Genetically raised serum bilirubin levels and lung cancer: a cohort study and Mendelian randomisation using UK Biobank.

BACKGROUND: Moderately raised serum bilirubin levels are associated with lower rates of lung cancer, particularly among smokers. It is not known whether these relationships reflect antioxidant properties or residual confounding. OBJECTIVE: This study aimed to investigate potential causal relationships between serum total bilirubin and lung cancer incidence using one-sample Mendelian randomisation (MR) and UK Biobank. METHODS: We instrumented serum total bilirubin level using two variants (rs887829 and rs4149056) that together explain ~40% of population-level variability and are linked to mild hereditary hyperbilirubinaemia. Lung cancer events occurring after recruitment were identified from national cancer registries. Observational and genetically instrumented incidence rate ratios (IRRs) and rate differences per 10 000 person-years (PYs) by smoking status were estimated. RESULTS: We included 377 294 participants (median bilirubin 8.1 µmol/L (IQR 6.4-10.4)) and 2002 lung cancer events in the MR analysis. Each 5 µmol/L increase in observed bilirubin levels was associated with 1.2/10 000 PY decrease (95% CI 0.7 to 1.8) in lung cancer incidence. The corresponding MR estimate was a decrease of 0.8/10 000 PY (95% CI 0.1 to 1.4). The strongest associations were in current smokers where a 5 µmol/L increase in observed bilirubin levels was associated with a decrease in lung cancer incidence of 10.2/10 000 PY (95% CI 5.5 to 15.0) and an MR estimate of 6.4/10 000 PY (95% CI 1.4 to 11.5). For heavy smokers (≥20/day), the MR estimate was an incidence decrease of 23.1/10 000 PY (95% CI 7.3 to 38.9). There was no association in never smokers and no mediation by respiratory function. CONCLUSION: Genetically raised serum bilirubin, common across human populations, may protect people exposed to high levels of smoke oxidants against lung cancers.

Liver Growth Factor "LGF" as a Therapeutic Agent for Alzheimer's Disease.

Alzheimer's disease (AD) is a progressive degenerative disorder and the most common cause of dementia in aging populations. Although the pathological hallmarks of AD are well defined, currently no effective therapy exists. Liver growth factor (LGF) is a hepatic albumin-bilirubin complex with activity as a tissue regenerating factor in several neurodegenerative disorders such as Parkinson's disease and Friedreich's ataxia. Our aim here was to analyze the potential therapeutic effect of LGF on the APPswe mouse model of AD. Twenty-month-old mice received intraperitoneal (i.p.) injections of 1.6 µg LGF or saline, twice a week during three weeks. Mice were sacrificed one week later, and the hippocampus and dorsal cortex were prepared for immunohistochemical and biochemical studies. LGF treatment reduced amyloid-ß (Aß) content, phospho-Tau/Tau ratio and the number of Aß plaques with diameter larger than 25 µm. LGF administration also modulated protein ubiquitination and HSP70 protein levels, reduced glial reactivity and inflammation, and the expression of the pro-apoptotic protein Bax. Because the administration of this factor also restored cognitive damage in APPswe mice, we propose LGF as a novel therapeutic tool that may be useful for the treatment of AD.

RNA sequencing in human HepG2 hepatocytes reveals PPAR-α mediates transcriptome responsiveness of bilirubin.

Bilirubin is a potent antioxidant that reduces inflammation and the accumulation of fat. There have been reports of gene responses to bilirubin, which was mostly attributed to its antioxidant function. Using RNA sequencing, we found that biliverdin, which is rapidly reduced to bilirubin, induced transcriptome responses in human HepG2 hepatocytes in a peroxisome proliferator-activated receptor (PPAR)-α-dependent fashion (398 genes with >2-fold change; false discovery rate P < 0.05). For comparison, a much narrower set of genes demonstrated differential expression when PPAR-α was suppressed via lentiviral shRNA knockdown (23 genes). Gene set enrichment analysis revealed the bilirubin-PPAR-α transcriptome mediates pathways for oxidation-reduction processes, mitochondrial function, response to nutrients, fatty acid oxidation, and lipid homeostasis. Together, these findings suggest that transcriptome responses from the generation of bilirubin are mostly PPAR-α dependent, and its antioxidant function regulates a smaller set of genes.

Acute neonatal bilirubin encephalopathy in the State of Utah 2009-2018.

Herein we report a case series of seven newborn infants, all apparently well at birth, who in the period since 2009 were cared for in the State of Utah with acute bilirubin encephalopathy (ABE). This report summarizes our attempts to define common features of these seven through a state-wide voluntary registry, as a step toward devising new means of preventing such cases in the future. In previous reports of ABE, many of the affected neonates had no clearly defined explanation for their progressive hyperbilirubinemia. Our efforts to identify clear explanations in all seven cases included next generation DNA sequencing, testing a panel of 28 genes involved in bilirubin production and metabolism. We found that hemolytic disease was a unifying feature of these seven; two had DAT (+) Anti-D or anti-c hemolysis, while five had confirmed mutations in genes involved in bilirubin production and or metabolism that were previously unrecognized in these families.

The UGT1A1*28 gene variant predicts long-term mortality in patients undergoing coronary angiography.

BACKGROUND: Uridine diphosphate glycosyltransferases 1A1 (UGT1A1) plays an essential role in detoxification and excretion of several endogenous and exogenous compounds. A functional polymorphism in the promoter of the UGT1A1 gene (TA repeat insertion, UGT1A1*28, rs3064744) has been associated with reduced UGT1A1 enzyme activity. The purpose of the present study was to investigate the role of UGT1A1 genotypes in mortality. METHODS: UGT1A1 genotypes as well as baseline plasma bilirubin levels were analyzed in participants of the Ludwigshafen Risk and Cardiovascular Health study (n=3316). UGT1A1*28 genotypes were determined on an ABI PRISM 3730 genetic analyzer. RESULTS: As expected, UGT1A1 genotypes were associated with baseline bilirubin levels (*1/*1 genotype: 9.1±4.6 µmol/L; *1/*28 genotype: 10.8±5.3; *28/*28: 16.9±9.2; p<0.001). During a median follow-up of 10.4 years, 995 subjects (30.0%) died. In a multivariate regression analysis adjusting for age, sex, smoking, type 2 diabetes, dyslipidemia, alanine aminotransferase (ALT) levels and bilirubin levels, the UGT1A1*28 variant predicted lower overall mortality (hazard ratio [HR], 0.86; 95% confidence interval [CI], 0.78-0.95; p=0.003). Contrary to expected, higher baseline bilirubin levels predicted increased mortality (HR, 1.014; 95% CI, 1.002-1.025; p=0.019). CONCLUSIONS: The UGT1A1*28 gene variant is associated with lower mortality rates. The protective effect of the UGT1A1*28 variant likely includes mechanism other than bilirubin metabolism.

Genetic lesions in the UGT1A1 genes among Gilbert's syndrome patients from India.

The present study was undertaken to investigate genetic variations present in the coding regions of the UGT1A1 gene among the Gilbert's syndrome patients. Analysis of genetic variations was performed by direct DNA sequencing among the patients that do not have any polymorphic variations in the promoter regions of the UGT1A1 gene. We identified seven different sequence variations among Gilbert's Syndrome patients, of which four were novel. Out of seven variants, six missense and one silent single nucleotide substitutions were present in the UGT1A1 gene. In addition, molecular modeling of UGT1A1 (H55R, P152S and N212H) variants suggested a reduced activity of the enzyme. This study demonstrates that different variations present in the UGT1A1 gene and specifically, the H55R variation had a significant effect on bilirubin levels and could be genetic risk factors for hyperbilirubinemia.

Bilirubin and Stroke Risk Using a Mendelian Randomization Design.

BACKGROUND AND PURPOSE: Circulating bilirubin, a natural antioxidant, is associated with decreased risk of stroke. However, the nature of the relationship between the two remains unknown. We used a Mendelian randomization analysis to assess the causal effect of serum bilirubin on stroke risk in Koreans. METHODS: The 14 single-nucleotide polymorphisms (SNPs) (<10-7) including rs6742078 of uridine diphosphoglucuronyl-transferase were selected from genome-wide association study of bilirubin level in the KCPS-II (Korean Cancer Prevention Study-II) Biobank subcohort consisting of 4793 healthy Korean and 806 stroke cases. Weighted genetic risk score was calculated using 14 SNPs selected from the top SNPs. RESULTS: Both rs6742078 (F statistics=138) and weighted genetic risk score with 14 SNPs (F statistics=187) were strongly associated with bilirubin levels. Simultaneously, serum bilirubin level was associated with decreased risk of stroke in an ordinary least-squares analysis. However, in 2-stage least-squares Mendelian randomization analysis, no causal relationship between serum bilirubin and stroke risk was found. CONCLUSIONS: There is no evidence that bilirubin level is causally associated with risk of stroke in Koreans. Therefore, bilirubin level is not a risk determinant of stroke.

Association of neonatal hyperbilirubinemia in breast-fed infants with UGT1A1 or SLCOs polymorphisms.

Neonates have physiologically increased bilirubin production and immature bilirubin metabolism, and present hyperbilirubinemia in association with genetic and or epigenetic factors. We previously reported that maximal body weight loss (inadequate feeding) is an independent risk factor for the development of hyperbilirubinemia in breast-fed Japanese neonates, and the UGT1A1 211G>A genotype becomes a risk factor under conditions of inadequate feeding. We extended the study to the association of other genetic factors, the UGT1A1 (TA)7 and solute-carrier organic anion transporters (SLCOs) polymorphisms with neonatal hyperbilirubinemia. We enrolled 401 full-term Japanese infants who were exclusively breastfeeding and classified them into two groups based on the degree of maximal body weight loss. We analyzed the clinical characteristics and UGT1A1 and SLCOs genotypes. Statistical analysis revealed that maximal body weight loss is the only independent risk factor for the development of neonatal hyperbilirubinemia. UGT1A1, SLCO1B1 and SLCO1B3 polymorphisms become risk factors in neonates showing 10% or greater body weight loss during the neonatal period. Inadequate feeding may increase the bilirubin burden and cause apparent hyperbilirubinemia in neonates, who have a polymorphic change in the genes involved in the transport and/or metabolism of bilirubin.

[Study on effect of scutellarin in resisting liver fibrosis in rats].

Totally 80 rats were randomly divided into the control group, the model group, low, middle and high dose (25, 50, 100 mg x kg(-1)) scutellarin( SC) groups and the colchicine ( Col) group. Apart from the blank group, all of the remaining groups were intraperitoneally injected with 0.5 mL pig serum twice every week for consecutively 13 weeks and orally administered with the corresponding drugs since the 9th week. The blank group and the model group were orally given equal volume of normal saline once every for consecutively four weeks. After the experiment, efforts were made to detect the contents of alanine aminotransferase (ALT), aspertate aminotransferase (AST), albumin (ALB), total protein (TP), total bilirubin (TBIL), hyaluronic acid (HA), laminin (LN) and collagen type IV (CIV), collect liver tissues of fixed positions, observe the pathological changes through hematoxylin-eosin (HE) staining, conduct the pathological grading for liver fibrosis, determine the expressions of hepatic collagen type I and III (C I, C III) and calculate their color rendering index. Compared with the model group, low, middle and high dose (25, 50, 100 mg x kg(-1)) SC groups could decrease the contents of ALT, AST, TBIL, HA, LN, CIV, increase the contents of ALB, TP in serum and reduce the contents of C I, C III in liver tissues. In conclusion, scutellarin has a certain therapeutic effect on immune liver fibrosis in rats induced by pig serum.

A genome-wide association study for serum bilirubin levels and gene-environment interaction in a Chinese population.

Bilirubin is an effective antioxidant and is influenced by both genetic and environmental factors. Recent genome-wide association studies (GWAS) have identified multiple loci affecting serum total bilirubin levels. However, most of the studies were conducted in European populations and little attention has been devoted either to genetic variants associated with direct and indirect bilirubin levels or to the gene-environment interactions on bilirubin levels. In this study, a two-stage GWAS was performed to identify genetic variants associated with all types of bilirubin levels in 10,282 Han Chinese individuals. Gene-environment interactions were further examined. Briefly, two previously reported loci, UGT1A1 on 2q37 (rs6742078 and rs4148323, combined P = 1.44 × 10(-89) and P = 5.05 × 10(-69) , respectively) and SLCO1B3 on 12p12 (rs2417940, combined P = 6.93 × 10(-19) ) were successfully replicated. The two loci explained 9.2% and 0.9% of the total variations of total bilirubin levels, respectively. Ethnic genetic differences were observed between Chinese and European populations. More importantly, a significant interaction was found between rs2417940 in SLCO1B3 gene and smoking on total bilirubin levels (P = 1.99 × 10(-3) ). Single nucleotide polymorphism (SNP) rs2417940 had stronger effects on total bilirubin levels in nonsmokers than in smokers, suggesting that the effects of SLCO1B3 genotype on bilirubin levels were partly dependent on smoking status. Consistent associations and interactions were observed for serum direct and indirect bilirubin levels.

Ileal exclusion in children with progressive familial intrahepatic cholestasis.

OBJECTIVES: Children with progressive familial intrahepatic cholestasis (PFIC) rarely benefit from medical treatment and most patients require surgical intervention. Partial external biliary diversion (PEBD) is presently the treatment of choice but for those who cannot benefit from PEBD, an alternative surgical procedure--ileal exclusion (IE)--was introduced. The aim of this study was to analyze our experience with IE in children with PFIC. METHODS: This procedure was performed in 9 patients (6 girls, 3 boys) at the median age of 11 years (range 8-21). In 4 children, it was the primary operation (group 1), and in 5, IE was performed after PEBD (group 2). All of the patients were screened for ABCB11 and ATP8B1 mutations, and in 3 cases, PFIC type 2 was confirmed. RESULTS: Median follow-up after IE surgery was 8.5 years (range 3-14). In group 1, 1 patient had to be converted to PEBD and the remaining 3 children experienced alleviation in pruritus and decrease in bilirubin and bile acids concentrations 2 and 5 years after IE. After 10 years, only 2 children were still accessible for follow-up. In both, pruritus varied and elevated serum bile acids were observed. Of the 5 patients who underwent IE after PEBD, 1 eventually required liver transplantation, 1 developed varying degree of pruritus, and 3 female patients, operated on because of aesthetic reasons, had excellent outcomes. CONCLUSIONS: IE is an alternative rescue option to PEBD and should be offered cautiously, only to patients who cannot benefit from PEBD.

The Oral Intake of Organic Germanium, Ge-132, Elevates α-Tocopherol Levels in the Plas-ma and Modulates Hepatic Gene Expression Profiles to Promote Immune Activation in Mice.

The common water-soluble organic germanium compound poly-trans-[(2-carboxyethyl) germasesquioxane] (Ge-132) exhibits activities related to immune responses and antioxidant induction. In this study, we evaluated the antioxidative effect of dietary Ge-132 in the plasma of mice. Male ICR mice (seven mice per group) received an AIN-76 diet with 0.05% Ge-132; three groups received the Ge-132-containing diet for 0, 1 or 4 days. The plasma alpha-tocopherol (α-tocopherol) concentration increased from 6.85 to 9.60 µg/ml after 4 days of Ge-132 intake (p<0.05). We evaluated the changes in hepatic gene expression related to antioxidative activity as well as in the entire expression profile after one day of Ge-132 intake, using DNA microarray technology. We identified 1,220 genes with altered expression levels greater than 1.5-fold (increased or decreased) as a result of Ge-132 intake, and α-tocopherol transfer protein (Ttpa) gene expression was increased 1.62-fold. Immune activation was identified as the category with the most changes (containing 60 Gene Ontology (GO) term biological processes (BPs), 41 genes) via functional clustering analysis of altered gene expression. Ge-132 affected genes in clusters related to ATP production (22 GO term BPs, 21 genes), lipid metabolism (4 GO term BPs, 38 genes) and apoptosis (5 GO term BPs). Many GO term BPs containing these categories were significantly affected by the Ge-132 intake. Oral Ge-132 intake may therefore have increased plasma α-tocopherol levels by up-regulating α-tocopherol transfer protein (Ttpa) gene expression.

Induction of heme oxygenase-1 and inhibition of TPA-induced matrix metalloproteinase-9 expression by andrographolide in MCF-7 human breast cancer cells.

Matrix metalloproteinase-9 (MMP-9) plays a critical role in cancer metastasis. Andrographolide (AP) is a diterpene lactone in the leaves and stem of Andrographis paniculata (Burm. f) Ness that has been reported to possess anticancer activity. In this study, we investigated the effect of AP on 12-O-tetradecanoylphorbol-13-acetate (TPA)-induced MMP-9 expression and invasion in MCF-7 breast cancer cells and the possible mechanisms involved. The results showed that AP dose-dependently inhibited TPA-induced MMP-9 protein expression, enzyme activity, migration and invasion. In addition, AP significantly induced heme oxygenase-1 (HO-1) messenger RNA (mRNA) and protein expression. Transfection with HO-1 small interfering RNA knocked down the HO-1 expression and reversed the inhibition of MMP-9 expression by AP. HO-1 end products, such as carbon monoxide, free iron and bilirubin, suppressed the TPA-induced MMP-9 mRNA and protein expression, enzyme activity, migration and invasion in MCF-7 cells. Furthermore, TPA-induced extracellular signal-regulated kinase (ERK) 1/2 and Akt phosphorylation and the DNA binding activity of activator protein-1 (AP-1) and nuclear factor-kappa B (NF-κB) were attenuated by pretreatment with AP and HO-1 end products. In conclusion, these results suggest that AP inhibits TPA-induced cell migration and invasion by reducing MMP-9 activation, which is mediated mainly by inhibition of the ERK1/2 and phosphatidylinositol 3-kinase/Akt signaling pathways and subsequent AP-1 and NF-κB transactivation. Additionally, induction of HO-1 expression is at least partially involved in the inhibition of TPA-induced MMP-9 activation and cell migration in MCF-7 cells by AP.

Role of a homozygous A(TA)7TAA promoter polymorphism and an exon 1 heterozygous frameshift mutation UGT1A1 in Crigler-Najjar syndrome type II in a Thai neonate.

Crigler-Najjar syndrome is a rare autosomal recessive disease caused by mutations in the UGT1A1 gene. These mutations result in the deficiency of UGT1A1, a hepatic enzyme essential for bilirubin conjugation. This report describes the case of a 4-month-old boy with the cardinal symptoms of Crigler-Najjar syndrome type II. Molecular genetic analysis showed a homozygous UGT1A1 promoter mutation [A(TA)7TAA] and a heterozygous insertion of 1 adenosine nucleotide between positions 353 and 354 in exon 1 of UGT1A1 that caused a frameshift with a premature stop codon.

[Prevalence of Gilbert syndrome and its genetic determinants in Chile]. / Prevalencia de síndrome de Gilbert y sus determinantes genéticas en población chilena.

BACKGROUND: In Europeans the TATA box TA7 repeat promoter variant in the UGT1A1 gene (UGT1A1*28) is the major determinant of bilirubin levels. AIM: To study the prevalence of Gilbert Syndrome (GS) and its genetic determinants in Chile. MATERIAL AND METHODS: Three different studies were conducted. The prevalence of GS in Chile was assessed in 991 subjects with normal liver tests (ALT and GGT) from the 2nd National Health Survey. We defined GS as a total bilirubin (TB) between 1.4-5mg/dL. The second study assessed the genotype prevalence of SNP rs6742078 (in LD with UGT1A1*28) and rs4149056 in 500 DNA samples of non-related Hispanics. Finally, a case-control study was designed to assess the phenotype-genotype correlation. UGT1A1*28 and rs4149056 variants were determined by direct sequencing and allelic discrimination assays (TaqMan), respectively. RESULTS: Prevalence of GS in the general Chilean population was 2.6% (4.5% in males and 0.5% in female). No correlation with age, educational level or home location was found. Genotypes for UGT1A1*28 (TA6/6 50.5%, TA6/7 37.8%, TA7/7 11.7%) and rs4149056 (TT 74.1%, CT 22.8%, and CC 3.1%) variants were similar to Europeans. In the case-control study, most patients with GS were homozygotes for UGT1A1*28 (TA7/7, 74%). Of note, 44% of patients with intermediate TB levels were also TA7/7, compared to 7% in normal subjects. SLCO1B1 genotype was not correlated with TB levels. CONCLUSIONS: While the prevalence of GS was lower in Chile compared to Europeans (~5%), the prevalence of UGT1A1*28 homozygotes was similar (~12%). In Chilean Hispanics, the UGT1A1*28 variant explain 75% of GS phenotype.

Generation and characterization of a novel multidrug resistance protein 2 humanized mouse line.

The multidrug resistance protein (MRP) 2 is predominantly expressed in liver, intestine, and kidney, where it plays an important role in the excretion of a range of drugs and their metabolites or endogenous compounds into bile, feces, and urine. Mrp knockout [Mrp2(-/-)] mice have been used recently to study the role of MRP2 in drug disposition. Here, we describe the first generation and initial characterization of a mouse line humanized for MRP2 (huMRP2), which is nulled for the mouse Mrp2 gene and expresses the human transporter in the organs and cell types where MRP2 is normally expressed. Analysis of the mRNA expression for selected cytochrome P450 and transporter genes revealed no major changes in huMRP2 mice compared with wild-type controls. We show that human MRP2 is able to compensate functionally for the loss of the mouse transporter as demonstrated by comparable bilirubin levels in the humanized mice and wild-type controls, in contrast to the hyperbilirubinemia phenotype that is observed in MRP2(-/-) mice. The huMRP2 mouse provides a model to study the role of the human transporter in drug disposition and in assessing the in vivo consequences of inhibiting this transporter by compounds interacting with human MRP2.

UGT1A1 sequence variants and bilirubin levels in early postnatal life: a quantitative approach.

BACKGROUND: Fundamental to definitively identifying neonates at risk of developing significant hyperbilirubinemia is a better understanding of the genetic factors associated with early bilirubin rise. Previous genetic studies have focused on the UGT1A1 gene, associating common variation in the coding or promoter regions with qualitative assessments of bilirubin (i.e. significantly elevated or not). These studies have had conflicting results and limited success. We chose to approach the problem by focusing on the quantitative (absolute) change in bilirubin levels early in post-natal life. We apply this approach to the UGT1A1 gene--exploring the contribution of both rare and common variants to early bilirubin changes. METHODS: We sequenced the exons, PBREM, 5'-, and 3'- regions of the UGT1A1 gene in 80 otherwise healthy term neonates who had repeat bilirubin levels measured within the first five days of life. RESULTS: Three novel coding variants were observed, but there was no clear relationship between rare coding variants and bilirubin rise. Adjusted linear regression models fit to evaluate the relationship between changing bilirubin levels and common UGT1A1variants found that among 39 neonates whose bilirubin was resampled within 33 hours, individuals homozygous for the mutant allele of a 3'UTR SNP had significantly smaller changes in bilirubin (P=0.003) than individuals carrying the wild-type allele. CONCLUSIONS: Collectively, rare UGT1A1 coding variants do not appear to play a prominent role in determining early bilirubin levels; however common variants in the 3' UTR of UGT1A1 may modulate the early bilirubin rise. A quantitative approach to evaluating early bilirubin kinetics provides a more robust framework in which to better understand the genetics of neonatal hyperbilirubinemia.

Molecular Pathways and Pigments Underlying the Colors of the Pearl Oyster Pinctada margaritifera var. cumingii (Linnaeus 1758).

The shell color of the Mollusca has attracted naturalists and collectors for hundreds of years, while the molecular pathways regulating pigment production and the pigments themselves remain poorly described. In this study, our aim was to identify the main pigments and their molecular pathways in the pearl oyster Pinctada margaritifera-the species displaying the broadest range of colors. Three inner shell colors were investigated-red, yellow, and green. To maximize phenotypic homogeneity, a controlled population approach combined with common garden conditioning was used. Comparative analysis of transcriptomes (RNA-seq) of P. margaritifera with different shell colors revealed the central role of the heme pathway, which is involved in the production of red (uroporphyrin and derivates), yellow (bilirubin), and green (biliverdin and cobalamin forms) pigments. In addition, the Raper-Mason, and purine metabolism pathways were shown to produce yellow pigments (pheomelanin and xanthine) and the black pigment eumelanin. The presence of these pigments in pigmented shell was validated by Raman spectroscopy. This method also highlighted that all the identified pathways and pigments are expressed ubiquitously and that the dominant color of the shell is due to the preferential expression of one pathway compared with another. These pathways could likely be extrapolated to many other organisms presenting broad chromatic variation.

Genetically Raised Circulating Bilirubin Levels and Risk of Ten Cancers: A Mendelian Randomization Study.

Bilirubin, an endogenous antioxidant, may play a protective role in cancer development. We applied two-sample Mendelian randomization to investigate whether genetically raised bilirubin levels are causally associated with the risk of ten cancers (pancreas, kidney, endometrium, ovary, breast, prostate, lung, Hodgkin's lymphoma, melanoma, and neuroblastoma). The number of cases and their matched controls of European descent ranged from 122,977 and 105,974 for breast cancer to 1200 and 6417 for Hodgkin's lymphoma, respectively. A total of 115 single-nucleotide polymorphisms (SNPs) associated (p < 5 × 10-8) with circulating total bilirubin, extracted from a genome-wide association study in the UK Biobank, were used as instrumental variables. One SNP (rs6431625) in the promoter region of the uridine-diphosphoglucuronate glucuronosyltransferase1A1 (UGT1A1) gene explained 16.9% and the remaining 114 SNPs (non-UGT1A1 SNPs) explained 3.1% of phenotypic variance in circulating bilirubin levels. A one-standarddeviation increment in circulating bilirubin (≈ 4.4 µmol/L), predicted by non-UGT1A1 SNPs, was inversely associated with risk of squamous cell lung cancer and Hodgkin's lymphoma (odds ratio (OR) 0.85, 95% confidence interval (CI) 0.73-0.99, P 0.04 and OR 0.64, 95% CI 0.42-0.99, p 0.04, respectively), which was confirmed after removing potential pleiotropic SNPs. In contrast, a positive association was observed with the risk of breast cancer after removing potential pleiotropic SNPs (OR 1.12, 95% CI 1.04-1.20, p 0.002). There was little evidence for robust associations with the other seven cancers investigated. Genetically raised bilirubin levels were inversely associated with risk of squamous cell lung cancer as well as Hodgkin's lymphoma and positively associated with risk of breast cancer. Further studies are required to investigate the utility of bilirubin as a low-cost clinical marker to improve risk prediction for certain cancers.