Forest plots for XRCC1 Arg194Trp polymorphism.

<p>A: dominant model: ArgTrp+TrpTrp vs. ArgArg; B: allele comparison: Trp vs. Arg.</p

XRCC1 Arg194Trp and Arg280His Polymorphisms Increase Bladder Cancer Risk in Asian Population: Evidence from a Meta-Analysis

<div><p>Background</p><p>A lot of studies have investigated the correlation between x-ray cross complementing group 1 (XRCC1) polymorphisms and bladder cancer risk, but the results in Asian population were still inconclusive. We conducted a meta-analysis to ascertain the association of XRCC1 Arg194Trp, Arg280His and Arg399Gln polymorphisms with bladder cancer risk in Asian population.</p><p>Methodology/Principal findings</p><p>The association strength was measured with odds ratios (ORs) and 95% confidence intervals (95% CIs). A total of 9 eligible studies, conducted in China, India and Japan, were identified. We observed a significant increased risk of bladder cancer in dominant model (OR = 1.199, 95% CI: 1.021,1.408, P_{heterogeneity} = 0.372), allele comparison (OR = 1.200, 95% CI: 1.057,1.362, P_{heterogeneity} = 0.107) of Arg194Trp, heterozygote comparison (OR = 1.869, 95% CI: 1.205,2.898, P_{heterogeneity} = 0.011) and dominant model (OR = 1.748, 95% CI: 1.054,2.900, P_{heterogeneity} = 0.01) of Arg280His. Pooled results estimated from adjusted ORs further validated these findings. No publication bias was detected. Subgroup analyses found that significant increased risk was only found among community-based studies not hospital-based studies. There was no evidence of publication bias.</p><p>Conclusion</p><p>This is the first meta-analysis conducted in Asian investigating the correlation between XRCC1 polymorphisms and susceptibility to bladder cancer. Our meta-analysis shows that XRCC1 Arg194Trp and Arg280His polymorphisms are associated with a significantly increased risk of bladder cancer in Asian population.</p></div

Flow Chart.

<p>Flow Chart.</p

Meta-analysis results of XRCC1 polymorphisms and bladder cancer risk.

<p>M1: homozygote comparison; M2: heterozygote comparison; M3: dominant model; M4: recessive model; M5: allele comparison; P: P value for heterogeneity; a estimated from adjusted ORs and 95% CIs; NA: not analyzed;</p>*<p>significant difference.</p

Funnel plots for XRCC1 Arg194Trp (A, allele comparison: Trp vs. Arg) and Arg280His (B, heterozygote comparison: ArgHis vs. ArgArg).

<p>Funnel plots for XRCC1 Arg194Trp (A, allele comparison: Trp vs. Arg) and Arg280His (B, heterozygote comparison: ArgHis vs. ArgArg).</p

Forest plots XRCC1 Arg280His polymorphism.

<p>Heterozygote comparison (ArgHis vs. ArgArg) estimated with raw genotype frequencies (A) and adjusted odds ratios (B).</p

Characteristics of eligible studies.

<p>CB: community-based studies; HB: hospital-based studies.</p

Functional Dissection of <em>HOXD</em> Cluster Genes in Regulation of Neuroblastoma Cell Proliferation and Differentiation

<div><p>Retinoic acid (RA) can induce growth arrest and neuronal differentiation of neuroblastoma cells and has been used in clinic for treatment of neuroblastoma. It has been reported that RA induces the expression of several <em>HOXD</em> genes in human neuroblastoma cell lines, but their roles in RA action are largely unknown. The HOXD cluster contains nine genes (<em>HOXD1, HOXD3, HOXD4, and HOXD8-13</em>) that are positioned sequentially from 3′ to 5′, with <em>HOXD1</em> at the 3′ end and <em>HOXD13</em> the 5′ end. Here we show that all <em>HOXD</em> genes are induced by RA in the human neuroblastoma BE(2)-C cells, with the genes located at the 3′ end being activated generally earlier than those positioned more 5′ within the cluster. Individual induction of <em>HOXD8, HOXD9, HOXD10</em> or <em>HOXD12</em> is sufficient to induce both growth arrest and neuronal differentiation, which is associated with downregulation of cell cycle-promoting genes and upregulation of neuronal differentiation genes. However, induction of other <em>HOXD</em> genes either has no effect (<em>HOXD1</em>) or has partial effects (<em>HOXD3, HOXD4, HOXD11</em> and <em>HOXD13</em>) on BE(2)-C cell proliferation or differentiation. We further show that knockdown of HOXD8 expression, but not that of HOXD9 expression, significantly inhibits the differentiation-inducing activity of RA. HOXD8 directly activates the transcription of <em>HOXC9</em>, a key effector of RA action in neuroblastoma cells. These findings highlight the distinct functions of <em>HOXD</em> genes in RA induction of neuroblastoma cell differentiation.</p> </div

HOXD8 is a mediator of RA action.

<p>(<b>A</b>) qRT-PCR analysis of HOXD8 mRNA levels in BE(2)-C/Tet-Off cells with inducible expression of an shRNA sequence against Firefly <i>luciferase</i> (Luc-sh) or human <i>HOXD8</i> (HOXD8sh-1) in the absence of Doxy for 6 days. The <i>HOXD8</i> mRNA levels in BE(2)-C/Tet-Off/luc-sh cells in the presence of Doxy were designated as 1.0. The data were from two independent samples with each being assayed in triplicate and analyzed using two-tailed Student's <i>t</i>-test with the <i>p</i> values indicated. (<b>B–D</b>) Phase contrast imaging (<b>B</b>) and cell cycle analysis (<b>C–D</b>) of BE(2)-C/Tet-Off/Luc-sh and BE(2)-C/Tet-Off/HOXD8sh-1 cells that were cultured in the absence of Doxy for 6 days and then either untreated or treated with 10 µM RA for 3 or 6 days. The data in (<b>D</b>) were from three independent experiments and analyzed using two-tailed Student's <i>t</i>-test with the <i>p</i> values indicated. (<b>E</b>) qRT-PCR analysis of the mRNA levels of <i>CCNB1, CDK1,</i> and <i>RET</i> in BE(2)-C/Tet-Off/Luc-sh and BE(2)-C/Tet-Off/HOXD8sh-1 cells that were cultured in the absence of Doxy for 6 days and then treated with 10 µM RA for 6 days. The mRNA levels of the same genes in BE(2)-C/Tet-Off/Luc-sh cells cultured in the absence of Doxy without RA treatment were designated as 1.0 (dashed line). The data were from two independent samples with each being assayed in triplicate and analyzed using two-tailed Student's <i>t</i>-test with the <i>p</i> values indicated. Error bars (<b>A</b>, <b>D</b>, and <b>E</b>), SD.</p

<i>HOXC9</i> is a direct target gene of HOXD8.

<p>(<b>A</b>) qRT-PCR analysis of <i>HOXC9</i> mRNA levels in BE(2)-C/Tet-Off/Luc-sh and BE(2)-C/Tet-Off/HOXD8sh-1 cells that were cultured in the absence of Doxy for 6 days and then either untreated or treated with 10 µM RA for 3 or 6 days. The <i>HOXC9</i> mRNA levels in BE(2)-C/Tet-Off/Luc-sh cells cultured in the absence of Doxy without RA treatment were designated as 1.0 (dashed line). (<b>B</b>) qRT-PCR analysis of <i>HOXC9</i> mRNA levels in BE(2)-C/Tet-Off/myc-HOXD8 cells cultured in the presence or absence of Doxy for 3 or 6 days. The <i>HOXC9</i> mRNA levels in BE(2)-C/Tet-Off/myc-HOXD8 cells in the presence of Doxy were designated as 1.0. (<b>C</b>) Schematic representation of the <i>HOXC9</i> promoter region with a potential HOX-binding site 1,361 bp upstream of the transcription start site (TSS,+1). (<b>D</b>) ChIP-qPCR analysis of HOXD8 interaction with the <i>HOXC9</i> promoter region (-1,502 to -1,236, HOXC9_5Phox) in BE(2)-C/Tet-Off/myc-HOXD8 cells cultured in the presence or absence of Doxy for 6 days, presented as fold enrichment over IgG control (1.0, dashed line). HOXD8 did not bind to the region 6-kb upstream of the <i>HOXC9</i> promoter (HOXC9_5P6K) or the TSS of the <i>FBXW7</i> gene (FBXW7V1_0K), which is shown as negative control. (<b>E</b>) ChIP-qPCR analysis of H3K4me3 levels at the <i>HOXC9</i> promoter in BE(2)-C/Tet-Off/myc-HOXD8 cells cultured in the presence or absence of Doxy for 6 days, presented as fold enrichment over the IgG control (1.0, dashed line). The primer pairs target the <i>HOXC9</i> promoter region around −2,000, −1,500, and −1 bp. The data (<b>A</b>, <b>B</b>, <b>D</b>, and <b>E</b>) were from two independent samples with each being assayed in triplicate and analyzed using two-tailed Student's <i>t</i>-test with the <i>p</i> values indicated. Error bars, SD.</p