose-regulated protein 78 kDa (GRP78) as a high-affinity receptor for ISM (Kd=8.6 nM). We demonstrated that ISM-GRP78 interaction triggers apoptosis not only in activated ECs but also in cancer cells expressing high level of cell-surface GRP78. Normal cells and benign tumor cells tend to express low level of cell-surface GRP78 and are resistant to ISM-induced apoptosis. Upon binding to GRP78, ISM is internalized into ECs through clathrin-dependent endocytosis that is essential for its proapoptotic activity. Once inside the cell, ISM co-targets with GRP78 to mitochondria where it interacts with ADP/ATP carriers on the inner membrane and blocks ATP transport from mitochondria to cytosol, thereby causing apoptosis. Hence, ISM is a novel proapoptotic ligand that targets cell-surface GRP78 to trigger apoptosis by inducing mitochondrial dysfunction. The restricted and high-level expression of cell-surface GRP78 on cancer cells and cancer ECs make them uniquely susceptible to ISM-targeted apoptosis. Indeed, systemic delivery of recombinant ISM potently suppressed subcutaneous 4T1 breast carcinoma and B16 melanoma growth in mice by eliciting apoptosis selectively in the cancer cells and cancer ECs. Together, this work reveals a novel ISM-GRP78 apoptosis pathway and demonstrates the potential of ISM as a cancer-specific and dual-targeting anticancer agent.

Personalized medicine for the management of benign prostatic hyperplasia

PURPOSE

Benign prostatic hyperplasia affects more than 50% of men by age 60 years, and is the cause of millions of dollars in health care expenditure for the treatment of lower urinary tract symptoms and urinary obstruction. Despite the widespread use of medical therapy, there is no universal therapy that treats all men with symptomatic benign prostatic hyperplasia. At least 30% of patients do not respond to medical management and a subset require surgery. Significant advances have been made in understanding the natural history and development of the prostate, such as elucidating the role of the enzyme 5α-reductase type 2, and advances in genomics and biomarker discovery offer the potential for a more targeted approach to therapy. We review the current understanding of benign prostatic hyperplasia progression as well as the key genes and signaling pathways implicated in the process such as 5α-reductase. We also explore the potential of biomarker screening and gene specific therapies as tools to risk stratify patients with benign prostatic hyperplasia and identify those with symptomatic or medically resistant forms.

MATERIALS AND METHODS

A PubMed® literature search of current and past peer reviewed literature on prostate development, lower urinary tract symptoms, benign prostatic hyperplasia pathogenesis, targeted therapy, biomarkers, epigenetics, 5α-reductase type 2 and personalized medicine was performed. An additional Google Scholar™ search was conducted to broaden the scope of the review. Relevant reviews and original research articles were examined, as were their cited references, and a synopsis of original data was generated with the goal of informing the practicing urologist of these advances and their implications.

RESULTS

Benign prostatic hyperplasia is associated with a state of hyperplasia of the stromal and epithelial compartments, with 5α-reductase type 2 and androgen signaling having key roles in the development and maintenance of the prostate. Chronic inflammation, multiple growth factor and hormonal signaling pathways, and medical comorbidities have complex roles in prostate tissue homeostasis as well as its evolution into the clinical state of benign prostatic hyperplasia. Resistance to medical therapy with finasteride may occur through silencing of the 5α-reductase type 2 gene by DNA methylation, leading to a state in which 30% of adult prostates do not express 5α-reductase type 2. Novel biomarkers such as single nucleotide polymorphisms may be used to risk stratify patients with symptomatic benign prostatic hyperplasia and identify those at risk for progression or failure of medical therapy. Several inhibitors of the androgen receptor and other signaling pathways have recently been identified which appear to attenuate benign prostatic hyperplasia progression and may offer alternative targets for medical therapy.

CONCLUSIONS

Progressive worsening of lower urinary tract symptoms and bladder outlet obstruction secondary to benign prostatic hyperplasia is the result of multiple pathways including androgen receptor signaling, proinflammatory cytokines and growth factor signals. New techniques in genomics, proteomics and epigenetics have led to the discovery of aberrant signaling pathways, novel biomarkers, DNA methylation signatures and potential gene specific targets. As personalized medicine continues to develop, the ability to risk stratify patients with symptomatic benign prostatic hyperplasia, identify those at higher risk for progression, and seek alternative therapies for those in whom conventional options are likely to fail will become the standard of targeted therapy.

Abstract 2976: Dynamic expression of 5-alpha reductase 2 in aging prostate is regulated by DNA methyltransferase 1

Introduction: 5-alpha reductase type 2 (SRD5A2), an enzyme that is critical for prostatic development and growth, is utilized as an inhibitory target by Finasteride for patients with BPH. However, we have found that many aging benign prostate tissues do not express the enzyme. Since the SRD5A2 promoter region contains a CpG island, we hypothesized that somatic methylation of the promoter region may account for absence of SRD5A2 expression and DNA methyltransferases may play a role in silencing SRD5A2 expression.

Methods: Benign prostatic tissues from wild-type mice at 3, 6 and 12 months of age were used. Expression of SRD5A2 and DNA methyltransferases were analyzed by Western blot and quantitative RT-PCR. Methylation of SRD5A2 promoter region was assessed using Methylated CpG Island Recovery Assay (MIRA). DNMT1 siRNA and 5-AZA-C were used to determine the methylation status of SRD5A2 in benign prostatic cells (BPH-1). To determine the effect of CpG methylation, SDR5A2 promoter-luciferase contrsucts were methylated in vitro using M.SssI methylase. IL-6 expression was analyzed using ELISA.

Results: Benign prostatic tissues from wild-type mice of different ages (n=5 per group) were harvested. We found that expression of SRD5A2 and DNMT 1, 3a, 3b were not significantly changed in mice at the age of 3 and 6 months. However, 40% of mice at age of 12 months (2/5) demonstrated low SRD5A2 expression and high DNMT1 expression. Expression of DNMT3a and 3b were not altered. Consistently, the methylation status of SRD5A2 promoter was confirmed by Methylated CpG Island Recovery Assay (MIRA). To study the role of DNMT1 in silencing of SRD5A2, we silenced DNMT1 using siRNA in BPH-1 cells. Silencing DNMT1 led to re-expression of SRD5A2. Similarly, exposure of cells to 5-AZA-C led to re-expression of SDR5A2. The 5-AZA-C only led to increased expression of DNMT1 and not not DNMT3a or DNMT3b in BPH-1 cells. We used SDR5A2 promoter-luciferase contrsucts that were methylated in vitro using M.SssI methylase technique. When the methylated SDR5A2 promoter constructs were ectopically expressed in BPH-1 cells, we found that methylation of the SDR5A2 promoter caused reduction of luciferase gene expression by 80%, suggesting that methylation of the SDR5A2 promoter regulates the expression of SDR5A2. Since age-associated increased IL-6 has been shown to regulate DNMT-1, we next evaluated expression of IL-6 in aging prostate tissue. We found that expression of IL-6 was positively correlated with expression DNMT-1 in benign prostatic tissues.

Conclusions: Expression of SRD5A2 in aging prostates is dynamic. Absence of SRD5A2 expression is associated with methylation of the gene's promoter region, which is regulated by DNMT1 and not DNMT3a or DNMT3b. Dynamic and absence of SRD5A2 has implications for management of BPH and chemopreventive strategies for prostate cancer.

Citation Format: Rongbin Ge, Zongwei Wang, Chin-Lee Wu, Shahin Tabatabaei, Aria F. Olumi. Dynamic expression of 5-alpha reductase 2 in aging prostate is regulated by DNA methyltransferase 1. [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr 2976. doi:10.1158/1538-7445.AM2013-2976

Inhibition of TNF-α improves the bladder dysfunction that is associated with type 2 diabetes

Diabetic bladder dysfunction (DBD) is common and affects 80% of diabetic patients. However, the molecular mechanisms underlying DBD remain elusive because of a lack of appropriate animal models. We demonstrate DBD in a mouse model that harbors hepatic-specific insulin receptor substrate 1 and 2 deletions (double knockout [DKO]), which develops type 2 diabetes. Bladders of DKO animals exhibited detrusor overactivity at an early stage: increased frequency of nonvoiding contractions during bladder filling, decreased voided volume, and dispersed urine spot patterns. In contrast, older animals with diabetes exhibited detrusor hypoactivity, findings consistent with clinical features of diabetes in humans. The tumor necrosis factor (TNF) superfamily genes were upregulated in DKO bladders. In particular, TNF-α was upregulated in serum and in bladder smooth muscle tissue. TNF-α augmented the contraction of primary cultured bladder smooth muscle cells through upregulating Rho kinase activity and phosphorylating myosin light chain. Systemic treatment of DKO animals with soluble TNF receptor 1 (TNFRI) prevented upregulation of Rho A signaling and reversed the bladder dysfunction, without affecting hyperglycemia. TNFRI combined with the antidiabetic agent, metformin, improved DBD beyond that achieved with metformin alone, suggesting that therapies targeting TNF-α may have utility in reversing the secondary urologic complications of type 2 diabetes.

Reduced levels of 5-α reductase 2 in adult prostate tissue and implications for BPH therapy

BACKGROUND

5-α reductase 2 (5-AR 2) is a key enzyme that is responsible of proper development of prostate tissue. Inhibition of 5-AR 2 has proven to be efficacious for management of urinary symptoms secondary benign prostatic hyperplasia (BPH). However, some patients are resistant to the therapeutic effects of 5-AR 2 inhibitor. We wished to determine why some benign non-cancerous adult human prostates do not express 5-AR 2, and hypothesized that methylation of 5-AR 2 promoter region correlated with low expression of 5-AR 2 protein.

METHODS

The transition zone of 42 human prostate tissues after radical prostatectomy was used for evaluation. Initially, 21 paraffin embedded samples were used to assess immunoreactivity to 5-AR 2 antibody in non-cancerous BPH samples. In the next 21 samples, fresh frozen prostate transition zone samples without cancer were assessed for immunoreactivity and methylation of the 5-AR 2 promoter using methyl-specific PCR.

RESULTS

We show that 6/21 (29%) of benign human prostate samples did not express the 5-AR 2 protein. Moreover, the promoter region of 5-AR 2 contains a CpG island that is methylated in benign prostate epithelial cells in culture and also in 39% (7/18) human prostate tissues. We show a strong correlation between methylation of the 5-AR 2 promoter region and absence of 5-AR 2 protein expression (P = 0.0025, Fisher's exact test).

CONCLUSIONS

Methylation of 5-AR 2 promoter may account for low or absent expression of 5-AR 2 in some human adult prostate tissues.

Abstract 4099: F-box protein 10, an NF-κB-dependent anti-apoptotic protein, regulates TRAIL-induced apoptosis through modulating c-Fos/c-FLIP pathway

Background: Tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) holds great promise as a potential anti-cancer agent, but some tumors develop resistance to TRAIL. AP-1 family member, c-Fos, is an important modulator of apoptosis. Although F-box protein 10 (FBXL10) has been implicated to regulate an AP-1 family protein, significance and mechanism of FBXL10 in apoptosis has not been investigated.

Methods: In this study, different types of TRAIL-sensitive cells (A498, PC3, MBA-MD-231) and TRAIL-resistant cells (LNCaP, PC3TR) were used, and a quantitative analysis of apoptosis was performed by using MTS and caspase-3, PARP activity assay and flow cytometry assay of annexin V- and propidium iodide-stained cells. RNAi, Chromatin immunoprecipitation (ChIP), EMSA, hydrodynamic-based transfection, oligonucleotide decoy technologies were performed to analyze the molecular interaction between FBXL10, c-Fos and NF-κB. The anti-apoptotic role of FBXL10 in vivo was analyzed by Lexatumumab (an agonistic human monoclonal antibody against TRAIL-R2) intravenous injection into mice carrying xenograft prostate cancers. All statistical tests were two-sided.

Results: We found that FBXL10 was suppressed and c-Fos was upregulated in TRAIL sensitive cancer cells and xenografts after treatment with TRAIL. However, in TRAIL resistant cancer cells and xenografts, FBXL10 and c-Fos were not affected. Expression of FBXL11, a FBXL10 homologous protein and c-Jun, was not affected by TRAIL. Silencing of FBXL10 sensitized resistant cells to TRAIL. Conversely, over-expression of FBXL10 repressed TRAIL-induced apoptosis. To behave as an anti-apoptotic molecule, we found that FBXL10 directly binds and represses c-Fos promoter in vitro and in vivo. In addition, FBXL10 regulates c-FLIP, another anti−apoptotic molecule, by a c-Fos dependent pathway. We also found that expression of FBXL10 is NF-κB – dependent, and TRAIL or proteasome inhibitors down-regulate FBXL10 via inhibiting NF-κB signaling. Using ChIP, EMSA assays and oligonucleotide decoy technologies, we found that NF-κB -p65 directly binds the FBXL10 promoter in vivo and in vitro, and promotes expression of FBXL10.

Conclusions: Differentiating molecular mechanisms between TRAIL sensitive and TRAIL resistant cancer cells will improve the efficacy of apoptotic therapies for cancer patients. In this study, we demonstrate a novel functional role for FBXL10 as an anti-apoptotic molecule, and describe a new apoptotic mediated pathway that involves NF-κB/FBXL10/c-Fos/c-FLIP. Therefore, silencing FBXL10 can help overcome resistant cancer cells for pro-apoptotic therapies.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 4099. doi:10.1158/1538-7445.AM2011-4099

A meta-analysis of the relation of polymorphism at sites -1082 and -592 of the IL-10 gene promoter with susceptibility and clearance to persistent hepatitis B virus infection in the Chinese population

BACKGROUND

Up to now, many publications about the Chinese population have evaluated the correlation between interleukin-10 (IL-10) -1082 and -592 polymorphisms and persistent hepatitis B virus (HBV) infection. However, the results remain inconclusive. In order to resolve this conflict, a meta-analysis was performed.

METHODS

Seven studies were included and dichotomous data are presented as the odds ratio (OR) with a 95% confidence interval (CI).

RESULTS

The results of our study suggest that carriers of the IL-10 -592A allele were more likely to clear HBV spontaneously in the Chinese pooled population (A vs. C: OR = 0.799, 95% CI = 0.678-0.941, P = 0.007; AC vs. AA: OR = 1.343, 95% CI = 1.017-1.684, P = 0.011; AA vs. AC + CC: OR = 0.736, 95% CI = 0.594-0.912; AA + AC vs. CC: OR = 0.588, 95% CI = 0.408-0.848, P = 0.004) and the IL-10 -1082A allele was associated with significantly reduced persistent HBV infection risk in Chinese (A vs. G: OR = 0.701, 95% CI = 0.494-0.996, P = 0.047; AA vs. GG + GA: OR = 0.684, 95% CI = 0.476-0.982, P = 0.040).

CONCLUSIONS

Persistent HBV infection susceptibility is associated with the gene polymorphism IL-10 -1082GA in the Chinese population and the clearance of HBV is associated with the gene polymorphism IL-10 -592CA in the Chinese population.