Monika K. Świderska

Effect of DNA methylation profile on OATP3A1 and OATP4A1 transcript levels in colorectal cancer.

Epidemiological studies indicate that 17β-estradiol (E2) prevents colorectal cancer (CRC). Organic anion transporting polypeptides (OATPs) are involved in the cellular uptake of various endogenous and exogenous substrates, including hormone conjugates. Because transfer of estrone sulfate (E1-S) can contribute to intra-tissue conversion of estrone to the biologically active form -E2, it is evident that the expression patterns of OATPs may be relevant to the analysis of CRC incidence and therapy. We therefore evaluated DNA methylation and transcript levels of two members of the OATP family, OATP3A1 and OATP4A1, that may be involved in E1-S transport in colorectal cancer patients. We detected a significant reduction in OATP3A1 and a significant increase in OATP4A1 mRNA levels in cancerous tissue, compared with histopathologically unchanged tissue (n=103). Moreover, we observed DNA hypermethylation in the OATP3A1 promoter region in a small subset of CRC patients and in HCT116 and Caco-2 colorectal cancer cell lines. We also observed increased OATP3A1 transcript following treatment with 5-aza-2-deoxycytidine and sodium butyrate. The OATP4A1 promoter region was hypomethylated in analyzed tissues and CRC cell lines and was not affected by these treatments. Our results suggest a potential mechanism for OATP3A1 downregulation that involves DNA methylation during colorectal carcinogenesis.

Antibodies to hepatitis B virus surface antigen and survival of hemodialysis patients – a prospective study

ABSTRACT Background: Antibodies to hepatitis B virus (HBV) surface antigen (anti-HBs) may develop in response to HBV vaccination or infection. We investigated whether anti-HBs are an independent predictor of survival in hemodialysis (HD) patients. Methods: A 6-year prospective study was conducted in 532 HD patients. Survival analyses were performed using the Kaplan-Meier method and the Cox proportional hazard model. Results: In HBV non-infected patients, age (P = 0.005), coronary artery disease (P = 0.002), and non-response to HBV vaccine (P = 0.008) were the independent risk factors of all-cause mortality. In HBV infected patients, the only independent predictor of all-cause mortality was coronary artery disease (P = 0.002). Conclusion: The ability to produce the protective anti-HBs titer in response to HBV vaccine is a positive predictor of survival in HBV non-infected HD patients.

Antibodies to HBV surface antigen in relation to interferon-λ3 in hemodialysis patients.

AIM To investigate circulating IFN-λ3 and IFNL3 polymorphisms in hemodialysis (HD) patients differing in HBV surface antigen antibody (anti-HBs) production. METHODS The study included 106 HBV-vaccinated HD patients (88 developed anti-HBs) and 36 HBV-infected HD subjects (27 developed anti-HBs). Plasma IFN-λ3 (enzyme-linked immunosorbent assay) and rs12979860 (C>T) and rs8099917 (T>G) in IFNL3 (high-resolution melting curve analysis) were analyzed with regard to the association with anti-HBs production in response to HBV vaccination or infection. The results were adjusted for gender, age, cause of renal disease, dialysis vintage, dialysis modality, IFN-λ3, and 25(OH)D as appropriate. RESULTS HBV vaccine responders had higher circulating IFN-λ3 (ng/L) than non-responders (120, 36-233 vs. 53, 33-109, P<0.000001). Patients who generated anti-HBs after HBV infection also had higher circulating IFN-λ3 levels than those who did not (133, 35-215 vs. 71, 9-229, P=0.043). The IFN-λ3 concentration correlated with the anti-HBs titer in vaccinated (r=0.614, P<0.000001) and infected patients (r=0.589, P=0.0002). Plasma IFN-λ3 was the only significant indicator of responsiveness to HBV vaccination (adjusted P=0.018) and remained the only significant associate for the development of post-infection anti-HBs (adjusted P=0.049). A plasmaIFN-λ3 level of 85.5ng/L was thecut-off value for theprognosis of an anti-HBs titer below vs. equal to or over 10IU/L in the entire group of HD patients (ROC sensitivity 68.7%, specificity 85.2%, and AUC 0.827). Significant associations were not found between IFN-λ3 and IFNL3 rs12979860. Subjects treated with low flux HD that harbored the TT genotype in rs8099917 showed higher IFN-λ3 levels than patients bearing the G allele in rs8099917 (139, 68-233 vs. 103, 9-208, P=0.049). CONCLUSION In HD patients, circulating IFN-λ3 strongly correlates with anti-HBs production after HBV vaccination and infection. IFNL3 rs8099917 polymorphisms seem to be associated with IFN-λ3 plasma levels in HD subjects.

Polymorphisms of Vitamin D Signaling Pathway Genes and Calcium-Sensing Receptor Gene in respect to Survival of Hemodialysis Patients: A Prospective Observational Study

We evaluated in the 7-year prospective study whether variants in vitamin D pathway genes and calcium-sensing receptor gene (CASR) are determinants of mortality in hemodialysis (HD) patients (n = 532). HRM analysis was used for GC rs2298849, GC rs1155563, RXRA rs10776909, RXRA rs10881578, and CASR rs7652589 genotyping. GC rs7041, RXRA rs749759, VDR rs2228570, and VDR rs1544410 were genotyped using PCR-RFLP analysis. The minor allele in GC rs2298849 was associated with all-cause mortality in univariate analysis (HR 1.330, 95% CI 1.046–1.692, P = 0.020). Bearers of the minor allele in GC rs2298849 demonstrated higher infection/neoplasm mortality than major allele homozygotes also in multivariate analysis (HR 2.116, 95% CI 1.096–4.087, P = 0.026). Cardiovascular mortality was associated with major homozygosity (CC) in VDR rs2228570 (HR 1.896, 95% CI 1.163–3.091, P = 0.010). CC genotype patients were more often dyslipidemic than TT genotype subjects (46.1% versus 31.9%, P = 0.047). Dyslipidemics showed higher frequency of rs1544410_rs2228570 haplotype AC than nondyslipidemics (26 versus 18%, P corr = 0.005), whereas TT genotype patients were at lower risk of dyslipidemia compared with CC/CT genotype patients (HR 0.59, 95% CI 0.37–0.96, P = 0.04). In conclusion, GC rs2298849 and VDR rs2228570 SNPs are associated with survival on HD. VDR-related cardiovascular mortality may occur due to connections of rs2228570 with dyslipidemia.

Circulating Interferon-λ3, Responsiveness to HBV Vaccination, and HBV/HCV Infections in Haemodialysis Patients

The IFN-λ3 gene (IFNL3) plays a role in HCV clearance. We investigated circulating IFN-λ3 and IFNL3 SNPs in haemodialysis patients who differed in their response to HBV vaccination and their HBV/HCV infection status. In 201 patients, plasma IFN-λ3 was determined using ELISA. IFNL3 SNPs (rs12979860, rs8099917) were genotyped using HRM analysis. Differences in IFN-λ3 levels were shown between responders and nonresponders to HBV vaccination and between HBsAg-positive patients and those who developed anti-HBs after infection and became HBsAg negative. HBV vaccine responders without HCV resolution revealed lower IFN-λ3 than noninfected responders. HBsAg/HCV RNA-positive subjects showed lower IFN-λ3 than patients positive only for HCV RNA or subjects who resolved both infections. Circulating IFN-λ3 correlated positively with anti-HBs and negatively with positive HCV RNA testing in the adjusted regression analyses. HBV vaccine nonresponders, HBsAg-positive patients, and subjects with replicating HCV composed a group with unfavourable outcomes. Responders to HBV vaccination, subjects who became HBsAg negative, and those who cleared HCV were analysed as having favourable outcomes. The latter showed higher IFN-λ3 but did not differ in distribution of IFNL3 SNPs compared with subjects with unfavourable outcomes. Higher IFN-λ3 concentrations are associated with response to HBV vaccination, self-limited HBV infection, and HCV resolution.

IFN-λ4 gene polymorphisms, circulating IFN-λ3, and clinical variables in hemodialysis patients exposed to hepatitis E virus

Introduction Factors associated with hepatitis E virus (HEV) infection are rarely recognized in patients on renal replacement therapy (RRT), and the results of studies are inconsistent. Objectives We aimed to search for determinants of HEV seroprevalence among polymorphisms of the interferon‑λ4 gene (IFNL4) associated with seroclearance of hepatotropic viruses (IFNL4 rs12979860, rs8099917 near IFNL4), circulating interferon λ3 (IFN‑λ3), and clinical variables of patients treated with hemodialysis (HD) in a HEV‑endemic region. Patients and methods The study was carried out in 90 HD patients. HEV open reading frame 2 antigen (HEV Ag), immunoglobulin M and G antibodies to HEV (anti‑HEV IgM and anti‑HEV IgG, respectively) and IFN‑λ3 were tested, and IFNL4 polymorphic variants (rs8099917, rs12979860) were genotyped. Survival analysis was conducted concerning anti‑HEV IgG positivity. Results In the study group, there were 37.8% anti‑HEV IgG‑positive subjects. None was HEV Ag or anti‑HEV IgM positive. HD modalities utilizing high‑flux dialyzers (adjusted odds ratio [OR], 3.586; 95% confidence interval [CI], 1.142-11.263; P = 0.03) as well as major homozygosity in rs8099917 (adjusted OR, 4.933; 95% CI, 1.516-16.054; P = 0.008) and rs12979860 (adjusted OR, 3.537; 95% CI, 1.136-11.014, P = 0.03), but not circulating IFN‑λ3 levels, were positive determinants of anti‑HEV IgG positivity. Liver enzyme activities and C‑reactive protein levels tested as response variables to HEV exposure, as well as survival probability, were not different between patients stratified by anti‑HEV IgG positivity. Conclusions Among HD patients, IFNL4 polymorphisms and treatment with high‑flux HD are explanatory variables for isolated anti‑HEV IgG positivity indicating spontaneous HEV resolution.

The Calcium-Sensing Receptor Gene Polymorphism rs1801725 and Calcium-Related Phenotypes in Hemodialysis Patients

Background/Aims: The calcium-sensing receptor gene (CASR) rs1801725 variant is responsible for a non-conservative amino-acid change (A986S) in the calcium-sensing receptor cytoplasmic tail. We hypothesized that rs1801725 polymorphism might be helpful in understanding Ca-related abnormalities in HD patients. Methods: In 1215 subjects (245 on cinacalcet), we determined the associations of rs1801725 with secondary hyperparathyroidism (sHPT)-related laboratory parameters, PTH-decreasing effect of cinacalcet hydrochloride, coronary artery disease (CAD), myocardial infarction (MI), nephrolithiasis-related ESRD, and mortality. CASR rs7652589(AT) haplotypes and rs1801725 epistatic interactions with vitamin D signaling pathway genes were examined for associations with selected phenotypes. Results: The rs1801725 variant allele showed an increasing independent effect on plasma PTH (Pcorrected = 0.009). CASR rs7652589_rs1801725 AT haplotype was associated with 1.7-fold higher frequency of PTH levels over 437 pg/mL than the reference haplotype GG (P = 0.001). CASR rs7652589_rs1801725 AG haplotype was 1.5-fold more frequent in nephrolithiasis-related ESRD than the GG haplotype (P = 0.004). There were no significant associations between rs1801725, CAD, MI, and response to cinacalcet. Variant homozygosity of rs1801725 correlated independently with higher infection-related mortality compared with heterozygosity (HR 7.95, 95%CI 2.15 – 29.37, P = 0.003) and major homozygosity (HR 5.89, 95%CI 1.69 – 20.55, P = 0.040). CASR rs1801725 did not show epistatic interactions with vitamin D signaling pathway genes concerning tested associations. Conclusion: The variant allele of CASR rs1801725 solely and together with the variant allele of rs7652589 increases risk of more advanced sHPT. Homozygosity of the rs1801725 variant allele contributes to infection-related mortality in HD patients.